Resin cage for tapered roller bearing and tapered roller bearing including the resin cage

Patent metadata

Field	Value
Publication number	US-9995341-B2
Application number	US-201715499289-A
Country	US
Kind code	B2
Filing date	Apr 27, 2017
Priority date	Apr 4, 2013
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

Provided is a resin cage for a tapered roller bearing in which a mold parting line which is extended in an axial direction is formed in a pillar portion defining a pocket. On facing surfaces of adjacent pillar portions, on an outer diameter side from the mold parting line, a first conical surface which slides in contact with an outer peripheral surface of a tapered roller is formed, and a first flat surface in a radial direction is formed in a portion on the outer diameter side from the first conical surface. On an inner diameter side from the mold parting line, a second conical surface which slides in contact with the outer peripheral surface of the tapered roller is formed, and a second flat surface in a radial direction is formed in a portion on the inner diameter side from the second conical surface.

First claim

The invention claimed is:

1. A resin cage for a tapered roller bearing, the resin cage being injection-molded such that a large-diameter ring portion and a small-diameter ring portion which are separated from each other in an axial direction are connected to each other by a plurality of pillar portions which is in slide contact with an outer peripheral surface of a tapered roller which is a rolling element, and a plurality of pockets are equally formed in a circumferential direction for housing and holding the tapered roller,
wherein a mold parting line which is extended in the axial direction is formed in the pillar portion defining the pockets,
wherein on facing surfaces of the adjacent pillar portions, on an outer diameter side from the mold parting line, a first conical surface which comes in slide contact with the outer peripheral surface of the tapered roller is formed, and a substantially flat surface in a first radial direction which is continuous to the first conical surface is formed in a portion on the outer diameter side from the first conical surface, and
wherein on an inner diameter side from the mold parting line, a second conical surface which comes in slide contact with an outer peripheral surface of the tapered roller is formed, and a flat surface in a second radial direction which is continuous to the second conical surface is formed in a portion on the inner diameter side from the second conical surface.

2. The resin cage for a tapered roller bearing according to claim 1 ,
wherein the large-diameter ring portion, the small-diameter ring portion, and the pillar portion of the cage are molded by extracting a pair of moldings in the axial direction.

3. The resin cage for a tapered roller bearing according to claim 1 ,
wherein a recessed groove along the mold parting line is formed on the facing surface of the pillar portion.

4. The resin cage for a tapered roller bearing according to claim 3 ,
wherein a depth of the recessed groove is within a range of 0.1 mm to 0.8 mm.

5. The resin cage for a tapered roller bearing according to claim 4 ,
wherein a boundary between the first conical surface and the substantially flat surface in the first radial direction, and a boundary between the second conical surface and the substantially flat surface in the second radial direction match each other, and
wherein the depth of the recessed groove is within a range of 0.1 mm to 0.6 mm in the vicinity of an intersection position of the boundary and the mold parting line.

6. The resin cage for a tapered roller bearing according to claim 1 ,
wherein the mold parting line is formed substantially in a center portion of the pillar portion in the radial direction such that the first conical surface and the second conical surface are substantially the same as each other in a length along an extension direction of the pillar portion.

7. The resin cage for a tapered roller bearing according to claim 1 ,
wherein the pillar portion is formed such that an opening width on an inner diameter side in the pocket is smaller than a roller diameter of the tapered roller on a large-diameter side while an overlapping allowance ranges from 0.2 mm to 0.7 mm in at least a portion on the inner diameter side of the pocket and that an opening width on an outer diameter side in the pocket is smaller than a roller diameter of the tapered roller on a small-diameter side while an overlapping allowance ranges from 0.1 mm to 0.5 mm in at least a portion on the outer diameter side of the pocket.

8. The resin cage for a tapered roller bearing according to claim 1 ,
wherein an annular notch portion is formed on at least one of an inner peripheral surface of the large-diameter ring portion and an outer peripheral surface of the small-diameter ring portion such that a thickness of the ring portion is smaller than a thickness of the pillar portion.

9. The resin cage for a tapered roller bearing according to claim 8 ,
wherein the notch portion is formed on the inner peripheral surface of the large-diameter ring portion,
wherein a thickness of the large-diameter ring portion is 40% to 80% of a thickness of the pillar portion, and
wherein the thickness of the pillar portion is 30% to 70% of an averaged roller diameter of the tapered roller.

10. The resin cage for a tapered roller bearing according to claim 1 ,
wherein an inclination angle of the cage is set to be equal to or greater than 32° 30′ and less than 55°.

11. The resin cage for a tapered roller bearing according to claim 1 , the resin cage being injection-molded using an axial-draw molding,
wherein on facing surfaces of the adjacent pillar portions, on the outer diameter side from the mold parting line, a conical surface on the inner diameter side which comes in slide contact with the outer peripheral surface of the tapered roller and which is the first conical surface is formed in a portion on the inner diameter side from a virtual conical surface connecting to respective rotation axes of a plurality of tapered rollers, and the substantially flat surface in the first radial direction which is continuous to the conical surface on the inner diameter side is formed in a portion on the outer diameter side from the virtual conical surface, and on the inner diameter side from the mold parting line, a conical surface on the outer diameter side which comes in slide contact with the outer peripheral surface of the tapered roller and which is the second conical surface is formed in a portion on the outer diameter side from the virtual conical surface, and the substantially flat surface in the second radial direction which is continuous to the conical surface on the outer diameter side is formed in a portion on the inner diameter side from the virtual conical surface.

12. A tapered roller bearing comprising:
an outer ring which includes an outer ring raceway surface on an inner peripheral surface;
an inner ring which includes an inner ring raceway surface on an outer peripheral surface;
a plurality of tapered rollers which are rollably arranged between the outer ring raceway surface and the inner ring raceway surface; and
the resin cage according to claim 1 ,
wherein a flange is formed at an end portion on a large-diameter side of the inner ring, the inner ring raceway surface is provided to be continuous to an end surface of a small-diameter side of the inner ring, and a contact angle α of the tapered roller bearing is set to be within a range of 37° 30′ to 50°.

13. The tapered roller bearing according to claim 12 ,
wherein a flat surface or a recessed portion which faces a notch portion of the cage is formed in the flange such that the flange is formed into a shape of entering the notch portion.

14. A tapered roller bearing comprising:
an outer ring which includes an outer ring raceway surface on an inner peripheral surface;
an inner ring which includes an inner ring raceway surface on an outer peripheral surface;
a plurality of tapered rollers which are rollably arranged between the outer ring raceway surface and the inner ring raceway surface; and
the resin cage according to claim 1 ,
wherein a flange is formed only at an end portion on a large-diameter side among the end portion on the large-diameter side and an end portion on a small-diameter side of the inner ring, and a contact angle α of the tapered roller bearing is set to be within a range of 37° 30′ to 50°.

Assignees

• Nsk Ltd

Inventors

• Koganei Makoto
• Sakamoto Hiroshi
• Tominaga Daisuke
• Kiyono Shunichi
• Aoki Mamoru
• Minamiyama Tatsuya
• Nakamura Masayoshi
• Yamamoto Kiyoshi

Classifications

• F16C2361/61

  Toothed gear systems, e.g. support of pinion shafts · CPC title

• F16C19/364

  with tapered rollers, i.e. rollers having essentially the shape of a truncated cone · CPC title

• F16C2240/34

  Contact angles · CPC title

• F16C43/065

  in cages · CPC title

• F16C2300/02

  General use or purpose, i.e. no use, purpose, special adaptation or modification indicated or a wide variety of uses mentioned · CPC title