This paper mainly introduces the basic knowledge of gear pump, including gear pump model, material and use, pump routine operation. Common faults and troubleshooting methods.
Gear pump model:
1: NYP gear pump
NYP represents internal gear pump, A represents theoretical displacement, in unit of L/100r, b represents rated pressure difference, in unit of MPa.
For example, NYP24/1.0 indicates the rated pressure difference of 1.0MPa. Theoretical displacement of 24L/ 100R internal gear pump.
Because NYP is generally used to transport high viscosity liquid. The pump body has a heat preservation jacket. Use water, heat conduction oil or steam circulation heating.
2:2CY gear pump
Involute tooth profile oil gear pump without safety valve, its model is expressed as follows:
2CY-a/b
A indicates the traffic, in m3/h. B indicates the rated differential pressure, expressed in MPa.
3: KCB gear pump
K stands for safety valve, C for gear, AND B for pump
which is interpreted as involute gear oil pump with safety valve.
4: YCB gear pump
Y stands for round plate, C and B for gear and pump. Interpretation of arc gear pump with safety valve.
YCB-a/b
A represents the flow rate, in m3/h, and B represents the rated pressure difference, in MPa.
5: LYB type gear pump
L in LYB means vertical, YB is pinyin abbreviation of oil pump. Interpretation of the arc vertical oil transmission gear pump with safety valve.
LYB-a/b
A represents the flow rate, in m3/h, and B represents the rated pressure difference, in MPa.
Gear pump material and use
Popular materials are cast iron, cast steel, stainless steel, ductile iron, copper.
- Different materials, different uses.
- Transfer lubricating oil, dirty oil. Cast iron material can be satisfied.
- To transfer high temperature oil, it is recommended to use cast steel or ductile iron. ,
- Transfer corrosive or edible oil, should choose stainless steel gear pump. In this way the service life of the pump will be longer.
- Copper gear pumps are often used to transfer gasoline.
Routine operation of gear pumps
1: Basic equipment knowledge
1.1 Working Principle
Gear pump depends on the volume change of gear meshing space to transport liquid.
1.2 Device Structure
Reciprocating pump is mainly composed of pump housing, driving gear, driven gear, front (rear) end cover.
1.3 Main Performance Indicators
The main parameters include: flow rate, speed, exclusion pressure, power, efficiency.
1.4 Device Usage
Used for conveying viscous liquid, such as lubricating oil, fuel oil.
2: Start and stop steps
2.1 Check and Prepare before starting
(1) Prepare the necessary driving tools: valve hook, wrench, etc.
(2) Check whether the screws of each connection part of the pump are fastened, the grounding wire of the motor is good, and the valve is flexible and easy to use.
(3) There is no jam and abnormal sound.
(4) Check the liquid level, should meet the suction height requirements of the pump.
(5) Check pressure gauge, flow valve should be flexible and easy to use.
(6) open the inlet valve and inject the conveying medium into the pump.
(7) Confirm the rotation direction of the motor is correct.
2.2 Startup Procedure
(1) Open the outlet valve, open the inlet valve, fill the pump body with liquid, open the vent valve, and close the air after cleaning.
(2) Start the motor.
2.3 Routine inspection and maintenance
(1) Check whether the equipment has abnormal sound and vibration, and whether the fasteners are loose.
(2) Check whether the outlet pressure indication is normal.
(3) Check whether the leakage of shaft seal meets the requirements.
(4) Check whether the temperature of motor and bearing is over temperature.
2.4 Shutdown Procedure
(1) Close the inlet valve.
(2) Stop the motor.
(3) Close the outlet valve.
Common faults and troubleshooting methods
| Fault phenomenon | Cause of the problem | Processing method |
| No oil suction pump | Suction line blocked or air leakage.Suction height exceeds allowable suction vacuum height.Motor reverses.Medium viscosity is too large. | Check the suction line.Lower inhalation height.Change the motor steering.Heat the medium. |
| High pressure fluctuation | Suction line leaks air.The relief valve is not adjusted well or the working pressure is too large, so that the relief valve is open and closed.Insufficient suction height. | Check the suction line.Adjust relief valve or reduce working pressure.Increase the liquid level. |
| Handling insufficient traffic | Pump body or inlet line leakage.Blocked inlet line or filter.Medium viscosity is large, the replacement of internal gear pump, motor using gear motor.Excessive radial clearance or tooth-side clearance of gears.Relief valve spring is too loose or disc and seat contact is not strict.The motor doesn't rotate fast enough. | Replace the gasket line, tighten the bolt, repair the pipeline.Clean lines or filters.Reduce the viscosity of the medium.Replace pump housing or gears.Adjust spring, grind disc and seat.Repair or replace the motor. |
| Shaft power increases sharply | The discharge line is blocked.Serious friction between gear and pump.Medium viscosity is too large. | Stop the pump to clean the pipeline.Repair or replace the relevant parts.Heat up the medium. |
| Vibration increase | Pumps are different from motors.Gear and pump different heart or clearance is too small.There is gas in the pump.Installation height is too large, the pump cavitation. | Adjust the concentricity and check jaw coupling rotates smoothly.Maintenance and adjustment.Check the suction line to eliminate air leakage.Lower the mounting height or speed. |
| Heat pump | The temperature of the suction medium is too high.Bearing clearance is too large or too small.The clearance of radial, axial and tooth side of gear is too small.Outlet valve opening too small resulting in high pressure. | Lower the temperature of the medium.Adjust the clearance or replace the bearing.Adjust clearance or change gears.Open outlet valve wide to reduce pressure. |
| There was a lot of oil leaking from the mechanical seal | Wrong assembly position.The sealing gland is not flattened.Sealing surfaces of moving ring and static ring are bruised.Movable ring and static ring sealing ring damage. | Reinstall as required.Adjust the sealing gland.Grind sealing surface or replace new parts.Replace the sealing ring. |
| Short pump life | Consider whether the liquid is corrosive.Whether the liquid has particles. | Replace the pump material and use stainless steel to transfer liquid. The stainless steel material is SS304, 316, 316L. |
The above is the Basic Knowledge Of Gear Pump, or you can browse more China gear pump manufacturers products.