JPH0631612B2 - Piston pump or motor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a piston-type pump or motor that can be used in various fields of hydraulic equipment and the like.

[Prior Art] A pump or motor mainly used in the field of hydraulic equipment (means a fluid machine that functions as a pump when rotational power is applied and functions as a motor when high-pressure hydraulic oil is input. There are roughly three types of gears: vane type, piston type and piston type, but recently, there is a tendency that piston type pumps are used instead of the gear type pump or vane type pump. It is in. This is because the piston-type pump has the advantages that it is highly efficient, the pump size can be changed steplessly, and that it is suitable for high pressure. The high tilting shaft type piston pump is attracting attention.

By the way, in this type of oblique shaft type pump, it is necessary to synchronize the rotations of the cylinder block and the torque plate in order to enhance the pump rotation efficiency. There is known a structure in which the portion and the shaft center portion of the rotary shaft are connected via a so-called universal link having universal joints at both ends.

[Problems to be Solved by the Invention] However, the conventional synchronizing mechanism using the universal joint has a complicated structure, and when the both ends of the rotating shaft are to be supported by the casing, the interference with the rotating shaft occurs. Is a problem. Therefore, there is an inconvenience that it cannot be applied to a small, lightweight and stable support structure in which the rotary shaft is provided so as to penetrate the torque plate and the cylinder block and both ends thereof are supported by the casing.

Therefore, in order to eliminate such a difficulty, as shown in FIG. 13, the rotary shaft d is moved from the cylinder block a whose rear end surface is brought into sliding contact with the valve surface c of the casing b toward the torque plate g. A spline formed by extending a surrounding cylindrical body f, providing inward teeth e at the tip of the cylindrical body f, and engraving the inward teeth e on a rotary shaft d for fitting a torque plate g. It has also been proposed to employ a synchronization mechanism that is adapted to engage with the extra length of the rear end of the groove i. However, with such a structure, the rotation of the cylinder block a and the rotation axis d can be synchronized, but the rotation center of the cylinder block a cannot be completely positioned. The center of rotation is regulated by fitting the inner peripheral surface of the cylinder block a to the outer peripheral surface of the inclined cylinder j that is fitted in the casing b and protrudes from the valve surface c in the direction of the predetermined inclination axis L. It is necessary to add a centering mechanism separately. However, if this is done, energy loss due to friction between the cylinder block a and the inclined cylinder j becomes a problem that cannot be ignored in order to improve efficiency.

[Means for Solving Problems] The present invention has been made by paying attention to such circumstances.
The oblique shaft type piston or pump synchronizing mechanism as described above is provided with a cylindrical body extending from the cylinder block toward the torque plate and further provided with a convex portion at the tip thereof, while the torque plate is provided with the rotating shaft. A concave portion into which the convex portion fits is provided concentrically, and these concave and convex portions are engaged so as to be integrally rotatable in the circumferential direction of the rotary shaft and slidable in the rotation center direction of the rotary shaft. I am trying.

[Operation] With such a configuration, since the convex portion and the concave portion are engaged with each other in the circumferential direction of the rotation shaft, the rotation of the torque plate and the cylinder block can be reliably synchronized, and both are Since it can slide in the direction of the center of rotation of the rotary shaft, smooth operation is ensured even if the axis of the torque plate and the axis of the rotary shaft are inclined. Further, since the concave portion on the torque plate side is provided concentrically with the rotary shaft, the cylinder block can be positioned at a predetermined tilt axial center through the positioning of the rotation center of the convex portion engaged with this.

