Inertial balance system for a de-orbiting scroll in a scroll type fluid handling machine

• US 5,282,728 A
• Filed: 06/02/1993
• Issued: 02/01/1994
• Est. Priority Date: 06/02/1993
• Status: Expired due to Term

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Swain, James C.
• Primary Examiner(s): Bertsch, Richard A.
• Assistant Examiner(s): FREAY, CHARLES GRANT
• Application Number:
  US08/070,582
• Time in Patent Office: 244 Days
• Field of Search: 418/55.1, 418/55.3, 418/55.5, 418/57, 418/151
• US Class Current: 418/55.5
• CPC Class Codes: F04C 18/0215 where only one member is moving
• CPC Class Codes: F04C 28/06 specially adapted for stopping, starting, idling or no-load operation
• CPC Class Codes: F04C 28/22 by changing the eccentricity between cooperating members
• CPC Class Codes: F04C 29/0057 for eccentric movement

Abstract

A scroll compressor (10) with a fixed scroll (18) and an orbital scroll (20) has an axial thrust and anti-rotation assembly (22), a drive assembly (24), a balance assemblly (26) and a control system (28). The drive assembly (24) includes a crankshaft (116) and a bushing assembly (108). The bushing assembly includes a bushing body (146) with a slot (154) journaled on the orbital scroll and a drive lug (150) positioned in the slot and non-rotatably secured to the crankshaft (116). Springs (156) bias the bushing body toward a position in which the axis of the bushing body (178) coincides with the axis (176) of the crankshaft and the crankshaft can rotate without moving the orbital scroll (20). The bushing body (146) can be moved by compressed fluid to a position in which the springs (156) are compressed, the scroll wraps (34 and 56) are in sealing contact and the drive assembly will drive the orbital scroll (20) in a circular orbit with a radius R. The balance assembly includes two weight assemblies (184 and 186) with four weights (192, 196, 210, and 214) that are rotated about the axis of a cylindrical extension (182) in response to movement of the drive lug (150) relative to the bushing body (146) between a position in which the orbital scroll is balanced and a position in which the weights balance themselves when the crankshaft (116) rotates without driving the orbital scroll.

Claims

1. A balance system for a scroll type fluid handling machine having a housing with a front section and a rear section;

a fixed scroll with an end plate and a wrap in the rear section of the housing;

an orbital scroll with an end plate and a wrap that cooperates with the fixed scroll to displace fluid;

an orbital scroll drive including a crankshaft rotatably journaled in the front section of the housing and operable to drive the orbital scroll in an orbit; and

a pair of balance assemblies that are rotated by the crankshaft and are shiftable relative to each other to change the balance force exerted by the balance assemblies.

2. A balance system for a scroll type fluid handling machine having a housing with a front section and a rear section;

a fixed scroll with an end plate and a wrap in the rear section of the housing;

an orbital scroll with an end plate and a wrap that cooperates with the fixed scroll to displace fluid;

an orbital scroll drive including a crankshaft rotatably journaled in the front section of the housing and selectively connected to the orbital scroll to drive the orbital scroll in an orbital path or to rotate without driving the orbital scroll; and

a balance system including a cylindrical member which surrounds a portion of the crankshaft, rotates with the crankshaft and has a central axis that is parallel to the axis of rotation of the crankshaft, a first balance weight assembly journaled on the cylindrical member and having an arm that extends radially inward through a slot in the cylindrical member and engages the crankshaft, a second balance weight assembly journaled on the cylindrical member and having an arm that extends radially inward through a slot in the cylindrical member and engages the crankshaft, and an actuator connected to the cylindrical member and operable to displace the cylindrical member relative to the crankshaft and rotate the first and second balance weight assemblies about the axis of the cylindrical member.

3. A balance system for a scroll type fluid handling machine having a housing with a front section and a rear section;

a fixed scroll with an end plate and a wrap in the rear section of the housing;

an orbital scroll with an end plate and a wrap that cooperates with the fixed scroll to displace fluid;

an orbital scroll drive including a crankshaft rotatably journaled in the front section of the housing and connected to the orbital scroll by a bushing assembly;

a bushing assembly shifter that is operable to change a radius of the orbit scroll orbit; and

a balance system including a cylindrical member which surrounds a portion of the crankshaft, rotates with the crankshaft and has a central axis that is parallel to the axis of rotation of the crankshaft, a first balance weight assembly journaled on the cylindrical member and having an arm that extends radially inward through a slot in the cylindrical member and engages the crankshaft, and an actuator connected to the cylindrical member and operable to displace the cylindrical member relative to the crankshaft and rotate the balance weight assembly about the axis of the cylindrical member.