JPH022946Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a piston-type pump or motor that can be used in various hydraulic equipment fields.

(b) Prior art Pumps or motors used primarily 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; below, 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. Tall oblique shaft piston pumps are attracting attention. Therefore, it is strongly desired that such oblique shaft type piston pumps be further reduced in size and weight and provided at low cost.

Incidentally, a diagonal shaft type piston pump has a rotating shaft supported by a casing via a bearing, a torque plate integrally formed on the inner end of this rotating shaft,
a cylinder block which is rotatably provided around an inclined axis that intersects with the center of rotation of the rotating shaft and has a plurality of cylinder holes opened toward the torque plate portion parallel to the inclined axis, and each cylinder of this cylinder block; The cylinder block includes a plurality of pistons that are slidably fitted into holes, a connecting rod that connects these pistons to the torque plate, and a synchronization mechanism that rotates the cylinder block in synchronization with the torque plate. Things are common. By the way, as a conventional synchronization mechanism, one is known in which the axial center of a cylinder block and the axial center of a rotating shaft are connected via a so-called universal link having a universal joint at both ends. However, these structures are complex. In particular, recently, as will be described later, the inclination angle of the tilted axis with respect to the rotation center of the rotary shaft is set to a small value, and the rotary shaft is provided so as to pass through a torque plate and a cylinder block, and both ends of the rotary shaft are mounted on bearings. It has been considered to significantly reduce size and weight by supporting the casing through the casing, but with such a structure, interference between the rotating shaft and the universal link, etc., becomes a problem. , it is impossible to use the conventional synchronization mechanism described above. In other words, when a torque plate is provided at the free end of the rotating shaft and the rotating shaft is cantilever-supported only by a pair of bearings housed in the front cover of the casing, in other words, the commonly used type In some cases, in order to ensure the distance between the pair of bearings, it is necessary to make the front cover part elongated in the axial direction, and to prevent this, if the two bearings are brought close together, the front cover will act on each bearing. It is well known that there is a dilemma in that as the bending load increases, it is necessary to use large bearings with a large capacity. On the other hand, a shaft is provided to pass through the torque plate and cylinder block,
When the rotating shaft is supported by a bearing housed in the front cover part of the casing and a bearing housed in the rear cover part, the torque plate and cylinder block are located between these two bearings. Therefore, it is possible to easily secure the axial distance between the two bearings. Therefore,
The rotary shaft can be supported without making the front cover portion elongated in the axial direction or making each bearing large in load capacity, and the overall weight and size can be reduced. However, if such a configuration is adopted, the rotating shaft will be inserted through the part where a synchronization mechanism such as a universal joint was conventionally arranged, making it impossible to incorporate such a conventional synchronization mechanism. . In addition, as a synchronization mechanism that can be used even with such a structure, for example, helical gears are provided on the outer peripheral edges of the cylinder block and torque plate, respectively,
It is conceivable that both of these gears are brought into mesh with each other at a portion where the cylinder block and the torque plate are closest to each other. However, with such a structure, a large diameter helical gear must be formed on both the cylinder and the torque plate, which is disadvantageous in that it takes time and effort to manufacture. Furthermore, since there is a limit to the meshing depth of both helical gears, this device has the problem that it is difficult to apply it to a variable displacement type device in which the inclination angle of the cylinder block can also be changed.

(c) Purpose The present invention was developed with attention to the above-mentioned circumstances, and even if the rotating shaft is provided through the torque plate and the cylinder block, the cylinder block can be reliably synchronized with the torque plate using a simple structure. It is an object of the present invention to provide a piston pump or motor that can be manufactured easily, and can be made smaller and lighter.

(D) Structure In order to achieve the above object, the present invention provides a piston pump or motor as described above, in which the synchronization mechanism is formed by a ring member having an annular mounting portion at the base end and inwardly facing teeth at the distal end. A torque electric engagement portion such as a spline groove or a key groove, in which the annular mounting portion is fitted and fixed to the inner periphery of the cylinder block, and the inwardly directed teeth are provided on the outer periphery of the rotating shaft, that is, a torque plate. It is characterized in that it is meshed with a torque transmission engagement portion for connection to a rotating shaft, and that the rotating shaft is provided so as to penetrate through the ring member, the torque plate, and the cylinder block.

