Belts and Pulleys

Question 1

First Users of Belts and Pulleys

Answer 1

• Ancient Egyptians
• Mesopotamia & Roman Empire

Question 2

Ancient Egyptian Usage

Answer 2

• lift weights for pyramids

Question 3

Mesopotamia & Roman Empire Use

Answer 3

• ships and other moving machines
• simple machines

Question 4

What are the two working principles?

Answer 4

• at least two pulleys with a belt in tension (driver and driven)
• pulling action due to friction

Question 5

Rope Belt - Types

Answer 5

1) Fiber - 60 meters
2) Wire - 150 meters

Question 6

Rope Belt Application

Answer 6

Used to transmit large amounts of power using one pulley to another over a large distance

Question 7

Rope Belt - Primary Advantage

Answer 7

• High frictional grip
• Allow one driver to be connected to several driven systems

Question 8

Most common used belt

Answer 8

V Belt

Question 9

First Belt to be used

Answer 9

Round Belt (Rope)
- High localized pressure on top

Question 10

What was created after the Round Belt?

Answer 10

Flat Belt
- good pressure distribution
- easy for cracks to form due to thin nature

Question 11

Disadvantages of Flat Belts

Answer 11

• slippage of extremely high
• high tension required

Question 12

Components of V Belts

Answer 12

• Tension
• Compression
• Tensile Cords
• Envelope

Question 13

Raw Edge V Belt

Answer 13

• does not have protective envelope
• higher friction

Question 14

Double V Belt

Answer 14

• all sides of the belt responsible for power transmission
• pulleys on both sides

Question 15

Cogged V Belt

Answer 15

• purpose of grooves allow for more control for flexibility of the belt

Question 16

Synchronous/Timing V Belt

Answer 16

• depends on friction & meshing cogs
• grooves for slippage
• used when indexing and weight are important
• thin width
• deep grooves perpendicular
• eliminate excessive heat

Question 17

Ribbed V Belt

Answer 17

• series of grooves
• increased surface area
• stability in high-vibration
• low mass & high flexibility
• high speed ratio

Question 18

Multi-Strand/Banded V belt

Answer 18

combine multiple v belts for more HP

Question 19

What is the horsepower limitations for a single V Belt?

Answer 19

1 - 500 HP

Question 20

Fractional Horsepower v belts

Answer 20

• transmit less than 1 HP
• low weight and cost
• prefix number is top width of belt

Question 21

Wedge V Belt

Answer 21

increased surface area of supported tensile cords

Question 22

Belt Dimensions (4)

Answer 22

• Outer Circumference
• Inner Circumference
• Pitch Length
• Datum Length

Question 23

Belt Nomenclature XXxXX - Section 1

Answer 23

Outer Circumference

Question 24

Belt Nomenclature XXxXX - Section 2

Answer 24

Type of Belt

Question 25

Belt Nomenclature XXxXX - Section 3

Answer 25

Dimensions of the Inner Circumference

Question 26

For Type A, you subtract ____ from the Outer to get the Inner.

Answer 26

2

Question 27

For Type B, you subtract ____ from the Outer to get the Inner.

Answer 27

3

Question 28

For Type C, you subtract ____ from the Outer to get the Inner.

Answer 28

4

Question 29

For Type D, you subtract ____ from the Outer to get the Inner.

Answer 29

5

Question 30

For Type E, you subtract ___ from the Outer to get the Inner.

Answer 30

6