Spur Gear : Machine Design

Spur Gear : Machine Design           

In

Introduction :                                     

Slipping  of a belt or rope is the transmission of motion or power between two shafts. The effect of slipping is to reduce the velocity ratio of system . The motion and power transmitted by gears is equivalent to transmitted by functional wheel or disc .

Advantages of Gear Drive :.         

1. Transmits exact velocity ratio
2. Transmit large power
3. Used for small centre distance if shafts
4. High Efficiency
5. Reliability Service
6. Compact Layout

Disadvantages of Gear Drive :.   

1. Require special tools and equipment
2. Require lubricant and proper operation
3. Vibration and noise during operation

Classification of Gears :                   

1. According to position of axes of shifts :.                                           

1. Parallel - Spur Gear , Single Helical Gear , Double Helical , Rack and Pinion 
2. Intersecting or Non - Parallel - Bevel Gear
3. Non - Intersecting and Non - Parallel - Worm and Wormed Gear , Spiral Gear

Rock and Pinion

Single Bevel Gear

Double Helical Gear

Bevel Gear

Worm Gear

2. According to the peripheral velocity of gear :.                             

1. Low velocity - less than 3m/s
2. Medium velocity - (3 - 15) m/s
3. High velocity - more than 15 m/s 

3. According to the type of gearing :.                                            

1. External Gearing
2. Internal Gearing
3. Rack and Pinion

External Gearing

External Gearing - Two shafts mesh externally, larger wheel - Spur Gear or Gear , Smaller wheel - Pinion.

Internal Gearing : Two shafts mesh internally , larger wheel - Annular Wheel , Smaller Wheel - Pinion .

Rack and Pinion : Externally and internally ,straight line gear is called rack and circular wheel is called pinion . 

4. According to position of teeth on gear surface :.                             

1. Straight -  Spur Gear.    
2. Inclined -  Helical Gear 
3. Curved -    Spiral Gear.  

Terms Used in Gears :                       

1. Pitch Circle    2. Pitch Circle Diameter    3. Pitch Point    4. Pitch Surface   5. Pressure angle or angle of obliquity    6. Addendum     7. Dedendum      8. Addendum Circle           9. Dedendum Circle            10. Circular Pitch        11. Diametral Pitch    12. Module       13. Clearance     14. Total Depth      15. Working Depth        16. Tooth Thickness          17. Tooth Space        18.Backlash        19. Face of Tooth       20. Top Land        21. Flank of Tooth      22. Face wide       23. Profile 2224. Fillet Radius       25. Path of Contact        26. Length of path of Contact      27. Arc of Contact      (a) Arc of Approach  AOA       (b) Arc of Recess  AOR  

Terminology of Spur Gear

Comming soon.....