JPH0460215A - Roller bearing - Google Patents

Abstract

PURPOSE:To correct excessive skew movement and suppress heat generation of a bearing by reducing an effective contact length between an inner ring and a roller compared to an effective contact length between an outer ring and the roller, and enlarging a crowning amount of an inner ring raceway surface compared to that of an outer ring raceway surface. CONSTITUTION:Effective contact length li between an inner ring 10 and a roller 30 is set shorter than the effective contact length le between an outer ring 20 and the roller 30. A crowning amount of a raceway surface 12 of the inner ring 10 is set larger than that of an outer ring raceway surface 22. Pressure distribution which may cause edge stress is generated between the outer ring 20 and the roller 30 compared to the case of the inner ring 10. When a skew is going to generate on the roller 30, a skew preventive resistant moment is largely applied to a portion between the outer ring 20 and the roller 30, so that excessive skew of the roller 30 is corrected. Correcting the skew of the roller 30 is overlapped since the contact pressure is distributed to a center of the roller 30 only on the side of the inner ring, while the pressure is distributed to both side points of the roller 30 on the side of the outer ring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a roller bearing that suppresses friction and heat generation due to roller skew and has a long life.

[Prior Art] Radial roller bearings, especially cylindrical roller bearings and needle roller bearings that do not have a contact angle, are integrated types such as so-called full roller bearings in which rollers are incorporated individually, and roller bearings with separators. It is known that rollers without a cage are susceptible to skewing during roller transfer.

When roller skew occurs, heat generation due to friction in the bearing increases, shortening its life. Therefore, measures to reduce the roller skew are desired, but since no effective means have been developed for full-roller bearings or roller bearings with separators, at present, only types with integrated cages are available. It is said that there is no suitable means other than to improve the guidance of the rollers by changing the

[Problem to be solved by the invention]

However, roller bearings using integrated cages are limited in the number of rollers that can be installed, so the basic load rating is reduced compared to full roller bearings or roller bearings with separators, resulting in a short life span and resistance to indentation. This method has disadvantages in that it is inferior in terms of performance, and also has disadvantages in that the cage is likely to be damaged, design and usage restrictions are increased, and costs are relatively high.

In view of the above, the present invention has been made with the object of preventing excessive skew movement of rollers in a roller bearing that does not have an integrated retainer.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a full roller bearing or a roller bearing with a separator, in which the effective contact length with the inner ring and the roller is out of the effective contact length caused by the contact between the raceway surfaces and the rolling surface of the inner and outer rings. of each raceway surface of the inner and outer rings.
Either the inner raceway surface is crowned, or the amount of crowning applied to each raceway surface of the inner and outer rings is such that the amount of crowning on the inner raceway surface is greater than the amount of crowning on the outer raceway surface.

[Effect]

As described above, in the roller bearing of the present invention, the effective contact length between the raceway surface and the rolling surface of the inner ring and outer ring is different, and the amount of crowning of the raceway surface of the inner ring and outer ring is different, so that the load can be reduced. When a load is applied, the axial distribution of contact pressure between the outer ring and the rollers is longer in the axial direction between the outer ring and the rollers than between the inner ring and the rollers, and between the inner ring and the rollers. The tendency for the contact pressure to increase closer to the axial center than between the outer ring and roller becomes more pronounced.

When roller skew occurs, two ends of the roller on the outer ring side
On the inner ring side, there is a tendency for the roller center point to be per point, but since the roller bearing of this invention has the above-mentioned effect, on the outer ring side there is a tendency for it to be per two points at both ends of the roller. becomes very strong.

As a result, roller skew is prevented and large skews are corrected.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a longitudinal sectional side view showing an embodiment in which the present invention is applied to a needle roller bearing.

In the needle roller bearing shown in the same figure, between the inner ring 10 and the outer ring 20,
This is a so-called full roller type bearing in which the needle rollers 30 are incorporated alone (without using a cage).

The outer peripheral surface 11 of the inner ring 10 of this needle roller bearing is the raceway surface 1
2 and a tapered portion 1 formed on both ends of the raceway surface 12 in the axial direction.
3, and the inner circumferential surface 21 of the outer ring 20 has a raceway surface 22 and a relief portion 23 formed at the root portion of the collar 24.

The raceway surface 12 of the inner ring 10 and the raceway surface 22 of the outer ring 20 include
Each has a crowning with a different curvature,
The amount of crowning (curvature) of the inner ring raceway surface 12 is larger than the amount of crowning of the outer ring raceway surface 22.

Further, the outer circumferential surface 31 of the roller 30 has a rolling surface 32 and a rolling surface 3.
The rolling surface 32 is formed into a cylindrical surface.

The effective contact length caused by the contact between the inner ring 10 and 30 above! i is the length in the axial direction of the portion where the raceway surface 12 of the inner ring 10 and the rolling surface 32 of the raceway 30 overlap, and is the effective contact length R caused by the contact between the outer ring 20 and the raceway 30.
e is the axial length of the portion where the raceway surface 22 of the outer ring 20 and the rolling surface 32 of the outer ring 30 overlap. In this embodiment, the axial length of the raceway surface 12 of the inner ring 10 is
By making the axial length of the rolling surface 32 of the roller 30 and the outer ring raceway surface 22 substantially the same, Re>11.

