JPH0483916A - Roller bearing - Google Patents

Abstract

PURPOSE:To improve lubrication of a contact area by curving the circumferential surface of a roller so as to decrease gradually its circumference from the outer contact area contacting with an outer race, which is around the central area in the axial direction, to both end areas, so that the distance from either of both the end areas to the axial line of an inner race is smaller than the distance from the outer contact area to the axial line. CONSTITUTION:The circumferential surface 21 of a roller 16 is curved in a crown shape from an outer contact area 21a to both end areas 21b, and distance Db to either end area is smaller than distance Da to the outer contact area. Therefore, as the circumferential surface 21 revolves while being sprayed with lubricating oil 23, the lubricating oil 23 adheres to the circumferential surface 21 of the roller 16. On the lubricating oil 23 adhering due to self-rotation and revolution of the roller 16 act adhering force F1 perpendicularly to the circumferential surface 21 and centrifugal force F2 radially outward so as to produce resultant force F3 which acts approximately in the tangential direction of the circumferential surface 21. On the lubricating oil 23 acts the moving force F3 (arrow P) toward the outer contact area 21a around the central part, said outer contact area 21a being radially outer than both the end areas 21b of the circumferential surface 21, so as to shift the spray toward the outer contact area 21a, or toward the peak point of the crown-shaped circumferential surface 21. This peak point is the contact area 21a of the circumferential surface 21 with an outer race 14, and the lubricating oil concentrates in this outer contact area 21a.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a roller bearing, for example, a roller bearing used in a rotating part of a vehicle.

(Prior Art) An example of a conventional roller bearing is the one shown in FIG. 5.6. In FIG. 5, 1 is a tapered roller bearing, which is a roller bearing, and the tapered roller bearing 1 has an inner ring 3 and an outer ring 4 that share an axis 2. Between the inner ring 3 and the outer ring 4, an outer ring 3 and an inner ring It has a plurality of conical rollers 5 that rotate while contacting the rollers 4. When the tapered roller bearing 1 is used as a bearing in a rotating part of a vehicle, for example, the inner ring 3 and the outer ring 4 rotate while contacting the rollers 5, and the rollers 5 contact the rolling surfaces 3a and 4a of the inner ring 3 and the outer ring 4, respectively. It rotates while contacting the inner ring 3 and revolves around the inner ring 3. In addition, in order to remove frictional heat generated at the rolling surfaces 3a, 4a of the inner ring 3 and outer ring 4 and the contact portion 5a with the rollers 5, and to suppress wear of the contact portion 5a, these rolling surfaces 3a, 4a are The lubricating oil 7 is sprayed onto the contact portion 5a in the form of droplets or sprays, or is circulated so that the contact portion 5a comes into direct contact with the lubricating oil 7.

(Problem to be solved by the invention) However, in such conventional roller bearings,
As shown in FIG. 6, the rolling surface 4a of the outer ring 4 is tapered,
The outer peripheral surface 5b of the roller 5 is a straight line, and the axis 2
It rotates at an angle to the Therefore, as the rollers 5 rotate, the lubricating oil 7 adhering to the portion 5c having a radius of rotation Rb larger than the radius of rotation Ra of the contact portion 5a of the outer ring 4 radiates from the tapered roller bearing l due to centrifugal force as the rollers 5 rotate. There is a problem in that the lubricating oil 7 flies outward and scatters, and the lubricating oil 7 tends to collect at the contact portion 5a, resulting in insufficient lubrication in the vicinity of the contact portion 5a. Another problem is that the lubricating oil 7 is poorly retained in the tapered roller bearing 1.

Therefore, the present invention has been made by focusing on such conventional problems, and in claim 1, the outer peripheral surface of the roller approaches both ends from the circumferential part with the outer ring near the center in the axial direction. Accordingly, by curving the outer circumference so as to gradually reduce the length, and by making the distance between both ends and the axis of the inner ring smaller than the distance between the circumscribed part and the axis, lubricating oil collects at the circumscribed part, and the contact part The roller bearing can improve lubrication, and in the second aspect, the outer circumferential surface of the roller is curved as described above, and the inner circumferential surface of the outer ring is curved from the inscribed part near the axial center to the inner circumference as it approaches both ends. Curved so that the length gradually decreases,
In addition, by making the distance between both ends of the inner circumferential surface and the axis of the inner ring smaller than the distance between the inscribed part of the outer ring and the axis, it is possible to improve the lubrication of the contact area and further improve the retention of lubricating oil. The objective is to provide an improved roller bearing.

