Introduction of Gyroscope

1. Sanjivani Rural Education Society’s
Sanjivani College of Engineering, Kopargaon-423603
( An Autonomous Institute Affiliated to Savitribai Phule Pune University, Pune)
NAAC ‘A’ Grade Accredited, ISO 9001:2015 Certified
Subject :- Theory of Machines II
T.E. Mechanical (302043)
Unit 5 GYROSCOPE
5.1 Introduction of Gyroscope
By
Prof. K. N. Wakchaure(Asst Professor)
Department of Mechanical Engineering
Sanjivani College of Engineering
(An Autonomous Institute)
Kopargaon, Maharashtra
Email: wakchaurekiranmech@Sanjivani.org.in Mobile:- +91-7588025393

2. INTRODUCTION
• A gyroscope is a device used for measuring or
maintaining orientation and angular velocity. It is a spinning wheel or disc in
which the axis of rotation (spin axis) is free to assume any orientation by itself.
• When rotating, the orientation of this axis is unaffected by tilting or rotation of
the mounting, according to the conservation of angular momentum.
• Gyroscopes can be used to construct gyrocompasses, which complement or
replace magnetic compasses (in ships, aircraft and spacecraft, vehicles in
general), to assist in stability (bicycles, motorcycles, and ships) or be used as
part of an inertial guidance system.
• Gyroscopes based on other operating principles also exist, such as the
microchip-packaged MEMS gyroscopes found in electronic devices,
solid-state ring lasers, fibre optic gyroscopes, and the extremely
sensitive quantum gyroscope.
• Applications of gyroscopes include inertial navigation systems, such as
in the Hubble Telescope, or inside the steel hull of a submerged
submarine. Due to their precision, gyroscopes are also used
in gyrotheodolites to maintain direction in tunnel mining.
• MEMS gyroscopes are popular in some consumer electronics, such as
smartphones. https://en.wikipedia.org/wiki/Gyroscope#:~:text=A%20gyroscope%20(from%20Ancient%20Greek,assume%20any%20orientation%20by%20itself.

3. INTRODUCTION
• In vehicles having engines with rotating parts of high moment of inertia, gyroscopic
forces are in action when the vehicle is changing direction of motion.
• When automotive vehicles turn with high velocities, gyroscopic forces act on spinning
parts such as crankshaft, flywheel, clutch, transmission gears, propeller shaft and
wheels.
• Engine parts as well as the propeller and the gear reduction system of an airplane are
under the influence of gyroscopic effects in turns and pullouts.
• Locomotives and ships are similarly affected.
• In this chapter, we shall study the gyroscopic and precessional motion of road vehicles,
aeroplanes and ships.

4. INTRODUCTION
• Gyroscope: It is a body which while spinning about an axis is free to move in other direction under the action of external
forces.
• Axis of spin: It is axis about which the body revolves.
• Gyroscopic effect: Consider a body spinning about an axis OX . If a couple represented by a vector OZ perpendicular to
OX is applied, then the body tries to precess about an axis OY, which is perpendicular to both OX and OZ. This combined
effect is called gyroscopic or precessional effect.
• The plane of spin, plane of precession, and plane of gyroscopic couple are mutually perpendicular.
• Precession: It means the rotation about the third axis OY, which is perpendicular to both the spin axis OX and the couple
axis OZ.
• Axis of precession: The third axis OY about which a body revolves and is perpendicular to both the spin axis OX and
couple axis OZ, is called the axis of precession.
• Mechanical gyroscope: It is a special mechanism generally employed for the control of angular motion of a body.
Gyroscope is an instrument, which appears as a device possessing intelligence. Gyroscopic effects can be used in several
applications for directional control, e.g. in Gyrocompass used on aeroplanes and ships and in inertia guidance control
system for missiles and space craft control.

5. Plane of Precession
Plane of
Spinning
Plane of Gyroscopic
couple
Axis of Spinning
AxisofPrecession
Plane of Precession
Plane of
Spinning
Plane of
Gyroscopic couple
INTRODUCTION

6. Axis of Spinning
AxisofPrecession

7. INTRODUCTION
Axis of Spin
x’
𝞈 + 𝞭𝞈
𝞈
o
𝞭𝞱
Axis of Spin
x
𝞭𝞱
x x A
x’
𝞈
Angular acceleration along OX

8. INTRODUCTION
Axis of Spin
x’
𝞈 + 𝞭𝞈
𝞈
o
𝞭𝞱
Axis of Spin
x
𝞭𝞱
x x A
x’
𝞈
Angular (or gyroscopic) acceleration perpendicular to OX,
𝞪 𝑪
𝞪 𝑪
𝞪 𝑪
𝞪 𝑪
This angular velocity of the axis of spin (i.e.
𝞉𝝷
𝞉𝐭
) is known as angular velocity
of precession and is denoted by 𝞈 𝐩

9. INTRODUCTION
Axis of Spin
x’
𝞈 + 𝞭𝞈
𝞈
o
𝞭𝞱
Axis of Spin
x
𝞭𝞱
x x A
x’
𝞈
Angular (or gyroscopic) acceleration perpendicular to OX,
𝞪 𝑪
𝞪 𝑪
𝞪 𝑪
𝞪 𝑪
This angular velocity of the axis of spin (i.e.
𝞉𝝷
𝞉𝐭
) is known as angular velocity
of precession and is denoted by 𝞈 𝐩

10. Nose EndTail End
Axis of Spinning
AxisofPrecession
Rotor Rotates in Anticlockwise direction.
Axis of Spinning

11. Tail EndNose End
Axis of Spinning
AxisofPrecession
Rotor Rotates in Anticlockwise direction.
Axis of Spinning

12. Nose EndTail End
Axis of Spinning
AxisofPrecession
Rotor Rotates in clockwise direction.
Axis of Spinning

13. Tail EndNose End
Axis of Spinning
AxisofPrecession
Rotor Rotates in clockwise direction.
Axis of Spinning

14. Anticlockwise
Nose EndTail End
Axis of Spinning
AxisofPrecession
Rotor Rotates in clockwise direction.
Axis of Precession
Left

15. Anticlockwise
Nose EndTail End
Axis of Spinning
AxisofPrecession
Rotor Rotates in Anticlockwise direction.
Axis of Precession
Left

16. Nose EndTail End
Axis of Spinning
AxisofPrecession
Rotor Rotates in clockwise direction.
Axis of Precession
Clockwise
Right

17. Nose EndTail End
Axis of Spinning
AxisofPrecession
Rotor Rotates in Anticlockwise direction.
Axis of Precession
Clockwise
Right

18. Anticlockwise
Nose EndTail End
Axis of Spinning
AxisofPrecession
Rotor Rotates in clockwise direction.
Left
Dip The Nose Raise the Tail
Axis of Gyroscopic coupleCondition
Nose End
CW
LEFT

19. Anticlockwise
Tail EndNose End
Axis of Spinning
AxisofPrecession
Rotor Rotates in clockwise direction.
Left
Raise The Nose Dip the Tail
Axis of Gyroscopic couple
Condition
TAIL End
CW
LEFT

20. Thank You….
20Subject :- Theory of Machines II