JPH0660630B2 - Oblique tandem piston pump or motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a piston-type pump or motor that can be used in various fields of hydraulic equipment.

(B) Conventional technology Pumps or motors used mainly 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 oblique shaft type piston pump is attracting attention.

By the way, the oblique shaft type piston pump includes a rotating shaft supported by a casing through a bearing, a torque plate integrally formed at an inner end of the rotating shaft, and an inclined shaft center that intersects with a rotation center of the rotating shaft. A cylinder block rotatably provided in parallel with the tilt axis and having a plurality of cylinder holes opened toward the torque plate portion; and a plurality of pistons slidably fitted in the cylinder holes of the cylinder block. Generally, a connecting rod that connects these pistons to the torque plate and a universal link that rotates the cylinder block synchronously with the torque plate are provided. However, in the conventional case, in order to suppress the weight per displacement volume to be low and improve the performance, the tilt angle is made as large as possible to lengthen the piston stroke to make the piston stroke longer. It is common knowledge that the inclination angle with respect to the rotation center is set to about 20 ° to 45 °. Therefore, in such an oblique shaft type, there is no structure in which the rotary shaft is provided by penetrating the torque plate and the cylinder block. Therefore, the rotary shaft is shared and the tandem type is arranged. There is no such thing.

(C) Objective The present invention has been made in view of such circumstances.
Equipped with the high efficiency characteristics of the diagonal axis system,
An object is to provide an oblique shaft type tandem piston pump or motor which has a simple structure and can be made small and lightweight.

(D) Configuration In order to achieve the above object, the present invention includes a torque plate and a plurality of cylinder holes that are rotatably provided around an inclined axis that intersects with the rotation center of the torque plate and that are parallel to the inclined axis. Two sets of pump structures each including a cylinder block opened toward the torque plate and a plurality of pistons slidably fitted in the cylinder holes of the cylinder block and connected to the torque plate, The cylinder block is slidably contacted with a common port block and arranged back to back, and a common rotary shaft is provided so as to penetrate the torque plate and the cylinder block of each pump structure, and each torque plate is provided on the rotary shaft. It is characterized in that it is attached so as to be integrally rotatable.

