Your Selections

Parts and Components
Parts
Bearings
Cables
Compressors
Counterfeit parts
Fasteners
Bolts
Nuts
Screws
Washers
Fittings
Gears
Hardware
Mountings
Nozzles
Pumps
Seals and gaskets
Splines
Synchros
Valves
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

Series

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Heat Pumps for BEVs: Architectures and Performance Analysis

Centro Ricerche Fiat SCpA-Walter Ferraris, Federica Bettoja, Mauro Casella, Matteo Rostagno, Angela Tancredi
  • Technical Paper
  • 2020-37-0030
To be published on 2020-06-23 by SAE International in United States
Electric vehicles have never been more popular, yet fears around being left stranded by an exhausted battery remain a key reason why some car buyers resist making a purchase. Bigger batteries are not always the solution because of the direct link with higher costs and high impact on weight. A re-engineering of the most energy-consuming auxiliaries is mandatory and the thermal management function is on top of the redesign request list. Heat Pump solution is considered one of the best way to save energy and reduce the impact on vehicle range of heating and cooling function, but the automotive application requires a careful definition of the system features to avoid unjustified growing up of complexity as well as an unneeded system over-sizing. The paper aims to give an overview on the heat pump design best practices through a virtual performance comparison of different lay-out configurations, which have been selected starting from a benchmark analysis crossed with a detailed vehicle segment-oriented functions selection. Control strategies role, costs, and target requirements have been used as drivers for…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Study of Friction Reduction Potential in Light- Duty Diesel Engines by Lightweight Crankshaft Design Coupled with Low Viscosity Oil

General Motors-Salvatore Mafrici
  • Technical Paper
  • 2020-37-0006
To be published on 2020-06-23 by SAE International in United States
Over the last two decades, engine research has been mainly focused on reducing fuel consumption in view of compliance with more stringent homologation cycles and customer expectations. As it is well known, the objective of overall engine efficiency optimization can be achieved only through the improvement of each element of the efficiency chain, of which mechanical constitutes one of the two key pillars (together with thermodynamics). In this framework, the friction reduction for each mechanical subsystem has been one of the most important topics of modern Diesel engine development. The present paper analyzes the crankshaft potential as contributor to the mechanical efficiency improvement, by investigating the synergistic impact of crankshaft design itself and oil viscosity characteristics (including new ultra-low-viscosity formulations already discussed in SAE Paper 2019-24-0056). For this purpose, a combination of theoretical and experimental tools have been used to design an extremely lightweight crankshaft and to evaluate the effects of main and conrod bearings dimensioning, clearances and oil viscosity, considering not only the impact from a friction perspective but also from a structural and…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Experimental Evaluation of Steady State Performance of an Automotive Electric Supercharger

Università Degli Studi di Genova-Silvia Marelli, Vittorio Usai
  • Technical Paper
  • 2020-37-0008
To be published on 2020-06-23 by SAE International in United States
Nowadays, the electric supercharger for turbocharged downsized automotive engines is mainly used to improve torque at low engine speeds in order to obtain an improvement of the time to boost. These components are usually designed to fill the gap in terms of torque in transient operation caused by the main turbocharger with reference to the typical turbo lag issues. An advanced solution of the engine boosting system was taken into account, considering the adoption of an e-booster system coupled to a waste-gated turbocharger, typically adopted alone in order to provide a reduced turbo-lag, i.e. an optimized transient response of the system. In the experimental activity described in this work, the maximum speed of the e-booster used is about 70000 rpm, the maximum pressure ratio is 1.5 and the maximum power required on the shaft is less than 4 kW. The compressor unit have to be maintained in the idle condition in order to avoid excessive electric consumption and overheating problem when the boost given by this component is not required. In order to highlight the…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Diagnostic Technology of Powertrain Parts that Cause Abnormal Noises using Artificial Intelligence

