Patent ID: 6528919
Filing Date: 2003-03-04
Classification: H02K

Abstract:
A brushless motor comprising:a motor holder including a stator secured thereto, said stator rotatably supporting a rotor, said motor holder having a circuit board connected thereto, said circuit board having an excitation circuit for supplying exciting current to said stator; and a case connected to said motor holder, said case covering said circuit board and defining a ventilation chamber in cooperation with said motor holder, said ventilation chamber including an air inlet portion, an air outlet portion and a water draining portion, said air inlet portion being in communication with an atmosphere, said air outlet portion being in communication with said stator, said water draining portion draining water introduced into said ventilation chamber out of said brushless motor, said brushless motor providing a flow of cooling air passing through said ventilation chamber via said air inlet portion and said air outlet portion toward said stator for cooling heat generated during rotation of said rotor, said motor holder having one or more guide ribs arranged in said ventilation chamber, said case having one or more guide ribs arranged in said ventilation chamber, at least a portion of at least one of said one or more guide ribs of said motor holder being placed adjacent to and extending substantially parallel to at least a portion of at least one of said one or more guide ribs of said case to define an air passage for guiding said cooling air from said air inlet portion to said air outlet portion, said water draining portion being located outside of said air passage.