Theory of Machines

1. 6.BRAKES &
DYNAMOMETERS
(10 Marks)

2. PURPOSE
►TO STOP THE VEHICLE IN THE
SHORTEST DISTANCE POSSIBLE
WHILE MAINTAINING CONTROL.

3. How do Brakes Work ?
Drum
Disc

4. CLASSIFICATION OF BRAKES

5. * TYPES OF BRAKES ON THE BASIS OF
TRANSFORMING ENERGY-
►1. Internal expanding Brake
(Mechanical)
►2. Hydraulic Brake
►3. Vacuum Brake
►4. AIR or Pneumatic Brake

6. Drum Brake Systems
►Function: To slow wheel speed down by
pushing shoes against the inside of a drum

9. HYDRAULIC BRAKING SYSTEMS
► PASCALS LAW:
► WHEN A FORCE IS APPLIED TO A LIQUID IN A
CLOSED CONTAINER IT IS TRANSFERRED EQUALLY
IN ALL DIRECTIONS.
► A FLUID TRANSMITS:
► 1. MOTION
► 2. PRESSURE
► 3. FORCE

10. Hydraulic Advantage
►Fluids cannot be compressed
►A fluid pressurized by a small piston will
move a larger piston with greater force, but
less distance

11. Hydraulic Brakes
Wheel Cylinder
BRAKE PEDAL
Brake Caliper
Brake Warning Light
Rear Brake Lights
Steel Brake Lines
Wheel Cylinder
Brake Caliper
Master Cylinder

13. COMPONENTS
►MASTER CYLINDER:
►PURPOSE:
►1. STORE FLUID
►2. ACTIVATES THE BRAKES
►3. PROVIDES OUTPUTS FOR 2
CIRCUITS....Why?

17. WHEEL CYLINDERS:
PURPOSE:
►CONVERTS HYDRAULIC PRESSURE
INTO MECHANICAL FORCE.
Found Where?:
used in drum type systems to force the
brake shoes against the drums.

18. DOUBLE ENDED WHEEL
CYLINDER

19. FIGURE – Steel brake shoes are made from two stampings welded together—the web and
the lining table.
Brake shoe -

20. Disc Brake Systems
►Function:
►Slows wheel speed by squeezing 2 brake
pads against a disc (rotor)

22. ► FIXED CALIPER
►FLOATING
►CALIPER

25. DISC BRAKE SYSTEMS
►ADVANTAGES:
►1. BETTER COOLING
►2. LESS BRAKE FADE
►3. EASIER TO MAINTAIN
►4. SELF CLEANING
►5. SELF ADJUSTING
►6. NO ADJUSTMENTS REQUIRED
► (ON FRONT WHEEL SYSTEMS)

26. DISADVANTAGES
►1. OPEN TO ROAD SPLASH
►2. HIGHER TEMPERATURE DEVELOPED
IN CALIPER (HIGHER TEMPERATURE
BRAKE FLUID IS NEEDED)
►3. GREATER HYDRAULIC PRESSURE
REQUIRED TO STOP VEHICLE
►4. NO “SELF ENERGIZING” ACTION

27. Block or Shoe Brake-
i)Single Block , ii)Double Block
i) Single Block Brake
Fulcrum Joint Effort
Block or shoe

28. ii)Double Block

29. Band Brake
i)Simple , ii) Differential
i) Simple

30. ii) Differential Band Brake

31. Band Brake
Single Block Brake

32. DYNAMOMETERS
1. Absorption dynamometer
2. Transmission dynamometer
3. Driving dynamometer

33. 1.Rope Brake Dynamometer- (construction working 4 marks)

34. 1.Prony Brake Dynamometer- (construction working 4 marks)

35. 1.Hydraulic Dynamometer- (construction working 4 marks)

36. 4.Eddy current Dynamometer- (construction working 4 marks)

38. Difference between Brakes and Dynamometer

39. 1.Give a complete classification of brakes. (4marks)
2.Explain with the help of neat sketch Double block or shoe brake.
(4marks)
3.Give construction and working of band brake. (4marks)
4.Draw the neat labeled sketch of internal expanding brake and state its
applications. (4marks)
5.Draw the diagram of hydraulic brake system & give the functions of
components of the system.(4marks)
6.Explain with neat sketch working of rope brake dynamometer.
(4marks)
7.Explain with neat sketch working of eddy current dynamometer.
(4marks)
8.Differentiate between brake and dynamometer. (4marks)
IMP QUESTIONS ….???