JP2009168171A - Roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller bearing achieving reduced rotating torque and having no risk of causing seizure between the flange portion of a bearing ring and a roller. <P>SOLUTION: This roller bearing includes the bearing ring 2 having the flange portion 3 formed on its peripheral surface, and a plurality of rollers 10 rolling on the bearing ring 2. A through-hole 11 passing a rotation center and axially extending is formed in each of the rollers 10, a substantially hemispherical recessed portion 12 communicating with the through-hole 11 is formed in the end surface of the roller 10, and a ball 13 is rotatably interposed between the recessed portion 12 and the flange portion 3 of the bearing ring 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a roller bearing used in a drive system such as a differential gear of a car, a transaxle, a transmission, or a general industrial machine.

FIG. 5 is a cross-sectional view of a main part of a conventional tapered roller bearing. In the following description, the right side of the figure is referred to as the large diameter side, and the left side is referred to as the small diameter side.
A large flange portion 23 is provided on the outer periphery of the inner ring 22 of the tapered roller bearing 21 on the large diameter side, and a small flange portion 24 is provided on the outer periphery on the small diameter side. A raceway surface 25 is formed. An outer ring 26 is disposed on the outer periphery of the inner ring 22 so as to face the inner ring 22. A raceway surface 27 is formed on the inner peripheral surface.

  A tapered roller 28 is rotatably held in a pocket 30 of a retainer 29 provided with a plurality of pockets 30 at predetermined intervals in the circumferential direction, and its axial length is a large collar portion 23 of the inner ring 22. The inner ring 22 and the outer ring 26 are disposed between the raceway surfaces 25 and 27 of the inner ring 22 and the outer ring 26. The outer peripheral surface of the tapered roller 28 is in contact with both raceway surfaces 25 and 27, the large diameter side end surface is in contact with the inner side surface 23a of the large collar part 23, and the small diameter side end surface is in contact with the inner side surface of the small collar part 24, Preload is applied.

  In the tapered roller bearing 21 as described above, for example, the inner ring 22 is press-fitted into the drive shaft, and the outer ring 26 is fixed to the housing and installed between the two. When the inner ring 22 integrated therewith rotates by the rotation of the drive shaft, the tapered rollers 28 roll along the raceway surfaces 25 and 27 of the inner ring 22 and the outer ring 26 while rotating, and the axial and radial directions of the drive shaft. Support the load. At this time, the end surface on the large diameter side of the tapered roller 28 is in sliding contact with the inner side surface 23 a of the large collar portion 23 of the inner ring 22.

  As described above, the large-diameter side end surface of the tapered roller 28 is in sliding contact with the inner side surface 23a of the large collar portion 23 of the inner ring 22, and therefore has a large friction. Since the sliding contact surface may be damaged such as seizure during high-speed rotation, the maximum rotation of the drive shaft could not be made very high.

  In order to solve such a problem, a conical or spherical concave portion is provided on the end surface on the large diameter side of the tapered roller, and a steel ball that rotates freely between the concave portion and the inner wall surface of the large collar portion of the inner ring is provided. There is a tapered roller bearing which is arranged and has reduced friction between them (for example, see Patent Document 1).

  In addition, a circumferential groove is provided on the end surface on the large-diameter side of the tapered roller, and a large number of small balls are rotatably attached to the circumferential groove by caulking, and the small ball is interposed between the flange surface and the end surface of the tapered roller. There is a tapered roller bearing which is provided as a rolling contact to prevent damage such as seizure by almost eliminating relative sliding (for example, see Patent Document 2).

Japanese Patent No. 118838 (pages 35-37, Fig. 4) Microfilm (No. 4-5, Fig. 4-6) of No. 56-148096 (No. 58-52316)

The tapered roller bearing of Patent Document 1 has a problem that seizure is likely to occur in this portion because the lubricating oil does not sufficiently spread to the contact portion between the steel ball and the concave portion provided in the tapered roller.
In addition, the tapered roller bearing disclosed in Patent Document 2 has a large number of small spheres attached to the circumferential groove provided on the end face of the tapered roller by caulking, so that the structure is complicated and the manufacturing is troublesome, resulting in a significant increase in cost. There was a problem of becoming.

  The present invention has been made to solve the above-described problems, and provides a roller bearing that has a small rotational torque and does not cause seizure between the inner surface and the end surface of the flange portion of the bearing ring. It is aimed at.

