Belt Drive Applications 241

alignment

In a belt drive system, the arrangement of pulleys or the shafts on which the pulleys are mounted. Proper alignment is necessary for effective power transmission.

backing

The material that surrounds the tensile member of a synchronous belt. The backing is generally made of neoprene.

backlash

The maximum distance that any part of a mechanical system may move in one direction without applying force or motion to the next part in the mechanical sequence. Backlash is a form of mechanical inefficiency that cannot be completely eliminated but should be minimized as much as possible.

bearings

A friction-reducing device that allows one moving part to glide past another moving part. A common example of a bearing is a ball bearing.

belt

A band of flexible material that is looped around two or more fixed pulleys to transmit motion. Belts are made of various materials and come in different types, such as flat belts, round belts, and V-belts.

belt drive system

A mechanical system that uses a flexible belt and at least two fixed pulleys to transmit motion. Belt drive systems are low maintenance and do not require lubrication.

belt joint

A device used to join a flat belt into an endless loop. Common types of belt joints include lacing and hooks.

belt span

The distance on a belt from the center of the shaft on one pulley to the center of the shaft on the other pulley. Checking the belt span is a necessary step to determining a belt's tension.

belt tension gauge

A very common manual belt tension tester with two different scales that maintenance personnel use to check the tension of a belt drive system. A belt tension gauge helps ensure that a belt drive system is operating under proper tension.

belt tension tester

An electric or manual device that maintenance personnel use to check the tension of a belt drive system. Belt tension testers help to ensure that a belt is operating under proper tension.

bias-cut material

Fabric that is cut diagonally across its grain. Bias-cut materials are used to make the V-belt jackets that surround V-belts.

chain drive system

A system consisting of a chain and sprockets. A chain drive system transmits motion from one sprocket to the other.

chain drives

A power transmission system consisting of a chain and sprockets. Chain drives transmit motion from one sprocket to the other using chains.

classical multiple V-belt

A type of V-belt designed for heavy-duty applications, which can be used together with other belts to transmit power. Classical multiple V-belts are also known as classical V-belts.

classical V-belt

A type of V-belt designed for heavy-duty applications, which can be used together with other belts to transmit power. Classical V-belts are also known as classical multiple V-belts.

cogged V-belt

A type of V-belt that is notched on its underside to allow the belt to flex more easily. Certain types of cogged V-belts offer quieter operation than other types of V-belts.

compression section

The part of a V-belt that supports the tension section. The compression section is generally made of rubber or rubberized fabric.

conveyor belt

A belt used in industry to transport materials over a distance. Some belt drive systems can be used as conveyor belts.

creep

A condition that occurs in flat belt drives. Creep is when the belt moves forward slightly on the driving pulley, causing the driven pulley to rotate at a slower speed.

cross section

A surface or shape that is exposed or would be exposed by making a cut at a right angle to the object's axis. Cross sections for V-belts are measured in height and width.

deflection scale

A scale on a belt tension gauge that marks the belt span. The deflection scale, which is one of two scales on a belt tension gauge, may also be called the span scale.

driven pulley

A fixed pulley in a belt drive system. The driven pulley receives energy from the driver pulley via a belt.

driver pulley

A fixed pulley in a belt drive system. The driver pulley receives energy from a power source and transfers it to the driven pulley via the belt.

earplugs

Hearing protection that is designed to fit into the ear. Earplugs can be single-use or preformed for long-term use.

efficiency

A measure of the work output of a system versus the total energy input. An efficient system is able to convert a greater amount of the supplied energy into the intended useful work.

electric motor

A machine that converts electricity into mechanical energy or motion. An electric motor is a common power source for a mechanical system.

endless belt

A belt that has been joined in a loop. Belts that are not manufactured as endless can be joined with a belt joint.

energy

The ability to do work. Energy, which is never created or destroyed, may be potential or kinetic and may appear as electrical, mechanical, thermal, or chemical energy.

facing

A tough fabric used to cover a synchronous belt and protect tooth surfaces. Facing is usually made of nylon.

