JPH06280876A - Hydrostatic gas bearing device - Google Patents

Abstract

PURPOSE:To decrease the number holes of the outer peripheral surface of a bearing member not to be blocked up so as to improve assembling efficiency by providing an exhaust means for communicating the respective spaces with each other between the space between bearing members and the external space on the bearing member side. CONSTITUTION:In a bearing device, a turbine blade nozzle 11 blows off air supplied from an air hole 10b of a housing 19 from a gas supply outlet 11a toward a turbine blade 7 to rotate a rotary shaft 1. A bearing nozzle 12 blows off gas supplied from the air hole 10a from a gas supply outlet 12a toward a shaft part 6 to support the rotary shaft 1 in the radial direction with static pressure, and the gas flows along the shaft part to apply static pressure to a collar part 3 so that the rotary shaft 1 is supported in the axial direction. Air jetted from the nozzles 11, 12 is discharged to the outside through an exhaust hole 29 piercing a bearing nozzle member 18. As the exhaust hole 20 is thus formed, holes opened on the outer peripheral surface of the housing 10 can be decreased. Accordingly, restrictions on assembling can be lessened so as to improve assembling efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrostatic gas bearing device which is easy to assemble and easy to manufacture.

[0002]

2. Description of the Related Art Conventionally, a static pressure gas bearing device of this type is shown in FIG. This bearing device has a rotating shaft 32 having turbine blades 31 provided on the outer periphery thereof, and a bearing body 33 into which the rotating shaft 32 is inserted. The bearing body 33
Has a turbine blade nozzle 35 facing the turbine blade 31, and a bearing nozzle 36 facing the rotating shaft 32 with a slight gap. Further, the bearing body 33 is formed with exhaust holes 37 located on both sides in the axial direction of the turbine blade nozzle 35 and adjacent to the bearing nozzle 36, extending in the radial direction and communicating with the outside. There is.

In the above static pressure gas bearing device, gas is blown from the nozzle holes 35a of the turbine blade nozzle 35 onto the turbine blade 31 to rotate the rotary shaft 32. Further, gas is blown from the nozzle hole 36a of the bearing nozzle 36 onto the shaft portion of the rotary shaft 32 to support the rotary shaft 32 in the radial direction. The gas blown out from the turbine blade nozzle 35 and the bearing nozzle 36 is exhausted to the outside through the exhaust hole 37.

[0004]

By the way, in the above-mentioned hydrostatic gas bearing device, the outer peripheral surface of the bearing body 33 generally serves as a mounting portion. However, the conventional static pressure gas bearing device described above,
Since not only the nozzle holes 35a and 36a but also the exhaust holes 37 extend in the radial direction and open to the outer peripheral surface of the bearing body 33, there are many holes that should not be blocked on the outer peripheral surface of the bearing body 33. There is a problem of poor attachment.

Further, the above-mentioned static pressure gas bearing device is generally
Since it is necessary to form a large number of through holes on the outer peripheral surface of the bearing body 33, which is a cylindrical surface that is difficult to drill, there is also the problem of poor workability.

Therefore, an object of the present invention is to provide a hydrostatic gas bearing device which is excellent in assemblability and easy to manufacture.

[0007]

In order to achieve the above object, a static pressure gas bearing device according to a first aspect of the present invention comprises a rotary shaft inserted through a through hole of a fixing member and an inner circumference of the fixing member. A plurality of substantially cylindrical bearing members axially spaced apart from each other and having a bearing hole forming a minute gap with the rotating shaft, and each of the bearing members has an inner peripheral surface of the bearing hole. A plurality of bearing nozzles that open and eject gas toward the rotating shaft are provided on the circumference, and exhaust means for communicating the spaces between the bearing members and the external space is provided on the bearing member side. It is characterized by The invention according to claim 2 is the static pressure gas bearing device according to claim 1, characterized in that the exhaust means is constituted by an axial through hole formed in a bearing member. The invention described in claim 3 is the static pressure gas bearing device according to claim 2, wherein the axial through hole is formed between the bearing nozzles.

[0008]

In the hydrostatic gas bearing device having the above structure, gas is jetted from the bearing nozzle to the outer peripheral surface of the rotary shaft to support the rotary shaft in the radial direction. The gas ejected from the bearing nozzles of the plurality of bearing members is exhausted to the outside from a bearing hole provided in the axial direction of the bearing member as an exhaust means.

As described above, in the above-mentioned static pressure gas bearing device, since the through hole penetrating in the axial direction is formed in the bearing member as the exhausting means, compared with the conventional example in which the through hole penetrates in the radial direction, Fewer holes open to the outer peripheral surface of the member. Therefore, the number of holes that should not be blocked on the outer peripheral surface of the bearing member can be reduced as compared with the conventional example, and restrictions on the assemblability can be reduced.

