Rick Stewart Belt Drives on HVAC Equipment Advantages Terms Belt Construction Belt Length Variation Replacement amp Equipment Dynamics Proper Drive Maintenance Importance Safety Belt Tension Worn Sheave Increasing Drive Life ID: 400446
Download Presentation The PPT/PDF document "V-Belt Drive Application" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
V-Belt Drive ApplicationRick StewartSlide2
Belt Drives on HVAC Equipment:
Advantages, Terms, Belt Construction, Belt Length Variation, Replacement & Equipment Dynamics, Proper Drive Maintenance: Importance, Safety, Belt Tension, Worn Sheave, Increasing Drive LifeEnergy Savings Opportunities:Upgrade Belt, Sheave Wear & Proper TensionEnergy Savings Opportunities Part II: Retrofitting old worn out drivesSustaining Drive Efficiency: Self- Tensioning Motor Bases & Automatic Bearing LubricatorsSummary: Tools & Available Resources Questions? & Contact Information
WHAT WE WILL COVER:Slide3
Belt Drives on HVAC Equipment
Slide4
Equipment Dynamics
Traditional Center
Distance Requirement
(20-28 inches)
New Center Distance
Trend
(
12-18 inches)
Shorter Center
Distances –
Increased Belt Cycles
Lighter
Structural
Framework –
Harder to maintain proper alignment & drive tension. Drive is twisted causing issues. Higher Speeds – Need for better system balance to prevent vibration & noise issues.
OEM trends
for smaller center
distances.
This puts much greater but demands more
for the entire drive Slide5
Economical -Low initial cost and low cost to maintainQuiet - Smooth, quiet operationClean- N
o lubrication is required
Easy to install & maintain – Belts wear gradually Forgiving - Withstand installation/maintenance abuse & still give good drive lifeEfficient – Drive performance between 94 - 98% when maintained & installed correctlyAvailability – Replacements can be purchased everywhereVersatile – cover a wide range of horsepower's & speedsRugged – Last for long periods of time Shock AbsorbingAdvantages of using V-Belt drivesSlide6
Key Terms and Definitions
Center
Distance - Amount of distance between driver and driven shaftsService Factor - Required Horsepower x Service Factor = Design HorsepowerDatum Diameter – The Datum Diameter as the effective diameter for determine the pitch length of the belt for center distance calculation. Listed for A, B, C & D Sheaves. Adopted in 1987 by RMA/MPTA.Pitch Diameter – The diameter where the belt cords are placed in a belt. Torque - A twisting or turning force As speed decreases, torque increasesRatio – Driver divided by DrivenSlide7
Fabric Polyester cords Neoprene Rubber
Belt construction
What they do:Transmit torque & HorsepowerHeat and Oil ResistantStatic ConductingLow VibrationLow MaintenanceGood for Shock LoadsWrapped BeltCogged (Raw-Edge) Belt
Fabric
Polyester cords
EPDM
Cogged Belts:
Transmit
more horsepower
Run cooler; Ave 16º to 30º
Temperature Range -60º to +250º
Slightly louder
Need closer alignment
Slide8
Belt Length Variation
Standard Standard Datum Lengths Permissible Matching Matching Matching
Length Cross Section Deviation from Limits for Limits for Limits forDesignation A,AX B,BX C,CX D Std. Datum Lgth One Set Code 1
Machine
26 27.3 +0.6 -0.6 0.15 0.15 0.10
31 32.3 +0.6 -0.6 0.15 0.15 0.10
35 36.3 38.8 +0.6 -0.6 0.15 0.15 0.10
38 39.3 39.8 +0.7 -0.7 0.15 0.15 0.10
42 43.3 43.8 +0.7 -0.7 0.15 0.15 0.10
46 47.3 47.8 +0.7 -0.7 0.15 0.15 0.10
51 52.3 52.8 53.9 +0.7 -0.7 0.15 0.15 0.10
55 56.3 56.8 +0.7 -0.7 0.15 0.15 0.10
60 61.3 61.8 62.9 +0.7 -0.7 0.15 0.15 0.10
69.3 69.8 70.9 +0.7 -0.7 0.30 0.24 0.10
75 76.3 76.8 77.9 +0.7 -0.7 0.30 0.24 0.10
80 81.3 +0.7 -0.7 0.30 0.24 0.1081 82.8 83.9 +0.7 -0.7 0.30 0.24 0.10
RMA*
* RMA = Rubber Manufacturers of America (also ANSI Standard)Slide9
Always replace with like or higher design. Different styles of belts may have the same dimensions, but mush different horsepower characteristics.Replacing a B for a BX or a 5L with a B Belt will lead to:
Shorter belt life and continuing to install incorrect belt on drive.
