Caterpillar Inc.

Perkins Engines Company Limited

Steven Spencer

Michael David Beyer

Adam Martin Nackers

Rustin Glenn Metzger

Brian Douglas Hoff

Michael G Cronin

Mark E Rettig

Christopher Michael Ruemelin

Santosh Ancha

Matthew Mauritzson

Chris Rustu Cesur

Kevin Stutzman

A mechanical swing brake variable control system for an earth-moving machine including an upper revolving car body with swing components mounted on the upper revolving car body, a lower traveling car body with traction components mounted on the lower traveling car body, and a mechanical service brake interconnected with the upper and lower car bodies, controls relative rotation between the upper and lower car bodies. A pressure control device controls a variable pressure applied to the mechanical service brake to vary an amount of swing drive holding torque. An electronic controller monitors and processes signals received from sensors associated with the swing components and machine operator commands, and variably controls the amount of holding torque exerted on the upper revolving car body using the mechanical service brake as a function of one or more of machine roll angle, operational configuration of the swing components, inertial mass of the swing components, and machine operator commands.

Swing motion variable control system

A hydraulic system may include a first actuator to control a first linkage member, a second actuator to control a second linkage member, a first primary hydraulic circuit and a first secondary hydraulic circuit that include the first actuator, a second primary hydraulic circuit and a second secondary hydraulic circuit that include the second actuator, a first pump to cause fluid to flow through the first primary hydraulic circuit and the second secondary hydraulic circuit, a second pump to cause fluid to flow through the second primary hydraulic circuit and the first secondary hydraulic circuit, and a controller. The controller may be configured to determine that an operator assistance mode is enabled, and cause closing of a first valve that controls fluid flow through the first secondary hydraulic circuit and a second valve that controls fluid flow through the second secondary hydraulic circuit.

Control of a hydraulic system

According to the present invention, there is provided a method of reducing output torque deficits during the launch of a vehicle having a continuously variable transmission, wherein the variator has an input connected to a prime mover and an output. The method comprises the steps of determining a rate of change of ratio in the transmission, and predicting a required motor speed ratio rate of change value of the variator on the basis of: (i) the determined rate of change of ratio in the transmission, and (ii) the configuration of the transmission. The speed of the variator output is adjusted so as to achieve the required motor speed ratio rate of change value.

Method of reducing output torque deficits during launch of a continuously variable transmission

A launch control method is provided for a vehicle having an accelerator, a brake and a continuously variable transmission (CVT). The method comprises determining: (i) a braking torque set by a vehicle operator by pressing a brake pedal of the vehicle; and (ii) a holding torque required to hold the vehicle in a stationary position. The method also determines that the operator has released the brake pedal. The brake is released whilst engaging a launch clutch of the CVT, wherein the launch clutch is engaged by increasing a clutch engagement pressure at a first pressure ramp rate, such that the sum of the braking torque and a clutch torque of the clutch remains equal to the holding torque. An acceleration torque requested by the operator via the accelerator is determined. The clutch engagement pressure is increased at a second pressure ramp rate when it is determined that the braking torque is substantially zero, such that the clutch torque is increased by the acceleration torque. A fixed minimum pressure ramp rate is stored, wherein the minimum pressure ramp rate increases the clutch engagement pressure towards a maximum engagement pressure. The current pressure ramp rate is compared with the minimum pressure ramp rate, and the clutch engagement pressure is switched to the minimum pressure ramp rate if the current pressure ramp rate is less than the minimum pressure ramp rate.

Launch control method for a vehicle

A transmission system is disclosed for use with an engine. The transmission system may have a plurality of gear sets, an input member configured to be powered by the engine and to drive the plurality of gear sets, an output member driven by the plurality of gear sets, and at least one clutch configured to selectively engage select gears of the plurality of gear sets. The transmission system may also have a controller in communication with the engine. The controller may be configured to generate an estimated temperature of the at least one clutch. The controller may further be configured to selectively derate the engine based on the estimated temperature.

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Germantown Hills, IL, United States of America

Steven Spencer