Lubricating oil supply apparatus of reciprocating compressor

Abstract

A lubricating oil supply apparatus of a reciprocating compressor comprises: an oil cylinder penetratingly-formed at a lower side of a frame, for supporting a compression unit which compresses a fluid; an oil piston reciprocatingly-inserted into the oil cylinder and reciprocated by a vibration of the compressor, for pumping lubricating oil; a spring connected to a rear side of the oil piston and providing an elastic force to the oil piston; and a valve assembly disposed at a front side of the frame, for opening and closing a passage of lubricating oil supplied to a sliding part of the compressing unit. A dead volume existing at the oil supply apparatus is reduced thereby to smoothly supply lubricating oil even at the time of an initial driving that requires less pumping amount, thereby enhancing a lubricating performance.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lubricating oil supply apparatus of a reciprocating compressor, and more particularly, to a lubricating oil supply apparatus of a reciprocating compressor capable of enhancing an oil supply performance and reducing a fabrication cost by reducing the number of components.

2. Description of the Conventional Art

Generally, a compressor is divided into a rotary compressor, a reciprocating compressor, a scroll compressor, and etc. according to a fluid compression method.

FIG. 1 is a sectional view of a reciprocating compressor in accordance with the conventional art.

The conventional reciprocating compressor comprises: a case 106 to which a suction pipe 102 and a discharge pipe 104 are connected and containing lubricating oil at a lower portion thereof; a reciprocating motor 108 disposed in the case 106 for generating a reciprocation force; a compressing unit 110 for compressing a fluid by receiving the reciprocation force generated from the reciprocating motor 108; frames 112, 114, and 116 for supporting the reciprocating motor 108 and the compressing unit 110; a lubricating oil supply apparatus for supplying lubricating oil contained in the case 106 to each frictional part of the compressor; and etc.

The reciprocating motor 108 includes: an outer stator 118 having a cylindrical shape and on which a winding coil to which a power is applied is wound; an inner stator 120 disposed at an inner circumferential surface of the outer stator 118 with a certain air gap; and a magnet 124 disposed between the outer stator 118 and the inner stator 120 with a certain interval for performing a linear reciprocation when a power is applied to the winding coil 122.

The magnet 124 is fixed to an outer circumferential surface of a magnet holder 126 with the same interval, and the magnet holder 126 is integrally formed with a piston 128 of the compressing unit 110.

A first resonant spring 134 and a second resonant spring 136 are respectively disposed between one side surface of the magnet holder 126 and the frame 112 and between another side surface of the magnet holder 126 and the frame 116, thereby inducing a resonant movement of the piston 128.

The compressing unit 110 is constituted with the piston 128 connected to the magnet holder 126 and linearly reciprocated, a cylinder 142 to which the piston 128 is slidably inserted and forming a certain compression chamber 140, a suction valve 146 for opening and closing an inlet mounted at the front side of the piston 128, and a discharge valve assembly 148 mounted at the front side of the cylinder 142 for discharging a compressed fluid to outside when a pressure inside the compression chamber 140 is more than a preset pressure.

The discharge valve assembly 148 includes: a discharge valve 150 adhered to the front side surface of the cylinder 142 for discharging a compressed fluid; a discharge cover 152 mounted at the front side of the cylinder 142 and to which the discharge valve 104 for discharging a fluid is connected; and a spring 154 disposed between the inner side surface of the discharge cover 152 and the discharge valve 150 for elastically supporting the discharge valve 150.

The frames include: a first frame 112 to which the outer circumferential surface of the cylinder 142 is fixed, for fixing the front side of the reciprocating motor 108; a second frame 114 for supporting the rear side of the reciprocating motor 108; and a third frame 116 coupled to the second frame 114 for supporting the second resonant spring 136.

The lubricating oil supply apparatus for supplying lubricating oil contained at the lower portion of the case 106 to a sliding part between the cylinder 142 and the piston 128 includes: a pumping unit 160 fixed at one side of the first frame 112, for pumping lubricating oil by using vibration generated at the time of driving the compressor; a valve assembly 164 for opening and closing a passage of lubricating oil pumped by the pumping unit 160; and a lubricating oil supply passage 166 formed at the first frame 112 for supplying lubricating oil to the sliding part between the cylinder 142 and the piston 128.

