JPH0735030A - Hydraulic pump/motor - Google Patents

Abstract

PURPOSE:To suppress the cost to make the rotor and provide a hydraulic pump/ motor with less noise generation. CONSTITUTION:A pipe 14 is inserted in a hole provided in each ring 15 made of an elastic material, for example rubber, and these pipes 14 and rings 15 are arranged between the first end plate 12 and the second end plate 13, and a rotor 16 consisting of these members 12, 13, 14, 15 is made by means of flow coupling of each pipe with the second end plate 13. Thereby the rotor 16 can be manufactured without any complicated process of boring, wherein the sounds emitted therefrom are absorbed by the elastic material.

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 has 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 reciprocated 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. Furthermore, various attempts have been made to reduce noise, but in any case, noise that propagates through the rotor and is radiated to the outside of the casing cannot be blocked, so it is necessary to sufficiently reduce noise. There was also a problem that I could not do it.

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

[0006]

In order to achieve the above object, the present invention provides a casing, a rotating shaft rotatably supported by the casing, a rotor rotating in conjunction with the rotating shaft, In a hydraulic pump / motor including a piston that reciprocates in a plurality of cylinders provided in a rotor, the rotor includes a pair of end plates facing each other at a predetermined interval in the axial direction of the rotating shaft, The most main feature is that it has a plurality of pipes interposed between these end plates and a rubber-like elastic body that encloses these pipes, and that the piston reciprocates in the pipes. I am trying.

[0007]

According to the above-mentioned means, since the portion corresponding to the cylinder can be constituted by an inexpensive pipe, for example, a honing pipe whose inner surface is ground, a complicated boring process as in the prior art is unnecessary, and the rotor Cost reduction can be realized. Further, since the rubber-like elastic body is filled around the plurality of pipes, the damping action of the rubber-like elastic body can significantly reduce noise generation. Further, when the rubber-like elastic body is compressed by the pair of end plates, a reaction force of the rubber-like elastic body can preload the rotor in the thrust direction of the rotating shaft.

[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.

12 is a first end plate, 13 is a second end plate, 1
4 is a plurality of pipes interposed between both end plates 12 and 13,
Reference numeral 15 is a ring made of a rubber-like elastic body which is also provided between both end plates 12 and 13, and the rotor 16 is constituted by these end plates 12 and 13, each pipe 14 and the ring 15. The first end plate 12 is integrally formed with the rotary shaft 3, but the rotary shaft 3 penetrates the second end plate 13 made of a metal material such as steel or aluminum. Further, a plurality of holes 17 are formed in the first end plate 12 along the circumferential direction, and the upper portions of the pipes 14 are slidably fitted in the holes 17. On the other hand, the second end plate 13 is formed with an annular groove 18 and a small-diameter suction / discharge path 19, and the lower end of the pipe 14 and the second end plate 13 are the peripheral edge of the groove 18 (the portion indicated by the symbol F). Are flow coupled to each other at. Each pipe 1
4 is a honing pipe etc. with internal grinding,
The flow connection is a connection method in which one of the two members is locally plastically deformed to cause a plastic inflow in the other member to mechanically connect the two members. In the case of the present embodiment, as shown in FIG. 2, an undercut-shaped recess 20 is formed on the inner peripheral surface of the pipe 14, and the second end plate 1 is formed.
By locally applying plastic deformation to the F portion of 3 using the pressing technique, a part of the second end plate 13 is metal-flowed into the recess 20.

FIG. 3 is a plan view of the ring 15. As shown in FIG. 3, the ring 15 has a central hole 15a and a plurality of holes 15b formed around the central hole 15a, and has an overall lotus root shape. Is presenting. The rotating shaft 3 is provided in the center hole 15a.
Is inserted with a certain clearance, and each hole 1
The pipe 14 is tightly inserted in 5b.
The ring 15 includes the first end plate 12 and the second end plate 13.
It is arranged in a compressed state between the end plates 12 and 13 and is slightly longer than the length between the both end plates 12 and 13.

