Porting plate, cylinder block, hydraulic pump / motor

Abstract

Provided is a flow distribution disc that can avoid problems such as seizure between the flow distribution disc and the end surface of the cylinder even in high-pressure high-speed conditions. The flow distribution disc has discharge ports 52 and suction ports 51 on a circumference centered on the rotational axis 20C, and has an annular oil groove 54 provided in a loop shape and a plurality of radial oil grooves 55 from the annular oil groove 54 toward the outer periphery in a portion further outward than the discharge ports 52 and the suction ports 51. In an outer ring region 57 between the radial oil grooves 55 that abuts against the end surface 40a of the cylinder 40, a portion of the outer periphery of the discharge ports 52 on the downstream side of relative rotation is provided with a plurality of outer ring oil grooves 58 that communicate with the annular oil groove 54 and open toward the end surface 40a of the cylinder 40. The plurality of outer ring oil grooves 58 are provided so that the proportion of the opening area with respect to the end surface 40a of the cylinder 40 is greater on the downstream side of relative rotation than on the upstream side of relative rotation.

Description

Technical Field

[0001] The present invention relates to a hydraulic pump or motor, and a distributor plate and cylinder body suitable for the hydraulic pump or motor, wherein the hydraulic pump or motor includes a cylinder body that rotates while its end face abuts against the distributor plate. Background Technology

[0002] This type of hydraulic pump / motor has an annular oil groove and multiple radial oil grooves provided between the end faces of the distributor plate and the cylinder body. The annular oil groove is a ring-shaped groove without ends, located on the outer periphery of the high-pressure and low-pressure ports of the distributor plate. The radial oil grooves extend radially outward from the annular oil groove and are located at multiple points at equal intervals. In this hydraulic pump / motor, oil between the end faces of the distributor plate and the cylinder body is discharged into the interior of the housing via the annular oil groove and the radial oil grooves. Therefore, there is a risk that it is difficult to maintain an oil film between the end faces of the distributor plate and the cylinder body in the region on the outer periphery of the annular oil groove (hereinafter referred to as the outer ring region). To solve the above problem, inventions have been provided in the past that form an oil reservoir in the region on the outer periphery of the annular oil groove to achieve lubrication of the outer ring region (for example, see Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2010-116813 Summary of the Invention

[0004] On the other hand, there is a demand for high-pressure and high-speed hydraulic pumps and motors. Even with the aforementioned oil reservoir, it is difficult to maintain an oil film in the outer ring region after these high-pressure and high-speed hydraulic pumps and motors have been installed. This poses a risk of problems such as cylinder jamming or wear between the distributor plate and the cylinder block end face.

[0005] The present invention was made in view of the above-mentioned problems, and its object is to provide a distributor plate, cylinder block, hydraulic pump / motor that can avoid problems such as cylinder jamming or wear between the end faces of the distributor plate and the cylinder block even under high pressure and high speed conditions.

[0006] To achieve the above objectives, the distribution plate of the present invention is a distribution plate for a hydraulic pump or motor. It has a high-pressure side port and a low-pressure side port on a circumference centered on a rotation axis. In a portion of the distribution plate that is further outward from the high-pressure side port and the low-pressure side port, it has a first oil groove that is endless and a plurality of second oil grooves extending outward from the first oil groove. The distribution plate rotates relative to the rotation axis while abutting against the end face of the cylinder body, such that the high-pressure side port and the low-pressure side port alternately communicate with the cylinder bore of the cylinder body. In the outer ring region between the second oil grooves and abutting against the end face of the cylinder body, the outer periphery of the high-pressure side port, at least in the downstream side of the relative rotation, is provided with a plurality of outer ring oil grooves. The plurality of outer ring oil grooves communicate with the first oil groove and open toward the end face of the cylinder body. The plurality of outer ring oil grooves are configured such that the ratio of the opening area of ​​the plurality of outer ring oil grooves to the end face of the cylinder body is such that the downstream side of the relative rotation is larger than the upstream side of the relative rotation.

[0007] According to the present invention, oil from the first oil groove is supplied to the outer ring region via the outer ring oil groove. This ensures an oil film between the distributor plate and the cylinder end face even under high pressure and high speed conditions, preventing problems such as cylinder jamming or wear. Furthermore, the outer ring oil groove is configured such that the ratio of its opening area to the cylinder end face is such that the downstream side of the relative rotation, which is less accessible to oil from the second oil groove, is larger than the upstream side of the relative rotation, which is more easily accessible to oil from the second oil groove. In other words, the portion of the outer ring region on the upstream side of the relative rotation ensures a sliding state with the cylinder. Therefore, there is no risk of cylinder rotation becoming unstable due to the presence of the outer ring oil groove, enabling high pressure and high speed operation. Attached Figure Description

[0008] Figure 1A The hydraulic pump and motor of Embodiment 1 of the present invention are shown in a cross-sectional view with the plane containing the axis of rotation in the state where the high-pressure side region is located above.

[0009] Figure 1B The hydraulic pump / motor of Embodiment 1 of the present invention comprises a rotating shaft and is... Figure 1A A cross-sectional view taken from an orthogonal plane.

[0010] Figure 2A express Figure 1A and Figure 1B The structural elements of the hydraulic pump and motor shown are along... Figure 1B Arrow A in the diagram shows the end face of the cylinder block.

[0011] Figure 2B express Figure 1A and Figure 1BThe structural elements of the hydraulic pump and motor shown are end view diagrams showing the contact surface between the distributor plate and the cylinder body.

[0012] Figure 3A yes Figure 2B The enlarged view of the main part of the distribution plate shown is an enlarged view of approximately 1 / 4 of the section.

