WO2012077157A1

WO2012077157A1 - Skew plate-type hydraulic rotary machine

Info

Publication number: WO2012077157A1
Application number: PCT/JP2010/007103
Authority: WO
Inventors: 大野　猛; 鈴木　孝尚; 寿夫和田
Original assignee: 川崎重工業株式会社
Priority date: 2010-12-07
Filing date: 2010-12-07
Publication date: 2012-06-14
Also published as: EP2650538A1; CN103069161A; JPWO2012077157A1; KR20130030761A; US20130327208A1

Abstract

Provided is a skew plate-type rotary machine equipped with: a rotary shaft (3); a valve plate (4); a skew plate (15); a cylinder block (9) fitted onto rotary shaft (3) so as to be in sliding contact with the valve plate (4); cylinders (11) provided in the cylinder block (9); pistons (13) inserted in the axial direction (L) into the cylinders (11) so as to be capable of reciprocating movement; shoes (14) fitted onto the tips of the pistons (13); a circular pressing plate (17) that is provided between the skew plate (15) and the cylinder block (9) and supports the shoes (14); a bushing (80) that is inserted at the inner circumference of the pressing plate (17) and that supports the pressing plate (17) while pressing it toward the skew plate (15); and set springs (20) that bias the bushing (80) and the cylinder block (9) so as to repel in the axial direction (L). In addition, when assembled, the clearance in the axial direction (L) between the cylinder block (9) and the bushing (80) is 0 or minimal.

Description

Swash plate type hydraulic rotating machine

The present invention relates to a swash plate type hydraulic rotating machine suitable as, for example, a swash plate type hydraulic pump or a swash plate type hydraulic motor.

Conventionally, swash plate type hydraulic pumps and swash plate type hydraulic motors are known as swash plate type hydraulic rotating machines (see Patent Document 1). FIG. 8 shows a conventional swash plate type hydraulic pump. As shown in FIG. 8, a conventional swash plate type hydraulic pump 100 includes a cylindrical cylinder block 9 that is spline-fitted to the rotary shaft 3, a plurality of cylinders 11 formed in the cylinder block 9, and a cylinder 11. And a valve plate 4 with which one end of the cylinder block 9 is in contact, and a presser plate 17 and a swash plate 15 provided opposite to the other end of the cylinder block 9. ing. The tip of the piston 13 is a spherical portion 13 a that protrudes from the cylinder 11, and the spherical portion 13 a is spherically supported by a shoe 14 that is in sliding contact with the sliding contact surface 15 c of the swash plate 15. The shoe 14 is fitted in a shoe support hole 17 a provided in the presser plate 17 corresponding to the cylinder 11. The spherical bush 80 that supports the presser plate 17 is a cylindrical member that is spline-fitted to the rotary shaft 3, and is positioned between the cylinder block 9 and the swash plate 15. The outer peripheral surface of the spherical bush 80 gradually increases in diameter from the swash plate 15 side toward the valve plate 4 side, and the outer peripheral surface and the inner peripheral surface of the presser plate 17 are in contact with each other. A set spring 20 is provided between the spherical bush 80 and the cylinder block 9. Due to the spring force of the set spring 20 and the hydraulic pressure in each cylinder 11, the cylinder block 9 is pressed against and closely contacts the valve plate 4, and the shoe 14 is pressed against the sliding contact surface 15 c of the swash plate 15.

In the swash plate type hydraulic pump configured as described above, when the rotary shaft 3 rotates, the piston 13 reciprocates in the cylinder 11 along the inclination of the swash plate 15. The swash plate type hydraulic pump uses the movement of the piston 13 to suck a required amount of working fluid at a low pressure and discharge it to the high pressure side. In the swash plate type hydraulic motor, the rotation of the rotary shaft and the movement of the working fluid are opposite to those of the swash plate type hydraulic pump.

