JPH06317248A - Hydraulic pump motor - Google Patents

Abstract

PURPOSE:To dispense with complicated work, and reduce cost by constituting a rotor by connecting a pair of metallic disks opposing at a prescribed interval in the axis direction of a rotary shaft in a single flow to each other by plural pipes. CONSTITUTION:A rotor 15 is composed of the first disk 12, the second disk 13 and respective pipes 14. The first and the second disks 12 and 13 are composed of a metallic material such as steel or aluminium, and though the first disk 12 is connected to a rotary shaft 3 through a spline 16, the rotary shaft 3 passes penetratingly through the second disk 13. Plural holes 17 and 18 are bored respectively in the circumferential direction in both disks 12 and 13, and a small diameter suction and exhaust passage 19 continuing to the respective holes 18 is bored in the second disk 13. The pipe 14 is composed of a honing pipe or the like whose inside surface is ground, and this pipe 14 and the first and the second disks 12 and 13 are connected in a single flow to each other on both opening ends of the hole 17 and in the bottom part F of the hole 18. Thereby, complicated boring work can be dispensed with, so that cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic pump / motor provided in a hydraulic machine, and more particularly to the structure of a rotor having a plurality of cylinders.

[0002]

2. Description of the Related Art Generally, a swash plate type or swash shaft type hydraulic pump / motor has a casing as a main body, a rotary shaft rotatably supported by the casing, and a plurality of cylinders interlocking with the rotary shaft. It is equipped with a rotor and a piston that reciprocates in these cylinders.In the case of a hydraulic pump, the low-pressure fluid sucked into the cylinder is caused by reciprocating the piston by rotating the rotor in conjunction with the rotating shaft. Is pressurized by a piston and discharged.In the case of a hydraulic motor, a high-pressure fluid is introduced into the cylinder to reciprocate the piston, thereby rotating the rotor and the rotary shaft. ing.

Conventionally, in such a hydraulic pump / motor, the rotor is constructed by forming a large number of holes in a cylindrical metal block, and each hole is used as a cylinder. As a technique related to this type of hydraulic pump / motor, for example, Japanese Patent Laid-Open No. 61-2597.
4 and Japanese Utility Model Laid-Open No. 63-57374.

[0004]

By the way, in the conventional rotor constructed as described above, it is necessary to machine a large number of holes in the metal block with high precision, and it is difficult to grind the inner surface of these holes. Since it takes time, the cost of the rotor has risen. Further, it is usually necessary to form an intake / exhaust passage having a diameter smaller than the inner diameter of the cylinder at one opening end (portion in contact with the valve plate) of the cylinder in order to narrow the passage. Since it is a continuous stepped hole, complicated processing such as milling is required, and from this point also the cost has been soared.

The present invention has been made in view of the circumstances of the prior art as described above, and an object thereof is to reduce the cost of the rotor and to provide an inexpensive hydraulic pump / motor.

[0006]

In order to achieve the above object, the present invention provides a casing, a rotating shaft rotatably supported by the casing, and a rotor having a plurality of cylinders interlocking with the rotating shaft. In a hydraulic pump / motor including a piston that reciprocates in these cylinders, a pair of metal discs that face the rotor at a predetermined interval in the axial direction of the rotating shaft, It is characterized by comprising a plurality of pipes connecting the plates, and fixing at least one of the two disks and the pipe. As a result of various studies as this fixing means, it was found that two methods are particularly effective. One is cold working, in which the metal disc is locally plastically deformed to flow-couple the disc and the pipe. Examples of such flow coupling include a metal flow for plastically inflowing a part of a disc into a recess formed in the outer peripheral surface of the pipe, or a seal material made of plastic or rubber interposed between the pipe and the disc. A plastic flow or a rubber flow that plastically flows a part of the above into the recess of the pipe is adopted. The other method is brazing, which should also be called hot bonding, in which a brazing agent is melted to join a disc and a pipe.

[0007]

According to the above means, a metal disk having a simple shape and an inexpensive pipe, for example, a honing pipe whose inner surface is ground are mechanically plastically joined by a pressing technique or joined by melting a brazing agent. Since the rotor can be configured by the simple operation of performing, it is not necessary to perform complicated drilling processing as in the past, and cost reduction can be realized.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a swash plate type hydraulic pump according to a first embodiment of the present invention. In FIG. 1, 1 is a main case, 2 is a sub-plate fixed to the lower surface of the main case 1, and The main case 1 and the sub plate 2 form a casing that forms a main body. Reference numeral 3 is a rotary shaft supported by bearings 4 and 5 in the casing, and 6 is a shaft seal interposed between the rotary shaft 3 and the main case 1. Reference numeral 7 denotes a valve plate fixed on the sub plate 2, and the valve plate 7 has suction and discharge ports 10 and 11 communicating with suction and discharge passages 8 and 9 provided in the sub plate 2.

