Characterizaton of Retained Austenite in Case Carburized Gears and Its Influence on Fatigue Performance
Carburized helical gears with high retained austenite were tested for surface contact fatigue. The retained austenite before test was 60% and was associated with low hardness near the case's surface. However, the tested gears showed good pitting resistance, with fatigue strength greater than 1,380 MPa.
Performance of Skiving Hobs in Finishing Induction Hardened and Carburized Gears
In order to increase the load carrying capacity of hardened gears, the distortion of gear teeth caused by quenching must be removed by precision cutting (skiving) and/or grinding. In the case of large gears with large modules, skiving by a carbide hob is more economical than grinding when the highest accuracy is not required.
Large Scores and Radial Cracks on Case-Hardened Worms
In the last couple of years, many research projects dealt with the determination of load limits of cylindrical worm gears. These projects primarily focused on the load capacity of the worm wheel, whereas the worm was neglected. This contribution presents investigations regarding damages such as large scores and cracks on the flanks of case-hardened worms.
The Two-Sided-Ground Bevel Cutting Tool
In the past, the blades of universal face hobbing cutters had to be resharpened on three faces. Those three faces formed the active part of the blade. In face hobbing, the effective cutting direction changes dramatically with respect to the shank of the blade. Depending on the individual ratio, it was found that optimal conditions for the chip removal action (side rake, side relief and hook angle) could just be established by adjusting all major parameters independently. This, in turn, results automatically in the need for the grinding or resharpening of the front face and the two relief surfaces in order to control side rake, hook angle and the relief and the relief angles of the cutting and clearance side.
Holding Our Breath (Publishers Page)
As we sign off on this issue, the was has just begun in Iraq. The world seems to be holding its breath, and waiting.
Product News (Product News)
Complete Product News for May/June 2003.
Welcome to Revolutions, the column that brings you the latest, most up-to-date and easy-to-read information about the people and technology of the gear industry.
Technical Calendar (Events)
Complete Technical Calendar for May/June 2003.
Industry News (Industry News)
Complete Industry News for May/June 2003.
A Bicycle with Real Gears (Addendum)
The Addendum team was in Chicago in early March, for the National Manufacturing Week show, when it saw something unusual: a bicycle with gears. Real gears, Spiral bevel gears, in fact.