Coordinate measuring machine with carbon fiber air bearings

• US 10,323,920 B2
• Filed: 04/25/2017
• Issued: 06/18/2019
• Est. Priority Date: 04/04/2014
• Status: Active Grant

• Current Assignee: Hexagon Metrology Incorporated (Hexagon AB)
• Original Assignee: Hexagon Metrology Incorporated (Hexagon AB)
• Inventors: Singh, Gurpreet, Langlais, John, Zheng, Jie, Spanedda, Joseph G.
• Primary Examiner(s): Bennett, George B
• Application Number:
  US15/496,806
• Publication Number:
  US 20170227343A1
• Time in Patent Office: 784 Days
• Field of Search: 33503
• CPC Class Codes: F16C 2206/06 Composite carbon material, e.g. carbon fibre reinforced carbon (C/C)
• CPC Class Codes: F16C 2370/00 Apparatus relating to physics, e.g. instruments in general G01 - G12
• CPC Class Codes: F16C 29/025 Hydrostatic or aerostatic this type of bearing for rotary parts F16C32/06
• CPC Class Codes: G01B 1/00 Measuring instruments characterised by the selection of material therefor
• CPC Class Codes: G01B 5/0009 Guiding surfaces; Arrangements compensating for non-linearity there-of
• CPC Class Codes: G01B 5/0014 due to temperature on machine tools B23Q11/0003
• CPC Class Codes: G01B 5/008 using coordinate measuring machines

Abstract

A coordinate measuring machine has a base for supporting an object, a movable assembly having a probe for measuring the object, and a rail movably guiding the movable assembly along its length. The rail includes carbon fiber and has a rail CTE. The coordinate measuring machine also has an air bearing member circumscribing the rail and fixedly coupled with the movable assembly. The air bearing member has a member CTE, which is about equal to the rail engineered CTE.

Claims

1. A coordinate measuring machine comprising:

a base for supporting an object;

a probe for measuring the object;

a movable assembly configured to move either the base or the probe;

a rail guiding the movable assembly along its length, the rail comprising carbon and having a rail CTE; and

an air bearing member movably coupled with the rail and fixedly coupled with the movable assembly, the air bearing member forming an air bearing with the rail and having a member CTE,

the rail CTE being about equal to the member CTE.

2. The coordinate measuring machine as defined by claim 1 wherein the rail comprises carbon fiber.

3. The coordinate measuring machine as defined by claim 2 wherein the air bearing member comprises a torroidally shaped member completely circumscribing the rail.

4. The coordinate measuring machine as defined by claim 3 wherein the torroidally shaped member comprises metal or ceramic.

5. The coordinate measuring machine as defined by claim 3 wherein the torroidally shaped member comprises carbon.

6. The coordinate measuring machine as defined by claim 3 wherein the torroidally shaped member includes a groove for distributing air and a plurality of through-holes fluidly connected with the groove for directing air toward the rail.

7. The coordinate measuring machine as defined by claim 1 wherein the air bearing includes a sleeve and at least one ring member supported by the sleeve.

8. The coordinate measuring machine as defined by claim 7 wherein the sleeve and at least one ring are formed from different materials.

9. The coordinate measuring machine as defined by claim 1 wherein air bearing is formed on more than one side of the rail, the rail being formed mostly from carbon material.

10. The coordinate measuring machine as defined by claim 1 wherein the air bearing comprises a radial bearing.

11. The coordinate measuring machine as defined by claim 1 wherein the air bearing comprises a thrust bearing.

12. The coordinate measuring machine as defined by claim 1 wherein the movable assembly is configured to move the base, the movable assembly being configured to not move the probe.

13. A coordinate measuring machine comprising:

a base for supporting an object;

a probe for measuring the object;

a movable assembly configured to move the base, the probe being substantially stationary;

a rail guiding the movable assembly along its length, the rail comprising carbon and having a rail CTE; and

an air bearing member movably coupled with the rail and fixedly coupled with the movable assembly, the air bearing member forming an air bearing with the rail and having a member CTE,

the rail CTE being about equal to the member CTE.

14. The coordinate measuring machine as defined by claim 13 wherein the rail comprises carbon fiber.

15. The coordinate measuring machine as defined by claim 14 wherein the air bearing member comprises a torroidally shaped member circumscribing the rail.

16. The coordinate measuring machine as defined by claim 15 wherein the torroidally shaped member comprises metal, carbon, or ceramic.

17. The coordinate measuring machine as defined by claim 15 wherein the torroidally shaped member includes a groove for distributing air and a plurality of through-holes fluidly connected with the groove for directing air toward the rail.

18. The coordinate measuring machine as defined by claim 13 wherein the air bearing includes a sleeve and at least one ring member supported by the sleeve.

19. The coordinate measuring machine as defined by claim 13 wherein the air bearing comprises a radial bearing.

20. The coordinate measuring machine as defined by claim 13 wherein the air bearing comprises a thrust bearing.

21. A coordinate measuring machine comprising:

a base for supporting an object;

a probe for measuring the object;

a movable assembly configured to move no more than one of the base and the probe;

a rail guiding the movable assembly along its length, the rail comprising carbon and having a rail CTE; and

an air bearing member movably coupled with the rail and fixedly coupled with the movable assembly, the air bearing member forming a thrust air bearing with the rail and having a member CTE,

the rail CTE matching the member CTE.

22. The coordinate measuring machine as defined by claim 21 wherein the rail comprises carbon fiber.

23. The coordinate measuring machine as defined by claim 22 wherein the air bearing member comprises a torroidally shaped member circumscribing the rail.

24. The coordinate measuring machine as defined by claim 23 wherein the torroidally shaped member comprises metal, carbon, or ceramic.