JPS5934019A - Multiple-row thrust conical roller bearing - Google Patents

Abstract

PURPOSE:To avoid a differential slide of a conical roller by setting an intersecting point of generating lines of planes of orbits of inner and outer races of a bearing and a cone center of the conical roller in such a manner that at least the intersecting point of the generating lines of the planes of orbits is offset from the central axis of the bearing. CONSTITUTION:A bearing comprises an inner race formed by fitting a countershaft 1 to a rotary shaft and bringing collars 42, 43 into contact with both side end surfaces thereof to be positioned and fixed, and a conical roller 48 rotatably interposed between both side end surfaces of the inner race and the plane 45 of an orbit of an outer race 44. In this case, an intersecting point P2 of generating lines of planes 41a, 45 of orbits of the inner race 41 and the outer race 44 is set to be on the left side of the central axis O-O, and the cone center P1, of the conical roller 48 is set to be on the right side of the central axis O-O. In this arrangement, an angle eta formed by the generating lines of each plane 41a, 45 of an orbit is smaller than the conical angle 2beta of the conical roller 48 by an angle theta of inclination of the inner race 41 so as to prevent the occurrence of a differential slide between the rolling surface of the conical roller 48 and the planes 41a, 45 of orbits.

Description

Detailed Description of the Invention The present invention relates to a double-row thrust tapered roller bearing, and particularly to a thrust tapered roller bearing in which the end face of the inner ring of the bearing is fixed to the shaft via a collar. By making an offset configuration in which at least the intersection of the generatrix of the raceway surface is shifted by the center axis force of the bearing, among the intersection of the generatrix and the cone center of the tapered roller,
The thrust load capacity is greatly increased by reducing the generation of edge load and heat generation at the rolling contact surface of the tapered rollers caused by the axial deflection of the inner ring.

For example, double-row thrust tapered roller bearings with a small volume and large thrust recoil capacity are suitable as thrust bearings for the roll neck of a rolling mill. Becomes extremely dog-like. In conventional double-row thrust tapered roller bearings, when such a large thrust load is applied, the load distribution between the rolling surface on the tail side of the tapered roller and the raceway surface becomes high, and edge load occurs. It had the disadvantage that it could not withstand long-term use, such as generating abnormally high heat and causing firing accidents.

In order to investigate the cause of this phenomenon, various experiments were repeated and it was found that it was caused by the axial deflection of the inner ring.

In other words, edge load is caused by the tail of the tapered roller (ill) coming into strong contact with the raceway surface due to the deflection of the inner ring, and is particularly likely to occur if the crowning shape of the tapered roller is not appropriate. Due to the deflection, the intersection point of the generatrix of the inner ring raceway surface and the outer ring raceway surface shifts from the center axis (rotation center) of the bearing, so the tapered rollers in contact with the raceway surface are also displaced, causing their cone centers to shift from the center axis and roll. When we investigated the cause of the axial deflection of the inner ring, we found that the conventional inner ring has a thin wall thickness, and the collar for positioning the inner ring is thin. We came to the conclusion that this is because the inner ring's fixing force was insufficient due to the low end face height, resulting in a state close to free support.Incidentally, the conventional inner ring and collar end face The surface pressure on the rib 30 is 77 mA or more, and the maximum deflection amount of the inner ring in this case is 15 to 40 times that of the case where the inner ring is freely supported and calculated by 1-1.

This invention has been made in view of the above-mentioned viewpoints, and an object of the invention is to generate edge loads at the rolling contact surface between the tapered rollers and the bearing ring even when the inner ring is deflected in the axial direction. Another object of the present invention is to provide a double-row thrust tapered roller bearing that has a large load capacity.

That is, the present invention can be applied to a shaft (roll neck), for example, as in the illustrated embodiment of a rolling mill roll neck.
12 between shoulder 16 and collar 16 or between collar 4
2.43 Inner ring 41 positioned and fixed by sandwiching 1C between each other
Tapered rollers 48 are arranged in double rows through a cage between the outer ring 44 and the outer ring 44 fitted to the housing 14.15. 44
orbital surface 41a.

In the thrust tapered roller bearing 40 in which at least one of the inner ring 41 and the outer ring 44 is crowned, the intersection point I]2 of the raceway surfaces 41a of the inner ring 41 and the outer ring 44, and the generatrix of 45
A double-row thrust tapered roller bearing characterized in that, between the cone center P1 of the tapered roller 48 and the intersection point P2 of the generatrix of the raceway surfaces 41a and 45, the center axis of the bearing is 0-0 to h. Pertains to.

