PTB's two microgear measurement standards and their analyses using seven measurement methods which are then presented, evaluated and compared with each other.

Polymer gears find increasing applications in the automotive industry, office machines, food machinery, and home appliances. The main reason for this success is their low cost. Their low weight, quietness of operation, and meshing without lubricant are also interesting. However, they have poor heat resistance and are limited to rotational transmission. In order to improve the gears' behavior, glass fiber is added

New book from Gleason's Vice President Bevel Gear Technology will be exclusively excerpted in Gear Technology magazine.

With this first installment we begin a series of randomly excerpted chapters from Dr. Hermann J. Stadtfeld's new book — Practical Gear Engineering.

Klingelnberg presents the technical aspects of its roughness measurement system.

The oil-off (also known as loss-of-lubrication or oil-out) performance evaluation of gears is of significant interest to the Department of Defense and various rotorcraft manufacturers, so that the aircraft can safely land in an accidental loss-of-lubricant situation. However, unlike typical gear failure modes such as pitting or bending fatigue where early detection is possible, gear failure in an oil-off situation is very rapid and likely catastrophic. Failures rapidly result in the loss of torque transmission and the inability to control the aircraft.

Inspection of the cutting blades is an important step in the bevel gear manufacture. The proper blade geometry ensures that the desired gear tooth form can be achieved. The accuracy of the process can be compromised when the blade profile consists of several small sections such as protuberance, main profile, top relief and edge radius. Another common obstacle - are outliers which can be caused by dust particles, surface roughness and also floor vibrations during the data acquisition. This paper proposes the methods to improve the robustness of the inspection process in such cases.

This paper outlines the basic principles of involute gear generation by using a milling cutter; the machine and cutting tool requirements; similarities and differences with other gear generative methods; the cutting strategy; and setup adjustments options. It also discusses the applications that would benefit the most: for coarse-pitch gears the generative gear milling technologies offer improved efficiency, expanded machine pitch capacity, decreased cutter cost, and a possibility for reducing the number of machining operations.

The paper is not the proof of a discovery, but it is the description of a method: the optimization of the microgeometry for cylindrical gears. The method has been applied and described on some transmissions with helical gears and compound epicyclic, used on different hybrid vehicles. However, the method is also valid for industrial gearboxes.

Gear honing is a highly productive process for the production of small and medium sized gears and is used mainly in the serial production of the automotive industry. The low robustness of the process is a particular challenge in gear honing. The consequences range from an inadequate gear quality to an early breakage of the honing tool. In order to describe the processmachine interaction, the machining forces must be known.