JPH11125260A - Rolling bearing - Google Patents

Abstract

(57) [Summary] [Object] To provide a rolling bearing that appropriately supplies lubricating oil to the inside of a bearing, thereby reducing the bearing temperature and improving seizure resistance. When the spindle 1 rotates with the start of operation of the apparatus, the inner ring 7 rotates integrally with the spindle 1, and at the same time, the tapered rollers 13 also roll between the inner ring 7 and the outer ring 11. At this time, the lubricating oil 2 in the tapered roller bearing 5 is formed by the rotation of the tapered rollers 13, the rotation of the inner ring 7, and the inclined arrangement of the tapered rollers 13.
Centrifugal force acts on 9 and air, and as shown by the arrow, a flow of the lubricating oil 29 is generated from the outer space 23 toward the inner space 25. However, when the lubricating oil 29 and air flow from the outer space 23 to the inner space 25, a hydraulic pressure difference due to a difference in oil level and a pressure difference between the two spaces occur, so that the outer ring 1
The lubricating oil 29 in the inner space 25 flows back to the outer space 23 via the communication groove 21 formed in the first space 1, thereby preventing the oil level in the outer space 23 from lowering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing used for supporting a rotating shaft and the like, and more particularly to a technique for reducing a bearing temperature and improving seizure resistance.

[0002]

2. Description of the Related Art In mechanical devices such as automobiles and machine tools, various rolling bearings are used in various parts to rotatably support spindles, rollers, wheels and the like. A rolling bearing usually includes a pair of bearing rings, a number of rolling members disposed between the two bearing rings, and a retainer for preventing contact between the rolling members and dropping of the rolling members. Rolling bearings are classified into ball bearings that use steel balls as rolling elements, and roller bearings that use cylindrical or conical rollers as rolling elements. Ball bearings and bearings are further radial bearings that receive a radial load. And a thrust bearing receiving a thrust load. Thrust bearings receive only a thrust load exclusively, but most of radial bearings can partially receive a thrust load. In particular, tapered roller bearings and angular ball bearings have a structure that actively receives a thrust load.

In a rolling bearing, it is necessary to appropriately lubricate each component in order to prevent heat generation, abrasion, seizure, etc. due to metal contact. In general, lubrication methods include oil bath method, splash method, and dropping method using relatively low-viscosity lubricating oil, and encapsulation method in bearings or bearing housings using relatively high-viscosity grease. It is. When the lubrication mode of the oil bath method is adopted and the center line of the bearing is arranged horizontally, the oil level when the bearing is stationary is generally about the center line of the lowermost rolling element.

[0004]

When a rolling bearing is lubricated by an oil bath method, when an abnormality occurs, an excessive rise in the bearing temperature or galling of the rolling surface may occur, and the life of the rolling bearing may be significantly impaired. Was. For example, when the inner ring and the outer ring rotate relative to each other with the rotation of the spindle or the like, the centrifugal force acts on the lubricating oil to some extent due to the rotation of the rolling element or the rotation of the inner ring. The flow of the lubricating oil toward the end face side may occur. This phenomenon is particularly remarkable in bearings in which the rolling elements and the inner and outer rings are in contact with each other in an inclined state (that is, tapered roller bearings shown in FIG. 6 and angular ball bearings shown in FIG. 7), and the rotational speed increases. The flow of the lubricating oil also becomes stronger as it does.

For this reason, depending on the amount of oil stored in the bearing housing 3 and the device casing 16, etc., as shown in FIG.
A part of the lubricating oil 29 in the space 23 on the one end surface side of the bearing 5 flows out to the space 25 on the other end surface side, and in the space 23 on the one end surface side, the oil surface has a contact position between the lowermost rolling element 13 and the outer ring 11. May be lower. In such a state, since the flow of the lubricating oil 29 does not occur at all, the rolling elements 13 and the inner and outer rings 7, 1
1. The heat generated by the rolling and sliding between the retainers 15 cannot be carried away, and these components come into metallic contact with each other in a very short time. Then, an excessive rise in the bearing temperature and galling of the rolling surface and the like are likely to occur. In some cases, seizure of the bearing 5 may occur.

On the other hand, even when lubrication is performed by a droplet method or a dropping method using a lubricating oil, the air flowing from one end surface side to the other end surface of the bearing by the same mechanism as the flow of the lubricating oil described above. Flow occurs. Therefore, depending on the lubricating oil droplet supply position, as shown in FIG.
The inflow of the lubricating oil droplets 41 into the interior 1 is obstructed (blown off) by the flow of air, and the same problems as those described in the oil bath method may occur. Also, in the encapsulation method using grease, the inflow of the grease softened and melted in the vicinity of the bearing into the inside of the bearing is hindered by the flow of air, and the same problem may occur. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a rolling bearing that appropriately supplies lubricating oil to the inside of a bearing, thereby achieving a reduction in bearing temperature and an improvement in seizure resistance. .