Returning to FIG. 1, reference numeral 21 denotes a piston disposed 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, reference numeral 26 is a spring wound in the clearance around the rotary shaft 3, and the spring 26 includes the first end plate 12 and the second end plate 13.
Is installed between and. The spring 26 and the ring 15 apply a preload to the rotor 16 in the thrust direction of the rotary shaft 3, and the second end plate 13 is pressed against the valve plate 7 under the preload.

When the rotary shaft 3 is rotated in the hydraulic pump constructed as described above, the rotational force is transmitted to the first end plate 12, and the rotor 16 as a whole rotates in conjunction with the rotary shaft 3. The rotation of the rotor 16 causes the piston shoe 22 that engages with the tip of the piston 21 to move to the shoe plate 2.
5, the shoe plate 25 is provided so as to be inclined with respect to the axis of the rotating shaft 3, so that each piston 21 reciprocates in the pipe 14 while the rotor 16 is rotating. Further, when the rotor 16 rotates, the intake / exhaust passage 19 of the second end plate 13 communicates intermittently with the intake / exhaust ports 10 and 11 of the valve plate 7, and in the intake process in which the piston 21 extends from the pipe 14, the intake / exhaust passage 19 is formed. Pipe 14 communicating with port 10
In the discharge process in which the low pressure fluid is sucked into the pipe 14 and the piston 21 enters the pipe 14, the suction / discharge passage 19 communicates 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 of the first end plate 12 and the grooves 18 of the second end plate 13 have a simple shape, and the holes 17 and the grooves 18 are also formed. Since it is not necessary to grind the inner surface of the rotor, it is possible to omit the conventional complicated drilling process, and the rotor 16 can be manufactured by a simple press work called flow coupling. In particular, due to recent advances in precision drawing technology, it has become possible to inexpensively obtain pipes with high dimensional accuracy and surface roughness, so that the cost of the rotor 16 can be significantly reduced. Further, since the rotor 16 is composed of the pair of end plates 12 and 13, the plurality of pipes 14 and the ring 15 made of a rubber-like elastic body, the weight can be reduced as compared with the conventional cylinder-integrated rotor. In particular, when the above rotor structure is applied to a hydraulic pump, a rapid rotor switching operation can be realized. Further, since the ring 15 made of a rubber-like elastic body is used in addition to the spring 26 as a member for applying a preload to the rotor 16, the damping action of the ring 15 causes the close contact between the second end plate 13 and the valve plate 7. In addition, since the ring 15 is filled around each pipe 14, the sound emitted from the rotor 16 is absorbed,
It is possible to reduce noise.

FIG. 4 is a sectional view of a hydraulic pump according to a second embodiment of the present invention, FIG. 5 is a sectional view of a rotor provided in the hydraulic pump, and FIG. 6 is a plan view of a ring provided in the rotor. Parts corresponding to those in FIGS. 1 to 3 are designated by the same reference numerals. In the case of this embodiment, the spline 2 is attached to the first end plate 12.
A tubular body 28 having 7 is integrally formed, and the first end plate 12 is connected to the rotary shaft 3 via the spline 27. Each pipe 14 is not flow-connected to the first end plate 12 and the second end plate 13, but is pinched and fixed between the both end plates 12 and 13 by a pin 29. That is, as shown in FIGS.
A plurality of small holes 15c for inserting the first end plate 1 are provided on both ends of each pin 29 with the ring 15 compressed.
By caulking the second end plate 13 and the second end plate 13, the rotor 16 in which the both end plates 12 and 13 and the pipe 14 are integrated is configured. Therefore, the rotational force of the rotating shaft 3 is transmitted to the first end plate 12 via the spline 27, and the rotor 16
The whole rotates in conjunction with the rotary shaft 3. A hemispherical body 30 is splined to the rotating shaft 3, and the shoe retainer 23 is pressed against the spherical surface of the hemispherical body 30.
A connecting rod 31 is in contact with the lower surface of the hemispherical body 30, and the connecting rod 31 is inserted through the tubular body 28 to form the ring 1.
5 to the central hole 15a. The spring 26 wound around the rotary shaft 3 is connected to the connecting rod 31 and the second
Of the rotor 16 by being installed between the rotor 16 and the end plate 13.
Preload is applied to. Other than that, the configuration of the part whose description is omitted is basically the same as that of the first embodiment described above.

