JPS60188620A - Fluid bearing - Google Patents

Abstract

PURPOSE:To form an economical fluid bearing with high performance by heating fluid in a fluid reservoir at the inside of a driven member constituted from a high heat resisting property material to float the driven member and a fixed member with heightened pressure. CONSTITUTION:An outer tube 1 of heat resisting material is formed on the inner peripheral surface with a peripheral groove to provide a fluid reservoir 1a for reserving fluid 2, and a heating unit 3 is attached to the inside of the outer tube 1 of the reservoir 1a. The fluid in the reservoir 1a is blocked from outflow to the outside by a flange 1b on the axial end of the outer tube 1. Since this fluid bearing is constituted to utilize the thermal expansion of air or liquid used, an economical and stable fluid bearing is formed by a simple construction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydrodynamic bearing using air or liquid. Recently, new sliding bearings and rolling bearings using new materials such as ceramics have been proposed. An object of the present invention is to provide an inexpensive and high-performance fluid bearing using a heat-resistant material such as ceramic.

In the present invention, a highly heat-resistant material such as ceramic is used as a moving member and a fixed member, a fluid retention portion is formed on the inner surface of the moving member, and the fluid is retained by heating the fluid in the fluid retention portion. This bearing has a structure in which the fluid inside the bearing has a high pressure, and this pressure causes the moving member and the fixed member to float.

A few examples of the present invention will be explained below with reference to the drawings. 1st
The figure shows the simplest and cheapest example of the structure, in which the outer cylinder 1 is made of a heat-resistant material such as ceramic, and a circumferential groove is formed on the inner peripheral surface of the outer cylinder to form a fluid retention section 1a to retain the fluid 2. Fluid storage part 1
The heating element 3 is attached in contact with the inner surface of the outer cylinder of a. The heating element 3 may be a known heater that has high thermal conductivity and is easy to heat, such as a heater made of copper alloy or ceramic. A flange portion 1b is formed at the axial end of the outer cylinder 1, and the inner surface of the flange portion 1b is structured to prevent the fluid from flowing out to the outside within the fluid storage portion 1a.This sealing structure is also constructed using various known techniques. Good too. A heating device 4 that heats the heating element 3 inside the bearing is installed outside the bearing, and the heating device 4 and the heating element 3 are connected with an electric wire or the like. 5
is the axis.

Although not shown, it is also possible to install a control device that measures the temperature or pressure inside the fluid storage section and turns the heating device ON/OFF based on the measured value, if necessary. As shown in Fig. 1(C), it is also possible to fit the inner cylinder 1' to the steel shaft 5 to prevent the shaft from becoming too hot.Furthermore, the shaft itself can be made of a heat-resistant material such as ceramic. It's okay.

FIG. 2 is an improved example of FIG. 1. If the load increases,
It is necessary to increase the pressure of the fluid in the fluid storage portion, and the fluid 2 tends to leak from the outer cylinder flange portion 1a. If the fluid leaks, the pressure inside the fluid storage section 1a will drop, so
An inflow pipe having a valve 6 is connected through the fluid storage part 1a, the valve 6 is opened to allow fluid to flow in, and the pusher 6 is closed to heat the fluid.

It is also possible to have the above-mentioned control device perform this intermittent operation.

FIG. 3 shows an example of a hydrodynamic bearing that moves linearly on a plane, and the basic structure is the same as that of FIG. 2. This uses heat-resistant materials for the table 7 and the bed 8, and the table 7 has a plurality of rows of fluid retaining portions 7a formed on its inner surface, and a plurality of fluid inlet holes 7b provided on its outer surface. In this example, since a plurality of rows of fluid retention sections are formed, for example, the valves 6 of the first and third inflow holes 7b+ and 7ba in the rear and front rows of the upper surface are opened to allow fluid to flow into the fluid retention sections. The valve is closed, and after a certain period of time, the fluid is allowed to flow in from the second and fourth inflow pipes, so that the load of each group is balanced between two or more groups. It is possible to implement a method that stabilizes the load capacity of the bearing, resulting in a bearing with smooth movement and high accuracy. Sho 9
is a pedestal member, which fixes the bed 8 with mounting bolts 10.

