JPH02146311A - Heat resisting deep groove ball bearing - Google Patents

Abstract

PURPOSE:To make the assembling of a ball bearing easy in a ball bearing whose ball is at least made of ceramics by insertedly providing a graphite spacer having dimensions larger than a clearance between the shoulders of both raceway surfaces of inner and outer rings between the balls, and forming one slit on the outer ring. CONSTITUTION:A dimension h1 between expanding parts 6 of a graphite spacer 4 is established to be slightly smaller than a dimension l1 of a clearance between raceway grooves 1a, 2a of inner and outer rings 1, 2 and larger than a dimensions l2 of a clearance between flat shoulders of raceway surfaces, and width on both sides of the expanding parts 6 is established to be slightly smaller than the dimensions l2. In addition to that, recesses 7 are partially formed into a spherical shape. In assembling a ball bearing, a slit 5 formed at one position of the outer ring 2 is widened, and after ceramic balls 3 and spacers 4 are alternately fitted into the widened slit 5, the slit 5 is narrowed to that both the ends of the outer ring 2 may be joined to return the ring 2 to the nearly round outer shape. Thus the spacer 4 does not crack in its assembling, and can be prevented from slipping out of the ball bearing after its assembling.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a heat-resistant deep groove ball bearing used in a high-temperature atmosphere such as a heat treatment furnace.

<Prior Art> Conventionally, the following lubrication methods have been considered for ball bearings used in bearings in heat treatment furnaces and the like.

Specifically, for example, a coating method in which a solid lubricant such as molybdenum disulfide is coated on one or all of the sliding contact parts of the ball, raceway, or cage, which are rolling bodies, or a cage is coated with solid lubricant such as molybdenum disulfide. For example, a transfer method using a material having self-lubricating properties such as graphite may be used.

In the above-mentioned coating method, if the coated solid lubricant wears away, there are disadvantages such as the area becoming prone to seizure, whereas in the latter transfer method, the entire cage is self-lubricating. Since the above-mentioned disadvantages do not occur because the material is made of a material having

<Problems to be Solved by the Invention> By the way, in the case of deep groove ball bearings that are easy to use as a single item, a cage called a so-called upper type is used due to installation problems.

In the case of this upper-shaped cage, the cage must be deformed when the balls are housed in the cage, but if it is made of graphite, this graphite is relatively fragile and does not deform elastically, so It may crack due to the stress it receives when storing balls.

The applicant has strictly set the pocket opening dimensions of the graphite rectangular cage so that the above-mentioned cracks are less likely to occur, but even so, it is difficult to reliably prevent the above-mentioned cracks. It is. Furthermore, when stress is applied to the rectangular cage during rotation due to delays in the advancement of the balls, side deviation occurs as described above.

Therefore, it was not possible to use deep groove ball bearings with rectangular cages, which were easy to use, as heat-resistant ball bearings.
An angular contact ball bearing with a machined cage was used that was free from cracking when the balls were accommodated or rotated. but,
When using angular contact ball bearings, if a single row is used, the thrust load can only be received from one side, and since they are usually used in a double row combination, the mounting structure becomes complicated and the installation space becomes large.

By the way, the present applicant considered an angular contact ball bearing with a structure using a graphite spacer instead of the machined cage (see Fig. 8), and proposed an angular contact ball bearing with this structure used in a high-temperature atmosphere. In the angular contact ball bearing 20 shown in Fig. 0, the balls 221 and spacer 23 are
Since the outer ring 24 is assembled by fitting from the axial direction into the assembly holding the outer ring 24, it can be assembled even if the dimension of the spacer 23 is larger than the gap between the inner and outer ring shoulders. Spacer 23 cannot be removed even during operation.
In addition, based on the same idea, the applicant used a graphite spacer for deep groove ball bearings, but in the case of this structure, a graphite spacer that does not deform is fitted between the inner and outer rings from the axial direction. In order to make it possible to insert the spacer, the dimensions of the spacer must be smaller than the gap between the shoulders of the raceway surfaces of the inner and outer rings, and the spacer may come out from the direction in which it was inserted during transportation or operation. It has its drawbacks.

