Driven shaft

Types of driven shafts

A driven shaft is a component of a vehicle transmission system that transmits power from the engine to the wheels. It rotates to deliver torque, which accelerates the vehicle. Generally, there are three major types of driven shafts, which are described below.

• Propeller shafts

  The propeller or drive shaft is a long, cylindrical metal component that connects the transmission system to the rear axle. In rear-wheel-drive vehicles, it transmits power to the rear wheels. Power is transmitted through universal joints located at both ends of the propeller shafts. Some modern vehicles have a single propeller shaft, while others have two connected by a shaft or intermediate bearing.

• Drive shafts

  A drive shaft transfers torque generated from the rotation of the motor to the wheels, allowing a car to move. Front-wheel drive vehicles typically have a single drive shaft connected directly to the wheels. Rear-wheel vehicles have two drive shafts due to the longer distance from the transmission to the wheel. Rear and front-wheel drive shafts work similarly, but four-wheel and all-wheel vehicles have an extra drive shaft located centrally that transfers torque to the four wheels.

• Flexible shafts

  Flex shafts are unique drive shaft types used mainly in high-performance vehicles. They consist of a metal housing that carries coils of spring steel. This coil can bend and twist, allowing them to easily maneuver and transmit power to the wheels despite the vehicle's movement.

Specification and maintenance of driven shafts

Specification

• Material: Noticeably, the material of the drive shaft affects the overall weight of the car. As such, numerous automobile manufacturers have selected lightweight materials like aluminum alloys or carbon fiber for their vehicles. This choice enhances fuel efficiency and minimizes energy consumption by reducing the car's weight.
• Sizes: The universal joints of a drive shaft have a known diameter of 76mm/3 inches. The diameter is big enough for the u-joint to fit. For bigger vehicles like trucks, however, the diameter will be bigger to transfer more power.
• Lengths: Drive shafts can be found in numerous lengths depending on the kind of car. Conventional sedans with long drive shafts may have lengths of about 60 cm to 80 cm. Shortened drive shafts can be found in sedan models with rear-wheel drives measuring approximately 40 cm to 60 cm.

Maintenance

• Check the connection: One should frequently inspect the connections of the drive shafts to see if there are any breaking or loosening issues. If any issue arises, the user should tightly fasten the parts and then seek expert help in case of significant disturbances.
• Lubrication: Lubrication is vital for the u-joint, which is always under immense pressure as it pivots to enable the wheels to move. Keeping it well-lubricated aids in reducing friction during movement. As a result, it will wear out slowly, and its lifespan will be extended.
• Balanced driveshaft: If a driven shaft is out of balance, it will vibrate and cause excessive wear. Therefore, it is imperative to ensure that the driving shafts are balanced all the time.

Industry scenarios of driven shafts

Driven shafts are commonly found in a few industries. The agricultural industry as a whole makes extensive use of shafts. Various farm equipment, such as harvesters, tractors, tillers, and power mowers, have operational units that consist of driven shafts.

In the mining industry, driven shafts are used in ore conveyor belts. The driven shaft transfers impetus to the belt, enabling it to move ore from the bedrock in the bowels of the earth to the surface. Moreover, some ore processing machinery employs driven shafts to help them work.

The automotive industry uses driven shafts extensively. The drive shaft of an automobile is an example of a driven shaft working under the impact of high torque.

The manufacturing industry often employs belts, fans, and pumps that have driven shafts as part of their machinery.

Among emerging industries, the wind energy industry employs driven shafts in wind turbines to convert kinetic energy into electrical energy.

How to choose driven shafts

Stock driven shafts are commonly used in standard applications, while custom driven shafts are usually applied in specialized industries (e.g., aerospace applications). Depending on specific needs, customers can choose driven shafts made of various materials.

• Core material: The core of a driven shaft is usually made of steel (e.g., alloy steel or stainless steel). The steel material gives the driven shaft excellent tensile strength, which helps the shaft to overcome heavy loads and high levels of pressure with ease.
• Surrounding material: The surrounding (or known as the casing) of a driven shaft is often composed of aluminum alloy or stainless steel. Aluminum alloy casings provide lightweight features to driven shafts, making them suitable for high-speed rotation. However, this kind of material is not ideal for heavy loads. Aluminum alloy casings may crack or deform if the loads are too heavy. Stainless steel casings have more excellent durability than aluminum alloy casings. Businesses can apply them to heavy industries.

U-joint

A universal joint, or U-joint, connects two shafts that are not in line with each other. It allows the driven shaft to transfer torque even though the driving shaft and the driven shaft are at different angles. U-joints are widely used in automotive applications.

Double Cardan

A Double Cardan is a more complex version of a U-joint. It has two yokes surrounding an intermediate shaft in an angled configuration. The Double Cardan provides smoother motion and higher load-carrying capability than U-joints. They are often used in off-road vehicles or applications where higher angles are involved.

Fixed joint

Also known as a rigid joint, fixed joints connect two shafts at a set angle. They allow torque to transfer without slip or loss. While fixed joints offer advantages like precise movement and uncomplicated construction, they are limited by the angle they can operate.

FAQ

Q1: When does a drive shaft need to be replaced?

A1: Users may notice the driveshaft issue by hearing strange noises like grinding or rattling. Besides, there will be a noticeable vibration in the car, especially when accelerating. In severe circumstances, failure to replace the propshaft could disconnect the wheels from the vehicle. In this case, people need to replace the drive shaft immediately.

Q2: What are the symptoms of a failing drive shaft?

A2: The failing drive shaft will cause several symptoms. The most common signs include knocking sounds, vibrations, twist, or slip. The knocking sounds usually occur when the U-joint wears out. The drive shaft may vibrate if it's out of balance or the bearings are damaged. A bad drive shaft might fail to spin.

Q3: What materials are used for a drive shaft?

A3: The drive shaft could be made from different materials like alloy steel, aluminum alloy, carbon fiber, or any other tubular material. Aluminum and carbon fiber are lightweight materials that can reduce the total vehicle weight. However, they are only suitable for some cars and are more expensive. Most cars use steel due to its durability and strength.