Some customers are confused by the characteristics between the lubrication medium of Oil and Grease form our website, now we are listing 8 different features between oil and grease below:
1. Adhesion Feature Between Oil And Grease
When the friction part is at rest condition, the grease can maintain its original shape, will not be automatically lost by gravity, and will not slip on the vertical surface and drip out from the gap. This feature is very suitable for the frictional parts that are stopped or infrequently activated, which are very difficult to refill the grease in the friction part (such as the lubrication part of the overhead crane air work), and the open or poorly sealed parts. When the frictional part is in a moving state, the grease does not leak as a lubricating oil by the centrifugal force, and does not splash out from the poorly sealed portion. Some dripping or splashing oil can be almost completely avoided, thus ensuring that the environment is not or less contaminated and that it can prevent contamination of the product. This is especially important for industries such as paper, weaving, and food machines.
2. Operating Temperature Range Feature Between Oil And Grease
Greases have a wider operating temperature range than lubricant oil. For example, general-purpose lithium grease can be used in the temperature range of -20~120 °C. Generally, calcium-based or sodium-based grease can also be used at -20~60 °C or -20~120 °C. However, a certain grade of oil uses a much narrower temperature range.
3. Pressure Resistance Feature Between Oil And Grease
The grease has a much higher adsorption capacity on the metal surface than the lubricating oil, and can form a relatively strong oil film, which is subjected to a relatively high working load due to the large amount of polar substances contained in the grease. In addition, as a base grease, when a polar additive is added, the sensitivity is also better than that of the lubricating oil.
4. Service Life Feature Between Oil And Grease
When the grease is used for a long time without replacement, the lubrication function can still be ensured, because only a small part of the grease close to the friction surface is really lubricated, and it can be seen that the service life is quite long by relying on the lubrication cycle of the soap fiber. Lubricating oils need to be added frequently, or recycled oil, otherwise the machine can’t be properly lubricated. In terms of quantity, the consumption of lubricating oil is 15 to 20 times more than that of grease, so the parts lubricated with grease are much more than the lubricating oil. For example, the lubricating parts of the car use about 2/3 of the grease. On the other hand, due to the infrequent refueling, the maintenance period is long, the consumption is reduced, and the maintenance cost is also low.
5. Lubrication Equipment Construction Feature Between Oil And Grease
The construction of grease lubrication equipment is relatively simple, which simplifies design and reduces investment. In addition, the installation space of the lubrication system is quite small, the lubrication points are very flexible while putting into operation, maintenance and management costs can be saved. Some equipment and electronic equipment with small internal space which is not allowed to have a special lubrication system and equipment. It needs longer life and even grease lubrication for life. But the Lubricating oils need to be lubricated in a closed system. The structure of the lubricated equipment is also complicated, and the investment and floor space are also large. It is not suitable for use in semi-closed or unclosed lubrication parts.
6. Protection Performance Feature Between Oil And Grease
Grease is not automatically lost from the parts’ surface due to its own weight, the grease has the ability to maintain and the general grease layer is thicker than the oil layer, thus preventing the water or water vapor from penetrating the metal surface, and It can isolate acid, alkali, moisture, oxygen and water to directly etch the working surface. Some greases are not dissolved by chemicals, basic organic materials, fuels and lubricants. The lubricating oil has a relatively poor protection ability and can only provide a certain protective effect in a short period of time.
7. Sealing Performance Feature Between Oil And Grease
Grease prevents dust from entering the work surface, prevents impurities from mixing in, and wears mechanical parts. For working parts such as bearings with complex spatial structure and high precision of lubrication surface, the grease can block dust impurities on the outer surface of the bearing and fill the main gap to seal. For some rough machinery such as agricultural tractors, harvesters, bulldozers, etc., the whole machine is in contact with dirt and sand, and its rotating parts are lubricated with grease, which not only can play a lubricating role, but also play a sealing role to a certain extent. But lubricating oil does not have this ability.
8. Cushion Damping Feature Between Oil And Grease
Because the viscosity of the grease is large and good oil characteristics, the grease can be used for some lubrication parts that often need to change the direction of motion and bear a large impact force, such as a shaft, a universal joint, a crusher, etc. To a certain buffer damping effect. On some components, such as gearing, grease can also reduce noise, but in general, the lubricant oil is poor in cushioning and noise reduction.