SCROLL FLUID MACHINE

Abstract

A scroll fluid machine includes a compressor body having a first scroll and a second scroll which form a compression chamber, a cover forming an air guiding space by covers at least a portion of the compressor body, and a blower fan supplying cooling air to at least one of the first scroll and the second scroll. A portion of the cooling air is supercharged into the intake port via the air guiding space whereby satisfactory compression efficiency is achieved with a simple configuration.

Description

TECHNICAL FIELD

The present disclosure relates to a scroll fluid machine.

BACKGROUND

A fluid machine including a compressor that compresses gas such as air is used in various fields of an industrial world, and a scroll compressor is known as one type thereof. In a scroll compressor, typically, a compression chamber is formed between a fixed scroll and a revolving scroll disposed to face each other, and the compression chamber shrinks while moving toward the center with rotation of the revolving scroll whereby a pressurized gas is generated.

In this manner, in a compression cycle of a scroll compressor, since the pressure of the pressurized gas increases as the compression chamber approaches the center, the temperature of the pressurized gas also increases. In the scroll compressor, it is necessary to form an enclosed compression chamber by combining the fixed scroll and the revolving scroll with high accuracy. However, such an increase in temperature may cause mechanical distortion (thermal deformation) in the fixed scroll and the revolving scroll.

The scroll compressor includes a cooling means in order to suppress the increase in temperature of the fixed scroll and the revolving scroll. For example, Patent Document 1 discloses a structure in which cooling air is generated by a blower fan connected to a driving shaft for rotating a revolving scroll and the cooling air is supplied to radiating fin formed on a back surface of the revolving scroll and a fixed scroll through a duct to thereby cool the fixed scroll and the revolving scroll.

CITATION LIST

Patent Literature

Patent Document 1: JP2010-196677A

SUMMARY

Technical Problem

By the way, for example, in a scroll fluid machine including this type of scroll compressor, although outside air at the atmospheric pressure is often taken in as a compression target gas, it is effective to introduce a supercharging means in order to realize more excellent compression efficiency. As such a supercharging means, adding another blower fan for delivering outside air to an intake port of the compressor body may be considered, for example. However, in a scroll compressor, as in Patent Document 1, a cooling means for suppressing the increase in temperature of the fixed scroll and the revolving scroll is necessary, and introduction of the supercharging device in addition to such a cooling means may increase the size of a device and make the device complex, which is disadvantageous in a manufacturing cost and an installation space.

At least one embodiment of the present invention has been made in view of the above-described problems, and an object thereof is to provide a scroll fluid machine capable of realizing satisfactory compression efficiency with a simple configuration.

In Patent Document 1, an intermediate cooler for cooling a pressurized gas generated in a low-pressure-side compression chamber is provided outside a compressor body. In such a configuration, since it is necessary to arrange an intermediate cooler outside the compressor body, the device size increases, and the installation space and the manufacturing cost increase.

At least one embodiment of the present invention has been made in view of the above-described problems, and an object thereof is to provide a scroll fluid machine capable of decreasing a manufacturing cost and an installation space of entire facility, the scroll fluid machine including an intermediate cooler having a simple configuration, disposed between a low-pressure-side compression chamber and a high-pressure-side compression chamber.

By the way, in a scroll fluid machine including this type of scroll compressor, for example, when the machine stops in the course of operation, a pressurized gas on a downstream side of a compression chamber flows backward temporarily (instantaneously), and the revolving scroll rotates in an opposite direction to generate noise. In order to prevent occurrence of such noise, a check valve for preventing backflow of a pressurized gas may be disposed on the downstream side of the compression chamber.

However, since the usable temperature range of a check valve used for such use is limited due to a structure thereof, the check valve may be unable to endure high-temperature gas immediately after being discharged from the compression chamber. Therefore, in a conventional typical configuration, it is necessary to arrange the check valve so that the high-temperature pressurized gas discharged from the compression chamber passes through the check valve after being cooled by an after-cooler which is an external device provided on the downstream side. In such a configuration, since it is necessary to arrange an after-cooler, a check valve, and the like outside the scroll fluid machine, the device size increases, and the installation space and the manufacturing cost increase.

At least one embodiment of the present invention has been made in view of the above-described problems, and an object thereof is to provide a scroll fluid machine capable of effectively decreasing the temperature of discharged gas with a simple configuration.

In a scroll fluid machine including this type of scroll compressor, for example, since the revolving scroll is rotated by the torque from the driving shaft, the revolving scroll is more likely to be distorted than the fixed scroll. Therefore, in order to suppress distortion of the revolving scroll, a reinforcement structure may be provided on the back surface of the revolving scroll to secure mechanical strength. For example, a rib-shaped reinforcement member provided on the back surface of a revolving end plate having an approximately disc shape so as to extend in one direction is used as such a reinforcement structure.

However, since such a rib-shaped reinforcement member has a convex shape protruding from the back surface of the revolving end plate to which cooling air is supplied, the reinforcement member may disturb the flow of cooling air to deteriorate the cooling performance of the revolving scroll. Moreover, although the rib-shaped reinforcement member provides a relatively effective reinforcement effect in the vicinity of the reinforcement member, it is difficult to obtain a sufficient reinforcement effect in a region distant from the reinforcement member, and the entire revolving scroll is not reinforced sufficiently.

At least one embodiment of the present invention has been made in view of the above-described problems, and an object thereof is to provide a scroll fluid machine capable of improving the strength in a wide range of regions while suppressing the increase in temperature of the revolving scroll effectively.

As in Patent Document 1, typically, a plurality of radiating fins provided in the fixed scroll and the revolving scroll as the cooling means for the fixed scroll and the revolving scroll are provided at equal intervals in a blowing direction of the cooling air. Therefore, although the cooling air supplied to the radiating fins has a relatively satisfactory cooling effect on the upstream side, since the temperature of the cooling air increases as it advances toward the downstream side, the cooling effect weakens gradually, and the cooling effect decreases. As a result, a difference in the degree of cooling occurs between the upstream side and the downstream side, and a temperature difference may occur on the fixed scroll and the revolving scroll. Such a temperature difference may cause distortion of the fixed scroll and the revolving scroll.

At least one embodiment of the present invention has been made in view of the above-described problems, and an object thereof is to provide a scroll fluid machine capable of obtaining a uniform cooling effect over a wide range of regions of the fixed scroll or the revolving scroll.

Solution to Problem

(1) In order to solve at least one of the problems, a scroll fluid machine according to at least one embodiment of the present invention includes: a compressor body capable of compressing fluid introduced from an intake port in a compression chamber formed between a first scroll and a second scroll; a cover forming an air guiding space by covering at least a portion of the compressor body; and a blower fan supplying cooling air to at least one of the first scroll and the second scroll, wherein a portion of the cooling air is configured to be supercharged into the intake port via the air guiding space.

According to the configuration of (1), a portion of the cooling air supplied from the blower fan in order to cool the first scroll and the second scroll that form the compression chamber is configured to be supplied to the intake port of the compressor body. Due to this, since a portion of the cooling air used as air for cooling the first scroll and the second scroll can be supercharged, in spite of a simple configuration, it is possible to realize a scroll fluid machine capable of obtaining satisfactory compression efficiency while suppressing the increase in temperature of the first scroll and the second scroll.

Furthermore, according to the configuration of (1), a portion of the cooling air for cooling the first scroll and the second scroll is supercharged into the intake port via the air guiding space formed by the cover. Since the cooling air passes through the air guiding space, dynamic pressure of the cooling air is converted to static pressure and the cooling air having the static pressure is supercharged into the intake port. Therefore, even if the amount of air blown from the blower fan varies greatly, the cooling air can be stably supercharged into the intake port.

(2) In some embodiments, in the configuration of (1), the air guiding space has a larger passage area than a duct for introducing outside air from the blower fan into the compressor body.

According to the configuration of (2), since the air guiding space has a larger passage area than the duct, it is possible to generate static pressure satisfactorily from the dynamic pressure of the cooling air delivered from the duct.

(3) In some embodiments, in the configuration of (1) or (2), the cover has a curved inner wall so that the outside air introduced into the air guiding space is rectified toward the intake port.

According to the configuration of (3), the cover that forms the inner wall of the air guiding space is formed in a curved form, the cooling air introduced into the air guiding space is rectified toward the intake port. Due to this, the cooling air supplied into the air guiding space is efficiently guided to the intake port and satisfactory supercharging efficiency is obtained.

(4) In some embodiments, in the configuration of any one of (1) to (3), the scroll fluid machine further includes a filter for removing a foreign material included in the outside air supercharged into the intake port.

According to the configuration of (4), by removing a foreign material included in the supercharged cooling air in order to supercharge a portion of the cooling air supplied to the first scroll and the second scroll, it is possible to prevent the foreign material from entering the compression chamber.

(5) In some embodiments, in the configuration of (1), the scroll fluid machine further includes a discharge pipe through which the pressurized gas discharged from the compression chamber flows, wherein the discharge pipe is provided to penetrate the air guiding space so that the pressurized gas flowing through the discharge pipe is cooled by the cooling air introduced into the air guiding space.

