JPH0332787Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a piston-type pump or motor that can be used in various hydraulic equipment fields.

[Prior Art] Pumps or motors mainly used in the field of hydraulic equipment (meaning fluid machines that function as pumps when rotary power is applied and as motors when high-pressure hydraulic oil is input; hereinafter, when used as pumps) (The explanation will proceed based on the assumption that It is in. This is because piston pumps have the advantage of being highly efficient, allowing the pump size to be changed steplessly, and being suitable for high pressure applications. Oblique shaft type piston pumps are attracting attention.

By the way, oblique shaft type piston pumps are generally
A torque plate is integrally formed on the inner end of the rotating shaft supported by the casing via a bearing, and a thrust bearing or a combined thrust/radial bearing is provided to receive the axial force applied to this torque plate. . However, this requires a large bearing, which is one of the causes of disadvantages such as an increase in the size and weight of the pump, an increase in price, and a shortened lifespan. Therefore, as a measure to eliminate such inconvenience, the casing side surface of the torque plate is brought into sliding contact with a pressure receiving surface formed on the inner wall of the casing, so that the axial force is received by the pressure receiving surface. It is being considered. With such a pump, there is no need to provide a mechanical thrust bearing, so the pump can be made smaller, lighter, cheaper, and have a longer life.

However, in this case, among the forces acting on the torque plate, a force in a direction perpendicular to the axis (hereinafter referred to as an axis-perpendicular force) is applied via the rotating shaft to a bearing that supports the rotating shaft. Therefore, the bearing needs to have a size and weight sufficient to withstand the force in the direction perpendicular to the axis, which hinders the pump from being smaller and lighter, lower in price, and longer in life. In particular, in conventional models, a torque plate is fixed to the tip of the rotating shaft, and this rotating shaft is cantilever-supported by the front cover of the casing via a pair of bearings. It was necessary to use a very large bearing to support the rotating shaft, or to make the front cover part long to ensure a large distance between both bearings.

[Problems to be solved by the invention] The present invention was developed with a focus on these circumstances, and eliminates the need for thrust bearings or thrust/radial bearings, resulting in smaller size, lighter weight, lower cost, and longer life. In addition, by preventing large axis-perpendicular force due to fluid pressure from being applied to the bearing that supports the rotating shaft, and by allowing both ends of the rotating shaft to be supported by bearings, the compact and lightweight It is an object of the present invention to provide a piston pump or motor that can further promote reduction in price, reduction in price, and extension of service life. Furthermore, it is an object of the present invention to be able to easily disassemble and assemble the rotary shaft even though it is of the oblique shaft type and has both ends of the rotating shaft supported by bearings as described above, and to easily connect the torque plate and cylinder block. The purpose is to enable accurate rotational synchronization by adjusting the configuration.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a torque plate formed on the inner wall of the casing, which is rotatably provided on the rotating shaft and pivotally supports the outer end of the piston. A radial bearing is provided on the inner circumferential wall of the casing to make sliding contact with the pressure receiving surface and to support the outer circumferential surface of the torque plate, and further, the rotating shaft is provided so as to pass through the cylinder block and the torque plate. . A spline groove is provided on the rotating shaft, the torque plate is spline-fitted into the spline groove portion, and inward teeth fixed to the cylinder block are engaged with the spline groove to form a rotation synchronization mechanism. It is characterized by the presence of

[Function] With such a device, the axial force applied to the torque plate based on fluid pressure is received by the pressure receiving surface of the inner wall of the casing, and the axially perpendicular force applied to the torque plate is received by the inside of the casing that supports the torque plate. Since it is received by a radial bearing on the peripheral wall,
A thrust bearing is not required, and furthermore, no axis-perpendicular force due to fluid pressure is applied to the bearing supporting the rotating shaft. Furthermore, since the rotating shaft is provided so as to pass through the cylinder block and torque plate, the rotating shaft can be supported at both ends with the cylinder block and torque plate interposed therebetween. Therefore, the load is easily distributed to each bearing, and the load acting on each bearing can be significantly reduced compared to the case where the rotating shaft is supported cantilevered. Therefore, each bearing can be further downsized.

