This document provides an overview of bogies used in Jaipur Metro trains. It discusses the key components of bogies, including wheels, axles, suspension systems, and traction motors. It also outlines the main functions of bogies in supporting loads, transmitting traction and braking forces, and ensuring stable riding quality. The document is divided into chapters that cover bogie fittings and characteristics, the mechanical drive system, how bogies function, their design and major components, and aspects of bogie maintenance.
1. A
TABLE OF CONTENT
INTRODUCTION
CHAPTER 1: BOGGIE
1.1 BOGGIE FITTINGS
1.2 CHARACTERISTICS
CHAPTER 2: MECHANICAL DRIVE SYSTEM
2.1 DRIVE SYSTEM
2.2 MAINTENANCE
CHAPTER 3:FUNCTIONING OF BOGIE
3.1 LOAD SUPPORT
3.2 HAULING
3.3 RIDE QUALITY
3.4 NEGOTIATE CURVE
3.5 VEHICLE DEFLECTION
CHAPTER 4: DESIGN AND COMPONENTS
4.1 DESIGN AND ENGINEERING
4.2 MAJOR COMPONENTS
CHAPTER 5: BOGIE MAINTENANCE ASPECTS
5.1 BOGIE FRAME
5.2 Axles & Wheelsets
5.3 PRIMARY SUSUPENSION
5.4 SECONDARY SUSPENSION
5.5 ANTI-ROLL BAR
5.6 VERTICAL DAMPER
5.7 BOGIE TESTS
CONCLUSION
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INTRODUCTION
Jaipur Metro is a rapid transit system in the city
of Jaipur, Rajasthan, India Construction on the mostly elevated part of the first
line, called Phase 1A, comprising 9.63 kilometres (5.98 mi) of route
from Mansarovar to Chandpole Bazaar, started on 13 November 2010, and was
completed in 2014. The project's commercial run was delayed to December 2014,
and then to April 2015. After receiving safety clearance from Commissioner of
Metro Rail Safety (CMRS) in May 2015, Jaipur Metro began commercial service
between Chandpole and Mansarovar on 3 June 2015. The Jaipur Metro Rail system
is India's sixth metro rail system after those in Kolkata, Delhi
NCR, Bangalore, Gurgaon and Mumbai. Jaipur Metro is the first metro in India to
run on triple-storey elevated road and metro track.
ROUTE OF METRO
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CHAPTER 1
BOGIE:
Bogie is a frame work carrying wheel sets, traction motors, gears, brakes and
suspension system. Main functions are:
i. Support the car body.
ii. Allow relative movement between car body & bogie.
iii. Ensure stable running.
iv. Ensure adequate ride comfort.
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Bogie Fittings
Wheel disc
The wheel-mounted brake disc is that part of the vehicle brake system that
serves to convert kinetic energy into heat by means of friction. The wheel-
mounted brake discs are heated by braking as they rub against the brake pads
during braking. Cooling is provided by a stream of air generated by the fanning
effect of the rotating wheel. The air flows between the brake disc and wheel
web, passes through radically arranged cooling fins, and carries off the heat
into atmosphere
Driving Gear:
The driving gear is mounted on both of the transom and the power motor axle.
One side of the driving gear is mounted to the transom by the reaction rod,
which is resiliently fixed by a rubber bush to the bogie frame and another is
mounted to the axle by the large gear wheel of the driving gear, which is fitted
into the axle by an interference fit method.
Traction Motor
The traction motor is bogie frame mounted type, complete with suitable and
suspension and transfers the traction force the electro-dynamic braking force
to the driving gear by means of the gear coupling. The traction motor is
mounted on bogie frame.
Wheels
The mono block wheels have a tread diameter of 860mm in new condition, and
780mm in maximum worn condition. Wheels for each bogie are equipped with
two wheel disks.
Centre Pivot Device
The center pivot device forms the main connection between the bogie and the
carbody. This allows for full movement of the bogie (lateral, vertical, yaw and
pitch) with respect to the carbody structure but restricts the longitudinal
displacement between the bogie and the carbody. Traction and brake forces are
transmitted to the carbody from the bogie by means of the center pivot device.
Vertical Hydraulic damper
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secondary spring assembly without disconnection or removal of the
carbody from the bogie.
TBU
The friction wheel mounted disk brakes are on the DT, M & T bogie frame.
One parking brake per axle is installed.