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

FIG. 1 is a schematic vertical cross-sectional view of a piston pump or motor according to the present invention, in which 1 is a casing having the structure of this pump or motor. This casing 1
Is composed of a front cover 2 which is a hollow cylinder, and a rear cover 3 which is liquid-tightly attached to a rear end opening of the front cover 2, and the pump which is connected to the connection port described later is connected to the rear cover part 3. Alternatively, an inflow / outflow port (not shown) forming a pair of motors is opened. The rotary shaft 4 is housed in the casing 1. The rotary shaft 4 is for input or output, and is supported by the casing 1 via a first bearing 5, and its outer end portion 4a is passed through an opening 2a provided in the Froton cover portion 2. It is extended to the outside. In addition, the spline groove 4b is formed in a portion of the rotary shaft 4 located in the casing 1 and having a required length in the middle.
Is engraved, and the torque plate 6 is spline-fitted to the portion of the spline groove 4b. Torque plate 6
Is a disk-shaped member that rotates together with the rotary shaft 4. The torque plate 6 has its front end surface 6b via a pressure receiving plate 7 whose contact surface is finished flush.
The front cover 2 is closely supported by a step wall 8 formed inside the front cover 2 in a direction orthogonal to the rotating shaft 4. Then, the cylinder block 9 is provided behind the torque plate 6.
Are installed. The cylinder block 9 is a thick-walled cylindrical body that is provided at an angle of a certain angle θ with respect to the rotation center M of the torque plate 6 and the rotation shaft 4, and its axis is not the inclination axis L. ing. The rear end surface of the rear cover 3 is slidably contacted with the valve surface 11 which is inclined by a constant angle θ with respect to the rotation center M. The rotation center M and the tilt axis L intersect at an intersection O ₁ . Further, the cylinder block 9 is provided with a plurality of cylinder holes 13 parallel to the tilt axis L and opening in the direction of the torque plate 6 at equal angular intervals in the circumferential direction. A piston 14 is slidably fitted in each of the cylinder holes 13. The piston 14 includes a piston body 15 fitted in the cylinder hole 13, and a piston body 15
Is integrally formed with a rod portion 16 extending outwardly from the above. The main body portion 15 is fitted into the inner periphery of the cylinder hole 13 with an appropriate gap (about 0.05 mm). Joint part 1
7 and a piston ring 19 provided between the fitting portion 17 and the pressing plate 18. The tip of the rod portion 16, that is, the outer end 14a that is the end of the piston 14 on the side opposite to the cylinder block is formed in a spherical shape, and the outer end 14a is pivotally supported on the torque plate 6. There is. Specifically, the same number of spherical seats 21 as the pistons 14 are provided on the end surface of the torque plate 6 at equal angular intervals in the circumferential direction, and the spherical seats 21 are provided on the outer surfaces of the pistons 14 respectively. The end 14a is rotatably fitted. The piston retainer 22 integrated with the end surface of the torque plate 6 prevents the pistons 14 from coming off the torque plate 6. Further, a synchronization mechanism 23, which will be described in detail later, is provided between the torque plate 6 and the cylinder block 9, and the torque plate 6 and the cylinder block 9 are provided.
The inner ends 1 of the pistons 14 are rotated in synchronization with
The volume of the pump chamber 12 formed on the 4b side is increased or decreased.

The pump chamber 12 is a chamber formed by the piston body 15 of the piston 14 and the cylinder hole 13, and is opened to the rear end surface of the cylinder block 9 via a fluid passage 27. Then, on the valve surface 11 of the casing 1 which slides with the rear end surface of the cylinder block 9, connection ports 28 and 29 communicating with the respective inflow / outflow ports are opened. Here, the connection port 28 communicating with one of the inflow and outflow ports exists in the region I on the right side in FIG. 4 with respect to the virtual dividing plane N including the rotation center M of the torque plate 6 and the inclined axis L. Connection port 2 communicating with chamber 12 and communicating with the other inflow / outflow port
9 are each formed in a semi-circular shape so as to communicate with the pump chamber 12 existing in the region II on the left side of the virtual dividing surface N. In this piston pump or motor, the fitting length t of the piston 14 with respect to the cylinder hole 13 is set to a small value of about 1 mm, and the tilt angle is set to 15 ° or less, preferably about 10 °. ing.

Further, the inner end 4b side of the rotary shaft 4 extends through the torque plate 6 and the cylinder block 9 to the rear cover 3 of the casing 1, and the extended end is provided on the rear cover 3. It is supported by bearings 31.