Further, since the through-hole extends in the axial direction and penetrates the bearing member, the through-hole can be formed by making a hole in the axially outer end surface of the bearing member, which is generally flat. The workability is improved as compared with the conventional example in which the through hole has to be formed on the curved outer peripheral surface.

[0011]

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of the static pressure gas bearing device of the present invention. As shown in FIG. 1, this embodiment has a rotating shaft 1 and a bearing body 2. The rotary shaft 1 includes a collar portion 3,
It includes a turbine portion 5 sandwiched between 3 and a shaft portion 6 extending from the turbine portion 5 to both sides in the axial direction. A plurality of turbine blades 7, 7, ... Are provided on the outer periphery of the turbine section 5.

The bearing 2 is fitted into the housing 10 so as to be located on both sides of the housing 10, the turbine blade nozzle member 17 inserted into the housing 10, and the turbine blade nozzle member 17. A bearing nozzle member 18 as a bearing member. The turbine blade nozzle member 17 may be separate from the bearing body 2. The housing 10 is formed with air supply holes 10a, 10a and 10b which penetrate the housing 10 in the radial direction. Further, the turbine blade nozzle member 17 includes a turbine blade nozzle 11 communicating with the air supply hole 10 b of the housing 10. O-rings 13, 13 are provided between the turbine blade nozzle member 17 and the inner peripheral surface 8 of the housing 10 to provide the air supply holes 10
The air from b to the nozzle 11 is prevented from leaking outside. Further, the turbine blade nozzle 11 has a gas outlet 11a.

The bearing nozzle members 18, 18
Are adjacent to both sides of the turbine blade nozzle member 17 in the axial direction and face the shaft portion 6 of the rotary shaft 1 with a slight gap t.

The bearing nozzle member 18 has a substantially cylindrical shape, and the center hole is a bearing hole 18e.

Further, the bearing nozzle member 18 has the bearing nozzle 1 communicating with the air supply hole 10a of the housing 10.
Have two. A plurality of the bearing nozzles 12 are evenly arranged in the circumferential direction, and have the gas outlets 12a opened in the bearing holes 18e. Nozzle member 18 for the bearing
And the inner peripheral surface 8 of the housing 10 between the O-ring 1
5 and 15 are provided, and the nozzle 1 for bearings is provided from the air supply hole 10a.
The air to 2 is prevented from leaking outside.

The bearing nozzle member 18 has a stepped portion 18a at its axially inner end. The bearing nozzle member 18 has the step surface 18b of the step portion 18a.
And an exhaust hole 20 that extends in the axial direction and that opens to the outer end surface 18c in the axial direction. At least one exhaust hole 20,
It is provided between the bearing nozzles 12. Nozzle member for bearing 1 in which nozzle 11 for turbine blade exists due to exhaust hole 20
The space between 8 and 18 communicates with the outside. In the present embodiment, the exhaust holes 20 are connected to the nozzle members 1 for both bearings.
However, if there is no problem with the exhaust performance, the exhaust hole 20 may be provided only in one of the bearing nozzle members 18.

In the hydrostatic gas bearing device having the above structure, the turbine blade nozzle 11 is provided with the air supply hole 1 of the housing 10.
The air supplied from 0b is blown from the gas outlet 11a toward the turbine blade 7 to rotate the rotating shaft 1.

Further, the bearing nozzle 12 blows out the gas supplied from the air supply hole 10a of the housing 10 from the gas outlet 12a toward the shaft portion 6 to rotate the rotary shaft 1
Are supported in the radial direction by static pressure. Further, the air blown out from the nozzle hole 12a of the bearing nozzle 12 flows along the shaft portion 6 and applies a static pressure to the collar portion 3 to support the rotary shaft 1 in the axial direction.

The air blown from the turbine blade nozzle 11 and the air blown from the bearing nozzle 12 pass through the bearing nozzle member 18 through an exhaust hole 20.
Exhausted from the outside.

In the above static pressure gas bearing device, the bearing nozzle member 18 is provided with the exhaust hole 20 which extends in the axial direction from the step surface 18b and opens to the outer end surface 18c in the axial direction.
As compared with the conventional example in which the exhaust hole penetrates in the radial direction, it is not necessary to provide the exhaust hole in the housing 10, and the number of holes opened on the outer peripheral surface of the housing 10 can be reduced. Therefore, the number of holes that should not be blocked on the outer peripheral surface of the bearing body 2 can be reduced as compared with the conventional example, and the necessity of aligning the exhaust holes 20 with the exhaust holes provided in the housing 10 is eliminated. Therefore, according to the above-described embodiment, it is possible to reduce restrictions on the assemblability and improve the assemblability.

Further, since the number of holes penetrating the inner peripheral surface 8 of the housing 10 can be reduced as compared with the conventional example, the housing 1
When the turbine blade nozzle member 17 and the bearing nozzle members 18, 18 are inserted into 0, the probability that the O-rings 13, 15 are damaged at the edge of the hole penetrating the inner peripheral surface 8 of the housing 10 can be reduced. it can.

