Three-Dimensional Finite Element Analysis of Contact Problem in Dry Friction Clutches

We present an investigation through numerical analysis (FEM) of the solution of the contact problem in friction clutch systems during engagement manoeuver. The case of high contact pressure between the sliding elements of a clutch system (flywheel, friction clutch and pressure plate) has been also considered. A finite element model of a dry friction clutch system (single disc) to estimate the distributions of the contact pressure between the contact elements of the clutch system under different working conditions has been developed and the main findings are discussed. Furthermore, the effect of modules of elasticity (contact stiffness) on the distribution of contact pressure of the mating surfaces was investigated. Also, the results encompass the deformations of the contacting surfaces for different cases. This work could provide a fundamental intermediate step to obtain a partial solution to the thermos-elastic problem in order to compute the thermal-driven deformations and stresses in the automotive clutches and brakes under different working conditions.

Analytical and Numerical Solutions for the Thermal Problem in a Friction Clutch System

The dry friction clutch is an important part in vehicles, which has more than one function, but the most important function is to connect and disconnect the engine (driving part) with driven parts. This work presents a developed numerical solution applying a finite element technique in order to obtain results with high precision. A new three-dimensional model of a single-disc clutch operating in dry conditions was built from scratch. As the new model represents the real friction clutch including all details, the complexity in the geometry of the clutch is considered one of the difficulties that the researchers faced using the numerical solution. The thermal behaviour of the friction clutch during the slip phase was studied. Meanwhile, in the second part of this work, the transient thermal equations were derived from scratch to find the analytical solution for the thermal problem of a clutch disc in order to verify the numerical results. It was found, after comparison of the numerical results with analytical results, that the results of the numerical model are very accurate and the difference between them does not exceed 1%.

Development of e-automated control system friction clutch of the vehicle

Problem. One of the most pressing problems of modern automotive industry is to simplify and facilitate driving. As for such a branch of the automotive industry as military equipment. One of the keys to successful completion of the task by the crew of any combat vehicle is the least possible distraction from the process of driving a vehicle and focus on the task. This is possible if the vehicle is provided with relatively comfortable driving conditions, good dynamic properties and the required minimum of controls. The solution to the issue of facilitating car driving cannot be solved without automation of transmission control. Goal. The aim of the project is to create a prototype of an electronic system of automated control of the friction clutch of a vehicle to increase the reliability and efficiency of special and military vehicles. Methodology. Analytical methods of research, program and full-scale modeling, experimental researches on real object of management are used. Originality. New interrelations between the structural elements of the actuator of the friction clutch are proposed, which allow to ensure the required speed of the actuator of the electropneumatic clutch control drive without losing control accuracy when using two electropneumatic valves. The proposed control algorithm of the actuator allows the use of both normally closed valves without residual pressure in the power cylinder. Practical value. The stages of synthesis of the electronic control system are carried out. The algorithm of operation of the tracking system with the use of PID-regulator and taking into account the features of the actuator is proposed and debugged. A new clutch pedal design with an induction sensor is proposed, which provides high accuracy and speed, and also requires only two wires to connect.

HIGH-PERFORMANCE METHOD OF PRODUCTION OF POWDER FRICTIONAL PRODUCTS ON FE-BASIS WITH HIGH TECHNOLOGICAL AND OPERATIONAL PROPERTIES

Physical and technological bases of DHP-PFM method for production of dry friction powder friction articles on Fe-base with high technological and operational indices for a wide range of practical use have been developed. The DHP-PFM method is that the dynamic hot pressing (DHP) provides production of the new powder frictional materials (PFM) through an underlayer from carbonyl iron between frictional material and a basis (framework) with electroplated nickel coating. Friction lining compaction is made of charge of ФМК-79 type and has high hardness and low porosity. Processes of the choice of composition of furnace charge, formation of structure and properties of new powder frictional materials on Fe-to a basis are investigated. The method is characterized by high productivity, energy saving, simplified technology and provides the possibility to use existing technological equipment for making structural powder products. Method of DHP-PFM manufacturing of dry friction powder friction linings can be used for manufacturing of friction units of transmissions of light track machines with high specific power. The friction material received by this method from furnace charge of FMK-79 type can be used as unified for such frictional units as the main friction clutch, an onboard friction clutch, tape and disk brakes.