Abstract: In a scroll fluid machine, a driving shaft extends axially to allow an orbiting scroll to revolve with respect to a fixed scroll thereby compressing a gas introduced from the outer circumference of the fixed scroll in a compressing chamber formed between the orbiting and fixed scrolls. From one end of the driving shaft, external air is introduced in a cooling hole extending axially of the driving shaft to cool the driving shaft. A cooling fan is rotatably secured at one end of the driving shaft to rotate by the driving shaft to cool the fixed scroll. The cooling fan comprises a base plate having a main fin on one side surface facing the side of the fixed scroll and a plurality of auxiliary fins on the other side surface to prevent cooling-finished air from invading into the cooling hole of the driving shaft.

Abstract: In a scroll fluid machine, a fixed scroll has a fixed wrap, and an orbiting scroll has an orbiting wrap which engages with the fixed wrap to form a compressing chamber between the orbiting and fixed wraps. The orbiting scroll is rotatably mounted around an eccentric axial portion of a driving shaft and revolved by the driving shaft. A gas introduced from the outer circumference of the fixed scroll is compressed in the compressing chamber as it flows towards the center. Parts near the center is heated by a compressed gas. On the other surface of the fixed scroll to the surface having the fixed wrap, a plurality of cooling fins are provided. Air is introduced between the cooling fins to cool the machine. Between the cooling fins, a heat-releasing projection is provided to improve cooling efficiency.

Abstract: The present invention discloses an evacuation apparatus for evacuating a tank, a chamber, and the like; wherein a mechanical vacuum booster pump is provided at an up-stream side of an exterior side vacuum pump; wherein the mechanical booster pump has a discharge openings for low compression and a discharge opening for discharging a high compression gas; wherein, in case when the exterior side vacuum pump starts discharging a gas, the gas is sent to the exterior side vacuum pump through all of the discharge openings for low compression and the discharge opening for discharging a high compression gas and, in case when the discharged gas pressure reaches afterward an ultimate pressure (a medium vacuum) attainable by the exterior side vacuum pump, the gas is sent to the exterior side vacuum pump only through the discharge opening for discharging a high compression gas.

Abstract: In a scroll fluid machine, a driving shaft extends axially to allow an orbiting scroll to revolve with respect to a fixed scroll thereby compressing a gas introduced from the outer circumference of the fixed scroll in a compressing chamber formed between the orbiting and fixed scrolls. From one end of the driving shaft, external air is introduced in a cooling hole extending axially of the driving shaft to cool the driving shaft. A cooling fan is rotatably secured at one end of the driving shaft to rotate by the driving shaft to cool the fixed scroll. The cooling fan comprises a base plate having a main fin on one side surface facing the side of the fixed scroll and a plurality of auxiliary fins on the other side surface to prevent cooling-finished air from invading into the cooling hole of the driving shaft.

Abstract: In a scroll fluid machine, a fixed scroll has a fixed wrap, and an orbiting scroll has an orbiting wrap which engages with the fixed wrap to form a compressing chamber between the orbiting and fixed wraps. The orbiting scroll is rotatably mounted around an eccentric axial portion of a driving shaft and revolved by the driving shaft. A gas introduced from the outer circumference of the fixed scroll is compressed in the compressing chamber as it flows towards the center. Parts near the center is heated by a compressed gas. On the other surface of the fixed scroll to the surface having the fixed wrap, a plurality of cooling fins are provided. Air is introduced between the cooling fins to cool the machine. Between the cooling fins, a heat-releasing projection is provided to improve cooling efficiency.