The pumping unit 160 includes: an oil cylinder 170 fixed at a lower portion of the first frame 112; an oil piston 172 disposed in the oil cylinder 170 to be linearly movable and reciprocated by a vibration of the compressor, for pumping lubricating oil; and springs 174 and 176 for elastically supporting both sides of the oil piston 172.

The valve assembly 164 includes: an oil cover 182 mounted at the front side of the first frame 112 and provided with a lubricating oil passage 180 therein, the lubricating oil passage 180 through which lubricating oil passes; a suction valve 184 disposed in the oil cover 182 for opening and closing an inlet through which the lubricating oil is sucked; a discharge valve 186 disposed in the oil cover 182 for opening and closing an outlet through which the compressed lubricating oil is discharged; and a suction pipe 188 mounted at the oil cover 182 for sucking lubricating oil contained at the lower portion of the case 106.

The first frame 112 is provided with a lubricating oil hole 190 connected to the oil cylinder 170 for sucking and discharging lubricating oil.

FIGS. 2A and 2B are sectional views showing an operational state of a lubricating oil supply apparatus of the reciprocating compressor in accordance with the conventional art;

Operation of the conventional lubricating oil supply apparatus of the reciprocating compressor will be explained.

As shown in FIG. 2A, once the oil piston 172 is retreated by a vibration generated when the compressor is driven, a suction pressure is generated. By the suction pressure, the suction valve 184 is opened and lubricating oil is sucked through the suction pipe 188. The lubricating oil is introduced into the oil cylinder 170 through the lubricating oil hole 190 formed at the first frame 112.

Then, as shown in FIG. 2B, when the oil piston 172 advances by a vibration generated when the compressor is driven and thereby the lubricating oil contained in the cylinder 170 is discharged through the lubricating oil hole 190, the suction valve 184 is closed and the discharge valve 186 is opened. According to this, the lubricating oil is supplied to the sliding part between the cylinder 142 and the piston 128 through the lubricating oil supply passage 166 thus to perform a lubricating operation.

However, in the conventional lubricating oil supply apparatus of the reciprocating compressor, the lubricating oil hole 190 for sucking lubricating oil into the oil cylinder 170 and discharging out is formed at the first frame 112, and a space for installing the spring 174 at the front side of the oil piston 172 is required. Therefore, the lubricating oil hole 190 and the installation space of the spring 174 become a dead volume. By the dead volume, in case that a vibration amount is less, for example, at the time of an initial driving of the compressor, lubricating oil is not smoothly supplied to the sliding part and thereby a friction is generated at the sliding part of the compressing unit.

Additionally, in the conventional lubricating oil supply apparatus of the reciprocating compressor, the pumping unit 160 for pumping lubricating oil has a great number of components and complicated structure and assembly processes, thereby increasing a fabrication cost.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a lubricating oil supply apparatus of a reciprocating compressor capable of enhancing a lubricating performance by reducing a dead volume existing at an oil supply apparatus and thus by smoothly supplying lubricating oil even at the time of an initial driving that requires less pumping amount.

Another object of the present invention is to provide a lubricating oil supply apparatus of a reciprocating compressor capable of enhancing an assembly characteristic and reducing a fabrication cost by simplifying a structure of a pumping unit for pumping lubricating oil.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a lubricating oil supply apparatus of a reciprocating compressor comprising: an oil cylinder penetratingly formed at a lower side of a frame, for supporting a compression unit which compresses a fluid; an oil piston reciprocatingly inserted into the oil cylinder and reciprocated by a vibration of the compressor, for pumping lubricating oil; a spring connected to the rear side of the oil piston and providing an elastic force to the oil piston; and a discharge valve assembly disposed at the front side of the frame for opening and closing a passage of lubricating oil supplied to a sliding part of the compressing unit.

The oil cylinder is penetratingly formed at a lower side of the frame in a longitudinal direction of the compressor, and is positioned to be higher than a surface of lubricating oil contained at a lower portion of the compressor case.

The oil piston is disposed to be protruded towards a rear side of the oil cylinder.

The spring is formed as a plate spring, of which one side is connected to a rear side of the oil piston and another side is connected to the frame.