According to the second embodiment of the present invention thus constructed, each pipe 14 is connected to the end plate 1 through the pin 29.
Since it is connected to the pipes 2 and 13, the pipe 14 and the both end plates 12 and 13 can be joined without using plastic working accompanied by some deformation such as flow joining, and the pipe 14 and the piston 21 can be joined.
The sliding characteristics of can be improved. In addition, each pipe 14
Since the ring 15 is filled in a compressed state in the periphery of the ring 15, not only can the radiation sound be absorbed by the ring 15 and noise can be reduced, but also the ring 15 can be used as a sealing material for the pipes 14. Can also function as.

In the second embodiment, the pin 29 is fixed to the both end plates 12 and 13 by caulking, but other fixing means such as screwing may be used. Also, without using the pin 29, each pipe 1
Both ends of 4 may be directly flow-coupled to the first end plate 12 and the second end plate 13. In this case, after the pipes 14 are flow-coupled, a step of correcting the slightly smaller pipe inner diameter is required, but the configuration of the rotor 16 can be simplified because the pin 29 is unnecessary.

[0017]

As described above, according to the present invention,
Since the part corresponding to the cylinder is made up of inexpensive pipes, complicated drilling as in the past is not required, the cost of the rotor can be reduced, and a rubber-like elastic body is provided around multiple pipes. Since it is filled, the rubber-like elastic body can absorb the radiated sound from the rotor, so that it is possible to provide an inexpensive hydraulic pump / motor that can reduce the noise.

[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 plan view of a ring included in the hydraulic pump of FIG.

FIG. 4 is a sectional view of a swash plate type hydraulic pump according to a second embodiment of the present invention.

5 is a cross-sectional view of a rotor included in the hydraulic pump of FIG.

FIG. 6 is a plan view of a ring included in the hydraulic pump of FIG.

[Explanation of symbols]

 1 Main Case 2 Sub Plate 3 Rotating Shafts 4, 5 Bearings 7 Valve Plates 8, 9 Suction / Exhaust Passages 10, 11 Suction / Exhaust Ports 12 First End Plates 13 Second End Plates 14 Pipes 15 Rings (Rubber-like Elastic Body) 15a Center Hole 15b hole 15c small hole 16 rotor 17 hole 18 groove 19 suction / discharge passage 20 recess 21 piston 22 piston shoe 23 shoe retainer 25 shoe plate 26 spring 27 spline 28 tubular body 29 pin 30 hemispherical body 31 connecting rod

Claims (3)

[Claims] 1. A casing, a rotating shaft rotatably supported by the casing, a rotor that rotates in conjunction with the rotating shaft, and a piston that reciprocates in a plurality of cylinders provided in the rotor. In a hydraulic pump / motor provided, the rotor includes a pair of end plates facing each other at a predetermined interval in the axial direction of the rotating shaft, and a plurality of pipes interposed between these end plates, A hydraulic pump having a rubber-like elastic body enclosing a pipe, wherein the piston reciprocates in the pipe.
motor. 2. A hydraulic pump / motor according to claim 1, wherein at least one of the both end plates is locally plastically deformed to flow-couple the end plates and the pipe. 3. The hydraulic pump / motor according to claim 1, wherein the both end plates are connected by a pin, and the rubber-like elastic body is compressed by the both end plates.