JPH065067B2 - Rotary fluid energy converter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rotary fluid energy converter used as a variable displacement fluid pump or fluid motor.

[Prior Art] In this type of rotary energy converter, for example, a static pressure type rotary fluid pump / motor, a cylinder barrel in which pistons are respectively retained in radial cylinder bores so as to be capable of projecting and retracting, A housing provided on the outer periphery of the cylinder barrel and the piston, a support element for rotatably supporting the cylinder barrel at a position eccentric from the axial center of the housing, and a relative relation between the housing and the cylinder barrel formed in the cylinder bore. A space is provided in which the volume is periodically increased and decreased by the protruding and retracting operation of each piston due to the rotation, and a pair of fluid flow passages are respectively connected to the space whose volume is increasing and the space whose volume is decreasing. The displacement volume of one rotation is changed by displacing the support element in a direction orthogonal to the axis of the housing. There is a so-called variable displacement type configured so that it can function as a variable displacement pump or a variable displacement motor.

By the way, recently, in a power recovery type hydraulic drive system, there has been a demand for a system that maintains a constant pressure regardless of discharge and suction of liquid.
On the other hand, the variable displacement energy converter as described above is equipped with a pressure compensating mechanism, and when the load pressure reaches a certain set value, its capacity is adjusted to adjust the discharge amount according to the discharge pressure of the pump. Although configured to change, the fourth
The pressure control as shown in the figure can be performed. That is, when the discharge pressure increases and reaches a preset pressure when operating at a predetermined flow rate a, the pressure compensating valve opens, and the discharge flow rate gradually decreases as shown in b, and the discharge flow rate automatically decreases. It only changes the capacitance so that the output is not output. Therefore, under the present circumstances, it is a fact that no energy converter of this kind can efficiently recover energy while freely switching between a pump and a motor.

[Problems to be Solved by the Invention] The present invention has been made in view of such circumstances.
It is an object of the present invention to provide a rotary fluid energy converter capable of having an extremely high energy recovery function that cannot be achieved by a conventional pressure compensation mechanism.

[Means for Solving the Problems] In order to achieve the above object, the present invention is, firstly, in a variable capacity type fluid energy converter as described above.
A spring member for urging the supporting element to displace it to one side of the neutral position where the displacement volume becomes zero.
A hydraulic actuator that is actuated by the pressure of the introduced fluid to displace the support element from the displacement position on the one side to the other side by passing through the neutral position against the biasing force of the spring member; When the pressure of the high-pressure side fluid existing in any one of the fluid flow paths exceeds a set pressure, a part of the high-pressure side fluid is introduced into the fluid type actuator and the pressure of the high-pressure side fluid reaches a set value. And a pressure compensating valve for stopping the introduction of the fluid on the high pressure side to deactivate the urging force of the hydraulic actuator. Secondly, the present invention is, secondly, in the fluid energy converter, the high-pressure side fluid existing in any one of the fluid flow paths is always introduced, and the pressure of the fluid causes the supporting element to move to the neutral position with the spring member. A balance piston is provided to urge it to be displaced to one side.

[Operation] According to such a configuration, as an operation common to the rotary fluid energy converters according to the first and second aspects of the present invention, when the converter is used as a pump, its supporting element is biased. The spring member positions the support element at a position displaced to one side from the neutral position where the displacement volume is zero and provides a constant pump displacement, while the pressure of the high-pressure side fluid of the pump increases the set pressure. When it exceeds, the displacement fluid type actuator for displacing the support element to the side opposite to the spring member is actuated to move the support element from the displacement position on the one side to the neutral position against the biasing force of the spring member. When the pump is displaced to the other side, the rotation axis of the pump is the same as that of the rotation axis, and this time the motor operates as a motor that outputs from the rotation axis. When the pressure of the fluid on the high-pressure side of the motor becomes equal to or lower than the set pressure in the state of use as the motor, it returns to the original state and operates as the pump. At this time, the pressure on the high-pressure side fluid is maintained at the set pressure of the pressure compensation valve during both the pump function and the motor function. Further, particularly in the second invention,
Since the supporting element of the spring member is backed up by the balance piston that uses the pressure of the fluid on the high pressure side of the converter so as to back up the urging force of the spring member, the load imposed on the spring member is reduced and its design It is supposed that the above restrictions can be effectively solved.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

