Powertrain and Method for a Kinetic Hybrid Vehicle

Abstract

A kinetic hybrid device and method for a vehicle may include a planetary gear system configured as a continuously variable transmission comprised of three or four ports. The kinetic hybrid device and method may include a flywheel connected to a first port of the system, a final drive connected to a second port of the system, and the variator for the flywheel connected to a third or fourth port of the system. The prime mover and/or other power sources may share a port with the flywheel, but do not share a port with the final drive.

Description

CROSS REFERENCE TO RELATED APPLICATION(S)[0001]This application claims priority from a U.S. Non-provisional patent application Ser. No. 13 / 193,728, filed Jul. 29, 2011, and from U.S. Provisional Patent Application Ser. Nos. 61 / 438,267 filed Feb. 1, 2011; 61 / 471,213, filed Apr. 4, 2011; and 61 / 495,993, filed Jun. 11, 2011, and which all are incorporated by reference herein.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention pertains to a powertrain and method of a kinetic hybrid vehicle, such as a gas and / or electric powered vehicle that includes a flywheel. The powertrain and method may be used to store and use energy of the flywheel device for vehicle propulsion and optimizing fuel efficiency.[0004]2. Description of the Related Art[0005]Improving fuel economy is an important objective in vehicle design, since it enables reduced fuel consumption and reduced emissions. Especially with the current situation of dwindling fossil fuel resources and worsening en...

AI Technical Summary

Benefits of technology

[0021]In a further aspect, the invention consists of a flywheel, an electrically controlled continuously variable transmission with preferably four ports for input/output, a prime mover, a control unit, and a plurality of gears working together to provide the vehicle with a powertrain, an additional power source, energy storage, and an energy recovery system. The prime mover used with the invention may be either an internal combustion engine or a motor/generator. The prime mover, the flywheel, the CVT variator, and the final drive are coupled to separate ports, allowing the CVT to be used for both the prime mover and the flywheel. As a kinetic energy storage device, the flywheel stores energy in the same form it is used in. When provided a direct mechanical path by the CVT for transfer of energy between the flywheel and the vehicle, the flywheel can recover the vehicle's kinetic energy during deceleration as well as directly power the drivetrain to drive the vehicle during acceleration or cruise, all with minimal energy conversion and conversion losses because of the direct mechanical transfer of energy. Using the flywheel as a secondary mover can also result in higher performance since flywheels have a much higher power density than motors or batteries. In an embodiment where the prime mover is a traction motor, an engine may be coupled to the same port to extend the vehicle's range. In an embodiment where the prime mover is an internal combustion engine, a torquer motor/generator may share the same port to improve efficiency.

[0022]When the IC engine is configured to be the primary power source and the flywheel is configured to be the secondary power source and energy storage, the system is configured as a kinetic hybrid vehicle. When the IC engine is not used, the torquer motor is configured to be the primary power source, and the flywheel is configured to be the secondary power source and energy storage, the system is configured as a kinetic-electric hybrid vehicle. In a four port compound CVT, the speed change in any input/output port may cause speed changes in the other ports; therefore, with appropriate methods to control the variator motor/generator, both the engine and the torquer motor/generator can be controlled as well so as to exchange energy between the flywheel and the vehicle's wheels, to pass energy from the engine and/or torquer motor/generator to the vehicle's wheels, to pass energy from the engine and/or torquer motor/generator to the flywheel, and even to pass energy from the flywheel through a motor/generator to charge the battery pack. Besides physical embodiments or configurations, good control methods are also important to achieving fuel economy. The vehicle's operation during driving can typically be classified into two states: a first state where the vehicle's speed is significantly changing, such as during acceleration and deceleration, where inertia and change in the vehicle's kinetic energy are involved, and a second state where the vehicle's speed is not changing significantly, such as during cruise. In the first state both high efficiency and high performance are desired, whereas in the second state only high efficiency is desired, since there is no appreciable change in the vehicle's speed.

[0023]In yet another aspect of the invention, a “de-inertia operation” method is provided for controlling the flywheel with the powertrain so that the vehicle's inertial effects are drastically reduced. The flywheel can be precharged so that when the vehicle's kinetic energy is low (vehicle speed is low or zero), the flywheel is at its maximum energy level. The flywheel provides most of the power used to launch the vehicle from rest, starts the engine, and continues to participate in accelerating the vehicle, thus helping the vehicle overcome its rest inertia. There is an inverse relationship between the kinetic energy in the flywheel and the kinetic energy in the...

Problems solved by technology

Although automotive technology has been advancing and there have been improvements in fuel economy, there still exists an inherent conflict between fuel economy and accelerative power in conventional vehicles.

Thus an IC engine achieves its best efficiency at relatively high power; automotive vehicles, however, require only low power most of the time.

On the other hand, this means that when the vehicle is not accelerating, its engine is operating at a lower load level and lower efficiency state, wasting the maximum efficiency potential of the engine.

If a smaller engine is used, then the engine will be working at a higher efficiency to improve fuel consumption, but there will be less reserve power, which means poorer performance in acceleration.

In addition, much of the vehicle's kinetic energy is dissipated as heat in the brakes when decelerating, reducing the vehicle's potential fuel efficiency.

Although more efficient and environment friendly than some conventional vehicles, these electric hybrids may be difficult to produce without the added costs of a large traction motor, controller, and electrochemical and/or electric storage devices.

These costs, which may outweigh the amount of money saved from consuming less fuel, may result in an increased price to consumers that limits market penetration.

Aside from cost, a main disadvantage of electric hybrids is that they are greatly limited in the fuel economy improvements they can provide.

Part of conventional electric hybrids' efficiency limitations comes from the fact that energy is not stored in the ...

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