JP2000170775A - Conical roller bearing and gear shaft support device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conical roller bearing which can form a sufficient oil film to the contact area between a conical roller large end face and an inner gear large flange surface of an inner gear, and does not hurt the large end face of the conical roller, and to provide a gear shaft support device for vehicle which has a long maintenance cycle. SOLUTION: To the conical surface 13a of the large flange surface 13 of an inner gear 15 which contacts with the large end face 18 of a conical roller 16, a bending flank 13b is connected smoothly, and an acute angle of wedge form clearance is formed near the outer edge of a contact ellipse 20 generated by the contact. As a result, the lubricating oil drawing-in operation to the contact ellipse 20 is improved, and a sufficient oil film is formed between both contact surfaces, and at the same time, a damage by the hitting to the large flange surface 13 of the inner gear 15 in the skew condition of the conical roller 16 is to be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a tapered roller bearing and a vehicle gear shaft support device.

[0002]

2. Description of the Related Art A tapered roller bearing is a bearing suitable for applying a radial load, an axial load, and a combined load thereof. Since the load capacity is large, power transmission of a differential or a transmission in an automobile, a construction machine, or the like is performed. It is often used for gear shaft support of equipment.

FIG. 1 shows a differential of an automobile in which a gear shaft is supported by a tapered roller bearing according to an embodiment of the present invention. The differential includes a drive pinion 4 rotatably supported by two tapered roller bearings 2, 3 in a housing 1, a ring gear 5 meshing with the drive pinion 4, and a ring gear 5 attached thereto, and a pair of tapered roller bearings 6. A differential gear case 7 rotatably supported by the housing 1, a pinion 8 disposed in the differential gear case 7, and a pair of side gears 9 meshing with the pinion 8. These are housed in a housing 1 in which gear oil is sealed. This gear oil also serves as lubricating oil for the tapered roller bearings 2, 3, and 6.

FIG. 4 shows an embodiment of a conventional tapered roller bearing. The tapered roller bearing has an outer race 22 having a conical raceway surface 21 and a conical raceway surface 23.
3, an inner ring 26 provided with a large flange surface 24 on the large diameter side and a small flange surface 25 on the small diameter side, and respective raceway surfaces 21 of the outer ring 22 and the inner ring 26;
23, a plurality of tapered rollers 27 that are arranged to be able to roll freely.
And a retainer 28 that holds the tapered rollers 27 at a predetermined circumferential interval.

[0005] The tapered roller 27 comprises an outer ring 22 and an inner ring 26.
Are designed to be in line contact with the respective raceway surfaces 21 and 23, and that the apex of each conical angle of the tapered roller 27 and each raceway surface 21 and 23 coincide at one point O on the center line of the tapered roller bearing. As a result, the tapered rollers 27 can roll along the respective raceway surfaces 21 and 23.

In the tapered roller bearing, each of the raceway surfaces 21, 2
Since the cone angles of No. 3 are different, the resultant of the loads applied to the tapered rollers 27 from the respective raceway surfaces 21 and 23 acts in the direction of pushing the tapered rollers 27 toward the large collar surface 24 of the inner ring 26. Therefore, the tapered roller 27 is guided by the large end surface 29 being pressed against the large flange surface 24 when the bearing is used, and the large end surface 29 and the large collar surface 2 are guided.
4 and a relative slippage occurs while in contact.

[0007] As shown in FIG.
Is formed as a conical surface centered on the point O shown in FIG. 4, and a chamfer 30 is provided outside the conical surface. The large end surface 29 of the tapered roller 27 is formed of a spherical surface having a radius of curvature slightly smaller than the distance R _O from the point O to the large flange surface 24, and a part of this spherical surface is formed as a conical surface of the large flange surface 24. Contact at the elliptical contact area.