According to the configuration of (5), although supercharging into the intake port is performed using the air guiding space as described above, in this case, cooling of the pressurized gas discharged from the compression chamber can be realized using the air guiding space. The pressurized gas generated in the compressor body is discharged through a discharge pipe provided to penetrate the air guiding space. Therefore, the pressurized gas flowing through the discharge pipe is cooled by the cooling air introduced into the air guiding space. By cooling the pressurized gas flowing through the discharge pipe using the air guiding space provided for supercharging into the intake port in this manner, an external device such as an after-cooler, for example, is not necessary, and it is possible to reduce a system size and to effectively save an installation space and a manufacturing cost.

(6) In some embodiments, in the configuration of (5), a check valve is included in the discharge pipe.

In a scroll fluid machine, when the machine stops in the course of operation, a pressurized gas on a downstream side of a compression chamber flows backward temporarily (instantaneously), and the revolving scroll rotates in an opposite direction to generate noise. In order to prevent occurrence of such noise, a check valve for preventing backflow of a pressurized gas may be disposed on the downstream side of the compression chamber. Since the usable temperature range of a check valve used for such use is limited due to a structure thereof, the check valve may be unable to endure high-temperature gas immediately after being discharged from the compression chamber. However, according to the configuration of (6), since it is possible to decrease the temperature of the pressurized gas flowing through the discharge pipe as described above, it is possible to arrange a backflow-prevention check valve in the discharge pipe.

(7) In order to solve at least one of the problems, a scroll fluid machine according to at least one embodiment of the present invention includes: a housing; a fixed scroll which is fixed to the housing and in which a spiral groove formed by a fixed wrap formed on a fixed end plate is blocked by a partition wall that partitions a low-pressure-side compression chamber and a high-pressure-side compression chamber; a revolving scroll which is accommodated in the housing so as to face the fixed scroll to form the low-pressure-side compression chamber and the high-pressure-side compression chamber together with the fixed scroll and is resolvable supported by a driving shaft; a cover that forms an air guiding space between the fixed scroll and the cover so that a portion of cooling air supplied to at least one of the fixed scroll and the revolving scroll can be introduced into the air guiding space; and an intermediate cooler configured to cool pressurized gas discharged from the low-pressure-side compression chamber by heat exchange with the cooling air in the air guiding space so that the cooled pressurized gas is returned to the high-pressure-side compression chamber.

According to the configuration of (7), the spiral groove formed by the fixed wrap included in the fixed scroll is partitioned by the partition wall, whereby the low-pressure-side compression chamber and the high-pressure-side compression chamber are formed between the fixed scroll and the revolving scroll. Since the pressurized gas discharged from the low-pressure-side compression chamber is cooled by the intermediate cooler and is then returned to the high-pressure-side compression chamber, the scroll fluid machine according to this configuration is configured as a multi-stage compressor.

The cover forms the air guiding space to which a portion of the cooling air supplied to at least one of the fixed scroll and the revolving scroll can be introduced. The air guiding space forms an intermediate cooler that cools the pressurized gas discharged from the low-pressure-side compression chamber. In the intermediate cooler, the high-temperature pressurized gas discharged from the low-pressure-side compression chamber is cooled by heat exchange with the cooling air of the air guiding space, and the cooled pressurized gas is returned to the high-pressure-side compression chamber. In this manner, since the intermediate cooler capable of realizing cooling using a portion of the cooling air supplied to at least one of the fixed scroll and the revolving scroll can be formed integrally with the compressor body in the air guiding space formed by the cover, it is possible to simplify the configuration as compared to a conventional configuration and to effectively reduce a manufacturing cost and an installation space of entire facility.

(8) In some embodiments, in the configuration of (7), the intermediate cooler includes a radiating pipe arranged in the air guiding space so as to connect a low-pressure-side discharge port of the low-pressure-side compression chamber and a high-pressure-side inlet port of the high-pressure-side compression chamber.

According to the configuration of (8), the high-temperature pressurized gas discharged from the low-pressure-side discharge port of the low-pressure-side compression chamber is supplied to the high-pressure-side inlet port of the high-pressure-side compression chamber after being cooled by heat exchange with the cooling air introduced into the air guiding space when passing through the radiating pipe arranged in the air guiding space.

(9) In some embodiments, in the configuration of (8), the radiating pipe is arranged to be folded back on an inner wall of the air guiding space.

According to the configuration of (9), since the radiating pipe through which the high-temperature pressurized gas which is a cooling target in the intermediate cooler flows is arranged to be folded back on the inner wall of the air guiding space, it is possible to secure a large contact area between the radiating pipe and the cooling air introduced into the air guiding space and to obtain a satisfactory cooling effect.

(10) In some embodiments, in the configuration of (9), the radiating pipe is configured such that a plurality of radiating portion extending along the cooling air are connected by a plurality of folded-back portions formed to be lower than the plurality of radiating portions.

According to the configuration of (10), since the radiating pipe has a configuration in which a plurality of radiating portions are connected by a plurality of folded-back portions, it is possible to arrange a long radiating pipe in a limited compact space. Moreover, since the plurality of radiating portions extend along the blowing direction, the radiating portions do not disturb the flow of outside air. Furthermore, since the folded-back portions are formed to be lower than the radiating portions, the outside air can be introduced smoothly between the adjacent radiating portions. In this manner, the radiating pipe of this configuration provides a satisfactory cooling effect.

(11) In some embodiments, in the configuration of any one of (8) to (10), the low-pressure-side discharge port is disposed on a downstream side of the cooling air as compared to the high-pressure-side inlet port.

According to the configuration of (11), since the high-temperature pressurized gas is discharged from the low-pressure-side compression chamber in the low-pressure-side discharge port, the low-pressure-side discharge port is disposed on the downstream side of the cooling air as compared to the high-pressure-side inlet port through which the low-temperature pressurized gas cooled by the intermediate cooler flows. On the upstream side, since the cooling air is heat exchanged with the pressurized gas after being cooled by the intermediate cooler, the increase in temperature of the cooling air is small, and a relatively low-temperature cooling air can be supplied to the downstream side. In this way, it is possible to effectively cool the high-temperature pressurized gas before being cooled by the intermediate cooler on the downstream side.

(12) In some embodiments, in the configuration of at least one of (7) to (11), the scroll fluid machine further includes a discharge pipe through which the pressurized gas discharged from the high-pressure-side compression chamber flows, wherein the discharge pipe is provided so as to penetrate the air guiding space so that the pressurized gas flowing through the discharge pipe is cooled by the cooling air introduced into the air guiding space.

According to the configuration of (12), cooling of the pressurized gas discharged from the high-pressure-side compression chamber can be realized using the air guiding space that forms the intermediate cooler as described above. The pressurized gas generated in the compressor body is discharged through a discharge pipe provided to penetrate the air guiding space. Therefore, the pressurized gas flowing through the discharge pipe is cooled by the cooling air introduced into the air guiding space. By cooling the pressurized gas flowing through the discharge pipe using the air guiding space that forms the intermediate cooler in this manner, an external device such as an after-cooler, for example, is not necessary, and it is possible to reduce a system size and to effectively save an installation space and a manufacturing cost.

(13) In some embodiments, in the configuration of (12), a check valve is provided in the discharge pipe.

In a scroll fluid machine, when the machine stops in the course of operation, a pressurized gas on a downstream side of a compression chamber flows backward temporarily (instantaneously), and the revolving scroll rotates in an opposite direction to generate noise. In order to prevent occurrence of such noise, a check valve for preventing backflow of a pressurized gas may be disposed on the downstream side of the compression chamber. Since the usable temperature range of a check valve used for such use is limited due to a structure thereof, the check valve may be unable to endure high-temperature gas immediately after being discharged from the compression chamber. However, according to the configuration of (13), since it is possible to decrease the temperature of the pressurized gas flowing through the discharge pipe as described above, it is possible to arrange a backflow-prevention check valve in the discharge pipe.

(14) In order to solve at least one of the problems, a scroll fluid machine according to at least one embodiment of the present invention includes: a compressor body capable of generating a pressurized gas in a compression chamber formed by a fixed scroll and a revolving scroll; a cover forming an air guiding space between the compressor body and the cover so that cooling air can be introduced into the air guiding space; and a discharge pipe connected to a discharge port formed in the compressor body in order to discharge the pressurized gas generated in the compression chamber and provided so as to penetrate the air guiding space.

According to the configuration of (14), the pressurized gas generated in the compressor body is discharged from the discharge port to the outside through the discharge pipe. Since the discharge pipe is provided so as to penetrate the air guiding space to which the cooling air is introduced, the high-temperature pressurized gas flowing through the discharge pipe is cooled by the cooling air introduced into the air guiding space. The air guiding space is formed by the cover provided so as to cover the compressor body, and the temperature of the discharged gas can be decreased effectively with a simple configuration.

(15) In some embodiments, in the configuration of (14), the discharge pipe is configured such that a heat exchanging portion exposed to the air guiding space has a higher heat conductivity than portions therearound.

According to the configuration of (15), since the discharge pipe through which a high-temperature pressurized gas flows has the heat exchanging portion which is exposed to the air guiding space and has a high heat conductivity, heat exchange with the cooling air introduced into the air guiding space is accelerated, and the temperature of the discharged gas can be decreased more effectively.

(16) In some embodiments, in the configuration of (14) or (15), cooling fins are formed on an outer surface of the discharge pipe.

