Caterpillar Inc.

Caterpillar Sarl

William Christopher Swick

David P Smith

Paul Anthony Dvorak

Paul John Cairns

Christopher Mark Elliott

Jerry D Marr

Reid W Waitt

Christopher J Demick

Christopher Erik Bright

Gregory August Epplin

Arick Matthew Bakken

Christopher W Pruess

Arick M Bakken

Peter R Hildner

David D Henderson

Friedrich Konrad Diecke

Clint W Paulson

Vincent Guyard

Niall Mc Namee

Paul Cairns

An axial piston pump controller for an axial piston pump having a fixed valve plate and a variable displacement is provided. The axial piston pump controller is configured to determine a displacement of the axial piston pump, and to calculate a pump displacement control current to be supplied to the axial piston pump to control the displacement of the axial piston pump. Calculating the pump displacement control current comprises calculating a nominal value for the pump displacement control current based on a rotational speed of the axial piston pump, calculating a pump stiffness adjustment factor based on a pump stiffness control map having as inputs: an output pressure of the axial piston pump; and the estimated pump displacement, and calculating the pump displacement control current to be supplied to the axial piston pump based on the nominal value and the pump stiffness adjustment factor. The controller is further configured to output an instruction to output the calculated pump displacement control current to the axial piston pump in order to control the displacement of the axial piston pump.

Axial piston pump controller

The hydraulic braking or steering system of a vehicle driven by a hydraulic motor is provided with a secondary supply of hydraulic pressure in the event of failure of the primary supply to the system. The secondary supply is generated by the hydraulic motor when ground-driven by the momentum of the moving vehicle.

Hydrostatically driven vehicle with a secondary braking or steering supply

When the driving force between a driven wheel of a wheel and the surface on which the vehicle is travelling exceeds the available traction, wheel slippage may occur. Wheel slippage may result in a loss of control of the vehicle. The present disclosure may facilitate the control of drive power sent to a driven wheel of a vehicle from consideration of a torque setting and a speed of the vehicle.

Method and apparatus for controlling the drive power of a vehicle

A closed hydrostatic circuit with variable charge and variable flushing systems is disclosed. A variable displacement charge pump is configured to supply charge fluid and pilot control fluid to the hydrostatic circuit. An electronically controlled pressure regulating valve is in communication with an output of the charge pump and is linked to a controller. When the hydrostatic control system detects a high hydraulic temperature condition, the electronically controlled pressure regulating valve, that is in communication with an output of the charge pump and that is linked to a controller, increases the charge pump flow. A bidirectional variable displacement hydrostatic motor is connected in parallel to two input/output lines. A flush valve is in communication with the hydrostatic motor and both input/output lines. The flush valve and hydrostatic motor are both in communication with the flush orifice and a flush relief valve. When the pressure regulating valve causes the charge pump to operate at or near a full capacity, fluid exits the flush valve and passes through both the flush orifice and the flush relief valve. In contrast, when the pressure regulating valve causes the charge pump to operate at a lower or near minimum capacity, fluid exits the flush valve and passes through the flush orifice only without passing through the flush relief valve.

Hydrostatic circuits with variable charge and variable flushing systems

A machine, including a hydraulic pump and one or more hydraulic implements connected to the hydraulic pump. The machine may also include a hydraulic motor connected to the hydraulic pump and one or more propulsion devices. Additionally, the machine may include drive-system controls operable to selectively cause the hydraulic motor to supply power to one or more of the propulsion devices.

Drive system for a machine

A protection system is provided for a work machine with a power source. At least one sensor is configured to monitor a fluid parameter of a work machine system external to the power source. The sensor is further configured to produce a signal indicative of a value of the fluid parameter. The component protection system has a control module in communication with the at least one sensor, the control module being configured to derate a power source output base upon the value of the fluid parameter.

Power source derating component protection system

An improved landscape rake including a rotatably operable rake mechanism for performing a raking function, a bucket for receiving material raked by the rake mechanism, and a fluid actuator connected to the rake mechanism operable for moving the rake mechanism relative to the bucket, the fluid actuator having a first port adapted for connection to a source of pressurized fluid for receiving the pressurized fluid therefrom for moving the rake mechanism to a position proximal to the bucket and a second port adapted for connection via a fluid path to a fluid receiver for discharging fluid thereto, the improvement including a fluid control system for the fluid actuator including a second fluid path connecting the first port of the fluid actuator with the first named fluid path and a valve disposed in the second fluid path operable for allowing fluid flow therethrough from the first port to the first named fluid path while preventing fluid flow from the first named fluid path to the first port to allow the rake mechanism to float when in the position proximal to the bucket.

Landscape rake with fluid controlled float capability

A rotomolded hydraulic oil tank includes an integral dividing baffle which strengthens the tank structure, and diverts and slows returning oil for better air removal and oil mixing. This occurs by positioning the dividing baffle so that the top of the baffle is just below the oil level in the tank so that returning oil must flow a greater distance around the baffle at a reduced velocity thereby increasing the time the oil is in the tank before exiting the tank through the tank suction. The lower velocity of the oil and the increased passage time allows air in the returning oil more time to float to the surface of the oil in the tank.

Hydraulic oil tank with integral baffle

A braking apparatus includes a brake cylinder having a first opening and a second opening defined therein. The braking apparatus also includes a movable member located within the brake cylinder which has a channel defined therein. The braking apparatus further includes a brake chamber in fluid communication with the brake cylinder. The brake chamber has a brake member located therein. The movable member is moved to a position which allows fluid communication between the first and second opening through the channel thus creating a subsequent pressure drop in the system. The pressure drop causes a hydrostatic transmission in fluid communication with the brake apparatus to be neutralized by a responsive displacement of a pump and motor which reduces the travel speed of a vehicle. Additionally, the movement of the movable member causes a brake member to be forced against a moving object.

Braking apparatus and method for use with a moving vehicle

Hydrostatic transmissions are useful for propelling a machine to do work and travel relative to the ground. In performing work functions and during travel it is desirable to adjust machine speed to aid in handling the machine. The subject hydrostatic transmission control system includes a infinitely adjustable creeper hand lever which can be moved to any desired position and be maintained in the selected position until moved by the operator. A spring biased inching pedal can be used in combination with the creeper lever to further adjust the machine speed. This arrangement of components provides a control system for the hydrostatic transmission which can be adjusted and maintained at a desired setting.

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Raleigh, NC, United States of America

William Christopher Swick