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings:

FIG. 1 is a sectional view of a reciprocating compressor in accordance with the conventional art;

FIGS. 2A and 2B are sectional views showing an operational state of a lubricating oil supply apparatus of the reciprocating compressor in accordance with the conventional art;

FIG. 3 is a sectional view of a reciprocating compressor according to one embodiment of the present invention; and

FIGS. 4A and 4B are sectional views showing an operational state of a lubricating oil supply apparatus of a reciprocating compressor according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Hereinafter, one embodiment of a reciprocating compressor according to the present invention will be explained with reference to attached drawings.

Even though a plurality of preferred embodiments of the reciprocating compressor according to the present invention can exist, the most preferred embodiment will be explained.

FIG. 3 is a sectional view of a reciprocating compressor according to one embodiment of the present invention.

The reciprocating compressor according to the present invention comprises: a case 6 of a certain hermetic space to which a suction pipe 2 for sucking a fluid and a discharge pipe 4 for discharging a compressed fluid are connected and containing lubricating oil at a lower portion thereof; a reciprocating motor 8 disposed in the case 6 for generating a reciprocation force when a power is applied; a compressing unit 10 for compressing a fluid by receiving the reciprocation force generated from the reciprocating motor 8; frames 12, 14, and 16 for supporting the reciprocating motor 8 and the compressing unit 10; and a lubricating oil supply apparatus for supplying lubricating oil contained in the lower portion of the case 6 to a sliding part of the compressor 10.

The reciprocating motor 8 includes: an outer stator 18 of a cylindrical shape; an inner stator 20 disposed at an inner circumferential surface of the outer stator 18 with a certain air gap; a winding coil 22 wound either on the outer stator 18 or on the inner stator 20, for generating a flux between the outer stator 18 and the inner stator 20 when a power is applied; and a magnet 24 reciprocatingly disposed at the air gap between the outer stator 18 and the inner stator 20.

The magnet 24 is fixed to an outer circumferential surface of a magnet holder 26 with the same interval, and the magnet holder 26 is integrally formed with a piston 30 of the compressing unit 10.

A first resonant spring 48 and a second resonant spring 50 are respectively disposed between one side surface of the magnet holder 26 and the frame 12 and between another side surface of the magnet holder 26 and the frame 16, thereby inducing a resonant movement of the piston 30.

The compressing unit 10 is constituted with the piston 30 connected to the magnet holder 26 and reciprocated, a cylinder 34 into which the piston 30 is slidably inserted and forming a certain compression chamber 32, a suction valve 38 for opening and closing an inlet mounted at the front side of the piston 30, and a discharge valve assembly 36 mounted at the front side of the cylinder 34 for discharging a compressed fluid to outside when a pressure inside the compression chamber 32 is more than a preset pressure.

The discharge valve assembly 36 includes: a discharge valve 40 which comes in contact with the front side surface of the cylinder 34 and opens/closes an outlet through which a compressed fluid is discharged; a discharge cover 42 mounted at the front side of the cylinder 34 and to which the discharge valve 4 is connected; and a spring 44 disposed between the inner side surface of the discharge cover 42 and the discharge valve 40 for elastically supporting the discharge valve 40.

The frames include: a first frame 12 fixed to an outer circumferential surface of the cylinder 34 and supporting one side surface of the reciprocating motor 8; a second frame 14 for supporting another side surface of the reciprocating motor 8; and a third frame 16 for supporting the second resonant spring 50.

The lubricating oil supply apparatus includes: a pumping unit 50 fixed at lower side of the first frame 12, for pumping lubricating oil by using a vibration generated at the time of driving the compressor; an oil valve assembly 52 for opening and closing a passage of lubricating oil pumped by the pumping unit 50; and a lubricating oil supply passage 54 formed at the first frame 12 for supplying lubricating oil to a sliding part between the cylinder 34 and the piston 30.

The pumping unit 50 includes: an oil cylinder 56 penetratingly formed at a lower portion of the first frame 12; an oil piston 58 linear-movably inserted into the oil cylinder 56 and reciprocated by a vibration of the compressor, for pumping lubricating oil; and an oil spring 60 connected to a rear surface of the oil piston 58, for elastically supporting the oil piston 58.

