JP2013238169A - Pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress wear caused by back pressure acting on a clearance between a rotating member and a casing.SOLUTION: A pump device 48 includes: a third lid member 28; a pump chamber 32 and a rotor 50 in a casing 30; a pinion 52; and a rotary shaft 53. The third lid member 28 is fastened to a side of the casing 30 by means of three mounting bolts 29 and occludes the pump chamber 32. An end face 52b on a third lid member 28 side receives discharge pressure of the discharge port 32b during pump operation, and thus liquid-gas pressure acts as back pressure on a clearance between the rotor 50 and an inner surface of the pump chamber 32. Thus, while the pinion 52 is pressed in a direction to slidingly contact a wall surface 26a of an inner wall 26 of the third lid member 28, the end face 52b is pressed in a direction to be spaced apart from the wall surface 26a of the inner wall 26 of the third lid member 28, by the discharge pressure of the discharge port 32b introduced from a pressure introduction hole 27 into an annular recessed portion 24.

Description

  The present invention relates to a pump device.

  A pump device that pumps the liquid stored in the underground tank and pumps it to the nozzle is mounted in the housing of the fuel supply device. The pump device casing contains various devices such as a strainer, check valve, pump, air separation chamber, gas-liquid separation chamber, and float valve. The pump is driven to rotate by a rotating shaft connected to a motor. Pump member having a rotating member (rotor), a suction port for sucking liquid, a discharge port for discharging liquid by rotation of the rotating member, and an opening for accommodating the rotating member, and a lid for closing the opening A member is provided (see, for example, Patent Document 1).

  In addition, as the pump, there are a vane pump and a gear pump, both of which are configured to pressurize and discharge the liquid from the pump by the rotation of the rotating member.

JP 2009-264141 A

  In the pump device, the liquid is sucked in by the suction side pressure (negative pressure) generated by the rotation of the rotating member, and the liquid is discharged by the discharge side pressure (positive pressure). At this time, the liquid on the discharge side of the rotating member flows into the clearance between the rotating member and the casing, thereby generating a back pressure in the clearance. As a result, the rotating member is pressed toward the lid member side with respect to the axial direction of the rotating shaft by the back pressure acting on the rotating member, so that the rotating member is displaced toward the lid member side with respect to the axial direction of the rotating shaft, The rotating member and the lid member are in contact with each other. When the rotating member rotates while the rotating member and the lid member are in contact with each other, the rotating member and the lid member are worn, and the more this wear progresses, the lower the discharge capacity of the pump device and the durability. There was a problem that the performance would be lowered.

  In view of the above circumstances, an object of the present invention is to provide a pump device that solves the above problems.

In order to solve the above problems, the present invention has the following means.
(1) The present invention includes a casing having an inlet and an outlet and an opening;
A rotating member provided rotatably in the casing;
A rotating shaft that rotatably supports the rotating member;
A lid member that closes the opening;
In a pump device comprising:
A pressure introducing hole for introducing a pressure from the discharge port of the casing is provided between the lid member and the rotating member in the lid member.
(2) The base end of the rotating shaft of the present invention is fixed to a bearing portion drilled in the lid member,
A recess is formed around the attachment point of the rotating shaft of the lid member,
The pressure introducing hole is formed in the recess.

  According to the present invention, by providing the pressure introduction hole for communicating between the discharge port of the casing of the pump chamber and the clearance generated between the lid member and the rotating member, the pressure (discharge pressure) on the discharge port side of the pump chamber is provided. ) Is supplied between the lid member and the rotating member, the discharge pressure can be applied so that the rotating member is biased in a direction away from the lid member. Therefore, even when a back pressure acts on the side surface (casing side) of the rotating member and a biasing force toward the lid member acts on the rotating member, the lid member acts on the opposite surface (side surface on the lid member side) of the rotating member. The force that the rotating member tries to move to the lid member side can be reduced or eliminated by the biasing force in the opposite direction, and the wear of the rotating member and the lid member can be suppressed accordingly, and the pump can be reduced accordingly. The discharge capability of the apparatus itself can be maintained, and the durability can be improved.