[0008]

As described above, in the conventional tapered roller bearing, the conical surface of the inner ring large flange surface in contact with the large end surface of the tapered roller is directly connected to the chamfered portion having a large clearance angle. Therefore, no wedge-shaped gap is formed in the contact area where the oil film is to be formed, and lubricating oil cannot be sufficiently drawn into the contact area. Therefore, it is difficult to form a sufficient oil film between the tapered roller large end surface and the inner ring large flange surface that cause relative slippage while in contact with each other, and particularly when used for supporting a gear shaft such as a differential rotating under a high load, This may cause a problem due to the maintenance cycle of the shaft support device.

In the tapered roller bearing, the tapered roller may be slightly skewed due to slippage or the like. The large end surface of the skewed tapered roller hits the edge where the large flange chamfered portion is connected to the tapered surface, and the tapered roller is skewed. A flaw on the large end face of the roller may be a problem.

Therefore, an object of the present invention is to form a sufficient oil film in a contact region between the tapered roller large end surface and the inner ring large flange surface,
Another object of the present invention is to provide a tapered roller bearing that does not damage the large end face of the tapered roller, and a vehicle gear shaft support device having a long maintenance cycle.

[0011]

In order to solve the above-mentioned problems, the present invention has an outer race having a conical raceway surface, a conical raceway surface, and a large-diameter side of the raceway surface. An inner ring provided with a flange surface, a plurality of conical rollers arranged so as to be able to roll freely between the raceway surface of the outer ring and the raceway surface of the inner ring, and a retainer for holding the conical rollers at predetermined circumferential intervals. In the tapered roller bearing, the large collar surface of the inner ring is smoothly connected to the outside of the conical surface that contacts the large end surface of the tapered roller, and is curved in a direction away from the large end surface of the tapered roller. It consisted of a flank.

That is, a curved flank is smoothly connected to the conical surface of the inner ring large flange surface which comes into contact with the tapered roller large end surface,
By forming a sharp wedge-shaped gap near the outer edge of the contact area, the lubricating oil drawing action into the contact area is enhanced, and a sufficient oil film can be formed. In addition, the formation of the smooth flank can prevent scratches due to contact with the inner ring large flange surface at the time of tapered roller skew.

By adopting an arc as the cross-sectional shape of the flank, the flank having an excellent lubricating oil drawing action can be easily processed.

In the center of the large end surface of the tapered roller, a circular area is provided with a slack, and the outer end of the slack is extended to the vicinity of the boundary between the conical surface and the flank surface of the inner ring large flange surface, so that the vicinity of the wedge-shaped gap is reduced. Thus, sufficient lubricating oil can be supplied to the wedge-shaped gap, and the allowable skew angle of the tapered rollers can be further increased.

The boundary between the conical surface and the flank surface of the inner ring large flange surface is located near the outer edge of the maximum contact ellipse generated by the contact between the tapered roller large end surface and the inner ring large flange surface under the allowable maximum axial load of the tapered roller bearing. The wedge-shaped gap for drawing in the lubricating oil can be appropriately formed in all the working load ranges of the tapered roller bearing.

The present invention also provides a vehicle gear shaft support device in which a gear shaft is rotatably supported by a tapered roller bearing in a housing filled with gear oil, wherein the tapered roller bearing has a conical raceway surface. And an inner ring having a conical raceway surface, and a large flange surface provided on the large diameter side of the raceway surface, and a rolling arrangement between the raceway surface of the outer ring and the raceway surface of the inner ring. A plurality of tapered rollers, and a retainer that holds the tapered rollers at a predetermined circumferential interval, wherein the large collar surface of the inner ring contacts the large end surface of the tapered roller, Since it is composed of a flank that smoothly connects to the outside of the conical surface and curves in a direction away from the large end surface of the tapered roller, the bearing part is kept in a good lubricated state, and the maintenance cycle of the gear shaft support device is significantly extended. be able to.

In the vehicle gear shaft support device, by adopting a circular arc as the cross-sectional shape of the flank, a flank having excellent lubricating oil drawing action can be easily formed.

