In Wheel Motor

In Wheel Motor

TM4
The Advanced Technology Trasportation Institute explains that an in-wheel motor assembly consists of:

1. Highly efficient electric motor
2. Motor-Wheel Slave Controller (MWSC) including power and control electronics
3. Brake
4. Wheel bearings
5. Steerable front suspension interface
6. Heat sink embedded in the stator.

The configuration of the 3-phase synchronous motor consists of a central stator which supports the windings and the inverter, surrounded by an external rotor which supports the permanent magnets. The motor assembly is liquid-cooled to sustain high continuous power demands.
Currently, one of the more interesting designs for an electric drivetrain, the motor-wheel assembly is an elegant integration of an electric motor and other components into a package that fits inside a regular-size tire. Mounting the wheel directly on the rotor provides for direct transmission of torque, enhanced freewheeling, regenerative braking, and more economical inclusion of vehicle control, e.g., braking, traction, and stability systems.
Note: Nissan has an even more economical approach: two motors doing the job of four, nevertheless, this design relies upon a more traditional four wheel drive arrangement.
These in-wheel motors are becoming the norm in personal mobility and robots. Mitsubishi has set a precedent by offering cars with in-wheel motors; it remains to be seen whether the majority of carmakers will adopt this design.
There are advantages and disadvantages to providing propulsion in the wheel and removing a tremendous amount of mechanical devices from a main engine compartment. Some of the advantages include:

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