G Veerapathiran et al. Int. Journal of Engineering Research and Applications www.ijera.

com
ISSN : 2248-9622, Vol. 5, Issue 3, ( Part -5) March 2015, pp.20-25

RESEARCH ARTICLE OPEN ACCESS

Power Transmission Through Timing Belt In Two Wheeler

Motors
Gurumurthy Veerapathiran1, Prabu Dhanapal1, Ranjithkumar Koumaravel2,
Padmanaban Narayanamoorthy2, Vignesh Ravi2, Chandran2
1
assistant Professor, Department Of Mechanical Engineering, Dr.Sjs Paul Memorial College of Engineering And
Technology, Puducherry
2
research Scholars, Department Of Mechanical Engineering, Dr.Sjs Paul Memorial College of Engineering
And Technology, Puducherry

Abstract
This paper studies the effect of noise and friction on performance of the chain drive system for motor bikes.
Experiment shows that chain transmission in chain drive system leads to poor overall performance, due to its
noise and chain gets loose due to aging and sprockets wear due to chain friction etc., the proposed system
consists of drive and driven pulley with timing belt transmission. Compared to conventional method, proposed
method give improved tension in pulleys and belt by the additional arrangement called belt tensioner. This
gives good overall performance of the system, and reduces noise, vibration and gives high transmission speed.
Keywords: Timing belt, Transmission system, Belt drive.
the caseofrollerchains.
I. INTRODUCTION
Timing belts are parts of synchronous rive II. CONSTRUCTION & WORKING
which represent an important category of drives. Belt Construction
Characteristically, these drives employ the positive The load-carrying elements of the belts are the
engagement of two sets of meshing teeth. Hence, tension members built into the belts. These tension
they do not slip and there is no relative motion members can be madeof:
between the two elements in mesh. Due to this 1. Spirallywoundsteelwire.
feature, different parts of the drive will maintain a 2. Woundglassfibbers.
constant speed ratio or even a permanent relative 3. Polyestercords.
position. This is extremely important in applications 4. Kevlar.
such as automatic machinery in which a definite The tension members are embedded in neoprene
motion sequence and/or indexing is involved. or polyure thane. The neoprene teeth are
The positive nature of these drives makes them protectedbyanylonfabricfacingwhichmakesthemwear
capable of transmitting large torques and with resistant.Thecontributionsoftheconstructionmembers
standing large accelerations. Belt drives are ofthesebeltsareasfollows:
particularly useful in applications where layout
flexibility is importan. They enable the designer to 1.TensileMember–Provides high strength, excellent
place component sinmo read vantageous flex life and higher sistance to elongation.
locationsatlarger distances without payinga price
penalty. Motors, which areusually thelargesthea 2. NeopreneBacking –Strong neoprene bonded to
tsource, can be place daway from the rest of the the tensile member for protection against grime, oil
mechanism. Achieving this with a gear train would and moisture. It also protects from frictional wear if
represent anexpensive solution. idlers are used on the back of the belt.
Timing belts are basically flat belts with a series
of evenly spaced teeth on the inside circumference, 3. Neoprene Teeth– Shear-resistant neoprene
thereby combining the advantages of the flat belt compound is melded integrally with the neoprene
with the positive grip features of backing. They are precisely formed and accurately
chainsandgears.There is no slippage or creep as with spaced to assure smooth meshing with the pulley
plain flat belts. Required belt tension is low, grooves.
therefore producing very small bearing loads.
Synchronous belts will not stretch and do not require 4. NylonFacing–
lubrication. Speed is transmitted uniformly because To ughnyl on fabric with alowco efficient off
riction covers the wearing surfaces of the belt. It
there is no choralrise and fall of the pitch line as in protects the tooth surfaces and provides a durable
www.ijera.com 20 | P a g e
G Veerapathiran et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 3, ( Part -5) March 2015, pp.20-25

wearing surface for long service Thermal Conductivity 0.19 W/m-k

Material Selection
1. Chloroprene III. DESIGN
2. Fibber glass cord
3. Polyester
4. Kevlar

Polyester
Tensile Strength 160,000 lbs/in2
Elongation at break 14.0%
Modulus (approx.) 2,000,000 lbs/in2

