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:
Jul. 30, 1991
Filed:
Sep. 12, 1989
Erik Nielsen, Odense, DK;
Erland F Hansen, Morke, DK;
I.K. Trading Aps., Odense SV, DK;
Abstract
A yawing system for a wind mill consists of two yawing motors (9, 11) acting on a toothed rim of the yawing bearing. On each its drive shaft (21) the motors (9, 11) are provided with a free wheel (23) and an electromagnetic friction brake (25). The free wheel devices (23) are directed opposite each other. A control system operates in a passive state in such a manner that the motors give opposite and relative to the braking moment of the brake (25) of a second motor smaller torque thereby avoiding dead clearance between drive wheel (15) and toothed rim (17) while at the same time keeping the generator housing (5) of the mill at rest. In the active state of the control system both brakes (25) are disengaged and both motors give a higher torque in the same direction. The system acts as a shock absorber by loads exceeding the fixed slip moment of the friction brake (25).