Drive apparatus having a motor, a heat sink, and a plurality of semiconductor modules

A drive apparatus comprising:

• a motor having a motor case formed in a cylindrical shape to define an outer periphery, a stator located radially inside the motor case and wound with winding wires to provide a plurality of phases corresponding to a U-phase, V-phase, and W-phase, a rotor located radially inside the stator and rotatable relative to the stator, and a shaft rotatable together with the rotor;
• a heat sink arranged in an axial direction of the motor case and having a plurality of column-shaped parts spaced apart from one another;
• and
• a plurality of semiconductor modules provided for a plurality of power supply systems, each of which switches over coil currents for the plurality of phases corresponding to a U-phase, V-phase, and W-phase supplied to the winding wires by a plurality of switching elements, and arranged on the plurality of column-shaped parts such that one power supply system corresponds to one column-shaped part,
• wherein a part of the plurality of semiconductor modules forming the one power supply system is arranged on the one column-shaped part corresponding to the one power supply system;
• the heat sink has a first column-shaped part and a second column-shaped part, as the plurality of column-shaped parts;
• the plurality of power supply systems has a first power supply system and a second power supply system in correspondence to the first column-shaped part and the second column-shaped part, respectively;
• the plurality of semiconductor modules has a first part of semiconductor modules forming the first power supply system and a second part of semiconductor modules forming the second power supply system;
• and
• all the first part of semiconductor modules and all the second part of semiconductor modules are provided on the first column-shaped part and the second column-shaped part, respectively.