电梯曳引机外文翻译.docx

1、电梯曳引机外文翻译英文翻译Traction machineAs 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

2、not, it is classified into geared and gearless types.Geared traction machineGeared traction machineis 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

3、 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

4、 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: Give

5、n 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

6、 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

7、of repetitious short time operation, electrical control and regeneration. Therefore, with low start-up current, large start-up torque, mechanically rigid features and low noise, it is required that traction machine should not only be adapted for frequent start-up, brake, but also start up and functi

8、on well when power oltage fluctuates within normal range. Being special machine for lift, traction machine is characteristic of complicated operation, whose Hp can be calculated through following formula: Where: P shaft Hp of traction machine (kw) G rated load of car (kg) offsetting coefficient tota

9、l mechanical efficiency v lift speed（m/s） For lift with geared traction machine, if worm gear is Archimedes type, total mechanical efficiency ranges from 0.5 to 0.55; for lift with gearless traction machine, total mechanical efficiency ranges from 0.75 to 0.8.For example: For an AC two-speed lift wh

10、ose rated load is 2000kg and rated speed is 0.5m/s, worm gear is Archimedes type, rated speed of motor is 960r/min, what is hp of motor?According to G = 2000kg, = 0.5，v = 0.5m/s，= 0.5, we can calculate by inputting given values. Geared traction machine is classified into AC and DC types. W191 tracti

11、on machine is AC frequency-variable motor. Currently, besides worm geared machine, bevel and star geared machines are also available.Gearless traction machineGearless traction machine is used in lifts with speed of more than 2.0m/s. With traction sheave fixed in motor shaft, this traction machine is

12、 simple in structure without any mechanical geared machine. Specially designed for manufactured for lift, traction motor is suitable for lift operation and classified into speed-variable DC and frequency-variable AC motor.In figure 2-2 is shown an AC frequency-variable gearless traction machine.This

13、 machine needs much more brake torque than geared machine when it is manufactured, therefore, it needs a rather bigger brake. Gearless traction machine is more often than not used in compound winding drive, therefore, force applied on traction sheave, compound winding sheave and bear is much larger

14、than that on traction machine; corresponding shaft is of longer diameter.With no geared machine, it has longer usage life.Permanent magnet synchronous gearless traction machine We cant help mentioning the application of permanent magnet synchronous gearless traction machine in lift. With the rapid d

15、evelopment of traction technology in lift, more and more lifts without machine room are adopting permanent magnet synchronous gearless trailing technology. For lifts without machine room, there is no need to enlarge well dimensions, simplifying and beautifying construction, saving cost, especially t

16、he application value of such lifts is enhanced by low noise, high efficiency and power economization, and what distinguishes lifts without machine room from others lies in the permanent magnet synchronous gearless traction machine. In figure 2-3 is shown PMS425AL permanent magnet synchronous gearles

17、s traction machine used in Thyssens lifts without machine room. The traction machine is flat in structure, so only a very small space is needed between well walls and car to complete installation. With gearless design , motor torque directly passes on to traction sheave, combined with static frictio

18、n of non-deceleration part, driving efficiency can exceed 90%; besides, due to low rotation speed, traction machine runs with low noise and is free from vibration. The traction machine has two mechano-electronic brakes, therefore, the other brake can provide sufficient jerk force to stop car with 10

19、0% rated load if one brake fails to function. Characteristics of permanent magnet synchronous gearless traction machine: Comfortable riding; Low running noise; High efficiency; Low load of electrical devices; Convenient and reliable maintenance, without need to change oil, eliminating oil leakage; E

20、asy to replace assembly, with exterior brake; Wide range of setting and installation in traction machine.Composed of springs, brake block with liner, brake arm and magnet-iron, magnetic brake is most frequently used in traction machine, as shown in figure 2-4 . When magnetic coil is power on, brake

21、will release; when magnetic coil is power off, brake block will produce torque, relying on springs pressed tightly on brake gear. Brake functionBrake has two functions:In case of power cut-off, brake can make lift stop automatically. When brake engages, deceleration of lift should not exceed that pr

22、oduced by overspeed governor or needed to stop car on buffer.If lift is in normal operation with speed of more than 1m/s, lift is usually decelerated through electrical control before mechanical brake engages.When lift stops moving, brake should guarantee that lift remains stationary under 125%150%

23、rated load. Brake does not release until lift starts moving. Characteristic of brakeWhen lift runs, i.e. motor is power-on, brake will release; when lift stops, i.e.motor is power-off, brake will engage.Mounting position For geared lift, brake is mounted between motor and geared machine (see figure2

24、-5), i.e. on high-speed shaft. Small brake torque is needed by high-speed shaft, so that brake dimensions can bereduced. Gearless traction machine adopts adapter, i.e. is adaptor disk etween motor and geared machine, as shown in figure 2-6. Brake gear is arranged on worm gear side instead of on moto

25、r side, to ensure that lift can also stop in case of ruptured adapter.Cast into one with traction rope, brake gear of gearless traction machine is directly mounted on traction machine shaft. As a main safety part of lift system, brake has an direct impact on comfortable ride and accurate leveling. D

26、uring lift operation, to achieve comfortable ride and accurate leveling, such factors can be adjusted as brake release time, brake release time and brake torque size. To reduce brake engage, release time and noise, it is required the gap between two magnets in coils be proper rather than too wide. T

27、he smaller the gap between brake block and gear is, the better. Brake block should not touch rotating gear after brake releases.Traction sheaveTraction sheave is shown in figure 2-7.Geared traction sheave is located on side ofgeared machine. Operators stand on the shaftside of motor, facing motor. L

28、eft-placed traction machine is the one with sheave on the left of geared machine; while right-placed traction machine is the one with sheave on the right of geared machine, as shown in figure 2-8. Traction sheave of gearless traction is directly connected with motor. Traction machine suportSoldered

29、by cast iron or secion iron with steel board, traction machine support is a seat that connects motor, brake and geared machine. Parts of tractrion machine are mounted on the support, facilating transportaion, installation and adjustment. When lift is installed, the support will be fastened on two pa

30、rallel H-stell beams with designated specification that serve to bear weight. Main performance and application requirement of traction machineTake geared traction for instance, we will give a briefing on typical requirement. Traction sheave diameter D should be more than 40d (d is diameter of tracti

31、on rope)Traction sheave diameterWhere: D Traction sheave diameter in mm vs Traction rope rated speed in m/s i Gear ratio n Motor rated speed in r/min Fore example: Given the fact that traction ratio is 1:1, rated speed is 1.75m/s, I = 25:1, n=1326r/min, rope diameter is 13mm, what is diameter of tra

32、ction sheave?Given the fact that i = 251，n=1326 r/min, Traction ratio is 1/1, therefore, lift rated speed is traction rope rated speed vs= 1.75m/s, Fill in the formula 2-3 with these values, Traction rope diameter d = 13mm, so 40d = 1340=520mm Obviously, 630520mmSince 630mm traction machine diameter meets D40d, a conclusion can be drawn that traction mac