FAQ

In the process of gear transmission in reducers, tooth surface wear is inevitable. Tooth surface wear also includes adhesive wear, abrasive wear, scoring, corrosive wear, and scuffing. For adhesive wear, lubrication is the primary factor. If the lubricating oil film is complete and sufficiently thick, metal-to-metal contact will be reduced, and wear will not occur.
 

If the oil film temperature and pressure are the same, higher oil viscosity results in less wear. Under conditions of low speed, heavy load, or extreme temperatures, the oil film may break down. In such cases, wear occurs on most of the tooth surface except for the pitch circle. This type of wear can be improved by increasing tooth surface hardness, reducing surface roughness, and increasing oil viscosity.
 

Abrasive wear and scoring mainly refer to impurities in the lubricant or the generation of wear debris due to metal-to-metal contact during operation, leading to gear wear in the reducer and causing transmission failure.
 

If the gear alignment is proper and scoring is not caused by raised micro-convexities on the tooth surface, the wear will extend to most areas of the gear. Corrosive wear refers to chemical reactions between substances in the lubricant and the metal on the tooth surface, resulting in metal corrosion.

Tooth Surface Pitting and Scuffing

During gear transmission, the contact stress at various points on the contact surface shows pulsating cyclic changes. After a period of time, cracks will form due to metal fatigue on the contact surface. The expansion of these cracks will cause metal spalling, forming pitting. This situation can be prevented by measures such as increasing tooth surface hardness and reducing surface roughness.
 

Under conditions of high speed, heavy load, or lubrication failure, gears can develop local high temperatures on the tooth surface, leading to adhesive welding on the contact surface. This phenomenon is called scuffing. To prevent scuffing, tooth surface hardness and smoothness should be improved. Different steel grades should be selected for different gear models, and proper selection of lubricating oil is an important measure to reduce gear failure.
 

Failure Caused by Tooth Surface Plastic Deformation

Plastic deformation mainly includes ripples and ridge-like extensions caused by rolling and hammering deformation. This is primarily due to the relatively soft gear material, which causes metal flow along the friction direction. Changes in temperature and humidity in the gear working environment can also cause plastic deformation of the tooth surface. Higher viscosity lubricating oil can be selected to prevent plastic deformation, or tooth surface hardness can be increased.
 

Finding the true causes of gear transmission failure in reducers is essential for solving corresponding problems, ensuring the effectiveness of mechanical operation, improving operational efficiency, and promoting work progress.

01: For reducers that are newly put into operation, the lubricating oil needs to be replaced regularly after about half a month. If operating in relatively harsh environments, regular checks are required to determine if the oil has deteriorated or been contaminated with impurities. For reducers that have been idle for an extended period, the oil must be replaced with new oil before being put back into service. When adding lubricating oil, ensure it matches the original oil in model, specification, and brand, and pay attention to selecting lubricating oil with appropriate viscosity.
 

02: When replacing lubricating oil for the reducer, it is necessary to wait for the reducer to cool to room temperature to avoid the risk of combustion. If the reducer has completely cooled down, it will not be conducive to oil replacement or drainage. We need to run it at idle speed until it reaches normal temperature.
 

03: During operation, if the reducer shows abnormal conditions such as excessive temperature or unusual noises, it is necessary to stop the machine immediately for inspection. Only after troubleshooting can it be returned to normal operation.
 

04: Operators should strictly follow operating procedures and maintenance systems to ensure the equipment maintains good working condition over the long term. During equipment inspection and maintenance, detailed records should be kept for future reference.
 

Reducers achieve speed reduction through gear meshing on the input shaft. Due to their working principle, gears will experience a certain degree of wear during long-term use. Adding lubricating oil between gears during operation will effectively reduce gear wear. Therefore, the service life of a reducer is closely related to the lubricating oil used.

Reducers are widely used in many industries, but numerous problems can occur during the installation process. Here are the main installation issues and their solutions:

Shaft breakage caused by insufficient load capacity of the reducer:

During selection, users mistakenly believe that as long as the rated output torque of the selected reducer meets the working requirements, it will be sufficient. This is not the case. First, the value obtained by multiplying the rated output torque of the matching motor by the reduction ratio should in principle be less than the rated output torque of the similar reducer provided in the product catalog. Second, the overload capacity of the drive motor and the maximum working torque actually required must also be considered.

Theoretically, the rated output torque of the reducer should be greater than twice the maximum working torque required by the user. This criterion must be strictly followed in some applications, not only to protect the gears inside the reducer but, more importantly, to avoid the output shaft of the reducer from being twisted off. This is mainly because if there are problems with the equipment installation and the output shaft of the reducer and its load working host get stuck, the overload capacity of the drive motor will still cause it to continuously increase output, which may cause the force on the reducer's output shaft to exceed twice its rated output torque and twist off the reducer's output shaft. Secondly, during acceleration and deceleration processes, if the instantaneous torque on the reducer's output shaft exceeds twice its rated output torque, and this acceleration and deceleration are too frequent, it will eventually cause the reducer shaft to break.

The solution is as follows:

When purchasing a reducer, pay attention to selecting the appropriate model. It is better to choose a model slightly higher than your requirements rather than selecting a model that is barely sufficient due to lower price or other reasons, as this is more likely to cause problems.