Furthermore, since the torque plate and cylinder block are engaged with spline grooves provided on the rotating shaft, the rotating shaft can be easily inserted into and removed from the torque plate and cylinder block. Therefore, disassembly and assembly can be easily performed. Moreover, since the torque plate and cylinder block are synchronized in rotation via a common spline groove provided on the rotating shaft, the number of parts can be reduced and the accumulation of errors between transmission parts can be reduced. be able to.
Therefore, with a simple configuration, it is possible to rotationally synchronize the torque plate and the cylinder block with high accuracy.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is a schematic vertical sectional view of a piston pump or motor according to the present invention, and numeral 1 in the figure is a casing. The casing 1 includes a cylindrical front cover part 2 having a front end bearing part 2a and a rear end opening part 2b, and a rear cover part 3 liquid-tightly attached to the rear end opening part 2b of the front cover part 2. A pair of inflow and outflow ports 4 and 5 are opened in the rear cover portion 3. A rotating shaft 6 is housed within this casing 1. The rotating shaft 6 is for input or output, and is supported by the casing 1 via a first bearing 7.
The outer end 6a is the open end 1a of the casing 1.
It extends to the outside through. Further, a spline groove 6b is formed in a portion of the rotating shaft 6 located inside the casing 1, and a torque plate 8 is spline-fitted into the spline groove 6b portion. The torque plate 8 has a disk-shaped piston pivot portion 8a disposed within the rear end opening 2b of the front cover portion 2, and a base end fitting portion 8b disposed within the bearing portion 2a. The rotary shaft 6 rotates integrally with the rotary shaft 6. A cylinder block 9 is disposed behind this torque plate 8. The cylinder block 9 is a thick-walled cylindrical body rotatably provided around an inclined axis L that is inclined by a certain angle θ with respect to the rotation center M of the torque plate 8 and the rotation shaft 6. It is rotatably fitted onto the outer periphery of an inclined cylinder 12 implanted in the rear cover part 3 with its rear end surface slidingly in contact with a valve surface 11 formed on the rear cover part 3. Further, the cylinder block 9 is provided with a plurality of cylinder holes 13 which are parallel to the inclined axis L and open toward the torque plate 8 at equal angular intervals in the circumferential direction. A piston 14 is slidably fitted into each of these cylinder holes 13. and,
The outer end 14a of the piston 14 is formed into a spherical shape, and is pivoted on the torque plate 8. Specifically, the piston 14 is attached to the end surface of the torque plate 8 on the piston side.
The same number of spherical seats 15 are provided at equiangular intervals in the circumferential direction, and the outer end 14a of each piston 14 is rotatably fitted into each of these spherical seats 15. Further, a rotation synchronization mechanism 16 is provided between the torque plate 8 and the cylinder block 9, and as the torque plate 8 and the cylinder block 9 rotate synchronously, the inner end of each piston 14 is rotated. The volume of the pump chamber 17 formed on the 14b side is increased or decreased. The rotation synchronization mechanism 16, as clearly shown in FIG.
A cylinder block 9 is inserted into a spline groove 6b provided on the rotating shaft 6 in order to fit the torque plate 8.
Inward facing teeth 16a fixedly engaged with each other.

The pump chamber 17 is a chamber formed by the inner end 14b of the piston 14 and the cylinder hole 13, and is opened at the rear end surface of the cylinder block 9 via a fluid passage 18. Connection ports 19 and 21 communicating with the inflow and outflow boats 4 and 5 are opened in the valve surface 11 of the casing 1 which slides on the rear end surface of the cylinder block 9. A connection port 19 that communicates with one of the inflow and outflow ports 4 is connected to a pump chamber 17 that exists in a region to the right in FIG. In addition, the connection ports 21 communicating with the other inflow/outflow port 5 are each formed in a semicircular arc shape so as to communicate with the pump chamber 17 located in the region to the left of the virtual dividing plane N. .

Further, the inner end 6c side of the rotating shaft 6 extends through the torque plate 8 and the cylinder block 9 to the rear cover portion 3 of the casing 1, and the extending end is provided in the rear cover portion 3. It is supported by a second bearing 22. That is, the rotating shaft 6 is supported at both ends by the bearing 7 and the bearing 22, which are disposed on both sides of the torque plate 8 and the cylinder block 9.

