Air compressor

Abstract

An air compressor includes a cooling fan having a back plate serving as a plate shape part formed on a flat plate, a normal line thereof being set to a direction along a rotational shaft of a motor, blades extending parallel with the rotational shaft from an inner side of the back plate towards an outer periphery thereof and being centrifugally formed on the back plate, and a ring part having a cylindrical shape substantially parallel with the rotational shaft and extending from the back plate towards a heat generation surface. When the motor is operated, exterior air sucked by the cooling fan is guided to a central part thereof, flows towards an outer periphery thereof along the back plate, deflected by the ring part, flows towards and collides with the heat generation surface and further flows radially.

What is claimed is: 
     
         1 . An air compressor comprising:
 an air tank configured to store therein compressed air;   a compression part configured to compress air sucked from an outside and to supply the air to the air tank;   a motor configured to drive the compression part;   a cooling fan provided at one end-side of a rotational shaft of the motor, and   a cover configured to cover at least the compression part, the motor and the cooling fan,   wherein the cooling fan comprises a ring part provided at an outer peripheral part thereof and having a substantially cylindrical shape, and   wherein the cooling fan is configured to change a direction of an air stream by the ring part.   
     
     
         2 . The air compressor according to  claim 1 , wherein the ring part is configured to guide the air stream to a first heat generation part. 
     
     
         3 . The air compressor according to  claim 1 , wherein the cooling fan comprises a plate-shaped part partially bridging between an attaching part to the rotational shaft and the ring part. 
     
     
         4 . The air compressor according to  claim 3 , wherein the attaching part and the ring part are connected and integrated over an entire circumference by the plate-shaped part. 
     
     
         5 . The air compressor according to  claim 3 ,
 wherein the cooling fan comprises a blade for generating an air stream, and   wherein the blade is integrated with the plate-shaped part.   
     
     
         6 . The air compressor according to  claim 1 , wherein the cooling fan is configured to generate an air stream flowing from a center-side towards an outer peripheral direction by a rotation of the blade and to change a direction of the air stream such that the air stream has a component in a direction along the rotational shaft. 
     
     
         7 . The air compressor according to  claim 6 , wherein a first heat generation part is arranged at a position which faces the cooling fan and with which the air stream which direction has been changed by the ring part collides. 
     
     
         8 . The air compressor according to  claim 7 ,
 wherein a baffle wall part is provided at a position facing a part except for a central part of the cooling fan at the same side as the first heat generation part,   wherein the cooling fan is configured to suck the air stream through between the first heat generation part and the baffle wall part, and   wherein the ring part enables an outflow direction of the air stream of the cooling fan to be close to parallel with the suction direction of the air stream.   
     
     
         9 . The air compressor according to  claim 7 , wherein the first heat generation part is a control circuit board or a holding member of the control circuit board. 
     
     
         10 . The air compressor according to  claim 1 , wherein the cover comprises a ventilating window at a position facing a suction-side of the cooling fan. 
     
     
         11 . The air compressor according to  claim 1 , further comprising a baffle wall part configured to change a direction of the air stream outflowing from the cooling fan and to guide the air stream towards a second heat generation part. 
     
     
         12 . The air compressor according to  claim 11 , wherein the second heat generation part is a cylinder of the compression part. 
     
     
         13 . The air compressor according to  claim 12 , further comprising another cooling fan provided at the other end-side of the rotational shaft of the motor,
 wherein the baffle wall part is configured to guide the air stream outflowing from the cooling fan to a side of the cylinder with which an air stream from said another cooling fan does not collide.