WHAT IS A CONVEYOR?
A conveyor moves material.
A conveyor moves cardboard boxes, wood boxes, metal boxes and plastic boxes.
A conveyor can move material
This is called a GRAVITY CONVEYOR.
A conveyor can do more. It can move boxes UP against gravity . . . DOWN . . . or HORIZONTAL on a moving belt.
The belt is moved by electric power.
WHAT IS A BELT CONVEYOR?
It is a machine with a moving BELT.
|A pulley is like an IRON pipe.
Pulleys are put on each end of the bed.
The pulleys are as wide as the "bed".
|The shaft turns on a bearing . . . and the pulley turns with the shaft.|
|When two pieces of steel touch each other;
they cannot turn easily without bearings.
Bearings use little steel balls to keep the pulley shaft and the conveyor bed from rubbing together.
|Now the shaft can turn easily.|
|Pulley "A" is the drive pulley.
Pulley "B" is the tail pulley.
The drive pulley is usually larger because it does the work.
The drive pulley is turned (driven) by a motor. A sprocket is put on the drive pulley shaft.
A sprocket is put on the motor.
A sprocket is a metal "wheel" with "teeth" on the outside.
A chain is put around the Drive Pulley Sprocket and the motor sprocket.
The chain moves when the motor is started.
The chain turns the drive pulley.
Because a motor turns very fast (1750 times per
minute). . .
A SPEED REDUCER must also be used.
The SPEED REDUCER is put between the motor and the drive pulley.
. . . The motor is connected to the reducer with a V-Belt (like the fan belt in your car) or a "C" Face Coupling.
The reducer is connected to the drive pulley with a chain . . . Now the Drive Pulley turns slower.
All those parts (the motor, the speed reducer, and the drive pulley) are called:
THE CONVEYOR DRIVE
|They must be put together to take up as little
space as possible - so
The motor and reducer are put under and within the conveyor BED.
But what about the
The tail pulley is located at the tail end of the conveyor and it turns freely.
Now a "belt" can be put around the pulleys.
The Drive Pulley turns and moves the belt around . . . and around . . . and around.
. . . it is dangerous to have the belt hang down under the conveyor bed - So small rollers are put into the Conveyor Bed to hold up the belt.
These turn freely -- and just idle.
They are called "Return Idlers".
What to do?
1. Move the tail pulley! It can be moved to "take-up" the belt stretch.
There are "take-up" screws on both sides
of the conveyor.
Move these screws out slowly.
Move them the same amount on both sides!
This keeps the belt tight.
2. What do you do when the take-up screws are still all the way out - and the belt still stretches?
REMOVE THE SHORT PIECE(S) OF BELT.
Now you can start the "take-up" procedure all over again.
NOTE: If a "Dutchman" was not provided, you may need to add an UNDERSIDE TAKE-UP to your conveyor.
There is more belt stretch on a long, long conveyor than the regular take-up and dutchman will give. So an "Underside Take-Up" should also be used.
NOTE: AN UNDERSIDE TAKE-UP is often used when the overall length of conveyor cannot be changed and the TAIL PULLEY "take-up" cannot be used.
This is best speed to move objects from one place to another.
A person can walk about 4 miles per hour. If they were carrying a box they would walk much slower. Conveyors move boxes at about the same speed as a person carrying them. This is about 65 feet per minute (or about 3/4 of a mile per hour).
A. The drive pulley is larger in the center than the ends. This helps keep the belt in the center. This is called a "Crown".
B. The drive pulley is completely covered with vulcanized rubber. It is called "lagging". This keeps the pulley from slipping under the belt.
NOTE: If the belt movement were reversed, the pulley would be pushing the belt. When the conveyor was fully loaded or when the belt stretched, the pulley could turn and not move the belt.
The Snub Idler is closer to the drive pulley.
It makes the belt hug more of the drive pulley surface.
The Snub Idler is ADJUSTABLE.
It is ADJUSTABLE ON BOTH SIDES of the conveyor. (Each side of snub idler can be adjusted independently).
Reason - The Snub Idler is used to steer the belt.
IMPORTANT: Move snub idler or return idler only 1/16 in. at a time. Then wait a few minutes to see if belt moves back to center. Only small adjustments are usually necessary.
A. When boxes move from gravity conveyor to inclined belt conveyor, the box usually stops or "hangs up". The box will not transfer.
B. With a Power Feeder, transfer of the box is positive.
The Power Feeder is driven from main conveyor by a short chain connection.
A. When belt movement is REVERSIBLE (on conveyors 40 ft. long or more)
B. When overall length of conveyor cannot change (belt take up by tail pulley increases conveyor length)
A. Drive pulley now "pulls" belt in either direction
B. Take-up pulley can now be used to take-up belt.
When heavy total loads must be moved, it is best to use a conveyor bed with rollers (instead of regular conveyor bed).
This is a Roller Bed belt conveyor
Heavy total loads can be moved without using large motors when a ROLLER BED belt conveyor is used.
BELT CONVEYORS are often used with GRAVITY CONVEYORS.
You should know about GRAVITY CONVEYORS TOO!
A gravity conveyor moves objects without motor power.
To help objects move "easier" . . . and with as little slant or slope as possible -
|WHEELS OR . . .|
|ROLLERS . . .|
|The WHEELS or ROLLERS are put into channel
frames held together with "bed spacers."
Different widths can be made. Frames can be either STEEL or ALUMINUM.
|Wheels are put on axles. Aluminum spacer tubes are put on the axle between the wheels. This keeps wheels from moving from side to side on the axle.|
In the drawing above, the axles are on 3 in. centers (also available in 1-1/2 in. centers). The number of wheels on each axle can vary. This determines the number of wheels per foot on the conveyor.
BUT . .
There should always be a minimum of 10 wheels under a box.
This helps you decide the number of wheels per foot to order.
|Rollers have their own axles. Most axles are SPRING-LOADED. This means. . .|
|...The axle can be moved to one side.|
|Rollers can be easily removed or replaced in Conveyor Channel frame. The spring also keeps the roller in place.|
The rollers are put in the frame as close together -
or as far apart as necessary . . . BUT there should always be THREE (3) rollers under the box.
LESS THAN 3 ROLLERS . . . box tumbles
BEST-3 ROLLERS UNDER BOX AT ALL TIMES! This determines the ROLLER CENTERS to order.
(Any items with a smooth, flat bottom. These items can be wider than the conveyor, 6 in. over on each side is not too much. Extra wide items like plywood, can be moved O.K., but center it carefully.)
Tote boxes will not move easily
Use as many wheels as
Any Items with an uneven or open bottom, or with a rim on the bottom. These items should never be bigger around than the rollers are long.
1. ALL SECTIONS HAVE COUPLINGS
Sections can then be used together by coupling them to each other.
2. PORTABLE SET-UP USS TRIPOD STANDS
Always use one more stand than the number of conveyor sections (3 sections use 4 stands.)
3. PERMANENT SET-UP USES STATIONARY SUPPORTS
Always use one more support than the number of conveyor sections (3 sections use 4 supports.)
This is called a "Flow System".