When a radial load is applied to the needle roller bearing with the above configuration, if the amount of crowning of the inner ring 10 and the outer ring 20 is the same, the contact pressure generated between the outer ring 20 and the roller 30 will be 30 is smaller than the contact pressure generated between the two.

However, in this embodiment, since the amount of crowning of the inner ring raceway surface 12 is larger than the amount of crowning of the outer ring raceway surface 22, there is a greater distance between the outer ring 20 and the outer ring 30 than between the inner ring 10 and the bump 30. A pressure distribution is created that tends to cause edge stress. Therefore, when a skew occurs in the rollers 30 and the rollers 30 try to move forward, the resistance moment that prevents this is greater between the outer ring 20 and the rollers 30 than between the inner ring 10 and the rollers 30, The excessive skew of is corrected.

FIG. 2 shows the relationship between the skew of the roller 30 and the contact pressure. When a skew of the skew angle φ is about to occur in the roller 30, the contact pressure P between the inner ring 10 and the roller 30, and Contact pressure p8 between the outer ring 20 and the roller 30
The axial distribution of , on the inner ring side, tends to be per point at the center of the roller, and on the outer ring side, it tends to be per two points at both ends, so the contact pressure p on the inner ring side is maximum at the center of the roller. The contact pressure p8 on the outer ring side reaches the maximum value P8□1X at both ends. This skew angle φ generally increases in conventional full roller bearings, but in this embodiment, the distribution of the contact pressure P8 on the outer ring side is different from the contact pressure P8 on the inner ring side.
It is longer in the axial direction than the distribution of , and the contact pressure on the inner ring side tends to increase more at the center in the axial direction than on the outer ring side, so the tendency per two points at both ends of the roller on the outer ring side is This results in suppressing the increase in the skew of 30.

In this way, the functions of correcting the skew of the roller 30 work redundantly.

As a result of the above, the friction and heat generation of the bearing are reduced, and the rolling fatigue life is increased. Furthermore, since the amount of crowning on the inner ring raceway surface 12 is larger than the amount of crowning on the outer ring raceway surface 22, heavy loads are When it is done,
It is also possible to prevent a decrease in life due to an increase in the surface pressure of the inner ring 10.

In the embodiment described above, a case was described in which both the inner ring raceway surface 12 and the outer ring raceway surface 22 were crowned.
It is also possible to crown only the inner ring raceway surface 12 and omit the crowning of the outer ring raceway surface 22. Moreover, this crowning may be applied not only to the raceway surfaces 12.22 of the inner and outer rings 10.20 but also to the rolling surfaces 32 of the rollers 30.

The needle roller bearing of the above embodiment is composed of three parts: an inner ring, an outer ring, and rollers, and needle roller bearings that use a shaft as the inner ring raceway surface, or needle roller bearings that use a housing as the outer ring raceway surface. This invention can also be applied to.

The present invention also provides cylindrical roller bearings other than needle roller bearings,
It can also be applied to other roller bearings.

Furthermore, the present invention can be applied not only to full roller bearings in which rollers are incorporated alone, but also to roller bearings in which rollers are incorporated through a non-integral cage such as a separator type cage. In the roller bearing with a separator to which this invention is applied, the same effect as in the case of a full roller bearing is achieved.
Effects can be obtained.

[Effects of the Invention] As explained above, according to the present invention, the simple processing of adjusting the axial length of the tapered portion of the outer circumferential surface and crowning the raceway surface of only the inner ring of a conventional roller bearing is possible. By simply performing can.

Further, according to the present invention, the purpose can be achieved without using an integrated cage, which is a conventional skew prevention means, so that the disadvantages of roller bearings with an integrated cage can be solved. In other words, the basic load rating decreases, due to the design.
The effect is that all problems such as usage restrictions and cost increases are resolved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of the upper half of the embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the relationship between roller skew and contact pressure of a full roller bearing. In the figure, 10 is an inner ring, 12 is an inner ring raceway surface, 20 is an outer ring, 2
2 is the outer ring raceway surface, 30 is the roller, 32 is the roller rolling surface, ff
1i is the effective contact length with the inner ring roller, and 1e is the effective contact length with the outer ring roller.

Claims (1)

[Claims] In roller bearings in which rollers are incorporated individually or in roller bearings in which rollers are incorporated through a separator, the effective contact length caused by the contact between the raceway surfaces of the inner and outer rings and the rolling surfaces is equal to that between the inner and outer rings. The effective contact length is smaller than the effective contact length with the outer ring, and the inner ring raceway surface is crowned among the raceway surfaces of the inner and outer rings, or the amount of crowning applied to each raceway surface of the inner and outer rings. , a roller bearing characterized in that the amount of crowning on the inner ring raceway surface is greater than the amount of crowning on the outer ring raceway surface.