WO2019035355A1

WO2019035355A1 - Hydraulic rotary machine

Info

Publication number: WO2019035355A1
Application number: PCT/JP2018/028699
Authority: WO
Inventors: 竜乃介石川; 義博大林
Original assignee: Ｋｙｂ株式会社
Priority date: 2017-08-14
Filing date: 2018-07-31
Publication date: 2019-02-21
Also published as: JP2019035363A

Abstract

A piston pump (100, 200) comprises: a plurality of pistons (6); a cylinder block (2) having provided therein a plurality of cylinders (2a) coupled to a shaft (1) and housing the pistons (6); a shoe (10) rotatably coupled to the tip of the pistons (6); a swash plate (13) that reciprocally moves the pistons (6) in conjunction with the sliding contact of the shoe (10) and the rotation of the cylinder block (2); and a wave spring (30) that, as an impelling member that impels the shoe (10) towards the swash plate (13), has a wave-shaped belt material formed in a spiral.

Description

Hydraulic rotary machine

The present invention relates to a hydraulic rotary machine used as a piston pump or a piston motor.

JP2015-71978A discloses a hydraulic rotating machine including a swash plate for reciprocating a piston accommodated in a cylinder and a biasing member for biasing a shoe connected to the piston toward the swash plate. ing.

A compression coil spring is generally used as a biasing member for biasing the shoe toward the swash plate as described in JP2015-71978A. However, since the compression coil spring needs to be used so as not to have a close contact height, it is necessary to secure a space having a certain axial length to accommodate the compression coil spring. Moreover, in order to secure a desired load in a state where the axial length is limited, it is necessary to increase the outer diameter of the compression coil spring. For this reason, when a compression coil spring is used as a biasing member that biases the shoe toward the swash plate, there is a possibility that the hydraulic rotating machine becomes larger in the radial direction and the axial direction.

An object of the present invention is to make a hydraulic rotary machine compact.

According to an aspect of the present invention, a hydraulic rotating machine is rotatably coupled to a plurality of pistons and a cylinder block provided with a plurality of cylinders that are coupled to a rotation shaft and that accommodates the pistons, It comprises: a shoe to be connected; a swash plate which slides with the shoe and causes the piston to reciprocate as the cylinder block rotates; and a biasing member which biases the shoe toward the swash plate. The biasing member is a wave spring in which a corrugated strip is spirally formed.

FIG. 1 is a cross-sectional view of a hydraulic rotating machine according to a first embodiment of the present invention. FIG. 2 is a plan view showing a schematic shape of the wave spring. FIG. 3 is a side view showing a schematic shape of the wave spring. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 1 and is a view showing a restricting portion of the hydraulic rotating machine according to the first embodiment of the present invention. FIG. 5 is a view showing a restricting portion of a hydraulic rotating machine according to a second embodiment of the present invention, and is an enlarged view of a portion corresponding to a portion shown by a V portion in FIG.

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

First Embodiment
A hydraulic rotating machine 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In the present embodiment, the case where the hydraulic pressure rotary machine is a hydraulic piston pump motor 100 that uses water as a working fluid will be described. As shown in FIG. 1, the hydraulic piston pump motor 100 functions as a pump for supplying water which is a working fluid by the shaft 1 being rotated by the power from the outside and the piston 6 reciprocating, and supplied from the outside The piston 6 reciprocates by the fluid pressure of the water to rotate the shaft 1, thereby functioning as a motor for outputting a rotational driving force.

In the following description, the case where the hydraulic piston pump motor 100 is used as a piston pump is exemplified, and the hydraulic piston pump motor 100 is simply referred to as a “piston pump 100”.

The piston pump 100 is a hydraulic piston pump that uses water as a working fluid. The piston pump 100 includes a shaft 1 as a rotating shaft rotated by a power source, a cylinder block 2 coupled to the shaft 1 and rotated as the shaft 1 rotates, and a casing 3 accommodating the cylinder block 2.

