Drive Design Seminar

1

• Drive Design Seminar

2
Product Description
Materials
Cost Drivers
General Drive Design
Additional Considerations
3
Product Description
Product

• General Information
• Standard Product
• MTO Product

4
Two Major Belt Categories
Product - General

• V-Belt works on the principle of the wedge and
  relies on tension to create friction on the
  sidewall of the sheave to transmit power
• Synchronous or timing belt relies on accurate
  and smooth meshing of the teeth on the belt with
  the grooves of the sprocket

5
Two Major Types of V-Belts
Product - General

• Wrapped Molded which has a fabric cover and is
  molded into a V shape
• Raw Edge which is cured and then cut into a V
  shape

6
Industry Standards
Product - General

• Standards are determined by the following
  manufacturing associations
• RMA Rubber Manufacturers Association
• MPTA Mechanical Power Transmission Association
• ISO International Standard Organization
• SAE Society of Automotive Engineers
• API American Petroleum Institute
• ASAE American Society of Agricultural Engineers
• Government Standards

7
Standard Belts
Product - Standard

• Classical (Multiple)
• Single (FHP)
• Narrow (Wedge)
• Double-V (Hexagonal)
• Joined (Banded)
• V-Ribbed
• Variable Speed
• Synchronous (Timing)

8
Classical V-BeltsReference ASAE S211.5 RMA
Standard IP-20
Product - Standard
Nominal Cross-Section Dimensions (inches)
Belt Reference Nomenclature Part Number
A63 Belt Type A Outside
Length (O.L.) 65.3 Part Number 2.3 Belt
O.L.
Cross Section Top Width Th. Angle (degrees) O.L. Add-ons
A/AX 0.500 0.310 40/38 2.3
B/BX 0.660 0.410 40/38 2.8
C/CX 0.880 0.530 40/38 4.2
D/DX 1.250 0.750 40/38 5.2
Note(s) Typical cross section designation for
Aggie/LG Belts adds H prefix. For
example HA, HB, etc. For metric designations,
refer to appropriate Industry Standard.
Wrapped Molded (A, B, C, D Sections)
Raw Edge Cog (AX, BX, CX DX Sections)
Angle
9
Single (FHP) V-BeltsReference RMA Standard IP-23
Product - Standard
Nominal Cross-Section Dimensions (inches)
Belt Reference Nomenclature Part Number
4L500 Belt Type 4L Outside Length
(O.L.) 50.0 Part Number Belt O.L.
Cross Section Top Width Th. Angle (degrees)
2L 0.250 0.160 40/36
3L 0.380 0.220 40/36
4L 0.500 0.310 40/36
5L 0.660 0.380 40/36
Note(s) For metric designations, refer to
appropriate Industry Standard.
Raw Edge Laminated
Wrapped Molded
10
Narrow V-BeltsReference ASAE S211.5 RMA
Standard IP-22
Product - Standard
Nominal Cross-Section Dimensions (inches)
Belt Reference Nomenclature Part Number
5V630 Belt Type 5V Outside Length
(O.L.) 63.0 Part Number Belt
O.L. Note(s) Typical cross section
designation for Aggie/LG Belts adds an H
prefix. For example H3V, H5V,
etc. For metric designations, refer to
appropriate Industry Standard.
Cross Section Top Width Th. Angle (degrees)
3V/3VX 0.380 0.310 40/36
5V/5VX 0.620 0.530 40/36
8V 1.000 0.910 40
Wrapped Molded (3V, 5V, 8V Sections)
Raw Edge Cog (3VX 5VX)
11
Double-V (Hexagonal) V-BeltsReference ASAE
S211.5 RMA Standard IP-21
Product - Standard
Nominal Cross-Section Dimensions (inches)
Belt Reference Nomenclature Part Number AA60
