BME Unit-I Types of Brakes

1. A BRAKE :-A BRAKE :-
POWERPOWER
TRANSMITTINGTRANSMITTING
DEVICE. . .!!!DEVICE. . .!!!

2. A BRAKE
A BRAKE IS A DEVICE BY MEANS OF WHICH
ARTIFICIAL RESISTANCE IS APPLIED ON TO A
MOVING MACHINE MEMBER IN ORDER TO RETARD
OR STOP THE MOTION OF THE MEMBER OR
MACHINE.

3. CLASSIFICATION OF BRAKES
BRAKES ARE CLASSIFIED ON TWO BASIS:-
•ON THE BASIS OF CONFIGURATION
• ON THE BASIS OF MODE OF ACTUATION

4. CLASSIFICATION OF BRAKES
BRAKES
SHOE
BRAKES
DRUM
BRAKES
DISC
BRAKES
BAND
BRAKES
BAND &
BLOCK
BRAKES
INTERNAL
EXPANDING SHOE
BRAKE
EXTERNAL
CONTRACTING SHOE
BRAKE
• ON THE BASIS OF CONFIGURATION

5. CLASSIFICATION OF BRAKES
BRAKES
MECHANICAL
BRAKES
PNEUMATIC
BRAKES
HYDRAULIC
BRAKES
ELECTRICAL
BRAKES
AUTOMATIC
BRAKES
• ON THE BASIS OF MODE OF ACTUATION

6. BLOCK OR SHOE
BRAKE
FRICTION LINING
FIG. (1)

7. BLOCK OR SHOE BRAKE
IT CONSISTS OF A SIMPLE BLOCK/SHOE,WHICH IS PRESSED
AGAINST A ROATING DRUM,BY MEANS OF A LEVER.THE
BLOCK WHICH IS RIGIDLY ATTACHED TO THE LEVER OR IN
SOME CASES PIVOTED TO THE LEVER,IS LINED WITH
FRICTION MATERIAL LIKE
ASBESTOS,LEATHER,CORK,WOOD.THE ACTUATING FORCE IS
APPLIED AT THE END OF THE LEAVER.THE FRICTION
BETWEEN THE FRICTION LINING ON THE BLOCK & BRAKE
DRUM CAUSES THE RETARDATION OF THE DRUM.
REFER FIG. (1)

8. DOUBLE BLOCK/SHOE BRAKE
FIG.(2)

9. DOUBLE BLOCK/SHOE BRAKE
IT CONSISTS OF TWO SYMMETRICAL SHOES ON THE
OPPOSITE SIDES OF THE BRAKE DRUM TO AVOID DIRECT
EXERTION OF HEAVY LOAD ON THE DRUM SHAFT
BEARINGS.THESE SHOES PRESSED AGAINST ROATING
DRUM,BY MEANS OF A LEAVER.THE ACTUATNING FORCE IS
APPLIED AT THE END OF THE ACTUATING LEAVER.SO THE
FRICTION BETWEEN THE FRICTION LINING ON THE BLOCKS
& THE BRAKE DRUM CAUSES THE RETARDATION OF THE
DRUM.
REFER FIG.(2)

10. INTERNAL EXPANDING SHOE
BRAKE
FIG.(3)

11. IT CONSISTS OF TWO SHOES.THE OUTER SURFACE OF THE
SHOES ARE LINED WITH SOME FRICTIONAL MATERIAL.EACH
SHOE IS PIVOTED AT ONE END ABOUT A HINGE PIN &
SUBJECTED TO AN ACTUATING FORCE AT THE OTHER
END.THE ACTUATING FORCE ON THE BOTH SHOES IS
APPLIED BY A HYDRAULIC CYLINDER OR A CAM
MECHANISM.WHEN THE ACTUATING FORCE IS APPLIED,THE
SHOES ARE PRESSED AGAINST THE ROTATING BRAKE DRUM,
THUS CAUSING THE BRAKE DRUM EITHER TO RETARD OR
STOP COMPLETELY.WHEN THE ACTUATING FORCE IS
RELEASED,THE RETRACTING SPRING RETURN THE BRAKE
SHOES,SO THAT THEY NO LONGER CONTACT THE
DRUM..REFER FIG.(3)
INTERNAL EXPANDING SHOE BRAKE

