SlideShare a Scribd company logo
1 of 16
Download to read offline
Final-drive
or
Rear Axles Final-drive
Rear Axles Final-drive
The rear axles final drive
(i) Transmits the drive through a angle of 90degrees, and
(ii) Gears down the engine revolutions to provide a
‘direct top’ gearbox ratio.
(iii) In the case of cars a final drive ratio of approximately
4 : 1 is used.
(iv) Bevel or worn gears are employed to achieve the
various functions of the final drive.
TYPES OF FINAL DRIVES
1. Bevel Gears
– Straight Bevel.
– Spiral Bevel.
2. Hypoid Gear
3. Worm and Wheel Drive
Bevel Gears
• The geometry of a bevel gear
layout, which represents two
friction cones ‘A’ forming the
crown wheel and ‘B’ the pinion.
• For avoidance of slippage and
wear, the apex of the pinion must
coincide with the centre line of the
crown wheel.
• It is necessary to mount the gear in
the correct position so that angle
of the bevel is governed by the
gear ratio.
11 final drive
Types of Bevel Gear.
1. Straight Bevel.
2. Spiral Bevel.
Backlash In Gears
• Backlash is most commonly created by cutting
the teeth deeper into the gears than the ideal
depth.
• Another way of introducing backlash is by
increasing the center distances between the
gears.
• Standard practice is to make allowance for half
the backlash in the tooth thickness of each gear.
Straight Bevel
• The tapered teeth, generated from the centre, are machined on the case-
hardened steel gears and then ground together to form a ‘mated pair’.
• The position of the crown wheel relative to the pinion determines the
direction of rotation of the axle shaft.
• For correct meshing and for setting the clearance between the teeth
(backlash), adjusters in the form of distance pieces, shims or screwed rings
are used.
• When backlash is too small, expansion results due to heat and wear is
caused by lack of lubrication.
• On the other hand excessive backlash produces slackness and noise.
• Each manufacturer recommends a suitable backlash, but it is generally in
the region of 0.15 mm for cars and 0.25 mm for heavy vehicles.
11 final drive
Spiral Bevel
• Although the straight bevel is cheaper and
mechanically efficient, the meshing of the gears
causes an unwanted noise, which has been
reduced by introducing a helical form of tooth.
• Figure illustrates the construction of the gear, A
number of teeth are generated from the centre of
the crown wheel, and form a left-handed spiral in
the case of the pinion.
11 final drive
Hypoid Gear
• This type of gear is the commonly used now a days.
• The pinion axis of this gear is offset to the centre line of the crown wheel.
• Although the gear can be placed above or below the centre, but in cars it is
always placed below to allow for a lower propeller shaft so that a reduction
in the tunnel height is possible.
• If the axis is lowered, the tooth pitch of the pinion increases, so that for a
given ratio, the pinion diameter can be larger (30 percent for normal offset).
• This enables the use of a stronger gear specifically on commercial vehicles.
11 final drive
Worm and Wheel Drive
• Since this drive is expensive, it is rarely used nowadays as a
final drive on light vehicles, but is still used on heavy vehicles.
• However, this type of gear has a number of other applications
on motor vehicles.
• It can be employed to provide a very quiet and long-lasting
gear, but efficiency is less than the bevel (94 percent against 98
percent).
• This type of gear provides a large reduction in a small space.
11 final drive
11 final drive

More Related Content

What's hot

Different types of suspension system
Different types of suspension systemDifferent types of suspension system
Different types of suspension systemHOME
 
Unit 1 Front Axle & Steering System
Unit 1 Front Axle & Steering SystemUnit 1 Front Axle & Steering System
Unit 1 Front Axle & Steering SystemVishal Niphade
 
Gear box
Gear boxGear box
Gear boxdeep388
 
4 independed suspension system
4 independed suspension system4 independed suspension system
4 independed suspension systemshaikusmanshag
 
Steering Brake and Suspension System
Steering Brake and Suspension SystemSteering Brake and Suspension System
Steering Brake and Suspension SystemPraveenManickam2
 
Sliding mesh gear box
Sliding mesh gear boxSliding mesh gear box
Sliding mesh gear boxGopinath Guru
 
Automobile- drive systems
Automobile- drive systems Automobile- drive systems
Automobile- drive systems scholar777
 