(E) Embodiment An embodiment of the present invention will be described below 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 consists of a cylindrical front cover part 2 and a rear cover part 3 which is liquid-tightly attached to the rear end opening of the front cover part 2.The rear cover part 3 has a pair of outflow ports. Inlet ports 4 and 5 are open. 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.
Its outer end 6a extends outside through an opening 2a provided in the front cover section 2.
Further, a spline groove 6 serving as a torque transmission engagement portion is provided in a portion of the rotating shaft 6 located inside the casing 1.
A torque plate 8 is spline-fitted into the spline groove 6b. The torque plate 8 is disc-shaped and rotates together with the rotating 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 tube 12 implanted in the rear cover section 3 with its rear end surface slidingly in contact with an inclined surface 11 formed on the rear cover section 3. Also, this cylinder block 9
A plurality of cylinder holes 13 which are parallel to the tilt axis L and open toward the torque plate 8 are provided at equal angular intervals in the circumferential direction. A piston 14 is slidably fitted into each of these cylinder holes 13. Piston 14
The piston body 15 is integrally formed with a piston body 15 that fits into the cylinder hole 13 and a rod portion 16 that extends outward from the piston body 15. It includes a fitting part 17 that fits into the inner periphery of the hole 13 with an appropriate gap (approximately 0.05 mm), and a piston ring 19 interposed between the fitting part 17 and the holding plate 18. .
The tip of the rod portion 16, that is, the outer end 14a of the piston 14 is formed into a spherical shape, and the outer end 14a is pivotally supported on the torque plate 8. Specifically, the same number of spherical seats 21 as the pistons 14 are provided on one end surface of the torque plate 8 at equal angular intervals in the circumferential direction, and each of the spherical seats 21 is provided with the same number of spherical seats 21 as the pistons 14 .
The outer ends 14a of the two are rotatably fitted together. A piston retainer 22 prevents each piston 14 from coming off the torque plate 8. Further, a synchronizing mechanism 23 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 ends 14b of each piston 14 The volume of the pump chamber 24 formed on the side is increased or decreased.

As shown in FIGS. 1 and 5, the synchronizing mechanism 23 includes a ring member 27 having an annular attachment portion 25 at its base end and inward teeth 26 at its distal end. 25 is fitted and fixed to the inner periphery of the cylinder block 9, and the inward teeth 26 are engaged with the rear end of the spline groove 6b. Specifically, the ring member 27 is
It is a stepped cylindrical body made of thin steel plate, etc., and the annular attachment part 25 that forms the large diameter part is connected to the pin 2.
8 to the inner periphery of the cylinder block 9. Then, a number of inward facing teeth 2 corresponding to the number of spline grooves 6b are provided at the open end of the small portion.
6 are provided at equal pitches, and these inward teeth 26 are tiltably engaged with the splines 6b.

The pump chamber 24 is a chamber formed by the piston body 15 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 29. Connecting ports 31 and 32 communicating with the inflow and outflow ports 4 and 5 are opened in the inclined surface 11 of the casing 1 which slides on the rear end surface of the cylinder block 9. A connection port 31 that communicates with one of the inflow and outflow ports 4 is connected to a pump chamber 24 that is located in a region to the right in FIG. In addition, the connection ports 32 communicating with the other inflow/outflow port 5 are each formed in a semicircular arc shape so as to communicate with the pump chamber 24 located in a region to the left of the virtual dividing plane N. There is.

And this piston pump or motor is
The fitting length t of the piston 14 into the cylinder hole 13 is set to a small value of about 1 mm, and the inclination angle is set to 15 degrees or less, preferably about 10 degrees.

Further, the inner end 6b 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 thereof is provided in the rear cover portion 3. It is supported by a second bearing 33.

