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:
Jun. 12, 2001
Filed:
Aug. 12, 1999
Charles D. Syverson, North Mankato, MN (US);
Motion Systems, L.C., White Lake, WI (US);
Abstract
A drive roller has a brushless D.C. motor with a stator or armature mounted on a fixed shaft and directly driving a 16 pole permanent magnet rotor mounted inside a roller tube. A motor controller drive supplies three-phase power to a Y-connected three phase winding having three groups of two coils, forming twelve electromagnets which drive the rotor. The modular motor is readily built in one inch increments to supply one lb-in of torque for each increment. The controller operates at a relatively low frequency of 15-75 Hz. Hall effect sensors provide feedback on motor speed and position. The armature laminations are relatively thick because of the relatively low power necessary to drive the motor and the resultant relatively low eddy currents present in the motor core. A 4.0 lb-in torque motor with a rotor and stator length of four inches will draw approximately 0.8 amps consuming about 15 Watts.