This paper presents a new approach to repair industrial gears by showing a case study where pressure angle modification is also considered, differently from the past repairing procedures that dealt only with the modification of the profile shift
coefficient. A computer program has been developed to automatically determine the repair alternatives under two goals: minimize the stock removal or maximize gear tooth strength.
The common calculation methods according to DIN 3990 and
ISO 6336 are based on a comparison of occurring stress and
allowable stress. The influence of gear size on the load-carrying
capacity is considered with the size factors YX (tooth root bending)
and ZX (pitting), but there are further influences, which
should be considered.
In the following, major influences of gear size on the load factors
as well as on the permissible tooth root bending and contact
stress will be discussed.
This paper addresses the lubrication of helical gears - especially
those factors influencing lubricant film thickness and pressure.
Contact between gear teeth is protected by the elastohydrodynamic
lubrication (EHL) mechanism that occurs between nonconforming
contact when pressure is high enough to cause large
increases in lubricant viscosity due to the pressure-viscosity
effect, and changes of component shape due to elastic deflection.
Acting together, these effects lead to oil films that are stiff
enough to separate the contacting surfaces and thus prevent
significant metal-to-metal contact occurring in a well-designed
gear pair.
Broaching is a machining technique commonly used to cut gear teeth or cam profiles for the high volume manufacture of power transmission parts used in vehicles (Refs. 1–2). This article shows how the right gear blank material can make all the difference if you want to get more parts out of each tool.