Stacked thrust bearing arrangement

A stacked thrust bearing arrangement including a central washer arranged between a first and second bearing assembly is disclosed. The central washer is axially positioned between a first inner bearing ring of the first bearing assembly, and a second inner bearing ring of the second bearing assembly. An inner sleeve defines a first retention flange adapted to engage a first cage of the first bearing assembly, and a second retention flange adapted to engage a second cage of the second bearing assembly.

FIELD OF INVENTION

The present invention relates to a stacked thrust bearing arrangement.

BACKGROUND

Bearings are generally used in a wide range of application. One type of bearing is a thrust bearing, which is designed to accommodate axial loads. One specific type of thrust bearing is a stacked bearing, which includes multiple bearing sub-assemblies with multiple rows of rolling elements.

Known arrangements of bearing arrangements are disclosed in U.S. Pat. Nos. 8,523,453 and 6,857,787. Tiered bearings are disclosed in US Pub. 2016/0230809 and U.S. Pat. No. 9,933,010. An isolating layer in a bearing assembly is disclosed in US Pub. 2011/0182542.

Some known thrust bearing arrangements include a common central washer sandwiched between two bearing assemblies. These common central washers are formed from metal and define raceways on either axial side of the washer. These known washer suffer undesirable wear and slippage, which causes excessive noise and reduces efficiency.

It would be desirable to provide an improved stacked thrust bearing arrangement that does not suffer from excessive wear or inefficiencies, and also does not produce undesirable noise.

SUMMARY

An improved stacked thrust bearing arrangement is disclosed.

The stacked thrust bearing arrangement includes a first bearing assembly including a first outer bearing ring, a first inner bearing ring, a first cage, and a first plurality of rolling elements. The first outer bearing ring defines a first outer axial raceway for supporting the first plurality of rolling elements and the first inner bearing ring defines a first inner axial raceway for supporting the first plurality of rolling elements. The first cage defines a first plurality of pockets for the first plurality of rolling elements. A second bearing assembly includes a second outer bearing ring, a second inner bearing ring, a second cage, and a second plurality of rolling elements. The second outer bearing ring defines a second outer axial raceway for supporting the second plurality of rolling elements and the second inner bearing ring defines a second inner axial raceway for supporting the second plurality of rolling elements. The second cage defines a second plurality of pockets for the second plurality of rolling elements. A central washer is axially positioned between the first inner bearing ring and the second inner bearing ring. An inner sleeve defines a first retention flange adapted to engage the first cage and a second retention flange adapted to engage the second cage.

In one embodiment, the first inner bearing ring and the second inner bearing ring are each formed from steel.

In one embodiment, the inner sleeve defines a first groove adapted to receive an inner portion of the first cage, and defines a second groove adapted to receive an inner portion of the second cage.

In one embodiment, the central washer has a thickness (ta) that is less than a thickness (tb) of the first inner bearing ring and the second inner bearing ring.

In one embodiment, the central washer, the first inner bearing ring, and the second inner bearing ring have a combined thickness (tc), and the combined thickness is 20%-30% of an overall thickness (to) of the stacked thrust bearing arrangement.

In one embodiment, the central washer has a radial depth that is equal to or less than a radial depth of the first inner bearing ring and the second inner bearing ring.

In one embodiment, the central washer has a uniformly flat profile.

In one embodiment, the first outer bearing ring and the second outer bearing ring each have an L-shaped profile including axially inwardly extending flanges.

In another embodiment, a stacked thrust bearing arrangement includes a first bearing assembly including at least one first bearing ring, a second bearing assembly including at least one second bearing ring, and an inner sleeve defining a first retention flange adapted to engage the first bearing assembly and a second retention flange adapted to engage the second bearing assembly. A central washer is axially positioned between the at least one first bearing ring and the at least one second bearing ring. The central washer being formed from rubber, and the at least one first bearing ring and the at least one second bearing ring being formed from steel.

Additional embodiments are disclosed herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain terminology is used in the following description for convenience only and is not limiting. The words “front,” “rear,” “upper” and “lower” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from the parts referenced in the drawings. “Axially” refers to a direction along the axis of a shaft. A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof. The terminology includes the words specifically noted above, derivatives thereof and words of similar import.

As shown inFIGS. 1-4, a stacked thrust bearing arrangement10is disclosed. The arrangement10includes a first bearing assembly20including a first outer bearing ring22, a first inner bearing ring24, a first cage26, and a first plurality of rolling elements28.

The first outer bearing ring22defines a first outer axial raceway23for supporting the first plurality of rolling elements28and the first inner bearing ring24defines a first inner axial raceway25for supporting the first plurality of rolling elements28. The first cage26defines a first plurality of pockets27for the first plurality of rolling elements28.