The casing 3 has a case body 3a having both ends open, an end cover 5 supporting one end of the shaft 1 and closing one open end of the case body 3a, and the other end of the shaft 1 being inserted through the other of the case body 3a And a front cover 4 for closing the open end of the cover. Although the case body 3a and the end cover 5 are formed as separate members, they may be integrally formed.

The shaft 1 is a rod-like member, and is rotationally driven by the power of a power source such as an engine or an electric motor. The shaft 1 is provided such that one end 1 a protrudes from the front cover 4 to the outside, and the other end 1 b of the shaft 1 is accommodated in an accommodation recess 5 a formed in the end cover 5. A power source (not shown) is connected to one end 1 a of the shaft 1 protruding from the casing 3.

The cylinder block 2 has a through hole 2 a through which the shaft 1 passes, and is splined to the shaft 1 at a connecting portion 22. Thus, the cylinder block 2 rotates with the rotation of the shaft 1.

In the cylinder block 2, a plurality of cylinders 2 b having openings at one end face 2 d are formed in parallel with the shaft 1. The plurality of cylinders 2 b are formed at equal intervals in the circumferential direction of the cylinder block 2. A cylindrical piston 6 that divides the volume chamber 7 is inserted in the cylinder 2 b so as to freely move back and forth. The tip end side of the piston 6 protrudes from the opening of the cylinder 2b, and a spherical seat 6a is formed at the tip end.

The front cover 4 is formed with a through hole 4 a through which the shaft 1 is inserted. A bearing 19 rotatably supporting the shaft 1 is fitted in the through hole 4a. Further, the front cover 4 is provided with a seal 24 so that water does not leak to the outside from between the shaft 1 and the front cover 4.

The front cover 4 is further formed with a cylindrical extension 4 b extending along the shaft 1 toward the cylinder block 2. The bearing 20 is press-fitted to the outer peripheral surface of the extension 4 b. A cylindrical sliding contact portion 2c in sliding contact with the bearing 20 is formed on the cylinder block 2 positioned opposite to the outer peripheral surface of the extension portion 4b. The cylinder block 2 is rotatably supported by the front cover 4 because the inner peripheral surface of the sliding contact portion 2 c is in sliding contact with the outer peripheral surface of the bearing 20.

The end cover 5 is formed with a supply passage 8 for guiding the water sucked into the volume chamber 7 and a discharge passage 9 for the water discharged from the volume chamber 7. The end cover 5 further has a bearing 18 fitted on the inner peripheral surface of the housing recess 5a. The end cover 5 rotatably supports the other end 1 b of the shaft 1 accommodated in the accommodation recess 5 a via the bearing 18.

The bearings 18 to 20 are formed of resin, ceramic, DLC (Diamond Like Carbon) or the like. The material of the bearings 18 to 20 may be any material which can ensure the slidability even if the working fluid is water in particular.

The piston pump 100 further includes a valve plate 17 interposed between the cylinder block 2 and the end cover 5.

The valve plate 17 is a disk member in sliding contact with the base end surface of the cylinder block 2, and is fixed to the end cover 5. The valve plate 17 is formed with a supply port 17 a connecting the supply passage 8 and the volume chamber 7, and a discharge port 17 b connecting the discharge passage 9 and the volume chamber 7.

The piston pump 100 includes a shoe 10 rotatably connected to a spherical seat 6 a of the piston 6, a swash plate 13 in sliding contact with the shoe 10 as the cylinder block 2 rotates, and a retainer plate 11 for holding the shoe 10. And a retainer holder 12 in sliding contact with the retainer plate 11.

The shoe 10 has a receiving portion 10 a for receiving a spherical seat 6 a formed at the tip of each piston 6 and a circular flat plate portion 10 b in sliding contact with the swash plate 13. The inner surface of the receiving portion 10a is formed in a spherical shape and is in sliding contact with the outer surface of the received spherical seat 6a. The shoe 10 can be angularly displaced in any direction with respect to the spherical seat 6a.

The swash plate 13 is fixed to the inner wall of the front cover 4 and has a sliding contact surface 13 a inclined from the direction perpendicular to the axis of the shaft 1. The flat plate portion 10b of the shoe 10 makes surface contact with the sliding contact surface 13a.

