KR100959462B1 - Axial piston type hydraulic component - Google Patents

Abstract

An object of the present invention is to increase the swing angle of a shoe and a piston in an axial piston of a piston pump and a piston motor.

The present invention provides an escape portion 18 at a portion that interferes with the piston 6 by the rotation of the connecting member in the connecting portion in which the connecting member and the piston 6 are rotatably connected. Form.

 Axial piston, shoe, shoe retainer, piston, discharge part, spherical part, spherical recess,

Description

Axial piston fluid machine {AXIAL PISTON TYPE HYDRAULIC COMPONENT}

1 is a schematic cross-sectional view of an inclined plate hydraulic pump.

2 is a perspective view of a valve plate.

3 is a view showing a neutral state of the inclined plate.

4 is an illustration of a piston assembly in an embodiment of the invention.

Fig. 5 is a diagram showing a state in which the shoe swings.

Figure 6 is a view of the piston assembly of the second embodiment.

7 is a view of a piston assembly of the third embodiment.

8 is a view of a conventional piston assembly.

9 is a view showing a state where a conventional shoe is swung.

[Explanation of Significance in Drawing]

1: shaft 2: connecting member 4: inclined plate 5: shoe

6: piston 7: cylinder block 8: valve plate 10: bore

18: discharge part 20: coil spring 21: shoe retainer 22: suction valve hole

23: discharge valve hole 24: shoe insertion hole 25: communication port 30: shoe sliding movement surface
31: Tokyo part 32: spherical part 33: stenosis 35: spherical important part

36: piston assembly A: hydraulic pump L1: shaft rotation axis                 

: 경사각S1: suction area S2: discharge area

Tilt angle

The present invention relates to an axial piston fluid machine for a piston pump and a piston motor.

In the axial piston pump, the related art is a cylinder block having a plurality of bores by rotationally driving a cylinder block device through a drive shaft that is driven by a power of a driving source. BACKGROUND OF THE INVENTION Machines for converting mechanical energy into fluid energy by sucking and discharging oil in a tank and discharging it as high pressure oil by reciprocating each piston therein are widely known. In addition to the flow of oil, the high-pressure oil discharged from the external pump is introduced into the plurality of cylinder blocks to reciprocate each piston to rotate integrally with the cylinder block device and the cylinder block device incorporating the cylinder block and the piston. An axial piston motor is also known which has a mechanism for converting fluid energy into mechanical energy by rotating the drive shaft.

Axial piston pumps or motors also have a swash plate type with an inclination in which the drive shaft and the cylinder block central axis are inclined and inclined plates which are coaxially fixed to the same axis.

Since the basic structure of the cylinder block device does not change even in an inclined or inclined plate type axial piston pump and an axial piston motor, the present invention will be described below using an inclined plate type axial piston pump.

In the present invention, it should be noted that the matters described in the inclined plate type axial piston pump are also applied to the inclined type axial piston pump as well as in the inclined and inclined plate type axial piston motor.

)제어가 이루어진다. 도시되지 않은 케이스에 의해 샤프트(1)는 회전축선(L1)주위에 축지지(軸支持)된다.Fig. 1 shows a cross-sectional view of the main part of a typical inclined plate axial piston pump (hereinafter, referred to simply as an hydraulic pump). In the inclined plate type hydraulic pump, the inclination angle of the inclined plate 4 is provided by a regulator and a servo piston (not shown) in order to control the output constantly.

Control is made. The shaft 1 is axially supported around the rotation axis L1 by the case which is not shown in figure.

The cylinder block 7 mounted on the shaft 1 and integrally rotating with the shaft 1 is accommodated in the case, and an inclined plate 4 is disposed on the axial side of the cylinder block 7 (left of FIG. 1). It is fixedly placed in 1). The cylinder block 7 is also housed in the case not shown. The cylinder block 7 is formed with a plurality of bores 10 in the circumferential direction around the axis L1, and the bore 10 is opened at one end surface of the cylinder block 7 and is parallel to the shaft 1. It is formed and arranged in plural at equal intervals in the circumferential direction. The bore 10 is inserted into the bore 10 in such a manner that the piston 6 can be inserted and removed in the axial direction, and the connecting member is rotated (rotating) at the distal end of the piston 6, respectively. ) Possibly connected. As the connecting member 2, the connecting member 2 is provided on the inclined plate, and the connecting member 2 is used as a shoe separately from the inclined plate. The associated configuration of the connecting member and the piston has the same configuration, so the shoe 5 will be described here.

