It S Customisation That Sets The Standard
01 February 2005
It's customisation that sets the standard
Nigel Evenett argues the case for using 'special' electric motors
outside of the IEC standards and illustrates his argument with several
OEM applications that have clearly benefited from a 'non-standard'
For many years now, the IEC/BS standards have dictated what constitutes a
'standard' industrial electric motor. These cover the main areas of
power, dimensions and tolerances for both mechanical and electrical
characteristics, which allow for a large degree of interchangeability
between different manufacturers products.
The reasoning behind these standards is, at first glance, sensible and
practical. For example, if an end-user wishes to replace a faulty 4kW, 4
pole, foot-mounted motor he knows that this should be available in a 112
frame (i.e. the height from the base of the feet to the centre of the
shaft is 112mm). Because the dimensions of the shaft and feet fixings are
covered by the standards and, so-long as the terminal box position is
specified, a motor from any reputable source will fit the job.
The standard motor, however, is not ideal for every application. As a
result, many OEMs choose to 'tailor' the primary driver for their
equipment in order to gain a competitive edge in the market. This may
sound a bit like Fred-in-a-shed tinkering with his Ford Focus to earn his
go-faster stripes but it is in fact being practised, to good advantage,
by all the major machine tool companies and many other primary industrial
equipment suppliers on a large scale. The point is reinforced by the fact
that of 500,000 motors produced at just one of the author's company's
factories, some 60% are customised specials.
The reason an OEM opts for customised motors is to gain a competitive
advantage in his market place. The benefits are improved machine design
or performance, or even a combination of the two.
Customisation in action
An illustration of enhanced machine design is an industrial blower from
Air Control Industries of Chard. For this application, motor shafts are
employed as the main impeller shaft saving the weight and space of a
motor coupling whilst also simplifying assembly and eliminating potential
maintenance demands. The fact that the motors can be supplied with
multiple different shaft lengths (200mm, 350mm & 500mm) adds to
flexibility of the ACI blower range.
Another example is a motor supplied with a specially engineered,
squared-off stator housing (picture right) for grinding machines produced
by Wadkin UltraCare of Leicester, a manufacturer of machines for the
woodworking industry. This configuration permits a laterally moving arbor
to travel along the length of the motor during the blade grinding process
whilst offering a cutting capacity of up to 150mm length and 200mm
cutting circle diameter. As well as being ideal for the task, the custom
motor gives the OEM a technology edge. This ensures that the product is
less likely to be mimicked because of the investment required and the
time it takes to bring copies to market.
The use of special motors can give equipment manufacturers a real market
edge. True, there are initial costs to be borne when resources are
committed to motor development, but the rewards can include easier and
faster machine building, superior machine performance, reduced
inventories and the opportunity to create a market leading product that
is technically more advanced that its competition.
Nigel Evenett is with AEG Electric Motors
Contact Details and Archive...