JPS6376911A - Gas journaling device - Google Patents

Abstract

PURPOSE:To achieve the miniaturization of a device body and the simplification of compressed gas passages, by making the rotating shaft part hollow, and, inside the shaft part, arranging a hollow member whose journaling surface is made the external surface thereof, and further supplying compressed gases into the interior through the end part of the hollow member. CONSTITUTION:In order to rotatably support a shaft body 1 having a hollow part, on the inner circumferential surface 1a of the shaft body 1, a hollow member 2 forming a journaling surface 2d is arranged. And the end parts 2a of the hollow member 2 are fixed in a prescribed position by means of supporting members 3, and one end thereof is made an opened part 2b to which a pump is connected, and further compressed gases are flowed into a gas reserving part 2c. In addition, a plurality of rows of inlet ports 2e are radially provided with a space in the axial direction, each of which is directed toward the outer circumferential surface to be the journaling surface 2d from the gas reserving part 2c of the hollow member 2. Furthermore, on both sides of the end parts 1b of the shaft body 1, flange parts 2f are provided so as to be positioned in the ends of the hollow member 2, and through the flange parts 2 compressed gases are released.

Description

[Detailed Description of the Invention] [Summary] The present invention provides a novel gas shaft support device suitable for supporting a hollow shaft body with a gas coating.

[Industrial application field]

The present invention relates to a gas shaft support device suitable as a shaft support means for precision instruments and various devices such as measuring instruments and testing machines.

[Conventional technology]

Conventionally, in a static pressure gas bearing provided on the outer periphery of the shaft end of a rotating shaft, it is necessary to connect an external pressure source to the air supply hole provided in the bearing, and to provide a passage between the pressure source and the air supply hole. For this reason, it requires a complicated configuration, has the disadvantage that its load capacity is low in comparison to the complexity of the configuration, and its use as a bearing device is restricted.Furthermore, the overall device has to be larger. It also had some drawbacks.

[Problem that the invention seeks to solve]

The present invention provides a novel gas shaft support device that eliminates the above-mentioned drawbacks of conventional hydrostatic gas bearings, and is compact and has support from the inside of the shaft body and extending in the length direction of the shaft body. It is an object of the present invention to provide a gas shaft support device that has a simple configuration and has a higher load capacity than a gas bearing.

[Means for solving problems]

The gas shaft support device of the present invention has a hollow member that can rotatably support the hollow part of the shaft, a compressed gas supply source can be connected to one end of the hollow member, and The interior is a gas reservoir, and the annular portion of the hollow member is characterized by having a plurality of rows of air supply holes made of radial micro holes at appropriate intervals in the axial direction.

[For production]

With the configuration of the present invention, the compressed gas sent from the compressed gas supply source is supplied into the gas reservoir from the end of the hollow member,
The gas is fed from the gas reservoir through the air supply holes provided in multiple rows in the axial direction and in a plurality in the circumferential direction between the inner circumferential surface of the shaft, which is a rotating member, and the outer circumferential surface of a hollow member, which is a shaft supporting surface. Here, the gas is released into the atmosphere from both ends of the shaft and the hollow member while forming a gas film surface.

In this case, since the shaft body is hollow and the hollow member serving as the shaft support body can be located over the entire length of the shaft body in the axial direction, it is also possible to provide air supply holes only at both ends of the hollow member. In addition, it is possible to provide a large number of rows of air supply holes at appropriate intervals along the entire length of the shaft, making it suitable for supporting shafts with light to heavy loads. Air pressure acts on the shaft in the thrust direction by the flange of the member, giving an effect to restrict movement of the shaft in the thrust direction.

〔Example〕

An embodiment of the gas shaft support device of the present invention will be described.

Fig. 1 relates to a gas bearing device that supports the entire length of the shaft, and in order to rotatably support the shaft 1 having a hollow part, the inner circumferential surface 1a of the shaft 1 has a shaft bearing surface. A hollow member 2 constituting 2d is located.

The hollow member 2 has its ends 2a, 2a connected to supporting members 3, 3.
is fixed in place. One end of the hollow member 2 is an opening 2b, a pump (not shown) serving as a compressed gas supply source is connected to the opening 2b, and the compressed gas is supplied to a gas reservoir 2c provided inside the hollow member 2. Inflow.

Two rows of air supply holes 2e, 2e, . The air supply holes 2e in each row are made up of eight radially small air supply holes.

The number of rows of air supply holes in the axial direction and the number in the radial direction can be increased or decreased depending on the length of the supported shaft, the load applied to the shaft, etc.