The present invention has been made in view of these circumstances, and in order to enable a user-friendly deep groove ball bearing to be used in a high-temperature atmosphere, it uses a graphite spacer, while also making it easy to fit the spacer. The purpose of the present invention is to provide a heat-resistant deep groove ball bearing with a structure that does not allow for extraction.

<il! Means for Solving n> In order to achieve such an object, the present invention has the following configuration.

That is, the heat-resistant deep groove ball bearing according to the present invention has at least the balls made of ceramic, and a graphite spacer having a size larger than the gap between the shoulders of both raceway surfaces of the inner and outer rings is interposed between the balls. It is also characterized by having a split at one location on the outer ring.

Effect〉 The effects of the configuration of the present invention are as follows.

If the rectangular cage that press-fits the balls is made of graphite, there is a risk of cracking during storage and rotation, so instead of using the cage form, we used a separated graphite spacer from the beginning as a material between the balls. The wear powder of the spacer generated by sliding contact between the spacer and the raceway surfaces of the balls and inner and outer rings is transferred to the raceway grooves of the inner and outer rings, thereby lubricating each raceway part. I did it like that.

This spacer is also made of graphite and does not deform elastically, so in order to be able to fit it between the inner and outer rings from the axial direction, the spacer's dimensions must be larger than the gap between the shoulders of the raceway surfaces of the inner and outer rings. I have to make it smaller, but if I do that, it will inevitably come out regardless of the direction I put it in, which is a problem. Therefore, once the spacer of the present invention is fitted between the inner and outer rings,
To prevent the gap from coming out, the gap was made larger than the gap between the shoulders of the raceway surfaces of the inner and outer rings, and the method of inserting the gap was devised.

That is, one part of the outer ring is split, the split part is expanded, and the spacers are successively fitted between the balls from here,
After all the fittings were completed, we considered returning the split portions of the outer ring to their original shape so that their palms would fit together.

However, if a part of the outer ring is split, there is a problem in terms of strength, but if this split part is placed in a non-negative trading area, the strength is comparable to that of a normal bearing.

<Example> Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a front view of a heat-resistant deep groove ball bearing showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■--■ in FIG. 1, and FIG. 3(a) is a perspective view of a spacer.

In the figure, 1 and 2 are inner rings made of high-speed steel or the like.

The outer ring 3 is a ceramic ball, and 4 is a spacer made of graphite that is interposed between the balls 3 and interposed in the gap between the inner and outer rings 1 and 2. A split 5 is provided at one location on the outer ring 2.

As shown in FIG. 3, the spacer 4 has a partially arcuate bulge 6.6 on two long and narrow surfaces, and a partially spherical recess 7.6 on two long and wide surfaces. It has 7. This bulging portion 6 fits into the raceway grooves 1a and 2a of the inner and outer rings 1 and 2 to prevent the spacer 4 from being pulled out in the axial direction from the gap between the inner and outer rings, and
Provides rotational guidance.

Further, the recess 7 makes rolling contact with the circumferential surface of the ball 3 smooth.

The dimension between the bulges 6 and 6 of the spacer 4 is the same as that of the inner and outer rings 1.
The width dimension h2 on both sides of the bulging portion 6.6 is set to be slightly smaller than the gap dimension 11 between the raceway grooves 1a and 2a of No. is the gap dimension between the flat raceway shoulders! , is set slightly smaller than . This dimensional relationship prevents the spacer 4 from collapsing or locking.

On the other hand, in order to comply with this dimensional relationship, the following method is used to incorporate it.

That is, a split 5 provided at one location on the outer ring 2 is expanded, for example, as shown in FIG. After inserting the spacer 4, the split 5 is narrowed and the palms are brought together to return the outer ring 2 to a nearly perfect circle. Therefore, there is no cracking of the spacer 4 during assembly, and there is no need to remove it after assembly.

In the case of the spacer 4 made of graphite, the inner and outer rings are 1.2
The sliding contact between each raceway surface and the balls 3 generates extremely minute wear powder, which is generated on the inner and outer rings 1. 2 raceway surface and ball 3
This results in good lubrication.

