US Patent 7673598 Electric camshaft adjuster

The invention relates to an electric camshaft adjuster for adjusting and securing the phase angle of a camshaft of an internal combustion engine with respect to its crankshaft, having a three shaft gearing which is embodied as a harmonic drive (19, 19′) of sleeve design, and a drive wheel (1) which is fixed to the crankshaft and has a first ring gear (2) as well as an output component (4) which is fixed to the camshaft and has a second ring gear (5) arranged next to the first ring gear (2) and an adjustment shaft (10, 10′, 10″, 10′″) which can be driven by an electric adjustment motor, with a wave generator (17, 17′, 17″) which has means for elliptically deforming a flexurally elastic, externally toothed sleeve (18).