JPH0735808B2 - Needle roller bearings - Google Patents

Description

TECHNICAL FIELD The present invention relates to a needle roller bearing suitable for being incorporated in a roller follower, a cam follower or the like.

"Prior Art" As shown in FIG. 4, there is known a radial / thrust composite bearing in which thrust ball bearings are arranged on both sides of a needle roller bearing in order to receive a thrust load. However, the guide surface of the ball 60 receiving the combined radial and thrust type load is formed on the washer 36, and the shoulder portion formed on the side surface of the outer ring of the washer 36 is referred to. Because it is partly fitted and fixed to 44,
The thrust load acting on the inner ring 26 or the outer ring 22 is indirectly received via the side surface of the washer.

For example, when a thrust load acts on the inner ring 26 side, the washer 36 is bent in the axial direction, so that it has a function of preventing play in the axial direction. Although it can withstand this, it may be separated from the shoulder portion 44 when the thrust load repeats left and right and the thrust load fluctuates, and there is a defect that the function as a composite bearing cannot be sufficiently exhibited.

Also, forming a shoulder for fitting parts such as washers to the outer ring or inner ring causes grinding and assembly errors, making it extremely difficult to provide a highly accurate radial / thrust composite bearing. .

Further, the ball retainer 62 is incorporated and the balls are aligned so that the outer ring is prevented from swinging. However, there is a problem in that the cage has a high cost and the thrust capacity is reduced due to the reduction in the number of balls.

Therefore, a vertical wall surface is formed on an annular step portion having a substantially inverted L-shaped cross section, in which the raceway surface of the ball with respect to the inner peripheral surface of the outer ring for guiding the rotation of the rollers is formed inward from the end surface of the outer ring, and the raceway surface A raceway surface is formed on the inner wall of a ball accommodating portion having a substantially L-shaped cross section of the corresponding thrust washer, and the ball is located between the raceway surface of the outer ring and the raceway surface of the ball accommodating portion of the thrust washer. By forming the radial width of the vertical wall surface slightly larger than the diameter of the ball to be incorporated, without receiving a radial load,
It is a technical problem of the present invention that only a large thrust load can be received.

"Means for Solving the Problems" Means for solving the above-mentioned technical problems are as follows.

Thrust ball bearings are arranged on both sides of the needle roller bearing, and an annular step portion having a substantially inverted L-shaped cross section is formed inward from the end surface of the outer ring, and a vertical wall surface of the annular step portion is formed. A raceway surface is formed, a ball accommodating portion having a substantially L-shaped cross section is formed outward from the inner wall of the thrust washer corresponding to the raceway surface, and a raceway surface is formed on the vertical wall surface of the thrust washer. Between the orbital surface of the thrust washer and the orbital surface of the thrust washer, and the width of the vertical wall in the radial width direction is slightly larger than the diameter of the ball to be incorporated.

[Action] The radial load of the roller is supported by the inner peripheral surface of the outer ring, and at the same time, the thrust load is applied to the outer surface of the raceway surface of the annular step formed inward from the end surface of the outer ring and the inner wall of the thrust washer. The ball is supported by the raceway surface of the ball storage portion formed toward the side, and the ball is held in place by the ball storage portion of the thrust washer and the raceway surface of the outer ring.

[Example] An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional front view in which the needle roller bearing of the present invention is applied to a cam follower.

Reference numeral 10 denotes an outer ring, and the outer ring 10 is formed thick so as to rotate while being in contact with the outer peripheral surface or the inner peripheral surface of the cam, and inside the outer ring 10, needle rollers 11.11. A guideway surface 101 is formed.

Reference numeral 102 denotes a substantially inverted cross section L formed inward of the end surface 103 of the outer ring 10.
A vertical wall surface 1021 is formed on the ring-shaped step portion 102 and the radial width of the vertical wall surface 1021 is formed slightly larger than the diameter d of the ball 12 to be incorporated. Can be supported, but is not in contact with the radial load.

1022 is a raceway surface formed on the vertical wall surface 1021 of the outer ring,
The raceway surface 1022 determines the ball rolling position on the vertical wall surface of the outer ring.
It is on the 1021 side. Reference numeral 13 denotes a thrust washer on the side of the stud screw portion 153, and a through hole 131 having substantially the same outer diameter as that of the stud 15 of the cam follower is formed in the center of the thrust washer 13 and corresponds to the annular step portion 102 of the outer ring 10. A ball accommodating portion 132 having a substantially L-shaped cross section is formed outward from an inner wall of the thrust washer 13 and a raceway surface 133 is formed on a vertical wall surface thereof.

