Structures and methods for controlled thermal expansion

Patent metadata

Field	Value
Publication number	US-10280974-B2
Application number	US-201715661242-A
Country	US
Kind code	B2
Filing date	Jul 27, 2017
Priority date	Jul 27, 2017
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

Products and methods are provided for controlling thermal expansion. In various exemplary embodiments, a structure includes a body constructed of a material exhibiting a first coefficient of linear thermal expansion. A component is disposed inside the body and exhibits a second coefficient of linear thermal expansion that is lower than the first coefficient of linear thermal expansion. A layer is wrapped around the body and constrains thermal expansion of the body. The layer includes a composite containing fibers that are aligned with one another to constrain expansion in a desired direction or in multiple directions. The layer is independently useful to provide a retention function for the body.

First claim

What is claimed is:

1. A structure comprising:
a body comprised of a material exhibiting a first coefficient of linear thermal expansion;
a component disposed inside the body and exhibiting a second coefficient of linear thermal expansion that is lower than the first coefficient of linear thermal expansion; and
a layer wrapped around the body the layer configured to constrain thermal expansion of the body and configured to maintain contact between the body and the component, the layer comprising a composite containing fibers that are aligned with one another.

2. The structure of claim 1 wherein the body is cylindrical and has a circumference around the body defining a circumferential direction wherein the fibers are aligned in the circumferential direction.

3. The structure of claim 1 wherein the body is formed of an aluminum alloy and the component is formed of steel and wherein the layer constrains thermal expansion of the body toward the second coefficient of linear thermal expansion.

4. The structure of claim 1 wherein a number of grooves are formed in the body and the layer is formed on the body including in the grooves.

5. The structure of claim 4 wherein the grooves are dovetail shaped and extend from an outer circumference of the body into the body to a bottom, wherein the grooves have a first width at the outer circumference and a second width at the bottom that is greater than the first width.

6. The structure of claim 1 wherein the component comprises a bearing and wherein the layer is formed in a band disposed outside and around the bearing.

7. The structure of claim 1 wherein the body is cylindrical and has a circumference around the body and comprising a series of keys and keyways alternating around the circumference.

8. The structure of claim 1 wherein the body is formed in a hollow cylindrical shape and a shaft extends through the body and is rotationally supported on the body by the component.

9. The structure of claim 8 wherein the component comprises a pair of bearings spaced apart along the body.

10. The structure of claim 1 wherein the fibers comprise a material that exhibits a stiffness greater than 70 gigapascal and a coefficient of linear thermal expansion less than 10 ppm/K.

11. The structure of claim 1 wherein the fibers comprise carbon and the composite comprises a polymer in which the fibers are disposed.

12. The structure of claim 1 wherein the layer is configured to constrain the thermal expansion of the body to match a second thermal expansion of the component.

13. A structure comprising:
a body comprised of a material exhibiting a first coefficient of linear thermal expansion;
a component disposed inside the body and exhibiting a second coefficient of linear thermal expansion that is lower than the first coefficient of linear thermal expansion; and
a layer wrapped around the body and constraining thermal expansion of the body, the layer comprising a composite containing fibers that are aligned with one another, wherein the fibers comprise a first set of fibers oriented in alignment with one another at a first angle relative to the body and a second set of fibers oriented in alignment with one another at a second angle relative to the body, wherein the first and the second angles are variable relative to one another.

14. A method of controlling coefficient of linear thermal expansion comprising:
forming a body of a material exhibiting a first coefficient of linear thermal expansion;
surrounding the body with a layer of a fibrous material wherein the fibrous material comprises fibers oriented in alignment with one another;
including a polymer in the layer with the fibers disposed in the polymer as a composite;
positioning a component inside the body, wherein the component is comprised of a material exhibiting a second coefficient of linear thermal expansion that is lower than the first coefficient of linear thermal expansion; and
constraining thermal expansion of the body with the layer; and
maintaining, by the layer and during temperature increases of the body, contact between the body and the component.

15. The method of claim 14 comprising:
forming the body in a cylindrical shape with a circumference around the body defining a circumferential direction; and
aligned the fibers in the circumferential direction.

16. The method of claim 14 comprising:
forming the body of an aluminum alloy; and
forming the component of steel, wherein the layer constrains thermal expansion of the body to reduce the coefficient of linear thermal expansion of the body.

17. The method of claim 14 comprising:
forming a number of grooves in the body disposed in at least one of a radial direction, an axial direction or at an angle; and
forming the layer on the body including in the grooves.

18. The method of claim 14 wherein the component comprises a bearing and comprising forming the layer in a band shape disposed radially outside and around the bearing, wherein the band shape extends around the body and has a dimension in an axial direction of the body that is less than a length of the body in the axial direction.

19. The method of claim 14 comprising forming a series of keys and keyways alternating around the circumference.

20. The method of claim 14 wherein the first coefficient of linear thermal expansion is approximately two times the magnitude of the second coefficient of linear thermal expansion, and wherein constraining thermal expansion of the body with the layer further comprises constraining, by the layer, the thermal expansion of the body to match the thermal expansion of the body to a second thermal expansion of the component.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Newcomb Bradley A
• Kennell Jevon
• Schulz David S
• Kia Hamid G

Classifications

• F16C2326/06

  Drive shafts · CPC title

• B29L2031/04

  Bearings · CPC title

• F16C2202/06

  Strength or rigidity · CPC title

• F16C19/525 Primary

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

• F16H2048/423

  characterised by bearing arrangement · CPC title