GB1562181A - Method for assembling spherical roller bearings - Google Patents

Description

(54) METHOD FOR ASSEMBLING SPHERICAL ROLLER BEARINGS (71) We, LSB INDUSTRIES, INC., a corporation of the State of Delaware, United States of America, of 16 South Pennsylvania, Oklahoma City, Oklahoma 73101, United States of America. do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates generally to an improved method for assembling a spherical roller bearing and, more particularly, but not by way of limitation, to a method for assembling a spherical roller bearing by temporarily deforming the outer race ring to facilitate insertion of the inner race assembly.

Various methods for assembling balltype bearing assemblies requiring temporary deformation of the outer race ring have been disclosed in the following U.S. Patents: 2,633,627, issued to Olmstead: 2,885,767, issued to Barish; and 3,783,482, issued to Kunert et al. An analogous method for assembling a self-aligning rod end bearing is taught in U.S. Patent No.

3,068,551, issued Cobb. In contrast, present methods for assembling spherical roller bearing assemblies, such as that taught in U.S. Patent No. 1,906,259, issued to Gibbons, teach the insertion of a partially assembled inner race assembly directly into the outer race ring, with the remaining bearing roller elements being inserted into their respective pockets in a subsequent operation. However, the inherit deficiences in multi-part cage assemblies, such as those taught in the Gibbons reference cited immediately above and in U.S. Patent No.

2,989,353, issued to Nyberg, has led to the widespread use of integral cages such as those taught in the following U.S. Patents: 2,611,669 issued to Palmgren; 2,611,670 issued to Palmgren; 2,705,176 issued to Palmgren: 2,805,108 issued to Palmgren: 3,022,125 issued to Bratt et al.; 3,046,065 issued to Lobeck et al.; 3,046,066 Issued to Lobeck et al.; 3,307,889 issued to Grange: 2,430,397 issued to Hendricks; 3,495.888 issued to Greiner et al.; 3,912,346 issued to Boratynski et al.: and 3,990,753 issued to Kellstrom et al. Unfortunately, present methods for assembling spherical roller bearings employing such integral cages usually require substantial amounts of additional labor as well as highly specialized equipment for inserting the spherical bearing roller elements following insertion of the incomplete inner race assembly into the outer race ring. In addition, the use of such assembly methods in conjunction with window-type cages, such as those taught in the Palmgren references (No. 2,705,176 and No. 2,805,180), and in the Boratynski reference (No. 3,912,346), demand very close machining tolerances in the manufacture of such cages while still introducing substantial likelihood of burnishing or plastically deforming either the roller elements or inner raceway, or both, in the final assembly process.

An object of the present invention is to provide a highly efficient method for assembling spherical roller bearings.

Another object of the present invention is to provide a method for assembling spherical roller bearings wherein the cage tolerances are less stringent.

Yet another object of the present invention is to provide a method for assembling spherical roller bearings wherein the likelihood of plastically deforming the spherical bearing rollers and the inner raceway is minimized.

According to the invention there is provided a method for assembling a spherical roller bearing from: an outer race ring having a spherical section, outer raceway of predetermined diameter about a center of curvature concentric with the center of the outer race ring and of a predetermined chordal height.

the axis of the outer race ring defining a bearing axis and an inner race assembly including: an inner race ring having at least one toric section.

inner raceway of predetermined diameter about a center of curvature lying on a predetermined pressure axis extending through the center of the inner race ring, the axis of the inner race ring defining an axis of rotation; a plurality of barrel-shaped spherical bearing rollers; and means for maintaining the bearing rollers in rolling engagement with the inner raceway: the method comprising the steps of: applying diametrically opposed forces to the outer race ring to elastically deform the outer race ring until the outer raceway assumes a substantially elliptical shape having a major axis in the plane perpendicular to the bearing axis at the center thereof exceeding the predetermined diameter of the outer raceway by at least .95 times the predetermined chordal height, said major axis and the bearing axis defining a plane of insertion; positioning the inner race assembly adjacent to the deformed outer race ring in an insertion position with the plane of insertion extending perpendicularly through the center of the axis of rotation; maintaining the inner race assembly in the insertion position while moving the inner race assembly into the deformed outer race ring until the center of the inner race ring coincides with the center of the outer race ring; removing the deforming forces applied to the outer race ring; and rotating the inner race ring about the axis of rotation while pivoting the inner race ring about the center thereof until the axis of the rotation is substantially coaxial with the bearing axis.