In the above-described conventional swash plate type hydraulic pump 100, the holding plate 17 pressed against the swash plate 15 side by the spring force of the set spring 20 and the hydraulic pressure in each cylinder 11 causes each shoe 14 to slide on the swash plate 15. It is in close contact with the contact surface 15c. However, when the rotating shaft 3 and the cylinder block 9 rotate at a high speed, the speed at which the piston 13 reciprocates within the cylinder 11 increases, and the force with which the piston 13 pulls the shoe 14 toward the valve plate 4 increases. When the hydraulic pressure in the cylinder 11 decreases due to low pressure operation or the like in this high speed rotation state, the force with which the shoe 14 presses the swash plate 15 depends on the spring force of the set spring 20, and the piston 13 causes the shoe 14 to move the valve plate 4. The force pulling toward the side exceeds the force pressing the shoe 14 by the set spring 20 and the hydraulic pressure. As a result, as shown in FIG. 9, the shoe 14 may float from the swash plate 15 or may fall (tilt). When the shoe 14 is lifted from the swash plate 15, the shoe 14 comes into contact with the sliding contact surface 15 c of the swash plate 15. When the shoe 14 in the one-sided state rotates while sliding on the swash plate 15, a torque cross is generated, and the pump efficiency is greatly reduced. In addition, the swash plate 15 and the shoe 14 may be unevenly worn or galling and seizure may occur due to the contact of the shoe 14, and the life of the shoe 14 and the swash plate 15 may be reduced.

In order to prevent the shoe from lifting up as described above, in the swash plate type hydraulic pump described in Patent Document 1, a taper is provided at the peripheral portion of the presser plate 17 pressing the shoe 14 against the swash plate 15. With this configuration, the presser plate 17 is prevented from being lifted by increasing the rigidity of the presser plate 17 and preventing the presser plate 17 from being deformed.

Further, in the axial plunger type hydraulic device described in Patent Document 2, the bearing surface that comes into contact with the swash plate of the shoe is made of an aluminum-silicon alloy that is lighter and more excellent in wear resistance than a copper alloy, thereby acting on the shoe. By reducing the centrifugal force, lifting of the shoe from the swash plate is prevented.

Japanese Patent Laid-Open No. 5-164038 JP 50-146907 A

As described in Patent Document 1, even if the press plate 17 is prevented from being deformed in the conventional swash plate hydraulic pump 100, if the set spring 20 is contracted, the press plate 17 moves to the valve plate 4 side. There is a possibility that the shoe 14 may be lifted from the swash plate 15. In order to prevent the shoe from lifting up as described above, it is conceivable to increase the spring force of the set spring 20 that presses the presser plate 17 toward the swash plate 15 side. However, the spring force of the set spring 20 is limited, and if the spring force increases, the frictional force between the shoe 14 and the swash plate 15 increases, which may reduce the efficiency or cause seizure. The rotation speed of the rotary shaft 3 cannot be greatly increased.

In addition, in the axial plunger type hydraulic device described in Patent Document 2, a frame is provided to hold the shoe in a state where it is in contact with the swash plate, not the presser plate, in order to fix the position of the shoe. Yes. In this configuration, when the hydraulic device is operated, a relative slip occurs between the frame of the swash plate and the shoe, so that it cannot withstand a significant increase in rotational speed.

Therefore, an object of the present invention is to provide a technique for preventing the shoe from lifting from the swash plate in a swash plate type hydraulic rotating machine such as a swash plate type hydraulic pump or a swash plate type hydraulic motor. As a result, it aims at providing the structure which can be equal to the further increase in the rotational speed of a swash plate type hydraulic rotating machine.

The swash plate type hydraulic rotating machine according to the present invention is in sliding contact with the valve plate between the rotary plate, the valve plate and the swash plate facing away from each other in the axial direction of the rotary shaft, and between the valve plate and the swash plate. A cylinder block externally fitted to the rotating shaft, a plurality of cylinders provided in the cylinder block, a plurality of pistons inserted into the cylinder so as to reciprocate in the axial direction, and the swash plate from the cylinder A plurality of shoes pivotably connected to the tip of the piston protruding to the side, and an annular presser plate that is loosely fitted to the rotary shaft between the swash plate and the cylinder block and holds the shoe And a bush that supports the presser plate, a bush that is provided between the bush and the cylinder block, and the bush that is provided between the presser plate and the cylinder block. The pressing plate and a spring member for urging the bush so as to press the swash plate side, gap between the axial direction of the bush and the cylinder block is one that is 0 or very small in the assembled state.

In the swash plate type hydraulic rotating machine, the size of the gap is preferably 0 or more than 0 and 1.2 mm or less.

Further, the swash plate type hydraulic rotating machine according to the present invention includes a rotating shaft, a valve plate and a swash plate facing away from each other in the axial direction of the rotating shaft, and the valve plate and the sliding plate between the valve plate and the swash plate. A cylinder block that is externally fitted to the rotating shaft so as to be in contact; a plurality of cylinders provided in the cylinder block; a plurality of pistons that are inserted into the cylinder so as to be capable of reciprocating in the axial direction; A plurality of shoes that are swingably connected to the tip of the piston that protrudes toward the swash plate, and an annular ring that is loosely fitted to the rotary shaft between the swash plate and the cylinder block and holds the shoe A presser plate, provided between the presser plate and the cylinder block, a bush for supporting the presser plate, and provided between the bush and the cylinder block. A spring member which shoe urges the bush so as to press the pressing plate to the swash-plate-side, but with a filling member to fill the axial clearances of the bush and the cylinder block.