Reference numeral 12 is a first disk, 13 is a second disk, 1
Reference numeral 4 denotes a plurality of pipes that connect both the circular plates 12 and 13, and the first circular plate 12, the second circular plate 13 and each pipe 14 constitute a rotor 15. The first and second discs 12 and 13 are made of a metal material such as steel or aluminum, and the first disc 12 is connected to the rotary shaft 3 via a spline 16, but the rotary shaft 3 is the second. Disc 13
Penetrates through. In addition, a plurality of holes 17 and 18 are formed in both discs 12 and 13 along the circumferential direction,
The second disc 13 has a small-diameter suction passage 1 continuous with each hole 18.
9 is provided. The pipe 14 is a honing pipe or the like whose inner surface is ground. The pipe 14 and the first and second discs 12 and 13 are provided at both open ends of the hole 17 and the bottom of the hole 18 (indicated by reference numeral F, respectively). Parts) are flow-coupled to each other. This flow coupling gives a local plastic deformation to one of the two members,
This is a joining method of mechanically joining both members by causing a plastic inflow to the other member. In the case of the present embodiment, as shown in FIG. 2, an undercut-shaped recess 2 is formed on the peripheral surface of the pipe 14.
0 is formed, and a local plastic deformation is applied to the F portion of the first or second disc 12 or 13 by using a pressing technique, so that a part of the disc 12 or 13 is metal-deposited in the recess 20. It's flowed.

Returning to FIG. 1, reference numeral 21 denotes a piston arranged in each pipe 14 so as to be reciprocally movable.
The spherical distal end of the piston is swingably engaged with the piston shoe 22. A shoe retainer 23 holds the piston shoe 22, and the shoe retainer 23 is guided by a spherical seat 24 of the rotating shaft. Reference numeral 25 denotes a shoe plate, and the piston shoe 22 rotates and slides on the shoe plate 25. Further, 26 is a spring wound around the rotary shaft 3, and the spring 26 is interposed between the collar portion 27 provided on the rotary shaft 3 and the second disc 13. The spring 26 applies a preload to the rotor 15 in the thrust direction of the rotating shaft 3, and the second disc 13 is pressed against the valve plate 7 under the preload.

In the hydraulic pump constructed as described above, when the rotary shaft 3 is rotated, the rotational force is transmitted to the first disc 12 via the spline 16, and the rotor 15 as a whole is interlocked with the rotary shaft 3. Rotate. The rotation of the rotor 15 causes the piston shoe 22 that engages with the tip end portion of the piston 21 to rotate and slide on the shoe plate 25, and the shoe plate 25 is provided so as to be inclined with respect to the axis of the rotating shaft 3. , Each piston 21 reciprocates in the pipe 14 while the rotor 15 is rotating. When the rotor 15 rotates, the intake / exhaust passage 19 of the second disc 13 is intermittently communicated with the intake / exhaust ports 10 and 11 of the valve plate 7, and the piston 21 is connected to the pipe 1.
In the suction process extending from 4, the suction and discharge passage 19 is connected to the port 1
In the discharge step in which the low pressure fluid is sucked into the pipe 14 by communicating with 0 and the piston 21 enters the pipe 14, the suction / discharge passage 19 is communicated with the port 11 and discharges the high pressure fluid pressurized by the piston 21. .

According to the first embodiment of the present invention described above, the holes 17 and 18 of the first and second discs 12 and 13 have a simple shape, and the inner surfaces of these holes 17 and 18 need not be ground. Therefore, it is possible to omit the complicated drilling work as in the related art, and the rotor 15 can be manufactured by a simple press work called flow coupling. In particular, recent advances in precision drawing technology have made it possible to inexpensively obtain pipes with high dimensional accuracy and surface roughness, so that the cost of the rotor 15 can be significantly reduced. In addition, the rotor 15 includes the first and second discs 12 and 13 and the plurality of pipes 14.
Since it is configured by, the weight can be reduced as compared with the conventional cylinder-integrated rotor, and in particular, when the above rotor structure is applied to a hydraulic pump, a rapid rotor switching operation can be realized.

