Lubricating grease, commonly known as "butter", is a viscous semi-solid paste like substance that appears yellow brown. Its main function is to protect, lubricate, and seal the bearings of agricultural machinery. It has strong adhesion ability and is not easily slipped or lost from the friction surface, even under the action of large centrifugal force, it will not be completely shaken off.

1. Performance characteristics of lubricating grease

Compared with lubricating oil, lubricating grease has the following advantages: it has good adhesion on metal surfaces and is not easily lost; Used in areas that are difficult to seal, it can simplify the structure of the lubrication system; Anti rolling, with good lubrication ability under high load and impact load; The lubrication cycle is long and does not require frequent replenishment or replacement. It also has a certain degree of rust resistance for metal components, which relatively reduces maintenance costs; The applicable temperature range is wide, and the applicable working conditions are also wide. However, the viscosity of lubricating grease is high, resulting in high resistance during operation and significant power loss. The flowability of lubricating grease is also poor, and it basically does not have the cooling and cleaning effect of liquid lubricants. It is difficult to remove solid impurities mixed in. In addition, it is difficult to add or replace lubricating grease in certain areas of use. So, the use of lubricating grease is subject to certain limitations.

2. Classification and selection of lubricating grease

2.1 Calcium based grease (butter)

Calcium based grease is a commonly used lubricant for vehicles. Its main characteristics are good water resistance and lubricity, but poor heat resistance. Mainly used on components with working temperatures not exceeding 70 ℃ and prone to water contact, it can also be used on various bearings with speeds below 3000r/min. Such as the friction parts of the vehicle chassis, water pump bearings, wheel hub bearings, intermediate bearings of the transmission shaft, steel plate pins, and active joint parts of the steering and braking control system.

The calcium based lubricating grease specified by national standards is divided into five grades according to penetration: ZG-1, ZG-2, ZG-3, ZG-4, ZG-5, etc. Penetration reflects the deformation and flow performance of lubricating grease under low shear rate conditions. The higher the penetration value, the softer the fat, that is, the lower the viscosity, and the easier it is to deform and flow; The lower the needle penetration number, the harder the fat, that is, the greater the viscosity, and the less likely it is to deform and flow. From this, it can be seen that needle penetration can effectively indicate the viscosity of lubricating grease and is an important basis for selecting lubricating grease. ZG-1 is suitable for working conditions with lower temperatures; ZG-2 is suitable for ball bearings with light loads and temperatures not exceeding 55 ℃; ZG-3 is suitable for mechanical friction parts with medium load, intermediate speed, and temperature below 60 ℃; ZG-4 and ZG-5 are suitable for lubrication of heavy-duty low-speed machinery with temperatures below 70 ℃. Vehicles usually use three grades: ZG-2, ZG-3, and ZG-4.

2.2 Composite calcium based grease

Composite calcium based grease is an improved product based on calcium based grease. Its main features are good heat resistance, excellent water resistance, and low temperature performance. It can be used at low temperatures of -40 ℃ and can also be used for friction parts under high temperature and high humidity conditions. Such as vehicle wheel hub bearings, water pump bearings, steel plate pins, and other parts.

The composite calcium based grease specified by the standards of the Ministry of Petroleum Industry is divided into four grades: ZFG-1, ZFG-2, ZFG-3, ZFG-4, etc.

2.3 Graphite calcium based lubricating grease

The graphite calcium based grease specified by the standards of the Ministry of Petroleum Industry is mainly characterized by strong load-bearing capacity, good water resistance, and poor heat resistance (the operating temperature should not exceed 60 ℃). Mainly used for working parts where heavy loads, low-speed simple machinery come into contact with water. Such as steel plate springs for cars, gear discs for cranes and hoists, winch gears, and other parts.

2.4 Sodium based lubricating grease

The main characteristics of sodium based grease are: good heat resistance, melting point above 150 ℃, suitable for high-temperature friction parts below 120 ℃. The disadvantage is poor water resistance, which makes it easy to emulsify when in contact with water and lose its lubricating effect. It cannot be used in parts that come into direct contact with water or work under humid air conditions. Sodium based grease is generally used on the bearings of medium-sized electric motors, generators, and generators in cars and tractors that rotate quickly and have high temperatures.

Sodium based lubricating grease specified by national standards is divided into three grades based on penetration: ZN-2, ZN-3, and ZN-4. Generally used for dry and high-temperature friction parts. ZN-2 and ZN-3 are suitable for friction parts with temperatures not exceeding 115 ℃; ZN-4 is suitable for friction parts with temperatures not exceeding 135 ℃.

2.5 Calcium sodium based lubricating grease

The performance of calcium sodium based grease is between that of calcium based grease and sodium based grease. Its heat resistance is superior to calcium based grease, second only to sodium based grease, and its water resistance is superior to sodium based grease, second only to calcium based grease. So, calcium sodium based grease is suitable for friction parts with a working temperature of around 100 ℃ and not too humid.

The calcium sodium based lubricating grease specified by the standards of the Ministry of Petroleum Industry is divided into two grades according to penetration: ZGN-1 and ZGN-2. It is generally used for mechanical lubrication parts with a working temperature not exceeding 100 ℃, and cannot be used for lubrication parts at low temperatures and in contact with water. Mainly used for transmission shaft intermediate bearings, clutch bearings, wheel hub bearings, and other parts. In addition, calcium sodium based grease has a high viscosity under low temperature conditions, so it is not suitable for use at low temperatures.

2.6 Lithium based grease

Lithium based grease is a type of grease with excellent performance in all aspects. Its characteristics are: wide temperature range, good low-temperature performance, strong water resistance, long service life, and comprehensive performance better than the various lubricating greases mentioned above.

The lithium based grease specified by the standards of the Ministry of Petroleum Industry is divided into four grades according to penetration: ZL-1, ZL-2, ZL-3, ZL-4, etc. Lithium based grease is particularly suitable for high-speed bearings and can replace other greases, widely used in vehicle bearings and friction parts.

3. Precautions for using lubricating grease

When adding lubricating grease to the bearing, do not overfill it. Generally, only add 1/2 to 1/3 of the volume. Overfilling can increase friction resistance and cause the bearing to heat up.

When replacing the bearing grease, the bearing should be cleaned first, then wiped dry, and then filled with grease, taking care to prevent dirt and moisture from entering the bearing.

3.3 Lubricating grease should not be stored in wooden or paper packaging, nor should it be placed outdoors in direct sunlight or rain, and should not allow dust or sand to enter.

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Agricultural Bearings:

Farm machinery equipment and agricultural bearings are often subjected to harsh weather conditions and season operations. These are just some of the factors that place them under more difficult conditions than many other applications.

Special Agricultural Bearings for planters, mowers and agricultural equipment. Bearings below include hex bore bearings. As one of the leading agricultural bearings manufacturers and suppliers in China for more than 50 years, we warmly welcome you to buy top quality agricultural bearings from FK Group.

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