Abstract: Hydraulic axial piston unit having a rotational group for driving or being driven by a driving shaft, and a tiltable displacement element for adjusting the displacement volume of the rotational group. The rotational group includes a rotatable cylinder block in which working pistons are mounted reciprocally moveable in cylinder bores for conveying hydraulic fluid from an inlet port to an outlet port on a valve segment. At least two control ports are located on the valve segment each between the inlet port and the outlet port. The control ports can be brought sequentially in fluid connection with the cylinder bores when the cylinder block is rotating. At least one hydraulic fluid injector is connected fluidly to one control port, for sequentially injecting pressurized hydraulic fluid via the control port into the passing cylinder bores. Via the other control port hydraulic fluid can be drained from passing cylinder bores.

Abstract: The invention relates to a method (19) of operating a hydraulic arrangement (1) including a mounting base (5), a boom (3) that is pivotably arranged on the mounting base (5), and a Z-kinematics (2) that is arranged on the boom (3). The Z-kinematics (2) tilts a tool attachment device (10), that is pivotably arranged on the boom (3). The boom (3) is moved by a lifting hydraulic piston (7) that is connected to the boom (3) and to the mounting base (5). The Z-kinematics (2) is moved by at least a tilting hydraulic piston (11) that is connected to a lever of the Z-kinematics (2) and to the mounting base (5). On application of an input control command for changing the position of the lifting hydraulic piston (7), a compensation command is automatically generated and applied to the tilting hydraulic piston (11), to essentially maintain the attitude of the tool attachment device (10).

Abstract: A pump control system, comprising: a motor (12) configured to drive a pump (14); a pressure relief valve (22) in fluid communication with the pump (14); a torque control valve (32) connected to a swashplate of the pump (14) and in fluid communication with the pressure relief valve (22); a swashplate angle sensor (36) connected to the swashplate (34); and a computer (40) connected to the swashplate angle sensor (36) and the pressure relief valve (22) wherein the computer (40) controls the pressure relief valve (22) based upon swashplate displacement to achieve maximum system pressure. The corresponding method of controlling is also disclosed.

Abstract: A control arrangement for a variable displacement pump includes a pressure control unit and a separate mechanical control unit, each mounted on a housing of the variable displacement pump. The pressure control unit provides pressure control for the variable displacement pump and the mechanical control unit provides rotary feedback control for the variable displacement pump.

Abstract: A hydraulic piston unit including a rotational group for driving or being driven by a driving shaft, and having a tiltable displacement element for adjusting the displacement volume of the rotational group between a minimum or a maximum displacement, wherein, on t valve segment between a kidney-shaped inlet port and a kidney-shaped outlet port at respective dead end positions of reciprocally moveable working pistons first and second control ports are located in fluid connection with cylinder bores in the cylinder block, for controlling the position of the displacement element. The hydraulic piston unit further includes a control valve with a shiftable control valve spool fluidly connected via a high pressure port to a high pressure side of the hydraulic piston unit. The control valve spool is configured to conduct hydraulic fluid from the high pressure side to one of the first or the second control port.

Abstract: According to the present disclosure, a steering system and method for a machine includes a vehicle control system configured to command steering of the machine, and a steering sensor in communication with the vehicle control system. The steering sensor is configured to detect a position of a steering actuator of the machine. The vehicle control system is configured to detect an acceleration rate of the machine and to command steering of the machine based at least in part on the position of the steering actuator and the acceleration rate of the machine.

Abstract: A bearing attachment system for a pump product having a seal carrier and a cover plate. The attachment system is configured to produce a force deflection curve that provides a clamping force on a pair of tapered roller bearings such that a tight bearing endplay on the tapered roller bearings is maintained through a full range of manufacturing tolerances. The geometric shape of the cover plate and the top surface of the seal carrier provide the desired deflection characteristics.

Abstract: The invention relates to a method (25) of determining the health status of a hydraulic circuit arrangement comprising at least one hydraulic fluid working machine (2, 3). The health status is determined (29) using at least in part an actual temperature information (12) of the hydraulic circuit arrangement (1) that is compared to an expected temperature information (24) of the hydraulic circuit arrangement (1).

Abstract: A bearing assembly having an inner race, an outer race, and a plurality of rollers positioned between the inner race and the outer race. A pad is attached to the inner race and a bed is attached to the outer race. A timing mechanism is slidably mounted to the pad and the bed. Preferably the pad and bed are made of plastic and the inner race is embedded within the pad and the outer race is embedded within the bed.

Abstract: According to the present disclosure, a system for providing steering control in a dual path machine includes a propulsion controller operatively connected to plants of the machine for driving ground contacting elements, the propulsion controller being configured to control steering of the dual path machine through drive signals sent to the plants, and a brake controller operatively connected to left and right brakes of the machine, the brake controller being configured to control steering of the machine by providing differential brake pressures to the left and right brakes. The system of the present disclosure provides redundant steering control by receiving an input signal at the brake controller with an indication of steering position, receiving an input signal at the brake controller with an indication of brake position, and providing a differential brake pressure to brakes of the dual path machine based on the steering input signal and brake input signal.

Abstract: A hydrostatic system that provides different volumetric efficiency at different states and includes a pump with a discharge and supply line. Connected between the discharge and supply line is a valve. The valve is adapted to move to a position having a cross port orifice when the pump is in a neutral state and a position where the ports are blocked when the pump is in an operation state.

Abstract: A pressure limiting system for a dual path machine wherein an input propel command from a propel device is scaled based upon the largest detected pressure in a hydraulic system to determine a modified propel command. Also, response time is adjusted within an electrical control system based upon the type of input propel command signal received.

Abstract: According to the present disclosure, a system and method for providing stability control to a machine includes generating a yaw signal at a gyroscope disposed on the machine and receiving the yaw signal at a controller in communication with the gyroscope. The controller is also in communication with a user input that generates control signals for driving at least one plant of the machine. The controller is configured to alter the control signals provided to the at least one plant from the user input based at least in part on the yaw signal.