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1 rear-drive
rear-drive, i.e., front engine, rear wheel drive (Frontmdash; engineRearmdash; drive, referred to as FR), which is one of the most conventional type of driving. Most domestic and foreign trucks (including pickups), part of the car (especially the sedan) and some passenger cars are using this type of drive, but with the type of small cars rarely.
Advantages
uses a pre-drive type rear-wheel drive vehicle has the following advantages:
1 on a split road good start, when accelerating or climbing, drive wheel load is increased (i.e., drive wheel with a pressure increase), its performance is superior traction type pre-precursor;.
axis 2 more uniform load distribution, which has a good steering stability and with ride, and help extend the life of the tire;.
3 of the engine, clutch and transmission assembly, and other near the cab, simplifying the arrangement of the operating mechanism;.
the steering wheel 4 is driven wheel, a steering mechanism is simple in structure, easy maintenance.
Also, FR type has the following drawbacks:
As a result of a drive shaft means, not only to increase vehicle weight, while reducing the transmission efficiency of the powertrain, affect fuel economy; [. 123]
2 cartridge is disposed vertically disposed engine, transmission and drive shaft, so that the cabin space is reduced, the influence comfort;. Meanwhile, reducing the height of the floor is also limited;
3 when you start to accelerate in the snow or slippery road, the rear-wheel driven vehicle, fishtailing phenomenon prone.
The front-engine, rear-wheel-drive layout bus mode, easy, and many modified by the truck wagon common member. In addition to having the advantages and disadvantages of similar-drive truck, but also there is a disadvantages:
Since the hood 4 protruding above the floor, reduced area utilization in the compartment, and guideLarge induced interior noise, heat, vibration isolation is more difficult, affecting comfort;.
5 easily overloaded front axle, axle load distribution is not ideal, affecting the handling and stability;
[ 123] 6. Since the front suspension is limited, leading to the long suspension, easy scraping uphill.
In recent years, with the city bus to the further development of quasi-low-floor, ultra-low-floor direction, drive type buses have shown a trend to replace the rear drive of FF’s.