Structure of vehicle power train

#The present invention relates to a structure of a vehicle power train which comprises an engine situated lengthwise in a vehicle and a transmission disposed adjacent to the engine in parallel.

#In the FF vehicle (Front engine, Front wheel drive vehicle) or FF derivative four wheel drive vehicle, a known power train has an engine situated transversely so that the axis of the output shaft of the engine extends in the widthwise direction of the vehicle body and a transmission situated to the rear of the engine in the longitudinal direction. This power train is defined as a transversaly situated power train herein below. This transversaly situated power train possesses an advantage such as a smooth transmittance of the driving power since the output shaft of the engine and input and output shafts of the transmission are parallel to an axle shaft of the front wheel. However, if the transversaly situated power train is placed on the vehicle having a normal wheel base, almost all the weight of the power train is loaded on the front wheels. Accordingly, the weight loaded on the front wheels is too large compared with the FR vehicle (Front engine, Rear drive vehicle) having an engine and a transmission situated lengthwise in a line (this power train is defined as a lengthwise situated power train herein below).

#Therefore, a method that arranges the front wheel to further front than the normal vehicle so as to set the centroid to the rear of the front wheel may be taken in order to reduce the load on the front wheel. However, the wheel base between the front wheels and the rear wheels gets longer by this arrangement and the turning radius to the steering angle gets large, i.e., the steering worsens.

#FIG. 1 is a side view of a four wheel drive vehicle comprising a power train of a first embodiment wherein a vehicle body is removed.

#FIG. 2 is a front view of a four-wheel vehicle from the view of an engine room.

#FIG. 3 is a front view of a power train.

#Preferred embodiments are described below.

#In the first embodiment, as shown in FIGS. 1 and 2, a power train P of a FF derivative four wheel drive vehicle WD (defined as a vehicle below) is situated in an engine compartment 4 formed by a bonnet 1, a dash panel 2, and a bottom member 3.

#This power train P transmits torque outputted from a V-type lengthwise situated engine 5 to an automatic transmission 8 through both a torque convertor 6 adjacent to the rear end of the engine 5 and a drive chain mechanism 7, and further transmits the torque converted at the transmission 8 to a front wheel drive shaft 11 and a rear wheel drive shaft 12 through a center differential unit 9. The torque of the front wheel drive shaft 11 is transmitted to right and left front wheels 17, 16 through right and left front axle shafts 15, 14. The torque of the rear wheel drive shaft is transmitted to right and left rear wheels through rear differential unit and right and left rear axle shafts (not shown in the drawing).