14 is a flange of the stud head 152, and a ball accommodating portion 142 is formed outward from an inner wall of the flange 14,
A raceway surface 143 is formed on the vertical wall surface, and a tightening hexagonal hole 141 is formed substantially at the center of the stud head portion 152.

151 is a sliding surface formed on the outer periphery of the stud 15 on the side of the stud head 152, and supports the needle rollers 11.11 ..

Since the above-described embodiment is formed as described above, the radial step of the roller is supported by the inner peripheral surface of the outer ring, and at the same time, the annular step formed inward from the end surface of the outer ring against the thrust load. The ball is supported by the raceway surface of the thrust washer and the raceway surface of the ball storage portion formed outward from the inner wall of the thrust washer, and the ball is held in place by the ball storage portion of the thrust washer and the outer raceway surface. Retained.

Next, the raceway surfaces 1022 ′ of the outer ring 10 and the thrust washer 13,
And 133 'have a circular arc groove close to the diameter of the ball 12, so there is a two-point contact between the ball and the raceway surface, the ball elastically deforms, a wide contact width is obtained, and the elasticity increases. A large thrust load can be received.

(See FIG. 2-2) FIG. 3 is a partially omitted cross-sectional view in which the needle roller bearing of the present invention is applied to a roller follower.

Reference numeral 16 denotes an inner ring having a sliding surface 161 for supporting the needle rollers 11.11 .., which is formed on the outer periphery, and a thrust washer 17 is press-fitted and fixed to an end surface portion of the inner ring 16. The other parts are the same as those in the first embodiment and are designated by the same reference numerals, and the description thereof is omitted.

"Effects of the Invention" In the needle roller bearing of the present invention, an annular step portion having a substantially inverted L-shaped cross section is formed inward from the end surface of the outer ring, and a raceway surface is formed on a vertical wall surface of the annular step portion. A ball accommodating portion having a substantially L-shaped cross section is formed outward from an inner wall of the thrust washer corresponding to the raceway surface, and a raceway surface is formed on a vertical wall surface thereof.
Since the ball is located between the raceway surface of the outer ring and the raceway surface of the thrust washer, and the radial width of the vertical wall surface is formed slightly larger than the diameter of the ball to be incorporated, the radial load is It is assumed that it is in a non-contact state, and only a large thrust load is received without receiving a radial load, and the function as a combined radial / thrust type bearing can be fully exerted.

Further, since the raceway surface is formed on the annular step portion of the outer ring, the flatness of the thrust rolling surface and the perpendicularity to the roller rolling surface are likely to occur, and the outer ring and thrust washer that receive the thrust load have a cross section of approximately L Since it is in the shape of a letter, the processing accuracy is easy to obtain and the production cost is stable.

Further, according to the structure of claim 2, the ball raceway is formed on the vertical wall surface of the annular step portion of the outer ring and the vertical wall surface of the ball receiving portion of the thrust washer, and the raceway surface is a circular arc groove close to the diameter of the ball. Therefore, it has a feature that it can receive a large thrust load and has high rigidity.

[Brief description of drawings]

FIG. 1 is a partially sectional front view in which the needle roller bearing of the present invention is applied to a cam follower, FIG. 2-1 is an enlarged sectional view in brackets of FIG. 1A, and FIG. 2-2 is a circular arc raceway surface. FIG. 3 is an enlarged cross-sectional view in which the needle roller bearing of the present invention is applied to a roller follower, and FIG. 4 is a partially omitted cross-sectional view showing a conventional example. 10: Outer ring, 11: Needle roller 12: Ball, 101: Needle roller raceway surface 102: Annular step 1022, 133: Ball raceway surface 13,17: Thrust washer 14: Flange, 16: Inner ring

Claims (2)

[Claims] 1. A thrust ball bearing is arranged on both sides of a needle roller bearing, and an annular step portion having a substantially inverted L-shaped cross section is formed inward from an end surface of an outer ring, and the annular step is formed. A raceway surface is formed on a vertical wall surface of the portion, a ball accommodating portion having a substantially L-shaped cross section is formed outward from an inner wall surface of the thrust washer corresponding to the raceway surface, and a raceway surface is formed on the vertical wall surface, The needle roller bearing is characterized in that the ball is between the raceway surface of the outer ring and the raceway surface of the thrust washer, and the radial width of the vertical wall surface is slightly larger than the diameter of the ball to be incorporated. . 2. The needle roller bearing according to claim 1, wherein the raceway surface is a circular arc groove having a diameter close to that of the ball.