Brose Fahrzeugteile (Germany)

Volllastschaltbare Getriebe mit hoher Ganganzahl werden in Standardtraktoren aus Kosten- und Bauraumgrunden als Gruppen- und Mehrfachgruppengetriebe ausgefuhrt. Diese Bauweise erfordert bei einigen Gangwechseln getriebeinterne Ubersetzungswechsel in mehreren Getriebegruppen. Solche Mehrfachgruppenschaltungen unter Last stellen eine Herausforderung fur die Schaltparameterabstimmung dar und konnen vom Fahrer als ruckbehaftet wahrgenommen werden. Die Analyse existierender Forschungsarbeiten und Veroffentlichungen zeigt als wesentliches Problem die Synchronisations- und Drehmomentubergaben der vielfach hoheren Drehzahl- und Drehmomentsprunge innerhalb der einzelnen Gruppen im Vergleich zum Stufensprung des direkten Getriebegangwechsels. Fur einfache Gruppengetriebe mit zwei Gruppen ist weiterhin bekannt, dass sich die Schaltablaufe eines Getriebes nennenswert unterscheiden, wenn sich der grosere interne Stufensprung (Hauptstufe) in der ersten anstatt in der zweiten Gruppe befindet. Fur Mehrfachgruppenlastschaltungen sind dahingehend keine Aussagen bekannt, obwohl durch die hohere Gruppenanzahl eine Vielzahl moglicher Getriebestrukturen existiert. In der vorliegenden Arbeit werden systematische Untersuchungen der charakteristischen Besonderheiten und Vorgange bei Mehrfachgruppenlastschaltungen auf Basis des bekannten Wissens zum Ablauf einfacher Lastschaltungen und einfacher Gruppenlastschaltungen durchgefuhrt. Daraus resultieren allgemeingultige Beschreibungen des theoretischen Ablaufs von Mehrfachgruppenlastschaltungen fur verschiedene Getriebestrukturen und Empfehlungen fur die Getriebesteuerung. Beispielsweise sollten die Kupplungen der Hauptstufe und der ausgangsseitigen Getriebegruppe im Drehmoment modulierbar sein, um schwingungsarme Lastschaltvorgange zu erzielen. Auserdem bieten Getriebe mit Hauptstufe in der hinteren Getriebegruppe Vorteile fur Zug-Hochschaltungen und Getriebe mit der Hauptstufe in der ersten Gruppe Vorteile fur Zug-Ruckschaltungen. Dabei stellen erstgenannte Getriebe geringere Anforderungen an die Getriebesteuerung. Anhand eines Viergruppengetriebes mit Hauptstufe in der hinteren Gruppe werden die zugehorigen Empfehlungen zum Schaltablauf auf einem Getriebeprufstand und in der Simulation uberpruft. Die Ergebnisse bestatigen die aufgestellten Theorien und die aus der Literatur bekannte Aussage, dass bei jeder Schaltung das Getriebeeingangsdrehmoment kurzzeitig in der kleinsten der beteiligten Ubersetzungen ubertragen wird. Weiterhin ist die Hauptstufenkupplung mit der groseren nachgelagerten Ubersetzung beim Schaltvorgang geringfugig belastet und unterliegt spurbarem Fliehkraftdruckeinfluss im Kupplungskolben, sodass bei der Getriebekonstruktion genaues Augenmerk auf die Steuerbarkeit dieser Kupplung zu legen ist. Abschliesend zeigt die Simulation, dass die direkten Schaltverluste die Effizienz eines Lastschaltgetriebes marginal reduzieren.

<p>A method for BH curve identification of the magnetic core of synchronous reluctance machines is presented. It starts from the knowledge of machine torque or phase voltages measured at normal operation with ac balanced currents or obtained from dedicated experiments proposed for the BH curve identification. The identification is formulated as an inverse optimization problem where the experimental data based on appropriate experiments serve as the inputs and the BH curve parameters represented with a closed-form expression as the optimization variables. The influence of the different types of measurements on the identified parameters and the optimization process is discussed and compared. Moreover, the impact of geometrical uncertainties due to manufacturing tolerances is investigated and addressed. Virtual measurements obtained from finite-element simulations are used for the study. It is shown that the proposed method can identify the BH curve of the machine core with good accuracy.</p>

Abstract For a company it is necessary to know, which products can be configured using carry-over-parts or the same technology. This can become quite relevant in the context of automobile electrification, where complex mechatronic systems are used. Consisting of various mechanical components, these systems perform the required function while being actuated by electronically controlled motors. To solve this, a novel mechanism for data driven portfolio analysis based on product platforms using knowledge-based systems is proposed in this paper. Further, the mechanism is tested by applying it to an electrical motors' case study. Using this method, all possible combinations of a product platform are calculated and finally displayed in different product portfolios. Additionally, all the non-feasible motor designs are removed from the solutions portfolio using the acquired knowledge base and performing design checks. The latter are employed for penalising and eliminating from the pareto-front of the designs, which violate the thermal, mechanical and acoustic constraints. The generated product portfolio can be used further to expand the systems engineering collaboration and support decision-making.

