Transcript Intro to Sync Belts

Introduction to Synchronous Belts
Introduction to Synchronous Belts
Timing belts were invented
in the late 1940’s by Richard
Y. Case, an engineer with
the former L.H. Gilmer
company, which was
eventually absorbed into
Uniroyal Inc. The sewing
machine provided the
impetus for the development
of a belt capable of
synchronizing two or more
shafts.
Introduction to Synchronous Belts
Applications required a very high modulus (no
stretch) tensile member to prevent distortion of
the pitch (the distance between the teeth) as it
rotated around the sprockets. Steel wire was
first used as a tensile member until later being
replaced by fiberglass and aramid fiber cords.
Introduction to Synchronous Belts
Synchronous drives represent
a modern and efficient system
of power transmission. They
essentially combine the
advantages of mechanical
components (gears & chain)
and flexible components
(flat & V-belts) while
eliminating the inherent
disadvantages of these
components.
Basic Design Principles
Synchronous belts operate on a basic principle:
molded teeth of the belt and mating grooves of the
pulley make positive engagement. The teeth enter
and leave the pulley in a smooth rolling manner with
low friction. This positive engagement results in:
• Exact shaft synchronization
• Elimination of slippage and speed loss common to
v-belts.
• Synchronous operation at speeds higher than most
chain drives.
Basic Design Principles
All synchronous belts operate on the positive
engagement principle. Chains operate on the
same principle but synchronous belts have many
superior characteristics. Synchronous belts wrap
around the pulley by means of flexion and not by
rotation of articulated parts (as chains do). This
eliminates one of the causes of wear and noise.
Basic Design Principles
To maintain the correct tooth
pitch as the belt flexes around
the pulley, the belt pitch line
(tensile cord) must coincide
with the pitch diameter of the
pulley. The difference between
pulley O.D. and pulley pitch
diameter is referred to as Pitch
Line Differential (PLD). For
proper tooth meshing the PLD
of the belt must match the PLD
of the pulley.
When to Use a Synchronous Belt Drive
•
•
•
Synchronous transmission between shafts is a must
•
•
•
•
•
Compact drive layout is necessary
•
High torque, low RPM requirements
High mechanical drive efficiency and energy savings required
Precise relative positioning of shafts (non-slip and minimal
backlash)
Low maintenance is required
Combines power transmission and conveying needs
Low noise requirements (compared to chain)
Environmental or contamination concerns (no lubrication
required)
Synchronous Belt Advantages
vs. chain
• Increased service life for belts and sprockets
• No need for lubrication
- Improper lubrication of chain drives severely reduces life
- Lubrication attracts dirt and leads to wear
• Reduction in noise over chain (& polyurethane drives)
• Environmentally cleaner – no grease or oil
• Increased productivity — less down time
(vs. chain and v-belts)
• Increased efficiency and registration accuracy
Synchronous Belt Advantages
vs. chain
• Chain is heavier than belt systems
• Limited take-up or inaccessible drives - with synchronous
belts, the required take-up allowances for tensioning are
significantly less (v-belts and chain).
• No Hidden Costs — chain cost of lubrication, disposal cost of
lubrication, reservoirs
• Chain available only in full box lengths
- (Typically 10 ft. in box)
Synchronous Belt Disadvantages
vs. chain
•Less initial cost (although synchronous payback is rapid
due to reduced maintenance)
•Design Flexibility — larger availability of ratios and
lengths
•Less sensitivity to improper installation —
alignment and tensioning
Belt Construction
The main components of a synchronous belt are the
tensile cords, the teeth, rubber backing and tooth
facing.
tensile cords
tooth facing
rubber backing
teeth
Belt Construction
Steel was originally used as a tensile cord material. Most belts
today use high modulus (low-stretch) fiberglass or aramid fiber as
the tensile member. (Kevlar is the Dupont trademark for an aramid
fiber). Tensile cord is the load bearing element of the synchronous
belt.
The belt teeth are molded of a hard rubber compound jacketed with
a tough, abrasion resistant nylon tooth facing. The compressive
and shear strength of the teeth exceeds that of the tensile cords
when there are at least six teeth in mesh with the driver pulley.
