Composition and main properties of lubricating grease
author: Ann
2024-11-19
Grease is a semi-solid lubricant composed of base oil, thickener, and additives. Grease suitable for the application should be selected according to the combination of these.
(1) Base oil
Most of the base oils of grease are generally mineral oils, but synthetic oils such as silicone oil are also used to improve heat resistance and low-temperature fluidity.
(2) Thickener
Thickeners include various compounding agents, which control mechanical stability, water resistance, operating temperature range and other characteristics.
(3) Additives
Various additives are added according to the purpose of use.
Additives improve impact load and heavy load characteristics.
Oxidation additives prevent oxidation degradation when not replenished for a long time.
Rust-proof additives prevent rust on bearings and their surroundings.
(4) Viscosity
It is a physical quantity that indicates the degree of hardness of grease. It is the depth (expressed in 0.1mm) of grease poured into a metal cone of a specified weight within 5 seconds. The larger the value, the softer it is.
(5) Dropping point
The temperature at which the grease starts to drip from the specified hole after being heated and becomes fluid is called the dropping point. The higher the value, the higher the operating temperature.
(6) Mixing of different greases
When thickeners and additives are mixed, the properties of the grease change. Therefore, in principle, different greases should be avoided from mixing.
(7) Grease encapsulation amount
(8) Grease life
(9) Grease replenishment interval
Even if high-quality grease is used, the performance of the grease will deteriorate and the lubricating performance will decrease due to long-term use and the influence of the surrounding environment. Therefore, it is necessary to replenish and replace the grease in a timely manner. Generally, the operating temperature is about 50℃ once a year, and it is replaced 2 to 3 times a year when the operating temperature exceeds 100℃ even if it has good heat resistance.
(1) Base oil
Most of the base oils of grease are generally mineral oils, but synthetic oils such as silicone oil are also used to improve heat resistance and low-temperature fluidity.
(2) Thickener
Thickeners include various compounding agents, which control mechanical stability, water resistance, operating temperature range and other characteristics.
(3) Additives
Various additives are added according to the purpose of use.
Additives improve impact load and heavy load characteristics.
Oxidation additives prevent oxidation degradation when not replenished for a long time.
Rust-proof additives prevent rust on bearings and their surroundings.
(4) Viscosity
It is a physical quantity that indicates the degree of hardness of grease. It is the depth (expressed in 0.1mm) of grease poured into a metal cone of a specified weight within 5 seconds. The larger the value, the softer it is.
(5) Dropping point
The temperature at which the grease starts to drip from the specified hole after being heated and becomes fluid is called the dropping point. The higher the value, the higher the operating temperature.
(6) Mixing of different greases
When thickeners and additives are mixed, the properties of the grease change. Therefore, in principle, different greases should be avoided from mixing.
(7) Grease encapsulation amount
(8) Grease life
(9) Grease replenishment interval
Even if high-quality grease is used, the performance of the grease will deteriorate and the lubricating performance will decrease due to long-term use and the influence of the surrounding environment. Therefore, it is necessary to replenish and replace the grease in a timely manner. Generally, the operating temperature is about 50℃ once a year, and it is replaced 2 to 3 times a year when the operating temperature exceeds 100℃ even if it has good heat resistance.
ما هي وظيفة واستخدام الشحوم
The road to carbon reduction of lubricants under the background of "dual carbon"(3)
