Injection-molded bonded magnet with multi-pole anisotropic orientation

Problem solved

Enables compact, complex-shaped permanent magnets with tailored multi-pole magnetization patterns (radial, pole-anisotropic, convergent) for high-precision sensors and miniaturized motors, while offering rare-earth-free material options.

Application contexts

• EV/PHEV high-voltage contactor magnets
• Motor rotor magnets (radial and pole-anisotropic)
• Encoder position sensor magnets (fine-pitch multi-pole)
• Magnet rollers for OA equipment (patented 2-part shaft-integrated)
• Automotive sensor magnets (steering angle, rotation speed)

Technical principle

Bonded magnets are produced by compounding magnetic powder (ferrite, NdFeB, SmFeN, or iron nitride) with thermoplastic resin and injection-molding under an orienting magnetic field. In-house magnetic field simulation is used to design the mold cavity's magnetic circuit, controlling the anisotropic alignment of magnetic powder particles. Convergent orientation (patented, licensed from JFE Chemical) concentrates magnetic flux by varying N/S pole area ratios. Multi-pole indexing magnetizers enable fine-pitch (sub-mm) magnetization patterns for encoder and sensor applications.

Typical use cases

• Multi-pole encoder magnets for EV traction motor position sensing
• High-voltage DC contactor magnets for PHEV battery disconnects
• Radial-orientation bonded magnet rings for miniaturized servo motors
• Convergent-orientation magnets for high-torque-density actuators