The structure is compact and its production efficiency is high. The use of bowl shaped bearing offers a high accuracy reserve. The centralized thin oil lubrication, water, or grease sealing and dust control system are used. When the uncrushable materials enter the crushing chamber, the spring safety device can protect equipment from damages. It is usually used in secondary and tertiary crushing. It is suitable for crushing various ores and rocks with a hardness above medium level, such as iron ore, copper ore, limestone, quartz, granite, sandstone, etc. Standard type is applicable to the medium crushing. The medium and short head types are used for fine crushing, and they are widely used in mineral processing, building materials, water conservancy, chemical industry and other fields.