What is a Gravity Conveyor?
Non-powered conveyor is the simplest form of conveyor that uses gravity to keep products moving. Gravity conveyors offer a green, affordable way to transport packages distances that they cannot be carried. Portable sections of non-powered conveyor are often used for loading packages on to and off trucks. Gravity conveyor can also serve as takeaway conveyor for cartons coming out of an automated sorter, and it’s often used in workstations and pick modules where employees complete their tasks and then push their work along to the next zone or station.
Gravity conveyors can be installed on the horizontal or can also be set up with declining stand heights to allow product to flow from a high to a lower elevation. Though much less expensive than power conveyors, the force of the flow cannot be controlled.
The two most common types of non-powered conveyor are skate wheel and roller. Skate wheel gravity conveyor is a good choice for light packages that have a firm bottom.
Gravity Skate Wheel Conveyor
Only a little energy is needed to turn the small wheels of a skate wheel conveyor, and that makes skate wheel good at maintaining the speed of a product. Because each wheel turns independently, skate wheel conveyor is also a good choice for the curved sections of a conveyor line and can complement light duty gravity or power conveyors.
Skate wheel gravity conveyors can only be used for packages with flat surfaces that do not have soft bottoms. Though there are several skate wheel patterns, there should always be a minimum of ten wheels under a box. The wheels can be made of galvanized aluminum, galvanized steel or even plastic.
Gravity Roller Conveyor
Gravity roller conveyors are more suited to heavier loads than skate wheel. It is commonly used for workstations and pick modules because it provides a better working surface and is often less expensive than skate wheel conveyor. It’s also good at slowing the inertia of products coming out of a high-speed sorter. Rollers are recommended for uneven, open, or rimmed bottom packages. They have spring-loaded axles for easy removal & replacement. Unlike skate wheel conveyors, the product should never be wider than the rollers. Use at least three rollers under a product at any given time.
Curved roller sections can have straight rollers or tapered rollers. Tapered roller curves allow the packages to maintain better orientation through the curve; whereas packages on a straight roller may not exit the curve in the same position they entered.
Both types of gravity conveyor can be used alone or in conjunction with power conveyor to form a complete system.