How to ensure the normal performance of the brake of the hand chain hoist

How to ensure the normal performance of the brake of the hand Chain Hoist

The importance of the brake performance of the hand chain hoist
The hand chain hoist is a small lifting equipment widely used in factories, mines, construction sites and other places. Its brake performance is directly related to the normal use and operation safety of the equipment. A good brake can accurately brake when lifting heavy objects, prevent the heavy objects from accidentally sliding down, and ensure the safety of workers and equipment. If the brake fails, it will not only reduce work efficiency, but also may cause serious safety accidents, such as heavy objects falling and causing casualties and property losses.

Structural principle of hand chain hoist brake
The hand chain hoist usually adopts a ratchet friction plate one-way brake, which is mainly composed of ratchet, friction plate, pawl and other components. Its working principle is: when the hand chain hoist lifts the heavy object, the manual chain is pulled to rotate the hand chain wheel, driving the friction plate ratchet and brake seat to rotate together, and then driving the lifting sprocket to rotate, so that the lifting chain lifts the heavy object. At this time, the pawl engages with the ratchet under the action of the spring. When the hand chain stops pulling, the pawl will jam the ratchet teeth, causing the ratchet to stop rotating, thereby achieving braking. The friction between the friction plate and the ratchet can reliably support the suspended load.

Methods to ensure the normal performance of the hand chain hoist brake
Daily inspection:
Appearance inspection: Regularly check whether the various components of the brake have obvious deformation, cracks, wear and other damage, check whether the surface of the friction plate is flat, whether there is oil or excessive wear, and whether the shape of the ratchet and pawl is normal. If there is any abnormality, the damaged parts should be replaced in time.
Check the cleanliness of the brake: The friction surface of the brake must be kept clean. If it is contaminated with oil, dust and other impurities, it will affect the friction between the friction plate and the ratchet, resulting in a decrease in braking performance. Therefore, it is necessary to regularly clean the impurities on the brake to ensure that the friction surface is clean.
Check the lubricant: Although the brake needs to be kept clean, it is not completely unlubricated. On the contrary, proper lubrication can reduce wear between components and improve the service life and performance of the brake. Generally speaking, a proper amount of lubricating oil should be applied to the non-working surface of the transmission parts and friction plates of the brake, but be careful to avoid the lubricating oil from getting on the working surface of the friction plates.
Perform no-load tests regularly: Perform no-load tests before each use of the hand chain hoist or regularly (such as every day or every week). Pull the chain to make the hand chain hoist rise and fall several times without load, check whether the operation of each component is flexible, whether there is any jamming or loose and tight phenomenon, and observe whether the brake can brake normally during the lifting and lowering process and whether the action is reliable. If the brake is found to be abnormal during the no-load test, it should be repaired or adjusted in time.

Perform load tests regularly:
Light load test: According to relevant standards, apply a test load of 3% of the rated lifting weight to the hand chain hoist, perform lifting and lowering operations, and check whether the brake action is reliable and whether the load lifting and lowering are normal.
Rated load test: Lift the hand chain hoist to the rated load, suspend it in the air for a period of time (such as 10 minutes), observe whether the heavy object slides down, and whether the brake can stably support the load. At the same time, you can also pause several times during the lifting and lowering process to check the instant braking effect of the brake.
Overload test: In order to test the performance of the brake under extreme conditions, overload tests can be carried out regularly, but the magnitude of overload should be controlled within a safe range. Generally, the load can be loaded at a ratio of 1.25 times or higher of the rated load, but it should be noted that it should not exceed the maximum load that the hand chain hoist can bear, otherwise it may cause equipment damage or even safety accidents. In the overload test, observe whether the brake can work normally, whether there is slippage, failure and other phenomena. If there is an abnormality, the test should be stopped immediately and the brake should be inspected and repaired.
Regular maintenance:
Replacement of worn parts: The friction pads, pawls and other parts of the brake will deteriorate due to wear during long-term use. Therefore, the degree of wear of these parts should be checked regularly. When the wear reaches a certain degree, they should be replaced in time to ensure the braking torque and reliability of the brake.
Adjust the brake clearance: After the brake has been used for a period of time, the wear of the friction pads may cause the brake clearance to increase, affecting the braking effect. The brake clearance needs to be adjusted regularly to keep it within the appropriate range. The adjustment method is generally to change the gap between the friction plate and the ratchet by adjusting the nut or gasket. The specific operation can be carried out according to the instruction manual of the hand chain hoist.

Common problems and solutions
Brake failure:
Reason: It may be due to excessive wear of the friction plate, resulting in insufficient braking torque; or poor meshing of the ratchet and the pawl, such as deformation of the pawl, weakening of the spring elasticity, etc., so that the pawl cannot effectively clamp the ratchet teeth; it may also be that the friction surface of the brake is contaminated with impurities such as oil, dust, etc., which reduces the friction coefficient.
Solution: First check the wear of the friction plate. If the wear is serious, replace it in time; then check the shape and fit of the ratchet and the pawl, repair or replace the damaged parts; at the same time, clean the friction surface of the brake to ensure that it is clean and dry.
Insensitive brake:
Reason: It may be due to the excessive gap of the brake, which requires a large braking torque to make the friction plate and the ratchet in close contact during braking; or due to poor lubrication, the transmission parts of the brake are not flexible, affecting the timeliness of braking.
Solution: Adjust the clearance of the brake to meet the requirements; at the same time, check the lubrication and add an appropriate amount of lubricating oil to the transmission parts of the brake to ensure its flexible operation.
Industry standards and specifications
Internationally, the performance test and related standards of hand chain hoist brakes usually follow some general specifications, such as the general requirements of ISO 9001 quality management system for product quality, and related lifting equipment safety standards. These standards have made strict regulations on the materials, design, manufacturing, testing and other aspects of the brake to ensure the safety and reliability of the hand chain hoist during use.
For example, ISO 12078:2011 "Lifting Machinery - Manual Hoist - Safety Specifications" stipulates the safety requirements of manual hoists (including hand chain hoists) in brakes and other aspects, including that the design of the brake should be able to reliably support the rated load, and the friction material of the brake should have sufficient wear resistance and friction coefficient.

Conclusion
Ensuring the normal performance of the hand chain hoist brake is of vital importance to ensure the normal operation of the equipment, improve work efficiency, and protect the safety of personnel and equipment. By strengthening daily inspections, carrying out load tests regularly, doing regular maintenance and promptly dealing with common problems, you can effectively ensure that the performance of the brake is always in good condition. At the same time, following relevant industry standards and specifications, choosing reliable quality products and professional maintenance services are also key factors in ensuring the performance of the hand chain hoist brake.