2b9fc module iii steering system_ part-ii (2)
2b9fc module iii steering system_ part-ii (2)2b9fc module iii steering system_ part-ii (2)
2b9fc module iii steering system_ part-ii (2)Tanvi Gautam
 
Study of transmission system of automobile
Study of transmission system of automobileStudy of transmission system of automobile
Study of transmission system of automobileNikhil Chavda
 

What's hot (20)

Different types of suspension system
Different types of suspension systemDifferent types of suspension system
Different types of suspension system
 
Unit 1 Front Axle & Steering System
Unit 1 Front Axle & Steering SystemUnit 1 Front Axle & Steering System
Unit 1 Front Axle & Steering System
 
Gear box
Gear boxGear box
Gear box
 
Brakes
BrakesBrakes
Brakes
 
4 independed suspension system
4 independed suspension system4 independed suspension system
4 independed suspension system
 
Steering Brake and Suspension System
Steering Brake and Suspension SystemSteering Brake and Suspension System
Steering Brake and Suspension System
 
Unit 2 Front and Rear Axles, Steering Sysytem, Wheels and Tyres
Unit 2 Front and Rear Axles, Steering Sysytem, Wheels and TyresUnit 2 Front and Rear Axles, Steering Sysytem, Wheels and Tyres
Unit 2 Front and Rear Axles, Steering Sysytem, Wheels and Tyres
 
Propeller shaft
Propeller shaftPropeller shaft
Propeller shaft
 
Clutch ppt
Clutch pptClutch ppt
Clutch ppt
 
Sliding mesh gear box
Sliding mesh gear boxSliding mesh gear box
Sliding mesh gear box
 
Automobile- drive systems
Automobile- drive systems Automobile- drive systems
Automobile- drive systems
 
Hydraulic Power steering system
Hydraulic Power steering systemHydraulic Power steering system
Hydraulic Power steering system
 
Clutches
ClutchesClutches
Clutches
 
2b9fc module iii steering system_ part-ii (2)
2b9fc module iii steering system_ part-ii (2)2b9fc module iii steering system_ part-ii (2)
2b9fc module iii steering system_ part-ii (2)
 
Gear box
Gear boxGear box
Gear box
 
Differential
DifferentialDifferential
Differential
 
Study of transmission system of automobile
Study of transmission system of automobileStudy of transmission system of automobile
Study of transmission system of automobile
 
Reare axle
Reare axleReare axle
Reare axle
 
Gear box
Gear boxGear box
Gear box
 
Steering geometry 8
Steering geometry 8Steering geometry 8
Steering geometry 8
 

Viewers also liked

rear axle ppt
rear axle  pptrear axle  ppt
rear axle pptNk Babul
 
Differential and Rear Axle Drives, by Jeevan B M
Differential and Rear  Axle Drives, by Jeevan B MDifferential and Rear  Axle Drives, by Jeevan B M
Differential and Rear Axle Drives, by Jeevan B MJeevan B M
 
Automotive Differential Unit
Automotive Differential Unit Automotive Differential Unit
Automotive Differential Unit Parth Vaishnav
 
Automotive Air Conditioning systems
Automotive Air Conditioning systemsAutomotive Air Conditioning systems
Automotive Air Conditioning systemsAnand Prithviraj
 
5 classification of brakes
5 classification of brakes5 classification of brakes
5 classification of brakesshaikusmanshag
 
Differential in automobile
Differential in automobileDifferential in automobile
Differential in automobilePadam Yadav
 

Viewers also liked (11)

Automobile Differential Unit
Automobile Differential Unit Automobile Differential Unit
Automobile Differential Unit
 
rear axle ppt
rear axle  pptrear axle  ppt
rear axle ppt
 
Differential and Rear Axle Drives, by Jeevan B M
Differential and Rear  Axle Drives, by Jeevan B MDifferential and Rear  Axle Drives, by Jeevan B M
Differential and Rear Axle Drives, by Jeevan B M
 
Automotive Differential Unit
Automotive Differential Unit Automotive Differential Unit
Automotive Differential Unit
 
Differential system
Differential systemDifferential system
Differential system
 
9 diferential
9 diferential9 diferential
9 diferential
 
7 steering mechanisms
7 steering mechanisms7 steering mechanisms
7 steering mechanisms
 