[0013] Figure 3B yes Figure 2B The enlarged view of the main part of the distribution plate shown is an enlarged view of the outer ring area and the outer ring oil groove.

[0014] Figure 4 This is an end view of the distribution plate in Modified Example 1.

[0015] Figure 5 yes Figure 4 An enlarged view of the main parts of the distribution plate shown.

[0016] Figure 6 This is an end view of the distribution plate in variant example 2.

[0017] Figure 7 yes Figure 6 An enlarged view of the main parts of the distribution plate shown.

[0018] Figure 8 It is a graph showing the relationship between the tilt angle of the outer ring oil groove and the amount of oil in the outer ring area, corresponding to the speed range of the cylinder block.

[0019] Figure 9 This is an end view of the distribution plate in variant example 3.

[0020] Figure 10 yes Figure 9 An enlarged view of the main parts of the distribution plate shown.

[0021] Figure 11 This is an end view of the distribution plate in variation example 4.

[0022] Figure 12 yes Figure 11 An enlarged view of the main parts of the distribution plate shown.

[0023] Figure 13A The structural elements of the hydraulic pump and motor according to Embodiment 2 of the present invention are shown in the end view of the cylinder body.

[0024] Figure 13B The structural elements of the hydraulic pump and motor according to Embodiment 2 of the present invention are shown in the end view of the contact surface between the distributor plate and the cylinder body.

[0025] Figure 14 yes Figure 13A The image shows an enlarged view of the main parts of the cylinder block.

[0026] Figure 15 This is an end view of the cylinder block in variant example 5.

[0027] Figure 16 yes Figure 15 The image shows an enlarged view of the main parts of the cylinder block. Detailed Implementation

[0028] Hereinafter, embodiments of the distributor plate, cylinder, hydraulic pump, and motor that conform to the present invention will be described in detail with reference to the accompanying drawings.

[0029] Implementation Method 1

[0030] Figure 1A and Figure 1B This describes a hydraulic pump / motor according to Embodiment 1 of the present invention. The hydraulic pump / motor in this example is an axial type that operates as a hydraulic pump when supplied with external power, and it has an input / output shaft 20 inside a housing 10. The housing 10 has a housing body 11 and a cylinder head 12, with a housing 13 formed between them. The input / output shaft 20 is a columnar member arranged transversely through the housing 13 of the housing 10, with one end rotatably supported on the housing body 11 and the other end rotatably supported on the cylinder head 12. One end of the input / output shaft 20 protrudes outward from the housing body 11 as an input end receiving power from a power source such as an engine. The other end of the input / output shaft 20 terminates inside the cylinder head 12. A swashplate 30 and a cylinder 40 are provided on the outer periphery of the portion of the input / output shaft 20 housed in the housing 13.

[0031] The swashplate 30 is a plate-shaped component with a flat sliding surface 31 on the side opposite to the cylinder head 12. It is disposed near the inner wall surface 11a of the housing body 11 with an opening 30a in the center through which the input / output shaft 20 passes. The swashplate 30 is supported on the inner wall surface 11a of the housing body 11 by two generally hemispherical spherical retainers 32, allowing the sliding surface 31 to be tilted relative to the input / output shaft 20. The symbol 33 in the figure is a servo device provided on the housing body 11. The servo device 33 is movable along the axis of the input / output shaft 20 and is a hydraulic cylinder that abuts against the swashplate 30 via the tilting member 34. When the servo device 33 is subjected to hydraulic pressure such as pilot pressure or self-discharge pressure and performs a telescoping action, the swashplate 30 moves along the spherical surface of the spherical retainer 32, thereby changing the tilt angle of the swashplate 30 relative to the axis of the input / output shaft 20.

[0032] The cylinder block 40 is a cylindrical component with a central hole 41, which is disposed between the cylinder head 12 and the swashplate 30 with the input / output shaft 20 passing through the central hole 41. A spline is provided between the central hole 41 of the cylinder block 40 and the outer circumferential surface of the input / output shaft 20 to allow the cylinder block 40 and the input / output shaft 20 to rotate integrally. Figure 1B Arrow A perspective, i.e. Figure 2A As shown, the hydraulic pump in this embodiment 1 is configured such that, when viewed from the cylinder head 12 side, the cylinder body 40 rotates clockwise around the rotation axis 20C of the input / output shaft 20. Figure 2B The symbol B in the diagram is rotated.

[0033] In this cylinder block 40, a plurality of cylinder bores 42 are formed on a circumference centered on the rotation axis 20C of the input / output shaft 20. The cylinder bores 42 are hollow cylinders arranged circumferentially at equal intervals and formed parallel to the rotation axis 20C of the input / output shaft 20. For example... Figure 2A As shown, in this embodiment 1, the cylinder body 40 is provided with nine cylinder bores 42. Each cylinder bore 42 is open on the end face opposite to the swashplate 30, and its end near the cylinder head 12 terminates in the interior of the cylinder body 40, and is open on the end face 40a of the cylinder body 40 via a connection port 43 with a reduced cross-sectional area.

[0034] like Figure 1A and Figure 1B As shown, pistons 44 are provided in the cylinder bores 42 of the cylinder block 40. Each piston 44 is a cylindrical object with a circular cross-section, and is fitted into the interior of the cylinder bore 42 in a axially movable state. Each piston 44 has a piston slide 45 at its end opposite to the swashplate 30. The piston slide 45 is configured to be tiltable relative to the piston 44 and to slide relative to the sliding surface 31 of the swashplate 30. Embodiment 1 shows a piston slide 45 having a spherical portion 45a and a sliding portion 45b, and is tiltably supported on the front end of each piston 44 via the spherical portion 45a. Alternatively, a spherical portion can be provided at the end of the piston 44 as a structure that allows the piston slide 45 to be tiltably supported on the piston 44.

