Abstract: In order to avoid cavitation in a boom cylinder head end at the beginning of a dig cycle, fluid from an alternate source is supplied to the head end before or in addition to fluid supplied by the main boom-up hydraulic circuit. In one embodiment, an electronic hydraulic valve, related sensors, and control system determines the beginning of a dig operation and uses fluid at an intermediate pressure to rapidly provide fluid to a boom head end cylinder to prevent voiding or cavitation before fluid under high pressure from the main pump can be brought to the cylinder. An on/off fluid switch is activated early in a dig operation to address low pressure at the boom cylinder head end and provide an alternate path for fluid into the cylinder in reaction to the boom being lifted by a motion of the stick and bucket in contact with the work surface.

Abstract: A method of calculating payload material weight is executable by an electronic controller of a machine and includes steps of determining a first force on first front and rear struts of the machine in an unloaded condition of the machine, and adjusting the first force based on at least one of an unloaded front strut friction force and an unloaded rear strut friction force to define an unloaded weight. The method also includes steps of determining a second force on the first front and rear struts in a loaded condition of the machine, and adjusting the second force based on at least one of a loaded front strut friction force and a loaded rear strut friction force to define a loaded weight. A payload material weight is calculated by the method based on a difference between the loaded weight and the unloaded weight.

Abstract: In order to avoid cavitation in a boom cylinder head end at the beginning of a dig cycle, fluid from an alternate source is supplied to the head end before or in addition to fluid supplied by the main boom-up hydraulic circuit. In one embodiment, an electronic hydraulic valve, related sensors, and control system determines the beginning of a dig operation and uses fluid at an intermediate pressure to rapidly provide fluid to a boom head end cylinder to prevent voiding or cavitation before fluid under high pressure from the main pump can be brought to the cylinder. An on/off fluid switch is activated early in a dig operation to address low pressure at the boom cylinder head end and provide an alternate path for fluid into the cylinder in reaction to the boom being lifted by a motion of the stick and bucket in contact with the work surface.

Abstract: A method of calculating payload material weight is executable by an electronic controller of a machine and includes steps of determining a first force on first front and rear struts of the machine in an unloaded condition of the machine, and adjusting the first force based on at least one of an unloaded front strut friction force and an unloaded rear strut friction force to define an unloaded weight. The method also includes steps of determining a second force on the first front and rear struts in a loaded condition of the machine, and adjusting the second force based on at least one of a loaded front strut friction force and a loaded rear strut friction force to define a loaded weight. A payload material weight is calculated by the method based on a difference between the loaded weight and the unloaded weight.

Abstract: A hydraulic system includes a cylinder assembly with a rod, a pressurized fluid source, a fluid tank, and a control valve. The control valve is fluidly connected to the cylinder assembly. The hydraulic system also includes a line relief, first makeup valve, and second makeup valve fluidly connected to a head end of the cylinder assembly. The second makeup valve is configured to provide fluid flow to the head end of the cylinder assembly when the rod is urged toward an extended position and the control valve is in a neutral position.

Abstract: A hydraulic system is disclosed. The hydraulic system may have a first pump, a boom cylinder, and a first closed loop fluidly connecting the first pump to the boom cylinder. The hydraulic system may also have a second pump, a swing motor, and a second closed loop fluidly connecting the second pump to the swing motor. The hydraulic system may further have a third pump, an auxiliary actuator, and a third closed loop fluidly connecting the third pump to the auxiliary actuator. The hydraulic system may additionally have a combining valve configured to selectively connect the second closed loop to the first closed loop during a boom raising operation, and a control valve configured to selectively connect the third closed loop to the first closed loop during a boom lowering operation.