Abstract:
Actuators and corresponding methods and systems for controlling such actuators offer efficient, fast, flexible control with large forces. In an exemplary embodiment, an fluid actuator includes a housing having first and second fluid ports, an actuation cylinder in the housing defining a longitudinal axis and having first and second ends in first and second directions, an actuation piston in the cylinder with first and second surfaces moveable along the longitudinal axis, a spring subsystem biasing the actuation piston to a neutral position, a first fluid space defined by the first end of the actuation cylinder and the first surface of the actuation piston, and a second fluid space defined by the second end of the actuation cylinder and the second surface of the actuation piston. A first flow mechanism controls fluid communication between the first fluid space and the first port, whereas a second flow mechanism controls fluid communication between the second fluid space and the second port. The first and second flow mechanisms are substantially restricted through two integrated snubbing mechanisms when the actuation piston approaches the first and second direction ends of its travel, respectively. In addition to a differential fluid force on the actuation piston, there is a centering or returning spring force available to help open the engine valve against the high cross-over passage pressure, without the need for the fluid actuation system to be bulky and consume too much energy.
Abstract:
The present invention provides a motorcycle having a valve-operating mechanism for actuating a valve which opens and closes a combustion chamber of an internal combustion engine. The valve-operating mechanism includes a biasing means for biasing the valve toward a valve closing direction and a drive means for driving the valve toward the valve opening direction against the biasing means, the biasing means is a gas spring formed by filling a gas spring chamber with compressible gas, and a compressed-gas container for supplying the compressible gas is connected to the gas spring chamber, and the compressed-gas container is disposed in an outermost line of body components of the motorcycle except for the compressed-gas container when the motorcycle is viewed from above.
Abstract:
An engine has a rotatable crankshaft. A compression piston is received within a compression cylinder and operatively connected to the crankshaft such that the compression piston reciprocates through an intake stroke and a compression stroke during a single rotation of the crankshaft. An expansion piston is received within an expansion cylinder and operatively connected to the crankshaft such that the expansion piston reciprocates through an expansion stroke and an exhaust stroke during a single rotation of the crankshaft. A crossover passage interconnects the compression and expansion cylinders. The crossover passage includes a crossover compression valve and a crossover expansion valve defining a pressure chamber therebetween. A fuel injector is disposed in the pressure chamber of the crossover passage. Fuel injection from the fuel injector into the crossover passage is timed to occur entirely during the compression stroke of the compression piston.
Abstract:
A split-cycle engine includes separate compression and expansion cylinders connected by a crossover passage. Crossover compression and expansion valves define a pressure chamber between them in the crossover passage for storing pressurized gas prior to timed delivery into the expansion cylinder. A fuel-air mixture is delivered into the expansion cylinder for ignition and expansion, developing power. One or more ignition sources, such as spark plugs, are positioned to encourage rapid combustion after ignition in the expansion cylinder but far enough from the crossover expansion valve(s) to prevent burning gases from reaching the crossover expansion valves before they are substantially closed to avoid entry of burning gas therein. A “safe distance” (“S”) between the ignition source and an opening of the crossover expansion valve is expressed by the function: S (mm)=combustion speed (mm/crank angle degree)×crank angle degrees from ignition to crossover expansion valve closing.
Abstract:
The invention is concerned with a method of deriving mechanical work from a combustion gas in internal combustion engines and reciprocating internal combustion engines for carrying out the method. The invention includes methods and apparatuses for managing combustion charge densities, temperatures, pressures and turbulence in order to produce a true mastery within the power cylinder in order to increase fuel economy, power, and torque while minimizing polluting emissions. In its preferred embodiments, the method includes the steps of (i) producing an air charge, (ii) controlling the temperature, density and pressure of the air charge, (iii) transferring the air charge to a power cylinder of the engine such that an air charge having a weight and density selected from a range of weight and density levels ranging from below atmospheric weight and density to heavier-than-atmospheric weight and density is introduced into the power cylinder, and (iv) then compressing the air charge at a lower-than-normal compression ratio, (v) causing a pre-determined quantity of charge-air and fuel to produce a combustible mixture, (vi) causing the mixture to be ignited within the power cylinder, and (vii) allowing the combustion gas to expand against a piston operable in the power cylinders with the expansion ratio of the power cylinders being substantially greater than the compression ratio of the power cylinders of the engine. In addition to other advantages, the invented method is capable of producing mean effective cylinder pressures ranging from lower-than-normal to higher-than-normal. In the preferred embodiments, the mean effective cylinder pressure is selectively variable (and selectively varied) throughout the mentioned range during the operation of the engine. In an alternate embodiment related to constant speed-constant load operation, the mean effective cylinder pressure is selected from the range and the engine is configured, in accordance with the present invention, such that the mean effective cylinder pressure range is limited, being varied only in the amount required for producing the power, torque and speed of the duty cycle for which the engine is designed.
Abstract:
The invention relates to an internal combustion engine provided with at least one cylinder and comprising a fuel injection system, an intake air charging system for supplying air under pressure to an air intake manifold, a controller for controlling the fuel injection system, a spark ignition system and the intake air charger. The control unit is adapted to switch the engine from a first combustion mode using a higher manifold pressure to a second combustion mode using a lower manifold pressure, and further adapted to control the intake air charging system to cause a surge in the intake air, in order to evacuate the higher manifold pressure. The invention further relates to a method for controlling the internal combustion engine and a vehicle provided with such an internal combustion engine.
Abstract:
A valve gear includes a housing provided with a passage, a valve member arranged within the housing, which is movable between a first, closed position, in which the passage is closed, and a second, open position, a piston connected to the valve member, which can oscillate in an at least substantially closed piston chamber, and a locking device which are capable of holding the valve member periodically in the closed position. The piston chamber is provided with at least three closable openings, which may each be in communication with a gas pressure device. The first opening and the second opening are each in communication with another part of the piston chamber separated therefrom by the piston, and which are open when the valve member is held in the closed position, and wherein the third opening is open during movement of the piston.
Abstract:
A bellows unit and a compression coil spring are located in series with each other between a first member and a second member. The bellows unit has an inner bellows, an outer bellows, and first and second end members. A sealed space is defined in the bellows unit. A compressed gas is sealed in the sealed space. The bellows unit is caused to extend and contract in the direction of an axis by the compressed gas. The sealed space contains an uncompressible liquid that can exchange heat with the gas. The liquid is an example of a heat exchange material.
Abstract:
The invention relates to an internal combustion engine provided with at least one cylinder and comprising a fuel injection system, an intake air charging system for supplying air under pressure to an air intake manifold, a controller for controlling the fuel injection system, a spark ignition system and the intake air charger. The control unit is adapted to switch the engine from a first combustion mode using a higher manifold pressure to a second combustion mode using a lower manifold pressure, and further adapted to control the intake air charging system to cause a surge in the intake air, in order to evacuate the higher manifold pressure. The invention further relates to a method for controlling the internal combustion engine and a vehicle provided with such an internal combustion engine.
Abstract:
A valve spring mechanism is provided which is suitable for use with the inlet or exhaust valves of an internal combustion engine, and includes a valve head and a valve stem. The mechanism includes a piston/cylinder arrangement in which the cylinder surrounds a portion of the valve stem to define a chamber. The piston is slidable and sealingly mounted on the valve stem. The mechanism also has force transmitting means for transmitting the force produced on the piston by gas pressure within the chamber to the valve stem, and a spring operating on the piston and the stem of the valve for applying a force to the stem tending to close the valve in the event of failure of chamber gas pressure. The spring is positioned to maintain it in a compressed condition during normal operation of the mechanism as a result of gas pressure within the chamber.