Patent ID: 7357627

Claim:
A scroll fluid machine comprising: a housing; a driving shaft comprising an eccentric axial portion at one end of the driving shaft; a stationary scroll comprising a stationary wrap, the stationary scroll being fixed to the housing; an orbiting scroll comprising an orbiting wrap and a rear surface, the orbiting scroll being positioned and configured to revolve with the eccentric axial portion of the driving shaft, the orbiting wrap being positioned and configured to engage with the stationary wrap to form a sealed chamber between the stationary wrap and the orbiting wrap; the orbiting scroll being axially slidable for adjusting axial engagement of the orbiting scroll with respect to the stationary scroll; a bearing plate fixed to the rear surface of the orbiting scroll and comprising an eccentric boss positioned at an outer circumference of the bearing plate, the eccentric boss having a hole; and a plurality of self-rotation preventing devices positioned on the orbiting scroll, the plurality of self-rotation preventing devices being configured to prevent the orbiting scroll from rotating on its own axis, each device of the plurality of self-rotation preventing devices comprising: an eccentric tube connected to a main shaft rotatably fitted in the housing, an eccentric shaft comprising an inner end face, the eccentric shaft being positioned and configured to rotate eccentrically with respect to the main shaft, the eccentric shaft being engaged in the hole of the eccentric boss, a bolt screwed in the eccentric shaft of the device through the bearing plate, a nut screwed in the eccentric shaft engaging with the bearing plate, the bolt and the nut being positioned and configured to adjust engagement between the stationary scroll and the orbiting scroll, a gap between a bottom of the hole of the eccentric boss and the inner end face of the eccentric shaft, and a resilient material positioned in the gap.