A rack master of a stocker is provided to maximize power transfer efficiency and improve productivity by simplifying a power transfer path. A speed reducer(242) is installed at a motor(241). A driving wheel receives power output through the speed reducer and is moved by the received power. A shaft(247) is installed between two shafts. A ball joint(295) is installed between the speed reducer and the shaft. A roller bearing(290) is provided outside the shaft. The shaft maintains balance by confining torque between the two shafts. The ball joint compensates for eccentricity between the two shafts. The speed reducer decreases a speed of high-speed rotation of the motor. The roller berating prevents vertical and horizontal movements of the shaft.
展开▼
