Patent Application
20070262584
Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates to an energy recovery system for a moving vehicle, and in particular, to such a system which is controllable to maximize the energy recovery based on vehicle operation conditions and operator actions.
2. Brief Description of the Related Art
Various patents are related to the concept of mounting a fan or turbine on a vehicle to generate electricity when the vehicle is moving. For example, U.S. Pat. No. 5,287,004 to Finley discloses a horizontally mounted turbine at the rear of the vehicle. The passage of air over the vehicle turns the turbine and generates electricity.
Other patents disclose devices that combine electricity generation and aerodynamic braking. For example, U.S. Pat. No. 3,556,239 to Spahn discloses an automobile with air scoops feeding air to an internal air turbine to generate electricity. A front air scoop has doors that can be opened to increase the drag. In addition, the electrical generator is stated to produce some braking force when it is operating.
U.S. Pat. No. 4,632,205 to Lewis also discloses a combined generator and brake system for an automobile. An electricity generator is driven by air pressure when the car is moving and also when the car is at rest so long as sufficient wind is blowing. When braking is desired, a plate is extended to oppose the movement of the vehicle and to direct air into a passageway to turn a generator.
U.S. Pat. No. 1,181,988 to Breitung discloses a windmill mounted to a boat to generate electricity. The windmill serves a dual function—when it rotates it generates electricity and when it is not rotating it can act as an additional sail to provide motive power to the boat.
The present invention is a system to recover energy from the air stream associated with a moving vehicle, such as an automobile, a boat, an airplane and the like, and thereby to improve the energy efficiency of the operation of the vehicle. The present invention may, for example, generate electricity and provide braking for the moving vehicle. The system comprises a turbine, a fan or the like (hereinafter referred to as a “turbine”) variably coupled to an electrical generator.
The turbine is disposed within the air stream and operatively connected through a drive shaft to an electrical generator. When accelerating or operating at a constant speed, the vanes or blades (hereinafter “vanes”) of the turbine are parallel to the wind flow and thus provide minimal drag on the vehicle. When braking or decelerating, the vanes are pitched at an angle to the wind flow to assist in slowing the vehicle by increasing the drag of the wind on the vehicle and, in addition, the system generates electricity through the rotation of the turbine.
The pitch of the vanes may be manually controlled or a mechanical or electrical device, such as a computer, may determine the pitch of the vanes based on the operating conditions of the vehicle, such as its speed, and the actions of the user. For example, when the vehicle is an automobile and the user desires to slow the vehicle, the accelerator pedal is released and/or the brake pedal is depressed. From the inputs of vehicle speed and the actions of the user with respect to the accelerator and/or the brake pedal, a computer may determine a pitch of the vanes that generates an amount of electricity to charge the battery and allow safe slowing of the vehicle. Instead of generating electricity, the turbine may be used to provide mechanical power to operate auxiliary devices or to boost the performance of the engine.
In order to optimize the generation of electricity, in an alternative embodiment of the present invention, the electrical generator may be provided with a plurality of rotors, each with its associated electrical coil. Each rotor is operatively connected to the drive shaft from the turbine by means of a releasable pin. Thus one or any number of rotors up to the full complement may be selected to be connected to the drive shaft at any time. Rotors that are not connected by the pin to the drive shaft are free wheeling and do not provide any addition to the generation of electricity. Rotors that are connected by their associated pins to the drive shaft are rotated by the turbine and assist in generating electricity. By the same means, the turbine may be released from the drive shaft. For example, it may be desirable for the turbine to be released from the drive shaft to avoid the braking effect of the turbine, but still allow any residual momentum of the drive shaft to continue to operate the rotors.
Under some conditions, the selection of the pitch of the turbine vanes may cause the generator to operate at a level that could causes it to overheat. In such a condition, all the rotors may be made free wheeling.
These and other features, objects and advantages of the present invention will become better understood from a consideration of the following detailed description of the preferred embodiments and appended claims in conjunction with the drawings as described following:
With reference to
As shown in
As shown in
As shown in
In order to optimize the generation of electricity, in an alternative embodiment of the present invention, the electrical generator 11 may be provided with a stator 50 and a plurality of rotors 51, each with its associated electrical coil 52. Each rotor 51 is operatively connected to the drive shaft 12 from the turbine 10 by means of a releasable rotor pin 53 controlled by the controller 40. Thus the controller 40 may select one or any number of rotors 51 up to the full complement to be connected to the drive shaft 12 at any time by moving a respective rotor pin 53 into or out of engagement with a rotor 51. Rotors 51 that are not connected by a rotor pin 53 to the drive shaft 12 are free wheeling and do not provide any addition to the generation of electricity. Rotors 51 that are connected by their associated rotor pins 53 to the drive shaft 12 are rotated by the turbine 10 and assist in generating electricity.
A releasable rotor pin 53 slides in an opening 54 in the drive shaft 12 and may be moved into and out of an opening 55 in the rotor 51 so as to engage the rotor 51 and couple it to the drive shaft 12. The rotor pin 53 may be moved into and out of engagement by any of various means that would be well known to those of skill in the art and could include, without limitation, electrical, mechanical or pneumatic means.
Under some conditions, the selection of the pitch of the turbine vanes 30 may cause the generator 11 to operate at a level that could cause it to overheat. In such a condition, the controller 40 may determine that a different pitch of the vanes is desirable or that the turbine 10 and/or some or all of the rotors 51 should be free wheeling in order to optimize the efficiency and safety of the system.
When the user decides to slow down momentarily, the accelerator pedal is released and then depressed again after a short time interval. When the accelerator pedal is released, the pitch of the vanes 30 are then immediately altered to provide a braking force and to turn the turbine 10. When the user then depresses the accelerator pedal to resume speed, there may be some residual momentum in the drive shaft 12 and the rotors 51 that would be wasted if the vanes 10 were immediately turned parallel to the wind flow. This situation is addressed in a further alternative embodiment of the present invention as shown in
The present invention has been described with reference to certain preferred and alternative embodiments that are intended to be exemplary only and not limiting to the full scope of the present invention as set forth in the appended claims.
