JP5050297B2 - Radial plunger pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radial plunger pump having a plurality of plungers arranged radially in the same plane with respect to the axial direction of the shaft, and more particularly to shortening the axial length of the shaft as a whole of the pump. .
[0002]
[Prior art]
Conventionally, for example, as described in JP-A-5-187349, a pump housing having a discharge port, a shaft rotatably supported in the pump housing, and the same surface with respect to the axial direction of the shaft There is known a radial plunger pump which has a plurality of plungers which are disposed in a pump housing radially and reciprocate by rotation of a shaft to suck working fluid into a discharge port.
[0003]
[Problems to be solved by the invention]
By the way, in the case of a radial plunger pump having a plurality of plungers, in the discharge path in the pump housing, it is necessary to combine the discharge side passages of each plunger and connect them to the discharge port. At this time, the radial plunger pump described in the above document has a discharge path in which the discharge side passages of the plungers are combined and then extended in the axial direction of the shaft and then communicated to the discharge port. In the pump housing, the discharge port is disposed at a position offset from the arrangement surface of the plurality of plungers by a predetermined distance in the axial direction of the shaft.
[0004]
Therefore, in the above-mentioned document, the axial length of the shaft of the pump (pump housing) becomes longer by the offset, and the configuration of the discharge path in the pump housing becomes complicated. was there.
[0005]
The present invention has been made to solve the above-described problems, and provides a radial plunger pump capable of shortening the axial length of a shaft in a pump housing and simplifying the configuration of a discharge path. It is the purpose.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a pump housing having a discharge port, a shaft rotatably supported in the pump housing, and the pump housing radially in the same plane with respect to the axial direction of the shaft. In the radial plunger pump provided with an accumulator capable of accumulating the discharged working fluid, having a plurality of plungers that suck in the working fluid by being reciprocated by rotation of the shaft and discharge it to the discharge port. The discharge port is provided on the arrangement surface of the plurality of plungers, the accumulator is arranged coaxially with one of the plurality of plungers, and the discharge port is in relation to the hole in which the accumulator is arranged, La characterized in that it is connected through a passage provided on the arrangement surface of the plurality of plungers It was Al plunger pump.
[0007]
According to the present invention, since the discharge port is provided on the arrangement surface of the plurality of plungers, as in the conventional technique described above, the offset of the arrangement surface of the plurality of plungers and the discharge port is equivalent to the offset of the pump housing. The axial length of the shaft is not increased, and the axial length of the shaft of the pump housing can be shortened by the offset. Further, according to the present invention, since it is not necessary to extend a part of the discharge path in the axial direction of the shaft, the structure of the discharge path in the pump housing can be simplified.
[0008]
More preferably, it is desirable to provide a communication path for communicating the discharge sides of each of the plurality of plungers on the arrangement surface of the plurality of plungers. Thereby, since all the discharge paths can be configured on the arrangement surface of the plunger, the configuration of the discharge path can be further simplified.
[0009]
When such a radial plunger pump is used as a pressure source for vehicle brake control, an accumulator capable of accumulating discharged working fluid may be provided in the discharge path. In this case, the accumulator may be disposed in the pump housing coaxially with one of the plurality of plungers. As a result, the accumulator is also formed on the arrangement surface of the plunger, and the axial length of the shaft of the pump housing is not increased by disposing the accumulator. In order to dispose the plunger in the pump housing, it is usually necessary to provide a plunger disposition hole that opens outward in the pump housing. Therefore, by disposing the accumulator in the pump housing coaxially with one of the plurality of plungers, the hole can be used when the accumulator is attached to the pump housing. Therefore, it is not necessary to provide a new passage in the pump housing for attaching the accumulator, so that the discharge path can be simplified.
