Chains

Question 0

Power transmission chain

Answer 0

• used as a positive drive to transmit power between widely spaced shafts
• 98% efficient

Question 1

Number one reason for chain wear?

Answer 1

-lubrication

Question 2

Two types of Pre-lubricated chain

Answer 2

• sintered bushing

- o ring

Question 3

Sintered bushing

Answer 3

• Bushings are charged with lubricant that is squeezed out when chain is under load
• has no roller
• lasts 5 times longer
• 10% less loading capacity than standard chain

Question 4

O-ring

Answer 4

• intended to provide lifetime lubrication and to exclude contaminants. 10 times cleaner than without for food places
• stronger than standard chain but 5% less than sintered

Question 5

Oilfield chain

Answer 5

• multiple strand chain that is made to ANSI dimensions and upgraded to API standards
• uses press fit instead of slip fit

Question 6

Types of chain

Answer 6

• roller

- silent

Question 7

Roller less chain

Answer 7

• designation #5
• run in sheaves instead of sprockets
• maintain tension where there is no or very little movement

Question 8

Silent chain (timing chain)

Answer 8

• Consists of links made up of tooth side plates
• highest efficiency
• high speed
• widest range of speeds
• widest range of load
• compact

Question 9

3 silent chain designs

Answer 9

• side guide
• centre guide
• duplex/serpentine drive

Question 10

What tools do you need for sprocket alignment

Answer 10

-straight edge and feeler gauge

Question 11

Chain wrap

Answer 11

-chain climbing up the back of the sprocket caused by too little tension

Question 12

Appropriate chain tension

Answer 12

• slow to med 4-6% sag

- high speed or vertical drive 2-3% sag

Question 13

Double Pitch

Answer 13

• same as standard chain but the pitch is double.

- used for long spans and low speed, low horsepower

Question 14

Master Clip installation

Answer 14

• closed end in the direction of travel

- remember trailing edge (end with split) is the back edge

Question 15

slip fit side plate

Answer 15

-reduces the working capacity of the chain by 30%

Question 16

press fit side plates

Answer 16

-do not reduce working capacity

Question 17

Too much chain tension

Answer 17

• will prevent lubrication from getting all around the shaft

- put undo pressure on the shafts, etc…

Question 18

Chain lubrication

Answer 18

• apply to inside of slack span
• low speed drives (under 600 ft per min) use manual or drip feed
• chains at 1500 ft per min use bath lubrication
• forced (oil pump from above)

Question 19

Elongation

Answer 19

-over 3% and the chain should be changed

Question 20

Galled

Answer 20

-Metal has been torn away from the surface of the pin

Question 21

Backstop

Answer 21

• restraining device that prevents the load from turning the drive when the drive is shut off.
• one way clutch is often used

Question 22

Minimum chain wrap angle

Answer 22

-120 degrees

Question 23

Double strand chain

Answer 23

• 1.7 times stronger than single strand
• side plates are press fit, but centre plates are slip fit
• higher load and speed capacity

Question 24

Heavy Duty

Answer 24

- does NOT have a higher load capacity, but lets it last longer - has thicker side plates

Question 25

Single pitch offset link (half link)

Answer 25

- reduces the length of the chain by one pitch | - consists of two bent side bars that are riveted to a bush and roller at one end

Question 26

Most common light duty chain

Answer 26

- #41 | - has 1/4 wide rollers

Question 27

Hunting Link

Answer 27

- used when an odd number of pitches is required | - offset link

Question 28

Joining pin or connecting link

Answer 28

- used to change the chain length by two pitches | - convenient for assembling the chain in the field

Question 29

Chain Length

Answer 29

- 1/2 the total sprockets times the pitch which represents the length the chain will wrap around the sprockets - then double the drive centre distance.

Question 30

To order new sprockets

Answer 30

-you need to provide chain pitch, chain type, number of strands and hub style

Question 31

Bushing Failure

Answer 31

- Caused by overload - sprockets too small - imperfect form on the sprocket teeth - badly worn or oversized gullet on the sprocket teeth

Question 32

Roller Failure

Answer 32

-Caused when the sprocket repeatedly engages the sprocket teeth under load

Question 33

Stretch

Answer 33

- One way a chain can be elongated | - could jump off the sprocket

Question 34

Pin Failure

Answer 34

- From constant flexing of the pin as each chain link moves over the sprocket. - exposure to corrosives

Question 35

Side Bar Failure

Answer 35

-Repeated stressing and unstressing of the chain as the links moved from the loaded and unloaded strands

Question 36

Ways to improve service life on driver to driven

Answer 36

- increase centre distance | - change the speed in two steps using a jack shaft

Question 37

Idler Sprockets

Answer 37

- used as chain tensioner - to prevent chain whip - improve chain wrap - to provide reverse rotation of a sprocket outside the chain

Question 38

Idler Sprockets mount?

Answer 38

-on the slack span to reduce wear on the chain and sprockets

Question 39

Hub Style A

Answer 39

-flat sprocket that can mount on any hub

Question 40

Hub Style B

Answer 40

-Hub on one side

Question 41

Hub Style C

Answer 41

-hub on both sides

Question 42

Hub Style D

Answer 42

-split in the middle so you can mount it between bearings without having to remove them.

Question 43

Sheer Pin Hub

Answer 43

- Provides the sprocket drive with overload protection in case of a jam - shears off with too much force - Uses Type A sprocket

Question 44

Sprocket

Answer 44

-toothed wheel designed to mesh with power transmission chains

Question 45

Installing sprocket

Answer 45

-there should be .002-.005 clearance between the top of the key and the sprocket -none on the sides (some applications allow .002 -

Question 46

Sprocket runout

Answer 46

-.002