Rod mills are widely used in many industrial departments. In beneficiation production, rod mills are one of the main grinding equipment. Here is some introduction of rod mill working principles or operation.
Rod mills are suitable for coarse grinding operation. Rod mill operation are as follow. With asynchronous motor speed reducer and small wheel gear connected, the peripheral big wheel gears are driven to gearing-down state. Under the combined effects of centrifugal force and friction force, the grinding media in the shell, rod mills, are carried up to a certain height and then fall down or are threw off to drop. Meantime, raw materials are constantly fed into the shell from feeding end and then crushed by the moving grinding media; after grinding, the products are discharged under the effect of overflow force and continuous feeding force and are transmitted to the next process. Rod mills are mainly composed of 15 parts, including tube feeding mechanism, main bearing parts, hydraulic brace device, high and low pressure pump stations, rotary mechanism, slow device, drive part, lubrication jetting system, middle spindle unit, discharging screening device, coupling, pneumatic clutch, synchronous motor, electric control system and gas path system.
There into, the structure of main bearing is designed into totally enclosed rocker type self-aligning bearing, with central bearing equipped with round high pressure oil chamber and with bearing Babbitt layer equipped with serpentine cooling water pipe. ZDG-3A high-low pressure joint pump station is used for oil support. The top bearing is linked to low pressure oil pump via lubricate pipe while the bottom bearing is provided with oil return pipe and high pressure oil pump. Static pressure jacking and dynamic pressure moving is the characteristics of the bearing. The parts of rotary system include feeding and discharging end cap, shell, feeding and discharging spiral drum, rubber lining and mound layer. There into, the feeding and discharging end has an opposite spiral direction. With wear-resistant rubber and mound layer, the shell lining has a lot of advantages like wear resistance, erosion resistance, shock absorption and noise control. The accessories of drive parts are big wheel gear, small wheel gear, bearing block, small wheel gear with lubricate oil, and etc. The big wheel gear consist of two half wheel gear and is installed on the flange of the shell discharging end. The lubrication of big and small wheel gears are controlled by RPC-4 pneumatic jet lubrication mechanism. This system works based on exposed drive and the characteristics of the big and small wheel gears, like low speed, heavy load and continuous running. Made of gas pump, jet nozzle, filter, valve, instrument and fuel tank, RPC-4 can jet proper lubricant onto the working surface of the wheel gears regularly, quantificationally, orientedly and automatically. Therefore, the lubricate conditions of wheel gears are improved and the service life extent. Besides, the small wheel gearings with oil are equipped under the gear cover to improve their lubrication conditions. During commissioning, maintenance and overhaul, the slow device drive the mill to rotate at a low speed and drive the turning when the mill is running, which has a simple operation and can achieve interlocking with pneumatic cluth. Rod adding machine is used to add steel rods into the shell.