Further, in this piston or motor, the first pressure pocket (the connection port 28) is provided between the valve surface 11 and the cylinder block 9, and the outer end 14 a of the piston 14 and the torque plate 6 are provided. A second pressure pocket 32 is formed between the first pressure pocket 32 and the second pressure pocket 32, and a working fluid in the pump chamber 12, for example, a working oil, is provided in the second pressure pocket 32 through a fluid passage 33 formed in the axial center portion of the piston 14. I am trying to introduce a part of. And
The hydraulic oil in the first pressure pocket 28 presses the cylinder block 9 toward the torque plate 6 and the hydraulic oil in the pump chamber 24 presses the cylinder block 9 toward the valve face 11. And the force of the hydraulic oil in the second pressure pocket 32 pressing the piston 14 toward the cylinder block 9 side.
The hydraulic oil in the pump chamber 12 substantially balances the force pressing the piston 14 toward the torque plate 6. More specifically, as shown in FIG. 4, the opening width w ₁ of one of the connection ports 28 constituting the first pressure pocket and the width w of the sliding contact surface portion between the valve surface 11 and the cylinder block 9 will be described. _By setting ₂ to an appropriate value,
The force F _{1 by} which the hydraulic oil presses the rear end surface of the cylinder block 9 is set to a desired value. The force F ₂ by which the hydraulic oil in each pump chamber 12 presses the cylinder block 9 toward the valve surface 11 changes transiently when the pump chamber 12 and the connection port 28 are connected and disconnected. And the pump chamber 1 connected to the connection port 28.
The number of 2 changes from 4 to 5, and from 5 to 4. Therefore, the hydraulic oil in the pump chamber 12 communicating with the connection port 28 causes the cylinder block 9 to move to the valve face 1.
Although the resultant force of the force F ₂ pressing in one direction changes periodically (about 1.5% in the illustrated example), the average value of the resultant force and the force F _{1 are} small in this embodiment. The pressing force F ₂ −F ₁ is left (F ₂ > F ₁ ) so as to be substantially balanced. That is, F ₂ is slightly increased to press the cylinder 9 against the valve surface 11 to prevent the hydraulic oil from leaking from this surface. on the other hand,
The hydraulic balance for the piston 14 is as follows.
That is, the outer end 14a of the piston 14 is provided with an annular groove 34 having substantially the same diameter as the inner diameter of the cylinder hole 13, and the annular groove 34 and the recessed portion 35 provided in the spherical seat 21 in communication with the annular groove 34. And form the second pressure pocket 32. Then, the force F ₂ for pressing the operating oil the piston 14 in the pressure pocket 32 and the force F ₃ that presses the cylinder block 9 direction, the operation oil in the pump chamber 24 the piston 14 to the torque plate 8 direction ′ And the balance are almost balanced.

Further, the front end face 36 located on the side opposite to the cylinder block of the torque plate 6 is connected to the step wall 8 on the inner face of the casing 1.
A pressure pocket 38 into which the hydraulic oil in the pump chamber 12 is introduced is formed between the both surfaces 36 and 37 by being brought into close contact with the pressure receiving surface 37 of the pressure receiving plate 7 provided in the above. The thruster for pressing the torque plate 6 and the thrust force acting on the torque plate 6 from the piston 14 side can be substantially balanced. Specifically, a portion of the front surface of the torque plate 6 corresponding to each of the spherical surface seats 21 is circularly projected, and a front end surface 36 thereof is provided on the front cover 2 as a pressure receiving surface 37.
Is closely related to. Further, a pressure pocket 38 having a shape as shown in FIG. 5 is provided on the front end face 36, and a part of the hydraulic oil is introduced into the pump chamber 12 through a pressure liquid introduction passage 39 in the pressure pocket 38. There is. Then, the hydraulic oil in the pressure pocket 38 is transferred to the torque plate 6
Force F ₄ for pushing the torque plate 6 toward the piston 14 and the force F ₂ ′ for pushing the torque plate 6 toward the pressure receiving surface 37 by the hydraulic oil in the pump chamber 24 via the piston 14 in the thrust direction F ₂ ′ cos θ. I try to balance and. Therefore, the force F ₄ is substantially balanced with the thrust direction component F ₃ ′ cos θ of the force F ₃ ′ that the hydraulic oil in the pressure pocket 32 presses the torque plate 6 toward the pressure receiving surface 37.

Reference numeral 41 is a spring for pressing the torque plate 6 so that it is constantly in contact with the pressure receiving surface 37 and pressing the cylinder block 9 against the valve surface 11 with a weak force.

