The magnetically loaded noncontact couple between valve tip and surface of cam follower or rocker arm

The lightweight valves are more and more commonly used in cam and camless valvetiming in combustion engine. They can be made as drilled steel valves or as full but of TiAl alloys or of ceramic material. They usually can mate with the same valve guides and seat inserts made of cast iron, as in case of the standard full steel valves. Sometimes in the high speed engine, the valve insert should be made of chromium steel and valve guides of phosphorous bronze. The one of sources for wear and for resistance of motion for valve is a friction contact area between the valve tip and the surface of rocker arm or of cam follower. To minimize the wear the valve tip should be hardened or have a special hard cup, which makes greater mass of the valve. To avoid the wear and friction resistance in such contact area the mentioned friction contact can be eliminated. Such friction contact type can be replaced by a noncontact couple loaded by magnetic field force. Such solution requires introducing the set of the cylindrical permanent magnet fixed to nonmagnetic valve tip and of the similar magnet fixed to the bottom face of a cam follower or of the set of small plane magnets on the cam surface. The cam should be made of nonmagnetic material either. The model of such assembly of magnets has been made with the help of the finite element method. The values of magnetic force loading noncontact couple have been obtained for some configurations of magnets and for different positions for elements of valvetrain and presented in the article.