  The present invention provides a roller bearing having a bearing ring having a flange on the peripheral surface and a plurality of rollers that roll on the bearing ring, the roller having a through hole extending in the axial direction through the center of rotation, A substantially hemispherical concave portion communicating with the through hole is provided on the end surface of the roller, and a ball is interposed between the concave portion and the collar portion of the raceway so as to allow rolling.

  Further, the tapered roller bearing according to the present invention is rotatably held in an inner ring having a large collar portion on the outer periphery on the large diameter side, an outer ring provided on the outer periphery of the inner ring, and a plurality of pockets provided in the cage. A plurality of tapered rollers disposed between the inner ring and the outer ring, the tapered roller having a through-hole extending in the axial direction through the center of rotation, and a large-diameter side end surface of the tapered roller A substantially hemispherical concave portion communicating with the through hole is provided, and a ball is interposed between the concave portion and the inner side surface of the large collar portion of the inner ring so as to allow rolling.

  Moreover, the track | orbit recessed part where the said ball rolls in the circumferential direction is provided in the inner surface of said collar part.

According to the present invention, since the ball is interposed between the concave portion provided on the end surface of the roller and the inner side surface of the collar portion of the race, the slip component of the contact portion between the ball and the inner side surface is almost non-existent. Therefore, the rotational torque of the bearing is greatly reduced. In addition, since the sliding surface between the concave surface of the roller end surface and the surface of the ball is reliably lubricated by the lubricant supplied from the through hole provided in the roller, seizure may occur at these contact portions. Absent.
For this reason, it is possible to obtain a roller bearing in which the torque at the time of low-speed rotation of the rotation shaft is small and the maximum rotation speed of the bearing is high.

[Embodiment 1]
1 is an axial cross-sectional view of a roller bearing according to Embodiment 1 of the present invention, FIG. 2 is an explanatory view of the main part of FIG. 1, FIG. 3 is an explanatory view of a tapered roller and a ball of FIG. It is a front view of a diameter part.
1 to 3, a large collar portion 3 is provided on the outer periphery of the inner ring 2 of the roller bearing 1 on the large diameter side, and a small flange portion 4 is provided on the outer periphery on the small diameter side. , 4 is formed with an inner ring raceway surface 5 formed of an inclined surface whose diameter is reduced on the small diameter side. The inner side surface 3 a of the large collar portion 3 is formed as an inclined surface that is substantially orthogonal to the inner ring raceway surface 5.

Reference numeral 6 denotes an outer ring provided on the outer periphery of the inner ring 2, and an inner ring has an inclined surface whose diameter is reduced on the small diameter side, and an outer ring raceway surface 7 facing the inner ring raceway surface 5 is provided.
Reference numeral 10 denotes a tapered roller which is a rolling element, which is made of a steel material for bearings, and is provided with a through hole 11 extending in the center axis direction through the center of rotation. The recess 12 is formed. The length L of the tapered roller 10 is slightly shorter than the width W between the inner side surfaces of the flanges 3 and 4 of the inner ring 2.

Reference numeral 13 denotes a ball made of a steel material for a bearing, ceramics, or the like and accommodated and held in the recess 12 of the tapered roller 10 so as to be able to roll. The inner diameter d of the recess 12 is slightly larger than the outer diameter d ₁ of the ball 13 so that an oil film is formed between the ball 13 and the rolling surface of the ball 13.
Reference numeral 14 denotes a cage in which a plurality of pockets 15 are provided at predetermined intervals in the circumferential direction, and the tapered rollers 10 are rotatably held in the pockets 10.

  In the roller bearing 1 as described above, a plurality of tapered rollers 10 in which balls 13 are accommodated in the recesses 12 and held in the pockets 15 of the cage 14 are fitted to the outer circumference of the inner ring 2 from the small diameter side, and the outer ring is arranged on the outer circumference. 6 is fitted. At this time, the outer peripheral surface of each tapered roller 10 abuts against the inner ring raceway surface 5 and the outer ring raceway surface 7, the large-diameter side end surface faces the inner side surface 3 a of the large collar portion 3 with a gap, and the ball 13 is the inner side surface. Each tapered roller 10 abuts against 3a and is accommodated between both flange portions 3 and 4 of the inner ring 2, and is held between the inner and outer races to be preloaded.

In the roller bearing 1, for example, the inner ring 2 is press-fitted into the drive shaft, and the outer ring 6 is fixed to the housing, and is installed between the two.
When the drive shaft rotates and the inner ring 2 integrated therewith rotates, the tapered roller 10 rolls between the inner ring raceway surface 5 and the outer ring raceway surface 7 while rotating to support the load on the drive shaft. At this time, the ball 13 provided on the tapered roller 10 is in rolling contact with the inner surface 3a of the large collar portion 3 while rotating (including a slight sliding contact), and slips from the surface of the concave portion 12 of the concave portion 12 of the tapered roller 10. Contact.

