JP2578991Y2 - Tapered roller bearing - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tapered roller bearing which is used in a pair of two parts, for example, a transmission for an automobile, and which prevents a loss of preload.

[0002]

2. Description of the Related Art Tapered roller bearings 21 are generally used in automobile transmissions to support an output shaft and an input shaft as shown in FIG. The inner ring 22 of the tapered roller bearing 21 is attached to the shaft end small diameter portion 23a of the shaft 23 in a press-fit state. The outer ring 24 is attached to the cylindrical portion 25 a of the housing 25 by loose fitting, and the width of the outer ring 24 is
Is positioned in the axial direction by contacting the locking surface 25b.

The tapered roller bearing 21 has a pair of shafts 2.
3 are provided with the front faces facing each other, and between the tapered roller bearings 21 on both sides, a preload is applied by shim adjustment on the outer ring 24 side in order to improve rigidity and rotational accuracy. The material of the housing 25 is an aluminum alloy for weight reduction, and the shaft 23 is made of a steel material.

[0004]

Since the housing 25 is made of an aluminum alloy as described above, its linear expansion coefficient is about twice as large as that of the shaft 23 made of a steel material. Therefore, when the temperature changes during operation, the dimensional change of the housing 25 becomes larger than the dimensional change of the shaft 23, and a gap may be formed between the outer ring 24 and the engaging surface 25 b of the housing 25. For this reason, preload loss occurs. Although the initial preload is set to a large value in consideration of such thermal expansion, the preload adjustment alone cannot absorb all of the expansion due to the temperature rise, and cannot reliably prevent the preload from dropping out.

An object of the present invention is to provide a tapered roller bearing which can prevent preload loss due to a rise in temperature during operation and is easy to handle.

[0006]

The tapered roller bearing according to the present invention is provided with a ring-shaped plate having an annular notch groove at the corner between the thick side width surface and the outer diameter surface of the outer ring, and a J-shaped cross section. A spring is provided. In this J-shaped leaf spring, the outer peripheral portion is a curled portion that fits in the notch groove, and the inner peripheral portion is fixed to the width surface of the outer ring. The J-shaped leaf spring has a dimension in which the axial width of the curled portion in the natural state is larger than the axial depth of the cutout groove.

[0007]

The tapered roller bearing according to the present invention is mounted on the inner diameter surface of the housing in a preloaded state in which the curl portion of the J-shaped leaf spring is pressed against the axial locking surface of the housing. When the temperature rises due to the operation, the axial gap between the outer ring of the bearing and the locking surface of the housing increases due to the difference in the coefficient of linear expansion between the housing and the shaft. The curl resiliently restores and maintains contact with the locking surface. Therefore, preload loss is prevented. Since the J-shaped leaf spring is fixed to the outer ring, this bearing can be easily handled as a single component similarly to a normal bearing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. The tapered roller bearing 1 is of a type in which a rolling element 5 held by a retainer 4 is interposed between an inner ring 2 having a flange and an outer ring 3 having no flange. The outer ring 3 has an annular cutout groove 6 at a corner between the thick side width surface 3a and the outer diameter surface.
And a ring-shaped leaf spring 7 having a J-shaped cross section, into which the curl portion 7a on the outer periphery is loosely fitted. The J-shaped section leaf spring 7 is fixed to the width surface 3a by a flat inner peripheral portion 7b. The J-shaped leaf spring 7 may be a split ring divided at one or more locations in the circumferential direction.

The J-shaped section leaf spring 7 is formed of a metal plate such as stainless steel, and the dimensional relationship is set as follows. That is, in the natural state (no-load state), the axial width A of the curl portion 7a is equal to the axial depth H of the cutout groove 6.
Formed larger than, and curled portion 7a are separated by a gap [delta] ₁ from the axial direction of the groove bottom surface of the notched groove 6. Therefore, the curled portion 7a projects in the width direction from the outer ring 3 more than the inner peripheral portion 7b, and the initial projection amount δ ₀ is larger than the gap δ ₁ .

Due to this dimensional relationship, the spring characteristics when an external force W in the axial direction (FIG. 1) is applied, as shown in FIG.
Three different spring stiffnesses. That is, until the curled portion 7a contacts the bottom surface of the cutout groove 6 of the outer race 3 at the point c as shown in FIG. The spring stiffness is low as shown by the curve from the origin O to the point a. After the contact, the curl portion 7a becomes rigid until the point b is reached, that is, until the housing 8 hits the inner peripheral portion 7b as shown in FIG. After point b, the outer ring 3 is pushed by the housing 8 via the flat inner peripheral portion 7b of the J-shaped leaf spring 7, so that there is no displacement δ of the J-shaped leaf spring 7 with respect to the external force W.

