Search results for " gearbox"

Split-Way CVTs: Parametric Analysis and Design

The thesis provides a parametric analytical method for the analysis and design of power-split continuously variable transmissions, which represent the state of the art for heavy-duty vehicles and hybrid electric cars. The functioning of any driveline is described by mean of a simple set of kinematic parameters, regardless of the constructive scheme. The calculation of the control torques remains straightforward even when both inertial effects and mechanical losses are taken into account. A simple design procedure is described and generalized in order to address any order of driveline, including multimode transmissions. The final layout is generated additively, without the need to analyze hu…

Bearing fault detection based on time-frequency representations of vibration signals

2015

To prevent failures of a rolling bearing in the gearbox drive system, acceleration sensors are used to detect fault-related signals of the bearing. It is a big challenge to observe and identify signals caused by bearing defects in the time domain or the frequency spectrum by a conventional Fourier analysis. The time-frequency representation of the fault-related signals implemented by the windowed Fourier transform is studied in this work. It is shown that the fault characteristic frequencies can be clearly identified in the time-frequency spectrum if a fault occurs in the bearing of the gearbox at different speeds. Otherwise, the shaft frequency and its multiples are the main harmonics in t…

A review of diagnostics and prognostics of low-speed machinery towards wind turbine farm-level health management

2016

Abstract Large wind farms are gaining prominence due to increasing dependence on renewable energy. In order to operate these wind farms reliably and efficiently, advanced maintenance strategies such as condition based maintenance are necessary. However, wind turbines pose unique challenges in terms of irregular load patterns, intermittent operation and harsh weather conditions, which have deterring effects on life of rotating machinery. This paper reviews the state-of-the-art in the area of diagnostics and prognostics pertaining to two critical failure prone components of wind turbines, namely, low-speed bearings and planetary gearboxes. The survey evaluates those methods that are applicabl…