The filling member may be one or more shim plates. Further, a time-curable or thermosetting filler may be provided between the filling member and any one of the bush and the cylinder block. Alternatively, the filling member may be a press-fitting bush.

According to the swash plate type hydraulic rotating machine configured as described above, since the gap between the cylinder block and the bush is zero or very small, movement of the bush toward the valve plate is restricted when the bush comes into contact with the cylinder block. . That is, the movement of the press plate that presses the shoe against the swash plate toward the valve plate is restricted. Therefore, for example, when the rotational speed of the rotary shaft increases and the moment of overturning the shoe caused by the inertial force or centrifugal force that pulls the piston toward the valve plate becomes greater than the spring force of the set spring, the shoe is inclined. Do not lift or fall over the board. As described above, in the swash plate type hydraulic rotating machine according to the present invention, the shoe is prevented from being lifted or overturned from the swash plate, so that the shoe slides on the swash plate in a state where it comes into contact with the swash plate. However, it is possible to prevent a decrease in operating efficiency, uneven wear of the swash plate and the shoe, galling and seizure due to rotation. Since the shoe does not lift from the swash plate even when the rotation speed of the rotation shaft is increased in this way, the rotation speed of the rotation shaft can be further increased in the swash plate type hydraulic rotating machine.

According to the present invention, even when the moment of inertia that pulls the piston toward the valve plate or the moment of overturning the shoe due to centrifugal force is greater than the spring force of the set spring, the bushing is pressed against the cylinder block. Since the movement of the plate toward the valve plate is restricted, it is possible to prevent the shoe from being lifted from the swash plate or falling down.

FIG. 1 is a longitudinal sectional view showing a schematic configuration of a swash plate type hydraulic pump according to an embodiment of the present invention. FIG. 2 is an enlarged view of a portion X surrounded by a two-dot chain line in FIG. FIG. 3 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing Example 1 of a spherical bush and a cylinder block provided with a gap in the axial direction. FIG. 4 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing Example 2 of a spherical bush and a cylinder block provided with a gap in the axial direction. FIG. 5 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing an example 2 of a spherical bush and a cylinder block in which an interval in the axial direction is filled. FIG. 6 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing an example 3 of a spherical bush and a cylinder block in which an interval in the axial direction is filled. FIG. 7 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing a fourth example of a spherical bush and a cylinder block in which an interval in the axial direction is filled. FIG. 8 is a longitudinal sectional view showing a schematic configuration of a conventional swash plate type hydraulic pump. FIG. 9 is a view showing a state of a shoe lifted from a swash plate in a conventional swash plate type hydraulic pump.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted. Here, a swash plate type hydraulic pump will be described as an example of the swash plate type hydraulic rotating machine.

First, a schematic configuration of a swash plate type hydraulic pump will be described with reference to FIG. The swash plate type hydraulic pump 10 has a rotating shaft 3 supported by a casing (not shown). The rotary shaft 3 is connected to a drive source (not shown) such as an engine. A thick cylindrical cylinder block 9 is fitted on the rotary shaft 3. Specifically, a spline provided on the outer periphery of the rotating shaft 3 and a spline 9 b provided on the inner periphery of the cylinder block 9 are engaged. Thereby, the cylinder block 9 rotates around the rotating shaft 3 as the rotating shaft 3 rotates.

A disc-shaped valve plate 4 fixed to the casing is provided on one side of the cylinder block 9 (in the right side of the drawing in FIG. 1). The valve plate 4 is in sliding contact with a valve plate sliding contact surface 97 which is one end surface of the cylinder block 9. A pair of intake /

exhaust ports

5 and 6 are formed in the valve plate 4, and these communicate with an intake / exhaust passage (not shown) formed in the casing. On the other side of the cylinder block 9 (on the left side in FIG. 1), an annular swash plate 15 through which the rotary shaft 3 passes is provided so as to face the valve plate 4. The swash plate 15 and the cylinder block 9 are separated from each other, and the surface of the swash plate 15 facing the cylinder block 9 is a slidable contact surface 9c on which a shoe 14 described later slides. The swash plate 15 is tilted from a direction perpendicular to the axial direction of the rotating shaft 3 (hereinafter simply referred to as the axial direction L), and is configured such that its maximum tilt angle can be changed by a tilting actuator (not shown). Hereinafter, for convenience of explanation, the swash plate 15 side along the axial direction L is referred to as “first side”, and the valve plate 4 side along the axial direction L is referred to as “second side”. The first side is the opposite side of the second side.

