QTZ300 tower crane
QTZ300 tower crane is to meet GB/T5031<< tower crane >> and GB5144<< tower crane safety regulations >> and other standard design of the reinforced tower crane, rated lifting moment 300t·m, the maximum lifting weight is 12 tons, TC7030, TC6536, TC6042, TC5252,TC4565 and other types. The machine hoisting mechanism, slewing mechanism, luffing mechanism for variable frequency speed regulation agencies, electric control system adopts imported components, security protection device for mechanical or electromechanical integration products, complete and reliable, the machine has a fixed, walk, adhesion, climbing and so on work type, can meet the city the high-level construction, industrial plant, power station dam, Bridges and other construction needs.

[lifting mechanism] :

Lifting mechanism variable frequency motor, driven by the motor through the gear coupling to drive the reduction box, and then drive the drum. Speed is achieved by frequency setting of frequency converter. From 0 to each gear is stepless speed regulation, smooth start braking, small impact. When using 2 ropes, the speed can reach 0~102m/min and 0~51m/min; when using 4 ropes, the speed can reach 0~51m/min and 0~25.5m/min.

A normally closed hydraulic push rod brake is installed at the input shaft end of the reduction gear box and a height limiter is installed at one side of the drum. The height limiter can be adjusted according to the required height. Reliable control, simple operation, easy maintenance.

[rotating mechanism] :

The rotary mechanism is a transmission device that provides power for the upper part of the tower crane. The device is composed of a motor, a planetary reducer, a pinion and a rotary limiter. This tower machine adopts two sets of such devices, which are symmetrically distributed on both sides of the slewing bearing and mounted on the upper bearing. The pinion gear meshes with the large tooth ring of the slewing bearing and the mechanism is driven by the torque motor with brake.

The motor tail is provided with a normally closed disc brake; Can be used for tower crane jacking and fixed point operation of the boom brake positioning. The slewing limiter is used to control the tower crane to turn only 540° in one direction to avoid twisting the cable.

[luffing mechanism] :

The amplitude transformer adopts torque motor to drive the drum through the planetary reducer, and through the wire rope, the truck can achieve a speed of 0-80m/min and run at high speed back and forth on the derrick.

The tail of the motor is equipped with a disc brake, which is delayed when the trolley motor is cut off (see figure 4-15).

The amplitude limiter is used to prevent misoperation and stop the car before it hits the buffer at the base of the boom.

Lifting arm

The lifting arm is divided into 11 sections. The upper chord of the third, seventh and eighth sections of the arm is provided with a lifting point of a tie rod. The first arm is equipped with a trolley traction mechanism, and the arm end is equipped with a wire rope anti-twisting device. The maximum arm length is 70 meters, and can be assembled into 65 meters, 60 meters, 52.5 meters, 45 meters and other 5 kinds of arm length, to meet the needs of different rotating space. A trolley luffing mechanism is installed in the root section of the boom and a platform frame is provided to facilitate installation and maintenance.

【 balance arm 】

The balancing arm is divided into three sections, two sections of 7.5 m and one section of 3 m, connected by a pin shaft. With the help of the pin shaft, the balance arm and the balance arm tie rod are connected with the rotary tower body and the top of the tower into a whole.

[upper and lower supports]

The upper support is mounted on the slewing support and is connected with the inner ring of the slewing support. The lower support is a box bearing of the non-slewing part of the crane, the upper plane of which is equipped with a slewing ring. The lower support is connected with the outer ring of the slewing ring by bolts, and the relative slewing motion between the upper and lower supports is realized by the slewing mechanism. The upper support is connected with the rotary tower body, and the lower support is connected with the standard section of the tower body.

[rotary limiter] :

"The tower"

The top of the tower is an oblique cone, the upper end is connected to the boom arm and the balance arm by a pull rod to keep the two arms horizontal, and the lower end is connected by four pin shafts

The rotating tower body is connected. In order to install the heavy arm pull rod and the balance arm pull rod, the upper part of the tower top is provided with a working platform and pulley block.


[bridge]

The cab is the workshop where the driver operates the tower crane, which is fixed on the right side of the rotary tower. Each indicator light and handle of the linkage control console are located on both sides of the driver's cab seat, which is easy to operate and has a broad field of vision.

The bridge electric cabinet is arranged in the rear of the bridge, main circuit breaker, lighting and auxiliary circuit breaker and other devices.

[weight limiter] :

[walking device] :

Walking mechanism has four active trolley, the active trolley is composed of motor, hydraulic coupling, worm gear reducer, disc brake, open gear and walking wheel. The hydraulic coupler ensures the starting braking of the tower crane is stable and the walking speed is 20 meters/min.

The yz160m2-6-7.5kw ac motor controls the operation of the mechanism with the help of the main command controller. The normally closed disc brake at the end of the worm shaft is released when working, and the brake is delayed after shutdown and power failure. The delay time can be adjusted to ensure the short sliding distance of the stop and no shaking of the tower due to excessive braking.

Two travel switches are installed on the outside of the active trolley to control the tower crane to travel within the set limit position to ensure the safety of the tower crane.

[electronic control system and safety device] :

The QTZ300 electronic control system adopts the control mode of PLC+ frequency converter, which is more advanced nowadays, making the reliability, maneuverability, stability and working efficiency of the system greatly improved. As a result of the use of frequency converter to realize stepless speed control, the stability of the whole equipment has been relatively high.

The electronic control system adopts global procurement of electronic control components, the PLC is OMRON of Japan, the frequency converter is yaskawa of Japan, and the whole set of low voltage is schneider. It is because of this that the failure rate of the electronic control system is greatly reduced, and it also provides convenience for fault determination, location and troubleshooting. In addition, it also includes electrical safety devices such as anemometer, obstacle light, and mechanical safety devices such as trolley shaft breaking protection and traction rope breaking rope preventing slipping.