Key points and inspection precautions for gear installation of reducer

Key points and inspection precautions for gear installation of reducer
Tooth flank clearance: Reasonable tooth flank clearance is crucial for the normal operation of gears. The tooth flank clearance can be measured by pressing a lead wire, a feeler gauge, or a dial gauge. The clearance is too small, and the gears are prone to overheating and jamming during operation; If the gap is too large, it can cause impact and vibration.

Top clearance: Top clearance refers to the gap between the top of the gear and the bottom of the meshing gear. The correct clearance helps with the storage and flow of lubricating oil, ensuring the lubrication effect of gears. The top clearance is generally determined by the modulus and displacement coefficient of the gear.

1. Lead pressure method: It is a commonly used method for measuring top clearance and side clearance.

When measuring, first place the lead wire on the gear, and parallel two lead wires on the tooth surfaces at both ends in the tooth width direction (3-4 wires should be placed for tooth widths). Then, the gear is meshed and rolled, and the thickness of the flattened lead wire is equivalent to the values of the top clearance and side clearance, which can be measured with a vernier caliper or micrometer. The thickness of the thick part of the lead wire is the top clearance, and the sum of the thicknesses of the adjacent thinner parts is the side clearance.

For large wide gears, two or more lead wires must be placed to accurately measure the meshing clearance.

At this point, not only can the clearance be checked based on it, but the parallelism of the gear axis can also be checked.

2. Feeler gauge method: The top clearance and side clearance of the gear can be directly measured using a feeler gauge.

3. Micrometer method: The side clearance of a spur gear can be indirectly measured using a micrometer.

When measuring, try to fix the lower gear and slightly rotate the lever fixed on the upper gear shaft in both directions, so that the pointer on the dial gauge swings in both directions to obtain a reading.

Analysis of a case study of excessive gear clearance in a reducer of a certain steel plant
Fault phenomenon: After running for a period of time, the reducer on the rolling production line of a certain steel plant experienced abnormal vibration and noise, and the equipment's operating accuracy decreased.

Preliminary inspection: The maintenance personnel conducted a visual inspection of the gearbox and did not find any obvious signs of damage. Subsequently, using professional tools to measure the gear clearance, it was found that it far exceeded the normal range.

Troubleshooting: Inspection of the lubrication system, bearings, and other components of the gearbox revealed certain issues with the lubrication system, including insufficient lubricating oil and impurities.

Repair measures: Repair the gear and adjust the gear clearance to the standard value. At the same time, replace damaged components, clean the lubrication system, and replenish qualified lubricating oil.

Test verification: After the repair is completed, no-load and load tests are conducted, and the reducer runs smoothly with significantly reduced noise and vibration, and the operating accuracy returns to normal.

Cause analysis:

Long term load operation: The steel plant has heavy production tasks, and the reducer is in a high-intensity load operation state for a long time, resulting in gradual wear of the gears.

Insufficient lubrication maintenance: The lubrication system was not maintained in a timely manner, resulting in insufficient lubricating oil and impurities, which exacerbated gear wear.

Installation accuracy issue: There may be certain errors in the installation process of the reducer, resulting in poor gear meshing and gradually increasing clearance.

Preventive measures:

Strengthen lubrication management: Regularly inspect and replace lubricating oil to ensure the normal operation of the lubrication system and reduce gear wear.

Regular maintenance: Develop a regular maintenance plan for the gearbox, inspect and adjust key components such as gears and bearings, and promptly identify and address potential issues.

Improve installation accuracy: When installing the reducer, strictly follow the installation specifications to ensure the accuracy of gear meshing and avoid malfunctions caused by installation problems.

Monitoring operating status: Utilizing advanced monitoring equipment to monitor the operating status of the gearbox in real-time, such as vibration, temperature, etc. Once any abnormalities are detected, the machine should be stopped for inspection in a timely manner.