What are the differences between a Hollow Cup DC Brush Motor and an Ordinary DC Motor?

The structural characteristics of the hollow cup DC brush motor determine its essential difference from ordinary DC motors. The rotor of the hollow cup DC brush motor adopts an ironless design, and the cup-shaped winding directly constitutes the armature body. This topological structure eliminates the hysteresis and eddy current losses caused by traditional iron core laminations. The lightweight design of the winding skeleton reduces the rotational inertia of the rotating parts, which makes the dynamic response characteristics increase by an order of magnitude. The optimized configuration of the magnetic field path makes the air gap magnetic density distribution more uniform and reduces the torque pulsation phenomenon.

The iron core armature structure of ordinary DC motors has inherent magnetic resistance fluctuations during the magnetic field coupling process, resulting in a theoretical bottleneck in energy conversion efficiency. The closed magnetic circuit formed by the ring winding and permanent magnet of the hollow cup DC brush motor effectively reduces the leakage flux ratio and improves the effective magnetic flux utilization rate. The ironless structure also avoids the magnetic saturation effect of ferromagnetic materials in the alternating magnetic field, so that the linear working range can be expanded.

In terms of mechanical properties, the friction torque of the hollow cup DC brush motor is significantly lower than that of the traditional brush system, thanks to its special commutator and brush contact pressure adjustment mechanism. The non-contact design of the winding and the yoke reduces the energy transfer from mechanical vibration to the electromagnetic system, thereby reducing the spectral energy density of the operating noise. The optimized configuration of the heat dissipation path of the hollow cup DC brush motor controls the impact of the winding temperature rise on the performance within a smaller range, which is particularly evident under continuous load conditions.

In terms of material selection, the hollow cup DC brush motor adopts a high-strength composite dielectric support winding structure, and its high temperature resistance and insulation performance are better than the enameled wire core combination of ordinary motors. This difference makes the two motors present different attenuation curves in terms of overload resistance and service life.