Hybrid electric vehicle

Filing Information

• Patent Number: US5343970
• Application Number: US7947691
• Filing date: 09/21/1992
• Issue date: 09/06/1994
• Predicted expiration date: 09/21/2012

• U.S. Classifications: 180/652  · 180/656  ·
• International Classifications: B60K 604 ·
• International Classifications: 18065.2;65.3;65.4;65.6;165 ·

Patent Family

Abstract

An improved hybrid electric vehicle includes an internal combustion engine and an electric motor. Both the motor and the engine provide torque to drive the vehicle directly through a controllable torque transfer unit. Typically at low speeds or in traffic, the electric motor alone drives the vehicle, using power stored in batteries; under acceleration and during hill climbing both the engine and the motor provide torque to drive the vehicle; and in steady state highway cruising, the internal combustion engine alone drives the vehicle. The internal combustion engine is sized to operate at or near its maximum fuel efficiency during highway cruising. The motor is operable as a generator to charge the batteries as needed and also for regenerative braking. No transmission is employed. The motor operates at significantly lower currents and higher voltages than conventionally and has a rated power at least equal to that of the internal combustion engine. In this manner a cost efficient vehicle is provided, suffering no performance disadvantage compared to conventional vehicles.

Independent Claims | See all claims (40)

1. 1. A hybrid electric vehicle, comprising:two or more drive wheels receiving torque for propelling said vehicle from an output shaft, and a power unit supplying drive torque to said output shaft, said power unit comprising:a controllable torque transfer unit adapted to receive torque from two sources via first and second input shafts and transmit said torque to said output shaft;an engine adapted to consume combustible fuel and supply torque to said torque transfer unit;an electric motor adapted to receive electricity from a battery and supply torque to said torque transfer unit, said motor also being adapted to be operated as a generator, whereupon said motor receives torque and generates electric energy;a battery for supply of stored electric energy to said motor, and for receiving and storing electric energy from said motor when operated as a generator; anda controller for controlling the operation of said engine, said electric motor, and said torque transfer unit, such that said torque transfer unit receives torque from either or both of said internal combustion engine and said electric motor via said first and second input shafts and transmits torque therefrom to said drive wheels by way of said output shaft, and for controlling the relative contributions of the internal combustion engine and electric motor to the torque driving the wheels;wherein the relative ratios of the rates of rotation of said engine and said electric motor to said input shafts, and the relative ratio of the rate of rotation of an output member of said torque transfer unit to the rate of rotation of said driven wheels, are fixed.
2. 7. A hybrid electric vehicle comprising:two or more drive wheels receiving torque for propelling said vehicle from an output shaft, and a power unit supplying drive torque to said output shaft, said power unit comprising:a controllable torque transfer unit adapted to receive torque from two sources and transfer said torque to said output shaft;an engine adapted to consume combustible fuel and supply torque to said torque transfer unit;an electric motor adapted to receive electricity from a battery and supply torque to said torque transfer unit, said motor also being adapted to be operable as a generator;a battery for supply of stored electric energy to said motor, and for receiving and storing electric energy from said motor when operated as a generator; anda controller for controlling the operation of such engine, said electric motor, and said torque transfer unit such that said torque transfer unit receives torque from either or both of said internal combustion engine and said electric motor and transmits and for controlling the relative contributions of the internal combustion engine and electric motor to the torque driving the wheels, andwherein said battery provides a maximum current of no more than about 75 amperes at a voltage selected responsive to the characteristics of said motor.
3. 11. A hybrid electric vehicle, comprising:two or more drive wheels receiving torque for propelling said vehicle from an output shaft, and a power unit supplying drive torque to said output shaft, said power unit comprising:a controllable torque transfer unit adapted to receive torque from two sources and transfer said torque to said output shaft;an engine adapted to consume combustible fuel and supply torque to said torque transfer unit;an AC electric motor adapted to receive electric energy from a battery and supply torque to said torque transfer unit, said motor being further adapted to be operable as a generator;a battery for supply of stored electric energy to said motor, and for receiving and storing electric energy from said motor when operated as a generator;solid state switching means for converting DC supplied by said battery to AC for supply to said electric motor, and for rectifying AC generated by said motor when operated in a regenerative mode to provide DC to charge said battery; anda controller for controlling the operation of said engine, said electric motor, said solid state switching means, and said torque transfer unit, such that said torque transfer unit receives torque from either or both of said internal combustion engine and said electric motor and transmits torque therefrom to said drive wheels by way of said output shaft, and for controlling the relative contributions of the internal combustion engine and electric motor to the torque driving the wheels.
