JP2007255215A - Swash plate type hydraulic rotating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize contact surface pressure between a retainer and a retainer guide. <P>SOLUTION: An inner peripheral surface 11B of the retainer 11 is formed as a concave circular arc-shaped surface having a radius of curvature Rb larger than a radius Ra of an outer peripheral surface 12A of the retainer guide 12. The outer peripheral surface 12A of the retainer guide 12 is allowed to abut on an abutting part 11F positioned in the middle in the thickness direction among the inner peripheral surface 11B of the retainer 11. Thus, when the outer peripheral surface 12A of the retainer guide 12 is allowed to abut on the abutting part 11F of the retainer 11, a load acting on the retainer 11 from the retainer guide 12, can be set as a distribution load of forming a gentle mountain shape with an apex in the vicinity of the abutting part 11F of the retainer 11. As a result, a load sharing range in the inner peripheral surface 11B of the retainer 11 can be maximally widened, and the contact surface pressure can be minimized. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a swash plate type hydraulic rotating machine suitably used as, for example, a hydraulic motor or a hydraulic pump mounted on a construction machine or the like.

  In general, a swash plate type hydraulic rotating machine suitably used as a hydraulic motor and a hydraulic pump mounted on a construction machine such as a hydraulic excavator includes a hollow casing, a rotating shaft rotatably provided in the casing, A cylinder block that is provided in the casing so as to rotate integrally with the rotating shaft and is formed with a plurality of cylinders that are separated in the circumferential direction and extend in the axial direction, and is reciprocally inserted into each cylinder of the cylinder block. A plurality of pistons whose one end side in the axial direction protrudes from the cylinder, a shoe mounted on the protruding end of each piston, and each shoe on a surface facing the cylinder block and facing the cylinder block. Positioned between the swash plate on which the sliding surface is slid and each shoe and the projecting end of each piston, the shaft is inserted through the rotating shaft so that each shoe contacts the sliding surface of the swash plate. An annular retainer, and a retainer guide that is positioned between the retainer and the cylinder block and is inserted into the rotating shaft and presses the retainer toward the swash plate by the outer peripheral surface (for example, a patent) Reference 1).

Japanese Utility Model Publication No. 4-66377

  In this prior art swash plate type hydraulic rotating machine, the outer peripheral surface of the retainer guide is formed into a spherical shape, and the inner peripheral surface of the retainer is formed into a concave spherical shape or a tapered surface, thereby forming the outer peripheral surface of the retainer guide. The retainer guide is configured to press the retainer toward the swash plate in a state where the retainer is slidably brought into contact with the inner peripheral surface of the retainer.

  However, the swash plate type hydraulic rotating machine according to the above-described prior art, when the radius of the outer peripheral surface of the spherical retainer guide is different from the radius of curvature of the inner peripheral surface of the concave spherical retainer, The outer peripheral surface of the retainer comes into contact with the inner peripheral edge of the retainer. For this reason, the load from a retainer guide concentrates on the inner peripheral edge part of a retainer, and the contact surface pressure between both will become high. As a result, when the swash plate type hydraulic rotating machine is operated, there is a problem that the abutting portion between the retainer and the retainer guide is worn early, or the both are seized.

  In addition, if flash, dents, or the like during manufacture remain on the inner peripheral edge of the retainer, the slidability of the retainer guide with respect to the retainer is impaired. There is a problem that processing for removing traces or the like is required, and the number of processing steps of the retainer increases accordingly.

  The present invention has been made in view of the above-mentioned problems of the prior art, and provides a swash plate type hydraulic rotating machine capable of suppressing the contact surface pressure between the retainer and the retainer guide to be low and extending the life of the both. It is an object.