Never mix new and used of different manufacturers on the same drive. Cord location is different and may result in shorter belt life and maintenance issues with the unit.Replacement DynamicsSlide10
FHP are:
8000 HourDesign Life
Classical
& 358 are:
25,000 Hour
Design Life
Different Cross Section have
Different
Design
Life
&
D
ifferent
Horsepower Ratings
Belt Design Life:
Factors that can reduce belt life:
Excessive sheave groove wear & improper alignment
Lack of proper tension of the drive
Temperature: High Ambient or from a processSlide11
Proper Drive Maintenance
Slide12
Proper Maintenance Important
Poor Maintenance Cost Time!
Time is Money!Doing the same or more with fewer people!Resources leave & don’t get replaced
Budgets getting cut!
L
ess money to do all the things in need to get done.
Looking for Higher Return on What I do get to spend!
Return on Investment to the Organization (ROI). Slide13
Safety First!
Always turn off and lock
out power source. Observe all other safety procedures.Wear required protective gear or equipment, based on site requirements.Loss of production hours.Critical System – Unscheduled downtimeSlide14
What do you see once the belt guard is removed?
Look at the
drive elements – belts, sheaves, bearings Inspect belts for signs of failure:Glazing or cracked sidewalls
Uneven wear on sidewall of a belt
Excessive belt dust
Check sheave
alignment
Inspect
sheave
Even Groove wear
Belts bottoming out
Any bearing lubrication issues
Excessive heat
Inspect the blower for other problems
Inspect
the DriveSlide15
Inspect Sheaves on a regular basis
Clean dirt or rust out of sheave groove
Dirt and rust are abrasive to beltInspect for damaged or worn groovesCheck wear with groove inspection tool or straight edgeThe smaller sheave (Motor) will show wear firstSlide16
Worn sheaves
load
on the end cords higher, lead to rapid belt failure and more frequent replacementBelt should never ride in bottom of groove
Check for groove wear >
1/32”
Sheave Groove Wear
When do sheaves need replacing?
Check sheaves every time belts are changed.
The smaller diameter sheave (usually the motor sheave) will always wear out first, typically needs to be
replaced with every 3
rd
or 4
th
belt change.Slide17
What happens with continued use of worn sheaves
Loose adequate sheave sidewall contact. This can cause belts to slip causing excess friction & heat causing the belt to fail prematurely.
Sheave walls become “dished” which reduces the ability of the V-Belt to wedge in the groove. Less contact between the groove and belt surfaces.Reduced air flow for the blower unit. The smaller sheave will always wear out faster. In many cases this is the motor sheave, this will change the drive ratio & reduce air flow.Belt cords are un-evenly loaded.Not much different than using a new and used belt or 2 different manufacturers belts on the same drive. Just internal to the belt.Uneven wear on multiple groove sheaves can create uneven load sharing across all belts reducing efficiency and possibly creating vibration and noise.Slide18
Aligning Sheaves
4 point static contact with straight edge
ensures alignment4 point static contact per side when using cord or string
C
an use a laser, but they are expensive, need to be maintained and take a some time when variable pitch sheaves are involved.Slide19
Misalignment & V-Belt Angle
Sheave should aligned within tolerance of specific style of belts:
Wrapped Belts (FHP, A, B & 5V): ± 2˚ Notched Belts (AX, BX, 3VX & 5VX): ±1/2˚There are 3 Basic Types of Sheave & Shaft MisalignmentSlide20
How to correctly tension belts
+
Motor
Blower
+
The good old “Thumb Rule”
Deflect the belt about ½ inch
Too little tension the drive till the belt chirps on start up!
