Introduction
Propeller shaft is the most important
part of transmission system of a vehicle. It is located in between the gear box and the differential unit. One end of the propeller shaft is connected to the gear box and the
other end is connected with the differential unit, and transmits the engine power to the rear wheels. The two ends of propeller shaft are connected by the universal joints and
hence the engine’s power is transmitted to the rear wheels without any losses even with
the difference in distances. For operating the propeller shaft based on various load conditions of vehicle, sliding joint is fitted in between the universal joint and propeller shaft. The propeller shaft withstands the
full accelerating power comes from the gear box.
Material of Propeller shaft
It is made of hardened steel and
in tubular form. Two propeller shafts
are used if the vehicle length is more.
Bearing is fitted between the centre of
two propeller shafts.Propeller shaft is generally made up of alloy steel. Moreover it is made up of spring steel material.
Functions of propeller shaft
• It transmits the engine’s power from
gear box to the differential unit
smoothly.
• It transmits the rotational power from the gear box at different angles as per requirement.
• According to the load of the vehicle,
the length of the propeller shaft varies
and transmits the power through slip
joints.
• When the vehicle is running, it
completely withstands the vibration
occurring in the transmission system.
Types of propeller shaft drive
The operation of propeller shaft is
classified in to two types. They are
1. Hotchkiss Drive
2. Torque tube Drive
Hotchkiss drive
Construction
In this drive, the leaf springs are
tightly fixed at the center of the axis of rear axle. The back end of the spring is attached with Shackle (movable). The front end is attached to the chassis frame with anchor pin (fixed). The two universal joints and a sliding joint were connected to the Propeller Shaft. The first universal
joint is connected to the gear box shaft and second universal joint is attached with the bevel pinion shaft of the differential unit.
Working Principle
When the vehicle goes forward with
more loads, the front end of the propeller shaft elongates and the rear end of the leaf spring is pressed and the front part of the spring is elongated. This happens due to
the front and backward movements of the universal joint and sliding joint located at the front end of the propeller shaft. Due to this the vehicle moves easily on the road.This Hotchkiss drive is used in most of the vehicles. This type of drive makes the vehicle to move smoothly even
on the roads with ups and down.
Advantages
1. Weight is less
2. Simple in construction
3. It does not make more noise.
Disadvantages
1. Not protected well as the arrangement is in open outdoors.
2. Universal joints get damaged easily.
Torque tube drive
Construction
The propeller shaft of the vehicle is
kept inside on another tube called as the torque tube which looks like a pipe.
The bearing which is connected to
this allows the propeller shaft to rotate easily. Only one universal joint is fitted in this drive. The front part of the torque tube is like a cone and is connected at the back side of the gear box casing by using a ball and socket joint.
Working Principle
When the vehicle moves on the
road, the torque and the drive thrust are transmitted to the chassis frame through axle casing. Since the ball and socket joint in the torque tube is supported by the roller bearing, the propeller shafts rotates easily. This torque tube drive is mostly used in cars and in heavy commercial vehicles.
Advantages
1. It’s very safe to use.
2. It works for a long time.
3. Universal joint in this drive will not
damage quickly
Disadvantages
1. Overweight.
2. It is not very strong.
3. It is not suitable for transmitting more power.
