Application Digest 7547

DN Staff

March 25, 1996

3 Min Read
Application Digest

Why consider frameless motors

Robert White Jr., Industry Manager, Kollmorgen, Motion Technologies Group

Integrating a frameless PM motor directly into the load eliminates the need for associated couplings, shafts, and mechanical transmissions. Direct Drive a motors also allow more design options and higher machine performance in a wide variety of applications.

Originally developed for military and aerospace applications where exacting performance and accuracy must coexist with severe space and weight restrictions, Direct Drive frameless motor designs can help the design engineer:

1) Streamline machine design by eliminating gears, pulleys, chains, and belts.

2) Improve positioning accuracy by eliminating backlash or compliance from mechanical transmissions.

3) Enhance machine performance by improving servo stiffness for faster response to load changes.

4) Provide ultra-precise, low-speed operation through reduced speed/torque variations.

5) Gain maximum efficiency via superior torque/inertia, torque/weight, and power/volume ratios.

Able to withstand harsh operating environments, compact frameless motors have been integrated into remote-control cameras, high-speed machine tool spindles, and life-saving artificial heart pumps to provide smooth and precise performance under even the most demanding circumstances.

To speak with an applications engineer from Kollmorgen Motion Technology Group, call (800) 77SERVO.

CE mark: passport to Europe

Larry Sunday, Product Manager, Square D Company

The 16 countries of the new European Union (EU), along with Iceland, Liechtenstein, and Norway, have instituted the CE mark system to ensure that products conform to a common level of safety. Because of their importance to world trade, the need for CE marking is becoming a requirement for goods shipped in the global marketplace.

As a supplier of components and equipment that carries the CE mark, and with the ability to provide a "Manufacturers Declaration of Conformity," Square D and its parent company, Groupe Schneider, will help OEMs understand the CE marking process.

The EU has issued three directives for conformity as-sessment and the application of the CE mark. The Machinery directive is for machines with at least one moving part, and it addresses safety components, such as logic modules for two-handed control. Most machinery can be self-certified by the manufacturer. Only "Annex IV" machines, including saws, woodworking ma-chinery, presses, and injection molding machines, require the approval of a third party.

For the Electromagnetic Di-rective, the vendor may either self-certify, provide a Technical Construction File, or pass examination by a third party.

The Low Voltage Directive applies to components and equipment intended to operate at 50-1,000V ac or 75-1,500V dc. The components and equipment should conform with either harmonized standards, IEC standards, or a specific country's standards.

In general, the following are the steps to CE marking:

* Identify applicable directives and standards.
* Assess product or machine according to all essential requirements and standards.
* Prepare the technical file.
* Prepare the EC Declara-tion of Conformity Affix CE marking.

To speak with an applications engineer from Square D Co., call (919) 266-8305.

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