[0035] Each piston slide 45 is pressed against the sliding surface 31 of the swashplate 30 via a pressing plate 46. The pressing plate 46 is a flat plate with an outer diameter approximately the same as that of the cylinder body 40, a pressing hole 46a in its center, and mounting holes 46b in portions corresponding to each piston 44. The mounting holes 46b are openings with an inner diameter that allows the ball portion 45a to pass through but prevents the sliding portion 45b from passing through. The pressing plate 46 is disposed between the cylinder body 40 and the swashplate 30 with the input / output shaft 20 passing through the pressing hole 46a and the piston slides 45 inserted through each mounting hole 46b.

[0036] The inner circumferential surface of the pressing hole 46a formed in the pressing plate 46 is spherical, and a retainer guide 47 is provided inside. The retainer guide 47 is hemispherical and has an outer diameter that can fit into the pressing hole 46a of the pressing plate 46. It is disposed between the pressing plate 46 and the cylinder 40 with its central portion penetrating through the input / output shaft 20 and its spherical portion abutting against the pressing hole 46a of the pressing plate 46. The retainer guide 47 is splined to the outer circumferential surface of the input / output shaft 20, so that the retainer guide 47 rotates integrally with the input / output shaft 20, and the retainer guide 47 can move along the rotation axis 20C of the input / output shaft 20. The pressing force of the pressing spring 48 built into the center of the cylinder 40 is always applied to the retainer guide 47 via the transmission rod 49. The pressing force of the pressing spring 48 applied to the retainer guide 47 is applied to the piston slide 45 via the pressing plate 46, thereby ensuring that the sliding part 45b of the piston slide 45 always abuts against the sliding surface 31 of the swashplate 30.

[0037] On the other hand, a distributor plate 50 is provided in the portion of the cylinder head 12 opposite to the connection port 43 of the cylinder block 40. For example... Figure 2B As shown, the distributor plate 50 is a circular plate-shaped component with an intake port 51 (low-pressure side port) and an outlet port 52 (high-pressure side port). The distributor plate 50 is slidably abutted against the end face 40a of the cylinder body 40, allowing the connection port 43 of the cylinder body 40 to alternately communicate with the intake port 51 and the outlet port 52. That is, the intake port 51 and the outlet port 52 are through holes located on the same circumference centered on the rotation axis 20C of the input / output shaft 20, and are respectively formed in an arc shape. In the example above, the intake port 51 is provided in the low-pressure side region 50A of the distributor plate 50 where the piston 44 moves from top dead center to bottom dead center, such that multiple connection ports 43 can be simultaneously connected. The outlet port 52 is provided in the high-pressure side region 50B where the piston 44 moves from bottom dead center to top dead center, such that multiple connection ports 43 can be simultaneously connected. A closed region 50C is ensured between the intake port 51 and the outlet port 52, which is used to close the connection port 43 of the cylinder bore 42 where the piston 44 is located at top dead center and bottom dead center. Figure 1B As shown, the intake port 51 communicates with the intake passage 12a formed in the cylinder head 12, thereby connecting to the fuel tank T via the intake passage 12a. The exhaust port 52 is connected to the exhaust passage 12b formed in the cylinder head 12. Figure 2B The symbol 53 in the figure represents a groove located at the bottom dead center side of the outlet 52. Furthermore, for ease of illustration, a dotted pattern is provided at the contact point between the cylinder block 40 and the distributor plate 50.

[0038] Furthermore, the distribution plate 50 is provided with an annular oil groove (first oil groove) 54 and a plurality of radial oil grooves (second oil grooves) 55. The annular oil groove 54 is an endless annular groove provided in the portion closer to the outer periphery of the inlet 51 and outlet 52. The annular oil groove 54 is, for example, formed with a cross-section of approximately a semi-circle of fixed radius, and opens only on the face opposite to the end face 40a of the cylinder body 40. The radial oil grooves 55 are straight grooves extending outward from the annular oil groove 54, and are formed at equal intervals in the circumferential direction. These radial oil grooves 55 are, for example, formed with a cross-section of approximately a semi-circle of fixed radius, open on the face opposite to the end face 40a of the cylinder body 40, and their outer peripheral ends open toward the outer peripheral surface of the distribution plate 50. In this embodiment 1, six radial oil grooves 55 are formed radially along a radius r direction centered on the rotation axis 20C in the portion closer to the outer periphery of the annular oil groove 54. In the illustrated example, three radial oil grooves 55 are provided symmetrically in the high-pressure side region 50B and the low-pressure side region 50A. The outermost portions of the radial oil grooves 55 are interconnected by the outermost peripheral grooves 56 extending in the circumferential direction.

[0039] Furthermore, such as Figure 2B and Figure 3A , Figure 3B As shown, in the distributor plate 50, an outer annular oil groove 58 is provided in the outer annular region 57, which is located on the outer periphery of the annular oil groove 54 and is formed between the radial oil grooves 55. The outer annular oil groove 58 is a straight groove with one end connected to the annular oil groove 54 and the other end closed. Multiple outer annular oil grooves 58 are formed only in the two outer annular regions 57 located on the outer periphery of the outlet 52. These outer annular oil grooves 58 are, for example, formed with a roughly semi-circular cross-section of a fixed radius and open on the surface opposite to the end face 40a of the cylinder block 40. The width of the outer annular oil groove 58 is smaller than that of the radial oil grooves 55, and it is located between approximately half the radial dimension from the annular oil groove 54 to the outer annular region 57. It can be clearly seen in the figure that the multiple outer annular oil grooves 58 are arranged at unequal intervals, gradually decreasing in size towards the downstream side when rotating relative to the cylinder block 40. Specifically, in Figure 3A In the example, for the outer ring region 57, outer ring oil grooves 58 are respectively arranged at five positions at a distance of α1 = approximately 18.1°, α2 = approximately 30.1°, α3 = approximately 39.6°, α4 = approximately 46.8°, and α5 = approximately 51.6° from the radial oil grooves 55 located on the relatively rotating upstream side. Therefore, the ratio of the opening area of ​​the outer ring oil grooves 58 relative to the end face 40a of the cylinder body 40 is such that the portion located on the downstream side is larger than the portion located on the upstream side when the cylinder body 40 rotates relative to it.

