Measurement of pressure distribution and hydrodynamic axial forces of wet clutch discs

Neupert, Thomas; Bartel, Dirk

doi:10.1016/j.triboint.2021.107172

Cited by 15 publications

(4 citation statements)

References 17 publications

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“…With test rigs of this design, one can consider the influence of the interaction and axial movement of the plates of the clutch pack on the drag loss behavior. Single-disk test rigs are usually used for the verification and validation of analytical and numerical calculation models [44,[54][55][56]. As a result of the different test rig concepts, different test procedures are sometimes selected for the experimental studies [6,12].…”

Section: Step 1: Data Generationmentioning

confidence: 99%

A methodology for data-driven modeling and prediction of the drag losses of wet clutches

Pointner-Gabriel

Voelkel

Pflaum

et al. 2023

Forsch Ingenieurwes

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In wet clutches, load-independent drag losses occur in the disengaged state and under differential speed due to fluid shearing. The drag torque of a wet clutch can be determined accurately and reliably by means of costly and time-consuming measurements. As an alternative, the drag losses can already be precisely calculated in the early development phase using computing-intensive CFD models. In contrast, simple analytical calculation models allow a rough but non-time-consuming estimation. Therefore, the aim of this study was to develop a methodology that can be used to build a data-driven model for the prediction of the drag losses of wet clutches with low computational effort and, at the same time, sufficient accuracy under consideration of a high number of influencing parameters. For building the model, we use supervised machine learning algorithms. The methodology covers all relevant steps, from data generation to the validated prediction model as well as its usage. The methodology comprises six main steps. In Step 1, the data is generated on a suitable test rig. In Step 2, characteristic values of each measurement are evaluated to quantify the drag loss behavior. The characteristic values serve as target values to train the model. In Step 3, the structure and quality of the dataset are analyzed and, subsequently, the model input parameters are defined. In Step 4, the relationships between the investigated influencing parameters (model input) and the characteristic values (model output) are determined. Symbolic regression and Gaussian process regression have both been proven to be suitable for this task. Lastly, the model is used in Step 5 to predict the characteristic values. Based on the predictions, the drag torque can be predicted as a function of differential speed in Step 6, using an approximation function. The model allows a user-oriented prediction of the drag torque even for a high number of parameters with low computational effort and sufficient accuracy at the same time.

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Section: Step 1: Data Generationmentioning

confidence: 99%

A methodology for data-driven modeling and prediction of the drag losses of wet clutches

Pointner-Gabriel

Voelkel

Pflaum

et al. 2023

Forsch Ingenieurwes

View full text Add to dashboard Cite

show abstract

“…The wet clutches are mainly used to transfer and cut off the torque from the engine to the axle, change gear, and locking-up components to prevent motion [1][2][3]. Typically, wet clutches used in heavy vehicles are under high energy density friction conditions which should possess stable and excellent friction-wear characteristics to ensure effective work performance and the long service life [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Effect of Silicon Carbide Nanoparticles on the Friction-Wear Properties of Copper-Based Friction Discs

Zheng

et al. 2022

Materials

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To study the influence of nano-additives on the friction-wear characteristics of friction materials, the nano-sized silicon carbide particles which have excellent chemical and physical properties are considered to add in composite to form the modified friction material. The influence of the silicon carbide nanoparticles (SCN) on the friction-wear characteristics of copper-based friction materials (CBFM) is investigated via the SAE#2 (made in Hangzhou, China) clutch bench test with the applied pressure, rotating speed, and automatic transmission fluid (ATF) temperature taken into account. Moreover, the variations of friction torque and temperature are considered to evaluate the friction performance, and the variable coefficient is employed to describe the friction stability. The wear characteristics of friction materials are investigated by the disc changes in thickness and micro-morphology. The results show that the CBFM with SCN can provide a higher friction torque, which increased by 30% to 50% compared with CBFM. The variable coefficient of CBFM with SCN changes from 674 to 52 with the rotating speed raised from 600 rpm to 3000 rpm, which shows that the friction stability is relatively worse. Furthermore, the micromorphology shows that the CBFM with SCN has lower porosity and surface roughness, which increases the microscopic contact area and the coefficient of friction (COF). Simultaneously, the reduction in porosity also leads to a decrease in the cooling quality, bringing about a rapid temperature rise. Thus, the wear amount of CBFM with SCN increases significantly, especially for the friction disc in the axial middle position.

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“…In the wet multi-plate clutch, the satisfactory performance of the friction material directly determines the application range and lifetime of the clutch [ 1 , 2 , 3 ]. With the development of the wet multi-plate clutch towards high power density, low energy consumption, and no environmental pollution, the requirements of paper-based friction materials are continuously being improved [ 4 , 5 , 6 , 7 ], especially in terms of friction-wear performance, mechanical strength, heat resistance, load adaptability, and environment-friendly performance [ 8 , 9 ]. Paper-based friction materials consist of fillers, fibers, binders, and modifiers, which are generally selected and mixed by trial-and-error method [ 10 , 11 , 12 ].…”

Section: Introductionmentioning

confidence: 99%

Friction-Wear Characteristics of Carbon Fiber Reinforced Paper-Based Friction Materials under Different Working Conditions

Zheng

Xiong

et al. 2022

Materials

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To study the friction and wear performance of carbon fiber reinforced friction materials under different working conditions, paper-based friction materials with different fibers were prepared. Experiments on the SAE#2 test bench were conducted to study the infectors including friction torques, surface temperature, coefficient of friction (COF), and surface morphologies. The results were analyzed, which indicated that the carbon fiber reinforced friction material could provide a higher friction torque and a lower temperature rising rate under the applied high pressure and high rotating speed conditions. As the pressure increased from 1 MPa to 2.5 MPa, the friction torque of plant fiber reinforced material increased by 150%, the friction torque of carbon fiber reinforced material increased by 400%, and the maximum temperature of plant fiber reinforced and carbon fiber reinforced material reached the highest value at 1.5 MPa. Thus, carbon fibers not only improved the COF and friction torque performance but also had advantages in avoiding thermal failure. Meanwhile, carbon fiber reinforced friction materials can provide a more stable COF as its variable coefficient (α) only rose from 38.18 to 264.62, from 1 MPa to 2.5 MPa, which was much lower than the natural fiber reinforced friction materials. Simultaneously, due to the good dispersion and excellent mechanical properties of PAN chopped carbon fibers, fewer pores formed on the initial surface, which improved the high wear resistance, especially in the intermedia disc.

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Measurement of pressure distribution and hydrodynamic axial forces of wet clutch discs

Cited by 15 publications

References 17 publications

A methodology for data-driven modeling and prediction of the drag losses of wet clutches

A methodology for data-driven modeling and prediction of the drag losses of wet clutches

Effect of Silicon Carbide Nanoparticles on the Friction-Wear Properties of Copper-Based Friction Discs

Friction-Wear Characteristics of Carbon Fiber Reinforced Paper-Based Friction Materials under Different Working Conditions

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