FIG. 3 is a sectional view of a rotor portion of a hydraulic pump according to a second embodiment of the present invention, and the portions corresponding to those in FIG. 1 are designated by the same reference numerals. The present embodiment is different from the above-described first embodiment in that the first disc 12 is integrally formed with the rotary shaft 3 and the pipe 14 is not flow-connected to the hole 17 of the first disc 12. The spring 26 for preload is wound around each of the pipes 14, and the rest of the structure is basically the same.

According to the second embodiment of the present invention constructed as described above, the rotational force of the rotary shaft 3 is directly transmitted to the first disc 12, so that the first embodiment in which both are spline-coupled to each other. By comparison, the clearance between the rotary shaft 3 and the first disc 12 required for spline coupling is eliminated, and the axial rigidity of the rotary shaft 3 can be increased. In addition, the pipe 14
Since they can be connected by simply inserting them into the holes 17 of the circular plate 12, the number of points for flow connection is reduced and workability can be further improved. In addition, the point where the flow is connected is the second
It is only on the disk 13 side of the
Since it is done from the inside of the pipe, the pipe 14
A force in the direction of bulging outward is applied to this, and the adverse effect on the sliding of the piston 21 and the leak can be reliably prevented. Further, since a plurality of springs 26 wound around each pipe 14 are used to preload the rotor 15,
It is possible to improve the adhesion between the disc 13 and the valve plate 7.
In addition, since the springs 26 having a small wire diameter can be used because the plurality of springs 26 are arranged in a dispersed manner, the shaft diameter dimension required for the rotating shaft 3 can be increased.

FIG. 4 is a sectional view of a rotor portion of a hydraulic pump according to a third embodiment of the present invention, in which 28 is a seal provided between the second disc 13 and the pipe 14. This is the O-ring. In the case of this embodiment, contrary to the second embodiment, the pipe 14 is slidably fitted in the hole 18 of the second disc 13 without flow coupling, and the first disc 12 is inserted. And the pipe 14 are flow-coupled to each other, but the same effect as that of the second embodiment is obtained.

FIG. 5 is a sectional view of a rotor portion of a hydraulic pump according to a fourth embodiment of the present invention, and FIG. 6 is a sectional view of a main portion of the rotor shown in FIG. 5. In these figures, 29 is plastic or rubber. 1 and the same reference numerals are given to portions corresponding to FIG. This embodiment differs from the first embodiment described above in that the second disc 13 and the pipe 14 are
And are flow-coupled via the sealing material 29,
The rest of the configuration is basically the same. That is, as shown in FIG. 6, after the pipe 14 is inserted into the hole 18 of the second disc 13 through the sealing material 29, the F portion of the second disc 13 is locally pressed by using a pressing technique. By giving plastic deformation, a part of the sealing material 29 is made to flow in the recess 20 of the pipe 14 with plastic or rubber. At this time, since the overhanging portion 30 due to the plastic deformation of the second disc 13 bites into the sealing material 29, the overhanging portion 30 functions as a retaining member that enhances the removal force of the sealing material 29. Also,
Protrusions 31 and 32 are formed on the bottom surface of the second disc 13 and the end face of the pipe 14, respectively.
Reference numeral 2 gives a sealing force to the sealing material 29 to enhance the sealing function, that is, the fluid leakage prevention effect.

According to the fourth embodiment of the present invention constructed as described above, in addition to the effect of the first embodiment described above, the second disc 13 and the pipe 14 are elastically coupled via the sealing material 29. Since the second circular plate 13 and the valve plate 7 are connected to each other, the adhesion between the second circular plate 13 and the valve plate 7 can be further enhanced, and a slight rotational movement of the rotor 15 can be allowed.

FIG. 7 is a sectional view of a rotor portion of a hydraulic pump according to a fifth embodiment of the present invention, which is an embodiment in which the sealing material 29 is applied to the second embodiment described above. That is,
In the case of the present embodiment, the first disc 12 is integrally formed on the rotary shaft 3, and one end of the pipe 14 is slidably fitted into the hole 17 of the first disc 12 without flow coupling. At the same time, the other end of the pipe 14 is inserted into the hole 18 of the second disc 13 to form a sealing material 29.
Are flow-coupled through. Therefore, according to the fifth embodiment of the present invention configured as described above,
In addition to the effects of the embodiment, the adhesive force between the second disc 13 and the valve plate 7 is further enhanced by the elastic force of the sealing material 29 interposed between the second disc 13 and the pipe 14. Can
This has the effect of permitting a minute rotational movement of the rotor 15.

