电梯曳引机外文翻译大学论文.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)
ί y — traction ratio（traction mode）
ί 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, ί y=2/1, ί j=53/3
From the given conditions, we learn that D=0.8m，N=1000r/min, ί y=2/1, ί 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 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 function 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)
α— offsetting coefficient
η— total 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 whose 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, α= 0.5，v = 0.5m/s，η= 0.5, we can calculate by inputting given values.

Geared traction machine is classified into AC and DC types. W191 traction machine is AC frequency-variable motor. Currently, besides worm geared machine, bevel and star geared machines are also available.

Gearless traction machine
Gearless 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 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.
图2 -2 无齿轮曳引机 DAF290
Figure 2-2 Gearless traction machine DAF
Brake
Motor
Traction sheave

This 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 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 can’t help mentioning the application of permanent – magnet synchronous gearless traction machine in lift. With the rapid development 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 the 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 gearless traction machine used in Thyssen’s 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 friction 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 100% 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;
● Easy 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 will release; when magnetic coil is power off, brake block will produce torque, relying on springs pressed tightly on brake gear.

Brake function
Brake 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 produced 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% rated load. Brake does not release until lift starts moving.
Characteristic of brake
When 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 figure2-5),
i.e. on high-speed shaft.
Small brake torque is needed by high-speed
shaft, so that brake dimensions can be
reduced.
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 motor 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. During 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. The smaller the gap between brake block and gear is, the better. Brake block should not touch rotating gear after brake releases.
Traction sheave
Traction sheave is shown in figure 2-7.
Geared traction sheave is located on side of
geared machine. Operators stand on the shaft
side of motor, facing motor. Left-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 suport
Soldered 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 parallel H-stell beams with designated specification that serve to bear weight.
Main performance and application requirement of traction machine
Take 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 traction rope)
Traction sheave diameter

Where:
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 traction sheave?
Given the fact that i = 25∶1，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 = 13×40=520mm
Obviously, 630>520mm
Since 630mm traction machine diameter meets D>40d, a conclusion can be drawn that traction machine diameter can be 630mm.
Reliable traction brake
When lift is moving upwards, offsetting coefficient should be 40% of car weight plus 150% rated load. During 10-minute travel, no slipping should occur between brake gear and brake block.
Given the fact that conditions stated in 2-7-2 is met, the minimum engage voltage of brake and maximum release voltage should be 80% and 55% lower than rated voltage of magnet respectively; time delay of brake engage should not exceed 0.8s.
Brake blocks should be mounted in two groups; if either of them does not work, brake can still obtain sufficient brake force to make car with rated load decelerate.
When traction machine is running with empty load at high speed, dB(A) surface value measured (mean value of values measured 1 meter from the top, front, left and right of traction machine respectively) should not exceed 67db(A).
When traction machine is running with 20~40% of rated load, valid value of retortion shocking speed of output shaft should be less than 1mm/s.
Traction machine should be inspected in factory prior to shipment. Power-on continuity should be 40% in inspection, clockwise and counter clockwise rotation with empty load should run well, with cycling time not less than 3 min, travel lasting 2 hours.
Working conditions of traction machine:
Sea level should not exceed 1000 meters.
Temperature of machine room should remain at 5~40℃.
Monthly ambient relative humidity should not more than 90%, meanwhile minimum average temperature should not exceed 25℃.
Deviation between voltage supply fluctuation and rated voltage should not exceed ±7%.
Ambient air should not contain corrosive and inflammable air.
Neither lubricant nor other substances should be applied on traction rope.
Quality of car and counterweight as well as the angle of traction rope should meet formula 1-1 in 1-3-4-1.
For V groove,

For semicircular groove or groove with cut,

Where:
ƒ — Friction coefficient of traction rope in groove;
β— Tangent angle of groove with cut or semi circular groove，β=0
(see figure 2-7).
γ— Angle of V-groove on traction sheave (see figure 2-7).
μ—Friction coefficient between traction rope and sheave，μ= 0.09

中文译文
电梯曳引机
曳引机是电梯的动力源（又称主机），通常由电动机、制动器、减速机和底座组成；是靠曳引钢丝绳与曳引轮的摩擦来实现轿厢运行的驱动机。曳引机又以电动机与曳引轮之间有无减速机区分为有齿轮曳引机和无齿轮曳引机两种。
2-1有齿轮曳引机
有齿轮曳引机广泛用于运行速度v ≤2.0m/s的各种货梯、客梯、杂物梯。为了减小曳引机运行时的噪音和提高平稳性，一般采用蜗轮副作减速传动装置。
这种曳引机主要由曳引电动机、蜗轮、蜗杆、制动器、曳引绳轮、机座等构成，其外形如图2-1。
电梯的载荷、运行速度等主要参数取决于曳引机的电机功率和转速，蜗轮与蜗杆的模数和减速比，曳引轮的直径和绳槽数，以及曳引比（曳引方式）等。
采用有齿轮曳引机的电梯，其运行速度与曳引机的减速比、曳引轮直径、曳引比、曳引电动机的转速之间的关系可用以下公式表示：