Hanyang University-Kyoungjin Noh, Joon-Hyuk Chang
Hyundai Motor Company-Insoo Jung, Dongchul Lee, Dongkyu Yoo, Kibeen Lim
  • Technical Paper
  • 2020-01-1565
To be published on 2020-06-03 by SAE International in United States
In general, when a problem occurs in a component, various phenomena appear, and abnormal noise is one of them. The service technicians diagnose the noise through the analysis using hearing and equipment. Depending on their experiences, the analysis time and diagnosis accuracy vary widely. The newly developed AI-based diagnostic technology diagnoses parts that cause abnormal noises within seconds when a noise is input to the equipment. To create a learning model for diagnosis, we collected as many abnormal noises as possible from various parts, and selected good and bad data. This process is very important in the development of diagnostic techniques. Artificial intelligence was learned by deep learning with selected good data. This paper is about the technology that can diagnose the abnormal noises generated from the engine, transmission, drivetrain and PE (Power Electric) parts of the eco-friendly vehicle through the diagnosis model composed of various methods of deep learning.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Advance CAE Methods for NVH Development of High Speed Electric Axle

AVL LIST GmbH-Mehdi Mehrgou, Julian Pohn, Bernhard Graf, Christoph Priestner, Inigo Garcia de Madinabeitia
AVL Software and Functions Gmbh-Mathias Deiml
  • Technical Paper
  • 2020-01-1501
To be published on 2020-06-03 by SAE International in United States
By developing more electric vehicles more and more focus are to the noise and vibration from Electric Drive unit. Here a high-speed E-axle for premium class vehicle is being developed up to 30,000 rpm, with high power density and lightweight design which introduce new challenges. Benchmarking of different E-axle and vehicles lead to targets which can be used at the begin of development as subsystem targets. This paper shows first how these targets like tonal noise can be simulated. Then the CAE method is used to optimize the source and structure to improve the NVH. Different aspects like torque ripple, electric whine, gears whine and mounting are discussed.
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Root Cause Analysis and Structural Optimization of E-Drive Transmission

AVL LIST GmbH-Thomas Resch
AVL-AST d.o.o.-Borislav Klarin, Ivan Grozdanovic, Denis Pevec
  • Technical Paper
  • 2020-01-1578
To be published on 2020-06-03 by SAE International in United States
We face a growing demand for so-called eAxles (electric axle drive) in vehicle development. An eAxle is a compact electric drive solution for full electric vehicles (and P4 hybrids) with integrated electric machine and transmission. The transmission can be rather simple using fixed gear with cylindrical gear steps but increasing demands on power and speed range as well as efficiency increase its complexity with planetary stages or switchable gear steps. Such an electro-mechanic system has different behavior than the classical ICE-driven powertrains, for example regarding NVH, where high frequency and tonal noise from gear whining and electro-magnetic excitation is an important comfort issue that needs to be understood and controlled. As knowledge base for such drives is currently low, development needs to be supported by methodologies, which are not only on high predictive level for NVH responses, but also allow a detailed understanding and insight into the causes and reasons of a certain behavior to identify noise effects and to accelerate learning for such systems. In addition, such methods should lead to the possibility to…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Multi-domain NVH Model for the Complete Electro-mechanical Power Unit

Goethe-Universität-Lars Hedrich
Robert Bosch GmbH-Yashwant Kolluru, Rolando Doelling
  • Technical Paper
  • 2020-01-1584
To be published on 2020-06-03 by SAE International in United States
Multi-domain NVH Model for the Complete Electro-mechanical Power Unit Yashwant Kolluru, Rolando Doelling eBike Department Robert Bosch GmbH Kusterdingen, Germany yashwant.kolluru@de.bosch.com rolando.doelling@de.bosch.com Lars Hedrich Institute of Informatics Goethe University Frankfurt Frankfurt, Germany hedrich@em.informatik.uni-frankfurt.de Acoustics and vibrations are amongst the foremost indicators in perceiving the quality of power units. Analyzing these factors is vital to improve the performances of electro-mechanical systems. This paper deals with development of a generic simulation method enabling the multi-domain vibro-acoustic modelling for the drive trains. Excitation's for these systems majorly arise from the electric motor and mechanical gears. The paper initially depicts a flexible gear model for gear whining, which are generated for reasons like gear tooth bending. The forces generated from gear mesh (lumped parameter model) to gear components (multi-body model and nonlinear static model) and the excitations resulting from motor model are coupled for the frequency domain analysis of complete drive train. Additionally, paper discusses the influences of these forces on bearings (dynamic implicit model) and effect of bearing deformations on the harmonics of drive unit. Furthermore, velocities on…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A generic testbody for low-frequency aeroacoustic buffeting