Teeth in mesh is a critical design factor.
A durable rubber backing encases the load bearing tensile cord. It
protects the cords from dirt, oil and other contaminants, as well as
frictional wear when a backside idler is used.
Belt Construction
“S” & “Z” Twist
" S " twist
" Z " twist
To reduce lateral movement, synchronous belts are constructed by
alternately spiraling “S” and “Z” type cords. The synchronous belt cord
is made up of a number of small fiber strands twisted together. These
strands can be twisted either clockwise or counterclockwise. The two
twist directions are referred to as “S” twist and “Z” twist.
Belt Construction
“S” & “Z” Twist
Most synchronous belts are made with both “S” and “Z” twist
cord to minimize belt tracking forces on the pulley flanges.
S - TWIST
(TOP VIEW)
direction of
belt rotation
direction of
lateral belt
movement
Z - TWIST
(TOP VIEW)
direction of
belt rotation
direction of
lateral belt
movement
Belt Construction
“Z” Twist
When necessary, the lateral movement of a belt can be pre-determined, if
the direction of rotation is constant (non-reversing drives).
A good example of this is Fin-Fan Drives. Because the fin-fan drive has a
vertical shaft, the belt is built with Z twist construction only. This gives the
belt an upward direction of lateral movement. This helps keep the belt off
of the bottom flanges and reduces excessive side belt wear. Carlisle offers
a special construction “Z” twist construction for Fin-Fan air-cooled heat
exchanger drives.
direction of lateral belt movement
direction of belt rotation
Side View
Z-Twist construction Fin-Fan Drive
Fin-Fan
Part Number Availability
3150-14M-55F
3150-14M-85F
3500-14M-55F
3500-14M-85F
3360-14M-55F
3360-14M-85F
3850-14M-55F
3850-14M-85F
Synchronous Drive Terms
Unlike the V-belt drive, the synchronous belt drive is not a friction
device. It is a positive engagement drive that is dependent upon
the meshing of the belt teeth with the pulley grooves.
The tooth profile indicates the type or shape of the belt teeth.
The spacing between two adjacent teeth on the belt (and pulley) is
referred to as the tooth pitch. The distance is measured from the
center of one tooth to the center of the next.
In synchronous belts, the belt length is determined by multiplying the
belt pitch by the number of teeth in the belt. This is known as pitch
length.
In synchronous drive systems, backlash is the necessary clearance
between belt teeth and pulley grooves for proper meshing.
Synchronous Drive Terms
The pitch diameter of the pulley or
(sprocket) refers to the diameter
determined by the tensile cord location
in the belt. Therefore, the pitch
diameter of the pulley will be
somewhat greater than the outside
diameter of the pulley across the teeth.
To maintain the correct tooth pitch as
the belt flexes around the pulley, the
belt pitch line (center of the tensile
cord) must coincide with the pitch
diameter of the pulley. The difference
between pulley O.D. and pulley pitch
diameter is referred to as pitch line
differential (PLD).
Synchronous Drive Terms
Tooth pitch is one indication of overall belt size. The larger the
pitch, the larger the teeth and tensile cord. The larger and stronger
the belt, the more horsepower it can transmit.
In conventional trapezoidal tooth profile belts, letters indicate
pitch, (MXL, XL, L, H, etc.) which are measured in inches.
In curvilinear tooth profile belts, pitch is measured in millimeters
(3M, 5M, 8M, etc).
The terms synchronous belt and timing belt are used
interchangeably.
Sprocket and pulley are also used interchangeably.
Synchronous Belt Tooth Profiles
There are two types of synchronous belt tooth profiles that make up
the majority of synchronous drives in use today.
• Trapezoidal tooth profile — (original technology) refers to the
tooth configuration of MXL, XL, L, H, XH AND XXH type belts.
• Curvilinear tooth profiles — have rounded tooth profiles that
eliminate stress concentrations at the base of the tooth and allow
more uniform stress distribution. Curvilinear profiles transmit high
torque and represent the latest evolution of synchronous belt
technology. Available in 3M, 5M, 8M, 14M, and 20M pitch.
