JP6267598B2 - Hydraulic rotating machine - Google Patents

Description

  The present invention relates to a hydraulic rotating machine that can be implemented as a hydraulic motor or a hydraulic pump.

  An example of a valve plate provided in a conventional hydraulic motor is shown in FIG. 9 (see, for example, Patent Document 1). The valve plate 1 is formed with main ports 2 and 3. The main ports 2 and 3 are formed in an arc shape along a path of rotation of a cylinder port (not shown), and the radial opening width is formed with a constant dimension W4.

  Here, the high-pressure hydraulic oil in the cylinder port (piston chamber) closed by the valve plate 1 is leaking through the seal region between the valve plate 1 and the cylinder block. There is a need to reduce the amount.

JP-A-45-39126

  Therefore, in order to reduce the amount of leakage of hydraulic oil from the main port, it is conceivable to reduce the opening width W4 of the main ports 2 and 3, but in this way, the hydraulic oil passing through the main ports 2 and 3 is reduced. There is a problem that the pressure loss is increased and the mechanical efficiency of the hydraulic motor is lowered.

  The present invention has been made to solve the above-described problems, and reduces the amount of high-pressure hydraulic fluid that leaks from the first or second port through the seal region between the cylinder block and the valve plate. An object of the present invention is to provide a hydraulic rotating machine capable of suppressing an increase in pressure loss of hydraulic oil passing through the first and second ports.

  A hydraulic rotating machine according to the present invention is rotatably provided, a cylinder block in which a plurality of piston chambers are formed at intervals in the circumferential direction, and the piston chambers are movable in an extending direction and a shortening direction. Between the two ports, a plurality of pistons that are fitted and reciprocated in the extending direction and the shortening direction, a first port and a second port that are disposed in contact with the cylinder block and communicated with the piston chamber. A switching plate formed on the valve plate, and the valve plate includes at least one of the first and second ports, and a portion near the switching land, A narrow portion with a narrow opening width in the radial direction is formed, an auxiliary port is formed in the switching land of the valve plate, and the auxiliary port is more than one of the high-pressure side ports of the first and second ports. The piston chamber is connected to the auxiliary port when the piston chamber is kept at a low pressure and the piston chamber is not in communication with the first or second port on the high pressure side. .

  According to the hydraulic rotating machine according to the present invention, the portion of the first and second ports close to the switching land is formed as a narrow portion where the opening width in the radial direction of rotation of the cylinder block is narrowed. The narrow area can increase the seal area between the cylinder block and the valve plate. With the seal area corresponding to the increased seal area, the amount of leakage of high-pressure hydraulic fluid in the piston chamber from the first or second port can be reduced.

  Here, the flow rate of the hydraulic fluid passing through the portion of the first and second ports close to the switching land (the amount of change per unit rotation of the piston chamber volume) is the portion far from the switching land of the first and second ports. Since the flow rate of hydraulic fluid that passes through (change amount per unit rotation of piston chamber volume) is small, even if a narrow portion is formed in the above portion, pressure loss based on the flow of hydraulic fluid is reduced to the extent that the effect becomes clear. It is possible to prevent the increase. The reason why the flow rate of the hydraulic fluid passing through the portion closer to the switching land is small is that the moving speed of the piston in the expansion / contraction direction becomes slower as it approaches the switching land.

  Further, since the narrow portion is not formed in a portion far from the switching land of the first and second ports, the pressure loss based on the flow of the working fluid passing through the far portion other than the narrow portion does not increase.

  Further, when the piston chamber rotates and moves around the dead point and near the dead point in a state where the piston chamber is not in communication with the first or second port on the high pressure side, the high pressure hydraulic fluid in the piston chamber is supplied to the auxiliary port. Can be discharged from. That is, the contribution to the rotation of the cylinder block is small, and the pressure of the working fluid in the piston chamber near the dead point and the dead point where the resistance force of the rotation becomes significant can be lowered. Can be improved.

  In the hydraulic rotating machine according to the present invention, the narrow portion may be formed within an angle range of 45 ° or less in the circumferential direction with reference to the position of the dead center.

  By forming the narrow portion in this way, it is possible to effectively reduce the amount of high-pressure hydraulic fluid that leaks from the first or second port through the seal region between the cylinder block and the valve plate, An increase in pressure loss due to the flow of the hydraulic fluid in the narrow portion can be effectively suppressed. In other words, the moving speed in the expansion / contraction direction of the piston is expressed as follows: the rotation angle when the piston is at the dead center position is 0 °, and the rotation angle that the piston has moved with the rotation of the cylinder block is θ. The moving speed in the expansion / contraction direction of the piston can be obtained as a value that changes in a sine function with the horizontal axis as the rotation angle of the piston. The piston moving speed at an angular position where the rotational angle θ of the piston is 45 ° is about 70% of the maximum moving speed (the maximum moving speed is obtained when the piston is at an angular position of θ = 90 °). The flow rate of the hydraulic fluid based on the movement of the piston is also about 70% compared to the maximum flow rate. Therefore, the opening width in the radial direction of the narrow portion can be about 70% of the opening width other than the narrow portion of the first and second ports, and a seal region having an appropriate width can be formed. it can.

  In the hydraulic rotating machine according to the present invention, an opening facing the valve plate of the piston chamber may be formed as a cylinder port, and the narrowed portion may have a narrower opening width in the radial direction toward the dead center. .