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 is a roll of a rolling mill, 12 is a roll neck, 14.
15 shows the housing 14
The large diameter portion 12a of the roll neck 12 is supported in the radial direction by a radial tapered roller bearing 16.
7, 2 jljl outer rows 18, 1 double row outer ring 19, 4
It consists of a row 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 18i1'
, 1... Fitted into the housing 14, but not positioned in the axial direction by the presser member 25 and the presser ring 26)9.
ing. There are two seals 28 on the presser member 25 and a spacer 29.
The shoulders of the roll 10 and the roll neck 1
The lip of the seal 28 is brought into sliding contact with the outer circumferential surface of the fillet ring 30 that fits into the large diameter portion 12a of No. 2, and
A seal 61 is fitted onto the axial end of the presser member 25 by a seal presser 62 so as to be in sliding contact with the fillet ring 30, and a seal 66 is provided between the knoll presser 32 and the roll 10.

Reference numeral 64 denotes an oil supply hole through which lubricating oil is forced to circulate.

The small diameter portion 121) of the roll neck 12 is provided with a thrust tapered roller holder 40 of the present invention.

This Iqi receiver fits the intermediate ring 41 into the small diameter portion 121 of the roll neck 12, and has collars 42 and 46 on both end surfaces.
are brought into contact and positioned and fixed to form the inner ring, and bouncing 1
4. Fit the outer ring 44 with a collar to 15 and h7 respectively,
Tapered rollers 48 are movably brought into contact between the raceway surface 45 of the outer ring 44 and both end surfaces of the inner ring 41 to form a double-row thrust bearing that supports the roll neck 12 in the axial direction. 51 is a cage that holds and guides the tapered rollers 48; 52 is a spacer for positioning the outer ring 44; the spacer 52 is provided with an oil passage hole 56; A plurality of oil drain holes 55 communicating with the hole 53 are provided.

Outer ring 44 slidingly contacts large end surface 49 of tapered roller 48 mentioned above
The guide surface (flange surface) 47 of the collar 46 is formed into a spherical shape, and the radius of curvature of the large end surface 49 of the tapered roller 48 is the same as that of the outer ring 4.
The outer ring 44 has a raceway surface 45 between the large end surface 49 of the tapered roller 480 and the collar surface 47 of the outer ring 44 by setting the radius of curvature of the collar 47 in the range of 70 to 85%. Oil supply hole 6 opened at the boundary with the flange surface 47 (grinding part)
A plurality of oil supply holes 60, 62 opening in the raceway surface 45 on the tail side are formed from the rear side, and the oil supply holes 60, 62 are provided in the housing 14, 15. 64
The two sleds are connected to each other.

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 above-mentioned thrust bearing 40 is lubricated by using lubricating oil as an oil jet and injecting it from the oil supply hole 60.62 of the outer ring 44 through the oil passage 64 of the housing 14.15. 7! Lubricates the sliding surface between the A ring 49 and the collar 47 of the outer ring 44, and lubricates the contact surface between the raceway surfaces of the inner ring 41 and outer ring 44 and the transfer surface of the tapered rollers 48 through the oil supply hole 62. After circulating inside the bearing, the oil passes through the oil passage hole 56 of the spacer 52 and is discharged to the outside from the oil drain hole 55 of the housing 14.

A so-called offset configuration is provided between the intersection of the generating lines of the raceway surfaces 41 a * 45 of the inner ring 41 and the outer ring 44 of the thrust bearing 40 and the cone center of the tapered rollers 48 . In other words, in conventional bearings, the second
As shown in Figure (a), when the bearing is under no load, the cone center P1 of the tapered roller 48, the inner ring 41, and the outer ring 4
4 and the orbital surface 41a.

The intersection point P2 of the generatrix of 45 coincides with the center axis O-0 of the bearing, but now the inner ring 41 is bent in the axial direction and tilted by an angle θ to the position shown by the broken line, and the generatrix of the rolling surface of the tapered rollers 48 Assuming that P coincides with the generatrix of the raceway surface 45 of the outer ring 44, P2 is the center axis. − p shifted by distance X from 〇
/2 position.

