Patent ID: 8702401
Filing Date: 2014-04-22
Classification: F04D

Abstract:
1. A cooling fan comprising: a housing including a base and a sidewall coupled to the base, with the sidewall defining a compartment, with the housing further including an air inlet, an air outlet, and a dust channel, with each of the air outlet and the dust channel having an inlet end and an outlet end, with the air inlet, the inlet end of the air outlet, and the inlet end of the dust channel being in communication with the compartment; a stator coupled to the base of the housing; an impeller rotatably coupled to the stator; and a control element including a driving circuit electrically connected to the stator and a rotating direction control circuit electrically connected to the driving circuit, with the inlet end of the air outlet and the inlet end of the dust channel located at and spaced along an inner periphery of the sidewall and separating the inner periphery into a first guiding wall section and a second guiding wall section, with the first guiding wall section having a guiding portion contiguous to the dust channel, with the guiding portion being in a form of an acute corner, with a first spacing between the guiding portion and a center of the impeller being smaller than a second spacing between the second guiding wall section and the center of the impeller, with the second guiding wall section including a bend contiguous to the dust channel, with the second spacing being between the bend and the center of the impeller.