JPH065068B2 - Rotary fluid energy converter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotary fluid energy converter used as a static pressure type 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 supporting element is reciprocated in the direction orthogonal to the axis of the housing to change the displacement per rotation. 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, in such a case, it may be necessary to display the operating position of the supporting element by a rotary pointer or to convert it into an electrical feedback signal by a rotary encoder. In the case of a pintle or the like that moves forward and backward, it is not easy to deal with it. That is, in order to meet such a demand, it is necessary to convert the forward / backward movement amount of the pintle into a rotational displacement amount and take it out of the housing. However, the forward / backward movement of the pintle is converted into a rotational movement using a gear mechanism or the like. If this is done, there arises a problem that the structure becomes complicated and it becomes difficult to make it compact, and the assembly work becomes complicated.

[Problems to be Solved by the Invention] The present invention has been made in view of such circumstances.
An object of the present invention is to easily and surely solve the problem that the structure is complicated and the assembling work is complicated when the reciprocating motion of the support element is converted into the rotational displacement to obtain various detection outputs.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a hydraulic actuator for reciprocating a supporting element in the variable capacity type fluid energy converter as described above, and A nut that is constantly attached to one end of the support element in the reciprocating direction, a screw rod that is rotatably and immovably held in the housing and has an inner end screwed into the nut, The present invention is characterized by further comprising: a conversion unit that is connected to an outer end portion of the screw rod and that converts a rotational displacement amount of the screw rod into a detection output such as an electric signal.

[Operation] According to this configuration, the reciprocating motion of the support element can be converted into a rotational displacement by the nut attached to the support element and the screw rod screwed to the nut, and the position different from the cylinder can be obtained. There is no complication of the structure and waste of space as in the case where a gear mechanism for motion conversion is provided.

