28-07-2014, 03:22 PM
AUTOMATIC
GEAR TRANSMISSION SYSTEM
[attachment=66338]
Introduction:-
Variety of controllers have been developed to improve driving as well as operating conditions of vehicles, such as to provide smooth throttle movement, zero steady state speed error, good speed tracking over rod slopes, and robustness to system variation and operating conditions. The complexity of the speed control algorithms has increased through the years to meet the Growing demands on more stringent automotive performance criteria. Only with the recent availability of inexpensive microprocessors more sophisticated control strategies have been implemented. The clutch-less automatic gear transmission system utilizes a gearbox that automatically changes the gear ratio, which allows the driver to simply select one gear to move or park the vehicle. There are two main types of transmission in cars: manual transmission and automatic transmission. The key difference between a manual and an automatic transmission is that the manual transmission locks and unlocks different sets of gears to the output shaft to achieve the various gear ratios, while in an automatic transmission the same set of gears produces all of the different but discrete gear ratios. The planetary gear set is the device that makes this possible in an automatic transmission. Manual transmissions can be very tiring to drive in heavy stop and-go traffic. It has the problem of Worn or slipping clutches. In cold weather manual transmissions can become sluggish and hard to shift. Also in the beginning can be difficult to learn.
History:-
This technology was first developed in the early 1900s in Germany for use in marine applications. The 1948 Oldsmobile was the first model to use a true automatic transmission. The Hyrdo-Matic, developed by GM engineer, Earl Thompson, was advertised as "The greatest advance since the self-starter." The Hydro-Matic went through continual upgrading and refinements through 1955. But, the basic design and theory used were consistent throughout its remarkably long life span. Americans lead the way in deploying automatics. Mercedes introduced their first automatic in 1962. Rolls Royce's 1955 intro was with GM's Hydro-Matic. Daimler (then owned by Jaguar) first used a BorgWarner 4-speed in 1962. Through the1980s changes and advances occurred quickly.
1. Rear wheel:-
On a rear wheel drive car, the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position. A drive shaft connects the rear of the transmission to the final drive which is located in the rear axle and is used to send power to the rear wheels. Power flow on this system is simple and straight forward going from the engine, through the torque converter, then through the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear wheels
2. Front wheel:-
On a front wheel drive car, the transmission is usually combined with the final drive to form what is called a transaxle. The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car. Front axles are connected directly to the transaxle and provide power to the front wheels. In this example, power flows from the engine, through the torque converter to a large chain that sends the power through a 180 degree turn to the transmission that is along side the engine. From there, the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles
Torque converter:
A type of fluid coupling, hydraulically connecting the engine to the transmission. It takes the place of a mechanical clutch, allowing the transmission to stay in gear and the engine to remain running while the vehicle is stationary, without stalling. A torque converter differs from a fluid coupling, in that it provides a variable amount of torque multiplication at low engine speeds, increasing breakaway acceleration. This is accomplished with a third member in the coupling assembly known as the stator, and by altering the shapes of the vanes inside the coupling in such a way as to curve the fluid's path into the stator. The stator captures the kinetic energy of the transmission fluid, in effect using the leftover force of it to enhance torque multiplication.
Advantages:-
*there is no clutch pedal in an automatic transmission car.
*Automatic Transmissions incorporate a lock-up clutch which provides a direct mechanical connection from the engine to the transmission. This maximizes fuel economy. Thus Automatic Transmission cars will always provide better fuel economy than Manual Transmission cars.
*The Torque Converter: torque converter is the main component in fully automatic transmission that provides many unique benefits such as multiplication of the engine torque and reduced shock and strain on the entire driveline. In Manual Transmission there is loss of momentum, power and speed because the clutch separates the engine from the transmission at every gear shift. IN Automatic transmission however, is more efficient because the engine and transmission are always connected.
*Automatic Transmissions incorporate a lock-up clutch which provides a direct mechanical connection from the engine to the transmission. This maximizes fuel economy. Thus Automatic Transmission cars will always provide better fuel economy than Manual Transmission cars
*A major concern for any driver is the loss of traction on muddy, slippery or slippery terrain. Automatic Transmission cars can be a solution to this concern as it can help maintain control even in the toughest ground conditions. The engine's power gets continually delivered to the wheels without any interruptions for gear shifts and thus the car can pull away gently.
*Lower running costs: The absence of the need for new clutches or flywheel regrinds for starters and the reduction of overall abuse on the rest of the driveline as compared to Manual Transmission helps keep the running costs low in Automatic Transmission cars.
Disadvantages:-
*automatics are more expensive
* Heavy maintenance
* Transmission boxes are heavier.
* Repair and maintenances are of high costs.
* Regularly need to change your automatic transmission fluid (ATF) during service intervals.
* A transmission will not work properly or may even slip or shudder with the incorrect fluid
Conclusion:-
Being able to drive a stick-shift means more than just understanding your gears, however.thats because to shift gears, you usually don’t just move shift lever and be done with it instead you have to press clutch pedal. to eradicate the gear shifting complication this system is implemented in the cars to make and understanding driving easy.
