Chap 9: transmission chains and sprockets

Question 1

examples of chain drive usage

Answer 1

Cessna 172 - control stick

B777 cabin door

Question 2

why are chains used?

Answer 2

strong (high load carrying capacity)
provides flexible connection
positive transmission of power (no slip/backlash)

Question 3

parts of chains

Answer 3

outer plate, bearing pin
inner plate, bush
roller

Question 4

how to test chain loads

Answer 4

proof test chain to 1/3 of breaking load

Question 5

what is safety hole used for in chains

Answer 5

check for sufficient thread engagement

Question 6

what is turnbuckle used for in chains?

Answer 6

use to tension the chains after installing

Question 7

what cannot be used to repair chains?

Answer 7

spring clips, offset links

replacing it is more practical

Question 8

how to change the direction of chains

Answer 8

using bi-planar block to change the direction in 2 planes by 90deg

Question 9

features of non reversible chain

Answer 9

chain guards, non-interchangeable end connectors, foolproof

Question 10

2 speed ratios

Answer 10

European: SR = input speed / output speed
teeth driven / teeth driver

American: flipped over

Question 11

what to inspect for chains

Answer 11

check chains:
freedom from twisting
proper tension
smooth engagement
damages, crack, wear and tear

check chain wheel:
no corrosion, chipping

Question 12

how to clean chains

Answer 12

clean in paraffin with stiff brush and dry immediately

Question 13

actual original length of chains formula

Answer 13

pitch distance * no. of links

Question 14

roller chain numbers meaning

Answer 14

1st digit: pitch in 1/8 of an inch

2nd digit: style of chain
0 - standard
1 - lightweight
5 - rollerless

Question 15

lubrication of chains

Answer 15

oil should be directed inside the chains

oil preferred over grease