JPS6410690B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a thrust tapered roller bearing,
In particular, the shape of the collar surface of the bearing raceway is made spherical, the radius of curvature of the end surface of the roller head is made smaller than the radius of curvature of the collar surface, and a lubrication hole is formed at the boundary between the raceway surface and the collar surface of the bearing ring. The thrust load capacity is greatly increased by providing an opening.

For example, a thrust tapered roller bearing with a small volume and large thrust load capacity is suitable as a thrust bearing for a roll neck of a rolling mill, but in recent high-load rolling operations, the thrust load generated on the rolls becomes extremely large. In conventional thrust tapered roller bearings, the contact between the large end face of the roller (end face of the head) and the collar face of the raceway is not appropriate for such a large thrust load, and the contact between the large end face of the roller and the raceway is not appropriate. Because there is insufficient lubrication between the ring and the collar surface, heat generated by sliding friction is not sufficiently removed, leading to early seizures.

This invention was made in order to eliminate the above-mentioned drawbacks, and an object of the invention is to make the contact state between the large end surface of the roller and the collar surface of the bearing ring appropriate,
It is an object of the present invention to provide a thrust tapered roller bearing that can effectively eliminate heat generation from sliding friction surfaces, and an object of the present invention is to provide a thrust tapered roller bearing that has a large load capacity.

That is, the present invention, as shown in the illustrated embodiment, includes an annular inner ring 41 fitted to a roll neck 12 of a rolling mill, and two rings arranged to sandwich the inner ring 41 and fitted into housings 14 and 15. In a thrust tapered roller bearing 40 in which tapered rollers 48 are rotatably disposed between two outer rings 44 to support the roll neck 12 in the axial direction, the bearing ring contacts the large end surface 49 of the tapered rollers 48. 44
The flange surface 47 of the housing is formed into a spherical shape, and the radius of curvature Rr of the large end surface 49 of the tapered roller 48 is set in the range of 70 to 85% of the radius of curvature Rf of the flange surface 47 of the bearing ring 44. A thrust tapered roller bearing characterized in that a plurality of oil supply holes 60 are bored in communication with the oil passages 64 of Nos. 14 and 15 and open at the boundary between the raceway surface 45 and the collar surface 47 of the bearing ring 44. Related.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which reference numeral 10 indicates a roll of a rolling mill, 12 indicates a roll neck, and 14 and 15 indicate a housing.
The large diameter portion 12a of the radial tapered roller bearing 1
6. It is supported radially by 6. The radial tapered roller bearing 16 has two double-row inner rings 17, 2.
It consists of two single-row outer rings 18, one double-row outer ring 19, and four rows of tapered rollers 20. 21 is a retainer, 22 is an outer ring spacer, and 23 is an inner ring spacer. Single row outer ring 18
is positioned in the axial direction by a presser member 25 and a presser ring 26 fitted into the housing 14. Two seals 2 are attached to the presser member 25.
8 is fitted through a spacer 29, and the lip of the seal 28 is brought into sliding contact with the outer peripheral surface of a fillet ring 30 fitted to the shoulder of the roll 10 and the large diameter portion 12a of the roll neck 12. Further, a seal 31 is fitted onto the axial end of the presser member 25 by a seal presser 32 and slidably contacts the fillet ring 30.
A seal 3 is installed between the seal presser foot 32 and the roll 10.
3 is provided. Reference numeral 34 denotes an oil supply hole through which lubricating oil is forced to circulate.

A thrust tapered roller bearing 40 of the present invention is provided in the middle diameter portion 12b of the roll neck 12.
In this bearing, an annular intermediate ring 41 is fitted into the middle diameter portion 12b of the roll neck 12, and collars 42 and 43 are brought into contact with both end surfaces of the ring to form an inner ring. The outer rings 44 with flanges arranged to sandwich the inner ring 41 are fitted to each other, and the tapered rollers 48 are brought into rolling contact between the raceway surface 45 of the outer ring 44 and both end surfaces of the inner ring 41, thereby forming the roll neck 12. It is constructed as a double-row thrust bearing that supports the shaft in the axial direction. 51
52 is a cage that holds and guides the tapered rollers 48;
is a spacer for positioning the outer ring 44, and the spacer 5
2 is provided with an oil passage hole 53, and the lower part of the housing 14 is provided with an oil drain hole 5 that communicates with the oil passage hole 53 of the spacer 52.
A plurality of numbers 5 are provided.

In the above bearing, the large end surface 49 on the head side of the tapered rollers 48 has a spherical shape, and the guide surface (flange surface) 47 of the collar 46 of the outer ring 44 that comes into sliding contact with this large end surface 49 is also spherical. Form into shape.
Then, the radius of curvature (roller head radius) Rr of the large end surface 49 of the tapered roller 48 is set smaller than the radius of curvature (flange surface radius) Rf of the collar surface 47 of the outer ring 44 (see FIG. 2). The ratio Rr/Rf of the roller head radius Rr and the rib surface radius Rf is 0.7 to Rf as described below.
It shall be selected as appropriate within the range of 0.85.

