The magnetic field comes from either wound coils or a permanent magnet. This type of motor has a mechanical switch or commutator, which reverses the current in the armature of the machine. The "speed per torque" characteristic is constant and the slope of the speed/torque curve depends on the strength of the magnetic field.

Universal motors
Universal motors are commutator fitted machines adapted to work with AC voltage. They can achieve high speeds. However, the speed is sensitive to the load applied. The main advantage is the flexibility to adjust speed to an appliance needs. This type of motor is widely used to drive horizontal axis washing machines and vacuum cleaners.

Permanent magnet DC motors
Permanent magnet DC motors are commutator fitted machines in which the magnetic field source is a permanent magnet. They require a DC power source and therefore are typically used in cordless appliances. In addition, speed control can be made available.

HCH bearings for brush motors
Except for the common requirements, HCH bearings used in brush motors are usually with non-contact rubber seals incorporating a special labyrinth design to meet high running speeds and provide good protection against ingress of brush dust contamination. Decades of research and development in the industry, HCH has produced several technological breakthroughs, setting new industry standards for performance:

> Noise free operation
> Increased dent resistance
> Ultra long life
> Elimination of bearing creep

Universal motors driving washing machines are fitted with metal shielded deep groove ball bearings. The internal radial clearance is optimized to meet the requirements of high speed and low noise. Bearings are typically charged with grease combining high speed lubrication capability and low noise properties. The design requirements on wet and dry vacuum cleaners are for deep groove ball bearings that can provide protection against ingress of brush dust contamination and humidity. Where brush dust is the contaminant, bearings are fitted with metal shields incorporating a special labyrinth design. In conditions where humidity is a problem, heavy contacting rubber seals are the preferred solution.