JP2019178658A - Fluid motor - Google Patents

Abstract

To effectively prevent the occurrences of a scratch and seizure between a peripheral edge part of a cylinder block and a timing plate in a fluid motor.SOLUTION: A timing plate 60 of a fluid motor 10 has notch grooves 62a, 62b connected to front side end parts hf1, hf2 so as to first face a cylinder chamber 41 due to rotation of a cylinder block 40 of one fluid port to be a high pressure side by being connected to a fluid pressure source to extend toward the other fluid port. In the timing plate, a part which is the same as at least a part of a point-symmetrical to an area with the notch grooves arranged in the peripheral edge part thereof centering on a rotation axis RA in a circumferential direction can be moved to an opposite side from the cylinder block in an axial direction AD.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluid motor.

  For example, as disclosed in Patent Document 1, a fluid motor that outputs rotation by being supplied with a fluid is known. The fluid motor disclosed in Patent Document 1 is configured as an axial piston type device. The axial piston type fluid motor includes a case, a rotatable cylinder block housed in the case, a piston slidably inserted into a cylinder chamber formed in the cylinder block, and a case and the cylinder block. And a timing plate attached to the case in an interposed state. The timing plate has a pair of fluid ports. One fluid port connects to a fluid pressure source and the other fluid port connects to a tank. A connection port that opens toward the timing plate and is connected to the cylinder chamber is formed in the cylinder block. The connection port is connected to the fluid port as the cylinder block rotates, and forms a flow path between the fluid pressure source or tank and the cylinder chamber.

  When the cylinder chamber communicates with the fluid pressure source, fluid is supplied into the cylinder chamber, and the piston advances in the axial direction from the cylinder block. Further, since the cylinder chamber communicates with the tank, the fluid can be discharged from the cylinder chamber, and the piston can be retracted in the axial direction. On the other hand, the protruding amount of the piston from the cylinder block is controlled according to the rotational position of the cylinder block. The fluid motor disclosed in Patent Document 1 is configured as a swash plate type. That is, a swash plate having an inclined surface inclined with respect to the axial direction is disposed so as to face the piston in the axial direction. Therefore, the piston driven by the fluid pressure acts on the slope of the swash plate, causing the cylinder block to rotate. As the cylinder block rotates, the piston moves forward or backward in the axial direction so that its head moves along the slope during rotation of the cylinder block.

  For the purpose of preventing sudden and large pressure fluctuations in the cylinder chamber, notch grooves extending along the movement path of the connection port are formed at both ends of each fluid port.

JP-A-9-287552

  However, in the case where such a fluid motor is used, in a circumferential region that is the same as a point-symmetric region with a specific notch groove around the rotation axis of the cylinder block, between the peripheral portion of the cylinder block and the timing plate. Scratches and burn-in may occur. The present invention has been made in consideration of such points, and an object thereof is to effectively prevent the occurrence of scratches and seizures between the peripheral edge of a cylinder block and a timing plate in a fluid motor.

A first fluid motor according to the present invention comprises:
Case and
A shaft member supported by the case so as to be rotatable about a rotation axis;
A cylinder block formed with a cylinder chamber and rotatable with the shaft member in the case;
A timing plate that is supported by the case and positioned between the case and the cylinder block, and is formed with a pair of fluid ports that connect to the cylinder chamber according to the rotation of the cylinder block;
A piston movably disposed in the cylinder chamber,
The timing plate is connected to a fluid pressure source through a fluid flow path formed in the case and faces the cylinder chamber first with the rotation of the cylinder block of one fluid port on the high pressure side. Has a notch groove connected to the front end that extends toward the other fluid port;
The timing plate has a peripheral portion in which the portion where the cutout groove is disposed and at least a part of a point-symmetrical region around the rotation axis are located at the same position in the circumferential direction. The case has a receiving portion that receives the portion when the portion of the timing plate is moved so that the portion can move to the opposite side of the cylinder block.

A second fluid motor according to the present invention comprises:
Case and
A shaft member supported by the case so as to be rotatable about a rotation axis;
A cylinder block formed with a cylinder chamber and rotatable with the shaft member in the case;
A timing plate that is supported by the case and positioned between the case and the cylinder block, and is formed with a pair of fluid ports that connect to the cylinder chamber according to the rotation of the cylinder block;
A piston movably disposed in the cylinder chamber,
The timing plate is connected to a fluid pressure source through a fluid flow path formed in the case and faces the cylinder chamber first with the rotation of the cylinder block of one fluid port on the high pressure side. Has a notch groove connected to the front end that extends toward the other fluid port;
The surface of the case that faces the timing plate is a position that is the same as the peripheral edge of the timing plate in the radial direction, and a region that is point-symmetric about the rotation axis and the region where the notch groove is disposed. A receiving portion spaced apart from the timing plate in the axial direction is provided at a position that is the same as at least a portion in the circumferential direction.

  In the first or second fluid motor according to the present invention, the surface of the case that faces the timing plate includes a support recess that houses the end of the shaft member, and a fluid passage that communicates with the support recess. The receiving portion may be formed by a part of the fluid passage.

