Car propeller shaft parts and function

The propeller shaft is one of the components included in the drive train system/wheel drive system. Propeller shafts are common in rear-drive cars and 4WD cars.

In general, the propeller shaft has the function to continue the rotation generated by the transmission to the axle shaft. However, to continue the rotation from the transmission to the axle on this vehicle is quite complicated. There are special conditions that must be met by the propeller shaft, for example:

Able to transmit the rotary force from the transmission to the axle gently.
Able to move freely up, down, and sideways while rotating from the transmission to the axle.
Able to move back and forth (sliding) when there is a change in angle between the transmission and the axle on uneven and bumpy roads.

Therefore, this propeller shaft is formed from several more components to meet the requirements required by a propeller shaft. So what are the parts of the propeller shaft, and what are their functions? Following are the parts of the propeller shaft and their functions in a vehicle.

1. Sleeve yoke

The first part of the propeller shaft is the sleeve yoke. The sleeve yoke has another name, called sliding joint or slips joint. It functions as a link between the transmission shaft and the propeller rod through a front universal joint.

The sleeve yoke is connected to the transmission output shaft. A serrated spline inside the front of the yoke sleeve will fasten the transmission output shaft. The U-shaped sleeve yoke on the back end connects to the front universal joint.

Functionally, the sleeve yoke has two main functions for the propeller shaft:

It connects between the transmission output shaft and the propeller rod through the front universal joint.
It is used as a place for shifting the propeller shaft to lengthen or shorten. A sleeve yoke is used when a distance change happens from the angle of the wheels and axles.

2. Universal joint

Universal joints on the propeller shaft are often known as a cross, spider, or hook joints. This universal joint is shaped like a plus sign (+), where a roller bearing is attached to each end.

The universal joint has two main functions for the propeller shaft:

As a liaison between the sleeve yoke and the propeller rod.
Allows the propeller shaft to rotate even if there is a change in angle between the shaft and transmission.

Yes, with the universal joint, the propeller shaft can move in several angles while rotating to compensate for height changes when passing uneven roads.

The number of universal joints on the propeller shaft is generally two at the front end, connected to the transmission output shaft, and the rear end connected to the axle shaft.

However, propeller shafts have more than two universal joints, known as three joint or more type propeller shafts (depending on the number of joints used)

The number of universal joints on the propeller shaft depends on the model and type of vehicle. The longer the car's wheelbase and the heavier the vehicle's weight, the more universal joints will increase.

3. Propeller rod (drive shaft)

The other parts of the propeller shaft is the propeller rod (drive shaft). The propeller rod is the main component of the propeller shaft. In general, the propeller rod's function is the part that will continue the twisting and turning forces from the transmission to the axle shaft.

The propeller rod is shaped like an elongated tube, made of mixed steel, which is empty in the middle. A U-shaped iron is attached at both ends of the propeller rod to connect to the universal joint for either the front universal joint or the rear universal joint.

At certain points of this propeller rod, we will find additional steel components attached to the propeller rod body. This component is known as the balance weight, which balances the propeller shaft while it rotates.

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4. Flange yoke

The next parts of the propeller shaft is the flange yoke. This flange yoke is made of mixed steel shaped like the letter U where the base connected to the axle shaft (differential) is made flat.

The flange yoke links the propeller rod and the axle shaft through the rear universal joint. This flange yoke allows universal joints to freely move when there is a change in angle between the transmission and the axle.

5. Center bearing

Center bearing on the propeller shaft generally only exist on type 3 joint or more propeller shafts. A Center bearing is a bearing that is installed right in the middle between the two propeller shafts.

In terms of function, there are at least four functions that the center bearing does on the propeller shaft, namely:

As a liaison between the two propeller shafts
Keep the propeller shaft rotation stable and straight
Reduces the torsional load on the propeller shaft
Reduces the vibrations that occur when the propeller shaft rotates.

The center bearing has a bracket that attaches directly to the body/frame of the vehicle. That way, the propeller shaft can rotate and work properly.