Carlisle Tooth Profile Evolution
Trapezoidal Profile
A trapezoidal belt
tooth has a constant
angle of pressure.
The profile of
curvilinear teeth has
an angle that increases
from the base, to the
top of the tooth and
allows for more
uniform stress
distribution resulting in
higher torque
transmission with
reduced occurrence of
tooth jump.
Original synchronous
belt tooth profile
Curvilinear (RPP Profile)
Modern tooth profile
Trapezoidal Profiles
tooth pitch
Trapezoidal profile belts are available in the following pitches:
Pitch
Designation
MXL =
XL
=
L
=
H
=
XH
=
XXH =
Pitch
Distance
0.080”
0.20”
0.375” (3/8”)
0.50” (1/2”)
0.785 (7/8”)
1.25” (1-1/4”)
Trapezoidal Pitch Sizes
MXL
=
Mini Extra Light
XL
=
Extra Light
L
=
Light Duty
H
=
Heavy duty
XH
=
Extra Heavy Duty
XXH
=
Double Extra Heavy Duty
Trapezoidal Profile Dimensions
pitch
2ß
h
ra
hd
rr
s
tooth
angle
Pitch
Belt
Type
tooth
height
radius at
tooth
base
radius at
tooth top
tooth root
width
pitch
distance
line
hd
rr
ra
s
pdl
2ß
mm
inch
(°)
(mm)
(mm)
(mm)
(mm)
(mm)
MXL
2.032
0.08
40
0.51
0.13
0.13
1.24
0.254
XXL
3.175
0.125
50
0.85
0.2
0.3
1.64
0.254
XL
5.080
0.2
50
1.27
0.38
0.38
2.57
0.254
L
9.525
0.375
40
1.91
0.51
0.51
4.65
0.381
HL
9.525
0.375
40
2.29
1.19
1.57
6.12
0.686
H
12.700
0.5
40
2.29
1.02
1.02
6.12
0.686
XH
22.225
0.875
40
6.35
1.57
1.19
12.57
1.397
XXH
31.750
1.25
40
9.53
2.29
1.52
19.05
1.524
Trapezoidal Construction
• Fiberglass tensile
member
• Synthetic rubber
compound body
• Nylon tooth facing
Trapezoidal Features
• Fiberglass tensile member
– High breaking load, length stability (low stretch)
– Good resistance to repeated flexing
• Belt body synthetic rubber
– Good resistance to fatigue
– Resists heat, oil & ozone
– Ground back for smooth operation – low vibration
• Nylon tooth facing
– High resistance to abrasion
– Low coefficient of friction for smooth engagement
– Extended sprocket & belt wear
• Low backlash
– Good for applications where high positional accuracy is
required
Explanation of Part Numbers
300L100
300 ÷ 10 = 30 inch pitch length
Pitch Length designated in tenths
of an inch
L = 3/8”
Tooth Pitch
(hundredths of an inch for MXL)
example: 440 MXL 025
440 ÷ 100 = 4.4 inch pitch length
D300L100 = dual sided
100 = 1.0”
Belt Width
in hundredths
of an inch
Sycnhro-Cog® Timing Belt
Standard Lengths and Widths
belt
type
belt
pitch (inch)
belt
pitch (mm)
pitch length
range (inch)
standard widths (inch)
MXL*
0.08 (2/25)
2.032
3.6 – 52.24
.012 - .019 - .025
XL
0.20 (1/5)
5.080
5.0 - 77
.025 & .037
L
0.375 (3/8)
9.525
12.4 – 90
.050 - .075 – 1.0
H
0.50 (1/2)
12.7
21 – 170
.075 – 1.0 – 1.5 – 2.0 – 3.0
XH
0.875 (7/8)
22.225
50.7 – 180
2.0 – 3.0 – 4.0
XXH
1.25 (1-1/4)
31.75
70 – 180
2.0 – 3.0 – 4.0 – 5.0
* MXL available but non-standard
Cotton Cleaner Belt
Carlisle Cotton Drive
Sycnhro-Cog® Dual Timing Belt
Standard Lengths and Widths
belt
belt
belt
pitch length
type
pitch (inch)
pitch (mm)
range (inch)
standard widths (inch)
DXL
0.20 (1/5)
5.080
15.0 – 33.0
.025 - .037
DL
0.375 (3/8)
9.525
15.0 – 66
.050 - .075 – 1.0
DH
0.50 (1/2)
12.7
24.0 – 140.0
.075 – 1.0 – 1.5 – 2.0 – 3.0
Trapezoidal Tooth Profile Availability
Trapezoidal belt tooth
profiles are available from
most synchronous belt
manufacturers.
