It's not always clear-cut which protective bellows or cover is most appropriate. Construction and material choices abound, and several combinations may work for one application. Among environmental variables to consider are contaminant type, source, and volume; machine operating speed and frequency; space restrictions — both in cross-section along travel path and for retracted length — and ambient and operating temperatures. The most suitable cover options must also be determined, including:

• Its shape and construction
• Supports for the cover along travel paths, including the maximum unsupported span
• The degree of sealing needed, including venting if necessary
• Aesthetics

Some preliminary engineering is usually necessary. Data sheets that can help in gathering parameters; these can include general operating conditions — for example, chip size, type and load, lubricants, temperatures, travel rates and cycles — as well as travel limits and space available for the cover when installed. Any drawings or dimensioned sketches of the machine parts to be protected are helpful; they should include cross-sectional and longitudinal views, and indicate any areas of interference — for example, from digital readouts, limit switches, or brackets. 3D models are the most useful for complicated applications.

Once the decision is narrowed down, bellows and other protective covers require little if any special tooling to meet most requirements.

Several designs

Bellows-type protectors are generally used to protect ways and cylinder rods against light to moderate volumes of chips, dirt, dust or coolants. They're cylindrically enclosed to fit over cylinder rods, or manufactured in open shapes to ride on top of machine ways. Way covers that span entire areas protect leadscrews located between or adjacent to machine ways.