(Means for Solving the Problems) A roller bearing according to claim 1 of the present invention includes a plurality of rollers rotatably held between an inner ring and an outer ring that share an axis while contacting the outer ring and the inner ring. In the roller bearing, the outer peripheral surface of the roller has a circumscribed part that contacts the outer ring near the axial center of the roller, and is curved so that the outer circumferential length gradually decreases as it approaches both axial ends of the roller from the circumscribed part. , and the distance between the both end portions and the axis of the inner ring is smaller than the distance between the circumscribed portion and the axis.

In the roller bearing according to a second aspect of the present invention, in addition to the first aspect, the inner circumferential surface of the outer ring increases as the inner peripheral surface of the outer ring approaches both ends of the outer ring in the axial direction from an inscribed portion near the axial center of the outer ring with which the rollers come into contact. It is characterized in that it is curved so that the inner peripheral length gradually decreases, and the distance between the both ends and the axis of the inner ring is smaller than the distance between the inscribed part and the axis.

(Function) In the present invention, the outer circumferential surface of the roller is curved so that the outer circumferential length gradually decreases as it approaches both ends from the circumscribed part near the axial center where it contacts the outer ring, and Since the distance is made smaller than the distance between the circumscribed part and the axis, when the roller bearing rotates while receiving splashes of lubricating oil, and the rollers contact the outer ring and inner ring and revolve while rotating, the outer peripheral surface of the roller The lubricating oil attached to both ends is subjected to an anti-adhesion force F in the direction perpendicular to the outer circumferential surface and a radially outward centrifugal force F2 due to the centrifugal force caused by the rotation and revolution of the rollers, and this resultant force F acts on the outer circumferential surface. It acts almost tangentially to . Therefore, the lubricating oil that adheres to both ends of the outer circumferential surface moves along the curvature of the outer circumferential surface toward the circumscribed part, and lubricates the vicinity of the circumscribed part that has contacted the outer ring and the circumscribed part. ,Furthermore,
Lubricate the vicinity of the outer part that contacts the inner ring.

Further, in claim 2, as described in claim 1, the outer circumferential surface of the roller is curved, and as the inner circumferential surface of the outer ring approaches both ends from the inscribed portion near the center in the axial direction,
The inner circumference is curved so that it gradually decreases, and the distance between both ends and the axis of the inner ring is smaller than the distance between the inscribed part and the axis, so the roller bearing rotates while receiving splashes of lubricating oil. However, when the rollers contact the outer ring and the inner ring and revolve while rotating, the lubricating oil is splashed and adhered to the inner circumferential surface of the outer ring and the outer circumferential surface of the rollers due to radially outward centrifugal force. The lubricating oil adhering to both ends of the inner circumferential surface of the outer ring moves along the curvature of the inner circumferential surface toward the inscribed part that is radially outward from both ends, and the lubricating oil adheres to both ends of the outer circumferential surface of the roller. The lubricating oil moves to the circumscribed portion side as described above. Therefore, the lubricating oil lubricates the vicinity of the external and internal parts and is retained within the roller bearing.

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

FIG. 1.2 is a diagram showing an embodiment according to claim 1 of the present invention.

First, the configuration will be explained.

In FIG. 1, 11 is a roller bearing, and the roller bearing 11
has an inner ring 13 and an outer ring 14 that share an axis 12,
A plurality of tapered rollers 16 (
The rollers (hereinafter simply referred to as rollers) are arranged at approximately equal intervals on the circumference. The rollers 16 are rotatably held around an inclined axis 17 inclined with respect to the axis 12 while contacting the inner ring 13 and the outer ring 14 .

In the cross section shown in FIG. 1, the inner ring 13 has an inner circumferential surface 13a substantially parallel to the axis L2r, and an inner circumferential surface 13a radially outward of the inner circumferential surface 13a that is substantially inclined with respect to the axis 12 corresponding to the inclined axis 17 of the rollers 16. It has a linear outer rolling surface 13b. The inner circumferential surface 13a normally fits into the rotating shaft 18, is fixed by a stepped portion of the rotating shaft 18 (not shown), etc., and is rotatable integrally with the rotating shaft 18.