[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 in the shape of a bottomed cone having an opening 1a at one end, and a taper surface 4 having a gradually smaller diameter in the direction of the opening 1a is formed at a portion of the inner periphery of the housing 1 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. In addition, the first hydrostatic bearing 3 has a shoe 5 fixed 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 has a pintle 14 having an axis n of the housing 1 and the torque ring 2, that is, an axis n parallel to the rotation axis m and having a sliding portion 14a supported by the housing 1. A ring-shaped cylinder barrel 15 rotatably fitted to the outer periphery of the pintle 14, and the cylinder barrel 15 has a plurality of cylinder bores 16 having an axis substantially orthogonal to the outer peripheral surface of the pintle 14. Are radially formed at equal angular intervals in the circumferential direction. The pistons 8 ... Are slidably fitted in the cylinder bores 16 ..., and the base end faces 8b of the pistons 8 ... and the cylinder bores 16 ... The space 13 ... Is formed by the inner surface. 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. The pintle 14 is a truncated cone whose outer peripheral surface is a conical surface that is substantially equal to the conical angle of the peripheral wall 2 a of the torque ring 2.
Are held so that they can move back and forth in a direction orthogonal to the peripheral wall 2a of the torque ring 2. The sliding portion 14a of the pintle 14 is shaped like a vertically elongated block having a trapezoidal cross section, and is slidably fitted in a trapezoidal groove 19 provided inside the housing 1. That is, the pintle 14 is held slidably in the direction orthogonal to the rotation axis m, whereby a desired separation distance D between the axis n of the pintle 14 and the axis m is zero. The value can be adjusted. Then, as shown in FIG. 2, the inside of the housing 1 is bordered by a virtual dividing line P that coincides with the sliding direction of the pintle 14.
It is divided into an area A and a second area B, and the space 13 ... Which is passing through the inside of the first area A is divided into the first fluid flow passage 21.
And the spaces 13 passing through the second region B are communicated with the second fluid flow path 22. The first fluid flow path 21 includes the spaces 13 ...
Flow path 2 for opening the inner peripheral surface of the cylinder barrel 15
3 ... and a first area A on the outer peripheral surface of the pintle 14 at one end
To the sliding portion 14a of the pintle 14 with the other end opened.
The pintle penetration port 24 opened on the slope 14b on the second region B side in the above, and the fluid outflow port 25 drilled in the housing 1 corresponding to the other end of the pintle penetration port 24. Then, at one end of the pintle through port 24, a pressure pocket 27 for forming a third hydrostatic bearing 26 is provided between the outer peripheral surface of the pintle 14 and the inner peripheral surface of the cylinder barrel 15, and A pressure pocket 29 for forming a fourth hydrostatic bearing 28 is provided at the end between the inclined surface 14 b of the pintle 14 and the inner surface of the housing 1. The pressure pockets 27 are elongated in the circumferential direction, and also have a role of communicating all the spaces 13 existing in the first region A with the pintle through port 24. Further, the pressure pocket 29 is elongated in the sliding direction of the pintle 14, and when the pintle 14 is slid, the communication between the pintle through port 24 and the fluid outflow port 25 is cut off. It also plays a role in preventing On the other hand, the second fluid flow passage 22 includes the fluid passages 23 ...
One end is opened to a portion of the outer peripheral surface of the pintle 14 on the side of the second region B, and the other end is the first portion of the sliding portion 14 a of the pintle 14.
It is provided with a pintle penetration port 34 opened on the slope 14c on the region A side, and a fluid outflow port 35 formed in the housing 1 so as to correspond to the other end of the pintle penetration port 34. A pressure pocket 37 for forming a third static pressure bearing 36 between the pintle 14 and the cylinder barrel 15 is provided at one end of the pintle through port 34, and the pintle 14 is provided at the other end.
A pressure pocket 39 for forming a fourth hydrostatic bearing 38 between the slope 14c of the shaft and the inner surface of the housing 1.
Is provided. Note that these pressure pockets 37, 39
Has the same structure as the pressure pockets 27 and 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. Then, these fluid passages 42
The a, 42b, 43c and the pressure pocket 11 constitute a slight valve element 50. That is, the slight valve element 50 utilizes the relative axial displacement of the piston 8 and the torque ring 2 to selectively interrupt the supply of fluid to the pressure pockets 7a, 7b, 7c. However, when the axial deviation between the position center of the first hydrostatic bearing 3 and the center of the piston 8 is within a certain range, the pressure pocket 11 is installed in all the fluid passages 42a, 42b, 43c. Although they are in communication,
When the positional deviation between the positional center and the center of the piston 8 in the axial direction exceeds a certain value, the communication between the fluid passage 42c or 42a on the side far from the piston 8 and the pressure pocket 11 is cut off. It is designed to In addition, throttles 40a, 40b and 40c are provided in the middle of the fluid passages 42a, 42b and 43c, respectively.
The directions and areas of the both hydrostatic bearings 3 and 9 are introduced to the second hydrostatic bearing 9 and the force acting on the torque ring 2 by the hydrostatic pressure of the fluid introduced to the first hydrostatic bearing 3. The force acting on the torque ring 2 by the static pressure of the fluid is set to a value such that the magnitudes are equal and the directions are 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
The force acting on the cylinder barrel 15 by the static pressure introduced into the static pressure bearing 26 (36) and the static pressure of the fluid in the space 13 existing in the corresponding region A (B) act on the cylinder barrel 15. It is set to a value that offsets the force with which it does. Further, the fourth hydrostatic bearing 28 (38) and the hydrostatic bearing 28 (38).
The inclination angle of the slope 14b (14c) provided with is
The force acting on the pintle 14 by the static pressure of the fluid introduced into the static pressure bearing 28 (38) and the slope 14
It is set to such a value that the force acting on the pintle 14 due to the static pressure of the fluid introduced into the third bearing 26 (36) existing in the area A (B) facing the b (14c) cancels each other out. ing.

Incidentally, 43 is a seal member, and 44 is a bearing for supporting the rotary shaft as an auxiliary.