GEAR TRANSMISSION SYSTEM
[attachment=66338]
Introduction:-
Variety of controllers have been developed to improve driving as well as operating conditions of vehicles, such as to provide smooth throttle movement, zero steady state speed error, good speed tracking over rod slopes, and robustness to system variation and operating conditions. The complexity of the speed control algorithms has increased through the years to meet the Growing demands on more stringent automotive performance criteria. Only with the recent availability of inexpensive microprocessors more sophisticated control strategies have been implemented. The clutch-less automatic gear transmission system utilizes a gearbox that automatically changes the gear ratio, which allows the driver to simply select one gear to move or park the vehicle. There are two main types of transmission in cars: manual transmission and automatic transmission. The key difference between a manual and an automatic transmission is that the manual transmission locks and unlocks different sets of gears to the output shaft to achieve the various gear ratios, while in an automatic transmission the same set of gears produces all of the different but discrete gear ratios. The planetary gear set is the device that makes this possible in an automatic transmission. Manual transmissions can be very tiring to drive in heavy stop and-go traffic. It has the problem of Worn or slipping clutches. In cold weather manual transmissions can become sluggish and hard to shift. Also in the beginning can be difficult to learn.
History:-
This technology was first developed in the early 1900s in Germany for use in marine applications. The 1948 Oldsmobile was the first model to use a true automatic transmission. The Hyrdo-Matic, developed by GM engineer, Earl Thompson, was advertised as "The greatest advance since the self-starter." The Hydro-Matic went through continual upgrading and refinements through 1955. But, the basic design and theory used were consistent throughout its remarkably long life span. Americans lead the way in deploying automatics. Mercedes introduced their first automatic in 1962. Rolls Royce's 1955 intro was with GM's Hydro-Matic. Daimler (then owned by Jaguar) first used a BorgWarner 4-speed in 1962. Through the1980s changes and advances occurred quickly.
1. Rear wheel:-
On a rear wheel drive car, the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position. A drive shaft connects the rear of the transmission to the final drive which is located in the rear axle and is used to send power to the rear wheels. Power flow on this system is simple and straight forward going from the engine, through the torque converter, then through the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear wheels
2. Front wheel:-
On a front wheel drive car, the transmission is usually combined with the final drive to form what is called a transaxle. The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car. Front axles are connected directly to the transaxle and provide power to the front wheels. In this example, power flows from the engine, through the torque converter to a large chain that sends the power through a 180 degree turn to the transmission that is along side the engine. From there, the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles
Torque converter:
A type of fluid coupling, hydraulically connecting the engine to the transmission. It takes the place of a mechanical clutch, allowing the transmission to stay in gear and the engine to remain running while the vehicle is stationary, without stalling. A torque converter differs from a fluid coupling, in that it provides a variable amount of torque multiplication at low engine speeds, increasing breakaway acceleration. This is accomplished with a third member in the coupling assembly known as the stator, and by altering the shapes of the vanes inside the coupling in such a way as to curve the fluid's path into the stator. The stator captures the kinetic energy of the transmission fluid, in effect using the leftover force of it to enhance torque multiplication.
Advantages:-
*there is no clutch pedal in an automatic transmission car.
*Automatic Transmissions incorporate a lock-up clutch which provides a direct mechanical connection from the engine to the transmission. This maximizes fuel economy. Thus Automatic Transmission cars will always provide better fuel economy than Manual Transmission cars.
*The Torque Converter: torque converter is the main component in fully automatic transmission that provides many unique benefits such as multiplication of the engine torque and reduced shock and strain on the entire driveline. In Manual Transmission there is loss of momentum, power and speed because the clutch separates the engine from the transmission at every gear shift. IN Automatic transmission however, is more efficient because the engine and transmission are always connected.
*Automatic Transmissions incorporate a lock-up clutch which provides a direct mechanical connection from the engine to the transmission. This maximizes fuel economy. Thus Automatic Transmission cars will always provide better fuel economy than Manual Transmission cars
*A major concern for any driver is the loss of traction on muddy, slippery or slippery terrain. Automatic Transmission cars can be a solution to this concern as it can help maintain control even in the toughest ground conditions. The engine's power gets continually delivered to the wheels without any interruptions for gear shifts and thus the car can pull away gently.
*Lower running costs: The absence of the need for new clutches or flywheel regrinds for starters and the reduction of overall abuse on the rest of the driveline as compared to Manual Transmission helps keep the running costs low in Automatic Transmission cars.
Disadvantages:-
*automatics are more expensive
* Heavy maintenance
* Transmission boxes are heavier.
* Repair and maintenances are of high costs.
* Regularly need to change your automatic transmission fluid (ATF) during service intervals.
* A transmission will not work properly or may even slip or shudder with the incorrect fluid
Conclusion:-
Being able to drive a stick-shift means more than just understanding your gears, however.thats because to shift gears, you usually don’t just move shift lever and be done with it instead you have to press clutch pedal. to eradicate the gear shifting complication this system is implemented in the cars to make and understanding driving easy.