The torque ring 2 is rotatably fitted to the inner circumference of the housing 1 via a plurality of first hydrostatic bearings 3 ... The housing 1 is a bottomed cylindrical body having an opening 1a at one end, and a tapered surface 4 having a diameter gradually decreasing in the direction of the opening 1a at a portion of the inner periphery thereof where the torque ring 2 is fitted. Are formed. Also, the torque ring 2
A cup-shaped member having a peripheral wall 2a having the same conical angle as that of the tapered surface 4, a rotary shaft 6 is integrally projectingly provided at one end of the shaft center portion thereof, and the opening portion is provided at the tip of the rotary shaft 6. It is exposed to the outside of the housing 1 through 1a. The first hydrostatic bearing 3 has a shoe 5 fixedly attached to the tapered surface 4 of the housing 1 at a required position on the outer circumference of the torque ring 3, and has three pressure pockets 7a, 7b, 7c are formed so as to be adjacent to each other in the axial direction, and a fluid pressure is introduced into each of these pressure pockets 7a, 7b, 7c. An odd number of static pressure bearings 3 ... Are arranged at equal angular intervals in the circumferential direction. Further, an inner flat surface 2c is formed on a portion of the inner circumference of the torque ring 2 corresponding to each of the first static pressure bearings 3 ... Then, the pistons 8 are respectively provided on the inner periphery of the torque ring 2 at the portions corresponding to the respective planes 2c.
... and the tip 8 of each of these pistons 8 ...
are affixed to the corresponding inner planes 2c ... Through the second hydrostatic bearings 9 ... The second hydrostatic bearing 9 is formed in a flat shape so that the tip surface 8a of the piston 8 is in close contact with the inner plane 2c ... And a pressure pocket 11 is formed in the tip surface 8a. The fluid pressure is introduced into the pocket 11. Further, the base end portion of each of the pistons 8 ... Is held by a piston holding structure 12, and spaces 13 for introducing fluid between the piston holding structure 12 and the pistons 8 ... Is formed. That is, the piston holding structure 12 is located at the axial center of the housing 1 and the torque ring 2, that is, the axial center parallel to the rotation axis m (in the embodiment, + n in the pump operating state and the motor operating state −n). Further, there is a neutral position between + n and -n), and a pintle 14 having a sliding portion 14a supported by the housing 1, and a ring shape rotatably fitted to the outer periphery of the pintle 14. And a cylinder barrel 15 of which the pintle 14
A plurality of cylinder bores 16 ... Having an axis substantially orthogonal to the outer peripheral surface of the are radially formed at equal angular intervals in the circumferential direction. And each of these cylinder bores 16 ...
Each of the pistons 8 ... Is slidably fitted to the.
And the inner surfaces of the cylinder bores 16 ... Form the spaces 13 ... The cylinder barrel 15 is connected to the torque ring 2 via the Oldham coupling 20 and the like, and is rotated at the same angular velocity as the torque ring 2. In addition, the pintle 14
Is a truncated cone whose outer peripheral surface is a conical surface substantially equal to the conical angle of the peripheral wall 2a of the torque ring 2,
Each of the pistons 8 ... Is a peripheral wall 2 of the torque ring 2.
It is held so that it can move back and forth in a direction orthogonal to a.
The sliding portion 14a of the pintle 14 is formed in the shape of a vertically elongated block having a trapezoidal cross section.
It is slidably fitted in a trapezoidal groove 19 provided inside. That is, the pintle 14 is held so as to be slidable in the direction orthogonal to the rotating shaft center m, whereby the distance ± n between the shaft center ± n of the pintle 14 and the shaft center m is ±.
It is possible to adjust D to a desired value including zero. Then, as shown in FIG. 2, the inside of the housing 1 is divided into two regions, a first region A and a second region B, with a virtual dividing line P coinciding with the sliding direction of the pintle 14 as a boundary. The spaces 13 ... Passing through the first region A are communicated with the first fluid flow passage 21, and the spaces 13 passing through the second region B are moved through the second fluid flow system 21. It communicates with the road 22. First fluid flow path 21
Is a fluid flow path 23 that opens each space 13 to the inner peripheral surface of the cylinder barrel 15, and one end is opened to a portion on the first region A side of the outer peripheral surface of the pintle 14 and the other end is opened. A pintle through port 24 opened on the slope 14b on the second region B side of the sliding portion 14a of the pintle 14, and a fluid outflow port 25 formed in the housing 1 corresponding to the other end of the pintle through port 24. It is equipped with. Then, at one end of the pintle through port 24, a pressure pocket 27 for forming a third static pressure bearing 26 is provided between the outer peripheral surface of the pintle 14 and the inner peripheral surface of the cylinder barrel 15, and Pintle 1 at the end
4 between the inclined surface 14b and the inner surface of the housing 1.
Pressure pocket 2 for forming a hydrostatic bearing 28 of
9 is provided. The pressure pockets 27 are elongated in the circumferential direction, and all the spaces 13 existing in the first area A.
.. also plays a role of communicating the pintle through port 24. Further, the pressure pocket 29 is elongated in the sliding direction of the pintle 14, and
It also plays a role of preventing the communication between the pintle through port 24 and the fluid outflow port 25 from being cut off when sliding. On the other hand, the second fluid flow passage 22 is opened at one end of the fluid passages 23 ... At the site on the second region B side of the outer peripheral surface of the pintle 14 and at the other end in the sliding portion 14a of the pintle 14. It comprises a pintle through port 34 opened to the slope 14c on the side of the first region A, and a fluid outflow port 35 bored in the housing 1 so as to correspond to the other end of the pintle through port 34. Then, at one end of the pintle through port 34, a third hydrostatic bearing 3 is provided between the pintle 14 and the cylinder barrel 15.
6, and a pressure pocket 39 for forming a fourth hydrostatic bearing 38 between the slope 14c of the pintle 14 and the inner surface of the housing 1 is provided at the other end. There is. The pressure pockets 37, 39 are the pressure pockets 27,
It has the same structure as 29.