BMW Group, Munich, Germany-Rafael Engelmann, Christoph Gabriel
Vienna University of Technology-Stefan Schoder, Manfred Kaltenbacher
  • Technical Paper
  • 2020-01-1515
To be published on 2020-06-03 by SAE International in United States
Raising demands towards lightweight design paired with a loss of originally predominant engine noise pose significant challenges for NVH engineers in the automotive industry. From an aeroacoustic point of view, low frequency buffeting ranks among the most frequently encountered issues. The phenomenon typically arises due to structural transmission of aerodynamic wall pressure fluctuations and/or, as indicated in this work, through rear vent excitation. A possible workflow to simulate structure-excited buffeting contains a strongly coupled vibro-acoustic model for structure and interior cavity excited by a spatial pressure distribution obtained from a CFD simulation. In the case of rear vent buffeting no validated workflow has been published yet. While approaches have been made to simulate the problem for a real-car geometry such attempts suffer from tremendous computation costs, meshing effort and lack of flexibility. Additionally, low frequency structural behavior strongly depends on appropriate boundary conditions being subject to manufacturing and mounting conditions. The goal of this work is to develop, simulate and experimentally validate a generic, easy-to-adjust experimental setup to test and assess low frequency vibro-aero-acoustic optimization…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Simulating and Optimizing the Dynamic Chassis Forces of the Audi e-tron

Audi AG-Stefan Uhlar
  • Technical Paper
  • 2020-01-1521
To be published on 2020-06-03 by SAE International in United States
With battery electric vehicles (BEV), due to the absence of the combustion process, the rolling noise comes even more into play. The BEV technology also leads to different concepts of how to mount the electric engine in the car. Commonly, also applied with the Audi e-tron, the rear engine is mounted on a subframe, which again is connected to the body structure. This concept leads to a better insulation in the high frequency range, yet it bears some problems in designing the mounts for ride comfort (up to 20Hz) or body boom (up to 70Hz). Commonly engine mounts are laid-out based on driving comfort (up to 20Hz). The current paper presents a new method to find an optimal mount design (concerning the stiffness) in order to reduce the dynamic chassis forces which are transferred to the body up to 100Hz. This directly comes along with a reduction of the sound pressure level for the ‘body boom’ phenomena. Here we use multibody simulation along with a sophisticated tire model in the time domain in order to…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Analytical Rotordynamic Study of a High-Speed Gear Transmission System for Race Applications

Loughborough Univ-Stephanos Theodossiades, Mahdi Mohammadpour
Loughborough Univ.-Brett Friskney
  • Technical Paper
  • 2020-01-1502
To be published on 2020-06-03 by SAE International in United States
In motorsport power transmission systems, high-speed operation can be associated with significant rotordynamic effects. Changes in the natural frequencies of lateral (bending) vibrational modes as a function of spin speed are brought about by gyroscopic action linked to flexible shafts and mounted gear components. In the investigation of high-speed systems, it is important that these effects are included in the analysis in order to accurately predict the critical speeds encountered due to the action of the gear mesh and other sources of excitation. The rotordynamic behaviour of the system can interact with crucial physical parameters of the transmission, such as the stiffnesses of the gear mesh and rolling element-to-raceway contact in the bearings. In addition, the presence of the gear mesh acts to couple the lateral and torsional vibration modes of a dual-shaft transmission through which a torque flows. The relative interactions and effects of bearing and gear components can be captured in the form of modal analysis with parametric studies of key stiffness elements, such as mean value as a linear representation of stiffness.…