JPH0351516A - Radial bearing device for hydraulic pump - Google Patents

Abstract

PURPOSE:To prevent pitching in a working liquid and seizure by providing a slide bearing material for a shaft, in which a spiral groove is provided, and a slide bearing for a hole, in which a spiral groove communicating from the inner deepest portion with the outside is provided. CONSTITUTION:A slide bearing material 11 for a shaft is fitted to the forward end portion of a rotary shaft 1'. The bearing material 11 is formed by carbon fiber reinforced plastic, and has a spiral groove 12 on the outer peripheral surface thereof. A slide bearing material 14 for a hole, where the slide bearing material 11 for a shaft is rotatably engaged, is fitted to an end plate 8'. A recess portion 16 for communicating the deep end of a spiral groove 15 with the inner deepest portion of the bearing hole and a notch 17 for communicating the outer end of the spiral groove 15 with the interior of a case are provided on the end plate 8'. With the rotation of the rotary shaft 1', a working liquid passes through the spiral grooves 12, 15 provided on both bearing materials 11, 14 to circulate through a contacting portion. Thus, pitching in the working liquid and seizure can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radial bearing device for a hydraulic pump.

[Conventional technology]

FIG. 4 shows a swash plate type pump, which is an example of a hydraulic pump. In this swash plate type pump, by rotating a rotating shaft 1, a cylinder block 2 splined to the rotating shaft 1 is rotated, and the cylinder block 2 is rotated. Due to the rotation of cylinder block 2,
A plurality of plungers 3 fitted therein reciprocate according to the inclination of the swash plate 4 to operate the pump, and the hydraulic fluid is provided in a valve plate 5 on which the end surface of the cylinder block 2 is in sliding contact. One of the pair of ports (
It is designed to be inhaled from the other (suction port) and discharged under high pressure from the other (discharge port).

The base end of the rotating shaft 1 is connected to the lid member 7 of the case 6, and the tip end is connected to the end plate 8 through radial bearings 9 and 1, respectively.
It is supported through 0.

Radial bearing in the above conventional swash plate pump 9.10
Of these, the radial bearing 9 on the base end side is a metal rolling bearing, and the radial bearing 10 on the tip side is a metal rolling bearing or a metal sliding bearing. As the rolling bearing, a roller, ball, twenty-one dollar, etc. are used, and as a sliding bearing, a normal push type, a push type containing a lubricant, etc. are used.

[Problem to be solved by the invention] Since all of the conventional radial bearings for hydraulic pumps are made of metal, they function normally in oil, that is, when the hydraulic fluid is oil, but when the hydraulic fluid is There is a problem of pitting and seizure occurring in low viscosity water or seawater. This was particularly noticeable in the bearings on the tip side, which had smaller diameters.

The present invention was conceived in consideration of the above, and even when used in water or seawater as a bearing on the tip side of the rotating shaft of the swash plate pump, it has the same performance as a conventional metal radial bearing in oil. It is an object of the present invention to provide a radial bearing device for a hydraulic pump that can be used for water or seawater without galling or pitching.

[Means to solve the problem]

In order to achieve the above object, the radial bearing device for a hydraulic pump according to the present invention is constructed of carbon fiber reinforced plastic, is fitted onto a rotating shaft, and has a shaft sliding shaft provided with a spiral groove on the outer circumferential surface. A bearing material and a sliding bearing material for a hole, which is fitted into a support member to rotatably fit and support the sliding bearing material for a shaft, and which has a spiral groove communicating from the inner back to the outside on the outer peripheral surface. It is being structured as such.

[For production]

The rotating shaft is rotatably supported by the support member by a shaft sliding bearing material fitted thereto and a hole sliding bearing material into which this shaft sliding bearing material is fitted. At this time, as the rotary shaft rotates, the hydraulic fluid circulates through the contact portion of both bearing materials through the spiral grooves provided in both bearing cages, and this portion is lubricated and cooled by the hydraulic fluid.

〔Example〕

Embodiments of the present invention will be described based on FIGS. 1 to 3.

This embodiment is an example in which the present invention is applied to a radial bearing on the tip side of the rotating shaft of the swash plate pump shown in FIG.