Further, in such a structure, the fluid pressure in the space 13 corresponding to each piston 8 is applied to the pressure of the corresponding second hydrostatic bearing 9 via the pressure introducing passage 41 provided at the axial center of the piston 8. The first pressure guide member is introduced into the pocket 11 and the fluid pressure in the pressure pocket 11 is corresponded to via the fluid passages 42a, 42b and 42c formed in the torque ring 2.
The static pressure bearing 3 is guided to the pressure pockets 7a, 7b and 7c. The directions and areas of the both hydrostatic bearings 3 and 9 are the same as the force acting on the torque ring 2 due to the hydrostatic pressure of the fluid introduced to the first hydrostatic bearing 3 and the hydrostatic bearing 9 introduced to the second hydrostatic bearing 9. The force acting on the torque ring 2 by the static pressure of the fluid is set to a value such that the magnitude is equal and the direction is opposite. Further, the area of the second hydrostatic bearing 9 depends on the force acting on the piston 8 due to the hydrostatic pressure of the fluid introduced into the hydrostatic bearing 9 and the hydrostatic pressure of the fluid in the space 13 to the piston 8. It is set to such a value that the forces acting on them cancel each other out. Further, the area of the third hydrostatic bearing 26 (36) is larger than the area of the hydrostatic bearing 26 (3).
6) by the static pressure introduced into the cylinder barrel 15
The force acting on the cylinder barrel 15 and the force acting on the cylinder barrel 15 due to the static pressure of the fluid in the space 13 existing in the corresponding area A (B) cancel each other out.
Further, the fourth static pressure bearing 28 (38) and the slope 14 on which the static pressure bearing 28 (38) is provided.
The inclination angle of b (14c) depends on the static pressure bearing 28 (3
8) by the static pressure of the fluid introduced into the pintle 14
And the third bearing 26 (36) existing in the area A (B) facing the slope 14b (14c).
It is set to such a value that the force acting on the pintle 14 is canceled by the static pressure of the fluid introduced into the.