Carlisle offers a full line
of trapezoidal products.
Curvilinear Tooth Profiles
Advantages of Curvilinear Profile
vs. Trapezoidal Profile
• Higher power ratings allow narrower widths to be
used than trapezoidal timing belts
• More compact drives
• Lower overhung bearing loads (narrower widths)
• Quieter than comparable trapezoidal belts
• Covers wider range of power
• Reduced sprocket wear
Evolution of Curvilinear Tooth Profiles
• HTD - Curvilinear - Introduced by Gates in 1971
• STPD - Modified Curvilinear - Introduced by Goodyear
in the early 1970’s
• GT - Modified Curvilinear - Developed by Gates in the
late 1970’s
• RPP - Parabolic – Dayco (Carlisle) introduced in the
USA in 1985
Evolution of Tooth Profiles
Carlisle — getting it right the first time
Goodyear
Gates
Carlisle
Trapezoidal
Trapezoidal
Trapezoidal
STPD
HTD
HPPD
GT
*Eagle
UPD
(copy of RPP)
* helical (non-curvilinear)
GT2
RPP
Curvilinear Availability
Manufacturer
Carlisle
Gates
Wood’s
Optibelt
Browning
Goodyear
Dodge
Bando
Jason
Curvilinear Product Type
RPP Plus / RPP Panther
HTD / PolyChain GT2 / PowerGrip GT2
RPP (Carlisle Licensee)
HTD (Gates Licensee)
RPP, Panther (Carlisle Licensee)
HPPD, Eagle, Blackhawk, Whitehawk
HTD / HT150, HT200 (Gates Licensee)
HT (copy of HTD)
HTB, Tiger (copy of HTD)
Curvilinear Profiles
Curvilinear profile belts are available in the following pitches:
Pitch
Designation
3M
5M
8M
14M
20M
Pitch
Distance (mm)
=
3
=
5
=
8
=
14
=
20
Curvilinear Product Evolution
Gates
HTD – Power Grip GT – Poly-Chain GT
HTD - introduced in 1971 - phased out
Power Grip GT
- Introduced in 1993
- Replaced HTD in 8M and 14M pitches only
- Fully compatible with HTD sprockets
Poly-Chain GT
- Developed in the late 1970’s
- 8M and 14M only
- Polyurethane with aramid tensile member
- Not interchangeable with other synchronous drives
Curvilinear Product Evolution
Gates
Power Grip GT2 – Poly-Chain GT 2
PowerGrip® GT®2
- Introduced in 2000
- For high speed, high horsepower drives
- 5, 8, 14 & 20M pitches
PolyChain® GT® 2
- Introduced in 2000
- For low speed, high torque applications
- Polyurethane with aramid tensile member
- 8M & 14M pitches only
- Not interchangeable
Curvilinear Product Evolution
Goodyear
STPD – HPPD Plus
STPD
- Introduced in the 1970’s to compete with HTD
- Components are not interchangeable with other profiles
HPPD Plus
- Introduced in 1990
- Similar to RPP
- Available in 3, 5, 8, 14, & 20M
HPPD Plus
Curvilinear Product Evolution
Goodyear
Eagle - Blackhawk - Whitehawk
Eagle PD - HOT ( Helical Offset Tooth) design
- Introduced in 1996
- System not interchangeable
- Reduces noise
Blackhawk
- UPD profile (similar to RPP)
- Available in 8 & 14M only
Whitehawk
- UPD profile (similar to RPP)
- Available in 8 & 14 M only
Eagle PD
Curvilinear Product Evolution
Jason
HTB – Tiger
HTB
- Direct copy of HTD
- Introduced after HTD patent expired
Tiger
- Designed as replacement for Panther
Curvilinear Product Evolution
Bando
HT, STS
Synchro-Link HT
- Direct copy of HTD
Introduced after HTD patent expired
STS
- same as STPD
-
Curvilinear Product Evolution
