Abstract: A hydrostatic assembly employing a 1st hydraulic piston drive unit is described in which the output is increased without using additional servo assemblies by incorporating a 2nd hydraulic piston drive unit, coupling the drive shafts of both drive units together, and employing a common means to simultaneously adjust displacement of both the 1st and 2nd hydraulic piston drive units. In such embodiments, coupling the drive shafts together such that the 1st hydraulic piston drive unit is rotationally offset with respect to the 2nd hydraulic piston drive allows for a reduction in the amplitude of pressure pulsations associated with the hydrostatic assembly output, thereby smoothing out operation and improving durability.

Abstract: A hydrostatic variator having a common yoke design and two or more bent axis piston drive units is disclosed in which the rotating group of a drive unit is arranged to be movable relative to the yoke to alter the angle between its drive shaft axis and rotating group axis independent of the other drive unit. This can be accomplished using movable sector plates coupled to the rotating groups that are arcuately movable within the yoke about the axis perpendicular to the respective drive shaft axes of the drive units. Such variators enjoy the response and packaging advantages of a common yoke design while still allowing dynamic adjustment of system size. In turn, varying system size allows for efficiency to be improved at conditions other than at the maximum design torque.

Abstract: A hydrostatic variator having a common yoke design and two or more bent axis piston drive units is disclosed in which the rotating group of a drive unit is arranged to be movable relative to the yoke to alter the angle between its drive shaft axis and rotating group axis independent of the other drive unit. This can be accomplished using movable sector plates coupled to the rotating groups that are arcuately movable within the yoke about the axis perpendicular to the respective drive shaft axes of the drive units. Such variators enjoy the response and packaging advantages of a common yoke design while still allowing dynamic adjustment of system size. In turn, varying system size allows for efficiency to be improved at conditions other than at the maximum design torque.

Abstract: A hydraulic machine includes a support structure and a rotating group rotatably mounted relative to the support structure. The rotating group includes a shaft and a cylinder barrel with a plurality of circumferentially spaced cylinder bores. Reciprocal pistons extend from the shaft with each one of the pistons extending into an associated one of the cylinder bores. A joining assembly joins the shaft and the cylinder barrel so that the shaft and the cylinder barrel rotate together. The hydraulic machine further includes at least one oil dam associated with the rotating group and adapted to trap hydraulic fluid used for lubricating portions of the joining assembly.

Abstract: A hydraulic machine includes a support structure and a rotating group rotatably mounted relative to the support structure. The rotating group includes a shaft and a cylinder barrel with a plurality of circumferentially spaced cylinder bores. Reciprocal pistons extend from the shaft with each one of the pistons extending into an associated one of the cylinder bores. A joining assembly joins the shaft and the cylinder barrel so that the shaft and the cylinder barrel rotate together. The hydraulic machine further includes at least one oil dam associated with the rotating group and adapted to trap hydraulic fluid used for lubricating portions of the joining assembly.

Abstract: The present invention relates to an arrangement for controlling a hydraulically driven motor, forming part of a hydraulic system in which hydraulic fluid under pressure forms a main flow through a main duct in which the motor is connected. The motor drives a varying load, and one or more valves (7) are adapted for controlling the hydraulic fluid flow through the motor on the one hand during operation and on the other hand for starting and stopping of the motor. One of the valves consists of a flow control valve (7) which is connected in the main duct (1) downstream of the outlet of the motor, and the flow control valve (7) is integrated with the motor housing (50).

Abstract: The present invention relates to an arrangement for controlling a hydraulically driven motor (2), forming part of a hydraulic system in which hydraulic fluid under pressure forms a main flow through a main duct (1) in which the motor is connected. The motor is adapted to drive a load with varying loading, and one or more valves (6, 7) are adapted for controlling the hydraulic fluid flow through the motor on the one hand during operation and on the other hand for starting and stopping of the motor. One of the valves consists of a flow control valve (7) which is connected in the main duct (1) downstream of the motor (2) and is adapted for on the one hand starting/stopping of the motor and on the other hand constant flow control of the hydraulic fluid flow through the motor.