[0040] Furthermore, each outer annular oil groove 58 is inclined relative to a radius r centered on the rotation axis 20C. In the illustrated example, the outer annular oil groove 58 gradually inclines towards the upper flow side of the rotation, towards the outer periphery. The outer annular oil grooves 58 have the same inclination angle β relative to each other, set at approximately 30° relative to the radius r centered on the rotation axis 20C. Figure 3B It can be clearly seen that in the outer ring oil groove 58 that is inclined relative to the radius r, the length of the outer peripheral side 58a is greater than the length of the inner peripheral side 58b that is closer to the annular oil groove 54.

[0041] like Figures 1A to 3B As shown, when the hydraulic pump configured as described above rotates the input / output shaft 20 relative to the housing 10, the cylinder 40 rotates integrally with the input / output shaft 20, thereby causing the piston 44, which abuts against the sliding surface 31 of the swashplate 30 via the piston slide 45, to move relative to the cylinder bore 42 during its stroke. Thus, in the low-pressure region 50A, the piston 44 moves in a stroke such that it protrudes from the cylinder bore 42 of the cylinder 40 (in... Figure 1A (Moving to the left), oil from the oil tank T is drawn into the cylinder bore 42 via the intake passage 12a and the intake port 51 of the distributor plate 50. On the other hand, in the high-pressure side region 50B, the piston 44 moves by entering the cylinder bore 42 of the cylinder block 40 during its stroke (in... Figure 1A (Moving to the right), the oil in the cylinder bore 42 is discharged to hydraulic equipment such as hydraulic cylinders via the outlet 52 and discharge channel 12b of the distributor plate 50. If pilot pressure and discharge pressure from the outlet 52 are supplied to the servo device 33, the tilt angle of the swashplate 30 changes accordingly, and the stroke distance of the piston 44 that rotates with the cylinder 40 changes, and the flow rate of the oil discharged through the discharge channel 12b also changes.

[0042] Between the cylinder block 40 and the distributor plate 50, the end face 40a of the cylinder block 40 abuts against the distributor plate 50, thereby forming an endless annular oil passage 54A between the cylinder block 40 and the distributor plate 50 via annular oil grooves 54. Similarly, between the cylinder block 40 and the distributor plate 50, multiple radial oil passages 55A are formed between the cylinder block 40 and the distributor plate 50, opening from the endless annular oil passages 54A toward the receiving chamber 13 via radial oil grooves 55. Therefore, during the relative sliding of the end face 40a of the cylinder block 40 and the distributor plate 50, the oil leaking from the connection port 43 lubricates the area between the cylinder block 40 and the distributor plate 50, and is then discharged into the receiving chamber 13 via the endless annular oil passages 54A and radial oil passages 55A. In addition, some of the oil flowing through the radial oil passages 55A reaches the outer ring region 57 as the cylinder block 40 rotates, thereby lubricating the area between the cylinder block 40 and the distributor plate 50. Therefore, for the portion of the annular oil passage 54A located on the inner circumference side, and for the portion of the radial oil passage 55A in the outer annular region 57 located near the relatively rotating upstream side, the oil film can be adequately maintained even under high pressure and high speed conditions. Thus, there is no need to worry about problems such as cylinder jamming or wear due to insufficient oil.

[0043] In contrast, oil from the radial oil passage 55A has difficulty reaching the portion of the outer annular region 57 located on the relatively rotating downstream side. Particularly at the outer periphery of the high-pressure side outlet 52, there is a risk that even oil flowing solely from the radial oil passage 55A may not be sufficient to maintain an adequate oil film. However, in the aforementioned hydraulic pump, the portion of the outer annular region 57 located on the relatively rotating downstream side is provided with an outer annular oil groove 58. When the cylinder body 40 abuts against the distributor plate 50, this outer annular oil groove 58 forms an outer annular oil passage 58A that connects the endless annular oil passage 54A to the portion of the outer annular region 57 located on the relatively rotating downstream side. Thus, oil from the endless annular oil passage 54A is supplied to the portion of the outer annular region 57 located on the relatively rotating downstream side via the outer annular oil passage 58A. Therefore, even when the hydraulic pump is subjected to high pressure and high speed, there is no risk of oil shortage in the portion where the cylinder body 40 end face 40a and the distributor plate 50 slide relative to each other, thus eliminating concerns about cylinder jamming or wear. Furthermore, for the outer ring region 57 that abuts against the outer periphery of the cylinder body 40, an outer ring oil groove 58 is formed only on the outer periphery of the high-pressure side of the outlet 52. Further, the outer ring oil groove 58 is configured such that the ratio of its opening area relative to the cylinder body 40 end face 40a is such that the downstream side of the relative rotation is larger than the upstream side. Therefore, it is possible to ensure contact with the cylinder body 40 in the outer ring region 57 other than the outer periphery of the outlet 52, and in the portion of the outer ring region 57 located on the upstream side of the relative rotation. As a result, there is no risk that the rotation of the cylinder body 40 will become unstable due to the presence of the outer ring oil groove 58, thereby enabling the hydraulic pump to achieve high pressure and high speed.