Carlisle Power Transmission
RPP
RPP
- Introduced in the USA in 1985
- Available in 5,8,14 & 20M pitches
- Unique parabolic profile
- Quieter
- Completely interchangeable with HTD,
HTB, HT, HPPD, and HPT systems
Curvilinear Product Evolution
Carlisle Power Transmission
RPP Plus
RPP Plus
- Same parabolic profile
- Different construction resulting in
higher horsepower
Curvilinear Product Evolution
Carlisle Power Transmission
RPP Panther
RPP Panther
-
Introduced in 1993
Same parabolic profile
Aramid tensile member
Available in 8 & 14M only
Curvilinear Product Evolution
Carlisle Power Transmission
RPP Panther with UltraCord and Able
RPP Panther
- Introduced in 2003
- Same parabolic profile
- New Able compound (advanced polymer) UltraCord tensile member
20% better HP rating
The RPP™ Line of Synchronous Belts
• Parabolic Tooth
profile
• Compatible with
most existing
Deep Profile
sprockets
• Higher power rating
than trapezoidal
profiles
The RPP™ Line of Synchronous Belts
S & Z Twist Cords
• ensures straight line tracking
Nylon Tooth Facing
• graphite impregnated
• wear resistant
• self-lubricating
Ground Back
• smooth operation with backside idlers
RPP Profile
• jump & shear resistance
• reduced sprocket wear
Tooth Indentation
• shock absorbing
• reduces noise
Curvilinear Tooth Profiles
Reinforced Parabolic Profile
The parabolic profile allows the transfer of greater power
and offers better resistance to tooth jump and shear.
Advantages of RPP Profile
• Interchangeable with existing deep groove
profiles (HTD, HPPD, UPD)
• Sprocket availability - most major sprocket
manufacturers provide RPP profile
• Sprockets use readily available QD bushing
• Quieter than competitive curvilinear belts
• RPP profile reduces sprocket wear
RPP Plus Synchronous Belt
• Highly energy efficient
• High Torque capability
• Provides up to 50%
more horsepower
capacity than first
generation high-torque
belts (HTD)
RPP Plus
Extra Strong
Fiberglass Cords
Patented nylon selflubricating graphite
loaded tooth facing
Neoprene Rubber Belt Teeth
Precision Ground
Neoprene Backing
Tooth Indentation
• Shock Absorbing
• Reduces Noise
RPP Plus
available in pitches of *3M, 5M, 8M, 14M, 20M
FEATURE
BENEFIT
Reinforced Parabolic Profile
Positive slip-proof engagement
No speed variations
Wide range load capacities & speeds
Speed range more than double of chain
High torque capacity
Wide range of applications
No lubrication
Clean, maintenance free
High mechanical efficiency
Energy savings
Does not require friction to operate
Reduced overhung bearing loads
Improved motor life. Less heat build-up.
Reduced maintenance
* 3M is non-stock. Contact Carlisle for availability.
RPP Plus
available in pitches of *3M, 5M, 8M, 14M, 20M
FEATURE
BENEFIT
High torque capability
Compact drive package
Lower cost
Precision ground rubber backing
Consistent uniform thickness
Reduced vibration
Compatible with backside idler
Length stability
Fiberglass cord
High belt strength
Nylon fabric tooth cover
High resistance to wear and shear
Longer belt life
* 3M is non-stock. Contact Carlisle for availability.
