JP2013113324A - Roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller bearing which satisfies both reduction in a friction loss of the roller bearing and improvement in bearing life by improving the lubrication performance of a cage guide surface.SOLUTION: A roller bearing 1 includes: an outer ring 2 which is formed cylindrical by press-working a steel plate and includes a raceway 22 in the axial direction center; a plurality of rollers 3 disposed on the raceway 22 of the outer ring 2; and a cage 4 holding the rollers 3. The outer ring 2 includes folded parts 23 which are folded toward an end face 32 of the roller 3 and disposed inward of both ends in the radial direction. An axial direction end on a roller side of the folded part 23 includes a flange 25 which crosses an axial line of the outer ring 2 and protrudes outward in the radial direction. An axial direction end face on a roller side of the flange 25 constitutes a roller guide surface 26.

Description

  The present invention relates to a roller bearing such as a needle roller bearing, and more particularly to a roller bearing having an outer ring manufactured by pressing a metal plate.

  Conventionally, there is a type in which a roller bearing having an outer ring manufactured by pressing a metal plate is bent so as to overlap an outer ring raceway portion to form a flange portion (see Patent Document 1). Roller bearings of the above-mentioned type are manufactured by reducing the number of processing steps because the flange is bent forward, the cage is assembled into the outer ring, and the roller is fitted from the inside in the radial direction of the cage, so that no bending after the flange is required. Cost is reduced.

  The main part of the above type of roller bearing is shown in FIG. The outer ring 120 is manufactured by pressing a single metal plate, and a folded portion 123 that is bent 180 degrees toward the inner diameter side with respect to the cylindrical portion 121 is formed at both axial ends of the cylindrical portion 121. By doing so, the cross section is a U-shaped sideways. The tip surfaces 126 of the two folded portions 123 serve as guide surfaces for the rollers 130, and the inner peripheral surfaces 124 of the two folded portions 123 serve as guide surfaces for the cage 4.

JP-A-6-264930

The front end surface 126 of the folded portion 123, which is the guide surface of the roller 130 of the roller bearing 100, is a fractured surface by press working, and it is difficult to ensure accuracy. For this reason, a position where the contact surface pressure is extremely high is generated on the contact surface with the end surface 132 of the front end surface 126 or 130, and the oil film may be cut off.
When the oil film breaks, the frictional resistance of the roller guide surface increases, and seizure occurs, which may shorten the bearing life.

  It is an object of the present invention to provide a roller bearing that satisfies both the reduction of friction loss of the roller bearing and the improvement of the bearing life by improving the lubrication performance of the cage guide surface.

  In order to solve the above-described problems, the structural feature of the invention according to claim 1 is that an outer ring having a raceway portion at a central portion in an axial direction formed cylindrical by pressing a steel plate, and a raceway of the outer ring. A roller bearing comprising a plurality of rollers arranged in a portion and a cage for holding the roller, wherein the outer ring is folded inward in the radial direction at both ends toward the end face of the roller A flange portion that intersects the axis of the outer ring and protrudes radially outward at the axially inner end of the folded portion, and the axially inner end surface of the flange portion is a roller guide surface. It is that.

  According to the configuration of the present invention, the axially inner end surface of the flange portion of the folded portion of the outer ring that is the roller guide surface is the surface of the steel plate, the surface is smooth compared to the fracture surface, and the contact surface pressure is extremely high. Therefore, the oil film breakage does not occur. That is, it is easy to obtain a stable lubrication state of the roller guide surface. As a result, the frictional resistance of the roller bearing is reduced, and even when used under high-speed conditions, problems such as seizure can be avoided, and the life of the roller bearing can be extended compared to this type of conventional roller bearing.

  In order to solve the above-mentioned problem, the structural feature of the invention according to claim 2 is that the radially outer end of the flange portion is further curved outward in the axial direction, and the radially outer roller guide surface. And a gap is formed between the roller end surface.

  According to the configuration of the present invention, since the flange is curved, the axial rigidity of the flange portion is improved, the variation in the contact position of the roller end surface and the guide surface is suppressed, and the frictional resistance between the roller end surface and the guide surface is reduced. Stabilize. Further, the lubricant is replenished to the roller guide surface and the contact portion with the end surface along the gap in the rotation state of the roller bearing, and the lubrication state of the roller guide surface is further improved.

  ADVANTAGE OF THE INVENTION According to this invention, the roller bearing which satisfies both reduction of the friction loss of a roller bearing and improvement of a bearing life can be provided by improving the lubrication performance of a cage guide surface.

It is sectional drawing of the roller bearing of embodiment of this invention. It is an expanded sectional view of the principal part of FIG. It is an expanded sectional view of the principal part of the conventional roller bearing.

Embodiments of the present invention will be described below with reference to the drawings.
In the description of each drawing, the direction toward the axial center of the bearing is referred to as the axially inward direction, and the direction toward both axial ends of the bearing is referred to as the axially outward direction.

FIG. 1 is a cross-sectional view of a roller bearing according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of the right half of the main part of FIG. Note that this embodiment is symmetrical.

As shown in FIGS. 1 and 2, the roller bearing 1 includes an outer ring 2, needle rollers 3, and a cage 4.
The outer ring 2 is manufactured by pressing a steel plate, and is folded back 180 ° so as to be rolled from both ends of the cylindrical portion toward the end face of the roller, with a raceway formed in the inner diameter portion at the center in the axial direction. A folded portion 23 is formed.

