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英文翻譯
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 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.
圖2 -2 無齒輪曳引機(jī) 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:
? — 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
中文譯文
電梯曳引機(jī)
曳引機(jī)是電梯的動(dòng)力源（又稱主機(jī)），通常由電動(dòng)機(jī)、制動(dòng)器、減速機(jī)和底座組成；是靠曳引鋼絲繩與曳引輪的摩擦來實(shí)現(xiàn)轎廂運(yùn)行的驅(qū)動(dòng)機(jī)。曳引機(jī)又以電動(dòng)機(jī)與曳引輪之間有無減速機(jī)區(qū)分為有齒輪曳引機(jī)和無齒輪曳引機(jī)兩種。
2-1有齒輪曳引機(jī)
有齒輪曳引機(jī)廣泛用于運(yùn)行速度v ≤2.0m/s的各種貨梯、客梯、雜物梯。為了減小曳引機(jī)運(yùn)行時(shí)的噪音和提高平穩(wěn)性，一般采用蝸輪副作減速傳動(dòng)裝置。
這種曳引機(jī)主要由曳引電動(dòng)機(jī)、蝸輪、蝸桿、制動(dòng)器、曳引繩輪、機(jī)座等構(gòu)成，其外形如圖2-1。
電梯的載荷、運(yùn)行速度等主要參數(shù)取決于曳引機(jī)的電機(jī)功率和轉(zhuǎn)速，蝸輪與蝸桿的模數(shù)和減速比，曳引輪的直徑和繩槽數(shù)，以及曳引比（曳引方式）等。
采用有齒輪曳引機(jī)的電梯，其運(yùn)行速度與曳引機(jī)的減速比、曳引輪直徑、曳引比、曳引電動(dòng)機(jī)的轉(zhuǎn)速之間的關(guān)系可用以下公式表示：
式中：
v — 電梯的運(yùn)行速度（m/s）
D — 曳引繩輪直徑（m）
N — 曳引電動(dòng)機(jī)轉(zhuǎn)速(r/min)
? y — 曳引比（曳引方式）
? j —減速比
例：:
由一臺(tái)電梯，其曳引輪的繩輪直徑為0.8m，電動(dòng)機(jī)轉(zhuǎn)速1500r/min，減速比為53∶3，曳引比為2∶1，求電梯的運(yùn)行速度？
解：已知 D=0.8m，N=1000r/min, ? y=2/1, ? j=53/3 代入式2-1得：
曳引電動(dòng)機(jī)是驅(qū)動(dòng)電梯上下運(yùn)動(dòng)的動(dòng)力源，其運(yùn)行工況比較復(fù)雜。運(yùn)行過程中需頻繁的起動(dòng)、制動(dòng)、正轉(zhuǎn)、反轉(zhuǎn)，而且負(fù)載變化很大，經(jīng)常工作在重復(fù)短時(shí)狀態(tài)、電動(dòng)狀態(tài)、再生制動(dòng)狀態(tài)的情況下。因此，要求曳引電機(jī)不但應(yīng)能適應(yīng)頻繁起、制動(dòng)的要求，而且起動(dòng)電流小，起動(dòng)力矩大，機(jī)械特性硬，噪聲小，當(dāng)供電電壓在標(biāo)準(zhǔn)波動(dòng)范圍內(nèi)變化時(shí)，還能正常起動(dòng)和運(yùn)行。因此電梯用曳引電動(dòng)機(jī)是專用電機(jī)。由于曳引電動(dòng)機(jī)的工作情況比較復(fù)雜，所以對(duì)電機(jī)功率的計(jì)算比較麻煩，一般常用以下公式計(jì)算：
式中：
P — 曳引電機(jī)軸功率(kw)
G — 電梯轎廂額定載重量(kg)
α— 電梯平衡系數(shù)
η— 電梯的機(jī)械總效率
v — 電梯的運(yùn)行速度（m/s）
采用有齒輪曳引機(jī)的電梯，若蝸輪副為阿基米德齒形時(shí)，電梯機(jī)械總效率取0.5～0.55；采用無齒輪曳引機(jī)的電梯，電梯機(jī)械總效率取0.75～0.8。
例：有一臺(tái)額定載重量為2000kg，額定運(yùn)行速度為0.5m/s的交流雙速電梯，曳引機(jī)的蝸輪副采用阿基米德齒形，電動(dòng)機(jī)的額定轉(zhuǎn)速為960r/min，求電機(jī)的功率應(yīng)為多少（kw）?
