Co-rotating scroll compressor and method for designing the same

1. A co-rotating scroll compressor, comprising:

a driving shaft driven by a drive unit so as to rotate;

a driving-side scroll member connected to the driving shaft, and including a plurality of spiral driving-side walls provided about a center of a driving-side end plate at predetermined angular intervals;

a driven-side scroll member including spiral driven-side walls, the driven-side walls being provided about a center of a driven-side end plate at predetermined angular intervals and in a number corresponding to the driving-side walls, the driven-side walls being engaged with the corresponding driving-side walls so as to form a compression space;

a synchronous driving mechanism provided between the driving-side scroll member and the driven-side scroll member, the synchronous driving mechanism synchronously transmitting driving force from the driving-side scroll member to the driven-side scroll member so that the driving-side scroll member and the driven-side scroll member rotationally move in a same direction at a same angular velocity;

a driving-side bearing that rotatably supports the driving-side scroll member; and

a driven-side bearing that rotatably supports the driven-side scroll member, wherein:

a center of gravity of at least one of the driving shaft, the driving-side scroll member, and the driven-side scroll member is shifted from a rotation center by a predetermined distance,

the predetermined distance being set so that a total bearing load obtained by centrifugal force and fluid compression that is 5% or more of a dynamic load rating of at least one of the driving-side bearing and the driven-side bearing or more is generated;

a driving-side supporting member arranged across the driven-side end plate, fixed to distal end sides of the driving-side walls in a rotating shaft direction, and the synchronous driving mechanism including a pin that engages the driven-side end plate to rotate the driven-side scroll member together with the driving-side scroll member; and

a driven-side supporting member arranged across the driving-side end plate, fixed to distal end sides of the driven-side walls in a rotating shaft direction, and the synchronous driving mechanism including a pin that engages the driving-side end plate to rotate the driving-side scroll member together with the driven-side scroll member, wherein a center of gravity of at least one of the driving-side supporting member and the driven-side supporting member is shifted from a rotation center.

2. The co-rotating scroll compressor according to claim 1 , wherein the predetermined distance is set so that a load to which a preload applied to at least one of the driving-side bearing and the driven-side bearing is added is 5% of the dynamic load rating or more.

3. The co-rotating scroll compressor according to claim 1 , wherein at least one of the plurality of driving-side walls and the plurality of driven-side walls is shifted from a position that is symmetrical to a rotation center.

4. A method for designing a co-rotating scroll compressor, the co-rotating scroll compressor including:

a driving shaft driven by a drive unit so as to rotate;

a driving-side scroll member connected to the driving shaft, and including a plurality of spiral driving-side walls provided about a center of a driving-side end plate at predetermined angular intervals;

a driven-side scroll member including spiral driven-side walls,

the driven-side walls being provided about a center of a driven-side end plate at predetermined angular intervals and in a number corresponding to the driving-side walls, the driven-side walls being engaged with the corresponding driving-side walls so as to form a compression space;

a synchronous driving mechanism that transmits driving force from the driving-side scroll member to the driven-side scroll member so that the driving-side scroll member and the driven-side scroll member rotationally move in a same direction at a same angular velocity;

a driving-side bearing that rotatably supports the driving-side scroll member;

a driven-side bearing that rotatably supports the driven-side scroll member;

a driving-side supporting member arranged across the driven-side end plate, fixed to distal end sides of the driving-side walls in a rotating shaft direction, and the synchronous driving mechanism including a pin that engages the driven-side end plate to rotate the driven-side scroll member together with the driving-side scroll member, and

a driven-side supporting member arranged across the driving-side end plate, fixed to distal end sides of the driven-side walls in a rotating shaft direction, and the synchronous driving mechanism including a pin that engages the driving-side end plate to rotate the driving-side scroll member together with the driven-side scroll member, wherein a center of gravity of at least one of the driving-side supporting member and the driven-side supporting member is shifted from a rotation center,

the method comprising:

shifting a center of gravity of at least one of the driving shaft, the driving-side scroll member, and the driven-side scroll member from a rotation center by a predetermined distance; and

setting the predetermined distance so that a total bearing load obtained by centrifugal force and fluid compression that is 5% or more of a dynamic load rating of at least one of the driving-side bearing and the driven-side bearing or more is generated.