© Copyright Bierens - 2014 1
Sep 08, 2014
© Copyright Bierens - 2014 1
Bierens companies
Since 1880.
Specialist in gears, gearboxes and mechanical
drives since seventy years.
Specialist in five axis milling of gears since twelve
years.
Present:
Turnaround to new economy of scale.
© Copyright Bierens - 2014 2
Bierens achievements
• The Inventor of five axis free form milling for
gears ( 2002).
• Mathematical description, direct data input
instead of CAD/CAM.
• Pro-active heat treatment distortion approach.
• Hardness profile measured on the gears.
• Horizontal contact pattern tester.
© Copyright Bierens - 2014 3
Developments (1/2):
Strong improvement delivery performance.
Production lead times from av 200 av 70.
© Copyright Bierens - 2014 4
Developments (1/2):
Strong improvement delivery performance
Production lead times from av 200 av 70
© Copyright Bierens - 2014 5
Developments (1/2):
Strong improvement delivery performance
Production lead times from av 200 av 70
© Copyright Bierens - 2014 6
Developments (2/2):
Methodologies:
QRM (Suri)
First time right
MRP (SSP)
MSA (manufacturing service agreement)
Investments:
New machines (DMU 210P / Mazak 670)
New engineers
New engineering & technology software (creo)
Brazil
© Copyright Bierens - 2014 7
Bierens International
• Brazil: Joint Venture
• China: Cooperation
• Vietnam: PSI-project
• France / Africa through Defawes
© Copyright Bierens - 2014 8
Strategy:
Bierens companies in The Netherlands and
Belgium aim to be successful worldwide by:
Product leadership: highest precision in gears
Operational excellence: direct data input to gear
manufacturing machines
Customer intimacy: transparency and partnering
© Copyright Bierens - 2014 9
Bierens ambition:
“Against the stream, full throttle ahead.”
Against the stream:
Growing turnover (>4% 2012, 10% 2013, 15%
2014)
Growing numbers in FTE’s (>20%)
Building new factory (operational end 2014)
Turnaround in black figures
© Copyright Bierens - 2014 10
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Bierens ambition:
“Against the stream, full throttle ahead.”
Full throttle ahead:
Five fold economy of scale (2011-2017)
New factory creates sustainability opportunities
Strong focus on technology and innovation
Intensive training for staff and operators
Strong development in new markets in South
America, Asia and Africa.
New factory
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Better internal logistics
Climatized production
Production technology ready for increase of
scale
Soft cutting: Pro-active Heat Treatment
Distortion approach
Change soft cutting 3D data in advance, in
order to compensate for hardening distortions.
Gear wheels tend to change the cone pitch
angle during hardening. When the amount of
change is known on forehand, this is used to
change the geometry for soft cutting.
© Copyright Bierens - 2014 13
Hardening: Distortion caused by hardening
1) Measuring tooth 3D form after hardening
allowing to re-position the gearwheel X, Y, Z
and alfa.
2) Turning bore and plane according to the
repositioned data
3) 5-axis free form milling with uniform material
removal on all tooth flanks
This leads to optimized remaining hardness layer
on all tooth flanks.
© Copyright Bierens - 2014 14
Finish Turning and Milling
Finish milling and turning according to the
optimized data from the measurement after the
hardening.
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Failure mechanism of
Tooth Interior Fatigue Fracture
TIFF
Initial crack some distance below the
tooth surface where tensile stress
reaches a critical value.
(ref. Dr. Braykoff )
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Residual stresses inside the tooth
Caused by:
• Compressive stresses in the
hardened layer
• Tensile stresses in the core
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Stress balance
The compressive stress in the
hardening layer is compensated by
the tensile stresses in the core.
Increasing the hardness layer
thickness, increases the tensile
stresses in the core.
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Contact pattern: Bevel Gear Testing
Machine
Horizontal gear wheel position:
To ensure correct mounting positions and
90 degree shaft angle.
Suited for:
Wheel diameters up to 3000 mm.
Pinion shafts up to 450 mm diameter.
© Copyright Bierens - 2014 19
Classification
Bierens is certified for re-stamping.
Local representatives of DNV, ABS, BV and
Lloyd’s.
Manufacturing Service Agreement is in process.
© Copyright Bierens - 2014 20