Variable valve timing apparatus

Abstract

A variable valve lift apparatus is mounted above a valve stem of a valve for opening and closing the valve. The apparatus includes an upper and a lower housing; an upper electromagnet in the upper housing; a lower electromagnet in the lower housing; at least one permanent magnet that penetrates the electromagnets; an upper plate between the permanent magnet and the upper housing; and a lower plate between the permanent magnet and the lower housing, which opens and closes the valve. The apparatus may also include an upper coil spring assembly mounted in the upper housing, and a lower coil spring assembly mounted in the lower housing, each coil spring assembly including at least two coil springs. The apparatus may also include an upper damper at the top of the upper housing, and a lower damper at the bottom of the lower housing. Oil may be provided in the housings.

Dependencies are inferred from the claim text.