Maintenance Technology May 2015 - 31

BEARING SECRETS

Temperatures - deg C
-40

20

40

100

80

60

HONEY

9300

120

VI = 95

2000
1000

4650

68
32

2317
927
MINIMUM SUGGESTED VISCOSITIES

0

463

500

ISO OIL SPECS

46

100

200

150 220 320 460

100

ROLLER THRUST BRGS

232

CYLINDRICAL, SPHERICAL,
AND TAPERED ROLLER BRGS

100

20

BALL BEARINGS

59

10

50

5

Does not apply under 50 rpm

Viscositiy - Centistokes (cSt)

Saybolt Viscosity - (SSU)

-20

2

32

ANTIFREEZE

THE LINES REPRESENT THE
SPECIFIED VISCOSITY RANGES.

-50

0

100

50

150

250

200

Temperatures - deg F
Fig. 1. A general guide to recommended viscosities for ball, roller and roller thrust bearings

Actual period = 8000 hours x Ft x Fc x Fm x Fv x Fp x Fb
= 8000 hours x 0.5 x 1.0 x 1.0 x 1.0 x 1.0 x 0.1 = 400 hours

Special Section

4000
3500

Bearing speed (rpm)

change the rate of oil separation, some operating conditions will require more oil than others.
Figures 2 and 3 reflect empirical charts developed
for and used successfully in setting up lubrication programs in several large manufacturing plants and paper
mills. (Note: These charts were not the result of laboratory research, but substantial trial and error.)
The information in Fig. 2 can help determine basic
re-greasing intervals for ball and roller bearings. The
five curves on the chart are for five different bearing
bores (shaft diameters). The approach is to use the shaft
speed and diameter to define the basic interval.
Referring to Fig. 2, we can see that the suggested
re-greasing interval for a 3-in. diameter shaft rotating at
1750 rpm would be 8000 hours. That value, though, has
to be modified by the factors that correct for the actual
conditions surrounding the bearing, as shown in Fig. 3.
If that 3-in. (75 mm) shaft in Fig. 2 were horizontal,
had two spherical roller bearings on it and was running
at about 160 F (71 C) in a dry but slightly dusty environment with very low vibration, the corrected re-greasing
period would be found by multiplying the original 8000
hours by each of the correction factors as follows:

1" (25MM) BEARING
BORE

2" (50MM)
BORE

3" (75MM)
BORE

3000
4" (100MM)
BORE

2500

5" (125MM)
BORE

2000
1500
1000
500

1000

2000

4000

8000

16000

32000

64000

Suggested re-greasing period (operating hours)
Fig. 2. A simple guide to re-greasing intervals for bearings

Accordingly, if the referenced plant were running two eighthour shifts per day, five days per week, the example bearings
would need to be greased every five weeks, and would likely be

