Ask any exhibitor at Pack Expo International and the co-located Healthcare Packaging Expo (Oct. 14-17 at McCormick Place, Chicago) why
they're there, and you'll probably get the same response: end users.
This paper provides a mathematical framework and its implementation for calculating the tooth geometry of
arbitrary gear types, based on the basic law of gear kinematics. The rack or gear geometry can be generated
in two different ways: by calculating the conjugate geometry and the line of contact of a gear to the given
geometric shape of a known geometry (e.g., a cutting hob), or by prescribing the surface of action of two gears in contact and calculating the correspondent flank shapes.
Tooth contact analysis (TCA) is an important tool directed to the determination of contact patterns, contact paths, and transmission errors in gear drives. In this work, a new general approach that is applicable to any kind of gear geometry is proposed.
Circular pitch gives me the size of the teeth in my mind, but diametral pitch does not. What is the purpose of the diametral pitch concept? Does it merely avoid pi in calculation?
Engineers typically learn that the bearing L10 life can be estimated using the so called “C/P method” — or the “basic rating life” of
the bearing, a method rooted in the 1940s. Major developments have since led to the “modified rating life,” released in ISO 281:2007,
which includes the aiso life modification factor. In this paper a succession of equations used for bearing life ratings are reviewed, and
current bearing life rating practices are discussed in detail. It is shown that — despite the introduction more than 30 years ago of
the adjustment factor of the basic rating life, and the standardization in 2007 of the aiso modification factor — use of these improved
calculation methods are not practiced by all engineers. Indeed — many continue referring to the old model as a way of seeking
compliance with existing, established practices.
Columnist Brian Langenberg provides a current outlook update, key findings
from a recent energy sector conference, and takes another look at education and employment.
Th e Allen Telescope Array at Hat Creek, CA is a joint venture between the University of California Berkeley and the SETI Institute of Mountain View, CA. SETI has hired Minex Engineering of Antioch, CA to help with the design and installation of state-of-the-art drives and controls for the antenna array.