式中：
v — 电梯的运行速度（m/s）
D — 曳引绳轮直径（m）
N — 曳引电动机转速(r/min)
ί y — 曳引比（曳引方式）
ί j —减速比

例：:
由一台电梯，其曳引轮的绳轮直径为0.8m，电动机转速1500r/min，减速比为53∶3，曳引比为2∶1，求电梯的运行速度？
解：已知 D=0.8m，N=1000r/min, ί y=2/1, ί j=53/3 代入式2-1得：

曳引电动机是驱动电梯上下运动的动力源，其运行工况比较复杂。运行过程中需频繁的起动、制动、正转、反转，而且负载变化很大，经常工作在重复短时状态、电动状态、再生制动状态的情况下。因此，要求曳引电机不但应能适应频繁起、制动的要求，而且起动电流小，起动力矩大，机械特性硬，噪声小，当供电电压在标准波动范围内变化时，还能正常起动和运行。因此电梯用曳引电动机是专用电机。由于曳引电动机的工作情况比较复杂，所以对电机功率的计算比较麻烦，一般常用以下公式计算：

式中：
P — 曳引电机轴功率(kw)
G — 电梯轿厢额定载重量(kg)
α— 电梯平衡系数
η— 电梯的机械总效率
v — 电梯的运行速度（m/s）

采用有齿轮曳引机的电梯，若蜗轮副为阿基米德齿形时，电梯机械总效率取0.5～0.55；采用无齿轮曳引机的电梯，电梯机械总效率取0.75～0.8。
例：有一台额定载重量为2000kg，额定运行速度为0.5m/s的交流双速电梯，曳引机的蜗轮副采用阿基米德齿形，电动机的额定转速为960r/min，求电机的功率应为多少（kw）?

解：已知：，代入式2-2得：

有齿轮曳引机的电机有交流的也有直流的。W191曳引机的电机为交流变频电动机。目前，除涡轮蜗杆减速机外，还有斜齿轮传动和行星齿轮传动两种形式的减速机。
2-2 无齿轮曳引机
无齿轮曳引机用于运行速度v＞2.0m/s的高速电梯上。这种曳引机的曳引轮紧固在曳引电动机轴上，没有机械减速装置，整机结构比较简单。曳引电动机是专为电梯设计和制造的，能适应电梯运行工作特点，具有良好调速性能的直流电动机或交流变频电动机。
图2-2所示为交流变频无齿轮曳引机。

图2 -2 无齿轮曳引机 DAF290

制动器

电动机

曳引轮

该曳引机制造时所需要的制动力矩要比有齿轮曳引机大得多，因此相应的制动器比较大。由于无齿轮曳引机多数情况是用于复绕传动结构中，所以曳引轮轴、复绕轮轴及其轴承的受力要比有齿轮曳引机大得多，相应的轴也显得粗大。
由于无齿轮曳引机没有减速机，所以使用寿命比较长。

2-3永磁同步无齿轮曳引机
在这里尤其值得提到的是永磁同步无齿轮曳引机在电梯上的应用。随着电梯曳引技术的
飞速发展，采用永磁同步无齿轮拖动技术的无机房电梯正越来越多地走进电梯市场。由
于无机房电梯无需设置机房，也无需加大井道尺寸，从而可以简化建筑设计，美化建筑
造型，节约建筑成本，尤其是无机房电梯噪声低、效率高、节能明显更提高了无机房电
梯的使用价值。而无机房电梯最突出的设计就是永磁同步无齿轮曳引机。
图2-3 所示的是蒂森无机房电梯所采用的PMS425AL型永磁同步无齿轮曳引机。它的扁平结构设计使得在井道壁和轿厢之间只需要一个很小的空间即可完成安装。由于它的无齿轮设计，电动机力矩直接传递到曳引轮上，再加上无减速部分的静摩擦，使得传动效率可达90%以上，还由于它具有很低的运转速度，使得机器在运行过程中噪声很低，也不会产生振动。此类曳引机采用两组机—电式制动器，如果其中一组制动器不起作用，另一组制动器能够提供足够的制动力使满载下行的轿厢停止。
永磁同步无齿轮曳引机的特点是：
● 乘坐舒适感好；
● 运行噪声低；
● 效率高；
● 安装电气载荷低；
● 维护方便可靠，无需换油，不存在油泄露；
● 采用外部制动器，便于装配更换；
● 曳引机设置和安装范围广泛。

2-4曳引机制动器（抱闸）
Br