JPH07217658A - Ceramic bearing - Google Patents

Abstract

PURPOSE:To enable a ceramic bearing to follow impact load by fluid force by dividing ring like or segment like ceramics axially, and providing a clearance between the divided ceramics so that each can be individually deformable while forming such structure as to be able to store water. CONSTITUTION:A ceramic bearing 3 is disposed being divided with an axial clearance. The ceramic bearing 3 is fixed to a bearing case 4 by shrinkage fitting or the like, and an elastic body 5 is further provided on the outer peripheral side of the bearing case 4. The elastic body 5 is fixed by a holder 6, and the outer peripheral side is provided with a bearing guide 7 and a keep plate 8. A shaft sleeve 2 is inserted on the inner peripheral side of the bearing 3. Since the bearing case 4 with the bearing 3 disposed on the inner peripheral side, and also the elastic body covering the outer peripheral surface of the bearing case 4 including both end faces are thus disposed with the axial clearance, bearing circulating liquid can be stored in the clearance so as to improve reliability in the cooling of the bearing sliding face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing that uses a hard material such as ceramics for a bearing that supports a rotating body.

[0002]

2. Description of the Related Art Conventionally, when the lubricating liquid for the bearing is water, rubber, resin or carbon has been used as the bearing material. However, when water containing hard particles such as river water or sewage is used as the lubricating liquid, the bearing material is worn out significantly,
The bearing became unusable in a short time, and it was necessary to use fresh water as the lubricating liquid.

However, in recent years, hard materials such as ceramics have been put to practical use as sliding materials and have been widely used.

Since cemented carbides and ceramics have a hardness higher than that of earth and sand, they hardly wear even when lubricated with water containing hard particles such as earth and sand such as river water and wastewater. Therefore, it became unnecessary to secure the fresh water required for using the bearing material such as rubber and the facility for supplying the fresh water.

In particular, ceramics are excellent in maintenance and running costs of hydraulic machines and are effective as bearing materials for hydraulic machines. However, ceramics have a major drawback of being brittle, and therefore ceramics bearings made of ceramics are also brittle.

In particular, in a hydraulic machine such as a pump, the rotary shaft having blades attached to its tip has a bearing structure by overhanging. For this reason, when the bearing is firmly supported, the rotary shaft comes into partial contact with the inner diameter surface of the bearing, and an impact load is easily received at the end portion of the inner diameter surface of the bearing. Therefore, the ceramic bearings are used by relaxing the impact load by elastic support. A ceramic bearing structure using ceramics for the bearing is disclosed in Japanese Utility Model Laid-Open No. 62-2831 and Japanese Patent Laid-Open No. 60-88215. In these structures, the ceramics are fixed to the inside of the metal case by adhesion or shrink fitting.
FIG. 1 shows an example thereof, but in this structure, segment-shaped ceramics are adhered and fixed inside a metal case. Further, FIG. 2 shows a known example in the case of being fixed by shrink fitting or the like.

[0007]

As described above, in a hydraulic machine such as a pump, the rotating shaft has a bearing supporting structure by overhanging. For this reason, when the rotating shaft comes into one-side contact with the end portion of the inner diameter surface of the bearing and firmly supports the bearing, the bearing directly receives the impact load. The frequency of this impact load consists of the frequency component of the rotating shaft, the frequency component of the number of blades, each frequency component of the harmonics of these components, and other frequency components not related to the rotation of the rotating shaft. In order to avoid the impact load, the bearing needs to be able to follow the frequency of the impact load.

Further, even if water as a lubricant contains hard particles such as earth and sand, it must be a bearing that can withstand use.

A ceramic bearing can be cited as a bearing which satisfies the above conditions. However, ceramic bearings have a major drawback that they are vulnerable to impact loads.
Therefore, it is necessary to dispose the shock load by disposing a cushioning material such as rubber that absorbs the shock load.

Further, it is necessary to further improve the reliability in terms of reliable replenishment of the bearing lubricating liquid.

