Transmission system
The transmission system in a vehicle is
essential for disconnecting the engine from the road wheels and managing
variable speeds. While the engine runs consistently, the transmission adjusts
energy output to suit different speeds. It also converts the high-speed, low-torque
output from the engine into the lower-speed and higher torque needed for smooth
operation through the drivetrain. Crucially, it allows wheels to rotate at
different speeds during turns, ensuring stable and controlled handling.
Manual Vs Automatic Transmission
When comparing manual
and automatic transmissions, each has distinct advantages and disadvantages.
Manual transmissions often come with a lower initial cost and are less
expensive to service. Enthusiasts appreciate the control and engagement that
manual shifting provides, along with better fuel efficiency and quicker
acceleration, qualities that attract race car and performance drivers. However,
they require a learning curve, as drivers must master the coordination of the
clutch, gas, and shifting, which can be cumbersome in stop-and-go traffic and
is less common in the market.
Manual Transmission
On the other hand,
automatic transmissions offer ease of use, contribute to less stress during
driving, and are highly favored in congested traffic conditions. They are great
for beginners, more widely available, and tend to have higher resale values. The
drawbacks include a higher purchase price, more expensive repairs, and
traditionally lower fuel efficiency compared to manuals, although technological
advancements are narrowing this efficiency gap.
Automatic Transmission
Automated
Manual transmission
Automated Manual
Transmissions (AMT) are mechanically akin to manual transmissions, but they
utilize sensors and actuators to automate clutch functions and gear shifts.
Electromagnetic actuators, mounted directly on the transmission, manage gear
selection and engagement with precision, effectively eliminating the need for a
clutch pedal. The advantages of AMTs are noteworthy; they improve fuel
efficiency and reduce CO2 emissions, feature a lighter gearbox that's
well-suited for electric vehicles, offer enhanced precision with lower fault
rates, and are more suitable for heavy-duty applications, making them an
increasingly popular choice in modern automotive design.
Cut out illustration of defining components of
Isuzu’s automated manual transmission.
Designing a solenoid actuator for an AMT
Designing a solenoid
actuator for an AMT presents a set of demanding challenges that require
sophisticated engineering solutions. The actuator must achieve a high force
density, with capabilities of up to 500N, coupled with rapid actuation times of
around 0.3 seconds, ensuring immediate response to force generation commands.
Moreover, it is essential to produce this high force at a relatively low
operating voltage of 33V, which necessitates an advanced design to maintain
high efficiency with minimal losses. Additionally, the system must be designed
to manage heat effectively to prevent performance degradation, ensuring
consistent operation under varying driving conditions and prolonging the
actuator's lifespan.
An AMT CAD model
Overcoming the Design Challenges
using EMWORKS
The rigorous demands
of designing a solenoid actuator for an AMT are adeptly met with EMWORKS’s
simulation software. Faced with the challenge of achieving high force density
up to 500N and rapid actuation within 0.3 seconds, EMWORKS allows engineers to
meticulously model and simulate the electromagnetic behavior and dynamic
response of actuators. The software plays a crucial role in optimizing actuator
design for high force output at low voltages, such as 33V, ensuring efficient
energy use and minimal losses. EMWORKS’s thermal analysis capabilities are
indispensable for predicting and limiting heat generation, a key factor in
maintaining actuator longevity and reliability. By providing a comprehensive
virtual testing environment, EMWORKS ensures that each design iteration brings
engineers closer to a solenoid actuator that meets the AMT’s high-performance
standards.
EMWORKS Sample Results for an AMT
Magnetic Flux Density at Different Airgap Distance
Force Results vs Airgap Distance
Force Results vs Housing Thickness
Force Results vs Coil Current
Force Results for Different Materials
Current Vs Time for Different Voltages
Ohmic Loss Vs Time for Different Voltages
Force Vs Time for Different Airgap at Voltage=33V
Speed Vs Time for Different Voltages
Eddy Loss Vs Time for Different Voltages
Magnetic Flux Density with Eddy Off
Magnetic Flux Density with Eddy ON
Eddy Current Density at Voltage = 33V
Temperature Distribution in the Coil and
Housing
Conclusion
In conclusion, the
evolution from manual to automatic, and now to AMT, showcases the relentless
pursuit of automotive efficiency, control, and innovation. The role of EMWORKS
in designing a solenoid actuator for AMTs is pivotal, providing engineers with
the advanced simulation tools necessary to overcome the challenges of force
density, actuation speed, and thermal management. Through detailed simulations,
EMWORKS ensures that actuators not only meet the required performance standards
but also operate efficiently and with durability in mind. The insights gained
from simulations inform design decisions that lead to improved fuel efficiency,
reduced emissions, and the precision needed for today’s high-performance
vehicles.
