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US 7,997,088 B2Granted
Hybrid spool valve for multi-port pulse tube
AssigneesSumitomo Heavy Industries, Ltd., SHI-APD Cryogenics, Inc.
InventorRalph C. Longsworth
Life of this patent
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Abstract
The problems of reducing the torque required to turn the valve, eliminating wear dust, and extending the life of the valves in Gifford McMahon (G-M) type multi-port pulse tube refrigerators are solved by using a rotary spool valve having radial clearance to control flow to and from the regenerator, and using face seal ports on the end of the spool to control flow to and from the pulse tubes.
Claims8
A multi-ported rotary spool valve for a G-M pulse tube refrigerator, comprising:
- a close fitting rotating spool mounted inside a fixed sleeve having multiple radial ports;
- and
- an end face on said rotating spool including a flat face in sliding contact with the flat face of a valve plate having multiple axial ports, wherein
- said sliding contact being maintained by virtue of a gas pressure being higher on an end of the spool opposite the ports than an average pressure on an end of the spool with the ports, and
- gas flows to a regenerator of said pulse tube through said radial ports and gas flows to a warm end of one or more pulse tubes through said axial ports.
2 more elements
Dependencies are inferred from the claim text.