US 11,773,969 B2
Operation of a multi-speed vehicle transmission
Jürgen Blaser, Meckenbeuren (DE); Fabian Ley, Friedrichshafen (DE); and Jens Winter, Tettnang (DE)
Assigned to ZF FRIEDRICHSHAFEN AG, Friedrichshafen (DE)
Filed by ZF Friedrichshafen AG, Friedrichshafen (DE)
Filed on Jan. 11, 2022, as Appl. No. 17/573,021.
Claims priority of application No. 10 2021 200 165.3 (DE), filed on Jan. 11, 2021.
Prior Publication US 2022/0221051 A1, Jul. 14, 2022
Int. Cl. F16H 61/30 (2006.01); F16H 61/06 (2006.01); F16H 61/28 (2006.01); F16H 61/04 (2006.01)
CPC F16H 61/30 (2013.01) [F16H 61/06 (2013.01); F16H 61/2807 (2013.01); F16H 2061/0455 (2013.01); F16H 2061/2823 (2013.01); F16H 2061/302 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for operating a multi-gear vehicle transmission having an input, an output, and a plurality of shifting elements for engaging the gears of the vehicle transmission, the method comprising:
decoupling the input from the output to place the vehicle transmission in a neutral gear;
coupling the input to the output by closing at least one shifting element to place the vehicle transmission in a driving gear and to propel the vehicle;
detecting, when the vehicle transmission is in the neutral gear, an actuation condition of a vehicle brake and drag losses of the vehicle transmission; and
venting, when the vehicle transmission is in the neutral gear, the at least one shifting element for the driving gear if the actuation condition of the vehicle brake is a released condition and if the drag losses are elevated.