Each shoe 5 is inserted into a shoe insertion hole formed in a concentric manner at equal intervals on the surface of the shroud retainer 21, and the shroud retainer 21 is inclined by a coil spring 20. Pressed on 4). As a result, the shoe 5 is pressed against the inclined plate 4 to be in contact with the sliding state, and the shoe 5 is rotated around the rotation axis L1 on the inclined plate 4 while being supported by the shroud 21. Piston 6 connected to the reciprocating sliding movement in the bore (10).

In the case where the connecting member 2 is provided on the inclined plate, since the copper retainer 21 is not used and the connecting member is directly installed on the inclined plate, the connecting member 2 does not slide against the inclined plate, and the piston 6 and The piston 6 rotates around the center of rotation with the connecting member and reciprocates in the bore 10.

The valve plate 8 is provided between the valve cover and the cylinder block 7 not shown, and the valve plate 8 is mounted in a state in which rotation around the rotational axis L1 with respect to the valve cover is prevented. Sliding contact with the other side of (7) is possible.

2 is a front view showing the valve plate 8 and the cylinder block 7, and is a perspective view from the shaft end side of the shaft 1. The valve plate 8 has one side with respect to the center line C which connects the upper and lower dead centers of the piston 6 which rotates through the axis L1 (the left side of FIG. 2 and the front side of the ground of FIG. 1). The suction valve hole 22 is formed in the suction area S1 of the discharge valve hole 23 in the discharge area S2 on the other side (right side of FIG. 2, inside of the ground of FIG. 1) with respect to the center line C. It is. The suction valve hole 22 and the discharge valve hole 23 are connected to an oil tank, a hydraulic actuator, etc. which are not shown, respectively.

The suction valve hole 22 and the discharge valve hole 23 are each formed in the groove | channel of semi-circular arc shape centering on the axis line L1. A communication port 25 communicates with each bore 10 formed in the cylinder block 7, and the other end of the communication port 25 has a valve plate 8 depending on the rotational position of the cylinder block 7. It is in communication with the suction valve hole 22 or the discharge valve hole 23 formed in the.

Therefore, when eight bore 10 are provided as shown in FIG. 2, the four communication bores 25 on the left side of the figure communicate with the suction valve hole 22 of the valve plate 8, and the discharge valve hole 23 ), Four communication ports 25 on the right side communicate with each other.

When the shaft 1 is rotated around the counterclockwise direction as seen from the left side indicated by the arrow of FIG. 1 while driving an engine or the like not shown, the piston 6 disposed in front of the ground of FIG. 1 is a cylinder block 7. The volume F at the time of taking out from the suction valve hole 22, draws hydraulic fluid from the suction valve hole 22, and draws maximum suction in the bore 10 is obtained. In addition, the piston 6 disposed inside the ground of FIG. 1 is pushed into the cylinder block 7 to discharge the hydraulic oil in the bore 10 to the discharge valve hole 23 side, and to suck the volume in the bore 10 to the maximum. It decreases from the volume F at one time and becomes the volume E at the time of maximum discharge.

That is, in the piston 6 arranged in front of the ground of FIG. 1, the volume of the cylinder interior is enlarged by the rotation of the cylinder block 7, and oil is sucked in the process. On the other hand, in the piston 6 disposed inside the ground of FIG. 1, the volume of the cylinder chamber is reduced by the rotation of the cylinder block 7, and oil is discharged in the process.