  In the first or second fluid motor according to the present invention, the fluid passage may be widened at a portion forming the receiving portion.

  In the first or second fluid motor according to the present invention, the entire notch groove is positioned between two straight lines passing through each of the circumferential ends of the receiving portion and the rotation axis. May be.

A third fluid motor according to the present invention comprises:
The case formed with the first fluid channel and the second fluid channel;
A shaft member supported by the case so as to be rotatable about a rotation axis;
A cylinder chamber opened on one side in the axial direction parallel to the rotation axis and a connection port connected to the cylinder chamber and opened on the other side in the axial direction are formed and rotated together with the shaft member in the case Possible cylinder block,
A piston movably disposed in the cylinder chamber;
A timing plate supported by the case and positioned between the case and the cylinder block;
The timing plate opens on one side facing the one side in the axial direction and passes through the timing plate and communicates with the first fluid flow path, and opens on the one side and the timing. A second fluid port penetrating the plate and communicating with the second fluid flow path; a first notch groove formed on the one side surface and connected to an end of the first fluid port; and formed on the one side surface and the first fluid port. A second notch groove connected to the end of the two fluid port;
The connection port moves to a position facing the first fluid port, the second fluid port, the first notch groove, and the second notch groove from the axial direction as the cylinder block rotates, and Forming a flow path between the cylinder chamber and the first fluid flow path or the second fluid flow path;
The first fluid port and the second fluid port include a first reference position that overlaps the piston that has entered the cylinder chamber most in the axial direction, and a second reference position that overlaps the piston that protrudes most from the cylinder chamber in the axial direction. The first notch groove is connected to an end portion of the first fluid port on the side close to the first reference position, and is located on the opposite side across a straight line connecting the reference position and the second notch A groove is connected to an end of the second fluid port on the side close to the first reference position;
The surface of the case facing the timing plate is located at the same position as the periphery of the timing plate in the radial direction around the rotation axis, and the region where the first notch groove is disposed and the rotation The second notch groove is disposed at a position that is the same in the circumferential direction as at least a part of a point-symmetric region about the axis, and a position that is the same as the peripheral edge of the timing plate in the radial direction. A receiving portion spaced from the timing plate to the other side in the axial direction is provided at a position that is the same in the circumferential direction as at least a part of the region and a point-symmetrical region about the rotation axis.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent effectively that a damage | wound and a burning | scorching generate | occur | produce between the peripheral part of the cylinder block in a fluid motor, and a timing plate.

FIG. 1 is a longitudinal sectional view showing a fluid motor for explaining an embodiment of the present invention. FIG. 2 is a plan view showing one side surface of the timing plate. FIG. 3 is a plan view showing the case lid from one side in the axial direction.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that the elements shown in each drawing may include elements whose sizes and scales are different from those actually shown for easy understanding.

  The fluid motor 10 described below functions as an axial piston type device, and outputs rotation when supplied with fluid. The illustrated fluid motor 10 is configured as a swash plate type fluid motor. The fluid motor 10 can typically be used as a drive device in a traveling device included in a construction machine, but may be applied to other uses, and the use is not particularly limited.

  The fluid motor 10 illustrated as a swash plate type includes a case 20, a shaft member 30, a cylinder block 40, a piston 50, a timing plate 60, and a swash plate 70 as main components. Hereinafter, each component will be described.

  The case 20 includes a case main body 21 and a case lid body 22 fixed to the case main body 21. The case body 21 is generally formed in a cylindrical shape with one end closed and the other end opened. The case lid 22 is fixed to the case main body 21 using a fastener such as a bolt so as to close the opening of the case main body 21. The case 20 has an accommodation space S formed therein. In the accommodation space S, a cylinder block 40, a piston 50, a timing plate 60, and a swash plate 70 are arranged.

  The shaft member 30 is rotatably held by the case 20. A pair of bearings 31 are provided in the case 20. The shaft member 30 can be rotated by the bearing 31 with its central axis as the rotation axis RA. One end 30 a of the shaft member 30 passes through a through hole provided in the case 20 and extends out of the case 20. In a portion where the shaft member 30 penetrates the case 20, a seal member 32 is provided between the case 20 and the shaft member 30 to prevent a fluid such as lubricating oil from flowing out of the case 20. A portion 30a extending from the case 20 of the shaft member 30 is connected to an external device such as a speed reducer. That is, the shaft member 30 functions as an output element that outputs rotation.

  Hereinafter, a direction parallel to the rotation axis RA is referred to as an axial direction AD, a circumferential direction around the rotation axis RA is referred to as a circumferential direction CD, and a direction orthogonal to the rotation axis RA is referred to as a radial direction RD. . Further, the end 30a side of the shaft member 30 located outside the case 20 is called one side in the rotation axis RA, and the end side located in the case 20 of the shaft member 30 is the other side in the rotation axis RA. Call it.

