Patent attributes
A cooling jacket for an electric motor and a motor unit with a cooling jacket mounted on an electric motor having simple structure and capable of being manufactured with reduced number of processes. A cooling pipe made of copper and the like is bent, and held by plate members and lid members, and resin having high heat-conductivity is filled in between to form a series of segments of the cooling jacket. Adjacent ones of the segments are connected with each other by connecting members to form the cooling jacket. The plate members are formed to conform with a shape of the electric motor. The series of segments are mounted on an outer surface of the electric motor and gaps between the adjacent segments are adjusted to bring the plate members into close contact with the outer surface of the electric motor. Since the cooling jacket is mounted on the electric motor after finishing the manufacturing of the electric motor, the electric motor is easily provided with cooling structure with reduced number of manufacturing processes.