에 의해 규정된다. 동 경사각

의 각도제어는 도시되지 않는 레귤레이터 및 서보 피스톤 등을 제어하므로서 경사판(4)의 경사각

를 변화시킴으로서 행할 수 있다. 경사가

의 제어에 의해서 보어(10) 내는 최대로 흡인한 때의 용적 F와 최대로 토출시킨 때의 용적 E로 변화시킬 수 있고, 용적 E와 F와의 차이(F-E)만큼 흡입 또는 토출할 수 있다. 경사각

가 90도인 때는 도 3에 표시한 바와 같이 실린더 내에 용적이 항상 일정하게 된다. 이때 샤프트(1) 및 실린더블록(7)이 회전하여도 피스톤(6)의 보어(10)에서의 왕복운동이 이루어지 않고 유압펌프에 의한 흡인도 토출도 이루어지지지 않는다. The discharge amount and suction amount in the hydraulic pump A are the inclination angle of the inclined plate 4.

Prescribed by East tilt angle

Angle control of the inclined plate 4 by controlling a regulator and a servo piston (not shown)

This can be done by changing. Slope

By the control of the inside, the bore 10 can be changed into the volume F at the maximum suction and the volume E at the maximum discharge, and can be sucked or discharged by the difference FE between the volumes E and F. Tilt angle

Is 90 degrees, the volume is always constant in the cylinder as shown in FIG. At this time, even when the shaft 1 and the cylinder block 7 rotate, the reciprocating motion of the bore 10 of the piston 6 does not occur, and neither suction nor discharge by the hydraulic pump is made.

An enlarged view of the configuration of the connecting member and the rotatable connecting engagement of the piston 6 is shown in FIG. 8. In this figure, an example of using a shoe as a connecting member is shown. However, even when the connecting member is installed on an inclined plate or a flange portion of a drive shaft, the arrangement relationship between the connecting portion and the piston is similar to that between the piston and the shoe shown in FIG. Since it is the same, it demonstrates here also using the connection member 2 and the shoe 5 here.

A shoe-proof pad is installed on the shoe sliding movement surface 30 which is in sliding contact with the inclined plate 4 of the shoe 5, and the shoe of the shoe retainer 21 is provided on the back side of the shoe sliding movement surface 30. The spherical part 32 is comprised integrally through the constriction part 33 in the east part 31 and the east part 31 inserted into the insertion hole 24. The copper spherical part 32 is rotatably connected to the spherical recess 35 formed in one end of the piston 6. The spherical concave portion 35 formed on one end of the spherical portion 32 and the piston 6 is rotatably connected while deforming the tip of the spherical concave portion 35 by means such as caking.

The shoe 5 and the piston 6 may be connected to each other by forming a spherical part at the tip of the piston 6 and having the spherical part formed in the shoe to connect the shoe 5 and the piston 6. do.

In the case where the connecting member is provided on the inclined plate or the flange portion, the connecting member is directly provided on the inclined plate or the flange portion without using the shoe sliding movement surface.

를 크게 하는 것에 의해 행하고 있었다.In the hydraulic pump and the axial piston motor (hereinafter referred to as the hydraulic motor), in order to increase the rotation angle of the shoe 5, the shoe sliding motion is performed at the center of the spherical part, which is the center of rotation of the shoe 5. If the distance to the surface h (see Fig. 4) is increased or the spherical portion is formed at the piston tip, the distance from the center of the spherical portion of the piston tip portion to the piston body as shown in FIG.

Was doing by enlarging it.

를 크게하면 펌프의 전길이가 길게 되는 문제점이 있다. 또 상기 슈(5)의 구중심에서 슈슬라이딩 운동면까지의 거리를 길게하면 동 슈(5)가 경사판(4)의 경사면 위를 고속 으로 슬라이딩 운동하면서 회전할 때에 슈(5)의 구 중심 둘레의 회전모멘트가 크게 되어, 슈(5)가 크게 흔들려서 슈의 장착강도상에 문제가 생기거나, 슈(5)가 슈 리테이너부의 슈 삽입공 내에서 격렬하게 충돌하여 소음이 발생하는 등의 문제가 생긴다. 상기 피스톤 선단부의 구형상부의 구중심에서 피스톤본체까지의 거리

를 크게 취한 경우에는 동 구형상부의 장착강도가 저하되는 문제가 생긴다.However, the distance h from the sphere center to the shoe sliding movement surface is increased or the distance from the sphere center of the spherical portion of the piston tip to the piston body.

