A power tool includes a motor having a motor shaft that rotates about a motor axis in a first rotational direction. The power tool also includes a fan assembly attachable to the motor shaft for rotation in the first rotational direction. The fan assembly includes a fan body, a bearing having a race that rotates with the fan body, and a flywheel rotatably affixed to the fan body. The race is freely rotatable relative to the motor shaft in the first rotational direction, and fixed against rotation relative to the motor shaft in a second rotational direction opposite the first rotational direction. The flywheel has a central portion that defines a central bore, and the race is received into the central bore and rotatably affixed to the flywheel.