电梯曳引机_外文翻译.doc

英文翻译 Traction machine As power provider for lift, traction machine, also called main machine, is composed of motor, brake, geared machine and seat. It is a drive to make car move by means of the friction between traction rope and sheave. According to whether the geared machine is provided or not, it is classified into geared and gearless types. Geared traction machine Geared traction machine is widely used in cargo lift, passenger lift and service lift with speed of not more than 2.0m/s. To reduce working noise and enhance stability, worm gear is normally used as geared drive. Such machine is composed of motor, worm, gear, brake, rope and seat, as shown is figure 2-1. Main parameters, such as lift load and speed are determined by Hp and speed of traction machine, worm and gear numbers, gear ratio, diameter of traction machine, rope grooves and traction ratio (traction mode). For lifts adopting geared traction machine, the relationship between lift speed, traction gear ratio, traction machine diameter, traction motor speed is as follows: Where: v — lift speed （m/s） D — diameter of traction machine（m） N — motor speed (r/min) ? y — traction ratio（traction mode） ? j —gear ratio For example: Given the fact that sheave diameter of traction sheave is 0.8m, motor speed is 1500r/min, reduction ratio is 53:3, gear ratio is 2:1, what is lift speed? D=0.8m，N=1000r/min, ? y=2/1, ? j=53/3 From the given conditions, we learn that D=0.8m，N=1000r/min, ? y=2/1, ? j=53/3. According to above mentioned formula, we can calculate that： As power provider for lift movement, traction machine features complicated operation procedures, among which is involved with frequent start-up, brake, clockwise and counterclockwise rotation. Due to constantly changing load, working status of traction machine is characteristic of repetitious short time operation, electrical control and