1 is a schematic configuration diagram schematically showing a pump unit to which an embodiment of a pump device according to the present invention is applied. It is a figure which shows the flow of the liquid in a pump unit in order. It is a disassembled perspective view which shows each member of a pump apparatus. It is a perspective view which expands and shows the structure inside a cover member. It is a longitudinal cross-sectional view which shows the internal structure of a pump apparatus. It is a figure which expands and shows the rotor and pinion of a pump apparatus. It is a longitudinal cross-sectional view which follows the AA line in FIG. It is a perspective view which shows the cover member of a modification.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Configuration of pump unit]
FIG. 1 is a schematic configuration diagram schematically showing a pump unit to which an embodiment of a pump device according to the present invention is applied. FIG. 2 is a diagram illustrating the flow of liquid in the pump unit in order. In FIG. 1, in order to show the overall configuration of the pump unit in an easy-to-understand manner, each part is described by shifting the vertical position, the front-rear position, and the left-right position, and are described in different locations from the positions shown in FIGS. Has been.

  As shown in FIGS. 1 and 2, the pump unit 10 is mounted on a fuel supply device that supplies liquid fuel (hereinafter referred to as “liquid”) such as gasoline or light oil, and is stored in the underground tank 12. The air bubbles are pumped up, and bubbles contained in the liquid are separated and fed to the flow meter 20. The liquid fuel measured by the flow meter 20 is supplied to the fuel tank of the vehicle through the hose and nozzle of the fuel supply device.

  In the pump unit 10, an inflow chamber 31, a pump chamber 32, an air separation chamber 33, an outflow path 34, and a gas-liquid separation chamber 36 are formed inside the casing 30. The inflow chamber 31 is provided with a strainer mounting chamber 38 communicating with an inflow port 37 that opens to the bottom of the casing 30 and a check valve mounting chamber 39 adjacent to the downstream side (outflow side) of the strainer mounting chamber 38. It has been. The strainer mounting chamber 38 and the check valve mounting chamber 39 are provided adjacent to the same side surface of the casing 30. Further, the outflow side of the strainer mounting chamber 38 and the inflow side of the check valve mounting chamber 39 are communicated with each other by a communication path 45.

  The strainer mounting chamber 38 includes a first opening 38a machined from the side surface of the casing 30, and a strainer receiving portion 38b formed at the back of the opening 38a. A strainer 44 is accommodated in the strainer mounting chamber 38. The strainer 44 is made of a wire mesh that captures foreign substances contained in the liquid flowing in from the inlet 37, and is formed in a cylindrical shape.

  The liquid sucked from the inlet 37 by driving the pump is filtered by the strainer 44, passes through the communication path 45, flows into the check valve mounting chamber 39, and flows out to the suction side flow path 46.

  A pump chamber 32 constituting a part of the pump device 48 is provided on the downstream side of the check valve mounting chamber 39, and the pump chamber 32 has a suction port 32 a communicating with the suction side flow path 46, and a discharge side flow. A discharge port 32 b communicating with the passage 47 is formed. The pump device 48 includes a gear pump, and includes a rotor 50 that rotates when a rotational driving force of a motor is transmitted, and a pinion 52 that is rotationally driven by the rotor 50. In this embodiment, the rotor 50 and the pinion 52 correspond to the rotating member of the present invention.

  In the pump device 48, when the rotor 50 and the pinion 52 are rotationally driven in the counterclockwise direction, the liquid is sucked from the suction-side flow path 46, and between the recess portions 52 a of the pinion 52 and each engaging portion 50 a of the rotor 50. And is discharged to the discharge side flow path 47 through the discharge port 32 b of the pump chamber 32.

  Further, the liquid discharged from the pump device 48 flows into the air separation chamber 33 disposed downstream of the discharge side flow path 47. In the air separation chamber 33, the inflowing liquid is divided into a liquid and a gas-enriched liquid, the liquid is supplied to the flow meter 20 through the check valve 64, and the gas-enriched liquid is passed through the gas-enriched liquid inflow hole 58. , And supplied to the gas separation chamber 36. In the gas separation chamber 36, the gas-enriched liquid is separated into a liquid and a gas, the liquid from which the gas has been separated passes through the return hole 60 and is returned to the suction side flow path 46, and the gas passes through the atmosphere opening 62. And discharged to the outside of the pump unit 10.

[Configuration of Pump Device 48]
FIG. 5 is a longitudinal sectional view showing the internal configuration of the pump device 48. FIG. 6 is an enlarged view showing the rotor and pinion of the pump device. In FIG. 6, for the convenience of explanation, the detailed configuration is shown in a simplified manner.

