In the two-cylinder hermetic compressor, a main bearing is disposed on one surface of a first cylinder, an intermediate plate is disposed on another surface of the first cylinder, the intermediate plate is disposed on one surface of a second cylinder, and an auxiliary bearing is disposed on another surface of the second cylinder. A shaft is constituted by a main shaft portion which has a rotor attached thereto and is supported by the main bearing, a first eccentric portion having a first piston attached thereto, a second eccentric portion having a second piston attached thereto, and an auxiliary shaft portion supported by the auxiliary bearing. A thrust receiving portion is provided on a side of the second eccentric portion facing the auxiliary shaft portion, and the auxiliary bearing is provided with a thrust surface on which the end face of the thrust receiving portion slides while contacting therewith. The thrust surface is provided with a ring groove.

In the two-cylinder hermetic compressor, a first compression mechanism unit includes a first cylinder and a first piston, and a second compression mechanism unit includes a second cylinder and a second piston. A main bearing is disposed on one surface of the first cylinder, and an intermediate plate is disposed on another surface of the first cylinder. The intermediate plate is disposed on one surface of the second cylinder, and an auxiliary bearing is disposed on another surface of the second cylinder. A shaft is constituted by a main shaft portion which has a rotor attached thereto and is supported by the main bearing, a first eccentric portion having a first piston attached thereto, a second eccentric portion having a second piston attached thereto, and an auxiliary shaft portion supported by the auxiliary bearing. The diameter of the auxiliary shaft portion is set larger than the diameter of the main shaft portion.

A rotary compressor includes a casing, an electric motor, a compression mechanism and a balance weight mechanism. The electric motor includes a stator fixed to the casing, and a rotor. The compression mechanism is connected to the electric motor via a drive shaft. The balance weight mechanism is configured to cause centrifugal force to act on the drive shaft. The rotor includes a rotor core including a plurality of stacked electromagnetic steel sheets, and a rivet configured to clamp the rotor core at axial ends of the rotor core. The balance weight mechanism includes an insertion portion into which drive shaft is press fit, and a flat portion forming a flat surface at an axial end of the drive shaft. The balance weight mechanism is disposed at an axial end portion of the rotor to cover a head of the rivet.

The purpose of the present invention is to provide a scroll fluid machine, the reliability of which is ensured and which can be manufactured with high productivity. The present invention provides a scroll fluid machine comprising: a stationary scroll having a spiral wrap upstanding therefrom; an orbiting scroll provided facing the stationary scroll and orbiting; a casing provided outside the orbiting scroll; a drive shaft for causing the orbiting scroll to orbit; an orbiting bearing for transmitting the rotational movement of the drive shaft to the orbiting scroll; and a plurality of rotation prevention mechanisms for preventing the orbiting scroll from rotating. The scroll fluid machine is characterized in that: the rotation prevention mechanisms have crankshafts and also have crank bearings for supporting the crankshafts; and the gap between each of the crankshafts and the corresponding one of the crank bearings is set to be greater than the gap between the drive shaft and the orbiting bearing.

A compressor may include a non-orbiting scroll, an orbiting scroll, a driveshaft and an Oldham coupling. The orbiting scroll meshingly engages the non-orbiting scroll. The driveshaft includes a crankpin engaging the orbiting scroll and driving the orbiting scroll in an orbital path relative to the non-orbiting scroll. The Oldham coupling may include an annular body and a plurality of first keys extending from the annular body and slidably received in slots formed in the orbiting scroll. Each of the first keys may include a first post and a first cap covering at least a portion of the first post. The first posts may be integrally formed with the annular body from a first material. The first caps may be attached to the first posts and formed from a second material.

A compressor includes a drive shaft having a main shaft and an eccentric portion, and a compression mechanism having a fitted tubular portion into which a fitted shaft portion of the drive shaft is fitted. The fitted shaft portion and the fitted tubular portion slide relative to each other with an oil film interposed between. The fitted shaft portion has first and second sliding surfaces formed as portions of an outer peripheral surface in the circumferential direction. The second sliding surface has a smaller axial width than the first sliding surface. A sliding portion between the fitted shaft portion and the fitted tubular portion has a gap adjacent to the second sliding surface into which a lubricating oil flows, and an oil retainer to keep the lubricating oil in the gap from flowing out toward an end surface of the fitted shaft portion.

A compressor includes a drive shaft having a main shaft and an eccentric portion, and a compression mechanism having a fitted tubular portion into which a fitted shaft portion of the drive shaft is fitted. The fitted shaft portion and the fitted tubular portion slide relative to each other with an oil film interposed between. The fitted tubular portion has first and second sliding surfaces formed as portions of an inner peripheral surface of the fitted tubular portion in the circumferential direction. The second sliding surface has a smaller axial width than the first sliding surface. A sliding portion between the fitted shaft portion and the fitted tubular portion has a gap adjacent to the second sliding surface into which a lubricating oil flows, and an oil retainer to keep the lubricating oil in the gap from flowing out toward an end surface of the fitted tubular portion.

A compressor crankshaft assembly includes a crankshaft and an eccentric drive pin extending from one end of the crankshaft. The shape of the drive pin viewed into the exposed end of the drive pin is defined by the intersection of a first cylinder that is coaxial with the axis of a substantially cylindrical orbital bearing journaled and installed to receive the eccentric drive pin and a second cylinder that is coaxial with the axis of a substantially cylindrical main bearing journaled and installed to rotatably receive the crankshaft, such that the area defined by the intersecting portion is less than the area defined by either cylinder.

A crankshaft for a rotary compressor comprising a body formed with an oil supply passage; and an eccentric portion, fitted over the body, having a central axis eccentrically disposed relative to a central axis of the body, and provided with an oil outlet hole communicated with the oil supply passage and penetrating an outer peripheral wall of the eccentric portion.

A scroll compressor including a first bearing rotatably supporting a rotary shaft relative to a casing at one side of the rotary shaft with respect to a motor, a second bearing rotatably supporting the rotary shaft relative to the casing at the other side of the rotary shaft with respect to the motor, and a third bearing rotatably supporting the rotary shaft relative to an orbiting scroll at the opposite side of the first bearing with respect to the second bearing. The distance between a first bearing center and a third bearing center is a predetermined distance, the distance between a motor center and the third bearing center is longer than the distance between the motor center and the first bearing center, and the distance between a second bearing center and the motor center is longer than the distance between the second bearing center and the third bearing center.