An object of the present invention is to provide a ceramics bearing structure which can follow an impact load due to a fluid force in a bearing using a hard material such as ceramics for a bearing for supporting a rotating body.

Another object of the present invention is to provide a ceramics bearing structure characterized by improving the reliability of the cooling effect of the bearing sliding surface.

[0013]

In order to achieve the above object, the structure of the first invention relating to the split structure type ceramic bearing of the present invention is a bearing case and a ring-shaped or segmented coaxially in the bearing case. -Shaped ceramic bearings are arranged in a divided manner, and a gap is provided between the ceramics to make it possible to store water, thereby enhancing the cooling effect.

In order to achieve the above object, the structure of the second invention relating to the split structure type ceramic bearing of the present invention is a bearing case and a ring-shaped or segment-shaped ceramic bearing coaxially in the bearing case. In the bearing in which the outer peripheral surface including both end surfaces of the bearing case is covered with an elastic body, and the elastic body is fixed with a metal holder, the bearing case is divided in the axial direction, and the bearing case and the bearing case are separated. A space is provided therebetween, and segment-shaped or ring-shaped ceramics are arranged on the inner peripheral side of the bearing case.

In order to achieve the above-mentioned object, the structure of the third invention relating to the split structure type ceramic bearing of the present invention is a bearing case, and a ring-shaped or segment-shaped ceramic bearing coaxially in the bearing case. In the bearing in which the outer peripheral surface including both end surfaces of the bearing case is covered with an elastic body and the elastic body is fixed by a metal holder, the elastic body is divided in the axial direction, and a gap is provided between the elastic bodies. Is provided.

[0016]

According to the split structure type ceramic bearing of the present invention, in the first aspect, the segment-shaped or ring-shaped ceramic bearing arranged on the inner peripheral side of the bearing case is
Since it has a gap in the axial direction and is divided, it is possible to independently follow the deformation, it is possible to store the lubricating liquid in the gap, and it is possible to improve the reliability in cooling the bearing sliding surface.

According to the second aspect of the invention, the bearing case is divided with a gap in the axial direction, and the segment shape or the ring is divided with a gap in the axial direction on the inner peripheral side of the bearing case. -Shaped ceramic bearings are arranged, so that the lubricating liquid can be stored in the gap, and the bearing case is divided, so that the load can also be divided by the individual segments to receive the load. Therefore, the bearing is strong against the load per one side.

According to the third aspect of the invention, the elastic body covering the outer peripheral surface including both end surfaces of the bearing case is divided with a gap in the axial direction. It becomes a good bearing.

[0019]

Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) One embodiment of the first invention is shown in FIG.
Will be described with reference to.

FIG. 3 is a vertical sectional view of a split structure type ceramic bearing according to an embodiment of the present invention.

As shown in the figure, the ceramic bearing 3 is
There is a gap in the axial direction, and they are arranged separately. These ceramics bearings 3 are fixed to the bearing case 4 by shrink fitting or the like, and further, an elastic body 5 is provided on the outer peripheral side of the bearing case 4.
The elastic body 5 is fixed by a holder 6, and a bearing guide 7 and a pressing plate 8 are provided on the outer peripheral side thereof. The shaft sleeve 2 is inserted on the inner peripheral side of the ceramic bearing 3.

Since the ceramic bearing 3 is arranged with a gap in the axial direction as shown in the figure, it is possible to store the bearing lubricating liquid in the gap and improve the reliability in cooling the bearing sliding surface. Can be made. This is a great feature of the present invention, which cannot be obtained with the ceramic bearing which is integrated in the axial direction.

(Embodiment 2) Next, an embodiment of the second invention will be described with reference to FIG.

FIG. 4 is a vertical sectional view of a split structure type ceramic bearing according to an embodiment of the present invention.

In the embodiment of FIG. 4, the bearing case 4 is divided with a gap in the axial direction, and the ceramic bearing 3 is arranged on the inner peripheral side of the bearing case 4. The bearing case 4, which has a gap in the axial direction and is divided, has an outer peripheral surface including both ends covered with an elastic body 5. That is, the structure is such that the ceramic bearing 3 and the bearing case 4 are supported by the elastic body 5 provided on the entire inner circumference of the holder 6.

