| 摘要 |
A four-wheel vehicle drive system, comprising an engine having an output shaft in a lateral direction of the vehicle, a power transmission gear unit including transmission input and output shafts having axes of rotation parallel with the engine output shaft, a final reduction gear rotatable about an axis parallel with the transmission input and output shafts, the transmission output shaft being in driving engagement with the final reduction gear, a gear housing rotatable with the final reduction gear, a main transaxle casing having enclosed therein the transmission gear unit, final reduction gear and gear housing, an auxiliary transaxle casing secured to the main transaxle casing, a first wheel drive gear unit to split driving power from the final reduction gear into two components and including a differential gear assembly enclosed in the auxiliary transaxle casing and operative to transmit one of the power components to a pair of road wheels, a second wheel drive gear unit enclosed in the auxiliary transaxle casing and operative to transmit therethrough the other of the two driving power components in a fore-and-aft direction of the vehicle to drive another pair of road wheels, and low-and-high speed shifting means including a shift gear assembly enclosed within the gear housing and operative to transfer driving power from the final reduction gear to the differential gear assembly selectively with two different gear ratios. |