[0010]
In the case where the accumulator is arranged in the pump housing in this way, when the plunger is housed in a cylinder separate from the pump housing, the pump housing in the axial direction of the cylinder housing the one plunger. It is preferable to fix to the pump housing by utilizing the end face of the port portion for attaching the accumulator to the pump housing. In this case, the end face of the accumulator mounting port portion may be brought into direct contact with the end face on the radially outer side with respect to the cylinder shaft, or when the both end faces are separated by a predetermined distance, In addition, an elastic body that generates a biasing force may be inserted in a direction in which the two are separated from each other. In this way, when a cylinder separate from the pump housing is fixed to the pump housing, the pump housing is caulked or an extra expensive fixing member is used only to fix the cylinder. Since it is not necessary, the cost can be reduced.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the mechanical configuration of a pump-motor assembly including an embodiment of a radial plunger pump according to the present invention will be briefly described with reference to FIGS. 1 is a main cross-sectional view in the axial direction of a pump-motor assembly including a radial plunger pump according to the present invention, and FIG. 2 is an enlarged view of the AA cross section in FIG.
[0012]
1 and 2, the pump-motor assembly is generally composed of a radial plunger pump 1, an accumulator 21, and a brush motor 3. First, the mechanical configuration of the radial plunger pump 1 will be described. The pump housing 5 is formed with a stepped cylindrical hole 5a having an opening at one end, and the shaft 9 is rotatably supported in the stepped cylindrical hole 5a via bearings 11 and 13 that are press-fitted and fixed in parallel with each other. Has been. An oil seal 53 is press-fitted and fixed to the left side of the bearing 13 in FIG. 1, and the oil seal 53 prevents the working fluid in the pump housing 5 from flowing out to the brush motor 3 side.
[0013]
The shaft 9 is integrally provided with an eccentric portion 9a, and a bearing 15 is disposed on the outer periphery of the eccentric portion 9a. The outer peripheral surface of the bearing 15 is in contact with the end surface of the plunger 19 which will be described later on the inner side in the shaft diameter direction.
[0014]
Around the eccentric portion 9a of the shaft 9, plungers 19 are radially arranged on the same surface (plunger placement surface) at an equal distribution of 120 °. The three plungers 19 are slidably accommodated in stepped cylindrical holes 17 a provided in the cylinders 17, and the three cylinders 17 are provided in the stepped steps provided in the pump housing 5. Each is accommodated in the cylindrical hole 5b. Hereinafter, for convenience of description, the description of the plunger 19 and the cylinder 17 will be made by paying attention only to those located in the vertical direction in FIG. The other two are identical in mechanical configuration.
[0015]
The plunger 19 is provided with a passage 19a in the axial direction and a passage 19b in a direction perpendicular to the shaft, and the passages 19a and 19b communicate with each other. The passage 19 b communicates with a space in the stepped cylindrical hole 5 a of the pump housing 5, and the space in the stepped cylindrical hole 5 a is connected to the suction pipe 45 via a passage 47 provided in the pump housing 5. Communicated with. Accordingly, the suction pipe 45 communicates with the passage 19a through the passage 47, the space in the stepped cylindrical hole 5a, and the passage 19b.
[0016]
A retainer 29 is fixed on the end surface side of the plunger 19 in the outer diameter direction of the shaft, and a ball 31 is accommodated in the retainer 29. The retainer 29 prevents the ball 29 from falling off. The ball 31 can be brought into contact with and separated from the valve seat surface formed on the end surface of the plunger 19 on the outer side in the shaft diameter direction. Therefore, a so-called check valve is formed in the plunger 19, the ball 31, and the retainer 29, and this check valve allows the flow of working fluid from the passage 19a to the space 49 in the cylinder 17, The reverse flow is prohibited.
[0017]
Similarly, a second check valve is formed in the cylinder 17 by a passage 49, a ball 39, and a retainer 41 fixed to the outer peripheral surface of the cylinder 17. The flow of the working fluid to the space 51 in the stepped cylindrical hole 5b of the pump housing 5 is allowed, but the reverse flow is prohibited. This space 51 communicates with the discharge port 25 through a passage 27 provided in the pump housing 5. Here, the passage 27 and the discharge port 25 are provided on the arrangement surface of the plunger 19.
[0018]
One end of the spring 33 is in contact with the end surface of the cylinder 17 on the inner side in the shaft diameter, and the other end of the spring 33 is in contact with a flange portion on the inner side in the shaft diameter of the plunger 19. Accordingly, the plunger 19 is constantly urged toward the inner diameter of the shaft with respect to the cylinder 17 by the urging force of the spring 33. Thereby, the end surface of the plunger 19 on the inner side in the shaft diameter is always in contact with the outer peripheral surface of the bearing 15.
