Gear Rattle during a start-up transient in a driveline equipped with a tuneable torsional Vibration Damper with Magneto-Rheological Elastomers

Proceedings of the Institution of Mechanical Engineers Part K Journal of Multi-body Dynamics ◽

10.1177/14644193211073016 ◽

2022 ◽

pp. 146441932110730

Author(s):

Ernesto Rocca ◽

Riccardo Russo

Keyword(s):

Torsional Vibration ◽

Vibration Damper ◽

Start Up ◽

Clutch Engagement ◽

Dynamical Parameters ◽

Dry Clutch ◽

Magneto Rheological ◽

Angular Displacements ◽

Transient Phases ◽

Gear Rattle

The paper reports a numerical investigation on the dynamic behaviour of a vehicle driveline, equipped with a Torsional Vibration Damper (TVD) based on Magneto-Rheological Elastomeric (MRE) spring elements, during the start-up transient considering an abrupt manoeuvre of clutch engagement. The TVD device consists of a flywheel and a damper disk, with interposed some elastomeric samples which react for relative angular displacements of the two disks. The dynamical parameters of the TVD can be properly tuned by varying the magnetic field surrounding the MRE springs to mitigate the torsional oscillations of the flywheel, causes of many undesired inconveniences as critical speeds or vibro-acoustic issues. The present study promotes the use of the MRE torsional vibration damper to reduce the annoying vibroacoustic phenomenon of “gear rattle” arising in the unloaded gear pairs of the gear box, during and after the rapid clutch engagement transients in the vehicle start-up phase and is conducted on a simplified automotive driveline equipped with a dry clutch. The possibility of quickly tuning the mechanical properties of the MRE-TVD, makes this device particularly eligible for suppressing the above disturbance, adapting to the various operative conditions of the automotive driveline. Results of the analysis, by the help of a Gear Rattle Index (GRI), demonstrate the effectiveness of the proposed device in reducing the vibroacoustic phenomenon during the transient phases of the vehicle start-up, until the vehicles speed conditions are reached.

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Gear rattle reduction in an automotive driveline by the adoption of a flywheel with an innovative torsional vibration damper

Proceedings of the Institution of Mechanical Engineers Part K Journal of Multi-body Dynamics ◽

10.1177/1464419319850664 ◽

2019 ◽

Vol 233 (4) ◽

pp. 777-791

Author(s):

Renato Brancati ◽

Ernesto Rocca ◽

Riccardo Russo

Keyword(s):

Torsional Vibration ◽

Gear Tooth ◽

Vibration Damper ◽

Dynamical Characteristics ◽

Speed Regime ◽

Magnetorheological Effect ◽

Magneto Rheological ◽

Gear Rattle ◽

Acoustic Phenomenon ◽

The Magnetic Field

An innovative device consisting of a flywheel equipped with a torsional vibration damper, based on the magnetorheological effect in elastomeric spring elements, is proposed in this paper. The feasibility study reports the dynamic behaviour of an automotive driveline equipped with the device aiming to explore the effectiveness of the damper in reducing the torsional oscillations of the flywheel, at low-speed regime, responsible for the vibro-acoustic phenomenon known as “gear rattle”. The spring elements of the device are constituted by magneto-rheological elastomeric samples, interposed between the flywheel and the damper disk, working for shear strains. Their dynamical characteristics can be properly tuned by varying the magnetic field surrounding the springs in order to mitigate the forced vibration causes of gear tooth impacts. The good attitude of the device in mitigating the rattle phenomenon is demonstrated by comparing the results provided by a numerical drive line model, equipped with a “monolithic” flywheel, with those obtained by adopting the present innovative vibration damper. The angular accelerations, resulting from the collisions between the teeth during the operation under “idle” conditions at different angular speeds, are thus compared.

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Tribodynamics of hydraulic actuated clutch system for engine-downsizing in heavy duty off-highway vehicles

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407018756789 ◽

2018 ◽

Vol 233 (4) ◽

pp. 976-993 ◽

Cited By ~ 5

Author(s):

Nader Dolatabadi ◽

Ramin Rahmani ◽

Stephanos Theodossiades ◽

Homer Rahnejat ◽

Guy Blundell ◽

...

Keyword(s):

Heavy Duty ◽

Multi Scale ◽

Clutch System ◽

Start Up ◽

Clutch Engagement ◽

Torque Capacity ◽

Reduce Emissions ◽

Dry Clutch ◽

Physics Model ◽

Multi Body

Engine downsizing is desired for modern heavy-duty vehicles to enhance fuel economy and reduce emissions. However, the smaller engines usually cannot overcome the parasitic loads during engine start-up. A new clutch system is designed to disconnect the downsized engine from the parasitic losses prior to the idling speed. A multi-scale, multi-physics model is developed to study the clutch system. Multi-body dynamics is used to study the combined translational–rotational motions of the clutch components. A micro-scale contact model is incorporated to represent the frictional characteristics of the sliding surfaces. Although the clutch is designed for dry contact operation, leakage of actuating hydraulic fluid can affect the interfacial frictional characteristics. These are integrated into the multi-body dynamic analysis through tribometric studies of partially wetted surfaces using fresh and shear-degraded lubricants. Multi-scale simulations include sensitivity analysis of key operating parameters, such as contact pressure. This multi-physics approach is not hitherto reported in the literature. The study shows the importance of adhesion in dry clutch engagement, enabling full torque capacity. The same is also noted for any leakage of significantly shear-degraded lubricant into the clutch interfaces. However, the ingression of fresh lubricant into the contact is found to reduce the clutch torque capacity.

