Motor drive apparatus

摘要

In a motor drive apparatus for driving a three-phase AC motor, a first mounting part of a heat sink is formed along an end. A second mounting part is formed in a direction perpendicular to the first mounting part and includes a first column part and a second column part. Three motor relay FETs are mounted on the first mounting part. Six inverter FETs and two power relay FETs are mounted on the second mounting part. Leads of the FETs are electrically connected to an electric circuit substrate. Heat generated by the FETs is radiated to the heat sink through an insulating and heat radiating sheet. By thus arranging the FETs, the motor drive apparatus is reduced in size.

主权项

1. A motor drive apparatus for driving a n-phase AC motor by converting a DC current to a n-phase AC current with “n” being an integer equal to or greater than 3, the motor drive apparatus comprising:
2n-units of inverter semiconductor switching elements forming high-side arms and low-side arms of an inverter circuit; n-units of motor relay semiconductor switching elements provided at an output side of the inverter circuit and capable of shutting off a current supply path to the motor; a heat sink mounting thereon the inverter semiconductor switching elements and the motor relay semiconductor switching elements and capable of absorbing heat; and an electric circuit substrate connected to leads of the inverter semiconductor switching elements and the motor relay semiconductor switching elements, wherein the heat sink has a first mounting part formed along one end thereof and a second mounting part formed perpendicularly to the first mounting part in a direction from the one end towards an other end opposite to the one end, wherein the n-units of the motor relay semiconductor switching elements are mounted on the first mounting part of the heat sink, and wherein at least n-units of inverter semiconductor switching elements of the 2n-units of inverter semiconductor switching elements are mounted on the second mounting part of the heat sink.