Belt Type AA Outside Length (O.L.)
63.4 Part Number Belt O.L.
Cross Section Top Width Th. Angle (degrees) O.L. Add-ons
AA 0.500 0.410 40 3.4
BB 0.660 0.530 40 4.6
CC 0.880 0.690 40 6.4
Note(s) Typical cross section designation for
Aggie/LG Belts adds H prefix. For
example HAA, HBB, etc. For metric
designations, refer to appropriate Industry
Standard.
Cross Sections (AA, BB, CC Sections)
12
Joined (Banded) V-BeltsReference ASAE S211.5
RMA Standards IP-20 IP-22
Product - Standard
Nominal Cross-Section Dimensions (inches)
Belt Reference Nomenclature Part
Number RB103-3 Belt Type
B Number of ribs/band 3 Outside Length
(O.L.) 107.0 Part Number 4.0 Belt O.L.
Cross Section Top Width Th. Angle (degrees) Sg (in.) O.L. Add-ons
B/BX 0.660 0.500 40/38 0.750 4.0
C/CX 0.880 0.660 40/38 1.000 5.3
D/DX 1.250 0.840 40/38 1.438 6.3
3V/3VX 0.380 0.380 40/38 0.406 1.1
5V/5VX 0.620 0.620 40/38 0.688 1.1
Note(s) Typical cross section designation for
Aggie/LG Belts adds H prefix.
For example RHB, R3V, etc. - For metric
designations, refer to appropriate Industry
Standard.
WRAPPED MOLDED (RB, RC, RD, R3V R5V)
RAW EDGE COG (RBX, RCX, RDX, R3VX R5VX)
13
V-Ribbed BeltsReference ASAE S211.5 RMA
Standard IP-26
Product - Standard
Nominal Cross-Section Dimensions (inches)
Belt Reference Nomenclature Part Number
400J6 Belt Type
J Number of ribs/band 6 Outside Length
(O.L.) 40.5 Part Number 0.5 Belt O.L.
Cross Section Top Width Th. Angle (degrees) Sg (in.) O.L. Add-ons
J 0.092 0.160 40 0.092 0.5
K 0.140 0.240 40 0.140 See Notes
L 0.185 0.380 40 0.185 1.0
M 0.370 O.660 40 0.370 2.0
Note(s) For metric designations, refer to
appropriate Industry Standard.
The K Section is primarily an MTO item and belt
section parameters are determined by application.
Cross Sections (J, K, L, M Sections)
14
Variable Speed V-BeltsReference RMA Standard
IP-25
Product - Standard
Nominal Cross-Section Dimensions (inches)
Belt Reference Nomenclature Part Number
3226V603 Belt Top Width in 1/16
32 Intended Pulley Angle 26 Outside
Length (O.L.) 61.1 Part Number 0.80
Belt O.L.
Cross Section Top Width Th. Angle (degrees) O.L. Add-ons
1422V 0.880 0.310 22 0.60
1922V 1.190 0.380 22 0.60
2322V 1.440 0.440 22 0.70
1926V 1.190 0.440 26 0.80
2926V 1.810 0.500 26 0.80
3226V 2.000 0.530 26 0.80
2530V 1.560 0.590 30 1.10
3230V 2.000 0.620 30 1.10
4430V 2.750 0.690 30 1.10
4036V 2.500 0.690 36 1.10
4436V 2.750 0.720 36 1.10
4836V 3.000 0.750 36 1.10
Raw Edge Cog Belts
Note(s) Aggie counterparts to these sections
are termed Adjustable Speed Belts and are listed
in the SAE S211.5 Standard. - For metric
designations, refer to appropriate Industry
Standard.
15
Product - Standard
Synchronous (Straight Sided) BeltsReference RMA
Standards IP-24
Nominal Cross-Section Dimensions (inches)
Belt Reference Nomenclature Part Number
770XL025 Belt Type
XL Width (1/100)
0.25 Pitch Length (nearest 1/10) 77.0 Part
Number Pitch Length 10 Notes For metric
information refer to
appropriate Industry Standard.
Cross Section Pitch Pb Hs Th. Hd Th. Ht Th.
MXL 0.080 0.045 0.020
XL 0.200 0.090 0.050
L 0.375 0.140 0.075
H 0.500 0.160 0.090
XH 0.875 0.440 0.250
XXH 1.250 0.620 0.375

