JPH01313678A - Bearing structure for rotary swash plate type pump - Google Patents

Abstract

PURPOSE:To prevent a bearing from wearing with supporting by a structure of center swash plate by fixedly providing a cylindrical member, extending in a direction opposite to a rotary shaft, in the peripheral part of the swash plate and equipping a pump body with the different radial bearing. CONSTITUTION:A rotary type swash plate 2 is mounted to be sucked into a working chamber 1A. A small contour part 3B is rotatably supported by a radial bearing 4 provided in the inside of a pump body 1. A collar 6, serving as a cylindrical member, is forced to be press fixed to the outside of a large contour part 3A. A different radial bearing 7, rotatably supporting the periphery of the collar 6, is provided in the inside of the pump body 1. The swash plate 2 is supported by a structure of center swash plate by the longitudinally arranged radial bearings 4, 7. By the structure thus obtained, the bearing is prevented from easily wearing with no concentration of a load to one part of the radial bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a support structure for a swash plate of a rotary swash plate pump.

(Prior Art) A rotating swash plate type pump in which a swash plate rotates a piston inserted into a fixed cylinder is configured as shown in FIG. 2, for example.

That is, a plurality of cylinders 1o are fixed in parallel so as to surround a central axis, facing a swash plate 2 that is rotatably housed inside a pump body 1, and a piston that is slidably housed in each cylinder 10. The base end 11A of 11 is attached to the bearing 1 on the swash plate 2.
7 and is held freely slidable. Each cylinder 10
communicates with a suction port 13 via a check valve 12, and also communicates with a discharge port 15 via a check valve 14.

The swash plate 2 is connected to a motor (not shown) provided outside the pump body 1 via an integral rotating shaft 3 formed at the rear. Further, the rotating shaft 3 is supported by a bearing 16 provided on the pump body 1 in both the thrust and full-length directions.

When the swash plate 2 rotates due to the operation of the motor, the piston 11 is sequentially driven in the axial direction while sliding the base end 11A along the rotating swash plate 2, and in the extension stroke, the piston 11 moves from the suction port to the cylinder 10.
The fluid introduced is pressurized in a compression stroke and supplied to the discharge port 15.

(Problem to be solved by the invention) In such a rotary swash plate pump, the pressure acting on the swash plate 2 through the base end 11A of the piston 11 acts at right angles to the swash plate 2, and is The swash plate 2 exerts forces in both thrust and radial directions, and in response to the component forces in the radial direction, the swash plate 2 is supported by the bearing 16 via the rotating shaft 3 in a so-called cantilevered structure.

As a result, a large moment load is applied to the bearing 16, resulting in a problem that the bearing 16 is easily worn out.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems in rotary swash plate type pumps, the present invention aims to support a swash plate in a dual support structure.

(Measures Pi for Achieving Problem H) The present invention includes a cylinder fixed in the axial direction inside a pump body, a swash plate that rotates relative to the cylinder, and a swash plate that extends from the swash plate in the opposite direction to the cylinder. A rotating swash plate type equipped with a radial bearing that supports the rotary shaft of the plate in the pump body for free rotation, and a piston whose base end is held by the swash plate for free displacement in the rotational direction and whose tip is slidably inserted into the cylinder. In the pump, a cylindrical member extending in a direction opposite to the rotation axis is fixed to the outer periphery of the swash plate, and the pump body is provided with another radial bearing that rotatably supports the outer periphery of the cylindrical member.

(Function) The swash plate has 21! radial bearings that support the rotating shaft and radial bearings that support the cylindrical member extending in the opposite direction. By the way,
Since it is supported by a so-called double support structure, the support is stable and the load on the bearing is reduced.

(Example) FIG. 1 shows an embodiment of the present invention.

Reference numeral 1 designates a pump body, in which a rotary swash plate 2 is housed in an inner working chamber IA, a rotating shaft 3 integral with the swash plate 2 projects rearward from the pump body 1, and a motor (not shown) is attached to the projecting end. Concatenated.

The rotating shaft 3 consists of a large diameter WS3A continuous to the swash plate 2, a small diameter part 3B at the rear, and a stepped g3c opening between these parts.
B is rotatably supported by a radial bearing 4 provided inside the pump body 1.

Further, the stepped portion 3C is supported in the axial direction by a thrust bearing 5 provided in an annular shape inside the pump body 1.

A collar 6 as a cylindrical member is press-fitted and fixed to the outside of the large diameter portion 3A constituting the outer peripheral portion of the diagonal [2].

The collar 6 extends forward in the direction opposite to the axis of rotation 3;
Another radial bearing 7 that freely supports the outer circumference of the
is provided inside the pump body 1.

