The study of the dynamic properties of some structural components of harmonic drive

The paper presents the geometric models of flexsplines and wave generators developed based on the actual construction and geometric dimensions of manufactured harmonic drives (type CSD, CSG, HFUS and HFUC). In order to enhance the data preparation process, the model geometry was recorded in a parametrical form. By altering the individual properties of the models, it is possible to automatically generate finite element grids for flexsplines and wave generators of various geometrical and structural properties. The calculations prepared for the sake of the study by application of the finite element method (FEM) were conducted using the Femap/NX Nastran software. A preliminary numerical modal analysis of the structural solutions for the harmonic driver flexsplines and wave generators assumed to be applied was conducted

Study of dynamic properties of composite flexsplines of harmonic drives

In the present study, as the structural material for toothed flexsplines of harmonic drivers, a composite material based on an epoxy resin matrix reinforced with glass or carbon fibres was used. A preliminary numerical modal analysis of the material and structural solutions for the harmonic driver flexsplines assumed to be applied was conducted. Under the studies performed, geometrical models of flexsplines being manufactured for the HFUC and HFUS type harmonic drivers were developed based on their actual structures and geometrical dimensions. The calculations prepared for the sake of the study by application of the finite element method (FEM) were conducted using the MSC Patran/Nastran and Femap/NX Nastran software

Study of dynamic properties of composite and steel-composite flexsplines of harmonic drives

In the present study, as the structural material for toothed flexsplines of harmonic drives, a composite material based on an epoxy resin matrix reinforced with glass or carbon fibres was used. A preliminary numerical modal analysis of the material and structural solutions for the harmonic drive flexsplines assumed to be applied was conducted. This paper includes presentation of a simplified method used to determine torsional stiffness of a flexspline. With reference to the material and design solutions of flexsplines assumed to be analysed, values of their torsional angle were determined. Under the studies performed, geometrical models of flexsplines being manufactured for the HFUC and HFUS type harmonic drives were developed based on their actual structures and geometrical dimensions. The calculations prepared for the sake of the study by application of the finite element method (FEM) were conducted using the MSC Patran/Nastran and Femap/NX Nastran software

Modern trends in diagnostics of technical condition of material handling equipment drives

This study presents problems of material handling equipment drives as objects of vibration diagnostics, as well as the concept of sensors integrated with a surface exposed to damage on an example of a DiaForce sensor integrated with the surface of the inner race of a rolling bearing according to the solution proposed by Fraunhofer Institute in Braunschweig

Dynamic model of a harmonic drive in a toothed gear transmission system

The present paper discusses certain aspects of dynamic modeling of the harmonic drive. In particular, a new original dynamic model of a harmonic drive has been proposed for a power transmission system. The model takes account of nonlinear changes in stiffness, as well as damping. The proposed model of a harmonic drive in the power transmission system is investigated in the Matlab-Simulink environment. Utilization of the identified, developed dynamic model will allow to expand the knowledge about torsional vibration which are present in power transmission systems equipped with harmonic drive as well as it will contribute to a reduction of expenses connected with performing costly experimental tests

Determination of the damping characteristics of hydro pneumatic suspension strut

The paper presents the results of the hydropneumatic suspension strut researches on indicator test stand. The front hydropneumatic suspension strut for Citroen BX and C5 was researched. The aim of this investigation was to determine the damping characteristics (points of force for maximum linear velocity). The stroke and rotary velocities were selected on indicator test stand. For that extortion parameters force versus displacement and force versus velocity diagrams were determined. The damping characteristics were determined too

Impact of Road Transport Means on Climate Change and Human Health in Poland

Operation of means of transport is one of major sources of environmental impact. The goal of this article was to analyse the greenhouse gas emissions and to assess the impact of operation of means of road transport in Poland on human health using the life cycle assessment technique based on an analysis of emission of dust and gas pollutants. Road transport was assessed by taking the following means of transport into account: passenger cars, other cars with weight of up to 3,500 kg, lorries, buses, motorcycles, mopeds and tractors. The analysis covered various dust and gas pollutants, including the emission of CO2, CO, N2O, CH4, NOx, NMVOC, PM and SO2. Using the IMPACT 2002+ life cycle impact assessment method, transport was assessed in a breakdown into the following impact categories: greenhouse gas emission and damage to human health, including damage caused by organic and inorganic compounds. It has been evidenced that the highest emissions of dust and gas pollutants are caused by passenger cars, which is mainly due to the number of vehicles of this type traversing Polish roads. The main cause of climate changes due to road transport is CO2 emission, while NOx emission is the main factor determining individual categories of damage to human health. The negative environmental impact is primarily related to the operation of combustion engine vehicles. Diesel oil and petrol are currently the main fuels used in Polish transport. In order to reduce their impact on the environment one should intensify the efforts aimed at increasing the share of alternative fuels in transport

Railway Line Capacity Relative to Additional Block Division

The article discusses the results of studies of railway line capacity relative to the application of additional block division using virtual blocks in the process of positioning a train reporting its position and train set integrity. The studies were conducted using the authors’ original simulation software enabling extensive parameterisation of infrastructure, including configuration of the train control system and signalling principles, by taking the actual characteristics of train movements into account based on data obtained from real-life measurements