Since the ceramic bearing 3 and the bearing case 4 are arranged with a gap in the axial direction as shown in the figure, the bearing lubricating liquid can be stored and the reliability in cooling the bearing sliding surface can be improved. Can be improved. Furthermore, since the ceramic bearing 3 and the bearing case 4 are arranged with a gap in the axial direction as shown in the figure, the ceramic bearing 3
The bearing case 4 has a large degree of freedom, and the bearing has a good followability with respect to a one-sided load.

(Embodiment 3) Next, an embodiment of the third invention will be described with reference to FIG.

FIG. 5 is a vertical sectional view of a split structure type ceramic bearing according to an embodiment of the present invention.

In the embodiment of FIG. 5, the elastic body 5 is divided with a gap in the axial direction, and the bearing case 4 and the ceramic bearing 3 are arranged on the inner peripheral side of the elastic body 5. The elastic body 5 divided and arranged with a gap in the axial direction is fixed to a holder 6 having an integral structure. That is, the ceramic bearings 3,
It has a structure in which a bearing constituting body composed of the bearing case 4 and the elastic body 5 is arranged with a gap.

As shown in the figure, since the ceramic bearing 3 and the bearing case 4 arranged on the inner peripheral side of the elastic body 5 are arranged with a gap similarly to the elastic body 5, the load per one-side load can be reduced. As a result, it becomes a bearing with better followability. This is a great feature of the present invention, which cannot be obtained by the ceramic bearing structure which is integrated in the axial direction.

[0032]

According to the split structure type ceramic bearing of the present invention, since the ceramic bearings are arranged with a gap in the axial direction, the cooling effect of the bearing sliding surface can be enhanced. In addition, the bearing case, in which the ceramic bearing is arranged on the inner peripheral side, and the elastic body, which covers the outer peripheral surface including both end surfaces of the bearing case, are also arranged in the axial direction with a gap. , Even if a one-sided load due to shock or vibration of the rotating shaft occurs, ceramic bearings, bearing cases,
Since the elastic body has a large degree of freedom, it is possible to reliably prevent damages such as cracks and chips on the sliding surfaces at both ends of the ceramic bearing. Further, by using a bearing structure having a high degree of freedom, the contact surface pressure between the bearing member sliding surface portion and the rotating shaft can be reduced, and burning damage such as heat cracks due to temperature rise can be eliminated. That is, by using this type of bearing structure, the ceramic bearing can obtain stable bearing performance for a long period of time, and a highly reliable ceramic bearing can be provided.

[Brief description of drawings]

FIG. 1 is a plan view showing a conventional ceramic bearing structure by adhesion.

FIG. 2 is a longitudinal sectional view showing a conventional ceramic bearing structure by shrink fitting.

FIG. 3 is a vertical cross-sectional view of a ceramic bearing according to the present invention, which is divided and arranged with a gap in the axial direction.

FIG. 4 is a vertical cross-sectional view of a ceramic bearing and a bearing case according to the present invention, which are divided and arranged with a gap in the axial direction.

FIG. 5 is a vertical cross-sectional view of a ceramic bearing, a bearing case, and an elastic body according to the present invention, which are separately arranged with a gap in the axial direction.

[Explanation of symbols]

1 ... Rotary shaft, 2 ... Sleeve, 3 ... Ceramics bearing, 4
... bearing case, 5 ... elastic body, 6 ... holder, 7 ... bearing guide, 8 ... presser plate.

Claims (1)

[Claims] 1. A bearing case, a plurality of ring-shaped or segment-shaped ceramic bearings arranged coaxially in the bearing case, and an outer peripheral surface including both end surfaces of the bearing case is covered with an elastic body. In a bearing fixed with a metal holder, the ring-shaped or segment-shaped ceramics are divided in the axial direction, a gap is provided between the ceramics, each of which is deformable independently, and has a structure capable of storing water. Ceramic bearings.