The retainer plate 11 is an annular flat plate member, and has a plurality of insertion holes 11 a formed at predetermined intervals in the circumferential direction. The retainer plate 11 holds the shoe 10 in a state where the receiving portion 10 a of the shoe 10 is inserted through the insertion hole 11 a.

The retainer holder 12 is a tubular member mounted on the outer periphery of the sliding contact portion 2 c of the cylinder block 2 and slidable along the axial direction of the shaft 1. The tip of the retainer holder 12 is in sliding contact with the central portion of the retainer plate 11.

The piston pump 100 further includes a wave spring 30 as a biasing member that biases the shoe 10 toward the swash plate 13 via the retainer holder 12 and the retainer plate 11. The schematic shape of the wave spring 30 is shown in FIG. 2 and FIG. FIG. 2 is a plan view of the wave spring 30, and FIG. 3 is a side view of the wave spring 30. As shown in FIG.

The wave spring 30 is formed by spirally winding a corrugated strip. Specifically, the wire has a rectangular cross section, and as shown in FIG. 2, the wire has a ridge 30 a and a valley 30 b formed by bending in the thickness direction of the wire along the circumferential direction. Are provided at predetermined intervals. Then, as shown in FIG. 3, the wire is spirally wound so that the ridges 30 a and the valleys 30 b of the wire adjacent in the vertical direction abut on each other. In addition, it is an example of the wave spring 30 shown in figure by FIG.2 and FIG.3, and as a wave spring 30, what kind of structure will be formed if the wave-shaped strip | belt-shaped wire is wound and formed helically. It may be one.

As shown in FIG. 1, the wave spring 30 is mounted on the outer periphery of the sliding contact portion 2c of the cylinder block 2, and between the bottom surface 12a of the retainer holder 12 and the end face 2d of the cylinder block 2 where the cylinder 2b opens. Is inserted in a compressed state. Therefore, the inner diameter d1 of the wave spring 30 is set larger than the outer diameter of the sliding contact portion 2c of the cylinder block 2, and the outer diameter D1 of the wave spring 30 is set smaller than the outer diameter of the retainer holder 12.

The biasing force of the wave spring 30 acts on the shoe 10 via the retainer holder 12 and the retainer plate 11, resulting in a pressing force that presses the shoe 10 against the swash plate 13. The biasing force of the wave spring 30 also acts as a pressing force that presses the cylinder block 2 against the valve plate 17. For this reason, leakage of water from between the cylinder block 2 and the valve plate 17 is suppressed.

Here, the biasing force of the general compression coil spring is generated due to the twisting stress of the wire, while the biasing force of the wave spring 30 is generated due to the bending stress of the wire. For this reason, when the outer dimensions are substantially the same, the biasing force of the wave spring 30 is larger than that of the compression coil spring. That is, in order to obtain the same biasing force, the wave spring 30 can shorten the length in the compression direction and can reduce the outer diameter. Therefore, by adopting the wave spring 30 as a biasing member for biasing the shoe 10 toward the swash plate 13, the space for housing the biasing member is reduced, so the entire piston pump 100 can be made compact. Is possible.

On the other hand, since the wave spring 30 expands its outer diameter when compressed, the wave spring 30 may come in contact with the piston 6 disposed radially outward with respect to the wave spring 30.

Therefore, the piston pump 100 further includes a pin member 32 as a restricting portion that restricts the radial expansion of the wave spring 30. FIG. 4 is a partial cross-sectional view taken along the line IV-IV of FIG. 1, in which the arrangement of the pin members 32 is shown.

The pin member 32 is a cylindrical member, and is fixed to the end face 2 d of the cylinder block 2 along the axial direction of the shaft 1 by press fitting or the like. A plurality of pin members 32 are disposed between the cylinder 2 b and the cylinder 2 b and radially outward of the wave spring 30. The arrangement of the pin members 32 is the most in each pin member 32 indicated by a dot and dash line than the diameter of a first virtual circle 34 connecting the most point on the shaft 1 side of each cylinder 2 b indicated in FIG. The diameter of the second virtual circle 33 connecting the points on the shaft 1 side is set to be smaller.

