What is the forklift hydraulic pump?

When the gear pump of forklift truck rotates, the volume of suction cavity expands continuously to form vacuum and hu oil, the pressure cavity shrinks continuously, and the oil between the gears is taken out to form pump oil. Forklift gears are simple in structure, convenient in manufacture, low in price, reliable in work and easy in maintenance, but the machine parts should be easy to wear and low in working pressure.

forklift hydraulic pump

  • The principle of the forklift hydraulic pump

The hydraulic pump is one of the power parts in the hydraulic system of forklifts, of which the working principle is as follows: The plunger and the pump body form a sealed volume. When the plunger moves downward under the action of the return spring, the volume increases, producing a local really empty. Oil in the tank under the action of atmospheric pressure, through the one-way valve into the pump body, which is oil absorption; when the plunger in the role of eccentric upward movement, the volume is reduced, the oil sucked into the pump body through the one-way valve is squeezed out, which is the process of oil pressure. From the above working principle we can see that the seal volume constantly changes is the fundamental reason for oil suction and oil pressure. In the oil suction process, the oil tank must be connected with the atmospheric pressure, which is the condition of oil suction. In the oil pressure process, the size of the oil pressure is determined by the yin force encountered when the oil is discharged from the check valve, that is, the oil pressure of the pump is also affected by the external load.

  • Common faults of hydraulic pump of forklift truck
  1. Deterioration of the working fluid due to the entry of dirt.

Dirt can cause wear and corrosion of parts, especially for finishing parts, they can abrade the inner wall of the rubber hose, oil seal ring and packing, and the damage of these things will lead to more dirt into the system, thus forming a vicious cycle of damage.

2. Overheating

Overheating will cause the oil to oxidize rapidly, and oxidation will release insoluble resins, sludge and acids, etc., and these substances accumulate in the oil to cause accelerated wear and corrosion of the parts, and they adhere to the surface of the finishing parts will also make the parts lose their original function. The oil becomes thin due to overheating will also make the transmission work sluggish.

3. Into the air

In addition to the overheating caused by air entering the oil, a considerable amount of air is dissolved in the oil under pressure. If about 10% of the compressed volume belongs to the dissolved air, foam will be formed when the pressure drops. And work hydraulic cylinder in the decompression back to the oil, the oil with foam will form a “sponge” nature of the oil. In addition, the presence of a lot of foam in the oil will increase the total volume and will cause an overflow of oil from the tank or reservoir.

  • Repair methods of forklift hydraulic pumps.
  1. Remove the hydraulic pump rear cover screws and remove the rear cover.
  2. check the gear inside, the cylinder wall for serious wear and tear.
  3. replace the copper repair kit inside the hydraulic pump, replace the hydraulic pump front shaft high pressure oil seal.
  4. after the completion of the replacement in reverse order to install back, and then loaded test to check the work.