US 11,885,081 B2
Milling machine with hydraulically actuated rotor drive transmission
Derek P. Nieuwsma, Loretto, MN (US); Nathaniel S. Doy, Maple Grove, MN (US); Brian J. Schlenker, Shoreview, MN (US); and Ryan A. Enot, Dunlap, IL (US)
Assigned to Caterpillar Paving Products Inc., Brooklyn Park, MN (US)
Filed by Caterpillar Paving Products Inc., Brooklyn Park, MN (US)
Filed on Aug. 11, 2021, as Appl. No. 17/399,786.
Prior Publication US 2023/0051433 A1, Feb. 16, 2023
Int. Cl. E01C 23/088 (2006.01); E01C 23/12 (2006.01); F16H 61/30 (2006.01); F16H 61/00 (2006.01); F16H 61/12 (2010.01); F15B 15/20 (2006.01); F16H 61/28 (2006.01)
CPC E01C 23/088 (2013.01) [E01C 23/127 (2013.01); E01C 2301/00 (2013.01); F15B 15/20 (2013.01); F16H 61/0025 (2013.01); F16H 61/12 (2013.01); F16H 61/2807 (2013.01); F16H 61/30 (2013.01); F16H 2061/1244 (2013.01); F16H 2061/1268 (2013.01)] 16 Claims
OG exemplary drawing
 
13. A method of operating a rotor drive transmission operatively associated with an electronic controller, the method comprising:
actuating a gearshift directional control valve to direct pressurized hydraulic fluid from a hydraulic fluid source to a hydraulic gearshift actuator operatively associated with the rotor drive transmission;
engaging a plurality of gears in the rotor drive transmission to establish a gear ratio of the rotor drive transmission;
transmitting motive power from an internal combustion engine to a cutting rotor through the rotor drive transmission in the gear ratio; and
actuating a gearshift trapping valve disposed between the gearshift directional control valve and the hydraulic gearshift actuator to maintain hydraulic pressure in the hydraulic gearshift actuator upon occurrence of a fault condition with a rotor transmission hydraulic circuit, the rotor transmission hydraulic circuit including the gearshift directional control valve and the hydraulic gearshift actuator,
sensing the fault condition with a pressure sensor operatively associated with the rotor drive hydraulic circuit, wherein the fault condition is a hydraulic pressure fault indicating a loss of hydraulic pressure in the rotor transmission hydraulic circuit.