[0044] Furthermore, in Embodiment 1 described above, the tilt angle of the swashplate 30 was shown to be changeable, but it is not necessarily required that the tilt angle of the swashplate 30 be changeable. Additionally, the case where the cylinder block 40 has nine cylinder bores 42 was shown, but the number of cylinder bores 42 is not limited to this. Furthermore, the case where six radially arranged oil grooves 55 in a straight line were shown was shown, but the shape and number of the radially arranged oil grooves 55 are not limited to those shown in Embodiment 1.

[0045] Furthermore, in Embodiment 1 described above, an outer ring oil groove 58 is also provided in the portion of the outer ring region 57 that is closer to the relatively rotating upstream side than the circumferential center position. However, the present invention is not limited to this. It is sufficient to provide an outer ring oil groove 58 only in the portion of the outer ring region 57 that is closer to the relatively rotating downstream side than the circumferential center position.

[0046] Furthermore, in Embodiment 1 described above, the outer annular oil groove 58 is inclined outwards towards the relatively rotating upstream side relative to the radius r direction centered on the rotation axis 20C. Therefore, in the outer annular oil groove 58, the length of the rotating outer peripheral side edge 58a is greater than the length of the inner peripheral side edge 58b. Thus, even when the cylinder block 40 rotates at a relatively low speed such as 1000 rpm, the amount of oil supplied from the portion of the outer peripheral side edge 58a in the outer annular oil passage 58A to the outer annular region 57 can be ensured, which is beneficial for lubrication. However, the extension direction of the outer annular oil groove 58 is not limited to this; it can also be provided along the radius r direction centered on the rotation axis 20C. Furthermore, when the outer annular oil groove 58 is inclined relative to the radius r direction centered on the rotation axis 20C, it can also be configured as follows: Figure 4 and Figure 5 The variation shown is Example 1 or Figure 6 and Figure 7 The variation shown is Example 2.

[0047] That is, in Figure 4 and Figure 5In the distribution plate 501 of Modified Example 1 shown, the outer annular oil groove 581 gradually slopes outwards towards the relatively rotating downstream side. The slope angle β1 of the outer annular oil groove 581 relative to the radius r direction centered on the rotation axis 20C is approximately 30° in the opposite direction to Embodiment 1. The spacing of the outer annular oil groove 581 is the same as in Embodiment 1. According to this Modified Example 1, the outer annular oil groove 581 gradually slopes outwards towards the relatively rotating downstream side relative to the radius r direction centered on the rotation axis 20C. Therefore, the edge of the outer annular oil groove 581 located on the relatively rotating downstream side is located on the inner circumferential side. Therefore, the oil supplied from the outer annular oil passage 58A to the inner circumferential side of the outer annular region 57 reaches the outer circumference in a roundabout way, making the path of the oil flowing through the outer annular region 57 longer. As a result, even when the cylinder block 40 rotates at a high speed exceeding 2300 rpm, the amount of oil supplied from the outer annular oil passage 58A to the outer annular region 57 can be ensured, which is beneficial to lubrication. Furthermore, the same symbols are used to mark the same structures as in Embodiment 1 in Modified Example 1. Additionally, similar to Embodiment 1, a dotted pattern is provided on the portion of the distributor plate 501 that abuts against the cylinder block 40.

[0048] exist Figure 6 and Figure 7 In the distribution plate 502 of Modified Example 2 shown, an upward-flowing outer ring oil groove 58 that gradually deviates towards the outer periphery and a downward-flowing outer ring oil groove 581 that gradually deviates towards the outer periphery and a relative rotation is alternately arranged. According to this Modified Example 2, lubrication can be improved in both the lower-speed rotation where Embodiment 1 is advantageous and the higher-speed rotation where Modified Example 1 is advantageous. Furthermore, the same symbols are used for structures in Modified Example 2 that are the same as those in Embodiment 1 and Modified Example 1. In addition, as in Embodiment 1, a dotted pattern is provided in the portion of the distribution plate 502 that abuts against the cylinder block 40.

[0049] Figure 8 This indicates the relationship between the tilt angle of the outer annular oil grooves 58 and 581, corresponding to the rotational speed range of the cylinder block 40, and the oil volume within the outer annular region 57. For the tilt angle, the radius r is 0° with respect to the rotational axis 20C. The case where the outer peripheral end tilts towards the relatively rotating upstream side, as in Embodiment 1, is designated as "-", and the case where the outer peripheral end tilts towards the relatively rotating downstream side, as in Modified Example 1, is designated as "+". Figure 8 As shown by the double-dotted line, when the cylinder block 40 rotates at a relatively low speed of around 1000 rpm, the outer ring oil grooves 58 and 581 are preferably inclined at an angle other than +5° to -10° relative to the radius r direction centered on the rotation axis 20C. On the other hand, as Figure 8As shown by the solid line or dashed line, when the cylinder block 40 rotates at relatively high speeds such as 2300 rpm (solid line) or 5400 rpm (dashed line), the outer ring oil grooves 58 and 581 are preferably inclined at an angle other than +5° to -25° relative to the radius r direction centered on the rotation axis 20C. That is, as shown by the solid line or dashed line, when the cylinder block 40 rotates at relatively high speeds such as 2300 rpm (solid line) or 5400 rpm (dashed line), the outer ring oil grooves 58 and 581 are preferably inclined relative to the radius r direction centered on the rotation axis 20C. Figure 8 As indicated by arrows X and Y, as the rotational speed of cylinder 40 increases, the position with the least oil volume in the outer ring region 57 tends to shift towards the "-" side of the tilt angle. Therefore, as a condition for ensuring that the outer ring oil grooves 58 and 581 tilt without interfering with each other, it is preferable to set the condition to be such that, when cylinder 40 rotates at a lower speed. Figure 8 The range is approximately -10° to the left. Furthermore, when the cylinder block 40 rotates at a relatively high speed, it is preferable to set the tilt angle of the outer ring oil grooves 58 and 581 to [value missing]. Figure 8 The range to the right of +5°.