解：已知：，代入式2-2得：
有齒輪曳引機(jī)的電機(jī)有交流的也有直流的。W191曳引機(jī)的電機(jī)為交流變頻電動(dòng)機(jī)。目前，除渦輪蝸桿減速機(jī)外，還有斜齒輪傳動(dòng)和行星齒輪傳動(dòng)兩種形式的減速機(jī)。
2-2 無齒輪曳引機(jī)
無齒輪曳引機(jī)用于運(yùn)行速度v＞2.0m/s的高速電梯上。這種曳引機(jī)的曳引輪緊固在曳引電動(dòng)機(jī)軸上，沒有機(jī)械減速裝置，整機(jī)結(jié)構(gòu)比較簡(jiǎn)單。曳引電動(dòng)機(jī)是專為電梯設(shè)計(jì)和制造的，能適應(yīng)電梯運(yùn)行工作特點(diǎn)，具有良好調(diào)速性能的直流電動(dòng)機(jī)或交流變頻電動(dòng)機(jī)。
圖2-2所示為交流變頻無齒輪曳引機(jī)。
圖2 -2 無齒輪曳引機(jī) DAF290
制動(dòng)器
電動(dòng)機(jī)
曳引輪
該曳引機(jī)制造時(shí)所需要的制動(dòng)力矩要比有齒輪曳引機(jī)大得多，因此相應(yīng)的制動(dòng)器比較大。由于無齒輪曳引機(jī)多數(shù)情況是用于復(fù)繞傳動(dòng)結(jié)構(gòu)中，所以曳引輪軸、復(fù)繞輪軸及其軸承的受力要比有齒輪曳引機(jī)大得多，相應(yīng)的軸也顯得粗大。
由于無齒輪曳引機(jī)沒有減速機(jī)，所以使用壽命比較長(zhǎng)。
2-3永磁同步無齒輪曳引機(jī)
在這里尤其值得提到的是永磁同步無齒輪曳引機(jī)在電梯上的應(yīng)用。隨著電梯曳引技術(shù)的
飛速發(fā)展，采用永磁同步無齒輪拖動(dòng)技術(shù)的無機(jī)房電梯正越來越多地走進(jìn)電梯市場(chǎng)。由
于無機(jī)房電梯無需設(shè)置機(jī)房，也無需加大井道尺寸，從而可以簡(jiǎn)化建筑設(shè)計(jì)，美化建筑
造型，節(jié)約建筑成本，尤其是無機(jī)房電梯噪聲低、效率高、節(jié)能明顯更提高了無機(jī)房電
梯的使用價(jià)值。而無機(jī)房電梯最突出的設(shè)計(jì)就是永磁同步無齒輪曳引機(jī)。
圖2-3 所示的是蒂森無機(jī)房電梯所采用的PMS425AL型永磁同步無齒輪曳引機(jī)。它的扁平結(jié)構(gòu)設(shè)計(jì)使得在井道壁和轎廂之間只需要一個(gè)很小的空間即可完成安裝。由于它的無齒輪設(shè)計(jì)，電動(dòng)機(jī)力矩直接傳遞到曳引輪上，再加上無減速部分的靜摩擦，使得傳動(dòng)效率可達(dá)90%以上，還由于它具有很低的運(yùn)轉(zhuǎn)速度，使得機(jī)器在運(yùn)行過程中噪聲很低，也不會(huì)產(chǎn)生振動(dòng)。此類曳引機(jī)采用兩組機(jī)—電式制動(dòng)器，如果其中一組制動(dòng)器不起作用，另一組制動(dòng)器能夠提供足夠的制動(dòng)力使?jié)M載下行的轎廂停止。
永磁同步無齒輪曳引機(jī)的特點(diǎn)是：
● 乘坐舒適感好；
● 運(yùn)行噪聲低；
● 效率高；
● 安裝電氣載荷低；
● 維護(hù)方便可靠，無需換油，不存在油泄露；
● 采用外部制動(dòng)器，便于裝配更換；
● 曳引機(jī)設(shè)置和安裝范圍廣泛。
2-4曳引機(jī)制動(dòng)器（抱閘）
Brake
曳引機(jī)制動(dòng)器最常用的是電磁式制動(dòng)器，它由一組彈簧、帶有制動(dòng)襯墊的制動(dòng)閘瓦、制動(dòng)臂以及電磁鐵組成，如圖2-4所示。當(dāng)電磁線圈通電時(shí)，制動(dòng)器松閘；當(dāng)電磁線圈失電，制動(dòng)閘瓦靠彈簧壓緊于制動(dòng)輪而產(chǎn)生制動(dòng)力矩。
