JPH05296245A - Fluid linear guide apparatus - Google Patents

Abstract

PURPOSE:To provide a low-cost fluid linear guide apparatus which can be used as easily as rolling element type linear guide apparatuses. CONSTITUTION:A fluid linear guide apparatus includes a shaft body 1 having a receiving face provided along its axis, a plurality of bearing bodies 2 each of which is provided with a bearing surface and forms a fluid bearing when a fluid is supplied between the receiving face and the bearing surface, and spherical bearings 10 for supporting the respective bearing bodies 2. The bearing bodies 2 are small in length and can easily be machined. The moment forces of the bearing bodies 2 around X-, Y and Z-axes are absorbed by the spherical bodies 10 and thereby a long-size one can easily be installed without requiring the mounting surface of a bed to be finished to high precision, and is low-costed and easy to use.

Description

Detailed Description of the Invention

[0001]

This invention relates to a machine tool, a measuring instrument,
The present invention relates to a fluid linear guide device used as a highly accurate linear guide in industrial equipment and the like.

[0002]

2. Description of the Related Art As a conventional fluid linear guide device of this type, a static pressure type and a dynamic pressure type are known. Both
The shaft body is provided with a shaft body having a bearing surface in the axial direction and a bearing body having a bearing surface facing the bearing surface, and the shaft body is formed by the pressure of the fluid sent into the bearing clearance between the bearing surface and the bearing surface. Alternatively, the bearing body is supported while linearly moving without contact. The former static pressure type fluid linear guide device pressurizes gas such as air or liquid such as oil and sends it to the bearing to form a gas or liquid film to support the weight. The dynamic pressure type linear guide device has a groove for generating dynamic pressure formed in advance on the bearing surface or the receiving surface, and the pumping action of the groove causes a pressure fluid film in the bearing clearance during relative movement between the shaft body and the bearing body. To support the weight. Therefore, in the case of the dynamic pressure type, the shaft body and the bearing are not in contact with each other only in the moving state.

[0003]

It is necessary to maintain the thickness of the fluid film of such a fluid linear guide device in the range of several μm to several tens of μm. Since this fluid film is not as rigid as a linear guide device using rolling elements such as steel balls, for example, a uniform thickness is maintained when an external force is applied to a part of the bearing body and a moment force acts. Is difficult.
Therefore, in the case of the conventional fluid linear guide device, in general, the bearing body is formed to have the same length as the shaft body, and substantially the entire length of the shaft body is surrounded by the bearing body to increase the rigidity, and the shaft body and the bearing body The relative displacement is controlled. However,
When producing a large fluid linear guide device with a length of several meters, high precision machining and scraping with a large mother machine in order to finish the long bearing surface and bearing surface accurately. However, there is a problem that productivity is difficult to improve. Also, the user needs to prepare a bed with high accuracy and to measure the coaxiality between the bearing body and the shaft body strictly before installing the fluid linear guide device. There was a problem that it took.

By the way, in the linear guide device using the rolling elements, since the rigidity is high, it is possible to withstand the moment force even if the length of the bearing body is short, and the long bearing body in the conventional fluid linear guide device is unnecessary. It is much easier to make and install and can be used easily. Therefore, the present invention has been made by paying attention to the above-mentioned conventional problems. The bearing body is divided into short pieces, and a plurality of short bearing bodies divides and supports several portions of the long shaft body, and each bearing is individually supported. An object of the present invention is to solve the above-mentioned conventional problems by providing a fluid linear guide device capable of adjusting its posture.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a fluid bearing is formed by supplying a fluid between a shaft body having a bearing surface provided in the axial direction and a bearing surface of the shaft body and facing the bearing surface. A plurality of bearing bodies provided with a bearing surface, and a spherical bearing mounted on the outer surface of the bearing body at a position opposite to the shaft body.

[0006]

Since a plurality of short bearing bodies support several places of the shaft body, the individual bearing bodies can be easily machined and the productivity is good.
Further, since the spherical bearings allow the spherical motion of each bearing body, the moment force around the X, Y, and Z axes can be absorbed, and the long one can be easily manufactured without finishing the bed mounting surface with high accuracy. Can be installed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a part of an embodiment of the present invention with a part omitted, and FIG. 2 is a sectional view taken along line II-II thereof. A long shaft body 1 having a rectangular cross section is supported by a plurality of (three in the figure) short bearing bodies 2 arranged at intervals in the axial direction.
Both side surfaces 1b and a lower surface 1c of the shaft body 1 are receiving surfaces of the fluid bearing, and a table 3 is fixed to the upper surface 1a by bolts (not shown). The bearing body 2 has a U-shaped cross section and has an inner surface 2b.
And the bottom surface 2c are bearing surfaces, both inner side surfaces 2b are both side surfaces 1b of the bearing surface of the shaft body, and the bottom surface 2c is a lower surface 1c of the bearing surface of the shaft body.
, And each face each other through a slight bearing clearance. The fluid bearing of this embodiment is a porous static pressure air bearing, and a porous material 4 is disposed on the bearing surfaces 2b and 2c of the bearing body 2, and the bearing is passed from an external compressed air source through an air pipe 5. The compressed air supplied to the body 2 is sent from the surface of the porous material 4 into the bearing clearance through the air passage 6.