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Simulations of Engagement Control in Actuated Dry-Clutch: Influence of Frictional Response of Facing Materials

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.868.15 ◽

2017 ◽

Vol 868 ◽

pp. 15-20

Author(s):

Adolfo Senatore ◽

Carmine D'Auria ◽

Mario Pisaturo

Keyword(s):

Frictional Coefficient ◽

Control Unit ◽

Interface Temperature ◽

Temperature Estimation ◽

Start Up ◽

Clutch Engagement ◽

Dry Clutch ◽

Effective Models ◽

And Control

This paper focuses on the simulation of clutch engagement behavior in automated manual transmissions (AMTs) to virtualize the vehicle start-up maneuver through implementation of the driveline model and the role of transmission control unit featuring different levels of knowledge regarding to clutch material frictional response. Simulation results underline the crucial requirement of accurate prediction of the frictional coefficient evolution in each clutch maneuver, particularly regarding to the interface temperature estimation to develop effective models and control algorithms.

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Dynamic analysis of vehicle start-up judder based on elasto-plastic friction model and dry clutch maneuvering characteristic

Proceedings of the Institution of Mechanical Engineers Part K Journal of Multi-body Dynamics ◽

10.1177/1464419318768157 ◽

2018 ◽

Vol 233 (2) ◽

pp. 455-469 ◽

Cited By ~ 2

Author(s):

Renfei Yuan ◽

Guangqiang Wu

Keyword(s):

Friction Model ◽

Step Response ◽

Negative Slope ◽

Stick Slip ◽

Clamp Force ◽

Powertrain System ◽

Start Up ◽

Clutch Engagement ◽

Engagement Process ◽

Dry Clutch

This paper presents a detailed investigation of the dry clutch engagement process, and vehicle start-up judder phenomenon that could result in the deterioration of vehicle ride comfort. Elasto-plastic friction model is elaborated through the slider-pulley system, which shows some friction characteristics such as presliding, stick-slip motion, Stribeck effects, etc., and applied to dry clutch. The axial compression characteristics of three elastic parts, which include diaphragm spring, cushion spring, and link strip have been taken into consideration, and nonlinear relationship between the release bearing travel and the clutch clamp force is also established. The powertrain system model of front-engine and front-wheel-drive vehicle equipped with manual transmission is set up to recreate the start-up judder phenomenon in the numerical simulation and analyze its mechanism. The sudden transfer of the engine torque during the clutch engagement process results in the initial judder, which can be supposed as the step response of system and is initially weakened due to the damping of the powertrain system. Then the judder gradually strengthens and gets in the most severe vibrance when the clutch is about to get in to the fully engaged state, which is related to the frictional characteristics that forms a closed-loop positive feedback system, as well as the frequent state transitions between sliding state and engaged state. The positive slope of Stribeck effect as well as the reduction of absolute value of negative slope can both effectively suppress the start-up judder, and the apparent judder occurs only if the negative slope is outside of a certain range, instead of in all of the range. In addition, the fluctuation of clutch clamp force can aggravate the start-up judder, in which a more chaotic oscillation is emerged.

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Applied research of the multi-stage torsional vibration damper on controlling the gear rattle

Journal of Vibroengineering ◽

10.21595/jve.2016.17722 ◽

2016 ◽

Vol 18 (7) ◽

pp. 4550-4562 ◽

Cited By ~ 2

Author(s):

Wei-wei Zhang ◽

Lei Wang ◽

Xun-cheng Wu

Keyword(s):

Torsional Vibration ◽

Applied Research ◽

Vibration Damper ◽

Multi Stage ◽

Gear Rattle

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Development of an Innovative Torsional Vibration Damper with Magneto-Rheological Elastomers for Vehicle Driveline

Mechanisms and Machine Science - Advances in Italian Mechanism Science ◽

10.1007/978-3-030-55807-9_98 ◽

2020 ◽

pp. 887-896

Author(s):

Ernesto Rocca ◽

Riccardo Russo

Keyword(s):

Torsional Vibration ◽

Vibration Damper ◽

Magneto Rheological

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Noise, vibration and harshness during dry clutch engagement oscillations

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406220927065 ◽

2020 ◽

Vol 234 (23) ◽

pp. 4572-4588

Author(s):

I Minas ◽

N Morris ◽

S Theodossiades ◽

M O’Mahony

Keyword(s):

Coefficient Of Friction ◽

Numerical Models ◽

Dynamic Coefficient ◽

Driving Experience ◽

Clutch Engagement ◽

Pin On Disc ◽

Dry Clutch ◽

Interacting Surfaces ◽

Noise Vibration ◽

Dynamic Coefficient Of Friction

Determining the root causes of various noise, vibration and harshness phenomena in modern automotive drivetrains is a critical task for industry, since noise, vibration and harshness issues often result in worsened driving experience. The aim of the current research is to investigate the dynamics during dry clutch engagement and the associated – often problematic – oscillations. This paper reports the development and partial validation of numerical models to study dry clutch behaviour. The models are used to investigate the influence of clutch and throttle actuation on the occurrence of unwanted clutch oscillations. The dynamic coefficient of friction between the clutch interacting surfaces was measured using a pin-on-disc rig under different slip speeds and contact pressure conditions, which are representative of a typical clutch engagement manoeuvre. The paper highlights the occurrence of instability issues in clutch dynamics (disc radial mode) as potential generators of aggressive noise, vibration and harshness, particularly during two different clutch pedal actuations. Such analysis has not hitherto been reported in the open literature.

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