Kevlar
Tensile Strength 400,000 lbs/in2
Elongation at break 2.5%
Modulus 18,000,000 lbs/in2

Fiberglas
Tensile Strength 350,000 lbs/in2 Open Belt Drive
Elongation at break 2.5 – 3.5% dL-Diameter ofthelarger pulley
Modulus 10,000,000 lbs/in2 dS–Diameter ofthesmaller pulley
αL-Angle of wrap of the larger pulley
Chloroprene
αS-Angle of wrap of the Smaller pulley
Tensile Strength 7 to 14 Mpa (1.0 to 2.0 x
103 psi) C- Centre distance between the two pulleys
Elongation at break 250 to 500%

Pulley and Belt Geometry

The trapezoidal shape timing belt was Stress pattern in belts

supers ededbyacurvilinear tooth profile which The photo elastic pattern shows the stress
exhibited some desirable and superior qualities. distribution within teeth of different geometry.
Advantage soft his type of drive are as follows: There is a definite stress concentration near the root
Proportionally deeper tooth; hence tooth jumping or of the trapezoidal belt tooth, with
loss of relative position is less probable. Light er verylowstrainselsewhere. Forth ecurvilineartooth,
construction, thereisauniform, nearlyconstant, strain distributiona
withcorrespondinglysmallercentrifugalloss. Smaller crossthebelt. The loadisl argest in the directi on of
unit pressure on the tooth since area of contact is the tension member to which it is transferred.
larger. Greatershearstrengthduetolargertoothcross Becauseoftheirsuperiorloadcarryingcapabilities,thec
section Lower cost since an arrowerbelt will handle urvilinearbeltsaremarketedunder
larger load. Energy efficient, particularly if replac in thenameofGates'HTDdrives. This is an abbreviation
ga"V" belt of High Torque Drives. Asa result of continuous
drivewhichincursenergylossesduetoslippage. research, a newer version of the curvilinear
technology was developed by Gates, which was
Installationtensionissmall,therefore,lightbearingload
design a ted as Gates' Power Grip GT be lt drives.
s.
Tension member

www.ijera.com 21 | P a g e
G Veerapathiran et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 3, ( Part -5) March 2015, pp.20-25

Trapezoidal Curvilinear

Basic Belt Dimensions

Belt tooth profile

The highest density 5mm rubber belt, the Power combination increases capacity, while improving
Grip GT3 belt has twice the load carrying capacity of registration. Power Grip GT3 has more tooth ratchet
its predecessor HTD. In addition, less width is resistance than HTD. Eliminates lubrication and re-
required compared to HTD, allowing lighter, more tensioning reduce maintenance and labour as
compact drives. compared to roller chain drives. Power Grip GT3
Power Grip GT3 belts are suitable for many belt/sprocket combinations match or exceed the
applications such as HVAC, office machines, positional accuracy of Power Grip Timing belt/pulley
machine tools, hand power tools, postage handling, systems.
spindle drives, food processors, sewing machines,
robotics, linear and light package conveyor.Fiberglas
tensile cord provides high strength excellent flex life
and high resistance to elongation. Neoprene body Noise Graph
provides protection against grime, grease, oil, and The smoother meshing action of the Power Grip
moisture. Nylon tooth facing provides a durable wear GT belt, with its optimized design, produces
surface for long service life. Gates patented tooth significantly lower noise levels when compared with
profile is designed for use with a specific sprocket other similar sized belt types operating under
groove profile. The sprocket groove-belt tooth similarspeedsandtensions. These improvements are
www.ijera.com 22 | P a g e
G Veerapathiran et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 3, ( Part -5) March 2015, pp.20-25

enhanced by the factthatnarrower belts can beused The greatly increased durability of the Power
duetoin creased power capacities. Grip GT design has resulted in power capacities far
above those quoted for similar size belts of previous
designs. The resulting small drive packages will
increase design flexibility, space utilization and cost
effectiveness.