Automotive Air Conditioning systems
Automotive Air Conditioning systemsAutomotive Air Conditioning systems
Automotive Air Conditioning systems
 
5 classification of brakes
5 classification of brakes5 classification of brakes
5 classification of brakes
 
Automobile Differential System
Automobile Differential SystemAutomobile Differential System
Automobile Differential System
 
Differential in automobile
Differential in automobileDifferential in automobile
Differential in automobile
 

Similar to 11 final drive

Gear Manufacturing.ppt
Gear Manufacturing.pptGear Manufacturing.ppt
Gear Manufacturing.pptRAMESHBABUSMEC
 
10 gear manufacturing process
10  gear manufacturing process10  gear manufacturing process
10 gear manufacturing processM Siva Kumar
 
Basic Fundamentals of Gear Drives R1.pdf
Basic Fundamentals of Gear Drives R1.pdfBasic Fundamentals of Gear Drives R1.pdf
Basic Fundamentals of Gear Drives R1.pdfVeeresh RK
 
Basic Fundamentals of Gear Drives R1.pdf
Basic Fundamentals of Gear Drives R1.pdfBasic Fundamentals of Gear Drives R1.pdf
Basic Fundamentals of Gear Drives R1.pdfveeresha10
 
Steering gearboxes
Steering gearboxesSteering gearboxes
Steering gearboxesPushpajeet .
 
Presentation: Wheels tyres and bearings
Presentation: Wheels tyres and bearingsPresentation: Wheels tyres and bearings
Presentation: Wheels tyres and bearingsDevendra Yadav
 
Manual transmission final
Manual transmission finalManual transmission final
Manual transmission finalSagar Ahire
 
Steering Geometry.pptx
Steering Geometry.pptxSteering Geometry.pptx
Steering Geometry.pptxRAMESHKUMARB6
 
Design and construction of gear1
Design and construction of gear1Design and construction of gear1
Design and construction of gear1SanskarSutrave1
 
Steering for general automobile
Steering for general automobile Steering for general automobile
Steering for general automobile sgrsoni45
 
Various types of gear profile.pdf
Various types of gear profile.pdfVarious types of gear profile.pdf
Various types of gear profile.pdfPrabhatRout2
 
How differential works
How differential worksHow differential works
How differential worksDev Singh
 
Aeps Pieces | Power transmission devices
Aeps Pieces | Power transmission devicesAeps Pieces | Power transmission devices
Aeps Pieces | Power transmission devicesAeps Pieces
 

Similar to 11 final drive (20)

Gear Manufacturing.ppt
Gear Manufacturing.pptGear Manufacturing.ppt
Gear Manufacturing.ppt
 
10 gear manufacturing process
10  gear manufacturing process10  gear manufacturing process
10 gear manufacturing process
 
Basic Fundamentals of Gear Drives R1.pdf
Basic Fundamentals of Gear Drives R1.pdfBasic Fundamentals of Gear Drives R1.pdf
Basic Fundamentals of Gear Drives R1.pdf
 
Basic Fundamentals of Gear Drives R1.pdf
Basic Fundamentals of Gear Drives R1.pdfBasic Fundamentals of Gear Drives R1.pdf
Basic Fundamentals of Gear Drives R1.pdf
 
Steering gearboxes
Steering gearboxesSteering gearboxes
Steering gearboxes
 
Steering System
Steering SystemSteering System
Steering System
 
Steering system
Steering systemSteering system
Steering system
 
Presentation: Wheels tyres and bearings
Presentation: Wheels tyres and bearingsPresentation: Wheels tyres and bearings
Presentation: Wheels tyres and bearings
 
Manual transmission final
Manual transmission finalManual transmission final
Manual transmission final
 
Steering Geometry.pptx
Steering Geometry.pptxSteering Geometry.pptx
Steering Geometry.pptx
 
Design and construction of gear1
Design and construction of gear1Design and construction of gear1
Design and construction of gear1
 
Steering for general automobile
Steering for general automobile Steering for general automobile
Steering for general automobile
 
Bevel gears
Bevel gears Bevel gears
Bevel gears
 
Types of gears
Types of gearsTypes of gears
Types of gears
 
About Gears
About Gears About Gears
About Gears
 
gears
gearsgears
gears
 
Various types of gear profile.pdf
Various types of gear profile.pdfVarious types of gear profile.pdf
Various types of gear profile.pdf
 