In the pump or motor having such a configuration, the torque plate 6 and the cylinder block 9 are
In order to ensure synchronous rotation with
Is provided. That is, as shown in FIGS. 1 to 3, the synchronization mechanism 23 has an inclined axis L about the rotary shaft 4 penetrating the inside of the casing 1 from the cylinder block 9 toward the torque plate 6. Direction cylindrical body 2
4 is integrally extended, and a divergent convex portion 25 is further provided at the tip thereof.
And a convex portion 25 which is concentric with the rotary shaft 4 at a position near the outer circumference of the rotary shaft on the rear end face of the torque plate 6 facing the convex portion 25.
Is provided, and these concavo-convex portions 25 and 26 are engaged so as to be integrally rotatable in the circumferential direction of the rotary shaft 4 and slidable in the direction of the rotation center M of the rotary shaft 4. More specifically, the convex portion 25 has a transverse section that is equally divided into nine pieces by providing a split groove 25b in the axial direction in the middle portion of each side of the tubular body whose cross-sectional shape is a regular hexagon. A mountain-shaped arm body 25a is projected from the cylindrical body 24, and the outer peripheral surface 25c of each arm body 25a is formed into an arcuate surface which becomes higher in the middle part in the axial direction. Then, in the convex portion 25, the ridge line 25d of each arm 25a and the maximum circle circumscribing the ridge line 25d are both drawn from the center O ₂ on the tilt axis L with a radius d / 2 of the sphere S. It is formed so as to form a part. On the other hand, in this case, the concave portion 26 on the side of the torque plate 6 is the projection wall 26 which is integrally provided from the inner surface of the piston retainer 22 in this case.
It consists of nine independent concave holes 26a separated by b, and each concave hole 2
The outer peripheral surface 26c of at least 6a has a cross-sectional shape corresponding to the arm 25a. In addition, these recessed holes 26a
The outermost portion of the arm 25a, on which the ridgeline 25d is fitted, is provided at a circumferential position with a radius of d / 2 from the rotation center M of the rotation shaft 4. The inner wall surface of each recess 26a is formed in a plane parallel to the rotary shaft 4. Then, the convex portion 2
5 and the concave portion 26, the convex portion 25 is inserted into the concave portion 26 whose axis coincides with the rotation center M of the rotating shaft 4 from the direction of the inclined axis L, and the center O ₂ of the convex portion 25 is rotated. The center M and the tilt axis L are engaged with each other at the intersection O _{1 where} they intersect. That is, in this state, each arm body outer peripheral surface 25c of the convex portion 25 is linearly slidably in contact with each concave hole outer peripheral surface 26c of the concave portion 26. In this engaged state, the inner peripheral surface of each arm 25a is not in contact with the recessed hole 26a.

Next, the operation and effect of this embodiment will be described.

For example, when the rotary shaft 4 such as a motor (not shown) is rotationally driven together with the torque plate 6 in the arrow X direction, the cylinder block 9 is rotated by hydraulic pressure in the same direction. At this time, due to the inclination of the inclination axis L, the piston 14 existing in the first region I is sequentially rotated along with the rotation of the cylinder bore 1.
It will be projected from inside 3. Therefore, the volume of the pump chamber 12 passing through the first region I communicating with the one connection port 28 decreases, and the other connection port 29
The volume of the pump chamber 12 passing through the second region II communicating with is gradually increased. Based on such a change in volume, one of the inflow / outflow ports or the working oil is sucked in, and the other inflow / outflow port is supplied. The pump function of discharging hydraulic oil will be exerted.

At this time, the synchronization between the torque plate 6 and the cylinder block 9 and the alignment of the cylinder block 9 are performed as follows. That is, when the rotary shaft 4 is rotated together with the torque plate 6, the cylinder block 9 is interlocked with this.
Will be rotated, but if no synchronization mechanism is provided, there is a risk of causing a rotational phase difference to both. However, in this case, as described above, the convex portion 25 of the tubular body 24 extending from the cylinder block 9, that is, the nine arm bodies 25a, is the concave portion 26 provided in the torque plate 6,
That is, since the nine corresponding recessed holes 26a are integrally rotatably engaged with each other in the circumferential direction of the rotary shaft 4, both can be reliably synchronously rotated without causing a rotational phase difference, and further, the rotary shaft 4 can be rotated. Since a relatively slidable coupling structure is adopted in the direction of the rotation center M, the rotation axes (centers) L and M of the two
Even if they cross, it is possible to smoothly rotate them synchronously because of the mechanism. It should be noted that in the static pressure balanced configuration of this embodiment, torque is hardly transmitted by this engaging portion, as will be described later in detail. Then, in this engaging portion, each arm 25a of the convex portion 25 and each concave hole 2 of the concave portion 26 are formed.
Since it is only linearly slidably in contact with 6a, the friction is slight even if both of them relatively slide in the direction of the rotation center M of the rotary shaft 4 due to the synchronous rotation. It also requires less energy loss. Further, in the case where such a synchronization mechanism 23 is provided, the center O ₁ of the convex portion 25 which is continuous with the cylinder block 9 via the tubular body 24 is such that the tilt axis L of the cylinder block 9 and the rotation center M of the rotary shaft 4 are rotated. Since the cylinder block 9 is positioned at the intersection point O ₁ of the rotation axis 4 (torque plate 6) and the cylinder block 9 synchronously, the center of rotation of the cylinder block 9 does not swing, and the rotation axis is always around the predetermined tilt axis L. It can be rotated and held. In other words, for that reason, the centering action can be obtained without providing a dedicated mechanism separately.