  The roller side end portion of the turn-up portion 23 is bent radially outward to form a flange portion 25 that expands in diameter approximately at right angles to the axial center line. The radially outer end of the flange portion 25 is further bent outward in the axial direction, the flange portion 25 has a convex shape inward in the axial direction, and the axially inner side surface of the flange portion 25 is axially inward. A convex roller guide surface 26 is formed. Inner diameter surfaces 24 of the folded portions 23 on both sides are cylindrical surfaces parallel to the raceway portion 22, the inner diameter surfaces of both inner diameter surfaces 24 are equal to each other, and both inner diameter surfaces 24 are guide surfaces of the cage 4. .

  The outer ring 2 is manufactured by the following process using a pipe material made of a steel plate. The pipe material cut into a predetermined length is expanded to a thickness capable of processing the inner diameter of the portion formed in the folded portion 23 at both ends. Next, the end portion of the pipe member is narrowed inward in the radial direction, and at the same time, the tip end portion is folded inward in the axial direction to form a prototype of the flange portion 25.

Next, at the same time that the prototype of the flange portion 25 at the front end is folded inward in the axial direction, the folded portion 23 is formed by narrowing the end portion of the cylindrical portion radially inward, and the prototype of the flange portion 25 is radially outward. The flange portion 25 spreads out. At this time, a chamfered shape is formed on the radially inner side of the axially inner end face of the flange portion 25 by deformation during processing.
Next, after molding the flange portion 25 and the folded portion 23, the outer ring 2 is cured to a predetermined hardness by heat treatment.

  The roller 3 is a so-called needle roller of a cylindrical shape, and has a cylindrical rolling surface 31 and flat end surfaces 32 perpendicular to the rolling surface 31 on both sides of the rolling surface 31.

  The cage 4 is formed in a cylindrical shape by pressing a metal plate. The cage 4 includes two ear portions 41 and a plurality of column portions 42 facing each other in the axial direction. The plurality of column portions 42 connect both the ear portions 41 in the axial direction, thereby rolling the plurality of rollers 2. A plurality of pockets 43 that are movably held are defined. The minimum value of the circumferential width of the pocket 43 is slightly smaller than the diameter of the roller 3. The outer diameter surfaces 44 of both ear portions 41 are contact surfaces that are in radial contact with the inner diameter surfaces 24 of both folded portions 23.

  In the roller bearing 1, the plurality of rollers 3 are held in the pockets 43 of the cage 4, both end surfaces 32 are guided by the roller guide surfaces 26 of the curved portion, and the transfer surface 31 is disposed in contact with the raceway 22 of the outer ring 2. ing.

  In the roller bearing 1, the cage 4 is disposed on the raceway 22 of the outer ring 2 with the pockets 43 facing radially inward, and the rollers 3 are directed from the radially inner side toward the raceway portion 22 of the outer ring 2. It is press-fitted into each pocket 43 and assembled. Thus, it is not necessary to bend the folded portion 23 after the roller 3 and the cage 4 are assembled in the raceway 22 of the outer ring 2, and a heat treatment step such as annealing for post bending is unnecessary.

  In the roller bearing 1, the roller guide surface 26 of the outer ring 2 has a convex shape inward in the axial direction, that is, the end surface 32 side of the roller 3, and the guide surface 26 and the end surface 32 of the roller 3 have a convex shape of the guide surface 26. Contact is made at the contact portion 27 at the apex. Here, the flange portion 25 has a convex shape inward in the axial direction, and the axial rigidity of the flange portion 25 is improved as compared with a flat surface. The contact state variation is suppressed, and the frictional resistance of the contact portion 27 is stabilized.

  Further, a gap 28 opened radially inward between the roller end surface 32 and the guide surface 26 at the radially inner side of the contact portion 27, and a roller end surface 32 at the guide surface at the radially outer side of the contact portion 27. An air gap 29 opened radially outward is interposed between the air gap 26 and the air gap 26.

When the bearing 1 rotates under the lubrication condition by the lubricant, the lubricant is supplied to the contact portion 27 from the gap 28 and the gap 29 of the roller guide surface, and the lubrication state of the roller guide surface can be greatly improved as compared with the conventional product. Further, the roller guide surface 26 is a surface of a steel plate, has a smooth surface compared to the fracture surface, and the contact surface pressure does not become extremely high.
As a result, even when used under high-speed conditions, the roller guide surface can be prevented from running out of lubricant and running out of oil film, avoiding problems such as seizure, and the life of roller bearings is longer than that of conventional roller bearings of this type. Can be extended.

  In the embodiment described above, the roller guide surface of the curved portion of the outer ring is convex inward in the axial direction. However, in this invention, the roller guide surface of the curved portion of the outer ring may be a plane parallel to the track 121.

  In the above-described embodiment, the curved portion of the outer ring is formed at the bent portions of the flange portions at both ends. However, in the present invention, the curved portion of the outer ring may be formed only at the bent portion of one of the flange portions.

DESCRIPTION OF SYMBOLS 1 ... Bearing 2 ... Outer ring 22 ... Raceway 23 ... Turn-up part 25 ... Flange part 26 ... Roller guide surface 28, 29 ... Air gap 3 ... Roller 4 ... Cage

Claims (2)

A roller provided with an outer ring provided with a raceway in a central portion in the axial direction formed into a cylindrical shape by pressing a steel plate, a plurality of rollers disposed on the raceway of the outer ring, and a cage that holds the roller A bearing,
The outer ring includes a folded portion that is bent inward in the radial direction at both ends toward the end face of the roller, and intersects the axial line of the outer ring at the axial roller side end of the folded portion and A roller bearing having a flange portion protruding in the direction, and an end surface on the axial roller side of the flange portion constituting a roller guide surface.   The radially outer end portion of the flange portion is further curved toward the axial opposite roller side, and a gap is formed between the radially outer roller guide surface and the roller end surface. Item 2. A roller bearing according to Item 1.

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