The automatic transmission looks straightforward; just put it in Drive and Go. But like most things in the auto industry, making it more comfortable involves a lot of complexity.
The engine has a heavy center-cylinder rotating crankshaft that provides rotational power to the wheels.
“Engine speed” is the speed of the crankshaft, measured in revolutions per minute.
Most engines generate power over a relatively narrow speed range, but a more comprehensive range is needed to drive a vehicle.
The transmission is a vital link, increasing torque to speed up, stopping, or preventing the engine from rolling excessively on the highway.
The automatic transmission uses sensors to determine when to change gears and changes them using internal oil pressure.
While several components are built into the drivetrain, and its actual operation is a bit more complicated than the simplified version shown here, the key elements are the torque converter and planetary gears.
According to Meineke, most cars use a form of automatic transmission called hydraulic planetary automatic transmission, which is also used in a larger version in some industrial and commercial equipment and heavy vehicles.
A fluid clutch has replaced the friction clutches, and the system sets speed ranges according to the car’s needs.
When you park the vehicle, all gears are locked to prevent the car from rolling forward or backward.
A less common option is an Automated Manual Transmission (AMT). Sometimes called a semi-automatic transmission, this model combines manual clutches and transmissions with various actuators, sensors, processors, and tires.
AMTs operate like automatic transmissions while providing fuel savings and the economic advantages of a manual transmission.
With this transmission type, the driver can change gears manually or opt for an automatic transmission.
In any case, you do not need to use the clutch, which is operated by the hydraulic system.
History of the Automatic Transmission
General Motors and REO introduced semi-automatic transmissions for vehicles in 1934.
These models posed fewer challenges than a standard manual transmission but still had to use a clutch to change gears.
GM’s transmission was the first to use a hydraulically operated planetary transmission, allowing speeds to vary based on the vehicle’s ground speed.
The planetary transmission was among the most relevant events on the way to a modern automatic transmission.
Although GM was the first to use a version with hydraulic controls, this technology dates back to Wilson-Pilcher’s invention in 1900.
This innovation consisted of four gears on two trains, each of which could be moved with a single lever.
Automatic Transmission Operation
The most typical type of automatic transmission uses hydraulic power to change gears.
According to How Stuff Works, this device connects a torque converter or fluid clutch with gears that provide the vehicle’s desired speed range.
The torque converter combines the engine with the transmission and uses pressurized fluid to transfer power to the gears.
This device replaces the manual friction grip and allows the vehicle to come to a complete stop without stopping.
The Art of Manliness data describes the operation of the automatic transmission.
When the engine transmits power to the torque converter pump, the pump converts that power into transmission fluid that powers the torque converter turbine.
This device increases the fluid’s power and transmits even more power to the turbine, creating a rotating vortex that turns the turbine and the connected central shaft.
The power generated by this rotation is transmitted from the shaft to the first epicyclic gear. This type of transmission has what is termed hydraulic steering.
The pressurized pump oil has an oil pump, which allows the speed to be changed depending on the vehicle speed, the speed of the tires per minute, and other factors.
The gear pump is located between the epicyclic gear train and the torque converter, where it sucks and pushes the transmission fluid from the bearing.
The pump inlet leads directly to the torque converter housing connected to the flexible motor board.
When the engine is not functioning, the transmission does not have the oil pressure required to work, so the vehicle cannot be pressurized.
A planetary gear train is a mechanical system in which belts and clutches connect the gears.
As the driver changes gears, the belts maintain a fixed gear while rotating the other to transmit engine torque and increase or decrease gears.
Different gears are sometimes called planetary, ring, and planetary gears.
The arrangement of the gears determines the amount of power that will be transferred from one stage to another and into the vehicle’s driving.
Automatic Transmission Gears
Automatic transmission gears include the list below:
- As How a Car Works states, putting the vehicle into gear includes all available forward gears. This means the transmission can be shifted through the full range of gears as needed. Six-speed automatic transmissions are the most frequent number of gears, but older cars and compact beginner cars may have four or five automatic speeds.
- The third gear locks the transmission into the third gear or limits it to the first, second, and third gears. This gives the power and traction needed to go up a hill or tow a boat, caravan, or trailer. When the engine reaches the set speed per minute (rpm), most vehicles will automatically lower the third gear to prevent damage to the engine.
- The second gear locks the transmission in the second gear or the gear limit of the first and second gears. This equipment is ideal for climbing and descending slopes in slippery conditions and driving on ice, snow, and other bad weather.
- First gear is utilized when you want to clasp the transmission in first gear, although some vehicles automatically disengage from that gear to protect the engine at a certain rpm. This gear is best used for towing, driving uphill or downhill, and traveling in slippery and icy conditions like second and third gears.
Benefits of an Automatic Transmission
According to How Stuff Works, the most significant benefit of an automatic transmission is the strength to drive without requiring a clutch, as is required with a manual transmission.
People with many disabilities can drive automatically because the surgery only requires two useful limbs.
Clutch failure also eliminates the need to manually pay attention to gear changes and monitor the attachment to make necessary changes, giving you more time to focus on driving.
Many drivers also find operating an automatic transmission at low speed easier than a manual transmission.
The hydraulic automatic transmission creates a creep phenomenon, encouraging the vehicle to move even when idle.
While the gearboxes don’t require as much maintenance as the engine, they still get a little love.
Be sure to check the transmission fluid level with each oil change, and if your vehicle’s maintenance schedule recommends it, change the transmission fluid on demand.
Most transmissions include radiators to regulate the fluid temperature, but if you tow the vehicle frequently, consider adding a heavy-duty radiator if yours isn’t equipped for higher workloads.
