Multistage transmission and shifting process therefor
AssigneeVolkswagen Aktiengesellschaft
InventorsArthur Schneider, Christian Klarhoefer
Life of this patent
Estimating the term…
Abstract
A multistage transmission has a plurality of gear stages and an additional gear stage which may be engaged to transmit part of the input shaft torque before disengagement of an engaged gear stage. A friction clutch is used to engage the additional stage. Alternatively, a variable-ratio pulley connection may be used for the additional stage. Synchronization of the transmission input shaft with a gear stage to be engaged is attained by controlling the change in input shaft speed in accordance with a selected speed gradient.
Claims15
A method of shifting a vehicle transmission having a transmission input shaft connectable to a drive motor, a transmission output shaft, a plurality of gear stages, each including a pair of gear wheels supported on the transmission input shaft and the transmission output shaft, respectively, one of each pair of gear wheels being fixed on its supporting shaft and the other of each pair of gear wheels being supported as a loose wheel on its supporting shaft and being connectable thereto by a coupling device for the purpose of engaging the corresponding gear, and at least one additional gear stage comprising applying torque from the transmission input shaft at least partly through the additional gear stage to the transmission output shaft in order to relieve a previously engaged gear stage and vary the speed of the transmission input shaft, disengaging the previously engaged gear stage by disconnecting the loose wheel thereof from the corresponding transmission shaft, synchronizing the speed of the transmission input shaft to a synchronous speed for a next gear stage to be engaged by controlling the change of speed of the transmission input shaft in accordance with a speed gradient value which is a function of at least one operating characteristic of the drive motor and engaging the next gear stage to be engaged by connecting the loose wheel thereof to the corresponding transmission shaft.
A multistage vehicle transmission comprising a transmission input shaft connectable to a drive motor, a transmission output shaft, a plurality of gear stages, each including a pair of gear wheels supported on the transmission input shaft and the transmission output shaft, respectively, one of each pair of gear wheels being fixed on its supporting shaft and the other of each pair of gear wheels being supported as a loose wheel on its supporting shaft and being connectable thereto by a coupling device for the purpose of engaging the corresponding gear, an additional gear stage with a transmission ratio which is smaller than that of at least one of the gear stages, and control means for controlling the speed change of the transmission input shaft in accordance with a speed gradient value which is a function of at least one operating characteristic of the drive motor by acting upon at least one of the drive motor and the additional gear stage.
A multistage transmission comprising a transmission input shaft connectable to a drive motor, a transmission output shaft, a plurality of gear stages, each including a pair of gear wheels supported on the transmission input shaft and the transmission output shaft, respectively, one of each pair of gear wheels being fixed on its supporting shaft and the other of each pair of gear wheels being supported as a loose wheel on its supporting shaft and being connectable thereto by a coupling device for the purpose of engaging the corresponding gear, an additional gear stage with a transmission ratio which is smaller than that of at least one of the gear stages, and control means for controlling the speed change of the transmission input shaft by acting upon at least one of the drive motor and the additional gear stage, wherein the gear ratio of the additional gear stage can be adjusted continuously or in stages.
Dependencies are inferred from the claim text.