外文翻译----有关带式输送机的驱动装置设计的一些研究(编辑修改稿)

外文翻译----有关带式输送机的驱动装置设计的一些研究(编辑修改稿)内容摘要：

eyor system. Conveyor systems have bee larger and more plex and drive systems have also been going through a process of evolution and will continue to do so. Bigger belts require more power and has brought the need for larger individual drives as well as multiple drives such as 4 drives of 1000 kW each on one belt. Shaft mounting of the plete drive unit is another change which has brought with it the requirement for more pact and lighter drive units. This tends to favor a right angle drive configuration with the motor next to the belt and hardened gears to reduce the dimensions and mass of the drive. 2. Drive Ratio and Belt speeds Depending on the quantity, size, distance and characteristics of the material to be conveyed, the absorbed power, width, tensile requirements and top cover thickness of the belt will be decided. Large volume conveyor belts run in the range of 2 to 6 metre/second and the allowable bend radius of the belt determines pulley diameters which for large belts is of the order of 0,8 to 1,5 m giving pulley speeds between 50 and 125 rpm. Assuming that 4 pole motors are used, this gives a reduction ratio required between 12:1 and 30:1. Most modern gear manufacturers do not use a higher ratio per stage than 5:1, which means that speed reducers will be either 2 or 3 stage reduction. (Except for small powers where worm reducers, or torque arms and V belt drives may be used). There is a misconception that one can reduce the cost of the gearspeed reducer by using a 6 or 8 pole motor, but even an 8 pole motor on the higher speeds would require a reduction above 6:1and a 2 stage unit would still be required. The bulk of the cost of a gearbox is related to the low speed shaft torque and therefore having determined this, there is generally no economic advantage at all in using anything but a 4 pole motor. The motor manufacturers, because of size and volume, generally supply 4 pole motors at the lowest price, and as a rule therefore, a 4 pole motor is the best choice with a gearbox of the appropriate ratio to arrive at the desired conveyor shaft speed. Where ball and roller bearings are used in the electric motors some manufacturers prefer 6 pole or even 8 pole speeds for motors over 1000 kW. . Choice of Single or Multiple Drive Having calculated the power required to drive the belt and having considered the belt tension and angle of contact, a decision can be taken on whether the belt should be fitted with single or multiple drive. This decision is often influenced by other equipment installed in a plant and multiples of other smaller drives are often used. Drive size may also be determined by the nearest standard motor available. Where a drive point is situated some considerable distance from the main power source, a long cable may be involved to supply electric power to the drive. In this case, the cable size and cost of transformers may play an important part in the selection of number and size of motors used. With direct on line starting, the peak current the motor will draw is likely to be of the order of 6 x full load current and the bination of running current of a motor or group of motors with the starting current of the last motor to start will have a strong influence on the drive choice. . Method of Low Speed Shaft Connections Drive from the reducer to the belt pulley shaft is either by flexible coupling。