Title:
PISTON POSITION DRIFT CONTROL FOR FREE-PISTON DEVICE
Document Type and Number:
WIPO Patent Application WO2004046532
Kind Code:
A3
Abstract:
A piston position drift control (110) for a free-piston device (112). The control includes a passage connecting internal volumes of the device, the passage (122) being substantially shorter than an acoustic wavelength of the device; and a check valve (124) in the passage for controlling fluid communication between the internal volumes, the check valve having an opening pressure not less than approximately 20% of a maximum pressure differential of the device at a maximum stroke. The control is passive, requires no active control once in service, provides low susceptibility to damage or fouling, and is amenable to adjustment or repair if needed. In addition, the control is small and inexpensive, and functions across the entire operational range of a free-piston device it supports. A related free-piston device including the piston position drift control is also provided.
Inventors:
COREY JOHN A
SPOOR PHILIP S
SPOOR PHILIP S
Application Number:
PCT/US2003/036901
Publication Date:
October 28, 2004
Filing Date:
November 19, 2003
Export Citation:
Assignee:
PRAXAIR TECHNOLOGY INC (US)
International Classes:
F01B11/00; F02B77/08; (IPC1-7): F15B11/08
Foreign References:
| US5461859A | 1995-10-31 | |||
| US6564552B1 | 2003-05-20 | |||
| US5873246A | 1999-02-23 | |||
| JPH09242903A | 1997-09-16 |
Other References:
See also references of EP 1563179A4
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