In the embodiment as described above, a relatively simple structure in which the convex portion 25 and the like are provided on the cylinder block 9 side and the concave portion 26 is provided on the torque plate side is sufficient, and moreover, with respect to the rotary shaft 4 of the cylinder block 9. The inclination angle θ also has the feature that it can be arbitrarily changed within a relatively wide range of application, and at the same time, there is no risk of interfering with the rotating shaft as in the conventional synchronization mechanism using a Umiversal joint. It is also possible to easily adopt a shaft-through type configuration.

The other features of the pump or the motor shown in the embodiment will be described below. In the configuration described above, the hydraulic pressures in the axial direction acting on the cylinder block 9, the piston 14 and the torque plate 8 are statically balanced, and finally the hydraulic pressure causes the torque plate 6 to rotate in the rotational direction. Is generated, and the torque is balanced with the input torque applied to the rotating shaft 4. That is, as shown in FIG.
The force F ₁ that presses the cylinder block 9 toward the piston 14 by the hydraulic oil in the connection port 28 that is the first pressure pocket, and the hydraulic oil in the pump chamber 12 that is passing through the first region I causes the cylinder block 9 to move. The sum of the forces F ₂ pressing in the direction of the valve surface 12 is approximately balanced, and the cylinder block 9 causes the oil film to move due to a slight balance difference (F ₂ −F ₁ ) and the weak biasing force of the spring 41. It comes into contact with the valve surface 11 through. Further, as shown in FIG. 7, the hydraulic oil in the pump chamber 12 presses the piston 14 toward the torque plate 6 and the force F ₂ ′ and the second pressure pocket 3 are applied.
The hydraulic oil in 2 balances with the force F ₃ that presses the piston 14 toward the cylinder block 9,
Is floating in oil. Furthermore, as shown in FIG. 8, a _'thrust force F ₂ of _the' cos [theta] force F ₂ hydraulic oil in the pump chamber 12 presses the torque plate 6 to the pressure receiving surface 37 direction via the piston 14, the pressure The hydraulic oil in the pocket 38 substantially balances the force F ₄ that presses the torque plate 6 toward the piston 14.
In other words, the hydraulic oil in the second pressure pocket 32 causes the thrust direction component F ₃ ′ cos θ of the force F ₃ ′ for pressing the torque plate 6 and the hydraulic oil in the _third pressure pocket 38 to move the torque plate 6 to the piston 14 The force F ₄ pressing in the direction is substantially balanced, and the slight force of F ₂ ′ cos θ−F ₄ and the weak biasing force of the spring 41 cause the torque plate 6 to contact the pressure receiving surface 37. Then, the torque in the rotational direction is generated in the torque plate 6 by the sum of the radial direction components F ₂ ′ sin θ of the force F ₂ ′, which opposes the torque input to the rotary shaft 4. Therefore, if this is the case, the piston 1
4, the piston 14 is rubbed against the inner surface of the cylinder block 9 due to a tilting moment, or the oil film is broken and the cylinder block 9 and the outer end 14a of the piston 14 directly contact the valve surface 11 and the spherical seat 21. It is possible to effectively prevent inconveniences such as seizure and abrasion caused by being pressed, and it is possible to significantly improve the mechanical efficiency.

