forging new generations of engineers. brakes friction & braking friction: a force that opposes...

11
Forging new generations of engineers

Upload: amy-turner

Post on 17-Jan-2016

216 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Forging new generations of engineers

Page 2: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Brakes

Page 3: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Friction & Braking

• Friction: A force that opposes motion, it prevents the sliding between two surfaces that are in contact.

• Amount of friction depends upon:– surface material– surface finish– force, acting upon the surfaces

• By using friction, brakes slow down or stop a rotating object.

Page 4: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Braking Action

• Brakes slow down a moving object by converting the kinetic energy of motion into another form.

• Most braking systems convert this kinetic energy into heat.

• The brake is cooled by moving air.

• If a brake becomes too hot, it will begin to lose its efficiency. This is called fade.

• Good brake design includes methods for adequate cooling of the brakes.

Page 5: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Brakes

• There are many different types of braking systems. Some of the more common types are:– Disc– Mechanical– Hydraulic– Pneumatic

Page 6: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Disc Brakes

• A friction pads is pressed against both sides of a rotating disc.

• This type of brake is commonly found on the front wheels of cars.

• They have good air flow around the brake which quickly dissipates heat.

Page 7: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Disc Brake

Page 8: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Mechanical Brakes

• Braking action is applied by physical force without the aid of hydraulics or pneumatics.

Page 9: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Hydraulics & Pneumatics

• Hydraulic and Pneumatic systems are closely related. Both use cylinders to produce a linear motion at varying speeds and forces.

• Hydraulics uses a fluid, hydraulic oil.• Pneumatics uses air.• Advantage of hydraulics is that oil can’t be

compressed.

Page 10: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Hydraulic - Pneumatic System

Page 11: Forging new generations of engineers. Brakes Friction & Braking Friction: A force that opposes motion, it prevents the sliding between two surfaces that

Hydraulic Brake