Hoisting Mechanism (Core Load-Bearing Component)
Responsible for vertical lifting of heavy objects, it is composed of a winch (including motor, reducer , and brake), steel wire rope, and hook block:
1.Winch: The motor provides power, the reducer converts high-speed rotation into low-speed and high torque, and the brake ensures that heavy objects do not slip when suspended (e.g., the hoisting brake of a tower crane must meet the "power-off braking" safety requirement).
2. Steel wire rope: Twisted from multiple strands of steel wire, it must have high strength (e.g., 6 ×37 type steel wire rope with a breaking force of over 1000kN) and wear resistance. Its service life is usually 1 to 3 years (replaced according to operation frequency).
3.Hook block: Includes a hook and pulleys (reducing the force on the steel wire rope). The hook is made of high-quality low-carbon alloy steel (e.g., 20MnSi), and its surface undergoes heat treatment to enhance hardness and prevent deformation or fracture.
Travel Mechanism (Horizontal Movement Component)
Enables horizontal movement of the entire crane or trolley, divided into two types:
1.Long travel mechanism: Such as the end beam wheels of a bridge crane (moving along workshop rails) and the crawler drive wheels of a crawler crane (driving crawler rotation via hydraulic motors).
2.Trolley travel mechanism: Such as the trolley wheels of a bridge crane (moving along the mainbeam rails) and the luffing trolley of a tower crane (moving along the jib rails to adjust the working radius).
Luffing Mechanism (Component for Adjusting Working Radius)
Only present in equipment such as luffing-jib tower cranes and truck cranes. For luffing-jib tower cranes, hydraulic cylinders push the jib to tilt (e.g., when the jib is lifted from an angle of 30° to 70 °, the working radius is reduced from 60 meters to 20 meters); for truck cranes, the working radius is adjusted by extending or retracting the jib length (e.g., a 5-section jib can reach a working radius of 35 meters when fully extended to 40 meters).
Control System (Operation Core)
Divided into manual operation (e.g., the control lever of a truck crane) and remote control (e.g., the wireless remote control system of a large crawler crane). It must display real-time parameters such as "lifting weight, working radius, and jib angle." Some intelligent cranes also have functions such as "overload early warning" (alarming when the actual lifting weight exceeds 10% of the rated value) and "anti-sway control" (reducing the sway amplitude of heavy objects to improve hoisting accuracy).