  In order to solve the above-described problems, the present invention provides a hollow casing, a rotating shaft that is rotatably provided in the casing, and a circumferentially spaced space provided in the casing so as to rotate integrally with the rotating shaft. A cylinder block formed with a plurality of cylinders extending in the axial direction, a plurality of pistons inserted into the cylinders of the cylinder block so as to reciprocate, and having one end side in the axial direction protruding from the cylinder, A shoe mounted on the projecting end of the piston, and a swash plate provided in the casing so as to face the cylinder block and having a sliding surface on which the shoe slides on a surface facing the cylinder block; An annular retainer positioned between each shoe and the projecting end of each piston, inserted through the rotary shaft and abutting each shoe against the sliding surface of the swash plate, The present invention is applied to a swash plate type hydraulic rotating machine including a retainer guide that is positioned between the retainer and the cylinder block and is inserted into the rotating shaft and presses the retainer toward the swash plate by an outer peripheral surface. .

  According to a first aspect of the present invention, the outer peripheral surface of the retainer guide is formed as a spherical surface having a radius Ra, and the inner peripheral surface of the retainer has a radius of curvature Rb larger than the radius Ra of the outer peripheral surface of the retainer guide. The concave guide is formed as a concave curved surface, and the outer peripheral surface of the retainer guide is in contact with a portion of the inner peripheral surface of the retainer excluding both end portions in the thickness direction.

  The invention according to claim 2 is that a contact portion between the inner peripheral surface of the retainer and the outer peripheral surface of the retainer guide is arranged in the middle in the thickness direction of the retainer.

  According to a third aspect of the present invention, the inner peripheral surface of the retainer is formed as a concave arc-shaped surface having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface of the retainer guide, and the center of the concave arc-shaped surface is the retainer The outer peripheral surface of the guide is set on a straight line connecting the abutting portion that contacts the inner peripheral surface of the retainer and the center of the outer peripheral surface of the retainer guide.

In the invention of claim 4, the radius of curvature Rb of the inner peripheral surface of the retainer is smaller than the radius Ra of the outer peripheral surface of the retainer guide.
1 <Rb / Ra <5
It is in the range that becomes.

  According to the first aspect of the present invention, the inner peripheral surface of the retainer with which the outer peripheral surface of the retainer guide abuts is a concave curved surface having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface of the retainer guide. The load sharing range on the peripheral surface can be increased as much as possible, and the contact surface pressure can be kept low. For this reason, it is possible to prevent the contact portion between the retainer and the retainer guide from being worn or seized during operation of the hydraulic rotating machine, and to improve the reliability of the hydraulic rotating machine.

  Further, by bringing the outer peripheral surface of the retainer guide into contact with the portion of the inner peripheral surface of the retainer excluding both end portions in the thickness direction, it is assumed that flashes, dents, etc. during manufacture remain at both end portions of the retainer. Even if it is, the slidability of the retainer is not impaired. For this reason, it is possible to eliminate the process of removing burrs, dents, and the like from the retainer, and it is possible to reduce the number of processing steps of the retainer, thereby contributing to a reduction in manufacturing cost.

  According to the invention of claim 2, by placing the contact portion between the inner peripheral surface of the retainer and the outer peripheral surface of the retainer guide in the middle in the thickness direction of the retainer, a load acting on the retainer from the retainer guide is obtained. It is possible to obtain a mountain-shaped distributed load widely distributed on the inner peripheral surface of the retainer with the intermediate portion in the thickness direction of the retainer as a maximum. Thereby, the load sharing range in the inner peripheral surface of the retainer can be increased, and the contact surface pressure can be kept low.

  According to the invention of claim 3, the inner peripheral surface of the retainer can be a uniform concave arc-shaped surface having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface of the retainer guide. As a result, even when the outer peripheral surface of the retainer guide comes into contact with any part of the inner peripheral surface of the retainer except for both end portions in the thickness direction, the load sharing range on the inner peripheral surface of the retainer is increased and contact is made. Surface pressure can be kept low.

  According to the invention of claim 4, the radius of curvature Rb of the inner peripheral surface of the retainer can be set to a value close to the radius Ra of the outer peripheral surface of the retainer guide having a spherical shape, so that the inner peripheral surface of the retainer is flat. Without approaching the surface, the load sharing range on the inner peripheral surface of the retainer can be increased as much as possible, and the contact surface pressure can be kept low.

  Hereinafter, an embodiment of the swash plate type hydraulic rotating machine according to the present invention will be described in detail with reference to FIGS. 1 to 11 by taking as an example a case where the embodiment is applied to a fixed capacity type swash plate type hydraulic motor.

  In the figure, reference numeral 1 denotes a hydraulic motor as a swash plate type hydraulic rotating machine. The hydraulic motor 1 is used as a rotation source of a traveling device, a turning device, etc. (none of which are shown) mounted on a hydraulic excavator, for example. It is. The hydraulic motor 1 includes a casing 2, a rotating shaft 3, a cylinder block 6, pistons 7, shoes 9, a swash plate 10, a retainer 11, a retainer guide 12, and the like, which will be described later.

  Reference numeral 2 denotes a hollow casing that forms the outer shell of the hydraulic motor 1, and the casing 2 is roughly composed of a casing body 2A formed in a bottomed cylindrical shape and a lid body 2B that covers the casing body 2A. It is configured. Here, the casing body 2A has a bottom portion 2C, and a shaft insertion hole 2D is provided at the center of the bottom portion 2C. On the other hand, a shaft housing hole 2E having a bottom and concentric with the shaft insertion hole 2D is provided at the center of the lid 2B.

  Reference numeral 3 denotes a rotating shaft that is rotatably provided in the casing 2, and one end side of the rotating shaft 3 is inserted into the shaft insertion hole 2D of the casing body 2A, and can be rotated by a bearing 4 provided in the shaft insertion hole 2D. It is supported by. Further, the other end side of the rotating shaft 3 extends into the shaft accommodating hole 2E of the lid 2B, and is rotatably supported by a bearing 5 provided in the shaft accommodating hole 2E. A shaft spline portion (male spline portion) 3A is provided at an intermediate portion in the axial direction of the rotary shaft 3, and a cylinder block 6 and a retainer guide 12 described later are inserted into the shaft spline portion 3A (spline connection). Has been.

  Reference numeral 6 denotes a cylinder block provided in the casing 2 so as to rotate integrally with the rotary shaft 3. The cylinder block 6 is formed in a stepped cylindrical shape as a whole, and the inner peripheral side thereof is a shaft spline of the rotary shaft 3. Splined to the part 3A. In the cylinder block 6, a plurality of cylinders 6A extending in the axial direction are formed apart from each other in the circumferential direction (only one is shown), and a piston 7 described later is inserted into each cylinder 6A. Yes.

  7, 7,... Are a plurality of pistons (only two are shown) fitted in the cylinders 6A of the cylinder block 6 so as to be reciprocally movable. It reciprocates within 6A. One end side of each piston 7 in the axial direction protrudes from the cylinder 6A, and a later-described shoe 9 is attached to the protruding end portion of the piston 7 protruding from the cylinder 6A.

  8 is a valve plate provided between the lid 2B of the casing 2 and the cylinder block 6. The valve plate 8 includes a pair of supply / discharge ports 8A (one side) intermittently communicating with each cylinder 6A of the cylinder block 6. Only shown). Each supply / discharge port 8A of the valve plate 8 communicates with a supply / discharge passage (not shown) provided in the lid 2B.

  .. Are shoes swingably attached to the protruding end portions of the respective pistons 7, and each shoe 9 is pressed against a sliding surface 10 </ b> A of a swash plate 10, which will be described later, by the piston 7. As the block 6 rotates, it slides on the sliding surface 10A so as to draw an annular locus.

