Design Methodology of Passenger Car Automatic Transmissions
Introduction
Automatic transmissions are a type of transmission that allows the driver to shift gears without using a clutch. They are typically used in passenger cars, but can also be found in other types of vehicles, such as trucks and buses.
Automatic transmissions are more convenient to use than manual transmissions, and they can also help to improve fuel economy. However, they are also more expensive to manufacture and maintain.
Design Considerations
When designing an automatic transmission, there are a number of factors that must be considered. These include:
Types of Automatic Transmissions
There are a number of different types of automatic transmissions, each with its own advantages and disadvantages. The most common types of automatic transmissions are:
Hydraulic Automatic Transmissions
Hydraulic automatic transmissions are the most common type of automatic transmission. They use a hydraulic fluid to transmit power from the engine to the wheels. Hydraulic automatic transmissions are relatively inexpensive to manufacture and maintain, and they offer a smooth and comfortable ride.
However, hydraulic automatic transmissions can be less efficient than other types of automatic transmissions, and they can also be heavier and bulkier.
Continuously Variable Transmissions
Continuously variable transmissions (CVTs) are a type of automatic transmission that uses a belt or chain to transmit power from the engine to the wheels. CVTs are more efficient than hydraulic automatic transmissions, and they can also be lighter and more compact.
However, CVTs can be more expensive to manufacture and maintain than hydraulic automatic transmissions, and they can also be less durable.
Dual-Clutch Transmissions
Dual-clutch transmissions (DCTs) are a type of automatic transmission that uses two clutches to transmit power from the engine to the wheels. DCTs are more efficient than hydraulic automatic transmissions, and they can also offer faster and more responsive shifting.
However, DCTs can be more expensive to manufacture and maintain than hydraulic automatic transmissions, and they can also be less durable.
Conclusion
The design of an automatic transmission is a complex process that requires careful consideration of a number of factors. The type of vehicle, the engine’s power and torque, the desired fuel economy, and the cost of manufacturing and maintenance must all be taken into account.
By understanding the different types of automatic transmissions and their advantages and disadvantages, engineers can design transmissions that meet the specific needs of their customers.