2-4-1 制動(dòng)器的作用
制動(dòng)器的作用有以下兩條：
2-4-1-1能夠使運(yùn)行中的電梯在切斷電源時(shí)自動(dòng)把電梯轎廂掣停住。制動(dòng)時(shí)，電梯的減速度不應(yīng)大于限速器動(dòng)作做產(chǎn)生的或轎廂停止在緩沖器上所產(chǎn)生的減速度。
電梯正常使用時(shí)，電梯速度v＞1m/s 的，一般都是在電梯通過電氣控制使其減速停止，然后再機(jī)械抱閘。
2-4-1-2電梯停止運(yùn)行時(shí)，制動(dòng)器應(yīng)能保證在125%～150%的額定負(fù)載下，電梯保持靜止、位置不變，直到工作時(shí)才松閘。
2-4-2 制動(dòng)器的工作特點(diǎn)
制動(dòng)器的工作特點(diǎn)是，電梯運(yùn)行即電動(dòng)
機(jī)通電時(shí)制動(dòng)器松閘，電梯停止運(yùn)行即
電動(dòng)機(jī)失電時(shí)抱閘。
2-4-3 安裝位置
對(duì)于有齒輪電梯，制動(dòng)器裝在電動(dòng)機(jī)和
減速機(jī)之間（見圖2-5），即裝在高轉(zhuǎn)速
軸上。因?yàn)楦咿D(zhuǎn)速軸上所需的制動(dòng)力矩小，這
樣可以減小制動(dòng)器尺寸。
有齒輪曳引機(jī)采用帶制動(dòng)輪的聯(lián)軸器，即制動(dòng)
器的制動(dòng)輪就是電動(dòng)機(jī)和減速機(jī)之間的聯(lián)軸器原盤，如圖2-6所示。制動(dòng)輪裝在蝸桿一側(cè)，不能裝在電動(dòng)機(jī)一側(cè)，以保證聯(lián)軸器破斷時(shí)，電梯仍能掣停。
無齒輪曳引機(jī)的制動(dòng)輪與曳引繩輪是鑄成一體的，并直接安裝在曳引電動(dòng)機(jī)軸上。制動(dòng)器是電梯機(jī)械系統(tǒng)的主要安全部件之一，而且直接影響電梯的乘坐舒適感和平層準(zhǔn)確度。電梯在運(yùn)行過程中，根據(jù)電梯的乘坐舒適感和平層準(zhǔn)確度，可以適當(dāng)調(diào)整制動(dòng)器的在電梯起動(dòng)時(shí)松閘，平層停靠時(shí)抱閘的時(shí)間，以及制動(dòng)力矩的大小等。
為了減小制動(dòng)器抱閘、松閘的時(shí)間和噪音，制動(dòng)器線圈內(nèi)兩塊鐵芯之間的間隙不宜過大。閘瓦與制動(dòng)輪之間的間隙也是越小越好，一般以松閘后閘瓦不碰擦運(yùn)轉(zhuǎn)著的制動(dòng)輪為宜。
2-5曳引輪
曳引輪如圖2-7所示。
有齒輪曳引機(jī)的曳引輪位于減速機(jī)的側(cè)面，人
站在電動(dòng)機(jī)出軸側(cè)，面對(duì)電動(dòng)機(jī)，曳引輪在減
速機(jī)左側(cè)，稱為曳引機(jī)左置，曳引輪在減速機(jī)
右側(cè)，稱為曳引機(jī)右置。如圖2-8所示。
無齒輪曳引機(jī)的曳引輪直接與電動(dòng)機(jī)軸相連。
2-6曳引機(jī)底座
曳引機(jī)底座是連接電動(dòng)機(jī)、制動(dòng)器、減速機(jī)的機(jī)座。由鑄鐵或型鋼與鋼板焊接在一起。曳引機(jī)個(gè)部件不減均裝配在底座上，便于整體運(yùn)輸、安裝和調(diào)整。按裝電梯時(shí)，底座又被固定在指定型號(hào)的兩個(gè)平行且具承重作用的工字鋼梁上。
Traction sheave
2-7曳引機(jī)主要性能與應(yīng)用要求
