Sharif Digital Repository

One of the most important parts of vehicles and most of mechanical machines is power transmission system, especially the Gearbox used in them.In order to optimize the use of energy, especially fossil fuel, researchers are looking for new mechanisms to refine the operation of vehicles and other machines.One of the mechanisms which absorbed researcher’s attention during recent years is the Continuously Variable Transmission. By using these gearboxes which are replaced with older samples, we can have the continuous range of aspect ratio between two constant values. This important property causes the decrease of the use of fuel.In recent decades many manufacturers have used different kinds of... 

In recent decades, the air pollution issue and fuel resource constraints have compelled researchers to find ways to replace fossil fuels or reduce their consumption. Since the Vehicles are one of the most important sources of pollution and energy consumer, efforts to reduce vehicles fuel consumption can be an effective action to reduce air pollution. A proper powertrain system has an important task to reduce fuel consumption and air pollution.
Uses of continuously variable transmission system (CVT) and infinitely variable transmission (IVT), which makes the internal combustion engine to operate in optimal condition, can help to achieve this goal. In this thesis, the target is find... 

Nowadays, industrial companies deal with a wide range of serious problems in the field of power transmission maintenance and also fault detection. A large amount of money and time is spent on these issues in order to solve them; consequently, there is an essential need for this subject. In this thesis, in order to tackle those major issues which were referred above, an artificial neural network is trained with only one hidden layer. Also, a suitable database for training an efficient neural network is needed. Thus, a one-stage gearbox system with appropriate degrees of freedom is used to set up referred database. In this system, a crack is imposed to a tooth of spur gear with different sizes... 

This research is focused on determination of optimum working conditions of a vessel power consisting of diesel engines, a twin input gearbox and a controllable pitch propeller. Combined dual input gearbox as an intermediate member of the power train is run by two diesel engines. This gearbox consists of gears, multi disk input clutches, and output. One diesel engine acts as master and works as primary driver, and the second diesel is used as auxiliary during excess power needs. Gearbox model includes nonlinear elements like multi disk clutch and gear backlash. Diesel engines are modeled as power sources controlled by PID control of power lever for maintaining the desired speed. Tejson-... 

Gearbox is one of the important components of power transmission chain in the car which the engagement of the gears inside it causes noise. The following thesis, is in line with the project that was defined as "NVH reduction of the Tiba X200 gearbox" and to increase the correlation between university and industry, the aim of which was to improve all the noise sources in the mentioned vehicle. The purpose of this project is to reduce the noise of the gearbox shell by using reinforcing blades called ribs. For this purpose, first the desired changes were made in Solidworks software on the 3D model of the gearbox shell, and then the finite element model of the gearbox shell was prepared in...