ROTARY COMPRESSOR WITH CAPACITY MODULATION

• US 3,767,328 A
• Filed: 07/19/1972
• Issued: 10/23/1973
• Est. Priority Date: 07/19/1972
• Status: Expired due to Term

• Current Assignee: William T. Ladusaw
• Original Assignee: William T. Ladusaw
• Inventors: Ladusaw, William T.
• Primary Examiner(s): Croyle, Carlton R.
• Assistant Examiner(s): Sher, Richard
• Application Number:
  US05/273,117
• Time in Patent Office: 461 Days
• Field of Search: 417/310,283X,299X
• US Class Current: 417/310
• CPC Class Codes: F04C 28/16 using lift valves

Abstract

A rotary refrigerant compressor comprising a compression cylinder, a rotor eccentrically rotatable in the cylinder, suction and discharge ports communicating with the cylinder and a vane slidably mounted in a slot in the cylinder wall between the ports dividing the cylinder into high and low pressure sides includes means for modulating the compressor capacity. The modulation means comprises a bore communicating with the cylinder at a point intermediate the suction and discharge ports and having a modulating port on a side wall of the bore connected to the suction port. The modulating port is opened or closed by means of a plunger slidably mounted in the bore to modulate the compressor capacity.

Claims

1. A hermetic rotary refrigerant compressor comprising:

a hermetic casing;

a rotary compressor positioned in said casing and comprising means including a cylindrical wall member defining a compression cylinder;

a rotor eccentrically rotatable in said cylinder;

spaced suction and discharge ports in said wall member communicating with said cylinder;

a vane slidably mounted in said cylindrical wall member between said ports for engagement with said rotor to divide said cylinder into high and low pressure sides; and

means for modulating the capacity of said compressor comprising;

a radially extending bore in said cylindrical wall member spaced from said suction port and communicating with said cylinder;

means including a passage in said wall member having a modulating port in a wall portion of said bore connecting said suction port to said bore; and

a plunger slidably mounted in said bore for movement between a retracted position opening said modulating port and an extended position closing said modulating port and contacting said rotor.

2. A compressor according to claim 1 including means connecting the volume of said bore behind said plunger to discharge pressure for normally holding said plunger to its extended position;

and means connecting said volume to suction pressure to move said plunger to its retracted position for opening said modulating port and thereby reducing the capacity of said compressor.

3. A compressor according to claim 1 including tension spring means biasing said plunger to its retracted position.

4. A compressor according to claim 1 in which the connection to said suction port is within the hermetic casing.