  Next, the cylinder block 40 will be described. The cylinder block 40 has a columnar shape or a cylindrical shape arranged around the rotation axis RA. The cylinder block 40 is penetrated by the shaft member 30. The cylinder block 40 is fixed with respect to the shaft member 30. Therefore, the cylinder block 40 can rotate around the rotation axis RA in synchronization with the shaft member 30.

  A plurality of cylinder chambers 41 are formed in the cylinder block 40. The plurality of cylinder chambers 41 are arranged at equal intervals along the circumferential direction CD with the rotation axis RA as the center. Each cylinder chamber 41 is provided along the rotation axis, and is provided in the axial direction parallel to the rotation axis here. Each cylinder chamber 41 is open to one side in the axial direction AD. A connection port 42 is formed corresponding to each cylinder chamber 41. The connection port 42 opens the cylinder chamber 41 to the other side of the rotation axis RA.

  A piston 50 is provided corresponding to each cylinder chamber 41. A part of each piston 50 is disposed in the cylinder chamber 41. Each piston 50 extends from the corresponding cylinder chamber 41 to one side in the axial direction AD. The piston 50 can move in the axial direction with respect to the cylinder block 40. That is, the piston 50 can be advanced to one side in the axial direction AD to expand the volume of the cylinder chamber 41. Further, the piston 50 can be retracted to the other side in the axial direction AD to reduce the volume of the cylinder chamber 41.

  The swash plate 70 is held by the case 20. The swash plate 70 is disposed to face the cylinder block 40 and the piston 50 from one side in the axial direction AD. The shaft member 30 passes through the swash plate 70. The swash plate 70 has a slope 71 inclined with respect to a plane perpendicular to the axial direction AD. The inclined surface 71 faces the cylinder block 40 and the piston 50. A shoe 73 is provided on the slope 71 of the swash plate 70. The shoe 73 holds the head of the piston 50. As a specific configuration, the head that is one end of the piston 50 is formed in a spherical shape. The shoe 73 has a hole that can accommodate approximately half of the spherical head.

  The shoe 73 holding the head of the piston 50 can slide on the slope 71 of the swash plate 70. When fluid is supplied into the cylinder chamber 41, the piston 50 advances from the cylinder block 40 toward the swash plate 70 side. At this time, the cylinder block 40 holding the piston 50 rotates, and the piston 50 moves from the thick part 70a of the swash plate 70 to the thin part 70b. When the fluid is discharged from the cylinder chamber 41, the piston 50 moves backward into the cylinder block 40. At this time, the cylinder block 40 holding the piston 50 rotates, and the piston 50 moves from the thin portion 70b of the swash plate 70 to the thick portion 70a.

  The fluid motor 10 further includes a retainer plate 34 disposed in the case 20. The retainer plate 34 is a ring-shaped and plate-shaped member. The retainer plate 34 is penetrated by the shaft member 30 and supported on the shaft member 30. The portion 30b that supports the retainer plate 34 of the shaft member 30 is formed in a curved surface shape. For this reason, the direction of the retainer plate 34 can be changed while being supported on the shaft member 30. As shown in FIG. 1, the plate-like retainer plate 34 is inclined along the inclined surface 71 of the swash plate 70. The retainer plate 34 is in contact with all the shoes 73 from the other side in the axial direction AD.

  Further, an urging member 35 made of a spring or the like is provided between the shaft member 30 and the retainer plate 34. The retainer plate 34 is biased to one side in the axial direction AD by the biasing member 35. As a result, the retainer plate 34 can press the shoe 73 and the piston 50 toward the inclined surface 71 of the swash plate 70. Further, the urging member 35 urges the shaft member 30 together with the cylinder block 40 to the other side in the axial direction AD. As a result, the cylinder block 40 is pressed toward the timing plate 60.

  The timing plate 60 is located between the cylinder block 40 and the case 20 on the other side in the axial direction AD than the cylinder block 40. The cylinder block 40 is held by the case lid 22 through a fixture such as a pin so that it cannot rotate. The timing plate 60 is formed in a ring shape and a plate shape. The timing plate 60 has a through hole at the center thereof. The shaft member 30 passes through the timing plate 60 through the through hole. As described above, the cylinder block 40 is in contact with the timing plate 60 by the biasing member 35. Further, the timing plate 60 is in contact with the case lid 22 of the case 20. That is, one side surface 60 a facing one side of the timing plate 60 is in contact with the cylinder block 40, and the other side surface 60 b facing the other side of the timing plate 60 is in contact with the case lid body 22 of the case 20.

  Here, FIG. 2 shows the timing plate 60 from the side surface 60a. In FIG. 2, the first reference position p <b> 1 is a position that overlaps the piston 50 that has entered the cylinder chamber 41 most in the axial direction AD. In other words, the first reference position p1 is a position obtained by projecting the center position of the piston 50 located at the bottom dead center in the axial direction AD. On the other hand, in FIG. 2, the second reference position p <b> 2 is a position that overlaps in the axial direction AD with the piston 50 that protrudes most from the inside of the cylinder chamber 41 (the piston 50 located at the top dead center).