In order to prevent the wear particles generated from the spacer 4 from scattering to the outside, in the deep groove ball bearing of this embodiment, the gap portions on both sides between the inner and outer rings 1.2 are closed with shield plates 8, 8. There is. This shield plate 8.8 is attached to both shoulders of the raceway surface of the outer ring 2, so that the inner peripheral edge of the shield plate 8.8 forms a minute gap with both shoulders of the raceway surface of the inner ring 1. They are placed facing each other.

By the way, there seems to be a strength problem because there is a split 5 in one place on the outer ring 2, but in normal bearings there is a non-negative trading area even when receiving a radial load, so the above-mentioned non-negative trading area exists in this non-negative trading area. If the split 5 is positioned properly, the bearing is comparable in strength to a normal bearing.

In this way, by using the self-lubricating graphite spacer 4, an easy-to-use deep groove ball bearing can be used in a high-temperature atmosphere, and the disadvantages of using an angular contact ball bearing can be solved. Become. Also, unlike the maximum type, there is no ball groove on the raceway shaft, so thrust loads can be applied.

It goes without saying that the spacer 4 is not limited to the shape explained in the above embodiment, and may be cylindrical as shown in FIG. Similarly, it may be made of ceramics.

In the spacer 4 shown in FIGS. 3(a) and 3(b) above,
The inner surface of the recess 7 is partially spherical, and as shown in FIG. 5, the top of the ball 3 is in contact with the center of the recess 7. The present invention also includes those shown in FIGS. 6 and 7.

That is, in the spacer 4 shown in FIG. 6, the inner surface of the recess 7 has a single conical surface 7A.
A predetermined circumferential portion of the ball 3 is brought into line contact or surface contact with the midsection of the ball 3. On the other hand, in the spacer 4 shown in FIG. 7, the inner surface shape of the recess 7 is divided into two conical surfaces 7B having different inclination angles.
, 7C, and the two circumferential portions of the ball 3 are brought into line or surface contact with the midsections of each of the conical surfaces 7B and 7C.

In the case of the spacer 4 that makes such a line contact or surface contact, it is possible to avoid early local wear of the spacer 4, and also to disperse the impact weight of the ball 3 during rotation, thereby preventing damage. It has the advantage of being less difficult.

<Effect of the invention> According to the present invention, the following effects are achieved.

As explained in detail above, in a deep groove ball bearing, a graphite spacer is inserted between the balls without using an upper cage, and the spacer can be removed by splitting one part of the outer ring and expanding it. Since it is possible to assemble the bearing without any protrusions, it is possible to ensure good lubrication in a high-temperature atmosphere, and to provide a heat-resistant deep groove ball bearing that does not cause cracks like a graphite upper cage.

Therefore, according to the present invention, an easy-to-use deep groove ball bearing can be used in a high-temperature atmosphere such as a heat treatment furnace, and the inconveniences when using an Angiela ball bearing can be solved.

[Brief explanation of the drawing]

1 to 5 relate to one embodiment of the present invention;
The figure is a front view of a heat-resistant deep groove ball bearing, and Figure 2 is the same as Figure 1.
-■ line sectional view, Figure 3 (al and (b)) is a perspective view of the spacer, Figure 4 is an explanatory diagram for explaining the assembly procedure, Figure 5 shows the state of contact between the spacer and the ball. FIG. 6 and FIG. 7 are partial longitudinal front views of other embodiments of the present invention and correspond to FIG. 5. Furthermore, FIG. 8 is a partial longitudinal front view of a conventional example. It is a vertical cross-sectional side view showing the upper half of the Angiela ball bearing used for explanation. 1... Inner ring, 2... Outer ring, 3... Balls.
4... Maza, 5... Wari,
6...bulge.

Claims (1)

[Claims] (1) In a heat-resistant deep groove ball bearing with at least the balls made of ceramic, a spacer made of graphite with a size larger than the gap between the shoulders of both raceway surfaces of the inner and outer rings is interposed between the balls, and at one location on the outer ring. A heat-resistant deep groove ball bearing characterized by having a split.