  Reference numeral 10 denotes a swash plate provided in the casing 2 so as to face the cylinder block 6, and the swash plate 10 is formed between the bottom portion 2 </ b> C of the casing 2 and the cylinder block 6 with the rotary shaft 3 inserted through the center thereof. Arranged between. Here, on the surface of the swash plate 10 facing the cylinder block 6, a sliding surface 10A inclined with respect to the axis center of the rotating shaft 3 is formed, and each shoe 9 slides on the sliding surface 10A. It is the composition to do.

  Reference numeral 11 denotes a retainer that is positioned between each shoe 9 and the projecting end of each piston 7 and is inserted through the rotary shaft 3. The retainer 11 abuts each shoe 9 against the sliding surface 10 </ b> A of the swash plate 10. It is something to be made. Here, as shown in FIG. 2, the retainer 11 is formed of an annular plate as a whole, and a shaft insertion hole 11A is formed at the center thereof, and a retainer described later is formed on an inner peripheral surface 11B of the shaft insertion hole 11A. 12 A of outer peripheral surfaces of the guide 12 contact | abut. In addition, a plurality of shoe holding holes 11C, 11C,... Are provided around the shaft insertion hole 11A in the retainer 11 at a predetermined angular interval, and each shoe 9 is attached to the swash plate 10 by the shoe holding holes 11C. It is configured to be held in contact with the sliding surface 10A.

  Reference numeral 12 denotes a retainer guide that is positioned between the retainer 11 and the cylinder block 6 and is fitted to the rotary shaft 3. The retainer guide 12 has an outer peripheral surface 12 </ b> A that contacts the inner peripheral surface 11 </ b> B of the retainer 11. The retainer 11 is pressed toward the swash plate 10 by the outer peripheral surface 12A. Here, the inner peripheral side of the retainer guide 12 is spline-coupled to the shaft spline portion 3A of the rotary shaft 3 so as to be movable in the axial direction, and a plurality of springs 13 (see FIG. 1 is shown). The retainer guide 12 is configured to constantly press the retainer 11 toward the swash plate 10 by the spring force of the spring 13 while rotating integrally with the cylinder block 6.

  Here, as shown in FIGS. 3 and 4, when the axial center of the retainer guide 12 is O1-O1, the outer peripheral surface 12A of the retainer guide 12 is centered on a point P on the axial center O1-O1. It is formed as a spherical surface with a radius Ra. The outer peripheral surface 12A of the retainer guide 12 is a portion of the inner peripheral surface 11B of the retainer 11 excluding both end portions 11D and 11E in the thickness direction (axial direction), that is, the middle of the retainer 11 in the thickness direction (for example, It is configured to abut against the abutting portion 11F located at the substantially center in the thickness direction.

  On the other hand, the inner peripheral surface 11B of the retainer 11 is a concave arcuate surface (concave curved surface) having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface 12A of the retainer guide 12, as shown in FIGS. Is formed.

  That is, when the outer peripheral surface 12A of the retainer guide 12 contacts the inner peripheral surface 11B of the retainer 11 and the center P of the outer peripheral surface 12A of the retainer guide 12 is LL, this straight line A concave arcuate surface obtained by drawing an arc having a radius of curvature Rb larger than the radius Ra around the point Q on LL and rotating the arc of the radius of curvature Rb around the axis center O2-O2 of the retainer 11 is a retainer. 11 is an inner peripheral surface 11B.

  Thereby, the inner peripheral surface 11B of the retainer 11 can be formed as an aspherical concave arc-shaped surface having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface 12A of the retainer guide 12. The surface 12A can be brought into contact with a portion (contact portion 11F) of the inner peripheral surface 11B of the retainer 11 excluding both end portions 11D and 11E in the thickness direction.

  Here, the radius of curvature Rb of the inner peripheral surface 11B of the retainer 11 is set to a range within 5 times the radius Ra of the outer peripheral surface 12A of the retainer guide 12, as shown in the following equation (1).

