Handheld grinder with brushless electric motor

A power tool comprising:

• an elongated housing defining a cavity therein, wherein the housing includes a motor case disposed at a front end thereof and a handle portion extending axially along a longitudinal axis of the housing from the motor case to a rear end of the housing;
• a motor having a drive shaft and mounted within the motor case;
• an output shaft drivably coupled to the drive shaft of the electric motor;
• a fan mounted on the output shaft and configured to generate airflow through the motor;
• a wall separating the cavity between the motor case and the handle portion of the housing, wherein the wall is configured to support a bearing for the drive shaft of the electric motor and includes one or more holes which permit air flow between the motor case and the handle portion of the housing;
• a planar circuit board disposed in the handle portion of the housing and extending axially along the longitudinal axis of the housing, where the planar circuit board axially divides the handle portion into a first section and a second section;
• a motor drive circuit accommodated within the handle portion of the housing on the planar circuit board and configured to deliver electric power to the motor, the motor drive circuit including a bridge circuit having a plurality of motor switches to control supply of electric power to the electric motor;
• a heat sink in thermal communication with the motor drive circuit disposed within the first section of the handle portion;
• and
• at least one air inlet disposed within the first section of the handle portion at the rear end of the housing, wherein the airflow generated by the fan enters through the at least one air inlet, flows through the first section of the handle portion in thermal communication with the heat sink, and enters the motor case through the one or more holes of the wall.