This machine is a hydraulically adjusted four-roll crusher, a piece of equipment featuring the core four roll structure, mainly designed for crushing relatively soft materials such as coal and coke. The four-roll crusher is composed of the following key components: motor, reducer, upper driving roll, lower driving roll, upper driven roll, lower driven roll, frame, machine cover, hydraulic adjustment system, and cutting device (to be ordered separately by the user), all of which cooperate seamlessly to guarantee the stable running of the four roll assembly.
Two electric motors drive the upper and lower driving rolls respectively via reducers and couplings. The upper driving roll drives the lower driven roll through belt transmission, while the lower driving roll drives the upper driven roll in the same manner. The four roll setup is divided into upper and lower pairs, rotating in opposite directions respectively. Materials entering the gap between the paired rolls are crushed by the extrusion force of the counter-rotating rolls, and the crushed materials are discharged from the crushing chamber by gravity and the friction generated by the counter-rotating rolls.
The gap between the two rolls in the four roll structure is adjusted by the hydraulic cylinders mounted on the movable rolls. If the hydraulic system malfunctions and fails to maintain the required roll gap, adjusting shims can be installed between the roll bearing blocks to limit the gap. During operation, a constant pressure is maintained inside the hydraulic cylinders to prevent the movable rolls from retreating under normal working conditions, thus ensuring sufficient crushing force between the rolls of the four roll system.
When the strength or hardness of materials entering the roll gap is excessively high, resulting in a pressure that exceeds the preset pressure of the hydraulic system, the hydraulic system is equipped with a safety protection device that will automatically release pressure to protect the machine, especially the critical four roll part, from damage.
To ensure long-term, continuous and safe operation of the machine, particularly the core four roll assembly, its working condition must be inspected and timely maintenance must be performed every day. The main maintenance items are as follows: Maintaining good lubrication of the machine is a critical condition for its normal operation. It is necessary to frequently check whether the bearings, slideways and other components related to the four roll system are well-lubricated and whether the oil is clean. Under normal circumstances, the lubricating grease of the main machine bearings that support the four roll structure should be thoroughly inspected every 2–3 months of use (or before use if the equipment has been stored for 6–8 months after leaving the factory or being shut down). If the grease is found to be deteriorated, contaminated or insufficient, it should be replaced or replenished in a timely manner.
![four roll crusher.jpg]( "four roll crusher.jpg")
