但还没有打滑的临界平衡状态。这时曳 引绳悬挂轿厢一端的拉力T1和悬挂对 重一端的拉力T2之间应满足什么关系 呢？根据著名的欧拉公式T1与T2之有如下关系（1-1式）：

Traction force exerted on the lift is shown as in fig.1- 3.The traction rope is in a balanced state, i.e. it is about to slip on the traction sheave. What’s the relation between pulling fore T1 on one side of the traction rope and T2 on the other side? In the following equation, we can see （formula1-1）:

式中： where:

ff间

— 曳引绳在曳引轮绳槽中的当量摩擦系数；

— friction coefficient of traction rope in traction sheave groove

α — 曳引绳与曳引轮相接触的一段圆弧所对应的圆心角，即曳引绳在曳引轮上的包角； α— circular angle in correspondence with an arch overlapped by traction rope and sheave, i.e. angle of traction rope in traction sheave

e — 自然常数 e=2.71828 e — nature constant e=2.71828

fα式中的e 称为曳引系数,曳引系数是一个客观量,它与?、α有关。 efα is referred to as traction coefficient, which is related to fand α.

fα限定了T1/T2的允许比值，e大，则表明T1/T2的允许比值大和（T1-T2）的允许值大，

也就表明电梯的曳引能力大。

efα limits T1/T2, the larger efα is，the larger T1/T2 is，indicating larger traction

capacity.

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因此，一台电梯的曳引系数代表了该台电梯的曳引能力。曳引系数越大，电梯的载货或 载客能力就越大；反之如果曳引系数较小，则电梯的载货或载客能力就越小。 Therefore, traction coefficient indicates traction capacity of lift.The larger the traction coefficient is, the larger capacity a lift has in terms of cargo or passenger load; while the smaller the traction coefficient is, the smaller capacity a lift has. 1-3-4-2 保证电梯正常工作的曳引条件 Requirement to ensure lift normal operation

根据分析和计算，电梯在下面两种工作状态下应保证曳引绳在曳引轮绳槽上不出现打滑 现象：

Based on analysis and calculation, traction rope slip in the groove can be avoided when lift is in either conditions:

1-3-4-2-1空载电梯在最高停站处上升制动状态（或下降起动状态）。

Lift is decelerating before stopping at the top landing or starting up by accelerating from the top landing.

1-3-4-2-2装有120%额定载荷的电梯，在最低停站处下降制动状态（或上升起动状态）。 For lift with 120% rated load, lift is decelerating towards bottom landing or accelerating from the bottom landing.

为了满足上述曳引条件，在设计曳引系数时应按以下公式进行：

To meet the above traction requirements, the traction coefficient should be computed according to the following formula:

式中： Where:

T1/T2 — 在载有125%额定负载的轿厢位于最底层站及空载轿厢位于最高层站的情况下， 曳引轮两边曳引绳中的较大静拉力与较小静拉力之比；

T1/T2 –the ratio of larger static pulling force to smaller one of the traction rope when lift with 125% rated load is at the bottom landing or with empty load at the top landing. C1 — 与加速度、减速度有关的动力系数，C1 =（g+a）/ (g-a) ，g为自由落体标准加 速度，g= 9.8m/s2 。a为轿厢的制动减速度（或起动加速度），单位为m/s2 。 C1 – the coefficient related to acceleration and deceleration, C1 = （g+a）/ (g-a), g is standard acceleration of falling object, g = 9.8m/s2 . a is deceleration of car before

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stopping or acceleration of star-up car, measured in m/s2 . C1 的最小允许值如下：

Minimum permissible C1 value is as follows:

电梯的额定速度 C1值

Lift rated speed C1 value

v≤ 0.63m/s 1.10

0.63m/s＜v≤ 1.00m/s 1.15 1.00m/s＜v≤ 1.60m/s 1.20 1.60m/s＜v≤ 2.50m/s 1.25

当额定速度v超过2.5m/s时，C1值应按各种情况具体计算，但不得小于1.25，见表1-1 When v exceeds 2.5m/s, C1 should be computed according to different circumstances, but must not less than 1.25. Details please see table 1-1.

C2 — 与因磨损而发生的绳槽形状改变有关的系数，对于曳引轮绳槽为半圆形和半圆形下部 开切口的C2=1，对于曳引轮绳槽为V形的C2=1.2 。

C2 – the coefficient related to groove shape alteration; for semicircular groove or the one with cut, C2 = 1; for V groove, C1 = 1.2

表1-1

电梯类型 Lift type 交流双速 AC double speed 交流调速 额定速度/ m/s Rated speed(m/s) ≤0.63 ＞0.63 ≤1.0 ＞1.0 ≤1.0 Table 1-1 C1 1.107 1.154 1.202 1.227 制动减速度①/ m/s2 Deceleration①( m/s2)0.5 0.7 0.9 1.0 Page 23 of 40

AC adjusting speed ＞1.0 ≤1.6 ＞1.6 1.1 1.2 1.2 1.4 1.6 1.253 1.279 1.279 1.333 1.390 交（直）流无齿轮 AC (DC) gearless ≤1.6 ＞1.6 ≤3.15 ＞3.15 ① 指紧急刹车时电梯的制动减速度 ①

Deceleration when lift is jerking.

1-3-4-3 电梯的最大曳引能力 Maximum traction capacity

当曳引系数e已经确定的情况下，应如何估算电梯的最大曳引能力：

When traction coefficient eis definite, the maximum traction capacity should be computed as follows:

设：G为空载轿厢自重，Q为额定载重量，G+0.5Q为对重重量，P为对应电梯提升高度这一 长度范围内的未被平衡的曳引钢丝绳的重量。

For example: G is the weight of car with empty load, Q is rated load, G+0.5Q is the weight of counterweight, P is the weight of unbalanced traction rope during lift is hoisted. (1) 对重重量等于G+0.5Q时，电梯的最大曳引能力 (1)

if the weight of counterweight is equal to G+0.5Q, the maximum traction capacity

当电梯有补偿链或补偿绳装置时，P=0;

When compensation chain or compensation rope is available in lift,P=0; (2) 当对重量已经确定时，电梯的最大曳引能力，设：已知对重重量为W，

(2) if the weight of counterweight is definite, given it is W, the maximum traction capacity

当电梯有补偿链或补偿绳装置时，P=0

When compensation chain or compensation rope is available in lift,P=0; 1-3-4-4 允许的轿厢最小自重

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fαfα