A turbine, driven from the exhaust gases of the internal combustion engine, and having a speed-flow volume and pressure differential characteristic which is only little speed-dependent drives a Foettinger hydrodynamic torque converter which has a pump element which is highly speed-dependent, a radial flow turbine which is only little speed-dependent, and a guide vane element, the radial flow turbine of the fluid coupling driving a displacement-type rotary compressor so that, even at low engine speeds of the internal combustion engine, substantial supercharging effect can be obtained, whereas, as the engine speed increases, less supercharging effect will be obtained so that the average cylinder pressure at low speeds will be increased of cylinder pressure and engine torque will increase with decreasing speed, keeping the output power constant over a wide range of engine-operating speeds.
The present invention combines an exhaust gas turbine, a supercharger and an accessory drive for an internal combustion engine in an automotive vehicle to provide instantly available maximum power for full throttle acceleration along with the recovery of energy from the exhaust gas to drive the engine accessories at a substantially constant speed independent of the engine speed.
An exhaust power recovery system for internal combustion engines. The engine exhaust gases drive a gas turbine that in turn drives a hydraulic turbine pump pressurizing a hydraulic fluid which then in turn is the driving source for a hydraulic motor which transmits power to the engine shaft. In a preferred embodiment for a turbocharged engine, the hydraulic fluid is also used as the drive fluid in a hydraulic supercharger system that provides additional supercharging at low engine speeds to supplement the exhaust driven turbocharging system. In this embodiment the pressurized hydraulic fluid for driving the supercharger hydraulic turbine is provided by a pump driven by the engine shaft. A hydraulic fluid control system is provided to match compressed air flow with engine needs. In this preferred embodiment more than enough energy is recovered from the exhaust gasses by the exhaust power recovery system to operate the hydraulic supercharger system. The horsepower of a 280 horsepower turbocharged diesel engine is increased by about 20 percent to about 335 horsepower. As to fuel efficiency, Applicant estimates that a cross country diesel truck operating 12 hours per day, 300 days per year will save between 6,000 and 10,000 pounds of fuel per year with substantial reductions in emitted pollutants.
Improved drives and controls for an exhaust gas turbocharger for an internal combustion engine in which the turbocharger is primarily driven by exhaust gases from the engine include an auxiliary hydraulic turbine which also has a driving connection to the turbocharger and which receives pressurized fluid from a fixed displacement pump to drive the turbine during certain operating conditions of the engine. The pump is connected to a rotary output shaft of the engine by means of a clutch member which selectively connects and disconnects the pump in response to a preselected operating characteristic of the engine. Such operating characteristic is selected from the group consisting of at least one of the engine speed, oil pressure, air manifold pressure, exhaust manifold pressure, and fueling rate characteristics of the engine. In a specific embodiment, the clutch is disconnected after the engine reaches a predetermined operating speed, as measured by a sensing unit or tachometer responsive directly to engine shaft speed, by sensing the pressure at which fluid is discharged from the pump and which corresponds to the preselected engine speed. In a preferred embodiment, the clutch control is also responsive to one of the operating characteristics of the engine for automatically disengaging the clutch in response to load conditions below a selected predetermined minimum, for example when the engine fuel demand rate is below 80 percent of the demand rate for maximum torque at a particular speed.
A supercharged internal combustion engine having an exhaust-driven turbocharger for supplying combustion air to the engine and auxiliary power means for additionally applying a driving force to the compressor under occasional and otherwise normally deficient combustion air conditions, to provide the desired amount of combustion air for proper combustion. The power means includes a hydraulic assist motor mechanically coupled with the turbocharger and a hydraulic pump connected by a fluid flow passageway with the motor and permanently coupled with a drive shaft of the engine. The pump is connected through a selector valve to the oil in the reservoir of the engine's crankcase or to the vapor chamber above the oil level in the reservoir or to the atmosphere. The selector valve may be manually controlled or automatically controlled by a sensor responsive to one or more of such engine conditions as manifold air pressure, engine speed, etc. The valve may also have a bleed passageway therein that connects with the oil reservoir when the pump is pumping vapor or air to assure adequate lubrication for the pump and, if need be, the hydraulic motor.
The invention relates to a method for optimizing engine braking in a drive unit, particularly used for motor vehicles, comprising an internal combustion engine consisting of a crankshaft, and an exhaust gas turbine which is connected to a crankshaft via a transfer device. A hydrodynamic coupling is arranged in the transfer device. The invention is characterized by the following features: in one operational state corresponding to braking operation with an engine brake, the exhaust gas is operated at a working point which is characterized by the maximum acceptable limiting speed n.sub.max-5 of the exhaust gas turbine at a minimum output moment M.sub.5 and in another operational state corresponding to the partial load operation or thrust operation, the exhaust gas turbine is operated at a working point which is characterized by a minimum speed n.sub.min5 and minimum receivable moment M.sub.min-5, wherein adjustment of both working points is carried out by the hydrodynamic coupling, such that it can be operated according to at least one characteristic whose transferable moment corresponds to the minimum outputtable or receivable moment M.sub.Min-5 of the exhaust gas turbine over a large part of the speed difference characterizing the slip range taking into account the multiplication of the transfer elements in the transfer device to the exhaust gas turbine.