Furthermore, a pressure pocket 36 is formed in which the surface 34 of the torque plate 8 on the side opposite to the cylinder block is brought into close contact with the pressure receiving surface 35 provided on the casing 1, and the working fluid in the pump chamber 24 is introduced between these surfaces 34 and 35. and is configured so that the axial force of the working fluid in the pressure pocket 36 pressing the torque plate 8 and the axial force acting on the torque plate 8 from the piston 14 side are approximately balanced. There is. Specifically, a pressure pocket 37 is provided in each spherical seat 21 of the torque plate 8.
At the same time, a pressure fluid introduction passage 38 is provided at the axial center of the piston 14, and this pressure pocket 37
A part of the working fluid in the pump chamber 24 is introduced into the pump chamber 24. Further, the portion of the other end surface of the torque plate 8 corresponding to each of the spherical seats 21 is made to protrude in a circular shape, and the protruding surface 34 thereof is brought into close contact with a pressure receiving surface 35 provided on the front cover portion 2. Further, a pressure pocket 36 having a shape as shown in FIG.
A part of the pressure liquid in 4 is introduced. The resultant force of the axial pressure P1 of the working fluid in the pressure pocket 36 and the resultant force of the axial pressure P2 of the working fluid in the pressure pocket 37 are approximately balanced.

In FIG. 1, for convenience of explanation, the arrangement phases of cylinder holes, connection ports, etc. are slightly different from the actual arrangement. The correct location for these is the second
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 24 passing through the first region communicating with one connection port 4 gradually increases, and the volume of the pump chamber 24 passing through the second region communicating with the other connection port 5 gradually decreases. As a result, the hydraulic oil sucked from one of the inflow and outflow ports 4 flows into the pump chamber 2 of the first region.
Hydraulic oil introduced into the pump chamber 4 and pushed out from the inside of the pump chamber 24 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, and as the synchronizing mechanism 23 for synchronously rotating the rotating shaft 6, the torque plate 8, and the cylinder block 9, the ring member 27 is used as the main body, as described above. Since it is used, it is possible to simplify the structure, thereby making it easier to manufacture and reducing the size and weight. That is, the ring member 27 is attached to the annular attachment portion 2 on the base end side.
5 is fixed to the cylinder block 9, and
Since the inward teeth 26 on the tip side only engage a part of the spline groove 6b for connecting the torque plate 8 to the rotating shaft 6, a synchronization mechanism is provided on the rotating shaft 6 and the cylinder block 9. No special processing is required. Therefore, compared to the case where a universal joint type synchronization mechanism is used, which requires complex and highly accurate machining of the cylinder block 9 and rotating shaft 6, the structure can be simplified and manufacturing can be facilitated. . Moreover, since the ring member 27 can be constructed only from a thin cylindrical member, the structure can be simplified and the overall size and weight can be reduced. Further, with such a synchronization mechanism 23, the rotating shaft 6 can be passed through the center of the synchronization mechanism 23 without any difficulty. Therefore, the rotating shaft 6 is connected to the ring member 2.
7. Torque plate 8 and cylinder block 9
Even if the structure is such that the rotary shaft 6 is provided through the rotary shaft 6 and both ends of the rotary shaft 6 are supported by the bearings 7 and 33, the synchronizing mechanism 23 will not get in the way. However, by doing this, a large moment is generated at the bearing part unlike the conventional system in which the rotating shaft supporting the torque plate at the free end is cantileverly supported by a pair of bearings housed in the front cover part. Therefore, the load acting on each bearing 7, 33 can be significantly reduced. Therefore, the rotating shaft 6 can be easily supported using the small bearings 7 and 33, and from this point of view as well, the device can be made smaller and lighter.

Then, in this way, the rotating shaft 6 is connected to the ring member 27.
If the pump can be provided through the cylinder block 9, it becomes easy to use a common rotating shaft for a plurality of pumps or motors to form tandem units.

Note that the structure of the ring member is not limited to that described above, and may be, for example, as shown in FIGS. 6 and 7. That is, the ring member 27' of the synchronizing mechanism 23' shown in these drawings
is made of a spring material, and the inward tooth 26' provided at the tip is elastically engaged with the spline groove 6a by the elasticity of the tongue piece 27a'. With such a structure, the inwardly directed teeth 26' and the spline groove 6b can always be engaged with each other without any gap, so that the backlash can be minimized. Further, in this device, an elastic piece 42 having a protrusion 41 is integrally provided on the annular mounting portion 25, and the protrusion 41 is attached to the inner periphery of the cylinder block 9 by utilizing the elastic deformation of the elastic piece 42. He is trying to engage with the provided recess 43. In this way, it is possible to simplify the assembly work.