[0007]

According to the present invention, in order to solve the above-mentioned problems, in a rolling bearing having a plurality of rolling elements disposed between an inner ring and an outer ring, a space on one end face side and a space on the other end face are provided. A communication path for communicating with the space on the side is formed in at least one of the inner ring and the outer ring. In the present invention, even if the flow of lubricating oil or grease into the inside of the bearing is prevented by the flow of lubricating oil or air in one direction,
In order to solve this, lubricating oil and grease flow into the bearing via the communication passage in the above flow.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a main part of a device according to a first embodiment of the present invention in a longitudinal section. In FIG. 1, reference numeral 1 denotes a spindle that is rotationally driven by a drive mechanism (not shown), and a tapered roller bearing 5 held in a bearing housing 3.
It is rotatably supported by. The tapered roller bearing 5
An inner ring 7 fitted on the spindle 1; an outer ring 11 fitted on the holding portion 9 of the bearing housing 3; a number of tapered rollers 13 interposed between the inner ring 7 and the outer ring 11; And a retainer 15 for holding. FIG.
Reference numeral 16 denotes an apparatus casing.

In the first embodiment, as shown in perspective in FIG. 2, the outer ring 11 has a large number (1 in the first embodiment) continuous from the outer peripheral surface 17 to the outer half of the outer end surface 19.
(Six) communication grooves 21 are formed. The two spaces 23 and 25 are communicated with each other through the gap between the tapered rollers 13 and also by the communication groove 21 described above.

In the first embodiment, the tapered roller bearing 5 is structured to be lubricated by an oil bath method, and a relatively low-viscosity lubricating oil 29 is stored in the bearing housing 3 and the device casing 16. The oil level is set so that the lower half of the lowermost tapered roller 13 is immersed when the bearing is stationary.

When the spindle 1 rotates with the start of the operation of the apparatus, the inner race 7 rotates integrally with the spindle 1, and at the same time, the tapered rollers 13 roll between the inner race 7 and the outer race 11. At this time, the tapered roller bearing 5 is rotated by the rotation of the tapered rollers 13, the rotation of the inner ring 7, and the inclined arrangement of the tapered rollers 13.
The centrifugal force acts on the lubricating oil 29 and the air inside, and FIG.
(Enlarged view of part A) in the outer space 23 as indicated by the arrow.
The lubricating oil 29 flows from the side toward the inner space 25 side. Therefore, as shown by a two-dot chain line in FIG. 3, the lubricating oil 29 in the outer space 23 gradually flows out to the inner space 25, and the oil level in the outer space 23 decreases, while the inner space 2
The oil level of 5 will rise.

However, in the case of the first embodiment, as shown by an arrow in FIG. 3, a communication groove 21 formed in the outer race 11 is formed.
Through the lubricating oil 29 on the inner space 25 side
The oil is returned to the side, and the oil level in the outer space 23 is prevented from lowering. This is because the lubricating oil 29 and the air
3, the hydraulic pressure difference between the two spaces 23, 25 occurs near the communication groove 21 due to the difference in oil level between the two spaces 23, 25.
Is higher than the internal pressure Po.

In the first embodiment, by adopting such a configuration, the oil level is always maintained at a predetermined level even in the outer space 23 of the bearing housing 3 and the lubricating oil penetrates the bearing, and the tapered roller bearing 5 It has become possible to supply a sufficient amount of lubricating oil 29 to each component. As a result, the inside of the tapered roller bearing 5 is appropriately cooled, so that the bearing temperature does not rise excessively. In addition, galling of the tapered rollers 13 and the rolling surfaces of the inner ring 7 and the outer ring 11 caused by boundary lubrication and metal contact. And burn-in were completely prevented.

FIG. 4 is a longitudinal sectional view showing a main part of an apparatus according to a second embodiment of the present invention. In the second embodiment as well, the overall configuration is substantially the same as in the first embodiment,
An angular contact ball bearing 31 is used to support the spindle 1. The angular ball bearing 31 includes an inner ring 7 fitted on the spindle 1, an outer ring 11 fitted on the holding portion 9 of the device casing 16, and a number of steel balls 33 interposed between the inner ring 7 and the outer ring 11. And a retainer 15 for holding these steel balls 33. In FIG. 4, reference numeral 35 denotes a ring nut for fixing the inner ring 7 to the spindle 1.

