The significant advantages of hollow cup motors.

The significant advantages of hollow cup motors.

The hollow cup motor has undergone significant innovation in structural design, breaking through the rotor design of traditional motors. This innovation not only reduces the electrical energy loss caused by eddy currents in the iron core, but also significantly reduces the mass and moment of inertia of the motor, thereby reducing the mechanical energy loss of the rotor itself. Overall, the hollow cup motor exhibits characteristics such as high power density, long service life, fast response, high peak torque, and excellent heat dissipation.

High power density:

The power density of hollow cup motors is excellent, mainly reflected in the ratio of their output power to weight or volume. Due to the fact that ironless rotors are lighter and more efficient than ordinary iron core rotors, hollow cup motors are able to output higher torque and power. The maximum efficiency of most hollow cup motors exceeds 80%, far higher than the efficiency of brushed DC motors, which is about 50%. Therefore, hollow cup motors are particularly suitable for battery powered applications that require long-term operation, such as portable air sampling pumps, humanoid robots, bionic hands, and handheld power tools.

High torque density:

The coreless design reduces the weight and moment of inertia of the rotor, resulting in faster acceleration and deceleration, and the ability to generate greater torque in a short period of time. Meanwhile, this design also makes the motor more compact, capable of providing high torque output within a limited space.

Long service life:
Hollow cup motors have more commutator segments, which reduce current fluctuations and motor inductance during commutation, thereby reducing the possibility of electrical corrosion in the commutation system and extending motor life. According to research data, brushed DC motors typically have a shorter lifespan, while hollow cup motors can provide stable operation for up to 1000 to 3000 hours.

Fast response speed: Due to the above advantages, the hollow cup motor can quickly start and reach the required speed, achieving fast response.

Traditional motors have a relatively large moment of inertia due to the presence of iron cores, resulting in slower response speeds. In contrast, the hollow cup motor achieves lightweight and low moment of inertia thanks to its compact size and unique cup-shaped self-supporting coil rotor design. This makes the hollow cup motor exhibit sensitive characteristics in start stop adjustment. According to the research progress on hollow cup micro motors and coils, the mechanical time constant of conventional iron core motors is about 100ms, while the mechanical time constant of hollow cup motors is significantly reduced, and even some products can achieve response speeds less than 10ms.

Excellent peak torque:
The hollow cup motor exhibits excellent peak torque, thanks to its linear relationship between current and torque. During the process of the current rising to its peak, the torque constant remains constant, thereby endowing the micro motor with strong peak torque capability. In contrast, ordinary iron core DC motors will not increase their torque even if the current is increased after reaching saturation.

Excellent heat dissipation performance:
The heat dissipation performance of hollow cup motors is superior to that of iron core rotors. The airflow on the rotor surface effectively improves the heat dissipation effect. The enameled wire of the iron core rotor is embedded in the groove of the silicon steel sheet, resulting in less airflow on the surface of the coil and relatively higher temperature rise. Under the same power output conditions, the temperature rise of the hollow cup DC motor is significantly lower.