feet per minute

ft./min. The distance in feet that a belt drive travels while it rotates around pulleys in one minute. Feet per minute is a unit in the English system that measures the speed of a belt drive.

fiberglass

A lightweight, strong material composed of fine glass fibers. Fiberglass cords are often used in synchronous belts.

fixed pulleys

A circular device that is used in belt drive systems to transmit motion. Fixed pulleys rotate around an axis that does not move.

flat belt

A flat loop of material that transmits motion between two fixed pulleys. Flat belts are made of various materials, such as rubber, canvas, or leather.

foot-pounds per second

ft-lbf/sec. A unit of measurement in the English system that indicates the amount of energy transferred when a pound-force moves a distance of one foot in a second. One horsepower is equal to 550 foot-pounds per second.

force scale

A scale on a belt tension gauge that marks the tension of the belt. The force scale is one of two scales on a belt tension gauge.

fractional horsepower

A horsepower rating less than 1 hp. Fractional horsepower applications use single V-belts.

fractional horsepower V-belt

A type of V-belt that can be used for light-duty applications, such as those that transmit less than 1 hp. Fractional horsepower V-belts are also known as single V-belts.

friction

The resistance between the contact surfaces of two objects. Friction generates heat and increases the wear between components.

ft./min.

Feet per minute. The distance in feet that a belt drive travels while it rotates around pulleys in one minute. Feet per minute is a unit in the English system that measures the speed of a belt drive.

gear drives

A power transmission system consisting of gear shafts and gears, which mesh with one another. Gear drives can alter the speed, torque, or direction of mechanical energy.

gloves

A type of hand and wrist covering that protects the skin from injury. Gloves are made from a variety of durable materials including leather and canvas.

hooks

A type of belt joint that uses implanted metal fasteners to connect the ends of a belt together. Hooks can be used to create an endless belt.

horizontal angle misalignment

A type of pulley misalignment that may arise in a belt drive system. Horizontal angle misalignment occurs when the driver and driven pulleys are not positioned parallel to one another.

horsepower

hp. A unit of power that describes the rate at which a machine accomplishes work. In the English system of measurement, one horsepower equals 550 foot-pounds per second (ft-lbf/sec.) and converts to 746 watts (W) in the metric system of measurement.

joined V-belt

A type of V-belt that includes mutiple V-belts joined together on the top to provide smoother operation. Joined V-belts can be used in classical V-belt drives.

Kevlar

A synthetic fiber of high tensile strength used especially as a reinforcing agent. Kevlar is sometimes used to create a synchronous belt's tensile member.

lacing

A type of belt joint that uses strong fibers to stitch the ends of a belt together. Lacing can be used to create an endless belt.

leather

Fabric made from cowhide that offers resistance to heat and other hazards. The earliest flat belts were made from leather.

lockout/tagout

A method of protecting employees from accidental machine startup through proper locking and labeling of machines that are hazardous to nearby employees. Lockout/tagout is an essential practice for safe repair of machines.

lubrication

The use of a slippery substance, such as oil or graphite, between two moving surfaces that are in contact with each other. Lubrication helps reduce friction and heat.

m/min.

Meters per minute. The distance in meters that a belt drive travels while it rotates around pulleys in one minute. Meters per minute is a metric unit that measures the speed of a belt drive.

machine guards

A shield or cover that is placed over hazardous areas on a machine to prevent accidental contact with body parts or to prevent debris, such as chips, from exiting the machine. Machine guards often partially cover the point of operation while allowing necessary access.

mechanical systems

A collection of machines functioning together to perform useful work. Mechanical systems include belt drives, gear drives, and chain drives.

meters per minute

m/min. The distance in meters that a belt drive travels while it rotates around pulleys in one minute. Meters per minute is a metric unit that measures the speed of a belt drive.

misalignment

A condition in a belt drive system when pulleys or their shafts are not arranged properly. Both shaft and pulley misalignment can damage belt drives.

multi-groove belt

A type of V-belt that resembles a flat belt on top with V-shaped ribs on the bottom. Multi-groove belts are also known as V-ribbed belts or poly-V belts.

narrow V-belt

A type of V-belt that can transmit more horsepower than a classical V-belt, though it is narrower in design. Narrow V-belts are also known as wedge V-belts.

neoprene

A lightweight synthetic material, similar to rubber. Neoprene is often used as backing for synchronous belts.

nylon

A strong, elastic synthetic material. Nylon is often used as facing in synchronous belts.

offset misalignment

A type of pulley misalignment that occurs when either pulley is incorrectly positioned on its respective shaft. Offset misalignment may also be known as pulley groove misalignment.