DXL 0.200 0.120 0.050
DL 0.375 0.180 0.075
DH 0.500 0.234 0.090
Synchronous Single Sided (MXL, XL, L, H, XH
XXH Sections)
Synchronous Double Sided (DXL, DH DXH Sections)
16
Product - Standard
Synchronous (Curvilinear Toothed) Belts Reference
RMA Standard IP-27
Nominal Cross-Section Dimensions (mm)
Belt Reference Nomenclature Part Number
600-8M-20 Belt Type
8M Width (mm)
20 Pitch Length (mm) 600 Part
Number Pitch Length
Cross Section Pitch Pb Hs Th. Hd Th. Ht Th.
8M 8.0 5.4 3.2
14M 14.0 9.7 6.0

D8M 8.0 7.8 3.2
D14M 14.0 14.5 6.0
Curvilinear Single Sided (8M 14M Sections)
Curvilinear Double Sided (D8M D14M Sections)
17
Made-to-Order (MTO)
Product - MTO

• Key Application-Specific Design
• Design machine around standard belt???
• or
• Design MTO belt around machine???

18
Modifications
Product - MTO

• The following may be changed to create a
  Made-to-Order (MTO) Belt
• Length
• Construction
• Materials
• Cross-Section

19
Length Modifications
Product - MTO

• Non-Standard Lengths (std 1 increments)
• Application-Specific Tolerances

20
Construction Modifications
Product - MTO

• Raw-Edge vs. Wrapped
• Cogged versus Plain RE
• Fabric Plies
• Cord Position

21
Material Modifications
Product - MTO

• Rubber abrasion resistance, heat resistance,
  oil resistance, fiber loading, flex resistance
• Cord shock loading, synchronous tracking, belt
  stretch
• Fabric clutching requirements, static
  conductivity

22
Cross Section Modifications
Product - MTO

• Width
• Thickness
• Angle

23
Product Description
Materials
Cost Drivers
General Drive Design
Additional Considerations
24
Three Basic Materials
Materials

• Rubber
• Cord
• Fabric

25
Rubber General Information
Materials - Rubber

• Used in all facets of our life
• Over 80 pounds in every car
• Natural rubber was primary elastomer prior to
  WWII
• Synthetic rubber (SBR) was introduced in the late
  1940s
• Chloroprene was introduced in the late 1950s
• Today we use rubber compounds blending natural
  and synthetic to achieve optimal properties

26
Rubber Compound Formulation
Materials - Rubber

• Improved processing characteristics
• Improved strength and/or hardness
• Protection from working environment
• Enhance vulcanizing (curing)

27
Typical Rubber Formulation
Materials - Rubber

• Elastomer (SBR, Neop, NBR, etc.)
• 50 - 60
• Fillers (Carbon Black, Fiber, etc.)
• 30 - 40
• Vulcanizers, Cure Agents, Accelerators,
• Retarders, Processing Aids
• 5 - 10

