This paper outlines the design considerations that go into construction of a drive system in order to explain the importance of specific data, why it is required, and where design freedom is necessary. Apart from loads and speeds, interface dimensions and site specific conditions are also needed. Deciding up front which gear rating practice to select can affect the torque capacity of the drive train by ~15%.

When software goes bad, what do we call it? System failure? Human failure? A virus? A number of words will work. How about this? Glitch. It has that onomatopoeic quality that fairly screams, Downtime! And with good reason -- software-generated miscalculations can have very expensive -- if not perilous -- repercussions.

A reader asks what are the required parameters to properly specify a gear.

The complete Industry News section from the December 2013 issue of Power Transmission Engineering.

When designing spur teeth, is there a formula/guideline/design guide for determining the amount of crowning?

A discussion of the basics in DC drives, DC motors, AC drives, AC motors and synchronous motors.

When designing a spur-crown pair, is there a formula, guideline or design guide for adapting the spur teeth for the radial angle of the teeth in the crown?

For the Seabees, hazardous construction zones have always been part of the job.

Dovetails, gears and splines have been widely used in aero engines where fretting is an important failure mode due to loading variation and vibration during extended service. Failure caused by fretting fatigue becomes a prominent issue when service time continues beyond 4,000 hours. In some cases, microslip at the edge of a contact zone can reduce the life by as much as 40–60 percent.

The complete Product News section from the August 2013 issue of Power Transmission Engineering