In the above-mentioned gear shaft support device for a vehicle, a circular area is provided with a slack in the center of the large end face of the tapered roller, and the outer peripheral end of the slack is extended to the vicinity of the boundary between the conical surface and the flank of the inner ring large flange surface. By extending, the lubricating oil can be guided to the vicinity of the wedge-shaped gap to supply a sufficient lubricating oil to the wedge-shaped gap, and the allowable skew angle of the tapered rollers can be further increased.

In the vehicle gear shaft support device, the boundary between the conical surface and the flank surface of the inner ring large flange surface may be defined by the tapered roller large end surface and the inner ring large flange surface under the maximum allowable axial load of the tapered roller bearing. By providing it near the outer edge of the maximum contact ellipse generated by the contact, the wedge-shaped gap for drawing the lubricating oil can be appropriately formed in all the working load ranges.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.
An embodiment of the present invention will be described. FIG. 1 shows a differential of an automobile, as described above. The tapered roller bearing 2 of the embodiment is used to support the shaft of the drive pinion 4 and the shaft of a differential gear case 7 to which the ring gear 5 is attached. A gear shaft support device using 3, 6 is adopted.

FIG. 2A shows a tapered roller bearing 6 as a representative example. The tapered roller bearing 6 has a conical raceway surface 10.
And a conical raceway surface 12 having a large flange surface 13 on the large diameter side and a small flange surface 14 on the small diameter side.
Are provided, a plurality of tapered rollers 16 arranged to be able to roll freely between the raceways 10, 12 of the outer ring 11 and the inner ring 15, and the tapered rollers 16 are held at predetermined circumferential intervals. And a retainer 17. As shown in FIG. 2B, the conical angle vertices of the tapered rollers 16 and the raceway surfaces 10 and 12 of the outer ring 11 and the inner ring 15 coincide with each other at a point O on the center line of the tapered roller bearing 6. 16 is each track surface 1
Rolling motion is possible along 0,12.

As shown in an enlarged manner in FIG.
Is composed of a conical surface 13a and a flank 13b of an arc cross-section smoothly connected to the outside of the conical surface 13a, and a chamfer 13c is provided outside the flank 13b. The conical surface 13a is formed around the point O shown in FIG. In addition, tapered rollers 16
Is formed by a spherical surface 18a having a radius of curvature R appropriately smaller than the distance R _O from the point O to the large flange surface 13 of the inner ring 15, and the central portion of the spherical surface 18a has
9 are provided. The outer peripheral end of the slush 19 extends to near the boundary between the conical surface 13a of the large flange surface 13 and the flank 13b.

As described above, since the tapered roller 16 rolls while the large end face 18 is pressed against the large flange face 13 when the bearing is used, a part of the spherical surface 18a comes into contact with the conical surface 13a, and the cross section shown in FIG. As shown in FIG.
Occurs. The boundary between the flank 13b and the conical surface 13a is provided near the outer edge of the contact ellipse 20, so that the flank 13b and the spherical surface 18a form an acute wedge-shaped gap close to the contact ellipse 20.

The contact ellipse 20 increases as the axial load during use of the bearing increases. The tapered roller bearing 6 is designed such that the boundary between the flank 13b and the conical surface 13a is near the outer edge of the maximum contact ellipse, assuming the maximum contact ellipse under the maximum allowable axial load.
The wedge-shaped gap for drawing in the lubricating oil can be appropriately formed in all the working load ranges.

Although not shown, the tapered roller bearings 2 and 3 are manufactured with the same configuration and specifications. The present invention can be applied to various types of tapered roller bearings.

[0026]

As described above, the tapered roller bearing of the present invention has a conical surface of the inner ring large flange surface which comes into contact with the tapered roller large end surface.
The curved flank is smoothly connected to form a sharp wedge-shaped gap outside the contact area, and the lubricating oil drawing action to the contact area is enhanced, so that a sufficient oil film can be formed between both contact faces. Together with the formation of this smooth flank,
During the skew of the tapered rollers, flaws due to contact with the inner ring large collar surface can be prevented. In addition, by supporting the gear shaft with the tapered roller bearing, the maintenance cycle of the gear shaft support device can be significantly extended.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a differential into which a gear shaft support device according to an embodiment is incorporated.

