Abstract: A gear shift device for a mobility machine has a plurality of gears between a first gear referred to as gear No. 1 and a top gear. The gear shift device includes a series of input pinions arranged so as to turn freely around a selection shaft with an axis X2, said selection shaft accommodating a worm screw and a shuttle. The gear shift device also includes a series of output pinions with an axis X3 that rotate conjointly with a hollow shaft a gear shift actuator arranged so as to displace the shuttle along the worm screw between a plurality of positions and to engage a selected gear. A mobility machine can include the gear shift device.

Abstract: The present invention concerns an assembly (1) comprising: an intake duct (4) extending between an air inlet (11) and a heat engine (2), a heat engine (2), an electric compressor (5) disposed on the intake duct and upstream from the heat engine (2), the electric compressor (5) being configured to allow the spark advance to be degraded during a transitory phase.