Patent ID: 7089897

Claim:
An electrical adjusting device for changing an angle of rotation of a camshaft ( 3 , 65 , 69 ) relative to a crankshaft of an internal-combustion engine, comprising an adjusting gear unit ( 1 ), which is formed as a triple-shaft gear unit, comprising an input part ( 4 ) that is fixed to the crankshaft; an output part ( 5 ) that is fixed to the camshaft; and an adjusting shaft ( 6 ); the electrical adjusting device further comprising an electric adjusting motor ( 2 ) having a permanent magnet rotor ( 8 ) and a stator ( 9 ) fixed to a housing, the adjusting shaft being connected in a torsion-proof manner to the electric adjusting motor ( 2 ); and a stationary gear ratio i 0 = Output ⁢ ⁢ tooth ⁢ ⁢ number ⁢ ⁢ Z NW Input ⁢ ⁢ tooth ⁢ ⁢ number ⁢ ⁢ Z KW , between the input part ( 4 ) and the output part ( 5 ) for the adjusting shaft ( 6 ), whose magnitude determines a type of the adjusting gear unit ( 1 ) as a positive or negative gear unit and determines a direction of adjustment of the camshaft ( 3 , 65 , 69 ) into an advanced or retarded base position, and through which an advanced and a retarded base position of the camshaft ( 3 , 65 , 69 ) can be reached exclusively through braking of the adjusting shaft ( 6 ) when the adjusting gear unit ( 1 ) is rotating, and the braking of the adjusting shaft ( 6 ) is carried out through short-circuit braking of the adjusting motor ( 2 ).