PUMP DEVICE

Abstract

The pump device has a driving member with one end connected to a diaphragm and another end connected to a driving mechanism. The driving mechanism side end repeats reciprocating motion along first axial direction and oscillation in second axial direction. The diaphragm side end performs the reciprocating motion in the first axial direction, and a problem is that the diaphragm easily deteriorates to be cut in a direction in which the diaphragm can be easily stretched, for example, in the second axial direction for performing oscillation. By embedding the base fabric having the fiber which extends in the second axial direction into the diaphragm, the strength in the second axial direction and the durability can be improved. By providing the index part to indicate the second axial direction, the extending direction of the fiber of the base fabric embedded within the diaphragm becomes distinguishable. In assembling the pump device, it becomes easy to place the diaphragm in a desired direction to the main body of the pump.

Description

TECHNICAL FIELD

The present invention relates to pump devices used as blowers or pressure pumps.

BACKGROUND ART

Pump devices called blowers or pressure pumps are widely known as equipment to increase the pressure of gases such as fuel gas and oxygen to a desired pressure. In this kind of pump devices, roots pumps, diaphragm pumps and the like have been used. For example, a diaphragm pump used as a blower for fuel gases in a fuel battery system is described in the following Patent Document 1.

Typically, as materials of diaphragms, elastic materials such as rubbers are used. Because of this, the diaphragm is easy to elastically change, and there are cases that the characteristics as the device would change. Therefore, in order to stabilize the characteristics of the diaphragm, a diaphragm in which a base fabric is provided embedded is described in Patent Document 2.

Patent Document 1: Japanese Patent Application Laid-open No. 2009-47084

Patent Document 2: Japanese Patent Application Laid-open No. Hei 10-132077

SUMMARY OF INVENTION

Problem To Be Solved By The Invention

In Patent Document 2, the base fabric has been provided embedded in order to suppress the excessive protrusion, of the outer circumferential part of the diaphragm, due to squeezing resulting in elastic change at the time of caulking by a press. However, in the diaphragm pump, the diaphragm is performing the following reciprocating motion. That is, while a peripheral edge of the diaphragm is supported by a main body of the pump, a part thereof is connected to a driving member. By a motion of the driving member made by a driving mechanism, the diaphragm performs a constant reciprocating motion with stretching, and changes the volume of a pump chamber. This means that when the diaphragm pump was driven for a long time, a failure by deterioration, fatigue and being partially cut may occur in a particular part, which is easy to be stretched, of the diaphragm.

In view of the circumstances as described above, an object of the present invention is to provide a pump device which is capable of stabilizing the performance of a diaphragm.

Means For Solving The Problem

To achieve the object described above, according to an embodiment of the present invention, there is provided a pump device including a main body, a diaphragm and a driving part.

The main body forms a pump chamber for intaking and discharging a fluid.

The diaphragm includes a base material, a base fabric and an index part. The base material is made of an elastic material which has a first surface to face the main body in a first axial direction, a second surface on a side opposite to the first surface, and a peripheral edge area supported by the main body. The base fabric is provided embedded in the base material, at least having a first fiber which extends in a second axial direction perpendicular to the first axial direction. The index part is provided, to the base material to indicate the second axial direction.

The driving part includes a driving mechanism and a driving member, which driving member has a first end connected to the second surface and a second end to be connected to the driving mechanism, and which driving mechanism allows the driving member to reciprocate along the first axial direction while allowing the driving member to oscillate in the second axial direction.

BRIEF DESCRIPTION OF DRAWINGS

[FIG. 1] A cross-sectional view showing a configuration of a pump device according to an embodiment of the present invention.

[FIG. 2] Diagrams showing a configuration of a main part of the diaphragm, where (A) is a cross-sectional view and (B) is a plan view.

[FIG. 3] A cross-sectional view of the main part for explaining an operation of the diaphragm pump according to the embodiment of the present invention.

[FIG. 4] Cross-sectional views of the main part for explaining a state of the diaphragm each of which corresponds to (A) and (B) of FIG. 3.

