JP2872877B2 - Hydrostatic bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrostatic bearing, and more particularly, to a radial bearing surface facing a peripheral surface of a rotating body and a thrust bearing surface facing a flange surface of the rotating body. Type hydrostatic bearing.

[0002]

2. Description of the Related Art In general, a hydrostatic bearing is for supporting a predetermined portion of a rotating body by static pressure of a pressurized fluid.
Particularly, in order to smoothly rotate the rotating body at high speed, a type having a radial bearing surface facing the peripheral surface of the rotating body and a thrust bearing surface facing the flange surface of the rotating body integrally is known. (For example, Japanese Patent Laid-Open No.
Reference).

In such a structure, as shown in FIG. 3, an annular main body integrally having a radial bearing surface 100 facing the peripheral surface of the rotating body R and a thrust bearing surface 101 facing the flange surface of the rotating body R. 110, a surge tank 102 formed in the main body 110 and regulating the pressure fluid supplied thereto, a radial-side discharge port 103 supplying the regulated pressure fluid to the radial bearing surface 100, And a thrust bearing discharge port 104 for supplying the pressurized fluid to the thrust bearing surface 101.

Further, in order to discharge the pressurized fluid after the application of the static pressure discharged from both the discharge ports 103 and 104, the thrust bearing surface 101 has a plurality of discharge grooves 105 extending in the radial direction of the thrust bearing surface 101. Was formed. The discharge groove 105 is formed at the same interval in the circumferential direction with respect to the discharge port 104 for the thrust bearing.

[0005]

As described above, in the conventional configuration shown in FIG. 3, the discharge grooves 105 are formed at the same intervals in the circumferential direction with respect to the discharge port 104 for the thrust bearing. When the rotating body R rotates in one rotation direction A, the flow rate of the pressure fluid discharged to the thrust bearing surface 101 sandwiched between the discharge grooves 105 is equal to the thrust bearing discharge port 10.
There is a tendency that the number is larger on the rotation direction A side than on the fourth side.
For this reason, the thrust bearing surface 101 on the rotation direction A side and the counter rotation direction A side with respect to the thrust bearing discharge port 104.
, The distribution of pressure in the axial direction becomes non-uniform, the discharge efficiency of the discharge groove 105 deteriorates, self-excited vibration occurs in the rotating body R, or the fluid discharged from the discharge groove 105 and the discharge port for the thrust bearing. There is a possibility that the fluid ejected from the fluid 104 may interfere with the fluid.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to make the distribution of the axial pressure acting on the thrust bearing surface uniform in the circumferential direction.
Accordingly, it is an object of the present invention to provide a hydrostatic bearing capable of improving discharge efficiency, preventing self-excited vibration, and preventing interference between a discharge fluid and a fluid that applies a static pressure to a rotating body.

[0007]

In order to solve the above-mentioned problems, a hydrostatic bearing of the present invention is formed in an annular shape, and
A main body having a thrust bearing surface opposed to a flange surface of the rotating body at an end; and a plurality of pressure fluids formed in the thrust bearing surface in a circumferentially equidistant manner and having a static pressure applied thereto. A discharge groove for discharging radially outward of the surface, and an opening between the circumferentially adjacent discharge grooves of the thrust bearing surface of the main body, and the thrust bearing surface and the flange surface of the rotating body for pressurized fluid. And a discharge port for discharging between the discharge ports, the discharge ports are arranged in the rotational direction of the rotating body more than the circumferential center position between the discharge ports and the adjacent discharge grooves. It is characterized in that it is formed in a state shifted to the downstream side.

[0008]

According to the above arrangement, the axial pressure distribution from the flange surface of the rotating body to the thrust bearing surface acting via the pressure fluid can be made uniform in the circumferential direction.

[0009]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a front view of a thrust bearing surface of a hydrostatic bearing according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of a bearing device employing the hydrostatic bearing. First, with reference to FIG. 2, the bearing device includes a casing 1, and a hydrostatic bearing 10 is accommodated in the casing 1. The casing 1 is a cylindrical member made of, for example, a steel material, and has a pressurized air inlet 1a for introducing pressurized air as a pressurized fluid on one side wall. Further, one end of the casing 1 is closed by a wall 1b. An annular groove 1c is defined on the other end (left side in FIG. 2) of the wall 1b in the center line direction.

On the inner surface of the annular groove 1c, a plurality of exhaust holes 1d communicating with the outside of the casing 1 and discharging pressurized air are provided on the periphery. The flange R1 of the rotating body R faces the annular groove 1c. This rotating body R is
This is a solid shaft member that is driven to rotate at high speed, and integrally includes the flange R1 and a shaft portion R3 that supports the flange R1. Then, the shaft portion R3 and the flange R1
Are supported by the hydrostatic bearing 10 of the present embodiment.

Referring also to FIG. 1, a hydrostatic bearing 10 of the present embodiment includes a main body 11 fixed to the inner periphery of the casing 1.
It has. The main body 11 is formed by forming a hollow metal member into an annular shape. The inner periphery of the main body 11 constitutes a radial bearing surface 12 facing the peripheral surface R31 of the shaft portion R3 of the rotating body R. The end surface of the main body 11 forms a thrust bearing surface 13 that faces the flange surface R11 of the flange R1 of the rotating body R.

An air supply port 14 facing the pressurized air inlet 1a of the casing 1 is formed on one outer wall of the main body 11, and the air supply port 14 and the pressurized air inlet 1a are formed through the air supply port 14a. Pressurized air is supplied from a pressurized air supply source (not shown). In the present embodiment, the hollow portion of the main body 11 constitutes a surge tank 15 for regulating the pressure of the pressurized air.

