Screw step drive internal volume ratio varying system for helical screw rotary compressor
US4909716A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1988 |
| Grant date | Mar 20, 1990 |
| Priority date | — |
| Expiry date | Oct 19, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04C28/125
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A large slide valve member concentrically mounts a small slide valve member or slide stop at one end thereof proximate to a helical screw rotary compressor discharge port with the small and large slide valve members movable as a unit for varying the built in volume ratio of the compressor. The small slide valve member is shiftable independently of the large slide valve member to vary the capacity of the machine. A large diameter cylinder fixedly mounted to the end of the compressor casing remote from an outlet port slidably mounts interiorly a smaller diameter cylinder fixed to the large slide valve via a spindle. The small slide valve is fixed to one end of a piston rod which extends through a bore within the large slide valve member and the spindle and terminates internally of the small diameter sliding inner cylinder and has fixed thereto a piston. Hydraulic fluid supplied to one side of the piston and removed from the other side shifts the small slide valve independent of the position of the large slide valve member. A stepping motor fixed to the outer cylinder has an output shaft fixed to an elongated ball screw mounted for rotation with its axis parallel to the concentric inn…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.