Abstract: A closed loop hydraulic system includes a hydraulic tank, a hydraulic power source, and an air pump. The hydraulic power source is in fluidly coupled to the hydraulic tank to draw the hydraulic fluid from the hydraulic tank. The air pump is in fluid communication with an air space in the hydraulic tank to pressurize the hydraulic tank. Further, a controller configured to receive a pressure signal from a pressure sensor associated with the hydraulic tank and regulate the hydraulic power source and the air pump based on the pressure signal.

Abstract: A hydraulic circuit including a hydraulic swing motor having a first port and a second port. A first motor conduit connected to the first port of the hydraulic swing motor, and a second motor conduit connected to the second port of the hydraulic swing motor. The hydraulic circuit further includes a pump to selectively supply a flow of pressurized hydraulic fluid to the hydraulic swing motor through the first and the second motor conduits. A controller electrically connected to the pump adjusts a torque output of the pump based on a swing speed of the hydraulic swing motor.

Abstract: A steering system for steering a machine having opposing first and second sides with first and second pairs of rotatably mounted rear wheels disposed along the respective sides and at least one rotatably mounted, spaced front wheel. The system includes at least one first drive unit and at least one second drive unit for rotating the rear wheels of the respective pairs, and a steering input device that provides a signal to a controller that produces drive unit request signals to control the drive units to rotate the associated rear wheels along one side at rotational speeds greater than those along the other side to facilitate turning.

Abstract: A filter assembly is disclosed having a filter base including an inlet and an outlet. The filter assembly also has a first valve disposed in the inlet, the first valve including a portion that protrudes from the filter base. The filter assembly additionally has a second valve disposed in the outlet, the second valve including a portion that protrudes from the filter base. The filter assembly also has a removably attachable filter configured to mechanically bias the first and second valves in an open position.

Abstract: A steering system for steering a machine having opposing first and second sides with first and second pairs of rotatably mounted rear wheels disposed along the respective sides and at least one rotatably mounted, spaced front wheel. The system includes at least one first drive unit and at least one second drive unit for rotating the rear wheels of the respective pairs, and a steering input device that provides a signal to a controller that produces drive unit request signals to control the drive units to rotate the associated rear wheels along one side at rotational speeds greater than those along the other side to facilitate turning.

Abstract: A steering system for steering a machine having opposing first and second sides with first and second pairs of rotatably mounted rear wheels disposed along the respective sides and at least one rotatably mounted, spaced front wheel. The system includes at least one first drive unit and at least one second drive unit for rotating the rear wheels of the respective pairs, and a steering input device that provides a signal to a controller that produces drive unit request signals to control the drive units to rotate the associated rear wheels along one side at rotational speeds greater than those along the other side to facilitate turning.

Abstract: A tandem drive arrangement includes one or more independently driven wheels (118) that are arranged in a tandem configuration along a beam (120). The beam (120) is rotatably connected to a frame (102) of a machine (100). The tandem drive arrangement further includes an actuator (206) operating to selectively impart a rotating moment to the beam (102). The rotating moment tends to rotate the beam (120) in one direction and counteracts a torque imbalance resulting from operation of motors (128) rotating one or more independently driven wheels (118) connected to the beam (120).

Abstract: A machine (100) includes a frame that is pivotally connected to a tandem drive arrangement. The tandem drive arrangement includes a beam (120) and a first motor (128) having a first stator portion (202) connected to a first end of the beam (120). The first motor (128) also includes a first rotor portion (204) connected to a first drive wheel (118). A load sharing arrangement (412) is associated with the tandem drive arrangement and includes a first collar (414) rotatably disposed around the first stator portion (202) and a second collar (426) rotatably disposed around a portion of the beam (120). A first linkage (424) is pivotally connected between the first and second collars such that the load sharing arrangement (412) balances unbalanced loading in the tandem drive arrangement by transferring the unbalanced loading to the frame.

Abstract: A steering system for steering a machine having opposing first and second sides with first and second pairs of rotatably mounted rear wheels disposed along the respective sides and at least one rotatably mounted, spaced front wheel. The system includes at least one first drive unit and at least one second drive unit for rotating the rear wheels of the respective pairs, and a steering input device that provides a signal to a controller that produces drive unit request signals to control the drive units to rotate the associated rear wheels along one side at rotational speeds greater than those along the other side to facilitate turning.

Abstract: A tandem drive arrangement includes one or more independently driven wheels (118) that are arranged in a tandem configuration along a beam (120). The beam (120) is rotatably connected to a frame (102) of a machine (100). The tandem drive arrangement further includes an actuator (206) operating to selectively impart a rotating moment to the beam (102). The rotating moment tends to rotate the beam (120) in one direction and counteracts a torque imbalance resulting from operation of motors (128) rotating one or more independently driven wheels (118) connected to the beam (120).

Abstract: A filter assembly is disclosed having a filter base including an inlet and an outlet. The filter assembly also has a first valve disposed in the inlet, the first valve including a portion that protrudes from the filter base. The filter assembly additionally has a second valve disposed in the outlet, the second valve including a portion that protrudes from the filter base. The filter assembly also has a removably attachable filter configured to mechanically bias the first and second valves in an open position.

Abstract: A machine (100) includes a frame that is pivotally connected to a tandem drive arrangement. The tandem drive arrangement includes a beam (120) and a first motor (128) having a first stator portion (202) connected to a first end of the beam (120). The first motor (128) also includes a first rotor portion (204) connected to a first drive wheel (118). A load sharing arrangement (412) is associated with the tandem drive arrangement and includes a first collar (414) rotatably disposed around the first stator portion (202) and a second collar (426) rotatably disposed around a portion of the beam (120). A first linkage (424) is pivotally connected between the first and second collars such that the load sharing arrangement (412) balances unbalanced loading in the tandem drive arrangement by transferring the unbalanced loading to the frame.

Abstract: A pilot control system for maintaining a constant operating hydraulic fluid pressure in a hydraulic system throughout a range of hydraulic fluid flow and temperature conditions. The pilot control system has a pilot pump and a pilot relief valve in fluid communication with the pilot pump. A first pressure reducing valve is in fluid communication with the pilot pump and the pilot relief valve so as to reduce the pressure to components downstream of the pressure reducing valve.