Chains Flashcards
What is a Heavy duty chain
Has identical dimensions to standard roller chain except the the side plate is one size up, recommended for heavy shock loads and reversing drives. Available in single or multiple strands
What are Power transmission chains
Do not slip on overload, provide positive drive, highly efficient(98%) or better. Used with any distance between shaft enters.
What are two basic types of roller chain links
Pin links and roller links
What are Rollerless chains
Same as a roller chain except bushings instead of rollers. Designated by the number 5
Pin link chains are made with what
No pin
What is the standard single strand roller chain code
North America ANSI
British BS:DIN
What are 3 types of lubrications of chains
Manual or drip, forced, bath
Cotter pins are usually used on what # chain
80 and larger
Multiple strand chain
Used for drives in which loads and speed are to great for single strand chain. Up to 12 strands, double strand is up to 1.7x stronger than single
What’s the correct tension on a chain
For slow to medium 4%-6%
For high seed reversing or impulse drives 2-3%
For certified drives 2%-3%
What are chains made of?
Harden carbon steel (standard chains)
Stainless steel for corrosion resistance
Synthetics such as various plastics for light duty drives.
Which direction should the closed end of spring clip be on for a con link?
Direction of travel
What are Types or power transmissions ?
Roller chain and silent chain
What is a single pitch offset link
Also called a half link, consist of two bent side bars that are rivited to a bush and roller at one end. Changes the length of the chain by one pitch in. Are the chain cannot be tensioned using a con link. They are weaker
Roller link chains are made with what
Bushings
After eight house of operation you should what?
Inspect for unusual noises, ensure chain is properly lubricated, I slept the sag and adjust if necessary
What is a Corrosion resistant chain
Produced by corrosion resistant material, or playing standard steel chains
ANSI chains are also a alive with modifications to suit various applications, what are they
Light duty, heavy duty, multiple strand, oilfield, pre lubed, corrosion resistant, synthetic, double pitch, roller less and silent.
What is a oilfield chain
Multiple strand chain, it’s a ANSI dimensions upgraded to API, engineered for the severe service for drilling Riggs. Use a press fit centre plates instead of slip fit. Recommends con link assembly uses a bushed centre plate.
What are synthetic chains?
Come in nylon and polypropylene, designed for light service instrument drives and office machines. Very light15%-20% weight of steel,
No lube required, low strength and high stretch under load
What’s a sintered bushing chain
Same as standard RC chain but uses a powdered metal bushing. When the bushings under pressure lub is squeezed out to lube pin. Has no roller, load capacity is 10% less than standard chain
What is a silent chain
Also called timing chain, is made up of tooth plates instead of links. Offers highest efficiency , made available in high performance series. Transmit high HP in a small place
Sprockets must be aligned to do what
Ensure smooth engagement, reduce wear, reduce fatigue. The alignment in each plane must be corrected for both offset and angular misalignment
To little tension causes what?
Chain whip and vibration
Chain sagging
Chain wrap up in sprocket
What are Pre lubricated chains
They don’t permit regular lubrications, 2 types - singers bushint chain and o ring chain
What is a connecting link
A connecting link is a unrivited link in a chain. Con links have one side rovited and one slip of press fit,
Spring clip retainers are used on what type of chains
25-60
When should you replace a chain
If it’s elongated by 3% or more.
To much tension causes what?
Reduced chain and Sprocket life, overloading of the bearings, inadequate lube and pin bushing
What is a Double pitch chain
Same as standard chain, except pitch is doubled, half number of pins, bushingsX and rollers. Used for long spans and slow to moderate speeds with low HP
What are O-ring chains
They provide life time lube, exclude contaminats, can’t operate at high temps if special o rings are ordered, 5% less than standard chain
What is a light duty chain
Used on drives where space is restricted, they are compact and have a have a lower power rating, used in electro mechanical devices. Most common type is #41 common use garage door opener
What are toothed links
Hunting link
2 ways to tension chain
Idlers, adjustable centres
What does lubrication of a chain provide
Resists wear at the pin joint, flushes foreign materials, lubricates chain and sprocket, prevents rust or corrosion, cushions impact loads, dissipates heat
What is a sprocket
Toothed wheelsdesigned to mesh with power transmission chains
What are sprockets made out of
Alloy cast iron (very large sprockets)
Medium carbon steel (small, medium, large sized)
Plastic(light-duty)
When replacing a sprocket you need to know what?
Chain pitch, chain type, number of strands, hub style
What is a wrap angle on a small sprocket?
When a small sprocket drives a larger one
What is a problem with small wrap angles?
The chain may jump teeth when operated at maximum load. Minimum wrap angle for full load is 120°, however a angle as small as 90° can carry full design if the tension is maintained
Why might a particular chain drive not provide satisfactory service life?
A smaller sprocket is too small for the center distance. Can improve this by, increasing centre distance, change the speed in the two steps using a jack shaft to obtain final ratio
What are the 3 drive angles of a sprocket centre?
Verticals, horizontal, or at an angle
What’s the difference between a double single strand sprocket and a2 strand sprocket?
Double single strand has a space between 2 sprockets, 2 strand has no space.
Sprockets with odd number of teeth are called what?
Hunting tooth sprockets
Silent chain sprockets have what type of tooth?
Involute fear tooth, they are hardened for improved flank wear
Hardened tooth sprockets are what?
They are common and intended for greater wear resistance. Beneficial when number of teeth is 25 or less, on drives that are heavily loaded, abrasive conditions, high speed drives, and drives that require long life
Four types of hub style sprockets?
Type A, B, C, D
What is a type A sprocket
(Absent) no hubs on either side. Flat circle, can mount on any type of hub, can have a bolt circle for attaching to desired hub, or it can be welded to a weld on hub
What is a type B sprocket?
(Beside) has a hub on one wide , allows to mount bearing close and reduce overhung load
What is a Type C sprocket?
(Center) has hubs in both sides, provides more stability and Adds support to sprocket with large diameters.
What is a type D sprocket
Split sprocket, allows you to change sprockets mounted between bearings without removing bearings
What kind of attachments can A,B,C sprockets have?
Sheer hub pins (provides drive with overload protection. Sheer pin will break)