Incidentally, 43 is a seal member, and 44 is a bearing for supporting the rotary shaft as an auxiliary. Further, 45 is a fastener for stopping the cylinder barrel 15 on the pintle 14.
Reference numeral 6 is a permanent magnet for attracting the pintle 14 to the inner surface side of the rear cover b forming a part of the housing 1.

Further, in such a static pressure type fluid energy converter, as a means for displacing the pintle 14 which is a supporting element of the torque ring (second member) in a direction orthogonal to the rotation axis, It is equipped with such a configuration. First, the base end block portion 14a of the pintle 14 fitted into the groove 19 of the housing 1 is provided with a recessed portion 51 in a direction orthogonal to the rotation axis from one end face which is in the longitudinal direction, and the inside of the recessed portion 51 is formed. A spring member 52 is interposed between the bottom surface 51a side and the housing inner surface side, and the pintle 14 is displaced to the eccentric position + n by the urging force of the spring member 52. Further, a fluid-type means 53 for providing an acting force cooperating with the urging force of the spring member 52 is provided. The means 53 comprises a cylinder member 55 which forms an introduction portion 54 for the working fluid therein, and a balance piston 56 which is slidably fitted in the cylinder member 55. The cylinder member 55 faces the concave portion 51 and the housing. 1 is fitted into the intermediary hole 57 provided in the first embodiment via a seal 58, and the outer surface thereof is supported by a sealing member 59 to be fixed to the housing 1.
6a is in contact with the inner bottom surface 51a of the recess 51.
The spring member 52 is interposed between the rear surface side of the balance piston tip surface 56 a of the means 53 and the base end surface side of the cylinder member 55, and applies a biasing force to the piston 14 via the balance piston 56. I have to. Further, the fluid type means 53 always causes the high-pressure side fluid discharged or inflowing from the converter to be introduced into the introduction portion 54 thereof, and the pintle 14 is provided with a support force for backing up the biasing force of the spring member 52. I am able to give That is, in the embodiment, the pintle through port 24 that communicates with the fluid outflow port 25, which is set in advance so as to become the outflow inflow port of the high pressure side fluid of the converter, and branches from the pintle through port 24. Further, a fluid passage 61 that opens to the inner bottom surface 51a of the recess of the pintle 14 to which the balance piston tip surface 56a is in close contact, and an opening end of the fluid passage 61 that penetrates the axis of the balance piston 56 and is at one end thereof. A fluid pressure circuit including a fluid passage 62, which is in fluid communication with the introduction portion 54 at the other end, is provided so that the pressure of the high-pressure fluid is always transmitted to the introduction portion 54. That is, the fluid-type means 53 always supports the pintle 14 with a force obtained by multiplying the cylinder cross-sectional area by the pressure of the introduced high-pressure side fluid. A seal 63 is interposed in the balance piston tip surface 56a, which comes into contact with the fluid passages 61 and 62, to prevent the working fluid from leaking from the contact surface. On the other hand, on the inner base end side of the cylinder member 55, when the fitting balance piston 56 contracts into the cylinder, that is, the pintle 14 is displaced to the other end side against the biasing force of the spring member 52 and the like. When the balance piston 56
A screw rod 64 that abuts against the lower end face of the pintle and prevents further displacement of the pintle 14 is screwed so as to be adjustable forward and backward. That is, the screw 64 serves as a restricting means for restricting the displacement of the pintle 14 to a certain amount. Specifically, in this case, the screw 64 is displaced from the axial center m of the housing 1 by -D. I try to stop at n.

