Globally, the number of electric vehicles is increasing day by day. From January to September 2023, China’s electric vehicle sales reached 4.468 million units, with a market share of more than 20%.
However, the cruising range of electric vehicles is still an issue of widespread concern. In electric vehicles, the motor is not the only power-hungry device. Especially in the winter, all the creature comforts you have on board consume electricity, and you pay the price for capability at the expense of range.
Schaeffler is deeply involved in this area. Mattis Zink, CEO of the Automotive Technology Division of the Schaeffler Group, said: “The innovative solutions developed by Schaeffler help eliminate drivers’ range anxiety. We provide Pure electric drive systems and intelligent technical solutions and various components and systems to improve the practicality of electric vehicles by reducing energy consumption and extending cruising range.”
Efficient bearing solutions
All cars rely on bearings – and electric cars are no exception.
Therefore, one of the ways to improve the cruising range of electric vehicles is to reduce the friction loss of bearings – the energy originally used to drive the vehicle will be lost in the form of heat due to friction in the bearings.
Schaeffler has developed targeted solutions for this purpose.
For example, Schaeffler’s high-efficiency gearbox bearings can significantly reduce friction and save about 50 watts of electricity compared to traditional bearing solutions. This energy can be directly used to improve endurance.
In addition, in winter, 50 watts of electricity can also be used to heat the exterior rearview mirrors or steering wheel without affecting battery life.
Equally important, Schaeffler e-Drive transmission bearings are specially optimized for the high rotational speeds of the transmission input shaft in the e-axle, thus ensuring optimal load-carrying capacity.
In order to further improve endurance, Schaeffler also developed the TriFinity three-row wheel hub bearing.
Wheel hub bearings are one of the important components of the electric vehicle chassis system. They are responsible for guiding and supporting the drive shaft and axle, ensuring that the wheels can rotate with minimal resistance even under high mechanical loads.
During normal driving, wheel hub bearings will bear huge loads and friction. They rotate constantly, rotating about 100 million times every 180,000 kilometers traveled.
Compared with traditional bearings, Schaeffler’s TriFinity three-row wheel hub bearings can significantly reduce friction losses by 67% and save more than 200 watts of electricity, which is equivalent to an electric SUV with a battery capacity of 120 kWh after being fully charged. , which can increase the cruising range by about 20 kilometers.
In addition, in winter, the extra 200 watts of power can be used to heat seats without affecting battery life. When heated continuously, a single heated seat can consume up to 100 watts per hour.
Under the same dimensions, TriFinity three-row wheel hub bearings are about 10% lighter than standard double-row ball bearings and have a longer service life. In addition, the bearing’s stiffness is increased by more than 20% and can transmit larger loads, which is a key advantage for heavy-duty electric vehicles.
Eliminate battery life anxiety with thermal management
Thermal management offers huge potential for improving cruising power – Schaeffler has been working in this field for about 15 years.
Schaeffler has been providing thermal management solutions to automotive customers since 2011.
Dr. Jochen Schroeder, head of Schaeffler Group’s Electric Drive Division, said: “Especially in electric vehicles, thermal management is directly related to cruising range and driving comfort, and therefore has gradually become a way to enhance the competitiveness of models. one of the key technologies.”
To this end, Schaeffler is developing various solutions, from multi-functional, multi-purpose components to highly integrated thermal management systems to four-in-one systems that integrate motor, reducer, electronic control and thermal management in one unit bridge.
The four-in-one bridge eliminates the need for additional hoses and cables required by a decentralized thermal management system, resulting in less energy loss, fewer parts, lighter weight, and easier installation.
This highly integrated solution enables the entire powertrain system, including the battery, to be maintained within the appropriate temperature range, further improving the cruising range and charging speed. The system can also control the temperature inside the cabin within an appropriate range, thereby improving driving comfort.
Thanks to the interaction between the various subsystems, the electric axle can save about 1 kWh of power for a compact electric vehicle equipped with a 75 kWh battery for every 100 kilometers driven, which is equivalent to extending the driving time by about 7% (or 36 kilometers). ) cruising range.
Schaeffler is also developing a new heat pump that can be used both in a four-in-one bridge and as a stand-alone component.
This heat pump converts heat energy in the surrounding air and waste heat generated by the motor, electronic controls and batteries into usable heat energy, thereby saving battery power.
Especially in the cold winter, battery power is particularly precious.
Compared with a compact car equipped with a 75 kWh battery and decentralized thermal management components, the same model equipped with a four-in-one electric axle and heat pump system consumes approximately 4 kWh less energy per 100 kilometers (at an outdoor temperature of minus 7 degrees Celsius). Under temperature conditions, selecting WLTC operating condition) is equivalent to extending the cruising range by 17% (or 48 kilometers).
In addition, the saved power can be used to improve driving comfort and safety, such as heating the seats, steering wheel, exterior mirrors and rear windshield (these systems consume approximately 410 watts*).
Another advantage of Schaeffler heat pump systems is the use of the natural refrigerant carbon dioxide (R744), which is much less harmful to the environment than conventional refrigerants (Rf1234yf). R744 is non-flammable, has low greenhouse effect potential and will not cause damage to the ozone layer of the atmosphere. For car manufacturers and car owners, this also means that they contribute to climate protection and green development.