28
Materials - Rubber
Engineering Properties
RUBBER TYPE TEMP Amb (F) PHYSICAL CHARACTERISTICS PHYSICAL CHARACTERISTICS PHYSICAL CHARACTERISTICS PHYSICAL CHARACTERISTICS PHYSICAL CHARACTERISTICS PHYSICAL CHARACTERISTICS
RUBBER TYPE TEMP Amb (F) OIL/CHEM FLEX HYSTERSIS ABRASION OZONE PDf
SBR -40/160 Fair/Poor Good Good Good Fair 4
SBR-F -40/160 Fair/Poor Fair Fair Exc Fair 3
CR -35/190 Good Exc Exc Good Good 2
CR-F -35/190 Good Fair Good Exc Good 1
NBR -45/220 Exc Fair Good Good Poor 4
BR -45/180 Fair/Poor Good Exc Exc Fair 4
HSN -30/230 Exc Exc Good Good Exc 3
LEGEND SBR Styrene-Butadiene
SBR-F Styrene-Butadiene Fiber Reinforced
CR Neoprene Rubber CR-F Neoprene Rubber
- Fiber Reinforced NBR Nitrile Rubber
BR Polybutadiene Rubber HSN Highly
Saturated Nitrile PDf Power Density Factor
Ability/strength of rubber to support power
transmission. 1 being the best.
29
Cord General Information
Materials - Cord

• Cotton used extensively in 1940s 1950s
• Rayon popular in the 1950s 1960s
• Polyester introduced in the 1950s, dominant
  belt tensile
• member today
• Steel introduced in the late 1950s
• Fiberglass - introduced in the late 1950s,
  popular in synchronous belts
• Nomex introduced in the 1960s
• Aramid (Kevlar) introduced in the 1970s,
  popular in lawn and
• grounds applications

30
Materials - Cord
Engineering Properties of Various Fibers
Material Specific Gravity Tensile Strength (psi)
Rayon 1.52 115,000
Nylon 1.14 140,000
Polyester 1.38 160,000
Fiberglass 2.54 195,000 / 310,000
Steel 7.85 340,000
Aramid 1.39 / 1.45 400,000 / 495,000
31
RD Efforts
Materials - Cord

• Focused on Treating and Construction
• Developing proper cord twist
• Temperature
• Tension
• Time

32
Most Commonly Used
Materials - Cord

• Polyester
• Fiberglass
• Aramid

33
Polyester
Materials - Cord

• Moderate Cost
• Good Tensile Strength with Moderate Stretch
• Excellent Flex Properties
• Shrinkage when Subjected to Heat
• Excellent Shock Absorption

34
Fiberglass
Materials - Cord

• Moderate Cost
• High Tensile Strength with No Stretch
• No Shrinkage
• Poor Flex Qualities
• Low Tolerance for Misalignment
• Low Shock Absorption Qualities

35
Aramid
Materials - Cord

• High Cost
• High Tensile Strength with Minimal Stretch
• No Shrinkage
• Good Flex Qualities
• Some Tolerance for Misalignment

36
Engineering Properties
Materials - Cord
CORD TYPE BELT SECTION ELONG. TENSILE (MIN) SHOCK FLEX
Polyester - A Sm PV 3.0 52 Excellent Exc
Polyester - B Sm WM 3.0 145 Excellent Exc
Polyester - C Sm RE 2.0 145 Good Good
Polyester - D Lg WM 3.0 210 Excellent Exc
Polyester - E Lg RE 2.5 210 Good Good
Polyester - F X-Lg RE/WM 2.5 385 Good Good
Aramid - A Sm PV 1.5 95 Good Good
Aramid - B Sm RE/WM 1.0 325 Good Good
Aramid - C Lg RE/WM 1.0 495 Good Good
Elongation is an approximation of belt
elongation over its normal life under normal load
and operating conditions. NOTE Common trade
names for Aramid are Kevlar (Dupont) and Twaron
(Teijin/Twaron) Legend WM Wrapped-Molded RE
Raw Edge belts PV V-Ribbed Belts
Fiberglass - A Sm RE/WM 1.0 150 Poor Poor
Fiberglass - B Lg RE/WM 1.0 220 Poor Poor
Fiberglass - C Sync Belts 0.5 175 Good Good
Fiberglass - K Sync Belts 0.5 230 Good Good
37
Fabric General Information
Materials - Fabric