RPP Plus
Explanation of Part Numbers
800-8M-30
800 = 800 mm pitch length
8M = 8mm pitch
30 = 30 mm width
RPP Plus
Standard Lengths and Widths
belt
belt
pitch length
type
pitch (mm)
range (mm)
standard widths (mm)
*3M
3
159 – 1263
6 – 9 - 15
5M
5
350 – 2525
9 – 15 – 25
8M
8
480 – 4400
20 – 30 – 50 – 85
14M
14
966 – 6860
40 – 55 – 85 – 115 – 170
20M
20
2000 – 6600
115 – 170 – 230 – 290 - 340
* 3M is non-stock. Contact Carlisle for availability.
Dual RPP Plus
- Used to drive shafts on (serpentine) multiple
pulley drives in opposite directions
- Available in RPP 8M & 14M profiles
- RPP molded teeth both sides - full power rating on both sides
- Goodyear molded teeth one side – Ground teeth on opposite
side - 33% rating reduction on ground tooth side due to lack
of fabric reinforcement on teeth
Dual RPP Plus
Standard Lengths and Widths
belt
belt
pitch length
type
pitch (mm)
range (mm)
standard widths (mm)
8
720 – 4400
20 – 30 – 50 – 85
14
1400 – 4956
40 – 55 – 85 – 115 – 170
8M
14M
Dual RPP Plus
Explanation of Part Numbers
D800-8M-30
D = Dual Sided
800 = 800 mm pitch length 8M = 8mm pitch
30 = 30 mm width
Introducing the New RPP Panther®
The Panther Rules!
The new RPP Panther
with ULTRA-CORD and
Able compound provides
fierce, unequaled
strength, efficiency and
durability.
New RPP Panther with “Able” Compound
The “Able” Advantage
Reduces Tooth Shear
The new “Able” compound is
reformulated for increased
performance. This advanced
polymer provides increased
resistance to tooth shear and
tooth jump.
New RPP Panther with “Able” Compound
The “Able” Advantage
Better Adhesion
“Able” adheres to the belt cords and
nylon tooth facing better than the old
Panther compound. This allows for
reduced tooth deflection and improves
belt life.
New RPP Panther with “Able” Compound
The “Able” Advantage
More Robust
The “Able” compound
is a robust material
that improves product
consistency.
New RPP Panther with ULTRA-CORD!
The ULTRA-CORD Advantage
Reduced Tension Decay
Holds drive tension better
than belts using aramid
fiber cords thus providing
dimensional stability for the
life of the drive.
New RPP Panther with ULTRA-CORD!
The ULTRA-CORD Advantage
Lower Installation Tensions
With ULTRA-CORD, there is no need to
“over-compensate” for aramid tension
decay. Lower tensions put less strain
on drive components such as bearings
and shafts.
New RPP Panther with ULTRA-CORD!
The ULTRA-CORD Advantage
Doesn’t Absorb Moisture
The use of ULTRA-CORD eliminates the need
for special handling such as plastic bags and
desiccants used with aramid belts to prevent
shrinkage from moisture absorption.
New RPP Panther with ULTRA-CORD!
The ULTRA-CORD Advantage
Improved Flex Life
Aramid tensile strength
degrades over time with
repeated flexing.
ULTRA-CORD resists tensile
degradation & dramatically
improves belt life and
shock load resistance.
New RPP Panther with ULTRA-CORD!
The ULTRA-CORD Advantage
Improved HP Ratings
The new RPP Panther
construction permits
increased drive horsepower
ratings as much as 20%
over the previous Panther.
The New RPP Panther…
Some things didn’t need to be improved…
SAME Great RPP Tooth Profile
The new RPP Panther still
utilizes the same RPP tooth
profile for reduced noise
levels, resistance to tooth
jumping, and improved
meshing with either RPP or
HTD sprockets!
The New RPP Panther…
Some things didn’t need to be improved...
SAME High Quality Fabric Facing
The New RPP Panther still
utilizes the same graphiteloaded, self-lubricating nylon
fabric facing for exceptional
wear resistance, low
coefficient of friction, and
superior drive efficiency.
The New RPP Panther…
Some things didn’t need to be improved…
SAME Industry Standard Sprockets
The New RPP Panther still
operates with the same
readily available, industry
standardized RPP Panther
sprocket systems.