As described above, since the pin member 32 is disposed closer to the wave spring 30 than the piston 6, the wave spring 30 is not the piston 6 even if the outer diameter of the wave spring 30 is expanded by being compressed. , And the pin member 32. Therefore, the radial expansion of the wave spring 30 is restricted by the pin member 32, and the piston 6 and the wave spring 30 are prevented from contacting with each other. The pin members 32 do not have to be provided between all the cylinders 2b, and a plurality, preferably three or more, may be provided.

Next, the operation of the piston pump 100 will be described.

When the shaft 1 is driven to rotate by external power and the cylinder block 2 is rotated accordingly, the flat plate portion 10b of each shoe 10 is in sliding contact with the swash plate 13 and each piston 6 corresponds to the inclination angle of the swash plate 13 Reciprocate in the cylinder 2b by the stroke amount. Then, as the pistons 6 reciprocate, the volume of each volume chamber 7 increases or decreases.

Water is introduced into the volume chamber 7 expanded by the rotation of the cylinder block 2 through the supply passage 8 and the supply port 17a. The water sucked into the volume chamber 7 is pressurized by the contraction of the volume chamber 7 by the rotation of the cylinder block 2 and is discharged through the discharge port 17 b and the discharge passage 9. Thus, in the piston pump 100, suction and discharge of water are continuously performed as the cylinder block 2 rotates.

Thus, while the suction and discharge of water are performed in the piston pump 100, the shoe 10 is always pressed against the swash plate 13 by the biasing force of the wave spring 30, and the shoe 10 may be separated from the swash plate 13. It is prevented.

According to the first embodiment described above, the following effects can be obtained.

The piston pump 100 includes a wave spring 30 as a biasing member that biases the shoe 10 toward the swash plate 13. Comparing the wave spring 30 with a general compression coil spring, the wave spring 30 can shorten the length in the compression direction and reduce the outer diameter in order to obtain the same biasing force. Is possible. For this reason, by adopting the wave spring 30, the space for accommodating the biasing member can be reduced, and as a result, the outer shape of the piston pump 100 can be made compact.

Further, the piston pump 100 is provided with a pin member 32 as a restricting portion that restricts the radial expansion of the wave spring 30. Since the pin member 32 is disposed closer to the wave spring 30 than the piston 6, the wave spring 30 is not the piston 6 but the pin member 32 even if the outer diameter of the wave spring 30 is expanded by compression. Will abut. Therefore, it can prevent that piston 6 and wave spring 30 contact.

Second Embodiment
Next, a piston pump 200 according to a second embodiment of the present invention will be described. Hereinafter, differences from the first embodiment will be mainly described, and the same configuration as the first embodiment is denoted by the same reference numeral, and the description thereof will be omitted.

The basic configuration of the piston pump 200 according to the second embodiment is the same as that of the piston pump 100 according to the first embodiment shown in FIG. The piston pump 200 according to the second embodiment differs from the piston pump 200 according to the first embodiment in that the configuration of the

regulation portions

2e and 12b for regulating the radial expansion of the wave spring 30 differs from the configuration of the regulation portion 32 of the piston pump 100 according to the first embodiment. This differs from the piston pump 100 according to one embodiment. FIG. 5 is a view for explaining the restricting

portions

2e and 12b of the piston pump 200 according to the second embodiment, and shows a portion corresponding to a portion shown by a V portion in FIG. 1 in an enlarged manner. In addition, since the structure except the part shown by FIG. 5 is the same as that of the piston pump 100 which concerns on 1st Embodiment, those illustration and description are abbreviate | omitted.

The piston pump 200 includes an annular convex portion 2 e as a first restricting portion that restricts the radial spread of the wave spring 30 and an annular wall portion 12 b as a second restricting portion.

