| 摘要 |
A piston (26) for an automatic transmission (10) including a pair of mutually meshing gears (16, 68) such as counter drive and driven gears mounted on respective two parallel shafts, the piston including a bottom portion (30), and a cylindrical portion (28) to be disposed radially outwardly of one (16) of the mutually meshing gears, wherein the cylindrical portion (28) has not only a cutout (66) formed in a first circumferential part thereof for permitting mutual meshing engagement of the mutually meshing gears (16, 68) such that a point of the mutual meshing engagement is located within a circumference of the cylindrical portion, but also a through-hole (62) formed in a second circumferential part thereof so that a speed sensor (64) extends through the through-hole, for detecting the rotating speed of the above-indicated one gear (16) disposed radially inwardly of the cylindrical portion. This arrangement of the cylindrical portion permits size reduction of the cutout (66), and assures sufficiently high degrees of strength and rigidity of the piston. |