[0050] Furthermore, in Embodiment 1, Modification 1, and Modification 2 described above, the outer peripheral ends of the outer annular oil grooves 58 and 581 are all closed. However, the present invention is not limited to this and can also be configured as follows. Figure 9 and Figure 10 The variation shown is Example 3 or Figure 11 and Figure 12 The variation shown is Example 4.

[0051] That is, in Figure 9 and Figure 10 In the distribution plate 503 of Modified Example 3 shown, similar to the radial oil grooves 55, the outer peripheral end of the outer annular oil groove 582 opens towards the outer peripheral surface of the distribution plate 503. The inclination angle β2 of the outer annular oil groove 582 relative to the radius r direction centered on the rotation axis 20C is approximately +30°. The spacing of the outer annular oil grooves 582 is the same as in Embodiment 1. According to this Modified Example 3, since the outer peripheral end of the outer annular oil groove 582 is formed as an opening, even when rotating at a low speed, the supply of oil from the annular oil groove 54 to the outer annular oil groove 582 can be promoted, which is beneficial to lubrication. In addition, the same reference numerals are used for the same structure as in Embodiment 1 in Modified Example 3. Furthermore, as in Embodiment 1, a dotted pattern is provided in the portion of the distribution plate 503 that abuts against the cylinder block 40.

[0052] exist Figure 11 and Figure 12In the distribution plate 504 of the modified example 4 shown, the outer peripheral end of the outer annular oil groove 583 opens towards the outer peripheral surface of the distribution plate 504, while the outer annular oil groove 583 is bent midway. The inclination angle of the outer annular oil groove 583 relative to the radius r direction centered on the rotation axis 20C is β3 = approximately +30° for the portion located on the inner peripheral side. The bending angle β4 between the inner peripheral side portion and the outer peripheral side portion is approximately 60°. The bending position of the outer annular oil groove 583 is approximately the same as the distance from the rotation axis 20C. The spacing of the outer annular oil groove 583 is the same as in embodiment 1. According to this modified example 4, since the outer peripheral end of the outer annular oil groove 583 is formed as an opening, even when rotating at a low speed, it is possible to promote the supply of oil from the annular oil groove 54 to the outer annular oil groove 583, which is beneficial to lubrication. Furthermore, since the inclination angle of the outer ring oil groove 583 changes opposite to the direction of the radius r centered on the rotation axis 20C midway, lubrication can be improved simultaneously in both low-speed and high-speed rotation driving situations. Additionally, the same symbols are used for the structures in Modification Example 4 that are the same as in Embodiment 1. Also, as in Embodiment 1, a dotted pattern is provided in the portion of the distributor plate 504 that abuts against the cylinder block 40.

[0053] Implementation Method 2

[0054] Figure 13A , Figure 13B and Figure 14 This diagram illustrates the cylinder body 401 and distributor plate 505 of a hydraulic pump / motor applicable to Embodiment 2 of the present invention. Similar to Embodiment 1, the cylinder body 401 and distributor plate 505 in this example are suitable for axial devices that operate as hydraulic pumps when supplied with external power. The cylinder body 401 and distributor plate 505 of Embodiment 2 differ from Embodiment 1 in that an annular oil groove (first oil groove) 411, a radial oil groove (second oil groove) 412, and an outer annular oil groove 413 are formed on the cylinder body 401. The differences from Embodiment 1 will be described below, while common structures will be labeled with the same symbols and detailed descriptions will be omitted. Furthermore, for ease of illustration, a dotted pattern is provided at the contact portion between the cylinder body 401 and the distributor plate 505.

[0055] like Figure 13B As shown, in embodiment 2, the distribution plate 505 is provided with an intake port 51, an outlet port 52 and a groove 53, and an outermost groove 56 is provided in the part located on the outermost periphery.

[0056] In contrast, such as Figure 13AAs shown, the cylinder block 401 is provided with an annular oil groove 411 and a plurality of radial oil grooves 412. The annular oil groove 411 is an endless annular groove provided in the portion of the cylinder block 42 near the outer periphery of the connection port 43. The annular oil groove 411 is, for example, formed with a cross-section of approximately a semi-circle with a fixed radius, and opens only on the face opposite to the end face 505a of the distributor plate 505. The radial oil grooves 412 are straight grooves extending from the annular oil groove 411 to the outer periphery, and are formed at equal intervals in the circumferential direction. These radial oil grooves 412 are, for example, formed with a cross-section of approximately a semi-circle with a fixed radius, open on the face opposite to the end face 505a of the distributor plate 505, and their outer peripheral ends open toward the outer peripheral surface of the cylinder block 401. In this embodiment 2, six radial oil grooves 412 are formed radially along a radius r direction centered on the rotation axis 20C in the portion of the cylinder block 411 near the outer periphery.

[0057] Additionally, in the cylinder block 401, an outer annular oil groove 413 is provided in the outer annular region 414, which is located on the outer periphery of the annular oil groove 411 and is formed between the radial oil grooves 412. The outer annular oil groove 413 is a straight groove with one end connected to the annular oil groove 411 and the other end closed; multiple outer annular oil grooves 413 are formed in all six outer annular regions 414. These outer annular oil grooves 413 are, for example, formed with a cross-section of approximately a semi-circle of fixed radius and open on the surface opposite to the end face 505a of the distributor plate 505. The width of the outer annular oil groove 413 is less than the width of the radial oil grooves 412. The length of the outer annular oil groove 413 is set to approximately half the radial dimension of the outer annular region 414 from the annular oil groove 411. As can be clearly seen in the figure, the multiple outer annular oil grooves 413 are arranged at unequal intervals, gradually decreasing in size as they rotate towards the downstream side of the cylinder block 401. Specifically, in Figure 13A In the example, for the outer ring region 414, outer ring oil grooves 413 are respectively arranged at five positions on the upper side of the radial oil grooves 412 when the distance relative to the distribution plate 505 is rotated: α1 = approximately 18.1°, α2 = approximately 30.1°, α3 = approximately 39.6°, α4 = approximately 46.8°, and α5 = approximately 51.6°. Therefore, the ratio of the opening area of ​​the outer ring oil grooves 413 relative to the end face 505a of the distribution plate 505 is such that the portion on the lower side is larger than the portion on the upper side when the cylinder block 401 rotates.

[0058] Furthermore, each outer annular oil groove 413 is inclined relative to the radius r direction centered on the rotation axis 20C. In the illustrated example, the outer annular oil groove 413 gradually inclines towards the outer periphery and towards the downstream side of the rotation. The inclination angle β6 of the outer annular oil grooves 413 is the same, set at approximately 30° relative to the radius r direction centered on the rotation axis 20C.

[0059] In the hydraulic pump configured as described above, the end face of the cylinder 401 abuts against the distribution plate 505, thereby forming an endless annular oil passage 411A between the cylinder 401 and the distribution plate 505 via an annular oil groove 411. Similarly, multiple radial oil passages 412A are formed between the cylinder 401 and the distribution plate 505 via radial oil grooves 412, opening from the endless annular oil passage 411A toward the receiving chamber 13. Therefore, during the rotation of the cylinder 401, the oil leaking from the connection port 43 lubricates the cylinder 401 and the distribution plate 505, and then is discharged to the receiving chamber 13 via the endless annular oil passage 411A and the radial oil passages 412A. In addition, some of the oil flowing through the radial oil passages 412A reaches the outer annular region 414 as the cylinder 401 rotates, thereby lubricating the cylinder 401 and the distribution plate 505. Therefore, by comparing the inner circumferential portion of the endless annular oil passage 411A and the radial oil passage 412A near the relatively rotating upstream side in the outer annular region 414, the oil film can be fully ensured, and there is no need to worry about problems such as cylinder jamming or wear due to lack of oil.

[0060] Conversely, because the oil from the radial oil passage 412A has difficulty reaching the portion of the outer annular region 414 located on the relatively rotating downstream side, it is difficult to ensure a sufficient oil film simply by the oil flowing through the radial oil passage 412A. However, in the hydraulic pump described above, the portion of the outer annular region 414 located on the relatively rotating downstream side is provided with an outer annular oil groove 413. When the cylinder body 401 abuts against the distributor plate 505, this outer annular oil groove 413 forms an outer annular oil passage 413A that connects the endless annular oil passage 411A with the portion of the outer annular region 414 located on the relatively rotating downstream side. Thus, the oil from the endless annular oil passage 411A is supplied to the portion of the outer annular region 414 located on the relatively rotating downstream side via the outer annular oil passage 413A. Therefore, even when the hydraulic pump is subjected to high pressure and high speed, there will be no oil shortage, and there is no need to worry about problems such as cylinder jamming or wear. Furthermore, for the outer ring region 414 that abuts against the outer periphery of the distribution plate 505, the outer ring oil groove 413 is configured such that the ratio of its opening area relative to the end face 505a of the distribution plate 505 is such that the downstream side, which rotates relatively, is larger than the upstream side. Therefore, the portion of the outer ring region 414 located on the upstream side, which rotates relatively, ensures contact with the distribution plate 505. As a result, the risk of instability in the rotation of the cylinder block 401 due to the presence of the outer ring oil groove 413 is eliminated, thereby enabling high-pressure, high-speed operation of the hydraulic pump.

[0061] Furthermore, in the above-described embodiment 2, an example is provided where the cylinder block 401 has nine cylinder bores 42 and six radial oil grooves 412 arranged in a straight line. However, the number of cylinder bores 42 and the shape and number of radial oil grooves 412 are not limited to those shown in embodiment 2.

[0062] Furthermore, in the above-described embodiment 2, an outer ring oil groove 413 is also provided in the portion of the outer ring region 414 that is closer to the relatively rotating upper flow side than the circumferential middle position. However, the present invention is not limited to this, and it is sufficient to provide an outer ring oil groove 413 only in the portion of the outer ring region 414 that is closer to the relatively rotating lower flow side than the circumferential middle position.

[0063] Furthermore, in the above-described embodiment 2, the outer annular oil groove 413 is inclined outwards and gradually towards the downstream side of the relative rotation relative to the rotational axis 20C in a radius r direction. However, the outer annular oil groove 413 may also be provided along the radius r direction centered on the rotational axis 20C. Alternatively, it may be as follows: Figure 15 and Figure 16 As shown in Modification 5, the cylinder block 402 is such that the outer annular oil groove 423 gradually slopes outwards and downwards relative to the radius r centered on the rotation axis 20C. The slope angle β7 of the outer annular oil groove 423 relative to the radius r centered on the rotation axis 20C is approximately 30° in the opposite direction to that of Embodiment 2. Furthermore, the same reference numerals are used to denote the same structures as in Embodiment 2 in Modification 5. In addition, as in Embodiment 2, a dotted pattern is provided in the portion of the cylinder block 402 that abuts against the distributor plate 505. Furthermore, the outer annular groove described in Modifications 2 to 4 of Embodiment 1 can also be applied to the cylinder block.