Regulations concerning the noise emission of home appliances have become stricter in recent years and this is pushing manufacturers to improve their vibroacoustic characteristics. In this regard, the reciprocating compressor, which is one of the main sources of noise and vibration in these appliances, is drawing particular attention and thus it has been investigated by many research groups aiming to reduce its vibratory energy and the noise emitted. While the compressor is operating, different mechanisms generate vibratory energy. Some of these have been extensively studied and their contribution to the overall noise is well understood. However, one of the noise and vibration sources in this type of equipment that has not been studied in depth is the electric motor. Until now, the majority of researchers dealing with the vibroacoustic problem of reciprocating compressors have considered the electric motor only as a transmission path of vibratory energy. The objective of this study was to model not only the structural behavior of the electric motor but also include the electromagnetic phenomena in order to ascertain the magnetic forces that are acting on the stator. Once these forces are obtained and validated, their influence on the overall noise of the compressor can be assessed. The finite element method was used to model both the electromagnetic and structural system. The results indicated that the magnetic forces contribute at some specific frequencies when the compression loads are considered. In cases without the load, due to the gas compression, it was observed that the magnetic excitations have a notable influence, within a wide frequency range, on the overall noise.

The paper reviews new drivetrain concepts including plug-in full hybrid, mild hybrid designed for 48 V and zero emission vehicles like battery electric vehicle. The presented drivetrain concepts should lead to reduction of CO2 emission what is one of the most important goals of future transportation. Comparison between parallel and series hybrid drivetrain is specially delivered. The series hybrid drivetrain could be efficient alternative to parallel one. Such drivetrain concept, where electric drivetrain can be separated from power unit, can be adapted for fuel cell vehicle or battery electric vehicle. Mild hybrid solutions for 48V due to optimised costs should have more importance in the near future.

The paper presents the analysis of losses of a three-phase, high speed 12/8 switched reluctance motor (SRM), intended to be used in automotive applications. The objective is to investigate by comparison the iron losses considering different types of short pitch winding arrangements, as well as different core laminations, and how much these affect the performance of a SRM having the same structure and working under the same conditions. The flux paths and static characteristics of several configurations are analyzed by means of 2D finite-element method (FEM). The effect of different lamination materials on the iron core losses are also studied. Dynamic simulation results were used to evaluate the performance of different SRM variants.

This paper deals with the losses of Switched Reluctance Machine Drives (SRDs) for electric vehicle propulsion, consisting of the losses in the Switched Reluctance Machine (SRM) and the converter, across some operating regions based on different control strategies, namely Firing Angle (FA) control and Torque Sharing Function (TSF) control. The SRM model which takes into account copper losses and converter losses is obtained through MATLAB/Simulink. The losses and efficiencies in the machine, the converter and the SRD as function of speed and average torque are compared for a 30 kW peak 8/6 SRD.

Purpose – The purpose of this paper is to reduce the torque ripple but not to decrease the average torque of synchronous reluctance machines by using one step or more than two axially laminated rotors with asymmetric flux-barrier. Design/methodology/approach – A 24-slot four-pole synchronous reluctance machine with overlapping windings and asymmetric flux-barrier in the rotor is, first, described and designed by finite element (FE) method for maximizing average torque. The dimensions of asymmetric flux-barrier including the pole span angle and flux-barrier angle will be optimized to minimize the torque ripple and its influence on the average torque is also investigated by FE analysis. The impact of current angle on the average torque and torque ripple are also analysed. The step laminations together with the asymmetric flux-barrier are employed for further torque ripple reduction which can consider the both rotation directions. Findings – The torque ripple of synchronous reluctance machine can be significantly reduced by employing asymmetric flux-barrier but the average torque is not reduced. Research limitations/implications – The purely sinusoidal currents are applied in this analysis and the effects of harmonics in the current on torque ripple are not considered in this application. The 24-slot/four-pole synchronous reluctance machine with single-layer flux-barrier has been employed in this analysis, but this work can be continued to investigate the synchronous reluctance machine with multilayer flux-barrier. This asymmetric flux-barrier can be easily applied to permanent magnet (PM)-assisted synchronous reluctance machine and the interior PM machine with flux-barrier in the rotor, since the space which is used for PM insertion is the same as the SynRM machines. Originality/value – This paper has analysed the torque ripple and average torque of synchronous reluctance machines with asymmetric flux-barrier and step laminations with asymmetric flux-barrier. The torque ripple can be reduced by this flux-barrier arrangement. The difference of this technique with the other techniques such as stator/rotor skew is that the average torque can be improved.