Linear Force Solenoid

With the rapidly increasing use of 8 to 10 speed transmissions for fuel efficiency, shift quality and shift speed become even more important. Bosch has addressed these and other transmission needs with their electromagnetic Linear Force Solenoid (LFS) replacing the hydraulic pilot valves in transmission clutch actuators. The LFS eliminates the efficiency losses and concerns with oil contamination of pilot valves, while helping to squeeze more gears and their controls into the tightly-limited transmission space. The LFS also enables modifying the transmission shift characteristics under software control. This saves months of time in optimizing the shift quality of new transmissions, compared to the iterative substitution of different pilot valves previously required. The Bosch LFS was first used on a 2014 Daimler 9-speed transmission, with subsequent applications in Ford and GM 9-speed transmissions.