Multidomain modeling approach for energy analysis and redesign of production machinery applied

to weaving looms

Authors: J. Croes1, S. Iqbal1, A. Reveillere2,D. Coemelck3, B. Pluymers1, W. De roeck1, W. Desmet1

1: KULeuven 2: LMS Imagine 3: Picanol

Table of contents

1. Introduction

2. Description of the model1. Losses in bearings & seals

2. Losses in cam & follower

3. Losses in 3D multibody mechanism

3. Model updating

4. Analysis

5. Multidomain modeling for redesign

6. Conclusions & future work

Description of the system

gearbox

cam&follower mechanism

3D mechanism

3D mechanism

rapier wheel with gripper

1. Introduction

System under investigation• High dynamic weaving machine• Strongly coupled modules• Losses in order of magnitude of kW

Most dominant loss sources• Friction in bearings, seals, gears, cam&follower• Losses in electric motor

Objective• Analysis of loss distribution in the system to improve the overall

efficiency

Requirements• Component loss models with reasonable level of accuracy• Accurate description of the dynamic behavior of the system

1. Introduction

2. Description of the model

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cosimulation

Bearing (seal) losses• Modeled as a friction torque in opposite direction of the velocity• Loss is estimated according to Palmgren or SKF model• Bearing loads come from contact in gear teeth, cam & joints• Implemented as an multidimensional loss map• Dedicated development of bearing component

2. Description of the model1. Losses in bearings & seals

)/( tanhTTT loss12

2. Description of the model

cosi

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cosimulation

2. Description of the model

Cam & follower mechanism• Extension of existing cam rocker model with conjugate part• Linear stiffness behavior at cam & follower contact• Losses implemented and added at the cam shaft• Forces are defined as external variables• Loop is closed inside the submodel

2. Losses in cam & follower

cam shaft

follower shaft

2. Description of the model

Cam & follower mechanism

2. Losses in cam & follower

slidingSslidingMrollingSrollingMbearingSbearingMloss PPPPPPP

)10/tanh()(

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PT lossloss

2. Description of the model

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cosimulation

2. Description of the model3. Losses in 3D multibody mechanism

3D mechanism• Model 3D kinematics(loads, velocities)

• Rotation vectors change in magnitude and orientation

• Need for multibody software

• AMESim calculates friction torque

• Modeled as equivalent inertia

2. Description of the model3. Losses in 3D multibody mechanism

Post processing motion signals

Action points• Axis definitions

• Joint definitions

• Mind sign conventions

• Discrete nature signals

• Communication interval

Computation time• Tolerance

• Step size

loss torqueloads, velocities

loads, velocities of each shaft

loss torque

input output shaft AMESim

cosim block

- radial load 1- radial load 2- axial load- velocity

3. Model updating

Use of two configurations to estimate & validate parameters

configuration 1

configuration 2

T(1,2)

T(2,1)

T(1,2)

T(2,1)ω(1,1)

α(2,2)

α(2,2)

ω(1,1)

3. Model updating

Procedure

Pre- and postprocessingr

Simulation

- Sensitivity analysis- Updating procedure

- Runs with different parameters

Dominant parameters/components- Stiffness & damping of the cam shaft- Bearing loss model- Motor loss map

Dynamic behaviorEnergetic behavior

3. Model updating

Configuration 1: 500 RPM mean velocity

Dynamic behavior

3. Model updating

Configuration 1: 600 RPM mean velocity

Dynamic behavior

3. Model updating

Configuration 2: 500 RPM mean velocity

Dynamic behavior

3. Model updating

Configuration 2: 600 RPM mean velocity

Dynamic behavior

3. Model updating

Properties• Measurements linear regression between different temperatures• Viscosity exponential curve• Slope 34.4W/°C (config 1) vs 53.2W/°C (config 2)

Losses at 48.4°• Configuration 1 2% overestimation losses in the model• Configuration 2 20% underestimation losses in the model

Preliminary conclusions• Temperature (viscosity) has significant influence (lubrication assumption)• Increase of damping decreases the losses• Motor losses contribute to the slope increase

Power measurements

4. Analysis

Energetic analysis• Usage of the model to asses energy loss distribution• Gain insight in how dynamics/components influence energetic behavior• Use the model to formulate design guidelines

Flow chart of energy losses

4. Analysis

5. Multidomain modeling for redesign

• Virtual energy analysis leads to more insight in the most dominant loss sources and the most influential parameters

1: Lubrication properties highly influence the friction losses

2: Dynamic excitation is the main input for mechanical loss models

Multidomain analysis allows you to quantify the losses!

Provides a basis for experimental testing

5. Multidomain modeling for redesign

1: Lubrication properties highly influence the friction losses

Virtual experiments• Increase the oil temperature by 10°

– 10% decrease in energy loss

Physical experiments:• Increase the oil temperature by 3°

– 3,8% decrease in energy loss

• Reduce the oil flow by 60%– 10% decrease in power consumption

– Increase of oil temperature by 6°

– Increase and decrease of bearing temperatures by ±3.5°

Lubrication regime can be optimized for energy consumption without jeopardizing performance & lifetime

5. Multidomain modeling for redesign

2: Dynamic excitation is the main input for mechanical loss models

Virtual experiments• Decrease equivalent inertia of the gearbox (scales with n²)• Reduces dynamic loads and by extension bearing friction

5. Multidomain modeling for redesign

2: Dynamic excitation is the main input for mechanical loss models

Virtual experiments• Increase damping on the main shaft by mounting damping layer• Significant reduction of dynamic forces • Dissipation caused by damper is small compared to the reduction in

friction loss in the bearings by decreasing the load

5. Multidomain modeling for redesign

2: Dynamic excitation is the main input for mechanical loss models

Virtual experiments• Reassess cam profile• A smaller curvature radius leads to

– Decrease in torsional vibrations– Lower rotational velocities at bearings– Decrease in rolling & sliding friction

cam shaft

follower shaft

5. Multidomain modeling for redesign

2: Dynamic excitation is the main input for mechanical loss models

Other virtual experiments can be• Assessing the effect of different bearings• Changing the load distribution to decrease the friction• Apply different topologies for some subsystems• Changing inertia’s & stiffness of specific components• …

5. Conclusions & future work

Conclusions• Dynamic and energetic behavior can be modeled using combined

1D/3D approach• Accurate estimation of dynamic behavior is necessary to estimate

the losses• Representative loss models are required• Virtual energetic analysis provides good insight in the physical

behavior and leads to a better design• Virtual experiments quantify the influence of redesign changes on

the energy efficiency

5. Conclusions & future work

Future work• Model updating of loss behavior• Usage of the model to do a detailed analysis• Usage of the model to do virtual experiments for redesign