(E) Embodiment An embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 (FIGS. 1 to 5) FIG. 1 is an external view of a piston pump or a motor according to the present invention, FIG. 2 is a schematic vertical sectional view thereof, and 1 in the drawing is a casing. The casing 1 includes a cylindrical port cover 4 and a cup-shaped rear cover 3 between which a cylindrical port block 4 is provided. The port block 4 has four pairs of ports. Inflow and outflow ports 5A, 5
B, 6A and 6B (6A and 6B are provided on the back surface side in FIG. 1 and not shown) are opened. In this casing 1, two sets of pump structures A and B are arranged back to back via the port block 4. The pump structures A and B are disk-shaped torque plates 8
Cylinder blocks 9A and 9B are opposed to A and 8B. The cylinder blocks 9A and 9B are thick cylindrical bodies provided rotatably around tilt axes LA and LB inclined by a constant angle θ with respect to the rotation center M of the torque plates 8A and 8B. In particular, the inclined surfaces 11A and 11A whose rear end surfaces are formed at both ends of the port block 4 are
It is rotatably fitted to the outer circumferences of the slanting cylinders 12A and 12B planted in the port block 4 in a state of sliding contact with B. The cylinder blocks 9A and 9B are provided with a plurality of cylinder holes 13A and 13B which are parallel to the tilt axes LA and LB and open in the direction of the torque plate 8 at equal angular intervals in the circumferential direction. . The pistons 14A and 14B are slidably fitted in the cylinder holes 13A and 13B, respectively. Piston 14A,
14B is a piston body 15A, 15B fitted in the cylinder hole 13A, 13B, and a rod portion 16A extending outward from the piston body 15A, 15B.
16B and the main body 15A, 1
5B is a fitting portion 17A, 1 which fits into the inner periphery of the cylinder holes 13A, 13B with an appropriate gap (about 0.05 mm).
7B, the fitting portions 17A, 17B and the holding plates 18A, 1
8B and piston rings 19A and 19B provided between the piston rings 19A and 8B. Then, the tips of the rod portions 16A, 16B, that is, the outer ends 14A of the pistons 14A, 14B.
a and 14Ba are formed in a spherical shape, and the outer end 14
Aa and 14Ba are pivotally supported on the torque plates 8A and 8B. Specifically, the torque plates 8A, 8
The same number of spherical seats 21A, 21B as the pistons 14A, 14B are provided at one end surface of B at equal angular intervals in the circumferential direction, and the spherical seats 21A, 21B are provided with the respective pistons 14A, 14B. The outer ends 14Aa and 14Ba are rotatably fitted together. And each of these pistons 14
Piston retainers 22A and 22B prevent A and 14B from coming off the torque plates 8A and 8B. Further, the fitting length t of the pistons 14A and 14B with respect to the cylinder holes 13A and 13B is set to a value of about 1 mm, and the tilt angle is set to 15 ° or less, preferably about 10 °. The common rotary shaft 20 is connected to the torque plates 8A of the pump structures A and B,
8B and the cylinder blocks 9A, 9B are provided so as to penetrate therethrough, and the rotary shaft 20 is provided with the torque plates 8A, 8B.
Is integrally rotatably installed. Specifically, spline grooves 23A and 23B are engraved at the portions of the rotary shaft 20 that correspond to the torque plates 8A and 8B, and the torque plates 8 are placed in the spline grooves 23A and 23B.
A and 8B are spline-fitted. The first and second bearings 24, 25 are provided on both sides of the penetrating portion of the rotary shaft 20.
The front cover portion 2 and the rear cover portion 3 of the casing 1 are respectively supported through the rotary shaft 20.
One end 20a of the above is extended to the outside through the opening of the front cover 2. Further, the torque plate 8
Synchronous mechanisms 26A and 26B are provided between A and 8B and the cylinder blocks 9A and 9B, respectively, and the pistons 14A and 14A are accompanied by synchronous rotation of the torque plates 8A and 8B and the cylinder blocks 9A and 9B. Pump chamber 27 formed on the inner ends 14Ab and 124Bb of 14B
The volumes of A and 27B are increased or decreased. The synchronization mechanisms 26A and 26B have annular mounting portions 28A and 28B at their base ends.
And ring members 31A and 31B having inward teeth 29A and 29B at the tips thereof, and the annular mounting portions 28A and 28B are attached to the cylinder block 9
The inward teeth 29 are fitted and fixed on the inner circumferences of A and 9B.
A and 29B are meshed with the spline grooves 23A and 23B. Further, the pump chambers 27A and 27B have piston main bodies 15A and 15B of the pistons 14A and 14B.
Is a chamber formed by the cylinder holes 13A and 13B, and is opened to the rear end surface of the cylinder blocks 9A and 9B through fluid passages 32A and 32B. And
Connection ports 33A, 33B, 34A, 34B are opened on the valve surfaces 11A, 11B of the port plate 4 which slide with the rear end surfaces of the cylinder blocks 9A, 9B. One of the connection ports 33A and 33B is located in a region I on the right side in FIG. 3 of the virtual chamber I including the rotation center M of the torque plates 8A and 8B and the tilt axes LA and LB. 27B, and the other connection ports 34A, 34B are formed in a semi-circular shape so as to communicate with the pump chambers 27A, 27B existing in the region II on the left side of the virtual dividing surface N. . Then, the connection ports 33A, 33B on the first region I side are communicated with one of the inflow / outflow ports 5A, 5B via a passage (not shown), and the connection ports 34A, 3A on the second region II side are connected.
4B through the passage (not shown) to the other inflow / outflow port 6
It communicates with A and 6B. Also, both valve surfaces 11
A and 11B are inclined in opposite directions to each other.