Next, another embodiment of the present invention will be described. In the above-mentioned embodiment shown in FIGS. 1 to 3, the arm 25a and the recessed hole 26a forming the concave and convex portion are formed in a chevron shape in cross section, but in the present invention, the recessed hole 26a is formed. With arm 25
The sectional shape of a can be variously modified. FIG. 9 and FIG. 10 show an example of such a modification. That is, in this case, although the numbers of the arm bodies 25a and the recessed holes 26a are the same as those described above, each recessed hole 26a is formed in a circular cross section parallel to the rotation center M, while Each of the arms 25a, which is expanded and projected, has a circular cross section and has a substantially barrel-shaped external shape in which a middle portion in the direction of the inclination axis L is bulged. Each arm 25a is in line contact with each concave hole 26a on the side of the torque plate 6 on its peripheral surface. That is, in this case, the maximum circle circumscribing each arm 25a and the contour line 25e of the outer edge formed by cutting each arm 25a in the direction of the tilt axis L at the center position (the outermost part of each arm 25a) And a line connecting the positions) is formed so as to form a part of a sphere S drawn with a radius d / 2 from the center O ₂ on the tilt axis L that coincides with the intersection O ₁ . The contour line 25f of the inner edge formed by cutting each arm 25a in the direction of the tilt axis L at the center position (the line connecting the innermost positions of each arm 25a) is the translated tilt axis L '. from the center O ₃ of the upper is formed again so as to form a portion of a sphere S 'drawn with a radius d / 2 (which by each arm 25a has a rotationally symmetrical body about its axis). With such a structure, each arm 15a and each recessed hole 26a intersect at an intersection O
While being linearly contacted in a plane T perpendicular to the tilt axis L passing through ₁ , it is integrally rotatable in the circumferential direction of the rotary shaft 4 and smoothly relative to the rotational center M in the same manner as in the above embodiment. It is slidably engaged and has the same effect as that of the above embodiment.

Further, in the present invention, the convex portion 25 on the cylinder block 9 side that constitutes the synchronization mechanism is not limited to the one having the plurality of arms 25a as shown in the above example. 11 and 12
The figure shows an example of such a modification. That is, in this case, unlike the one shown in FIGS. 1 to 3, the convex portion 25 is formed of an integral rectangular tubular body 25A without the split groove 25b, and the concave portion 26 on the torque plate 6 side also corresponds to this. It is formed in the annular rectangular circumferential groove 26A.
As described above, even if the convex portion 25 is formed in the integral rectangular tubular body 25A, it operates in the same manner as described above and effectively exhibits the synchronizing action and the like. In this case, in particular, in the illustrated example, the convex portion 25A is provided with its axis aligned with the direction of the rotation center M of the rotary shaft 4, and is fitted in the concave portion 26A in parallel. However, in this case, the length of the tubular body 24 in the direction of the tilt axis L needs to be changed at the circumferential portion as shown in the figure, and the tubular body 24 does not interfere with the torque plate 6. It is necessary to adjust the extension dimension and so on.

It is to be noted that although the one fried in the drawing has the convex portions 25 (and the corresponding concave portions 26) each having a regular hexagonal cross section or is composed of nine arm bodies 25a constituting a regular hexagon, Needless to say, the number of corners of the cross section and the number of arms 25a can be increased or decreased as needed.

The application of the synchronizing mechanism according to the present invention is not limited to the one shown in FIG. 1, and may be applied to, for example, a variable displacement type piston pump or a motor. Further, the piston pump or the motor includes the one in which the rotary shaft 4 is not penetrated through the torque plate 6 and the cylinder block 9 but is supported by the front cover 2 of the casing 1 in a cantilever manner. Torque plate 6 and cylinder block 9
The present invention is particularly effective in a case in which the rotary shaft 4 is provided by penetrating through and the both ends are supported.

Further, in the above-mentioned embodiment, the case where the fitting length of the piston and the inclination angle of the inclination axis are set to very small values has been described, but the present invention is not limited to those types. is not. By the way, in the piston pump or motor of the type described above, the axial length of the cylinder block 9 can be made extremely short. Moreover, when the cylinder block 9 is extremely shortened in this way, the outer dimensions of the casing 1 do not change to a certain extent even if the outer diameter of the cylinder block 9 is slightly increased. Therefore, each piston 14 and cylinder hole 13
It is possible to reasonably increase the diameter of the slab, and it is possible to reduce the size and weight and to secure a sufficient pushing volume.

Further, the present invention is not limited to the application in which the hydraulic pressures in the axial direction acting on the cylinder block 9, the piston 14, and the torque plate 6 are statically balanced as described above, and known roller bearings and Although it is possible to receive hydraulic pressure from a ball bearing or the like, if such a structure is used, the cylinder block 9, the piston 14 and the torque plate 6 will not be subjected to an unreasonable force or friction, and the service life can be extended. Can be planned.