Next, in this energy converter, the pintle 14 is used as a means for displacing the pintle 14 on the other side, that is, in a direction 180 degrees opposite to the direction in which the spring member 52 and the fluid type means 53 are biased and supported. A hydraulic actuator 66 is provided which is configured to operate utilizing the pressure compensation mechanism included in the converter. That is, a recess 67 is formed in the end face of the pintle base end block portion 14a fitted in the groove 19 of the housing 1 on the side opposite to the recess 51 and orthogonal to the axis of rotation and facing the recess 51. A working fluid introducing portion 68 is formed inside 67, and a spring member 71 is interposed between an engaging step portion 69b formed on the inner surface proximal end side and an inner bottom surface 67a of the recess 67. A cylindrical cylinder member 69 is fitted so as to be slidable relative to the inner peripheral surface of the recess 67 while the base end surface is in close contact with the inner surface of the housing 1. It should be noted that the seal 7 is attached to the cylinder base end surface 69a that abuts the contact surface with the inner surface of the housing 1.
2 to prevent the working fluid from leaking at the contact surface. In addition, a pintle support 74 is made to penetrate from the outer surface side of the housing 1 through the mounting hole 73 to the hollow portion of the cylinder member 69 fitted into the recess 67 of the pintle 14, and the tip end surface 74 a of the recess 67 is formed. It is in contact with the inner bottom surface 67a. The support head 74a is provided with an appropriate spring member 75 interposed between the inner surface of the head 74b protruding from the housing 1 and the outer surface of the housing 1.
Is fitted to a support cap 76 fixed to the housing 1, and a lock bolt 77 fitted to the top of the housing is tightened to fix the protruding length of the tip end surface 74a of the cylinder member 69 from the cylinder member 69. In other words, the pintle support tray 74 functions as a regulating means for regulating the displacement of the pintle 14 in one direction biased by the spring member 52 or the like. Specifically, in this case, the pintle 14 is mounted on the shaft of the housing 1. It is arranged to stop at the eccentric position + n which is displaced from the center m by D. Thus, the displacement fluid type actuator 66 is provided with a fluid pressure circuit for guiding the high pressure side fluid of the energy converter to the introduction portion 68 in the cylinder member 69 via a pressure compensation valve. There is. That is, the fluid circuit includes the piston through port 24 that communicates with the fluid outflow port 25, which is set in advance so as to become the outflow inflow port for the high-pressure side fluid of the converter, as described above, and the pintle through port. 24, a fluid passage 81 for guiding the working fluid to a port 82 provided on the side of the rear cover 1b of the housing 1 (indicated by a dashed line in FIG. 1), and the port 82 is attached to the rear cover 1b of the housing 1. A fluid passage 83 that communicates with a fluid passage 92 provided in the joined block 91 with built-in pressure compensation mechanism, and a fluid passage 84 that guides the working fluid from the fluid passage 92 in this block to the housing 1 side via a pressure compensation valve 93. Of the housing 1 in which one end communicates with the fluid passage 84 and the other end penetrates the introduction portion 68 in the cylinder member 69 and the pintle support screen 74. In which the more the fluid passage 85 are opened at and communicated from the sidewall position of the hole 73. The pressure compensating valve 93 built in the block 91 has a structure in which the spool 94 is slidably inserted into the fluid passage 92 while biasingly supporting the spool 94 corresponding to a predetermined operation set pressure. is there. More specifically, the spool 94 is arranged in the fluid passage 92 so that the land sliding surface of the spool 94 completely straddles the opening position of the fluid passage 84.
The movable side front end of the lock plate is exposed to the large-diameter support hole 95 through which the fluid passage 94 opens, and the press plate 96 crowned at the front end and the lock fitted from the other end side of the support hole 95. A spring member 98 is interposed between the inner surface of the bolt 79 and the inner surface of the bolt 79. The biasing force of the spring member 98 can be varied by adjusting the stroke by tightening the lock bolt 97. When the pressure of the high pressure side fluid of the converter transmitted from the fluid passage 83 overcomes the biasing force of the spring member 98, that is, the set pressure of the pressure compensating valve 93, the spool 94 slides slightly to the tip side. Is displaced, and at this time, the spool 9 of the fluid passage 84 is displaced.
4 is released and the fluid passage 84 and the fluid passage 9 are released.
2 is electrically connected to each other, so that the high-pressure side fluid is introduced into the displacement hydraulic actuator 66. Needless to say, when the pressure of the high pressure side fluid becomes equal to or lower than the set pressure, the spool 94 is restored and the supply of the high pressure side fluid to the actuator 66 is cut off. 8
Reference numerals 6, 87, 88 are fluid passages for guiding the working fluid returned from the actuator 66 to the case drain facing the inner surface of the housing. In addition, 99 is a spool 94
Is a stopper for maintaining the return position of.