If it is increased, there is a problem that the total length of the pump is long. In addition, when the distance from the center of the shoe 5 to the shoe sliding movement surface is increased, the shoe center circumference of the shoe 5 when the shoe 5 rotates while slidingly sliding on the inclined surface of the inclined plate 4 at high speed. The rotation moment of the motor becomes large, and the shoe 5 is greatly shaken to cause a problem in the mounting strength of the shoe, or the shoe 5 may collide violently in the shoe insertion hole of the shoe retainer to generate noise. . Distance from the center of the spherical portion of the piston tip to the piston body

If large is taken, there is a problem that the mounting strength of the same sphere is lowered.

The present invention solves these problems and shortens the distance from the spherical center of the spherical portion formed in the connecting member to the shoe sliding motion surface or the inclined plate or the flange, or from the spherical center of the piston tip to the piston body. The length of the hydraulic piston and the hydraulic motor can be shortened for the purpose of increasing the inclination angle of the inclined plate 4 or increasing the inclination angle of the inclined plate 4 by shortening the distance of An axial piston fluid machine is provided.

[Measures for solving the problem]

 In order to solve the above problems, in the present invention, the connection structure between the connecting member and the piston was examined from various angles, and the following points were found.

      That is, when the connecting member is described as an example of the shoe, when the shoe 5 rotates while sliding on the inclined surface of the inclined plate 4, the shoe 5 is centered on the center of the spherical portion 32. It swings with respect to the piston 6. At this time, when the shoe 5 rotates more than a predetermined angle, a part of the piston 6 and the shoe 5 interfere with each other and come into contact. In other words, the predetermined angle is defined as the maximum turning angle in the shoe 5.

Therefore, in order to increase the rotational angle of the shoe 5, the sphere of the shoe 5 can be formed by forming an escape 18 at a portion where the piston 6 and the shoe 5 interfere with each other when the shoe is rotated. The distance from the center of the shoe to the shoe sliding motion surface can be shortened, or when a spherical portion is formed in the piston tip, the distance from the center of the spherical portion to the piston body can be shortened. This is to increase the maximum rotation angle of the shoe (5). Since the distance between the shoe and the shoe sliding movement surface does not change, the vibration of the shoe cannot be increased by rotation, and the mounting strength of the spherical part can be maintained as it is. have. It has also been found that the length of the hydraulic pump and the hydraulic piston can be shortened by this.

The subject of this invention is achieved by each invention as described in this invention Claims 1-6. That is, the invention according to claim 1 of the present invention is a fluid machine such as an axial piston pump or a motor, wherein the copper connecting member and the piston 6 at the time of rotation of the connecting member relatively rotatably connected to the piston 6. An axial piston fluid machine, characterized in that the discharge portion 18 is formed on the interference portion with the.

In the present invention, at the time of rotation of the connecting member relatively rotatably connected to the piston, the discharge portion is formed on the interference portion between the connecting member and the piston, so that the conventional piston and the connecting member have the same dimension (standard) in a parallel line. Despite the configuration, the rotation angle between the connecting member and the piston can be increased, so that the suction capacity of the cylinder can be increased. For this reason, the discharge capacity can be increased even with the hydraulic pump of the same size. This is an axial piston piston fluid machine according to the present invention, which can cope with a small hydraulic pump with respect to a hydraulic pump of an output such as a hydraulic pump of a conventional size.                         

As the interference portion between the connecting member and the piston, the portion can be identified as a portion where a part of the piston contacts on the connecting member side or a portion where a portion of the connecting member contacts on the piston side. In the formation of the discharge portion, the contact portion can be formed by cutting the annular groove or the outer circumferential surface by chamfering or the like.

According to the present invention, the distance from the center of the spherical portion formed on the connecting member to the shoe sliding motion surface, the inclined plate or the flange portion can be shortened, and the distance from the center of the spherical portion of the piston tip to the piston body can be shortened. As a result, the inclination angle of the inclined plate can be increased.