[FIG. 5] An explanatory view showing an example of a plain weave fabric.

[FIG. 6] A plan view of a diaphragm showing a shape of an index part used in another embodiment of the present invention.

MODE(S) FOR CARRYING OUT THE INVENTION

A pump device according to an embodiment of the present invention includes a main body, a diaphragm and a driving part.

The main body forms a pump chamber for intaking and discharging a fluid.

The diaphragm includes a base material, a base fabric and an index part. The base material is made of an elastic material which has a first surface to face the main body in a first axial direction, a second surface on a side opposite to the first surface, and a peripheral edge area supported by the main body. The base fabric is provided embedded in the base material, at least having a first fiber which extends in a second axial direction perpendicular to the first axial direction. The index part is provided to the base material to indicate the second axial direction.

The driving part includes a driving mechanism and a driving member, which driving member has a first end connected to the second surface and a second end to be connected to the driving mechanism, and which driving mechanism allows the driving member to reciprocate along the first axial direction while allowing the driving member to oscillate in the second axial direction.

In the pump device, the diaphragm has the base material made of the elastic material, and the base fabric (reinforcing fabric) is provided embedded to the base material. The diaphragm is allowed to perform a reciprocating motion by the driving member connected thereto, in a state where the peripheral edge area of the diaphragm is supported by the main body. With this reciprocating motion, the diaphragm cyclically changes the volume of the pump chamber, to intake the fluid into the pump chamber and to discharge the fluid out from the pump chamber in an alternating manner.

One end of the driving member is connected to the diaphragm and another end of the driving member is to be connected to the driving mechanism. The driving mechanism is a motor which is a driving source, and a shaft that is eccentric from a driving shaft of the motor, for example. The end of the driving member in the driving mechanism side repeats the reciprocating motion along the first axial direction, and the oscillation in the second axial direction, by the driving mechanism. In conjunction with this, the end in the diaphragm side of the driving member performs the reciprocating motion in the first axial direction. Because of this, a problem that the diaphragm is easy to deteriorate to be cut, in a direction in which the diaphragm can be easily stretched, for example, in the second axial direction for performing oscillation, may arise.

In the pump device, by embedding the base fabric having the fiber which extends in the second axial direction into the diaphragm, it can increase the strength thereof in the second axial direction, and the durability can be improved. Further, by embedding the base fabric which can manage the stretching in the second axial direction into the diaphragm, the performance of the diaphragm is stabilized, and the changes in the volume of the pump chamber is also stabilized, and thus it can stabilize the performance as a pump.

Further, by providing the index part to indicate the second axial direction, the extending direction of the fiber of the base fabric embedded within the diaphragm becomes distinguishable. Therefore, at the time of assembling the pump device, it becomes easy to place the diaphragm in a desired direction to the main body of the pump.

The driving member may further have a fixture which includes a support surface to face the first surface, and a shaft part formed on the support surface, which shaft part penetrates the base material and is to be coupled to the first end. In addition, index part may be formed to an opening in which the shaft part penetrates.

The index part may be a linear portion perpendicular or parallel to the second axial direction forming a part of the opening.

The index part may be a notch which is connected to the opening in a direction perpendicular or parallel to the second axial direction.

By that the index part of the diaphragm is formed to the opening, it becomes possible to work while checking the desired direction when placing the diaphragm to the main body of the pump. Further, the index part can be formed easily.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing a structure of a pump device 3 according to an embodiment of the present invention. In this embodiment, the pump device 3 is configured with a diaphragm pump. In FIG. 1, Z-axis (first axis) indicates a vertical direction (gravity direction), and X-axis (second axis) and Y-axis indicate planer directions.

A main body 10 has a casing 11, a pump head 12 and a pump head cover 13.

The pump head 12 has an inlet port 101 and an outlet port 102, and is placed on a top surface of an annular base 110. The base 110 is attached to an open end at an upper part of the casing 11, and supports the peripheral edge part of a diaphragm 20 by sandwiching together with the pump head 12. The pump head 12 forms a pump chamber 100 between this and the diaphragm 20.

