Efficiency of disengaged wet brake packs

Leighton, Michael; Morris, Nicholas J.; Trimmer, G.; King, Paul D.; Rahnejat, Homer

doi:10.1177/0954407018758567

Cited by 9 publications

(8 citation statements)

References 13 publications

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“…Subsequently, these measured losses are subtracted from the measurements taken with the sump (4) filled to the shaft centre line (representative of wet brake operating conditions). The sump (4) temperature is altered by a heating element (6), which is used in conjunction with a control unit and thermocouple to regulate the sump temperature.…”

Section: Experimental Methodologymentioning

confidence: 99%

“…The primary purpose of the rig is to measure the frictional drag losses under different operating conditions: temperature and sliding speed. A detail description of the test rig is also provided in Leighton et al 11 The rig comprises an electric motor (1), connected to an inline torque limiting coupling (2), rotatory torque transducer (3) and an immersed brake disc (5), rotating between the two stator discs (6). The rotatory torque transducer has a sampling rate of 450 Hz, maximum operation speed of 15,000 r/min and a sensitivity and operational torque range of 50 ± 0 . 05 Nm .…”

Section: Experimental Methodologymentioning

confidence: 99%

“…In a similar manner to wet clutches, disengaged wet brake packs can experience significant losses due to viscous drag. [8][9][10][11] Leighton et al 11 presented a combined experimental-numerical study of partially submerged, centrifugally fed wet brake losses at different sump temperatures. It was shown that the combination of cold start-up and high-speed road driving conditions would lead to a 20 kW power loss.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Oil film separation and drag torque in disengaged wet brakes

Morris

Davies

Leighton

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part D:

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Multi-disc wet brake packs are commonly used for off-highway applications. Unfortunately, when disengaged, these components can generate significant levels of unwanted parasitic losses. This article presents a novel, validated model to predict the parasitic losses in disengaged multi-disc wet brake packs. The model employs pertinent boundary conditions to determine the position of the free boundary created by oil film separation. The experimental and analytical results demonstrate the significance of wet disengaged brake losses at a range of angular velocities, typically found in operation. The improved understanding accrued by the expounded time-efficient methodology presents significant opportunity to develop predictive tools for the whole driveline system efficiency calculations and component design optimisation for off-highway vehicles.

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Section: Experimental Methodologymentioning

confidence: 99%

Section: Experimental Methodologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Oil film separation and drag torque in disengaged wet brakes

Morris

Davies

Leighton

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part D:

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“…Leighton et al. 17 presented a Reynolds-based numerical model including the effect of fluid inertia and squeeze film transience for prediction of performance of wet brake systems. It was shown that cavitation becomes significant at low temperatures due to microhydrodynamic action, enhanced by high fluid viscosity.…”

Section: Introductionmentioning

confidence: 99%

“…Multibody vehicle dynamic model was built in multibody dynamic simulation software and suspension system, tire model, braking system, engine system, steer system, vehicle frame were included. Leighton et al 17 presented a Reynolds-based numerical model including the effect of fluid inertia and squeeze film transience for prediction of performance of wet brake systems. It was shown that cavitation becomes significant at low temperatures due to microhydrodynamic action, enhanced by high fluid viscosity.…”

Section: Introductionmentioning

confidence: 99%

Virtual prototype and field test study on hydraulic brake system performance of mining truck

Fan

Gan

2018

Proceedings of the Institution of Mechanical Engineers, Part K:

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In order to study the braking performance of mining dump truck, the modeling of the oil–gas suspension, front and rear brake of the dump truck were carried out first. Then the virtual prototype model of the dump truck was established in multibody dynamic simulation software. The simulation of braking and emergency braking performance, brake deviation on the flat road, and 9% downhill road were carried out. The brake in driving performance, emergency brake performance, disc brake retardance performance, transmission retardance performance, and hydraulic braking system response time were carried out by the real vehicle experiment, respectively. The result shows that the clearance elimination and pressure rise time of braking system are slightly long, especially the clearance elimination time, so the oil system should have an improvement. At the same time, the braking force distribution of the front and the rear is not reasonable, and the front wheel braking torque is slightly insufficient. After solving these problems by authors’ project team, the braking performance of the mine dump truck has been improved significantly.

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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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Efficiency of disengaged wet brake packs

Cited by 9 publications

References 13 publications

Oil film separation and drag torque in disengaged wet brakes

Oil film separation and drag torque in disengaged wet brakes

Virtual prototype and field test study on hydraulic brake system performance of mining truck

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

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