Design World – August 2019

16 August 2019 http://www.designworldonline.com DESIGN WORLD

http://www.designworldonline.com/MC

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Today’s conveyors are sophisticated designs at the core of myriad

automated operations. Consider synchronous conveyors — those that index

workpieces from workstation to workstation — as well as asynchronous

conveyors that advance workpieces or products in independent transport

tasks. Synchronous-conveyor installations run along fixed paths at set

speeds ... often quick and automated arrangements. The slowest tasks tend

to define overall cycle rate. In contrast, asynchronous conveyors service one

or just a few workpieces or products at a time over flexible paths to any

number of destinations or staging areas. Usually these conveyors are setup

to optimize use of automated machinery and minimize manual workers’

waiting for new product to assemble or otherwise service.

Synchronous conveyors are common for the packaging of bottles, boxes,

and bags that ride directly on the conveyor strand. Guides on the conveyor

sides and friction pads keep discrete items from sliding or going off course.

Contrast this with features often (though not always) more typical of

asynchronous conveyors. Some designs have discrete products sit in carriers

or pallets that go through standardized lift, diversion, rotation, and rerouting

stations. Units such as pallets in these setups often sport datatags for

workstation sensors to read. Such connectivity for data collection lets the

whole installation more intelligently route products — even letting plant

end-users produce or otherwise transport multiple items via one centralized

conveyor network.

In fact, general motion components as well as dedicated conveyor

designs are spurring new levels of material-transport flexibility only recently

thought impossible. That’s especially true in the proliferating designs of AS/

RS installations as well as self-contained vertical transfer units. The latter

might make use of spiraled elevators or (increasingly common) elevator units

that employ linear actuators for pushing, hoisting, and workpiece (or product

or bin) unloading operations. Some variations even employ linear guides on

Conveyor for discrete

material transport

Educational installment brought to you by:

Lisa Eitel

the hoists to steady loads within the elevator

cage — especially where the products being

lifted are of standard size or collected in bins or

pallets.

Elsewhere on asynchronous conveyors,

motion lifts (usually in the form of pneumatics)

can temporarily raise pallets holding

workpieces just a bit above the conveyor below;

work is then done on the product while the

conveyor is protected from damage. Next the

workpiece is lowered back onto the conveyor

to continue. Alternatively, other relatively new

conveyor designs omit such motion lifts and

include structural reinforcements to allow

assembly and other tasks to occur right on the

conveyor surface.

In the conveyor installment of Design

World’s MC^2 we’ve written and collected

more than a dozen references that detail

these and other material-handling types;

compare conveyor drive modes, controls, and

PT components; and describe how to size

subsystems during conveyor design.

References include:

Basics of conveyors

Chain on edge conveyors

Power and free overhead conveyors:

Where do they excel?

Chain-driven live roller versus belt and

over-under conveyors

Pitch: What is it in the context of conveyors?

What are precision-link conveyors? Summary

of one type of transfer system

What are pallet conveyors? (Not to be confused

with pallet-moving conveyors)

Access this and other MC^2 installments at

designworldonline.com/MC2.

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