电梯平衡系数（Elevator balance coefficient）
At prent, the inspection and testing institutions of special equipment in various parts of the elevator for acceptance inspection, the most time-consuming, but also the most cost, manpower, material resources, it is to detect the elevator balance coefficient. According to the inspection requirements: must be in the car carrying 0, 25%, respectively 40%, 50%, 75%, 100%, 110% rated load, measure the load current curve of the elevator, take the load coefficient of interction point of upward and downward curve, is the balance coefficient of the ladder, the interction in the range of 40% ~50% for qualified. In order to determine the parameters, in addition to the two inspection personnel, need more than the handling of weights of workers. As there are too many factors affecting the test, are the results credible? Even if the test results are within the range of 40%~50%, will they be qualified? If beyond this range, why not qualified? What is the meaning of the balance coefficient? What's the effect on the elevator? Somehow, the determination of the balance coefficient is meaningless.
1, the esnce of the balance coefficient
In order to discuss the esnce of the balance coefficient, we must start with the principle of the traction elevator. A vertical lift is a lifting device for vertical and downward movements of heavy objects.
From the angle of mechanics, to make a heavy stay still in the air, there must be a force of T and the weight of the object Q pha equilibrium, i.e. T = Q, when the body is at rest or in uniform motion state, known as the balance. The system is called a balanced system. If the object moves upward, the speed change, the tension T in addition to
英语考试反思overcome the gravity of the object is Q, but also provide a cau acceleration force F, T = Q + F = Q + m a (m for the quality of the object; a for acceleration).
韩式麻花辫If the weight of the object Q is balanced by another balance W, W = Q, which constitute a balance system, the tension T will not have to overcome gravity Q, and only need to provide objects acceleration force required is T = F= m a which significantly reduces tension T. This is the balance principle ud on the elevator". This balancing force is provided by re acting. Therefore, we require gravity W to be equal to the weight of the car and the load (P+Q).
But to really do that, it's very difficult in the actual application of the elevator, or that there's no way to do it yet. Becau the load on the car is random, Q may be any 0 (empty) or 100%QH (full load) range, so we can only choo an appropriate counterweight.
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accommodative什么是embaThat is W = P + K (QH - 1)
The coefficient K is the balance coefficient". Therefore, the esnce of the balance coefficient is to design the weight of the configuration to the weight. It will affect the weight of the counterweight and lift the unbalanced load. When the car and load are P + Q (wherein P is the weight of the car; Q--- is the actual load of the car; QH - the rated load of the car); the unbalanced load between the car side and the counterweight side is:
T = (P+Q) - (P+KQH) = Q - KQH - (2)
北京汇佳国际学校2. The value of equilibrium coefficient K
From the above (2), it can be en that the system is in equilibrium only when Q = KQH, therefore, no matter what the value of K is, the balance is relative, and the imbalance is absolute.
We can only hope that the system is as clo to balance as possible. A simple way is to take the average value of the change in the car load. Becau the change of car load is 0 to 100%, so it is reasonable to take K=50% or so, it is hard to say how much better. Elevator in the factory does not fully understand the actual operation of the load situation, in order to really achieve the ideal balance, should be in the actual operation of the elevator, the actual measurement of the daily load changes. For example, at prent, a large number of residential elevators, the actual load changes i
n the basic 0 ~ 60%, and rarely appear full load situation, so take K = 30% ~ 40% should be more appropriate. Now the general pasnger elevator in the load exceeds 80% into the straight state, so when the real load is less, so the balance coefficient K =40% ~ 50% for the right. On the contrary, some cargo elevator, becau the car over the area, the load will change during the 0 ~ 105%, so the balance coefficient K is larger than or equal to 50% should be more appropriate. It must be pointed out that the value of "K" here refers to the value of the balance coefficient K, which is called the design value, and is not the K value at random when the elevator is installed or ud.
3. The influence of the value of the balance coefficient K on
the lift
单词表Already indicated above, no matter how to balance coefficient K value, with the same K value should be Q of the load is not possible, so in the elevator car and counterweight system imbalance is absolute, from the design point of view, the value of K in the first effect on both sides of the traction wheel imbalance torque if the maximum load, overload load 110%QH, the value of K by 40%~50%, then the no-load unbalanced load: (0.4~0.5) QH, overload of load imbalance: (1.1-K) = QH (0.6~0.7) QH, according to the most rious load of 125% QH when the elevator acceptance inspection, not b
alance load is 1.25-K = (0.75~0.85) QH, which is the biggest lift possible unbalanced load (of static load), minimum static traction is the lift must be provided.kds是什么
This first affects the power of the lected host motor P. The main motor power P is determined by P / (1-K) QH VH. If the motor power supporting the u of the elevator is large enough, then K will affect the size of energy when the elevator is running, if the choice of motor power margin is small, then the equilibrium coefficient may cau inappropriate pull down the elevator after starting the car slipping or hoisting accident.
长征诗词 七律The value of balance coefficient of unbalanced load size, but also affects the traction wheel on both sides of the steel wire rope, the tension of wire rope traction rope in the groove of the pressure effect, the greater the tension is greater than the pressure, the traction ability of the traction rope is provided. Therefore, the value of the balance coefficient not only determines the unbalanced load, but also affects the
traction ability of the lift. When the maximum unbalanced load is greater than the maximum pulling force of the elevator, the traction rope will skid in the rope groove and slip accident occurs. In the elevator design, the choice of the balance coefficient K should take into account the power of the main motor and the influence of the traction capacity.
在线日文翻译The value of the equilibrium coefficient K also affects the total mass of the car and counterweight system:
M=P+Q+W+Y = (P+Q) + (P+K, QH), +Y (Y - traction, wire ropes, etc.) quality, which is easily overlooked. The total mass of the car and counterweight system will affect the safety factor of the elevator and influence the lection of the parameters of the traction rope, traction sheave and groove. At the same time, the total mass also affects the speed of lifting and braking during the operation of the elevator. Selection of safety components such as safety tongs and buffers ud in elevators. In the elevator installation, in order to deal with the acceptance inspection, reduce the acceptance of the unbalanced load, installation personnel tend to achieve greater balance coefficient K, configured to clo to 50%, the increa of weight balance coefficient is to increa the quality of the elevator will bring the start and braking acceleration decreas to brake hard. Therefore, the balance coefficient K is only a ratio on the surface, in fact, it is cloly related to the quality of the car and counterweight. It is one of the important parameters in the whole design of elevator. Apart from the parameters such as the rated load and the weight of the car, the pure balance coefficient is meaningless.
