Counterweight of reduced size

• US 6,305,914 B1
• Filed: 03/27/2000
• Issued: 10/23/2001
• Est. Priority Date: 03/27/2000
• Status: Expired due to Fees

• Current Assignee: Scroll Technologies (Danfoss A/S)
• Original Assignee: Scroll Technologies (Danfoss A/S)
• Inventors: Lifson, Alexander
• Primary Examiner(s): Freay, Charles G.
• Assistant Examiner(s): HAYES, ERIC D
• Application Number:
  US09/535,596
• Time in Patent Office: 575 Days
• Field of Search: 417/410.5, 418/151
• US Class Current: 417/410.5
• CPC Class Codes: F04C 18/0215 where only one member is moving
• CPC Class Codes: F04C 2240/807 Balance weight, counterweight
• CPC Class Codes: F04C 23/008 Hermetic pumps
• CPC Class Codes: F04C 29/0021 Systems for the equilibration of forces acting on the pump interstice adjustment other than by fluid pressure F01C21/102
• CPC Class Codes: F16F 15/28 Counterweights, i.e. additional weights counterbalancing inertia forces induced by the reciprocating movement of masses in the system, e.g. of pistons attached to an engine crankshaft rotating balancer shafts F16F15/264; correcting-weights for balancing rotating bodies F16F15/32; Attaching or mounting same

Abstract

Counterweight size is reduced by removing material from an electric motor rotor for a machine, such as a compressor. The material is removed asymmetrically with respect to shaft centerline to provide maximum benefit. Counterweight size reduction results in decrease of compressor dimensional envelope and weight.

Claims

1. A scroll compressor comprising:

a first scroll member having a base and a generally spiral wrap extending from said base;

a second scroll member having a base and a generally spiral wrap extending from said base, said wrap of said first and second scroll members interfitting to define compression chambers;

a shaft operably connected to cause said second scroll member to orbit relative to said first scroll member;

an electric motor for driving said shaft about a rotational axis, said electric motor incorporating a stator and a rotor, said rotor being fixed to rotate with said shaft; and

material removed from a portion of said rotor to assist in balancing forces during orbital movement of said orbiting scroll member, said removed material being non-symmetrical about a rotational axis of said rotor, and said removed material being removed as holes each formed entirely within a 90 degree circumferential section of said rotor.

2. A scroll compressor as recited in claim 1, wherein there are a plurality of said holes.

3. A scroll compressor as recited in claim 1, wherein said holes extend through the entire length of said rotor.

4. A scroll compressor as recited in claim 1, wherein said holes extend for only a portion of the length of said rotor.

5. A scroll compressor as recited in claim 1, wherein said removed material is formed by a notch at a circumferential location generally 180°

opposite to the counterweight located closest to the notch circumferential location.

6. A scroll compressor as recited in claim 5, wherein said removed material is formed by a notch at circumferential location generally coinciding with the counterweight location and a counterweight extension being mounted in said notch.

7. A scroll compressor as recited in claim 5, wherein said counterweight is formed of a material which is denser than the material of the rotor end.

8. A scroll compressor as recited in claim 7, wherein said counterweight extension includes a tooth protruding downwardly into said notch.

9. A scroll compressor as recited in claim 7, wherein said rotor includes a plurality of pins extending upwardly into openings in said counterweight to assist in positioning said counterweight on said shaft.

10. A scroll compressor comprising:

a first scroll member having a base and a generally spiral wrap extending from said base;

a second scroll member having a base and a generally spiral wrap extending from said base, said wrap of said first and second scroll members interfitting to define compression chambers;

a shaft operably connected to cause said second scroll member to orbit relative to said first scroll member;

an electric motor for driving said shaft about a rotational axis, said electric motor incorporating a stator and a rotor, said rotor being fixed to rotate with said shaft; and

material removed from a portion of said rotor to assist in balancing forces during orbital movement of said orbiting scroll member, said removed material being non-symmetrical about said rotational axis, said removed material being formed by a plurality of holes, and not being symmetric about said rotational axis, and said holes extending generally parallel to said rotational axis and said holes each formed entirely within a 90 degree circumferential section of said rotor.

11. A compressor comprising:

a compressor pump unit;

a shaft operably connected to drive said compressor pump unit;

an electric motor for driving said shaft about a rotational axis, said electric motor incorporating a stator and a rotor, said rotor being fixed to rotate with said shaft; and

material removed from a portion of said rotor to assist imbalancing forces during operation of said compressor pump unit, said removed material be non-symmetrical about said rotational axis of said rotor, said removed material being provided by a plurality of holes each formed within a 90 degree circumferential section of said rotor.