FIG. 2 shows an example in which the bearing 1 of FIG. 1 is incorporated in an automobile transmission. The shaft 9 serves as an output shaft or an input shaft, and has a gear (not shown) on its outer periphery.
Is installed. The tapered roller bearing 1 is provided with a pair of 1A and 1B facing each other at both ends of a shaft 9 so as to face each other. In this case, each tapered roller bearing 1 (1A, 1A)
B), the inner ring 2 is mounted to the shaft end small diameter portion 9a of the shaft 9 in a press-fit state, the outer ring 3 is loosely fitted to the inner diameter surface portion 8a formed by the cylindrical portion of the housing 8, and the J-shaped leaf spring 7 is mounted. The housing 8 is engaged with the axial locking surface 8b.

The initial preload applied to the tapered roller bearings 1A and 1B is such a displacement amount that the curled portion 7a of the J-shaped leaf spring 7 lightly contacts the bottom surface of the cutout groove of the outer ring 3 as shown in FIG. (Displacement amount at point a in FIG. 4).
This preload is dimensionally controlled by a shim or the like.

A state in which a thrust load F is applied to the shaft 9 from the meshing gear will be described. In the case of normal temperature (initial preload setting state), the J-shaped leaf spring 7 of the bearing 1A on the thrust load side is further displaced, and receives the thrust load in the range from the point a to the point b in FIG. The bearing 1B on the anti-thrust side feeds the outer ring 3 by the elastic restoring force in the range from the origin O to the point a in FIG.
No gap is generated between b. Therefore, no gap is formed between the rolling element 5 and the rolling surface in the bearing 1B.

When the temperature is high, the initial preload set at the point a in FIG. 4 is changed by the expansion of the housing 8 made of an aluminum alloy or the like into a preload state corresponding to the spring displacement δ and the load W at the point d. Become. At this time, no gap is formed between the J-shaped section leaf spring 7 and the locking surface 8b of the housing 8. With the thrust load F from the gear, the J-shaped leaf spring 7 of the load-load-side bearing 1A receives the thrust load in the range from the point a to the point b as in the case of normal temperature. Even at this time, the anti-thrust side bearing 1
No gap B occurs.

When the thrust load F is abnormally large, the engaging surface 8b of the housing 8 is connected to the bearing outer ring 3 via the flat inner peripheral portion 7b of the J-shaped leaf spring 7 as shown in FIG. Since the pressing is performed, breakage of the J-shaped section leaf spring 7 is prevented.

As described above, in the tapered roller bearing 1, when the pair of bearings 1A and 1B are arranged facing the housing 8 as a transmission bearing, a thrust load due to a rise in the temperature of the housing 8 and meshing of gears is applied. No bearing gap occurs. In addition, since the tapered roller bearing 1 has the J-shaped leaf spring 7 fixed to the outer ring 3, it can be handled as an integral part like a general bearing, and can be incorporated into the housing 8 or used for other operations. Good handling. Further, the spring stiffness of the J-shaped leaf spring 7 can be set in advance to a stiffness according to the transmission in which the bearing 1 is installed by appropriately setting the material, the plate thickness, and the like.

In the above embodiment, the J-shaped leaf spring 7 has the curled portion 7a separated from the bottom surface in the axial direction of the cutout groove 6 of the outer race 2 in a natural state. However, as shown in FIG. 7a may be in contact with the axial bottom surface of the notch groove 6.

[0018]

[Effects of the Invention] The tapered roller bearing of the present invention is provided with an annular notch groove at the corner between the thick side width surface and the outer diameter surface of the outer ring and a J-shaped leaf spring. By incorporating the curled portion of the J-shaped cross-section leaf spring into the housing in a compressed state, even if the gap between the bearing outer ring and the axial locking surface of the housing increases due to thermal expansion of the housing due to operation, the curled portion is prevented. The contact is maintained by the elastic restoration of the preload, and the preload is prevented from coming off. Moreover, since the J-shaped leaf spring is fixed to the outer ring, this bearing can be handled as an integral part, and is easy to handle.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a tapered roller bearing according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a usage example in which the bearing is incorporated in a housing of a transmission.

FIG. 3 is an operation explanatory view of the tapered roller bearing.

FIG. 4 is a characteristic diagram of a J-shaped leaf spring in the tapered roller bearing.

FIG. 5 is a sectional view of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Tapered roller bearing, 2 ... Inner ring, 3 ... Outer ring, 3a ... Thick side width surface, 5 ... Rolling element, 6 ... Notch groove, 7 ... J-shaped leaf spring, 7a ... Curl part, 7b ... Inner peripheral part, 8 ... housing,
9 ... axis

Claims (1)

(57) [Scope of request for utility model registration] An annular cutout groove is provided at a corner between a thicker width surface and an outer diameter surface of an outer ring, an inner peripheral portion is fixed to the width surface of the outer ring, and an outer peripheral portion fits into the notch groove. A tapered roller bearing provided with a ring-shaped leaf spring having a substantially J-shaped cross-section serving as a rounded curl portion, wherein an axial width of the curled portion in a natural state of the leaf spring is larger than an axial depth of the cutout groove.