Purdue Research Foundation

Cnh America LLC

Cnh Baumaschinen Gmbh

Monika Marianne Ivantysynova

Christopher Alan Williamson

Jürgen Weber

Edward C Hughes, Iv

Joshua D Zimmerman

Blake Adam Carl

Kyle Richard Williams

Robert Rahmfeld

Erik Lautner

Lizhi Shang

Meike H Ernst

Jonathan Baker

Jörg Grabbel

A hydraulic propulsion system is disclosed which includes an input interface configured to receive mechanical power from a power source, a pressure source comprising one or more fixed or variable displacement pumps coupled to the input interface and adaptable to convert mechanical power to hydraulic power and controlling outlet pressure of the pressure source (system pressure), one or more variable displacement motors coupled to the pressure source via a corresponding high-pressure line configured to be mechanically coupled to one or more aerodynamic rotors of an aircraft and comprising a closed loop speed control arrangement in response to a commanded rotor speed, and a controller configured to control the speed of one or more variable displacement motors by providing a control signal for controlling the system pressure.

Aviation hydraulic propulsion system utilizing secondary controlled drives

Positive displacement machines and methods therefor capable of increasing a load-carrying capacity of a piston-cylinder lubrication interface of positive displacement machines having a cylinder block, a cylindrical bore defined in the cylinder block, a piston reciprocably disposed within the cylindrical bore, and a working fluid within the piston-cylinder lubrication interface to provide a load-bearing function between the piston and the bore wall of the cylinder bore. The method includes providing at least one circumferential groove on a bore wall of the cylindrical bore within the piston-cylinder lubrication interface having an opening facing the piston and that is in fluidic communication with the piston-cylinder lubrication interface so as to contain a portion of the working fluid, and operating the positive displacement machine such that the working fluid enters the cylindrical groove and promotes hydrostatic balancing of pressure of the working fluid within the piston-cylinder lubrication interface.

Positive displacement machines and methods of increasing load-carrying capacities thereof

A machine and method for a hydrostatic axial sliding bearing that has bearing and sealing functions and is capable of exhibiting reduced power losses. The hydrostatic axial sliding bearing of the machine is defined by axial sliding bearing surfaces that are separated by a fluid film and adapted for movement relative to each other during operation of the machine. The machine has first and second elements that define a first and a second of the axial sliding bearing surfaces. In combination, the first and second axial sliding bearing surfaces function as bearing and sealing surfaces for the hydrostatic axial sliding bearing. The machine is adapted so that the first and second axial sliding bearing surfaces move relative to each other in a first direction of motion, and at least the second axial sliding bearing surface has a surface profile with an oscillatory waveform in the first direction of motion.

Axial sliding bearing and method of reducing power losses thereof

A system and method for performing a floating function in an earthmoving implement of an earthmoving machine without physically connecting chambers within a hydraulic actuator that is adapted to raise and lower the earthmoving implement. The system includes a device for delivering a pressurized fluid to and receiving pressurized fluid from the actuator, a valve for compensating for differences in volume between chambers of the actuator, and an electronic control circuit that includes electronic sensors for sensing the pressures in the chambers of the actuator, and a controller for receiving outputs of the sensors. The controller calculates an amount of the pressurized fluid that, when delivered to or received from the actuator, achieves a substantially constant pressures in the chambers of the actuator and enables the earthmoving implement to float regardless of motion of the actuator.

System and method for enabling floating of earthmoving implements

Power split drive (PSD) transmissions capable of energy recovery and suitable for use in automotive applications. Each PSD transmission includes a mechanical transmission system for mechanically transmitting mechanical power between a rotatable input shaft and a rotatable output shaft, and a hydraulic transmission system containing a fluid for hydraulically transmitting hydraulic power between the input shaft and the output shaft, and at least a third shaft operatively interconnected to one of the mechanical and hydraulic transmission systems. The hydraulic transmission system is operatively coupled by at least a first planetary gear train to the mechanical transmission system. According to the invention, the PSD further comprises means operatively associated with at least one of the mechanical and hydraulic transmission systems for storing and releasing energy within the PSD transmission, the energy storing and releasing means comprising a flywheel or an accumulator or a combination thereof.

Power split transmission with energy recovery

A system and method for controlling the movement of an implement of an earthmoving machine. The system includes a hydraulic actuator adapted to move the implement. A variable displacement pump is coupled to the actuator for delivering a pressurized fluid to and receiving pressurized fluid from chambers within the actuator. A sensor generates an output based on the position of the actuator's piston or piston rod, and a controller controls the displacement of the variable displacement pump in response to the output of the sensor by executing an algorithm to reduce the flow rate of the fluid to and from the actuator's chambers and thereby reduce the velocity of the piston as it approaches an end of a piston stroke thereof and prevent the piston from impacting the actuator at the end of the piston stroke.

System and method for pump-controlled cylinder cushioning

A displacement-controlled hydraulic system for installation on a multi-function machine, and multi-function machines equipped with the hydraulic system and having devices for propelling the machine, at least a first implement, and multiple actuators that perform multiple functions of the machine. The multiple actuators include first actuators that control the first implement and second actuators that control the propelling devices. The hydraulic system comprises multiple pumps for controlling the first actuators and optionally the second actuators, and valves that enable at least one of the pumps to sequentially control two of the multiple actuators and a corresponding two functions of the multiple functions performed thereby. None of the pumps sequentially controls the second actuators in combination with any of the first actuators.

Displacement-controlled hydraulic system for multi-function machines

A system for automatically controlling the position and level of an earthmoving implement on an earthmoving machine. The system includes at least one hydraulic actuator adapted to raise and lower the earthmoving implement, a device for delivering a pressurized fluid to and receiving pressurized fluid from the actuator, and an electronic control circuit that includes electronic sensors for sensing the absolute orientation of the machine and the position of the actuator, and a controller for receiving outputs of the sensors, calculating an amount of the pressurized fluid that must be delivered to or received from the actuator to achieve a desired position for the earthmoving implement, and control the delivering-receiving device to deliver or receive the amount of the pressurized fluid to achieve the desired position for the earthmoving implement.

System and method for blade level control of earthmoving machines

A hydraulic steering device for vehicles, especially construction machines, with which is simple and robust mechanically and can be precisely controlled, without possessing the disadvantages of the current state of the art. A hydraulic swivelling motor for producing the steering motion, which is connected to a variable flow rate pump with reversal of its direction of delivery.

Hydraulic steering device for vehicles

The invention concerns a hydraulic system for linear drives with a differential cylinder, in particular for mobile machines which through the use of displacement-control of the drives avoids the many and diverse disadvantages of the state of the art and renders possible a precise and energy-efficient control of linear drives with differential cylinders, and which is economical and simple to maintain and which can be well integrated into the total hydraulic system of such machines.

Hydraulic system for linear drives controlled by a displacer element

A method is described for controlling a hydraulic system, particularly of mobile working machine, with at least one internal combustion engine driving at least one hydraulic pump with adjustable volumetric displacement and possibly additional fixed-displacement pumps.

Method for controlling a hydraulic system of a mobile working machine

With a hydrostatic multi-motor drive unit with a least two hydraulic motors acting upon a common load, a solution should be created, with which a further operating range is covered by the use of several motors and at the same time a simple as possible and problem free coupling of the motors is assured. Furthermore, a method for controlling the drive unit is indicated, which permits continuous transitions between the different operating ranges. This is achieved in that the motors () are connected with each other through at least one freewheel device (), in which the motor () arranged after the freewheel device has a variable displacement volume.

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Lafayette, IN, United States of America

Monika Marianne Ivantysynova