The cylinder block 9 is integrally provided with a guide portion 91 inserted into a spherical bush 80 described later and a main body portion 92 provided with a cylinder 11 into which the piston 13 is inserted. The main body 92 has a larger diameter than the guide 91, and the guide 91 protrudes from the main body 92 to the first side. For this reason, the cylinder block 9 has a two-stage end face facing the first side. The first step end surface is a first end surface 95 located on the first side of the guide portion 91, and the second step end surface is a second end surface 96 located on the first side of the main body portion 92. On the other hand, the cylinder block 9 has the above-described valve plate sliding contact surface 97 as an end surface facing the second side. In the main body 92 of the cylinder block 9, a plurality of cylinders 11 (only two are shown in FIG. 1) are formed concentrically around the rotation shaft 3. The cylinder 11 is a cylindrical space extending in the axial direction L, and opens toward the first side. Further, the cylinder block 9 is provided with a cylinder port 11a for communicating the inside of each cylinder 11 with the intake /

exhaust ports

5 and 6. A piston 13 is inserted into each cylinder 11 so as to reciprocate in the axial direction L within the cylinder 11. A spherical portion 13 a that protrudes from the cylinder block 9 to the first side is formed at the end portion on the first side of the piston 13. The spherical portion 13 a of the piston 13 is fitted into a spherical support portion 14 a formed on the second side of the shoe 14. As a result, the shoe 14 is swingably connected to the tip of the piston 13. The first side of the shoe 14 is in sliding contact with the sliding contact surface 15 c of the swash plate 15. Each shoe 14 rotates around the rotary shaft 3 while being in sliding contact with the sliding contact surface 15 c of the swash plate 15 by the rotation of the rotary shaft 3.

An annular pressing plate 17 is provided between the cylinder block 9 and the swash plate 15. A plurality of shoe support holes 17 a provided corresponding to the cylinders 11 are formed in the presser plate 17. The shoe 14 is fitted in the shoe support hole 17a. The outer periphery of the shoe 14 has a small-diameter portion 14c that can be fitted into the shoe support hole 17a, and a large-diameter portion 14d that is larger in diameter than the shoe support hole 17a on the first side of the small-diameter portion 14c. The step 14 between the small-diameter portion 14c and the large-diameter portion 14d of the shoe 14 comes into contact with the peripheral portion of the shoe support hole 17a toward the second side, so that the movement of the shoe 14 to the second side is restricted.

The pressing plate 17 is supported on the rotary shaft 3 through a spherical bush 80 so as to be swingable. The outer peripheral surface 81 of the spherical bush 80 gradually increases in diameter toward the second side and is formed with a smooth curved surface. A flange 82 is formed at the end of the outer peripheral surface 81 of the spherical bush 80 on the second side. The spherical bush 80 is inserted toward the first side on the inner periphery of the presser plate 17, and the outer peripheral surface 81 of the spherical bush 80 is in contact with the inner peripheral surface 17 b of the presser plate 17. Then, when the inner peripheral surface 17 b of the presser plate 17 slides on the outer peripheral surface 81 of the spherical bush 80, the presser plate 17 can swing around the rotation shaft 3. On the other hand, on the inner periphery of the spherical bush 80, a fitting portion 83 and a guide hole portion 84 are formed in order from the first side. A spline extending along the axial direction L is formed in the fitting portion 83 of the spherical bush 80, and this spline is fitted with a spline formed on the outer periphery of the rotary shaft 3. Thereby, the spherical bush 80 can rotate integrally with the rotary shaft 3 and move in the axial direction L. The guide hole portion 84 of the spherical bush 80 has an opening directed to the second side, and is formed in a hollow shape into which the guide portion 91 of the cylinder block 9 can be inserted toward the first side. In a state where the guide portion 91 of the cylinder block 9 is inserted into the guide hole portion 84 of the spherical bush 80, the outer periphery of the guide portion 91 of the cylinder block 9 and the inner periphery of the guide hole portion 84 of the spherical bush 80 are in contact. Thus, the spherical bush 80 can be moved in the axial direction L without being shaken by being guided by the guide portion 91 of the cylinder block 9.

