Belt Drives

Question 1

Identify three factors which determine the potential grip of a v belt

Answer 1

Area of contact
Belt tension
Fiction between velt and pulley

Question 2

Belt width and the arc of contact determine

Answer 2

Belts area of contact

Question 3

Identify three methods used to increase the arc of contact

Answer 3

Crossed belt
Moving input and output shafts farther apart
Using an idler or snub pulley

Question 4

Belt idlers put an additional bending stress on the belt which reduces belt life to or f

Answer 4

True

Question 5

The best tension for a v belt is the —– at which the belts will not slip under full load.

Answer 5

Lowest tension

Question 6

Bearing life is —— when belts are over tightened

Answer 6

Shortened

Question 7

Friction between two surfaces

Answer 7

Is not influenced by the area of surface

Question 8

The wedging effect of v belts results in

Answer 8

Lower velt take up tension required

Question 9

Industry standards for v belts

Answer 9

Control sheave groove details for v belts

Question 10

Which component of a typical v belt receives the tension or pull

Answer 10

Tensile member

Question 11

Which type of v belt length system is most only used by belt manufacturers

Answer 11

Exact length

Question 12

Conventional v belts are identified as to cross section sizes

Answer 12

A b c d e

Question 13

Which type of v belt had a narrow cross section but sits deeper in the sheave groove?

Answer 13

High capacity v belts

Question 14

What is the top width of a 8 v v belt

Answer 14

1 inch

Question 15

Not he’s v belts have a —— horsepower rating than conventional c belts

Answer 15

Higher

Question 16

The notches in a notched v belt

Answer 16

Reduce bending stresses
Help to dissipate heat
Provide more uniform distribution of load

Question 17

Serpentine drives usually use why type of v belt

Answer 17

Double v belt

Question 18

To solve the problem of continually rolling or jumping v belts it is recommended to

Answer 18

Use power band v belts

Question 19

Which belts are generally used where power transmission is less than one horsepower

Answer 19

2l 3l 4l 5l v belts

Question 20

Are poly v belts as flexible as flat belts

Answer 20

Yes

Question 21

Poly v belts have —– area of belt sheave contact than eithe flat, standard or high capacity v belts

Answer 21

Greater

Question 22

What best gives the variable speed belt it’s flexibility over small sheave diameters

Answer 22

Inner cog construction

Question 23

What variable speed drive has a fixed shaft center distance

Answer 23

Dual variable sheave drive

Question 24

On dual variable sheave drives , the ratio of maximum driver pitch diameter to the minimum driven pitch diatmeter develops —– drive output speed

Answer 24

Maximum

Question 25

If the driver and driven sheaves of a variable speed are check and found to be the same width, a straightedge can be used

Answer 25

Without having to consider offset allowance

Question 26

Allowing a variable speed belt to bottom on the sheave is correct

Answer 26

No

Question 27

Which type of belt is used where slippage is not tolerated

Answer 27

Timing belt

Question 28

Positive drive belts have the same positive engagement as two other power tranission drive systems , these are

Answer 28

Chain | Gear

Question 29

Belt code 185 h 050

Answer 29

Pitch length 18.5 inches Pitch h Width 1/2 inch

Question 30

Pulley code 18 h 050

Answer 30

Number of grooves 18 Pitch h Width 1/2

Question 31

Linked v belts

Answer 31

Are used in conventional v belt sheave grooves Are used where it is difficult to install an endless v belt Are held together with metal studs

Question 32

What are two disadvantages of using flat belts

Answer 32

High belt tension | Failure to track properly

Question 33

The difference between the diameter of a flat belt pulley at its center and at it's edge is called

Answer 33

Pulley crown

Question 34

Excess crowning

Answer 34

Increases the tension at the center of the belt | Causes premature belt failure

Question 35

Identify two methods used to join flat belts

Answer 35

Vulcanizing | Mechanical fasteners

Question 36

A sheave groove gage is used to

Answer 36

Check cleave size Find groove wear Determine groove angle

Question 37

A straightedge touching the driver and driven sheave at ------ indicates good sheave alignment

Answer 37

Four points

Question 38

Taper lock bushings are used to

Answer 38

Located a sheave anywhere on a cylindrical shaft

Question 39

Which belts require the greatest amount of slack off and take up movement

Answer 39

Conventional v belts

Question 40

To remove v belts from a sheave it is best to pry them off while the sheave is rotated slowly t or f

Answer 40

False

Question 41

What usually causes the v belts cross section to swell up

Answer 41

Oil or grease on the belt

Question 42

Belt drives for power transmission are classed as

Answer 42

Frictional drives