Maglev Long-Stator Encapsulation Line in China

Illustration notice. Process illustrations are not verified photographs of this installation.

Project reference basis. Figures and configuration details are reported in the supplied project brief. They are reference values for the stated application, rather than verified acceptance results or a guarantee for another installation. Confirm the source records, material, tooling, operating schedule and test method when assessing a comparable project.

Project brief for review. The supplied document describes this configuration and reports the outcomes below. Original acceptance records, test reports and media are not attached to this import; attribution and outcomes require verification before publication.

The supplied brief describes the following project context.

A national commercial high-speed maglev operation and maintenance center in Shanghai deployed Haifeng’s three-component vacuum casting system to upgrade its long-stator linear synchronous motor overhaul and refurbishment facility. The installation was commissioned to rebuild stator packs intended for a long-stator refurbishment application; commercial operating speed is not established by this brief.

Previously, the maintenance center utilized legacy epoxy potting formulations. The low thermal conductivity of epoxy (0.22 W/(m·K)) caused stator core temperatures to exceed 115°C under maximum acceleration, triggering localized micro-cracks and partial discharge (PD) electrical flashovers. Furthermore, manual paddle-mixing of abrasive alumina filler powders introduced air pockets, causing an 18.5% component rejection rate and requiring over 4 hours per stator section.

Haifeng engineered an automated liquid encapsulation cell centered on the HF-MGV150-3K platform. Featuring in-line vacuum high-shear powder dispersion and deep 0.05 kPa vacuum chamber potting, the upgraded facility achieved low-void encapsulation with thermal conductivities reaching 1.15 W/(m·K) and dielectric breakdown strengths exceeding 22 kV/mm, drastically lowering operational motor temperatures.

Review point: The brief varies between a 38–40 minute potting cycle and a two-hour cure. Do not call the short cycle a completed cure/demold cycle. Destructive dielectric-breakdown testing and non-destructive partial-discharge testing are different measurements. Commercial operation at 600 km/h is not established by this brief.

Reported equipment configuration from the supplied brief:

Haifeng engineered an ultra-clean, heavy-duty three-component potting cell tailored for abrasive, high-filler polyurethane formulations. Micro-scale aluminum oxide (Al₂O₃) powders are vacuum-dried and inducted directly into polyol streams inside an oil-jacketed 150 L vessel, where high-shear dispersers achieve 50% powder loading under 0.05 kPa vacuum.

Components—filled polyol, aliphatic isocyanate, and liquid catalyst—are metered via tungsten-carbide-lined gear pumps monitored by Coriolis mass flow meters, holding stoichiometric accuracy within ±0.3%. Fluid lines are maintained at 65°C to stabilize viscosities.

The 3-meter-long maglev stator core is loaded into a sealed vacuum chamber and evacuated to 0.05 kPa. The wear-resistant dynamic mixing head traverses along the stator slots, dispensing 12 kg of reactive formulation within 50 seconds. The fluid self-levels deeply into narrow copper winding clearances without trapped air. The encapsulated core cures isothermally at 80°C in an integrated curing tunnel, followed by 100% partial discharge testing to confirm the specified electrical acceptance criteria.

The brief varies between a 38–40 minute potting cycle and a two-hour cure. Do not call the short cycle a completed cure/demold cycle. Destructive dielectric-breakdown testing and non-destructive partial-discharge testing are different measurements. Commercial operation at 600 km/h is not established by this brief.