[0019]
The second check valve portions of the three cylinders 17 are communicated with each other through the communication passages 43 and 43. Therefore, the discharge sides of these three cylinders 17 (plungers 19) are communicated with each other, The pump housing 5 communicates with the discharge port 25 through a space 51 and a passage 27 in the stepped cylindrical hole 5b. The communication passages 43 are also provided on the arrangement surface of the three plungers 19.
[0020]
The accumulator 21 is fixed to the pump housing 5 in a liquid-tight manner by inserting the mounting port portion 21 a thereof into the stepped cylindrical hole 5 b of the pump housing 5 through the O-ring 23. A space 51 communicating with the discharge side of the plunger 19 communicates with the inside of the accumulator through a passage 21b provided in the attachment port portion 21a. The accumulator 21 is in the space 51 and thus in the discharge port 25. The hydraulic pressure of the working fluid can be accumulated. In addition, since the mechanical structure of the accumulator 21 is known, the detailed description is abbreviate | omitted here.
[0021]
A spring 35 is sandwiched between the distal end surface of the attachment port portion 21a of the accumulator 21 and the end surface on the outer side of the shaft diameter of the cylinder 17 (only the one extending in the vertical direction in FIG. 2). Due to the urging force of the spring 35, the cylinder 17 (only the one extending in the vertical direction in FIG. 2) is urged downward in FIG. 2, and the step between the corner 17 b of the cylinder 17 and the pump housing 5 is urged. The cylinder 17 (only the one extending in the vertical direction in FIG. 2) is fixed in the axial direction with respect to the pump housing 5 by coming into contact with the step portion 5 c of the attached cylindrical hole 5 b. The other two cylinders 17 are fixed in the axial direction with respect to the pump housing 5 by caulking the caulking portion 5 of the pump housing 5.
[0022]
The brush motor 3 is inserted and fixed from the left side in FIG. 1 of the pump housing 5. At this time, the convex portion 7a at the front end portion of the motor shaft 7 and the concave portion 9b at the left front end portion in FIG. 1 of the shaft 9 on the pump side are engaged with each other. The rotational force of the shaft 7 is transmitted to the shaft 9 on the pump side. Since the mechanical configuration of the brush motor 3 is well known, a detailed description thereof is omitted here.
[0023]
The mechanical configuration of the pump-motor assembly including the radial plunger pump according to the present invention has been described above. Next, the operation of the pump-motor assembly will be described. When the brush motor 3 is driven by a motor control device (not shown), the rotational driving force of the motor shaft 7 is transmitted to the shaft 9 on the pump side, and the shaft 9 rotates. When the eccentric portion 9 a of the shaft 9 is rotated by the rotation of the shaft 9, the bearing 15 that is eccentric together with the eccentric portion 9 a also revolves with respect to the shaft 9. Since the end surfaces on the inner side in the shaft diameter direction of the three plungers 19 are always in contact with the outer peripheral surface of the bearing 15, the three plungers 19 reciprocate with respect to the cylinder 17 by the revolution of the bearing 15. By this reciprocating motion, the check valve provided in each plunger 19 and the second check valve provided in the cylinder 17 are operated, and both the check valves perform a pumping action, so that the working fluid sucked from the suction pipe 45 is operated. Is discharged to the discharge port 25 through the passage 47, the space in the stage pair cylindrical hole 5a, the passage 19b, the passage 19a, the space 49, the passage 37, (passage 43), the space 51, and the passage 27, not shown. It is transmitted to an external control target.
[0024]
According to the embodiment of the radial plunger pump according to the present invention as described above, the discharge port 25 is provided on the arrangement surface of the plurality of plungers 19. The axial length of the shaft of the pump housing is not increased by the offset between the plunger placement surface and the discharge port, and the axial length of the shaft 9 of the pump housing 5 is increased by the offset. It can be shortened.