A set spring 20 is provided between the spherical bush 80 and the cylinder block 9 to urge them so as to repel them in the axial direction L. Specifically, a plurality of spring accommodating holes 93 that open toward the first side are formed in the main body 92 of the cylinder block 9, and set springs 20 that are coil springs are fitted into the respective spring accommodating holes 93. Yes. The first side of the set spring 20 protrudes from the cylinder block 9 and abuts against the flange 82 of the spherical bush 80 at the protruding end. Due to the spring force of the set spring 20 and the hydraulic pressure in the cylinder 11, the valve plate sliding contact surface 97 of the cylinder block 9 is pressed against and closely contacts the valve plate 4. The presser plate 17 is pressed to the first side by the spherical bush 80 pressed to the first side by the spring force of the set spring 20 and the hydraulic pressure in the cylinder 11. The shoe 14 is pressed against the sliding contact surface 15 c of the swash plate 15 by the presser plate 17 pressed toward the first side.

Here, the operation of the swash plate type hydraulic pump 10 having the above-described configuration when one of the intake /

exhaust ports

5 and 6 is used as an intake port and the other intake / exhaust port 6 as a discharge port will be described. . First, when the rotary shaft 3 is rotationally driven by a drive device such as an engine, the cylinder block 9 rotates integrally with the rotary shaft 3, and the valve plate sliding contact surface 9 a of the cylinder block 9 slides with respect to the valve plate 4. Rotates while touching. Each shoe 14 held by the presser plate 17 rotates together with the cylinder block 9 and the piston 13 while making sliding contact with the sliding contact surface 15 c of the swash plate 15. As a result, each piston 13 reciprocates in the cylinder 11 with a stroke corresponding to the maximum tilt angle of the swash plate 15, and in the intake stroke in which each piston 13 pushes from the top dead center to the bottom dead center, In the discharge stroke in which the pressure oil is sucked into each cylinder 11 via the suction port 5 and moved back from the bottom dead center to the top dead center, the pressure oil sucked into each cylinder 11 is used as high pressure oil from the discharge port 6 to the suction / discharge passage. And discharge. When the maximum tilt angle of the swash plate 15 is adjusted by a tilt actuator (not shown), the stroke of each piston 13 is changed, whereby the discharge capacity discharged from each cylinder 11 can be variably controlled. .

The swash plate type hydraulic pump 10 is configured such that in the assembled state, the gap in the axial direction L between the cylinder block 9 and the spherical bush 80 is zero or very small. Here, “assembled state” means a state in which the swash plate type hydraulic pump 10 is assembled. However, the state in which the swash plate type hydraulic pump 10 is operating is not excluded, and the gap in the axial direction L between the cylinder block 9 and the spherical bush 80 may be 0 or very small in the operating state. . In the above, “the gap is 0” means that the spherical bush 80 and the cylinder block 9 are continuous in the axial direction L, and there is no gap between them. Therefore, when the gap in the axial direction L between the cylinder block 9 and the spherical bush 80 is 0, in addition to the state where the cylinder block 9 and the spherical bush 80 are in contact with the axial direction L, the cylinder block 9 and the spherical bush 80 are in contact with each other. A state in which the bush 80 has a gap G (gap) in the axial direction L and the gap G is filled with the filling member F is also included. If the gap between the spherical bush 80 and the cylinder block 9 in the axial direction L is 0, the spherical bush 80 is brought into direct or indirect contact with the cylinder block 9 so that the spherical bush 80 moves in the axial direction L toward the second side. It becomes impossible to move.

In the above, “the gap is very small” means that there is a minute gap ΔL in the axial direction L between the cylinder block 9 and the spherical bush 80. If there is a minute gap ΔL in the axial direction L between the spherical bush 80 and the cylinder block 9, the spherical bush 80 can move in the axial direction L to the second side by the size of the gap ΔL. However, the size of the gap ΔL is sufficiently small. The size of the gap ΔL is such that the amount of movement of the presser plate 17 to the second side accompanying the movement of the spherical bushing 80 to the second side is within a range in which the shoe 14 is not separated from the sliding contact surface 15 c of the swash plate 15. It is. Specifically, the size of the gap ΔL is greater than 0 and 1.2 mm or less, and more desirably greater than 0 and 0.8 mm or less. For reference, in a conventional general swash plate type hydraulic motor, the gap in the axial direction L between the cylinder block 9 and the spherical bush 80 is designed to be about 3 to 5 mm.