Furthermore, it goes without saying that the number of inward teeth of the ring member does not have to be the same as the number of spline grooves.
For example, various modifications can be made, such as making the ring member 27' have about three inward facing teeth.

Further, in the above embodiments, a fixed capacitance type was described, but the present invention can be similarly applied to a variable capacitance type. That is, in the present invention, even if the inclination angle of the inclination axis with respect to the rotation center of the rotating shaft is changed, the inward teeth of the ring member are positioned so as to face the intersection of the rotation center M and the inclination axis L. It is possible to prevent the engagement position with the spline groove from being displaced in the axial direction, and therefore, smooth variable displacement operation can be performed without causing any inconvenience to the synchronization mechanism.

Further, the torque transmission engaging portion is not limited to a spline groove, but may be, for example, a key groove.

(F) Effect Since the present invention has the above-mentioned configuration, the rotating shaft is provided so as to pass through the torque plate and the cylinder block, so this rotating shaft is supported at two locations, one in front and one behind the torque plate. be able to. Therefore, the distance between the two bearings can be increased without increasing the size of the casing, compared to the case where the rotating shaft is cantilever-supported by a bearing disposed only in front of the torque plate. Therefore, the bending load acting on the bearing can be reduced without difficulty, and it becomes possible to support the bearing using an inexpensive and small bearing. Therefore, the entire bearing can be made lighter and more compact, and the life of the bearing can be improved. Moreover, since the synchronization mechanism is constructed using a ring member that allows the rotating shaft to pass through, the cylinder block can be reliably synchronized with the torque plate with a simple structure even if the rotating shaft is installed to pass through the cylinder block. Therefore, it is possible to provide a piston pump or motor that can be manufactured easily, and can be made smaller and lighter.

In particular, this type uses a torque transmission engagement part to connect the torque ring to the rotating shaft, and the ring member is engaged with the rotating shaft, so when forming a special engagement part or tooth profile. The processing is simpler than that, and it can be easily implemented.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing one embodiment of the present invention, Fig. 2 is a view taken in the direction of the arrow in Fig. 1, Fig. 3 is a partial sectional view taken along the - line in Fig. 1, and Fig. 4 is an embodiment of the same. Partially enlarged sectional view of the example torque plate, No. 5
The figure is a perspective view showing a ring member of the synchronization mechanism of the same embodiment. FIG. 6 is a partial vertical sectional view showing another embodiment of the present invention, and FIG. 7 is a perspective view showing a ring member in the same embodiment. 1... Casing, 4, 5... Inflow/outflow port,
6... Rotating shaft, 6a... Torque transmission engaging portion (spline shaft), 8... Torque plate, 9... Cylinder block, 13... Cylinder hole, 14... Piston, 14b... Inner end, 23 , 23'... Synchronization mechanism, 24... Pump chamber, 25, 25'... Annular mounting part, 26, 26'... Inward tooth, 27, 2
7′...Ring member.

Claims (1)

[Scope of utility model registration request] A rotary shaft for input/output that has a torque transmitting engagement part such as a spline groove or a keyway on the outer periphery of a part located inside the casing, and a part of the rotary shaft that is fitted with the torque transmitting engaging part and A torque plate that is rotatable together with a rotating shaft; 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 and that open toward the torque plate. a cylinder block, a plurality of pistons slidably fitted into each cylinder hole of the cylinder block and connected to the torque plate, and a synchronization mechanism for rotating the cylinder block in synchronization with the torque plate. A piston pump or motor comprising: the synchronization mechanism;
It is constituted by a ring member having an annular mounting portion at the base end and internal teeth at the distal end, the annular mounting portion is fitted and fixed to the inner circumference of the cylinder block, and the internal teeth are connected to the torque transmission engaging portion. A piston pump or motor, characterized in that the rotating shafts are meshed with each other, and the rotating shafts pass through the ring member, the torque plate, and the cylinder block, respectively.