The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of a spherical roller bearing suitable for assembly using the preferred method of the present invention.

Figure 2 is a diagrammatic illustration of the inner race assembly being inserted into the outer ring which has been maximally deformed in accordance with the present method.

Figure 3 is a cross-sectional view of the illustration of Figure 2 taken along the line 3-3 therein, except that the outer race ring has been minimally deformed.

Referring to the drawings in general and to Figure 1 in particular, shown therein and referred to by the reference number 10 is a double-row spherical roller bearing which may be conveniently assembled using the preferred method of the present invention.

In particular, the bearing 10 is comprised generally of an outer race ring 12, and an inner race assembly 14: the inner race assembly 14 including an inner race ring 16.

a plurality of barrel-shaped spherical bearing rollers 18, a pair of bearing roller cages 20, and a center guide ring 22. The outer race ring 12 has a spherical section, outer raceway 24 of predetermined radius R1 about a center of curvature concentric with the center C1 of the outer race ring 12 and of a predetermined chordal height H. The chordal height H may be defined as the difference between the radius R1 of the outer raceway 24 and the minimum distance D between the outer raceway 24 and the axis A, of the outer race ring 12, the distance D being measured generally perpendicularly to the axis A1 at either of the shoulders 26 defining the highest latitudes of the outer raceway 24. For purposes of explanation it is convenient to consider the axis A, of the outer race ring 12 as defining the bearing axis..

The inner race ring 16 has a pair of oppositely inclined toric section, inner raceways 28 of predetermined radius R2 about centers of curvature C2 lying on predetermined pressure axes A2 extending through the center C3 of the inner race ring 16. Preferably, the radius of curvature R2 of the inner raceways 28 is substantially the same as the radius of curvature R, of the outer raceway 24. Again, for purposes of explanation, it is convenient to consider the axis A3 of the inner race ring 16 as defining an axis of rotation.

Each of the bearing rollers 18 is preferably symmetrical with a transverse curvature slightly less than the curvature of the raceways 24 and 28 and with a length substantially the same as the maximum diameter thereof. The cage 20, which is of the window-type, may be of any suitable shape in order to maintain each of the bearing rollers 18 in rolling engagement with a respective one of the inner raceways 28, with adiacent bearing rollers 18 being spaced at arcuate intervals thereabout. As will be clear to those skilled in the art, the bearing 10 is of substantially conventional construction, and is referred to herein merely for the purpose of illustrating the present method for assembling such spherical roller bearings 10.

In preparation for practicing the method of the present invention, each of the bearing rollers 18 are inserted into a respective one of the windows or pockets 30 formed in the periphery of the cage 20. With the center guide ring 22 in place, each filled cage 20 is thereafter disposed coaxially about the inner race ring 16 so as to bring the bearing rollers 18 into rolling engagement with respective inner raceways 28. Since all of the bearing rollers 18 are placed in the respective pockets 30 as an initial step in the assembly process, it is thus clear that the method of the present invention eliminates all possibility of broaching any of the windows 30 of the cages 20 and of burnishing any of the bearing rollers 18.

Either simultaneously with, or immediately following, assembly of the inner race assembly 14, the outer race ring 12 is disposed in a device capable of applying diametrically opposed forces to the outer race ring 12, such as the press 32 shown in Figure 2. Thereafter, the outer race ring 12 is elastically deformed until the outer raceway 24 assumes a substantially elliptical shape having a major axis A4 in the plane perpendicular to the bearing axis A1 at the center C, thereof. For reasons which will be made more apparent hereinafter, it is convenient to consider the major axis A4 and the bearing axis At as defining a plane of insertion.

Although the elastic limits of the outer race ring 12 will vary with the dimensions and materials of construction thereof, the outer race ring 12 may generally be deformed until the major axis A4 exceeds the normal diameter (2*R1) of the outer raceway 24 by at least about .95 times the chordal height H. On the other hand, the outer race ring 12 should not be deformed more than until the major axis A4 exceeds the normal diameter (2*R1) of the outer raceway 24 by 2.1 times the chordal height H. However, in order to minimize the possibility of damaging any of the components of the bearing 10 yet still maximize efficiency in assembly it is preferred that the major axis A4 exceed the diameter (2*R,) by from about .95 to about 1.1 times the chordal height H. If desired, conventional means, such as the travel stops 34, may be employed to limit the deformation of the outer race ring 12 to the desired limits.