The New RPP Panther…
Some things didn’t need to be improved…
Still Works on Backside Idlers
The new RPP Panther is still the
best choice (and sometimes
your only choice) for high
torque drive systems that
require backside idlers.
The New RPP Panther® Synchronous Belt
ULTRA-CORD
• Improves belt life
• Higher strength
• Reduced tension decay
• Dimensional stability
Nylon Tooth Facing
• Graphite-loaded
• Self-lubricating
• Wear resistant
Precision Ground Backing
• Smooth operation with backside idlers
Tooth Indentation
• Shock absorbing
• Reduced noise
Able Compound
• Engineered polymer
• Increased performance
• Increased belt life
Proven RPP Profile
• Greater transfer of power
• Jump & shear resistant
• Reduced sprocket wear
Advantages of RPP Profile
• Interchangeable with existing deep groove
profiles (HTD, HPPD, UPD)
• Sprocket availability - most major sprocket
manufacturers provide RPP profile
• Sprockets use readily available QD bushing
• Quieter than competitive curvilinear belts
• RPP profile reduces sprocket wear
The Energy Efficient RPP Panther®
• Panther improves energy efficiency
- 98% operating efficiency
• Reduces energy consumption
- As much as 5% over other PT systems
RPP Panther®
Explanation of Part Numbers
3600-PTH8M-35
3600 = 3600 mm pitch length
PTH8M = 8mm pitch
35 = 35 mm width
RPP Panther®
Standard Lengths and Widths
Belt
Type
8M
14M
Belt
Pitch (mm)
Pitch Length
Range (mm)
Standard Widths (mm)
8
480 – 4400
12 – 22 – 35 – 60
14
966 – 4956
20 – 42 – 65 – 90 – 120
Panther Advantages
over Poly-Chain
• Poly-Chain has a ribbed belt backing that does
not work well with backside idlers. Gates does not
recommend their use with Poly-Chain.
• Poly-Chain is made of polyurethane and has a
lower maximum operating temperature (185° F).
• Panther belts (rubber) have lower noise
characteristics than (polyurethane) Poly-Chain
belts.
RPP Panther®
NOISE COMPARISON
Panther vs Competitive System
90
76
80
65
70
67
82
73
84
88
76
80
90
83
60
57
50
40
30
20
10
0
600
1200
1800
2200
2800
3500
RPP PTH
Test on belt pitch 8 mm / 20 mm wide, 2 pulleys Z=44, tension 46kg/strand
rpm
POLYURETHANE
Synchronous Belt
Relative Horsepower Ratings
Panther ULTRA-CORD is capable of
exceeding the HP ratings referenced
in this chart. Contact Carlisle
Engineering for further information.
Synchronous Belt
Relative Horsepower Ratings
Panther ULTRA-CORD is capable of
exceeding the HP ratings referenced in
this chart. Contact Carlisle Engineering
for further information.
Drive Design Software
Drive Design Considerations
Excessive Shock Loads
• Some applications are not conducive to synchronous belt drives
• Use special consideration on drives with excessive or extreme
shock loads
• Synchronous belt’s positive drive engagement and the high
modulus cord (low-stretch) makes synchronous belts less tolerant
of severe shock loads than v-belts which allow slippage
• If you require the characteristics of synchronous belts in a shock
load application, an RPP Panther synchronous belt is your best
choice in these situations
Drive Design Considerations
Pulley Misalignment
• Synchronous belts are much more sensitive to misalignment
than v-belts
• Do not use on drives where severe misalignment is inherent in
the drive operation
• Misalignment leads to uneven belt and pulley wear and
premature tensile failure
• Total misalignment of synchronous belt drives should be less
than 1/16” per foot of drive center distance
• Any degree of pulley misalignment will result in some reduction
of belt life
Drive Alignment
The straight-edge should make contact at two distinct
points along the outside perimeter of both sheaves.
