Hydraulic-based rotational system for solar concentrators that resists high wind loads without a mechanical lock
First Claim
1. A rotational actuator system for controlling rotation of a solar collector, said system comprising:
- a bi-directional motor that establishes a flow direction of hydraulic fluid to cause rotation of a bi-directional rotational actuator through an arc substantially perpendicular to a plane of the ground, wherein the arc has a selected upper limit of about 180 degrees to about 240 degrees;
a control system hydraulically connected to said actuator for controlling rotation of the solar collector along the arc in either a clockwise or counter-clockwise direction depending on the flow direction of the hydraulic fluid from the bi-directional motor;
wherein the control system and the actuator are connected by a closed-loop hydraulic circuit comprising first and second hydraulic lines;
first and second pressure sensors for individually monitoring said first and second hydraulic lines; and
a solenoid valve that is opened in response to dual pressure signals from both said first and second pressure sensors.
1 Assignment
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Accused Products
Abstract
A rotational system is provided for controlling rotation of one or more solar collectors to track the movement of the sun, to automatically keep the collectors locked in stow position during high wind conditions, and advantageously also to prevent damage to the rotational system due to high pressures caused by high temperature conditions. The system utilizes a bi-directional hydraulic rotational actuator hydraulically connected to a control system. The actuator advantageously includes a system of helical gears and a piston, and the control system includes hydraulic lines equipped with check valves that prevent circulation of hydraulic fluid through the hydraulic lines and the actuator when backpressure is exerted in one of the hydraulic lines as a result of high wind force on the collectors. In addition, the control system advantageously comprises a pressure-relief system to prevent damage to the actuator during high temperature conditions. A single actuator can be used to operate up to sixteen or more large solar collectors.
236 Citations
17 Claims
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1. A rotational actuator system for controlling rotation of a solar collector, said system comprising:
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a bi-directional motor that establishes a flow direction of hydraulic fluid to cause rotation of a bi-directional rotational actuator through an arc substantially perpendicular to a plane of the ground, wherein the arc has a selected upper limit of about 180 degrees to about 240 degrees; a control system hydraulically connected to said actuator for controlling rotation of the solar collector along the arc in either a clockwise or counter-clockwise direction depending on the flow direction of the hydraulic fluid from the bi-directional motor;
wherein the control system and the actuator are connected by a closed-loop hydraulic circuit comprising first and second hydraulic lines;first and second pressure sensors for individually monitoring said first and second hydraulic lines; and a solenoid valve that is opened in response to dual pressure signals from both said first and second pressure sensors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17)
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14. A method of making a rotational actuator system for controlling rotation of a solar collector, said method comprising:
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providing a bi-directional motor that establishes a flow direction of hydraulic fluid to cause rotation of a bi-directional hydraulic rotational actuator along an arc substantially perpendicular to a plane of the ground, wherein the bi-directional motor and actuator are capable of exerting enough torque to rotate at least one solar collector through the arc having a selected upper limit of about 180 degrees to about 240 degrees; providing a control system for controlling operation of said actuator; and hydraulically connecting said control system to said actuator in a closed-loop hydraulic circuit comprising first and second hydraulic lines; providing first and second pressure sensors for individually monitoring said first and second hydraulic lines; and providing a solenoid valve that is opened in response to dual pressure signals from both said first and second pressure sensors. - View Dependent Claims (15, 16)
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Specification