In the swash plate type hydraulic pump 10 shown in FIGS. 1 and 2, an axis line is formed between the first end surface 95 of the cylinder block 9 and the hole bottom 85 (second end surface) of the guide hole portion 84 of the spherical bush 80. An interval G in the direction L is provided. This gap G is filled with a filling member F. Therefore, the cylinder block 9 and the spherical bush 80 are continuous in the axial direction L with no gap, and the gap in the axial direction L is zero. The filling member F is one or more shim plates 30. The number and thickness of the shim plates 30 are appropriately selected according to the size of the gap G. Since the shim plate 30 is used as the filling member F, even if the size of the gap G varies due to dimensional errors of individual parts, if the number of shim plates 30 is increased or decreased during assembly, the cylinder block 9 The gap G in the axial direction L with the spherical bush 80 can be filled with high accuracy.

In the swash plate type hydraulic pump 10 having the above-described configuration, when the rotary shaft 3 rotates at a high speed in a state where the hydraulic pressure in the cylinder 11 is reduced due to low pressure operation or the like, a shoe by inertia force or centrifugal force that pulls the piston 13 toward the second side. In some cases, the moment to cause 14 to fall is greater than the spring force of the set spring 20. In this case, if the presser plate 17 is pulled by the piston 13 and moves to the second side, the pressing force of the shoe 14 against the swash plate 15 decreases and the shoe 14 falls over. On the other hand, in the swash plate type hydraulic pump 10 according to the present embodiment, the spherical bush 80 is directly or indirectly connected to the cylinder block 9 when a force is generated to move the presser plate 17 to the second side. The contact to the second side is restricted by contact, and the presser plate 17 is restricted to move to the second side by making contact with the spherical bush 80. Thus, in the swash plate type hydraulic pump 10 according to the present embodiment, the movement of the presser plate 17 to the second side is restricted. Therefore, even in the above case, the shoe 14 is attached to the swash plate 15. It does not float or fall over from the sliding contact surface 15c. Therefore, in the swash plate type hydraulic pump 10 according to the present embodiment, the pump 14 is reduced in efficiency due to the sliding rotation of the shoe 14 in a state where the shoe 14 comes into contact with the sliding contact surface 15c of the swash plate 15, the swash plate 15 or Occurrence of uneven wear, galling and seizure of each shoe 14 and the like is suppressed. In addition, in the swash plate type hydraulic pump 10 according to the present embodiment, the set spring 20 having the conventional spring force can be used, so that the friction force between the shoe 14 and the swash plate 15 increases due to the increase of the spring force. Therefore, there is no possibility that the efficiency is lowered or seizure occurs. Further, since the swash plate 15 of the swash plate 15 of the shoe 14 is lifted or falls, the number of parts to be added is small and the structure is simple. Further, when the gap G in the axial direction L is filled with the filling member F, the cylinder block 9 and the spherical bush 80 rotate synchronously, so the filling member F and the cylinder block 9 do not slide relatively, and the filling member F and spherical bush 80 do not slide relatively. Therefore, excessive friction does not occur between the cylinder block 9 and the filling member F, and between the spherical bush 80 and the filling member F, and the rotation speed of the swash plate hydraulic pump 10 can be further increased. .

The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims.

For example, in the swash plate type hydraulic pump 10 according to the above embodiment, the gap in the axial direction L between the cylinder block 9 and the spherical bush 80 is 0, but this gap may be minute. FIG. 3 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing an example of a spherical bush and a cylinder block provided with a gap in the axial direction. In the assembled state, the swash plate type hydraulic pump 10 shown in FIG. 3 is provided with a small gap ΔL in the axial direction L between the cylinder block 9 and the spherical bush 80. More specifically, the first end surface 95 of the cylinder block 9 and the hole bottom 85 of the guide hole 84 of the spherical bush 80 are separated in the axial direction L, and a gap ΔL in the axial direction L exists between them. is doing. The size of the gap ΔL is designed to be greater than 0 and 1.2 mm or less, and more desirably greater than 0 and 0.8 mm or less in the assembled swash plate type hydraulic pump 10.

The position of the gap ΔL in the axial direction L between the cylinder block 9 and the spherical bush 80 is not limited between the first end face 95 of the cylinder block 9 and the hole bottom 85 of the guide hole 84 of the spherical bush 80. FIG. 4 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing Example 2 of a spherical bush and a cylinder block provided with a gap in the axial direction. In the example shown in FIG. 4, the second end face 96 of the cylinder block 9 and the flange 82 of the spherical bush 80 are separated from each other in the axial direction L, and a minute gap ΔL in the axial direction L exists between them. . In this example, the set spring 20 includes a plurality of disc springs provided so as to repel between the hole bottom 85 of the guide hole 84 of the spherical bush 80 and the first end surface 95 of the cylinder block 9. It is.

