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La lubrificazione con grasso dei motori elettrici

(in lingua inglese)

To offer a “state-of-the-art” lubricating grease for use in electric motor bearings that:
- Sets new standards for long-life grease performance
- Allows bearing manufacturers to supply grease-lubricated bearings capable of offering longer life, low-maintenance service, on an unprecedented scale in the marketplace
- Offers low-noise performance desired for noise-sensitive applications

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MCM ottobre 2015 Ingegneria di manutenzione: affidabilità e operatività degli impianti

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Veronafiere 27-28 ottobre 2015 Gli atti dei convegni e più di 6.000 contenuti su www.verticale.net Cogenerazione Termotecnica Industriale Pompe di Calore 27 ottobre Cogenerazione Termotecnica Industriale Pompe di Calore Alimentare Alimentare Petrolchimico Alimentare 28 ottobre Alimentare Petrolchimico Alimentare Alimentare Petrolchimico Visione e Tracciabilità 28 ottobre Luce Energia Domotica LED Luce Energia Domotica LED Advantages of using the high performance Grease Mobil PolyrexTM EM Electric motors grease lubrication © 2009 Exxon Mobil Corporation. All rights reserved MCM Verona 28 October 2015
Paolo Burchianti LFE Esso Italiana
1 Agenda Electric motor
grease trends Major OEMs and bearing suppliers Grease requirements for electric motors ExxonMobil''s vision for Polyrex EM Grease
compatibility Performance
summary Critical performance
characteristics 2 Electric Motor Lubricating Grease Trends Increasing power density ' Motors are becoming smaller for given power output ' Speeds and operating temperatures are increasing Greases required to last
throughout motor''s life : Fill
for Life
' Requires balance of bleed characteristics, oxidation
stability and structural stability Grease is considered a
fundamental component
of premium electric motors
' Grease requirements are specified by OEM as integral to
new designs Increasing need for
quieter greases for noise-
sensitive applications
' Automotive under-the-hood application ' Consumer goods 3 Electric Motors - Major OEMs 4 Electric Motors '' Major Bearing Suppliers 5 Electric Motor Design 6 Grease Requirements For Electric Motors Good channeling characteristics NLGI Grade 2 or 3 ' 3 grades used where dn>250,000 (dn=bore(mm) x rpm) 500-650 SUS @100°F (c.ca 38 °C) base-oil viscosity
(~100cSt @ 40°C)
High dropping point ' Measured by ASTM D2265 ' 450°F (232°C) minimum Low oil bleed characteristics ' Measured by ASTM D1742, ASTM D6184 or IP121 7 ...More Requirements For Electric Motor Greases Excellent resistance to high temperature oxidation ' Usually measured by ASTM D3336 spindle life
' 500 hour minimum at top operating temp (300-350°F)
(149-177°C) Good low temperature torque characteristics ' Usually measured by ASTM D 1478
' Typically 10,000 g-cm max starting torque at -20°F (-29°C) Good anti-wear characteristics but generally non-EP 8 ExxonMobil''s Vision for Mobil Polyrex EM To offer a ''state-of-the-art' lubricating grease for use
in electric motor bearings that:
Sets new standards for long-life grease
performance Allows bearing manufacturers to supply
grease-lubricated bearings capable of
offering longer life, low-maintenance
service, on an unprecedented scale in the
marketplace Offers low-noise performance desired for
noise-sensitive applications 9 Mobil Polyrex EM Delivers STEP-OUT Performance Excellent high-temperature long-life lubrication Good pumpability Good low temperature capabilities Outstanding shear stability (mechanical stability) Excellent corrosion resistance Excellent oil bleed characteristics Increased compatibility with most
conventional lithium greases 10 The Performance Breakthrough of Mobil Polyrex EM Extended life without compromise
in other grease properties
11 Test conditions ' 6204 bearing runs @ 10,000 rpm
' Light loading: 5 lb axial, 15 lb radial