  In this case, when the bridge portion between the cylinder ports is located in the narrow portion due to the rotation of the cylinder block, the circumferential seal width between the cylinder block and the valve plate is increased. It is possible to effectively suppress an increase in pressure loss based on the flow of the hydraulic fluid in the narrow portion while reducing the amount of high-pressure hydraulic fluid that leaks between the plates. That is, since the flow rate of the working fluid in the piston chamber decreases as the piston chamber moves toward the dead center (θ = 0 °) of the valve plate, the radial opening width of the narrow portion increases toward the dead point of the valve plate. By making it narrow, the above-described effects can be achieved.

  In the hydraulic rotating machine according to the present invention, an opening facing the valve plate of the piston chamber is formed as a cylinder port, and the cylinder port includes a base and a convex portion protruding outward or inward in the radial direction from the base. When the piston chamber communicates with the auxiliary port via the cylinder port, only the convex portion can be communicated with the auxiliary port. Before and after communicating with the auxiliary port via the cylinder port, the base portion may be formed with a seal portion having a predetermined seal width in the radial direction with respect to the auxiliary port.

  In this way, when the cylinder port rotates around the dead center and the vicinity of the dead center of the valve plate, the base portion of the cylinder port is positioned with a seal portion having a predetermined seal width in the radial direction with respect to the auxiliary port. Can do. As a result, the dead center of the valve plate and the base of the cylinder port near the dead center are in communication with the first or second port on the high pressure side, and the high pressure hydraulic fluid in the piston chamber is assisted through this base. It can be prevented from flowing into the port. As a result, communication between the base and the auxiliary port can be prevented, and the hydraulic fluid can be prevented from flowing out of the auxiliary port from other than the convex portion, so that the volumetric efficiency is improved.

  In the hydraulic rotating machine according to the present invention, the seal width may be 3 mm or more.

  In this way, when the base of the valve plate and the base of the cylinder port near the dead center are in communication with the first or second port on the high pressure side, the base is connected to the auxiliary port. Since the seal portion having a seal width of 3 mm or more is formed in the radial direction, the high-pressure hydraulic fluid in the piston chamber effectively leaks from the seal portion having a seal width of 3 mm or more and flows into the auxiliary port. Can be suppressed.

  According to the hydraulic rotating machine according to the present invention, the narrow portion is formed in the portion of the first and second ports close to the switching land, and passes through the seal region between the rear end surface of the cylinder block and the valve plate. Since the amount of leakage of the high-pressure hydraulic fluid from the first or second port can be reduced, and the increase in pressure loss of the hydraulic fluid flowing through the first and second ports can be suppressed, this liquid can be used. The overall efficiency of the pressure rotating machine can be effectively improved.

It is a front view which shows the valve plate of the hydraulic rotary machine which concerns on one Embodiment of this invention. It is sectional drawing which shows the hydraulic rotary machine which concerns on the same embodiment. FIG. 3 is an enlarged sectional view showing a part of the hydraulic rotating machine of FIG. 2. It is an enlarged front view which shows the upper half part of the valve plate of FIG. It is an enlarged front view which shows the lower half part of the valve plate of FIG. It is a figure which shows the relationship between the angular position (theta) of the piston chamber provided in the hydraulic rotary machine of FIG. 2, and the stroke position of a piston. It is a figure which shows the relationship between the angular position (theta) of the piston chamber provided in the hydraulic rotary machine of FIG. 2, and the pressure of the hydraulic fluid of a piston chamber. (A) is a front view which shows the valve plate of the hydraulic rotary machine which concerns on other embodiment of the invention, (b) is an AA expanded sectional view of the valve plate shown to Fig.8 (a). It is a front view which shows the valve plate of the conventional liquid motor.

  Hereinafter, an embodiment of a hydraulic rotating machine according to the present invention will be described with reference to FIGS. In this embodiment, an example in which a hydraulic rotating machine is applied to a hydraulic motor will be described. However, the hydraulic rotary machine can also be applied to a hydraulic pump.

  This hydraulic motor (hydraulic rotating machine) 10 is a swash plate type hydraulic motor that converts the pressure of hydraulic oil (hydraulic fluid) into rotational force and outputs it, and is provided in, for example, industrial machines and construction machines. Used to drive machines. As shown in FIG. 2, the hydraulic motor 10 includes a valve plate 11, a cylinder block 12, a plurality of pistons 13, a plurality of shoes 14, and a swash plate 15, which are casings provided in the hydraulic motor 10. 16 is housed. The casing 16 includes a casing body 16a, a front cover 16b, and a valve casing 16c.

  The hydraulic motor 10 further includes a rotating shaft 17, and the rotating shaft 17 has its one end 17 a partially protruding from the front cover 16 b and is attached to the front cover 16 b via the first bearing 19. It is rotatably supported around a rotation axis L10 that coincides with the axis. The other end 17b of the rotating shaft 17 is supported by the valve casing 16c via the second bearing 20 so as to be rotatable around the rotating axis L10.

  As shown in FIGS. 1 and 2, the valve plate 11 is generally disc-shaped, and is fixed to the valve casing 16 c with the rotating shaft 17 inserted therethrough. The valve plate 11 is formed with two supply / discharge ports 21 and 22 (first and second ports) and two auxiliary ports 23 and 24. The supply / discharge ports 21 and 22 are formed symmetrically in the valve plate 11 shown in FIG. 1, and are formed in an arc shape extending in the circumferential direction around the rotation axis L10. Each supply / discharge port 21, 22 has a tapered notch 90 at both ends in the circumferential direction. This notch 90 is a pressure change suppression unit for reducing the gradient of the pressure change of the hydraulic oil in the piston chamber 27 described later, and a sudden pressure change accompanying switching of connection and disconnection with the piston chamber 27, It is formed so that the noise generated with the pressure change can be reduced.