Abstract: An arrangement for controlling two drive units which interact with one another, one of which includes a hydraulically driven motor (2). The motor drives a varying load, and one or more valves (6, 7) control hydraulic fluid flow through the motor during operation and for starting and stopping of the motor. One of the valves is a flow control valve (7) for flow control of the hydraulic fluid flow through the motor. The second drive unit (37) performs a working movement which, under the action of hydraulic flow influences the loading of the motor. The flow of the hydraulic fluid to the second drive unit is controlled in a coordinated way with the control of the flow through the motor.

Abstract: The present invention relates to a device for reducing energy losses in a machinery unit (1), having at least one part (4) which is arranged to rotate in fluid about a rotation axis (6) in a substantially closed chamber (3) delimited in the radially outward direction by means of a wall (18) extending around the rotation axis. The wall (18) has a radially inward facing wall surface (10) extending wholly or partially around the revolution, which wall surface is highly smooth and extends close to, but with an interspace (14) to the radially outer surface which is generated around the revolution by the rotary part (4). The interspace is suited to minimizing the rotating fluid volume and, at the same time, maintaining necessary width for a boundary layer in the fluid between the generated surface and the wall surface.

Abstract: The present invention relates to an arrangement for controlling a hydraulically driven motor, forming part of a hydraulic system in which hydraulic fluid under pressure forms a main flow through a main duct in which the motor is connected. The motor drives a varying load, and one or more valves (7) are adapted for controlling the hydraulic fluid flow through the motor on the one hand during operation and on the other hand for starting and stopping of the motor. One of the valves consists of a flow control valve (7) which is connected in the main duct (1) downstream of the outlet of the motor, and the flow control valve (7) is integrated with the motor housing (50).

Abstract: The present invention relates to an arrangement for controlling a hydraulically driven motor (2), forming part of a hydraulic system in which hydraulic fluid under pressure forms a main flow through a main duct (1) in which the motor is connected. The motor is adapted to drive a load with varying loading, and one or more valves (6, 7) are adapted for controlling the hydraulic fluid flow through the motor on the one hand during operation and on the other hand for starting and stopping of the motor. One of the valves consists of a flow control valve (7) which is connected in the main duct (1) downstream of the motor (2) and is adapted for on the one hand starting/stopping of the motor and on the other hand constant flow control of the hydraulic fluid flow through the motor.

Abstract: The present invention relates to an arrangement for controlling two drive units which interact with one another, one of which consists of a hydraulically driven motor (2). This forms part of a hydraulic system in which hydraulic fluid under pressure forms a main flow through a main duct (1) in which the motor is connected. The motor drives a varying load, and one or more valves (6, 7) control the hydraulic fluid flow through the motor on the one hand during operation and on the other hand for starting and stopping of the motor. One of the valves consists of a flow control valve (7) for flow control of the hydraulic fluid flow through the motor. The second drive unit (37) performs a working movement which, under the action of hydraulic flow under pressure, influences the loading of the motor. The flow of the hydraulic fluid to/from the second drive unit is controlled in a coordinated way with the control of the flow through the motor.

Abstract: The present invention relates to a device for reducing energy losses in a machinery unit (1), having at least one part (4) which is arranged to rotate in fluid about a rotation axis (6) in a substantially closed chamber (3) delimited in the radially outward direction by means of a wall (18) extending around the rotation axis. The wall (18) has a radially inward facing wall surface (10) extending wholly or partially around the revolution, which wall surface is highly smooth and extends close to, but with an interspace (14) to the radially outer surface which is generated around the revolution by the rotary part (4). The interspace is suited to minimizing the rotating fluid volume and, at the same time, maintaining necessary width for a boundary layer in the fluid between the generated surface and the wall surface.