Then, when the working fluid is guided from the high pressure side of the converter to the fluid type actuator 66 through the pressure compensating valve 93, the urging force of the spring member 52 and the acting force from the balance piston 56 at the time of its operation. The pintle 14 is displaced to the other side against. Here, the operating force applied to the pintle 14 by the actuator 66 is obtained by multiplying the area of the inner bottom surface 67a of the recess 67, which is the introduction portion of the working fluid, by the pressure of the high-pressure side fluid introduced. The pintle 14 is displaced to the eccentric position -n. Therefore, the actuator 66 has a large output as compared with the acting force from the balance piston 56 having an actuating force that overcomes the opposing biasing force and the like. In other words, the spring member 52 is based on the acting force of the fluid type actuator 66 and the balance piston 56, and the fluid pressure of the high pressure side fluid of this converter increases from the set pressure of the pressure compensation valve 93. Pintle 14 when changing to the side
The spring characteristic is set to a predetermined value so that it can be smoothly displaced. Further, the spring characteristic of the spring member 52 is such that at the stage where the fluid pressure of the high pressure side fluid of the converter reaches the set pressure of the pressure compensating valve 93 and the fluid type actuator 66 is about to operate, its operating force is still. Than the spring member 52 and the balance piston 5
The acting force of 6 is slightly higher, and it is set so that the pintle 14 is immediately displaced to the other side when it increases the set pressure by a very small amount. As described above, at the time of this displacement, the screw thread 64 in the fluid type means 53 functions as a regulating means for regulating the displacement of the pintle 14.

Next, the operation of the illustrated embodiment will be described.

The basic operation of the main body of this converter is disclosed in JP-A-58-77178. That is, if the shaft center of the pintle 14 is set to the + n position and the torque ring 2 is rotated in the direction of arrow R by an external force, a high-pressure fluid is discharged from the first fluid flow passage 21 and serves as a pump. It will function. On the contrary, when the shaft center of the pintle 14 is set to the position of -n and a high-pressure fluid is supplied through the first fluid flow passage 21 into the space 13 ... A couple of forces that try to rotate the torque ring 2 in the direction of arrow S is generated, and the motor functions as a motor. Then, in the state of use as a pump / motor at each of these predetermined axial positions, the rotary shaft 6 of this converter is rotated in a fixed direction.

Next, the operation will be described when this converter is used while changing its capacity.