  In this case, when the ratio (Rb / Ra) between the radius Ra of the outer peripheral surface 12A of the retainer guide 12 and the curvature radius Rb of the inner peripheral surface 11B of the retainer 11 is 5 or more, the inner peripheral surface 11B of the retainer 11 becomes a flat surface. The effect of forming the inner peripheral surface 11B as a concave arcuate surface is reduced.

  For this reason, it is preferable that the radius of curvature Rb of the inner peripheral surface 11B is set to a range within 1.5 times the radius Ra of the outer peripheral surface 12A of the retainer guide 12 as shown in the following formula 2.

  Thereby, the inner peripheral surface 11B of the retainer 11 can be formed as a concave arcuate surface having a curvature radius Rb close to the radius Ra of the outer peripheral surface 12A of the retainer guide 12. For this reason, when the outer peripheral surface 12A of the retainer guide 12 is brought into contact with the contact portion 11F of the retainer 11, the load acting on the retainer 11 from the retainer guide 12 is applied to the retainer 11 as shown in FIG. It is possible to obtain a distributed load F having a gentle mountain shape in the vicinity of the contact portion 11F, to increase the load sharing range on the inner peripheral surface 11B of the retainer 11 as much as possible, and to keep the contact surface pressure low. It can be configured.

  The hydraulic motor 1 according to the present embodiment has the above-described configuration. Pressure oil discharged from a hydraulic pump (not shown) passes through the supply / discharge port 8A of the valve plate 8 and the like in each cylinder 6A of the cylinder block 6. , The piston 7 inserted in the cylinder 6A extends toward the swash plate 10 side.

  Then, the shoe 9 provided at the protruding end of the piston 7 slides on the sliding surface 10A so as to draw an annular locus while pressing the sliding surface 10A of the swash plate 10, whereby the cylinder block 6 It is possible to rotate the rotating shaft 3 that is splined to the shaft.

  At this time, the retainer 11 holds each shoe 9 in contact with the sliding surface 10 </ b> A of the swash plate 10, and the inner peripheral surface 11 </ b> B of the retainer 11 has an outer periphery of the retainer guide 12 biased by the spring 13. The surface 12A always abuts.

  In this case, according to the present embodiment, as shown in FIGS. 3 and 4, the inner peripheral surface 11B of the retainer 11 has a concave circle having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface 12A of the retainer guide 12. The outer peripheral surface 12A of the retainer guide 12 is formed as an arcuate surface, and the portion of the inner peripheral surface 11B of the retainer 11 excluding both end portions 11D and 11E in the thickness direction, that is, the middle of the retainer 11 in the thickness direction (for example, It is configured to abut on the abutting portion 11F located at a substantially central position in the thickness direction.

  As a result, as shown in FIG. 4, the load acting on the retainer 11 from the retainer guide 12 is distributed in a mountain-shaped distribution load F widely distributed on the inner peripheral surface 11 </ b> B of the retainer 11 with the vicinity of both contact portions 11 </ b> F being the maximum. can do. For this reason, the load sharing range on the inner peripheral surface 11B of the retainer 11 can be made as wide as possible to keep the contact surface pressure low. As a result, it is possible to prevent the retainer 11 and the retainer guide 12 from being worn and seized during the operation of the hydraulic motor 1, extend the life of the retainer 11 and the retainer guide 12, and increase the reliability of the hydraulic motor 1. .

  Further, the outer peripheral surface 12A of the retainer guide 12 is brought into contact with the abutting portions 11F of the inner peripheral surface 11B of the retainer 11 except for the both end portions 11D and 11E in the thickness direction, so that both end portions 11D of the retainer 11 are temporarily provided. , 11E, even when a flash, a dent or the like remains during manufacture, the slidability of the retainer 11 is not impaired. For this reason, the process which removes from the retainer 11, removes a dent, etc. can be made unnecessary, and since the processing man-hour of the retainer 11 can be reduced correspondingly, it can also contribute to the reduction of manufacturing cost.