  As shown in FIG. 2, the timing plate 60 has a first fluid port 61a and a second fluid port 61b. The first fluid port 61a and the second fluid port 61b extend along an arc centered on the rotation axis RA. The first fluid port 61a and the second fluid port 61b form an opening extending in the circumferential direction CD on one side surface 60a. The first fluid port 61 a and the second fluid port 61 b penetrate the timing plate 60. The first fluid port 61a and the second fluid port 61b are provided in regions opposite to each other across the straight line vl connecting the first reference position p1 and the second reference position p2. In the example shown in FIG. 2, the first fluid port 61a and the second fluid port 61b have a point-symmetric configuration (arrangement and shape) about the rotation axis RA. As the cylinder block 40 rotates, the connection port 42 of the cylinder block 40 moves to a position facing the first fluid port 61a and the second fluid port 61b from the axial direction AD. Thus, a fluid flow path is formed between the cylinder chamber 41 and the first fluid flow path fp1 or the second fluid flow path fp2 via the first fluid port 61a or the second fluid port 61b.

  FIG. 3 shows the case lid 22 from one side in the axial direction AD. That is, the surface 24 of the case lid 22 that faces the timing plate 60 is shown. The case 20 has a first fluid channel fp1 and a second fluid channel fp2. The first fluid channel fp1 and the second fluid channel fp2 open to the case lid 22 in the example shown in FIG. The first fluid flow path fp1 of the case 20 is always connected to the first fluid port 61a of the timing plate 60. The second fluid flow path fp <b> 2 of the case 20 is always connected to the second fluid port 61 b of the timing plate 60. The first fluid channel fp1 is connected to one of a fluid pressure source such as a fluid pump and a tank, and the second fluid channel fp2 is connected to the other of the fluid pressure source such as a fluid pump and the tank. The connection between the first fluid channel fp1 and the second fluid channel fp2, the fluid pressure source and the tank can be switched via a switching valve (not shown). That is, one of the first fluid channel fp1 and the second fluid channel fp2 is connected to the fluid pressure source and becomes the high pressure (supply) side. Further, the other of the first fluid channel fp1 and the second fluid channel fp2 is connected to the tank and becomes the low pressure (discharge) side. Further, the switching valve can be neutral by blocking the first fluid channel fp1 and the second fluid channel fp2 from both the fluid pressure source and the tank.

  When the first fluid flow path fp1 is connected to the fluid pressure source and becomes the high pressure side, and the second fluid flow path fp2 is connected to the tank and becomes the low pressure side, it is located on one side of the straight line vl (the right side in FIG. 2). The cylinder chamber 41 to be connected is connected to the first fluid flow path fp1 via the connection port 42 and the first fluid port 61a, and is supplied with fluid. Accordingly, the piston 50 located on one side of the straight line vl in FIG. 2 advances from the cylinder block 40 to one side in the axial direction AD. At this time, the cylinder block 40 rotates in the direction of the arrow Ar in FIG. 2 so that the piston 50 moving forward moves toward the second reference position p2 that can protrude most from the cylinder block 40 in the circumferential direction CD. On the other hand, the piston 50 located on the other side of the straight line vl (left side in FIG. 2) moves toward the first reference position p1 in the circumferential direction CD as the cylinder block 40 rotates in the direction of the arrow Ar. At this time, the piston 50 moves backward toward the cylinder block 40, and therefore the fluid in the cylinder chamber 41 is discharged to the second fluid flow path fp2 via the connection port 42 and the second fluid port 61b.

  On the other hand, when the first fluid flow path fp1 is connected to the tank and becomes the low pressure side, and the second fluid flow path fp2 is connected to the fluid pressure source and becomes the high pressure side, the other side of the straight line vl (left side in FIG. 2). Fluid is supplied to the cylinder chamber 41 located at the position. As a result, the piston 50 located on the other side of the straight line vl advances from the cylinder block 40 to one side in the axial direction AD, and the cylinder block 40 rotates in the direction opposite to the arrow Ar in FIG.

  The fluid supplied and discharged between the fluid pressure source and the tank and the fluid motor 10 is not particularly limited, but can typically be oil. The oil functions as hydraulic oil for driving the piston 50 and also functions as lubricating oil for smoothing the operation of the cylinder block 40 and the piston 50.

  When the high pressure fluid is supplied to the first fluid flow path fp1, the first fluid port 61a becomes the high pressure side fluid port, and the cylinder block 40 rotates in the direction of the arrow Ar. As shown in FIG. 2, a first cutout groove 62 a connected to the rotation direction front end hf <b> 1 of the first fluid port 61 a in the case of the high pressure side is formed on one side surface 60 a of the timing plate 60. On the other hand, when the high-pressure fluid is supplied to the second fluid flow path fp2, the second fluid port 61b becomes a high-pressure side fluid port, and the cylinder block 40 rotates in the direction opposite to the arrow Ar. As shown in FIG. 2, a second cutout groove 62 b is formed on one side surface 60 a of the timing plate 60 to connect to the front end hf <b> 2 in the rotation direction of the second fluid port 61 b when it is on the high pressure side.