FIG. 8 is a sectional view of a rotor portion of a hydraulic pump according to a sixth embodiment of the present invention, and the portions corresponding to those in FIG. 1 are designated by the same reference numerals. The first to fifth embodiments described above
The difference from the embodiment is that the first and second disks 12, 13 are
This is because brazing is adopted instead of the above-described flow coupling as a fixing means for fixing the pipe 14 and each pipe 14. That is,
An appropriate gap is formed between the holes 17 and 18 of both discs 12 and 13 and each pipe 14, and by filling a brazing agent in these gaps, the first and second discs 1 and 2 are formed.
2, 13 and each pipe 14 are in contact with each other (reference B).
Part) is brazed. The brazing method is a method of joining a metal by melting a low melting point brazing agent, and when, for example, a copper brazing agent is used as the brazing agent, the copper brazing material melts at about 1090 ° C. Completely penetrate by and at the same time form a fillet at the end.

According to the sixth embodiment of the present invention constructed as described above, since the first and second discs 12 and 13 and the respective pipes 14 are joined by brazing, in the case of flow connection. The deformation of the pipe 14, which is concerned about the above, does not occur at all, and the sliding characteristics of the piston can be improved. Also,
Since brazing can be processed in a conveyor furnace and is excellent in mass productivity, there is also an effect that manufacturing cost can be reduced.

In the sixth embodiment, the brazing method as the fixing means is applied to the first embodiment, and the first and second discs 12 and 13 and the pipes 14 are replaced by a flow joint. Although the case of brazing has been described, it is also possible to apply the brazing method to the second or third embodiment and replace the corresponding flow coupling portion with brazing.

[0022]

As described above, according to the present invention,
Since the rotor is configured by a simple work of mechanically connecting a pair of metal discs and a plurality of pipes using a pressing technique, a brazing technique, etc., a significant cost reduction of the rotor can be achieved. An inexpensive hydraulic pump / motor can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of a swash plate type hydraulic pump according to a first embodiment of the present invention.

FIG. 2 is an explanatory view of a main part of a rotor included in the hydraulic pump of FIG.

FIG. 3 is a sectional view of a rotor portion of a hydraulic pump according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a rotor portion of a hydraulic pump according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a rotor portion of a hydraulic pump according to a fourth embodiment of the present invention.

6 is a cross-sectional view of a main part of the rotor shown in FIG.

FIG. 7 is a sectional view of a rotor portion of a hydraulic pump according to a fifth embodiment of the present invention.

FIG. 8 is a sectional view of a rotor portion of a hydraulic pump according to a sixth embodiment of the present invention.

[Explanation of symbols]

 1 Main Case 2 Sub Plate 3 Rotating Shaft 4, 5 Bearing 7 Valve Plate 8, 9 Suction / Exhaust Passage 10, 11 Suction / Exhaust Port 12 First Disc 13 Second Disc 14 Pipe 15 Rotor 16 Spline 17, 18 Hole 19 Suction / Exhaust Road 20 Recessed portion 21 Piston 26 Spring 28 O-ring 29 Seal material 30 Overhanging portion 31, 32 Protrusion

Claims (8)

[Claims] 1. A hydraulic pump comprising a casing, a rotary shaft rotatably supported by the casing, a rotor having a plurality of cylinders interlocking with the rotary shaft, and a piston reciprocating in the cylinders. In the motor, the rotor is composed of a pair of metal discs facing each other at a predetermined interval in the axial direction of the rotating shaft, and a plurality of pipes connecting the both discs. A hydraulic pump / motor in which at least one of the plates and the pipe are fixed. 2. The hydraulic pump according to claim 1, wherein at least one of the circular plates is locally plastically deformed to flow-couple the circular plates and the pipe. ·motor. 3. The hydraulic pump / motor according to claim 2, wherein a recess is formed in the peripheral surface of the pipe, and the disc is metal-flowed in the recess. 4. The seal material according to claim 2, wherein a sealing material made of plastic or rubber is interposed between the pipe and the disc, and the sealing material is flow-coupled to a recess formed in an end portion of the pipe. A hydraulic pump / motor characterized by 5. The hydraulic pump / motor according to claim 1, wherein the disc and the pipe are fixed by brazing. 6. The pipe according to claim 2, wherein both ends of the pipe are fixed to the both discs, and one of the discs and the rotating shaft are spline-coupled in the axial direction. Hydraulic pump and motor. 7. The method according to claim 2 or 5, wherein one of the both discs is fixed to the pipe,
A hydraulic pump / motor, characterized in that the other end is connected to the pipe slidably in the axial direction. 8. The hydraulic pump / motor according to claim 7, wherein a spring for preload is wound around each of the pipes.