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:
Sep. 30, 2014
Filed:
Mar. 31, 2011
Masakazu Mori, Koga, JP;
Daisuke Kukita, Koga, JP;
Seiya Shimada, Koga, JP;
Seibu Electric & Machinery Co., Ltd., Fukuoka, JP;
Abstract
There is provided an actuator in which an worm is rotationally driven by an electric motor, and in which an angular velocity of the electric motor is repeatedly fluctuated so that the rotation of the worm is carried out as if the worm is oscillated in the rotational direction thereof, to thereby decrease contact friction of the worm against a worm wheel, resulting in an improvement of an efficiency of force transmission of the worm gear mechanism. Although the electric motoris inherently controlled so that an output shaftthereof is rotated at a target velocity based on a velocity command, a drive control sectioncontrols the angular velocity of the output shaftso as to be repeatedly increased and decreased with respect to the target velocity so that the angular velocity of the wormis finely fluctuated, and thus the fluctuation of the angular velocity may be regarded as a fine general-oscillation of the rotating wormin the rotational direction, whereby friction between the gear faces of the wormand the gear faces of the worm wheelcan be decreased, resulting in an improvement of the efficiency of force transmission of the worm gear, and in increase in a driving force and a torque value to be transmitted to an object to be driven by the actuator.