For the defects of the fulcrum of the lever chain hoist (i.e. lever chain crane), such as improper fulcrum position, loose or worn fulcrum, the following targeted solutions can be adopted, combined with mechanical principles and actual working conditions for optimization:

1、 Adjustment method for improper pivot position

Excessive pivot point leads to decreased sensitivity

Phenomenon: The position of the fulcrum blade is higher than the center of gravity of the measuring lever, or the fulcrum does not match the line connecting the force and key points, resulting in laborious operation or inaccurate measurement.

Solution:

Lowering pivot blade: By adjusting the pivot fixing device (such as bolts or buckles), the pivot blade is lowered to a reasonable position, ensuring that it is slightly lower than the center of gravity of the measuring lever and perpendicular to the line connecting the force and the key point.

Sensitivity testing: After adjustment, conduct no-load and load tests to observe whether the lever rotates smoothly without any jamming or jumping phenomenon.

Uneven force caused by offset of pivot point

Phenomenon: The fulcrum is not aligned with the center of the lever, resulting in excessive force on one side, which can easily cause deformation or fracture after long-term use.

Solution:

Repositioning the pivot point: Use a laser level or a square ruler to calibrate the pivot point position, ensuring that it coincides with the centerline of the lever.

Strengthening the pivot fixing device: Apply anti loosening treatment to the pivot bolt or buckle (such as installing spring washers or applying thread locking agent) to prevent displacement during use.

2、 Repair methods for loose or worn support points

Loose pivot point leads to unstable operation

Phenomenon: Loose pivot fixing bolts or worn buckles can cause the lever to shake during operation, affecting safety and accuracy.

Solution:

Tighten the pivot bolt: Use a torque wrench to tighten the bolt according to the instructions, ensuring that the pre tightening force meets the standard.

Replace worn buckles: If the buckles are severely worn, they should be replaced with original factory parts to avoid using non-standard parts that may cause excessive fit clearance.

Poor contact caused by worn support points

Phenomenon: The surface of the fulcrum blade or roller is worn, and the contact surface with the lever is uneven, resulting in friction or jamming.

Solution:

Polish and repair the blade: For slightly worn blades, use oilstone or sandpaper to polish along the direction of the blade edge to restore its sharpness.

Replace pivot component: If the wear is severe (such as dull blade or uneven roller surface), the entire pivot component needs to be replaced to ensure a smooth and even contact surface.

3、 Long term solution for optimizing pivot structure

Using high-strength materials

Principle: As a key load-bearing component, the fulcrum needs to have high strength and wear resistance.

measures

Choose alloy steel or stainless steel to make pivot blades and rollers, improving wear resistance.

Heat treatment (such as quenching) should be carried out on the fulcrum fixing device to enhance its hardness and fatigue resistance.

Add auxiliary support structures

Principle: By adding auxiliary support points, the force on the main pivot point is dispersed, and the single point load is reduced.

measures

Add auxiliary support points (such as rollers or sliders) on both sides of the lever to form a multi-point support structure.

Using a triangular support frame and utilizing the principle of geometric stability to enhance the overall structural strength.

Regular maintenance and inspection

Principle: Through preventive maintenance, potential issues with the pivot point can be identified and addressed in a timely manner.

measures

Develop a regular inspection plan (such as once a month), focusing on checking for looseness, wear, and positional deviation of the support points.

For frequently used lever chain hoists, shorten the maintenance cycle (such as every two weeks) to ensure that the fulcrum is always in good condition.

4、 Actual case reference

Case 1: The lever chain hoist in a certain factory experienced operational shaking due to loose support points. After tightening the support point bolts and replacing the worn buckles, the problem was completely solved and the operational stability was significantly improved.

Case 2: The sensitivity of a lever chain hoist at a construction site decreased due to the high position of the fulcrum. After lowering the fulcrum blade and recalibrating the position, the measurement accuracy was restored to the standard range.

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