[0064] Furthermore, in the above-described embodiments 1, variations 1 to 4, embodiments 2 and 5, examples of using it as a hydraulic pump are shown, but it can also be used as a hydraulic motor.

[0065] Furthermore, in Embodiment 1, Modifications 1 to 4, Embodiment 2, and Modification 5 described above, the annular oil groove and the radial oil groove are all provided in the same component. However, as long as the radial oil groove and the outer annular oil groove are provided in the same component, the annular oil groove and the radial oil groove can also be provided in different components.

[0066] Furthermore, by arranging outer annular oil grooves of the same size at unequal intervals, the ratio of the opening areas of the outer annular oil grooves on the relatively rotating upstream and downstream sides is changed, but the invention is not limited to this. For example, by arranging multiple outer annular oil grooves with different opening widths or different extension lengths at equal intervals, the ratio of the opening areas of the outer annular oil grooves on the relatively rotating upstream and downstream sides can also be changed. In addition, when the multiple outer annular oil grooves are tilted relative to the radial direction centered on the axis of rotation, they can be tilted at the same angle, but the tilt angles of the multiple outer annular oil grooves can also be different from each other.

[0067] Symbol Explanation

[0068] 20C rotating shaft

[0069] 40, 401, 402 cylinder blocks

[0070] 40a cylinder block end face

[0071] 42-cylinder bore

[0072] Distribution panels 50, 501, 502, 503, 504, and 505

[0073] 51 suction port

[0074] 52 discharge outlets

[0075] 54, 411 Annular Oil Grooves

[0076] 55, 412 radial oil tanks

[0077] 57, 414 Outer Ring Area

[0078] 58, 413, 423, 581, 582, 583 outer ring oil grooves

[0079] 505a distributor plate end face

Claims

1. A distribution plate for a hydraulic pump or motor, having a high-pressure side port and a low-pressure side port on a circumference centered on a rotation axis, and having a first annular oil groove and a plurality of second oil grooves extending from the first oil groove outwards from the outer circumference of the high-pressure side port and the low-pressure side port, wherein the distribution plate rotates relative to the rotation axis while abutting against the end face of a cylinder body, such that the high-pressure side port and the low-pressure side port alternately communicate with the cylinder bore of the cylinder body, characterized in that... In the outer ring region between the second oil grooves and abutting the end face of the cylinder body, the outer periphery of the high-pressure side port, at least on the downstream side of relative rotation, is provided with a plurality of outer ring oil grooves. These multiple outer ring oil grooves communicate with the first oil grooves and open toward the end face of the cylinder body. The plurality of outer ring oil grooves are configured such that the ratio of the opening area of ​​the plurality of outer ring oil grooves relative to the end face of the cylinder body is such that the lower flow side of the relative rotation is larger than the upper flow side.

2. The distribution plate according to claim 1, characterized in that, The plurality of outer ring oil grooves extend in a straight line and are inclined relative to the radial direction centered on the rotation axis.

3. The distribution plate according to claim 2, characterized in that, The plurality of outer ring oil grooves are inclined in the same direction relative to the radial direction.

4. The distribution plate according to claim 1, characterized in that, The plurality of outer ring oil grooves are only provided in the portion of the outer ring region located on the downstream side of the relative rotation.

5. The distribution plate according to claim 1, characterized in that, The plurality of outer annular oil grooves have the same extension length from the first oil groove and the same opening width relative to the end face of the cylinder body, and the plurality of outer annular oil grooves are arranged at unequal intervals such that the intervals between them gradually decrease towards the downstream side of the relative rotation.

6. The distribution plate according to claim 1, characterized in that, The outer peripheral ends of the plurality of outer ring oil grooves are closed.

7. A cylinder body for a hydraulic pump or motor, having a plurality of cylinder bores around a rotating axis, and having an annular first oil groove and a plurality of second oil grooves extending from the first oil groove toward the outer periphery in the end faces of the openings of the plurality of cylinder bores, wherein the cylinder body is rotated relative to the distributor plate with its end faces abutting against it, such that the plurality of cylinder bores alternately communicate with a high-pressure side port and a low-pressure side port provided on the distributor plate, characterized in that... In the outer ring region between the second oil tanks and in contact with the distribution plate, at least the portion located on the downstream side of the relative rotation is provided with a plurality of outer ring oil tanks. These plurality of outer ring oil tanks communicate with the first oil tanks and open towards the distribution plate. The plurality of outer ring oil grooves are configured such that the ratio of the opening area of ​​the plurality of outer ring oil grooves to the opening area of ​​the distribution plate is such that the downstream side of the relative rotation is larger than the upstream side of the relative rotation.

8. The cylinder block according to claim 7, characterized in that, The plurality of outer ring oil grooves extend in a straight line and are inclined relative to the radial direction centered on the rotation axis.

9. The cylinder block according to claim 8, characterized in that, The plurality of outer ring oil grooves are inclined in the same direction relative to the radial direction.

10. The cylinder block according to claim 7, characterized in that, The plurality of outer ring oil grooves are only provided in the portion of the outer ring region located on the downstream side of the relative rotation.

11. The cylinder block according to claim 7, characterized in that, The plurality of outer annular oil grooves have the same extension length from the first oil groove and the same opening width relative to the end face of the distribution plate, and the plurality of outer annular oil grooves are arranged at unequal intervals such that the intervals between them gradually decrease towards the downstream side of the relative rotation.

12. The cylinder block according to claim 7, characterized in that, The outer peripheral ends of the plurality of outer ring oil grooves are closed.

13. A hydraulic pump / motor, characterized in that, The distribution plate is provided with any one of claims 1 to 6.

14. A hydraulic pump / motor, characterized in that, The cylinder block is provided with any one of claims 7 to 12.

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