According to the configuration of (16), by forming the cooling fins on the outer surface of the discharge pipe, it is possible to increase a heat exchange area for heat exchange with the cooling air introduced into the air guiding space and to decrease the temperature of the discharged gas more effectively. Moreover, it is also possible to reinforce the mechanical strength of the discharge pipe through which a high-pressure pressurized gas flows.

(17) In some embodiments, in the configuration of (16), the cooling fin extends in a flowing direction of the cooling air introduced into the air guiding space.

According to the configuration of (17), since the cooling fin formed on the outer surface of the discharge pipe extends in the flowing direction of the cooling air, the cooling fin does not disturb the flow of the cooling air. As a result, heat exchange between the discharged gas and the cooling air is accelerated, and the temperature of the discharged gas can be decreased more effectively.

(18) In some embodiments, in the configuration of any one of (14) to (17), a check valve is provided in the discharge pipe.

According to the configuration of (18), since it is possible to decrease the temperature of the pressurized gas flowing through the discharge pipe as described above, it is possible to arrange a backflow-prevention check valve in the discharge pipe. Due to this, it is not necessary to provide a device such as an after-cooler outside the scroll compressor, and it is possible to decrease a device size and to save an installation space and a manufacturing cost.

(19) In some embodiments, in the configuration of any one of (14) to (18), the compression chamber includes a low-pressure-side compression chamber and a high-pressure-side compression chamber partitioned by a partition wall.

According to the configuration of (19), in a so-called single-winding two-stage scroll fluid machine in which the compression chamber is partitioned into a low-pressure-side compression chamber and a high-pressure-side compression chamber by the partition wall, it is possible to effectively cool the pressurized gas which is heated to a high temperature by being compressed in multiple stages.

(20) In order to solve at least one of the problems, a scroll fluid machine according to at least one embodiment of the present invention includes: a fixed scroll having a fixed end plate and a fixed wrap formed on the fixed end plate; and a revolving scroll having a revolving end plate and a revolving wrap formed on a first surface of the fixed end plate and forming a compression chamber together with the fixed scroll, wherein the revolving end plate has a convex shape in which a second surface which is positioned on an opposite side of the first surface and to which cooling air is supplied swells continuously, and the convex shape is formed so that a center of gravity of the revolving scroll is identical to a center of revolution shifted from a center of the revolving end plate.

According to the configuration of (20), the second surface of the revolving end plate that forms the revolving scroll has a convex shape. Due to this, the thickness of the revolving end plate increases as compared to a conventional scroll compressor, and the mechanical strength of the revolving scroll is improved. Moreover, since the convex shape of the second surface is formed so as to swell continuously, the convex shape does not disturb the cooling air supplied to cool the revolving scroll. As a result, a satisfactory cooling effect is obtained in the revolving scroll, and occurrence of distortion can be suppressed effectively.

Conventionally, in order to adjust balance of a revolving scroll rotating eccentrically with respect to a driving shaft, a process of adding a balance (padding) to the revolving scroll has been performed. However, such a countermeasure may make the device configuration complex and may increase a workload. According to the configuration of (20), by adjusting the convex shape formed on the revolving end plate, it is possible to eliminate the need of the process of adding such a balance (padding). As a result, it is possible to adjust balance easily with a simple configuration.

(21) In some embodiments, in the configuration of (20), the convex shape is formed in a region including the center of the revolving end plate.

According to the configuration of (21), since the convex shape is formed in such a wide region, the inclination of the convex shape becomes gentle. Due to this, the permeability of the cooling air on the second surface is improved, and a satisfactory cooling effect is obtained.

(22) In some embodiments, in the configuration of (20) or (21), a plurality of radiating fins extending in a blowing direction of the cooling air are formed on the second surface.

According to the configuration of (22), since the plurality of radiating fins are formed on the second surface, the cooling performance of the revolving scroll can be improved further and the strength of the revolving scroll can be improved further. Moreover, in the revolving scroll, since the convex shape is formed on the second surface of the revolving end plate, although the heat capacity increases as the volume of the revolving end plate increases, it is possible to sufficiently cool the revolving scroll having a large heat capacity by forming such radiating fins.

(23) In some embodiments, in the configuration of (22), the plurality of radiating fins are arranged more densely as the thickness of the revolving end plate on the second surface increases.

According to the configuration of (23), the plurality of radiating fins formed on the second surface are arranged more densely in a region as the thickness of the revolving end plate in the region increases. Due to this, since a radiation amount corresponding to the heat capacity per unit area is obtained, it is possible to cool a wide region of the revolving scroll uniformly and to suppress distortion effectively.

(24) In some embodiments, in the configuration of any one of (20) to (23), the first surface has a concave reduced thickness portion on a non-contacting region that does not make contact with the fixed scroll.

According to the configuration of (24), although balance adjustment is performed in a direction for increasing the weight of the revolving end plate by forming a convex shape on the second surface in the respective configurations described above, in the present embodiment, balance adjustment of the revolving scroll can be performed in a direction for decreasing the weight contrarily by forming the reduced thickness portion. In this way, the balance of the revolving scroll can be adjusted more finely. Moreover, it is also possible to increase the volume of the compression chamber considerably by forming the reduced thickness portion on the first surface.

(25) In some embodiments, in the configuration of at least one of (20) to (24), the compression chamber includes a low-pressure-side compression chamber and a high-pressure-side compression chamber partitioned by a partition wall.

According to the configuration of (25), the scroll fluid machine is configured as a multi-stage fluid machine including the low-pressure-side compression chamber and the high-pressure-side compression chamber partitioned by the partition wall as a compression chamber. In such a multi-stage fluid machine, the temperature of the pressurized gas in the high-pressure-side compression chamber increases particularly. Therefore, by employing the above-described configuration, it is possible to secure strength in a wide range of regions while suppressing the increase in temperature of the revolving scroll effectively and to realize a scroll fluid machine in which distortion rarely occurs.

(26) In order to solve at least one of the problems, a scroll fluid machine according to at least one embodiment of the present invention includes: a fixed scroll having a fixed wrap formed on a fixed end plate; and a revolving scroll having a revolving wrap formed on a revolving end plate and forming a compression chamber together with the fixed scroll, wherein at least one of the fixed end plate and the revolving end plate includes a first surface having the fixed wrap or the revolving wrap formed thereon, and a second surface positioned on an opposite side of the first surface and having a plurality of radiating fins extending along cooling air introduced from a blower fan, and the plurality of radiating fins are arranged more densely on a downstream side of the cooling air than on an upstream side.

According to the configuration of (26), the plurality of radiating fins are formed on a back surface (the second surface) on which the wrap of the fixed end plate or the revolving end plate is not formed. Since these radiating fins are arranged more densely on the downstream side of the cooling air than on the upstream side, the flow rate of the cooling air increases gradually from the upstream side toward the downstream side. Therefore, the cooling effect on the downstream side where the temperature of the cooling air increases is improved, and a temperature difference occurring between the downstream side and the upstream side can be suppressed. In this manner, it is possible to obtain a uniform cooling effect in a wide range of regions of the fixed scroll and the revolving scroll.

(27) In some embodiments, in the configuration of (26), the plurality of radiating fins are arranged so that a pitch distance between adjacent radiating fins on the upstream side of the cooling air is larger than that on the downstream side.

According to the configuration of (27), by changing the pitch distance between the adjacent radiating fins, the plurality of cooling fins can be arranged more densely on the downstream side of the cooling air than on the upstream side.

(28) In some embodiments, in the configuration of (26) or (27), the compression chamber is configured to be able to compress gas while moving toward the center when the fixed scroll and the revolving scroll are driven to rotate in relation to each other, and the plurality of cooling fins are arranged more sparsely on a central side than an outer circumference side on at least one of the fixed end plate and the revolving end plate.

According to the configuration of (28), since the compression chamber formed by the fixed scroll and the revolving scroll compresses gas toward the central side, the temperature of the fixed scroll and the revolving scroll is likely to increase as it approaches the central side. Therefore, by arranging the cooling fins more sparsely as it approaches the central side where the temperature is high, cooling according to a thermal load distribution can be realized.

(29) In some embodiments, in the configuration of at least one of (26) to (28), the revolving end plate has a convex shape in which the second surface swells continuously, and the plurality of radiating fins are arranged more densely as the thickness of the revolving end plate on the second surface increases.

According to the configuration of (29), when the second surface of the revolving end plate forming the revolving scroll is formed so as to have a convex shape that swells continuously, by setting the density of the radiating fins according to the thickness of the revolving end plate, it is possible to obtain a uniform cooling effect over a wide range of regions of the revolving end plate according to a heat capacity distribution of the revolving end plate. In this way, it is possible to improve the strength of the revolving scroll and to suppress occurrence of distortion due to a temperature difference effectively.

(30) In some embodiments, in the configuration of at least one of (26) to (29), the fixed scroll and the revolving scroll are configured to that the cooling air is introduced from the blower fan through a duct.

According to the configuration of (30), the cooling air supplied to the fixed scroll and the revolving scroll is introduced from the blower fan through a duct having a predetermined length. Therefore, although the cooling air is weakened considerably by a pressure loss occurring in the duct, since the present configuration has the plurality of cooling fins arranged as described above, a satisfactory cooling effect is obtained with a weak cooling air.

Advantageous Effects

According to at least one embodiment of the present invention, it is possible to provide a scroll fluid machine capable of realizing satisfactory compression efficiency with a simple configuration.

