Information of different types of Gears .pptx

Explanation regarding different types of Gears

1. Ms.Viddya S. Patil Assistant Professor Department of Mechanical Engineering 1 Sharad Institute of Technology, College of Engineering, Yadrav- Ichalkarnji Department of Mechanical Engineering Lecture 3: Gears Fundamentals of Mechanical Engineering

2. 2 Content Introduction of Gears Types of Gears with applications

3. 3 What is Gear? A toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion . A gear is a component within a transmission device that transmits rotational force to another gear or device. A gear is different from a pulley in that a gear is a round wheel which has linkages that mesh with other gear teeth, allowing force to be fully transferred without slippage. Depending on their construction and arrangement, geared devices can transmit forces at different speeds, torques, or in a different direction, from the power source . Gears are used to transmit motion from one shaft to another shaft or between shafts. This is accomplished by successively engaging teeth.

4. 4 CLASSIFICATION OF GEARS Gears can be classified according to the relative position of their shaft axis are follows: A : PARALLEL SHAFT Spur gear Spur rack and pinion Helical gears or Helical spur gear Double- helical and Herringbone gear B : INTER SECTING SHAFT (i)Straight bevel gear ( ii)Spiral bevel gear ( iii) Zerol bevel gear C : SKEW SHAFT Crossed- helical gear Worm gears( Non-throated, Single throated, Double throated)

5. 5 Spur Gears- They have straight teeth parallel to the axes and thus are not subjected to axial thrust due to teeth load. Spur gears are the most common type of gears. Spur gears are gears in the same plane that move opposite of each other because they are meshed together. Gear ‘A’ is called the ‘driver’ because this is turned by a motor. As gear ‘A’ turns it meshes with gear ‘B’ and it begins to turn as well. Gear ‘B’ is called the ‘driven’ gear.

6. 6 Helical gears- The teeth on helical gears are cut at an angle to the face of the gear. When two teeth on a helical gear system engage, the contact starts at one end of the tooth and gradually spreads as the gears rotate, until the two teeth are in full engagement . Helical Gear Crossed Helical Gear Double Helical Gear Herringbone gears: To avoid axial thrust, two helical gears of opposite hand can be mounted side by side, to cancel resulting thrust forces. These are called double helical or herringbone gears

7. 7 Worm Gear: Worm gear is a special case of spiral gear in which the larger wheel, usually, has a hollow or concave shape such that a portion of the pitch diameter is the other gear is enveloped on it. The smaller of two wheels is called the worm which also has larger spiral angle . NON-INTERSECTING AND NON-PARALLEL Rack and pinion gears are used to convert rotation (From the pinion) into linear motion (of the rack). A perfect example of this is the steering system on many cars. The steering wheel rotates a gear which engages the rack. As the gear turns, it slides the rack either to the right or left, depending on which way you turn the wheel. Rack and pinion gears are also used in some scales to turn the dial that displays your weight . Warm Gear Rack and Pinion

8. 8 Bevel Gear : Kinematically, the motion between two intersecting shafts is equivalent to the rolling of two cones, assuming no slipping. The gears, in general, are known as bevel gear. When teeth formed on the cones are straight, the gear is known as straight bevel and when inclined, they are known as spiral or helical bevel . Bevel Gear Spiral Bevel Gear

9. 9 This video is prepared for academic use only .