  The upper and lower auxiliary ports 23 and 24 are respectively provided in a top dead center switching land and a bottom dead center switching land formed between ends of the supply / discharge ports 21 and 22. 2 and 3, the supply / discharge port 21 is shown shifted from the actual position in the circumferential direction for easy understanding.

  The cylinder block 12 is provided at the rotary shaft 17 with the rotary shaft 17 inserted through the center thereof and prevented from rotating by, for example, a spline. In this way, the cylinder block 12 is provided rotatably around the rotary axis L10. Yes. In addition, a plurality of, for example, nine piston chambers 27 are formed in the cylinder block 12 at substantially equal intervals in the circumferential direction, and further, cylinder ports 28 individually connected to each piston chamber 27 are arranged at substantially equal intervals in the circumferential direction. Is formed. Each piston chamber 27 opens at the rear end portion in the axial direction of the cylinder block 12 via each cylinder port 28. The cylinder block 12 has a rear end surface 12 a that slidably contacts the valve plate 11 and achieves a seal structure with the valve plate 11. The cylinder ports 28 are connected to the left and right supply / discharge ports 21 and 22 and the upper and lower auxiliary ports 23 and 24 according to the rotational angle position of the cylinder block 12.

  Each piston 13 is substantially cylindrical, and is fitted and accommodated in each piston chamber 27 of the cylinder block 12 in a state where a mutual seal is achieved, thereby forming a hydraulic chamber 31. In addition, each piston 13 is provided so as to be movable in the extending direction and the shortening direction along the axis, and the volume of each hydraulic chamber 31 is changed by the movement of the piston 13. Further, one end portion 33 of each piston 13 on the side protruding from the piston chamber 27 has an outer surface formed in a spherical shape.

  Each shoe 14 has a flange portion 35 formed with a contact surface 34 perpendicular to the axis at one end thereof, and a fitting recess 36 that opens at the other end portion. The inner surface of each shoe 14 facing the fitting recess 36 is formed in a spherical shape, and one end 33 of the piston 13 is fitted into this fitting recess 36, so that each shoe 14 has a fitting recess 36. And it is connected to the piston 13 so as to be rotatable around three orthogonal axes with the center of the one end portion 33 as the rotation center.

  The swash plate 15 is provided on the left end side of the cylinder block 12 shown in FIG. 2 and has a flat support surface 37 that receives and supports the contact surface of each shoe 14. The swash plate 15 is provided so as to be freely tiltable about a tilt axis L11 orthogonal to the rotation axis L10. The swash plate 15 is tilted and driven about the tilt axis L11 by the servo mechanism 38 provided in the hydraulic motor 10. The angle formed with respect to L10 is changed.

  The hydraulic motor 10 shown in FIG. 2 further includes a retainer guide 40 and a pressing member 41. The retainer guide 40 is provided on the rotary shaft 17 in a state where the rotary shaft 17 is inserted coaxially and the mutual rotation is prevented by, for example, a spline. The retainer guide 40 has a spherical guide surface centered at one point on the rotation axis L10, in the present embodiment, the intersection of the axes L10 and L11. The pressing member 41 is supported by the guide surface of the retainer guide 40 and is provided so as to be rotatable about three orthogonal axes with the center of the sphere including the guide surface, and thus the intersection of the axes L10 and L11 as the rotation center. It has been. The pressing member 41 engages the flange portion 35 of each shoe 14 and presses each shoe 14 toward the support surface 37 of the swash plate 15. In this state, each shoe 14 is allowed to move slightly with respect to the pressing member 41 in the direction along the support surface 37 of the swash plate 15 and in the rotation direction about the intersection of L10 and L11.

  In the hydraulic motor 10, a spring member (not shown) such as a compression coil spring is provided in the cylinder block 12, and this spring force is transmitted to the retainer guide 40. In the state of being guided and supported as described above, the pressing member 41 is pressed toward the swash plate 15, the pressing member 41 presses each shoe 14 against the swash plate 15, and each shoe 14 floats away from the swash plate 15. Is prevented.

  The hydraulic motor 10 is configured such that each piston 13 reciprocates once for one rotation of the cylinder block 12. The reciprocating motion of each piston 13 has a top dead center and a bottom dead center at angular positions every 180 ° when the piston 13 rotates about the rotation axis L10. Specifically, the top dead center and the bottom dead center exist at an angular position that includes the rotation axis L10 and is perpendicular to the tilt axis L11 and the axis of the piston 13.

  A piston chamber 27 in which the piston 13 near the dead center and the dead center is fitted is connected to the auxiliary ports 23 and 24 via the cylinder port 28. Specifically, when there is a piston chamber 27 in the angular range of the angle θ1 on both sides in the circumferential direction with reference to the angular position when the piston 13 is at the top dead center which is the most shortened position, the piston chamber 27 is , Connected to one upper auxiliary port 23. In addition, when the piston chamber 27 exists in the angular range of the angle θ1 on both sides in the circumferential direction with reference to the angular position when the piston 13 is at the bottom dead center, which is the most extended position, the piston chamber 27 Connected to the auxiliary port 24. The angle θ1 is set to about 10 °, for example.

  On the other hand, the piston chamber 27 into which the piston 13 at a position other than the dead point and the vicinity of the dead point is fitted is connected to the supply / discharge port 21 or 22 via the cylinder port 28. Specifically, except for one top dead center and one top dead center, and the other bottom dead center and the other bottom dead center, the cylinder block 12 is viewed from one end 17a of the rotating shaft 17, When the cylinder block 12 rotates counterclockwise, which is the direction of the arrow A1 in FIG. 1, the piston chamber 27 arranged at an angular position where the piston 13 extends is connected to one supply / discharge port 21. . 1 except for one dead center and one dead center, and the other dead center and the other dead center, the cylinder block 12 is viewed from one end 17a in the axial direction of the rotating shaft 17, and the arrow A2 in FIG. When the cylinder block 12 rotates in the clockwise direction, which is the direction, the piston chamber 27 disposed at the angular position where the piston 13 extends is connected to the other supply / discharge port 22.

