Scroll fluid machine

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the invention will become more apparent from the following description with respect to embodiments as shown in accompanying drawings wherein:

FIG. 1 is a vertical sectional view showing one embodiment of a scroll fluid machine according to the present invention;

FIG. 2 is a front elevational view of a cooling fan;

FIG. 3 is a rear elevational view of the cooling fan; and

FIG. 4 is an enlarged vertical sectional view of the main part in FIG. 1.

Claims

1. A scroll fluid machine comprising: a driving shaft having an eccentric axial portion at one end and having an axial cooling hole through which cooling external air sucked from a front end flows to cool the driving shaft and is discharged from a rear end;a fixed scroll having a spiral fixed wrap;an orbiting scroll having a spiral orbiting wrap which engages with the fixed wrap to form a compressing chamber between the fixed and orbiting wraps, the orbiting scroll being rotatably secured around the eccentric axial portion of the driving shaft; anda cooling fan rotatably secured on the driving shaft and comprising a base plate that has a main fin on a rear surface and a plurality of auxiliary fins on a front surface, the driving shaft enabling the cooling fan to rotate to cool a side of the fixed scroll by the main fin, said plurality of auxiliary fins preventing cooling-finished air from invading into the cooling hole of the driving shaft.

2. A scroll fluid machine of claim 1 wherein each of said plurality of auxiliary fins extends from a vicinity of an opening of the cooling hole to an outer circumference.

3. A scroll fluid machine of claim 1 wherein one half of the base plate of the cooling fan is thicker than the other half of the base plate to form a balance weight of the cooling fan.

4. A scroll fluid machine of claim 1, further comprising a cover that covers the auxiliary fin of the base plate, the cover having an air-sucking hole at a center to introduce external air into the cooling hole of the driving shaft, and a discharge hole at an outer circumference to discharge the cooling-finished air to an outside.