Piezo-electric drive arrangement for a harmonic drive transmission

摘要

The invention relates to an apparatus and a method of rotatively empowering a harmonic drive transmission. The steps of the method include arranging a primary cup-shaped flexspline (20) and a secondary cup-shaped flexspline (10) co-axially within a rotatable rigid circular spline (14), and forming pivotable fingers (50) in the secondary flexspline (10), biasing radially outwardly the pivotable fingers (50) so as to contact and bias radially outwardly the primary flexspline (20) in a sequential manner. An array of teeth (24,18) between the primary flexspline (20) and the circular spline (14) engage one another to effect relative rotation therebetween. An array of elongate, rod-like piezo-electric elements (74) is arranged in contact with spoke-like bases (82) of the fingers (50) of the secondary flexspline (10) and an adjacent non-rotating component (70,72). An electric current is sequenced through the piezo-electric elements (74) to effect a dimensional change therein, thus to effect the biasing of the primary flexspline (20) by the fingers of the secondary flexspline (10).