As shown in FIGS. 5 and 6, the pump device 48 closes the opening 32 c formed in the pump chamber 32 in order to mount the pump chamber 32 and members such as the rotor 50 and the pinion 52 in the pump chamber 32. And a rotor 50 coupled to the rotor shaft 100, a pinion 52, and a rotating shaft 53.
The casing 30 is formed with insertion holes 102 and 104 through which the rotor shaft 100 is inserted. The rotor shaft 100 is inserted into the insertion holes 102 and 104, and one end 100 a is formed in the pump chamber 32 in the casing 30. Inserted and coupled to the rotor 50, the other end 100b projects to the outside of the casing 30, and a pulley 110 to which the rotational driving force of the drive motor is transmitted is coupled.

  In this embodiment, the rotational driving force of the drive motor is configured to be transmitted to the rotor shaft 100 via the pulley 110, but the transmission of the rotational driving force of the drive motor to the rotor shaft 100 is The rotation drive shaft of the drive motor and the rotor shaft 100 may be directly connected without passing through the pulley 110 for transmission.

  The rotor shaft 100 is inserted into the insertion holes 102 and 104 from the opening 32 c of the pump chamber 32, so that the rotor 50 is accommodated in the pump chamber 32 of the pump device 48. Then, the pinion 52 and the rotation shaft 53 of the pinion 52 are accommodated in the pump chamber 32 so as to be engaged with the gear of the rotor 50 from the opening 32 c of the pump chamber 32, and the opening 32 c ( The opening 32 c) formed in the pump chamber 32 is closed by attaching the lid member 28 with the attachment bolt 29.

  FIG. 4 is an enlarged perspective view showing the structure of the lid member 28. FIG. 7 is a longitudinal sectional view showing the structure of the pump device 48. 4 and 7, the lid member 28 has a crescent-shaped partition 51 for partitioning between the rotor 50 and the pinion 52, and a rotating shaft 53 that rotatably supports the pinion 52. Is formed. The base end of the rotation shaft 53 is fixed to a bearing portion 23 formed in the lid member 28, and the tip of the rotation shaft 53 protrudes toward the inside of the pump chamber 32 of the casing 30. Thus, the rotating shaft 53 fitted and fixed in the bearing hole 23 of the lid member 28 is fitted in the central through hole on the side surface on the pinion 52 side and rotatably supports the pinion 52.

  An inner wall 26 that faces the end face 52 b of the pinion 52 protrudes inside the lid member 28. The front side wall surface 26a of the inner wall 26 is opposed to the end surface 52b of the pinion 52 through a minute clearance 151 with the lid member 28, and the partition portion 51 protrudes sideways.

  Further, a groove that forms an inflow passage is formed as a suction portion 28a on the left side of the inner wall 26, and a groove that forms an outflow passage is formed as a discharge portion 28b on the right side of the inner wall 26. The suction part 28 a and the discharge part 28 b are recessed from the front side wall surface 26 a of the inner wall 26, and are defined by the side wall 26 b of the inner wall 26. The suction portion 28a and the discharge portion 28b open to the outside of the pump chamber 32 through the suction port 32a and the discharge port 32b of the pump chamber 32, respectively, and the liquid from the suction port 32a passes through the suction portion 28a of the lid member 28. Then, the air is sucked into the pump chamber 32 of the casing 30, and the liquid is discharged from the discharge portion 28 b of the lid member 28 to the discharge port 32 b of the casing 30 with the rotation of the rotor 50 and the pinion 52.

  Further, the lid member 28 is provided with a pressure introducing hole 27 in which one end opening 27 a opens in the side wall 26 b on the discharge port 32 b side and the other end opening 27 b opens in the front side wall surface 26 a of the inner wall 26. The pressure introducing hole 27 has one end opening 27 a formed radially from the side surface of the inner wall 26, and the other end opening 27 b formed axially from the front side wall surface 26 a of the inner wall 26. It is formed in a letter shape.

  Since the pressure introducing hole 27 is provided in the inner wall 26 of the lid member 28, there is no pressure between the clearance 151 (a minute gap between the front side wall surface 26 a and the end surface 52 b of the pinion 52 shown in FIG. 7) and the discharge port 32 b. The communication is made via the introduction hole 27, and the pressure (discharge pressure) on the discharge portion 28 b side is supplied to the clearance 150 via the pressure introduction hole 27 and the pressure introduction hole 27.

  The pressure introduction holes 27 may be provided at least at one place on the inner wall 26 of the lid member 28. However, the pressure introduction holes 27 may be provided at a plurality of places in consideration of clogging due to foreign matter, or the hole inner diameter is increased. Of course, it is good also as a shape which is hard to clog.

