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 TIMKEN PRODUCTS CATALOG  A

BEARING REACTIONS, DyNAMIC EQUIVALENT LOADS & BEARING LIFE - continued 

Equivalent dnamic radial bearing loads (Pr)To calculate the L10 lie, it is necessary to calculate a dynamic

equivalent radial load, designated by Pr. The dynamic equivalentradial load is defned as a single radial load that, i applied to thebearing, will result in the same lie as the combined loading underwhich the bearing operates.

Pr = XFr + Y1Fa

Where,

Pr = Dynamic Equivalent Radial LoadFr = Applied Radial LoadFa = Applied Axial LoadX = Radial Load FactorY = Axial Load Factor

For spherical roller bearings, the values or X and Y can bedetermined using the equations below. Calculate the ratio o theaxial load to the radial load. Compare this ratio to the e value or

 the bearing.

In equation orm,

Pr = Fr  + Y2 Fa  or Fa  /  Fr  e, and

Pr = 0.67Fr  + Y2 Fa  or Fa  /  Fr  > e.

Note that values or e, Y1 and Y2 are available in the bearing tables.

Needle roller bearings are designed to carry radial load withzero thrust load under normal conditions. With the thrust loadequal to zero equivalent radial load (Pr) is equal to the design radial

load (Fr). Your Timken representative should be consulted on anyapplications where thrust load is involved, as the resulting increasein internal riction may require cooling to prevent increasedoperating temperatures.

Tapered roller bearings use the equations based on the numbe

o rows and type o mounting utilized. For single-row bearings indirect or indirect mounting, the table on page A31 can be usedbased on the direction o the externally applied thrust load. Once theappropriate design is chosen, review the table and check the thruscondition to determine which thrust load and dynamic equivalenradial load calculations apply.

For cylindrical roller bearings with purely radial applied load:

P = Fr (kN)Note: The maximum dynamic radial load that may be

applied to a cylindrical roller bearing should be < C/3.

I, in addition to the radial load, an axial load Fa acts on the bearing

 this axial load is taken into consideration when calculating the lieo a bearing (with Fa < Faz; Faz is the allowable axial load).

Dimension Load ratio Equivalent

Series Dynamic Load

10.. 2..E, 3..E Fa /Fr < 0.11 P = Fr

Fa /Fr > 0.11 P = 0.93 • Fr + 0.69 • Fa

22..E, 23..E Fa /Fr < 0.17 P = Fr

Fa /Fr > 0.17 P = 0.93 • Fr + 0.45 • Fa

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A

    •A0  TIMKEN PRODUCTS CATALOG

 

BEARING REACTIONS, DyNAMIC EQUIVALENT LOADS & BEARING LIFE - continued 

For ball bearings, the dynamic equivalent radial load can beound in Table 3. The required Y actors are ound in the Table 4.

Bearing Contact Single-Row Double-RowDescription (ref.) Angle and Tandem and Preload Pair

Mountings Mountings

Bearing Tpe KT = Fa  KT = Fa

and or Series (# of bearings) x Co Co

 

RADIAL TyPE BALL BEARINGS Use larger of Resulting “P” Value*

 

M9300K,MM9300K

M9100K,MM9100K 0° P = Fr or P = Fr + 1.20Y1Fa or

M200K,MM200K P = 0.56Fr + Y1Fa P = 0.78Fr + 1.625Y1Fa

M300K,MM300K

Small inch and Metric

9300,9100,200,300 0° P = Fr or

and derivatives P = 0.56Fr + Y1Fa

XLS Large Inch

W and GW Tri-Ply

WIDE INNER RING BALL 0° P = Fr or

BEARINGS HOUSED UNITS P = 0.56Fr + Y1Fa

ANGULAR CONTACT BALL BEARINGS Use larger of Resulting “P” Value

7200K, 7200W

7300W, 7400W P = Fr P = Fr + 1.09Fa

5200K-5300W 20° or or

5311W-5318W P = 0.43Fr + Fa P = 0.70Fr + 1.63Fa

5218W, 5220W, 5407W

5221W, 5214W

5200, 5200W (see 20° exceptions) P = Fr P = Fr + 0.78Fa

5300, 5300W (see 20° exceptions) 30° or or

5400, 5400W (see 20° exceptions) P = 0.39Fr +0.76Fa P = 0.63Fr + 1.24Fa

7200WN P = Fr P = Fr + 0.55Fa

7300WN 40° or or

7400WN P = 0.35Fr +0.57Fa P = 0.57Fr + 0.93Fa

2M9300WI P = Fr P = Fr + 1.124Y2Fa

2M9100WI,2MM9100WI 15° or or

2M200WI, 2MM9100WI P = 0.44Fr +Y2Fa P = 0.72Fr + 1.625Y2Fa

2MM300WI

2MM9100WO P = Fr P = Fr + 1.124Y3Fa

or or

P = 0.44Fr + Y3Fa P = 0.72Fr + 1.625Y3Fa

 

3M9300WI P = Fr P = Fr + 0.92Fa

3M9100WI,3MM9100WI 25° or or3M200WI, 3MM200WI P = 0.41Fr +0.87Fa P = 0.67Fr + 1.41Fa

3MM300WI

 

TABLE

KT y y y

0.015 2.30 1.47 1.60

0.020 2.22 1.44 1.59

0.025 2.10 1.41 1.57

 

0.030 2.00 1.39 1.56

0.040 1.86 1.35 1.55

0.050 1.76 1.32 1.53

 

0.060 1.68 1.29 1.51

0.080 1.57 1.25 1.49

0.100 1.48 1.21 1.47

 

0.120 1.42 1.19 1.45

0.150 1.34 1.14 1.42

0.200 1.25 1.09 1.39

 

0.250 1.18 1.05 1.35

0.300 1.13 1.02 1.33

0.400 1.05 1.00 1.29

 

0.500 1.00 1.00 1.25

0.600 — — 1.22

0.800 — — 1.17

 

1.000 — — 1.13

1.200 — — 1.10

Equivalent Dnamic Thrust Bearing Loads (Pa)For thrust ball, cylindrical and tapered roller bearings, the

existence o radial loads introduces complex load calculations thatmust be careully considered. I radial load is zero, the equivalentdynamic thrust load (Pa) will be equal to the applied thrust load

(Fa). I any radial load is expected in the application, consult yourTimken representative or advice on bearing selection.

For thrust angular contact ball bearings, the equivalent dynamic thrust load is determined by:

Pa = Xr F + YFa

The minimum permissible thrust load to radial load ratios (Fa /Fr)and X and Y actors are listed in the bearing dimension tables in

 the thrust bearing section.Thrust spherical roller bearing dynamic thrust loads are

determined by:

Pa = 1.2Fr + Fa

Radial load (Fr) o a thrust spherical roller bearing is proportional to the applied axial load (Fa) with Fr 0.55 Fa. Because o the steeproller angle and the act that the bearing is separable, a radial loadwill induce a thrust component (Fai = 1.2 Fr), that must be resistedby another thrust bearing on the shat or by an axial load greater

 than Fai.

TABLE

*Note:If P > C0 or P > 1 / 2 CE consult with your Timken representative on

Life Calculations.