A second bearing assembly40includes a second outer bearing ring42, a second inner bearing ring44, a second cage46, and a second plurality of rolling elements48. The second outer bearing ring42defines a second outer axial raceway43for supporting the second plurality of rolling elements48and the second inner bearing ring44defines a second inner axial raceway45for supporting the second plurality of rolling elements48. The second cage46defines a second plurality of pockets47for the second plurality of rolling elements48.

In one embodiment, the rolling elements28,48are cylindrical rollers. One of ordinary skill in the art would understand that varying types of rolling elements could be used.

A central washer50is axially positioned between the first inner bearing ring24and the second inner bearing ring44. The central washer50is in direct contact with both first inner bearing ring24and the second inner bearing ring44. The central washer50is a separately formed part from the first inner bearing ring24and the second inner bearing ring44. In one embodiment, the central washer50is assembled between the first inner bearing ring24and the second inner bearing ring44, without any adhesive or other attachment or fastening means.

In one embodiment, the central washer50can be assembled or attached to either one of the inner bearing rings24,44. In one embodiment, the central washer50can be assembled to the inner bearing rings24,44via adhesive or mechanical fasteners.

The central washer50provides an improved configuration compared to arrangements having a single common middle ring that defines raceways on both axial sides for the sets of rolling elements. The central washer50eliminates excessive noise and wear compared to known thrust bearing arrangements.

An inner sleeve60defines a first retention flange62adapted to engage the first cage26and a second retention flange64adapted to engage the second cage46. The retention flanges62,64provide an axial interference with the cages26,46.

The inner sleeve60defines a first groove66adapted to receive an inner portion of the first cage26, and defines a second groove68adapted to receive an inner portion of the second cage46.

In one embodiment, the inner sleeve60defines a radially innermost portion of the assembly10. In one embodiment, the first outer bearing ring22and the second outer bearing ring42each define an axially outermost surface of the assembly10.

In one embodiment, the central washer50is formed from rubber. In one embodiment, the central washer50acts as an isolating layer. One of ordinary skill in the art recognizes that any type of material can be used to form the central washer50. In one embodiment, the central washer50can be formed from a vibration-attenuating material.

In one embodiment, the central washer50has a thickness (ta) that is less than a thickness (tb) of the first inner bearing ring24and the second inner bearing ring44. One of ordinary skill in the art would understand that the thicknesses of these components can be varied depending on the particular demands for a specific bearing assembly.

In one embodiment, the central washer50, the first inner bearing ring24, and the second inner bearing ring44have a combined thickness (tc), and the combined thickness (tc) is 20%-30% of an overall thickness (to) of the stacked thrust bearing arrangement10. In one embodiment, the combined thickness (tc) is less than 30% of an overall thickness (to) of the stacked thrust bearing arrangement10.

In one embodiment, the central washer50has a uniformly flat profile. Both axial end faces of the central washer50are oriented 90 degrees to the rotational axis (X). The central washer50provides identical contact surfaces on either axial side of the central washer50for contact with the first inner bearing ring24and the second inner bearing ring44.

In one embodiment, the central washer50has a radial depth that is equal to or less than a radial depth of the first inner bearing ring24and the second inner bearing ring44. In one embodiment, the central washer has a radial depth that is less than a radial depth of the first inner bearing ring24and the second inner bearing ring44.

In one embodiment, the first inner bearing ring24and the second inner bearing ring44are formed from metal. In one embodiment, the first inner bearing ring24and the second inner bearing ring44are formed from steel.

In one embodiment, a radially outer edge of the central washer50is positioned radially inward from radially outer edges of the first inner bearing ring24and the second inner bearing ring44. In one embodiment, the radially outer edge of the central washer50is positioned radially inward from radially outer edges of the first outer bearing ring22and the second outer bearing ring42. In one embodiment, a gap is provided between a radially inner edge of the central washer50and the inner sleeve60.

In one embodiment, the first outer bearing ring22and the second outer bearing ring42each include a radially extending body with an axially extending flange29,49. The axially extending flanges29,49of the first outer bearing ring22and the second outer bearing ring42extend axially inwardly. The axially extending flanges29,49include retention flanges. The first outer bearing ring22and the second outer bearing ring42have an L-shaped profile, while the first inner bearing ring24and the second inner bearing ring44each have a flat, straight profile.

In one embodiment, the first and second bearing assemblies20,40are identical to each other, including the same type of sub-components of identical sizes. In another embodiment, the first and second bearing assemblies20,40can have varying components, of varying orientations and/or sizes.

Having thus described the present invention in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.

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