محاكاة وتحليل لمنظومة نقل الحركة بلا حدود تعتمد على مبدأ الحدبة

Simulation and Multibody Dynamic Analysis of a Cam Based Infinitely Variable Transmission

Abstract

Continuously variable transmission (CVT) is a system that allows for smooth continuous change of transmission ratio between two driver and driven elements. A CVT is a subset of IVT; Infinitely Variable transmissions which can produce smooth transmission ratio including zero value. These are in contrast to traditional transmissions which typically have a discrete and limited number of transmission ratios or as commonly known as gear ratio. CVTs are started to be alternatives to the traditional gear trains in vehicles, as they can provide smoother acceleration and better fuel economy.
In this thesis, a cam based IVT is studied in details utilizing theoretical analysis and simulation model. In the current IVT contains two units, each unit consists of a cam, a follower, alterable slotted link, grooved wheel and a grooved wheel actuator. The selected cam profile consists of two parts which are constant velocity which represents forward stroke and polynomial for the return stroke, this will be investigated in this study.
The simulation of the system in the current study is carried out using Matlab Simscape software where the theoretical analysis is used to validate this simulation model. By using Matlab Simscape software, the geometry of each element should be constructed in details. Then, these elements are assembled using available specific joints depending on the actual joints in the systems. The locations of these elements or joints should also adjust using local frames and rigid transform in order to match them with the global system frames.
The results show that a smooth variation in output can be achieved for various positions of the transmission ratio alterable. However small jump in the output can be noticed during stroke change while the alterable is moving. This can be solved by
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adding a flywheel to the system. It can also be concluded that the vertical position and velocity of the alterable has a significant effect on the system output.