Proper
Off-Set
Pigeon-Toed
Angle
Tensioning
• Along with alignment, proper
belt tension is critical
• One method to assure precise
tensioning works on the
principle of forced vibration
• The Frequency-Finder from
Carlisle measures the frequency
of vibration which is directly
related to the tension of the belt
Drive Design Considerations
Fixed Center (Non-Adjustable) Drives
• Do not recommend a fixed center distance drive other than
motion transfer (low or no torque) drives
• Fixed center implies exact tolerances - length tolerances for
synchronous belts are less than those of other belts and no
belt can be manufactured to such exact specifications
• Pulley and drive geometry tolerances also contribute to
problems associated with fixed center drives
• Some applications do use fixed center drives with
synchronous belts, but not without some difficulties
Drive Design Considerations
Environments with Excessive Debris
• Synchronous belts should not be used in environments
where excessive debris is present
• Debris can be more damaging to a synchronous belt drive
than to a v-belt drive, which has a tendency to eject debris
from the sheave grooves as the drive operates
• Large debris trapped between a synchronous belt and pulley
will destroy belt tensile cords or drive hardware
• Small debris will become compacted in the pulley groove,
forcing the belt to ride out away from the pulley and leading to
belt failure by destroying the tensile member
Drive Design Considerations
Environments with Excessive Debris (cont.)
• Exposure of synchronous belts to oil and other lubricants
should be minimized
• Oil and petroleum distillates may alter the belt polymers and
adhesion systems
• Care must be taken to provide adequate shielding on drives
where debris or contaminants are likely
• Completely enclosing a synchronous belt drive may be
acceptable. Synchronous belts generate less heat than v-belts.
Air circulation around the drive is not a critical consideration
except in extremely high temperature environments.
Drive Design Considerations
Spring Loaded Idlers
• The use of spring loaded idlers should
be avoided with synchronous belts
• Synchronous belts “self-generate”
tension that overcomes the spring force
resulting in tooth jump
Synchronous Applications
In addition to synchronization, synchronous belts
offer a number of advantages and benefits over
chain or v-belts. In some applications their unique
construction and operating characteristics permit
designs that are undesirable with v-belts or chains.
There are certain combinations of load/speed/size
requirements that eliminate the use of other PT
systems, but are well suited to the characteristics
of synchronous belts.
Synchronous Applications
• Textile machinery
• Industrial washing
•
•
•
•
•
•
machine
Conveyor
Marble cutting
machine
Block cutter
Power tools
Office equipment
Household appliances
Packaging
• Box making
machinery
• Carton sealers
• Case palletizers
• Belt, chain &
screw conveyors
Synchronous Applications
Aluminum & Steel
• Bucket conveyors
• Shot blasters
• Scrap cutters
• Metal polishers
• Furnaces
• Foundries
• Sand & bucket elevators
• Grinders
Synchronous Applications
Petrochemical
• Air coolers
• Fin-fans
• Chlorine compressors
• Processing
• Centrifuges
• Dryers
• Pumps
Aggregate Industry
• Feeder drives
• Conveyors
• Screw conveyors
HVAC
• Air blower fans
• Ventilator fans
• Exhaust fans
Energy Efficiency
• One third of the electric motors in the industrial and
commercial sectors use belt drives
• Certain types of belts are more efficient than others,
offering energy cost savings
• V-belts can have a peak efficiency of 95% to 98% at the
time of installation but deteriorates by as much as 5% over
time
• Synchronous belts offer an efficiency of about 98% and
maintain that efficiency
• V-belts have a sharp reduction in efficiency at high
torque due to slippage
Selling Energy Efficiency
• Conduct a survey of belt driven equipment in a plant or
facility. Gather application and operating hour data.
Then, determine the cost effectiveness of replacing existing
v-belts with a synchronous system.
• Replace wrapped v-belts with Gold Label Cog Belts where
the retrofit of a synchronous belt drive is not cost effective.
• Consider synchronous belts for all new installations
because the payback overcomes the price premium over
v-belt drives.
www.CarlisleBelts.com
from
www.c-rproducts.com
[email protected]
Tel: +44 1327 701030
Fax: +44 1327 701031