JP2001173662A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing using a rolling body having easily handling performance as ball and a high load capacity as roller. SOLUTION: This rolling bearing comprises a pair of concentrically arranged bearing rings 21 and 22 and a number of rolling bodies interposed between the bearing rings 21 and 22 in such a manner as to be capable of rolling. The rolling body 1 comprises a circularly swollen rolling spherical surface part 2 and spherically swollen end surface spherical surface parts 3 and 3 at both ends of the rolling spherical surface part 2. This bearing is characterized by setting the circular radius of the rolling spherical surface part 2 larger than the curvature radius of the end surface spherical surface part, and setting the length (long diameter between the end surface spherical surface parts 3 and 3 larger than the maximum diameter (short diameter) of the rolling spherical surface part 2. The short diameter d is set within the range of about 80%<=15% to the long diameter W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an easy-to-use characteristic of a ball bearing by changing the point contact of the ball in a conventional ball bearing to a line contact structure having a spherical shape, and reducing the effective contact length to about 2/3 of the roller. The present invention relates to an extremely high-performance rolling bearing which has a load capacity of four times and a service life of 64 times its third power while being held, which is close to that of a bearing, and which has high rigidity, a high load and eliminates the difficulty of using a roller bearing.

[0002]

2. Description of the Related Art Conventional rolling elements used in this type of rolling bearing include a "ball" and a "roller". The ball is a point contact with a ball bearing and has a small load capacity, but is easy to use. On the other hand, the roller is a roller bearing that is in line contact and has a load capacity six times that of a ball bearing and can withstand a high load and high rigidity, but it is difficult to use because it requires high-precision machining and assembling technology of the bearing ring. And expensive.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rolling bearing using a rolling element having a performance like a ball and having a high load capacity such as a roller.

[0004]

In order to achieve the above object, according to the present invention, there is provided a pair of races arranged concentrically with each other, and a plurality of races rotatably interposed between the races. Wherein the rolling element comprises: a rolling spherical part bulging in an arc shape; and a spherical end face sphere bulging at both ends of the rolling spherical part. An arc radius of the spherical portion is made larger than a radius of curvature of the end surface spherical portion, and a length between the end surface spherical portions is made longer than a maximum diameter of the rolling spherical portion. Assuming that the maximum diameter of the rolling spherical surface portion is a short diameter and the length between the end surface spherical portions is a long diameter, it is preferable that the short diameter is set in a range of approximately 80% ± 15% with respect to the long diameter. Further, the contact direction between the rolling spherical surface of the rolling element and the raceway surface of each bearing ring is advantageous in the case of angular contact having a predetermined contact angle with respect to a plane orthogonal to the rotation center axis. In this case, it is preferable that one of the end surface spherical portions of the rolling spherical portion has a large diameter and the other has a small diameter, and the arc of the rolling spherical portion has a tapered spherical shape with a gradient in the longitudinal direction. It is.

[0005]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 (A)
FIG. 1 shows an angular contact type bearing as a rolling bearing according to an embodiment of the present invention in comparison with a conventional angular contact ball bearing (see FIG. 1B). This rolling bearing has an outer race 21 and an inner race 22 as a pair of races arranged concentrically with each other, and a large number of rolling elements 1 roll between raceways 23 and 24 of the outer race 21 and the inner race 22. It is freely interposed. The contact direction between the rolling spherical surface portion 2 of the rolling element 1 and each of the raceway surfaces 23 and 24 is an angular contact having a predetermined contact angle α with respect to a plane orthogonal to the rotation center axis. The rolling elements 1 are held at predetermined intervals by a ring-shaped holder 30.

