What gears does an automatic car have? Why does an automatic car have no clutch?

When learning to drive, most people learn to drive a manual transmission. Do you remember that when you first started driving, you couldn't tell the difference between the clutch, brake and accelerator pedals and always stepped on the wrong pedals? But when you buy a car, you find that automatic transmission cars don't have a clutch. There is a reason for this. The following is an introduction to the relevant content, I hope it will be useful to you.

Contents of this article

1. What are the gears in automatic transmission cars?

2. Introduction to the automatic transmission car gear lever diagram

3. Why do automatic transmission cars have no clutch?

4. Why do automatic transmission cars not shut down?

What gears are there in an automatic car?

1. P: Parking. When you park your car, the gear is in this position. The wheels are in a mechanically locked state to prevent slipping.

2. R: Reverse gear. Used for reversing.

3. N: None, neutral. Use this gear position when temporarily stopping (such as at a red light). Note that this gear position indicates neutral. To prevent the vehicle from sliding on a slope, you must step on the brake.

4. D: Forward gear, also known as drive gear. Needless to say, this gear is used when moving forward.

5. 2: Low gear, when going up a steep slope or starting on a relatively inclined slope, you can use this gear to start moving forward. Principle, by shifting the gear here, you can limit the car's gear to automatically switch only in the low gear (equivalent to the first and second gears of a manual transmission car) to ensure that the car obtains maximum forward momentum.

6. L: Low. When going down a hill or a long slope, putting the gear here can limit the car's gear to the lowest gear (equivalent to the first gear of a manual transmission car) automatically, so that the car can use engine power for braking when going downhill, and the driver does not need to brake for a long time, which may cause the brake pads to overheat and cause danger.

7. OD: OD is the overdrive gear, which is used when driving at high speed to save fuel. After understanding the functions of each gear of the automatic transmission, you can enjoy the fun of driving an automatic transmission car.

Automatic car gear lever diagram introduction

The P gear on or below the gear lever of an automatic car is the parking gear, which is mainly used when parking. R is the reverse gear, which is suitable for reversing. N is the neutral gear, which is suitable for waiting at traffic lights. D is the forward gear, which is the general gear for driving. S is the sport gear, which is suitable for high-speed driving or overtaking. And L is the low-speed gear, which is suitable for climbing a hill.

The gear lever of an automatic car usually has six gear positions marked on it, namely P, R, N, D, S and L. P stands for parking, R for reverse, N for neutral, D for forward, S for sport and L for low speed. L and S correspond to the 1st and 2nd gears in manual transmission respectively.

Different gears are suitable for different environments. P gear is suitable for parking, R gear is suitable for reversing, N gear is suitable for temporary parking or waiting for traffic lights, D gear is the general driving gear, S gear is suitable for highway driving and overtaking, and L gear is suitable for climbing and descending hills.

When driving an automatic car, be careful not to coast in neutral. When waiting at a traffic light, put the car in neutral and pull the handbrake. When encountering a steep slope, switch to S or L gear so that the car has enough power to climb the slope. During driving, if the gear shift is slow, you can reduce the throttle a little and the car will automatically shift up.

Why don't automatic cars have clutches?

1. Torque converter. It is because of the emergence of this component that the driver's feet are freed. Its working principle is actually not complicated. The torque converter is located between the engine and the gearbox and is fixed on the rear plane of the flywheel. Its output shaft is the input shaft of the gearbox. When the driver changes gears, he only needs to push lightly to achieve precise gear shifting without any operation.

2. The specific working process of the torque converter is to use hydraulic oil as the specific working medium to transmit torque, change torque and change speed. Because it is connected between the engine and the transmission, the torque converter itself transmits power through hydraulic oil. Due to the loss of hydraulic force, it cannot be fully transmitted to the transmission, and the power generation is not in a gradual form.

3. The clutch is located in the flywheel housing between the engine and the gearbox. The clutch assembly is fixed to the rear plane of the flywheel with screws. The clutch output shaft is the input shaft of the gearbox. When shifting gears, it connects and cuts off the power of the engine and gearbox for smooth gear shifting.

Why won't an automatic car shut down?

1. The structure of automatic transmission is different from that of manual transmission. There is a device called hydraulic coupling and torque converter in the automatic transmission. Its transmission is to increase the pressure of hydraulic oil by rotating the pump wheel (driven by the engine) to achieve power transmission. This connection can also be called flexible connection. The common principle is: in a pipe with a diameter of 500 mm, both ends of the pipe (temporarily called A end and B end) are equipped with 500 mm electric exhaust fans. When the electric fan at the A end is powered on and rotates at high speed to press the wind force to the B end (the exhaust fan at the B end is not connected to the power supply), the exhaust fan at the B end will rotate with it; the speed of the exhaust fan B changes with the speed of the exhaust fan A. At this time, if the exhaust fan B is braked (similar to stepping on the brake), the exhaust fan A (similar to the engine) will still rotate. Therefore, the engine will not stall when the brake is stepped on in the driving gear.

2. Reasons for the unstable idle speed and flameout of automatic transmission cars: insufficient driving skills. Fuel quality problems. The car has oil leakage problems, which may be the fuel injector, throttle or fuel tank. The idle motor and throttle are blocked or the contact with the motor carbon brush is poor. The cylinder carbon deposits of the valve are not cleaned.