The invention according to claim 2 is an axial piston, characterized in that in addition to the matters of claim 1, the connection member is limited to the sliding motion on the inclined plate.

In the present invention, it is characterized in that the connecting member is formed to slide on the inclined plate, and can be specified as the configuration of the inclined plate portion in the inclined plate type axial piston pump or motor.

The invention according to claim 3 is an axial piston fluid machine in which, in addition to the fact of claim 1, the connection member 2 is limited to a shoe 5.

In the present invention, the use of the shoe 5 formed of a separate body from the inclined plate 4 as the connecting member 2 is limited. As the structure of the shoe, the structure of the shoe described as the conventional technique can be used as it is.

According to the invention of claim 4, in addition to the matters of claim 3, a spherical recess is formed at the tip of the piston, and a spherical portion is formed at the shoe. The spherical portion is accommodated in the spherical recess, and the tip of the spherical recess is reduced in diameter. It is an axial piston fluid machine characterized by limiting the connection between the piston and the shoe by deforming in the 방향) direction.

In this invention, it is limited to the structure provided with the spherical part provided in the shoe side and accommodating the spherical part in the front-end | tip of a piston. As the shoe and the piston, the shoe and the piston described as the prior art can be used. However, the present invention is different from the conventional one in that the discharge portion is formed in the interference portion of the piston and the shoe.

In the case where a spherical portion is formed on the shoe side, an ejection portion is formed on a surface of the spherical portion side of the mirror portion (body diameter portion) and the interference position with the tip portion of the spherical recess of the piston connecting to the spherical portion is moved. Can be. In this case, the discharge portion can be formed by forming an annular groove centered on the central axis of the mirror portion. Alternatively, the distal end portion of the spherical recess formed on the piston side can be cut and formed along the circumferential direction.

In the case where the spherical portion is formed on the piston side, the interference position between the piston and the shoe can be shifted by forming the discharge portion at the tip of the spherical recess on the shoe side connecting the spherical portion. At this time, the discharge portion may be formed by cutting the spherical recessed end portion along the circumferential direction. Alternatively, the discharge portion can be formed by forming an annular groove on the outer circumferential surface of the connecting portion between the piston body and the spherical portion. In this case, it is necessary to be configured so that the strength of the connecting portion is maintained between the piston body and the spherical portion.                         

The invention according to claim 5 is an axial piston fluid machine, in which, in addition to the matters set forth in any one of claims 2 to 4, the discharge part defines a matter formed on the side of the connecting member.

  In the present invention, when the spherical portion is formed on the side of the connecting member that interferes with the piston, and the spherical portion is formed on the connecting member side, an annular groove is formed in the center line and the center line of the same spherical portion. The discharge portion can be formed. In addition, when the spherical recess for accommodating the spherical portion formed in the piston is formed on the side of the connecting member, the discharging portion can be formed by cutting the outer peripheral surface of the distal end of the spherical recess.

The invention according to claim 6 is an axial piston-type fluid machine in which, in addition to the matters of claim 1, the matters formed on the piston side are limited.

In the present invention, when there is a spherical portion on the connecting member side, an interference portion with the piston shoe can be shifted by forming a discharge portion at the tip of the spherical recess on the piston side connecting the spherical portion. Moreover, in the piston assembly in which the spherical part was formed in the piston side, the discharge part can be formed in the outer peripheral surface of the connection part from the piston body to the spherical part. At this time, it is necessary to form the discharge portion on the outer periphery of the connecting portion so as not to form the discharge portion beyond the diameter that withstands the rotational movement during the operation of the pump at the coupling portion of the connecting member and the piston. In addition, the discharge portion in the present invention can be formed by cutting the annular groove, the outer peripheral surface by chamfering and the like as described in claim 5 above.

Hereinafter, the configuration of the present invention in detail by the accompanying drawings in a preferred embodiment as follows.