Now, assuming the case where this converter is used as a fluid pressure source and is supplied to a fluid pressure driven hydraulic engine, the operation will be described. An eccentric state in which the axis of the pintle 14 is located at + n as shown in the figure. When operating as a pump in
The pump discharges a flow rate determined by the amount of eccentricity from the first fluid flow path 21 that hits the high pressure side. Then, when the load pressure on the high-pressure side, that is, the discharge pressure reaches a predetermined set pressure, the pressure compensating valve 93 provided in the fluid pressure circuit for guiding the fluid on the high-pressure side is opened to open the fluid pressure actuator. 66 introduces the high-pressure side fluid into its introduction portion 68,
Further, when the fluid pressure tends to increase even a little, the fluid pressure actuator 66 displaces the pintle 14 in order to transiently set the discharge amount according to the discharge pressure, and when the pressure further rises, the fluid pressure actuator 66 is changed. By overcoming the biasing force of the operating force of the opposing spring member 52 and balance piston 56, the axial center of the pintle 14 passes through the eccentric position -n defined by the restriction means, that is, the neutral position where the displacement volume becomes zero, and the other It will be displaced to the side. And this piston 1
When the displacement of 4 is completed, this converter automatically operates by switching to a pump that discharges a negative flow rate from the first fluid flow path 21, that is, a motor that flows in high-pressure fluid and rotates in the same direction. Will be done. FIG. 5 shows the relationship between the discharge flow rate and the load pressure of this converter that undergoes such a capacity change. As shown in the figure, in comparison with a conventional pump having a pressure compensation function, this pump exceeds the set pressure unlike the one in which the discharge amount is simply controlled according to the discharge pressure as in a and b. Then, like c, the pressure is kept almost constant (this pressure corresponds to the set pressure of the pressure compensating valve), and the inflow amount from the high pressure side is gradually increased until it reaches the predetermined inflow capacity and the high pressure fluid has Operates as a motor with fluid energy. Therefore, for example, if a unidirectional rotation type generator is connected to the rotary shaft 6 of this converter, the fluid energy can be recovered when used as the motor in the above c and d, and this energy recovery. Depending on the function, it can be operated as an energy-saving converter.

The embodiment described above relates to the second invention of the present invention, in which the pintle 14 is displaced and supported by the urging force of the spring member 52 and the operating force of the balance piston 56. In principle, even if the balance piston 56 is not used together, that is, the pintle 14 is displaced and supported only by the urging force of the spring member 52, and the required balance between this and the operating force of the fluid actuator 66 for displacement is required. Therefore, the present invention includes, as the first invention, the one having such a configuration. In implementing the present invention, it is advantageous to install the balance piston 56 as in the above embodiment. This includes the following matters. In the static pressure type converter of the above embodiment, the piston axis is + n.
When it is used as a pump by displacing it to the eccentric position, the force acting on the pintle 14, which is the supporting element, is balanced in principle and the displacement force does not work, but in reality it is due to compression of the working fluid. Then, the pressure change in each space 13 is delayed, and an unbalanced force that tries to return the pintle 14 to the neutral position acts. Therefore, if only the spring member 52 is supported, the spring member 52 needs to be capable of exhibiting a considerably large biasing force, and further requires a long stroke for displacement as described above. The design of the spring member 52 becomes very difficult (for example, the allowable shear stress of the coil spring may be exceeded, or the buckling may easily occur when the number of turns is increased). There is an inconvenience that the work becomes difficult and dangerous. However, if the balance piston 56 is used to support the pintle 14, such inconvenience can be eliminated, and the spring member 52 having ideal characteristics can be provided. It is possible to provide a stable capacity change mechanism.

In the converter of the present invention, the structure of the main body portion that performs the pump function or the motor function is not limited to that of the above-mentioned embodiment, and may be, for example, a normal radial piston type pump / motor or the like. Good.

Further, the "balance piston" referred to in claim 2 of the present invention includes a plunger type.