A shaft sliding bearing material 11 is fitted to the tip of the rotating shaft 1'. This shaft sliding bearing material 11 is made of carbon fiber reinforced plastic (CFRP), and a spiral groove 12 is provided on the outer circumferential surface of the material in the direction opposite to the rotational direction of the rotating shaft 1'. There is.

In addition, an elongated hole 13a that is elongated in the direction perpendicular to the axis is provided at the end of the sliding bearing material 11 for the shaft, and this elongated hole 13a is fitted with a protrusion 13b protruding from the tip of the rotating shaft 1'. This bearing member 11 is fixed so as not to rotate relative to the rotating shaft 1'.

A cylindrical hole slide bearing material 14 into which the shaft slide bearing material 11 is rotatably fitted is fitted into an end plate 8' that supports the tip of the rotating shaft 1'. The hole sliding bearing material 14 is made of a ceramic material, or a ceramic material or metal material whose inner surface is plated with a hard metal. A spiral groove 15 is provided on the outer peripheral surface of this.

The end plate 8' into which the hole sliding bearing material 14 is fitted has a recess 1B that communicates the back end of the spiral groove 15 with the inner back of the bearing hole, and a recess 1B that communicates between the outer end of the spiral groove 15 and the inside of the case. A notch 17 is provided to communicate with the.

The slide bearing material 14 for the hole is press-fitted into the end plate 8' so that it does not rotate, but if necessary, a rotation prevention device such as grooves and protrusions that engage with each other may be provided.

The carbon fiber reinforced plastic constituting the shaft sliding bearing material 11 is 30 vol% carbon fiber reinforced PEEK.
(Polyetheretherketone) was used, and a hard chrome plating material was used for the sliding bearing material 14 for the hole.

In the above configuration, the rotation of the rotating shaft 1' causes the rotating shaft 1 to
The shaft sliding bearing material 11 fitted on the end plate 8
The tip of the rotary shaft 1' is supported by sliding contact with the hole slide bearing material 14 fitted in the hole.

At this time, as the rotating shaft 1' rotates, the hydraulic fluid in the case flows into the helical groove 1 provided on the outer periphery of the shaft sliding bearing material 11.
2, the flow flows to the four parts 16 provided at the inner deep part of the bearing device, and from there returns to the inside of the case through the spiral groove 15 provided on the outer periphery of the sliding bearing material 14 for the hole.
1 and 14 are cooled at the operating branch, and their sliding surfaces are lubricated.

In addition, in this bearing device, due to the tolerance of the fitting diameters of both bearing members 11 and 14, the rotation is biased in the direction in which the supporting force is applied, as shown in FIG. Frictional heat is generated in this part due to large surface pressure, but in the present invention, the outer hole sliding bearing material 14 is made of ceramic or metal material,
Since the rotating shaft sliding bearing material 11 is made of carbon fiber reinforced plastic, the frictional heat is dispersed over the entire circumference of the shaft sliding bearing material 11 due to rotation, and combined with the cooling effect of the working fluid, it melts. Temperature rise to temperature is prevented.

〔Effect of the invention〕

According to the present invention, even if the hydraulic fluid is water or seawater with low viscosity, bearing performance equivalent to that in oil can be obtained, and pitting and seizure in these hydraulic fluids can be prevented.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and Fig. 1 is an exploded partially cutaway view of the main parts, Fig. 2 is a view taken along the line ■ in Fig. 1, and Fig. 3 is a plain bearing material for a shaft. FIG. 4 is a schematic diagram showing a state of rotational contact with a slide bearing material for a hole, and is a sectional view of a swash plate type pump which is an application example of the present invention. 1' is a rotating shaft, 11 is a sliding bearing material for the shaft, 12 and 15 are spiral grooves, and 14 is a sliding bearing material for a hole.

Claims (1)

[Claims] The rotating shaft 1' is made of carbon fiber reinforced plastic.
A sliding bearing material 11 for a shaft is fitted into the supporting member and has a spiral groove 12 on its outer circumferential surface, and a sliding bearing material 11 for a shaft is fitted into a supporting member to rotatably fit and support the sliding bearing material 11 for a shaft, and a sliding bearing material 11 for a shaft is fitted on the supporting member and has a spiral groove 12 on its outer circumferential surface. A radial bearing device for a hydraulic pump, characterized in that it consists of a hole sliding bearing material 14 provided with a spiral groove 15 that communicates from the inner deep part to the outer side.