The outer ring 14 has an outer circumferential surface 14a that is substantially parallel to the axis 12, and an inner inner rolling surface 14b that is substantially straight in cross section and is inclined corresponding to the inclined axis 17 of the rollers 16. Outer surface 14
a is usually fixed to the housing 19 or the like.

The outer circumferential surface 21 of the roller 16 has a circumscribed portion 21a that makes line contact or slight surface contact with the inner rolling surface 14b of the outer ring 14 near the axial center of the inclined axis 17, which is the axis of the roller 16. The outer circumferential surface 21 is curved in a so-called crown shape or drum shape so that the outer circumferential length L2+ of the outer circumferential surface 21 on a cross section perpendicular to the inclined axis 17 gradually decreases as it approaches both axial ends 21b from the circumscribed portion 21a, and The end path MDb between both ends 21b and the axis 12 of the inner ring 13 is made smaller than the circumscribed distance Da between the circumscribed portion 21a and the axis 12. The end distance Dc between the right end 21b in the figure and the axis 12 is the end distance Dc between the left end 21b in the figure and the axis 12.
b is smaller than that corresponding to the inclination of the inclination axis 17.

Next, the effect will be explained.

In the roller bearing according to the present invention, the outer peripheral surface 21 of the roller 16 is curved in a crown shape from the circumscribed portion 21a to both ends 21b, and the end distance Db is smaller than the circumscribed distance Da. The outer peripheral surface 21 is covered with droplets 23a of the lubricating oil 23 (
When the roller 16 is rotated while being coated with lubricating oil 23 (hereinafter also simply referred to as lubricating oil 23), the lubricating oil 23 adheres to the outer circumferential surface 21 of the roller 16. The rollers 16 are in contact with the inner ring 13 and the outer ring 14, and revolve around the inner ring 13 while rotating on their own axis. A vertical adhesion force F1 and a radially outward centrifugal force F2 act on the outer circumferential surface 21, and a resultant force F3 acts on the outer circumferential surface 21 in a substantially tangential direction. For this reason, the lubricating oil 23 flows toward the circumscribed part 21a near the center, which is radially outward from both ends 21b of the outer circumferential surface 21 (in the figure, arrow P
The moving force F3 (shown in ) acts, and the droplets 23a move toward the circumscribed portion 21a of the roller 16, that is, toward the apex of the crown-shaped outer circumferential surface 21. The apex of the outer circumferential surface 21 is the outer circumferential surface 2
Since the lubricating oil 23 is also the circumscribed portion 21a that contacts the outer ring 14 of No. 1, the lubricating oil 23 gathers at the circumscribed portion 21a, improving the lubricity of the circumscribed portion 21a and the vicinity of the circumscribed portion 21a. Regarding the second bacterium, the left end 21 b in FIG. 1 is shown, but it goes without saying that the droplets 23 a similarly move from both ends 21 b to the circumscribed part 21 a side at the right end 21 b.

Next, an embodiment of claim 2 of the present invention will be described.

Fig. 3.4 is a diagram showing an embodiment of the roller bearing according to claim 2, and the same components as in Fig. 1.2 are given the same reference numerals.

In the roller bearing 31 according to the second aspect, the inner circumferential surface 3 of the outer ring 34
6, the inner circumferential length L36 on the cross section perpendicular to the axis vA12 of the outer ring 34 gradually decreases as it approaches both axial ends 36b of the outer ring 34 from the inscribed part 36a near the axial center of the outer ring 34 where the rollers 16 contact. As shown in FIG.
It is designed to be smaller than a. Inscribed distance Ea
is equal to the circumscribed distance in claim 1.

Everything other than the above is the same as the embodiment of claim 1 shown in FIG. 1.2, and is given the same reference numeral.

In claim 2 of the present invention, as shown in FIG. 1, the outer circumferential surface 21 of the roller 16 is curved in a crown shape from the circumscribed part 21a to both ends 21b, and the end distance Db is the circumscribed part MD.
In addition, the inner circumferential surface 36 of the outer ring 34 is curved in an inverted crown shape from the inscribed portion 36a to both ends 36b, and the end distance Eb is smaller than the inscribed distance Ea. Therefore, when the inner circumferential surface 36 rotates while being sprayed with droplets 23a of the lubricating oil 23, the lubricating oil 23 adheres to the inner circumferential surface 36 of the outer ring 34. The rollers 16 contact the outer ring 34 and the inner ring 13. Then, while rotating, the inner ring 1
3, and the lubricating oil 23 scattered on the inner circumferential surface 36 by the rotation of the inner ring 13 and the rotation and revolution of the rollers 16 collides with the inner circumferential surface 36 due to centrifugal force.
The lubricating oil 23 on both ends 36b of the inner circumferential surface 36 is
The particles move along the curved inner circumferential surface 36 toward the inscribed portion 36a, which is more radially outward, and gather near the inscribed portion 36a.