[Configuration of Rotor 50 and Pinion 52]
As shown in FIG. 6, in the pump device 48, by the rotation of the rotor 50 and the pinion 52, the liquid is sucked into the suction portion 28 a of the lid member 28 through the suction port 32 a of the casing 30. The liquid is discharged to the discharge port 32b of the casing 30 through the 28 discharge portions 28b.

  The rotor 50 is formed in a disk shape corresponding to the inner diameter of the pump chamber 32, and each semicircular engaging portion 50a is arranged at a predetermined pitch (interval) in the rotation direction (circumferential direction) on the disk-shaped plane. A plurality are provided. The pinion 52 is rotatably supported by a rotating shaft 53, and a plurality of semicircular recess portions 52a corresponding to the respective engaging portions 50a of the rotor 50 are provided on the outer periphery at a predetermined pitch (interval). Is provided.

  Further, the rotation center of the rotor 50 and the rotation center of the pinion 52 are eccentric in the vertical direction. Between the outer periphery of the pinion 52 and the inner periphery of the rotor 50, a crescent-shaped partition portion 51 corresponding to the amount of eccentricity is provided. The inner peripheral surface 51a of the partition portion 51 is a pinion sliding contact surface on which the outer periphery of the pinion 52 is in sliding contact, and the outer peripheral surface 51b of the partition portion 51 is a rotor sliding contact surface on which each engaging portion 50a of the rotor 50 is in sliding contact. .

  During the pump operation, the engaging portion 50a of the rotor 50 is engaged with each recess 52a of the pinion 52, so that the rotor 50 is driven to rotate counterclockwise by the motor, and the pinion 52 is also driven to rotate in the same direction. Thus, pressure (negative pressure and discharge pressure) is generated on the suction port 32a side and the discharge port 32b side, respectively. Then, when negative pressure is generated on the suction port 32 a side of the pump chamber 32, the inflow check valve 40 (see FIG. 1) is opened, and the liquid that has passed through the strainer 44 is sucked into the suction port 32 a of the pump chamber 32. Is done. Thereafter, the liquid flows into the recess 52a of the pinion 52 and is discharged to the discharge port 32b by the pressure (discharge pressure) on the discharge side.

  During pump operation, the discharge-side liquid flows into the clearance 150 (shown in FIG. 7) between the rotor 50 and the casing 30, thereby generating back pressure in the clearance 150. When the back pressure acts, the urging force that presses the rotor 50 along the rotor shaft 100 toward the lid member 28 (Xa direction) acts on the side surface of the rotor 50 on the casing 30 side (inner wall of the pump chamber 32). To do. Therefore, the urging force in the Xa direction that narrows the clearance 151 on the lid member 28 side acts on the clearance 150 between the members of the rotor 50 and the pinion 52 and the casing 30, and the rotor 50 moves along the rotary shaft 100. Move to 28 side.

  As the rotor 50 moves, the pinion 52 also moves along the rotation shaft 53 toward the lid member 28 (Xa direction). At this time, since the lid member 28 is provided with the pressure introduction hole 27 (shown in FIGS. 4 and 6), the discharge pressure on the discharge port 32b side is transferred from the discharge portion 28b to the one end opening 27a of the pressure introduction hole 27. Then, it is introduced into the clearance 151 (shown in FIG. 7) between the lid member 28 and the pinion 52 through the other end opening 27b of the front side end surface 26a of the inner wall 26. Therefore, when the discharge pressure acts on the front side end surface 26 a of the inner wall 26 on the lid member 28 side of the pinion 52, an urging force in the direction opposite to the lid member 28 (Xb direction) is generated.

  As a result, the pressures of the clearances 150 and 151 are both maintained at the discharge pressure and the axial pressure is balanced, so that the force for pressing the rotor 50 and the pinion 52 toward the lid member 28 is reduced. Accordingly, the urging force that the pinion 52 and the rotor 50 try to move toward the lid member 28 (Xa direction) can be reduced or eliminated.

  As a result, the sliding resistance between the pinion 52 and the lid member 28 in the clearance 151 can be reduced, and the discharge capacity of the pump device 48 itself can be maintained and durability can be suppressed by suppressing the wear of the pinion 52 and the lid member 28. Improvement is achieved.