According to at least one embodiment of the present invention, it is possible to provide a scroll fluid machine capable of decreasing a manufacturing cost and an installation space of entire facility, the scroll fluid machine including an intermediate cooler having a simple configuration, disposed between a low-pressure-side compression chamber and a high-pressure-side compression chamber.

According to at least one embodiment of the present invention, it is possible to provide a scroll fluid machine capable of effectively decreasing the temperature of discharged gas with a simple configuration.

According to at least one embodiment of the present invention, it is possible to provide a scroll fluid machine capable of improving the strength in a wide range of regions while suppressing the increase in temperature of the revolving scroll effectively.

According to at least one embodiment of the present invention, it is possible to provide a scroll fluid machine capable of obtaining a uniform cooling effect over a wide range of regions of the fixed scroll or the revolving scroll.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating an appearance of a scroll compressor according to at least one embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view along a line passing through a driving shaft of the scroll compressor illustrated in FIG. 1.

FIG. 3 is a horizontal cross-sectional view along a line passing through the driving shaft of the scroll compressor illustrated in FIG. 1.

FIG. 4 is a plan view illustrating a revolving scroll provided in a compressor body illustrated in FIG. 1 when seen from a first surface side.

FIG. 5 is a plan view illustrating the revolving scroll illustrated in FIG. 4 when seen from a second surface side.

FIG. 6 is a comparative example of FIG. 5.

FIG. 7 is another modification of FIG. 5.

FIG. 8 is a plan view illustrating the fixed scroll included in the compressor body illustrated in FIG. 1 when seen from a second surface side.

FIG. 9 is a cross-sectional view along a line passing through a central axis of the revolving scroll illustrated in FIG. 6.

FIG. 10 is a cross-sectional view along a line passing through the central axis of the revolving scroll illustrated in FIG. 4.

FIG. 11 is a contour distribution on the second surface of the revolving scroll illustrated in FIG. 4.

FIG. 12 is a modification of FIG. 4.

FIG. 13 is a modification of FIG. 2.

FIG. 14 is another modification of FIG. 2.

FIG. 15 is a schematic diagram illustrating cooling fins provided on an outer surface of a discharge pipe illustrated in FIG. 14 when seen from the inner side of a cover.

FIG. 16 is a plan view illustrating a fixed scroll and a revolving scroll of a single-winding two-stage scroll compressor.

FIG. 17 is a perspective view illustrating a state in which a cover is detached from a scroll compressor according to the present embodiment.

FIG. 18 is a vertical cross-sectional view along a line passing through a driving shaft in a state in which a cover is attached to the scroll compressor illustrated in FIG. 17.

FIG. 19 is a vertical cross-sectional view of a supercharging scroll compressor.

DETAILED DESCRIPTION

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It is intended, however, that unless particularly specified, dimensions, materials, shapes, relative positions and the like of components described in the embodiments shall be interpreted as illustrative only and not limitative of the scope of the present invention.

For example, an expression of relative or absolute arrangement such as “in a direction”, “along a direction”, “parallel”, “orthogonal”, “centered”, “concentric” and “coaxial” shall not be construed as indicating only the arrangement in a strict literal sense, but also includes a state where the arrangement is relatively displaced by a tolerance, or by an angle or a distance whereby it is possible to achieve the same function.

Furthermore, for example, an expression of a shape such as a rectangular shape or a cylindrical shape shall not be construed as only the geometrically strict shape, but also includes a shape with unevenness or chamfered corners within the range in which the same effect can be achieved.

On the other hand, an expression such as “comprise”, “include”, “have”, “contain” and “constitute” are not intended to be exclusive of other components.

<1. Entire Configuration>

FIG. 1 is a perspective view illustrating an appearance of a scroll compressor 1 according to at least one embodiment of the present invention, FIG. 2 is a vertical cross-sectional view along a line passing through a driving shaft 22 of the scroll compressor 1 illustrated in FIG. 1, and FIG. 3 is a horizontal cross-sectional view along a line passing through the driving shaft 22 of the scroll compressor 1 illustrated in FIG. 1. In the description below, the left side of FIGS. 2 and 3 will be referred to as a front side and the right side will be referred to as a rear side.

The scroll compressor 1 is a compressor for compressing gas such as air and includes a filter unit 2 for taking in and purifying a compression target gas, a compressor body 4 for compressing the gas purified by the filter unit 2, a power transmission unit 6 for transmitting dynamic power from a dynamic power source (not illustrated) to respective portions of the scroll compressor 1, and a blower unit 8 for blowing cooling air of the scroll compressor 1. The filter unit 2 is disposed in an upper part on a front side of the scroll compressor 1, and the compressor body 4, the power transmission unit 6, and the blower unit 8 are disposed on a rear side of the filter unit 2 in that order from the front side.

The filter unit 2 has a hollow filter casing 10 as a casing. As illustrated in FIG. 2, the filter casing 10 includes a cylindrical portion 10a having an approximately cylindrical shape and an inclined portion 10b disposed on a rear side of the cylindrical portion 10a and inclined toward an outer surface of the compressor body 4. In the present embodiment, an intake port 12 for taking in a compression target gas from the outside is formed in an upper surface of the inclined portion 10b of the filter casing 10. The intake port 12 is formed in a form of a plurality of slits extending in parallel in a left-right direction. It is not always necessary to form the intake port 12. In this case, the compression target gas is supplied from a blower fan 52 (to be described later).

A filter element 14 for removing a foreign material such as dust or dirt included in the gas taken in from the intake port 12 is disposed in the filter casing 10. The gas introduced from the intake port 12 is rectified by passing through the filter element 14 and is supplied to the compressor body 4 positioned on the downstream side.

The compressor body 4 includes a compressor housing 16. The compressor housing 16 is formed of an aluminum alloy, for example. An upper part on the front side of the compressor housing 16 is connected to the filter unit 2, and the gas having passed through the filter element 14 is introduced into the compressor body 4 through an introduction path 15. Moreover, the rear side of the compressor housing 16 is connected to a bearing case 42 that forms the power transmission unit 6 by a plurality of bolts (not illustrated).

A fixed scroll 18 which is an example of a first scroll and a revolving scroll 20 which is an example of a second scroll are accommodated in the compressor housing 16. The fixed scroll 18 is fixed to the compressor housing 16, and the revolving scroll 20 is disposed in the compressor housing 16 so as to face the fixed scroll 18. The revolving scroll 20 is supported by an eccentric shaft portion 23 provided at a distal end of the driving shaft 22 and is rotated by dynamic power transmitted from the power transmission unit 6.

The fixed scroll 18 includes a fixed end plate 19 having an approximately disk shape. A fixed wrap 21 having a spiral shape is formed on a first surface of the fixed end plate 19 facing the revolving scroll 20. Radiating fins 24 for heat radiation are formed on a second surface of the fixed end plate 19 on the opposite side of the first surface. As will be described later, cooling air delivered from the blower unit 8 is supplied to the radiating fins 24 to cool the fixed scroll 18.

The revolving scroll 20 includes a revolving end plate 26 having an approximately disk shape. A revolving wrap 28 having a spiral shape is erected on a first surface of the revolving end plate 26 facing the fixed scroll 18. Radiating fins 30 for heat radiation are formed on a second surface of the revolving end plate 26 on the opposite side of the first surface. As will be described later, cooling air supplied from the blower unit 8 is introduced to the radiating fins 30 to cool the fixed scroll 18.

In respective embodiments including the present embodiment, the length of the fixed wrap 21 of the fixed scroll 18 and the length of the revolving wrap 28 of the revolving scroll 20 are different. That is, the scroll compressor 1 according to the respective embodiments is a so-called asymmetric wrap scroll compressor. However, the present application invention is not limited to the asymmetric wrap scroll compressor but may be a so-called symmetric wrap scroll compressor in which the length of the fixed wrap 21 and the length of the revolving wrap 28 are the same.

A revolving plate 32 having an approximately disk shape is fixed to the rear side of the revolving scroll 20 in a state of being directly connected to the eccentric shaft portion 23 of the driving shaft 22. A bearing portion 37 is formed integrally with the revolving plate 32. A rotating bearing 33 for rotatably supporting the eccentric shaft portion 23 provided at the distal end of the driving shaft 22 is disposed in the bearing portion 37. A plurality of rotation prevention mechanisms 34 for allowing the revolving scroll 20 to revolve while preventing rotation of the revolving scroll 20 are provided between the revolving plate 32 and the compressor housing 16 at approximately equal intervals in a circumferential direction of the revolving plate 32 (that is, the revolving scroll 20).

When the driving shaft 22 is rotated with the dynamic force from the power transmission unit 6, the revolving scroll 20 performs revolving motion whereby the volume of the compression chamber 36 formed between the fixed scroll 18 and the revolving scroll 20 decreases gradually from the outer circumference side toward the inner circumference side and intake and compression cycles are performed. More specifically, such a compression chamber 36 is formed in an approximately crescent shape by being partitioned by the fixed wrap 21 and the revolving wrap 28. In this way, the gas introduced from the introduction path 15 into the compressor body 4 is compressed gradually as it approaches the inner circumference side. The pressurized gas generated in the compression chamber 36 is discharged from a discharge port 38 formed in a central portion of the fixed scroll 18.