Further, for example, in the swash plate hydraulic pump 10 according to the above embodiment, the filling member F is the shim plate 30, but the filling member F is not limited to the shim plate 30. FIG. 5 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing a second example of a spherical bush and a cylinder block in which an interval in the axial direction is filled. In the example shown in FIG. 5, a gap G in the axial direction L is provided between the first end surface 95 of the cylinder block 9 and the hole bottom 85 of the guide hole portion 84 of the spherical bush 80. This gap G is filled with a filling ring 31. As a result, the gap in the axial direction L between the cylinder block 9 and the spherical bush 80 is zero. The filling ring 31 is an annular filling member F. An annular groove-shaped accommodation portion 32 is formed in the hole bottom 85 of the guide hole portion 84 of the spherical bush 80, and a part on the first side of the filling ring 31 is embedded in the accommodation portion 32. The end surface on the second side of the filling ring 31 is in contact with the first end surface 95 of the cylinder block 9. When the swash plate type hydraulic pump 10 is assembled, the time-setting or thermosetting filler 33 is first injected into the accommodating portion 32 of the spherical bush 80, and then the filling ring 31 is moved to the first side. Fit it. And the filler 33 is hardened in the state which the filling ring 31 and the 1st end surface 95 of the cylinder block 9 contact | abutted. By providing the filler 33 between the spherical bush 80 and the filling ring 31 in this way, even if there is a variation in the size of the gap G due to a dimensional error of individual parts, the gap G and the filling ring 31 are used. Filling with the filler 33 can be performed with high accuracy. It is desirable that the filler 33 has an adhesive performance that fixes the filling ring 31 to the housing portion 32 of the spherical bush 80. Further, in the case where a high-strength adhesive is applied to the outer peripheral portion of the filling ring 31 and is adhered on the contact surface between the filling ring 31 and the spherical bush 80 via the adhesive, the filler 33 may be omitted.

Alternatively, a press-fit bush can be used as the filling member F. FIG. 6 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing Example 3 of a spherical bush and a cylinder block in which the axial distance is filled. In the example shown in FIG. 6, a gap G in the axial direction L is provided between the first end surface 95 of the cylinder block 9 and the hole bottom 85 of the guide hole portion 84 of the spherical bush 80. This gap G is filled with the press-fitting bush 41. As a result, the gap in the axial direction L between the cylinder block 9 and the spherical bush 80 is zero. The press-fitting bush 41 is a cylindrical filling member F. An annular groove-shaped press-fit portion 42 is formed in the hole bottom 85 of the guide hole portion 84 of the spherical bush 80, and the press-fit bush 41 is press-fitted into the press-fit portion 42 toward the first side. The press-fit bush 41 press-fitted into the press-fit portion 42 of the spherical bush 80 cannot be inserted and removed from the press-fit portion 42 due to friction. In the assembled swash plate type hydraulic pump 10, the second end surface of the press-fitting bush 41 is in contact with the first end surface 95 of the cylinder block 9. As described above, by using the press-fitting bush 41 as the filling member F, by adjusting the press-fitting condition of the press-fitting bush 41, the variation in the size of the gap G can be absorbed. Note that a high-strength adhesive may be applied to the outer periphery of the press-fit bush 41, and the press-fit bush 41 and the press-fit bush 41 may be bonded via this adhesive. In this case, the press-fitting bush 41 may be loosely fitted without being press-fitted.

Further, for example, in the swash plate type hydraulic pump 10 according to the above embodiment, the position of the gap in the axial direction L between the cylinder block 9 filled with the filling member F and the spherical bush 80 is the first end surface 95 of the cylinder block 9. And the hole bottom 85 of the guide hole portion 84 of the spherical bush 80. FIG. 7 is a partially enlarged view of a longitudinal sectional view of a swash plate type hydraulic pump showing a fourth example of a spherical bush and a cylinder block in which an interval in the axial direction is filled. In the example shown in FIG. 7, a gap G in the axial direction L is provided between the second end surface 96 where the spring accommodation hole 93 of the cylinder block 9 is opened and the flange 82 of the spherical bush 80. The gap G is filled with a filling column 35 that is a filling member F. As a result, the gap in the axial direction L between the spherical bush 80 and the cylinder block 9 is zero. Similar to the spring accommodation hole 93, the cylinder block 9 is provided with a plurality of filling member accommodation holes 98 that open toward the swash plate 15. A filling column 35 is inserted into the filling member accommodation hole 98. The filling column 35 protrudes from the filling member accommodation hole 98 of the cylinder block 9 to the first side, and the protruding first side end surface is in contact with the flange 82 of the spherical bush 80. When assembling the swash plate type hydraulic pump 10, the time-curable or thermosetting filler 36 is first injected into the filling member accommodation hole 98 of the cylinder block 9, and then the filling column 35 is fitted. . Then, the filler 36 is hardened in a state where the end surface on the first side of the filling column 35 is in contact with the flange 82 of the spherical bush 80. By providing the filler 36 between the cylinder block 9 and the filling column 35 in this way, even if there is a variation in the size of the gap G due to dimensional errors of individual parts, the gap G is used as the filling column. 35 and the filler 36 can be filled with high accuracy. It is desirable that the filler 36 has an adhesive performance that fixes the filling column 35 in the filling member accommodation hole 98 of the cylinder block 9. In this way, when a high-strength adhesive is applied to the outer peripheral portion of the filling column 35 and the filling column 35 and the cylinder block 9 are bonded via this adhesive, the filler 33 may be omitted.

