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US 6,474,950 B1Granted
Oil free dry screw compressor including variable speed drive
AssigneeIngersoll-Rand Company
InventorKeith D. Waldo
Life of this patent
Estimating the term…
Abstract
An oil-free dry screw compressor system is provided and includes a variable speed drive and motor along with control logic to increase or decrease the speed of the drive and motor based on sensed pressures. By using an electric motor and a rectifier/inverter drive, a variable speed compressor system is provided having a drive system that can be stopped and started an unlimited number of times over a given time period. Methods of controlling pressure in a compressor system including an oil-free dry screw compressor are also provided.
Claims10
An oil-free dry screw compressor system comprising:
- an oil-free dry screw compressor;
- means for driving said compressor;
- and
- means for varying the speed of said means for driving, the means for varying configured to provide a drive signal to the means for driving such that the means for driving is operated at a speed within a range of speeds between a maximum speed and a minimum speed when a sensed compressor output pressure is less than a maximum compressor output pressure and the means for driving operates at a speed corresponding to the minimum speed for a given time T and thereafter is stopped when the sensed compressor output pressure is substantially equal to or greater than the maximum compressor output pressure.
1 more element
Dependencies are inferred from the claim text.