Design Engineering – March-April 2019

March/April | 2019 http://www.design-engineering.com

37

Industrial Encoder Corporation

http://www.globalencoder.ca

[email protected]

1-888-277-6205

Unbreakable code discs made in house

Hollow shaft ranges from 1/4” to 4.5”

5 YEAR WARRANTY

ATEX certified Explosion proof encoders

All encoder models are backed by a

Worldwide sales & support

Manufacturing in Canada and Germany

Continuous product development

Exeeding industry durability standards

Flexible production / rapid delivery

Customized designs and niche solutions

YOUR EXPERT SOURCE FOR

ENCODERS

TEN FUNDAMENTAL REASONS

WHY WE SHOULD BE YOUR FIRST CHOICE

DES_MayJune_IndustrialEncoder.indd 1 2018-04-20 9:26 AM

FluidPower:Pneumatics

immediately to deviations in the required

behavior and make the necessary adjust-

ments. Despite additional external loads,

electric drives therefore generally follow

their specified trajectory.

Pneumatic drives, on the other hand,

can respond flexibly to external influences,

even with high continuous forces and can

usually handle even overloading without

any damaging effects. This characteristic

can also absorb shock or impact loads that

would impair other drive types.

One of the main differences between

pneumatic and electric drive technology

is the actual system setup and the asso-

ciated complexity. Pneumatic systems

have a simple setup and are easy to install,

commission, operate and maintain.

While electric systems have been state-

of-the-art for decades, they are unques-

tionably more complicated and require

specialized staff with a higher level of

technical knowledge. This is an important

consideration for the plant manufacturer,

but also for the customer who will have to

operate and maintain the plant.

Economic comparison

Last but not least, the economic efficiency

of a solution is also of great importance.

An analysis of the procurement costs

reveals that pneumatic solutions generally

require much less investment than electric

solutions. In addition, pneumatics are

quick and easy to set up and commission.

However, the operating costs must also

be taken into account. Energy costs often

constitute a key part of a system’s total cost

of ownership. Electric drives are an ener-

gy-efficient option, especially for tasks

involving just motion. Their energy con-

sumption is also load-dependent.

Compressed air, on the other hand, is

often perceived as being a relatively expen-

sive form of energy. But very few custom-

ers know the (absolute) energy

consumption of their pneumatic actuators.

This means they don’t have the data needed

to discern if an alternative solution could

be more economical. Another challenge is

ensuring that pneumatic systems are cor-

rectly used and sized, as these factors are

also key to their efficient use.

The EnEffAH research project com-

pleted in 2012 (“Energy Efficiency in

Production in the Drive and Handling

Technology Field”, a joint project as part

of the German Federal Government’s 5th

and 6th energy research programme)

provides a simple guide to the efficiency

of an electric or pneumatic drive system.

It clearly shows that electric drives are very

efficient when it comes to large strokes with

short holding times, while pneumatics is

the preferred option for short strokes com-

bined with holding tasks.

The question about which technology

is more economical therefore depends on

the application. However, basic trends

about the efficiency of drives are often also

applicable to their economic efficiency.

Only a detailed investigation that consid-

ers the specific operating conditions can

provide a clear and reliable answer to the

question as to which technology is best.

The decision for or against a technology

is based on several criteria, only some of

which are examined here. Given the clear

differences between pneumatics and elec-

trics, it is not possible to make general

statements about which technology is best.

It is therefore important to focus on the

problem and the associated parame-

ters before choosing the most

suitable solution. That is the

only way to find the best

technical and most eco-

nomical solution. DE

http://www.festo.com

This article supplied by

Festo Canada

Best of both worlds: Flexible electric positioning drives for

motion along the X- and Y-axes and a compact pneumatic

drive with high performance density for the Z-axis

DES_MARCHAPRIL2019_LAZ.indd 37 2019-04-10 1:56 PM