Chap95
Chap95Chap95
Chap95
 
How differential works
How differential worksHow differential works
How differential works
 
Aeps Pieces | Power transmission devices
Aeps Pieces | Power transmission devicesAeps Pieces | Power transmission devices
Aeps Pieces | Power transmission devices
 

More from shaikusmanshag

More from shaikusmanshag (20)

Cylinder liner &materials
Cylinder liner &materialsCylinder liner &materials
Cylinder liner &materials
 
10 cylinder liners and piston ring manufacturing
10 cylinder liners and piston ring manufacturing10 cylinder liners and piston ring manufacturing
10 cylinder liners and piston ring manufacturing
 
10 cylinder liner and rings
10 cylinder liner and rings10 cylinder liner and rings
10 cylinder liner and rings
 
9 upset forging of valves
9 upset forging of valves9 upset forging of valves
9 upset forging of valves
 
8 gudgeon pin
8 gudgeon pin8 gudgeon pin
8 gudgeon pin
 
7 connecting rod
7 connecting rod7 connecting rod
7 connecting rod
 
6 crank shaft
6 crank shaft6 crank shaft
6 crank shaft
 
5 cylinder head
5 cylinder head5 cylinder head
5 cylinder head
 
4 engine block
4 engine block4 engine block
4 engine block
 
3 surface hardening
3 surface hardening3 surface hardening
3 surface hardening
 
3 forging
3 forging3 forging
3 forging
 
2 basics of casting
2 basics of casting2 basics of casting
2 basics of casting
 
2 introduction to cim. pptx
2 introduction to cim. pptx2 introduction to cim. pptx
2 introduction to cim. pptx
 
3 numerical control
3 numerical control3 numerical control
3 numerical control
 
5 accuracy and productivity
5 accuracy and productivity5 accuracy and productivity
5 accuracy and productivity
 
4 tooling in cnc
4 tooling in cnc4 tooling in cnc
4 tooling in cnc
 
6 blu
6 blu6 blu
6 blu
 
3 tyre types
3 tyre types3 tyre types
3 tyre types
 
1 wheels
1 wheels1 wheels
1 wheels
 
3 tyre materials
3 tyre materials3 tyre materials
3 tyre materials
 

Recently uploaded

EPE3163_Hydro power stations_Unit2_Lect2.pptx
EPE3163_Hydro power stations_Unit2_Lect2.pptxEPE3163_Hydro power stations_Unit2_Lect2.pptx
EPE3163_Hydro power stations_Unit2_Lect2.pptxJoseeMusabyimana
 
Mohs Scale of Hardness, Hardness Scale.pptx
Mohs Scale of Hardness, Hardness Scale.pptxMohs Scale of Hardness, Hardness Scale.pptx
Mohs Scale of Hardness, Hardness Scale.pptxKISHAN KUMAR
 
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...Amil baba
 
cloud computing notes for anna university syllabus
cloud computing notes for anna university syllabuscloud computing notes for anna university syllabus
cloud computing notes for anna university syllabusViolet Violet
 
IT3401-WEB ESSENTIALS PRESENTATIONS.pptx
IT3401-WEB ESSENTIALS PRESENTATIONS.pptxIT3401-WEB ESSENTIALS PRESENTATIONS.pptx
IT3401-WEB ESSENTIALS PRESENTATIONS.pptxSAJITHABANUS
 
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...Amil baba
 
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdfRenewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdfodunowoeminence2019
 
دليل تجارب الاسفلت المختبرية - Asphalt Experiments Guide Laboratory
دليل تجارب الاسفلت المختبرية - Asphalt Experiments Guide Laboratoryدليل تجارب الاسفلت المختبرية - Asphalt Experiments Guide Laboratory
دليل تجارب الاسفلت المختبرية - Asphalt Experiments Guide LaboratoryBahzad5
 
Technology Features of Apollo HDD Machine, Its Technical Specification with C...
Technology Features of Apollo HDD Machine, Its Technical Specification with C...Technology Features of Apollo HDD Machine, Its Technical Specification with C...
Technology Features of Apollo HDD Machine, Its Technical Specification with C...Apollo Techno Industries Pvt Ltd
 
How to Write a Good Scientific Paper.pdf
How to Write a Good Scientific Paper.pdfHow to Write a Good Scientific Paper.pdf
How to Write a Good Scientific Paper.pdfRedhwan Qasem Shaddad
 
