SECTION B
Question 12
(Use the sketch in Fig. 1 to answer question 12
Fig.1: Propeller Shaft
- Name the parts labelled V, W, X, Y and Z.
- State one function of the component in automobile transmission system.
- State the function of the part labelled Z.
- State three operational steps taken in checking the component for straightness.
Observation
Candidates’ performance in this question was not satisfactory.
Solution to the question
- Names of Labelled Parts
V: Spider/Trunion/Universal joint
W: Spline
X: Yoke
Y: Tubed shaft
Z: Sliding Joint
- Functions of Propeller Shaft
- It connects the output shaft of the gearbox to the final drive.
- It withstands the torsional stresses of the transmitting torque.
- Continuous rises and falls of the rear axle is compensated for by the splines on the shaft.
- It ensures that the pinion nose is forced upward when engine torque is applied to the pinion and is forced down when the brakes are applied.
- Function of Sliding Joint (the Part Labelled Z)
It (Sliding Joint) varies the length of the propeller shaft in line with road condition and suspension system.
- Operational Steps Taken in Checking Propeller Shaft for Straightness
- Placing a pair of V-block on a surface table
- Placing the propeller shaft on the V-block
- Moving a dial indicator or surface gauge along the length of the shaft
- Rotating the shaft through 90o
- Determining the straightness by the reading on the dial indicator or variation from the surface gauge