  Here, the front ends of the fluid ports 61a and 61b in the rotational direction are the connection ports 42 of the cylinder chambers 41 at both ends of the fluid ports 61a and 61b having the longitudinal direction as the cylinder block 40 rotates. It means the end of the side that comes to face and connect first. That is, the first notch groove 62a is connected to the end of the first fluid port 61a on the side close to the first reference position p1, and the second notch groove 62b is on the side close to the first reference position p1. It is connected to the end of the second fluid port 61b.

  The first notch groove 62a and the second notch groove 62b are disposed on the same circumference as the first fluid port 61a and the second fluid port 61b, and extend in the circumferential direction CD. For this reason, as the cylinder block 40 rotates, the connection port 42 moves to a position facing the first notch groove 62a and the second notch groove 62b. According to the first cutout groove 62a and the second cutout groove 62b, the connection port 42 of the cylinder chamber 41 overlaps with the high pressure side fluid ports 61a, 61b by the rotation of the cylinder block 40, and the cylinder is connected to the cylinder from the high pressure side fluid ports 61a, 61b. Immediately before a large amount of high-pressure fluid flows into the chamber 41, the high-pressure fluid flows into the cylinder chamber 41 through the notch grooves 62a and 62b while gradually increasing the flow rate. As a result, a sudden and significant pressure change in the cylinder chamber 41 accompanying the inflow of the high-pressure fluid is alleviated, and noise can be reduced.

  In the example shown in FIG. 2, the one side surface 60a of the timing plate 60 includes a fourth cutout groove 62d connected to the front end lf4 in the rotation direction of the second fluid port 61b when the pressure plate is on the low pressure side, and the low pressure side. In this case, a third cutout groove 62c connected to the rotation direction front end if3 of the first fluid port 61a is formed. The third notch groove 62c is connected to the end portion lf3 of the first fluid port 61a on the side close to the second reference position p2, and the fourth notch groove 62d is on the side close to the second reference position p2. It is connected to the end portion lf4 of the two-fluid port 61b. The third cutout groove 62c and the fourth cutout groove 62d are also arranged on the same circumference as the first fluid port 61a and the second fluid port 61b, and extend in the circumferential direction CD. Therefore, the connection port 42 moves to a position facing the third notch groove 62c and the fourth notch groove 62d.

  According to the third cutout groove 62c and the fourth cutout groove 62d, the connection port 42 of the cylinder chamber 41 is overlapped with the low pressure side fluid ports 61a, 61b by the rotation of the cylinder block 40 and is transferred to the low pressure side fluid ports 61a, 61b. Immediately before a large amount of fluid is discharged from the chamber 41, the fluid can be discharged from the cylinder chamber 41 through the cutout grooves 62c and 62d while gradually increasing the flow rate, thereby reducing noise. It becomes possible.

  In the example shown in FIG. 2, the width w of the fluid ports 61a and 61b, in other words, the length along the radial direction RD of the fluid ports 61a and 61b is constant along the circumferential direction CD. On the other hand, the widths of the cutout grooves 62a to 62d become narrower as they are separated from the ends of the corresponding fluid ports 61a and 61b. Thereby, the above-mentioned operation and effect expected in the notch grooves 62a to 62d can be more efficiently exhibited. In addition to the variation in the widths of the notch grooves 62a to 62d or in place of the variation in the widths of the notch grooves 62a to 62d, the depths of the notch grooves 62a to 62d are separated from the ends of the corresponding fluid ports 61a and 61b. You may make it shallow as you do. Also according to this example, it is possible to more efficiently exhibit the above-described operational effects expected for the notch grooves 62a to 62d.

  Next, the operation of the fluid motor 10 having the above configuration will be described.

  By operating a switching valve (not shown), the first fluid flow path fp1 and the first fluid port 61a are connected to the fluid pressure source to the high pressure side, and the second fluid flow path fp2 and the second fluid port 61b are connected to the tank. Assuming the low pressure side, as described above, the cylinder block 40 rotates in the direction of the arrow Ar in FIG. At this time, fluid is supplied to the cylinder chamber 41 located on one side of the straight line vl (the right side in FIG. 2), and the piston 50 advances from the cylinder chamber 41 to one side in the axial direction AD. The shoe 73 holding the head of the piston 50 slides on the inclined surface 71 as the cylinder block 40 rotates, moves in the circumferential direction CD, and moves toward the second reference position p2. The fluid is discharged from the cylinder chamber 41 located on the other side of the straight line vl (left side in FIG. 2), and the piston 50 moves back into the cylinder chamber 41 in the other direction in the axial direction AD. As the cylinder block 40 rotates, the shoe 73 that holds the head of the piston 50 slides on the inclined surface 71 and moves in the circumferential direction CD toward the first reference position p1. As described above, the cylinder block 40 rotates together with the shaft member 30, and a normal rotation is output from the fluid motor 10.

