Gears are found rarely in animals and have never been reported to intermesh and rotate functionally like mechanical gears. We now demonstrate functional gears in the ballistic jumping movements of the flightless planthopper insect Issus. The nymphs, but not adults, have a row of cuticular gear (cog) teeth around the curved medial surfaces of their two hindleg trochantera. The gear teeth on one ...

Gearboxes are one of the most power dense systems used today, and in certain instances their limiting factor is the ability to evacuate heat from the gear contact. This work analyses the efficiency (i.e. heat generation) and tooth temperature in the three lubricating conditions dip, into mesh spray and out of mesh spray for superfinished gears which are then compared to ground gears. A back-to-...

Gears are important element in a variety of industrial applications such as machine tool and gearboxes. An unexpected failure of the gear may cause significant economic losses. For that reason, fault diagnosis in gears has been the subject of intensive research. Vibration signal analysis has been widely used in the fault detection of rotation machinery. The vibration signal of a gearbox carries...

Transmission error in gearing system is a critical index for product quality. Gears with appropriate tooth modification can always behave well in transmission error, i.e. the double crowned gears. Nevertheless, to manufacture a gear with double crowning by CNC gear shaving machine indeed costly. This paper investigated the manufacture of double crowned gears by traditional gear shaving machine....

This paper describes design and analysis of Spur gear. In the present work, it is proposed to substitute the metallic gear of sugarcane juice machine with plastic gears to reduce the weight and noise. For the purpose of two different types of plastic materials were considered namely Nylon and Polycarbonate and their viability are checked with their counterpart metallic gear (Cast iron). Based o...

Global competitive business market had brought increasing awareness to optimize the gear design. Gears have the advantage over friction and belt drives in that they are positive drive, a feature which most of the machine tools require, since exact speed ratios are essential. The design and manufacture of precision cut gears, made from materials of high strength, have made it possible to produce...

ion, perception-based knowledge would turn into explicit description. However, we have failed to find evidence of bootstrapping from first-hand knowledge to secondhand knowledge. For example, we asked people to reason about chains of gears (Schwartz & J. Black, 1996). We asked, “Imagine a horizontal chain of five gears. If the gear on the far right tries to turn clockwise, what will the gear on...

In this thesis we build the parametric mathematical model of machine tool and solid models of traction gears using in subway locomotive by analyzing the machining process of involute gears and meshing principle of involute gears. The optimization design is done through deduce the relations between basic parameters of gear and loading capacity of transmission. On the base of analyzing optimizati...

During the previous micronekton inter-calibration experiments, the following gears were tested: IKMT, FMT (= HUFT), Cobb trawl, MOCNESS-1 and MOCNESS-10, MOHT and a midwater otter trawl (OT) with Multi-sampler), and the superiority of MOHT over the other gears was shown. However, no direct comparison has been made between the MOHT and the IKMT. The latter gear has been used widely in previous (...

in this paper, a fault diagnosis system based on discrete wavelet transform (dwt) and artificial neural networks (anns) is designed to diagnose different types of fault in gears. dwt is an advanced signal-processing technique for fault detection and identification. five features of wavelet transform rms, crest factor, kurtosis, standard deviation and skewness of discrete wavelet coefficients of...