Characteristics of Water Pump Motors and Their Assembly and Packaging Lines

Pump motors are high-efficiency, low-noise induction or PM machines, IP55/IP68 protected, designed for long, continuous duty. The automatic assembly line integrates high-speed winding, heated housing press, vision checks, dynamic balance and magnetizing. The packaging line uses VCI film, robot case-packing, on-line weighing and auto-palletizing to guarantee rust-proof, shock-proof, fully traceable shipment that meets global transport and environmental rules.
I. Key Features of Pump Motors
- Structure & Working Principle
- Squirrel-cage induction motors predominate; synchronous or permanent-magnet/BLDC versions are used for premium efficiency.
- Horizontal or vertical mounting; direct-coupled or connected through a coupling to the pump shaft.
- Operating Characteristics
- Low starting torque, infrequent starts, long continuous duty; low vibration & noise demanded.
- Power reserve ≥1.15. Two-pole (high head/low flow), four-pole (medium), six-pole (very high flow) are common.
- Reliability & Environmental Suitability
- Insulation class ≥F, protection ≥IP55; submersible types need IP68 and water-lubricated bearings.
- Corrosion-resistant shaft (stainless steel), mechanical-seal life ≥8,000 h, bearing life ≥25,000 h.
- Energy Efficiency & Speed Control
- Covered by China’s “Energy-Saving Product Subsidy” since 2010; IE3/IE4 efficiency + VFD control is mainstream; PM versions offer higher efficiency and smaller size.
- Typical Failure Modes
- Misalignment between motor and pump centerline, sand ingress, impeller rubbing, too small coupling gap → over-current.
II. Pump-Motor Assembly Line (example: automotive & domestic stator/rotor automatic line)
- Stator Key Operations
① Automatic core loading & vision check
② High-speed winding: servo tensioner, automatic wire stripping, in-line vision, precise cut
③ Heated housing press-fit: vision-guided pick, heat 80-120 °C, hot-shrinking press
④ Lead forming: turret stations, servo bending, height/angle check
⑤ Final test: hi-pot, surge, IR, resolver (if fitted) - Rotor Key Operations
① Core loading: belt + rotary table, pneumatic alignment
② Magnet insertion: 3-station dial, servo press, polarity check
③ Steel sleeve fitting: guided mandrel, closed-loop depth control
④ Dynamic balance & magnetizing: off-line correction, auto magnetizer, flux check
⑤ Final vision: AI inspection for cracks, missing parts - Line-Wide Requirements
- Automation ≥90%, tact 3-6 s; full MES traceability with laser-etched QR.
- 100 % force/displacement curve monitoring; automatic reject on NOK.
- Modular stations: change-over ≤15 min within same frame size.
III. Pump-Motor Packaging Line (industrial & domestic pumps)
- Pre-packing
- Sort & count stator, rotor, end-shield, capacitor, impeller; vision anti-mix; robot loads layered tray.
- Vibration, noise, current data captured randomly; auto-generated QR quality report bonded to carton.
- Mid-Assembly (if whole-motor line included)
- Auto bearing press & grease dispense; end-shield bolts tightened with servo (torque + angle).
- On-line air/water tightness test: submersible pumps 0.3 MPa, 30 s, leak ≤50 Pa.
- Final Packaging
- Auto bagging (VCI film) + desiccant; moisture protection per GB/T 5048.
- Robot case-packing: EPS or honeycomb cushioning, motor and pump head separated; drop test 1 corner/3 edges/6 faces ≥80 cm.
- Carton sealing: H-tape + PP/PET strapping; ≥20 kg needs 5 straps.
- Labeling: model, power, poles, serial no., efficiency label, CE/CCC; labels water-, oil-, UV-resistant.
- Palletizing: robot + in-line weighing + dimension check, height ≤1.5 m, interlocked layers; top stretch-wrap and edge protectors.
- Warehouse hand-off: automatic scan-in, WMS-MES linked, full after-sales traceability.
- Special Requirements
- Export by sea: vacuum Al-foil bag + container desiccant, 48 h salt-spray no rust.
- Food-grade or hazardous environments: full SUS304 frame + food-grade oil, FDA or REACH compliant.
IV. Summary
- Motor features: high efficiency, long life, low noise, environment-proof; power & poles matched to pump duty.
- Assembly line: stator & rotor move toward “high-speed winding—hot shrink—vision check—dynamic balance—magnetize” with closed-loop critical parameters.
- Packaging line: rust prevention, cushioning, traceability are core; robot packing + in-line weighing + auto palletizing are industry standard, meeting global transport and environmental regulations.