Furthermore, the casing 1 of the torque plate 8
The side end surface 23 is supported by a pressure receiving surface 25 provided on the casing 1 via a hydrostatic bearing 24. Specifically, a pressure pocket 26 is formed in each spherical seat 15 of the torque plate 8, and a pressure fluid introduction part 27 is formed in the axial center of the piston 14.
A portion of the working fluid in the pump chamber 17 is introduced into the pressure pocket 26. Further, the portion of the other end surface of the torque plate 8 corresponding to each of the spherical seats 15 is made to protrude in a circular shape, and the protruding surface 23 thereof is brought into close contact with the pressure receiving surface 25 provided on the front cover portion 2. Furthermore, a pressure pocket 28 having a shape as shown in FIG. 4 is provided on the protruding surface 23, and a part of the pressure fluid in the pump chamber 17 is introduced into the pressure pocket 28 through a pressure fluid introduction path 29. The above-mentioned hydrostatic bearing 2
4. And the pressure pocket 2
The resultant force of the axial pressure P1 of the working fluid in the pressure pocket 26 and the axial pressure P2 of the working fluid in the pressure pocket 26
The resultant force is approximately balanced.

Further, a coil spring 31 is wound around the outer periphery of the rotation synchronization mechanism 16, and the biasing force of the spring 31 keeps the torque plate 8 and the cylinder block 9 in contact with the corresponding pressure receiving surface 25 and valve surface 11, respectively. I try to let them do it.

In such a device, the inner peripheral wall 33 of the rear end opening 2b of the front cover portion 2 of the casing 1
A sliding bearing 34, which is a radial bearing, is attached in an annular manner to the piston pivot portion 8 of the torque plate 8.
The outer circumferential surface 35 of a is supported.

In FIG. 1, for convenience of explanation, the wiring phases of cylinder holes, connection ports, etc. are slightly different from the actual ones. The correct placement position for these is the third
See Figures and FIG.

Next, the operation of this embodiment will be explained.

For example, when the rotary shaft 6 is driven to rotate in the direction of arrow X by a motor (not shown) and the torque plate 8 and cylinder block 9 are synchronously rotated in the same direction, the piston 14 existing in the first region due to the inclination of the tilted axis L As the piston rotates, the piston 14 successively protrudes from the cylinder hole 13, and the piston 14 existing in the second region gradually retracts into the cylinder hole 13. Therefore, the volume of the pump chamber 17 passing through the first region communicating with one connection port 19 gradually increases, and the volume of the pump chamber 17 passing through the second region communicating with the other connection port 21 gradually decreases. Therefore, one of the inflow and outflow ports 4
The hydraulic oil sucked in from the pump chamber 17 in the first area is introduced into the pump chamber 17 in the first area, and the hydraulic oil pushed out from the pump chamber 17 in the second area is discharged from the other inflow/outflow port 5. Note that if the rotating shaft 6 is driven to rotate in the opposite direction, the operation will be opposite to that described above, and hydraulic oil will be sucked in from the other inflow/outflow port 5 and high pressure operation will occur from the one inflow/outflow port 4. Oil is discharged.

In this way, the pumping action is performed. In this embodiment, the surface 23 of the torque plate 8 on the casing 1 side is brought into sliding contact with the pressure receiving surface 25 formed on the inner wall of the casing 1, and the axial force is is received by the pressure receiving surface 25, there is no need to provide a thrust bearing to receive the axial force, and the pump can be made smaller, lighter, cheaper, and have a longer lifespan.

Further, since the outer circumferential surface 35 of the piston pivot portion 8a of the torque plate 8 is supported by a slide bearing 34 attached to the inner circumferential wall 33 of the casing 1, the force applied to the torque plate 8 in the direction perpendicular to the axis is transferred to the slide bearing. 34, and the force in the direction perpendicular to the axis is not applied to the bearings 7 or 22 via the rotating shaft 6. Therefore, the bearings 7 and 22 do not need to be large and heavy enough to withstand the force in the direction perpendicular to the axis, but can be small and lightweight and can withstand long-term use. As described above, according to this embodiment, the bearings 7 and 22 can be made smaller and lighter and have a longer life, so that the entire device can be made even more compact and have a longer life. In particular, since the rotary shaft 6 is provided through the torque plate 8 and the cylinder block 9, both the bearings 7, 2
2 can be disposed on both sides of the torque plate 8 and the cylinder block 9, and the rotating shaft 6 can be supported at both ends. Therefore, the load acting on each of the bearings 7 and 22 can be further reduced compared to the case where the rotating shaft 6 is supported in a cantilever manner. Therefore, each of these bearings 7, 22 can be further downsized, and durability can also be improved.

