Heavy duty apron feeder is widely used in metallurgical, coal, cement and other industrial sectors. It is a convenient short-distance transportation equipment. Because it is in harsh working conditions for a long time, the reliability of its design has certain requirements. This requires designers not only to have strict calculation, but also to have experienced personnel to guide the design of heavy duty apron feeder. Based on years of design experience, this paper introduces the key points that should be paid attention to in the design of heavy duty apron feeder. Heavy duty apron feeder is widely used in mining, metallurgy and other industries requiring short distance and large weight transportation. The feeder is mainly placed under the silo and funnel with a certain bin pressure. The bulk and heavy material separated by the silo will be transferred to the next level of crushing, screening and transportation equipment, the most suitable place to use is the primary crushing. The feeder can adapt to coarse materials and a variety of fine materials, which has good adaptability, can work in a variety of harsh working conditions, can run for a long time at full load, and for the change of material particle size composition, temperature, viscosity, frost, snow or ice materials have greater adaptability. The feeding quantity is uniform and reliable, and the feeder can be installed and operated in the angle range of 0°23°.
The main power of heavy duty apron feeder is the motor, which connects the motor with the coupling to drive the reducer to drive the sprocket shaft to rotate. Its transmission mode adopts the sprocket chain structure. Sprocket chain mechanism can work under harsh working conditions, which is characterized by heavy load and low speed, can complete the transportation of heavy objects, through the chain to drag the chain plate along the straight line movement, the chain plate is installed on the frame of the support wheel and support wheel support, the chain needs to set up the corresponding tension device to ensure the chain and sprocket correct meshing, complete the purpose of conveying materials.
Heavy duty apron feeder is mainly composed of driving device, chain plate device, tensioning device, spindle device, frame, weight support wheel, sprocket support wheel, etc. Its power part is through the motor belt, its internal use is a direct axis fulcrum floating type, motor rotation drive planetary reducer output to the spindle, the advantage of the fulcrum floating type is that for the shaft can reduce the installation of the shaft precision requirements, reduce the additional bending moment on the shaft, so that the shaft can use longer time, and disassembly is easier. The chain plate device is composed of groove plate, chain link and other parts. The groove plate is single arc or double arc joint type and is welded with low alloy steel plate. The overall material strength is high, not easy to wear, charging and no leakage. The crawler structure of the link is the same as that of engineering machinery. This structure can ensure small error and smooth movement. At the same time, the strength of the link is high, and it can bear large load without lubrication. The tensioning device is a screw rod tensioning mechanism, which is mainly composed of a shaft, two supporting wheels, both ends of the rolling bearing, bearing seat, compound spring, and tensioning screw and other parts. The supporting wheel is connected with the shaft through the expansion mechanism, and the two ends are equipped with double columns of centripetal spherical roller bearings. The bearing seat is arranged at both ends of the frame, which can slide on the slide rail. By adjusting the tightening screw, the tension of the two chains is uniform. The compound spring installed on the chain plate ensures that when the chain plate is impacted by the material, it can play a certain buffering role to avoid the impact directly transmitted to other parts of the feeder. The spindle device is composed of shaft, bearing seat, sprocket, supporting wheel and other parts. The main shaft drives the driving wheel to drag the chain plate for continuous movement, so as to complete the purpose of feeding, the device is characterized by the sprocket and supporting wheel for expansion sleeve connection, the main shaft sleeve in the output shaft of the reducer, simple disassembly, maintenance and release. The frame is an i-shaped structure welded by steel plates, which can be welded together to ensure the stability of the mechanism.
The original parameters required during the design are given by the user or the process design. The design needs to pay attention to the main parameters are: Slot plate width, head and tail wheel center distance, feeding capacity, material density, installation angle and other parameters provided by the user. Choose a reasonable driving device because of heavy duty apron feeder need to drive high load, the feeder belongs to constant torque equipment, assuming a certain traction force, torque and radius of rotation is proportional to, unrelated to other parameters, and the size of the traction determines the type of chain rail, drive sprocket pitch circle is determined, then the spindle torque is constant, you can choose a reasonable driving mechanism according to the above data.
(1) in the selection of the reducer, the output torque of the speed reducer should be matched with the load torque, and the input speed should be matched with the drive motor speed.
(2) when selecting the driving motor, the base speed should be close to the frequency of the motor at full speed, so that the motor can give full play to its maximum capacity. Because heavy duty apron feeder is usually variable frequency speed regulation, and the equipment is a constant torque equipment, in use should consider the surplus power and surplus output torque of the motor, if the output torque is surplus, the frequency can be adjusted in the motor at full speed frequency; if the power surplus is large, the frequency can be turned down again. No matter what the above situation, in the selection should exceed the load practical power and practical torque.
3.heavy duty apron feeder installation requirements the frame is generally installed on the basis of the storage bin or funnel below, through the embedded bolt and frame connection, if not bolt connection, the foundation should be equipped with embedded steel plate, through the welding method to weld the frame on the embedded steel plate, such as the height needs to be adjusted, you can use gasket, but gasket must be welded on the embedded steel plate, so that the three become one. When the driving device is safe, it is necessary to sleeve the motor speed controller connected together on the spindle, and lock it through the locking disc. The bolts of the locking disc should be tightened cross, and the torque should be applied evenly. The tightening torque of each bolt is 470n·m. Adjust the screw of the tensioning device to make the bearing seat reach the minimum position of the tensioning device. Before hoisting the chain plate device, the lower part of the frame (either front or back) should be raised with steel plate or channel steel, and the height of the bracket should be the same as that of the sprocket, and then the other end should be lifted by the crane. The steel wire rope hanging on the end of the chain plate will make the chain plate slide from one end to the other. When moving to a certain distance and then connecting the other end of the chain plate, the heavy duty apron chain live joint is the same as other joints, but the fitting tolerance between live pin and chain joint is looser than other joints. The pin shaft can be installed in the human chain with a hammer. The installation of the pin should be marked for future maintenance and disassembly. After installing the second broken chain plate, the chain will continue to be lifted. When the length of the exposed chain plate at both ends is basically equal, the other end of the chain plate can also be hung on the steel wire rope to lift the wire rope at the same time, so that the distance between the two joints is gradually reduced until you can put on the live pin shaft. Adjust the screw of the tensioning device and the tensioning chain plate, so that the tightness is moderate and the return section chain plate transition naturally. Further check whether each part is installed correctly, whether the connecting bolts are fastened reliably, whether lubricating oil has been injected into each lubricating part and the reducer box, whether the motor and electrical devices are connected correctly, and whether there are forgotten tools and other components affecting operation in each corner of the machine. After checking everything is normal, the machine can be started for not less than 2 small time and space load operation.