Further, the torque plate 8 of each of the pump structures A and B
The surfaces 36A, 36B on the side opposite to the cylinder block A, 8B are brought into close contact with the pressure receiving surfaces 37A, 37B provided on the casing 1 so that the working fluid in the pump chambers 27A, 27B is located between these surfaces 36A, 37A, 36B, 37B. Form pressure pockets 38A, 38B into which the working fluid in the pressure pockets 38A, 38B is introduced.
Axial force pressing A, 8B and the piston 14A, 1
The axial force acting on the torque plates 8A and 8B from the 4B side can be substantially balanced. Specifically, each spherical surface seat 2 of the torque plates 8A and 8B
The pressure pockets 39A and 39B are formed in the portions 1A and 21B, and the pressure liquid introduction passages 41A and 41B are provided in the shaft center portions of the pistons 14A and 14B.
A part of the working fluid in the pump chambers 27A and 27B is introduced into A and 39B. In addition, the spherical surface seats 21A on the other end surfaces of the torque plates 8A and 8B,
21B, the part corresponding to 21B is projected circularly, and the projecting surface 3
6A and 36B are in close contact with pressure receiving surfaces 37A and 37B provided on the front cover portion 2 and the rear cover portion 3. Further, pressure pockets 38A and 38B having a shape as shown in FIG. 4 are provided on the projecting surfaces 36A and 36B, and pressure liquid introduction paths 42A and 42B are provided in the pressure pockets 38A and 38B.
A part of the pressure liquid in the pump chambers 27A and 27B is introduced through the through. And the pressure pocket 3
8A, the resultant force of the axial pressure P1 of the working fluid in 38B,
The resultant force of the axial pressure P2 of the working fluid in the pressure pockets 39A and 39B is substantially balanced.

In addition, the ring members 31A and 31 of the respective pump structures A are
Coil springs 43A, 43B are wound around the outer periphery of B, and the pressure plates 37A, 43B corresponding to the torque plates 8A, 8B and the cylinder blocks 9A, 9B by the urging force of the coil springs 43A, 43B, respectively.
37B and the valve surfaces 11A and 11B are always contacted.

Note that FIG. 2 shows the cylinder holes 13A and 1A for convenience of explanation.
The arrangement phase of 3B and the connection ports 33A, 33B, 34A, 34B, etc. is slightly distorted. See FIGS. 3 and 4 for their correct placement.

Next, the operation of this embodiment will be described.

For example, when the rotary shaft 20 is rotationally driven in the direction of the arrow X by a motor (not shown) to synchronously rotate the troop plates 8A, 8B and the cylinder blocks 9A, 9B in the same direction, the first regions are inclined due to the inclinations of the inclination axes LA, LB. The pistons 14A and 14B existing in I are rotated one by one as the cylinder bore 1
Pistons 14A and 14B existing in the second region II while being immersed in 3A and 13B are sequentially cylinder holes 13A,
It will protrude from 13B. Therefore, the volume of the pump chambers 27A, 27B passing through the first region I communicating with one of the connection ports 5A, 5B is reduced, and the second chamber II communicating with the other connecting port 6A, 6B is being passed. The volume of the pump chambers 27A, 27B of the second region II is gradually increased, and the working oil sucked from the other inflow / outflow ports 6A, 6B is introduced into the pump chambers 27A, 27B of the second region II and the first region. Pump chamber 27A, 27B of I
The hydraulic oil pushed out from the inside is one inflow port 5A,
It is discharged from 5B. When the rotary shaft 20 is rotationally driven in the opposite direction, the operation is opposite to the above description, and the working oil is sucked from the one inflow / outflow port 5A, 5B and the other inflow / outflow port 6A, 6B. High-pressure hydraulic oil is discharged from.