FIG. 2 shows the rolling element 1 in detail. The rolling element 1 includes a rolling spherical portion 2 bulging in an arc shape, and a spherical spherical surface 3 at both ends of the rolling spherical portion 2.
And the radius of the arc of the rolling spherical surface portion 2 is set to be that of the end spherical surface portion 3.
, And the length W between the end spherical surfaces 3 and 3 is longer than the maximum diameter d of the rolling spherical surface 2. The raceway surfaces 23 and 24 with which the rolling spherical surface portion 2 contacts are in contact with the rolling spherical surface portion 2.
The arc-shaped concave surface has a diameter slightly larger than the radius of the arc. The centers O of the left and right end face spherical portions 3 and 3 are substantially equal and are located on substantially one virtual spherical surface B, and the arc of the rolling spherical portion 2 is located inside the virtual spherical surface B. Rolling surface spherical surface part 2
Has an arc shape that has the same diameter at both left and right ends and is symmetrical with respect to an axis passing through a center O orthogonal to the central axis X. The shape of the rolling element 1 is a shape obtained by combining the arc surface of the rolling spherical surface portion 2 and the spherical surfaces of the end spherical surface portions 3 and 3, and its longitudinal cross section has an intermediate shape between a substantially elliptical shape and a circular shape. The boundary between the rolling spherical surface portion 2 and the end spherical surface portions 3 and 3 is rounded. Assuming that the maximum diameter d of the rolling spherical portion 2 of the rolling element 1 is a short diameter and the length W between the end surface spherical portions 3 and 3 (between vertices) is a long diameter, the short diameter d is 80 ± 15% of the long diameter W. Is preferably set in the range. 2 (A) to 2 (C) show 80.
2 (D) to 2 (F) are examples of 90%. In other words, the smaller the ratio of the minor axis d to the major axis W (the smaller the difference), the closer to the ball, and the larger the ratio (the larger the difference), the closer to the roller, a high load capacity is obtained, which is suitable for heavy loads. In addition, it is preferable to change the ratio of the minor axis to the major axis of the rolling element 1 according to the magnitude of the contact angle α. For example,
If the contact angle α is 15 °, 20 °, 30 °,
90 to 95%, and in some cases up to about 97%, the contact angle α
Is preferably about 85% when the angle is 45 °.

The rolling element 1 can be manufactured by forming the rolling spherical surface portion 2 by crushing the central portion of a raw ball (raw ball) before quenching into an arc shape by rolling or the like. The portions remaining at both poles are the end surface spherical portions 3 and 3. Since the ball element balls have high dimensional accuracy and are homogeneous, a uniform rolling element 1 can be manufactured at low cost. After quenching, the rolling spherical surface portion 2 supports and grinds the left and right end surface spherical surface portions 3. In addition, the rolling spherical surface part 2 and the end spherical surface part 3
Does not have to be a spherical shape in a strict sense geometrically, and may be any shape as long as it is round and swelled. In addition, a center hole may be provided at the vertex (intersection with the central axis X) of the end surface spherical portions 3 and 3.

As shown in FIG. 4, the retainer 30 has a holding concave portion 31 for holding the spherical surface portion 3 on the end surface of the rolling element 1 on the outer ring 21 side.
And an inner cage part 34 having a holding concave part 33 for holding the spherical end face part 3 of the rolling element 1 on the inner ring 22 side, and the outer cage part 32 and the inner cage part 34 are connected. .

In the case of the rolling bearing according to the present embodiment, the contact length of the rolling spherical surface portion 2 is longer than that of the ball, so that the load capacity is several times larger than that of the ball. It is preferable that the effective contact length is set to about 2/3 of the roller. In this case, the aligning property is excellent, and a load capacity about four times that of the ball can be obtained. Further, as shown in FIG. 2A, assuming that the contact length is W1, the differential slip amount π (d−d0) caused by the difference in diameter between the center and both ends is π (d−d) in the case of a ball. d1-d
0), the frictional resistance is reduced. Therefore, it moves lightly and generates a small amount of heat. In particular, in the case of an angular contact bearing, the load in the thrust direction is large, and the rolling element 1 rolls while being pressed against the raceway surfaces 23 and 24, so that a load capacity is required.
It is necessary to prevent heat generation due to differential slip. By using the rolling element 1 of the present invention, an angular contact bearing having a high load capacity, a small differential slip, and excellent alignment can be realized. Further, in the case of the tapered roller bearing, a place where the raceway surface is inclined is one-sided, so that a considerably high dimensional accuracy is required for processing and assembling of the raceway ring. However, in the case of the rolling element 1 of the present invention, the rolling surface portion 2 is required. Since it has an arc shape, it has a self-aligning property like a ball, can tolerate the inclination of the raceway surfaces 23 and 24, and does not require high dimensional accuracy for machining and assembling the outer ring 21 and the inner ring 22 and is easy to handle.

In the case of angular contact, since the rotation axis of the rolling element 1 is greatly inclined with respect to the rotation axes of the outer ring 21 and the inner ring 22, as shown in FIG. A tapered spherical shape may be used according to the inclination.
That is, the rolling spherical surface portion 2 has a large diameter at one end and a small diameter at the other end, and is inclined in a longitudinal arc. In this way, it is possible to eliminate a difference in relative peripheral speed between the left and right of the rolling element 1 with respect to the raceway surface. However, since the rolling spherical surface portion 2 has an arc-shaped cross section, it is not necessary to strictly control the taper angle like a linear tapered roller, and there may be a slight difference.
The gradient between the raceway surfaces 23 and 24 and the rolling spherical surface portion 2 is strictly provided, however, the rolling spherical surface portion is an example in which the ratio of the minor diameter d to the major diameter W is 80%. If such a tapered rolling element 1 is used, there is no difference in peripheral speed between left and right, so that frictional resistance is reduced in combination with reduction in differential slip, which is suitable for a high-speed rotating angular contact bearing.