In the second embodiment, a plurality of (four in this embodiment) communication holes 37 and 39 are formed in the inner ring 7 and the outer ring 11.
Are formed in the outer space 2 of the angular contact ball bearing 31.
3 and the inner space 25 are communicated with each other through a gap between the steel balls 33, and also by these communication holes 37 and 39. The angular ball bearing 31 is structured to be lubricated by a droplet method, and an oil supply hole 43 for supplying a lubricating oil droplet 41 is formed in the device casing 16 toward the angular ball bearing 31.

Also in the second embodiment, when the spindle 1 rotates with the start of operation of the apparatus, the inner ring 7 rotates integrally with the spindle 1 and at the same time, the steel balls 33 also move with the inner ring 7 and the outer ring 1.
Rolls between 1 At this time, centrifugal force acts on the air in the angular ball bearing 31 due to the rotation of the steel ball 33, the rotation of the inner ring 7, the contact angle θ between the steel ball 33 and the inner and outer rings 7, 11, and the like. As indicated by the arrow in the B section enlarged view in FIG. 4), air flows from the outer space 23 side to the inner space 25 side. Therefore, the lubricating oil droplets 41 supplied from the oil supply hole 43 are prevented from directly flowing into the angular ball bearing 31 from between the inner ring 7 and the outer ring 11.

In the second embodiment, however, in the case of the second embodiment, as shown by the arrow in FIG. 5, the communication hole 3 formed in the inner ring 7 and the outer ring 11 by the lubricating oil droplets 41 is formed.
The lubricating oil 29 in the inner space 25 flows into the outer space 23 via the inner and inner space 25 via the inner and inner space 25 via the inner and inner space 25 via the inner and outer space 23.
1 flows into. This is because of the outer space 2 due to centrifugal force.
When air flows into the inner space 25 from the third space 25, the inner space 25
Is higher than the internal pressure Po of the outer space 23.

In the second embodiment, by adopting such a configuration, it becomes possible to sufficiently supply the lubricating oil droplets 41 into the inside of the angular ball bearing 31, and as in the first embodiment, the angular ball bearing 31 In addition to preventing the bearing temperature from being excessively increased by appropriately cooling the inside, the galling and seizure of the steel balls 33 and the rolling surfaces of the inner ring 7 and the outer ring 11 caused by boundary lubrication and metal contact can be completely prevented. Was.

The description of the specific embodiment has been completed.
Aspects of the present invention are not limited to these embodiments. For example, in the tapered roller bearing described in the first embodiment, a communication hole may be formed in the inner ring or the outer ring instead of the communication groove. In the angular ball bearing of the second embodiment, the communication hole may be formed in the outer ring instead of the communication hole. A communication groove may be formed, and in this case, substantially the same effect as in the above embodiment can be obtained. Further, the present invention is not limited to tapered roller bearings and angular ball bearings, but can be applied to deep groove ball bearings, magneto ball bearings, and the like to obtain a corresponding effect. Further, regarding the number and specific shape of the communication grooves and communication holes,
The present invention is not limited to the exemplifications in the above-described embodiment, and can be changed as appropriate according to the design convenience.

[0020]

As is apparent from the above description, according to the present invention, in a rolling bearing having a plurality of rolling elements disposed between an inner ring and an outer ring, a space on one end surface and another end surface are provided. Since the communication path for communicating with the space on the side is formed in at least one of the inner ring and the outer ring, even if the flow of lubricating oil or grease into the inside of the bearing is prevented by the flow of lubricating oil or air in one direction, In order to solve this problem, lubricating oil or grease flows into the bearing from the opposite direction through the communication passage, thereby preventing an increase in the temperature of the bearing and galling of components.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view of an outer race in the first embodiment.

FIG. 3 is an enlarged view of a portion A in FIG.

FIG. 4 is a longitudinal sectional view showing a main part of an apparatus according to a second embodiment of the present invention.

FIG. 5 is an enlarged view of a portion B in FIG. 4;

FIG. 6 is a longitudinal sectional view showing a main part of a conventional device.

FIG. 7 is a longitudinal sectional view showing a main part of a conventional device.

[Explanation of symbols]

 Reference Signs List 1 spindle 3 bearing housing 5 tapered roller bearing 7 inner ring 11 outer ring 13 tapered roller 21 communication groove 23 outer space 25 inner space 29 lubricating oil 31 angular ball bearing 33 steel ball 41 lubricating oil splash

Claims (1)

[Claims] In a rolling bearing having a plurality of rolling elements disposed between an inner ring and an outer ring, a communication passage for communicating a space on one end surface side with a space on the other end surface side is provided in the inner ring and the outer ring. A rolling bearing formed on at least one of the following.