In this way, the pump action is carried out. In this pump, two sets of pump structures A and B are arranged back to back through the port block 4, and a common rotary shaft 20 is provided for each pump structure A. , B torque plates 8A, 8B and cylinder blocks 9A, 9B are provided so as to penetrate therethrough, so that tandem construction is possible without causing any complication of the structure. Moreover, in this way, the rotary shaft 20
Since both ends of the rotary shaft can be supported by the bearings 24 and 25, a large moment does not act on the rotary shaft unlike the one that supports the rotary shaft in a cantilever manner, and each bearing 2
It is possible to significantly reduce the load acting on the parts 4 and 25. Therefore, the rotating shaft 20 can be supported without difficulty using the small bearings 24 and 25, and the life of the bearing can be extended and the size and weight of the bearing can be reduced. In addition, since each pump structure A and B has a basic structure of a swash plate type pump, a large tilting moment acts on the piston like a swash plate type pump, which causes an increase in friction loss. And high efficiency can be obtained.

Moreover, in this embodiment, the cylinder blocks 9A and 9B are
To the extent that the rolling phenomenon of the piston outer ends 14Aa, 14Ba associated with the rotation of the piston does not hinder the operation of the pistons 14A, 14B, and the fitting length t of the pistons 14A, 14B with respect to the cylinder holes 13A, 13B. Since the inclination angles θ of the inclination axes LA and LB are both set to small values, the connecting rod can be omitted without degrading the performance, and the structure can be simplified and the size and weight can be reduced. You can That is, the rolling phenomenon means the outer ends 14Aa of the pistons 14A and 14B,
Since the distance between 14Ba and the tilt axis LA, LB changes as the cylinder blocks 9A, 9B rotate,
This is a phenomenon in which the outer ends of the pistons 14A and 14B periodically cause lateral shake with respect to the cylinder blocks 9A and 9B. This rolling phenomenon has an amplitude of T (1-co, where T is the maximum value of the separation distance and θ is the inclination angle.
sθ), but when θ is set to 10 °, the value becomes small as T (1-cos10 °) = 0.015 × T.
Therefore, if the fitting length t of the pistons 14A, 14B is set to a small value of, for example, about 1 mm, the outer peripheral surfaces of the fitting portions 17A, 17B of the pistons 14A, 14B and the cylinder holes 13A, 13B are set. Even if the fitting gap with the inner peripheral surface is made approximately the same as the fitting gap between a general piston and cylinder,
There is no inconvenience that smooth operation is hindered by the engagement between the piston and the cylinder hole. Therefore, although the pistons 14A and 14B are directly connected to the torque plates 8A and 8B,
4B and the cylinder holes 13A, 13B can be sealed, and the pistons 14A, 1
It is possible to ensure the smooth operation of 4B. In addition,
By using the piston rings 19A and 19B as in this embodiment, the sealing property can be further improved. Then, if this is the case, the pistons 14A, 1
4B has a small fitting length t and the pistons 14A, 1
The synergistic effect with the shortening of the operation stroke of 4B makes it possible to extremely reduce the axial dimension of the cylinder blocks 9A and 9B. Therefore, the connecting rod can be omitted and the structure can be simplified, and the size and weight can be greatly reduced. When the cylinder blocks 9A and 9B are extremely shortened in this way, the outer dimensions of the casing 1 do not change much even if the outer diameters of the cylinder blocks 9A and 9B are slightly increased. Therefore, the diameters of the pistons 14A and 14B and the cylinder holes 13A and 13B can be reasonably increased, and a sufficient displacement can be secured.

Second Embodiment (FIGS. 6 and 7) The second embodiment is made up of substantially the same constituent elements as those of the first embodiment described above, and the same or corresponding parts will be denoted by the same symbols and described. Is omitted.

This piston pump or motor differs from that of the first embodiment in that a valve surface 11A 'with which a cylinder block 9A of one pump structure A is in sliding contact and a valve surface 11B with which a cylinder block 9B of another pump structure B is in sliding contact. ′
This is the point where and are provided in parallel. The connection port 33A on the first area I side of the one valve surface 11A 'and the connection port 34B on the second area II side of the other valve surface 11B' are connected to the inflow / outflow ports 5A and 5B, respectively. The connection port 34A on the second area II side of the valve surface 11A 'and the connection port 33B on the first area I side of the other valve surface 11B' are connected to the inflow / outflow ports 6A and 6B, respectively.