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Main characteristics of the Bogie
Track gauge 1,435mm
Maximum Axle load 16Tonne
Maximum design speed
inflated secondary suspension 95km/h
deflated secondary suspension 80km/h
Maximum service speed
inflated secondary suspension 85km/h
deflated secondary suspension 70km/h
Wheel base 2,200mm
Wheel Diameter(new/worn) 860 / 780mm
Distance between journal centers 2,100mm
The minimum clearance of bogie
mounted equipment
75mm(at worn wheel and fully loaded static)
Approximate un-sprung mass M bogie : 3,920 kg DT bogie : 3,300kg
Approximate bogie weight M bogie : 8,500 kg DT bogie : 6,150kg
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CHAPTER 2
MECHANICAL DRIVE SYSTEM
DRIVE SYSTEM
• Consists of-Traction motor, drive gear assembly, gear coupling and traction link
(torque arm or reaction link)
• Traction motor is mounted on bogie frame on the transom
• Drive gear is connected to traction motor through a flexible coupling and
connected to transom via traction link
• Flexible coupling transfers the traction force and electro dynamic braking force
from traction motor to gear box
• In the event of failure of traction link, a safety bracket provided in the drive gear
prevents drive gear from falling on the sleepers
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MAINTENANCE
• Driving gear & traction motor must be inspected every 6000km for oil level
and temperature rise
• For a newly assembled drive gear, first oil change shall be done at 20000km
• At every 150000km or 1 year (whichever is earlier) oil must be changed
• General inspection for driving gear & traction motor shall be carried out after
420000km
• Drive gear & traction motor must be overhauled and completely serviced after
840000km
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CHAPTER 3
FUNCTIONING OF BOGIE
LOAD SUPPORT
• Passenger distribution is neither continuous nor uniform
• Loading pattern changes during the running of vehicle
• CG of passenger load changes with running condition
• Intermittent moments are generated within the bogie-carbody system
• Hence a counter measure to nullify these moments is required-AIR SPRINGS
Air springs/Bellows/Secondary Suspension…etc
HAULING
• To impart motion to vehicle by transferring traction forces
• To overcome track friction for vehicle motion
• To stop vehicle by transferring braking forces
• Hence traction motor, gear box and brake system is required
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RIDE QUALITY
• Improve ride quality by damping the vibrations and oscillations
• Wheel-track interaction generates oscillations
• Bogie sub systems like traction motor, gearbox, brakes etc. also generate
vibrations
NEGOTIATE CURVE
• To safely negotiate tighter curves without derailing
• Inner wheels have a different speed than the outer wheels
• No differential gear box exists in a bogie contrary to on road vehicles
• Max wheel and track wear occurs at curve
• Hence a lubrication system is needed
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VEHICLE DEFLECTION
• Yaw, pitch and roll movements have to be controlled
• Soft springs results in more deflection while stiffer springs reduce ride comfort
• Bumping at vertical curves and track irregularities should be kept minimum
• Optimum selection of suspension and control system becomes important
• Hence anti-roll bar and two stage suspension system is required
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Majorcomponents of the Bogie
Motor bogie Trailer Bogie
Bogie Frame
Conventional H frame
with end beam
Conventional H frame with
end beam
Wheel sets
Monobloc wheel +
Solid Axle
Monobloc wheel + Solid Axle
Taper roller Bearing Taper roller Bearing
Driving system
Driving Gear + Flexible
Coupling
Friction Brake
system
Wheel Mounted disc
Brake
Wheel Mounted disc Brake
Primary
suspension
Conical rubber spring Conical rubber spring
Secondary
suspension
Air spring + Vertical
damper + Anti-roll
bar
Air spring + Vertical damper +
Anti-roll bar
Traction system
Center Pivot + mono-
link + Lateral
damper
Center Pivot + mono-link +
Lateral Damper
Additional Items Lubricator Lubricator
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CHAPTER 5
BOGIE MAINTENANCE ASPECTS
BOGIE FRAME
Inspect following-
• Weld cracks
• Rust marks
• Painting and surface coating
• Interference marks
• Integrity of brackets
Corrective action-
• MPI test for welds
• Degrease and re-paint after shot
blasting
• Apply metal paste for deep dents
• Check clearance for interfering part
Axles & Wheelsets
Inspect following-
• Relative movement between
wheel and axle
• Condition of sealant
• Painting and surface coating
• Dents and pitting
• Wheel profile
• Wheel gauge
• Corrosion
• Overheating
Corrective action-
• Rotation greater than 5deg,
replace wheel
• Axle end play more than 2mm,
replace assembly
• Re-apply sealant
• Apply metal paste, primer and re-
paint
• Re-profile wheel if necessary
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PRIMARY SUSUPENSION
Inspect following-
• Surface condition of spring, cracks
greater than 3mm,
• Crown height at 4 locations
• Fasteners integrity
• Deflection in 3 directions-
compression test
Corrective action-
• Replace spring for deeper cracks
• Insert liners to maintain crown
height
• Replace locking plates and apply
torque to fasteners
• 10% variation in stiffness is
acceptable
SECONDARY SUSPENSION
Inspect following-
• External surface for cracks,
depositions etc.
• Check height at tare load
Corrective action-
• Ozone cracks deeper than 5mm-
replace diaphagram
• Check height at tare load, if less
than 300mm, insert liners
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ANTI-ROLL BAR
Inspect-
• Surface defects like paint, cracks,
corrosion etc
• Abrasion
• Alignment of fork arms Cracks in
double bearing assembly
• Condition of rubber bearings
Corrective action-
• MPI inspection
• Abrasion more than 1mm due to
any defect makes it unfit for use
• UT is advisable at every
420,000kms
• Alignment of fork arms deviate
more than 0.5mm, replacement is
advised
• Cracks in DBA makes it unfit for
use
• Rubber bearing if de-formed or
cracked, better replace
• Re-paint after de-greasing for
surface defects
VERTICAL DAMPER
Inspect-
• Oil leakage
• Dents or signs of collision
• Surface condition of rubber bush
• Tightness of fasteners and fittings
Corrective action-
• Oil leakage or dripping on piston
tube is serious
• Dents with depth greater than
10mm-replace dampers
• Cracks deeper than 5mm-replace
damper
• Tightness of fasteners and fittings
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BOGIE TESTS
• Static & fatigue tests for bogie frame
• Clearance checking between bogie-carbody in inflated & deflated air springs
• Wheel unloading test (static & dynamic)
• Load deflection test and accelerated ageing test for primary suspension
• Ride index test
• Type test for brake lining & main components
• Rotational resistance test
• Ultrasonic test for axles
• Oscillation test (for measuring acceleration in lateral & vertical directions)
• Rotational resistance test (x-factor measurement)
• Wedge test( natural frequency of bogie & damping factor measurement)
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CONCLUSION
Overall I had a great experience while training with the engineers of Jaipur metro.
I feel very fortunate to be part of such a governmental organisation . this summer
training helped me in growing a lot and getting a deeper look into several mechanisms
and about metro trains.
Thanks to JMRC staff and Amit K. Bansal sir for making my training a worth journey.
