Gear pump can be divided two types according to the gear structure: internal gear(use for transfer low viscosity liquids) ; external gear (for transfer high viscosity liquids).
China Kemai gear Oil pump made of Cast iron, cast steel, copper, stainless steel (SS304 316 316L).
Gear Pump Applicable Scope：
Flow:0.6~570M3/H
Head:0.3~0.6~1.6~2.5MPA
Motor Power:0.55~250KW
Inlet/Outlet:less than 350mm (1/8″ 3/8″ 3/4″ 1″ 1.5″ 2″ 3″ 4″ 6″ 8″ 10″ 12″ 14″)
Applicable:Transfer lubricant, kerosene, diesel oil, resins, asphalt, chemical materials, polyurethane…
How does a external gear pump work?
External gear pumps are most widely used type of pump.
It’s structure is shown in the figure, mainly including driving gear, driven gear, pump body, pump cover and relief valve, etc.Pump and motor by a spider coupling link.
The sealing space of pump body, pump cover and gear is the working room of pump.
The two gear axles are respectively installed in the bearing holes on the two pump covers. The driving gear shaft extends the pump body and is driven by the motor to rotate.
External stainless steel gear pump can transfer edible oil and corrosive liquids, reliable operation and wide application range.
When the pump is working, driving gear with motor and drives the drive wheel to gear with the motor.
When the meshing teeth on one side of the suction chamber are gradually separated, the volume of the suction chamber increases and the pressure decreases, so the liquid in the suction pipe is sucked into the pump.
Internal Gear Pump Applicable Scope And Working Principle
Now ,popular internal pumps gear shape has involute gear and cycloid gear (also known as rotor pump) two types.
Pinion is automatic gear. When the pinion rotates in the direction shown, the pinion exits, the meshing volume increases, and then the liquid is sucked in.Gear volume decreases and the liquid is expelled.
An involute internal pump pinion and inner gear should be installed a separator to separate inlet and outlet.
Cycloidal gear have one gear less than internal gear , so there is no need to install divider.
Internal gear pump has compact structure, small size, light weight, stable operation, small flow pulsation and small noise.
Because the gear steering is the same, the relative sliding speed between the gears is small, the wear is small, the service life is long.
But the tooth shape is complex, the processing is difficult, the price is higher than the external meshing gear pump.China kemai pump mainly offer internal pump for transfer high viscosity liquid(Glue, molasses, etc).
Gear Pump Usual Troubles and Obviating Ways
|
Phenomena |
Reason |
Obviating Ways |
|
The pump does not discharge oil or the pump discharge little oil |
1. The height of suction is too high and exceed rated value. 2. The suction pipe leaks air. 3. The direction of rotation is wrong. 4. The sucion pipe is blocked or the valve is closed. 5. The safety valve shut up or wore way. 6. The temperature of liquid is too low, it makes viscosit of liquid increasing. |
1. Increase the area of suction oil 2. Check every connection you had better add asbestos sheet to seal them. 3. According to the directiion indicated correct the direction of rotation. 4. Check the flow aility of oil in the suction pipe and make the valves are all opened. 5. Preheating the liquid, if you can not manage, reduce the speed. |
|
The seal leaks oil |
1. The seal wore away 2. It’s not good to adjust the seal |
1. Tighten the nut properly or replace the seal. 2. Re-adjust it. |
|
Noise and shake |
1. The suction pipe is bolcked or the net of filter is stopped up. 2. It’s too shallow that the suction pipe inserted the oil box. 3. The air entered into the intake pipe. 4. The resistance of the discharge pipe is too strong. 5. Gears and bearingss stand sides show serious wear. 6.The viscosity of the suction liquid is too high. 7. The value of (NPSH)r exceeds the rated value. |
1. Clear the litter. 2. The suction pipe should be inserted into oil box about 0.5 meter. 3. Chect every connections 4. Check whether the discharge pipe or valve is stopped up. 5. Disassemble and maintain or replace them. 6. Raise the oil level for suction. |
How to understand gear pump’s output pressure?
Pump pressure is determined by the load ,nothing to do with the pump. according to load calculate the motor drive pressure. Add pressure loss of piping, valves, etc，The result is the pump’s output pressure，Let’s add some more. Such as: you pick up something，How much power does it take?It depends on the thing weight，It doesn’t matter how powerful you are.