Engine efficiency enhancement utilizing crankshaft roller bearings

Tobias Hultqvist¹, Aleks Vrcek¹

Tunander, H. ², Baubet, Y. ³, Marklund P.¹, Larsson R.¹

¹ Division of Machine Elements, Luleå University of Technology, Sweden

² Volvo Cars Coorporation, Gothenburg, Sweden

³ SKF Research and Technology development, Nieuwegein, The Netherlands

Introduction - Fuel consumption and friction

• Fuel consumption for passenger cars investigated by Holmberg (2012)

• 33% of fuel is used to overcome friction

• In 2009 this meant 208,000 million litres of fuel

2

Holmberg, K., Andersson, P., & Erdemir, A. (2012). Global energy consumption due to friction in passenger cars. Tribology International, 47, 221–234.

Introduction - Fuel consumption and friction

• Fuel consumption for passenger cars investigated by Holmberg (2012)

• 33% of fuel is used to overcome friction

• In 2009 this meant 208,000 million litres of fuel

• Engine friction losses (11.5%)

• Low cost low emission solutions to be found

3

Holmberg, K., Andersson, P., & Erdemir, A. (2012). Global energy consumption due to friction in passenger cars. Tribology International, 47, 221–234.

Engine friction (11.5%)

Piston assembly (45%)

Bearings and seals (30%)

Valve train (15%)

Hydraulics (10%)

Introduction - Fuel consumption and friction

• Fuel consumption for passenger cars investigated by Holmberg (2012)

• 33% of fuel is used to overcome friction

• In 2009 this meant 208,000 million litres of fuel

• Engine friction losses (11.5%)

• Low cost low emission solutions to be found

4

Holmberg, K., Andersson, P., & Erdemir, A. (2012). Global energy consumption due to friction in passenger cars. Tribology International, 47, 221–234.

Engine friction (11.5%)

Piston assembly (45%)

Valve train (15%)

Hydraulics (10%)

Bearings and seals (30%)

Introduction - Engine main bearings

• Journal bearings and roller bearings as main bearings

• Buchmiller (2015) showed a 1.5% fuel consumption reduction

• Baubet et al (2014) could see that 2% could be saved

• Roller bearings are also preferable for start-stop conditions

• Roller bearings reduces the amount of pressurized oil

5

Buchmiller, V. (2015). Wälzgelagerter Kurbeltrieb – Potenzial von Wälzlagern im Verbrennungsmotor. Baubet, Y., Pisani, C., Carden, P., Molenaar, L., & Reedman, A. (2014). Rolling Elements Assessment on Crankshaft Main Bearings of Light Duty Diesel Engine.

Introduction - Engine main bearings

• Journal bearings and roller bearings as main bearings

• Buchmiller (2015) showed a 1.5% fuel consumption reduction

• Baubet et al (2014) could see that 2% could be saved

• Roller bearings are also preferable for start-stop conditions

• Roller bearings reduces the amount of pressurized oil

• New challenges arise due to the different tribological contacts

• Crankshaft material & manufacturing

• Roller bearing performance with engine oil

• Cage material compatibility with engine oil

• Performance evaluation – plain vs. roller bearing

• Acoustics/NVH

6

Buchmiller, V. (2015). Wälzgelagerter Kurbeltrieb – Potenzial von Wälzlagern im Verbrennungsmotor. Baubet, Y., Pisani, C., Carden, P., Molenaar, L., & Reedman, A. (2014). Rolling Elements Assessment on Crankshaft Main Bearings of Light Duty Diesel Engine.

1. Tribological characterization

I. Lubricant characterization

Dynamic load

Static load

WAM – Ball-on-disc machine

Laboratory level

Experimental part

1. Tribological characterization

I. Lubricant characterization

II. Material characterization

Dynamic load

Static load

Twin-disc machine

Laboratory level

Experimental part

1. Tribological characterization

I. Lubricant characterization

II. Material characterization

III. Surface roughness characterization

Dynamic load

Static load

Laboratory level

Experimental part

Twin-disc machine

1. Tribological characterization

I. Lubricant characterization

II. Material characterization

III. Surface roughness characterization

IV. Cage material characterization

Dynamic load

Static load

Pin-on-disc machine + structural bending fatigue

Laboratory level

Experimental part

1. Tribological characterization

I. Lubricant characterization

II. Material characterization

III. Surface roughness characterization

IV. Cage material characterization

2. Laboratory engine tests

Dynamic load

Static load

Laboratory level System level

Experimental part

1. Tribological characterization

I. Lubricant characterization

II. Material characterization

III. Surface roughness characterization

IV. Cage material characterization

2. Laboratory engine tests

3. Real engine tests

Dynamic load

Static load

Laboratory level System level

Experimental part

1. Tribological characterization

I. Lubricant characterization

II. Material characterization

III. Surface roughness characterization

IV. Cage material characterization

2. Laboratory engine tests

3. Real engine tests

4. Durability tests

Dynamic load

Static load

Laboratory level System level Component level

Experimental part

Contact level Component level System level

• Load cases from system level

• Combustion and crankshaft

• Bearing dynamics at component level

• Bearings and contacts

• Lubrication performance on detailed contact level

• Single roller and lubricant film

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Simulation part - Approach

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Simulation part - Further improvements of simulations

Combustion and dynamics

Bearing dynamics

Detailed contact analysis

Bearing load

Roller load

Updated contact model

Fundamentals

Improvements

Conclusions

• Crankshaft roller bearings = Improved efficiency

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Conclusions

• Crankshaft roller bearings = Improved efficiency

• New tribological challenges • Friction performance

• Wear and damage mechanisms

• Noise, vibration and harshness

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Questions?

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Thank you for your attention!