In such a static pressure type fluid energy converter, a stepping motor 51 for converting an input electric digital signal into a mechanical displacement amount and a stepping motor 51 are supported in proportion to an output displacement amount of the stepping motor 51. A servo mechanism 52 for reciprocating the element pintle 14 is provided. The servo mechanism 52 includes the pintle 14 that can reciprocate in a certain direction, an actuator 53 that reciprocates the pintle 14 using fluid pressure, and a pintle 14 that is disposed opposite to the pintle 14 and receives an operation input. An input member 54 that reciprocates in the same direction, rack teeth 55 and 56 respectively provided at portions of the input member 54 and the pintle 14 that face each other, and the rack teeth 55 and 56 that are disposed between the rack teeth 55 and 56. A spool 57 that can reciprocate in a direction parallel to the input member 54, an idle gear 58 that is axially attached to the spool 57 and meshes with the rack teeth 55 and 56, and if the spool 57 is in the neutral position, When the actuator 53 is locked and the spool 57 is moved to the non-neutral position by the movement of the input member 57, the actuator 53 is locked. Yueta 53 the spool 57 is formed by and a hydraulic circuit 59 which switches as may be operated in a direction to return to the neutral position. More specifically, the actuator 53 includes the sliding portion 1 of the pintle 14.
4a is mainly composed of a pair of fluid pressure cylinders 61 and 62 provided at both ends in the longitudinal direction of 4a. The fluid pressure cylinders 61 and 62 are cylinder holes 61 that are provided by closing the respective end surfaces 14d and 14e of the sliding portion 14a of the pintle 14.
a and 62a, cylindrical pistons 61a and 62a are slidably fitted to the pistons 61a and 62a.
b and 62b are urged outward by springs 61c and 62c housed in the cylinder holes 61a and 62a, and the outer ends thereof are opposed to the inner surfaces 1a and 1b of the housing 1 through seal members 61d and 62d, respectively. I always try to attach them. Then, the inner surfaces 1a, 1 of the housing 1
Outflow ports 61e and 62e communicating with the cylinder holes 61a and 62a are provided in b. Further, the input member 54 is a prismatic member slidably accommodated in a cover 63 having a U-shaped cross section, and has a screw hole 54 at its axial center portion.
a. The input member 54 is provided on the output shaft 64 of the stepping motor 51 with a screw portion 64a.
It is screwed to. Further, the spool 57 has lands 65 and 66 in the vicinity of both ends thereof, and both ends thereof are slidably fitted into a port block 67 provided between the housing 1 and the cover 63. I am letting you. The port block 67 and the spool 57 form high-pressure passages 68 and 69 inside and outside the lands 65 and 66, and communicate with the case drain through return ports 71 and 72 to the outside. The low pressure passages 73 and 74 are formed. Further, on the inner periphery of the port block 67, high pressure ports 75 and 76 which are always in communication with the high pressure passages 68 and 69, and inflow / outflow ports which are in communication with outflow ports 61e and 62e of the angular fluid pressure cylinders 61 and 62, respectively. 77 and 78 are opened. When the spool 57 is held at the neutral position, the lands 65 and 66 are set to block the inflow / outflow ports 77 and 78. Further, a flat portion is provided at the center of the spool 57, and a pair of idle gears 58 are rotatably attached to both sides of the flat portion via a pin shaft 81. The fluid pressure circuit 59 includes the pressure ports 75 and 76, the high pressure passages 68 and 69,
The inflow / outflow ports 77 and 78, the low pressure passages 73 and 7
4 and the return ports 71 and 72. The pressure ports 75 and 76 are communicated with the high pressure side fluid flow passage, that is, the first fluid flow passage 21 in this embodiment.

