Motor with heat dissipation structure

Abstract

A motor includes a cylindrical housing, a cooling fan, and a rotating shaft. The cylindrical housing defines at least one upstream through hole at its circumferential wall. The cooling fan is mounted at the rotating shaft for generating airflow towards the cylindrical housing for dissipating the heat generated in the motor. The hollow hood is mounted to the cylindrical housing such that a head portion is located above the upstream through hole, thus defining an annular air-guiding channel therebetween, which can receive the airflow generated by the cooling fan and guide the airflow to enter the cylindrical housing via the upstream through holes, so that the heat generated therein can be dissipated effectively. Thus, heat is not easy to accumulate in the motor, and the performance and service life of the motor can be increased.

I claim: 
     
         1 . In a motor including a cylindrical housing, a cooling fan, and a rotating shaft, the cylindrical housing defining at least one upstream through hole at its circumferential wall, the cooling fan being mounted at the rotating shaft for generating an air current towards the cylindrical housing for dissipating the heat generated in the motor; wherein the improvement comprises:
 a hollow hood is provided for collecting the air current generated by the cooling fan, the hollow hood having a neck portion, a head portion, and a gradually enlarged transitional portion integrally formed between the neck portion and the head portion, the neck portion opening out at a first opening, the head portion opening out at a second opening which is opposite to the first opening, the hollow hood being mounted to the cylindrical housing, near the cooling fan, such that the neck portion is closely fitted around the cylindrical housing, and the head portion of the hollow hood is located above the upstream through hole, thus defining an annular air-guiding channel therebetween which communicates with the upstream through hole, and forming an intercepting surface at an inner surface of the gradually enlarged transitional portion of the hollow hood, the upstream through hole being located between the intercepting surface and the second opening of the hollow hood, whereby the air current can quickly pass through the annular air-guiding channel and the upstream through hole to enter the cylindrical housing to take away the heat generated therein.   
     
     
         2 . The motor of  claim 1 , wherein the first opening of the hollow hood is a circular opening; the second opening of the hollow hood is a circular opening; the hollow hood is a bell-shaped body, so that the annular air-guiding channel has a cross-sectional dimension which increases gradually as extending from the intercepting surface to the second opening of the hollow hood. 
     
     
         3 . The motor of  claim 2 , wherein the first opening of the hollow hood has a diameter of (Y), the second opening of the hollow hood has a diameter of (X), and the gradually enlarged transitional portion of the hollow hood generally has an internal diameter of (Z) at its intercepting surface, wherein the relationship of X>Y and X>Z and Y=Z is fulfilled.