“ It is very hard to find out any paper regarding ‘tiger stripes’ failure, created by electrical discharge current over the gear teeth.” I wish to have some more information on this issue + how it affects the vibration / noise signatures; why does it creates the tiger stripes profile; how deep are the pittings; why does it create the noise and the possibility of running a gear with this failure?”

The purpose of this article is to provide an overview of proven books or standards dealing with failure analysis. Following you will find a short description of ten books or standards. At the end of the document you will find an overview and a detailed reference list.

The wear behavior of polymer gears made of five different materials has been investigated using an existing polymer gear test rig. Step loading tests at a constant speed of 1,000 rpm were performed. Significant differences in failure modes and performance have been observed for the five polymer gear materials for gear engagements of gears, with the same material as each other.

This paper demonstrates an application of the tooth interior fatigue fracture (TIFF) analysis method, as implemented in SMT's MASTA software, in which loaded tooth contact analysis (LTCA) results from a specialized 3-D contact model have been utilized to determine the load boundary conditions for analysis of tooth flank fracture (TFF).

Cracks initiated at the surface of case-hardened gears may lead to typical life-limiting fatigue failure modes such as pitting and tooth root breakage. Furthermore, the contact load on the flank surface induces stresses in greater material depth that may lead to crack initiation below the surface if the local material strength is exceeded. Over time the sub-surface crack propagation may lead to gear failure referred to as “tooth flank fracture” (also referred to as “tooth flank breakage”). This paper explains the mechanism of this subsurface fatigue failure mode and its decisive influence factors, and presents an overview of a newly developed calculation model.

This paper proposes a new method — using neural oscillators — for filtering out background vibration noise in meshing plastic gear pairs in the detection of signs of gear failure. In this paper these unnecessary frequency components are eliminated with a feed-forward control system in which the neural oscillator’s synchronization property works. Each neural oscillator is designed to tune the natural frequency to a particular one of the components.

Tiger stripes on a high-speed pinion made of a carburized SAE 9310 steel were investigated. The morphology of the damage was typical of electric discharge damage. The cause of the stripes and potential damage to the gear tooth were analyzed and are presented in this report.

Understanding the morphology of micropitting is critical in determining the root cause of failure. Examples of micropitting in gears and rolling-element bearings are presented to illustrate morphological variations that can occur in practice.

Gear flank breakage can be observed on edge zone-hardened gears. It occurs, for example, on bevel gears for water turbines, on spur gears for wind energy converters and on single- and double-helical gears for other industrial applications.

A series of bench-top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the “chip” through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.