Here, a lid portion 53 having a flat plate shape is fixed to the front side of the compressor housing 16. The lid portion 53 is covered by a cover 63 from a more front side, and an air guiding space 57 to which a portion of the cooling air from the blower unit 8 can be introduced is formed between the lid portion 53 and the cover 63.

A discharge plug 67 connected to a pressurized gas supply destination present at the outside is provided on an outer surface of the cover 63. The discharge plug 67 is connected to the discharge port 38 formed in the central portion of the fixed scroll 18 through a discharge pipe 59 arranged on the inner side of the cover 63 so as to penetrate the air guiding space 57. In this way, the pressurized gas generated in the compression chamber 36 is discharged from the discharge port 38 to the outside through the discharge pipe 59.

The power transmission unit 6 is a unit having a function of transmitting dynamic power supplied from a dynamic power source (not illustrated) to respective portions of the scroll compressor 1. In the present embodiment, the power transmission unit 6 has a driven pulley 40 which is disposed at a rear end of a driving shaft 22 protruding toward a rear side of the blower unit 8 and to which the dynamic power from an external dynamic power source can be input. An upper part of an endless power transmission belt (not illustrated) of which the lower part is stretched around a main pulley (not illustrated) attached to an output shaft of a dynamic power source such as a motor or an engine provided on the lower side of the scroll compressor 1, for example, is stretched around the driven pulley 40, whereby rotation of the dynamic power source is transmitted to the driving shaft 22. The dynamic power input to the driven pulley 40 rotates the driving shaft 22 and is transmitted to the respective portions of the scroll compressor 1 such as the compressor body 4 and the blower unit 8.

The bearing case 42 that forms a casing of the power transmission unit 6 is formed of a casting, for example, having a higher strength than the compressor housing 16. Ball bearings 44 and 46 provided so as to be separated by a predetermined distance in a front-rear direction are disposed in the bearing case 42 and the driving shaft 22 is rotatably supported.

The eccentric shaft portion 23 is provided on a front end side of the driving shaft 22. Moreover, as illustrated in FIG. 2, a balance weight 48 for adjusting balance of the revolving scroll 20 is provided on an outer circumference of a front part of the eccentric shaft portion 23.

The blower unit 8 accommodates a blower fan 52 in the fan casing 50. The blower fan 52 is connected to the driving shaft 22 and is configured to be rotatable with the dynamic power transmitted from the power transmission unit 6. The blower fan 52 is a sirocco fan, for example.

When the blower fan 52 is driven, the blower unit 8 takes in the outside air (air) from an opening 55 formed on a front side of the fan casing 50, and the outside air is transferred toward the duct 54 formed on the downstream side of the blower fan 52. The duct 54 is a tubular member having an approximately cylindrical shape, and as illustrated in FIG. 3, is configured to circumvent a lateral side of the power transmission unit 6 from a lateral side of the fan casing 50 to be connected to the compressor body 4 from a lateral side. In this way, the outside air delivered from the blower unit 8 to the duct 54 is supplied to the compressor body 4 as cooling air.

As illustrated in FIG. 3, the cooling air introduced from the duct 54 into the compressor body 4 is distributed to a first air passage 56, a second air passage 58, and a third air passage 60 inside the compressor housing 16. The first air passage 56 is a passage for supplying the cooling air to the radiating fins 30 formed on the second surface of the revolving end plate 26 and mainly cools the revolving scroll 20. The second air passage 58 is a passage for supplying the cooling air to the radiating fins 24 formed on the second surface of the fixed end plate 19 and mainly cools the fixed scroll 18. The third air passage 60 is a passage for supplying the cooling air to the air guiding space 57 formed on the front side of the compressor housing 16.

<2. Configuration of Radiating Fins in Fixed Scroll and Revolving Scroll>

Next, the configuration of the radiating fins 24 and 30 provided in the fixed scroll 18 and the revolving scroll 20, respectively, in the scroll compressor 1 according to the present embodiment will be described in detail. In this section, although the radiating fins 30 formed on the revolving scroll 20 will be mainly described, the radiating fins 24 formed on the fixed scroll 18 have a similar configuration unless particularly stated otherwise.

FIG. 4 is a plan view illustrating the revolving scroll 20 included in the compressor body 4 illustrated in FIG. 1 when seen from the first surface, and FIG. 5 is a plan view illustrating the revolving scroll 20 illustrated in FIG. 4 when seen from the second surface. As illustrated in FIG. 4, a spiral revolving wrap 28 is erected on the revolving end plate 26 on the first surface of the revolving scroll 20. A groove portion 61 with which a tip seal (not illustrated) for sealing a gap between the fixed scroll 18 and the revolving wrap 28 can engage is formed at a distal end of the revolving wrap 28 along the length direction of the revolving wrap 28.

Moreover, as illustrated in FIG. 5, a plurality of radiating fins 30 are erected on the revolving end plate 26 on the second surface of the revolving scroll 20. The cooling air from the duct 54 is introduced to the plurality of radiating fins 30 through the first air passage 56 (see FIG. 3). The plurality of radiating fins 30 formed on the revolving end plate 26 have an approximately straight shape and extend approximately in parallel in the flowing direction of the cooling air introduced from the first air passage 56.

Here, FIG. 6 is a comparative example of FIG. 5. As illustrated in FIG. 6, in a conventional scroll compressor, a plurality of radiating fins 30′ formed on a revolving end plate 26′ have a non-straight shape (a wave form) curved in a wave form. In the radiating fin 30′ having such a non-straight shape, turbulence may be generated along the line curved in a wave form and a flow resistance may increase. In contrast, in the present embodiment, by using the radiating fins 30 having an approximately straight shape as in FIG. 5, since the heat exchange rate with the radiating fins 30 can be improved without disturbing the flow of the cooling air from the first air passage 56, it is possible to obtain a satisfactory cooling performance.

Moreover, since the cooling air introduced to the radiating fins 30 is supplied from the blower fan 52 at a distant position through the duct 54 having a predetermined length, the cooling air is introduced to the radiating fins 30 in a state in which the wind power is weakened considerably by a pressure loss. However, in the present embodiment, as described above, since the radiating fins 30 have an approximately straight shape, the cooling air of which the wind power is weakened in this manner can realize satisfactory heat exchange and provide an excellent cooling effect. For example, in this type of scroll compressor 1, although an electric motor is often integrated with the power transmission unit 6 as a dynamic power source, in this case, the size of the power transmission unit 6 may increase and hence, the length of the duct 54 also increases. When the length of the duct 54 increases in this manner, although the cooling air passing through the duct 54 is likely to be influenced from a pressure loss, a satisfactory cooling effect can be secured due to the above-mentioned effect.

Moreover, as illustrated in FIG. 6, a plurality of conventional radiating fins 30′ are typically provided at approximately equal intervals in the blowing direction of the cooling air. Therefore, although the cooling air introduced from the first air passage 56 can obtain a relatively satisfactory cooling effect on the upstream side of the radiating fins 30′, the temperature of the cooling air may increase gradually on the downstream side and the cooling effect may deteriorate. As a result, due to such a bias in the cooling effect, a temperature difference may occur on the revolving scroll 20, which may cause a distortion.

In contrast, in the present embodiment, as illustrated in FIG. 5, the plurality of radiating fins 30 are arranged more densely on the downstream side of the cooling air than on the upstream side. In the example of FIG. 5, particularly, the plurality of radiating fins 30 are configured so that a pitch distance between the adjacent radiating fins 30 is larger on the upstream side of the cooling air than on the downstream side. More specifically, a pitch distance L1 on the upstream side is larger than a pitch distance L2 on the downstream side. Therefore, the flow rate of the cooling air introduced from the first air passage 56 increases as it approaches the downstream side (that is, the flow rate V2 on the downstream side is larger than the flow rate V1 on the upstream side), and a bias in the cooling effect between the upstream side and the light sources can be alleviated. As a result, it is possible to cool the revolving scroll 20 uniformly and to effectively suppress occurrence of distortion in the revolving scroll 20.

The plurality of radiating fins 30 may be configured to be more densely on the downstream side of the cooling air than on the upstream side by forming the same to be thicker on the downstream side than on the upstream side of the cooling air. In this case, similarly to FIG. 5, since the gap between the radiating fins 30 narrows as it approaches the downstream side, the flow rate of the cooling air increases as it approaches the downstream side, and advantages similar to those described above can be obtained.

FIG. 7 is another modification of FIG. 5. As illustrated in FIG. 7, the plurality of radiating fins 30 may be arranged to be more sparsely on the central side than on the outer circumference side of the revolving scroll 20. As described above, since the temperature of the pressurized gas in the compression chamber 36 increases as it approaches the central portion of the compression chamber 36, by arranging the radiating fins 30 so as to be more sparsely as it approaches the inner side, it is possible to confine a larger amount of cooling air on the inner side (that is, the central side). Therefore, a higher cooling effect is obtained as it approaches the inner side where the temperature is likely to increase. In this way, it is possible to perform cooling according to a thermal load distribution of the revolving scroll 20 and to suppress occurrence of distortion in the revolving scroll 20 more effectively.