MAY 2015

LUBRICATION TECHNOLOGY

LubricationTechnologyOnline.com

31


http://www.LubricationTechnologyOnline.com

Maintenance Technology May 2015

Table of Contents for the Digital Edition of Maintenance Technology May 2015

Maintenance Technology May 2015 - Cover1
Maintenance Technology May 2015 - Cover2
Maintenance Technology May 2015 - 1
Maintenance Technology May 2015 - 2
Maintenance Technology May 2015 - 3
Maintenance Technology May 2015 - 4
Maintenance Technology May 2015 - 5
Maintenance Technology May 2015 - 6
Maintenance Technology May 2015 - 7
Maintenance Technology May 2015 - 8
Maintenance Technology May 2015 - 9
Maintenance Technology May 2015 - 10
Maintenance Technology May 2015 - 11
Maintenance Technology May 2015 - 12
Maintenance Technology May 2015 - 13
Maintenance Technology May 2015 - 14
Maintenance Technology May 2015 - 15
Maintenance Technology May 2015 - 16
Maintenance Technology May 2015 - 17
Maintenance Technology May 2015 - 18
Maintenance Technology May 2015 - 19
Maintenance Technology May 2015 - 20
Maintenance Technology May 2015 - 21
Maintenance Technology May 2015 - 22
Maintenance Technology May 2015 - 23
Maintenance Technology May 2015 - 24
Maintenance Technology May 2015 - 25
Maintenance Technology May 2015 - 26
Maintenance Technology May 2015 - 27
Maintenance Technology May 2015 - 28
Maintenance Technology May 2015 - 29
Maintenance Technology May 2015 - 30
Maintenance Technology May 2015 - 31
Maintenance Technology May 2015 - 32
Maintenance Technology May 2015 - 33
Maintenance Technology May 2015 - 34
Maintenance Technology May 2015 - 35
Maintenance Technology May 2015 - 36
Maintenance Technology May 2015 - 37
Maintenance Technology May 2015 - 38
Maintenance Technology May 2015 - 39
Maintenance Technology May 2015 - 40
Maintenance Technology May 2015 - 41
Maintenance Technology May 2015 - 42
Maintenance Technology May 2015 - 43
Maintenance Technology May 2015 - 44
Maintenance Technology May 2015 - 45
Maintenance Technology May 2015 - 46
Maintenance Technology May 2015 - 47
Maintenance Technology May 2015 - 48
Maintenance Technology May 2015 - 49
Maintenance Technology May 2015 - 50
Maintenance Technology May 2015 - 51
Maintenance Technology May 2015 - 52
Maintenance Technology May 2015 - Cover3
Maintenance Technology May 2015 - Cover4
https://www.nxtbook.com/atp/MaintenanceTechnology/efficient-plant-june-2021
https://www.nxtbook.com/atp/MaintenanceTechnology/epapril2021
https://www.nxtbook.com/atp/MaintenanceTechnology/epmarch2021
https://www.nxtbook.com/atp/MaintenanceTechnology/epjanfeb2021
https://www.nxtbook.com/atp/MaintenanceTechnology/epjulyaug2020
https://www.nxtbook.com/atp/MaintenanceTechnology/epjune2020
https://www.nxtbook.com/atp/MaintenanceTechnology/epmay2020
https://www.nxtbook.com/atp/MaintenanceTechnology/epapril2020
https://www.nxtbook.com/atp/MaintenanceTechnology/epmarch2020
https://www.nxtbook.com/atp/MaintenanceTechnology/epfeb2020
https://www.nxtbook.com/atp/MaintenanceTechnology/epjan2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epnovdec2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epseptoct2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epmay2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epapril2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epmarch2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epfebruary2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epjanuary2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epdecember2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epnovember2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epoctober2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epseptember2019
https://www.nxtbook.com/atp/MaintenanceTechnology/epaugust2018
https://www.nxtbook.com/atp/MaintenanceTechnology/0818schneider
https://www.nxtbook.com/atp/MaintenanceTechnology/epjuly2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epjune2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epmay2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epapril2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epmarch2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epfebruary2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epjanuary2018
https://www.nxtbook.com/atp/MaintenanceTechnology/epdecember2017
https://www.nxtbook.com/atp/MaintenanceTechnology/epnovember2017
https://www.nxtbook.com/atp/MaintenanceTechnology/epoctober2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtsept2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtaugust2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtjuly2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtjune2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtmay2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtapril2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtmarch2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtfebruary2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtjanuary2017
https://www.nxtbook.com/atp/MaintenanceTechnology/mtdecember2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtnovember2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtoctober2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtseptember2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtaugust2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtjuly2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtjune2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtmay2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtapril2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtmarch2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtfebruary2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtjanuary2016
https://www.nxtbook.com/atp/MaintenanceTechnology/mtdecember2015
https://www.nxtbook.com/atp/MaintenanceTechnology/mtnovember2015
https://www.nxtbook.com/atp/MaintenanceTechnology/mtoctober2015
https://www.nxtbook.com/atp/MaintenanceTechnology/mtseptember2015
https://www.nxtbook.com/atp/MaintenanceTechnology/MTAugust2015
https://www.nxtbook.com/atp/MaintenanceTechnology/MTJuly2015
https://www.nxtbook.com/atp/MaintenanceTechnology/MTJune2015
https://www.nxtbook.com/atp/MaintenanceTechnology/M
https://www.nxtbook.com/atp/MaintenanceTechnology/0415endress
https://www.nxtbook.com/atp/MaintenanceTechnology/MTApril2015
https://www.nxtbook.com/atp/MaintenanceTechnology/MTMarch2015
https://www.nxtbook.com/atp/MaintenanceTechnology/MTFebruary2015
https://www.nxtbook.com/atp/MaintenanceTechnology/MTJanuary2015
https://www.nxtbook.com/atp/MaintenanceTechnology/MTDecember2014
https://www.nxtbook.com/atp/MaintenanceTechnology/MTNovember2014
https://www.nxtbook.com/atp/MaintenanceTechnology/MTOctober2014
https://www.nxtbook.com/atp/MaintenanceTechnology/MTSeptember2014
https://www.nxtbook.com/atp/MaintenanceTechnology/MTAugust2014
https://www.nxtbook.com/atp/MaintenanceTechnology/MTJuly2014
https://www.nxtbookmedia.com