這里以有齒輪曳引機(jī)為例，僅對(duì)常用要求作一介紹。
2-7-1 曳引機(jī)曳引輪直徑D應(yīng)大于40d.(d為曳引鋼絲繩直徑)
曳引輪直徑計(jì)算：
式中：
D — 曳引輪節(jié)圓直徑 mm
vs — 曳引繩額定速度 m/s
i — 減速比
n— 電動(dòng)機(jī)額定轉(zhuǎn)速 r/min
例：一臺(tái)電梯曳引比為1∶1，額定速度1.75m/s , 其曳引機(jī)i = 25∶1，n=1326 r/min，鋼絲繩直徑為13mm。求：應(yīng)選用多大的曳引輪直徑？
解：已知i = 25∶1，n=1326 r/min，
因?yàn)橐芬葹?/1，所以電梯的額定速度即為曳引鋼絲繩的額定速度vs= 1.75m/s
將以上數(shù)據(jù)代入式2-3得：
因?yàn)殇摻z繩直徑d=13mm ，則40d=13×40=520mm
即可知 630＞520mm
因?yàn)?30mm的曳引輪直徑滿足D＞40d 的標(biāo)準(zhǔn)，故可得出結(jié)論：曳引輪直徑可以選用630mm。
2-7-2 曳引機(jī)制動(dòng)應(yīng)可靠
在電梯上行時(shí)，平衡系數(shù)為40%的轎廂內(nèi)加150%的額定負(fù)載，歷時(shí)10分鐘，制動(dòng)輪與制動(dòng)閘瓦之間應(yīng)無打滑現(xiàn)象。
2-7-3 在滿足2-7-2的條件下，制動(dòng)器的最低起動(dòng)電壓和最高釋放電壓，應(yīng)分別低于電磁鐵額定電壓的80%和55%，制動(dòng)器開啟遲后時(shí)間不超過0.8s。
2-7-4 制動(dòng)器部件的閘瓦組件應(yīng)分兩組裝設(shè)，如果其中一組不起作用，制動(dòng)輪上仍能獲得足夠的制動(dòng)力，使載有額定載重量的轎廂減速。
2-7-5 曳引機(jī)在空載高速運(yùn)行時(shí)，A計(jì)權(quán)聲壓級(jí)的噪音測(cè)量的表面平均值（距曳引機(jī)頂部和前后、左、右1米處測(cè)量的平均值）應(yīng)不超過67dB(A)
2-7-6曳引機(jī)在20～40%額定負(fù)載運(yùn)行時(shí)，輸出軸端的扭轉(zhuǎn)振動(dòng)速度的有效值應(yīng)小于1mm/s
2-7-7 每臺(tái)曳引機(jī)出廠前均應(yīng)進(jìn)行檢查試驗(yàn)。出廠檢驗(yàn)按通電持續(xù)率40%，空載正、反轉(zhuǎn)連續(xù)無故障運(yùn)行，周期不少于3min, 時(shí)間2小時(shí)。
2-7-8 曳引機(jī)的工作條件是：
2-7-8-1海拔高度不超過1000m；
2-7-8-2 機(jī)房?jī)?nèi)空氣溫度應(yīng)保持在5～40℃；
2-7-8-3 環(huán)境相對(duì)濕度月平均最大不大于90%, 同時(shí)該月月平均最低溫度不高于25℃；
2-7-8-4 供電電壓波動(dòng)與額定值偏差不超過±7%;
2-7-8-5 環(huán)境空氣不含有腐蝕性和易燃性氣體；
2-7-8-6 曳引鋼絲繩表面不得涂上潤(rùn)滑劑與其他雜物；
2-7-8-7 轎廂與對(duì)重裝置質(zhì)量和鋼絲繩在曳引輪上的包角應(yīng)滿足1-3-4-1中1-1式，
對(duì)V型槽：
對(duì)半圓槽或帶切口槽：
式中：
? — 曳引繩在曳引輪繩槽中的當(dāng)量摩擦系數(shù)
β— 曳引輪上帶切口的繩槽或半圓繩槽的切口角，對(duì)半圓槽，β=0 (見圖2-7)
γ— 曳引輪上V型槽的夾角 (見圖2-7)
μ— 曳引繩與鑄鐵曳引輪之間的摩擦系數(shù)，μ= 0.09