  Thus, since the balls 13 are in rolling contact with the inner surface 3 of the large collar 3, the rotational torque of the bearing due to the sliding contact between the tapered roller 10, the large collar 3 and the inner surface 3a is greatly reduced. To do. Further, since the contact area between the ball 13 and the concave portion 12 of the tapered roller 10 is increased, the contact surface pressure is decreased. Further, a lubricant such as oil or grease supplied between the inner ring 2 and the outer ring 6 is provided. Since the inside of the through hole 11 moves in the direction of the arrow and is reliably and sufficiently supplied to the contact portion between the recess 12 and the ball 13, the sliding contact is reduced, thereby preventing seizure.

  According to the present embodiment, the end surface on the large diameter side of the tapered roller 10 does not contact the inner peripheral surface 3a of the large collar portion 3 of the inner ring 2, and the ball 13 interposed therebetween rolls and contacts the inner surface 3a. Therefore, the rotational torque of the roller bearing can be made extremely small. Further, the contact surface pressure between the recess 12 and the ball 13 provided on the large-diameter side end surface of the tapered roller 10 is reduced, and the sliding contact surface between the recess 12 and the ball 13 is surely provided by the lubricant supplied from the through hole 11. Therefore, seizure or the like does not occur between the two.

[Embodiment 2]
FIG. 4 is an explanatory diagram of a main part of the roller bearing according to the second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the roller bearing according to the present embodiment, an arc-shaped track recess 3b corresponding to the outer shape of the ball 13 is provided on the circumference of the inner surface 3a of the large collar portion 3 of the inner ring 2 (on the trajectory through which the ball 13 passes). The ball 13 is made to roll along the track recess 3b. The space between the track recess 3b and the ball 13 is lubricated by a lubricant supplied between the inner ring 2 and the outer ring 6. Further, since the contact surface pressure between the track recess 3b and the ball 13 can be reduced, the contact condition of this portion is relaxed.
Other structures, operations, and effects are almost the same as those in the first embodiment.

  In the above description, the case where the present invention is applied to the tapered roller bearing 1 using the tapered roller 10 as the rolling element has been described. However, the present invention can also be applied to the cylindrical roller bearing using the cylindrical roller as the rolling element. it can. In this case, the cylindrical roller may be provided with a through hole that passes through the center of rotation and extends in the central axis direction, and a substantially hemispherical recess that communicates with the through hole on the end surface of the inner ring or the outer ring.

It is a longitudinal cross-sectional view of the roller bearing which concerns on Embodiment 1 of this invention. It is explanatory drawing of the principal part of FIG. It is explanatory drawing of the tapered roller and ball | bowl of FIG. 2, and the front view by the side of the large diameter of a tapered roller. It is explanatory drawing of the principal part of the roller bearing which concerns on Embodiment 2 of this invention. It is explanatory drawing of the principal part of the conventional roller bearing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Roller bearing, 2 Inner ring, 3 Large collar part, 3a Inner peripheral surface of 3d collar part, 3b Track recessed part, 5 Inner ring raceway surface, 6 Outer ring, 7 Outer ring raceway surface, 10 Tapered roller, 11 Through hole, 12 Recessed part, 13 ball.

Claims (3)

In a roller bearing having a bearing ring having a flange on the peripheral surface and a plurality of rollers rolling on the bearing ring,
The roller is provided with a through hole extending in the axial direction through the center of rotation, and a substantially hemispherical concave portion communicating with the through hole is provided on an end surface of the roller, and a ball is provided between the concave portion and the collar portion of the race ring. A roller bearing characterized in that it is installed so that it can roll. An inner ring having a large collar on the outer circumference on the large diameter side, an outer ring provided on the outer circumference of the inner ring, and a plurality of pockets provided on the cage are rotatably held, and are arranged between the inner ring and the outer ring. A plurality of tapered rollers provided,
The tapered roller is provided with a through hole that passes through the center of rotation and extends in the central axis direction, and a substantially hemispherical concave portion that communicates with the through hole is provided on the large-diameter side end surface of the tapered roller. A tapered roller bearing characterized in that a ball is interposed between the inner side surface of the portion so as to be able to roll.   The roller bearing according to claim 1, wherein a raceway concave portion in which the ball rolls in a circumferential direction is provided on an inner surface of the flange portion.

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