1. Gear Pump Structure
Gear pumps consist of a pump body, pump cover, seal, steel bushing, valve, and other components. They feature a simple structure and are suitable for transporting non-corrosive lubricating oils or fluids similar in nature, free of solid particles and fibers. The fluid temperature should not exceed 80°C, and viscosity should range between 5×10⁻⁶ to 1.5×10⁻³ m²/s (5–1500 cSt). Flow rates range from 0.6 to 60 m³/h, with pressure levels between 0.6–2.5 MPa. A pressure valve is included for overload protection, and its full return pressure is 1.5 times the rated discharge pressure of the pump.
2. Troubleshooting Noise or Pressure Fluctuation
If excessive noise or inlet/outlet pressure fluctuations occur during operation, consider the following:
- Excessive discharge pipeline resistance or overly long pipelines
- Worn bearings or internal components
- Suction height exceeding the pump’s limit
- Issues in rotating parts
- Air in the pipeline
- Gear sealing (tooth jamming) issues
- Suction pipeline too short
- Clogged filter or suction line
- High fluid viscosity
Gear pumps operate via meshing of two gears—one driving and one driven. Pressure typically remains below 6 MPa with high flow rates.
3. Gear Pump Maintenance Tips
- Preserve and Replace Parts Correctly: When disassembling, carefully keep all components, especially explosion-proof parts. Replace only with identical parts of matching materials and specifications.
- Proper Storage: Store the pump in a clean, dry, non-corrosive environment.
- Lubrication: Regularly check and replace lubricating oil to ensure smooth bearing operation.
- Routine Inspection: Frequently inspect power cables, insulation resistance, connections, bearings, and rotating components.
- Check Insulation Resistance: Before use, especially after long-term storage or exposure to moisture, use a 500V megohmmeter to check motor winding insulation. Resistance below 7 MΩ requires drying treatment.
4. Operational Best Practices
Follow the instruction manual strictly to extend pump service life. Ensure:
- Proper ventilation during use for heat dissipation.
- Remove any plastic films from the motor before starting.
- Check for sufficient oil in the pump before startup.
- Clean the pump chamber before storage or long idle periods.
5. Repairing Gear and Pump Cover Wear
The gap between the gear end face and pump cover is called the end face clearance, and increases with wear, affecting pump performance. To repair:
- Grind the gear end face flat and polish the split surface of the pump casing to restore proper clearance.
- If gear teeth wear unevenly, rotate gears 180° for continued use.
- Repair inner cavity wear via liner insertion (sleeving method).
6. Startup Checklist
- Check for loose pipe connections; ensure gears rotate smoothly by hand.
- Add lubricating oil to the bearing housing, keeping it at the oil level line.
- Fill priming water or slurry by opening the priming screw.
- Close outlet valves and pressure/vacuum gauges before startup.
- Working Principle: As gears disengage on the suction side, a vacuum forms, drawing fluid into the pump. The rotating gears carry the fluid to the discharge side, where meshing teeth force it out under pressure.