[Modification]
FIG. 8 is a perspective view showing a cover member according to a modification. As shown in FIG. 8, the cover member 28 has a bearing hole 23 (see FIG. 7) provided so that the base end of the rotating shaft 53 is fitted in the center of the side surface on the pinion 52 side, the bearing hole 23, An annular recess 24 is formed between the inner wall 26 and the base end so as to surround the outer periphery of the rotary shaft 53 fitted into the bearing hole 23. The annular recess 24 is a stepped portion of the bearing portion 23 in the lid member 28, and is formed so that the area where the formed opening side faces the end surface 52 b of the pinion 52 becomes large.

  The pressure introducing hole 27 passes through the inner wall 26 in the radial direction so that one end opening 27 a opens to the discharge portion 28 b communicated with the discharge port 32 b and the other end opening 27 b opens to the inner peripheral surface of the annular recess 24. doing. That is, the pressure introduction hole 27 is a communication hole that communicates the annular recess 24 and the discharge port 32b, and serves as a passage for supplying discharge pressure to the annular recess 24 during pump operation. Further, since the discharge pressure is introduced through the pressure introduction hole 27, the annular recess 24 is supplied with the discharge pressure during the pump operation, and functions as a pressure chamber for applying the discharge pressure to the end face 52b of the pinion 52. .

  Thus, in this modification, since the annular recess 24 is provided in the inner wall 26 of the lid member 28 facing the end surface 52b of the pinion 52, the lid member is placed in the clearance 150 on the casing 30 side of the rotor 50 by back pressure when the pump is driven. Even when the pressing force toward the 28 side (Xa direction) is applied, the discharge pressure of the discharge port 32 b is supplied to the annular recess 24 through the pressure introduction hole 27. Accordingly, the discharge pressure can be applied to the clearance 151 facing the opening of the annular recess 24, and the discharge pressure is applied to the entire area of the annular region facing the opening of the annular recess 24 with respect to the end surface 52 b of the pinion 52 in contact with the clearance 151. Can be made to act uniformly.

  Accordingly, the end face 52b of the pinion 52 receives a discharge pressure supplied through the pressure introducing hole 27 over the entire area of the annular region facing the opening of the annular recess 24, and an urging force that pushes back in the Xb direction acts. As a result, the pressures of the clearances 150 and 151 are both maintained at the discharge pressure and the axial pressure is balanced, so that the force for pressing the rotor 50 and the pinion 52 toward the lid member 28 is reduced. Therefore, the force that the pinion 52 and the rotor 50 try to move toward the lid member 28 (Xa direction) can be further reduced or eliminated.

  As a result, further wear between the pinion 52 and the lid member 28 is suppressed, so that the discharge capacity of the pump device 48 itself can be maintained and the durability can be improved. The shape of the annular recess 24 is not limited to a circle but may be a rectangle.

  In addition, by providing only the pressure introducing hole 27 in the inner wall 26 of the lid member 28 as in the above embodiment, it is possible to apply the discharge pressure to the end surface 52b of the pinion 52 facing the opening of the annular recess 24. In order to apply a uniform discharge pressure to the pinion 52, it is preferable to provide the annular recess 24 together with the pressure introduction hole 27.

  In the above embodiment, the gear pump has been described as an example. However, the present invention is not limited to this, and the present invention may of course be applied to a vane pump.

10 pump unit 23 bearing hole 24 annular recess 26 inner wall 26a front side end face 27 pressure introduction hole 27a one end opening 27b other end opening 28 lid member 28a suction part 28b discharge part 30 casing 31 inflow chamber 32 pump chamber 32a suction port 32b discharge port 33 Air separation chamber 34 Outflow path 36 Gas-liquid separation chamber 37 Inlet port 40 Inlet side check valve 44 Strainer 46 Suction side channel 47 Discharge side channel 48 Pump device 50 Rotor 51 Partition portion 52 Pinion 52a Depression portion 52b End surface 53 Rotating shaft 100 Rotor shaft 150, 151 Clearance

Claims (2)

A casing having an inlet and an outlet and an opening;
A rotating member provided rotatably in the casing;
A rotating shaft that rotatably supports the rotating member;
A lid member that closes the opening;
In a pump device comprising:
A pump device, wherein a pressure introduction hole for introducing pressure from a discharge port of the casing is provided between the lid member and the rotating member. The base end of the rotating shaft is fixedly provided to a bearing portion drilled in the lid member,
A recess is formed around the attachment point of the rotating shaft of the lid member,
The pump device according to claim 1, wherein the pressure introducing hole is formed in the recess.

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