Further, since the exhaust hole 20 extends in the axial direction and penetrates the bearing nozzle member 18, the exhaust hole 20 is formed by making a hole in the end surfaces 18b and 18c of the bearing nozzle member 18 which is a flat surface. Can be formed. That is, according to the above-described embodiment, the exhaust hole 20 can be formed in a flat surface. Can be improved. Further, since the exhaust hole 20 can be formed in a flat surface, deburring at the time of hole processing becomes easy.

In the above embodiment, the turbine portion 5, the turbine blades 7, and the collar portion 3 are provided integrally with the shaft portion 6.
As shown in FIG. 3, the turbine portion 5, the turbine blades 7, and the collar portion 3 are integrally molded resin members, and are separate from the shaft portion 6, and the resin member is press-fitted or adhesively fixed to the shaft portion 6. You may do it. In this case, the shaft portions 6 and 6 on both sides of the turbine portion 5 can be continuously machined once, and the concentricity of the shaft portions 6 and 6 can be improved. Moreover, since the turbine blade 7 having a complicated shape can be formed by resin molding, the turbine blade 7 can be easily processed, and the cost can be reduced. Further, since the turbine section 5, the turbine blades 7 and the like are made of resin, the weight can be reduced,
The imbalance of the center of gravity can be reduced.

Further, in the above embodiment, the bearing body 2 is formed by the housing 10, the turbine blade nozzle member 17 and the bearing nozzle member 18 which are separate bodies. However, these three kinds of components are integrated into one body. Good. Furthermore, in the above embodiment, the turbine blade nozzle member 17 is provided between the bearing nozzle members 18, 18 as a bearing member, but this may be omitted, and the upper space is simply the bearing nozzle member 18, 18.
It may be configured with only 18. Furthermore, when three or more bearing nozzle members 18 are axially separated in the bearing body 2, exhaust holes 20 are provided in all the bearing nozzle members 18 or bearings located at both ends. Exhaust holes 20 may be provided in all of the bearing nozzle members 18 except one of the bearing nozzle members 18 to communicate the space between the bearing members 18 and the outside.

[0026]

As is apparent from the above, in the static pressure gas bearing device of the present invention, a plurality of substantially cylindrical bearing members having bearing holes forming a minute space between the bearing shaft and the rotary shaft are provided with the above-mentioned bearing holes. A plurality of bearing nozzles, which are open to the inner peripheral surface and eject gas toward the rotary shaft, are provided on the circumference, and an exhaust means is provided for communicating each space between the space between each bearing member and the external space. Therefore, as compared with the conventional example in which the through hole as the exhaust means penetrates in the radial direction, the number of holes opened on the outer peripheral surface of the bearing member can be reduced. Therefore, the number of holes that should not be blocked on the outer peripheral surface of the bearing member can be reduced as compared with the conventional example, and restrictions on the assemblability can be reduced. Therefore, according to the present invention, the assembling property can be improved.

Further, when the exhaust means is constituted by an axial through hole formed in the bearing member, the through hole extends in the axial direction and penetrates the bearing member, so that the shaft of the bearing member which is generally flat is provided. A through hole can be formed by forming a hole in the outer end face in the direction, and the workability can be improved as compared with the conventional example in which the through hole must be formed in a curved surface.

[Brief description of drawings]

FIG. 1 is a half sectional view of an embodiment of a static pressure gas bearing device of the present invention.

FIG. 2 is a sectional view of a modified example of the above embodiment.

FIG. 3 is a half sectional view of a conventional static pressure gas bearing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating shaft, 2 ... Bearing body, 3 ... Collar part, 5 ... Turbine part,
6 ... Shaft part 7 ... Turbine blade, 8 ... Inner peripheral surface, 10 ... Housing, 10
a, 10b ... Air supply hole, 11 ... Turbine blade nozzle, 11
a ... Nozzle hole, 12 ... Bearing nozzle, 12a ... Nozzle hole, 20 ... Exhaust hole, 17 ... Turbine blade nozzle member, 1
8 ... Nozzle member for bearing, 18a ... Step portion, 18b ... Step surface, 18c ... Outer end surface, 18e ... Bearing hole, 13, 15 ... O
ring.

Claims (3)

[Claims] 1. A plurality of rotating shafts inserted through through holes of a fixed member, and a plurality of bearing holes axially separated from each other on an inner peripheral surface of the fixed member and forming a minute gap between the rotating shafts. And a plurality of bearing nozzles on the circumference, each of which has a substantially cylindrical bearing member, is formed on the inner peripheral surface of the bearing hole, and ejects gas toward the rotating shaft. A static pressure gas bearing device, characterized in that exhaust means for communicating each space between a space between members and an external space is provided on the bearing member side. 2. The static pressure gas bearing device according to claim 1, wherein the exhaust means is constituted by an axial through hole formed in a bearing member. 3. The static pressure gas bearing device according to claim 2, wherein the axial through hole is formed between the bearing nozzles.