With such a configuration, the same effects as those of the first embodiment can be obtained, and the load acting on the bearings 24 and 25 can be further reduced.
That is, in such a configuration, for example, the rotating shaft 20
When is driven to rotate in the direction of arrow X, the pump chamber 27A on the first region I side of one pump structure A and the pump chamber 27B on the second region II side of the other pump structure B become high in pressure. Therefore, the radial force w ₁ acting on the portion of the rotary shaft 20 corresponding to the pump structure A and the radial force w ₂ acting on the other portion of the rotary shaft 20 corresponding to the pump structure B are in opposite directions. As a result, the radial loads Pw ₁ and Pw acting on the bearings 24 and 25 due to the radial forces w ₁ and w ₂ , respectively.
w ₂ will cancel each other out, and each bearing 2
The load actually acting on 4, 25 is small. Therefore, it is possible to further promote the downsizing of the bearings 24 and 25 and the extension of their service lives.

In each of the above-described embodiments, the case where the torque plate is thrust-supported on the pressure receiving surface of the casing via the so-called static pressure bearing has been described, but the present invention is not limited to such a case, and for example, a torque plate and A mechanical thrust bearing may be interposed between the casings.

Further, in each of the above-described embodiments, the case where the suction of both pump structures is taken separately has been described, but the two suction ports may be made common.

Furthermore, in each of the above-described embodiments, the case where it functions as a pump has been described, but it is also possible to function as a motor by supplying a high-pressure working fluid to any of the inflow and outflow ports.

(F) Effect The present invention having the above-described configuration has the oblique shaft type high efficiency characteristics as it is, and further, the oblique shaft type tandem piston pump has a simple structure and can be reduced in size and weight. Alternatively, a motor can be provided.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 is a front view showing an external appearance, FIG. 2 is an enlarged vertical sectional view, and FIG. 3 is a perspective view schematically showing a valve face. 4 is a partial sectional view taken along line IV-IV, and FIG. 5 is a partially enlarged sectional view of the torque plate. FIG. 6 is a vertical sectional view showing another embodiment of the present invention, and FIG. 7 is a perspective view schematically showing a valve face portion of the same embodiment. 1 ... Casing 4 ... Port block 5A, 5B, 6A, 6B ... Inflow / outflow port 8A, 8B ... Torque plate 9A, 9B ... Cylinder block 13A, 13B ... Cylinder hole 14A, 14B ... Piston 27A, 27B ... Pump chamber 24, 25 ... Bearing A, B ... Pump structure LA, LB ... Inclined axis M ... Rotation center

 ─────────────────────────────────────────────────── ─── Continued front page (72) Masahiro Iwasaki, Inventor Masahiro Iwasaki 25, Saiin Oiwake-cho, Ukyo-ku, Kyoto Prefecture Shimazu Corporation Gojo Plant (72) Inventor Kazushige Nakagawa Saiin Oiwake-cho, Kyoto-shi, Kyoto 25 Incorporated company Shimadzu Gojo factory (72) Inventor Koyoshi 25 In Saiin Oiwake-cho, Ukyo-ku, Kyoto city Kyoto Prefecture Incorporated Shimadzu company Gojo factory (56) References 55-158281 (JP, U) US Patent 3162142 (US, A) US Patent 3291068 (US, A)

Claims (1)

[Claims] 1. A cylinder block in which a torque plate and a plurality of cylinder holes that are rotatably provided around an inclined axis that intersects with a rotation center of the torque plate and that are parallel to the inclined axis are opened toward the torque plate. And two sets of pump structures each including a plurality of pistons slidably fitted in the cylinder holes of the cylinder block and connected to the torque plate, and the cylinder blocks are slidably contacted with a common port block. And arranged back to back, and a common rotating shaft is provided so as to penetrate the torque plate and the cylinder block of each pump structure,
An oblique shaft type tandem piston pump or motor, wherein each of the torque plates is integrally rotatably attached to the rotary shaft.