US 11,692,622 B2
Transmission shift with pressure controlled cleaning pulses
Derek Kinch, Ypsilanti, MI (US); Joseph Scott Slayton, Stanwood, MI (US); Stephen Michael Cicala, Dearborn Heights, MI (US); Bradley D Riedle, Northville, MI (US); and Richard Reynolds Hathaway, Livonia, MI (US)
Assigned to Ford Global Technologies, LLC, Dearborn, MI (US)
Filed by FORD GLOBAL TECHNOLOGIES, LLC, Dearborn, MI (US)
Filed on Aug. 2, 2021, as Appl. No. 17/391,477.
Prior Publication US 2023/0049036 A1, Feb. 16, 2023
Int. Cl. F16H 61/12 (2010.01); F16H 61/00 (2006.01); F16H 61/02 (2006.01); F16H 61/30 (2006.01); F16H 61/682 (2006.01)
CPC F16H 61/12 (2013.01) [F16H 61/0025 (2013.01); F16H 61/0276 (2013.01); F16H 61/30 (2013.01); F16H 61/682 (2013.01); F16H 2061/1264 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A transmission comprising:
an input shaft;
an output shaft;
a plurality of shift elements engageable in sets to create a plurality of power flow paths between the input and output shafts at different speed ratios;
a hydraulic system in fluid communication with the shift elements and including at least one electrohydraulic valve configured to control fluid pressure to at least one of the shift elements; and
a controller in communication with the at least one valve and programmed to, during a shift of the transmission:
command a series of first pressures to a first of the valves associated with an oncoming one of the shift elements while an off-going one of the shift elements is engaged,
command a series of second, higher pressures to the first valve for a duration of time responsive to an expected ratio change between the input and output shafts not commencing and the off-going shift element slipping, and
command a series of pressure pulses, according to a duty cycle, to the first valve responsive to expiration of the duration of time and the expected ratio change not commencing.