  Next, by operating a switching valve (not shown), the first fluid flow path fp1 and the first fluid port 61a are released from the connection to the fluid pressure source, and the second fluid flow path fp2 and the second fluid port 61b are connected to the tank. Disconnect from the connection. That is, the fluid motor 10 is in a neutral state, and the flow of fluid into and out of each cylinder chamber 41 is stopped. Thereby, rotation of the cylinder block 40 and the shaft member 30 stops, and the rotation output from the fluid motor 10 stops.

  Further, by operating a switching valve (not shown), the first fluid flow path fp1 and the first fluid port 61a are connected to the tank to the low pressure side, and the second fluid flow path fp2 and the second fluid port 61b are connected to the fluid pressure source. When the high pressure side is set, the cylinder block 40 rotates in the direction opposite to the arrow Ar in FIG. Thereby, the cylinder block 40 rotates with the shaft member 30, and reverse rotation is output from the fluid motor 10.

  By the way, the direction of rotation of the shaft member 30 may be suddenly reversed during use of the fluid motor 10. At this time, scratches or burn-in may occur at specific positions of the cylinder block 40 and the timing plate 60. The specific portions pa1 and pa2 where scratches and burn-in occur coincide with the peripheral portions of the cylinder block 40 and the timing plate 60 in the radial direction RD, and the rotation of the fluid ports 61a and 61b on the high-pressure side in the circumferential direction CD. Symmetrical region sz1, which is point-symmetric about the rotation axis RA and the notch grooves 62a, 62b connected to the front end in the direction (the end of the fluid ports 61a, 61b on the side close to the first reference position p1) hf1, hf2. It was consistent with sz2. In the illustrated example, a fourth cutout groove 62d is formed in a symmetric region sz1 that is point-symmetric about the first cutout groove 62a and the rotation axis RA, and the second cutout groove 62b and the rotation axis RA are connected to each other. A third notch groove 62c is formed in a symmetric region sz2 that is point-symmetric with respect to the center. Here, the region that is point-symmetrical about the notch groove and the rotation axis RA refers to a region where the notch groove is located when the notch groove is rotated by 180 ° about the rotation axis RA. ing.

  As a result of diligent examination on the occurrence of such a defect, it was estimated that the problem occurred due to the combination of the following two causes.

  First, it is considered that the lubricating film caused by the fluid disappears between the piston 50 and the cylinder block 40 as the first cause. The piston 50 is most drawn into the cylinder chamber 41 when the piston 50 is located at the first reference position p1 in the circumferential direction CD. The piston 50 is pulled out from the cylinder chamber 41 to one side in the axial direction AD by the retainer plate 34 while moving in the circumferential direction CD from the first reference position p1 toward the fluid ports 61a and 61b on the high pressure side. . However, the fluid is not supplied to the cylinder chamber 41 corresponding to the piston 50 until the piston 50 moves to a position facing the notch grooves 62a and 62b. Therefore, the lubricating film due to the fluid is cut between the piston 50 and the cylinder chamber 41. As a result, the frictional force between the piston 50 and the cylinder chamber 41 increases abruptly, and the portion of the cylinder block 40 near the notch grooves 62a and 62b is moved to one side in the axial direction AD by the operation of the piston 50. That is, it is pulled away from the timing plate 60. As a result, at the specific position described above, the cylinder block 40 and the timing plate 60 rotate relative to each other about the rotation axis RA while being pressed against each other in the axial direction AD. This is considered to be one cause of causing scratches and seizures in the cylinder block 40 and the timing plate 60 at the specific position described above.

  However, the force estimated as the first cause is also generated during the normal operation of the fluid motor 10. Then, if the fluid motor 10 is continuously operated, the problem of scratches and burn-in hardly occurs. This problem is caused by suddenly reversing the direction of rotation of the shaft member 30. Therefore, not only the force estimated as the first cause, but also the above-described problem occurs due to the combination of the action by this force and the action of the force generated by suddenly reversing the direction of rotation of the shaft member 30. It is estimated that

  When the operation of the fluid motor 10 is reversed, that is, when the fluid pressure source to the fluid flow paths fp1 and fp2 and the connection to the tank are switched, the fluid flow paths fp1 and fp2 and the fluid port which are on the high pressure side A large fluid pressure peak occurs at 61a and 61b. This fluid pressure presses the portion of the cylinder block 40 facing the fluid ports 61a and 61b and the notch grooves 62a to 62d toward one side in the axial direction AD, that is, toward the side away from the timing plate 60. To do. This pressing force is presumed to be the second cause.

  From the combination of the frictional force between the cylinder block 40 and the piston 50, which is considered to be the first cause, and the peak pressure of the fluid pressure circuit, which is considered to be the second cause, the rotational direction front side of the fluid ports 61a and 61b on the high pressure side The cylinder block 40 is separated from the timing plate 60 at a position where the notch grooves 62a and 62b connected to the end portions hf1 and hf2 are provided. As this reaction, it is considered that the timing plate 60 is pressed by the cylinder block 40 in the specific portions pa1 and pa2 described above, and the cylinder block 40 or the timing plate 60 is scratched or burned.

