The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 07, 2001
Filed:
Nov. 01, 1999
Raymond Dexter Woodworth, Irvine, CA (US);
James Edwin Bobrow, Huntington Beach, CA (US);
Other;
Abstract
An improved rotary servovalve system employs a rotary magnetic solenoid having an armature that includes at least one permanent magnet. The armature is rotatable relative to a stator formed as an electromagnet which is energizable to create alternative electromagnetic fields having opposite polarities from each other. When deenergized, the stator allows the armature to return to a neutral, null position from positions of extreme rotation in opposite angular directions due to the magnetic force of the permanent magnet of the armature. The armature is coupled to carry a movable valve element in angular rotation therewith, so that flow through the servovalve of the system can occur in alternative directions. Also, the valve element is biased toward a position in which all of the valve ports are closed when power is removed from the rotary solenoid. The control circuit employed in the rotary servovalve system expands the bandwidth of response of the solenoid actuator by compensating for frequency variations in the input command signal and in the feedback signal. This compensation is achieved utilizing a combined proportional, integral, and differential amplification circuit. Also, imbalance of fluid forces within the servovalve mechanism can be avoided by utilizing a pair of inlet orifices, a pair of outlet orifices, a pair of first fluid control orifices, and a pair of second fluid control orifices. The orifices within each pair are located on opposite sides of the valve housing from each other.