716 coreless Motor Structure

The 716 hollow cup motor achieves high efficiency through a unique hollow cup winding design, the core of which lies in the combination of a coreless rotor and a precision magnetic circuit.

1. Stator Section

Permanent magnets utilize high-magnetic materials such as neodymium iron boron to form a stable magnetic field, ensuring the motor's torque output.

A metal casing provides structural support and heat dissipation, while internally press-fitted permanent magnets balance mechanical strength and temperature control.

2. Rotor Section

The hollow cup windings are cup-shaped, with copper wires without iron core support, reducing inertia by over 90% and achieving millisecond-level response.

High-precision shafts are typically made of stainless steel, with coaxiality error controlled within 0.01mm, ensuring smooth power transmission.

3. Energy Conversion System

The brush assembly uses silver-graphite composite material, maintaining dynamic contact with the commutator through spring pressure.

The commutator segments are segmented and insulated from hard copper, with 24-36 segments per motor, precisely controlling current phase switching.

This structure enables the 716 coreless motor to maintain 92% energy efficiency at 20,000 rpm, saving 40% more energy than traditional brushed motors. It is widely used in the gimbals of micro-drones and joint drives of surgical robots.