The radial bearing surface 12 of the main body 11 has
The radial outlet 16 is open. The radial discharge port 16 discharges pressurized air between the radial bearing surface 12 and the peripheral surface of the rotating body R. Further, a plurality of (two in this embodiment) discharge grooves 18 are formed in the thrust bearing surface 13 at equal intervals in the circumferential direction of the thrust bearing surface 13. The discharge groove 18 communicates radially outward of the thrust bearing surface 13 with the radial bearing surface 12, and pressurized air to which static pressure has been applied is applied to the thrust bearing surface 1.
3 for discharging radially outward.

Further, the thrust bearing surface 1 of the main body 11
3, a discharge port 17 for a thrust bearing is opened between the discharge grooves 18 adjacent to each other. The discharge port 17 for thrust bearing is for discharging pressurized air between the thrust bearing surface 13 and the flange surface R11 of the rotating body R. In the configuration as described above, the discharge ports 17 for the thrust bearings of the hydrostatic bearing 10 of the present embodiment are arranged in the rotation direction A of the rotating body R more than the center position between the adjacent discharge grooves 18. It is formed so as to be shifted toward the side, thereby making the distribution of pressure in the axial direction in the rotation direction uniform.

Referring to FIG. 1 in more detail,
The discharge grooves 18 form a pair by being formed along one diameter direction of the thrust bearing surface 13 of the main body 11, and each of the discharge grooves 18 has a discharge port 17 for a thrust bearing between one and the other.
Are formed one by one. The central angle θ1 from the thrust bearing discharge port 17 to the discharge groove 18 located on the rotation direction A side (hereinafter referred to as “downstream center angle”) θ1 is the rotation direction from the one thrust bearing discharge port 17 to the rotation direction. A to the other discharge groove 18 located on the opposite side to A
Smaller than θ2 (referred to as “upstream center angle”), preferably between about 5 ° and about 40 ° (in this embodiment, about 40 °).
°). The difference (or ratio) between the central angle θ1 on the upstream side and the central angle θ2 on the downstream side is appropriately changed according to the pressure of the pressurized air to be used, the number of rotations of the rotating body R, and other various specifications. Needless to say.

Next, the operation of this embodiment will be described. When pressurized air is supplied to the pressurized air inlet 1a of the casing 1 from a pressurized air supply source (not shown),
The pressure is introduced into the surge tank 15 from the pressurized air inlet 1 a through the air supply port 14 of the hydrostatic bearing 10, and the pressure is regulated by the surge tank 15. The regulated pressurized air is supplied to each of the discharge ports 16 and 17 similarly to the conventional configuration.
, The rotating body R is supported by the static pressure of the pressurized air. Then, the air discharged from the radial discharge port 16 is discharged from the inner peripheral side of the main body 11 to the radial outside of the thrust bearing surface 13 through the discharge groove 18,
The gas is discharged out of the casing 1 through the exhaust hole 1d.

On the other hand, the thrust bearing discharge port 17 discharges pressurized air from the portion of the rotating body R that is moved toward the rotation direction A into one discharge groove 18, and the flange surface R 11 of the rotating body R To support. Therefore, the thrust bearing surface 1 acting via the pressurized air from the flange surface R11 of the rotating body R
The distribution of the pressure in the axial direction to 3 becomes uniform in the circumferential direction.

Therefore, according to this embodiment, the discharge groove 1
8 can be prevented from lowering, and there is no possibility that the air discharged from the discharge groove 18 and the air discharged from the thrust bearing discharge port 17 will interfere with each other. Vibration can be prevented.
It should be noted that the above-described embodiment is merely an example of a preferred embodiment of the present invention, and it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[0019]

As described above, according to the present invention, the axial pressure distribution from the flange surface of the rotating body to the thrust bearing surface acting via the pressure fluid is made uniform in the circumferential direction. This allows
It is possible to prevent a decrease in the discharge efficiency due to the discharge groove, and there is no possibility that the fluid discharged from the discharge groove and the fluid discharged from the discharge port interfere with each other, so that the self-excited vibration occurs in the rotating body. Can be prevented.

Therefore, according to the present invention, there are remarkable effects that the discharge efficiency can be improved, self-excited vibration can be prevented, and interference between the discharged fluid and the fluid that applies static pressure to the rotating body can be prevented. .

[Brief description of the drawings]

FIG. 1 is a front view of a thrust bearing surface of a hydrostatic bearing according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a bearing device employing the hydrostatic bearing.

FIG. 3 is a front view of a thrust bearing surface of a conventional hydrostatic fluid bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Hydrostatic bearing 11 Main body 12 Radial bearing surface 13 Thrust bearing surface 16 Radial side discharge port 17 Thrust bearing discharge port 18 Discharge groove R Rotating body R11 Flange surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16C 32/00-32/06

Claims (1)

(57) [Claims] 1. A main body which is formed in an annular shape and has a thrust bearing surface facing the flange surface of a rotating body at an end portion, and a plurality of the main bodies are formed on the thrust bearing surface in a circumferential direction at equal intervals, and A discharge groove for discharging the pressurized fluid after the application of the static pressure radially outward of the thrust bearing surface, and an opening between the circumferentially adjacent discharge groove of the thrust bearing surface of the main body and a pressure. In a hydrostatic bearing having a discharge port that discharges a fluid between a thrust bearing surface and a flange surface of a rotating body, the discharge port is formed between the discharge port and the discharge groove adjacent to the discharge port. A hydrostatic bearing, wherein the hydrostatic bearing is formed so as to be closer to a downstream side of the rotating body in the rotation direction than a center position in the rotation direction.