  The angular range in which the piston 13 excluding the dead center and the vicinity of the dead center and the piston moves in the extending direction, and the angular range in which the piston 13 excluding the dead center and the vicinity of the dead center and the piston moves in the shortening direction are both {180− Since (2 × θ1)} °, this angular range is smaller than 180 °. In this way, each piston chamber 27 is individually connected to any one of the ports 21 to 24 according to the angular position.

  In the valve casing 16 c of the hydraulic motor 10, as shown in FIG. 2, one supply / discharge passage 51 connected to one supply / discharge port 21 of the valve plate 11 and the other supply / discharge passage connected to the other supply / discharge port 22 ( (Not shown) is formed. These supply / discharge passages are connected to a hydraulic source such as a pump or a tank (both not shown) provided separately from the hydraulic motor 10.

  In the present embodiment, as shown in FIG. 1, the supply / discharge ports 21 and 22 and the auxiliary ports 23 and 24 of the valve plate 11 are formed symmetrically with respect to the rotation axis L <b> 10 that is the axis of the valve plate 11. Therefore, the hydraulic motor 10 is configured to be rotatable in both forward and reverse directions. Hydraulic oil is discharged from the hydraulic source and supplied to one supply / discharge port 21 of the hydraulic motor 10 via one supply / discharge passage 51. Further, the hydraulic oil is discharged from the other supply / discharge port 22 of the hydraulic motor 10, and the hydraulic oil is discharged outside the hydraulic motor 10 through the other supply / discharge passage. As a result, the piston of the piston chamber 27 connected to one of the supply / discharge ports 21 is extended, and accordingly, the cylinder block 12 rotates in the rotation direction A1 and the rotation shaft 17 rotates in the same direction A1. The rotation of the rotary shaft 17 can be output from, for example, the one end portion 17a, and other machines can be driven in the same direction.

  One supply / discharge port 21 is a first port through which hydraulic oil of high pressure, for example, 35 MPa, that can drive the hydraulic motor 10 from a hydraulic source is guided, and the other supply / discharge port 22 receives hydraulic oil discharged from the hydraulic chamber 31. The second port flows out, and the hydraulic oil is discharged to the outside of the hydraulic motor 10. Further, each auxiliary port 23, 24 corresponds to a third port, and the pressure of the hydraulic oil guided to each auxiliary port 23, 24 is higher than the atmospheric pressure and is one of the high pressure first ports. The pressure is lower than the discharge pressure of the hydraulic source guided to the supply / discharge port 21, for example, 0.01 MPa to 2 MPa.

  Also, hydraulic oil is discharged from the hydraulic source and supplied to the other supply / discharge port 22 of the hydraulic motor 10 through the other supply / discharge passage. Then, hydraulic oil is discharged from one supply / discharge port 21 of the hydraulic motor 10, and the hydraulic oil is discharged outside the hydraulic motor 10 through one supply / discharge passage 51. As a result, the piston 13 of the piston chamber 27 connected to the other supply / exhaust port 22 is extended. As a result, the cylinder block 12 rotates in the other rotational direction A2 opposite to the rotational direction A1, and the rotational shaft 17 is the same. Rotate in direction A2. The rotation of the rotating shaft 17 can be output from, for example, the one end 17a to drive other machines in the direction.

  In this case, the other supply / discharge port 22 serves as a first port through which high-pressure hydraulic oil that can drive the hydraulic motor 10 is guided from a hydraulic source, and one supply / discharge port 21 receives hydraulic oil discharged from the hydraulic chamber 31. The second port flows out, and the hydraulic oil is discharged to the outside of the hydraulic motor 10. Also in this case, each auxiliary port 23, 24 corresponds to a third port, and the pressure of the hydraulic fluid guided to each auxiliary port 23, 24 is higher than the atmospheric pressure, and the second pressure on the high pressure side. The pressure is maintained at a low pressure lower than the discharge pressure of the hydraulic source led to the other supply / discharge port 22 which is one port, for example, 0.01 MPa or more and 2 MPa or less.

  As described above, in the hydraulic motor 10, the piston chamber 27 communicates with the first port of the valve plate 11 when the piston 13 is not located at the dead point or in the vicinity of the dead point and is located in the range of movement in the extending direction. Then, the high pressure hydraulic oil is guided to the piston chamber 27. In addition, when the piston 13 is not located at the dead point or near the dead point and is located in a range in which the piston 13 moves in the shortening direction, the piston chamber 27 is communicated with the second port of the valve plate 11, and the low-pressure hydraulic oil is supplied. Can be discharged to a discharge location. In addition, the auxiliary ports 23 and 24 of the valve plate 11 communicate with the piston chamber 27 in the angular range where the piston 13 is located at the dead center and in the vicinity of the dead center, and the high pressure operation accommodated in the piston chamber 27 is established. The oil can be discharged, for example, to a drain tank having a lower pressure through the auxiliary ports 23 and 24 and the drain port 137 (see FIG. 2).

  Thus, the cylinder block 12 can be rotationally driven by the pressure of the hydraulic oil, and the rotation of the cylinder block 12 can be taken out from the rotary shaft 17. In this way, it is possible to realize driving of a separately provided device or the like using the hydraulic motor 10. Further, an auxiliary port is connected to the piston chamber 27 in the range where the piston 13 is located at the dead center and the vicinity of the dead center, and hydraulic oil can be supplied and discharged. Thereby, smooth movement in the extending direction and shortening direction of the piston in the vicinity of the dead center can be achieved.