2A is a longitudinal sectional view showing the tapered roller bearing of FIG. 1, and FIG. 2B is a sectional view for explaining the design specifications of a.

FIG. 3 is an enlarged sectional view of a main part of the tapered roller bearing of FIG. 1;

FIG. 4 is a partially omitted longitudinal sectional view showing a conventional tapered roller bearing.

FIG. 5 is an enlarged sectional view of a main part of FIG. 4;

[Explanation of symbols]

 Reference Signs List 1 housing 2, 3 tapered roller bearing 4 drive pinion 5 ring gear 6 tapered roller bearing 7 differential gear case 8 pinion 9 side gear 10 raceway surface 11 outer ring 12 raceway surface 13 large flange surface 13a conical surface 13b flank surface 13c chamfered 14 small flange surface Reference Signs List 15 inner ring 16 tapered roller 17 retainer 18 large end face 18a spherical surface 19 looseness 20 contact ellipse 21 raceway surface 22 outer ring 23 raceway surface 24 large flange surface 25 small flange surface 26 inner ring 27 tapered roller 28 retainer 29 large end surface 30 chamfer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D039 AA11 AB01 AC22 AC86 3J101 AA16 AA25 AA32 AA42 AA54 AA62 BA05 BA53 BA57 CA13 FA31 FA32 GA01 GA51

Claims (8)

[Claims] 1. An outer race having a conical raceway surface, an inner race having a conical raceway surface and a large flange surface provided on a large diameter side of the raceway surface, a raceway surface of the outer race and a raceway of the inner race In a tapered roller bearing provided with a plurality of tapered rollers arranged to be able to roll freely between the rollers and a retainer for holding the tapered rollers at predetermined intervals in a circumferential direction, the large collar surface of the inner ring has a conical shape. A conical surface that comes into contact with the large end face of the roller and smoothly extends outside this conical surface,
A tapered roller bearing comprising a flank curved in a direction away from a large end face of the tapered roller. 2. The tapered roller bearing according to claim 1, wherein a cross-sectional shape of the flank is formed by an arc. 3. A circular-shaped slack is provided at a central portion of the tapered roller large end surface, and an outer peripheral end of the slack is extended to near a boundary between a conical surface and a flank surface of the inner ring large flange surface. 3. The tapered roller bearing according to 1 or 2. 4. A boundary between a conical surface and a flank surface of the inner ring large flange surface and a maximum contact ellipse generated by contact between the tapered roller large end surface and the inner ring large flange surface under an allowable maximum axial load of the tapered roller bearing. The tapered roller bearing according to any one of claims 1 to 3, provided near an outer edge. 5. A vehicle gear shaft supporting device in which a gear shaft is rotatably supported by a tapered roller bearing in a housing in which gear oil is sealed, wherein the tapered roller bearing comprises:
An outer ring having a conical raceway surface, an inner ring having a conical raceway surface, and a large flange surface provided on a large diameter side of the raceway surface;
A plurality of tapered rollers arranged rotatably between a raceway surface of an outer race and a raceway surface of an inner race; and a retainer for holding the tapered rollers at a predetermined circumferential interval. The large collar surface is constituted by a conical surface that contacts the large end surface of the tapered roller, and a flank surface that smoothly connects to the outside of the conical surface and curves in a direction away from the large end surface of the tapered roller. Gear shaft support device for vehicles. 6. The vehicle gear shaft support device according to claim 5, wherein the flank has a circular cross-sectional shape. 7. The tapered roller large end face according to claim 5, wherein a circular area is provided at the center of the large end face of the tapered roller, and an outer peripheral end of the small area is near the boundary between the conical face and the flank face of the inner ring large collar face. Gear shaft support device for vehicles extended to 8. The tapered roller large end face and the inner ring large flange according to claim 5, wherein the boundary between the conical surface and the flank of the inner ring large flange surface is under the maximum allowable axial load of the tapered roller bearing. A vehicle gear shaft support device provided near the outer edge of a maximum contact ellipse generated by contact with a surface.