Powertrain and method for achieving low exhaust emission and high fuel economy operation of a combustion engine

Claim 1

A powertrain comprising: a combustion heat driven engine having a power output shaft, a continuously variable ratio transmission having a power input shaft coupled to said engine output shaft, control means for controlling the ratio of said transmission, means connected to said control means for supplying an operator input signal corresponding to the desired power output of said engine, and means for generating a signal related to the power output of said engine and for applying said generated signal to said control means; said control means facilitating unthrottled flow of a lean burn and substantially constant strength air-fuel mixture to said engine for combustion, whereby fuel economy is improved and combustion exhaust gas emissions of carbon monoxide and nitrogen oxides are reduced, and said control means adjusting the ratio of said transmission in response to a difference between said operator input signal and said generated signal to establish said desired engine power output by increasing or decreasing the load on the engine to respectively, decrease or increase the engine speed.

Claim 14

A method for operating a powertrain comprising: supplying an unthrottle flow of a lean burn and substantially constant strength air-fuel mixture for combustion to produce heat expansion cycles in the engine, continuously variable controlling of the number of said cycles which deliver energy to each equivalent revolution of a drive axle of the powertrain, to regulate the brake torque produced at said drive axle to a variable desired value, establishing a wide frequency range of heat expansion cycles by increasing or decreasing the load on the engine to respectively decrease or increase the engine speed, whereby the fuel economy of the powertrain is improved and the exhaust gas emissions of carbon monoxide and nitrogen oxides from said combustion are reduced.

Claim 15

A method for operating a powertrain comprising: supplying an unthrottle flow of a lean burn and substantially constant strength air-fuel mixture for combustion to produce heat expansion cycles in the engine, continuously variable controlling of the number of said cycles which deliver energy to each equivalent revolution of a drive axle of the powertrain, to regulate the brake torque produced at said drive axle to a variable desired value, establishing a wide frequency range of heat expansion cycles by increasing or decreasing the load on the engine to respectively decrease or increase the engine speed, whereby the fuel economy of the powertrain is improved and the exhaust gas emissions of carbon monoxide and nitrogen oxides from said combustion are reduced.

Claim 16

A method for operating a combustion engine having a power output shaft coupled to a power input shaft of a continuously variable ratio transmission comprising: adjusting the ratio of the transmission to regulate the brake torque produced at an output shaft of the transmission to a desired value, and supplying, an unthrottled flow of lean burn and substantially constant strength air-fuel mixture to the engine for combustion, to improve fuel economy and reduce combustion exhaust gas emissions of carbon monoxide and nitrogen oxides, establishing a wide power output range for the engine by increasing or decreasing the transmission ratio to change the load on the engine and respectively, decrease or increase the speed of the engine.

Claim 17

A method for operating a combustion engine having a power output shaft coupled to a power input shaft of a continuously variable ratio transmission comprising: adjusting the ratio of the transmission to regulate the brake torque produced at an output shaft of the transmission to a desired value, and supplying, an unthrottled flow of lean burn and substantially constant strength air-fuel mixture to the engine for combustion, to improve fuel economy and reduce combustion exhaust gas emissions of carbon monoxide and nitrogen oxides, establishing a wide power output range for the engine by increasing or decreasing the transmission ratio to change the load on the engine and respectively, decrease or increase the speed of the engine.

Claim 18

A method for operating a vehicle having a combustion engine and drive wheels for propelling the vehicle, comprising: providing a continuously variable ratio transmission between the engine and the drive wheels, producing a lean burn and substantially constant strength air-fuel mixture in a fuel metering system of the engine, operating said fuel metering system at wide open throttle, producing, a predetermined engine output power by adjusting the ratio of the transmission to increase or decrease the load on the engine to respectively decrease or increase the engine speed, said transmission providing a range of overall gear ratio between the engine and drive wheels to allow said wide open throttle production of said lean burn air-fuel mixture throughout substantially the entire range of operating conditions of the vehicle.

Claim 19

A method for operating a vehicle having a combustion engine and drive wheels for propelling the vehicle, comprising: providing a continuously variable ratio transmission between the engine and the drive wheels, producing a lean burn and substantially constant strength air-fuel mixture in a fuel metering system of the engine, operating said fuel metering system at wide open throttle, producing, a predetermined engine output power by adjusting the ratio of the transmission to increase or decrease the load on the engine to respectively decrease or increase the engine speed, said transmission providing a range of overall gear ratio between the engine and drive wheels to allow said wide open throttle production of said lean burn air-fuel mixture throughout substantially the entire range of operating conditions of the vehicle.