Anti-reverse rotation valve for scroll compressor

Abstract

A scroll-type refrigeration compressor has a gas-liquid mixture discharge passage extending through the driver scroll drive shaft for discharging refrigerant gas and entrained lubricant into a high pressure chamber in the compressor housing. An anti-reverse rotation valve is connected to the distal end of the drive shaft and includes a valve housing with radially extending discharge ports and a closure member movable to prevent reverse flow of high pressure gas to the scroll compression chambers to prevent reverse rotation on compressor shutdown. A pressure equalization port may be formed in the valve closure member, valve housing or the distal end of the drive shaft to allow slow bleed down of pressure from the high pressure side to the low pressure side to minimize starting torque of the drive motor. The valve may be formed from a tubular metal housing and having a plug-type closure member slidably disposed therein with the housing being press fitted in a counterbore in the end of the shaft. A gas-liquid separation baffle may be disposed around the valve housing for assisting in gas-liquid separation after the mixture is discharged from the valve housing. Valve embodiments include a housing and closure member arrangement supported such that rotation of the drive shaft exerts a centrifugal force on the closure member to bias it toward an open position. Centrifugal force responsive valves may be moved to their closed position by a biasing spring, pressure forces and gravity forces acting thereon, respectively.