Further, a nut 83 is arranged in one cylinder 61 of the actuator 53, and a screw rod 84 is screwed onto the nut 83, and one end of the screw rod 84 is attached to the seal portion 8.
It extends through the housing 5 to the outside of the housing 1. Then, an encoder 86 as a first converting means and a display device 87 as a second converting means are provided on the extending end 84a of the screw rod 84.
Are installed in series. The nut 83 is a cylindrical body having a flange portion 83a at its inner end, and the flange portion 83a is abutted on the bottom surface 88 of the cylinder hole 61a. The nut 83 is constantly pressed against the bottom surface 88 by the elastic body in the cylinder 61, that is, the spring 61c, and reciprocates accurately following the movement of the pintle 14. Note that 83b is a locking projection for preventing the rotation of the nut 83. The screw rod 84 is for converting the reciprocating movement of the nut 83 into a rotational displacement amount, and one end thereof is connected to a rotary shaft 89 of the encoder 86 via a joint 91. The encoder 86 is a rotary type encoder configured to convert the rotation angle position of the rotation shaft 89 into an electric digital signal. Further, the display device 87 fixes a display plate 92 having scales printed on the upper end surface of the encoder 86, extends one end of the rotating shaft 89 onto the display plate 92, and extends the end 89a. The pointer 93 is attached to the.

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

Regarding the basic operation of the main body part, see JP-A-58-77.
This is as shown in Japanese Patent Publication No. 179. That is, when the high-pressure fluid is supplied into the space 13 existing in the first region A through the first fluid flow passage 21, the torque ring 2
In addition, a couple force for rotating the torque ring 2 in the arrow S direction is generated, and the function as a motor is exerted. Further, when the torque ring 2 is rotated in the direction of arrow R by an external force, the high-pressure fluid causes the first fluid flow passage 21 to flow.
It will be discharged from, and the function as a pump will be operated. The capacity of the pintle 14 can be adjusted by reciprocating the pintle 14 along the trapezoidal groove 19 and changing the eccentricity of the axis n of the pint 14 with respect to the axis m of the housing 1.

Next, the operation of the part that variably controls the capacity will be described. First, when the stepping motor 51 is stopped and the spool 57 is held at the neutral position as shown in FIG. 1, the land 65 of the spool 57,
Since the inflow / outflow ports 77, 78 are closed by 66, both the fluid pressure cylinders 61, 6 of the actuator 53 are
2 is locked and pintle 14 is held in place. From this state, when the stepping motor 51 is operated by a command from a computer (not shown) and its output shaft 64 rotates by a required angle, the input member 54 of the servo mechanism 52 screwed into the screw portion 64a of the output 64.
Will move forward and backward in a direction parallel to the operating direction of the pintle 14. It is assumed that the input member 54 has moved upward from the state shown in FIG. Then, the idle gear 58 meshing with the rack tooth 55 of the input member 54 rolls upward with the rack tooth 56 of the stopped pintle 14 as a scaffold. As a result, the spool 57 connected to the center of the idle gear 58 via the pin shaft 81 tries to move upward by a distance half the working distance of the input member 54. As a result, the one pressure port 75 and the one inflow / outflow port 77 communicate with each other through the high pressure passage 68. As a result, a part of the high-pressure fluid in the first fluid flow passage 21 passes through the ports 75 and 77 and the outflow port 6 of the one cylinder 61.
As a result, the pressurized fluid is introduced into the cylinder hole 61a. At this time, the other inflow / outflow port 78 is connected to the return port 7 via the other low pressure passage 74.
It will be connected to 2. Therefore, the pintle 14 moves downward due to the pressure of the high-pressure fluid supplied to the one cylinder 61. When the pintle 14 moves downward, the idle gear 58 rolls downward using the rack teeth 55 of the input member 54 as a scaffold, and the spool 57 is moved downward accordingly. Then, when the spool 57 returns to the above-mentioned neutral position, both the inflow and outflow ports 77,
78 is again closed by the lands 65 and 66, and the cylinders 61 and 62 are locked as before. Therefore, the pintle 14 moves in the opposite direction by the same distance as the input member 54 and stops. Next, when the input member 54 moves downward, the above description is reversed, and the pintle 14 moves upward by the same distance as the moving distance of the input member 54. .

