JP2664146B2 - Ceramic bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a ceramic bearing capable of preventing damage to a bearing due to an unexpected impact load during assembly or transportation, or a one-sided or twisted bearing during operation. About. [Prior art] Conventionally, Japanese Patent Application Laid-Open No. 60-30822 has been proposed in connection with this kind of technology, but it is a segment bearing divided in the axial direction, which is difficult to manufacture and is directly supported by an elastic body. Therefore, there is a disadvantage that the bearing is deformed and damaged. One of the problems with ceramic bearings is that ceramics are fragile and vulnerable to impact loads during assembly and transportation of equipment incorporating the ceramic bearings, so they must be protected from damage. Problems such as damage to the ceramic bearing during assembly and transportation cannot be detected from the outside, and it is difficult to attach a jig for preventing damage due to the structure, or even if it is attached, it becomes impossible to remove the jig later. Therefore, it is necessary to make it unnecessary to remove it once it has been assembled. Further, the conventional integral type or ceramic bearing divided in the axial direction has a problem that it is damaged due to an unexpected impact, an excessive load or deformation, in addition to a one-sided contact of the bearing or a kinking caused by the inclination of the shaft. [Problems to be Solved by the Invention] In the above-mentioned conventional technology, sufficient consideration has been given to the point that the ceramic bearings are reliably protected from damage during assembly, for example, collision between parts or during transportation or operation. However, there is a problem that it cannot be sufficiently protected from damage during use, at the time of assembly, or in other cases. The present invention has been made in view of the above circumstances, and has as its object to provide a ceramic bearing that can prevent damage to a ceramic portion during assembly, transportation, use, and the like. [Means for Solving the Problems] An object of the present invention is to provide a cylindrical ceramic bearing which is fitted with a shaft sleeve fitted on a shaft and forms a gap around the outer periphery of the shaft sleeve, and an axial end of the ceramic bearing. And a bearing housing that supports the ceramic bearing and a dummy bearing is disposed in the portion, and at least one end in the axial direction of the shaft has no problem as a bearing even if it is worn at one end in the axial direction. This is achieved by disposing a good dummy bearing with a gap equal to or less than a gap between the cylindrical ceramic bearing and the shaft sleeve, and supporting the ceramic bearing and the dummy bearing by the bearing housing. [Operation] A dummy bearing is arranged at least on one end side in the axial direction of the ceramic bearing, and a gap between the dummy bearing and the shaft sleeve is formed smaller than a gap between the ceramic bearing and the shaft sleeve. Therefore, it is possible to prevent the ceramic bearing from being damaged due to an unexpected impact or an excessive load during assembling or transferring. [Embodiment] A ceramic bearing of the present invention will be described below with reference to FIG. FIG. 1 is a sectional view of a main part. In the drawing, 1 is a ceramic bearing, 2 is a dummy bearing of lead bronze, for example, which has conformability and has no problem as a bearing even if worn, 3 is a shaft sleeve, 4 is a shaft, and 5 is a bearing housing. The gap a between the ceramic bearing 1 and the shaft sleeve 3 is smaller than the gap b between the shaft sleeve 3 and the dummy bearing 2 by b
<A. Therefore, the dummy bearing 2 protects the ceramic bearing 1 by receiving the interference of the shaft 4 when the shaft 4 is inserted at the time of assembling, and the dummy bearing 2 performs penetrating contact with the ceramic bearing 1 during the insertion of the shaft 4. It can be protected as a guide. Further, the ceramic bearing 1 can be protected against an excessive load due to the falling of the shaft 4 or the like due to the falling of the shaft 4, a damage due to a twist of the bearing, an impact when the device incorporating the ceramic bearing 1 is hung by a crane or during transportation. Further, since the dummy bearing 2 is made of a material having conformability as described above, the dummy bearing 2 can be disposed in a place where it cannot be removed once it is structurally assembled. I can do it for sure. In addition, since it is not necessary to remove the jig before operation as in the case where a jig is used, erroneous operation due to the fact that the jig is not removed, and costs for manufacturing and removing the jig are not required, thereby improving economic efficiency. . Furthermore, since the ceramic bearing 1 is incorporated inside the device,
The problem that the ceramic bearing 1 cannot be found from the outside even if the ceramic bearing 1 is damaged during assembly or transportation can be solved by using the dummy bearing 2. FIG. 2 is a cross-sectional view of a main part of another embodiment. In the drawing, the ceramic bearing 1 is divided in the axial direction, and after the back metal 6 is arranged adjacent to the outer periphery, the divided portion and the ceramic bearing 1 are separated. A cushioning material 7 is provided on the outer periphery of the back metal 6 on the outer periphery of the cushioning member 7, and the cushioning material 7 is supported by the bearing case 9 via the cushioning material case 8. Since the ceramic bearing 1 is press-fitted and supported by the rigid back metal 6, the deformation of the ceramic bearing 1 under a high load is prevented, and the ceramic bearing 1 is supported with the cushioning material 7 interposed therebetween, so that it follows the inclination of the shaft 4. As a result, the ceramic bearing 1 can move and can prevent the one-side contact due to the inclination of the shaft 4 due to the assembly system. Further, since the ceramic bearing 1 is divided in the axial direction, the load per piece is distributed to the individual ceramic bearings 1 and the length of the divided bearing is appropriately selected so that the shaft 4 may fall due to land subsidence or the like. The ceramic bearing 1 can be prevented from being twisted. As described above, in the ceramic bearing of the present embodiment, the dummy bearing is disposed at both ends of the ceramic bearing with the gap to the shaft sleeve being smaller than the gap between the ceramic bearing and the shaft sleeve, or the ceramic bearing is divided and The outer periphery is supported by metal, and the cushioning material is arranged on the outer periphery and the divided part of the back metal, and the cushioning material case is interposed and supported by the bearing case.Due to the dummy bearing during assembly work and during transportation, etc. In addition, it is possible to prevent the ceramic bearing from being damaged due to deformation, contact and squeezing during use or the like. Therefore, it is possible to prevent the ceramic bearing from being damaged during assembly, transportation or use. And the first
If the contents of FIG. 2 and FIG. 2 are carried out at the same time, the respective effects can be obtained at the same time. [Effect of the Invention] As described above, in the ceramic bearing of the present invention, since the inner diameter of the dummy bearing is smaller than the inner diameter of the ceramic bearing, an unexpected impact load during assembly or during transportation can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are cross-sectional views of a main part of an embodiment of a ceramic bearing according to the present invention. 1 ... ceramic bearing, 2 ... dummy bearing, 3 ... shaft sleeve, 6 ... back metal, 7 ... cushioning material, 9 ... bearing case,
a, b …… Gap.

Claims (1)

(57) [Claims] A shaft sleeve is fitted to the shaft, a cylindrical ceramic bearing is formed with a gap formed around the outer periphery of the shaft sleeve, and a dummy bearing is disposed at an axial end of the ceramic bearing and supports the ceramic bearing. A ceramic bearing having a bearing housing, at least one end in the axial direction of the shaft has a problem that does not cause any problem as a bearing even if it is worn. Wherein the ceramic bearing and the dummy bearing are supported by the bearing housing.