  Note that the same in the circumferential direction CD means that two positions or regions overlap in the radial direction RD, in other words, that they are positioned on the same straight line drawn from the rotation axis RA in the radial direction RD. means.

  For this problem, in the present embodiment, the notch grooves 62a and 62b connected to the rotation direction front ends hf1 and hf2 of the fluid ports 61a and 61b on the high pressure side in the peripheral portion of the timing plate 60 are provided. Parts pa1 and pa2 that are at the same position in the circumferential direction CD as at least a part of the symmetrical area sz1 and sz2 that are point-symmetrical with respect to the arranged area and the rotation axis RA are movable to the other side in the axial direction AD. Yes. For example, the timing plate 60 can be deformed such that a part pa1 and pa2 of the peripheral edge portion moves to the other side in the axial direction AD. That is, as described above, when the rotation of the shaft member 30 is suddenly reversed, the cylinder block 40 presses the timing plate 60 toward the case lid 22 in the specific portions pa1 and pa2. At this time, the specific portions pa <b> 1 and pa <b> 2 of the timing plate 60 are supported from the back by the surface 24 facing the timing plate 60 of the case lid 22 and are not restrained from being deformed. The timing plate 60 can be deformed with the pressing force from the cylinder block 40 at the specific portions pa1 and pa2. That is, the specific portions pa1 and pa2 can move to the side opposite to the timing plate 60, that is, the other side in the axial direction AD. Thereby, the generation | occurrence | production of the damage | wound and the burning | scorching in specific part pa1, pa2 resulting from the relative rotation while the cylinder block 40 and the timing plate 60 are pressed locally to the axial direction AD can be prevented effectively. .

  As shown in FIGS. 2 and 3, the case lid 22 has receiving portions 25 a and 25 b on the surface 24 facing the timing plate 60. The receiving portions 25a and 25b are separated from the timing plate 60 to the other side in the axial direction AD. The surface 24 of the case lid 22 that faces the timing plate 60 is pressed against the timing plate 60. Accordingly, the surface 24 includes a support portion 26 that contacts the timing plate 60 and supports the timing plate 60. The receiving portions 25a and 25b are formed as recessed portions with respect to the support portion 26, in other words, as portions positioned on the other side in the axial direction AD with respect to the support portion 26. As shown in FIG. 3, the first fluid flow path fp <b> 1 and the second fluid flow path fp <b> 2 are opened on the protruding portion forming the support portion 26. In FIG. 2, the receiving portions 25a and 25b and fluid passages 28a to 28d described later are indicated by dotted lines.

  When the timing plate 60 is deformed or the like and the specific portions pa1 and pa2 are shifted to the other side in the axial direction AD, the receiving portions 25a and 25b can receive the specific portions pa1 and pa2, in other words, can be received. Thereby, it is possible to stably and effectively prevent damage at the specific portions pa1 and pa2 due to the relative rotation of the cylinder block 40 and the timing plate 60 while being locally pressed in the axial direction AD. .

  In the illustrated example, the timing plate 60 includes a first specific portion pa1 corresponding to the first cutout groove 62a and a second specific portion pa2 corresponding to the second cutout groove 62b. Scratches and burn-in can easily occur at the specific portions pa1 and pa2. Therefore, the surface 24 of the case lid 22 that faces the timing plate 60 includes the first receiving portion 25a corresponding to the first specific portion pa1 and the second receiving portion 25b corresponding to the second specific portion pa2. It is included in the circumferential direction CD. According to such an example, the receiving portions 25a and 25b can be formed in a size as required, and a reduction in rigidity of the case lid 22 and the case 20 can be effectively suppressed.

  As shown in FIG. 3, the surface 24 of the case lid body 22 includes a support recess 27 that houses the ends of the bearing 31 and the shaft member 30, and fluid passages 28 a to 28 d that communicate with the support recess 27. . A plurality of, for example, four fluid passages 28a to 28 are provided. Each fluid passage 28a-28 extends in the radial direction RD. The first receiving portion 25a is formed by a portion of the first fluid passage 28a, and the second receiving portion 25b is formed by a portion of the second fluid passage 28b. According to such an example, the receiving portions 25a and 25b can be manufactured using, for example, a fluid passage for supplying lubricating oil. That is, it is not necessary to form a recess or the like on the surface 24 of the case lid 22 only for the purpose of forming the receiving portions 25a and 25b. Therefore, it is possible to effectively suppress a decrease in rigidity of the case lid 22 and the case 20. In addition, when the timing plate 60 moves or deforms, fluid flows out between the timing plate 60 and the cylinder block 40. Constituting the receiving portions 25a and 25b by a part of the fluid passages 28a and 28b is advantageous in that the leaked fluid can be flowed through the fluid passages 28a and 28b.

  Further, as shown in FIG. 3, the first fluid passage 28a is widened at a portion forming the first receiving portion 25a, and the second fluid passage 28b is widened at a portion forming the second receiving portion 25b. . According to such an example, the sufficiently large receiving portions 25a and 25b can be secured while using the fluid passages 28a and 28b. Thereby, generation | occurrence | production of a damage | wound and image sticking can be prevented effectively.

