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1. (WO2018077462) SHIFT CYLINDER OF AN AUTOMATED CHANGE-SPEED GEARBOX

Pub. No.:    WO/2018/077462    International Application No.:    PCT/EP2017/001205
Publication Date: Fri May 04 01:59:59 CEST 2018 International Filing Date: Fri Oct 13 01:59:59 CEST 2017
IPC: F16H 61/30
Applicants: WABCO EUROPE BVBA
Inventors: DIDWISZUS, Lars
FREYER, Andreas
POUX, Romain
REIMANN, Dennis
Title: SHIFT CYLINDER OF AN AUTOMATED CHANGE-SPEED GEARBOX
Abstract:
The invention relates to a shift cylinder (1) of an automated change-speed gearbox, which shift cylinder (1) is of asymmetrical construction and has a piston (33) which is fastened on the end side to a selector rod (21) of the change-speed gearbox, and which piston (33) is guided in an axially movable manner in a cylinder housing (2) of the shift cylinder (1), which cylinder housing (2) is stepped in a manner which is narrowed axially towards the outside, and which piston (33) divides the interior of the cylinder housing (2) axially into an outer pressure chamber (31) and an inner pressure chamber (32), wherein the piston (33) can be displaced selectively into the two end-side shifting positions and a middle shifting position by way of one of the two pressure chambers or the two pressure chambers being loaded with a pressure medium. In order to realise a shift cylinder of asymmetrical construction with improved control properties and compact dimensions, it is provided according to the invention that in each case one annular piston (42, 50) is arranged axially on both sides of the piston (33), that the two annular pistons (42, 50) are guided axially displaceably in the cylinder housing (2) and on the piston (33), and that, in the middle shifting position of the piston (33), the two annular pistons (42, 50) bear in each case with an axially inner collar or end surface (48, 49; 56, 57) at the same time against a stop surface (27, 28) of the cylinder housing (2) and against a stop surface (35, 36) of the piston (33).