Landsman converter for power factor improvement
Landsman converter for power factor improvementLandsman converter for power factor improvement
Landsman converter for power factor improvementVijayMuni2
 
nvidia AI-gtc 2024 partial slide deck.pptx
nvidia AI-gtc 2024 partial slide deck.pptxnvidia AI-gtc 2024 partial slide deck.pptx
nvidia AI-gtc 2024 partial slide deck.pptxjasonsedano2
 
Multicomponent Spiral Wound Membrane Separation Model.pdf
Multicomponent Spiral Wound Membrane Separation Model.pdfMulticomponent Spiral Wound Membrane Separation Model.pdf
Multicomponent Spiral Wound Membrane Separation Model.pdfGiovanaGhasary1
 
Basic Principle of Electrochemical Sensor
Basic Principle of  Electrochemical SensorBasic Principle of  Electrochemical Sensor
Basic Principle of Electrochemical SensorTanvir Moin
 
Dev.bg DevOps March 2024 Monitoring & Logging
Dev.bg DevOps March 2024 Monitoring & LoggingDev.bg DevOps March 2024 Monitoring & Logging
Dev.bg DevOps March 2024 Monitoring & LoggingMarian Marinov
 
ASME BPVC 2023 Section I para leer y entender
ASME BPVC 2023 Section I para leer y entenderASME BPVC 2023 Section I para leer y entender
ASME BPVC 2023 Section I para leer y entenderjuancarlos286641
 

Recently uploaded (20)

Lecture 2 .pptx
Lecture 2                            .pptxLecture 2                            .pptx
Lecture 2 .pptx
 
EPE3163_Hydro power stations_Unit2_Lect2.pptx
EPE3163_Hydro power stations_Unit2_Lect2.pptxEPE3163_Hydro power stations_Unit2_Lect2.pptx
EPE3163_Hydro power stations_Unit2_Lect2.pptx
 
Mohs Scale of Hardness, Hardness Scale.pptx
Mohs Scale of Hardness, Hardness Scale.pptxMohs Scale of Hardness, Hardness Scale.pptx
Mohs Scale of Hardness, Hardness Scale.pptx
 
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
 
cloud computing notes for anna university syllabus
cloud computing notes for anna university syllabuscloud computing notes for anna university syllabus
cloud computing notes for anna university syllabus
 
IT3401-WEB ESSENTIALS PRESENTATIONS.pptx
IT3401-WEB ESSENTIALS PRESENTATIONS.pptxIT3401-WEB ESSENTIALS PRESENTATIONS.pptx
IT3401-WEB ESSENTIALS PRESENTATIONS.pptx
 
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
 
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdfRenewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
 
دليل تجارب الاسفلت المختبرية - Asphalt Experiments Guide Laboratory
دليل تجارب الاسفلت المختبرية - Asphalt Experiments Guide Laboratoryدليل تجارب الاسفلت المختبرية - Asphalt Experiments Guide Laboratory
دليل تجارب الاسفلت المختبرية - Asphalt Experiments Guide Laboratory
 
Présentation IIRB 2024 Chloe Dufrane.pdf
Présentation IIRB 2024 Chloe Dufrane.pdfPrésentation IIRB 2024 Chloe Dufrane.pdf
Présentation IIRB 2024 Chloe Dufrane.pdf
 
Litature Review: Research Paper work for Engineering
Litature Review: Research Paper work for EngineeringLitature Review: Research Paper work for Engineering
Litature Review: Research Paper work for Engineering
 
Technology Features of Apollo HDD Machine, Its Technical Specification with C...
Technology Features of Apollo HDD Machine, Its Technical Specification with C...Technology Features of Apollo HDD Machine, Its Technical Specification with C...
Technology Features of Apollo HDD Machine, Its Technical Specification with C...
 
