Patent ID: 7534186
Filing Date: 2009-05-19
Classification: F16H

Abstract:
1. A method of starting in reverse drive in a vehicle having a continuously variable transmission and a reversing gearset such that an overall transmission ratio in the reverse drive is substantially equal to an overall transmission ratio in forward drive, the continuously variable transmission having a variator and the reversing gearset comprising a drive input shaft ( 6 ), a primary shaft ( 10 ), first and second shift elements ( 7 , 8 ), for shifting between the forward drive and the reverse drive, and a planetary gearset comprising a sun gear ( 2 ), a planet carrier ( 3 ) supporting a plurality of planetary gears ( 4 ), and a ring gear ( 5 ), and the reversing gearset ( 1 ) having a forward transmission ratio substantially equal to one, the method comprising the steps of: setting a highest variator transmission ratio upon starting the vehicle; compensating for a transmission ratio, which provides a speed-drop in the reverse drive, by a corresponding adjustment of the variator of the continuously variable transmission such that, for certain speeds, the overall transmission ratio in the reverse drive is equal to the overall transmission ratio in the forward drive; and as soon as the vehicle commences movement, reducing the variator transmission ratio to obtain one of a lower engine speed and a higher vehicle speed after starting.