Algorithm for improving energy efficient wheel motor for electric vehicles

In accordance with the tendency to reduce the number of mechanical assemblies in electric driven machines and mechanisms, attempts are made to bring the electric motor and the actuator of the mechanism into a single whole. Thereby increasing the quality and productivity of the machines. A motor-wheel is a kind of a driving wheel, an actuator of a traction electric drive system of a pneumatic-wheeled transport vehicle. The work is devoted to the modernization of urban electric transport by equipping it with high-energy efficiency motor wheels, based on the frequency converter system - asynchronous motor. This paper describes the improvement algorithm and technological features.

A CAD model for the tolerancing of mechanical assemblies considering non-rigid joints between parts with defects

During the design stage, the ideal simulation and visualization of the mechanical assemblies behavior require the modeling of parts with dimensional and geometrical defects. However, the deviations caused by parts deformations can generate an important difference between the ideal assembly and the real product. In this regard, this paper proposes a tolerance analysis method of CAD assemblies considering non-rigid joints between parts with defects. The determination of realistic rigid components with dimensional and geometrical defects is based on the worst case tolerancing approach and the Small Displacement Torsor (SDT) parameters. The Finite Element (FE) computation is executed to determine deformations of realistic non-rigid part models under external loads. Sub-algorithms to define non-rigid joints between realistic parts are developed. The tolerance analysis is established using the realistic CAD assembly. A case study is presented to evaluate the proposed model.

A Design Approach Of Mechanical Assemblies Based On MBSE And CAD Models Interoperability

The technological development of the last decades have been able to push human to develop their needs, so a way to new demands were opened and this can lead to a complexity problem. Thereby, a good interoperability between the product design activities can lead to the possibility of ensuring a promising satisfaction to all requirements. However, the major problem is the enormous discontinuity between them. Indeed, each one treats the product from its point of view without recourse to the requirements defined by others. This paper is interested in the collaborative work that brings together the system engineer, who deals with the system from a global view, and the designer, who is a specialist in the detailed design, in order to validate requirements. A new methodology has been proposed to define the role of each one in the design process. This methodology focuses on the product development cycle from the analysis of needs to the validation phase. This obviously requires interoperability between the two domains of Model Based System Engineering (MBSE) and Computer Aided Design (CAD). Based on a pedal bicycle case study which is an industrial mechatronic product, the proposed methodology will be illustrated for validation and highlighting its advantages and limitations.

Reliability-based tolerance redesign of mechanical assemblies using Jacobian-Torsor model

The purpose of this paper is to present a new method to redesign dimensional and geometric tolerances of mechanical assemblies at a lower cost and with higher reliability. A parametric Jacobian-Torsor model is proposed to conduct tolerance analysis of mechanical assembly. A reliability-based tolerance optimization model is established. Differing from previous studies of fixed process parameters, this research determines the optimal process variances of tolerances, which provide basis for the subsequent assembly tolerance redesign. By using the Lambert W function and the Lagrange multiplier method, the analytical solution of the parametric tolerance optimization model is obtained. A numerical example is presented to demonstrate the effectiveness of the model, while the results indicate that the total cost is reduced by 10.93% and assembly reliability improves by 2.12%. This study presents an efficient reliability-based tolerance optimization model. The proposed model of tolerance redesign can be used for mechanical assembly with a better economic effect and higher reliability.

Constructionist Learning Tool for Acquiring Skills in Understanding Standardised Engineering Drawings of Mechanical Assemblies in Mobile Devices

The purpose of Graphic Design is to transfer information about design into reality and concerns the analysis, design and representation of mechanical components and assemblies. For the correct rendering of mechanical components, this discipline requires a command of, and the ability to, manage techniques and systems for graphical representation and standardisation; 3D models in a virtual environment enable engineering students to develop graphical skills and spatial awareness. The objective of the present study is the development of an application for smart devices (mobile phones and tablets), based on the constructionist theory of learning, which will enable first year engineering degree students to acquire the technical drawing knowledge and skills necessary to render mechanical assemblies. The mobile application tested and designed in this work is called ARPAID. It is a learning tool aimed at teaching students about the representation of mechanical assemblies as part of an engineering Graphic Design course. Teaching material and a process for evaluation have been designed. A detailed description is given of a classroom activity accompanied by a tabulation and analysis of the results obtained. This mobile application, when used in a Graphic Design course, promotes a more rapid understanding of spatial relationships and problems, fosters students’ learning and motivation, and develops higher order skills. Results from before and after the use of the application will be presented and do indeed show significant improvements in student performance.