Although the radiating fins 30 of the revolving scroll 20 have been described, the same idea can be applied to the radiating fins 24 of the fixed scroll 18. For example, when an example of the radiating fins 24 of the fixed scroll 18 is described representatively by referring to FIG. 8, since the cooling air is introduced to the radiating fins 24 of the fixed scroll 18 through the second air passage 58, the radiating fins 24 having an approximately straight shape and extending approximately in parallel along the cooling air are arranged on the second surface of the fixed scroll 18. These radiating fins 24 are arranged so as to be more densely on the downstream side of the cooling air supplied from the second air passage 58 than on the upstream side and to be more sparsely on the outer circumference side than on the central side, and modifications similar to those of the radiating fins 30 of the revolving scroll 20 can be applied.

<3. Reinforcement Structure of Revolving Scroll>

Next, a reinforcement structure of the revolving scroll 20 in the scroll compressor 1 according to the present embodiment will be described in detail. In this type of scroll compressor 1, since the revolving scroll 20 is rotated by the torque of the driving shaft 22, distortion is more likely to occur in the revolving scroll 20 than in the fixed scroll 18 fixed to the compressor housing 16. Therefore, in the present embodiment, by employing a reinforcement structure to be described later in the revolving scroll 20, it is possible to improve mechanical strength and suppress distortion of the revolving scroll 20.

Here, a reinforcement structure according to a comparative example will be described as a premise according to the present embodiment. FIG. 9 is a cross-sectional view along a line passing through a central axis of the revolving scroll 20′ illustrated in FIG. 6 (comparative example). In the revolving scroll 20′ of the comparative example, a reinforcement rib 70 is formed on the revolving end plate 26 having a uniform thickness. The reinforcement rib 70 is formed so as to pass through the central portion of the revolving end plate 26 on the second surface on which the radiating fins 30 are formed and to extend in a direction approximately vertical to the radiating fins 30.

However, although such a linear reinforcement rib 70 provides a relatively effective reinforcement effect in the vicinity of the reinforcement rib 70, it is difficult to obtain a sufficient reinforcement effect in a region distant from the reinforcement rib 70, and it is not possible to sufficiently reinforce the entire revolving scroll 20. Moreover, as illustrated in FIG. 9, since the reinforcement rib 70 has a shape that protrudes in a convex shape from the second surface, the cooling air from the first air passage 56 may collide from a lateral surface of the reinforcement rib 70 to disturb the flow of the cooling air and may deteriorate the cooling performance of the revolving scroll 20.

In the present embodiment, the revolving end plate 26 has a convex shape 80 in which the second surface swells continuously. FIG. 10 is a cross-sectional view along a line passing through the central axis of the revolving scroll 20 illustrated in FIG. 4, and FIG. 11 is a contour distribution of the revolving end plate 26 on the second surface of the revolving scroll 20. The revolving end plate 26 has a non-uniform thickness so that the height increases about an apex 81 as a center and has a gentle mountain-shaped cross-sectional shape. Due to this, as compared to the revolving end plate 26 having a uniform thickness as in the conventional revolving scroll (see FIG. 9), the thickness of the revolving scroll 20 increases and the strength is improved. Moreover, since such a convex shape 80 is formed continuously (smoothly), it is possible to realize satisfactory heat exchange with the radiating fins 30 without disturbing the flow of the cooling air from the first air passage 56. In this manner, it is possible to reinforce the revolving scroll 20 with a compact configuration while securing a cooling performance.

As illustrated in FIG. 11, the convex shape 80 on the revolving end plate 26 is formed so that a center of gravity 82 of the revolving scroll 20 is identical to the center of revolution shifted from the center O of the revolving end plate 26. More specifically, in the example of FIG. 11, the apex 81 of the convex shape 80 is shifted to a top-left corner from the center O of the revolving end plate 26, and as a result, the center of gravity 82 is also shifted from the center O. Generally, since the revolving scroll 20 is rotated in an eccentric state, although a process of adding a balance (padding) to the revolving scroll 20 has conventionally been performed in order to adjust the balance of the revolving scroll 20 finely, this process may make the device configuration complex and may increase a workload. In this respect, in this configuration, since the position of the center of gravity 82 of the revolving scroll 20 can be adjusted arbitrarily by forming the convex shape 80 on the second surface, such a problem can be solved with a simple configuration.

Moreover, the convex shape 80 on the second surface of the revolving end plate 26 may be formed over a region including the center O. When the convex shape 80 is formed in such a wide region, the inclination of the convex shape 80 becomes gentle. As a result, the cooling air passes more easily and a satisfactory cooling performance can be achieved.

As described above, the plurality of radiating fins 30 extending in the blowing direction of the cooling air are formed on the second surface having such a convex shape 80. As described above, in the revolving scroll 20, since the thickness of the revolving end plate 26 increases due to the convex shape 80 formed on the second surface of the revolving end plate 26, although the heat capacity also increases, it is possible to effectively cool the revolving scroll 20 having a large heat capacity by forming such radiating fins 30. Moreover, by forming the radiating fins 30, it is possible to further improve the strength of the revolving scroll 20.

The plurality of radiating fins 30 are arranged on the second surface as described with reference to FIGS. 5, 6, and 7. However, as another embodiment, the plurality of radiating fins 30 may be arranged so as to be more densely as the thickness of the revolving end plate 26 on the second surface increases. That is, the arrangement density of the radiating fins 30 in a region which increases as the thickness of the revolving end plate 26 having the convex shape 80 in the region increases. Due to this, since a radiation amount can be distributed according to the heat capacity per unit area, it is possible to cool a wide region of the revolving scroll 20 uniformly and to suppress distortion of the revolving scroll 20 more effectively.

Moreover, the first surface of the revolving scroll 20 may have a concave reduced thickness portion 92 in at least a portion of a non-contacting region 90 that does not make contact with the fixed scroll 18. FIG. 12 is a modification of FIG. 4. The first surface of the revolving scroll 20 is disposed so as to face the fixed scroll 18 and forms the compression chamber 36 together with the fixed scroll 18. Here, the non-contacting region 90 that does not make contact with the fixed scroll 18 when the revolving scroll 20 revolves by being driven by the driving shaft 22 is present as illustrated in FIG. 12. The non-contacting region 90 is a region of the first surface of the revolving end plate 26 of the revolving scroll 20, located closer to the outer circumference side than at least the revolving wrap 28 at the outermost circumference (a portion of the revolving wrap 28 corresponding to one winding from the outermost circumferential end).

Although FIG. 12 illustrates a case in which the entire non-contacting region 90 is formed as a concave reduced thickness portion 92, a portion of the non-contacting region 90 may be formed as a partially concave reduced thickness portion 92.

In the respective embodiments, the balance is adjusted in the direction for increasing the weight of the revolving end plate 26 by forming the convex shape 80 on the second surface of the revolving scroll 20. However, in this configuration, the balance of the revolving scroll 20 can be adjusted in the direction for decreasing the weight contrarily by forming the reduced thickness portion 92. In this way, the balance of the revolving scroll 20 can be adjusted more finely. Moreover, the volume of the compression chamber 36 can be extended by forming the reduced thickness portion 92 on the first surface.

Although it has been described that the reduced thickness portion 92 may be formed on the first surface of the revolving scroll 20, the reduced thickness portion 92 may be formed on the first surface of the fixed scroll 18. In this case, since the fixed scroll 18 is fixed to the compressor housing 16, although a balance adjustment effect is not obtained, it is possible to decrease the weight of the fixed scroll 18 by forming the reduced thickness portion 92 and to contribute to increasing the volume of the compression chamber 36.

<4. Cooling Structure of Pressurized Gas>

Next, a cooling structure of the pressurized gas discharged from the compressor body 4 will be described. As illustrated in FIG. 2, the air guiding space 57 to which the cooling air can be introduced through the third air passage 60 is formed between the cover 63 and the fixed scroll 19 (the lid portion 53) of the compressor body 4. A discharge pipe 59 through which the pressurized gas discharged from the discharge port 38 of the compressor body 4 flows is disposed so as to penetrate the air guiding space 57 toward the outside.

The discharge pipe 59 is configured so as to make contact with the cooling air flowing through the air guiding space 57 from the outside, and the high-temperature pressurized gas flowing through the discharge pipe 59 is cooled by heat exchange with the cooling air introduced into the air guiding space 57. Conventionally, the high-temperature pressurized gas discharged from the compressor body 4 is supplied to a desired destination after being cooled by an after-cooler provided at the outside. However, in the present embodiment, since the pressurized gas can be cooled in the air guiding space 57 in this manner, an external device such as an after-cooler is not necessary, and it is advantageous in decreasing the size of the entire system.

Here, a heat exchanging portion 59a of the discharge pipe 59 exposed to the air guiding space 57 may be configured such that a heat conductivity thereof is higher than portions therearound. For example, the heat exchanging portion 59a may be partially formed of a material (for example, aluminum) having a high heat conductivity and may have a partially small thickness. In this manner, since the discharge pipe 59 through which the high-temperature pressurized gas from the compressor body 4 flows has the heat exchanging portion 59a having a high heat conductivity, exposed to the air guiding space 57, it is possible to accelerate heat exchange with the cooling air introduced into the air guiding space 57 and to cool the discharged gas more effectively.

