Scroll fluid machine

A scroll fluid machine comprising:

• a compression mechanism part comprising a stationary scroll member, an orbiting scroll member to mesh with the stationary scroll member, and compression chambers formed between the both scroll members;
• a driver for driving the compression mechanism part;
• a closed vessel receiving the compression mechanism part and the driver to be substantially under a discharge pressure;
• a crankshaft rotated by the driver and having an eccentric pin portion for causing the orbiting scroll member in an orbiting movement;
• a first frame fixedly mounted in the closed vessel and having a shaft support to support the crankshaft, the shaft support for the crankshaft being arranged only on a side closer to the compression mechanism part than the driver;
• an Oldham's ring serving as a mechanism for preventing the orbiting scroll member from rotating on its axis;
• a shaft support of the orbiting scroll member configured to engage with the eccentric pin portion of the crankshaft and to be axially movable;
• an oil feed system, by which a lubricating oil is supplied to the shaft support for the crankshaft and the shaft support of the orbiting scroll member;
• a space formed by the first frame, the stationary scroll member, and the orbiting scroll member;
• a second frame provided in the space to be separable from the first frame;
• a seal portion making an end surface of the shaft support of the orbiting scroll member a seat surface and providing sealing between the seat surface and the second frame to thereby make separation in pressure between a central space and an outer peripheral space;
• and
• a space, in which a balance weight is arranged, formed between the first frame and the second frame to be communicated to the central space,
• wherein a lubricating oil supplied to the respective shaft supports from the oil feed system flows into the central space or the space, in which the balance weight is arranged.

A scroll fluid machine comprising:

• a compression mechanism part comprising a stationary scroll member, an orbiting scroll member to mesh with the stationary scroll member, and compression chambers formed between the both scroll members;
• a driver for driving the orbiting scroll member through a crankshaft having an eccentric pin portion;
• a first frame having a shaft support to support the crankshaft, the shaft support for the crankshaft being arranged only on an upper side of the driver;
• an Oldham's ring for preventing the orbiting scroll member from rotating on its axis;
• a closed vessel receiving these elements to be substantially under a discharge pressure;
• a space formed by the first frame, the stationary scroll member, and the orbiting scroll member;
• a second frame provided in the space to be separable from the first frame;
• a seal portion formed between the orbiting scroll member and the second frame to divide the space into a central space substantially under a discharge pressure and an outer peripheral space under a lower pressure than that in the central space;
• an oil feed system, by which a lubricating oil accumulated in a lower portion of the closed vessel is supplied to the shaft support for the crankshaft and the shaft support of the orbiting scroll member;
• a lower space formed between an underside of the second frame and the first frame to be communicated to the central space communicated in pressure to the oil feed system, and
• a balance weight arranged in the lower space.

A scroll fluid machine comprising:

• an orbiting scroll member having a spiral scroll wrap, which is provided upright on an end plate;
• a stationary scroll member having a spiral scroll wrap, which is provided upright on an end plate;
• compression chambers formed by meshing of the orbiting scroll member and the stationary scroll member with each other, and decreased in volume with orbiting movement of the orbiting scroll member;
• drive means for orbitingly driving the orbiting scroll member through a crankshaft having an eccentric pin portion;
• a first frame having a shaft support to support the crankshaft, the shaft support for the crankshaft being arranged only on a side of the drive means to the compression chambers;
• an Oldham's ring for preventing the orbiting scroll member from rotating on its axis;
• a shaft support of the orbiting scroll member to engage with the eccentric pin portion of the crankshaft;
• a space formed by the first frame and the stationary scroll member to arrange therein the orbiting scroll member and the Oldham's ring;
• a seal portion dividing in pressure the space into a central space and an outer peripheral space and making an end surface of the shaft support of the orbiting scroll member a seat surface;
• an oil feed system, by which a lubricating oil substantially at a discharge pressure is supplied to the shaft support for the crankshaft and the shaft support of the orbiting scroll member;
• and
• a closed vessel receiving therein these elements to be substantially under the discharge pressure;
• wherein
• there is provided a second frame separable from the first frame and defining the seal portion between it and the end surface of the shaft support of the orbiting scroll member, and
• the seal portion, which is defined by the end surface of the shaft support of the orbiting scroll member and the second frame, separates a central space, into which the lubricating oil having been supplied to the respective shaft supports from the oil feed system flows and which is substantially under a discharge pressure, and an outer peripheral space under a lower pressure than that in the central space, and
• a lower space is formed between an upper portion of the shaft support of the first frame and a lower portion of the second frame to be communicated in pressure to the central space and to be arranged relative to the outer peripheral space under the lower pressure with the seal portion therebetween, and
• a balance weight is arranged in the lower space.