• Typically Square, Tubular Woven or Angle Induced
• Square Woven can be produced on high speed looms
• Highest bias angle 90 degrees
• Tubular Woven is produced as a tube on slow speed
  looms
• Bias angle can be 110 degrees
• High bias angle improved flexibility
• Angle Induced is produced on high speed looms as
  a square woven fabric and the angle is shifted
  during treatment
• Bias angle can be 110 degrees
• High bias angle improved flexibility

38
Polyester/Cotton Blends
Materials - Fabric

• Balance of Cost and Performance
• Easy to Process
• Good Bonding Qualities
• Good Abrasion Resistance
• Used to Develop Static Conductivity

39
Nylon
Materials - Fabric

• Excellent Abrasion Resistance
• Higher Elasticity
• Primarily Used in Synchronous Belts
• Very Difficult to Work With

40
Fabric Treating
Materials - Fabric

• Single-Sided Coating (Bareback)
• Low coefficient of friction for clutching drives
• Double-Sided Coating
• Used for wrapping of molded belts
• Used for crack barrier in wrapped-molded belts
• Used for laminates in raw edge belts

41
Methods of Treating
Materials - Fabric

• Frictioning
• Dipping / Spreading
• Skimming

42
Product Description
Materials
Cost Drivers
General Drive Design
Additional Considerations
43
Cost Drivers
Cost Drivers

• Construction
• Materials
• Secondary Operations
• Tooling

44
Wrapped-Molded V-Belt
Cost Drivers - Construction

• 2 Ply vs. 1 Ply Wrap
• Cord Types
• Rubber Core
• Profile Differences

45
Raw Edge V-Belt
Cost Drivers - Construction

• Multiple Layers of Fabric Laminate
• Cord Types
• Rubber
• Profile Differences
• Cogged vs. Non-Cogged

46
Cost Drivers - Materials

• Material Relative Cost
• Polyester 1.00
• Fiberglass 1.05
• Aramid 1.15/1.25
• SBR-G 1.00
• SBR-F 1.10
• Neoprene G 1.20
• Neoprene F 1.10/1.25
• Standard 1.00
• Dry Surface 1.20
• Extra Dry Surface 1.60
• Note Relative cost is based on total belt cost

Cord
Rubber
Fabric
47
Secondary Operations
Cost Drivers
Cost Drivers Secondary Operations

• Trimming
• Printing
• Packaging
• Measuring

48
Tooling
Cost Drivers Tooling

• Raw Edge - drums range from 2000 to 8000
• Wrapped-Molded - ring molds range from 2000 to
  20,000
• Synchronous - molds range from 2000 to 18,000

49
Product Description
Materials
Cost Drivers
General Drive Design
Additional Considerations
50
General Drive Design
Drive Design

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

51
Power Transmission and V-Belt Theory
Drive Design - Theory
The function of a belt is to simply transfer
rotation from the powered pulley to one or more
driven pulleys. The belt must be designed and
manufactured to transfer this torque efficiently
and reliably.
52
Means of Power Transmission
Drive Design - Theory

• V-Belts
• Chains
• Gears
• Synchronous Belts
• Hydraulics
• Electronics

53
V-Belt Characteristics
Drive Design - Theory

• Less expensive than other forms of power
  transmission
• Start, stop and run smoothly
• Operate noiselessly and without lubrication
• Absorb objectionable and harmful vibrations
• Clean and require minimum maintenance
• Rugged and long lasting
• Provide a wide selection of speed ranges
• Cover an extremely wide horsepower range
• Easy to install and simple to replace
• Relatively unaffected by moisture, abrasive
  dusts, or extreme variations in temperature

54
V-Belt Principle of Wedging
Drive Design - Theory
55
V-Belt Drive Terminology
Drive Design - Theory
56
General Drive Design
Drive Design
Drive Design - Tension

