Stepper motor control valves for refrigerant expansion and/or system controls

Patent metadata

Field	Value
Publication number	US-11619429-B2
Application number	US-202117220237-A
Country	US
Kind code	B2
Filing date	Apr 1, 2021
Priority date	Apr 1, 2021
Publication date	Apr 4, 2023
Grant date	Apr 4, 2023

Abstract

A valve includes a shaft having threads along at least a portion of a length of the shaft. A travel limit member (e.g., a coil spring, a washer, etc.) is disposed within one or more of the threads. The travel limit member may comprise a coil spring configured to be movable within the threads along the shaft when the shaft is rotated relative to the coil spring. The coil spring is configured to be operable for providing: a safety stall or hard stop for a fully open position of the valve when the coil spring is within the top thread and/or runs out of the threads after having traveled upwardly along the shaft within the threads; and a safety stall or hard stop for a fully closed position of the valve when the coil spring contacts a stop after having traveled downwardly along the shaft within the threads.

First claim

What is claimed is:

1. A valve comprising:
a shaft having threads along at least a portion of a length of the shaft, the threads including a top thread; and
a travel limit member disposed within one or more of the threads, the travel limit member configured to be movable within the threads along the shaft when the shaft is rotated relative to the travel limit member, the travel limit member configured to be operable for providing:
a safety stall or hard stop for a fully open position of the valve when the travel limit member is within the top thread and/or runs out of the threads after having traveled upwardly along the shaft within the threads; and
a safety stall or hard stop for a fully closed position of the valve when the travel limit member contacts a stop after having traveled downwardly along the shaft within the threads;

wherein the travel limit member comprises a coil spring disposed within one or more of the threads, the coil spring configured to be movable within the threads along the shaft when the shaft is rotated relative to the coil spring, the coil spring configured to be operable for providing:
the safety stall or hard stop for the fully open position of the valve when the coil spring is within the top thread and/or runs out of the threads after having traveled upwardly along the shaft within the threads; and
the safety stall or hard stop for the fully closed position of the valve when the coil spring contacts a stop after having traveled downwardly along the shaft within the threads;

wherein the coil spring consists of a single coil spring; and
wherein the single coil spring has only one coil.

2. The valve of claim 1 , wherein the threads comprise a worm gear thread along the at least a portion of the length of the shaft.

3. The valve of claim 1 , wherein the threads comprise an ACME thread along the at least a portion of the length of the shaft.

4. The valve of claim 1 , wherein the threads are machined into the shaft.

5. The valve of claim 1 , wherein the valve includes:
a valve port;
a stepper motor; and
a movable valve member movable relative to the valve port by the stepper motor between a closed position in which fluid flow through the valve port is inhibited and an open position in which fluid flow through the valve port is permitted.

6. The valve of claim 5 , wherein:
the valve includes a valve seat coupled to the movable valve member; and
the valve seat is configured to seat against and seal the valve port when the movable valve member is in the closed position and to be spaced apart from the valve port when the movable valve member is in the open position.

7. The valve of claim 6 , wherein:
the valve includes a pin coupled to the movable valve member; and
the valve seat comprises a collar disposed on the pin.

8. The valve of claim 7 , wherein:
the pin comprises a tapered metering pin; and
the collar comprises a polytetrafluoroethylene (PTFE) collar disposed on the tapered metering pin.

9. A stepper motor driven electronic expansion valve comprising the valve of claim 1 .

10. A valve comprising:
a shaft having threads along at least a portion of a length of the shaft, the threads including a top thread; and
a travel limit member disposed within one or more of the threads, the travel limit member configured to be movable within the threads along the shaft when the shaft is rotated relative to the travel limit member, the travel limit member configured to be operable for providing:
a safety stall or hard stop for a fully open position of the valve when the travel limit member is within the top thread and/or runs out of the threads after having traveled upwardly along the shaft within the threads; and
a safety stall or hard stop for a fully closed position of the valve when the travel limit member contacts a stop after having traveled downwardly along the shaft within the threads

wherein the threads include:
a threadform having a 29° thread angle with a thread height half of a pitch;
a flat apex or crux; and
a flat valley or root.

11. The valve of claim 10 , wherein the travel limit member comprises a coil spring disposed within one or more of the threads, the coil spring configured to be movable within the threads along the shaft when the shaft is rotated relative to the coil spring, the coil spring configured to be operable for providing:
the safety stall or hard stop for the fully open position of the valve when the coil spring is within the top thread and/or runs out of the threads after having traveled upwardly along the shaft within the threads; and
the safety stall or hard stop for the fully closed position of the valve when the coil spring contacts the stop after having traveled downwardly along the shaft within the threads.

12. The valve of claim 11 , wherein the coil spring consists of a single coil spring.

13. The valve of claim 12 , wherein the single coil spring has only one coil.

14. A valve comprising:
a shaft having threads along at least a portion of a length of the shaft, the threads including a top thread; and
a travel limit member disposed within one or more of the threads, the travel limit member configured to be movable within the threads along the shaft when the shaft is rotated relative to the travel limit member, the travel limit member configured to be operable for providing:
a safety stall or hard stop for a fully open position of the valve when the travel limit member is within the top thread and/or runs out of the threads after having traveled upwardly along the shaft within the threads; and
a safety stall or hard stop for a fully closed position of the valve when the travel limit member contacts a stop after having traveled downwardly along the shaft within the threads;

wherein the travel limit member comprises a washer disposed within one or more of the threads, the washer configured to be movable within the threads along the shaft when the shaft is rotated relative to the washer, the washer configured to be operable for providing:
the safety stall or hard stop for the fully open position of the valve when the washer is within the top thread and/or runs out of the threads after having traveled upwardly along the shaft within the threads; and
the safety stall or hard stop for the fully closed position of the valve when the washer contacts a stop after having traveled downwardly along the shaft within the threads.

15. A valve comprising:
a shaft having threads along at least a portion of a length of the shaft, the threads including a top thread; and
a travel limit member disposed within one or more of the threads, the travel limit member configured to be movable within the threads along the shaft when the shaft is rotated relative to the travel limit member, the travel limit member configured to be operable for providing:
a safety stall or hard stop for a fully open position of the valve when the travel limit member is within the top thread and/or runs out of the threads after having traveled upwardly along the shaft within the threads; and
a safety stall or hard stop for a fully closed position of the valve when the travel limit member contacts a stop after having traveled downwardly along the shaft within the threads;

wherein the valve includes:
a valve port;
a stepper motor; and
a movable valve member movable relative to the valve port by the stepper motor between a closed position in which fluid flow through the valve port is inhibited and an open position in which fluid flow through the valve port is permitted;

wherein:
the valve includes a rotor

Assignees

• Emerson Electric Co

Inventors

• Sisk Gregory E
• Arensmeier Jeffrey N
• Gilliam Christina M
• Sutton Iii Joseph B
• Stoneking Thomas
• Ridderhoff Jacob

Classifications

• F25B2600/2513

  Expansion valves · CPC title

• Y02B30/70

  Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating · CPC title

• F25B41/35 Primary

  by rotary motors, e.g. by stepping motors · CPC title