1. Brakes & Clutches 130310119001-Agarwal Prasoon 130310119002-Albad Ravindra 130310119003-Anandpari gosai B.E SEM-5 L.E COLLEGE MORBI MECHANICAL DEPT

2. Clutches  Clutch is a one of the form of coupling.  Clutches is used to transmit the power from driving shaft to driven shaft of machine which may be required to start or stop frequently.  It is so designed that the two members may be engaged or disengaged whenever required either by a hand operated device or automatically by the action of some power driven devices.

3. Types of clutches clutches mechanical positive contact clutche jaw clutchtoothed clutch friction clutches disc clutchcone clutch centrifugal clutch pneumatichydraulic electromagnetic

4. Disc clutches  This type of clutch consists of two flanges, one flange is rigidly to the driving shaft and other flange fitted to the driven shaft.  Single disc clutches are used in automobiles.  When large torque transmission is required the multi disc clutch are used.  Multi disc clutch has more number of contact surfaces discs on driving and driven shaft.

5. Disc clutches

6. Cone clutch  The cone clutch consists two cones, one internal cone fixed to the driven shaft and another cone fitted on the driven shaft.  The operating lever used only for disengagement of the clutch.  The main advantage of cone clutch over the disc clutch is very simple and required less axial pressure to disengaged the clutch.

7. Cone clutch

8. Centrifugal clutch  It consists of a number of shoes on the inside of a drum or rim of the pulley.  The upper surface of the shoes are covered with a friction material.  The spider is fitted on the driving shaft.  When centrifugal force is equal to spring force, the shoe is just floating. But, when centrifugal force higher than the spring force, the shoes moves outward and comes into contact with the driven member and pressure against it.  The increase of speed causes the shoes to press harder and clutch transmit more power.

9. Centrifugal clutch

10. Jaw clutch  It is consists of segmental projections on one of the flange and corresponding recesses on other flange on the driven shaft.  Driving flange rigidly keyed to the driving shaft while the other flange is keyed to driven shaft by splines so that it can slide on that shaft.  The sliding flange engage with the fixed flange to transmit the motion and power from driving shaft.  This clutch is used for the transmission of power in agricultural equipment like tractor, thresher, etc.

11. Jaw clutch

12. How clutch works

13. Brakes  A brake is a mechanical device which produces frictional resistance against moving machine member, in order to slow down the motion of machine.  In the process of performing this function, the brake absorbs kinetic energy of moving member and the brake absorbs potential energy of lowering member.  The energy absorbed by brakes is released to surrounding in form of heat.

14. Brake Application  A brake is mechanical device which produce frictional resistance against moving machine member,in order to slow down of machine.  In the process of performing this function, the brake absorbs kinetic energy of moving member and brake absorbs potential energy of lowering number.  The energy absorbed by brake is released to surrounding in form of heat.

15. Types of brakes BrakesMechanicalBlock brakeBand brake Internal or external expanding shoe brake ElectricalHydraulic

16. Block brake (1)Single block or shoe brake: A single block is consists of a block which is pressed against the rim of revolving brake wheel drum. This brake is used in railway trains and tram cars. The prony brake is example of block brake.

17. Single block or shoe brake:

18. Double block or shoe brake:  It consist of two brake blocks at the opposite ends of the wheel.  These shoes apply force to both the sides of wheel and reduces the Unbalanced force on the shaft.  This spring pull the upper end of the brake arms together and Brake is applied.  When a force is applied to the bell crank level, the spring is Compressed and the brake is released.  This brake is used in electric cranes. The bicycle brake is example of double block brake.

19. Double block or shoe brake:

20. Band brake  A band brake consists of a flexible steel band lined with friction material, which wrap to the brake drum. When an upward force is applied to the lever end, the lever turns about the fulcrum pin and tightens the band on the drum and hence the brakes are applied.  The friction between the band and the drum provides the braking force.  This type of brake is used in civil construction equipment and also in automobiles as hand brake. The rope brake is example of band brake.

21. Band brake

22. Internal expanding shoe brake  An internal expanding shoe brake consists of two shoes.  The outer surface of the shoes are covered with friction material.  Each shoe is pivoted at one end about a fixed fulcrum and other end rests against cam.  When the cam is operated, the shoe are pushed outwards against brake drum.  The friction between the shoes and the drum produces the braking torque.  This type of brake is commonly used in motor cars and light trucks.

23. Internal expanding shoe brake

24. Disc brake  Disc brakes are different from drum brakes in that the drum is replaced by a circular metal disc and the brake shoe are replaced by a caliper which supports a pair of friction pads, one on each side of the disc.  These pads are forced inward by the operating force and also retard the disc.

25. Disc brake

26. How disc brakes work

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