Noise Level Graph

Durability

Comparison of performance ratios for various belts

Belt Design selection

Horsepower Rating at Low Speed

WORKING motion, to transmit power efficiently, or to track
A belt is a loop of flexible material used to relative movement. Belts are looped over pulleys and
mechanically link two or more rotating shafts, most may have a twist between the pulleys, and the shafts
often parallel. Belts may be used as a source of need not be parallel. In a two pulley system, the belt

www.ijera.com 23 | P a g e
G Veerapathiran et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 3, ( Part -5) March 2015, pp.20-25

can either drive the pulleys normally in one direction

(the same if on parallel shafts), or the belt may be Therefore, smallerpulley governs the design.
crossed, so that the direction of the driven shaft is Stress calculation,
reversed (the opposite direction to the driver if on
parallel shafts). As a source of motion, a conveyor
belt is one application where the belt is adapted to
continuously carry a load. The mechanical output
from an engine is transmitted to the rear wheel 𝑇1 −29.58
= 218.97………….(1)
through the timing belt. The drive pulley is of small 𝑇2 −29.58
size and is connected to the output shaft of the Therefore Power transmitted per belt = (T 1-T2) x v
engine. And the driven pulley is of medium size and T1-T2 = 179.119 …………..(2)
is connected to the rear wheel. The drive and driven Comparing both equations,
pulleys are connected by means of timing belt. T1=207.877 N
T2=28.758 N
Calculation Recalculation of centre distance,
Selection of pulley diameter.
D=126mm; d=60mm; N1=3110rpm
N2=1975rpm; R.p=7kw; v=9.77m/sec
m= 3.028kg/m; c=490; t=5mm.
Determination of Wrap angle.

𝛼𝐿 = 180 + 2𝛽 = 3.27 rad

𝛼𝑠 = 180 − 2𝛽 =3.00 rad
Length of Open Belt
𝜋 1 2
𝐿 = 𝑑𝐿 + 𝑑𝑠 + 2𝑐 + 𝑑 − 𝑑𝑠
2 4𝑐 𝐿
L=1274.39 mm
Velocity
𝜋𝑑𝑠 𝑁1
𝑣=
60 × 1000

V=9.77 m/sec.
Belt tension ratio between smaller and larger pulley
𝜇 𝐿𝛼𝐿
𝑇1 𝑠𝑖𝑛 2
𝜃
=𝑒
𝑇2 𝐿
𝑇1
= 355.66 N
𝑇2 𝐿

𝜇 𝑠𝛼 𝑠
𝑇1 𝑠𝑖𝑛 2
𝜃
=𝑒
𝑇2 𝑠

𝑇1
= 218.97 N
𝑇2 𝑠
𝜇𝐿= 𝜇𝑠
𝑇1 𝑇1
<
𝑇2 𝑠
𝑇2 𝐿

www.ijera.com 24 | P a g e
G Veerapathiran et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 3, ( Part -5) March 2015, pp.20-25

IV. EXPARIMENTAL SETUP

Experiment setup

V. RESULT Conference „Modelling and Simulation in

This setup gives better performance compared Machinery Productions” 1997, Puchov,
over chain drive system.Noise will be reduced. Slovakia.
Vibration will be arrested completely. Pulleys have [5] PSG Design Data Book, Published by
life durability. High transmission speed compare to Kalaikathir Achchagam, Coimbatore –
chain drive. Belt capacity is 1, 00,000 kilometres 641037.
compared to chain drives.

VI. Conclusion
From the proposed system transmission
efficiency is very much improved compare to chain
transmission system. This system gives very narrow
range of vibration, and so Noise will be arrested. The
proposed system gives high performance. Future
work will focus on the variation in pulley diameter
and the dimension and material of the belt.

REFERENCES
[1] Abrate, S. (1992). Vibrations ofbeltsand
belt-drives. Mechanism and Machine
Theory, vol. 27, p. 645-659.
[2] Leamy,M.J.,Wasfy,T.M.(2002).Transient and
steady-state dynamic finite element
modeling of belt-drives. Journal of Dynamic
Systems, Measurement, and Control,vol.124,
p. 575-581.
[3] Hwang,S.J., Perkins, N.C.,Ulsoy, A.G.,
Meckstroth, R.J. (1994). Rotational response
and slip prediction of serpentine belt-drive
systems. ASME Journal of Vibration and
Acoustics, vol. 116, p. 71-78.
[4] M.Dudziak, Directionsin development of
flexible connector belts design, In:
Modelling and Simulation in Machinery
Productions, Proceedings ofInter.

www.ijera.com 25 | P a g e