CAD 154 MIDTERM

CHAINS, BELTS, BEARINGS

All industrial drive systems use belts.

False

The three types of idler pulleys are:

Kiss idler, backside idler, inside idler

Fractional Horsepower (FHP) belts are used primarily in heavy-duty applications.

False

The four layers of belt construction consist of:

Neutral axis, compression layer, cover, tension layer

What type of belt would you most likely find in a multiple-pulley drive system?

Double-angle V-belt

A synchronous belt is used in applications where:

No slippage can occur

Joined belts are:

Several belts of equal length banded together

All belts should be lubricated to ensure their flexibility.

False

Idler pulleys:

Provide tension where drive units are not adjustable

Drive system speed (not ratio) is determined by:

The speed at which sheaves rotate

When the drive sheave and the driven sheave are the same size:

Both sheaves rotate at the same speed

In a “speed-up” drive system:

The driven sheave rotates faster than the drive sheave

A system where the drive sheave has a diameter of 6 inches, and the driven sheave has a diameter of 12 inches, is called a:

Reduction drive

Belt dressing is always applied to the outside of the belt.

False

A tensiometer measures:

The amount of belt deflection between two pulleys

The tool that determines the wear in a sheave is called:

Sheave gauge

If a belt is squealing:

It is too loose

Over-tightening a belt can result in:

Excessive belt wear

Round belts are used in systems where:

Proper pulley alignment may not be possible

Most drive belt hardening and cracking is caused by:

Excessive heat

If a drive belt is whipping, you must check the:

Distance between drive centers

The drive ratio is based on:

The relative size of the pulleys

All belts can be spliced if the proper tools are used.

False

Typical belt code markings indicate:

The width, length, and type of duty the belt was designed to perform

The three most common belt shapes are:

Round, flat, and V

All industrial drive systems use chains.

False

The five types of chain lubrication systems are:

Manual, drip, oil bath, rotating disc, pump

Hooked sprocket teeth indicate:

Improper chain tension

Elongation is caused by:

Normal wear of the pins and bushings

The two types of tensioners or take-up devices are:

Rigid and flexible

The guide plates in silent chains are used to:

Keep the chain properly located on the sprocket

The distance between the center of a chain’s rollers determines:

The chain’s pitch

True or False: You should always grease a chain

FALSE

Side wear on a sprocket is an indication of:

Sprocket misalignment

Chain misalignment may be caused by:

Shafts that are not level with each other, not parallel to each other and incorrect axial alignment

Chain pitch is measured in what increments?

1/8”

Allowable chain deflection in a drive system is usually between:

2%-3%

A #160 chain is a:

Standard link roller chain with a pitch of 2”

A chain is no longer serviceable when:

It no longer engages properly on the sprockets due to damage or elongation

The clip or cotter pins in the master link must be installed:

So the closed end of the clip points in the direction of movement

Chain tension must be checked:

After lockout/tagout has been completed

Most industrial drive systems use the same type of chain.

False

Idler sprockets:

Are used to take up excessive slack in drive chains

Chain stretch helps when fitting a new chain over a sprocket.

False

Industrial drive chain needs to be greased at regular intervals

False

Roller chain is made up of:

Roller links and pin links

The most common types of industrial chains are:

Roller, rollerless, silent, detachable link, pintle, block

Excessive or accelerated chain wear is usually caused by:

Improper or inadequate lubrication

A chain that is too loose may cause the system to:

Pulsate

How do you find the Design HP?

HP x Service Factor = Design HP

To find the # of Teeth on the Drive Sprocket must be __ than the Design HP

Greater

How do you find the ratio for chains?

Drive RPM / Driven RPM= Ratio

How do you find the # of Teeth on the Driven Sprocket?

# of Teeth on Drive x Ratio = # of Teeth on Driven

How do you find the Center Distance in Chain Pitches?

Center Distance / Chain Pitch = Chain Pitches

What kind of lubrication does Type A need?

Manual or Drip Lubrication

What kind of lubrication does Type B need?

Bath or Disc Lubrication

What kind of lubrication does Type C need?

Oil Stream Lubrication

How do you find the Chain Length in Inches?

Chain Length in Pitches x Chain Pitch = Chain Length in Inches

Name the item that maintains equal spacing of rollers in a bearing.

CAGE

Shape used with bearings to compensate for minor misalignment.

SPHERICAL

Roller bearings are commonly referred to as “anti-friction” bearings because…

LESS FRICTION DURING STARTUP THAN IN FRICTION BEARINGS

AFBMA stands for what?

ANTI FRICTION BEARING MANUFACTURERS ASSOCIATION

Most common ball bearing.

SINGLE ROW DEEP GROOVE

Four specifications were mention for constructing an outer raceway as part of the machine

SURFACE FINISH, HARDNESS, OUT OF ROUNDNESS, TAPER

Roller bearings are also known as what?

ANTI FRICTION

What bearing type has a rubber seal between raceways and is considered maintenance free?

SEALED

Dimensionally, needle bearings have a relatively high ratio of what to their diameter?

LENGTH

List the term that identifies lubrication that is NOT supplied under pressure.

HYDRODYNAMIC

List the term that identifies lubrication that IS supplied under pressure.

HYDROSTATIC

Inner or outer part of a bearing assembly on which bearings travel as they rotate.

RACEWAY

Name the loads carried by any bearing.

AXIAL, RADIAL

Name one disadvantage of journal bearings over roller bearings.

STRICT LUBRICATION REQUIREMENTS, LIFE LIMITED BY SURFACE FINISH ACCURACY, NOT AS EFFICIENT AT HIGH TEMPS, SUSCEPTIBLE TO DAMAGE FROM INTERRUPTED LUBE SUPPLY

Name roller bearing element (not ball) types.

NEEDLE, TAPERED, CYLINDRICAL, SPHERICAL

Conrad is another name for what bearing.

SINGLE ROW DEEP GROOVE

Thrust load would have what type of relation to the axis of the shaft?

PARALLEL

Radial load would have what type of relation to the axis of the shaft?

PERPENDICULAR

Axial load would have what type of relation to the axis of the shaft?

PARALLEL

The primary difference between needle bearings and other roller bearings.

DIAMETER

Term that describes lining a bearing with a different metal to gain additional metallic properties.

BABBITTING

Journal bearings are a.k.a. …

PLAIN, JOURNAL, SLEEVE, BUSHING

A bearing designed to protect rollers from contaminants with a metal ring between raceways, which also makes them maintenance free.

SHIELDED

Name the oil groove that distributes lubricant lengthwise.

AXIAL

What is “A”? (Tap to expand picture)

OUTER RACEWAY

What is “B”? (Tap to expand picture)

INNER RACEWAY

What is “C”? (Tap to expand picture)

INNER RING LAND

What is “D”? (Tap to expand picture)

SIDE FACES

What is “E”? (Tap to expand picture)

OUTER RING LAND

Belt dressing is always applied to the _____ of the belt

Center