Light Duty：
Bearing Aperture: 80-100mm
The axle and the hub is connected by the simple key and it is the simple plate welding. The axle is unidirectional out.
Medium Duty:
Bearing Aperture: 120-180mm
The axle and the hub is connected by the ring lock.
Heavy Duty:
Bearing aperture: 200-220mm
The axle and the hub is connected by the ring lock. The shell body is aluminothermic welding  fabric. The axle can be unidirectional and two –way out.
The surface treatment of the driving pulley can be smooth steel herringbone or rhombic rubber lagging. The smooth steel pulley is available for the place which environment is small power, small belt width and dry. The herringbone rubber lagging has a big friction factor, better anti-slippery and drainage ability, but it has its own direction. The rhombic rubber lagging is available for two-way operating conveyors. The vulcanized rubber lagging pulley are mostly used for important applications.
The bearing housing of the pulley is lubricated by grease cup style lubrication.