Australia
Australia
1. Three Basic Dimensions
Pitch, Roller Diameter and Inner
Width are known as the "Three Basic Dimensions of Roller Chain." When these three
dimensions are identical, roller chains and sprockets are dimensionally compatible.
2. Basic Parts
Link Plate
The plate is
the component that bears the tension placed on the chain. Usually this is a repeated
loading, sometimes accompanied by shock. Therefore, the plate must not only have
great static tensile strength, it must also hold up to the dynamic forces of load
and shock.
Pin
The pin is subject to shearing and bending forces transmitted
by the plate. At the same time, it forms a load-bearing part (together with the
bush) when the chain flexes during sprocket engagement. Therefore, the pin needs
high tensile and shear strength, resistance to bending, and must also have sufficient
endurance against shock and wear.
Bush
The bush is subject to complex forces from all parts,
especially from the repetition of shock loads when the chain engages the sprocket.
Therefore, the bush needs extremely high shock resistance. In addition, the bush
forms a load-bearing part together with the pin and as such requires great wear
resistance.
Roller
The roller is subject to impact load as it mates with
the sprocket teeth during engagement of the chain with the sprocket. After engagement,
the roller changes its point of contact and balance. It is held between the sprocket
teeth and bush, and moves on the tooth face while receiving a compression load.
Therefore, it must be resistant to wear and still have strength against shock, fatigue
and compression. (RS25 and RS35 are bush chains and do not have rollers).
Roller Link
Two bushes are press fit into two roller link
plates and rollers are inserted to allow rotation around the outside of the bushes
during operation. This is the same for single and for multi strand chains.
Pin Link and Intermediate Plate
The pin link consists of
two pins that have been press fit into two pin link plates. In case of multi-strand
roller chain up till size 08B, an intermediate plate is added to the pin link. In
case of multistrand roller chain above size 08B, two intermediate plates are added
to the pin link. The intermediate plates are slip fit for standard roller chain
and press fit for SUPER roller chain.
3. Assembly Parts
Roller chains are usually made up of a
number of inner and outer links in an endless formation. Although offset links can
be used when there is an odd number of links in the roller chain, it is better to
use a design that requires an even number of links. If an odd number of links cannot
be avoided, it is recommended to use a two-pitch offset link in stead of a one-pitch
offset link. As it is riveted into the chain, a two-pitch offset link has a 100%
Maximum Allowable Load, where as the one-pitch offset link has a Maximum Allowable
Load of 65%.
Connecting Links
There are three types of connecting links:
spring clip connecting link, cotter pin connecting link and spring pin connecting
link.
It's common to use slip fit spring clip connecting links for small size
roller chains. Cotter pin and spring pin connecting links are used for large size
roller chains and on customer request.
Offset Links
An offset link is used when an odd number of
chain links is required. Different types are available:
One pitch offset link (OL).
The pin and two plates are slip fit.
The fatigue strength is 35% lower than the chain itself.
Two pitch offset link (2POL).
Two pitch offset links are the combination
of a roller link and an offset link connected with a rivet pin. The fatigue strength
is the same as the fatigue strength of the base chain. Please refer to the dimension
tables for roller chain types and sizes suitable for offset links.
