VALVE GEAR

PROBLEM TO BE SOLVED: To reduce size/weight of an upper cover, to reduce the number of part items, and to improve assembling workability by arranging a lubricating oil filling hole arranged to communicate with a valve stem inserting hole to supply lubricating oil to a lubricating oil supply member arranged in the valve stem inserting hole by penetrating through a yoke and the upper cover. SOLUTION: When a driving shaft is moved in the vertical direction by a valve operating unit, a valve stem 5 connected to this slides in a valve stem inserting hole 6 to control opening/closing of a valve plug in a valve body. At this time, sliding resistance generated in the valve stem 5 is reduced by grease stored in a lantern ring 7. In this case, the lower limit position to arrange packing 8 can be set in a position higher than usual by arranging the lantern ring 7 in a position higher than usual by forming a grease filling hole 16 of a through hole 16a of a yoke 14 and a through hole 16b of an upper cover 2. Therefore, size/weight of a valve gear can be reduced by reducing a thickness of the upper cover 2 by arranging a gland 6a in a shallow position.