The Causes and Solutions of Crane Sheave Bearing Damage

The sheave block in the crane is an important component and is also an important component of the crane’s lifting. The sheave block is generally composed of rolling bearings, sheaves, sheave shafts, and rolling bearing spacers. This structure can withstand radial force better than axial force. During use of this structure, rolling bearing retaining rings, support rings, and spacers are often damaged, causing the sheave to be unable to rotate, and the wire rope to be severely worn, making normal construction impossible.

The main reasons for the damage of the lifting pulley bearing are as follows:

1. Crane safety factor is low

The design link of the crane is directly related to the safety factor of the crane and the use of quality and other factors, in the actual design link, there may be a lack of business ability of some designers, which leads to the design of the relevant safety factors of the crane, the designer only considers the static load of the lifting sheave bearing. The impact load of the lifting sheave bearing is ignored, so that the safety factor and other factors of the whole crane are small and the carrying capacity is poor. In such a case, the bearing capacity of the designed crane can not meet the actual demand, which is easy to cause premature damage to the lifting pulley bearing of the crane, accelerate the decline of life, and bring adverse effects to the use of the entire crane.

2. The quality of crane sheave is not qualified

In the actual use of the crane, the weight of the load is transferred directly to the bearing through the steel wire rope wound on the sheave, that is, the bearing needs to carry a larger weight. In the design of the crane, if the center of the pulley and the bearing of the two items is not on the same plane, that is, the quality of the crane sheave is not qualified, then the weight of the load can not be evenly distributed in the two bearings, this actual situation is often easy to cause the weight of the item carried by a bearing phenomenon, thus bringing great damage to the use of bearings. And then bring the risk of damage to the whole crane pulley bearing.

3. The crane is overloaded

Each crane has its limit load weight, in the actual use of the process, the limit of the crane load weight is often achieved under the control of the overload limiter, but in the actual production and life, there will be inspectors work is not careful, inspection is not timely or overload limiter sudden failure and other situations, the emergence of these circumstances will make the utility of the overload limiter loss. In this case, the utility of the overload limiter is lost, and the crane is easy to carry items exceeding its own limited load weight, which brings the risk of excessive damage to the crane.

4. Heavy objects move too much

In the process of lifting heavy objects, if the operator does not control the center of the heavy objects, it is easy to appear that the speed of heavy objects is too fast, the existence of this phenomenon often causes the phenomenon of heavy objects shaking in the air, which will not only make the bearing on both sides of the uneven bearing load, but also bring greater lateral force to the bearing. The existence of lateral force, when its strength exceeds a certain limit value, is easy to cause the internal structure of the bearing to collapse, bearing utility failure, and eventually cause the lifting pulley bearing damage phenomenon.

Measures to reduce the probability of damage to the lifting pulley bearing

In the actual industrial production and life, the existence of the crane is extremely important, among which the lifting pulley bearing is an important part of the crane, ensuring the normal operation of the sheave bearing has an extremely important role in the normal use of the crane, combined with the actual situation, it can be seen that the relevant measures to reduce the crane lifting pulley bearing damage probability mainly have the following aspects:

1. Add overload limiting device

According to the load table, the maximum bearing capacity of the bearing is calculated, and when the bearing load force is equal to the rated force, an alarm should be issued to prompt the operator. When the bearing load force exceeds the rated load or exceeds the safety factor, the crane action is locked under the action of the safety device, forcing the construction personnel to construct according to the crane load table, and then reduce the bearing force, protect the bearing and extend the service life of the bearing.

2. Increase the number of pulleys to ensure the quality of the pulleys

In actual production and life, since there are many factors that cause pulley damage, in order to bring more and better protection to the pulley bearings, the designer and production personnel can consider appropriately increasing the number of pulleys without affecting the production efficiency of the crane. In the actual production process, a reasonable increase in the number of pulleys can not only increase the pulley magnification, but also reduce the load-bearing strength of each pulley, thus giving better quality assurance to the entire pulley bearing and reducing the risk of damage.

3. Increase the frequency of inspections of the crane overload limiter

In actual production and life, the crane’s overload limiter is usually automatically locked. Such a setting can still easily bring greater risk of damage to the crane’s lifting pulley bearings when the overload limiter is prone to failure or the crane is used frequently.

In order to better reduce the risk of damage to the crane lifting pulley bearings, you can mainly start from the following points:

First, replace the automatic locking overload limiter to allow operators to carry heavy objects within the rated limit weight value based on the actual importance of each heavy object;

Second, increase the frequency of inspections of the crane’s overload limiter. Once there is a problem with the overload limiter, repair and replace it in a timely manner;

The third is to provide safety and quality education to operators, strictly prohibit overloading of cranes, and establish a corresponding reward and punishment system, especially a punishment system to impose material and job penalties for illegal operations.