When the pintle 14 reciprocates in this manner, the nut 83 housed in the cylinder 61 follows the pintle 14 by the urging force of the spring 61 and moves forward and backward. Then, the screw rod 8 screwed into the nut 83
4 rotates by an angle corresponding to the amount of forward / backward movement of the nut 83, and the rotational displacement amount is converted into an electric digital signal which is a detection output by the encoder 86 and is sent to a control device (not shown) as a feedback signal. To be Further, the rotational displacement amount of the screw rod 84 is displayed on the display device 87.
Is also transmitted to the pointer 93 and converted into a display value by the pointer 93 which is a detection output. That is, the operating position of the pintle 14 is displayed by the pointer 93, and can be directly read from the outside.

Then, in such a case, the pintle 14 is moved by a distance corresponding to the forward / reverse rotation amount of the stepping motor 51.
Can be reciprocated in the corresponding directions, so that the capacity can be appropriately changed corresponding to the digital signal supplied to the stepping motor 51. Then, the change amount can be converted into a digital signal by the encoder 86 and can be directly displayed on the outside by the display device 87.

Moreover, in obtaining the detection output, the actuator 53
In order to transmit the operating position of the pintle 14 to the encoder 86 or the like, the screw rod 84 is screwed to the nut 83 arranged in the cylinder 61 of the engine and the screw rod 84 is connected to the encoder 86 or the like. The mechanism is not bulky and the structure is simple. In addition, since the nut 83 is constantly abutted on the pintle 14 by the spring 61c in the actuator 53, the nut 83 can be fixed to the pintle 14 without using a special fixing tool. The operation of 14 can be accurately followed. Therefore, the operating position of the pintle 14 can be detected with high accuracy without causing difficulty in processing or assembling and complicating the structure. It is also possible to use a hydraulic pressure as the urging means of the nut. In that case, it is necessary to seal the lower part of the nut 83 and communicate the inner side thereof with the drain.

The mechanism for reciprocally moving the support element such as the pintle is not limited to that of the above embodiment,
Various modifications can be made without departing from the spirit of the present invention.

Further, in the above-mentioned embodiment, the case where both mechanical display and conversion into an electric signal are performed has been described.
However, the present invention is not limited to this, and only one of display and signal conversion may be performed.

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

EFFECTS OF THE INVENTION Since the present invention has the above-described configuration, if the reciprocating motion of the supporting element is converted into rotational displacement to obtain various detection outputs, the structure becomes complicated and the assembling work becomes complicated. It is possible to provide a rotary fluid energy converter that can easily and surely solve the problem of inviting.

[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. 1 ... Housing 2 ... Torque ring 8 ... Piston 13 ... Space 14 ... Support element (pintle) 16 ... Cylinder bore 51 ... Stepping motor 52 ... Servo mechanism 83 ... Nut 84 ... Screw rod 86 ... Conversion means (encoder) 87 ... Conversion means (display device) 93 ... Pointer

Claims (3)

[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 the relative rotation of the housing and the cylinder barrel; And a pair of fluid flow paths that respectively communicate with the starting space and the space whose volume is decreasing, and the supporting element is reciprocated in a direction orthogonal to the axis of the housing for each rotation. It can function as a variable displacement pump or variable displacement motor by changing the displacement. In the rotary fluid energy converter configured as described above, a hydraulic actuator that reciprocates the support element, a nut that is constantly attached to one end of the support element in the reciprocating direction, and a nut that is rotatable in the housing. And a screw rod whose inner end is screwed onto the nut and which is held immovably in the axial direction, and a screw rod connected to the outer end of the screw rod to detect the rotational displacement of the screw rod by detecting an electric signal or the like. A rotary fluid energy converter comprising: a conversion means for converting the output. 2. The rotary fluid energy converter according to claim 1, wherein the converting means is an encoder and the detection output is an electric digital signal. 3. A display device in which the conversion means has a pointer,
The rotary fluid energy converter according to claim 1, wherein the detection output is a value displayed by the pointer.