| 摘要 |
PROBLEM TO BE SOLVED: To provide a pulley 1 which satisfies both prevention of intrusion of muddy water and dust, and accurate detection of a number of rotations or a crank angle of a crankshaft 4.SOLUTION: A pulley comprises a main body 11 arranged outside an engine case 3 and fixed to a shaft end of a crankshaft 4, and an annular rotation detection element 12 attached to the main body 11. The rotation detection element 12 comprises a magnetization part 122 where magnetic poles with opposite polarities are magnetized in a multi-pole manner at predetermined intervals in a circumferential direction, and a seal cylinder part 121c which protrudes toward the engine case 3. A dust lip 24 which is arranged at an oil seal 2 attached to a shaft hole 31 of the engine case 3 for sealing an axial periphery of the crankshaft 4, and extends toward the main body 11 is closely opposed to or slidably in contact with an internal peripheral face of the seal cylinder part 121c.SELECTED DRAWING: Figure 1 |