[Effects of the Invention] Since the present invention has the above-described configuration, the following effects can be obtained.

That is, a cylindrical body provided with a convex portion at its tip is extended from the cylinder block, and is slidable in a concave portion provided in the torque plate so as to be integrally rotatable in the circumferential direction of the rotary shaft and in the direction of the rotation center of the rotary shaft. Since they are engaged with each other as much as possible, the structure is simple and the manufacture is easy as compared with the conventional synchronizing mechanism using a umiversal joint, and the implementation is easy.

Further, in this synchronizing mechanism, since the structure in which the rotary shaft penetrates through the central portion thereof can be easily adopted, it is possible to easily adopt the type in which the rotary shaft is supported at both ends by the piston pump or the motor.

In addition, since this synchronizing mechanism also has a centering function for positioning the center of rotation of the cylinder block, it is not necessary to provide a separate centering mechanism for this purpose. Since it is easy to make the sliding friction at the engaging portion extremely small, it is possible to perform operation with less energy loss.

[Brief description of drawings]

1 to 8 show an embodiment of the present invention. 1 is a vertical sectional view of a piston pump or a motor, and FIG. 2 is a sectional view taken along the line AA of FIG. FIG. 3 is a schematic perspective view showing the engaging convex portion and the engaging concave portion in an exploded manner. Figure 4 shows the first
FIG. 5 is a sectional view taken along line VV in FIG.
FIG. 6 is a partial cross-sectional view taken along the line VI. FIG. 6, FIG. 7 and FIG. 8 are operation explanatory views for explaining the pressure balance state in the I region. 9 and 10 and FIGS. 11 and 12 show other embodiments of the present invention. 9 is a longitudinal sectional view of a main part of a piston pump or a motor, and FIG. 10 is a sectional view taken along the line BB of FIG. FIG. 11 is a longitudinal sectional view of a main part of a piston pump or a motor,
FIG. 12 is a sectional view taken along the line CC of FIG. First
FIG. 3 is a schematic partial sectional view showing a comparative example. 1 ... Casing, 4 ... Rotating shaft 6 ... Torque plate 9 ... Cylinder block 11 ... Valve face, 12 ... Pump chamber 13 ... Cylinder hole 14 ... Piston 14a ... Outer end, 14b ... Inner end 23 ... Synchronizing mechanism, 24 ... Cylindrical body 25 ... Engagement convex portion, 26 ... Engagement concave portion 25a ... Arm body, 25A ... Square tubular body 26a ... Engagement concave hole, 26A …… Rectangular groove 28 …… Connection port (pressure pocket) 29 …… Connection port 32 …… Pressure pocket L …… Inclination axis M …… Rotation center O ₁ …… Intersection O ₂ …… point

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koyoshi 25, Saiin Oiwake-cho, Ukyo-ku, Kyoto-shi, Shimazu Corporation Gojo factory (72) Inventor Tadashi Ozeki 25 Saiin Oiwake-cho, Ukyo-ku, Kyoto-shi, Kyoto Address Company Shimadzu Corporation Gojo Factory

Claims (1)

[Claims] 1. A casing having an inflow / outflow port, an input / output rotary shaft supported by the casing, a torque plate integrally rotatably provided on the rotary shaft, and a rotation center of the torque plate. A cylinder block rotatably provided around the intersecting tilt axis and having a plurality of cylinder holes parallel to the tilt axis opened toward the torque plate, and slidably fitted in each cylinder hole of the cylinder block. And a plurality of pistons whose outer ends are pivotally supported by the torque plate, and the inflow / outflow port and each cylinder hole that are provided in the casing to be attached to the end surface of the cylinder block on the side opposite to the torque plate. And a synchronization mechanism for synchronizing the rotations of the cylinder block and the torque plate. A piston pump or a motor provided, wherein the synchronization mechanism extends a cylindrical body from the cylinder block toward the torque plate, and further has a convex portion at a tip thereof, while the torque plate includes the rotation member. A concave portion into which the convex portion fits is provided concentrically with the shaft, and these concave and convex portions are engaged so as to be integrally rotatable in the circumferential direction of the rotary shaft and slidable in the rotation center direction of the rotary shaft. A piston pump or motor characterized by.