SAE Update - February 2025 - 46

PUBLICATIONS
Most in-demand
publications of 2024
Celebrating a year of high-quality research.
SAE is known as a standards development
organization, or SDO, but that's not all we
do. Just take a look at SAE's most popular
publications from 2024. From energy
efficiency to vehicle connectivity, SAE's
global community of authors and
researchers has been very busy covering
the most critical topics in mobility today.
By the numbers
In 2024, SAE released a whopping 3,339
new publications. Here's the breakdown:
* 3,213 technical papers
* 45 journal issues
* 4 special focus journal issues
* 30 Edge™ Research Reports
* 34 eBooks
* 15 books (over 6,000 pages!)
These publications were led by a brilliant
community of 5,437 authors and
contributors from around the world.
46 February 2025
TOP TECHNICAL
PAPERS
Development of
New Motor
for Electric
Vehicles
Authors: Ken Jozaki, Ryosuke Shibata,
Hiroshi Hoshina
Excerpt: " High-strength electromagnetic
steel was adopted to allow for magnets to
be placed in a novel polygonal arrangement.
This new material and design improved the
motor torque performance. Increasing the
rotor core design flexibility allowed for a
reduction of the demagnetizing field. Hence,
the adoption of heavy-rare-earth-free
magnets in the generator became a reality.
UPDATE
Shutterstock/MMD Creative
2024-01-2206 Published 09 Apr 2024
Development of New Motor for Electric Vehicles
Ken Jozaki, Ryosuke Shibata, and Hiroshi Hoshina Toyota Motor Corporation
Citation: Jozaki, K., Shibata, R., and Hoshina, H., " Development of New Motor for Electric Vehicles, " SAE Technical Paper 2024-01-2206,
2024, doi:10.4271/2024-01-2206.
Received: 20 Oct 2023
Abstract
High-strength electromagnetic steel was adopted
T
he world is currently facing environmental issues
such as global warming, air pollution, and high energy
demand. To mitigate these challenges, the electrification
of vehicles is essential as it is effective for efficient
fuel utilization and promotion of alternative fuels. The
optimal approach for electrification varies across different
markets, depending on local energy conditions and current
circumstances. Consequently, Toyota has taken the initiative
to offer a comprehensive lineup of battery electric
vehicles (BEV), hybrid electric vehicles (HEV), plug-in hybrid
electric vehicles (PHEV), and fuel cell electric vehicles
(FCEV), aiming to provide sustainable solutions tailored to
the unique situations and needs of each region.
As part of this effort, Toyota has developed the 5th
generation of hybrid electric vehicles. This paper describes
the electric motor used in the new Toyota Camry which
achieves high torque, high power, low losses, and compact
design.
to allow for magnets to be placed in a novel polygonal
arrangement. This new material and design improved
the motor torque performance. Increasing the rotor
core design flexibility allowed for a reduction of the
demagnetizing field. Hence, the adoption of heavyrare-earth-free
magnets in the generator became a
reality. In addition, the stator core adopted annealing
after the press lamination to facilitate the growth of
crystal grains, enabling a reduction in power losses
compared to the previous generation motor. A fractional-pitch
winding was adopted, and the amount of
insulating resin was reduced by using foaming insulating
paper that fixes the windings with the stator core. As
a result, the end winding height was reduced compared
to the previous model. Through these actions, this
motor achieves a reduction of 26% in end winding height
and an increase of 23% in power density, compared to
the previous model.
Revised: 16 Jan 2024
Accepted: 22 Jan 2024
1. Introduction
T
he world is currently facing environmental issues
such as global warming, air pollution, and high
energy demand. To mitigate these social challenges,
the electrification of vehicles is essential for encouraging
more efficient fuel utilization and promoting alternative
fuels. The optimal solution for electrified vehicles varies
depending on the local energy situation and present
circumstances. Consequently, Toyota Motor Corporation
is taking the initiative and offering a comprehensive lineup
of battery electric vehicles (BEVs), hybrid electric vehicles
(HEVs), plug-in hybrid electric vehicles (PHEVs), and fuel
cell electric vehicles (FCEVs) aiming to provide sustainable
solutions tailored to the unique situations and needs of
each region. As part of this effort, Toyota has developed
a fifth generation of HEVs. This paper describes the new
electric motor developed for the new Toyota Camry,
which combines high torque, high power, and low losses
in a compact package. Figure 2 shows a model of the
transaxle in which the motor is installed.
FIGURE 1 The New Toyota Camry
https://www.sae.org/publications/technical-papers/content/2024-01-2206/ https://www.sae.org/publications/technical-papers/content/2024-01-2206/ https://www.sae.org/publications/technical-papers/content/2024-01-2206/ https://www.sae.org/publications/technical-papers/content/2024-01-2206/ https://www.sae.org/publications/technical-papers/content/2024-01-2206/
SAE Update - February 2025

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