  Further, as shown in FIG. 2, in the observation in the axial direction AD or in the projection in the axial direction AD, two straight lines la1 passing through both ends of the circumferential direction CD of the first receiving portion 25a and the rotation axis RA. , La2 lies in the entirety of the first notch groove 62a. Further, in the observation in the axial direction AD or in the projection in the axial direction AD, between the two straight lines lb1 and lb2 that pass through each of the both ends of the circumferential direction CD of the second receiving portion 25b and the rotation axis RA line, The entire second notch groove 62b is located. Such regions where the receiving portions 25a and 25b are formed include all regions where the timing plate 60 tends to be damaged or burned in the circumferential direction CD. Thereby, generation | occurrence | production of a damage | wound and image sticking can be prevented further effectively.

  In the illustrated example, the first notch groove 62a and the fourth notch groove 62d have a point-symmetrical configuration (arrangement and shape) about the rotation axis RA, and the second notch groove 62b and the third notch groove The grooves 62c also have a point-symmetric configuration with respect to the rotation axis RA. Similarly, the first fluid passage 28a and the fourth fluid passage 28d have a point-symmetric configuration with respect to the rotation axis RA, and the second fluid passage 28b and the third fluid passage 28c also have the rotation axis RA as the center. They have a point-symmetric configuration. Therefore, the third fluid passage 28c has a widened first widened portion 25c, and the first widened portion 25c is point-symmetric with respect to the second receiving portion 25b and the rotation axis RA. The fourth fluid passage 28d has a widened second widened portion 25d, and the second widened portion 25d is point-symmetric with respect to the first receiving portion 25a and the rotation axis RA. By having such a symmetrical configuration, it is possible to effectively prevent the occurrence of local strength reduction.

  As mentioned above, although this invention was demonstrated based on embodiment shown in figure, this invention is not limited to these embodiment, In addition, it can implement in a various aspect. For example, in the above-described example, the example in which the fluid motor 10 is configured as a swash plate type has been described. However, the present invention is not limited thereto, and the fluid motor may be configured as an inclined shaft type.

10 fluid motor 20 case 24 surface 25a first receiving portion 25b second receiving portion 27 support recess 28a first fluid passage 28b second fluid passage 30 shaft member 40 cylinder block 41 cylinder chamber 50 piston 60 timing plate 61a first fluid port 61b Second fluid port 62a First notch groove 62b Second notch groove 64a First symmetry region 64b Second symmetry region hf1 Rotational direction front end hf2 Rotational direction front end p1 First reference position p2 Second reference position fp1 First fluid Channel fp2 second fluid channel

Claims (5)

Case and
A shaft member supported by the case so as to be rotatable about a rotation axis;
A cylinder block formed with a cylinder chamber and rotatable with the shaft member in the case;
A timing plate that is supported by the case and positioned between the case and the cylinder block, and is formed with a pair of fluid ports that connect to the cylinder chamber according to the rotation of the cylinder block;
A piston movably disposed in the cylinder chamber,
The timing plate is connected to a fluid pressure source through a fluid flow path formed in the case and faces the cylinder chamber first with the rotation of the cylinder block of one fluid port on the high pressure side. Has a notch groove connected to the front end that extends toward the other fluid port;
The timing plate has a peripheral portion in which the portion where the cutout groove is disposed and at least a part of a point-symmetrical region around the rotation axis are located at the same position in the circumferential direction. The fluid motor, wherein the case has a receiving portion that receives the portion when the portion of the timing plate is moved, so that the case can move to a side opposite to the cylinder block. Case and
A shaft member supported by the case so as to be rotatable about a rotation axis;
A cylinder block formed with a cylinder chamber and rotatable with the shaft member in the case;
A timing plate that is supported by the case and positioned between the case and the cylinder block, and is formed with a pair of fluid ports that connect to the cylinder chamber according to the rotation of the cylinder block;
A piston movably disposed in the cylinder chamber,
The timing plate is connected to a fluid pressure source through a fluid flow path formed in the case and faces the cylinder chamber first with the rotation of the cylinder block of one fluid port on the high pressure side. Has a notch groove connected to the front end that extends toward the other fluid port;
The surface of the case that faces the timing plate is a position that is the same as the peripheral edge of the timing plate in the radial direction, and a region that is point-symmetric about the rotation axis and the region where the notch groove is disposed. A fluid motor having a receiving portion that is spaced apart from the timing plate in the axial direction at a position that is at least partially the same in the circumferential direction. The surface of the case facing the timing plate has a support recess that houses an end of the shaft member, and a fluid passage that communicates with the support recess.
The fluid motor according to claim 1, wherein the receiving portion is formed by a part of the fluid passage.   The fluid motor according to claim 3, wherein the fluid passage is widened at a portion forming the receiving portion.   The fluid according to any one of claims 1 to 4, wherein the entire notch groove is located between two straight lines passing through each of the circumferential ends of the receiving portion and the rotation axis. motor.

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