As can be seen generally in Figures 2 and 3, the inner race assembly 14 is thereafter positioned generally adjacent to the deformed outer race ring 12 in an insertion position with the plane of insertion extending substantially perpendicularly through the center C3 of the axis of rotation A3. Taking care to maintain the inner race assembly 14 in the insertion position, the inner race assembly 14 may then be moved into the deformed outer race ring 12 until the center C3 of the inner race ring 16 generally coincides with the center C1 of the outer race ring 12.

If the outer race ring 12 has been maximally deformed, that is until the major axis A4 exceeds the normal diameter (2*R1) of the outer raceway 24 by at least 2.0 times the chordal height H, as shown in Figure 2, the inner race assembly 14 may be freely moved into the outer race ring 12 regardless of the orientation of the bearing rollers 18.

On the other hand, if the other race ring 12 has been only minimally deformed, that is until the major axis A4 exceeds the normal diameter (2*R1) of the outer raceway 24 by only .95 to 1.1 times the chordal height H, it will be necessary to "cock" the inner race assembly 14 by allowing adiacent bearing rollers 18 on one side of the inner race assembly 14 to straddle the shoulder 26, as shown in Figure 3, so that the bearing rollers 18 on the opposite side of the inner race assembly 14 will clear the opposite portion of the shoulder 26 upon further movement of the inner race assembly 14 toward concentricity with the outer race ring 12.

Once the inner race assembly 14 has been positioned concentrically with the outer race ring 12, the deforming forces applied to the outer race ring 12 via the press 32 may be removed, thereby allowing the outer race ring 12 to assume a normal configuration and bringing the outer raceway 24 into relative engagement with diametrically opposed sets of bearing rollers 18. Having thus effectively "assembled" the bearing 10, the inner race ring 16 need only be rotated about the axis of rotation A3 while simultaneously pivoting the inner race ring 16 about the centre C3 thereof until the axis of rotation A3 is substantially coaxial with bearing axis A1 As will be clear to those skilled in the art, the preferred method of the present invention embodies a highly efficient method for assembling spherical roller bearings in a manner which minimizes assembly steps and eliminates numerous opportunities for damaging the various elements comprising such bearings.

Although the present method has been described relative to a double-row, spherical roller bearing only, it will be clear that the present method may be employed with similar results in spherical roller bearings having different configurations.

WHAT WE CLAIM IS: 1. A method for assembling a spherical roller bearing from: an outer race ring having a spherical section, outer raceway of predetermined diameter about a center of curvature concentric with the center of the outer race ring and of a predetermined chordal height, the axis of the outer race ring defining a bearing axis; and an inner race assembly including: an inner race ring having at least one toric section, inner raceway of predetermined diameter about a center of curvature lying on a predetermined pressure axis extending through the center of the inner race ring,

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   respective pockets 30 as an initial step in the assembly process, it is thus clear that the method of the present invention eliminates all possibility of broaching any of the windows 30 of the cages 20 and of burnishing any of the bearing rollers 18.

   Either simultaneously with, or immediately following, assembly of the inner race assembly 14, the outer race ring 12 is disposed in a device capable of applying diametrically opposed forces to the outer race ring 12, such as the press 32 shown in Figure 2. Thereafter, the outer race ring 12 is elastically deformed until the outer raceway 24 assumes a substantially elliptical shape having a major axis A4 in the plane perpendicular to the bearing axis A1 at the center C, thereof. For reasons which will be made more apparent hereinafter, it is convenient to consider the major axis A4 and the bearing axis At as defining a plane of insertion.

   Although the elastic limits of the outer race ring 12 will vary with the dimensions and materials of construction thereof, the outer race ring 12 may generally be deformed until the major axis A4 exceeds the normal diameter (2*R1) of the outer raceway 24 by at least about .95 times the chordal height H. On the other hand, the outer race ring 12 should not be deformed more than until the major axis A4 exceeds the normal diameter (2*R1) of the outer raceway 24 by 2.1 times the chordal height H. However, in order to minimize the possibility of damaging any of the components of the bearing 10 yet still maximize efficiency in assembly it is preferred that the major axis A4 exceed the diameter (2*R,) by from about .95 to about 1.1 times the chordal height H. If desired, conventional means, such as the travel stops 34, may be employed to limit the deformation of the outer race ring 12 to the desired limits.

