ALGOR SUPPORTS DESIGN OPTIMIZATION AND CREATIVITY AT BLACK
Creativity is the key requirement for design engineers at Black
& Decker. Because the company produces such a wide variety
of consumer products, the capabilities of both the engineers and
their design engineering software are tested on a daily basis.
At Black & Decker Canada Inc., located in Brockville, Ontario,
that challenge is met by a team of engineers, headed by Colin
Overy, Manager - Product Development, with the help of Algor design
and analysis software.
Overy, Manager - Product Development (left) and Richard P. Rosa,
Design Engineer, are pictured with optimized wheel design used
for a revolutionary new Black & Decker lawnmower. Note stress
analysis model on computer screen.|
Design and Analysis Integrated
Mr. Overy has taken full advantage of Algor software's integration
of design and analysis capabilities on desktop computers. In his
words: "Algor allows FEA to become a process to be used by
capable engineers and technologists on an as-needed basis. We
have found it to be complimentary to, but not a substitute for,
sound engineering judgment and innovative design."
Black & Decker engineers use a number of techniques in the
creation of models. "One technique we use is to import various
elevations from a company-standard CAD system into Superdraw and
construct the model there," says Mr. Overy. "We see
modeling as the real challenge. A few minutes spent planning the
model construction technique can save hours later." Algor
software has been used in the design of a large number of Black
& Decker products. The photos and descriptions below are just
a few examples of the innovative use of Algor software at Black
& Decker Canada.
A Mower on the Cutting Edge
One of the most innovative products Black & Decker has introduced
recently is the cordless electric lawnmower. The new mower is
designed to greatly reduce the amount of air and noise pollution
that is created by standard gasoline-powered mowers. A gasoline-powered
lawnmower creates more air pollution in 30 minutes than does a
typical automobile driving the 200-mile distance between Washington,
DC and Philadelphia. The new cordless mower is also nearly half
as noisy as a gasoline-powered model.
new Black & Decker cordless electric mower is the first of
its kind. It produces less pollution and noise than gasoline-powered
Several components of the new mower were designed and analyzed
with Algor software, including the patented cutting blade. "The
blade rotates at 3,600 rpm," says Mr. Overy. Algor software
was used to confirm blade deflection and maximum stresses. The
deflection was confirmed by actual measurement and stresses by
a strain gauge telemetry system. The analysis data were used to
verify infinite fatigue life design criteria. Correlation and
confidence in the analysis was so good that deflection and strain
gauge testing of a subsequent new mulching blade design was considered
light-shaded rendering of the cordless mower blade. This complex
model was constructed to study deflection behavior.|
Algor software also played a part in a needed redesign of the
mower's wheels. According to Mr. Richard Rosa, Design Engineer
for Lawnmower Product Development, "Field trials of the new
cordless mower revealed a problem with wheel durability just after
production began. Unforeseen lateral loading was occurring when
cutting parallel to slopes, in conjunction with impact loading.
The Algor analysis showed elastic deflection closely duplicating
the permanent deflection seen in the failed part.
"The fix," continues Mr. Rosa, "was a small circular
rib (later to become known as the "Rosa rib"). This
was modeled and a new analysis showed acceptable deflection and
stress levels. The production mold was modified overnight and
production resumed in a day or two. The confidence in the Algor
analysis reduced the problem to a short production delay and all
the funds spent on the software were recovered ten times over!"
stress analysis rendering shows the lawnmower wheel with the added
The Wheel Bracket
"In this case," says Mr. Overy, "the analysis of
a new concept in lawnmower height adjustment, using a unique wheel
bracket, indicated changes were needed to reduce stresses. The
use of Algor software eliminated at least one, and probably three
prototyping steps. Again," he continues, "the cost effectiveness
of the software was appreciated."
optimization of the lawnmower's unique wheel bracket with Algor
software eliminated costly prototypes.|
"This component," says Mr. Overy, "Is a liner for
a coffee maker carafe. Algor software was used to model the liner
and perform analyses of structural stresses due to vacuum and
thermal loads. In addition, the effects of changing the glass
to a type with lower thermal expansion properties were evaluated.
The volume capacity of new liner configurations was also calculated
The Black & Decker design team has used Algor's fluid flow
analysis processor to investigate flow patterns associated with
new Dustbuster designs. "The data allowed many configurations
to be evaluated initially, and the better ones were selected for
subsequent prototyping and analysis," says Mr. Overy. "Full
color plots, showing pressure and velocity, were created in Superview
for discussion and reporting purposes." Unfortunately, we
cannot show any photos of the analyses, because the details are
Algor in the Future
Mr. Overy and his team plan to continue finding creative ways
to use Algor software. In his words: "We will continue to
utilize Algor software as we expand our analytical work. I foresee
using Algor for advanced conceptual design and analysis, in-depth
analysis, design optimization and investigating what-if situations.
Algor features we appreciate include the family-style related
formats of the different programs, and the added features and
speed improvements included in the latest release."
Copyright © 1993 Algor, Inc. All rights reserved.