Lab 6 P. 1

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Autumn Quarter Gateway Engineering Education Coalition

Gears

Lab 6

Lab 6 P. 2

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Autumn Quarter Gateway Engineering Education Coalition

Gear: Definition

• A gear is a wheel with teeth along its rim. • It is used to transmit effort from one shaft to

another.

Lab 6 P. 3

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Autumn Quarter Gateway Engineering Education Coalition

Gear Train

• Combination of two or more meshed gears. Used to change the rate of rotation, the direction of rotation, and the amount of torque.

Lab 6 P. 4

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Autumn Quarter Gateway Engineering Education Coalition

Gear Ratio

• Gear ratio is also called “Mechanical Advantage”

Gear ratio Number of Driver Teeth

Number of Driven Teeth

Lab 6 P. 5

Engineering H191 - Drafting / CAD

Autumn Quarter Gateway Engineering Education Coalition

Types of Gears• Spur gears

• Worm gear

• Rack and pinion

• Bevel gears

Lab 6 P. 6

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Autumn Quarter Gateway Engineering Education Coalition

Spur Gears

• Simplest• Most widely used in Instrumentation and Control

Systems• Used to drive parallel shafts

Lab 6 P. 7

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Autumn Quarter Gateway Engineering Education Coalition

Spur Gear Terminology

• Pitch circle diameters• Size of teeth (Diametral pitch)• Center distance• Number of teeth• Pinion• Gear

Lab 6 P. 8

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Autumn Quarter Gateway Engineering Education Coalition

Worm Gears

• Used to change speed and direction of rotation. • Used for connecting skew shafts (usually 90

degrees)• High gear ratios.• Higher load capacity.

Lab 6 P. 9

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Autumn Quarter Gateway Engineering Education Coalition

Rack and Pinion

• Used to convert rotational motion into linear motion, or vice-versa.

Lab 6 P. 10

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Autumn Quarter Gateway Engineering Education Coalition

Bevel Gears

• Used for intersecting shafts.• Most transmissions occur at right angles but

shaft angles can be any value.

Lab 6 P. 11

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Autumn Quarter Gateway Engineering Education Coalition

Sprockets

• Gears are connected by a chain instead of directly.

• The input and output shaft rotations are in the same direction.

Lab 6 P. 12

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Autumn Quarter Gateway Engineering Education Coalition

Today’s Lab:

• Window Lift Motor• Lego Robot Gripper• Gears at Table• Build Gearbox• Bicycle Gears

Lab 6 P. 13

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Autumn Quarter Gateway Engineering Education Coalition

Questions ?