Today’s conveyor systems can boost the performance of your storage, production or distribution facility, improve safety and significantly reduce labor expenses. Conveyor systems can transport both individual cartons and entire pallets within your facility and they are an essential component to modern material handling design.
Conveyors fall into three different classification in most material handling applications:
• Powered roller or belt conveyors (for unit or carton handling)
• Powered chain or roller conveyors (for pallets)
• Non-powered conveyors
Powered Package Handling Roller or Belt Conveyors
Powered belt or roller systems are quite often used to move packages and cartons within a warehouse. In general, belts are used for moving items along a line, while rollers are employed for accumulating or diverting items in certain areas along the line.
For over 100 years, belt conveyors have been indispensable systems in many material handling designs. Less costly than roller systems and often better suited to specific tasks like moving light weight items, belt conveyors are used in many warehouse automation designs.
Conveyor belts employ a long, looped belt that sits on top of a metal slider belt or a set of non-powered rollers. Motor driven pulleys turn the belt and move items along the conveyor line.
Belt systems can be made of different materials and surfaces depending to the application of the conveyor. For example, a belt surface may be totally flat in segments where items need to be pushed off the line and may have a gripping texture on segments where goods must be moved up inclines.
Although belt conveyors are extremely useful and exceptionally reliable, roller conveyors can offer more efficiency in many applications. For example, roller systems can allow accumulation of items on a line where belt conveyors cannot. This is an important consideration because there are many applications where items have to be slowed down and/or accumulated in material handling system designs. Accumulation processes are often used when item flow has to be slowed down before being forwarded to sorters, palletizers or other warehouse automation equipment.
More sophisticated roller conveyor systems also have the capability to track objects on the line and implement zero pressure accumulation, meaning none of the products collecting on the line come into contact as they decelerate and finally stop.
Roller designs are made up of a series of cylindrical rollers that are typically powered by one of these methods:
- Line-shaft conveyors: in a line shaft configuration, a metal shaft runs underneath the cylinders at a 90 degree angle and is attached to each roller with rubber O-rings. A drive mechanism turns the shaft, and in doing so rotates the cylinders via the connected O-rings.
Line-shaft configurations are the least costly of all roller setups, but they also require the most service. O-ring connectors between the shaft and rollers tend to need adjustment and often fail.
- Belt-driven roller conveyors: As implied by the name, these conveyors are driven by a belt that lies beneath the roller platform. A motor drives the belt, which propels the rollers.
- MDR conveyors: Motor-driven roller (MDR) conveyors are configured in segments where a single roller in each segment is connected to a motor and it is responsible for powering all the other rollers. All non-powered rollers in the segment are connected to the motorized roller by flexible O-rings. Powered units are placed in succession to configure the conveyor line.
MDR conveyors are typically powered by 24 volt DC motors that engage only when an item is present on the an individual segment, meaning they are extremely energy efficient.
Although MDR conveyors are more expensive than line-shaft and belt drive systems, lower maintenance and energy costs can make them a good investment in the long term.
- Segmented belt conveyor: the segmented configuration of MDR conveyors ultimately led to the concept of segmented belt conveyors. Similar to motor driven roller conveyors, segmented belts are powered as independent segments and offer many of the same advantages of motor driven rollers, including the ability to accumulate items.
Powered Pallet Handling Conveyors
Powered pallet-handling conveyors are sometimes combined with automatic palletizers and AS/RS setups. Pallet handling conveyors are slower than package handling conveyors, but they can handle units of up to two tons.
Pallet-handling conveyors come in a couple of varieties: chain conveyors and roller conveyors.
- Pallet-handling chain conveyor: the most basic of all conveyor systems, pallets on a chain conveyor line are set directly on two or more lengths of heavy duty chain. Motors propel the lengths of chain which then move pallets along the line.
- Pallet-handling roller conveyor: similar to MDR package conveyors, pallet handling roller conveyors use larger rollers and heavy duty chains to connect a powered cylinder to the remaining cylinders in a conveyor segment.
Roller or skatewheel conveyors are the most frequently used types of non-powered systems used in material handling. Non-powered rollers or skatewheels use gravity and inertia to move cartons and items though pick modules, warehouses, sorters, workstations, package sorting areas and loading docks.
- Skatewheel conveyors are made up of many individual wheels and need minimal energy to maintain the inertia of objects as they move down a conveyor line. On the whole, they move products quicker than non-powered roller configurations and they offer more flexibility. They can also be used in curved segments of a conveyor line since they are individual wheels.
- Non-powered roller conveyor systems are typically less expensive than skatewheel systems. They are frequently used for pick modules, workstations, and other areas where it’s beneficial to have a flat platform to work on items as they go down the line. Roller systems can also be used to slow down items coming from higher speed systems like sorters so that workers can keep up with conveyor performance.
Non-powered skatewheel and roller conveyors have one major disadvantage when compared to powered conveyors: by using inertia and gravity to move products you lose the ability to control the force applied to those products, so it’s harder to control speed.
Conveyor Systems Near Me
If you’d like a full analysis of conveyor system options for your storage, production or distribution facility, call a material handling expert at Welch Equipment Company today.
Welch Equipment Company
2181 South 3200 West
Salt Lake City, UT 84119
Serving Alta, Bluffdale, Cottonwood Heights, Draper, Grantsville, Herriman, Holladay, Midvale, Millcreek, Murray, Ophir, Riverton, Rush Valley, Salt Lake City, Sandy, South Jordan, South Salt Lake, Stockton, Taylorsville, Tooele, Vernon, Wendover, West Jordan, West Valley City