  Here, the retainer 11 according to the present embodiment shown in FIGS. 3 and 4, the retainer 21 according to Comparative Example 1 shown in FIGS. 5 and 6, the retainer 31 according to Comparative Example 2 shown in FIGS. 9 and comparison with the retainer 41 according to the comparative example 3 shown in FIG. 10 will be described.

  First, in the retainer 21 according to the comparative example 1 shown in FIGS. 5 and 6, the inner peripheral surface 21B of the shaft insertion hole 21A is a concave spherical surface having a radius of curvature Rb1 larger than the radius Ra of the outer peripheral surface 12A of the retainer guide 12. ing. For this reason, the outer peripheral surface 12A of the retainer guide 12 is in contact with one end portion 21C in the thickness direction of the inner peripheral surface 21B of the retainer 21.

  In this case, the load acting on the retainer 21 from the retainer guide 12 is a distributed load F1 having a half mountain shape with the vicinity of one end 21C of the retainer 21 being the maximum, as shown in FIG. For this reason, compared with the distributed load F (see FIG. 4) acting on the retainer 11 according to the present embodiment, the load sharing range on the inner peripheral surface 21B of the retainer 21 is reduced, and the contact surface pressure is increased accordingly. End up.

  As a result, the contact portion between the retainer guide 12 and the retainer 21 is likely to be worn and seized, and the life of the retainer guide 12 and the retainer 21 is reduced. Further, since the outer peripheral surface 12A of the retainer guide 12 abuts on one end portion 21C in the thickness direction of the inner peripheral surface 21B of the retainer 21, flashes, dents, and the like at the time of manufacture remain on the one end portion 21C. In that case, the slidability of the retainer 12 is impaired.

  Next, the retainer 31 according to the comparative example 2 shown in FIGS. 7 and 8 has a concave spherical surface in which the inner peripheral surface 31B of the shaft insertion hole 31A has a curvature radius Rb2 smaller than the radius Ra of the outer peripheral surface 12A of the retainer guide 12. It has become. For this reason, the outer peripheral surface 12A of the retainer guide 12 is in contact with the other end portion 31C in the thickness direction of the inner peripheral surface 31B of the retainer 31.

  In this case, the load acting on the retainer 31 from the retainer guide 12 is a concentrated load F2 having a spire shape with the vicinity of the other end 31C of the retainer 31 being maximum as shown in FIG. For this reason, compared with the distributed load F (see FIG. 4) acting on the retainer 11 according to the present embodiment, the load sharing range on the inner peripheral surface 31B of the retainer 31 becomes extremely small, and the contact surface pressure is locally reduced accordingly. It becomes expensive.

  As a result, the contact portion between the retainer guide 12 and the retainer 31 is more likely to be worn and seized, and the life of the retainer guide 12 and the retainer 31 is reduced. In addition, when a flash, a dent, or the like at the time of manufacture remains on the other end 31C in the thickness direction of the inner peripheral surface 31B of the retainer 31, the slidability of the retainer 31 is impaired.

  Next, in the retainer 41 according to the comparative example 3 shown in FIGS. 9 and 10, the inner peripheral surface 41B of the shaft insertion hole 41A is a tapered surface (flat surface). The outer peripheral surface 12A of the retainer guide 12 is in contact with the intermediate portion 41C in the thickness direction of the inner peripheral surface 41B of the retainer 41.

  In this case, since the outer peripheral surface 12A of the retainer guide 12 abuts on the inner peripheral surface 41B of the retainer 41 having a flat tapered surface, the load acting on the retainer 41 from the retainer guide 12 is as shown in FIG. Further, the distribution load F3 forms a steep mountain shape with the maximum near the intermediate portion 41C of the retainer 41. For this reason, compared to the distributed load F (see FIG. 4) acting on the retainer 11 according to the present embodiment, the load sharing range on the inner peripheral surface 41B of the retainer 41 is reduced, and the contact surface pressure is increased accordingly. End up. As a result, the contact portion between the retainer guide 12 and the retainer 41 is likely to be worn and seized, and the life of the retainer guide 12 and the retainer 41 is reduced.

