High-speed bearing with grooved and cylindrical races

Patent metadata

Field	Value
Publication number	US-11236779-B2
Application number	US-202017015573-A
Country	US
Kind code	B2
Filing date	Sep 9, 2020
Priority date	Sep 23, 2019
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A high-speed shaft assembly includes a shaft of a first material and an outer member of a second material disposed about the shaft, the shaft or outer member being rotatable about an axis. The two materials have substantially different coefficients of thermal expansion such that the shaft and/or the outer member is relatively displaceable along the axis at temperatures over 120° C. and less than −18° C. A bearing inner ring is disposed about the shaft and has an outer race which is a cylindrical surface or an annular groove. A bearing outer ring is disposed about the inner ring and coupled with the outer member. The outer ring has an outer race which is the other one of the cylindrical surface and the groove. A plurality of balls disposed between the races are displaceable axially along the cylindrical race surface during relative displacement of the shaft and outer member.

First claim

I claim:

1. A high-speed shaft assembly comprising:
a shaft formed of a first material and having a central axis;
an outer member formed of a second material and disposed about the shaft, at least one of the shaft and the outer member being rotatable about the central axis, the second material having a coefficient of thermal expansion different than a coefficient of thermal expansion of the first material such that at least one of the shaft and the outer member is displaceable along the central axis relative to other one of the shaft and the outer member at temperatures greater than 120° Celsius and at temperatures less than −18° Celsius;
a bearing inner ring disposed about and coupled with the shaft, the inner ring having an outer circumferential surface providing an inner race, the inner race being one of a substantially cylindrical surface and an annular groove;
a bearing outer ring disposed about the inner ring and coupled with the outer member, the outer ring having an inner circumferential surface providing an outer race, the outer race being the other one of the substantially cylindrical surface and the annular groove; and
a plurality of balls disposed between the inner and outer races so as to rotatably couple the inner and outer rings, each ball being displaceable axially along the substantially cylindrical surface during relative axial displacement of the shaft and the outer member;
wherein each one of the bearing inner ring and the bearing outer ring are heat treated to prevent substantial dimensional changes between negative seventy-three degrees Celsius (−73° C.) and three hundred fifteen degrees Celsius (315° C.).

2. The shaft assembly as recited in claim 1 wherein the inner ring has a bore with a diameter and a product of the rotational speed of the shaft or the outer member and a value of the bore diameter in millimeters is greater than one million.

3. The shaft assembly as recited in claim 1 wherein the substantially cylindrical surface has a width and the relative axial displacement of the shaft or of the outer member is up to about half the width of the substantially cylindrical surface.

4. The shaft assembly as recited in claim 1 wherein each one of the balls is formed of a ceramic material.

5. The shaft assembly as recited in claim 1 wherein the one of the inner ring and the outer ring having the annular groove includes another annular groove and the shaft assembly further comprises another plurality of balls disposed within the other annular groove and rollable circumferentially about the axis and axially along the substantially cylindrical surface.

6. The shaft assembly as recited in claim 1 wherein the inner ring is connected with the shaft or an intermediate member disposed upon the shaft by an interference fit, the interference fit generating at least sixty-nine megapascals (69 MPa) of hoop stress within the inner ring.

7. The shaft assembly as recited in claim 1 wherein each one of the bearing inner ring and the bearing outer ring are at least one of hardened, carburized, nitrided and carbo-nitrided.

8. A high-speed shaft assembly comprising:
a shaft formed of a first material and having a central axis;
an outer member formed of a second material and disposed about the shaft, at least one of the shaft and the outer member being rotatable about the central axis, the second material having a coefficient of thermal expansion different than a coefficient of thermal expansion of the first material such that at least one of the shaft and the outer member is displaceable along the central axis relative to other one of the shaft and the outer member at temperatures greater than 120° Celsius and at temperatures less than −18° Celsius;
at least one bearing inner ring disposed about and coupled with the shaft, the inner ring having an outer circumferential surface and an annular groove extending inwardly from the outer surface and providing an inner race;
a bearing outer ring disposed about the at least one inner ring and coupled with the outer member, the outer ring having a cylindrical inner circumferential surface providing an outer race; and
a plurality of balls disposed between the inner and outer races so as to rotatably couple the inner and outer rings, each ball being displaceable axially along the outer race during relative axial displacement of the shaft and the outer member;
wherein the at least one inner ring is a first bearing inner ring providing a first inner race, the plurality of balls is a first set of balls and one of:
the shaft assembly further comprises a second bearing inner ring disposed about and coupled with the shaft, the second inner ring having an outer circumferential surface and annular groove extending inwardly from the outer surface and providing a second inner race and a second set of balls disposed between the second inner race and the outer race; and
the inner ring includes another annular groove spaced axially from the annular groove and the shaft assembly further comprises another plurality of balls disposed within the other annular groove and rollable circumferentially and axially along the outer race.

9. A high-speed shaft assembly comprising:
a shaft formed of a first material and having a central axis;
an outer member formed of a second material and disposed about the shaft, at least one of the shaft and the outer member being rotatable about the central axis, the second material having a coefficient of thermal expansion different than a coefficient of thermal expansion of the first material such that at least one of the shaft and the outer member is displaceable along the central axis relative to other one of the shaft and the outer member at temperatures greater than 120° Celsius and at temperatures less than −18° Celsius;
a bearing inner ring disposed about and coupled with the shaft, the inner ring having an outer circumferential surface providing a cylindrical inner race;
a bearing outer ring disposed about the inner ring and coupled with the outer member, the outer ring having an inner circumferential surface and an annular groove extending into the inner surface and providing an outer race; and
a plurality of balls disposed between the inner and outer races so as to rotatably couple the inner and outer rings, each ball being displaceable axially along the cylindrical inner race during relative axial displacement of the shaft and the outer member;
wherein each one of the bearing inner ring and the bearing outer ring are heat treated to prevent substantial dimensional changes between negative seventy-three degrees Celsius (−73° C.) and three hundred fifteen degrees Celsius (315° C.).

Assignees

• Skf Ab

Inventors

• Anthony Don L

Classifications

• F16C19/525 Primary

  related to temperature and heat, e.g. insulation · CPC title

• F16C2202/22

  Coefficient of expansion · CPC title

• F01D25/16

  Arrangement of bearings; Supporting or mounting bearings in casings (bearings per se F16C) · CPC title

• F16C19/08

  with two or more rows of balls · CPC title

• F16C33/585 Primary

  of raceways, e.g. ribs to guide the rollers · CPC title