JPH0612252Y2 - Deformation prevention device for hydrostatic bearings - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a device for preventing deformation of a static pressure bearing sleeve, which supports a rotary shaft under static pressure, due to temperature rise during operation.

[Prior Art] Conventionally, as a bearing for a high-speed spindle motor or the like, as shown in FIG. 4, a housing 2 provided with a static pressure supply pipe and a refrigerant passage 5 is fitted to a motor frame 1, and further the housing 2 A bearing is used in which a bearing sleeve 3 having a flange 8a provided on one side is airtightly fitted on the inner diameter side, and the rotary shaft 6 is statically supported via a gap.

[Problems to be solved by the invention] However, when the temperature of the bearing portion rises during motor operation, the sleeve expands in the radial direction and the gap increases, and the rigidity of the flange 8a is significantly high as shown in FIG. Displacement on the opposite side of the sleeve became large, and non-uniformity of voids occurred in the axial direction, making stable support impossible.

[Means for Solving the Problems] According to the present invention, a housing provided with a static pressure supply pipe and a refrigerant passage is fitted to a motor frame, and a bearing sleeve is airtightly fitted to the inner diameter side of the housing, and one side is fitted to the housing. In a hydrostatic bearing in which a bearing sleeve provided with a flange is opposed to a rotating shaft through a gap and is hydrostatically supported, a constraint made of a material having a high tensile strength and a small linear expansion coefficient is provided in an annular groove provided in the inner diameter of the bearing sleeve. A plurality of rings are embedded in the axial direction and firmly fixed with tightening screws, and another flange made of a material with high tensile strength and a small linear expansion coefficient is firmly fixed to both the housing and bearing sleeve on the opposite side in the axial direction with mounting screws. The axial displacement is constrained, and when the temperature of the bearing portion rises, the displacement of each sleeve portion is constrained.

[Operation] Firmly restrains the thermal displacement of each part of the bearing sleeve to make the voids uniform.

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

A housing 2 provided with a static pressure supply pipe and a refrigerant passage 5 is fitted to the motor frame 1, and a bearing sleeve 3 is airtightly fitted to the inner diameter side of the housing 2.

On the inner diameter side of the bearing sleeve 3, the orifice 4 communicating with the static pressure supply pipe of the housing 2 is fitted in the annular groove 11.
A plurality of constraining rings 7 made of ceramics or carbon fiber having a high tensile strength and a small linear expansion coefficient, which are embedded and firmly fixed to the bearing sleeve 3 by a tightening screw 10, are arranged in the axial direction.

At both axial ends of the bearing sleeve 3, flanges 8a formed integrally with the bearing sleeve 3 are attached to the housing 2 with mounting screws 9a, and flanges 8b made of ceramics or carbon fiber having high tensile strength and a small linear expansion coefficient are attached. The screws 9b and 9b are firmly fixed to both the housing 2 and the bearing sleeve 3 to restrain the axial displacement.

The inner diameter of the bearing sleeve 3 is opposed to the rotary shaft 6 through a gap and is statically supported by the air supplied from the orifice 4.

FIG. 3 shows another embodiment. A knock 12 is provided at the end of the bearing sleeve 3 on the side opposite to the load side, the flange 8b is fitted into the knock 12, and the mounting screw 9a is firmly fixed to the housing 2 for assembly. It's easy.

[Advantages of the Invention] According to the present invention, since it is configured as described above, the displacement of each part of the bearing sleeve is restrained and the variation of the air gap can be prevented even if the temperature of the bearing part rises. Can be realized.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, and FIG.
FIG. 3 is a partial sectional view of a section taken along the line AA, FIG. 3 is a partial side sectional view of an end portion on the anti-load side showing another embodiment, FIG. 4 is a side sectional view showing a conventional example, and FIG. It is a schematic diagram which shows a deformation | transformation state. Note that the same components are given the same reference numerals. DESCRIPTION OF SYMBOLS 1 is a motor frame, 2 is a housing, 3 is a bearing sleeve, 4 is an orifice, 5 is a refrigerant passage, 6 is a rotating shaft, 7 is a retaining ring, 8a and 8b are flanges, 9a and 9b are mounting screws, and 10 is a tightening screw. , 11 are annular grooves, and 12 is a knock.

Claims (2)

[Scope of utility model registration request] 1. A static bearing wherein a bearing sleeve having a flange on one side and an orifice on the inner diameter is fitted to the inner diameter of a housing having a static pressure supply pipe and a refrigerant passage, and the bearing sleeve is opposed to the rotary shaft through a gap. In the pressure bearing, a plurality of annular grooves axially provided in the inner diameter of the bearing sleeve, a restraint ring made of a material having a high tensile strength and a small linear expansion coefficient to be fitted in the groove, and a screw for fastening the restraint ring to the bearing sleeve. And the other side of the flange provided on the one side in the axial direction, the other flange made of a material having a high tensile strength and a small linear expansion coefficient, which is fixed to both the housing and the bearing sleeve by a mounting screw. Bearing deformation prevention device. 2. The deformation preventing device for a hydrostatic bearing according to claim 1, wherein the other flange and the bearing sleeve are fixed by a knock.