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

57
Drive Design - Tension
58
Effective Pull
Drive Design - Tension
Effective pull can be calculated by EP T1
T2 24 Q (LBS.) D Where Q Torque
(FT-LBS) at the sheave D Pitch
diameter of sheave (Inches) Effective pull can
also be calculated using the horsepower (HP) and
belt speed (S) of the drive as follows EP
HP x 33000 (LBS.) S This
difference in belt tensions also introduces a
term known as tension ratio (R) Tension Ratio
(R) T1
T2
59
Strand Tension
Drive Design - Tension
The following formula is used when calculating
static strand tension (Ts) for fixed speed
drives.   Ts DHP x K    Tc  
N x S Where K Add-on value based on
D-d                                      
C (See Design Guide,
Table 29, Page 287)              DHP Design
horsepower of the drive              N Number
of belts on the drive              Tc Add-on
value for centrifugal force.  (See Design Guide,
Table 31, Page 291)              S Belt
speed/1000 This formula will produce a tension
ratio of 51 once the drive is operating at the
design horsepower.
60
General Drive Design
Drive Design Stress Fatigue

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

61
Stress Fatigue Analysis
Drive Design Stress Fatigue

• Design Method
• Tensions
• Drive Speeds
• Sheave / Pulley Diameters
• Belt Length
• Estimates Belt Life in Hours
• Evaluates Various Drive Conditions
• Compares New Drive with an Existing Drive
• Variance Between Calculated Life Actual Service
  Life
• Manual versus Computer System

62
General Drive Design
Drive Design Geometry

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

63
Drive Layout
Drive Design Geometry
Idler
Dr
Dn
64
Drive Layout
Drive Design Geometry

• Relative sheave arrangement
• Sub-minimum diameter sheaves
• Maximize belt wrap (AOC)
• Minimize misalignment
• Avoid interference with other machine components
• Utilize proper belt guides / restraints
• Avoid long unsupported spans
• Belt installation and take-up provisions

65
Idlers
Drive Design Geometry

• Lawn Garden drives make extensive use of idlers
• Location in Span
• Location on Inside
• Belt Wrap
• Diameters
• Face Width
• Flat Idler Crowns
• Flanging Requirements
• Reference ASAE S211.5 and RMA bulletin
  IP-3-6

66
Sheaves
Drive Design Geometry

• Avoid Using Sub-Minimum Diameters
• HA 3.0 (80mm)
• AW 5.4 (140mm)
• HB 5.4 (140mm)
• Deep Groove Sheaves
• Clutching Drives
• Misaligned Drives
• Twist (Mule) Drives
• Quarter Drives
• Sheave Condition
• Surface Finish
• Avoid Sharp Edges

67
Effective versus Pitch Diameter
Drive Design Geometry

• Pitch Diameter
• Effective Diameter
• Effective Diameter / Pitch Diameter Relationships
• Relationship of the AW Cross-Section Belt

68
Drive Design Geometry

• Assume HA Deep Groove Sheaves 102.0mm EOD (for HA
  Belt)
• HA PD Calculation AW EOD Calculation
• 102.00 mm 102.00 mm
• - 6.35 mm 4.90 mm
• 95.65 mm PD 106.90 mm EOD
• i
• AW PD Calculation
• 106.90 mm
• - 6.60 mm
• 100.30 mm PD

69
Drive Design Geometry

• Assume HB Groove 127.0m EOD (for HB Belt)
• HB PD Calculation AW EOD Calculation
• 127.00 mm 127.00 mm
• - 8.89 mm - 6.96 mm
• 118.11 mm PD 120.04 mm EOD
• i
• AW PD Calculation
• 120.04 mm
• - 6.60 mm
• 113.44 mm PD

70
Drive Design Geometry

• Effective Diameter Relationships

Note Dimensions shown above are millimeters, and
are based on sheave radius.
AW to HA 4.90mm (0.193) AW to HB
6.96mm (0.274) HA to HB 11.86mm (0.467)
71
Pitch Diameter Relationships
Drive Design Geometry
Note Dimensions shown above are millimeters, and
are based on sheave radius.
2a Values HA 6.35mm (0.25) HB 8.89mm
(0.35) AW 6.60mm (0.26)
AW to HA 4.65mm (0.183) AW to HB 4.67mm
(0.184) HA to HB 9.32mm (0.367)
72
General Drive Design
Drive Design Multiple Plane

