9 Common Misunderstandings About Mechanical Equipment Lubrication

When it comes to lubrication, everyone is familiar with it. Correct lubrication methods can improve equipment performance and extend working life. Any equipment is inseparable from lubrication, but in actual production, misunderstandings about lubrication may occur due to various reasons. For example, it is believed that oil can lubricate, and the greater the viscosity of the oil, the better the effect. In order to avoid damage to the machine caused by incorrect operations, this article introduces 9 common misunderstandings for your reference.

01 Think that the purpose of lubrication is to make the machine run faster

The contact surfaces of relatively moving parts in the machine will produce friction and wear. According to statistics, more than 1/3 of the world's energy consumption is due to friction loss. When the amount of wear exceeds the allowable limit, it directly affects the normal operation and service life of the machine. Therefore, lubricant is added between relatively moving parts to form a lubricating oil film to reduce friction and wear. It can also play a role in cooling, buffering, vibration absorption, and sealing.

The purpose of lubrication is not only to make the machine run faster, but more importantly, to ensure the normal operation of the machine and extend its service life.

02 Mistakenly believe that oil can lubricate

Lubricating oils have different types and working properties. In order to improve certain aspects of lubricating oil performance, corresponding additives should be added to them.

In order to ensure reasonable lubrication of the machine, different types of lubricants and additives should be selected for different types, different working conditions, and different oil supply methods.

Therefore, it cannot be assumed that any oil can lubricate. What's more, improper selection of lubricating oil will cause lubrication accidents, which account for a large proportion of equipment failures.

03The greater the amount of lubricating oil, the better the lubrication effect

If it is grease lubrication, if it is too much, the resistance will increase, causing the bearing to heat up and lead to grease leakage, especially in high-speed and heavy-load machines.

For general oil lubrication, the oil level indicator can be used to display the oil level. For example, the oil immersion depth of the large high-speed gear in the reduction box is 1 to 2 tooth heights to avoid poor lubrication of the high-speed gear. It can also reduce the movement resistance of the gear and the increase in oil temperature. The grease filling amount of rolling bearings generally does not exceed 1/3~1/2 of the bearing gap.

04The greater the viscosity of the lubricating oil, the better the lubrication effect

Viscosity is the main indicator of lubricating oil, and its standard is usually determined at a temperature of 100°C to determine the grade of lubricating oil. The higher the grade, the thicker the lubricating oil film formed. Although the friction on the friction surface is reduced, the resistance is increased, the power loss is increased, and the waste of energy is increased.

When the machine is just started, the temperature is low. After working for a period of time, part of the lubricating oil on the friction surface is lost due to the increase in temperature. The lubrication cannot form an effective lubricating oil film, and the oil cannot be quickly replenished to the friction surface of the machine. Due to the oil The viscosity is high and the flow is slow, resulting in greater wear and tear on machine parts.

Some data show that if the viscosity of lubricating oil is reduced by 1mm2/s, 15% of fuel can be saved. The choice of viscosity should consider factors such as working speed and working temperature. Lowering the viscosity of lubricating oil is one of the current fuel-saving measures.

05 Select oil according to the oil grade specified in the manual.

Most equipment managers believe that the oil specified by the equipment manufacturer is the regulation. In fact, the oil specified in the manual refers to general working conditions and may not be suitable for actual working conditions. It should be flexibly selected according to actual usage conditions.

06 If the lubricating oil turns black, it means that the lubricating oil has deteriorated.

If the lubricating oil turns black, it means that the lubricating oil has deteriorated and should be replaced. This understanding is one-sided.

For example, it is normal for mechanical oil containing detergent and dispersant to turn black after a short period of use, and the oil should not be easily considered to have deteriorated. Lubricating oil with additives often produces a dark protective oil film on the bearing surface. It is normal for the bearing surface to turn black during use, and there is no need to remove the blackened lubricant. Therefore, to determine whether the lubricating oil has deteriorated, a comprehensive analysis should be conducted and the oil should be changed according to the quality.

07 Used lubricating oil cannot be used and must be thrown away

In fact, in addition to spoiled oil, there are more lubricating oils that can be used.

If the replaced oil is only mixed with impurities, it can be reused after sedimentation and filtration; after simple treatment, the heavily polluted oil can be used as a lubricant for rough processing equipment to prevent rust in open-air equipment, or the waste oil can be used Collect and hand over the waste oil for reuse (it is used in other less demanding equipment, not continued use in air compressors). Oil that is difficult to recycle can generally be burned as fuel oil after simple treatment.

08 Lubricant oils can be used interchangeably

The selection of lubricating oil depends on the working conditions, working environment, specific characteristics of the friction surface and lubrication method of the machine. The type and brand of lubricating oil selected are also different. Generally, they cannot be replaced.

09 Failure to replace and replenish lubricating oil for a long time

After the lubricating oil is used for a period of time, its performance decreases or changes. As the oil quality decreases, if the lubricating oil is not replaced or replenished in time, the lubrication will be poor and it will easily cause high temperature.

In addition, many people extend the oil change interval of air compressors in order to save money, but in fact, poor lubrication will cause high current, serious waste of power, increase operating costs, and the gain outweighs the gain.