O-ring

A small rubber ring on a belt tension tester. O-rings are used to mark the belt-span and belt-tension readings.

overtension

A condition in which a belt drive is operating under excess tension. The damaging effects of overtension include wear of belts and pulleys and permanent stretching of the belt.

parallel

A pair of lines that are equidistant from each other at all points along their length. Parallel lines never intersect with each other.

perpendicular

An intersection of two lines or objects at a 90° angle. Perpendicular lines form the corner of a square or rectangle.

personal protective equipment

PPE. Any clothing or device worn to minimize exposure to hazards and prevent injury. Personal protective equipment may include safety glasses, safety gloves, and a breathing mask.

poly-V belt

A type of V-belt that resembles a flat belt on top with V-shaped ribs on the bottom. Poly-V belts are also known as V-ribbed belts or multi-groove belts.

power

The rate at which a machine accomplishes work. Power is expressed in foot-pounds (ft-lb), or newton-meters (N-m), and is the result of the amount of work accomplished divided by the time it took to do the work.

power source

A device that generates electricity. Power sources include batteries, electric motors, and generators.

power transmission

The movement of energy from a source to an output device that performs work. Power transmission can be performed in many different mechanical systems, including gear trains, belt drives, and chain drives.

premium quality

A type of classical V-belt construction that eliminates the use of a V-belt jacket and, thus, allows for a larger tension section than standard quality classical V-belts. Premium quality, or raw edge, V-belts can operate under severe or shock loads, and they can be subjected to extreme temperatures or vibration.

pulley groove misalignment

A type of pulley misalignment that occurs when either pulley is incorrectly positioned on its respective shaft. Pulley groove misalignment may also be known as offset misalignment.

raw edge

A type of classical V-belt construction that eliminates the use of a V-belt jacket and, thus, allows for a larger tension section than standard quality classical V-belts. Raw edge, or premium quality, V-belts can operate under severe or shock loads, and they can be subjected to extreme temperatures or vibration.

rubber

An elastic material made from the latex sap of the rubber tree. Rubber is sometimes used to make flat belts.

rubber adhesive

A sticky rubber-based substance that joins two or more materials. Rubber adhesives, which are used in the tension section of V-belts, help absorb shock loads.

safety glasses

Protective eyewear with metal or plastic frames and impact-resistant lenses. Safety glasses shield the eyes from flying debris.

safety shoes

Footwear that protect the feet from impact, electric shock, and heat. Safety shoes sometimes include reinforced toe areas.

serpentine belt system

A type of belt drive system that includes more than two fixed pulleys and requires a belt to twist or go around corners. Serpentine belt systems use either flat belts or poly-V belts.

service life

The length of time a component or device is expected to be in operation before needing to be replaced. The service life for belts depends on several factors, including temperature, speed, and load.

shock loads

A type of load characterized by extreme speed and a tremendous amount of force. The tension section of a V-belt is designed to help absorb shock loads.

single V-belt

A type of V-belt that can be used for light-duty applications, such as those that transmit less than 1 hp. Single V-belts are also known as fractional horsepower V-belts.

slip

A condition that occurs in flat belt drives. Slip is when the load causes the belt to slide out of proper position on the pulley.

span scale

A scale on a belt tension gauge that marks the belt span. The span scale, which is one of two scales on a belt tension gauge, may also be called the deflection scale.

speed

The rate at which an object travels along a straight path. Speed describes the amount of distance an object travels in a given period of time.

sprockets

A gear or wheel with metal teeth that mesh with the links of a chain. Sprockets are used in chain drive systems to transmit motion.

