QTZ200 Tower Crane

  The QTZ200 tower crane is a reinforced tower crane designed to meet standards such as GB/T50311 “Tower Cranes” and GB5144 “Safety Regulations for Tower Cranes.” It features a rated lifting moment of 200 t·m and a lifting capacity of 12 tons, with models including TC7020, TC6524, TC6028, and TC5236. with a lifting capacity of 12 tons. Available models include TC7020, TC6524, TC6028, and TC5236. The hoisting mechanism, slewing mechanism, and luffing mechanism all utilize variable frequency speed control. The electrical control system employs imported components, while safety protection devices consist of mechanical or mechatronic products, ensuring comprehensive reliability. This crane supports fixed, traveling, attached, and internal climbing configurations, meeting diverse construction needs for mid-to-high-rise urban buildings, industrial plants, power station dams, bridges, and other structures.

QTZ200 Technical Specifications 

【Hoisting Mechanism】:

     The hoisting mechanism (2200 kg) employs a YZP280M-6-65KW variable frequency motor. The motor drives the reduction gearbox via a splined coupling, which in turn drives the drum. Speed is adjusted via frequency settings on the inverter. Speed control is stepless from 0 to all gear positions, ensuring smooth starts and stops with minimal impact. When using 2 ropes, speeds reach 0~102 m/min and 0~51 m/min; with 4 ropes, speeds reach 0~51 m/min and 0~25.5 m/min.

    A normally closed hydraulic push-rod brake (YWZ3H315/90) (850-900Nm) is installed at the input shaft end of the reduction gearbox (see Figure 4-13). A height limiter is mounted on one side of the drum, adjustable to the required height. It offers reliable control, simple operation, and convenient maintenance.

【Rotary Mechanism】:

     The slewing mechanism is the transmission device that provides power for the upper slewing of the tower crane. This device consists of a motor, planetary reducer, pinion gear, slewing limiter, and other components. This tower crane employs two such mechanisms, symmetrically distributed on both sides of the slewing bearing and mounted on the upper support. Their pinion gears mesh with the large ring gear of the slewing bearing, and the mechanism is driven by a torque motor equipped with a brake.

  The motor tail features a normally closed disc brake, which can be used for tower crane jacking operations and boom braking/positioning during fixed-point work. The slewing limiter restricts the tower crane's rotation to 540° in any single direction to prevent cable breakage. 

【Variable-Angle Mechanism】:

    The hoist mechanism (470 kg) employs a YLEF112L-95Nm torque motor. This motor drives the drum via a planetary gear reducer, enabling the load trolley to traverse the boom at speeds ranging from 0 to 80 m/min through wire rope operation.

   The motor tail end is equipped with a disc brake that provides delayed braking when the trolley motor is de-energized (see Figure 4-15).

   The amplitude limiter prevents misoperation by stopping the trolley before it contacts the buffer at the base of the boom.

【Lifting Arm】

    The boom consists of 11 sections, with a tie rod lifting point installed on the upper chord of the third, seventh, and eighth sections. Each section is connected to the next via pins. A trolley traction mechanism is mounted on the first section, while a wire rope anti-twist device is installed at the boom tip. With a standard length of 70 meters, the boom can be reconfigured into five alternative lengths—65m, 60m, 52.5m, and 45m—to accommodate varying rotation space requirements. A trolley luffing mechanism with a walkway frame is integrated into the base section for convenient installation and maintenance.

【Balancing Arm】

   The counterweight boom consists of three sections: two 7.5-meter sections and one 3-meter section, connected by pins. Using these pins, the counterweight boom and its tie rods are integrated with the rotating tower body and tower top. Guardrails and walkways are installed on both sides of the counterweight boom.

【Upper and Lower Supports】

   The upper support is mounted on the slewing bearing and connected to its inner ring. The lower support is a box-shaped support for the non-rotating section of the crane. Its upper surface is fitted with the outer gear ring of the slewing bearing. The lower support is bolted to the outer ring of the slewing bearing, enabling relative rotational movement between the upper and lower supports via the slewing mechanism. The upper support connects to the rotating tower body above, while the lower support connects to the standard tower sections below.

【Rotary Limit Switch】:

【Tower Top】

    The top of the tower is a sloping cone, with its upper end connected to the lifting arm and counterweight arm via tie rods to maintain the horizontal alignment of both arms. Its lower end is secured with four pins to

    The rotating tower body connection features a work platform and pulley system at the top of the tower to facilitate the installation of the boom tie rods and counterweight boom tie rods.

【Driver's Cab】

    The cab serves as the operator's workstation for controlling the tower crane, fixed to the right side of the rotating tower body. The indicator lights and control handles of the integrated control console are positioned on both sides of the operator's seat, offering convenient operation and a wide field of view.

    The cab electrical control box is located at the rear of the cab, housing the main circuit breaker, lighting circuit breakers, auxiliary circuit breakers, and other devices.

【Load Limiters】:

【Walking Device】:

    The traveling mechanism comprises four powered trolleys, each consisting of an electric motor, hydraulic coupling, worm gear reducer, disc brake, open gear rim, and travel wheels. The hydraulic coupling ensures smooth starting and braking of the tower crane, with a travel speed of 20 meters per minute.

    The YZ160M2-6-7.5KW AC motor controls the operation of the control mechanism via the master controller. The normally closed disc brake at the tail end of the worm shaft releases during operation and applies delayed braking after shutdown and power disconnection. The delay time is adjustable to ensure a short stopping distance and prevent tower crane sway caused by abrupt braking.

    Two limit switches are installed on the outer side of the active trolley to prevent the tower crane from traveling beyond its preset limit positions, ensuring operational safety.

【Electrical Control System and Safety Devices】:

     The QTZ200 electronic control system employs a state-of-the-art PLC + variable frequency drive (VFD) control approach, significantly enhancing system reliability, operability, stability, and machine efficiency. The integration of VFDs enables stepless speed regulation across all mechanisms, substantially improving the overall stability of the equipment.

  The electrical control components of this system are globally sourced: the PLC is from Japan's OMRON, the frequency converter from Japan's Yaskawa, and the complete low-voltage system from Schneider Electric. This approach significantly reduces the failure rate of the electrical control system while also facilitating fault diagnosis, localization, and troubleshooting. Additionally, the system incorporates electrical safety devices such as anemometers and obstruction lights, along with mechanical safety features including trolley shaft break protection and traction rope break anti-runaway mechanisms.