[0025]
In addition, since the communication passages 43 and 43 that communicate the discharge sides of the plurality of plungers 19 are also provided on the arrangement surface of the plurality of plungers 19, all of the discharge paths are arranged on the arrangement surface of the plungers 19. It is possible to simplify the configuration of the discharge path.
[0026]
Furthermore, since the accumulator 21 disposed in the pump housing 5 is disposed in the pump housing 5 coaxially with the single plunger 19, the accumulator 21 is also configured on the arrangement surface of the plunger 19. By arranging the accumulator 21, the axial length of the shaft 9 of the pump housing 5 is not increased. Further, by disposing the accumulator 21 in the pump housing 5 coaxially with the single plunger 19, it is not necessary to provide a new passage in the pump housing 5 for mounting the accumulator 21, thereby simplifying the discharge path. It becomes possible.
[0027]
Further, the cylinder 17 accommodating one plunger 19 is fixed to the pump housing 5 in the axial direction by using the biasing force of the spring 35 disposed on the end surface of the port portion 21 of the accumulator 21 to the pump housing. Therefore, when the cylinder 17 separate from the pump housing 5 is fixed to the pump housing 5, the pump housing 5 is attached to the pump housing 5 like two cylinders other than the cylinder 17 extending in the vertical direction in FIG. There is no need to apply a caulking process. Therefore, the manufacturing cost can be reduced. In this case, needless to say, the end face of the attachment port portion 21a of the accumulator 21 may be brought into direct contact with the end face on the radially outer side with respect to the shaft of the cylinder 17.
[0028]
In the embodiment of the radial plunger pump according to the present invention described above, the number of plungers (or cylinders) is not limited to three, and a motor that is a pump drive source is not a brush motor but a brushless motor. Needless to say, a motor or a so-called SR motor may be used.
[0029]
【Effect of the invention】
As described above, according to the present invention, it is possible to provide a radial plunger pump capable of shortening the axial length of the shaft in the pump housing and simplifying the configuration of the discharge path.
[Brief description of the drawings]
FIG. 1 is an axial main cross-sectional view of a pump-motor assembly including a radial plunger pump according to the present invention.
2 is an enlarged view of an AA cross section in FIG. 1. FIG.
[Explanation of symbols]
5 Pump housing 9 Shaft 17 Cylinder 19 Plunger 21 Accumulator 21a Mounting port 25 Discharge port 43 Communication path

Claims (4)

A pump housing having a discharge port; a shaft rotatably supported in the pump housing; and disposed radially in the pump housing in the same plane with respect to an axial direction of the shaft, In a radial plunger pump having a plurality of plungers for sucking the working fluid by reciprocating by rotation and discharging the working fluid to the discharge port, and provided with an accumulator capable of accumulating the discharged working fluid, the discharge port includes the plurality of discharge ports. The accumulator is provided on a placement surface of the plunger, the accumulator is disposed coaxially with one of the plurality of plungers, and the discharge port is provided with respect to the hole in which the accumulator is disposed. radial characterized in that it is connected through a passage provided on the placement surface Run Ja pump.   2. The radial plunger pump according to claim 1, wherein the discharge port is connected to a hole in which the accumulator is disposed through a passage provided on an arrangement surface of the plurality of plungers.   A pump housing having a discharge port; a shaft rotatably supported in the pump housing; and disposed radially in the pump housing in the same plane with respect to an axial direction of the shaft, In a radial plunger pump having a plurality of plungers for sucking the working fluid by reciprocating by rotation and discharging it to the discharge port, and provided with an accumulator capable of accumulating the discharged working fluid, the discharge port includes the plurality of discharge ports. The accumulator is provided on the arrangement surface of the plunger, and is disposed in the pump housing coaxially with one of the plurality of plungers. The plunger is accommodated in a cylinder separate from the pump housing. And the axial direction of the cylinder containing the one plunger Serial fixed relative to the pump housing, a radial plunger pump, characterized in that it is performed by using the end face of the attachment port portion to said pump housing of said accumulator.   The radial plunger pump according to any one of claims 1 to 3, wherein a communication passage that communicates the discharge sides of each of the plurality of plungers is also provided on an arrangement surface of the plurality of plungers. .

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