In the examples shown in FIGS. 5, 6, and 7, the filling member F (filling ring 31, press-fit bush 41, filling column 35) is used to fill the gap G in the axial direction L between the cylinder block 9 and the spherical bush 80. However, these filling members F may be provided on either the cylinder block 9 or the spherical bush 80. In the above embodiment, a swash plate type hydraulic pump has been described as an example of the swash plate type hydraulic rotary machine. However, the swash plate type hydraulic rotary machine to which the present invention is applied is not limited to this. For example, the swash plate type hydraulic rotating machine may be a swash plate type hydraulic motor.

According to the present invention, in a swash plate type hydraulic rotating machine such as a swash plate type hydraulic pump or a swash plate type hydraulic motor, the lift of the shoe from the swash plate can be prevented even if the rotational speed of the rotary shaft is increased. The present invention can be widely applied to a swash plate type hydraulic rotating machine having a swash plate having a variable maximum tilt angle regardless of the detailed structure.

G interval F Filling member 3 Rotating shaft 4

Valve plate

5, 6 Intake / exhaust port 9 Cylinder block 11 Cylinder 13 Piston 14 Shoe 15 Swash plate 17 Presser plate 20 Set spring 30 Shim plate 31 Filling ring 32 Receiving part 33 Filler 35 Filling column 36 Filler 41 Press-fit bush 80 Spherical bush

Claims

A rotation axis;
A valve plate and a swash plate facing away from each other in the axial direction of the rotating shaft;
A cylinder block externally fitted to the rotary shaft so as to be in sliding contact with the valve plate between the valve plate and the swash plate;
A plurality of cylinders provided in the cylinder block;
A plurality of pistons inserted into the cylinder so as to reciprocate in the axial direction;
A plurality of shoes connected to the tip of the piston projecting from the cylinder toward the swash plate;
An annular press plate that is loosely fitted to the rotating shaft between the swash plate and the cylinder block and holds the shoe;
A bush provided between the presser plate and the cylinder block, and supporting the presser plate;
A spring member that is provided between the bush and the cylinder block and biases the bush so that the bush presses the presser plate toward the swash plate;
A swash plate type hydraulic rotating machine in which the axial gap between the bush and the cylinder block is 0 or very small in an assembled state.
The swash plate type hydraulic rotating machine according to claim 1, wherein the size of the gap is 0 or more than 0 and 1.2 mm or less.
A rotation axis;
A valve plate and a swash plate facing away from each other in the axial direction of the rotating shaft;
A cylinder block externally fitted to the rotary shaft so as to be in sliding contact with the valve plate between the valve plate and the swash plate;
A plurality of cylinders provided in the cylinder block;
A plurality of pistons inserted into the cylinder so as to reciprocate in the axial direction;
A plurality of shoes connected to the tip of the piston projecting from the cylinder toward the swash plate;
An annular press plate that is loosely fitted to the rotating shaft between the swash plate and the cylinder block and holds the shoe;
A bush provided between the presser plate and the cylinder block, and supporting the presser plate;
A spring member that is provided between the bush and the cylinder block and biases the bush so that the bush presses the presser plate toward the swash plate;
A swash plate type hydraulic rotating machine including a filling member that fills the gap between the bush and the cylinder block in the axial direction.
The swash plate type hydraulic rotating machine according to claim 3, wherein the filling member is one or more shim plates.
The swash plate type hydraulic rotating machine according to claim 3, further comprising a time curable or thermosetting filler between the filling member and any one of the bush and the cylinder block.
The swash plate type hydraulic rotating machine according to claim 3, wherein the filling member is a press-fitting bush.