1. Encloser:made of high-classed steel, more firmly and dexterous.

2. The encloser trailing bar assembly is arranged behind the gear case assembly.

3. The invention discloses an uninterrupted dual power supply changeover switch, which comprises an encloser, a contact on-off system and a mechanical transmission system.

4. This bearing is a kind of ong-way thrust ball Bearing without keeper but with encloser and, it is inseparable, It canbear one-way axial loading and its dust prevention effect is good.

5. The production line breathes in less amount of air due to being provided with the encloser and movable doors, thereby effectively reducing environment pollution and improving operation environment.