The object of the present invention is to provide a blower including a bearing structure wherein the number of components is reduced, the cost for manufacturing can be reduced, and the
diameter of the shaft can be increased. The bearing structure is good at its durability, eliminates or reduces the rotational run out, and provides superior quietness. The blower of the present invention having an
impeller adapted to be rotated upon energizing the blower comprising; a bearing device for supporting a rotational center portion of the
impeller, the bearing device including; a sleeve, a stepped shaft including a larger
diameter portion and a reduced
diameter portion provided at one end thereof, the first inner raceway groove formed at an appropriate position around the outer
peripheral surface of the larger diameter portion, the first outer raceway groove formed on an inner
peripheral surface of the sleeve so as to correspond with the first inner raceway groove, balls of the first row interposed between the first and second grooves, an inner ring slidably fit over the reduced diameter portion, the second inner raceway groove formed around an outer
peripheral surface of the inner ring, the second outer raceway groove formed on the inner peripheral surface of the sleeve so as to correspond with the second inner raceway groove, balls of the second row interposed between the second inner and outer raceway grooves, a stop ring provided around the inner periphery of the distal end of the reduced diameter portion, and a pre-loading spring interposed between the stop ring and an end surface of the inner ring to provide a suitable amount of pre-loading force to the inner ring.