The United States of America as Represented by the Administrator of the U.S. Environmental Protection Agency

The United States of America as Represented by the Administrator of the

U.S. Environmental Protection Agency

The Government of the United States of America

United States Environmental Protection Agency

Government of the United States of America, as Represented by the Administrator of the U.S. Environmental Protection Agency

Charles L Gray, Jr

Karl H Hellman

Matthew J Brusstar

Daniel W Barba

David James Haugen

Andrew James Moskalik

Mark Stuhldreher

Michael J Safoutin

David K Gill

Craig Douglas Moffat

Kevin Berent Fuqua

Anthony Tesoriero

Ruonan Sun

James G Bryson

Ronald M Schaefer

Keven Berent Fuqua

Michael Prince

Fakhri J Hamady

Andrew J Moskalik

Fail-safe methods for utilizing an over-center pump/motor in a hydraulic hybrid vehicle are disclosed. A high-pressure fluid shutoff valve and an optional electrically or manually operated valve are additionally provided as means to ensure disconnection of the high pressure source in the event of a failure. Displacement stroke position and pressure differentials across the pump/motor are continually monitored. On detection of various modes of failure or irregularity in control of displacement, actions are taken including any of: the high pressure and low pressure accumulators are shut off automatically or manually, a check valve between the high and low pressure ports of the pump/motor is activated, and a small amount of pressurized fluid is released from the high pressure circuit to depressurize the captive fluid. Safe startup and shutdown procedures are also specified. The system provides for safe operation of a hydraulic hybrid vehicle that includes an engine pump and drive motor, at least one of which operates over-center. The system optionally provides a displacement control valve that is controlled by feedback from an actuator or displacement position sensor and that on loss of electric power to the displacement control valve will cause the controlled pump/motor to stroke to a zero displacement position.

Methods for safe operation of hydraulic hybrid vehicles with over-center pump/motors

A rotating group of a bent-axis axial piston pump/motor is assembled as a subassembly with a removable stabilizing component that holds together and compresses the subassembly while it is outside of the pump/motor case. A yoke that carries a permanent or attachable back plate is installed in the case and positioned aside to allow clearance for installation of the rotating group. After the rotating group is installed, the yoke is moved back into proximity with the barrel, the stabilizing component is removed, and the remaining connections are completed.

Method for assembling a bent-axis pump/motor

To reduce emissions at higher engine loads and speeds, methanol fuel is port-injected with charge-air into a diesel engine, and diesel fuel is then direct-injected to initiate combustion. The charge-air has a reduced oxygen concentration sufficient to prevent pre-ignition of the methanol prior to injection of the diesel fuel, and to reduce NOx formation. At low engine speeds and loads, the engine may run on diesel fuel alone.

Low temperature dual fuel combustion utilizing diesel and methanol fuels

A drive module for a hydraulic hybrid vehicle includes two variable displacement over-center bent-axis hydraulic pump/motors with respective yokes that reside and pivot within a common fluid-filled case. The cylinder barrel of each pump/motor is connected to high pressure through fluid-conducting yoke legs, and is connected to low pressure through the fluid-filled case, which is connected by a port to a low pressure source. As a drivetrain for a vehicle, one pump/motor acts primarily as a pump driven by an engine and the other pump/motor acts primarily as a motor to propel the vehicle. A removable support structure facilitates installation to a variety of vehicle chassis.

Modular hydraulic hybrid drivetrain

A hydraulic hybrid vehicle includes elements such as a hydraulic pump driven by an internal combustion engine and arranged to draw in low pressure fluid and pump the fluid at high pressure to an accumulator. A hydraulic motor is powered by the pressurized fluid. Safety processes are provided for detecting and addressing a number of conditions that may arise in the operation of the hydraulic hybrid vehicle, including an initialization procedure for start-up of the vehicle, a shut-down procedure, and procedures for detecting and responding to failure of the pump or motor, internal and external fluid leaks, and non-responsive actuation and mode control systems.

Hydraulic hybrid vehicle method of safe operation

A hydraulic brake system includes a piston that separates a first pressure chamber from a second pressure chamber of a cylinder bore. A valve within a piston bore is movable between three positions. In the first position, the first and second pressure chambers are in fluid communication with a low-pressure fluid supply; in the second position, the second pressure chamber is isolated from the first pressure chamber and the low-pressure fluid supply; in the third position, a high-pressure fluid supply is in fluid communication with the second pressure chamber, allowing high-pressure fluid to flow into the second pressure chamber. High pressure in the second pressure chamber moves the boost piston, applying boosted braking pressure to a vehicle brake. Pressure in the second chamber against a surface of the valve biases the valve toward the first position. An accumulator stores pressurized fluid and provides the high-pressure fluid supply, enabling on-demand brake boosting force during engine-off operation of a hybrid vehicle.

On-demand power brake system and method

A turbocharged engine system is configured to vaporize methanol using heat from exhaust gases and uses the vaporized methanol to drive the engine's turbocharger. The methanol may also be dissociated into hydrogen and carbon monoxide. After passing through the turbocharger, the vapor is injected into the engine by port injection. By selective timing of exhaust valves, the exhaust gases are separated into two streams, a first stream comprising gases ejected during exhaust blowdown, and a second stream of gases ejected during the remainder of the engine's exhaust stroke. The blowdown gases are employed to drive a separate turbine of the turbocharger.

