Ball seal for thermal sensor assembly of thermostatic expansion valve

Patent metadata

Field	Value
Publication number	US-12460844-B2
Application number	US-202218693355-A
Country	US
Kind code	B2
Filing date	Sep 14, 2022
Priority date	Dec 8, 2021
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A thermal sensor assembly for a thermostatic expansion valve includes an enclosure that forms an enclosed interior space containing a thermal sensing fluid, and an opening in the enclosure for charging the thermal sensing fluid. A ball is arranged in the opening and forms a fluid seal between a sealing surface and a sealing interface of the assembly. The sealing surface may be made with a material that is softer than a material of the sealing interface, such that the sealing surface conforms to the sealing interface and fluidly seals the thermal sensing fluid in the enclosed interior space of the enclosure. The opening may include a tapered lead-in hole that tapers radially inwardly as the lead-in hole extends toward the interior space to thereby form the seal. A cover may be attached to an exterior surface of the enclosure to hold the ball in the opening to form the seal.

First claim

What is claimed is:

1 . A thermal sensor assembly for a thermostatic expansion valve, the thermal sensor assembly comprising:
an enclosure forming an enclosed interior space containing a thermal sensing fluid, the enclosure having a charge opening configured for charging the thermal sensing fluid into the enclosure; a ball arranged in the charge opening and having a sealing interface; and a sealing surface layer located between a surface of the charge opening of the enclosure and the sealing interface of the ball forming a fluid seal between the enclosure at the charge opening and the ball; wherein the sealing interface is formed by a first material and the sealing surface layer is formed by a second material having a greater softness than the first material such that the sealing surface layer conforms to the sealing interface and fluidly seals the thermal sensing fluid in the enclosed interior space of the enclosure at the charge opening, wherein the sealing interface is formed by an outer surface of the ball, such that the sealing surface layer at the charge opening conforms to the outer surface of the ball, and wherein the enclosure includes a third material as a substrate layer for the sealing surface layer, the third material of the substrate layer being harder than the second material of the sealing surface layer to enhance a strength of the enclosure.

2 . The thermal sensor assembly according to claim 1 , wherein the enclosure includes a second sealing interface formed by a surface of the charge opening of the enclosure, such that the sealing surface layer conforms to the surface of the charge opening.

3 . The thermal sensor assembly according to claim 2 ,
wherein the ball includes the sealing surface layer of the second material as a first layer on at least part of the ball, and a third material as a substrate layer of at least part of the ball that supports the first layer, the third material of the substrate layer being harder than the second material of the first layer to enhance a strength of the ball.

4 . The thermal sensor assembly according to claim 1 ,
wherein the first material is steel, the second material is copper or copper alloy, and the third material is steel.

5 . The thermal sensor assembly according to claim 1 ,
wherein the portion of the enclosure having the charge opening is formed as a cap that is attached to a main body portion of the enclosure.

6 . The thermal sensor assembly according to claim 1 ,
wherein the thermal sensor assembly further includes a cover attached to an exterior surface of the enclosure such that the cover holds the ball in the charge opening to form the seal.

7 . The thermal sensor assembly according to claim 6 ,
wherein the cover is formed as a flat disc, and wherein the ball is sized to fit in the charge opening such that the ball does not protrude beyond a flat of the disc.

8 . The thermal sensor assembly according to claim 6 ,
wherein the cover is ultrasonically welded to the enclosure.

9 . The thermal sensor assembly according to claim 6 ,
wherein the portion of the enclosure adjacent the sealing surface layer is formed as a cap that is attached to a main body portion of the enclosure, wherein the cap forms a recessed portion of the enclosure, and the cover is configured to fit within the recessed portion of the enclosure.

10 . The thermal sensor assembly according to claim 1 ,
wherein a joint is formed at the interface between the ball and the sealing surface layer at the charge opening, the joint including an adhesive that increases the strength of the joint.

11 . The thermal sensor assembly according to claim 1 ,
wherein the charge opening includes a lead-in hole adjacent the sealing surface layer which faces radially inwardly toward the ball.

12 . The thermal sensor assembly according to claim 11 ,
wherein the sealing surface layer at the lead-in hole tapers radially inwardly as the sealing surface layer extends toward the enclosed interior space of the enclosure.

13 . The thermal sensor assembly according to claim 12 ,
wherein the lead-in hole is formed by a frustoconical portion of the enclosure adjacent the sealing surface layer, the frustoconical portion of the enclosure protruding into the enclosed interior space of the enclosure.

14 . The thermal sensor assembly according to claim 13 ,
wherein the thermal sensor assembly further includes a cover attached to the enclosure, the cover being configured to hold the ball in the charge opening to form the seal, and wherein the frustoconical portion of the enclosure provides a spring bias that urges the ball toward the cover to hold the ball.

15 . A thermal sensor assembly for a thermostatic expansion valve, the thermal sensor assembly comprising:
an enclosure forming an enclosed interior space containing a thermal sensing fluid, the bulb having a charge opening configured for charging the thermal sensing fluid into the enclosure; and a ball arranged in the charge opening and forming a seal that fluidly seals the thermal sensing fluid in the enclosed interior space of the enclosure; wherein the charge opening includes a tapered lead-in hole formed by a portion of the enclosure, the lead-in hole including a tapered surface that tapers radially inwardly as the tapered surface extends toward the enclosed interior space, the tapered surface sealingly engaging against the ball to form the seal, wherein a sealing interface of the ball forming a fluid seal between the enclosure at the charge opening and the ball is formed by a first material and a sealing surface layer located between a surface of the charge opening and the sealing interface is formed by a second material having a greater softness than the first material such that the sealing surface layer conforms to the sealing interface, wherein the sealing interface is formed by an outer surface of the ball, such that the sealing surface layer at the charge opening conforms to the outer surface of the ball, and wherein the enclosure includes a third material as a substrate layer for the sealing surface layer, the third material of the substrate layer being harder than the second material of the sealing surface layer to enhance a strength of the enclosure.

16 . The thermal sensor assembly according to claim 15 , wherein the lead-in hole is formed by a frustoconical portion of the enclosure that includes a sealing surface, the frustoconical portion of the enclosure protruding into the enclosed interior space of the enclosure.

17 . The thermal sensor assembly according to claim 16 ,
wherein the thermal sensor assembly further includes a cover attached to the enclosure, the cover being configured to hold the ball in the charge opening to form the seal, and wherein the frustoconical portion of the enclosure provides a spring bias that urges the ball toward the cover to hold the ball.

18 . A thermal sensor assembly for a thermostatic expansion valve, the thermal sensor assembly comprising:
an enclosure forming an enclosed interior space containing a thermal sensing fluid, the enclosure having a charge opening configured for charging the thermal sensing fluid into the enclosure; a ball arranged in the charge opening and forming a seal that fluidly seals the thermal sensing fluid in the enclosed interior space of the enclosure; and a cover attached to an exterior surface of the enclosure and configured to hold the ball in the charge opening to form the seal; wherein the cover is formed as a flat disc, and wherein the ball is sized to

Assignees

• Parker Hannifin Corp

Inventors

• Coyle Eric R
• Yegge Dylan T

Classifications

• F25B2500/01

  Geometry problems, e.g. for reducing size · CPC title

• F25B41/335 Primary

  via diaphragms · CPC title