  Thus, according to the present embodiment, the inner peripheral surface 11B of the retainer 11 is formed as a concave arcuate surface (concave curved surface) having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface 12A of the retainer guide 12. The outer peripheral surface 12A of the retainer guide 12 is brought into contact with a portion of the inner peripheral surface 11B of the retainer 11 excluding both end portions 11D and 11E in the thickness direction, that is, the contact portion 11F located in the middle in the thickness direction. It is configured.

  Further, the radius of curvature Rb of the inner peripheral surface 11B of the retainer 11 is in the range of 1 <Rb / Ra <5, preferably 1 <Rb / Ra <1.5, with respect to the radius Ra of the outer peripheral surface 12A of the retainer guide 12. The range is set to be set.

  As a result, the inner peripheral surface 11B of the retainer 11 can be curved with a curvature radius Rb close to the radius Ra of the outer peripheral surface 12A of the retainer guide 12, and the outer peripheral surface 12A of the retainer guide 12 becomes the contact portion 11F of the retainer 11. As shown in FIG. 4, the load acting on the retainer 11 from the retainer guide 12 is a distributed load F having a gentle mountain shape with the vicinity of the abutment portion 11 </ b> F of the retainer 11 being maximized. Can do.

  Therefore, compared with the retainer 21 according to the comparative example 1, the retainer 31 according to the comparative example 2, and the retainer 41 according to the comparative example 3, the load sharing range on the inner peripheral surface 11B of the retainer 11 can be widened as much as possible. Therefore, the contact surface pressure can be kept low. As a result, it is possible to prevent the retainer 11 and the retainer guide 12 from being worn and seized during the operation of the hydraulic motor 1, extend the life of the retainer 11 and the retainer guide 12, and improve the reliability of the hydraulic motor 1. .

  In the above-described embodiment, the case where the inner peripheral surface 11B of the retainer 11 is formed as a concave arcuate surface having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface 12A of the retainer guide 12 is illustrated. However, the present invention is not limited to this, and may be formed as a concave curved surface different from the concave circular arc surface using an arbitrary curve such as a multi-degree curve including a quadratic curve, a hyperbola, and an ellipse.

  Moreover, in embodiment mentioned above, the case where the internal peripheral surface 11B of the retainer 11 is formed as a uniformly continuous concave arcuate surface is illustrated. However, the present invention is not limited to this, and can also be applied to an inner peripheral surface 51B that is interrupted by the groove 51A, such as a retainer 51 according to another modification shown in FIG.

  Moreover, in embodiment mentioned above, the case where the substantially center of the thickness direction among the internal peripheral surfaces 11B of the retainer 11 is made into the contact part 11F with which 12 A of outer peripheral surfaces of the retainer guide 12 contact is illustrated. However, the present invention is not limited to this, and the contact portion 11F may be set at any portion of the inner peripheral surface 11B of the retainer 11 except for both end portions 11D and 11E in the thickness direction.

  In the above-described embodiment, the hydraulic motor 1 in which the rotating shaft 3, the cylinder block 6, and the retainer guide 12 are configured as separate members is described as an example. However, the present invention is not limited to this, and can be applied to, for example, a hydraulic rotating machine in which these three members are integrally formed, or a hydraulic rotating machine in which two of the three members are integrally formed.

  Moreover, in embodiment mentioned above, the spring 13 is provided between the cylinder block 6 and the retainer guide 12, and the case where the retainer guide 12 is pressed (pressurization) to the swash plate 10 side with this spring 13 is illustrated. . However, the present invention is not limited to this. For example, the retainer guide 12 may be pressed toward the swash plate 10 by using elastic deformation of other components without using the spring 13.