      The present invention is effectively applied, for example, as a hydraulic motor and a hydraulic pump in a construction / civil engineering machine, a vehicle, etc. not shown. In addition, in the present embodiment, a hydraulic pump equipped in a construction vehicle will be described as an example, but the present invention is not limited to a hydraulic pump in a construction vehicle, but is applied to, for example, a hydraulic pump, various machines using a hydraulic motor, a transport vehicle, and the like. Naturally, the technical scope readily applicable to those skilled in the art is also included.

4 is a schematic cross-sectional view schematically showing an example of a piston assembly having a configuration in which a piston shoe rotational movement is a representative embodiment of the present invention;

5 is a cross-sectional schematic diagram illustrating a state in which the shoe 5 swings.

In addition, since the component parts other than a piston assembly are not different from the "conventional technique", the same code | symbol is attached | subjected to the same component, and description is abbreviate | omitted.

Example

4 is a cross-sectional view of the piston assembly 36 according to the present invention, which is composed of a shoe 5 and a piston 6 as in the prior art. The spherical part 32 of the shoe 5 is connected to the spherical recess 35 of the piston 6 so that rotational movement is possible. The connection is connected by means of connection as in the prior art.

The piston has a circumference formed with a hole in one end face side (one end face side), and the one end side of the hole is blocked, so that the oil supplied to the spherical recess 35 is filled in the hole. A part of the lubricating oil supplied to the spherical recessed part 35 is supplied to the shoe sliding movement surface 30 in the hole formed in the central shaft part of the shoe 5, and used for lubrication on the inclined plate 4 surface.

The tip of the spherical recess 35 for connecting the spherical portion 32 of the shoe 5 to be rotatable in rotation is deformed by a means such as caulking and connects the spherical portion 32 of the shoe 5 to form a spherical shape. Rotational movement is possible in the range where the recess and the shoe come into contact with each other. The outer diameter circumferential surface side of the piston 6 is axially inserted into the bore 10 provided in the cylinder block 7, and the high pressure oil acting on the end surface of the piston 6 receives the outer circumference of the piston 6. It is sealed in).

The Tokyo part (body diameter part) 31 of the shoe 5 is inserted with some play in the inner peripheral surface of the shoe insertion hole 24 formed in the shoe retainer 21 (refer FIG. 1), and the shoe retainer 21 The shoe 5 is prevented from falling in the axial direction by the large-diameter portion forming the shoe sliding motion surface 30. The shoe retainer 21 is pressed against the inclined plate side by the coil spring 20.

The discharge part 18 can be formed by cutting the contact part of the diameter part 31 of the shoe 5 which contact | connects the front-end | tip part of the said spherical recessed part 35 to some annular shape. As the discharge | release part 18, it can be formed by cutting into the shape or envelope which an envelope formed by the front-end | tip part of the said spherical recess 35 is accommodated, or an annular groove. As shown in FIG. 5, the rotational movement angle of the shoe 5 in which the discharge part 18 is formed can be made larger than the shoe (see FIG. 9) in which the discharge part 18 is not formed. At this time, since the outer diameter of the mirror portion 31 does not change, the strength of the shoe 5 can be configured without comparable with the case where the conventional discharge portion 18 is not formed, and conversely, the swing angle of the shoe 5 is This can be made larger than when the discharge portion 18 is not formed.

As the formation part of the discharge part 18, the said spherical shape provided in the front-end | tip of the piston 6 as shown in FIG. 6 instead of forming an annular groove in the contact part of the mirror part 31 in the said shoe 5 is shown. The circumferential surface of the tip outer peripheral portion of the recessed portion 35 can be formed by cutting or the like.

In FIG. 6, the solid line indicates the state where the discharge unit 18 is formed, and the dotted line indicates the state before the discharge unit 18 is formed. Even if the discharge portion 18 is formed at the tip end of the spherical recess 35, the swing angle of the shoe can be increased.

In addition, as shown in Fig. 6, the spherical portion 32 is formed on the piston 6 side, and the spherical recess 35 for accommodating the spherical portion 32 is provided on the shoe 5 side. The oscillation angle of the shoe 5 can be made large by forming the discharge | release part 18 in the site | part of the front-end | tip part of the spherical recess 35 which contact-interacts with the attachment part of the spherical part of the piston 6 by the rocking | swing.