In the above embodiment, the outer peripheral surface 35 of the piston pivot portion 8a of the torque plate 8 is connected to the radial bearing 34.
I explained what was supported by
Of course, the present invention is not limited to such a structure. For example, as shown in FIG. 42 may be attached in an annular shape, and the outer circumferential surface 43 of the proximal end fitting portion 8b of the torque plate 8 may be supported by the slide bearing 42.

Furthermore, radial bearings are not limited to sliding bearings.

Furthermore, the present invention is not limited to one in which a pressure pocket is provided between the torque plate and the casing to balance the axial force acting on the torque plate by means of a working fluid, but it is not limited to one in which both surfaces are simply brought into sliding contact. However, as long as the axial force is balanced by the working fluid, the sliding contact can be smoothly performed.

Various other modifications can be made without departing from the spirit of the present invention.

[Effects of the invention] Since the present invention has the above-mentioned configuration, it is possible to eliminate the need for thrust bearings or thrust/radial bearings, making it possible to achieve smaller size, lighter weight, lower cost, and longer life. This prevents the application of a large force in the direction perpendicular to the axis due to fluid pressure, and the bearings can be placed on both sides of the torque plate and cylinder block to support the rotating shaft at both ends, making it compact and lightweight. Accordingly, it is possible to provide a piston pump or motor that can further promote reduction in cost, cost reduction, and longevity. In addition, in this invention, the torque plate and cylinder block are engaged with the spline groove provided on the rotating shaft.
The rotary shaft can be easily inserted into and removed from the torque plate and cylinder block, allowing for easy disassembly and assembly. Therefore, it is possible to simplify manufacturing and maintenance work.
Moreover, since the torque plate and cylinder block are synchronized in rotation via a common spline groove provided on the rotating shaft, the number of parts can be reduced and the accumulation of errors between transmission parts can be reduced. be able to. Therefore, with a simple configuration, it is possible to rotationally synchronize the torque plate and the cylinder block with high precision. Therefore, from this point as well, it is possible to achieve a reduction in size and weight.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, with Figure 1 being a longitudinal sectional view, Figure 2 being an enlarged sectional view of the main parts, and Figure 3 being an enlarged sectional view of the main parts.
The figure is a view taken in the direction of the arrows in FIG. 1, FIG. 4 is a partial sectional view taken along the - line in FIG. 1, and FIG. 5 is an explanatory diagram showing the hydraulic balance. FIG. 6 is a sectional view corresponding to FIG. 2 showing the main parts of another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Casing, 6... Rotating shaft, 6b... Spline groove, 7... Bearing, 8... Torque plate, 14... Piston, 14a... Outer end, 16
... Rotation synchronization mechanism, 16a ... Inward tooth, 22 ...
Bearing, 25...pressure receiving surface, 33, 41...inner peripheral wall,
34, 42... Radial bearing, 35, 43... Outer peripheral surface.

Claims (1)

[Scope of utility model registration request] A torque plate, which is provided to be integrally rotatable with the rotating shaft supported by the casing via a bearing and pivots the outer end of the piston, is brought into sliding contact with a pressure-receiving surface formed on the inner wall of the casing, and the rotating shaft an oblique shaft-shaped piston, which is provided so as to pass through a cylinder block that holds an inner end side of the piston and the torque plate, and is provided with a radial bearing that supports the outer peripheral surface of the torque plate on the inner peripheral wall of the casing. A pump or a motor, in which a spline groove is provided on the rotating shaft, the torque plate is spline-fitted into the spline groove portion, and internal teeth fixed to the cylinder block are engaged with the spline groove to synchronize the rotation. A piston pump or motor comprising a mechanism.