How to use broken gears during the running-in period of construction machinery

I. Characteristics of the Running-in Period

1. Fast wear rate

Due to the influence of factors such as the processing, assembly and adjustment of new machine parts, the friction surfaces are rough, the contact area of the mating surfaces is small, and the pressure-bearing state of the surfaces is uneven. During the operation of the machine, the protruding and recessed parts on the surface of the components interlock and rub against each other. The metal debris worn off then acts as an abrasive and continuously participates in the friction, further accelerating the wear of the mating surfaces of the components. Therefore, during the running-in period, it is easy for the components (especially the mating surfaces) to wear out, and the wear rate is fast. At this point, if the operation is overloaded, it may lead to the damage of components and cause early failure.

2. Poor lubrication

Due to the small fit clearance of the newly assembled components and the difficulty in ensuring the uniformity of the fit clearance due to assembly and other reasons, the lubricating oil (grease) is not easy to form a uniform oil film on the friction surface to prevent wear. This reduces the lubrication efficiency and causes premature abnormal wear of the machine parts. In severe cases, it may cause scratches or seizing on the precisely fitted friction surfaces, leading to malfunctions.

3. Loosening occurs

Newly processed and assembled components have deviations in geometric shape and mating dimensions. In the initial stage of application, due to the influence of alternating loads such as impact and vibration, as well as factors like heat and deformation, coupled with rapid wear and other reasons, the originally tight components are prone to loosening

4. Leakage occurs

Due to the loosening of machine parts, vibration and the influence of machine heating, leakage may occur at the sealing surfaces and pipe joints of the machine. Some casting and processing defects are difficult to detect during assembly and debugging. However, due to the vibration and shock during the operation process, these defects are exposed and manifested as oil (water) leakage. Therefore, leakage is prone to occur during the running-in period.

5. There are many operational errors

Due to insufficient understanding of the structure and performance of the machine (especially for new operators), it is easy to cause malfunctions or even mechanical accidents due to operational errors.

Ii. Application and Protection during the Running-in Period

1. As construction machinery is a special type of vehicle, the operators should receive training and guidance from the manufacturer, have a sufficient understanding of the machine's structure and performance, and acquire certain operation and maintenance experience before operating the machine. The product usage and protection manual provided by the manufacturer is an essential material for operators to operate the equipment. Before operating the machine, it is necessary to read the usage and protection manual first and operate and maintain it in accordance with the requirements of the manual.

2 Pay attention to the working load during the running-in period. Generally, the working load during the running-in period should not exceed 80% of the rated working load, and an appropriate workload should be arranged to prevent overheating caused by the machine's continuous operation for a long time.

3. Pay attention to frequently checking the indications of all instruments. If any abnormality is found, stop the machine in time to eliminate it. The operation should be ended before the cause is found and the fault is eliminated.

4. Pay attention to frequently checking the levels and quality of lubricating oil, hydraulic oil, coolant, brake fluid and fuel (water), and also pay attention to checking the sealing performance of the entire machine. If excessive oil and water deficiency is found during the inspection, the cause should be analyzed. At the same time, the lubrication of each lubrication point should be strengthened. It is recommended that during the running-in period, grease be added to the lubrication points every shift (except for special requests).

5. Keep the machine clean and adjust and tighten loose parts in time to prevent accelerated wear of parts or loss of parts due to looseness.

6. After the running-in period is over, the machine should be forcibly maintained, and the review and adjustment work should be done well. At the same time, attention should be paid to the change of oil.