EFFECTS OF THE INVENTION Since the converter of the present invention has the above-described configuration, the operating state is automatically switched according to the pressure on the high pressure side while keeping the rotation direction of the rotary shaft constant, and the converter is used as a pump. Also functions as a motor, and therefore can exhibit a high energy recovery function that cannot be achieved by an energy converter having a normal pressure compensation function.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
II-II sectional drawing in the figure, FIG. 3 is II in FIG.
It is a sectional view taken along the line I-III. FIG. 4 is a diagram for explaining operation characteristics of a conventional energy converter having a pressure compensation function, and FIG. 5 is a diagram for explaining operation characteristics of the converter according to the present invention. DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Torque ring 8 ... Piston 13 ... Space 14 ... Support element (pintle) 15 ... Cylinder barrel 16 ... Cylinder bore 52 ... Spring member 56 ... Balance piston 64 ... Regulation Means (screw) 66 ... Fluid actuator for displacement 64 ... Regulation means (screw) 93 ... Pressure compensation valve

Claims (2)

[Claims] 1. A cylinder barrel in which pistons are respectively retained in radial cylinder bores so as to be capable of projecting and retracting, a housing provided on the outer periphery of the cylinder barrel and the piston, and the cylinder barrel is eccentric from the axial center of the housing. A support element that is rotatably supported at a predetermined position, a space that is formed in the cylinder bore, and that has a volume that periodically increases and decreases due to the projecting and retracting action of each piston that accompanies relative rotation of the housing and the cylinder barrel; and a volume that increases. A pair of fluid flow passages respectively communicating with the starting space and the space whose volume is decreasing, and the supporting element is displaced in a direction orthogonal to the axis of the housing for each rotation. Can function as a variable displacement pump or variable displacement motor by changing the displacement of the In urchin constructed rotary fluid energy converter, and a spring member for urging to contrast to displace the side from the neutral position to the volume displacement of said supporting element is zero,
A hydraulic actuator that is actuated by the pressure of the introduced fluid to displace the support element from the displacement position on the one side to the other side by passing through the neutral position against the biasing force of the spring member; When the pressure of the high-pressure side fluid existing in any one of the fluid flow paths exceeds a set pressure, a part of the high-pressure side fluid is introduced into the fluid type actuator and the pressure of the high-pressure side fluid reaches a set value. A rotary fluid energy converter comprising: a pressure compensating valve for stopping the introduction of the fluid on the high pressure side to deactivate the urging force of the hydraulic actuator when the fluid pressure is lowered. 2. A cylinder barrel in which pistons are retained in radial cylinder bores so as to be capable of projecting and retracting, a housing provided on the outer periphery of the cylinder barrel and the piston, and the cylinder barrel is eccentric from the axial center of the housing. A support element that is rotatably supported at a predetermined position, a space that is formed in the cylinder bore, and that has a volume that periodically increases and decreases due to the projecting and retracting action of each piston that accompanies relative rotation of the housing and the cylinder barrel; and a volume that increases. A pair of fluid flow paths communicating respectively with the starting space and the space whose volume is decreasing, and the supporting element is displaced in the direction orthogonal to the axial center of the housing to perform one rotation. Can function as a variable displacement pump or variable displacement motor by changing the displacement of the In urchin constructed rotary fluid energy converter, and a spring member for urging to contrast to displace the side from the neutral position to the volume displacement of said supporting element is zero,
A high-pressure side fluid existing in any one of the fluid flow paths is always introduced, and a balance piston that biases the support element together with the spring member to one side from the neutral position by the pressure of the fluid is introduced. A hydraulic actuator that is actuated by the pressure of the fluid to displace the supporting element against the biasing force of the spring member from the displacement position on the one side to the other side by passing through the neutral position; When the pressure of the high pressure side fluid existing in either one of the fluid flow paths exceeds the set pressure, a part of the high pressure side fluid is introduced into the fluid type actuator and the pressure of the high pressure side fluid falls below the set value. And a pressure compensating valve for stopping the introduction of the high-pressure side fluid to turn off the urging force of the hydraulic actuator when the rotating type. Body energy conversion machine.