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

73
Three Basic Types
Drive Design Multiple Plane

• Quarter Turn
• Mule
• Crossed Belt (180 degree Twist)
• Reference ASAE S211.5 and RMA IP-3-10

74
Quarter Turn Drives
Drive Design Multiple Plane
75
Quarter Turn Drives
Drive Design Multiple Plane

• Use Deep Groove Sheaves
• Not Recommended for Drives with Speed Ratios gt
  2.5
• Minimum Center Distance 5.5 x (D Fb)
• D Diameter Large Sheave
• Fb Belt Top Width
• The center of the face of the sheave on the
  vertical shaft shall be below
• the axis of the horizontal shaft by amount e
  which is dependent on the
• center distance.
• Up to 39 e 0.2
• 40 to 59 e 0.4
• 60 to 99 e 0.5
• Direction of Rotation must be such that the
  Tight Side of the drive is on
• the bottom.
• The axis of the Vertical Shaft shall lie in a
  plane perpendicular to the
• horizontal shaft, and intersecting it at the
  center of the face of the
• sheave on the horizontal shaft. (See Top
  View)
• For 1/8 Turn Drives, use 4.0 instead of 5.5 in
  the Formula.

76
Mule Drives
Drive Design Multiple Plane

• Key Points
• Use Deep Groove Sheaves
• Alignment Very Important (Idler Positioning)
• Construction Considerations
• - Low Modulus Cord
• - Low Coefficient of Friction Wrap
• Minimum Spans for 90 Degree Twist Angles
• HA 9.0 HB 11.0 AW 12.0
• Minimum Spans for Other Twist Angles
• Span at 90 x Angle/90
• Ex HA Belt at 45 Twist
• 9.0 x (45/90) 4.5

77
General Drive Design
Drive Design Misalignment

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

78
Two Basic Types of Misalignment
Drive Design Misalignment

• Off-Set (common in mower deck drives)
• Angular (cocked sheaves)

Proper Parallel Horizontal
Vertical (Off-Set) Angular Angular
79
Drive Design Misalignment
Common Mower Deck Drive
80
Drive Design Misalignment

• Use Deep Groove Sheaves
• Recommended Maximum Misalignment 5 Degrees
• Concerns and Problems
• Belt Rollover
• Edge Cord Failures
• Belt Take-Up Provisions
• Related Component Issues
• Minimize Tight Strand Misalignment
• Belt Construction and Profiles
• Polyester vs. Aramid Cord
• HA vs. AW Section

81
General Drive Design
Drive Design Idlers

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

82
Spring Loaded Idlers
Drive Design Idlers

• Constant Tension Characteristics
• Reduced Maintenance
• Pretensioning avoided
• Tensions proportional to Loads Transmitted
• Higher Peak Load Transmission Possible
• Idler Location
• Not Recommended for Reversing Drives
• Concerns with High Shock or Pulsating Drives
• Belt Installation and Take-Up Concerns

83
Drive Design Idlers

• Calculation of Idler Shaft Loads

F

a

Idler Force 2T sin a 2
84
Drive Design Idlers
Drive Tensions Fixed vs. Moveable Idler
85
General Drive Design
Drive Design Tolerances

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

86
Guidelines
Drive Design Tolerances
Belt Section
87
Guidelines
Drive Design Tolerances

• Length Range Y Tolerance ASAE
  Tolerance
• Up to 1000mm (39) /- 3mm
  (.118) /- 5mm (.197)
• 1000mm to 1500mm (39 to 59) /- 4mm
  (.157) /- 5mm (.197)
• 1500mm to 2500mm (59 to 98) /- 5mm
  (.197) /- 6.5mm (.256)
• 2500mm to 4000mm (98 to 157) /- 6mm
  (.236) /- 8/10mm(.32/.39)
• Note Consider these as MINIMUM tolerances under
  normal circumstances.