   As can be seen generally in Figures 2 and 3, the inner race assembly 14 is thereafter positioned generally adjacent to the deformed outer race ring 12 in an insertion position with the plane of insertion extending substantially perpendicularly through the center C3 of the axis of rotation A3. Taking care to maintain the inner race assembly 14 in the insertion position, the inner race assembly 14 may then be moved into the deformed outer race ring 12 until the center C3 of the inner race ring 16 generally coincides with the center C1 of the outer race ring 12.

   If the outer race ring 12 has been maximally deformed, that is until the major axis A4 exceeds the normal diameter (2*R1) of the outer raceway 24 by at least 2.0 times the chordal height H, as shown in Figure 2, the inner race assembly 14 may be freely moved into the outer race ring 12 regardless of the orientation of the bearing rollers 18.

   On the other hand, if the other race ring 12 has been only minimally deformed, that is until the major axis A4 exceeds the normal diameter (2*R1) of the outer raceway 24 by only .95 to 1.1 times the chordal height H, it will be necessary to "cock" the inner race assembly 14 by allowing adiacent bearing rollers 18 on one side of the inner race assembly 14 to straddle the shoulder 26, as shown in Figure 3, so that the bearing rollers 18 on the opposite side of the inner race assembly 14 will clear the opposite portion of the shoulder 26 upon further movement of the inner race assembly 14 toward concentricity with the outer race ring 12.

   Once the inner race assembly 14 has been positioned concentrically with the outer race ring 12, the deforming forces applied to the outer race ring 12 via the press 32 may be removed, thereby allowing the outer race ring 12 to assume a normal configuration and bringing the outer raceway 24 into relative engagement with diametrically opposed sets of bearing rollers 18. Having thus effectively "assembled" the bearing 10, the inner race ring 16 need only be rotated about the axis of rotation A3 while simultaneously pivoting the inner race ring

   16 about the centre C3 thereof until the axis of rotation A3 is substantially coaxial with bearing axis A1 As will be clear to those skilled in the art, the preferred method of the present invention embodies a highly efficient method for assembling spherical roller bearings in a manner which minimizes assembly steps and eliminates numerous opportunities for damaging the various elements comprising such bearings.

   Although the present method has been described relative to a double-row, spherical roller bearing only, it will be clear that the present method may be employed with similar results in spherical roller bearings having different configurations.

   WHAT WE CLAIM IS: 1. A method for assembling a spherical roller bearing from: an outer race ring having a spherical section, outer raceway of predetermined diameter about a center of curvature concentric with the center of the outer race ring and of a predetermined chordal height, the axis of the outer race ring defining a bearing axis; and an inner race assembly including: an inner race ring having at least one toric section, inner raceway of predetermined diameter about a center of curvature lying on a predetermined pressure axis extending through the center of the inner race ring,

   the axis of the inner race ring defining an axis of rotation; a plurality of barrel-shaped spherical bearing rollers; and means for maintaining the bearing rollers in rolling engagement with the inner raceway: the method comprising the steps of: applying diametrically opposed forces to the outer race ring to elastically deform the outer race ring until the outer raceway assumes a substantially elliptical shape having a major axis in the plane perpendicular to the bearing axis at the center thereof exceeding the predetermined diameter of the outer raceway by at least .95 times the predetermined chordal height, said major axis and the bearing axis defining a plane of insertion; positioning the inner race assembly adjacent to the deformed outer race ring in an insertion position with the plane of insertion extending perpendicularly through the centre of the axis of rotation; maintaining the inner race assembly in the insertion position while moving the inner race assembly into the deformed outer race ring until the center of the inner race ring coincides with the center of the outer race ring; ~~~~~~~~~~~~~~~~~~~ removing the deforming forces applied to the outer race ring; and rotating the inner race ring about the axis of rotation while pivoting the inner race ring about the center thereof until the axis of rotation is substantially coaxial with the bearing axis.
2. 2. The method of claim 1,wherein the step of applying diametrically opposed forces to the outer race ring is further characterized as elastically deforming the outer race ring until the outer raceway assumes a substantially ellipitical shape having a major axis in the plane perpendicular to the bearing axis at the center thereof exceeding the predetermined diameter of the outer raceway by from .95 to 1.1 times the predetermined chordal height.
3. 3. A method for assembling a spherical roller bearing substantially as described with reference to the accompanying drawings.