FIG. 13 is a modification of FIG. 2. In this modification, the discharge pipe 59 has an enlarged diameter portion 97 having an enlarged diameter, and a check valve 98 for preventing backflow of the discharged gas is included in the enlarged diameter portion 97. In this type of scroll compressor 1, when a compression cycle stops, a phenomenon that the pressurized gas remaining in the discharge pipe 59 temporarily flows back toward the compressor body 4 may occur. Although a configuration in which a check valve is provided on the downstream side of the discharge port 38 has conventionally been used in order to suppress occurrence of such a backflow phenomenon, this type of check valve has a limited range of use temperature and cannot endure the high-temperature pressurized gas discharged from the discharge port 38. Therefore, it is necessary to cool the high-temperature pressurized gas using an after-cooler provided on the downstream side as described above and to arrange a check valve on the downstream side thereof, which may increase the size of a system. In this respect, in the present embodiment, since the pressurized gas of the discharge pipe 59 is cooled by the air guiding space 57, the check valve 98 can be included in the enlarged diameter portion 97 provided in the discharge pipe 59. In this way, it is possible to decrease the size of the entire system effectively.

FIG. 14 is another modification of FIG. 2, and FIG. 15 is a schematic diagram illustrating the cooling fins 95 formed on the outer surface of the discharge pipe 59 illustrated in FIG. 14 when seen from the inner side of the cover 63. In this modification, the cooling fins 95 are formed on the outer surface of the discharge pipe 59. By forming such cooling fins 95, it is possible to increase a heat exchange area for heat exchange with the cooling air introduced into the air guiding space 57 and to decrease the temperature of the discharged gas more effectively. Moreover, such cooling fins 95 are effective in reinforcing the mechanical strength of the discharge pipe 59 through which the high-pressure pressurized gas flows. Particularly, when the thickness of the discharge pipe 59 is partially decreased as described above, although the strength of the discharge pipe 59 itself decreases, the strength can be reinforced by forming such cooling fins 95.

Moreover, in this modification, the cooling fins 95 extend in the flowing direction (the left-right direction) of the cooling air introduced into the air guiding space 57 through the third air passage 60 and are configured so as not to disturb the flow of the cooling air. As a result, it is possible to accelerate heat exchange between the discharged gas and the cooling air and to decrease the temperature of the discharged gas more effectively.

<5. Intermediate Cooler>

In the above-described embodiments, although the scroll compressor 1 that compresses gas in a single stage has been described, the scroll compressor 1 may be configured as a multi-stage compressor that compresses gas in multiple stages. In the following embodiment, a case in which the scroll compressor 1 is configured as a single-winding two-stage scroll compressor will be described.

FIG. 16 is a plan view illustrating the fixed scroll 18 and the revolving scroll 20 of a single-winding two-stage scroll compressor 1. In this scroll compressor 1, a partition wall 102 for partitioning a low-pressure-side compression chamber 36a and a high-pressure-side compression chamber 36b is formed in a spiral groove formed by a fixed wrap 21 formed on the fixed end plate 19 of the fixed scroll 18. That is, the partition wall 102 is formed in a boss shape on the fixed end plate 19 so that the spiral groove formed by the fixed wrap 21 is blocked halfway. When the passage of the pressurized gas of the compression chamber 36 is blocked by such a partition wall 102, the compression chamber 36 is partitioned into the low-pressure-side compression chamber 36a and the high-pressure-side compression chamber 36b.

The partition wall 102 may be formed integrally with the fixed end plate 19 and may be formed as a separate member.

A low-pressure-side discharge port 104 and a high-pressure-side inlet port 106 are formed on both sides (that is, the inner side of the low-pressure-side compression chamber 36a and the outer side of the high-pressure-side compression chamber 36b) of the partition wall 102 of the spiral groove 100. The low-pressure-side discharge port 104 and the high-pressure-side inlet port 106 are formed so as to penetrate the fixed end plate 19 approximately in parallel to the central axis line of the fixed scroll 18. The low-pressure-side compression chamber 36a is positioned on the outer side as compared to the high-pressure-side compression chamber 36b and a compression target gas (outside air) is introduced therein from the introduction path 15. The pressurized gas pressurized in the low-pressure-side compression chamber 36a is discharged from the low-pressure-side discharge port 104 and is cooled by an intermediate cooler 110 to be described later and is then introduced into the high-pressure-side inlet port 106 of the high-pressure-side compression chamber 36b. In the high-pressure-side compression chamber 36b, the pressurized gas cooled by the intermediate cooler 110 is further compressed, and the pressurized gas is finally discharged from the discharge port 38 formed on a central side of the fixed end plate 19.

Here, FIG. 17 is a perspective view illustrating a state in which the cover 63 is detached from the scroll compressor 1 according to the present embodiment, and FIG. 18 is a vertical cross-sectional view along a line passing through the driving shaft 22 in a state in which the cover 63 is attached to the scroll compressor 1 illustrated in FIG. 17.

The scroll compressor 1 includes the intermediate cooler 110 configured to cool the pressurized gas discharged from the low-pressure-side compression chamber 36a and to return the cooled pressurized gas to the high-pressure-side compression chamber 36b. The intermediate cooler 110 is an air-cooled cooler and includes the air guiding space 57 to which cooling air is introduced and a radiating pipe 112 which is disposed inside the air guiding space 57 and through which the pressurized gas discharged from the low-pressure-side compression chamber 36a flows.

As described above, the air guiding space 57 is formed by the lid portion 53 fixed to the fixed scroll and the cover 63 covering the lid portion 53, and the cooling air is introduced into the air guiding space 57 through the third air passage 60. Moreover, the radiating pipe 112 connecting the low-pressure-side discharge port 104 of the low-pressure-side compression chamber 36a and the high-pressure-side inlet port 106 of the high-pressure-side compression chamber 36b is disposed on the lid portion 53 within the inner wall of the air guiding space 57. The radiating pipe 112 is exposed to the cooling air introduced from the third air passage 60 through an opening 100 formed in the vicinity of an edge of the lid portion 53 of the air guiding space 57 whereby the high-temperature pressurized gas flowing through the radiating pipe 112 is cooled. In this manner, the intermediate cooler 110 for cooling the pressurized gas using the cooling air introduced into the air guiding space 57 can be formed to be integrated with the compressor body 4. Such a configuration is simpler than the conventional configuration, and it is possible to reduce a manufacturing cost and an installation space of entire facility effectively.

The radiating pipe 112 is formed of a metal material having an excellent heat conductivity such as aluminum, for example. Moreover, the radiating pipe 112 is formed in a convex shape on the lid portion 53 and is configured so that a contact area contacting the cooling air introduced into the air guiding space 57 increases.

Moreover, as illustrated in FIG. 17, the radiating pipe 112 is arranged on the lid portion 53 so as to be folded back in a predetermined pattern. Since the radiating pipe 112 has such a folded-back shape, it is possible to secure a large contact area with the cooling air introduced into the air guiding space 57 and to obtain a satisfactory cooling effect.

When the configuration of the radiating pipe 112 is described in further detail, the radiating pipe 112 has a shape in which a plurality of radiating portions 113 extending along the cooling air introduced from the third air passage 60 are connected by a plurality of folded-back portions 114 formed to be lower than the plurality of radiating portions 113. Since the radiating pipe 112 has such a folded-back shape, it is possible to arrange the long radiating pipe 112 in a limited compact space on the lid portion 53. Moreover, since the plurality of radiating portions 113 extends in the blowing direction, the radiating portions do not disturb the flow of the cooling air. Furthermore, since the folded-back portions 114 are formed to be lower than the radiating portions 113, the outside air is introduced smoothly between the adjacent radiating portions 113. In this manner, a satisfactory cooling effect is obtained with the radiating pipe 112.

In the present embodiment, the low-pressure-side discharge port 104 is disposed on the downstream side of the cooling air as compared to the high-pressure-side inlet port 106 on the lid portion 53 that forms the inner wall of the air guiding space 57. Moreover, as illustrated in FIG. 17 in which the passage of the pressurized gas in the radiating pipe 112 is indicated by a broken line, the radiating pipe 112 is configured to pass more closely through the downstream side than the central portion of the lid portion 53 and to be connected to the high-pressure-side inlet port 106 while circumventing the upstream side so as to surround the central portion. Due to this, the pressurized gas flowing through the radiating pipe 112 flows from the downstream side toward the upstream side as indicated by arrows in FIG. 17. As a result, the temperature of the pressurized gas flowing through the radiating pipe 112 on the upstream side of the cooling air decreases as compared to on the downstream side. Therefore, the cooling air on the upstream side exchanges heat with a relatively low-temperature pressurized gas and the cooling air having a low temperature can be supplied to the radiating pipe 112 on the downstream side, through which a relatively high-temperature pressurized gas flows. In this way, a satisfactory cooling effect is obtained in the entire radiating pipe 112.

The air guiding space 57 that forms the intermediate cooler 110 may be used for cooling the pressurized gas passing through the discharge pipe 59 similarly to the above-described embodiments. In this case, since the pressurized gas discharged from the discharge pipe 59 is cooled using the air guiding space 57 that forms the intermediate cooler 110, an external device such as an after-cooler, for example, is not necessary, and it is possible to reduce a system size and to effectively save an installation space and a manufacturing cost.

Moreover, as illustrated in FIGS. 14 and 15, when the radiating fins 97 are formed on the outer surface of the discharge pipe 59, the permeability of the cooling air introduced from the third air passage 60 may be improved by arranging the radiating fins 97 in an arrangement pattern corresponding to an arrangement pattern of the radiating pipes 112 of the intermediate cooler 110.