  4 is an enlarged view showing the vicinity of the upper auxiliary port 23 in FIG. The cylinder port 28 is formed in a shape in which an opening facing the valve plate 11 has a base portion 67 and a convex portion 68 protruding from the base portion 67 at least one of radially outward and inward. In the present embodiment, the base 67 has a substantially long cylindrical shape, and the inner peripheral edge 70 and the outer peripheral edge 71 are formed so as to coincide with a virtual cylindrical surface centering on the rotation axis L10. The convex portion 68 is formed so as to protrude radially inward from the circumferential central portion of the base portion 67.

  FIG. 6 is a diagram showing the relationship between the angular position θ of the piston chamber 27 and the stroke position of the piston 13. FIG. 7 is a diagram showing the relationship between the angular position θ of the piston chamber 27 and the hydraulic oil pressure P in the piston chamber 27. 6 and 7, the horizontal axis indicates the angle position θ of the piston chamber 27 when the piston 13 is at one dead center as 0 °, and the angle in the rotation direction A1 from this position is indicated by θ. In FIG. 6, the vertical axis represents the stroke position of the piston 13, where one dead point is 0 and the other dead point is 1. In FIG. 7, the vertical axis represents the pressure P of the hydraulic oil in the piston chamber 27, and the minimum pressure while the piston 13 reciprocates once, and thus the piston chamber 27 rotates once, is denoted as P1 and the maximum pressure is denoted as P2. .

  As described above, assuming that the angle θ1 is 10 °, when the piston chamber 27 and therefore the cylinder port 28 are in an angle range of more than 10 ° and less than 170 ° (10 <θ <170), one supply / discharge port 21 is connected to the other supply / exhaust port 22 when it is in an angular range of more than 190 ° and less than 350 ° (190 <θ <350). Further, when the cylinder port 28 is in an angle range of 0 ° to 10 ° (0 ≦ θ ≦ 10) and 350 ° to less than 360 ° (350 ≦ θ <360), it is connected to one upper auxiliary port 23, When it is in an angle range of 170 ° to 190 ° (170 ≦ θ ≦ 190), it is connected to the other lower auxiliary port 24.

  When the cylinder port 28 is in an angle range connected to one upper auxiliary port 23, the stroke position of the piston 13 is in a position range of 0 or more and about 0.008 or less, with the total stroke movement amount of the piston being 1. . When the cylinder port 28 is in an angular range where it is connected to the other lower auxiliary port 24, the stroke position of the piston is in a position range of about 0.992 or more and 1 or less, where the total stroke movement amount of the piston is 1. When the piston 13 is at the dead point and near the dead point, the stroke movement amount relative to the unit angle movement amount of the cylinder block 12 is small. Accordingly, the angular range in which the cylinder port 28 is connected to the auxiliary ports 23 and 24 occupies about 11% (≈40 ° / 360 °) of one rotation, whereas the stroke position of the piston 13 corresponding to this range. The range is about 1.6% (= about 0.008 × 2).

  In the present embodiment, each notch 90 is configured so that the gradient of the pressure change of the hydraulic oil pressure P in each piston chamber 27 is reduced. Accordingly, the pressure P of the hydraulic oil in each piston chamber 27 does not always become a constant pressure while the cylinder port 28 is connected to each port 21 to 24 of the valve plate 11, for example, the first pressure on the high pressure side. Or, while connected to the second port, the maximum pressure P2 is not always reached, and the connection state with respect to the high-pressure side port is in the vicinity of an angular position where switching is performed by connection and disconnection, and therefore, near 10 ° and 170 °. In the vicinity, it changes gradually.

  In the hydraulic motor 10, when the cylinder port 28 exceeds 10 ° and is in an angle range of less than 170 ° (10 <θ <170), the piston chamber 27 serves as one of the high-pressure side ports 21. , A pressure equal to or higher than the average pressure (P1 + P2) / 2 of the lowest pressure P1 and the highest pressure P2 is introduced. Further, when the cylinder port 28 is in the remaining angle range, and therefore in the angle range of 0 ° to 10 ° (0 ≦ θ ≦ 10) and 170 ° to less than 360 ° (170 ≦ θ <360), the low pressure A pressure less than the average pressure (P1 + P2) / 2 of the lowest pressure P1 and the highest pressure P2 is introduced into communication with the other supply / discharge port 22 or auxiliary ports 23, 24 serving as a side port.

  Next, the features of the hydraulic motor 10 that is a hydraulic rotating machine according to the present invention will be described in more detail. As shown in FIGS. 4 and 5, each supply / discharge port (first and second port) 21, 22 is formed so as to face a path through which the base 67 of the cylinder port 28 passes when the cylinder block 12 rotates. Has been. However, each of the supply / discharge ports 21 and 22 may be formed so as to face a path through which both the base portion 67 and the convex portion 68 of the cylinder port 28 pass.

  As shown in FIG. 4, each supply / discharge port 21, 22 has a wide portion 130, a narrow portion 131, and a notch 90. The wide peripheral portion 130 has inner peripheral edges 75 and 76 that substantially coincide with the inner peripheral edge 70 of the movement path of the cylinder port 28, and the outer peripheral edges 77 and 78 of the supply / discharge ports 21 and 22 are the movement paths of the cylinder port 28. Substantially matches the outer peripheral edge 71.