  In the embodiment described above, the fixed displacement hydraulic motor 1 is described as an example of the swash plate type hydraulic rotating machine. However, the present invention is not limited to this, and may be applied to, for example, a variable displacement hydraulic motor, and may be applied to a fixed displacement hydraulic pump and a variable displacement hydraulic pump.

1 is a cross-sectional view showing a hydraulic motor according to an embodiment of the present invention. It is a perspective view which shows a retainer alone. It is sectional drawing which shows the retainer and retainer guide in FIG. It is an expanded sectional view which shows the contact part of the retainer and retainer guide in FIG. It is sectional drawing which shows the retainer and retainer guide by the comparative example 1. It is an expanded sectional view which shows the contact part of the retainer and retainer guide in FIG. It is sectional drawing which shows the retainer by the comparative example 2, and a retainer guide. It is an expanded sectional view which shows the contact part of the retainer and retainer guide in FIG. It is sectional drawing which shows the retainer and retainer guide by the comparative example 3. FIG. 10 is an enlarged cross-sectional view illustrating a contact portion between the retainer and the retainer guide in FIG. 9. It is a perspective view which shows the modification of a retainer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic motor 2 Casing 3 Rotating shaft 6 Cylinder block 6A Cylinder 7 Piston 9 Shoe 10 Swash plate 10A Sliding surface 11,51 Retainer 11B, 51B Inner peripheral surface 11F Contact part 12 Retainer guide 12A Outer peripheral surface

Claims (4)

A hollow casing, a rotary shaft rotatably provided in the casing, and a plurality of cylinders provided in the casing so as to rotate integrally with the rotary shaft and spaced apart in the circumferential direction and extending in the axial direction A formed cylinder block; a plurality of pistons that are reciprocably inserted into the cylinders of the cylinder block and projecting from the cylinder at one end in the axial direction; and a shoe attached to the projecting end of each piston; A swash plate provided in the casing so as to face the cylinder block and having a sliding surface on which the shoe slides formed on a surface facing the cylinder block; and protruding ends of the shoes and the pistons Between the retainer and the cylinder block, and an annular retainer that is inserted between the rotating shafts and is inserted into the rotary shaft and abuts the shoes on the sliding surface of the swash plate. In the swash plate type hydraulic rotary machine comprising a retainer guide to press toward the swash plate the retainer by inserting to the outer circumferential surface to the rotation shaft located,
The outer peripheral surface of the retainer guide is formed as a spherical surface having a radius Ra, and the inner peripheral surface of the retainer is formed as a concave curved surface having a radius of curvature Rb larger than the radius Ra of the outer peripheral surface of the retainer guide. A swash plate type hydraulic rotating machine characterized in that an outer peripheral surface is in contact with a portion of the inner peripheral surface of the retainer excluding both end portions in the thickness direction.   2. The swash plate type hydraulic rotating machine according to claim 1, wherein a contact portion between the inner peripheral surface of the retainer and the outer peripheral surface of the retainer guide is arranged in the middle of the retainer in the thickness direction. An inner circumferential surface of the retainer is formed as a concave arcuate surface having a radius of curvature Rb larger than a radius Ra of the outer circumferential surface of the retainer guide;
The center of the concave arcuate surface is configured to be set on a straight line connecting a contact portion where an outer peripheral surface of the retainer guide contacts an inner peripheral surface of the retainer and a center of the outer peripheral surface of the retainer guide. A swash plate type hydraulic rotating machine according to 1 or 2. The radius of curvature Rb of the inner peripheral surface of the retainer is smaller than the radius Ra of the outer peripheral surface of the retainer guide.
1 <Rb / Ra <5
The swash plate type hydraulic rotating machine according to claim 1, 2 or 3, wherein the swash plate type hydraulic rotating machine is set within a range.

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