Lecture 4 .pdf
Lecture 4                              .pdfLecture 4                              .pdf
Lecture 4 .pdf
 
How to Write a Good Scientific Paper.pdf
How to Write a Good Scientific Paper.pdfHow to Write a Good Scientific Paper.pdf
How to Write a Good Scientific Paper.pdf
 
Landsman converter for power factor improvement
Landsman converter for power factor improvementLandsman converter for power factor improvement
Landsman converter for power factor improvement
 
nvidia AI-gtc 2024 partial slide deck.pptx
nvidia AI-gtc 2024 partial slide deck.pptxnvidia AI-gtc 2024 partial slide deck.pptx
nvidia AI-gtc 2024 partial slide deck.pptx
 
Multicomponent Spiral Wound Membrane Separation Model.pdf
Multicomponent Spiral Wound Membrane Separation Model.pdfMulticomponent Spiral Wound Membrane Separation Model.pdf
Multicomponent Spiral Wound Membrane Separation Model.pdf
 
Basic Principle of Electrochemical Sensor
Basic Principle of  Electrochemical SensorBasic Principle of  Electrochemical Sensor
Basic Principle of Electrochemical Sensor
 
Dev.bg DevOps March 2024 Monitoring & Logging
Dev.bg DevOps March 2024 Monitoring & LoggingDev.bg DevOps March 2024 Monitoring & Logging
Dev.bg DevOps March 2024 Monitoring & Logging
 
ASME BPVC 2023 Section I para leer y entender
ASME BPVC 2023 Section I para leer y entenderASME BPVC 2023 Section I para leer y entender
ASME BPVC 2023 Section I para leer y entender
 

11 final drive

  • 2. Rear Axles Final-drive The rear axles final drive (i) Transmits the drive through a angle of 90degrees, and (ii) Gears down the engine revolutions to provide a ‘direct top’ gearbox ratio. (iii) In the case of cars a final drive ratio of approximately 4 : 1 is used. (iv) Bevel or worn gears are employed to achieve the various functions of the final drive.
  • 3. TYPES OF FINAL DRIVES 1. Bevel Gears – Straight Bevel. – Spiral Bevel. 2. Hypoid Gear 3. Worm and Wheel Drive
  • 4. Bevel Gears • The geometry of a bevel gear layout, which represents two friction cones ‘A’ forming the crown wheel and ‘B’ the pinion. • For avoidance of slippage and wear, the apex of the pinion must coincide with the centre line of the crown wheel. • It is necessary to mount the gear in the correct position so that angle of the bevel is governed by the gear ratio.
  • 6. Types of Bevel Gear. 1. Straight Bevel. 2. Spiral Bevel.
  • 7. Backlash In Gears • Backlash is most commonly created by cutting the teeth deeper into the gears than the ideal depth. • Another way of introducing backlash is by increasing the center distances between the gears. • Standard practice is to make allowance for half the backlash in the tooth thickness of each gear.
  • 8. Straight Bevel • The tapered teeth, generated from the centre, are machined on the case- hardened steel gears and then ground together to form a ‘mated pair’. • The position of the crown wheel relative to the pinion determines the direction of rotation of the axle shaft. • For correct meshing and for setting the clearance between the teeth (backlash), adjusters in the form of distance pieces, shims or screwed rings are used. • When backlash is too small, expansion results due to heat and wear is caused by lack of lubrication. • On the other hand excessive backlash produces slackness and noise. • Each manufacturer recommends a suitable backlash, but it is generally in the region of 0.15 mm for cars and 0.25 mm for heavy vehicles.
  • 10. Spiral Bevel • Although the straight bevel is cheaper and mechanically efficient, the meshing of the gears causes an unwanted noise, which has been reduced by introducing a helical form of tooth. • Figure illustrates the construction of the gear, A number of teeth are generated from the centre of the crown wheel, and form a left-handed spiral in the case of the pinion.
  • 12. Hypoid Gear • This type of gear is the commonly used now a days. • The pinion axis of this gear is offset to the centre line of the crown wheel. • Although the gear can be placed above or below the centre, but in cars it is always placed below to allow for a lower propeller shaft so that a reduction in the tunnel height is possible. • If the axis is lowered, the tooth pitch of the pinion increases, so that for a given ratio, the pinion diameter can be larger (30 percent for normal offset). • This enables the use of a stronger gear specifically on commercial vehicles.
  • 14. Worm and Wheel Drive • Since this drive is expensive, it is rarely used nowadays as a final drive on light vehicles, but is still used on heavy vehicles. • However, this type of gear has a number of other applications on motor vehicles. • It can be employed to provide a very quiet and long-lasting gear, but efficiency is less than the bevel (94 percent against 98 percent). • This type of gear provides a large reduction in a small space.