  As shown in FIG. 4, the narrow portion 131 is formed at an end portion on the side close to the top dead center switching land 132 of each supply / discharge port 21, 22, and the opening width W <b> 2 in the radial direction of rotation of the cylinder block 12 is The wide portion 130 is formed as a portion narrower than the opening width W1 in the same direction. In other words, each narrow portion 131 has an inner peripheral edge 131 a formed radially outside the inner peripheral edge 70 of the movement path of the cylinder port 28, and the outer peripheral edge 131 b of each narrow portion 131 is the movement of the cylinder port 28. It substantially coincides with the outer peripheral edge 71 of the route.

  Further, as shown in FIG. 4, the narrow portion 131 is arranged in the rotational direction of the piston chamber 27 with reference to a predetermined angular position (θ = 0) in the top dead center switching land 132 where the piston 13 is at the top dead center position. It is formed within an angle range of 55 ° (preferably 45 °) or less. Furthermore, the notch 90 of each supply / discharge port 21, 22 is a groove.

  As shown in FIGS. 4 and 5, each auxiliary port 23, 24 avoids the path through which the base portion 67 of the cylinder port 28 passes and faces the path through which the convex portion 68 passes when the cylinder block 12 rotates. Is formed. The inner peripheral edges 80 and 81 of the auxiliary ports 23 and 24 coincide with the inner peripheral edge of the movement path of the convex portion 68 of the cylinder port 28, and the outer peripheral edges 82 and 83 of the auxiliary ports 23 and 24 correspond to the cylinder port 28. The base 67 is formed on the inner side in the radial direction with a gap W3 from the inner peripheral edge 70 of the moving path.

  That is, the base portion 67 of the cylinder port 28 is formed with a seal portion 136 having a predetermined seal width W3 (preferably 3 mm or more) in the radial direction with respect to the auxiliary ports 23 and 24.

  Further, as shown in FIGS. 4 and 5, each auxiliary port 23, 24 is connected to the dead center of the valve plate 11 and the piston chamber 27 near the dead point to the high pressure side supply / discharge ports 21, 22. It is formed so as to communicate with the piston chamber 27 when there is no state.

  Next, the operation of the hydraulic motor 10 that is a hydraulic rotating machine configured as described above will be described. According to the hydraulic motor 10, as shown in FIG. 4, the portion near the top dead center switching land 132 of the supply / discharge ports 21, 22 is narrow so that the opening width W 2 in the radial direction of rotation of the cylinder block 12 is narrow. Since it is formed as the portion 131, the sealing area between the rear end surface 12 a of the cylinder block 12 and the valve plate 11 can be increased in a range where the cylinder port 28 of the cylinder block 12 does not overlap the narrow portion 131. it can. Accordingly, the amount of high-pressure hydraulic oil in the piston chamber 27 leaking from the supply / discharge ports 21 and 22 can be reduced by the amount of the seal region corresponding to the increased seal area.

  Here, the flow rate of the hydraulic oil passing through the portion near the top dead center switching land 132 (narrow portion 131) of the supply / discharge ports 21, 22 is a portion far from the top dead center switching land 132 of the supply / discharge ports 21, 22. Since it is smaller than the flow rate through the (wide portion 130), it is possible to prevent the pressure loss based on the flow of the hydraulic oil from increasing even if the narrow portion 131 is formed in this way. The reason why the flow rate of the hydraulic oil passing through the portion near the switching land 132 is small is that the moving speed of the piston 13 becomes slower as the switching land 132 is approached (see FIG. 6).

  Similarly, the flow rate of the hydraulic oil passing through the portion closer to the bottom dead center switching land 133 on the supply / discharge ports 21, 22 is higher than the flow rate passing through the portion far from the bottom dead center switching land 133 on the supply / discharge ports 21, 22. small.

  Further, the narrow portion 131 is not formed in a portion far from the top dead center and the bottom dead center switching lands 132 and 133 of the supply / exhaust ports 21 and 22 but is the original wide portion 130, and therefore passes through the wide portion 130. Pressure loss based on hydraulic fluid flow does not increase. Thereby, the volumetric efficiency of the hydraulic motor 10 can be effectively improved without impairing the mechanical efficiency of the hydraulic motor 10.

  As shown in FIG. 4, the narrow portion 131 is 55 ° (= θ2) in the rotational direction of the piston chamber 27 with reference to a predetermined angular position in the top dead center switching land 132 where the piston 13 is located at the dead center. ) By being formed within the following angle range, high-pressure hydraulic oil is passed from the supply / discharge ports 21 and 22 through the seal region between the rear end surface 12a of the cylinder block 12 and the valve plate 11 shown in FIG. The amount of leakage can be effectively reduced, and an increase in pressure loss due to the flow of hydraulic oil in the narrow portion 131 can be effectively suppressed.

  Moreover, it is preferable that the angle range for forming the narrow portion 131 is within an angle range of 45 ° (= θ2) or less. That is, the moving speed of the piston 13 is such that the predetermined angular position in the top dead center switching land 132 of the valve plate 11 when the piston 13 is at the top dead center position is 0 ° (= θ), and the piston chamber 27 rotates. It can be obtained as a value that changes in a sinusoidal manner with the angle θ (see FIG. 6). The moving speed of the piston 13 at the angular position where the rotation angle θ of the piston chamber 27 is 45 ° is about 70 of the maximum moving speed (the maximum moving speed is obtained when the piston 13 is at the angular position θ = 90 °). %, And the inflow or outflow flow rate of the hydraulic oil to the piston chamber 27 is about 70% compared to the maximum flow rate. Therefore, the opening width W2 in the radial direction of the narrow portion 131 can be set to about 70% of the opening width W1 of the wide portion 130 of the supply / exhaust ports 21 and 22, and a seal region having an appropriate width is formed. can do.