A pump head 12 has an inlet passage T1 to contact between the inlet port 101 and the pump chamber 100, and has an outlet passage 12 to contact between the pump chamber 100 and the outlet port 102. The pump chamber 100 is communicable through the inlet passage T1 and the outlet passage 12, to the inlet port 101 and the outlet port 102, respectively. In the inlet passage T1 and the outlet passage 12, respectively, an inlet valve 103 and an outlet valve 104 are attached.

The pump head cover 13 is attached to an upper part of the pump head 12. Each of the inlet passage T1 and the outlet passage 12 is formed by combining the pump head 12 and the pump head cover 13. The casing 11, the pump head 12 and the pump head cover 13 are integrally fixed with the use of a plurality of screw members B.

The casing 11 forms an operating space 105 inside the main body 10 to house a connecting rod 32, a bearing 33 and an eccentric cam 34.

FIG. 2 (A) is a cross-sectional view showing a configuration of a main part of the diaphragm 20. The Z-axis to indicate the vertical direction, X-axis and Y-axis to indicate the planer directions are shown in FIG. 2 as well. The diaphragm 20 has a base material 200 made of an elastic material which has a top surface 201 and a lower surface 203, and a reinforcing fabric 202 provided embedded in the base material 200. The peripheral edge parts of the top surface 201 and the lower surface 203 are sandwiched between the base 110 and the pump head 12. However, in FIG. 2 (A), the base 110 and the pump head 12 are omitted.

Each of the top surface 201 and the lower surface 203 is made of a synthetic rubber. Examples of rubber materials to be used may include nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluorocarbon rubber (FKM), and other rubber materials which are resistant to hydrocarbon gas such as methane and propane. The reinforcing fabric 202 is made of synthetic fiber such as nylon (polyamide), for example. In addition, the reinforcing fabric 202 and the top surface 201, the lower surface 203 are integrated by vulcanization bonding or the like.

FIG. 2 (B) is a plan view showing a configuration of a main part of the diaphragm 20. For illustrative purposes, in FIG. 2 (B), some part of the base material 200 is removed, thereby exposing the reinforcing fabric 202. The reinforcing fabric 202 includes a group of fibers F1 parallel to the X-axis. In addition, the reinforcing fabric 202 may further include a group of fibers F2 crossing the group of fibers F1 as shown.

It should be noted that although the reinforcing fabric 202 is formed in an entire plane of the diaphragm 20, it is not limited thereto. The shape of the reinforcing fabric 202 is not limited to a circular shape, and for example, may be a symmetrical shape with respect to the X-axis that passes through the center of the diaphragm 20. The length of the group of fibers F1 is not particularly limited either, and may be any length as long as the strength in the X-axis direction can be increased sufficiently.

The diaphragm 20 has an index P to indicate the X-axis direction. Typically, the index P shows one of the modes that can be distinguished through the five senses of human such as visual and tactile, but otherwise, the index M may be any mode that can distinguish the X-axis direction using techniques such as electrical and optical. Further, an area where the index M is placed is not limited as long as an operator can distinguish the index P when placing the diaphragm 20 to the main body 10. In FIG. 2 (B) of this embodiment, the index M is an opening 201 which has a “D” shape including a linear portion L perpendicular to the X-axis direction. That is, in this embodiment, the direction perpendicular to the linear portion L would be recognized by the operator as the X-axis direction of the diaphragm 20. It should be noted that this example is not limitative, but the linear portion L may be formed parallel to the X-axis direction.

A driving part 30 has a fixture 31, the connecting rod 32, the bearing 33, the eccentric cam 34 and a driving source 35.

