Compressor having main and adjustable balancer portions

1. A compressor comprising:

a compression unit for compressing gas to a desired pressure;

a drive shaft connected to the compression unit for driving the compression unit, imbalance on the drive shaft being generated due to movement of the compression unit; and

a balancer mounted on the drive shaft, the balancer having a main portion and an adjustable portion for correcting the imbalance on the drive shaft, said balancer further including a correction member placed between said main portion and said adjustable portion, wherein said correction member is a pin.

2. The compressor according to claim 1 , wherein the imbalance includes static imbalance due to tolerance.

3. The compressor according to claim 1 , wherein the imbalance includes dynamic imbalance that is generated while driving the compression unit.

4. The compressor according to claim 1 , wherein at lease one of the weight and the shape of said adjustable portion is adjustable.

5. The compressor according to claim 1 , wherein said correction member has a set of predetermined shapes.

6. The compressor according to claim 1 , wherein said correction member has a set of predetermined weights.

7. The compressor according to claim 1 , wherein a material of said correction member has greater specific gravity than that of said main portion and said adjustable portion.

8. A scroll type compressor comprising:

a housing;

a drive shaft supported in the housing by a bearing, the drive shaft having a central axis and a predetermined end;

a crankshaft connected to the predetermined end of the drive shaft, the crankshaft being offset in an eccentric direction from the central axis of the drive shaft;

a fixed scroll member fixed to the housing and having a fixed scroll base plate and a fixed scroll wall;

a movable scroll member operatively mounted on the crankshaft, the movable scroll member engaging with the fixed scroll member, the movable scroll member having a movable scroll base plate and a movable scroll wall;

a counter weight mounted on the drive shaft so as to apply a load substantially in an opposite direction relative to the eccentric direction;

a first balancer mounted on the drive shaft so as to apply a load substantially in the opposite direction; and

a second balancer mounted on the drive shaft so as to apply a load substantially in the eccentric direction; and

wherein at least one of said first balancer and said second balancer includes a main portion and at least one adjustable portion, the weight and the shape of said adjustable portion being adjustable for correcting imbalance among the load applied to the drive shaft, a plurality of holes being formed in said main portion, at least one hole being formed in said adjustable portion, said adjustable portion being connected to said main portion by a bolt through said at least one hole of said adjustable portion and at least one of the plurality of holes of said main portion.

9. The scroll type compressor according to claim 8 , wherein said first balancer is placed at an opposite side of the crankshaft relative to the bearing.

10. The scroll type compressor according to claim 8 , wherein said second balancer is placed at an opposite side of the crankshaft relative to the bearing.

11. The scroll type compressor according to claim 8 , wherein said first balancer is closer to the bearing than said second balancer.

12. The scroll type compressor according to claim 8 , wherein at least one of the weight and the shape of said adjustable portion is adjustable.

13. The compressor according to claim 8 , wherein said adjustable portion has a plurality of sub-portions, the sub-portions each having a unique shape.

14. The compressor according to claim 8 , wherein said adjustable portion has a pair of asymmetrical sub-portions.

15. The scroll type compressor according to claim 8 , further comprising a self rotation preventing mechanism with a plurality of movable pins, which allows the movable scroll member to orbit around the central axis of the drive shaft and prevents the movable member from self rotating, wherein said first balancer and said second balancer are placed on the drive shaft substantially in accordance with the following equation:

M 1 ×R 1 −M 2 ×R 2 −M 3 ×R 3 +M 4 ×R 4=0,

wherein M1 denotes the weight of the movable scroll member, a plurality of the movable pins and the crankshaft, M2 denotes the weight of the counter weight, M3 denotes the weight of the first balancer and M4 denotes the weight of the second balancer, and R1, R2, R3 and R4 respectively denote the distances between the center of gravity of the rotary components as included in the weights M1 through M4 and the central axis of the drive shaft.

16. The scroll type compressor according to claim 15 , wherein said first balancer and said second balancer are placed on the drive shaft substantially in accordance with the following equation:

M 1 ×R 1 ×L 1 −M 2 ×R 2 ×L 2 +M 3 ×R 3 ×L 3 −M 4 ×R 4 ×L 4=0,

wherein L1, L2, L3 and L4 respectively denote the distances between the first bearing and the center of gravity of the rotary components as included in the weights M1 through M4 along the central axis of the drive shaft.

17. The scroll type compressor according to claim 8 , wherein at least one of said first balancer and said second balancer has a correction member between said main portion and said adjustable portion.

18. The scroll type compressor according to claim 17 , wherein said correction members has a set of predetermined shapes.

19. The scroll type compressor according to claim 17 , wherein said correction member has a set of predetermined weights.

20. The scroll type compressor according to claim 17 , wherein a material of said correction member has a greater specific gravity than that of said main portion and said adjustable portion.

21. The scroll type compressor according to claim 17 , wherein said correction member is a pin.

22. A compressor comprising:

a compression unit for compressing gas to a desired pressure;

a drive shaft connected to the compression unit for driving the compression unit, imbalance on the drive shaft being generated due to movement of the compression unit;

a balancer mounted on the drive shaft, the balancer having a main portion and an adjustable portion for correcting the imbalance on the drive shaft; and

a correction member placed between said main portion and said adjustable portion, a material of said correction member has a greater specific gravity than that of said main portion and said adjustable portion.

23. A compressor comprising:

a compression unit for compressing gas to a desired pressure;

a drive shaft connected to the compression unit for driving the compression unit, imbalance on the drive shaft being generated due to movement of the compression unit; and

a balancer mounted on said drive shaft for correcting the imbalance on the drive shaft, said balancer further comprises a main portion and an adjustable portion, said main portion and said adjustable portion forming an internal area for receiving a correction member.

24. The compressor according to claim 23 , wherein the imbalance includes static imbalance due to tolerance.

25. The compressor according to claim 23 , wherein the imbalance includes dynamic imbalance that is generated while driving the compression unit.

26. The compressor according to claim 23 , wherein the correction member has a set of predetermined shapes.

27. The compressor according to claim 23 , wherein the correction member has a set of predetermined weights.

28. The compressor according to claim 23 , wherein at lease one of the weight and the shape of said adjustable portion is adjustable.

29. The compressor according to claim 23 , wherein a material of the correction member has greater specific gravity than that of said main portion and said adjustable portion.