4、QPG QPK QPT QPG系列启闭机的钢丝绳采用6W(19)型，公称抗拉强度1550～1700N/mm2。钢丝绳随机供应，常规每单机供40m。
The hoisting hoist can be divided into single hoisting point and double hoisting point. The hoisting force QPQ, QPG and QPT are 50 kN-2500 kN, and the QPT is 50 kN-1250 kN, which can be selected by users. 1. Type description of this series of products. 2. The opening force or holding force of QPQ QPK QPG QPT series products are selected according to the priority series stipulated in GB/783-65 lifting crane series. 3. QPQ QPK QPT QPG series hoist can not be done and can be operated with inclined crane. 4. The steel wire rope of QPG QPK QPT QPG series hoist adopts 6W (19) type with nominal tensile strength of 1550-1700N/mm2. Wire rope is supplied randomly and 40 m per machine is supplied routinely. The good operation of hoisting hoist can not be separated from its good partner - Brake device, which plays a greater role in the operation of hoisting hoist. In the various mechanisms of lifting machinery, only with reliable braking devices, can the machinery work safely and accurately. The function of the brake is to reduce the movement speed of the mechanism from the cutting value to zero (stop brake). On the hoisting hoist which drops the gate at a fast speed of 1, the function of the brake restricts the movement speed of the mechanism within a certain range (speed regulating brake). There are many kinds of brakes used in lifting machinery, which can be divided into block type, belt type and disc type according to their structural characteristics, among which block type is widely used. They can be divided into normal group type and open type according to their working status. The normal closed type brakes are often in the closing state under the action of spring force. When the mechanism starts, the electromagnet or electro-hydraulic push rod, etc. Thrust overcomes spring force to loosen the brake. On the contrary, the open brake is often in a state of loosening, and only by applying external force can it be closed. Starting from working safety, the hoisting mechanism and luffing mechanism of crane must be equipped with normal closed brakes.