The radiating pipe 112 may be arranged more densely on the downstream side of the cooling air introduced through the third air passage 60 than on the upstream side similarly to the radiating fins 30 described with reference to FIG. 5. In this way, since the passage area decreases from the upstream side toward the downstream side, the flow rate of the cooling air introduced to the radiating pipes 112 increases as it approaches the downstream side where the temperature of the cooling air increases. As a result, a uniform cooling effect is obtained in the entire radiating pipe 112.

<6. Supercharge Structure of Cooling Air>

Although the above-described embodiment employs a natural intake scroll compressor in which gas compressed by the compressor body 4 is introduced directly from an intake port of the filter unit 2, a supercharging scroll compressor may be employed as in the embodiment to be described later. FIG. 19 is a vertical cross-sectional view of a supercharging scroll compressor 11.

FIG. 19 is a modification of FIG. 2, the corresponding elements will be denoted by the same reference numerals, and redundant description will be omitted appropriately.

In the embodiment of FIG. 19, a compression target gas is taken in from an opening 55 of the blower unit 8. That is, in the present embodiment, a portion of the outside air taken in from the blower unit 8 is used as the compression target gas, and the remaining is used as the cooling air of the compressor body 4. In the present embodiment, the intake port 12 of the filter unit 2 illustrated in FIG. 2 is sealed.

In the scroll compressor 1, when the blower fan 52 is driven by the driving shaft 22, outside air is taken in from the opening 55 of the blower unit 8. The outside air taken in from the opening 55 is delivered to the compressor body 4 through the duct 54 connected to a lateral side of the blower unit 8. The duct 54 is connected to the lateral side of the compressor body 4, and similarly to the above-described embodiment, branches into the first air passage 56, the second air passage 58, and the third air passage 60. The outside air introduced into the first air passage 56 and the second air passage 58 is supplied to the radiating fins 24 and 30 formed on the back surface of the fixed scroll 18 and the revolving scroll 20, respectively, to thereby cool the fixed scroll 18 and the revolving scroll 20, respectively.

On the other hand, the outside air introduced into the third air passage 60 is supercharged into the introduction path 15 of the compressor body 4. Here, the air guiding space 57 formed by the lid portion 53 and the cover 63 communicates with the filter casing 10 of the filter unit 2 disposed on the upper side thereof (that is, an opening 120 is formed in the lower part of the filter casing 10 so as to communicate with the air guiding space 57). Therefore, the outside air supplied from the third air passage 60 is delivered to the filter unit 2 through the air guiding space 57. In the filter unit 2, the outside air delivered from the air guiding space 57 passes through the filter element 14 whereby a foreign material is removed therefrom, and after that, the outside air is supercharged into the compressor body 4.

In this manner, a portion of the cooling air supplied from the blower fan 52 in order to cool the fixed scroll 18 and the revolving scroll 20 is configured to be supercharged into the compressor body 4. That is, since a portion of the cooling air used as air for cooling the fixed scroll 18 and the revolving scroll 20 can be supercharged, in spite of a simple configuration, it is possible to realize the scroll compressor 1 capable of obtaining satisfactory compression efficiency while suppressing the increase in temperature of the fixed scroll 18 and the revolving scroll 20.

Here, the cooling air supercharged into the compressor body 4 is supercharged through the air guiding space 57. Since the cooling air passes through the air guiding space 57, dynamic pressure of the cooling air from the duct 54 is converted to static pressure and the cooling air having the static pressure is supercharged into the compressor body 4. Therefore, even if a variation such as pulsation is present in the gas supplied from the duct 54, stable supercharging can be realized. Particularly, since the air guiding space 57 has a larger passage area than the duct 54, it is possible to convert the dynamic pressure of the cooling air delivered from the duct 54 to static pressure satisfactorily, and stable supercharging can be realized.

Moreover, the cover 63 that forms the air guiding space 57 has a curved inner wall so that the cooling air introduced into the air guiding space 57 is rectified toward the introduction path 15 of the compressor body 4. In this way, the cooling air introduced into the air guiding space 57 through the third air passage 60 is efficiently guided to the introduction path 15 of the compressor body 4, and satisfactory supercharging is realized.

In the present embodiment, although the air guiding space 57 is used for supercharging the outside air from the third air passage 60 to the compressor body 4, the air guiding space 57 may be also used for cooling the pressurized gas passing through the discharge pipe 59 similarly to the above-described embodiment. Since the air guiding space 57 is configured to realize a plurality of functions in this manner, it is possible to reduce a system size and to effectively save an installation space and a manufacturing cost.

Embodiments of the present invention were described in detail above, but the present invention is not limited thereto, and various amendments and modifications may be implemented within a scope that does not depart from the present invention.

For example, the respective embodiments relate to a so-called belt-driven scroll fluid machine in which the driving shaft 22 rotates with the aid of a power transmission belt that rotates with a dynamic power source such as a motor or an engine. However, the present invention is not limited to the belt-driven scroll fluid machine. For example, the present application invention can be applied to a so-called dynamic-power-source-direct-coupled scroll fluid machine in which the revolving plate 32 is directly connected to one end of the driving shaft of a dynamic power source and the blower fan 52 is fixed to the other end of the driving shaft.

Moreover, the scroll compressor according to the respective embodiments is a compressor having the fixed scroll 18 and the revolving scroll 20. However, the present invention is not limited to such a scroll compressor. For example, the present invention can be applied to a scroll fluid machine including a driving scroll as the first scroll and a driven scroll as the second scroll.

INDUSTRIAL APPLICABILITY

At least one embodiment of the present invention can be applied to a scroll fluid machine.

REFERENCE SIGNS LIST

• • 1: Scroll compressor
  • 2: Filter unit
  • 4: Compressor body
  • 6: Power transmission unit
  • 8: Blower unit
  • 10: Filter casing
  • 12: Intake port
  • 14: Filter element
  • 15: Introduction path
  • 16: Compressor housing
  • 18: Fixed scroll
  • 19: Fixed end plate
  • 20: Revolving scroll
  • 21: Fixed wrap
  • 22: Driving shaft
  • 23: Eccentric shaft portion
  • 24: Radiating fin
  • 26: Revolving end plate
  • 28: Revolving wrap
  • 30: Radiating fin
  • 32: Revolving plate
  • 33: Rotating bearing
  • 34: Rotation prevention mechanism
  • 36: Compression chamber
  • 37: Bearing portion
  • 38: Discharge port
  • 40: Driven pulley
  • 42: Bearing case
  • 44: Ball bearing
  • 48: Balance weight
  • 50: Fan casing
  • 52: Blower fan
  • 53: Lid portion
  • 54: Duct
  • 55: Opening
  • 56: First air passage
  • 57: Air guiding space
  • 58: Second air passage
  • 59: Discharge pipe
  • 60: Third air passage
  • 61: Groove portion
  • 63: Cover
  • 70: Reinforcement rib
  • 80: Convex shape
  • 90: Non-contacting region
  • 92: Reduced thickness portion
  • 95: Cooling fin
  • 97: Enlarged diameter portion
  • 98: Check valve
  • 102: Partition wall
  • 104: Low-pressure-side discharge port
  • 106: High-pressure-side inlet port
  • 110: Intermediate cooler
  • 112: Radiating pipe

Claims

1. A scroll fluid machine comprising:

a housing;

a fixed scroll which is fixed to the housing and in which a spiral groove formed by a fixed wrap formed on a fixed end plate is blocked by a partition wall that partitions a low-pressure-side compression chamber and a high-pressure-side compression chamber;

a revolving scroll which is accommodated in the housing so as to face the fixed scroll to form the low-pressure-side compression chamber and the high-pressure-side compression chamber together with the fixed scroll and is resolvable supported by a driving shaft;

a cover that forms an air guiding space between the fixed scroll and the cover so that a portion of cooling air supplied to at least one of the fixed scroll and the revolving scroll can be introduced into the air guiding space;

and an intermediate cooler configured to cool pressurized gas discharged from the low-pressure-side compression chamber by heat exchange with the cooling air in the air guiding space so that the cooled pressurized gas is returned to the high-pressure-side compression chamber.

2. The scroll fluid machine according to claim 1, wherein

the intermediate cooler includes a radiating pipe arranged in the air guiding space so as to connect a low-pressure-side discharge port of the low-pressure-side compression chamber and a high-pressure-side inlet port of the high-pressure-side compression chamber.

3. The scroll fluid machine according to claim 2, wherein

the radiating pipe is arranged to be folded back on an inner wall of the air guiding space.

4. The scroll fluid machine according to claim 3, wherein

the radiating pipe is configured such that a plurality of radiating portion extending along the cooling air are connected by a plurality of folded-back portions formed to be lower than the plurality of radiating portions.

5. The scroll fluid machine according to claim 2, wherein

the low-pressure-side discharge port is disposed on a downstream side of the cooling air as compared to the high-pressure-side inlet port.

6. The scroll fluid machine according to claim 1, wherein

the scroll fluid machine further includes a discharge pipe through which the pressurized gas discharged from the high-pressure-side compression chamber flows, wherein the discharge pipe is provided so as to penetrate the air guiding space so that the pressurized gas flowing through the discharge pipe is cooled by the cooling air introduced into the air guiding space.

7. The scroll fluid machine according to claim 6, wherein

a check valve is provided in the discharge pipe.