Sealing member with visible pressure and temperature indication

• US 9,631,726 B2
• Filed: 07/14/2015
• Issued: 04/25/2017
• Est. Priority Date: 07/14/2015
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Sabotta, Christian Earl, Flanigan, Sarah Talbot, Cline, Jay Hamilton
• Primary Examiner(s): LEE, GILBERT Y
• Application Number:
  US14/798,724
• Publication Number:
  US 20170016539A1
• Time in Patent Office: 651 Days
• CPC Class Codes: F16J 15/02 between relatively-stationary surfaces F16J15/46, F16J15/48 take precedence
• CPC Class Codes: F16J 15/064 the packing combining the sealing function with other functions
• CPC Class Codes: F16J 15/3296 Arrangements for monitoring the condition or operation of elastic sealings F16J15/326 takes precedence; Arrangements for control of elastic sealings, e.g. of their geometry or stiffness
• CPC Class Codes: G01K 11/12 using changes in colour, translucency or reflectance
• CPC Class Codes: G01L 1/24 by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis using infrared, visible light, ultraviolet

Abstract

A sealing member for a machine may include an elastomeric body configured to fit at least partially into a recess defined in at least one of two sealing surfaces of two mating parts of the machine. The elastomeric body may include a visible indicator portion extending out from between the two mating parts. The elastomeric body may further include an elastomeric compound, and at least one of a thermochromic dye and a piezochromic dye mixed into the elastomeric compound, wherein the thermochromic dye is adapted to change color upon exposure of the elastomeric body to a temperature above a threshold temperature, and the piezochromic dye is adapted to change color upon exposure of the elastomeric body to a pressure above a threshold pressure.

Claims

1. A sealing member for a machine, comprising:

an elastomeric body configured to fit at least partially into a recess defined in at least one of two sealing surfaces of two mating parts of the machine, the elastomeric body including;

a visible indicator portion extending out from between the two mating parts;

an elastomeric compound;

a thermochromic dye; and

a piezochromic dye,

wherein the thermochromic dye is adapted to change color upon exposure of the elastomeric body to a temperature above a threshold temperature, and the piezochromic dye is adapted to change color upon exposure of the elastomeric body to a pressure above a threshold pressure.

2. The sealing member of claim 1, wherein the elastomeric body includes a flexible coating applied to a sealing component configured for engagement between the two sealing surfaces of the two mating parts of the machine.

3. The sealing member of claim 2, wherein the flexible coating includes at least two layers applied to the sealing component.

4. The sealing member of claim 3, wherein one of the at least two layers applied to the sealing component includes the thermochromic dye, and another of the at least two layers includes the piezochromic dye.

5. The sealing member of claim 4, wherein the change in color of at least one of the thermochromic dye or the piezochromic dye upon exposure of the elastomeric body to a temperature above the threshold temperature or a pressure above the threshold pressure results in a second of the at least two layers that is applied to the sealing component over a first of the at least two layers becoming colorless and transparent so that a change in color of the first of the at least two layers is also visible.

6. The sealing member of claim 1, wherein the change in color of at least one of the thermochromic dye or the piezochromic dye is irreversible.

7. The sealing member of claim 1, wherein the change in color of at least one of the thermochromic dye or the piezochromic dye is reversible.

8. The sealing member of claim 1, wherein the thermochromic dye and the piezochromic dye are mixed into the elastomeric compound.

9. A sealed sub-assembly of a machine, the sealed sub-assembly comprising:

a first machine part, the first machine part having a first sealing surface;

a second machine part configured to mate with the first machine part, the second machine part having a second sealing surface; and

an elastomeric body configured to be retained between the first and second sealing surfaces, the elastomeric body including;

a visible indicator portion extending out from between the two machine parts;

an elastomeric compound;

a thermochromic dye; and

a piezochromic dye,

wherein the thermochromic dye is adapted to change color upon exposure of the elastomeric body to a temperature above a threshold temperature, and the piezochromic dye is adapted to change color upon exposure of the elastomeric body to a pressure above a threshold pressure.

10. The sealed sub-assembly of claim 9, wherein the elastomeric body includes a flexible coating applied to a sealing component configured for engagement between the two sealing surfaces of the two mating parts of the machine.

11. The sealed sub-assembly of claim 10, wherein the flexible coating includes at least two layers applied to the sealing component.

12. The sealed sub-assembly of claim 11, wherein one of the at least two layers applied to the sealing component includes the thermochromic dye, and another of the at least two layers includes the piezochromic dye.

13. The sealed sub-assembly of claim 12, wherein the change in color of at least one of the thermochromic dye or the piezochromic dye upon exposure of the elastomeric body to a temperature above the threshold temperature or a pressure above the threshold pressure results in a second of the at least two layers that is applied to the sealing component over a first of the at least two layers becoming colorless and transparent so that a change in color of the first of the at least two layers is also visible.

14. The sealed sub-assembly of claim 9, wherein the change in color of at least one of the thermochromic dye or the piezochromic dye is irreversible.

15. The sealed sub-assembly of claim 9, wherein the thermochromic dye and the piezochromic dye are mixed into the elastomeric compound.

16. A method of maintaining a sealed interface between two mating parts of a machine, the method comprising:

assembling the two mating parts with an elastomeric body positioned between two surfaces of the two mating parts of the machine, the elastomeric body including;

a visible indicator portion extending out from between the two mating parts;

an elastomeric compound;

at least one of a thermochromic dye; and

a piezochromic dye,

wherein the thermochromic dye is adapted to change color upon exposure of the elastomeric body to a temperature above a threshold temperature, and the piezochromic dye is adapted to change color upon exposure of the elastomeric body to a pressure above a threshold pressure;

receiving an indication of a color change of the visible indicator portion correlating to the elastomeric body having been exposed to at least one of a temperature above a threshold temperature and a pressure above a threshold pressure;

disassembling the two mating parts and removing the elastomeric body from between the two mating parts; and

replacing the elastomeric body with another elastomeric body.