JPS60159415A - Mechanism for preventing rotary element from concentrated stress - Google Patents

Abstract

PURPOSE:To prevent edge stress and high local stress by providing slant portions on the longitudinal end of contact surfaces producing line contact between rotary elements while permitting connecting lines of these slant portions and longitudinal contact surface to coincide with each other. CONSTITUTION:An inner ring 1 and an outer ring 2 are formed on both end sides of track surfaces with slant portions 12, 22 at a gentle angle to respective rolling surfaces 11, 21. Also a roller 3 is formed on both end sides with slant portions 32 at a gentle angle to a rolling surface 31. And connecting lines 13, 23 of the rolling surfaces 11, 21 of the inner and outer rings 1, 2 and the slant portions 12, 22 and the connecting line 33 of the rolling surface 31 of the roller 3 and the slant portion 32 are assembled to be approximately axially aligned with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanism for preventing stress concentration at the end of a surface where pure contact occurs in a rotating element that involves line contact during rotation, such as a roller bearing, a sliding bearing, a gear, a cam, etc.

Conventionally, in a cylindrical roller bearing as shown in Fig. 1, a rotating element that makes line contact during rotation, elongation is caused by the rolling surface 15 of the rollers 10.
Near the end of the raceway surface of a raceway wheel, a finished surface such as ground or super-finished and a non-ground surface (material) form a boundary.
Generally, the ends of the rolling surface 15 of the roller lO and the raceway surface 5 of the raceway ring do not coincide in the axial direction c (longitudinal direction of the roller), resulting in a difference d in the position of the contact portion. Therefore, during rotation, one raceway surface comes into contact with the end of the other force and the non-ground surface, and is subject to edge stress and localized high stress, which tends to cause damage such as surface roughness and scratches, shortening the life of the roller bearing. This is a contributing factor. To prevent this, in roller bearings, methods such as crowning or loose surface roughening are used on the roller transfer surface near the end face and on the raceway surface of the raceway ring near the end face. However, if the load conditions applied to the rolling bearing change or the misalignment increases significantly, even if the above measures are taken, edge stress will occur and cause the roughness and damage described above. , which shortens the life of the roller bearing.

In addition, in gears, especially spur gears that have a pronounced line contact, the edges of the teeth, and in cam mechanisms as well, the edges of the contact surface in the longitudinal direction are affected by the edge stress described above for roller bearings. However, there was a problem with the generation of concentrated stress, which was one of the causes of shortened lifespan.

This invention was made to solve the above-mentioned problems. In rotating elements that make line contact during rotation, such as roller bearings, sliding bearings, gears, and cams, the contact surface that makes line contact has a A sloped portion is formed at the longitudinal end to relieve concentrated stress, and in mutual members that make line contact, the joining line between the sloped portion and the longitudinal contact surface is aligned to reduce edge stress and localized stress. This is a mechanism for preventing concentrated stress in rotating elements, which is characterized by preventing high stress.

Next, one embodiment of the present invention will be described with reference to the drawings.

1 is an inner ring of a cylindrical roller bearing which is an example of a rotating element, 2 is an outer ring of the cylindrical roller bearing, and 3 is a plurality of rollers arranged between the inner ring 1 and outer ring 2. The raceway surface of the inner ring 1 has a raceway surface 11, that is, a cylindrical surface or an arcuate surface, precisely machined by grinding, super finishing, etc. in the center, and a raceway surface 11 on both ends of the raceway. Slanted part 12 with a gentle angle
is formed by grinding, super finishing, etc. The raceway surface of the outer ring 2 also has a precision-machined raceway surface 21, that is, a cylindrical surface or an arcuate surface, in the center part, as in the case of the inner ring 1, and a raceway surface 21, that is, a cylindrical surface or an arcuate surface, which is precision machined in the same way as the inner ring 1, and a raceway surface 21 near the end surface, similar to the inner ring. loose~
- Each of the angled inclined parts n has a rolling surface consisting of an inclined part 32, and the angle 1 of the inclined part 32 with respect to the rolling surface 31 is a gentle inclined angle 1 The above-mentioned inner ring 11 outer ring 2
The joining line 13 between the cylindrical surface or arcuate surface and the inclined portion 30, and the joining line 33 between the cylindrical surface or arcuate surface and the inclined portion 32, should be approximately -line in the axial direction when assembling the bearing. In other words, it is necessary that the axial lengths of the cylindrical surfaces or arcuate surfaces of the inner ring, outer ring, and rollers should be made as equal as possible so that they ideally match.

