Articulation system for an earthmoving machine

An articulation system for an earthmoving machine, the articulation system comprising:

• a pair of cylinders;
• 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 pair of cylinders 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.

An earthmoving machine comprising:

• a front frame and a rear frame pivotally coupled by an articulation joint, and
• an articulation system associated with the front and rear frames, the articulation system comprising:
• a pair of cylinders located between the front and rear frames;
• 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 pair of 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.