In addition, although the discharge part 18 may be formed in the attachment part of the spherical part of the piston 6, since the intensity | strength which hold | maintains a spherical part may be weakened, the spherical part 32 is formed in the piston 6 side. In this case, it is preferable to form the discharge portion 18 at the tip of the spherical recess on the shoe side.

When the connecting member is provided in the flange portion of the inclined plate or the drive shaft, the swinging surface side of the shoe 5 described with reference to FIGS. 4 to 7 described above is configured as the inclined plate, and thus the connecting member 2 and the piston Since the relationship can be explained, the description for forming the discharge portion is replaced with that described with reference to FIGS. 4 to 7.

In the axial piston of the piston pump and the piston motor of the present invention, the swing angle of the shoe and the piston is increased, and the discharge portion is formed at the portion where the connecting member and the piston are rotatably connected to interfere with the connecting member and the rotating piston. 18), the rotation between the connecting member and the piston, despite the configuration of the same dimensions (standard) in parallel with the conventional piston and the connecting member in a straight line at the time of the rotation of the connecting member relatively rotatably connected to the piston Since the angle can be increased, the suction capacity of the cylinder can be increased. For this reason, even with a hydraulic pump of the same size, the discharge capacity can be increased, and this is an axial piston piston fluid machine according to the present invention, which can cope with a hydraulic pump of a small size with respect to a hydraulic pump having the same output as a conventional hydraulic pump. will be.

In addition, when the discharge portion 18 is formed, the distance from the spherical center of the shoe 5 to the shoe sliding movement surface can be shortened, or when a spherical portion is formed at the tip of the piston 6, It is also possible to shorten the distance from the center of the sphere to the piston body. This is to increase the maximum rotation angle of the shoe (5), the distance between the shoe and the shoe sliding movement surface does not change, so the vibration of the shoe cannot be increased by the rotation, and the mounting strength of the spherical part can be maintained as it is. have. Moreover, this length can be shortened with respect to the full length of a hydraulic pump and a hydraulic piston.

That is, by shortening the distance from the spherical center of the spherical portion formed on the connecting member to the shoe sliding motion surface or the inclined plate or the flange portion, or shortening the distance from the spherical center of the spherical portion of the piston tip to the piston body. By increasing the inclination angle of the inclined plate 4 or increasing the inclination angle of the inclined shaft, an axial piston fluid machine capable of shortening the entire length of the hydraulic piston and the hydraulic motor can be provided. have.

The present invention can identify the site as a site where a part of the piston is in contact with the connection member side or a site where a part of the connection member is in contact with the piston as an interference site between the connection member and the piston. It can be formed by cutting the annular groove or the outer circumferential surface on the contacting portion by chamfering, etc. to increase the rotation angle between the connecting member and the piston, the center of the spherical portion formed in the connecting member according to the present invention Can shorten the distance from the shoe sliding movement surface, or the inclined plate or flange

The invention according to claim 2 is an axial piston, characterized in that in addition to the matters of claim 1, the connection member is limited to the sliding motion on the inclined plate.

The present invention is characterized in that the connecting member is formed to slide on the inclined plate, and can be specified as a configuration of the inclined plate part in the inclined plate type axial piston pump or motor.

The invention according to claim 3 is an axial piston fluid machine in which, in addition to the fact of claim 1, the connection member 2 is limited to a shoe 5.

In the present invention, the use of the shoe 5 constituted separately from the inclined plate 4 as the connecting member is limited. As the structure of the shoe 5, there is a feature that the structure of the shoe described as the conventional technique can be used as it is.

According to the invention of claim 4, in addition to the matters of claim 3, a spherical recess 35 is formed in the piston tip, and a spherical portion 32 is formed in the shoe 5, and the spherical recess 32 is formed in the spherical recess. (3) is an axial piston fluid machine characterized by limiting the connection between the piston (6) and the shoe (5) by deforming the distal end of the spherical recess (35) in the axial diameter direction. .

