Lubrication and sealing problems of cast iron gear pump

Cast iron gear pump is widely used in the industrial field, its lubrication and sealing problems are very important. The following is a detailed introduction to the lubrication and sealing of cast iron gear pumps:

First, lubrication problems

1. Importance of lubrication
   Reduce friction: During the operation of the gear pump, friction occurs between gear and bearings and other components. Good lubrication can reduce the coefficient of friction, reduce energy loss, and improve the efficiency of the pump.
   Reduce wear: The lubrication film can prevent direct contact with metal parts, reduce wear, and extend the service life of the gear pump.
   Cooling effect: the lubricating oil can take away the heat generated when the gear pump is running, prevent the parts from overheating, and ensure the normal working temperature of the pump.
2. Lubrication method
   Immersion lubrication: some parts of the gear pump are immersed in lubricating oil, such as gears, bearings, etc. This method is simple and easy, but it is necessary to pay attention to the level of the lubricating oil to ensure that the parts can be fully immersed in the lubricating oil.
   Splash lubrication: Lubrication is achieved by the rotation of the gear to splash the lubricating oil onto other components. This method is suitable for small gear pumps, but the lubrication effect may not be as uniform as immersion lubrication.
   Forced lubrication: The oil pump is used to force the lubricating oil to the part that needs lubrication. This method has good lubrication effect, but the system is more complex and the cost is higher.
3. Selection of lubricating oil
   Viscosity: According to the gear pump operating temperature, speed and load and other factors to choose the appropriate viscosity of the lubricating oil. In general, in the case of high operating temperature, fast speed and large load, the lubricating oil with high viscosity should be selected.
   Oxidation resistance: lubricating oil should have good oxidation resistance to prevent oxidation deterioration under high temperature and high pressure, affecting the lubrication effect.
4. Corrosion resistance: gear pump may come into contact with various corrosive media during the working process, so the lubricating oil should have a certain corrosion resistance.
5. Cleanliness: The lubricating oil should be kept clean to avoid impurities entering the gear pump and damaging the parts.

second,Sealing problem

1. The importance of sealing
   Prevent leakage: When the gear pump is transporting liquid, if the seal is not good, it will lead to liquid leakage, which will not only waste resources, but also pollute the environment, and may even cause safety accidents.
   Maintain pressure: The seal can prevent external air from entering the inside of the gear pump, keep the pressure in the pump stable, and ensure the normal operation of the pump.
2. Sealing method
   Packing seal: The packing (such as asbestos rope, graphite, etc.) is filled in the gap between the shaft and the pump housing to achieve sealing. This sealing method has simple structure and low cost, but the sealing effect is relatively poor, and the packing needs to be adjusted and replaced frequently.
   Mechanical seal: consists of dynamic ring, static ring, spring and other components, through the dynamic ring and static ring tight fit to achieve seal. Mechanical seal has good sealing effect and long service life, but the structure is complex and the cost is high.
   Magnetic seal: The use of magnetic force to pull the moving ring and the static ring together to achieve sealing. This sealing method has no leakage, and is suitable for conveying gear pumps with toxic, harmful, flammable, explosive and other special media, but the cost is higher.
3. Selection of seals
   Select seals according to the nature of the conveying medium: if the conveying medium is corrosive, corrosion resistant sealing materials should be selected; If the temperature of the conveying medium is high, high temperature resistant sealing materials should be selected.
   Select seals according to the working pressure: When the working pressure is high, seals with good pressure resistance should be selected.
   Select the seal according to the speed: When the speed is fast, the seal suitable for high-speed rotation should be selected.