Economic times are good right now in America and in the gear industry. We're in the seventh year of an up cycle. The tough shake-outs of the 1980s and early 90s are over. Orders are up. Backlogs are at comfortable levels. We're looking at what promises to be the biggest, most successful trade show in the industry's history coming up in Detroit in October. The most pressing question on the immediate horizon seems to be "How long can the good times go on?"
When traveling about in search of gears and other adventures, wise explorers bring along as much important information as they can. In the interest of keeping our readers as well-informed as possible, we bring you the following collection of Important Facts About Motor City.
When you have a multi-million-dollar transfer line sitting on the shop floor waiting for gears that might take up to two months to get, you have a costly bottleneck.
In 1961 I presented a paper, "Calculating Conjugate Helical Forms," at the semi-annual meeting of the American Gear Manufacturers Association (AGMA). Since that time, thousands of hobs, shaper cutters and other meshing parts have been designed on the basis of the equations presented in that paper. This article presents the math of that paper without the formality of its development and goes on to discuss its practical application.
Several articles have appeared in this publication in recent years dealing with the principles and ways in which the inspection of gears can be carried out, but these have dealt chiefly with spur, helical and bevel gearing, whereas worm gearing, while sharing certain common features, also requires an emphasis in certain areas that cause it to stand apart. For example, while worm gears transmit motion between nonparallel shafts, as do bevel and hypoid gears, they usually incorporate much higher ratios and are used in applications for which bevel would not be considered, including drives for rotary and indexing tables in machine tools, where close tolerance of positioning and backlash elimination are critical, and in situations where accuracy of pitch and profile are necessary for uniform transmission at speed, such as elevators, turbine governor drives and speed increasers, where worm gears can operate at up to 24,000 rpm.
The present article contains a preliminary description of studies carried out by the authors with a view toward developing asymmetrical gear teeth. Then a comparison between numerous symmetrical and asymmetrical tooth stress fields under the same modular conditions follows. This leads to the formulation of a rule for similar modules governing variations of stress fields, depending on the pressure angle of the nonactive side. Finally a procedure allowing for calculations for percentage reductions of asymmetrical tooth modules with respect to corresponding symmetrical teeth, maximum ideal stress being equal, is proposed. Then the consequent reductions in size and weight of asymmetrical teeth are assessed.
The trend toward moving coordinate measuring machines to the shop floor to become an integral part of the manufacturing operations brings real time process control within the reach of many companies. Putting measuring machines on the shop floor, however, subjects them to harsh environmental conditions. Like any measuring system, CMMs are sensitive to any ambient condition that deviates from the "perfect" conditions of the metrology lab.
Move over, Michael Jordan. While the Addendum staff is as proud as any other Chicagoans of our unbeata-Bulls, we confess to a soft spot in our hearts for the hometown's other championship basketball team: The Chicago American Gears.
In 1877, Irish immigrant William Gleason, owner of a machine tool business in Rochester, NY, suffered a terrible blow. Gleason's son Tom died. The loss was not merely a personal one. Tom had been his father's assistant, and the senior Gleason had no one to fill the gap and help him carry on his business.
Who wants or needs technical details about gearing? Who cares about it? Three out of every four people who are reading this magazine make up at least 75% of those who have an interest in the subject. The members of AGMA, EUROTRANS, JGMA and JSIM have an interest. All the people attending the Gear Expo in Detroit have an interest. Clearly, however, the people with the most pressing interest in our industry are our customers, the end users of gear products. The unfortunate reality, though, is that in many cases, these customers don't even know that's what they want.
Gleason Corporation has announced that agreement has been reached on all terms to acquire for approximately $36 million in cash the Hermann Pfauter Group, including, among other operations, Hermann Pfauter GmbH & Co., a privately held leading producer of gear equipment based in Ludwigsburg, Germany; its 76% interest in Pfauter-Maad Cutting Tools, a leading cutting tool manufacturer basked in Loves Park, IL; and Pfauter-Maag management's 24% ownership interest in that company. The acquisition includes all assets and liabilities, including the assumption of approximately $56 million in bank debt.