In this invention, it is limited to the structure provided with the spherical part 32 in the shoe 5 side, and provided with the spherical recessed part 35 which accommodates the same spherical part 32 in the front-end | tip part of the piston 6. As the shoe 5 and the piston 6, the shoe and the piston described as the prior art can be used. However, the present invention is different from the conventional one in that the discharge portion is formed at the interference portion of the piston 6 and the shoe 5.

In the case where the spherical portion 32 is formed on the shoe 5 side, the discharge portion 18 is formed on the surface of the spherical portion 32 side of the mirror portion (body diameter portion) 31, The interference position with the distal end of the spherical recess 35 of the piston 6 connecting with the spherical portion 32 can be moved. At this time, the discharge portion 18 can be formed by forming an annular groove centered on the central axis of the mirror portion 31. Alternatively, the distal end portion of the spherical recessed part 35 formed on the piston 6 side is formed by cutting with a chamfer or the like along the circumferential direction to form a spherical recessed part on the discharge part 18 of the mirror part 31 and the piston 6 side ( It is possible to increase the swing angle of the shoe 5 by moving the position of the tip and the interference of 35) to prevent the interference (Fig. 5).

Or by forming an annular groove on the outer circumferential surface of the connection portion between the piston 6 body and the spherical portion 32, that is, by forming the discharge portion 18, the strength of the connection portion between the piston 6 body and the spherical portion 32. Is configured to remain.

The invention according to claim 5 is an axial piston fluid machine, characterized in that in addition to the matters described in any of claims 2 to 4, the discharge portion 18 defines a matter formed on the connection member side.

  In the present invention, the discharge portion 18 is formed on the interference portion on the side of the connecting member that interferes with the piston 6, and when the spherical portion 32 is formed on the side of the connecting member, the center line and the center line of the same spherical portion 32 are the same. In the case where the spherical recess 35 is formed to form the discharge portion 18 by accommodating the annular groove in the shape and to accommodate the spherical portion 32 formed in the piston 6 on the connecting member side. In the cutting portion circumferential surface of the front end portion of the concave concave portion 35 is chamfered to form the discharge portion 18 can be prevented from interference.

The invention according to claim 6 is an axial piston type fluid machine characterized by the fact that the discharge portion 18 is formed on the piston 6 side in addition to the matter of claim 1 in the present invention. In the case where there is (32), an interference portion between the piston 6 and the shoe 5 is formed by forming the discharge portion 18 at the tip of the spherical recess 35 on the side of the piston 6 connecting the copper spherical portion 32. Can be moved.

In addition, in the piston assembly in which the spherical portion 32 is formed on the piston 6 side as shown in FIG. 6, the discharge portion 18 may be formed on the outer peripheral surface of the connection portion from the piston 6 body to the spherical portion 32. At this time, by forming the discharge portion 18 on the outer periphery of the connecting portion, so as not to form the discharge portion 18 beyond the diameter to withstand the rotational movement during operation of the pump at the coupling portion of the connecting member and the piston (6). In the present invention, the discharge portion 18 can be formed by cutting the annular groove and the outer circumferential surface by chamfering or the like as described in claim 5.

Claims (6)

Axial piston. In axial piston pumps or motor fluid machines, In the rotational movement of the connecting member 2 which is connected to the piston 6 so as to be relatively rotatable, the discharge portion 18 is formed at the interference portion between the connecting member 2 and the piston 6, The connecting member 2 has a spherical portion 32, a spherical recess 35 is formed at the piston tip, a spherical portion 32 is accommodated in the spherical recess 35, and the tip end of the spherical recess 35 is reduced in diameter. Direction by connecting the piston 6 and the connecting member 2, The connecting member 2 is a shoe 5, The discharge | release part 18 becomes an annular groove of the cross-sectional shape in which the envelope formed in the front-end | tip part of the spherical recess 35 is accommodated, and is formed in the surface of the spherical part side of the copper part 31 of the shoe 5. Axial piston fluid machine, characterized in that. delete delete delete delete delete

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