The connecting rod 32 includes a first support surface in contact with the lower surface 203 of the diaphragm 20, and is fixed to the center of the lower surface 203. On the other hand, the fixture 31 has a second support surface in contact with the top surface 201, and a protrusion 310 to be fitted to the opening 204 of the diaphragm 20. The protrusion 310 may have a plane shape corresponding to the shape of the opening 204. The fixture 31 and the connecting rod 32 are assembled in a manner of vertically sandwiching the diaphragm 20, and, for example, are integrated thereto via a screw 320. Thus, the fixture 31 and the connecting rod 32 make up a driving member 300 which drives the diaphragm 20 up and down. It should be noted that the fixture 31 may be without the protrusion 310, and the screw 320 may be fitted in the opening 204.

The driving source 35 includes a motor having a rotating shaft 350 extending along the Y-axis direction, and the like. A distal end of the rotating shaft 350 is attached to the center of rotation of the eccentric cam 34. An end of the connecting rod 32, opposite to the first support surface, is connected to the circumferential surface of the eccentric cam 34 via the bearing 33. The eccentric cam 34 is formed in an eccentric manner with respect to the inner race of the bearing 33 and the eccentricity gives the reciprocation amount (stroke amount) of the diaphragm 20.

FIG. 3 is a cross-sectional view of the main part of the diaphragm pump 3 when viewed from the Y-axis direction, and shows a typical operation of the driving part 30. Although the details of the pump head 12 in this case is different from actual one, the configuration of the pump head 12 is depicted in the same manner as in FIG. 1 for ease of understanding.

When the rotating shaft 350 is rotated by the driving source 35; the end of the driving member 300 that is connected to the eccentric cam 34 performs a reciprocating motion in the Z-axis direction accompanied by an oscillation in the X-axis direction. Simultaneously, since the end of the driving member 300 that is connected to the diaphragm 20 performs a reciprocating motion in the Z-axis direction, the diaphragm 20 also performs a reciprocating motion in the Z-axis direction.

FIG. 3 (A) shows an example where the rotating shaft 350 and the center of the eccentric cam 34 are lined in a row in the Z-axis direction, and the volume of the pump chamber 100 has become minimal (exhaustion process). FIG. 3 (B) shows an example where the rotating shaft 350 and the center of the eccentric cam 34 are lined in a row in the X-axis direction, and the driving member 300 has descended in the Z-axis direction while inclining (intake process). In conjunction with this, the diaphragm 20 also descends in the Z-axis direction, and the volume of the pump chamber 100 becomes larger than in FIG. 3 (A). Thus, with the movement of the diaphragm 20 in the Z-axis direction, the volume of the pump chamber 100 changes. In addition, as shown in FIG. 3 (B), when the volume of the pump chamber 100 is increased, suction of gas is made by closing the outlet valve 104 while opening the inlet valve 103. Conversely, as shown in FIG. 3 (A), when the volume of the pump chamber 100 is decreased, compression and conveyance of gas is made by opening the outlet valve 104 while closing the inlet valve 103.

In the diaphragm 20, fatigue or deterioration may arise in a part which is easy to be stretched due to the reciprocating motion of the above. In FIG. 4, (A) and (B) schematically show the shapes of the diaphragm 20 each corresponding to (A) and (B) of FIG. 3. In FIG. 4, the diaphragm 20 is described separately in five areas X1 to X5. Each of X1 and X5 is the area which is supported by the main body 10; X2 and X4 are the areas with elastic deformation; and X3 is the area which is supported by one end of the driving member 300. The areas X1 and X5 belong to a common annular area of the diaphragm 20. The areas X2 and X4 belong to a common annular area of the diaphragm 20 as well.

In FIG. 4 (A), X3 is raised in the Z-axis direction with respect to X1 and X5, and between X2 and X4 has a stretch. In FIG. 4 (B), X3 is lowered in the Z-axis direction with respect to X1 and X5, with a stretch between X2 and X4, and further, there is a distortion generated between X2 and X3. This is due to that a stress is applied thereto by the inclination of the driving member 300, as shown in FIG. 3 (B). As described above, the diaphragm 20 is easily stretched in the X-axis direction by the motion shown in FIG. 3. In view of this, by embedding the reinforcing fabric 202 having the group of fibers F1 which extends in the X-axis direction into the diaphragm 20, the strength of the diaphragm 20 can be increased, and the durability can be improved. Further, by managing the stretching of the diaphragm 20, the performance as the diaphragm is stabilized, and the changes in the volume of the pump chamber 100 is also stabilized, and thus it can stabilize the performance as a pump.