The annular convex portion 2 e protrudes from the end face 2 d of the cylinder block 2 along the axial direction of the shaft 1 and is annularly formed so as to surround the outer periphery of the wave spring 30. As shown in FIG. 5, since the annular convex portion 2 e is disposed between the wave spring 30 and the piston 6, the wave spring 30 can be compressed even if the outer diameter of the wave spring 30 is expanded by being compressed. , Not the piston 6 but the annular convex portion 2e. Therefore, the radial expansion of the wave spring 30 is restricted by the annular convex portion 2e, and the piston 6 and the wave spring 30 are prevented from contacting with each other.

In addition, the annular convex part 2e does not need to be continuously provided in the circumferential direction, and may be partially provided. Further, instead of the configuration in which the annular convex portion 2e is protruded from the end face 2d, a groove capable of accommodating the wave spring 30 is processed on the end face 2d of the portion where the wave spring 30 is disposed, and the wave spring 30 is disposed in the groove. Thus, the radial spread of the wave spring 30 may be restricted.

On the other hand, the annular wall portion 12 b protrudes from the bottom surface 12 a of the retainer holder 12 along the axial direction of the shaft 1 and is annularly formed so as to surround the outer periphery of the wave spring 30. As shown in FIG. 5, since the annular wall portion 12 b is disposed between the wave spring 30 and the piston 6, the wave spring 30 can be compressed even if the outer diameter of the wave spring 30 is expanded by being compressed. , Not the piston 6 but the annular wall 12b. Therefore, the radial expansion of the wave spring 30 is restricted by the annular wall 12b, and the piston 6 and the wave spring 30 are prevented from contacting with each other. The annular wall portion 12 b does not have to be continuously provided in the circumferential direction, and may be partially provided.

Both the annular convex portion 2 e and the annular wall portion 12 b may be provided, or only one may be provided. By arranging both the annular convex portion 2 e and the annular wall portion 12 b, the contact between the piston 6 and the wave spring 30 can be reliably prevented.

According to the above second embodiment, the following effects can be obtained.

The piston pump 200 includes an annular convex portion 2 e and an annular wall portion 12 b as a regulating portion that regulates the radial expansion of the wave spring 30. Since the annular convex portion 2 e and the annular wall portion 12 b are provided between the wave spring 30 and the piston 6, the wave spring 30 can be compressed by the piston 6 even if the outer diameter of the wave spring 30 is expanded by compression. Instead, it comes in contact with the annular convex portion 2e and the annular wall 12b. Therefore, it can prevent that piston 6 and wave spring 30 contact.

Note that both or any one of the annular convex portion 2e and the annular wall portion 12b, which are the restricting portions of the piston pump 200 according to the second embodiment, and the pin member 32 which is the restricting portion of the piston pump 100 according to the first embodiment. And may be used in combination. By arranging the plurality of restricting portions, contact between the piston 6 and the wave spring 30 can be reliably prevented.

The configuration, operation, and effects of the embodiment of the present invention configured as described above will be collectively described.

The piston pumps 100 and 200 have a plurality of pistons 6, a cylinder block 2 provided with a plurality of cylinders 2 b coupled to the shaft 1 and accommodating the pistons 6, and a shoe 10 rotatably coupled to the tip of the pistons 6. As a swash plate 13 which reciprocates the piston 6 in accordance with the rotation of the cylinder block 2 as the shoe 10 slides, and as a biasing member which biases the shoe 10 toward the swash plate 13, the corrugated strip is helical. And a wave spring 30 formed on the

According to this configuration, the piston pumps 100 and 200 include the wave spring 30 as a biasing member that biases the shoe 10 toward the swash plate 13. Comparing the wave spring 30 with a general compression coil spring, the wave spring 30 can shorten the length in the compression direction and reduce the outer diameter in order to obtain the same biasing force. Is possible. For this reason, by adopting the wave spring 30, the space for housing the biasing member can be reduced, and as a result, the external shape of the

piston pump

100, 200 can be made compact.

The piston pumps 100 and 200 further include restricting

portions

32 and 2e and 12b that restrict the radial spread of the wave spring 30, respectively.