A spherical bearing 10 is attached to an outer surface 2d of the bearing body 2 opposite to the bottom surface 2c by a bolt (not shown). The convex spherical member 11 of the spherical bearing 10 is provided with a bolt mounting hole 12 penetrating its axial center with a counterbore 12a. The preloading coil spring 13 is inserted into the counterbore 12a to attach the bolt 14 thereto. The bolt 14 is threaded through the concave spherical member 15. The spherical bearing 10 of this embodiment is also a porous static pressure air bearing, and the porous material 4 is disposed on the concave spherical surface 15a of the concave spherical member 15 which faces the convex spherical surface 11a of the convex spherical member 11. Compressed air supplied from an external compressed air source through the air pipe 5 is sent from the surface of the porous material 4 into the bearing clearance through the air passage 6 to form a fluid film.

The concave spherical member 15 of the spherical bearing 10 has positioning plates 21, 22 on a base plate 20 having an L-shaped cross section.
It is fixed with a bolt (not shown) through. The positioning plate 21 is interposed between the bottom surface 15c of the concave spherical member and the base plate 20 to position the height (Z direction) of the fluid linear guide device. On the other hand, the positioning plate 22 is interposed between the one side surface 15b of the concave spherical member and the base plate 20 to position the fluid linear guide device in the lateral direction (Y direction).

Next, the operation will be described. When this fluid linear guide device is mounted on the bed B, positioning is performed in the Y and Z directions by the straight edge method or the laser method, and the thickness of the positioning plates 21, 22 is adjusted to position each bearing body 2. .. Since the bearing body 2 absorbs the displacement around the X, Y, and Z axes by the action of the spherical bearing, it is not necessary to finish the upper surface of the bed B (the mounting surface of the fluid linear guide device) with high accuracy. Further, the finishing of the bearing body 2 does not require as high precision machining as the conventional one. Therefore, if only the shaft body 1 is manufactured with relatively high accuracy, a long fluid linear guide device can be easily manufactured, installation is easy, and it can be used as easily as a rolling element linear guide device. it can.

FIG. 3 shows another embodiment. This example
The difference is that the bearing body 2 of the above-mentioned embodiment is a single film type having a U-shaped cross section surrounding three sides of the shaft body 1, whereas it is a box-shaped double film type surrounding the four sides of the shaft body 1. ing. That is, the width of the upper portion of the shaft body 1 is narrowed to form the neck portion 25 and the shoulder surface 26 as a receiving surface, and the upper portion of the bearing body 2 is inwardly projected toward the neck portion 25 so that the shoulder surface 26 has a bearing. A bearing surface 27 is provided so as to be opposed to the other via a clearance. Then, the porous material 4 is arranged on the bearing surface 27, and the compressed air supplied through the air pipe 5 is sent from the surface of the porous material 4 into the bearing clearance through the air circuit 6 to form a fluid film. Then, the shaft 1 is supported from above, below, left and right in a non-contact manner, and has an advantage of higher rigidity than the single film type.

The other structure, function and effect are similar to those of the first embodiment. In each of the above embodiments, the case where a porous static pressure air bearing is used as the fluid bearing has been described.
Alternatively, a multi-hole type or surface drawing type static pressure type bearing or a dynamic pressure type bearing may be used. As the spherical bearing, various types of static pressure type bearings and dynamic pressure type bearings can be used as in the above, but the present invention is not limited to this, and solid lubricating bearings may be used.

In each of the above embodiments, the shaft body 1 is supported by the bearing body 2. However, the shaft body 1 is fixed upside down and the shaft body 1 is fixed to the base, and the bearing body 2 is not mounted thereon. It is also possible to support contact.

[0014]

As described above, according to the present invention, a plurality of short bearing members support a plurality of positions of a long shaft member, and a spherical bearing is attached to each bearing member so that the posture can be adjusted. .. Therefore, the bearing body can be easily machined and the productivity is good, and since the spherical bearing allows the spherical movement of each bearing body, the moment force around the X, Y, and Z axes can be absorbed, and the bearing bed can be installed. It is possible to provide an effect that a fluid linear guide device that is convenient for the user can be provided, such that the mounting surface can be installed without finishing with high accuracy.

[Brief description of drawings]

FIG. 1 is an overall perspective view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view corresponding to FIG. 2 of another embodiment of the present invention.

[Explanation of symbols]

 1 shaft body 2 bearing body 10 spherical bearing

Claims (1)

[Claims] 1. A plurality of shaft bodies provided with a bearing surface in the axial direction, and a plurality of bearing surfaces facing the bearing surface of the shaft body and supplying a fluid between the bearing surface to form a fluid bearing. Bearing body,
A fluid linear guide device comprising: a spherical bearing attached to a position on the outer surface of the bearing body opposite to the shaft body.