Recently, bicycles are used as exercising machines and traffic vehicles. Planetary gear trains can be used as the transmission systems with multi-speed for bicycles. The purpose of this work is to propose a design methodology for the design of automatic three-speed gear hubs with planetary gear trains for bicycles. First, applying the check list method (combining and extending methods), the des...

With the continuous development of national economy, big gear was widely applied in metallurgy and mine domains. So, big gear plays an important role in above domains. In practical production, big gear abrasion and breach take place often. It affects normal production and causes unnecessary economic loss. A kind of intelligent test method was put forward on worn big gear mainly aimed at the big...

In-line skating injuries and protective gear use were explored in a sample of college students (n = 217). A minority of respondents wore protective gear. One third of skaters had experienced at least one minor injury, and a smaller percentage had experienced fractures or head injuries. Most minor injuries occurred during the first 1-2 times skating, while more serious injuries tended to occur a...

Landing gear is one of the critical subsystems of an aircraft. The need to design landing gear with minimum weight, minimum volume, high performance, improved life, and reduced life cycle cost have posed many challenges to landing gear designers and practitioners. Further, it is essential to reduce the landing gear design and development cycle time while meeting all the regulatory and safety re...

The aim of this study is to evaluate the effect of super finishing on gear acceleration and noise level. Many researchers [1-13] have studied the gear dynamic models to study the effect of various parameters on gear dynamics. A 6DOF model is developed and experimental studies were conducted. In this study, the effects of super finishing [14, 15] on gear acceleration and noise level were evaluat...

the new device made in this study could calculate the proper position of tillage tools relative to the land surface at each point, and hydraulic operator set its optimum position. the optimum position of tools is calculated by depth control software developed for this device, and its input data were depth for root development. the performance of device was tested on subsoiler for precision till...

Comparing with fixed shaft gearbox, vibration properties of planetary gearbox are much more complicated. In a planetary gearbox, there are multiple vibration sources as several pairs of sun-planet gears and several pairs of ringplanet gears mesh simultaneously. In addition, the signal transmission path changes due to the rotation of the carrier. To facilitate fault detection of a planetary gear...