12. INTERNAL EXPANDING SHOE BRAKE
The brake drum is commonly produced on cast iron. Few automobiles
contain aluminum drums, mostly for front wheel braking. Aluminum
conducts the heat better than cast iron, which enhances heat dissipation
and decreases fade. Drum brakes are also rarely fitted as the parking and
emergency brake even when the rear wheels use disk brakes as the chief
brakes. In this situation, a little drum is generally fixed within or as part
of the brake disk

15. CALIPER DISK BRAKE
FIG.(4)

16. CALIPER DISK BRAKE
IN THIS BRAKE ONE DISK IS FIXED & OTHER IS
ROTATING.THE FIXED DISK APPLIES THE BRAKEING TORQUE
ON THE ROTATING DISK SO AS TO RETARD OR COMPLETELY
STOP ITS MOTION.IT ALSO CONSISTS OF THE NUMBER OF
FRICTION PADS OR CALIPERS OF SMALL SIZE PRESSED
AGAINST THE ROTATING DISK.THE FRICTION PADS OR
CALIPERS ARE EITHER ANNULAR SEGMENTS OR CIRCULAR
IN SHAPE.THE CALIPERS,WHICH ARE HYDRAULICALLY
ACUATED,CONTACT ONLY A SMALL PORTION OF THE DISK
SURFACE,LEAVING THE REMAININGSURFACE EXPOSED TO
DISSIPATE THE HEAT.IT GIVES EXCELLENT CONTROL.
REFER FIG.(4)

17. CALIPER DISK BRAKE
Discs in disc brakes are slotted, where deep controls are equipped into
the disc to help in removing dust and gas. Slotting is the favored
method in most racing situation to remove gas, water, and de-glaze
brake pads. Few discs are both drilled and slotted. Slotted discs are
normally not used on standard vehicles because they quickly wear
down brake pads. This elimination of material is helpful to race
vehicles because it maintains the pads soft and avoid vitrification of
their surfaces.

20. BAND BRAKE
FIG.(5)

21. BAND BRAKE
A BAND BRAKE CONSISTS OF A FLEXIBLE LEATHER BAND OR
A FLEXIBLE MATERIAL,WHICH EMBRACES A PART OF
BRAKE DRUM.THE ENDS OF THE BAND ARE JOINED TO THE
LEVER WHICH IS PIVOTED AT A POINT.IN ORDER TO APPLY
THE BRAKE, THE BAND IS TIGHTENED AROUND THE BRAKE
DRUM BY APPLYING THE ACTUATING FORCE AT THE END OF
THE LEVER.THE FRICTIONAL FORCE BETWEEN THE BAND &
THE BRAKE DRUM PROVIDES THE NECESSARY BRAKING
FORCE.
REFER FIG.(5)

22. BAND AND BLOCK
BRAKE
FIG.(6)

23. BAND AND BLOCK BRAKE
IT CONSISTS OF A NUMBER OF WOODEN BLOCKS FIXED
INSIDE THE STEEL BAND.A STEEL BAND FIXED WITH
WOODEN BLOCKS EMBRACES THE PART OF THE
CIRCUMFERENCE OF THE BRAKE DRUM.THE ENDS OF THE
STEEL BAND ARE ATTACHED TO THE LEVER WHICH IS
PIVOTED AT A POINT.WHEN THE ACTUATING FORCE IS
APPLIED AT THE END OF LEVER, THE WOODEN BLOCKS ARE
PRESSED AGAINST THE BRAKE DRUM.THE FRICTIONAL
FORCE BETWEEN THE WOODEN BLOCKS & THE BRAKE
DRUM PROVIDS THE NECESSARY BRAKING FORCE.
REFER FIG.(6)

24. APPLICATIONS OF BRAKES
• BLOCK/ SHOE BRAKE :- IN TRAINS & TRAM CARS
• DOUBLE BLOCK/SHOE BRAKE :- IN HOISTING MACHINERY
(e.g. CRANES) & TRAINS
• DRUM BRAKE :- IN VEHICLES SUCH AS
TRUCKS, BUSES, CARS,
MOTORCCYCLES, SCOOTERS
• CALIPER DISK BRAKE :- IN VEHICLES , RACING CARS
& CONVEYERS
• BAND BRAKE :- IN MATERIAL HANDDLING
EQUIPMENT
• BAND & BLOCK BRAKE :- IN MATERIAL HANDDLING

25. AT A GLANCE. . .!!
NOW WE COME TO KNOW :-
• CLASSIFICATION OF BRAKES…
• TYPES OF BRAKES ...
• WORKING OF DIFFERENT TYPES OF BRAKES ...
• APLLICATIONS OF BRAKES ...