This generates heat and will cause belts to fail prematurely
Too much tension can over
load
the bearings!
Excessive
load can
damage the motor and fan bearings
Move the sheaves as close to the bearings as possible
Reduce the cantilevered load on the shafts
This is what most technicians are using!
What
should be using!
Accuracy and Consistency are Key!Slide21
Percent Slip
98%
Optimal
82%
Under-Tensioned
Energy loss from Belt slip
(result of poor tensioning)
Under-tensioned V-belts slip which causes efficiency
loss, premature belt wear and sometimes noise.Slide22
So why are Belts under tensioned?
Belts that are
“rolled” onto the sheaves without adjusting the motor base do not apply sufficient tension to prevent belt slip.Old belts are cuts off the drive and the motor base is not repositioned toward the blower the belt is forces over the rim of the sheaves. This damages the cores of the belt and if a screwdriver or pry bar is used, could create nicks in the groove of the sheaves. Worn sheaves don’t provide adequate sheave sidewall contact. The belt are pulled deeper in the grooves providing less over all tension to the drive. Belts go slack after being run for a little while. When they seat themselves in the groove of the sheave. Replacing belts and moving the motor base back to a “preset mark” does not ensure proper tension.Using an idler can help to apply tension but must be adjusted or re-adjusted to provide the proper force.Slide23
Double Check Belt HP Rating Verify motor nameplate
HP
ratingExample: 20HP @ 1760 RPMInstalling NEW BeltsInstalling new belts:Use all the same brand on the drive.Never Pry Belts onto sheaves.Slide24
Energy Saving Opportunities
Slide25
The Browning “Save the Green Campaign!”Slide26
HVAC Fan and Blowers
Proper Belt Tension
– 10-15% loss if under-tensioned Belt type
– 3-5% gain by replacing wrapped V-Belts with raw edge V-Belts
Maintenance
- 5-8% loss can occur due to Sheave wear
Ask to see our Energy Calculator that can run specific
application for horsepower and by state.Slide27
Energy Efficiency for Different Belt TypesWrapped vs. Raw Edge
Raw edge cogged V-Belts provide a higher coefficient of friction with the sheave groove wall. This creates less slip when the belts are properly tensioned.
Raw edge belts directly replace wrapped belts (BX48 replaces B48).Raw edge belts transmit more Hp than the equivalent wrapped belts.Raw edge belts provide better sheave groove wall contact than wrapped belts, even when used with smaller diameter sheaves.Slide28
Energy Loss from Worn Sheaves
“As a sheave wears, the belt fits more loosely in the groove, so loads don’t transmit as well. This causes an uneven load distribution across the belt tension member, with more load being applied at the belt edges. The effect is similar to that of high temperature. Because of this uneven loading, worn sheaves reduce belt life by as much as 50%. But their adverse effect on efficiency is even more costly. The efficiency of a belt drive with visibly worn sheaves and loose, slipping belts can easily drop below 90%. To translate this into operating costs, consider a 50-hp belt-driven machine that costs $25,150 (at $0.07/kWh) to operate year-round. The efficiency loss due to loose, slipping belts and worn sheaves costs about $1,300 per year, more than enough to replace the belts and sheaves several times”. Power Transmission Design – June 1995 Neville W. Sachs, Salvaterra & Associates Check for groove wear 1/32 “
Worn sheaves cause more load on the end cords – and more rapid failure
Sheave Groove WearSlide29
Span = 32”
How to correctly tension
a belt
If belt span is 32” then a
properly tensioned new V-belt
should only deflect ½ inch when 8.0 lbs. of
force
is applied
.
