US 10,889,965 B2
Articulation system for an earthmoving machine
Travis Neale Richards, Chillicothe, IL (US); Ernest Everett Stoops, Decatur, IL (US); Michael Lemoyne Repscher, Taylorville, IL (US); Matthew David Roley, Morton, IL (US); Ramalho Stive, Isle d'Abeau (FR); Michael Robert Kunde, Decatur, IL (US); Dwanz Mwalimu Mwasi, Seco Green Valley, AZ (US); Charles Eric Nail, Macon, IL (US); and Bart Jerome Bradford, Mt. Zion, IL (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Deerfield, IL (US)
Filed on Jun. 11, 2019, as Appl. No. 16/436,959.
Prior Publication US 2020/0392702 A1, Dec. 17, 2020
Int. Cl. E02F 9/22 (2006.01); B62D 12/00 (2006.01); E02F 9/08 (2006.01)
CPC E02F 9/2285 (2013.01) [B62D 12/00 (2013.01); E02F 9/0841 (2013.01); E02F 9/225 (2013.01); E02F 9/2296 (2013.01); F15B 2211/205 (2013.01); F15B 2211/3051 (2013.01); F15B 2211/3056 (2013.01); F15B 2211/40553 (2013.01); F15B 2211/575 (2013.01); F15B 2211/8609 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A hydraulic circuit for a pair of cylinders associated with an articulation system of an earthmoving machine, the hydraulic circuit comprising:
a pump;
a reservoir;
a directional control valve fluidly coupled to the pump and the reservoir via a supply line and a fluid return line respectively, the directional control valve disposed in fluid communication with the pair of cylinders via a pair of cylinder supply lines, the cylinder supply lines having a pair of load check valves disposed therein; and
a pair of actuator valves disposed in fluid communication with the pump via a pilot supply line and the directional control valve, each actuator valve configured to selectively actuate movement of the directional control valve; and
an articulation charge circuit associated with the pilot supply line and the pair of cylinder supply lines downstream of the pair of load check valves, the articulation charge circuit having:
a pilot feed line branched-off from the pilot supply line at a point located downstream of the pair of actuator valves, the pilot feed line having an orifice disposed therein and configured to branch into a pair of pilot feed branch lines downstream of the orifice, the pair of pilot feed branch lines fluidly coupled with the pair of cylinder supply lines downstream of the pair of load check valves, wherein:
the pair of pilot feed branch lines are provided with a pair of check valves disposed therein such that each check valve operably charges a corresponding cylinder supply line downstream of the pair of load check valves with fluid from the pilot supply line, via the pilot feed line and the orifice, for increasing a pressure in the corresponding cylinder supply line downstream of the pair of load check valves when the pressure in the corresponding cylinder supply line falls below the pressure of fluid associated with the pilot feed branch line coupled thereto.