The oil cylinder 56 is penetratingly formed at a lower side of the first frame 12 in a longitudinal direction of the compressor, and is positioned to be higher than a surface of lubricating oil contained in the lower portion of the case 6. The reason why the oil cylinder 56 is positioned to be higher than the surface of the lubricating oil is to make the oil cylinder 56 not be soaked in the lubricating oil since noise and vapor are generated when the frames 12, 14, and 16 having wide surface areas come in contact with the lubricating oil.

The oil piston 58 is linear-movably inserted into the oil cylinder 56, and is disposed to be protruded towards the rear side of the first frame 12 with a certain length.

One side of the oil spring 60 is connected to the oil piston 58 and another side thereof is connected to the first frame 12, thereby providing an elastic force to the oil piston 58 when the oil piston 58 is reciprocated.

The oil spring 60 is preferably formed as a plate spring.

The oil valve assembly 52 includes: an oil cover 72 mounted at the front side of the first frame 12 and provided with a lubricating oil passage 70 therein, the lubricating oil passage 70 through which lubricating oil passes; an oil suction valve 74 disposed in the oil cover 72 for opening and closing an inlet through which the lubricating oil is sucked; an oil discharge valve 76 disposed in the oil cover 72 for opening and closing an outlet through which the compressed lubricating oil is discharged; and a suction pipe 78 mounted at the oil cover 72 for sucking lubricating oil contained at the lower portion of the case 6.

FIGS. 4A and 4B are sectional views showing an operational state of a lubricating oil supply apparatus of a reciprocating compressor according to the present invention.

Operation of the lubricating oil supply apparatus according to the present invention will be explained as follows.

As shown in FIG. 4A, once the oil piston 58 is retreated in the oil cylinder 56 formed at the first frame 12 by a vibration generated when the compressor is driven, a suction pressure is generated. By the suction pressure, the oil suction valve 74 is opened and lubricating oil is sucked into the oil cylinder 56 through the suction pipe 78.

Then, as shown in FIG. 4B, when the oil piston 58 advances by a vibration generated when the compressor is driven and thereby the lubricating oil contained in the oil cylinder 56 is discharged. According to this, the oil suction valve 74 is closed and the oil discharge valve 76 is opened, so that the lubricating oil is supplied to the sliding part between the cylinder 34 and the piston 30 through the lubricating oil supply passage 54 thus to perform a lubricating operation.

In the lubricating oil supply apparatus of the reciprocating compressor according to the present invention, the oil cylinder is formed at the first frame and thereby the oil cylinder and the lubricating oil passage formed in the oil cover are directly connected to each other. Also, the spring disposed at the front side of the oil piston is removed thus to minimize a dead volume. According to this, lubricating oil can be smoothly supplied even when a lubricating oil pumping amount is less, for example, at the time of an initial driving of the compressor.

Additionally, the oil cylinder is directly formed at the first frame and the spring is provided only at the rear side of the oil piston thus to simplify a construction of the pumping unit, thereby reducing the number of components, enhancing an assembly characteristic, and reducing a fabrication cost.

As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims

1. A lubricating oil supply apparatus of a reciprocating compressor comprising:

an oil cylinder penetratingly-formed at a lower side of a frame, for supporting a compression unit which compresses a fluid;

an oil piston reciprocatingly-inserted into the oil cylinder and reciprocated by a vibration of the compressor, for pumping lubricating oil;

a spring connected to a rear side of the oil piston and providing an elastic force to the oil piston; and

a valve assembly disposed at a front side of the frame, for opening and closing a passage of lubricating oil supplied to a sliding part of the compressing unit.

2. The apparatus of claim 1, wherein the oil cylinder is penetratingly-formed at a lower side of the frame in a longitudinal direction of the compressor,

3. The apparatus of claim 1, wherein the oil cylinder is positioned to be higher than a surface of lubricating oil contained at a lower portion of the compressor case.

4. The apparatus of claim 1, wherein the oil piston is disposed to be protruded towards a rear side of the oil cylinder.

5. The apparatus of claim 1, wherein one side of the spring is connected to a rear side of the oil piston and another side thereof is connected to the frame.

6. The apparatus of claim 5, wherein the spring is formed as a plate spring.