American Bearing Manufacturers Association (ABMA) Standard 9 and ISO 281 give equations for calculating the basic dynamic radial load rating for ball bearings. These equations are based on a number of assumptions, many of which are not valid for thin-section bearings. (Thin-section bearings are described in ABMA standard 26.2.) Nevertheless, many thin-section bearing catalogs report load ratings based on these equations. Kaydon has developed a new method for calculating the dynamic radial load rating for thin-section ball bearings. The new method uses the contact stress and the number of stress-cycles-per-revolution to calculate the capacity. The new numbers are based on five years of actual test results. These equations can also be used to calculate the dynamic radial load rating for four-point contact ball bearings, which are not covered in ABMA standard 9 or ISO 281.

Suggesting a bicycle is environmentally friendly is stating the obvious. But the Copenhagen Wheel, unveiled at the 2009 COP15 United Nations Climate Conference, is taking green technology and cycling in a new direction.

Despite posting its slowest quarter since early 2007, AWEA remains optimistic that the wind industry can and will work successfully with the revolving doors in Washington.

New generation sensors are improving our quality of life.

One of the driving forces behind the industrial revolution was the invention—more than a century ago—of the electric motor. Its widespread use for all kinds of mechanical motion has made life simpler and has ultimately aided the advancement of humankind. And the advent of the inverter that facilitated speed and torque control of AC motors has propelled the use of electric motors to new realms that were inconceivable just a mere 30 years ago. Advances in power semiconductors—along with digital controls—have enabled realization of motor drives that are robust and can control position and speed to a high degree of precision. The use of AC motor drives has also resulted in energy savings and improved system efficiency. This paper reviews the development and application of inverter technology to AC motor drives and presents a vision for motor drive technology.

A look back at a turbine-powered fire engine that was years ahead of its time.

Motion systems bring award-winning and energy-optimizing “Smart House” to life.

The complete Product News section from the October 2010 issue of Power Transmission Engineering.

The latest offering by machine design experts J.R. Hendershot and T.J.E. Miller is an 822-page brushless permanent-magnet (PM) machine design book that serves as a worthy follow-up to their 1994 work.

Calendar of upcoming events from the August 2010 issue of Power Transmission Engineering.