Flange portions 2f located at the ends of the hollow member 2 are provided on both sides of the ends 1b, lb of the hollow shaft body 1.

2f is provided, and the compressed gas is supplied to the end 1b of the shaft body 1 in the hollow part.
, lb and the flange portion 2f of the hollow member 2.

2f and is emitted into the atmosphere. At this time, the air pressure passing through the gap between the end portions 1b, lb and the flange portions 2f, 2f acts to position the shaft body 1 in the thrust direction by the flange portions 2f, 2f.

In the embodiment shown in FIG. 3, the shaft 1 is supported by a hollow member 2 over its entire axial length in the embodiment shown in FIG. This relates to a gas shaft support device supported by a member 2, and FIG. 3 shows only the right end (compressed gas supply side) in FIG. 1.

The shaft body 1 has a hollow part, and the shaft support surface 2d of the hollow member 2 is located on the inner circumferential surface 1a of the hollow part, and the hollow member 2 has an air pocket 2c inside, and an air pocket 2c at one end. An opening 2b is provided,
This embodiment is similar to the embodiment shown in FIG. 1 in that a pump as a compressed gas supply source can be connected to the opening 2b.

In order to support both end portions of the shaft body 1 by the hollow member 2,
The inner circumferential surface at the end of the shaft body 1 and the outer circumferential surface at the end of the hollow member are processed so as to maintain a predetermined interval, and radial grooves are formed on the two sides at the end of the hollow member. 8 air supply holes 2
e, 2e... are provided.

Flange portions 2f, 2f are provided at the ends of the hollow member 2, and the flange portions 2f are provided with a gap between them and the end portion 1b of the shaft body 1, and the air supply holes 2e, 2e are connected to the shaft. The air film flowing out into the atmosphere through the space between the inner circumferential surface 1a of the body 1 and the outer circumferential surface 2d of the hollow member 2 acts in the thrust direction in this gap, making it possible to position the shaft body 1 in the axial direction. do.

5 is a heat-resistant thermotube provided on the outer peripheral surface of the shaft body, and 2g is an inner wall surface forming the air pocket 2c.

With the above configuration, a pump as a compressed gas supply source is connected to the opening 2b provided at one end of the hollow member 2, compressed gas is supplied to the air reservoir 2c of the hollow member 2, and the Air supply holes 2e, 2e formed in member 2...
The gas is sent to the gap between the outer circumferential surface 2d of the hollow member 2 and the inner circumferential surface 1a of the rotating shaft 1, where a thin gas film is formed, and the shaft 1 is sent to the gap between the outer circumferential surface 2d of the hollow member 2 and the inner circumferential surface 1a of the rotating shaft 1. rotates smoothly through a thin gas film.

The gas in the gap between the outer circumferential surface 2d of the hollow member 2 and the inner circumferential surface 1a of the shaft body 1 is released into the atmosphere along the flange portion 2f of the hollow member 2 at both ends 1b of the shaft body 1. A thin gas film between the end portion 1b of the shaft portion 1 and the flange portion 2f of the hollow member 2 plays the role of regulating movement of the shaft body 1 in the thrust direction.

〔effect〕

The present invention employs a structure in which the rotating shaft part is hollow and a hollow member with the shaft support surface as the outer surface is placed inside the shaft part, thereby making the gas shaft support device smaller than the conventional one. At the same time, the compressed gas supply means can be connected to the end of the hollow member, and the inside of the hollow member can be used as an air reservoir, thereby providing a conventional type of gas in which a bearing is arranged on the outer periphery of the shaft body. Compared to bearings, it does not require any complicated passages or configurations necessary to send compressed gas to the air supply holes, and has the effect of providing a highly accurate gas shaft support device at low cost with a simple configuration. Moreover, since the entire axial length of the rotating shaft portion can be supported by the shaft bearing surface, there is an advantage that the load capacity can be increased.

[Brief explanation of the drawing]

FIG. 1 shows a side view of an embodiment of the gas shaft support device of the present invention, FIG. 2 shows a sectional view taken along the line A-A in FIG. 1, and FIG. Figure 3 shows a partial side view of another embodiment of the device. DESCRIPTION OF SYMBOLS 1... Shaft body, 2... Hollow member, 2c... Gas reservoir part, 2e... Air supply hole.

Claims (1)

[Claims] It has a hollow member that can rotatably support the hollow part of the shaft, a compressed gas supply source can be connected to one end of the hollow member, and the inside of the hollow member is used as a gas reservoir, and the hollow member A gas shaft support device characterized in that the annular portion of the member is provided with a plurality of rows of air supply holes consisting of radial micro holes at appropriate intervals in the axial direction.