  Further, as shown in FIG. 5, the lower auxiliary port 24 has a cylinder port 28 (piston chamber 27) in the vicinity of the bottom dead center and the bottom dead center of the valve plate 11 communicating with, for example, the supply / discharge port 21 on the high pressure side. It is formed so as to communicate with the cylinder port 28 (piston chamber 27) when not in the state. Similarly, the upper auxiliary port 23 is in a state where the top dead center of the valve plate 11 and the cylinder port 28 (piston chamber 27) near the top dead center are not in communication with, for example, the supply / discharge port 21 on the high pressure side. The cylinder port 28 (piston chamber 27) is communicated with the cylinder port 28.

  As a result, the bottom dead center when the cylinder port 28 of the piston chamber 27 is not in communication with the high-pressure side supply / exhaust port 21 and is sealed by the valve plate 11, that is, in a state in which high-pressure hydraulic oil is accommodated. When rotating around the bottom dead center, the lower auxiliary port 24 communicates with the piston chamber 27, and high-pressure hydraulic oil in the piston chamber 27 can be discharged from the lower auxiliary port 24. Therefore, it is possible to suppress the high-pressure hydraulic oil in the piston chamber 27 from leaking between the rear end surface 12a of the cylinder block 12 and the valve plate 11, and the volumetric efficiency can be improved.

  In addition, the force applied from the piston 13 to the swash plate 15 via the shoe 14 and the force applied from the cylinder block 12 to the valve plate 11 can be reduced, and between the shoe 14 and the swash plate 15, In addition, it is possible to reduce the frictional force between the members sliding with each other such as between the valve plate 11 and the cylinder block 12. As a result, it is possible to reduce mechanical loss and improve the seizure resistance of the members sliding with each other, in other words, it is possible to make seizure difficult to occur.

  As described above, the hydraulic motor 10 can be driven at a lower pressure than before by starting up by reducing the leakage amount of the high-pressure hydraulic oil.

  Further, when the cylinder port 28 shown in FIG. 5 rotates around the dead center and the vicinity of the dead center of the valve plate 11, the base 67 of the cylinder port 28 has a predetermined seal width in the radial direction with respect to the auxiliary ports 23 and 24. The seal portion 136 of W3 can be positioned apart. As a result, the high pressure hydraulic oil is connected to the auxiliary port via the base 67 while the dead center of the valve plate 11 and the base 67 of the cylinder port 28 near the dead point are in communication with the supply / discharge port 21 on the high pressure side. 23 and 24 can be prevented from flowing out. As a result, the energy of the high-pressure hydraulic oil can be used efficiently.

  Then, the convex portion 68 of the cylinder port 28 communicates with the auxiliary ports 23 and 24 at a predetermined timing when the base portion 67 of the cylinder port 28 shown in FIG. 5 does not communicate with the high-pressure side supply / discharge port 21. Can be set as follows. As a result, the high-pressure hydraulic oil in the piston chamber 27 communicating with the cylinder port 28 can be discharged from the auxiliary ports 23 and 24.

  When the seal width W3 is 3 mm or more, the dead center of the valve plate 11 and the base 67 of the cylinder port 28 near the dead center are in communication with the supply / discharge port 21 on the high pressure side. Since the base 67 is formed with a seal portion 136 having a seal width W3 of 3 mm or more in the radial direction with respect to the auxiliary ports 23 and 24, the high-pressure hydraulic oil in the piston chamber 27 has a seal width of 3 mm or more. It is possible to effectively suppress leakage from the sealing portion 136 and flowing into the auxiliary ports 23 and 24.

  Further, according to the hydraulic motor 10, the piston chamber 27 in the angular range where the piston 13 is located near the dead center can supply and discharge the hydraulic oil via the auxiliary ports 23 and 24. Thereby, smooth movement in the extending direction and shortening direction of the piston 13 in the vicinity of the dead center can be achieved. Moreover, when hydraulic oil having a pressure higher than the atmospheric pressure is guided to the auxiliary ports 23 and 24 and the piston 13 moves in the extending direction near the dead point, the hydraulic oil is sucked by the negative pressure due to the movement of the piston 13. Therefore, cavitation can be prevented.

  Further, according to the hydraulic motor 10, when the piston chamber 27 contains high-pressure hydraulic oil and rotates around the dead point and the vicinity of the dead point without communicating with the high-pressure side supply / discharge port 21 or 22. In addition, the auxiliary ports 23 and 24 can communicate with the piston chamber 27, and high-pressure hydraulic oil in the piston chamber 27 can be discharged from the auxiliary ports 23 and 24.

  However, in the above embodiment, as shown in FIG. 4, the narrowed portion 131 is formed with a substantially constant opening width W2, but instead, the opening width W2 becomes narrower toward the top dead center of the valve plate 11. Can be formed.

  That is, since the flow rate of the hydraulic oil in the piston chamber 27 decreases as the piston chamber 27 moves toward the dead center (θ = 0 °) of the valve plate 11, an increase in pressure loss due to the flow of hydraulic oil in the narrow portion 131 is suppressed. However, the amount of high-pressure hydraulic fluid that leaks from the supply / discharge ports 21 and 22 through the rear end surface 12a of the cylinder block 12 and the valve plate 11 can be efficiently reduced.

  And in the said embodiment, as shown in FIG.4 and FIG.5, although the auxiliary | assistant ports 23 and 24 were made into the through-hole formed in the valve plate 11, it replaces with this and FIG.8 (a), (b) As shown in FIG. 3, it is good also as a recessed part formed in the inner edge part of the mounting hole 134 of the rotating shaft 17 formed in the center of the valve plate 11. FIG. The pressure of the hydraulic oil guided to the concave portion is higher than the atmospheric pressure and lower than the discharge pressure of the hydraulic power source guided to one of the high-pressure supply / discharge ports 21 or 22 as in the above embodiment, for example, It is maintained at 0.01 MPa or more and 2 MPa or less. Since other than this is the same as the auxiliary ports 23 and 24 of the above-described embodiment, detailed description is omitted.

