Biplab Das 
General Motors (GM) has unveiled a novel approach to enhancing electric vehicle (EV) transmissions through a recent patent filing. The patent, published by the United States Patent and Trademark Office (USPTO) on 16 May 2024, and originally filed on 10 November 2022, details a new clutch actuation system that aims to simplify and improve the efficiency of EV transmissions.
At the core of GM’s new system is a hydraulic actuator designed to operate a clutch in automatic EV transmissions. According to the patent, a controller varies the fluid pressure within the actuator, which moves a piston to open or close the clutch based on the controller’s real-time assessments. This method promises a simpler mechanism compared to traditional automatic transmissions and addresses instabilities typically associated with electric motors.
Why this matters
Most electric vehicles currently on the market do not use multi-speed transmissions due to the instantaneous torque provided by electric motors. However, GM’s system could offer advantages by decoupling the motor from the drive wheels when appropriate, thereby improving overall vehicle efficiency. This innovation stands to benefit the performance of EVs, particularly in urban environments where stop-and-go driving is prevalent.
Comparing industry innovations
While GM is focusing on hydraulic actuation, other automakers are also exploring innovative transmission technologies for EVs. Porsche’s Taycan, for instance, features a 2-speed gearbox, and Stellantis has developed a 2-speed transmission for off-road EVs. Additionally, Ford and Toyota have patented manual transmissions for EVs, allowing drivers to manually control shifting and clutch actuation.
Potential applications
GM’s new clutch actuation system could lead to more efficient EVs by reducing energy losses during operation. This would be particularly advantageous for urban driving, where frequent stopping and starting can impact efficiency. Moreover, the system’s ability to mitigate motor instabilities could enhance the driving experience, making EVs more appealing to a broader audience.
Looking ahead: broader implications
The patent highlights GM’s commitment to advancing EV technology and addressing some of the current challenges in the industry. As the demand for electric vehicles grows, innovations in transmission systems will be vital in improving performance and efficiency. GM’s hydraulic actuation system could set a new standard, prompting other manufacturers to develop similar technologies.
GM’s latest patent filing for a hydraulic actuator in EV transmissions marks a significant step forward in electric vehicle technology. By simplifying the transmission mechanism and improving efficiency, GM is contributing to the broader adoption of electric vehicles. This innovation not only enhances the performance of EVs but also aligns with global sustainability goals by promoting more efficient urban mobility.