Efficiency turbocharged engine system with bottoming cycle, and method of operation

A turbocharger system includes first and second turbines arranged such that exhaust gas passes through the first turbine then the second turbine. A bypass channel is configured such that exhaust gas entering the channel passes only through the second turbine. A valve positioned in the bypass channel regulates the flow of gas therethrough. The valve accelerates a stream of gas and focuses the stream toward the second turbine such that a large part of the added velocity of the stream is preserved as it enters the second turbine. Operation of the valve may be controlled so as to maintain the valve in a closed position while exhaust gas pressure above the first turbine pressure is below a first threshold, to progressively open the valve as the pressure increases above the first threshold, and to maintain the valve in a full-open position while the pressure is above a second threshold.

Efficient bypass valve for multi-stage turbocharging system

A method for operating a series hybrid vehicle is provided, in which an engine generates secondary power that is either stored or used as direct input energy by a secondary power source to provide motive power to the vehicle. Regenerative braking is used to convert kinetic energy of the vehicle into secondary energy, which is also stored. When the vehicle driver makes a power demand, the secondary power source is powered by secondary energy from an energy storage device, direct input energy generated by the engine, or both, depending on the amount of stored secondary energy in combination with vehicle speed. When in use, the power level at which the engine is operated is also determined on the basis of available stored energy and vehicle speed. At higher vehicle speeds, the amount of stored energy is allowed to be depleted in order to increase the available storage capacity for regenerative braking.

Methods of operating a series hybrid vehicle

A hydraulic manifold has features adapted to the needs of hybrid vehicle applications. In one embodiment, multifunction valves selectively regulate fluid flow among primary and auxiliary flow paths. A normally closed butterfly valve is biased by a relatively small secondary biasing force against rotation in first and second (opposite) directions, and by a relatively large principal biasing force against rotation in the first direction past a transitional angular position at which the principal biasing force takes effect. An actuator selectively controls the transitional angular position and the magnitude of the principal biasing force. In the first direction, flow must overcome only the secondary biasing force to pass the valve. In the second direction, any flow sufficient to overcome the secondary biasing force but not the principal biasing force will divide into a first flow passing the valve and a second flow induced to enter an auxiliary path upstream. Additional flow causing the principal biasing force to additionally be overcome will substantially pass the valve as part of the first flow. This and other embodiments provide a manifold that is controllable to allocate flow among primary and auxiliary paths while remaining responsive to sudden large changes in flow independently of immediate control response.

Hydraulic circuit and manifold with multifunction valve

A fail-safe system for a hybrid vehicle employing an over-center variable-displacement hydraulic motor includes an actuator configured to stroke the motor to a zero angle if each of two control ports is supplied with fluid at an equal pressure. A control valve is configured, in the event of loss of power to the valve, to default to a position in which high-pressure fluid is supplied to both control ports. A pilot-controlled check valve is coupled between high- and low-pressure ports of the motor such that, during normal operation, passage of fluid through the check valve from the high-pressure port to the low-pressure port is checked, while passage of fluid through the check valve from the second port to the first port is enabled. When the pilot control is activated, passage of fluid in the opposite direction is also enabled.

Safe over-center pump/motor

In a bent axis hydraulic machine, a back plate and cylinder barrel vary in distance from a drive plate as a stroke angle of the cylinder barrel changes, thereby minimizing unswept fluid volume in the cylinders of the barrel at any stroke angle. Distance is controlled by one or more rollers, engaging respective tracks that define a profile of contact that determines the distance as a function of the stroke angle. Telescoping fluid supply channels are employed to maintain a fluid supply to the cylinder barrel as the distance changes.

Variable length bent-axis pump/motor

In a series hybrid vehicle, a system for determining a shift schedule for shifting a multi-gear transmission connected to a drive means is disclosed. A vehicle operator selects among a plurality of shift styles respectively representing a plurality of shift schedules variously optimized for performance or fuel economy. A performance-based shift schedule favors providing maximum power to the road by starting at the first (lowest) gear when accelerating from a stop and utilizing all available gears of the transmission. An economy based shift schedule favors energy efficiency by skipping the first gear and optionally one or more higher-numbered gears in order to bias operation of the drive means toward lower speeds and higher torque output while reducing shift frequency. The invention provides for maintaining the number of gear ratio choices provided by a transmission having relatively many distinct gear ratios, while providing for reduced frequency of shifting and driver choice of a shift schedule favoring either performance or economy.

Methods for optimizing the efficiency of a series hybrid vehicle with multi-gear transmission

A variable displacement engine comprises two engine modules fed from a common fuel source, each engine module having an individual crankshaft. The first engine module has a high compression ratio (e.g., greater than 13:1), while the second module has a typical compression ratio for a gasoline engine (e.g., between 9:1 and 11:1). In one embodiment, the first engine module operates through high efficiency optimized alcohol fuel combustion when the fuel content exceeds a minimum alcohol content. In an alternative embodiment, the first engine module operates at high efficiency through gasoline HCCI combustion when conditions permit. When operating conditions do not permit the first engine module to operate at high efficiency, the second engine module operates as the primary engine module, with the first engine module available to provide supplemental power (at less than optimal efficiency) if needed to meet driver demand.

Two mode dual crankshaft engine

A hydraulic machine includes first and second opposing motors. Displacement of the first and second motors is controlled such that while the sum of the displacements of the first and second motors is below a threshold, the displacement of the first motor is substantially equal to the sum, and the displacement of the second motor is substantially equal to zero. While the sum of the displacements is above the threshold, the displacement of the first motor may be substantially equal to the displacement of the second motor, either as a displacement percentage or as a displacement volume. The first motor may be equal in capacity, or smaller than the second motor.

Growing community of inventors

Pinckney, MI, United States of America

Charles L Gray, Jr