In addition, in order to match the above-mentioned joining line, the gap between the inner ring l's flange and the end surface 34 should be adjusted as much as the temperature and other conditions permit.
Make it smaller.

As mentioned above, the inclined parts of the inner and outer rings and rollers are precisely processed by grinding, super finishing, etc., and the joining lines of the rollers, the inclined parts of the inner and outer rings, and the cylindrical or arcuate surfaces are approximately aligned in the axial direction. As a result, in this cylindrical roller bearing, one joining line does not come into contact with the raceway surface of the other force or its position changes moment by moment as it rotates, so there is no possibility of damage to the raceway surface. It is less likely to cause scratches, surface roughness, and edge stress is significantly alleviated, so in some cases, the crowning applied to the raceway surfaces of rollers and inner and outer rings can be simplified.
It also makes up for the lack of crowning.

The second embodiment shown below is a case where the present invention is implemented in a cam mechanism having a cam 5 and a roller 6 as main parts, and when considering a cross section of a plane including a contact line between the cam 5 and the roller 6,
The cam 5 is formed with a straight line portion 51 and gently inclined line portions 52 at both end sides of the straight line portion 51. - The force roller 6 is also formed with a straight line portion 61 and inclined line portions 62 near both end faces. The angle formed by the straight line portion and the inclined line portion of the cam 5 and the roller 6 is a relatively gentle angle. The actual shape of the above-mentioned cams and rollers is that the straight part forms an inclined line part so that the contact point with the cylindrical surface or the circular arc surface coincides with the contact point (junction line) when attached to the equipment. ) If used in such a way that they match, the edge stress will be alleviated and the contact surface will be less likely to be scratched, as in the first embodiment.

Since this invention is configured as described above, when applied to rotating elements that involve line contact during rotation, such as roller bearings, sliding bearings, gears, and cams, damage to the contact surfaces is prevented or reduced, and load conditions Even if the line contact changes, edge concentrated stress (edge stress) is prevented from occurring on the surface where line contact occurs.

As a result, fatigue and wear are reduced, and the lifespan of each component is extended.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional cylindrical roller bearing with the outer ring omitted.
2 and 3 each show an embodiment of the present invention, FIG. 2 is a schematic side view partially longitudinally showing a first embodiment intended for a cylindrical roller bearing, and FIG. 3 is a cam. FIG. 2 is a schematic cross-sectional view of main parts when applied to a mechanism. 7' Explanation of symbols l is the inner ring, 2 is the outer ring, 3 is the roller, 5 is the cam, 6 is the roller, 11 is the cylindrical surface, 12 is the inclined part, 13 is the joining line, 21 is the cylindrical surface, 22 is the inclined part, n is the joining line, 31 is the cylindrical surface, 3
2 is an inclined part, 33 is a joining line, 51 is a straight part, 52 is a polygonal part.
Figure 1

Claims (1)

[Claims] In a rotating element with line contact such as a roller bearing, a drift bearing, a gear, a cam, etc., the contact surface of the rotating element where the line contact occurs has an inclined part formed at its end to relieve concentrated stress, Moreover, the mechanism for preventing concentrated stress in rotating elements is characterized in that the joining lines between the inclined portions of the rotating elements and the contact surfaces that cause line contact are made to coincide with each other.