| 摘要 |
The mechanism consists of a housing (34) containing a bracket for supporting a propulsion unit and a bearing (24) for a wheel (25). The propulsion unit is itself mounted on a frame (11) which is fixed to the surface of the door or gate and is able to move so that the wheel can follow irregularities in the ground, while a spring (33) holds the wheel against the ground with a given minimal pressure. The frame has two parallel slideways for the propulsion unit bracket, which has the bearing for the wheel axle (28) at its lower end and a motor/reduction unit above it. The output shaft (26) of the drive unit lies parallel to the wheel axle and is connected to it through a chain and sprocket transmission system (27). The frame (11) has a flat sole plate for the slideways and holes (18,19) along it sides for fixing to the door or gate. |