ILa -1γ fanθ cosβ tan 2β+tanθ where K, Ra - length between the large end face of the tapered roller and the cone center PIP3) lγ = generatrix length of the rolling surface of the tapered roller (P3I'4) 2β
- Tapered angle of tapered rollers In this way, as a result of the intersection point I)2 between the cone center Pl and the raceway surface generating line being shifted from the center axis (')-0, there is a difference between the transfer surfaces of the tapered rollers 48 and the transfer surfaces. Dynamic slip will occur.

Therefore, as shown in FIG. The raceway surface 41 a of the inner ring 41 and the outer ring 44 is located on the right side of the central axis 11JO-0.

45 is made smaller than the conical angle 2β of the tapered rollers 48 by the inclination angle θ of the inner ring 41, η-2
Let β−θ.

Curve the distance from the center axis 0-0 of the intersection point 1)2 of the cone center P1 and the raceway surface generatrix.'11. s,,s2
Then, S 1”' Ra @θ・5in2β 52=T′La#θ(casec (2β−θ)−si
n2β] Here, Ra = P 1P g = P 6
P 3 Therefore, when the inner ring 41 of the bearing set in this way bends in the axial direction under the thrust load and tilts by an angle θ as shown by the broken line, the tapered rollers 48 also tilt by the same angle and the cone center P.

The intersection point P2 of the raceway surface generatrix is a point P on the central axis 0-0. Since K coincides, the angle η0 formed by the generatrix of the raceway surfaces of the inner ring 41 and the outer ring 44 under load is equal to the conical angle 2β of the inner tapered roller 48. As a result, no differential slip occurs between the rolling surface of the tapered rollers 48 and the raceway surface.

Although the offset in the above embodiment is provided at both the generatrix intersection of the raceway surface and the cone center of the tapered roller, at least the generatrix intersection of the raceway surface may be offset.

In fact, the rolling surface of the tapered rollers 48 of the above-mentioned bearing is rounded as shown in FIG. 3.

The total effective length of the tapered roller 48 is tl, the head 48a and the tail 4
81] respectively, and the length of the intermediate portion 48c is +2, the intermediate portion 48C has a crowning with a radius of curvature R2, and the head portion 48a and the tail portion 481) have a radius of curvature R.
1 is crowned, and the generatrix of the intermediate portion 48c and the generatrix of the head portion 48a and the tail portion 48b meet the intersection point A.
, B are circular arcs having a common tangent line. and,
The length +2 of the intermediate portion 481) is l for the total effective length tγ.
z = 0.74γ, and the radius of curvature R2 of the intermediate portion 48c
For example, the radius of curvature T1 of the head portion 48a and the tail portion 48b. , let n be ≧301 octopuses. By crowning the entire transfer surface of the tapered roller 48 and making the radius of curvature at both ends of the head 48a and tail 48b significantly smaller than the radius of curvature t2 of the intermediate portion 48c, the tapered roller 48 The occurrence of edge load in terms of transfers can be suppressed.

The above crowning may be applied to the raceway surfaces of the inner ring and the outer ring, or may be applied to both the tapered rollers and the inner ring and the outer ring.

Furthermore, in the above bearing, in order to suppress the deflection of the inner ring 41 in the 1lQf+ direction, the wall thickness of the inner ring 41 is set as follows. In Fig. 4, the wall thickness of the inner ring 41 is W1.
Let H be the length in the radial direction from the inner circumferential edge of the inner ring 41 to the intersection point C between the raceway surface 41a of the inner ring 41 and the extension line of the generatrix of the large end surface 49 of the tapered roller 48 that contacts this (the contact upper limit height). The wall thickness W is increased so that W/II≧08. The upper limit value of W/IT is limited by the allowable range of space provided in the bearing portion, but can be up to about 11.

Further, the radial clearance IIC between the inner peripheral edge of the inner ring 41 and the inner peripheral edge of the cage 51 and the upper limit contact height I of the inner ring 41
-1, the ratio II c /I-1 is 11c/I-1≧0
．． 26. Regarding the upper limit of ITc/II,
If 11c is made too large, the length of the cone 48 will decrease relative to the given contact upper limit height + 1, which may lead to a decrease in the bearing rated load. Although it is necessary to select it appropriately, it can be set to about 0.35. By increasing the radial clearance T-Ic in this manner, the height of the end surface of the collar 42, 43 for positioning the inner ring 41 can be increased to abut against both end surfaces of the inner ring 41.

