Get Power units -> Construction of electric drive motors Guide for Audi RS E Tron Gt 4 Door First Generation (2021-2026)

Introduction

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Permanently excited synchronous motors are fitted on front and rear axles of the e-tron GT and RS e-tron GT (type F8). The high

power density of the motors allows for a very dynamic motor response. The construction of the electric drive motors differs in the

active length of the rotor/stator core. The design of the power electronics is also different on the front and rear axles. The power

electronics on the front axle can process a maximum current of 300 amperes. The power electronics on the rear axle can manage

600 amperes.

Construction of electric drive motors

General information

The electric drive motors on the Audi e-tron GT (type F8) are permanently excited synchronous motors. On the rear axle, this is a

construction parallel to the axle, and on the front axle it is coaxial. Different power outputs from the electric drive motors are ach-

ieved by different rotor/stator core lengths. The larger the rotor/stator core is, the larger the magnetic field will be. This is referred

to as the length of the active components.

Active length of front axle

160 mm

190 mm

130 mm

245 mm

210 mm

245 mm

Diameter of axle

Active length of rear axle (e-tron GT)

Diameter of rear axle (e-tron GT)

Active length of rear axle (RS e-tron GT)

Diameter of rear axle (RS e-tron GT)

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Drive motor on rear axle (e-tron GT)

Drive motor on rear axle (RS e-tron GT)

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Front axle

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Rear axle

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Rotor

The rotor is made up of permanent magnets arranged with alternating poles. The magnets used are very strong ferrite magnets

that are magnetised artificially during manufacturing. The air gap between the rotor and the stator is kept very small, increasing

the efficiency of the motor.

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Stator

The stator is made of thin metal plates that are insulated from one another. The plates strengthen the magnetic field produced by

the current flowing through the copper windings. The copper windings are integrated in the metal plates and are known as hairpin

windings. The advantage of this type of winding is that, compared to conventional windings, a higher amount of copper can be

housed in the same amount of space. Heat dissipation characteristics are also improved by this type of winding.

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Conventional winding

Hairpin winding

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Drive motor rotor position sender 1 G713 / rear drive motor rotor position sender G1095

The rotor position senders work on the resolver principle. The senders consist of a rotor disc made of field-conducting material,

field coils and receiver coils. All receiver coils have a different number of windings. Because the field coils are supplied with a sinus-

oidal voltage, a magnetic field is generated in the field coils. This magnetic field is induced in the receiver coils.

If one of the lobes of the rotor disc now intersects the magnetic field of a receiver coil, the magnetic field in the corresponding coil

is strengthened.

Because of the different number of windings, the control unit can detect the position of the rotor precisely. The speed of the elec-

tric drive motors is determined based on the number of occurrences. The rotor position senders do not wear and are resistant to

ageing.

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Power units -> Construction of electric drive motors for Your Audi RS E Tron Gt 4 Door First Generation (2021-2026)

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