Schmierung

OBJECT OF LUBRICATION

The lubrication method and the lubricant have a direct effect on the bearing life; the most suitable lubrication must therefore be selected for each application. Effects of lubrication are described as follows:

1)     DECREASE OF FRICTION AND ABRASION
It decreases rolling friction between the raceway and the rolling elements, sliding friction between rolling element and cage and sliding friction of guide surface between the cage and the bearing ring.

2)      REDUCTION OF HEAT GENERATION
It dissipates heat generated inside the bearing as well as heat conducted from the outside thus preventing overheating of the bearing and deterioration of the lubricant.

3)     PROTECTION FROM CORROSION AND CONTAMINANTS
It prevents corrosion of rolling elements, bearing rings and cages and also prevents the ingress of contaminants and moisture into the bearing.

REQUIRED CHARACTERISTIC OF THE LUBRICANT

  • LOW FRICTION AND ABRASION
  • HIGH STABILITY AGAINST HEAT, GOOD THERMAL CONDUCTIVITY
  • STRONG OIL FILM
  • NON-CORROSIVE
  • PROVIDE A GOOD BARRIER AGAINST DUST AND MOISTURE
  • MAINTAIN A STABLE VISCOSITY

LUBRICATION METHOD

There are two types of lubricant: oil and grease. It is important to select the correct lubricant and lubrication method for each application and its conditions.

LUBRICATING OIL AND GREASE

  LUBRICATING OIL LUBRICATING GREASE
ROTATING SPEED Low - Medium - High speed Low - Medium speed
LUBRICANT EFFICIENCY Excellent Good
COOLING EFFECT Good None
TORQUE Comparatively low Comparatively high
LUBRICANT LIFE Long Comparatively short
LUBRICANT REPLACEMENT Easy Difficult
LUBRICANT LEAKAGE Should not be used where oil leakage is unacceptable Little grease leakage
IMPURITIES FILTRATION Easy Difficult
SEALING EQUIPMENT Complex Simple

GREASE FILLING VOLUME

SYMBOL FILLING VOLUME(%) OPERATIVE CONDITION
SPEED LOAD
M 70±10 LOW HEAVY
S 50±10 LOW MEDIUM
G 40±10 MEDIUM MEDIUM
L 30±10 MEDIUM MEDIUM
Q 25±5 MEDIUM MEDIUM
K 20±5 HIGH LIGHT
X 10±5 HIGH LIGHT

note:
Light load: ≤ 0.06Cr
Standard load: ≤ 0.12Cr

CRITERIA FOR LUBRICATING OIL SELECTION

OPERATING TEMPERATURE OF BEARING (°C) dn ISO VISCOSITY GRADE OF LUBRICATING OIL (VG)
MEDIUM LOAD HEAVY LOAD / SHOCK LOAD
-30~0 up to permissible rotating speed 15,22,32 32,46
0~+60 up to 15000 32,46,68 100
15000~80000 32,46 68
80000~150000 22,32 32
150000~500000 10 22,32
+60~+100 up to 15000 150 220
15000~80000 100 150
80000~150000 68 100,150
150000~500000 32 68
+100~+150 up to permissible rotating speed 320

note:
- If heavy loads occur at low speeds, a higher viscosity lubricating oil should be used.
- This table is for oil bath lubrication system and recirculating oil systems.
- dn = bearing bore diameter d(mm) × rotating speed n(rpm).

LUBRICANT

Usually, open bearings are lubricated in advance with Jinzhi Hangu 2; bearings with shields are usually greased with Jinzhi Hangu 2.
Bearings can be lubricated with other lubricants as follows:

COMMON GREASE BRANDS AND EFFICIENCY
MANUFACTURER BRAND CODE OPERATING TEMPERATURE APPROVED STANDARD
°C °F
Shell Alvania RS AV 2 -25/+120 -13/+248 -
Aeroshell N° 6 AG 6 -40/+120 -40/+248 MIL-G-7711 A
Aeroshell N° 7 AG 7 -70/+150 -94/+302 MIL-G-23827 A
Aeroshell N° 15 A AG 5 -70/+230 -94/+446 MIL-G-25103 D
Aeroshell N° 16 AG 16 -55/+200 -67/+392 MIL-G-25760 A
Exxon (Esso) Beacon 325 B 32 -55/+120 -67/+248 MIL-G-3278 A
Andok C AKC -25/+120 -13/+248  
Andok B AKB -30/+110 -22/+230 MIL-G-18709 A
Klüber Isoflex Super LDS 18 ISF 1 -60/+130 -76/+266 MIL-G-3278 A / MIL-G-7118 A
Isoflex LDS 18 Spec. A ISF 2 -60/+130 -76/+266 MIL-G-23827 A / MIL-G-15793
Isoflex Alltime SL 1 ISF 3 -70/+150 -94/+302  
Isoflex Alltime SL 2 ISF 4 -50/+150 -58/+302  
Isoflex NBU 15 ISF 5 -40/+130 -40/+266 MIL-G-771 A / MIL-G-25760
Isoflex PDB 38/CX2000 ISF 6 -70/+120 -94/+248  
Isoflex Topas NB 52 ISF 7 -60/+160 -76/+320 MIL-G-81322 C
Unisilicon TK 44-N2 TK 44-N2 -60/+230 -76/+446  
Staburags NBU 12 NBU 12 -35/+150 -31/+302  
Mobil Mobil Grease 28 MG 28 -60/+75 -76/+347 MIL-G-81322 A
Chevron Chevron SRI 2 SRI -30/+175 -22/+347  
Texaco Low Temp EP LTEP -70/+120 -94/+248 MIL-G-23827 A
Unitemp Grease 500 UT 500 -54/+177 -65/+350  
Dow Corning DC 33 DC 33 -70/+180 -94/+356 MIL-G-46886
DC 44 DC 44 -40/+200 -40/+392 MIL-G-15719 A
Du Pont Krytox 240 AB K 240 AB -40/+227 -40/+440 MIL-G-38220
Krytox 240 AC K 240 AC -34/+288 -30/+550 MIL-G-27617 A
Gen. Electr. Versilube G 300 VG 300 -70/+230 -94/+446  
Jinzhi Hangu 2 HG 2 -20/+120 -4/+248  
COMMON OIL BRANDS AND EFFICIENCY
MANUFACTURER BRAND CODE OPERATING TEMPERATURE APPROVED STANDARD
°C °F
Shell AeroShell Fluid3 AF 3 -56/+115 -70/+240 MIL-L-7870 A
AeroShell Fluid12 AF 2 -60/+120 -76/+248 MIL-L-6085 A
Klüber Isoflex PDB 38 PDB 38 -70/+120 -94/+248 MIL-L-6085 A
Dow Corning DC 550 Fluid DC 550 F -40/+230 -40/446