US 11,773,966 B2
Method and transmission control apparatus for operating a multiple-speed vehicle transmission
Ralf Beck, Oberteuringen (DE)
Assigned to ZF Friedrichshafen AG, Friedrichshafen (DE)
Filed by ZF Friedrichshafen AG, Friedrichshafen (DE)
Filed on Sep. 8, 2022, as Appl. No. 17/930,512.
Claims priority of application No. 10 2021 214 376.8 (DE), filed on Dec. 15, 2021.
Prior Publication US 2023/0184327 A1, Jun. 15, 2023
Int. Cl. F16H 61/16 (2006.01); F16H 59/72 (2006.01); F16H 59/44 (2006.01); F16H 59/48 (2006.01); F16H 59/40 (2006.01)
CPC F16H 61/16 (2013.01) [F16H 59/40 (2013.01); F16H 59/44 (2013.01); F16H 59/48 (2013.01); F16H 59/72 (2013.01); F16H 2059/443 (2013.01); F16H 2200/006 (2013.01); F16H 2200/0052 (2013.01); F16H 2200/0082 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for operating a multi-gear vehicle transmission that includes shifting elements for engaging gears of the vehicle transmission, the method comprising:
decoupling a transmission drive input from a transmission drive output of the vehicle transmission when in a neutral gear, wherein some of the shifting elements of a driving gear are already actuated;
coupling the transmission drive input and the transmission drive output of the vehicle transmission while in the driving gear by closing the shifting elements associated with the driving gear, in order to propel the vehicle;
determining whether a transmission condition with elevated drag losses exists when the neutral gear is engaged; and
closing a shifting element of the vehicle transmission associated with a reversing gear if the transmission condition with elevated drag losses exists, in addition to the shifting elements actuated in the neutral gear.