The lifting components and rotation radius of the lever chain crane are key elements of its core function and safety, which need to be comprehensively analyzed in combination with mechanical principles and engineering design

1、 Enhance component functionality and principles

Core component composition

Leverage system: As the core force bearing structure, it follows the principle of lever balance of "power arm x power=resistance arm x resistance". The fulcrum is usually located at the base of the crane, the power arm (operating end) applies force through human or electric devices, and the resistance arm (load end) carries heavy objects to achieve torque amplification. For example, when the length of the power arm is three times that of the resistance arm, only one-third of the force is needed to balance the load.

Chain and gear set: The chain transmits power and connects various components, while the gear set (such as ratchet and worm) achieves lifting control and self-locking function to prevent heavy objects from accidentally falling.

Pulley system: By using multi-stage pulleys to change the direction of force and amplify mechanical benefits, for example, n-section load-bearing ropes can reduce the required tension to 1/n of the weight of the object.

Brakes and clutches: Normally closed brakes automatically lock when power is off, ensuring that heavy objects remain stationary; The clutch controls the engagement and disengagement of power transmission, ensuring precise operation.

Power transmission path

The power system (electric motor/internal combustion engine) drives the winch or hydraulic motor, and the lifting hook is lifted and lowered through wire rope/chain retraction; The rotating mechanism drives the turntable through a motor to adjust the horizontal position of the arm frame; The amplitude changing mechanism adjusts the working radius by changing the elevation angle of the boom through hydraulic cylinders or connecting rods.

2、 Definition and influencing factors of rotation radius

Definition of Rotation Radius

The horizontal distance from the center of the hook or arm end to the center of rotation when the crane arm rotates, that is, the radius of the rotation trajectory. Narrowly defined, it can be understood as a function of arm length and elevation angle, and broadly encompasses the operating range and stability boundary.

Key influencing factors

Arm length and elevation angle: Increasing arm length or decreasing elevation angle will expand the rotation radius, but may increase the risk of overturning. For example, the maximum lifting amplitude (rotation radius) is inversely proportional to the distance and mass of the counterweight, and stability needs to be verified through the lever balance formula (such as G_counterweight × L_counterweight=G_load × L_load).

Weight design: The position and mass of the weight directly affect the torque balance. For example, when the counterweight is 4 meters away from the fulcrum and weighs 3 tons, the maximum lifting amplitude of 10 meters can estimate the load capacity, and it is necessary to ensure that the total torque does not exceed the safety threshold.

Ground support: Support legs, supporting wheels, and tracks (if any) distribute the load to the ground, and expanding the effective support area can reduce the impact of rotation radius on stability.

Safety and efficiency optimization

The three-point arc principle: The lifting point of the equipment, the center of the base, and the center of the foundation should be located on an arc with the center of rotation as the center and the radius of rotation as the radius, to ensure the stability of the center of gravity during rotating lifting.

Dynamic adjustment: Real time adjustment of boom extension or elevation angle through hydraulic system to adapt to different operational needs; When lifting with two or three machines, it is necessary to coordinate the rotation radius and load distribution to avoid overloading or imbalance.

3、 Design parameters and safety standards

Structural parameters: arm length, elevation angle, counterweight mass, pivot position, etc. must meet the requirements of mechanical balance and strength. For example, the arm length of a crawler crane can be extended to 52 meters (such as the QUY50 model), and multiple standard arms can be connected by a pin shaft to enhance adaptability.

Safety devices: including overload limiters, torque limiters, wind speed sensors, etc., to monitor and warn potential risks in real time; The brake must meet the requirement of "normally closed" to ensure automatic braking when power is cut off.

Materials and processes: High strength steel or alloy materials are used to ensure structural rigidity and durability; Welding, bolt connections, or pin connections must comply with engineering standards to avoid stress concentration or fatigue failure.

In summary, the lifting components of the lever chain crane achieve high efficiency transmission through the principle of lever and pulley system, and the rotation radius needs to be balanced between the operating range and stability. When designing, multidimensional factors such as mechanics, materials, and safety need to be comprehensively considered to ensure operational safety and performance optimization.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment