On April 10, 2026, LONGWELL opened a project to evaluate a structural transition from a plastic cross-flow rotor to an aluminum impeller assembly. The customer had previously used a plastic impeller measuring 180 mm in diameter by 700 mm in length. During testing at 3000 RPM, the plastic design exhibited dynamic centrifugal imbalance and joint separation along connection and welding points. While plastic testing achieved an air velocity of approximately 25 m/s, the target requirement specified 3000 RPM operation and an air velocity of 30 m/s.
Engineering Requirements and Technical Specifications
Transitioning to an aluminum construction addresses joint integrity and structural rigidity under elevated rotational stress. LONGWELL engineering developed the drawing and technical specifications for model LWMI-φ180*700-01 to meet these requirements.
| Parameter | Original Plastic Requirement | Revised Aluminum Specification |
|---|---|---|
| Model Identifier | LW180*700-01 | LWMI-φ180*700-01 |
| Material | AS+GF30% | Aluminum construction |
| Outer Diameter | 180 mm | 180 (+0.5/0) mm |
| Rotor Length | 700 ±2 mm | 700 ±0.5 mm |
| Rated Operating Speed | 1600 RPM (bearing test) | 3000 RPM |
| Dynamic Balance Criteria | ≤ 0.3g @ 1200 RPM | Residual unbalance < 300mg (L > 500mm) |
Mechanical Tolerances and Quality Criteria
The revised engineering drawing establishes precise mechanical requirements for the 700 mm active length. Assembly specifications mandate riveting fastening secured without loosening or slipping. The chord length difference between adjacent blade outlet ends must not exceed 0.5 mm. Operational stability is controlled by limiting steel shaft end radial runout to ≤ 0.10 mm and middle plate radial runout to < 0.5 mm.
Project Scope and Deliverables
Engineering proposals, standardized technical drawings, and cost calculations were finalized by April 16, 2026. The technical supervisor review was completed on April 16, 2026, providing the updated drawing and specifications for customer evaluation.
Discuss a Custom Impeller Requirement
If you are upgrading cross-flow impellers or reviewing structural requirements for high-speed air movement, contact our engineering team. Please share your required airflow duty point, operating speed, motor interface, and dimensional constraints through our contact page or explore fan configurations on the LONGWELL Fan Selector.
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