Examples of weaves of the fabric in which the group of fibers F1 extends in a parallel manner to the X-axis include a plane weave shown in FIG. 5. The plane weave is one in which fibers f2 are alternately combined, in a direction perpendicular to a group of fibers f1 arranged in parallel. By using such a plane-weave reinforcing fabric 202, the strength in the X-axis direction can be increased, and the durability can be improved. The distance between each fiber, which is the pattern density of the weave, is not particularly limited but may be any as long as the strength is sufficient.

Meanwhile, since the diaphragm typically has a disc shape, the extending direction of the fiber in the embedded reinforcing fabric 202 might be undistinguishable when placing the diaphragm 20 to the main body 10. In view of this, by using the index M for indicating the X-axis direction, the extending direction of the fiber of the reinforcing fabric 202 embedded to the diaphragm 20 becomes distinguishable. Therefore, it becomes easy to place the diaphragm 20 in a desired direction to the main body 10. For example, when placing the diaphragm 20 having the index M including the linear portion L, which has been described in this embodiment, to the main body 10, the diaphragm 20 may be placed in a manner that the linear portion L is parallel to the extending direction of the rotating shaft 350 (Y-axis direction in FIG. 1). In the case where the reinforcing fabric 202 further includes the group of fibers F2 crossing the group of fibers F1, the linear portion L may be placed either parallel or perpendicular to the extending direction of the rotating shaft 350.

Hereinabove, the embodiment of the present invention has been described, but the present invention is not limited to the above-mentioned embodiment and can be variously modified without departing from the gist of the present invention, as a matter of course.

For example, in the embodiment described above, the index M was the opening 204 having the “D” shape including the linear portion L perpendicular to the X-axis direction. However, for example, as shown in FIG. 6, the index M may be the opening 204 to which a notch R is connected in a direction parallel to the X-axis direction. The shape of the notch R is not particularly limited as long as it can indicate the X-axis direction, and for example, it may be connected in a direction perpendicular to the X-axis direction. Further, the part to form the notch R is not specified as long as it is within the opening 204.

In addition, a fluid used in the pump device of an embodiment of the present invention is not limited to gas, and may be liquid.

DESCRIPTION OF REFERENCE NUMERALS

3 pump device

10 main body

20 diaphragm

30 driving part

100 pump chamber

101 inlet port

102 outlet port

Claims

1. A pump device comprising:

a main body forming a pump chamber for intaking and discharging a fluid;

a diaphragm including a base material made of an elastic material which has a first surface to face the main body in a first axial direction, a second surface on a side opposite to the first surface, and a peripheral edge area supported by the main body, a base fabric, provided embedded in the base material, at least having a first fiber which extends in a second axial direction perpendicular to the first axial direction, and an index part, provided to the base material, to indicate the second axial direction; and

a driving part including a driving mechanism and a driving member, which driving member has a first end connected to the second surface and a second end to be connected to the driving mechanism, and which driving mechanism allows the driving member to reciprocate along the first axial direction while allowing the driving member to oscillate in the second axial direction.

2. The pump device according to claim 1, wherein

the driving member further has a fixture which includes a support surface to face the first surface, and a shaft part formed on the support surface, which shaft part penetrates the base material and is to be coupled to the first end, and

the index part is formed to an opening in which the shaft part penetrates.

3. The pump device according to claim 2, wherein

the index part is a linear portion, perpendicular or parallel to the second axial direction, forming a part of the opening.

4. The pump device according to claim 2, wherein

the index part is a notch which is connected to the opening in a direction perpendicular or parallel to the second axial direction.

5. The pump device according to claim 1, wherein

the base fabric further includes a second fiber which extends in a third axial direction crossing the second axial direction within the first surface.