Patent attributes
A power drive unit is configured to comprise a heat sink, a power module pressed by a press member to the heat sink to be fastened thereto and a spring member that has a substantially circular shape and is installed between the power module and the press member. With this, the power module can be fastened to the heat sink without incurring layout limitation, degradation of heat release performance and the like. Also, since the power drive unit further includes a projection that protrudes from the press member to be engaged with an engagement hole bored at the center of the spring member, engagement of the projection of the press member with the engagement hole of the spring member functions to prevent displacement of the press member relative to the spring member, thereby making loads acting on the power modules uniform.