' 350°F (177 °C) bearing temperature
' Failure detected by an increase in bearing starting torque or a 27+ °F temperature spike ' Duty cycle: 20 hours on, 4 hours off ASTM D3336 Grease Life Test Mobil Polyrex EM achieves : >750 hrs. @ 350°F (177°C) 12 FAG FE9 Grease Life (Variation A) 130 135 140 145 150 155 160 165 Mobil Polyrex EM Competitor C Conventional Polyurea Conventional Li-Complex T e mperature (°C) to obtain 100 hr minimum life (L50) 13 Shear Stability Based on 100,000 Penetration 0 20 40 60 80 100 120 Mobil Polyrex EM Competitor C Conventional Polyurea Conventional Li-Complex 100KX '' 60X Penetration, Mm/10 14 ' Spinning ball rotates against 3 stationary balls
' Load on spinning ball = 40 kg
' Test temperature = 167°F
' Speed of rotating ball = 1200 rpm
' Test duration = 1 hour
' Diameter of circular wear scar on stationary balls is measured in mm ' Industry standard = <0.5-0.6 mm scar Anti-Wear Protection Mobil Polyrex EM achieves : 0.4 mm scar Wear protection is measured in the 4-ball wear test (ASTM D 2266) Test conditions 15 Water washout test (ASTM D1264) ' Bearing tested in a shielded, but unsealed housing ' Test temperature = 79°C
' Typical lithium complex grease achieves 3-5% washout Mobil Polyrex EM Exhibits Excellent Water Resistance Mobil Polyrex EM achieves 1.9% 16 Bearings run in duplicates
' Rating scale is from 0 to 5
' 0 = no corrosion
' 5 = severe corrosion Rating 0 Rating 5 EMCOR Rust Test Mobil Polyrex EM achieves 1, 0 rating 17 Controlled oil bleed is key to achieving long lubrication life Mobil Polyrex EM Controls Oil Bleed Mobil Polyrex EM achieves 0.5% ASTM D1742 oil separation test Predicts the amount of static oil
separation at 25 °C
' Measures the amount of oil bleed through a wire mesh with 0.25 psi
pressure on the grease ' Typical Lithium Complex greases achieve <3% oil bleed 18 Controlled oil bleed is key to achieving long lubrication life ' Measures oil bleed through a wire mesh at 100 °C (30 hours) ' Low bleed is critical for long-life performance at high temps Mobil Polyrex EM Controls Oil Bleed Mobil Polyrex EM achieves <0.1% bleed ASTM D6184 high temperature oil bleed test 19 Mobil Polyrex EM Controls Oil Bleed IP 121 oil bleed test ' Similar equipment set-up as ASTM D1742
' IP 121 tests run on Mobil Polyrex EM and Competitor C at 40, 70, 120, and 150°C ' Oil bleed measured at times ranging from 42 hours to 1 week. See graph for details 20 IP 121 Oil Bleed Results 0 5 10 15 20 25 30 35 0 20 40 60 80 100 120 140 160 180 Time (hours) Oil Separation (%) Polyrex EM @ 120°C
Competitor C @ 120°C
Polyrex EM @ 150°C
Competitor C @ 150°C
Polyrex EM @ 70°C
Competitor C @ 70°C
IP 121 oil separation @ 70°C, 120°C and 150°C 150°C 70°C 70°C 150°C 120°C 120°C 21 Mobil Polyrex EM Mobil Polyrex EM = Excellent Overall Performance Bearing Life
Mobil Polyrex EM exhibits 3
to 7 times longer bearing life
than conventional electric
motor greases Noise Performance Mobil Polyrex EM uses a
controlled proprietary
manufacturing technique to
deliver consistent low-noise
performance Compatibility Mobil Polyrex EM exhibits
enhanced compatibility with Li-
complex and other Polyurea
greases Oil Bleed Mobil Polyrex EM exhibits
controlled oil separation
even at high temperatures Shear Stability Mobil Polyrex EM exhibits
significantly improved shear stability
over conventional polyurea greases 22 Grease Compatibility All Mobil electric motor greases are compatible or moderately compatible with each other Grease Compatibility Guide Mobil Polyrex EM Mobil Polyrex EM 103 Unirex N2 Unirex N3 Mobilith SHC 100 Mobil temp SHC 100 Mobil
Polyrex
EM Comp Comp (FE9) Comp (FE9) Comp M-Comp Mobil
Polyrex
EM 103 Comp r/a r/a r/a M-Comp Unirex N2 Comp (FE9) r/a Comp M-Comp r/a Unirex N3 Comp (FE9) r/a Comp M-Comp Comp Mobilith
SHC 100 Comp r/a M-Comp M-Comp Comp Mobiltemp
SHC 100 M_Comp M-Comp r/a Comp Comp Compatible Moderately Compatible Incompatible Thanks Questions '


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