A lubricating passage 8 is formed inside the pump body 1 for supplying lubricating fluid to these bearings 4.5 and 7. Further, a spiral group is carved on the sliding surface of the thrust bearing 5, and the sliding surface is lubricated by the lubricating fluid that enters into this spiral group from the lubrication passage 8 as the swash plate 2 rotates.

A cylinder (not shown) is fixedly provided in the working chamber IA opposite to the swash plate 2, and the base end of a piston that is freely slidably inserted into the cylinder is held in sliding contact with the swash plate 2.

Next, the action will be explained.

When the swash plate 2 is rotationally driven by the operation of a motor (not shown), the pistons are sequentially driven in the axial direction while their base ends are in sliding contact with the rotating swash plate 2, pressurizing and discharging the fluid introduced into the cylinder.

At this time, a force in a right angle direction is applied to the swash plate 2 via the base end of the piston that is in sliding contact with the swash plate 2. This force exerts a component force in the thrust direction and a component force in the radial direction on the rotating shaft 3. On the other hand, the oblique fj2 is supported by the thrust bearing 7 against this component force in the thrust direction, and the component force in the radial direction is The force is supported by radial bearings 4 and 7. Note that lubricating fluid is supplied to the radial bearings 4 and 7 and the thrust bearing 5 through a lubricating passage 8.

In this way, the support of the swash plate 2 against the component force in the radial direction is a so-called dual-support structure by the radial bearings 4 and 7 arranged in the front and rear, so the swash plate 2 is supported stably, and the radial bearing 4 The load applied to and 7 is not concentrated in one part but acts in a distributed manner. Therefore, there is no need to worry about wear even if the radial bearings 4 and 7 are made of resin or ceramic 7. Also, since the swash plate 2 is supported by dual support, the load on the thrust bearing 5 is also made uniform. Therefore, the sliding condition between the thrust bearing 5 and the stepped portion 3C is also maintained in good condition.

Furthermore, all sliding contact parts between the pump body 1, rotating shaft 3, and collar 6 are made of non-metallic materials such as resin or ceramic, or stainless steel, etc.! By using a resistant material, water, seawater, or the like can be used as the lubricant. In this case, in a pump that handles water or seawater, the fluid to be handled can be supplied as is to the lubricating passage 8, and there is no need to seal different types of liquids from each other within the pump, so the overall configuration of the pump can be simplified. In addition, as mentioned above, bearing 4.5
Since the load acting on and 7 is dispersed, sufficient lubrication can be achieved even with a low viscosity fluid.

(Effects of the Invention) As described above, the present invention provides a pump in which a cylindrical member extending in the opposite direction to the rotating shaft is fixed to the outer periphery of the swash plate, and a radial bearing that rotatably supports the outer periphery of the cylindrical member. Since the swash plate is mounted on the body, the swash plate is supported by the radial bearing and the radial bearing supporting the rotating shaft in a dual-support structure against loads in the radial direction.

Therefore, the load is not concentrated on a part of the radial bearing unlike in a conventional rotary swash plate pump in which the swash plate is supported in a cantilever manner, and the bearing is less likely to wear out. Further, since the pressure acting on the bearing can be suppressed to a low level, the sliding portion of the bearing can be made of resin or ceramic material. Furthermore, the reduction in pressure applied to the bearings allows the bearings to be lubricated by low-viscosity fluids such as water or seawater, which eliminates the need for lubricating oil in pumps that handle these fluids, simplifying the structure of the pumps. be done.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part of a rotary swash plate type pump showing an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of a rotary swash plate type pump showing a conventional example. DESCRIPTION OF SYMBOLS 1... Pump body, 2... Swash plate, 3... Rotating shaft, 3A... Large diameter part, 3B... Small diameter part, 3C... Stepped part, 4°7... Radial bearing, 5... Thrust bearing, 6... Collar, 8... Lubrication passage,
10...Cylinder, 11...Piston. Patent Applicant: Kayabae Gyo Co., Ltd. Figure 1 1--Ba (Mbu Body 3C-11 Kei Shi Isuku 3A---person@g6- Color)

Claims (1)

[Claims] A cylinder fixed in the axial direction inside the pump body, a swash plate that rotates relative to the cylinder, and a radial bearing that supports the rotating shaft of the swash plate, which extends from the swash plate in the opposite direction of the cylinder, to the pump body for free rotation. and a piston whose base end is held by the swash plate so as to be freely displaced in the rotational direction and whose tip is slidably inserted into the cylinder. A bearing structure for a rotary swash plate pump, characterized in that an extending cylindrical member is fixedly installed, and the pump body is provided with another radial bearing that rotatably supports the outer periphery of the cylindrical member.