Common faults of ATOS plunger pump gear pump

Common faults of ATOS plunger pump gear pump

Specializing in industrial system automation, the company is a comprehensive enterprise integrating technology, equipment supply, engineering and trade. The company mainly sells industrial control components, industrial control automation and other products in Germany, Europe, America, Japan, Italy, South Korea, Taiwan, China and other countries.

Cannot discharge materials
(1) Fault phenomenon: The pump cannot discharge the material
Three pictures of the entire gear pump machine
Reason for malfunction: a. Reverse rotation direction; b、 The suction or discharge valve is closed; c、 No material or low pressure at the inlet; d、 The viscosity is too high, and the pump cannot bite the material
Countermeasure: a. Confirm the direction of rotation; b、 Confirm if the valve is closed; c、 Check valves and pressure gauges; d、 Check the viscosity of the liquid and whether there is a flow rate proportional to the speed when running at low speed. If there is a flow rate, it indicates insufficient inflow
insufficient traffic
(2) Fault phenomenon: Insufficient pump flow
Reason for malfunction: a. The suction or discharge valve is closed; b、 Low inlet pressure; c、 Blockage of export pipeline; d、 Leakage of packing box; e、 Speed too low
Countermeasure: a. Confirm if the valve is closed; b、 Check if the valve is open; c、 Confirm if the discharge volume is normal; d、 Fastening; When a large amount of leakage affects production, the operation should be stopped and disassembled for inspection; e、 Check the actual speed of the pump shaft
Abnormal sound
(3) Fault phenomenon: abnormal sound
Reason for malfunction: a. Large eccentricity or poor lubrication of the coupling b. Motor malfunction; c、 Abnormal gearbox; d、 Poor installation at the shaft seal; e、 Shaft deformation or wear
Countermeasure: a. Correct or fill with lubricating grease; b、 Check the electric motor; c、 Check the bearings and gears; d、 Check the shaft seal; e、 Parking disassembly inspection
excessive current
(4) Fault phenomenon: Excessive current in gear pump series
Reason for malfunction: a. High outlet pressure; b、 Excessive viscosity of the melt; c、 Poor assembly of shaft seal; d、 Wear of shaft or bearing; e、 Motor malfunction
Countermeasure: a. Check downstream equipment and pipelines; b、 Test viscosity; c、 Check the shaft seal and adjust it appropriately; d、 After parking, check if the hand cranked vehicle is too heavy; e、 Check the electric motor
Pump stopped
(5) Fault phenomenon: The pump suddenly stops
Reason for malfunction: a. Power outage; b、 Motor overload protection; c、 Coupling damage; d、 Excessive export pressure, interlocking reaction; e、 Abnormal biting inside the pump; f、 The shaft and bearing are stuck due to adhesion
Countermeasure: a. Check the power supply; b、 Check the electric motor; c、 Open the safety cover and conduct a turning inspection; d、 Check the instrument interlocking system; e、 After parking, confirm the front and rear turntables; f、 Confirmation of turning gear
Sealing oil leakage
(6) Fault phenomenon: Sealing oil leakage
Cause: a. The shaft seal was not adjusted properly; b、 The sealing ring is worn and the gap is large; c、 The friction surfaces of the dynamic and static rings of the mechanical seal are damaged; d、 Spring relaxation
Countermeasure: a. Adjust again; b、 Tighten the gland bolts appropriately or replace the sealing ring; c、 Replace the dynamic and static rings or re grind them; d、 replace the spring

Common faults and other phenomena of atos plunger pump gear pump
1. Cause of occurrence
① The tooth clearance between the inner and outer rotors is too large, causing the suction oil chamber to communicate with each other. The volumetric efficiency is significantly reduced, and the output flow rate is insufficient;
② The axial clearance is too large;
③ The sealing at the joint surface in the oil suction pipeline is not tight, which causes the pump to suck in air and reduces the effective suction flow rate;
④ Poor oil absorption, such as a decrease in suction flow due to excessive viscosity of the oil or blockage of the oil filter by dirt;
⑤ The overflow valve is stuck in the half open position, and a portion of the flow from the pump returns to the oil tank through the overflow valve, resulting in insufficient flow into the system. At this time, a system pressure failure occurs.
2. Exclusion method
① Replace the inner and outer rotors to ensure that the backlash is within the specified range (generally less than 0.07mm);
② Grind the two end faces of the pump body to ensure that the axial clearance between the inner and outer rotors is within the range of 0.02~0.05mm after assembly;
③ Replace the damaged oil suction pipe seal, wrap the threaded part of the pipe joint with polytetrafluoroethylene tape, and then tighten the pipe joint;
④ Select oil with appropriate viscosity and clean the oil inlet filter to ensure smooth oil suction. And increase the diameter of the oil suction pipe as appropriate;
⑤ Repair the overflow valve and eliminate the phenomenon of the overflow valve partially short circuiting the oil tank, which causes a decrease in the effective flow rate of the pump.
Oil entrapment phenomenon
To ensure smooth operation of the gear pump, the meshing overlap of the gears must be greater than 1. Therefore, there are always two pairs of gears meshing simultaneously, and a portion of the oil is trapped between the enclosed chambers formed by the two pairs of gear teeth. This closed chamber gradually decreases with the rotation of the gear, and then gradually increases again. The reduction in the volume of the enclosed chamber will cause the trapped oil to be compressed, resulting in high pressure and extrusion from the gaps, causing the oil to heat up and causing additional loads on the components; The increase in the volume of the enclosed chamber causes local vacuum, which separates the dissolved gases in the oil and produces cavitation. These will generate strong vibrations and noise, which is the phenomenon of trapped oil in gear pumps.
harm

When the radial unbalance force is large, it can cause the shaft to bend, the tooth tip to come into contact with the housing, and accelerate the wear of the bearing, reducing its lifespan.
Elimination methods
The method to eliminate trapped oil is usually to open unloading slots on both sides of the cover plate, so that when the volume of the closed chamber decreases, it is connected to the pressure chamber through the unloading slot on the left, and when the volume increases, it is connected to the suction chamber through the unloading slot on the right

Common faults of ATOS plunger pump gear pump