Multi-Speed Transmission with Uninterrupted Shifting (MSTUS) for high speed application (EV)

Operating Principle of MSTUS

Transition from Ratio A and Ratio B

 MSTUS uses 4 engaging and disengaging operations using dog clutches to achieve smooth uninterrupted shifting : 

  • While the transition module is in the same ratio as the transmission output gear ratio, the transition module is also linked to the output shaft.
  • This is followed by unlinking of the transmission output gear to the output shaft while the transition module enters the ramp region.
  • After the transition module ratio is transitioned to the target transmission ratio, the output gear set having the ratio matching the transition module ratio is linked in to the output shaft.
  • Before the transition module cycles to next ramp region, it is disconnected from the output shaft thereby culminating the uninterrupted shifting.

All engagement and disengagement operations occur via dog clutches while the RPM of the gears and their respective shafts are synchronized, requiring minimal force to engage/disengage. A graphical representation of the above steps for up-shift from ratio A to B and down-shift from ratio B to A is shown in the figures below.

Upshift Scenario from Ratio “A” to “B” 

Downshift Scenario from Ratio “B” to “A”

Custom Geneva Pin and Slot Mechanism for Controlled Rotation

  • Use of custom Geneva mechanism in transmissions (patent pending)
  • Customized to transition between two angular velocities
  • Retractable pins eliminate the need for a clutch