  Moreover, in the said embodiment, as shown in FIG. 1, although the narrow part 131 was formed in each upper end part of each supply / discharge port 21,22, it replaces with this and either one of the supply / discharge port 21,22 You may form in the lower end part.

  Furthermore, in the above embodiment, as shown in FIG. 1, the narrow portion 131 is formed in the portion near the top dead center switching land 132 on the supply / exhaust ports 21 and 22, and the side near the bottom dead center switching land 133 is formed. The narrow portion 131 is not formed in the portion, but instead, the narrow portion 131 is formed in the portion closer to the top dead center switching land 132 of the supply / discharge ports 21, 22, The narrow portion 131 may also be formed in a portion close to the bottom dead center switching land 133 of 22.

  Moreover, in the said embodiment, as shown in FIG.4 and FIG.5, although the upper auxiliary port 23 and the lower auxiliary port 24 were provided, it may replace with this and may provide either one auxiliary port.

  Further, in the above embodiment, as shown in FIG. 1, one supply / discharge port 21, 22 is provided on each of the left and right, but instead of this, as shown in FIG. It is good also as what provided multiple each on the right and left, for example, 3 each. In this case, it is preferable to form the narrow portion 131 at a port closer to the top dead center switching land 132 among the three supply / discharge ports 21 and 22 provided.

  In the above embodiment, the hydraulic rotating machine of the present invention is applied to a variable displacement swash plate type motor. Instead, a variable displacement swash plate type pump or a fixed displacement type is used. It can be applied to motors and pumps.

  Furthermore, the hydraulic rotating machine of the present invention can be applied to a machine that can rotate both forward and reverse, and can also be applied to a machine that rotates only in one direction.

  And in the said embodiment, although it comprised so that the pressure of each auxiliary | assistant port 23,24 might become a pressure larger than atmospheric pressure and a pressure smaller than the pressure of a high voltage | pressure side supply / exhaust port, it replaces with this, The auxiliary ports 23 and 24 may be connected to a drain tank so that the pressure of the drain tank is reached.

  Moreover, although the example which uses oil as a hydraulic fluid was given in the said embodiment, it may replace with this and may use water.

  Furthermore, in the said embodiment, although it was set as the structure which has the notch 90, the structure which does not have the notch 90 may be sufficient.

  As described above, the hydraulic rotating machine according to the present invention can reduce the amount of high-pressure hydraulic fluid that leaks from the first and second ports through the seal region between the rear end face of the cylinder block and the valve plate. It has an excellent effect of suppressing an increase in pressure loss of hydraulic oil flowing through the first and second ports, and is suitable for application to such a hydraulic rotating machine.

DESCRIPTION OF SYMBOLS 10 Hydraulic motor 11 Valve plate 12 Cylinder block 13 Piston 14 Shoe 15 Swash plate 16 Casing 17 Rotating shaft 21 Supply / exhaust port (1st port)
22 Supply / exhaust port (2nd port)
23 Upper auxiliary port (3rd port)
24 Lower auxiliary port (3rd port)
27 piston chamber 28 cylinder port 67 base 68 convex 90 notch 130 wide part 131 narrow part 131a inner peripheral edge 131b outer peripheral edge 132 top dead center switching land 133 bottom dead center switching land 134 mounting hole 136 seal part 137 drain port L10 rotation axis L11 Tilt axis W1 Opening width of wide part W2 Opening width of narrow part W3 Seal width of sealing part

Claims (5)

A cylinder block which is rotatably provided and has a plurality of piston chambers formed at intervals in the circumferential direction;
A plurality of pistons fitted in the piston chambers so as to be movable in the extending direction and the shortening direction, and reciprocating in the extending direction and the shortening direction;
A valve plate in which a first port and a second port, which are arranged in contact with the cylinder block and communicated with the piston chamber, and a switching land formed between the two ports are formed. Prepared,
In the valve plate, at least one of the first and second ports is formed with a narrow portion in which a portion close to the switching land has a narrow opening width in the radial direction,
An auxiliary port is formed in the switching land of the valve plate,
The auxiliary port is held at a pressure lower than any one of the first and second high-pressure ports, and the piston chamber is not in communication with the first or second port on the high-pressure side. Further, the hydraulic rotary machine is characterized in that the piston chamber and the auxiliary port communicate with each other.   2. The hydraulic rotating machine according to claim 1, wherein the narrow portion is formed within an angle range of 45 ° or less in the circumferential direction with respect to a position of a dead center. An opening facing the valve plate of the piston chamber is formed as a cylinder port,
3. The hydraulic rotating machine according to claim 1, wherein the narrowed portion has an opening width in the radial direction that becomes narrower toward a dead center. 4. An opening facing the valve plate of the piston chamber is formed as a cylinder port,
The cylinder port has a shape having a base and a convex portion protruding outward or inward in the radial direction from the base,
When the piston chamber communicates with the auxiliary port via the cylinder port, it is formed so that only the convex portion can communicate with the auxiliary port,
Before and after the piston chamber communicates with the auxiliary port via the cylinder port, the base portion is formed with a seal portion having a predetermined seal width in the radial direction with respect to the auxiliary port. The hydraulic rotating machine according to any one of claims 1 to 3.   The hydraulic rotary machine according to claim 4, wherein the seal width is 3 mm or more.

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