| 摘要 |
A constant mesh change speed gear more especially for vehicle use comprises a gear box casing (70) containing rotatably mounted therein layshafts (1, 3) one for each ratio and disposed about and parallel with an input drive receiving shaft (5) and an out drive shaft (6) co-axial with the input driven shaft (5). The input driven shaft (5) carries a gear (50) in constant mesh with gears (11) one each on a corresponding layshaft (1, 3) each layshaft having a further gear (12) in constant mesh with a corresponding gear (60) of a gear cluster (600) on the output drive shaft (6), one of the gears (11, 12) on each layshaft being fast therewith whilst the other gear is adapted to be clutched to its layshaft by a clutch (10, 30) for effecting a drive at a selected ratio between the driven input shaft (5) and the output drive shaft (6) via the layshaft (1, 3). The clutches (10, 30) are mounted at the same ends of their respective layshafts (1, 3) and are positioned within the gear box casing (70) at the same end of the latter so as to be accessible for servicing and/or replacement purposes through removable or openable covers (71, 73) at said end of the casing (70). |