4. 13. A hybrid electric vehicle, comprising:two or more drive wheels receiving torque for propelling said vehicle from an output shaft, and a power unit supplying drive torque to said output shaft, said power unit comprising:a controllable torque transfer unit adapted to receive torque from two sources and transfer said torque to said output shaft;an engine adapted to consume combustible fuel and supply torque to said torque transfer unit;an electric motor adapted to receive electricity from a battery and supply torque to said torque transfer unit, said motor being further adapted to be operated as a generator;a battery for supply of stored electric energy to said motor, and for receiving and storing electric energy from said motor when operated as a generator; anda controller for controlling the operation of said engine, said electric motor, and said torque transfer unit such that said torque transfer unit receives torque from either or both of said internal combustion engine and said electric motor and transmits torque therefrom to said drive wheels by way of said output shaft, and for controlling the relative contributions of the internal combustion engine and electric motor to the torque driving the wheels;wherein said electric motor produces maximum power at a level at least equal to 100% of the maximum power of said internal combustion engine.
5. 15. A method of operating a hybrid electric vehicle, said vehicle comprising:a controllable torque transfer unit, operable to transfer torque in three modes (a) from either or both of two input shafts to an output member, said output member transmitting torque to drive wheels of said vehicle; (b) between said input shafts; and (c) from said output member to one or both of said input shafts;an electric motor adapted to apply torque to a first of said input shafts responsive to supplied electrical energy, said motor being further operable in a generator mode, to provide electrical energy when driven by torque transferred thereto via said first input shaft;a combustible-fuel-burning internal combustion engine adapted to apply torque to a second of said input shafts;a battery adapted to supply electrical energy to and store energy received from said electric motor; anda controller adapted to receive input commands from a driver of said vehicle to monitor operation of said vehicle and to control operation of said controllable torque transfer unit, said motor, and said internal combustion engine, said method comprising the following steps:selecting an appropriate mode of operation of said vehicle from the following possible modes of operation:low speed running;steady state running;acceleration or hill climbing;battery charging;braking; andengine starting;selecting the appropriate flow paths of electrical energy and/or combustible fuel and of torque to effectuate the selected mode of operation; andcontrolling operation of said controllable torque transfer unit, said electric motor and said internal combustion engine in accordance with said selected appropriate flow paths.
6. 32. A hybrid electric vehicle, comprising:a controllable torque transfer unit, operable to transfer torque in three modes: (a) from either or both of two input shafts to an output member, said output member transmitting torque to drive wheels of said vehicle; (b) between said input shafts; and (c) from said output member to one or both of said input shafts;an electric motor adapted to apply torque to a first of said input shafts responsive to supplied electrical energy, said motor further being operable in a generator mode, to provide electrical energy when driven by torque transferred thereto via said first input shaft;a combustible-fuel-burning internal combustion engine adapted to apply torque to a second of said input shafts;a battery adapted to supply electrical energy to and store energy received from said electric motor; anda controller adapted to receive input commands from a driver of said vehicle to monitor operation of said vehicle and to control operation of said controllable torque transfer unit, said motor, and said internal combustion engine, wherein said controller comprises means for performing the following functions responsive to input commands and monitored operation of said vehicle:selecting an appropriate mode of operation of said vehicle from at least the following possible modes of operation:low speed running;steady state running;acceleration or hill climbing;battery charging;braking; andengine starting;selecting the appropriate flow paths of electrical energy and/or combustible fuel and of torque to effectuate the selected mode of operation; andcontrolling operation of said controllable torque transfer unit, said electric motor and said internal combustion engine in accordance with said selected appropriate flow paths and selected mode of operation.