Figure 3 shows that the inventors manufactured test bearings with several different dimensions and conducted critical thrust load tests on the bearings with various changes in the ratio Rr/Rf of the roller head radius Rr and the rib surface radius Rf. The results are shown in a diagram. In the same figure, when the vertical line is the limit thrust load ratio (the ratio of the limit thrust load to the dynamic load rating of the bearing) and the horizontal axis is the ratio of the roller head radius to the rib surface radius, line a is 200 rpm, line b is 400rpm, c
Each line shows the case of 600 rpm. As is clear from this diagram, the critical thrust load ratio increases markedly when Rr/Rf exceeds 70%, reaches its maximum at 85%, but decreases when it exceeds 85%. Thus, it can be seen that by setting Rr/Rf to 0.7 to 0.85, the contact condition between the large end surface of the tapered roller and the rib surface of the outer ring, which is one of the factors that restricts the thrust load capacity, is improved.

The outer ring 44 also includes a raceway surface 45 and a collar surface 47.
Oil supply hole 60 that opens at the boundary part (grinding part) with
A plurality of oil supply holes 60 are bored from the back side, and these oil supply holes 60 are communicated with oil passages 64 provided in the housings 14 and 15. In this embodiment, an oil supply hole 62 is provided which opens in the raceway surface 45 on the tail side of the tapered roller 48, but this oil supply hole 62 may be omitted.

Furthermore, two seals 65 are disposed on both sides with a spacer 65 interposed between the housing 15 and the collar 43 for sealing.

The thrust tapered roller bearing 40 having the above configuration is lubricated by using lubricating oil in the housing 1.
The oil supply hole 6 of the outer ring 44 passes through the oil passages 64 of 4 and 15.
The lubricating oil that is injected from zero and circulated inside the bearing passes through the oil passage hole 53 of the spacer 52 and is discharged to the outside from the oil drain hole 55 of the housing 14. The oil supply hole 60 of the outer ring 44 is located between the raceway surface 45 and the collar surface 47 of the outer ring 44.
Since the lubricating oil is provided at the boundary between the tapered rollers 48 and the flange surface 47, the lubricating oil is injected toward the sliding surface formed between the large end surface 49 of the tapered roller 48 and the flange surface 47 of the outer ring 44. This results in proper lubrication of the friction surfaces between the parts. Further, when the oil supply path is provided on the tail side of the tapered rollers 48, the lubrication between the raceway surfaces of the outer ring 44 and the inner ring 41 and the rolling surface of the tapered rollers 48 can be performed more appropriately.

In the above embodiment, the end face of the intermediate ring is used as the raceway surface of the inner ring, and the outer ring is provided with a collar. It is also possible to have both the inner ring and the inner ring configured as described above.

As explained above, according to the present invention, the contact state between the large end surface of the tapered roller and the collar surface of the bearing ring becomes appropriate, and the heat generation due to sliding friction on these surfaces can be suppressed to a minimum. Instead, the lubricating oil can be spread directly between the large end face of the tapered rollers and the collar face of the raceway ring, making it possible to eliminate heat generation due to sliding friction extremely effectively. Since the thrust load capacity can be greatly increased, a tapered roller thrust bearing is most suitable for use, for example, in the roll neck of a rolling mill where a large thrust load is generated.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the present invention, FIG. 2 is an enlarged view of the main part thereof, and FIG. 3 is a diagram showing the critical thrust load ratio. In the figure, 12 is a roll neck, 14 and 15 are housings, 40 is a thrust tapered roller bearing, 41 is an inner ring, 44 is an outer ring, 45 is a raceway surface of the outer ring, 47 is a collar surface of the outer ring, 48 is a tapered roller, and 49 is a tapered roller bearing. The large end surface of the roller, 60 is the oil supply hole, Rr is the radius of curvature of the large end surface of the tapered roller, and Rf is the radius of curvature of the rib surface of the outer ring.

Claims (1)

[Claims] 1. Tapered rollers are disposed such that they can freely roll between an annular inner ring fitted to the shaft and two outer rings arranged to sandwich the inner ring and fitted to the housing. In a thrust tapered roller bearing supported in the direction, the collar surface of the bearing ring that contacts the large end surface of the tapered roller is formed into a spherical shape, and the radius of curvature of the large end surface of the tapered roller is equal to the curvature of the collar surface of the bearing ring. It is characterized by having a plurality of oil supply holes set in a range of 70 to 85% of the radius, and further communicating with the oil passage of the housing and opening at the boundary between the raceway surface and the collar surface of the raceway ring. Thrust tapered roller bearing.