Deflection
calculated: Span/64 in this example 32/64 = .5 or ½”
If deflection is greater than ½ inch, more
tension must
be
applied by adjusting the motor base. Each drive is unique.Move sheaves as close as possible to the bearings.Reducing the overhung load &stresses on the bearings
+
Motor
Blower
8.0
lbs.Slide30
Energy Saving Program Part II
Drive RetrofittingSlide31
Gather DataSlide32
Retrofit Project:50 HP Supply Fan
Existing Drive:
4 Groove C128 belt drive Redesign: 2 Groove 5VX1400 v-belt driveEnergy Savings: = Over $1300 per year Solution: Expensive MVP Sheave on the motor & Companion Sheave on the Blower ALMOST 90% less than Existing Drive
Motor Sheave Cost: $2,276
Fan Sheave Cost: 1,113
Large Commercial Property
Management Company
Total Sheave Cost: $3,390
Total Sheave Cost for Retro Fit: $ 350
3 ½ Month - ROISlide33
Retrofit Project –50 HP Supply Fan Cost Savings Example
$959
per year in Energy Savings, using DOE 3% calculations$2000 Sheave Replacement Cost Savings, comparing existing drive to new driveExtend Belt PM Cycle from 12 months to 30+ months, annual belt cost alone is $340 – not including labor cost and time.Existing (4) C120 Belt Drive New (2) 5VX1250 Belt Drive Slide34
What can be done to optimize drive life?
Properly tension belts.
Use a tool for consistency and accuracy.Don’t use the “Rule of Thumb”.Check sheave for wear on a regular basis & replace worn sheaves.Always replace the existing belt with like or higher design. Upgrading belt design may even improve drive life.Make sure the drive in properly tensioned.Slide35
Sustaining Drive EfficiencySlide36
Promotes greater efficiency.
Compensates for variations in load
Compensation is obtained by combination of a one-piece movable carriage acted upon by a spring contained within the carriageCarriage design promotes superior alignment
Auto Tensioning Motor Bases
Spring Controlled ActionSlide37
OfferingSlide38
EFFICIENT LUBRICATION
One GoldPlex
™-SPL (EM) Can Service up to 8 Bearings
UNIT CONSTRUCTION
High Strength Polymer Design
GREASE CAPACITY
125 cc or 250cc
UNIT INSPECTION
Clear Top for Quick and Easy Inspection
CORROSION RESISTANCE
GoldPlex-SPL (V) Unit Is Supplied With Clear Plastic Cover to Protect Variable Control Pad
GREASE TYPE
Factory Filled with SealMaster GoldPlex
™-HP Grease
VARIABLE CONTROL PAD
Control Pad Allows for Variable Lubricant Dispensing
No Need for Activator Keys or Control Rings
SealMaster
GoldPlex
-SPL-EM
FEATURES & BENEFITS
OPERATING RANGESlide39
(1) Replacement Grease Pouch 125cc or 250cc
(1) Battery Pack
(1) Disposable Dust Cover
Using Divider Blocks, One SPL-EM Lubricator Can Be Installed to Service up to 8 Ball or Roller Bearings. Consult PPP-04 Catalog Installation Kit Selection.
REPLACEABLE SERVICE PACK
MULTI-BEARING CAPABILITY
Unlike the V Unit, The GoldPlex-SPL-EM Model Allows for Fresh Lubricant to Be Added when Unit Grease Bladder Has Been Depleted.
SPL-EM
Divider Block
Accessories – (V Unit Installation Kit)Slide40
Tools & Available ResourcesSlide41
Browning V-Belt Energy Efficiency Calculation I-Phone App
Viral Campaign with Facebook page and LinkedIn promotions
Magazine Ad Campaign centered around App Release committed
Compatible with I-Touch and I-PadSlide42
Belt Efficiency Calculator APPSlide43
Browning Toolbox Technician APPWhere to Find FunctionSlide44
Connect With Us
Visit our Facebook page @BrowningBeltDrives
Search Browning Belt Drives Save the Green. Join in on our belt drive conversations for energy savings and benefits.Visit our website for: Application Engineering contact information, installation instructions, product interchange software www.emerson-ept.com.
Download the Browning Energy Efficiency Calculator for your iPhone
® or
Droid
®.
Search “Browning vbelts”
ThePowerTransmission
for the latest product videos and trade show clips about Emerson Browning brand belt drive products and online tools. Slide45
Any Questions?Slide46
Contact Information