In this configuration, in order to restrict the radial spread of the wave spring 30, restricting

portions

32, 2e and 12b are provided. For this reason, even if the outer diameter of the wave spring 30 is expanded by being compressed, the wave spring 30 abuts not on the piston 6 but on the

restriction portions

32, 2e and 12b. Therefore, it can prevent that piston 6 and wave spring 30 contact.

The piston pumps 100 and 200 further include a retainer holder 12 for transmitting the biasing force of the wave spring 30 to the shoe 10, and the wave spring 30 is interposed between the cylinder block 2 and the retainer holder 12 in a compressed state. The

restriction portions

32, 2e, 12b are mounted on at least one of the cylinder block 2 and the retainer holder 12 on the radially outer side of the wave spring 30.

In this configuration, in order to restrict the radial expansion of the wave spring 30, restricting

portions

32, 2e and 12b are provided on at least one of the cylinder block 2 and the retainer holder 12. As described above, since the restricting

portions

32, 2e and 12b are provided near the portion where the wave spring 30 is mounted, the wave spring 30 is a piston even if the outside diameter of the wave spring 30 is expanded by being compressed. It comes in contact with the restricting

portions

32, 2e, 12b instead of 6. Therefore, it can prevent that piston 6 and wave spring 30 contact.

The restricting portion is a plurality of pin members 32 provided in the cylinder block 2, and the pin members 32 are disposed closer to the wave spring 30 than the piston 6 in the radial direction of the cylinder block 2.

In this configuration, a pin member 32 is provided on the cylinder block 2 to restrict the radial expansion of the wave spring 30. Further, since the pin member 32 is disposed closer to the wave spring 30 than the piston 6, even if the outer diameter of the wave spring 30 is expanded by being compressed, the wave spring 30 is not the piston 6 but a pin member It will contact 32. Therefore, it can prevent that piston 6 and wave spring 30 contact. Further, since the restricting portion is configured only by attaching the pin member 32 to the cylinder block 2 and a large-scale additional processing to the cylinder block 2 etc. is unnecessary, it is possible to suppress an increase in the manufacturing cost of the piston pump 100.

As mentioned above, although the embodiment of the present invention was described, the above-mentioned embodiment showed only a part of application example of the present invention, and in the meaning of limiting the technical scope of the present invention to the concrete composition of the above-mentioned embodiment. Absent.

In the present embodiment, water is used as the working fluid, but instead, a working fluid such as a working oil or a water-soluble alternative liquid may be used. In addition, although the piston pump motor 100 has a fixed angle of the swash plate 13, it may be a variable displacement piston pump motor capable of changing the tilt angle of the swash plate.

This application claims the priority based on Japanese Patent Application No. 2017-156666 filed on Aug. 14, 2017 to the Japan Patent Office, and the entire contents of this application are incorporated herein by reference.

Claims

A hydraulic rotating machine,
With multiple pistons,
A cylinder block coupled to the rotation shaft and provided with a plurality of cylinders accommodating the pistons;
A shoe rotatably connected to a tip of the piston;
A swash plate which is in sliding contact with the shoes and causes the piston to reciprocate as the cylinder block rotates;
A biasing member for biasing the shoe toward the swash plate;
The fluid pressure rotating machine according to the present invention, wherein the biasing member is a wave spring in which a corrugated strip is spirally formed.
A hydraulic rotating machine according to claim 1, wherein
The hydraulic rotating machine further comprising a restricting portion that restricts the radial spread of the wave spring.
The hydraulic rotating machine according to claim 2, wherein
It further comprises a retainer holder for transmitting the biasing force of the wave spring to the shoe,
The wave spring is interposed between the cylinder block and the retainer holder in a compressed state.
The hydraulic restrictor is provided on at least one of the cylinder block and the retainer holder on the radially outer side of the wave spring.
A hydraulic rotating machine according to claim 3, wherein
The restriction portion is a plurality of pin members provided on the cylinder block,
The hydraulic rotating machine wherein the pin member is disposed closer to the wave spring than the piston in a radial direction of the cylinder block.