88
General Drive Design
Drive Design Software

• Power Transmission and V-Belt Theory
• Static and Dynamic Tension
• Stress Fatigue Analysis
• Drive Geometry
• Multiple Plane Drives
• Misalignment
• Spring Loaded Idlers
• Tolerances
• Drive Analysis Software

89
Drive Design Software
90
Drive Design Software

• Order from customer service 866-773-2926 Part
  109022
• Download from website http//www.cptbelts.com/cu
  stomercenter/drivepro

91
Product Description
Materials
Cost Drivers
General Drive Design
Additional Considerations
92
Additional Considerations

• Safety / Liability
• Failure Analysis
• Testing Capabilities

93
Proper Guard Design
Drive Considerations
Additional Considerations Safety/Liability

• Sufficient Strength
• Prevent Accidental Contact
• Caution Labels
• Prevent Dirt and Debris from Entering the Drive
• Reduction of Noise
• Ventilation

94
Static Conductive Belts
Additional Considerations Safety/Liability

• Explosive Environments
• Potential Fire Hazard
• Shock / Human Contact

95
Clutching Drives
Additional Considerations Safety/Liability

• Do not use high thermal shrinkage cord
• Safety of person should not depend on belt
  function

96
Leading Causes of Belt Failure
Additional Considerations Failure Analysis

• Improper Tensioning
• Misalignment
• Related Component Defects
• Abrasive Conditions
• Unusual Loading Cycles
• Operating Temperature

97
Symptoms of Drive Problems
Additional Considerations Failure Analysis

• Flex Cracking
• Shock Break
• Belt Slippage
• Rollover
• Jumping Off Sheaves
• Belt Squeal
• Premature Wear

98
Testing Capabilities
Additional Considerations Testing

• Materials Testing
• Static Product Testing
• Bench Tests
• Application Specific Testing

99
Materials Testing
Additional Considerations Testing

• Rubber
• Raw material
• Mixed compounds
• Cord
• Raw material
• Treated cord
• Fabric
• Raw material
• Coated/Treated fabric

100
Static Product Testing
Additional Considerations Testing

• Tensile / Elongation
• Adhesion
• Belt Size / Length
• Belt Variation / Deflection
• Static Conductivity

101
Bench Tests
Additional Considerations Testing

• Dead Weight Testers
• Waterbrake / Differential Testers

102
4 Pulley Dead Weight Testwith back side idler
Additional Considerations Testing

• Constant tension supplied by weight on lower
  pulley
• Constant speed provided by electric motor
  connected to top pulley
• Adjustable alignment angle
• Small diameter pulleys and backside pulley

103
4 Pulley Power Test
Additional Considerations Testing

• Constant tension supplied by weights on driven
  pulley
• Constant speed from electric motor on driver
  pulley
• Constant HP load supplied by generator on driven
  pulley
• Small inside and backside idler
• Adjustable alignment angle

104
High HP Variable Speed Tester
Additional Considerations Testing

• 2200 RPM driver
• 300 HP load capability
• Computer controlled speed and load cycle

105
CVT Drive Test
Additional Considerations Testing

• Production clutch mechanism
• Adjustable center distance
• Computer controlled speed and load cycle

106
Traction Drive Test
Additional Considerations Testing

• Production tensioning mechanism
• Constant speed from electric motor on driver
  pulley
• Constant HP load supplied by water brake on
  driven pulley

107
Application-Specific Testing
Additional Considerations Testing

• Special Drive Configuration Testing
• Special Customer Machine Testing

108
www.CarlisleBelts.com
from
www.c-rproducts.com sales_at_c-rproducts.com Tel
44 1327 701030 Fax [phone]