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Large-Bore Motor Casing
Jiangsu Yufeng Electric Co., Ltd. ISO 9001 · IATF 16949
Large-bore motor casing designed for high-torque, heavy-duty electric machines. Manufactured with integrated stamping, automated welding, precision machining, and anti-corrosion surface treatment. Dimensional stability maintained across batch production, with bore diameters ranging from 200 mm to 800 mm and wall thickness variations controlled within ±0.15 mm. The casing structure incorporates reinforced ribs and optimized coolant channels to support thermal management in continuous operation. Jiangsu Yufeng Electric Co., Ltd. applies 40 years of forming and welding expertise to deliver casings that meet the geometric tolerances required for industrial drives, wind turbine generators, marine propulsion, and large-scale compressors. Each unit is verified through coordinate measuring machines and pressure-testing procedures before dispatch.
Core Advantages
- Full-process in-house production: stamping, welding, machining, and coating under one quality system, reducing lead time and interface risks.
- Dedicated large-bore welding fixtures and robotic welding cells to maintain circularity and coaxiality within 0.2 mm for diameters up to 800 mm.
- Engineering team with average 20+ years in motor housing metallurgy and structural analysis, supporting custom flange patterns, mounting feet, and cable exit configurations.
- Capacity of 5 million units per year across all casing types, with dedicated production cells for large-bore orders (batch sizes from 50 to 2000 units).
- On-site material testing, dimensional inspection, and hydrostatic pressure testing (up to 1.2 MPa) to validate structural integrity.
Product Characteristics
| Geometric tolerance | Roundness ≤ 0.2 mm; coaxiality ≤ 0.15 mm; flatness of mounting faces ≤ 0.1 mm |
| Wall thickness deviation | ±0.15 mm (machined surfaces); ±0.3 mm (as-welded areas) |
| Surface roughness | Ra 1.6 – 3.2 μm on sealing and bearing interfaces |
| Pressure rating | Hydrostatic test 1.0 MPa for 5 minutes, no leakage or deformation |
| Temperature range | -30 °C to +150 °C (continuous operation) |
| Customizable features | Integrated cooling jackets, terminal boxes, lifting lugs, vibration-damping mounts |
Application Scenarios
- Industrial drives: Large AC/DC motors for pumps, fans, mills, and conveyors in mining, cement, and steel plants.
- Wind turbine generators: Main frame casings for 2 MW to 6 MW direct-drive and geared turbines, with corrosion-resistant coating for offshore environments.
- Marine propulsion: Podded thrusters and azimuth drives requiring compact, high-strength casings with salt-spray resistance.
- Compressors & blowers: Centrifugal and screw compressors in petrochemical and HVAC systems, where bore stability affects rotor dynamics.
- Special equipment: Test bench dynamometers, traction motors for heavy electric vehicles, and generator sets for data centers.
Technical Notes & Considerations for B2B Procurement
- Material traceability: Each batch of steel coils is marked with mill test reports (MTR) and heat numbers. Chemical composition and mechanical properties are verified before cutting.
- Welding procedure specifications (WPS): Qualified to AWS D1.1 and EN 1090, with pre-qualified parameters for different thicknesses. Welders are certified to ISO 9606.
- Machining allowance: For large-bore casings, a 1.0 – 1.5 mm machining allowance is reserved on critical diameters to correct welding distortion.
- Surface preparation: Degreasing, phosphate conversion, and drying are applied before coating to ensure adhesion ≥ 5 MPa (cross-cut test).
- Packaging and logistics: Anti-rust oil coating + VCI film + wooden crates with edge protectors. For export orders, casings are packed in sea-worthy plywood cases with desiccant.
- Sample approval: First-article inspection report (FAIR) with full dimensional, material, and NDT results is provided for each new tooling or design revision.
Frequently Asked Questions (FAQ)
MOQ depends on the specific diameter and wall thickness. For standard configurations (bore ≤ 500 mm), MOQ is 50 units. For custom designs with non-standard flanges or cooling channels, MOQ is 100 units. Sample orders of 5–10 units are accepted for qualification and testing.
For casings with standard dimensions and materials, lead time is 4–5 weeks from material arrival. For custom patterns or special coatings, add 1–2 weeks for tooling and process validation. Expedited delivery (3 weeks) is available for an additional charge.
Yes. We provide FEA reports for static and dynamic loading, thermal expansion, and modal analysis upon request. Reports are generated using ANSYS or Abaqus, and include mesh details, boundary conditions, and safety factor margins.
JIT delivery and consignment stock are available for long-term contracts with stable monthly forecasts. We maintain buffer inventory for frequently ordered sizes and can adjust production schedules based on your consumption data through our VMI portal.
We use hard gauges and CMM (coordinate measuring machine) sampling at every stage: after stamping, after welding, after machining, and before coating. Statistical process control (SPC) charts track bore diameter, roundness, and flange flatness. Any drift beyond control limits triggers tooling adjustment.
Jiangsu Yufeng Electric Co., Ltd. · www.yufengmotor.com · Specifications subject to change based on final engineering agreement.
Manufacturing Solutions
We offer full-process manufacturing capabilities from steel processing to finished product delivery, supported by stamping lines, automated welding equipment, machining facilities, and inspection instruments. Backed by an engineering team with an average of over 20 years of experience, we provide technical support from development to mass production.
With 40 years of focus on motor housing manufacturing, we have served more than 50 customers and achieved an annual production capacity of over 5 million units. Guided by quality, efficiency, and fast response, we are committed to delivering high-precision and high-reliability motor housing solutions.