By setting the dimensions of the inner ring 41 and the collars 42 and 43 as described above, the bending rigidity of the inner ring 41 itself increases, and the roll neck 121) of the inner ring 41 can be supported firmly and fixedly. Even if a large thrust load acts on the inner ring 41, the axial deflection of the inner ring 41 can be reduced. However, the structure for regulating the thickness of the inner ring and the structure for regulating the height of the end surface of the collar can be omitted if necessary.

In the above embodiment, collars 42.4 are provided on both end surfaces of the inner ring 41.
However, one collar 42 is omitted and the roll neck 12 a (f
The same can be applied to a bearing in which the end face of the illumination is fixed by abutting against the shoulder 16 of the roll neck 12;1.

As described above, the present invention supports the shaft in the axial direction by disposing tapered rollers between both end surfaces of the inner ring positioned and fixed to the ill+ via the collar and the outer ring on the housing side. In a thrust tapered roller bearing in which at least one of the rolling surface of the tapered rollers and the raceway surface of the raceway ring is crowned, at least one of the intersection of the generatrix of the raceway surface and the circle 1 - the cone center of the tapered roller, An offset configuration is used in which the generatrix intersection point is shifted from the center axis of the bearing. Therefore, according to this invention, when the inner ring receives a large thrust load and deflects in the axial direction, the intersection point of the generatrix of the raceway surface and the cone center of the tapered rollers coincide on the central axis of the bearing. , it is possible to avoid differential sliding of the tapered rollers, and it is not only possible to effectively suppress heat generation due to sliding friction at the rolling contact surface between the tapered rollers and the raceway surface, but also to prevent the tapered rollers and the raceway ring from If the shape of the crowning is appropriately selected, it is also possible to prevent the occurrence of edge lobes, so the thrust load capacity is greatly increased, making it the most suitable for roll necks of rolling mills where large thrust loads occur. A suitable double row thrust tapered roller bearing is obtained.

[Brief explanation of drawings]

Fig. 1 is a longitudinal side view showing an embodiment of the present invention, Fig. 2 shows the positional relationship between the cone center of the tapered roller and the intersection of the raceway surface generatrix of the bearing ring, and (Xl) in the same figure shows the offset. Figure 3 is a generatrix diagram of the rolling surface of the tapered roller of the present invention, and Figure 4 is a diagram showing the relationship between the inner ring, the force, and the roller. FIG. 3 is a cross-sectional view showing related dimensions. In the figure, 12 is the roll neck (shaft), 13 is the shoulder of the roll neck, 1'4, 15 housing, 4° is the thrust bearing, 41 is the inner ring, 41a is the raceway surface of the inner ring, 42.43 is the collar, 44 is the outer ring, 45 icl, the raceway surface of the outer ring, 48
is the tapered roller %T'l is the circle-4-cone center of the tapered roller, L)2 is the intersection of the generatrix of the raceway surfaces of the inner ring and outer ring, 0-
0 is the center axis of the bearing. Patent applicant: NSK Ltd. Mitsubishi Heavy Industries, Ltd. Representative Patent attorney: Tetsuya Mori, patent attorney
Yoshiaki Katsu, Patent Attorney Masaru Shimizu, Patent Attorney Masaru Kajiyama Figure 3: No. 1, Marunouchi 2-chome, Chiyoda-ku, Tokyo

Claims (1)

[Claims] (]) Tapered rollers are arranged in a cage between an inner ring that is positioned and fixed between the shoulder of the shaft and the collar or between the collars, and an outer ring that is fitted into the housing. In the thrust tapered roller 1 front receiver, which is arranged in double rows through the tapered rollers and crowned on at least one of the transfer surface of the tapered rollers and the raceway surfaces of the inner ring and the outer ring, the generatrix of the raceway surface of the inner ring and the outer ring is A double-row thrust tapered roller bearing, characterized in that the intersection of the cone center of the tapered rollers, the cone center of the tapered rollers, and the generatrix of the raceway surface is at least a distance from the center axis of the bearing. (2) Crowning with different radii of curvature and having a common tangent to the generatrix is applied to the intermediate portion of at least one of the transfer surfaces of the tapered rollers and the raceway surfaces of the inner ring and outer ring, and to both ends of the head side and the tail side. The double-row thrust tapered roller bearing according to claim 1, wherein the intermediate portion is 70 times the total effective length of the tapered rollers, and the radius of curvature of the intermediate portion is 30 times or more of the radius of curvature of both ends.