standard quality

A type of classical V-belt construction that includes a V-belt jacket. Standard quality V-belts are suitable for most V-belt drives that operate under normal loads.

straightedge

A flat, rectangular hand tool that can be used to draw straight lines or determine the straightness of a line. A straightedge is used to check if a belt drive has become misaligned because the grooves in a pulley are not aligned correctly.

synchronous belt

A toothed belt that meshes with the grooves of a pulley in a synchronous belt drive allowing it to maintain constant speed during power transmission and avoid slippage. Synchronous belts are also called timing belts or synchronous drive belts.

synchronous belt drive

A type of belt drive in which the teeth of a synchronous belt mesh with the grooves in a pulley to transmit power. A synchronous belt drive transmits power in a similar fashion as a chain drive system but does not require lubrication.

synchronous drive belt

A toothed belt that meshes with the grooves of a pulley in a synchronous belt drive allowing it to maintain constant speed during power transmission and avoid slippage. Synchronous drive belts are also called synchronous belts or timing belts.

synthetic fiber

A thin, elongated piece of reinforcing material that is from manufactured, or artificial, substances. Synthetic fibers can be made from a variety of materials, including many plastics.

tapered

Gradually decreasing in size from one end of an object to its other end. A V-belt has tapered sides and a flat bottom.

tensile member

The part of a synchronous belt that supports the load. Tensile members, or tension members, consist of cords and are surrounded by the backing.

tension

A pulling force that is directed away from the object and attempts to move, stretch, or elongate the object. Belt drive systems must operate under proper tension to transfer power effectively.

tension member

The part of a synchronous belt that supports the load. Tension members, or tensile members, consist of cords and are surrounded by the backing.

tension section

The part of a V-belt that supports the load. The tension section contains synthetic fibers surrounded by a rubber coating.

timing belt

A toothed belt that meshes with the grooves of a pulley in a synchronous belt drive allowing it to maintain constant speed during power transmission and avoid slippage. Timing belts are also called synchronous belts or synchronous drive belts.

tooth pitch

On a synchronous belt, the distance between the centers of two belt teeth or two grooves in the belt. Synchronous belts are classified by tooth pitch, length, and width.

torque

A force that produces rotation. Torque is measured in pound-feet in the English system and Newton-meters in the metric system.

traction

The ability of a moving object to remain in contact with the surface over which it moves. Traction keeps a belt in contact with a rotating pulley.

twisted misalignment

A type of pulley misalignment that occurs when one pulley is at a twisted angle from that of the other pulley. Twisted misalignment may also be known as vertical angle misalignment.

undertension

A condition in which a belt drive is operating under too little tension. The damaging effects of undertension include loss of efficiency and belt slippage.

V-belt

A belt with a flat bottom and tapered sides that transmits motion between two pulleys. V-belts are the most common type of belts used for power transmission.

V-belt jacket

The part of a V-belt that surrounds and encloses the compression and tension sections. V-belt jackets are made from tough material and designed to help the V-belt withstand extreme operating conditions.

V-belt pulley

A pulley designed with one or more grooves. A V-belt pulley, or V-belt sheave, allows a V-belt to wedge into each groove for power transmission.

V-belt sheave

A pulley designed with one or more grooves. A V-belt sheave, or V-belt pulley, allows a V-belt to wedge into each groove for power transmission.

vertical angle misalignment

A type of pulley misalignment that occurs when one pulley is at a twisted angle from that of the other pulley. Vertical angle misalignment may also be known as twisted misalignment.

vibration

A rapid, continued, repetitive motion in a machine or other structures. Vibration can negatively affect mechanical operations.

V-ribbed belt

A type of V-belt that resembles a flat belt on top with V-shaped ribs on the bottom. V-ribbed belts are also known as multi-groove belts or poly-V belts.

watts

W. A metric unit of measurement that indicates the amount of energy transferred when a force of one newton moves a distance of one meter in a second. One horsepower is equal to 746 watts.

wedge V-belt

A type of V-belt that can transmit more horsepower than a classical V-belt, though it is narrower in design. Wedge V-belts are also known as narrow V-belts.