Belt Replacements

A normal maintenance item on a belt conveyor is the replacement of belts. Prior to ordering, it is necessary to make sure you have the correct Serial Number of the conveyor to ensure the proper belt is ordered.

On End Drive Units, set the tail pulley (See Figure 1) to its full retracted position by loosening the flange bearing bolts on both ends of the pulley and running out the adjuster screws to their maximum.

On Center Drive Units, set the take-up pulley (See Figure 2) to its full retracted position by loosening the jam nuts on both adjuster screws and running out the adjuster screws to their maximum. If provided, set both tail pulleys to their full retracted position by loosening the flange bearing bolts on both ends of the pulley and running out the adjuster screws to their maximum. Unroll the conveyor belting, and pull belting along conveyor bed with the carrying side up. Note: With standard PVC black belting, the smooth, dark black surface must be installed up for normal operation. Installation with this surface down will cause excessive friction and increased drive force.

Figure 2: Belt routing - standard center drive.

The drive chain is pre-lubricated from the manufacturer by a hot dipping process that ensures total lubrication of all components. However, continued proper lubrication will greatly extend the useful life of every drive chain.

Drive Chain lubrication serves several purposes including:

• Protecting against wear of the pin-bushing joint

• Lubricating chain-sprocket contact surfaces

• Preventing rust or corrosion

For normal operating environments, lubricate every 2080 hours of operation or every 6 months, whichever comes first. Lubricate with a good grade of non-detergent petroleum or synthetic lubricant (i.e., Mobile 1 Synthetic). For best results, always use a brush to generously lubricate the chain. The proper viscosity of lubricant greatly affects its ability to flow into the internal areas of the chain. Refer to the table below for the proper viscosity of lubricant for your application.

Ambient Temp.             SAE                ISO

Degrees F

  20-40                         20               46 or 68

  40-100                       30                  100

100-120                        40                 150

The drive chain's lubrication requirement is greatly affected by the operating conditions.  For harsh conditions such as damp environments, dusty environments, excessive speeds, or elevated temperatures, it is best to lubricate more frequently.  It may be best, under these conditions, to develope a custom lubrication schedule for your specific application.

Precautions

A) Only trained employees shall be permitted to operate

conveyors. Training shall include instruction in operation

under normal conditions and emergency situations.

B) Where employee safety is dependent upon stopping

and/or starting devices, they shall be kept free of obstructions

to permit ready access.

C) The area around loading and unloading points shall be

kept clear of obstructions which could endanger personnel.

D) No person shall ride the load-carrying element of a conveyor

under any circumstances unless that person is specifically

authorized by the owner or employer to do so. Under

those circumstances, such employee shall only ride a conveyor

which incorporates within its supporting structure,

platforms or control stations specifically designed for carrying

personnel. Under no circumstances shall any person

ride on any element of a vertical conveyor. Owners of conveyors

should affix warning devices to the conveyor reading

Do Not Ride Conveyor.

E) Personnel working on or near a conveyor shall be

instructed as to the location and operation of pertinent stopping

devices.

F) A conveyor shall be used to transport only material it is

capable of handling safely.

G) Under no circumstances shall the safety characteristics

of the conveyor be altered if such alterations would endanger

personnel.

H) Routine inspections and preventive and corrective maintenance

programs shall be conducted to insure that all safety

features and devices are retained and function properly.

I) Personnel should be alerted to the potential hazard of

entanglement in conveyors caused by items such as long

hair, loose clothing, and jewelry.

J) As a general rule, conveyors should not be cleaned while

in operation. Where proper cleaning requires the conveyor

to be in motion and a hazard exists, personnel should be made aware of the associated hazard.

Precautions

A) Maintenance, such as lubrication and adjustments, should be

B) It is Important that a maintenance program be established

to insure that all conveyor components are maintained in a

condition which does not constitute a hazard to personnel.

C) When a conveyor is stopped for maintenance purposes,

starting devices or powered accessories shall be locked or

tagged out in accordance with a formalized procedure

designed to protect all person or groups involved with the conveyor

against an unexpected start.

D) Replace all safety devices and guards before starting

equipment for normal operation.

E) Whenever practical, DO NOT lubricate conveyors while

they are in motion. Only trained personnel who are aware of

the hazard of the conveyor in motion should be allowed to lubricate.

Safety Guards

Warning Signs

Maintain all warning signs in a legible condition and obey all

warnings.

When belt tracking adjustments are made, they should be minor (1/16 in. at a time on idlers, etc., should be sufficient.). Give the belt adequate time to react to the adjustments. It may take several complete revolutions around the conveyor for the belt to begin tracking properly on long, slow conveyor lines.

A) Stand at tail pulley looking toward drive and note what direction belt is traveling.

B) Having observed belt and determined tracking problem, follow procedures in “How to Steer The Belt”

HOW TO STEER THE BELT

Condition 1. . .When the belt is running from the INFEED to DISCHARGE

(FLOW), but tracking (drifting) towards the RIGHT Side,

move the Snub Idler nearest the INFEED end of the LEFT Side

towards the DISCHARGE end of the conveyor.

Condition 2. . . When the belt is running from the

INFEED to DISCHARGE (FLOW) but tracking

(drifting) towards the LEFT Side, move the Snub

Idler nearest the INFEED end of the RIGHT Side

towards the DISCHARGE end of the conveyor.

If Belt Direction (FLOW) is reversed, all the above

conditions will remain the same, except you are

now viewing the conveyor from the opposite end.

If the belt continues to track improperly, re-check all items covered

in “Pre-Tracking Inspection” and make corrections as necessary.

How to determine the type, number and mounting arrangement of ball transfer units. 

BALL TRANFER LOAD CAPACITY

Equal load distribution over many ball transfers is seldom, if ever achieved. Load distribution is governed by the flatness, hardness and smoothness of the load surface in contact with the balls and the ball transfer installation height variance and system deflection. Absolute flatness of the application is difficult to insure under field service conditions. To avoid exceeding the rated capacity of any individual ball transfer units, sufficient ball transfers should be provided to afford a safety factor of 3. As an example: The number of ball transfers (75 lb maximum capacity) to support a load of 750 lbs would be 10 units x 3 or 30 units to obtain smooth rolling motion under varying degrees of flatness and ball contact.  

The force required to put a load in motion is also governed by the flatness, hardness and smoothness of the surface in contact with the balls. Engineering calculations will usually determine that the force required ranges between 1 and 5% of the load weight. As the number of ball transfers under a load is increased, the force required to put a load in motion will be decreased. 

When calculating loads, the possibility of impact and unequal leveling should be considered. Self-leveling rubber cushions placed under each unit can reduce these problems. The rubber cushions allow the units to equalize, thus reducing the possibility of excessive loading on some of the units.

BALL TRANSFER ARRANGEMENT 

Arrangement of the ball transfer units depends on the weight of the load, surface of the application and undersurface of the conveyed load. Determine the number of ball transfers required to support the load based on the considerations above. Once the number of units has been calculated, these units should be arranged symmetrically under the load. The minimum distance between the ball transfers should be the length of the shortest dimension of the load divided by 2.5. This minimum spacing will support the conveyed article and prevent it from becoming unstable on the conveyor. 

Application engineers should be conscious of load sharing considerations in the design of the application. Our technical staff is available to assist you with mounting and spacing recommendations for your applications. 

BALL TRANSFER MAINTENANCE 

All carbon steel ball transfers are prelubricated and sealed, thus not requiring further maintenance. Most units have a drain hole in the bottom of the unit to expel dirt and moisture. In certain extreme applications, units may be maintained with a cleaner or lubricating fluid applied to the main ball at regular intervals.