In the above embodiment, an angular contact bearing has been described as an example. However, as shown in FIG. 5, the rolling spherical surface portion 2 of the rolling element 1 and the raceway surfaces 23 and 24 of the outer ring 21 and the inner ring 22 are provided. Can be applied to a radial bearing having a contact angle of 0 degree.
Needless to say, the present invention can be applied to a thrust bearing having a certain degree.

[0012]

As described above, in the present invention, since the contact length of the rolling spherical portion is longer, the load capacity is several times larger than that of the ball, and the load and the load are as high as those of the roller bearing. Rigidity can be improved. Further, since the difference in diameter between the central portion and both ends of the rolling spherical portion is smaller than that of the ball, differential slip is small and frictional resistance is reduced. Therefore, it moves lightly and generates less heat than a ball. Furthermore, in the case of a tapered roller bearing, the place where the raceway surface inclines is one-sided, so that considerably high dimensional accuracy is required for machining and assembling of the raceway ring. However, in the case of the rolling element of the present invention, the rolling surface portion is circular. Since it is arc-shaped, it can tolerate the inclination of the raceway surface like a ball, and high dimensional accuracy is not required for machining and assembly of the raceway, and it is easy to handle. In particular, in the case of an angular contact bearing, the load in the thrust direction is large, and the rolling element shifts while being pressed against the raceway surface, so a load capacity is required and heat generation due to differential sliding is prevented. Although it is necessary, by using the rolling element of the present invention, an angular contact bearing having a high load capacity, a small differential slip, and excellent alignment can be realized. Further, if the rolling spherical surface portion has a tapered shape, there is no difference in peripheral speed between the left and right sides of the rolling element, so that the differential slip is reduced and the frictional resistance is reduced, so that a high-speed rotating angular contact bearing can be realized.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view showing a rolling bearing according to an embodiment of the present invention, and FIG. 1B is a longitudinal sectional view showing an example of a conventional ball bearing.

FIG. 2 shows a rolling element used in the rolling bearing of FIG. 1. FIGS. 2 (A), 2 (B) and 2 (C) show a ratio of the minor axis to the major axis of 80%, and FIG. ), (E) and (F) are minor axes,
It is the front view, top view, and side view of the rolling element whose ratio of a major axis is 90%, respectively.

FIGS. 3A and 3B show a rolling element having a tapered rolling spherical surface portion according to the present invention. FIG. 3A is a front view, and FIG.
Is a side view.

FIG. 4 shows a retainer of the apparatus of FIG. 1, wherein FIG. 4 (A) is a front sectional view and FIG. 4 (B) is a plan view.

FIG. 5 is a longitudinal sectional view showing a rolling bearing according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling element 2 Rolling spherical part 3 End spherical surface part 20 Rolling bearing 21 Outer ring 22 Inner ring 23, 24 Track surface 30 Cage 31 Holding recess 32 Outer cage part 33 Holding recess 34 Inner cage part

Claims (4)

[Claims] 1. A rolling bearing comprising: a pair of races arranged concentrically with each other; and a number of rolling elements rotatably interposed between the races, wherein the rolling elements are arc-shaped. A rolling spherical portion that bulges into a sphere, and an end spherical surface that bulges in a spherical shape at both ends of the rolling spherical portion, wherein an arc radius of the rolling spherical portion is larger than a curvature radius of the end spherical surface portion, A rolling element characterized in that the length between the end surface spherical portions is longer than the maximum diameter of the rolling spherical portion. 2. When the maximum diameter of the rolling spherical portion is a short diameter and the length between the end surface spherical portions is a long diameter, the short diameter is approximately 80 to the long diameter.
2. The rolling bearing according to claim 1, wherein the rolling bearing is set in a range of% ± 15%. 3. The contact direction between the rolling spherical surface portion of the rolling element and the raceway surface of each bearing ring is an angular contact having a predetermined contact angle with respect to a plane orthogonal to the rotation center axis. 3. The rolling bearing according to 2. 4. An end surface spherical portion of the rolling spherical portion has one large diameter and the other small diameter, and the arc of the rolling spherical portion has a tapered spherical shape with a gradient in a longitudinal direction. Item 3
The rolling bearing according to the above.