FIG. 4 is a modification of FIG. 3. In this example, heating element 3
is installed outside the bearing. In a high-pressure tank 11 having a heating element 3 and a heating device @4, the fluid 2 in the tank is heated, thermally expanded, and has a high pressure. High temperature (high pressure) tank 11
is communicated with a constant pressure tank 13 through an inflow pipe having a valve 12, and the constant pressure tank 13 is further communicated with a fluid retention portion 7a formed on the inner surface of the table 7 made of a heat-resistant material through the inflow pipe. When the fluid in the fluid storage part 7a gradually flows out of the bearing and the pressure in the constant pressure tank 13 decreases, the pressure adjustment valve 12 opens, and the fluid in the high temperature (high pressure) tank 11 flows into the constant pressure tank 13. The pressure increases to the required pressure. When the pressure in constant tank 13 increases to the appropriate pressure, valve 12 closes. Conversely, the pressure inside the high temperature (high pressure) tank 11 decreases, so the valve 14 is opened and fluid is replenished, and the valve 1
4 is closed, the sprout 3 is heated again to increase the pressure inside the high temperature (high pressure) tank 11.

The technology for automatically controlling the above-described pressure adjustment operation as described above is fully possible with known technology.

It should be noted that these embodiments are merely examples, and the present invention can be implemented in various known bearing structures.

As described above, the present invention constructs a fluid bearing simply by utilizing air or liquid and its thermal expansion, so there is no need for a large compressor or a bearing member with a complicated shape as in the past. , it is possible to provide a stable hydrodynamic bearing with a simple structure at low cost.

[Brief explanation of the drawing]

FIGS. 1(A) and 1(B) are a partial vertical sectional view and a horizontal sectional view showing a first embodiment of the present invention, and FIG. 1(C) is a partial longitudinal sectional view and a horizontal sectional view showing a modification thereof
FIG. Fig. 2 is a partial longitudinal sectional view showing the second embodiment, Figs. 3 (A) and (B) are sectional views and perspective views showing the third embodiment, and Fig. 4 is a modification of Fig. 3. FIG. The symbols in the drawings indicate the following members, respectively. 1: Outer cylinder 2: Fluid 3: Heating element 4: Heating device 5: Shaft 6: Valve 7: Table 8: Bed 9: Pedestal member 10: Mounting bolt 11: High temperature (high pressure) tank 12: Valve 13: Constant pressure tank 14: Valent patent applicant Nippon Thomson Co., Ltd. 11!1 (A) Spear 2 Illustration 3 Figure (A) Spear 4 Figure

Claims (1)

[Claims] 1. A highly heat-resistant material such as ceramic is used as the moving member or the fixed member, and a fluid retention portion is formed on the inner surface of the moving member or the fixed member, and the fluid in the fluid retention portion is 1. A fluid bearing, characterized in that by heating the fluid, the fluid in the fluid storage section becomes high pressure, and this pressure causes the moving member and the fixed member to float. 2. A circumferential groove is formed on the outward inner circumferential surface that fits with the shaft to form a fluid storage section, and a heating element is attached in contact with the inner surface of the outer cylinder of the fluid storage section, and a heating device for the heating element is installed. A hydrodynamic bearing according to claim 1, characterized in that a hydrodynamic bearing is provided. 3. Forming a circumferential groove on the inner circumferential surface of the outer cylinder that fits with the shaft to form a fluid retention part, mounting a heating element in contact with the inner surface of the outer cylinder of the fluid retention part, and a heating device for the heating element. 2. The fluid bearing according to claim 1, further comprising: an inflow pipe with a valve that communicates with the fluid storage section. 4. A groove is formed on the inner circumferential surface of the table that fits with the bed to form a fluid storage section, and a heating element is mounted in contact with the inner surface of the table of the fluid storage section, and a heating device for the heating element and the fluid are installed. The fluid bearing according to claim 1, further comprising an inflow pipe with a valve that communicates with the storage section. 5. A groove is formed on the inner circumferential surface of the table that fits into the bed to form a fluid storage section, and a constant pressure tank is connected to the fluid storage section via an inflow pipe, and a pressure adjustment tank is further provided in the constant pressure tank. The fluid according to claim 1, characterized in that a high temperature (high pressure) tank is provided which communicates through an inflow pipe with a valve, and the high temperature (high pressure) tank is provided with a heating element and a heating device for the same. bearing. 6. After opening the valve in the inflow pipe equipped with a pressure adjustment valve to introduce fluid into the fluid storage section, the cough valve is closed, and then the heating device is operated;
The hydrodynamic bearing according to claims 1, 3, 4, and 5, characterized in that a manual or automatic control device for performing the operation is provided.