Therefore, the lubricity near the internal part 36a is improved and the lubricating oil 23 is retained within the inner circumferential surface 36. That is, in the roller bearing 31 of the present invention, the outer circumferential surface 21 of the rollers 16 is formed into a crown shape, and the inner circumferential surface 36 of the outer ring 34 is formed into an inverted crown shape. The lubricity of the inner contact portion 36a and the outer contact portion 21a) which are in line contact or surface contact between the roller bearing 16 and the outer ring 34 is improved, and the seizure resistance of the roller bearing can be greatly improved. Furthermore, by forming the inner circumferential surface 36 of the outer ring 34 into an inverted crown shape, the contact area between the outer ring 34 and the rollers 16 increases, surface pressure can be reduced, and the durability of the roller bearing 31 can be improved.

(Effects) As explained above, according to claim 1 of the present invention, the outer circumferential surface of the roller is curved so that the outer circumferential length gradually decreases as it approaches both ends from the circumscribed part with the outer ring near the axial center. ,
In addition, the distance between both ends and the axis of the inner ring is smaller than the distance between the circumscribed part and the axis (thereby, lubricating oil collects in the circumscribed part, and the roller bearing can improve lubrication of the contact part, and In claim 2, the outer circumferential surface of the roller is curved as described above, the inner circumferential surface of the outer ring is curved in an inverted crown shape, and the distance between both ends of the inner circumferential surface and the axis of the inner ring is set to By making the distance smaller than the distance between the contact part and the axis, it is possible to improve the lubrication of the contact part, and furthermore, it is possible to improve the retention of lubricating oil, and the seizure resistance of the roller bearing can be greatly improved.

Furthermore, by forming the inner circumferential surface of the outer ring into an inverted crown shape, the outer circumferential surface of the rollers can be made into a crown shape, and the contact pressure between the outer ring and the rollers can be reduced, and the durability of the roller bearing can be greatly improved.

[Brief explanation of drawings]

1 and 2 are diagrams showing one embodiment of a roller bearing according to claim 1 of the present invention, with FIG. 1 being a partial sectional view thereof, and FIG. 2 being a sectional view of an essential part thereof. Figure 3.4 shows claim 2 of the present invention.
FIG. 3 is a partial cross-sectional view of the roller bearing, and FIG. 4 is a cross-sectional view of the main part thereof. Fifth.
6 is a diagram showing a conventional roller bearing, FIG. 5 is a partial sectional view thereof, and FIG. 6 is an enlarged sectional view thereof. 11.31... Roller bearing, 12... Axis line, 13... Inner ring, 14.34... Outer ring, 16... Roller, 21...Outer circumferential surface, 21a...Externally connected portion, 21b...Both ends, 36...Inner circumferential surface, 36a...Inscribed Part, 36b...Both ends, L2□...Outer circumference length, Li2-...Inner circumference length, Da... Circumscribed distance, Db, Eb... ... End distance, Ea ... Inscribed distance. Patent applicant: Nissan Motor Co., Ltd.

Claims (2)

[Claims] (1) In a roller bearing having a plurality of rollers rotatably held between an inner ring and an outer ring that share an axis while contacting the outer ring and the inner ring, the outer circumferential surface of the roller is located near the axial center of the roller. It has a circumscribed part that contacts the outer ring, and is curved so that the outer circumference gradually decreases as it approaches both axial ends of the roller from the circumscribed part, and the distance between the both ends and the axis of the inner ring is set by the circumscribed part. A roller bearing characterized in that the distance between the axis and the axis is smaller than the distance between the axis and the axis. (2) The inner circumferential surface of the outer ring is curved so that the inner circumferential length gradually decreases as it approaches both axial ends of the outer ring from the inscribed part near the axial center of the outer ring where the rollers contact, and The roller bearing according to claim 1, wherein a distance between the inner ring and the axis of the inner ring is smaller than a distance between the inscribed portion and the axis.