초록 ▼

The present invention provides a motor driven by shape memory alloys for use in a variety of applications. In the disclosed embodiment, the motor is used to drive a photovoltaic panel so that the panel may remain in appropriate alignment with the sun throughout the day. In such a configuration, the

The present invention provides a motor driven by shape memory alloys for use in a variety of applications. In the disclosed embodiment, the motor is used to drive a photovoltaic panel so that the panel may remain in appropriate alignment with the sun throughout the day. In such a configuration, the motor assembly relies upon the intrinsic properties of shape memory alloys, in conjunction with a spring assembly, in order to generate sufficient torque in order to rotate the photovoltaic panel. In order to control the orientation of the panel, the system relies upon a sun tracking mechanism which includes an analog sensor circuit, a plurality of phototransistors and a power source. Accordingly, the device is able to rotate the photovoltaic panel in discrete and precise increments as the day progresses.

대표청구항 ▼

We claim: 1. A solar tracking device comprising: A stationary base; A rotatable output shaft mounted on said stationary base, said shaft having a first end suitable for affixation of a solar receptor panel and a second end terminating in a worm gear; A photovoltaic panel attached to said first end

We claim: 1. A solar tracking device comprising: A stationary base; A rotatable output shaft mounted on said stationary base, said shaft having a first end suitable for affixation of a solar receptor panel and a second end terminating in a worm gear; A photovoltaic panel attached to said first end of said output shaft; A drive platform having a locking arm assembly pivotably connected at a first end of said drive platform and a drive assembly secured at a second end; said drive assembly having a worm drive in mesh with said worm gear on said output shaft; said drive platform being further pivotably connected by a platform pivot to said stationary base; said drive assembly being disengageable from said worm gear through release of said locking arm; An engagement mounting plate secured to said drive platform at a point proximate to the second end of said drive platform, the engagement mounting plate having a terminal suitable for the application of electric current; A forward mounting plate secured to said drive platform at a point proximate to said first end of said drive platform, the forward mounting plate having a terminal suitable for the application of electric current; A return spring secured to said stationary base at a first end and further attached to said output shaft at a second end; A means to drive the drive assembly; A means to pivotably disengage said drive assembly from said worm gear; and A means to coordinate said means to drive the drive assembly and said means to pivotably disengage the worm gear as a function of the position of the sun; Whereby the drive mechanism axially rotates said shaft around the long axis of said shaft based upon the position of the sun. 2. The device as in claim 1 wherein said means to drive the drive assembly comprises: A drive shaft; At least one drive clutch mounted on said drive shaft; At least one backlash clutch mounted in said drive shaft; At least one forward actuator wire secured at one end to said terminal of said drive assembly and attached to said drive clutch at the other end; A forward spring secured at one end to said drive platform and attached at the other end to said drive clutch; Whereby the drive clutch is first rotated in the slip direction by said forward actuator wire and then said forward spring torques the drive clutch in the drive direction thereby rotating the drive shaft which in turn rotates the worm gear. 3. A device as in claim 2 wherein said forward actuator wire is composed of a shape memory alloy. 4. The device as in claim 1 wherein said means to pivotably disengage said drive assembly from said worm gear comprises: A disengagement actuator fixed at a first end to said locking arm and fixed at the second end to said engagement mounting plate; At least one engagement spring secured to said fixed base at one end and secured to a point in said locking arm at the other end; At least one arm roller affixed to said locking arm such that said arm roller is in rollable contact with said stationary base; A plurality of arm stoppers affixed to said base in such locations so as to define the range of movement of said arm rollers; Whereby a contraction of the disengagement actuator releases the locking arm permitting a force generated by said at least one engagement spring to pivot the entire drive platform around the platform pivot thus disengaging the worm drive from the worm gear. 5. A device as in claim 4 wherein said disengagement actuator is composed of a shape memory alloy. 6. A device as in claim 3 or 5 wherein said shape memory alloy is composed of a nickel-titanium alloy. 7. A device as in claim 1 wherein said means to coordinate said means to drive the drive assembly and said means to pivotably disengage the worm gear comprises: A sensor mount incorporated into said output shaft; A plurality of phototransistors secured to said sensor mount; An analog circuit connected to said plurality of phototransistors; A power source which supplies power to said means to drive the drive assembly and said means to pivotably disengage said drive assembly from said worm gear wherein said power source is controlled by said analog circuit. 8. A device as in claim 7 wherein said power source is said photovoltaic panel. 9. A device as in claim 7 wherein said power source is a battery.