JEC COMPOSITES MAGAZINE - Issue #121 - May 2018 - 43

LAND TRANSPORTATION
e-mobility

Lighter construction for electric motors

Werner FauLhaber,
Head of R&D Electrical
Engineering
Arburg

he project is sponsored by the
German Aerospace Centre (the
participating agency) and the
German Federal Ministry for Economic
Affairs and Energy. The partners in the
project are working together all along
the value chain.

The project's principal goals concerning products have been the mass production of parts using iron-filled polymer materials, the use of lightweight
construction materials in the rotor and
the rotor shaft, and the production of
motor crankcases made of fibre-reinforced materials.
Achieving these goals should make it
possible to lower the weight of the rotors and total motor weight, reduce its
moment of inertia, and obtain higher
revolution rates yet lower energy consumption.
High flexibility, low unit cost
A core component of the project is the
construction of an electric motor with
the roughly 90 kW (123 hp) power
range typical for an electric vehicle
and a maximum torque of 260 newton
metres (Nm).
A principal production goal was to
keep manufacturing costs down while
ensuring high flexibility in terms of the

number of units produced.
A material called Soft Magnetic
Compo-site (SMC) was chosen as
base material for manufacturing the
rotor segments.
This material consists of a PA-6 matrix
filled with Fe8Ni92 permalloy. Its
advantages include minimum energy
loss through eddy currents and less
heat dissipation than with standard
laminated rotors. Besides the selection
criteria for flow path length, other
important factors were the magnetic
and electrical properties, unit costs,
and production automation potential.
The engaging discs for power transmission are modular, with magnet
holders made of the SMC material into
which the magnets are inserted. This
allows for a simpler, trimmed-down
machine technology that is more
easily managed. Making the flow paths
shorter was a high priority, since that
is required to maintain the highest
level of quality during high-volume
production. Also, the rotor disc struc-

ProLemo drive with
hollow steel shaft
(source wkb)

N°121 May - June 2018

/ jec composites magazine

Land Transportation

These include Wittenstein Cyber
Motor, Index-Werke Hahn & Tessky,
and Aumann, and as research body,
the Karlsruhe Institute of Technology
(KIT) along with its research centres,
wbk Institute for Production Science
and FAST Institute of Vehicle Systems
Technology.
Arburg is supplying the multi-component injection moulding technology
and helping to make the more lightweight components that are required,
using an Allrounder 520 A electric
press and complex materials and mould
technology.

For single-axle electric power units that are produced for the electric-mobility mass market and for mechanical engineering, achieving
cost-effective use depends on finding innovative technologies for
series production and lightweight construction. The ProLemo project is focusing on production technologies for efficient lightweight
motors for electric vehicles.

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #121 - May 2018