We know the output power of the engine is not directly acting on the wheel to drive the vehicle up, but subject to a series of power transmission mechanism. How that power is transmitted to the wheels in the end? Here we look at how the work of automotive driveline.
● What is the power delivered?
Engine power output is to go through a series of power transmission device before reaching the drive wheels. The engine to the power transmission mechanism between the drive wheels, called powertrain vehicles, mainly by the clutch, transmission, drive shaft, main gear, differential and axle and other components.
Engine power output, the first through the clutch, after the transmission torque and speed, the drive shaft to transfer power to the main gear, and finally through the differential and axle to transfer power to the drive wheels.
Arrangement of the car and the location of the drive train and engine-driven forms, generally can be divided into pre-precursor, rear-drive, rear-drive rear, rear-drive four forms in the home.
● What is the FF?
Front engine front drive (FF) is placed in front of the engine means the vehicle, and using the front wheel as the drive wheel. Most cars are now taking this arrangement. Since the engine is arranged in front of the car, so the center of gravity of the vehicle's front concentrated in the body, will be a little "top-heavy." But because the car is front-wheel experience pulled away, so straight FF car driving stability is very good.
In addition, due to the engine power through the rear differential with front wheel drive axle directly, without going through the drive shaft, the power loss is small, suitable for small cars. However, because the front-wheel drive and is also responsible for steering, so turning radius is relatively large, the phenomenon is prone to understeer.
● What is the rear-drive?
Rear-drive (FR) refers to the engine is placed in front of the car department, and the use of the rear wheels as driving wheels. FR vehicle weight around more balanced, with good handling performance and driving stability. However, transmission parts, large transmission quality, throughout the passenger compartment shaft compartment occupied floor space.
FR car has better handling, stability, braking, and now the high-performance cars still prefer this form of arrangement of the line.
● What is the rear rear-wheel drive?
Rear-wheel drive rear (RR) refers to the engine at the back of the rear axle, and rear-wheel as the wheels. Due to the weight of the entire vehicle are mostly concentrated in the rear, and because they are rear-wheel drive, so the start, acceleration performance are very good, so generally used RR supercar way.
RR vehicle cornering performance is more sensitive than the FF and FR, but when the rear grip to the limit, there will be slipping flick, which is not easy to control.
● What is in the home after flooding?
Rear mid-engine, rear-wheel-drive layout (MR) is a means of driving room between the engine and the rear axle is placed, and the use of the rear wheels as driving wheels. MR This design has an advanced sports car drivers mainstream way. Because of the inertia of the biggest sports car engine placed in the center of the vehicle, the vehicle weight distribution close to the ideal balance, making MR safeguarded best sports car performance.
MR car because the engine in the home, the car is quite narrow, generally only two seats away from the driver and the engine near the noise is relatively large. Of course, the pursuit of motorists who do not care about the performance of these.
● clutch action
Clutch flywheel housing located between the engine and the transmission, is fixed to the rear plane of the flywheel, and the other end connected to the input shaft of the transmission. Clutch is equivalent to a power switch, you can pass or cut off power from the engine to the transmission input. Mainly in order to make the car a smooth start, timely interruption to the powertrain to suit shifting drivetrain can also prevent overloading.
Mainly by the active part of the clutch (flywheel, clutch cover, etc.), the driven portion (friction plates), pressing means (diaphragm spring) and steering mechanism composed of four parts. Automobile clutch friction clutch, fluid coupling, electromagnetic clutches and other types. Currently cooperating with the manual transmission clutch vast majority of dry friction clutch, the following friction clutch works to be explained.
The friction clutch cover sheet is connected with the input shaft of the gearbox by screws to the rear end surface of the flywheel, the friction disc clutch under the force of the spring inside the pressure plate is pressed against the flywheel surface. By friction the flywheel and the pressure plate and the driven plate contact surface, the engine torque is transmitted to the transmission sent.
Before no clutch pedal, the friction plates are pressed against the end face of the flywheel, the engine power can be transmitted to the gearbox. When the clutch pedal, through the operating mechanism, the power delivered to the release fork and release bearing, release bearing advances to the flywheel side of the diaphragm spring compression, diaphragm spring to support the ring as a fulcrum to move in the opposite direction, the pressure disc friction plate left, then the engine power transmission is interrupted; when the clutch pedal is released, the diaphragm spring return again, clutch recombine, the engine power to pass.
(Diaphragm spring clutch structure principle)
● role gimbal
Refers to the use of ball joints and other devices to achieve the type of shaft power output in different directions, at the end of the drive shaft, drive shaft and drive axle play connection, axle and other parts. Structure and function of gimbal joints on a bit like human limbs, it allows the angle between the parts to be connected in a certain range.
Such as the rear-drive car, you must be connected to the power transmission and drive axle through the shaft, then why should gimbal it? Mainly to meet the power transmission, steering and adapt to angle up and down when the car is running generated caused changes.
By reversing the direction of the universal joint on whether there is significant flexibility can be divided into rigid joints and flexible joints. Rigid joints can be divided into non-constant velocity joint (commonly used for the cross-axis), quasi-constant velocity joints (such as double universal joints) and constant velocity joints (eg ball cage Wan to the festival) three. CVJ currently used on cars for CV joint.