# Determining the Size of Universal Joints with Needle Bearings

## DIN 808-NB

The graph shows the transmitted outputs "N" or torques "M" of universal joints as defined in DIN 808-FB (single, friction bearing), depending on the speed "n."   This information is applicable for uniform speed, uniform load and a maximum working angle of 10°. It is not applicable for stainless steel universal joints.

Where the working angles "ß" are larger, an assumed reference output "N" or an assumed torque "M," increased by correction factor "k" must be used (see example below).

Conversion formulas:

Torque M [Nm] = 9550 N [kW] / n [rpm]
Output N [kW]= M [Nm] x n [rpm]
1 kW = 1.36 hp     1 hp = 0.736 kW

Example 1:

Transmitted output N= 5.5 kW
Speed n= 2300 rpm
Working angle ß= 10°
Correction factor k= 1
Reference output N = Rated
Output N Intersection "P" is derived from 5.5 kW and 2300 rpm (corresponding to a torque of 23 Nm).
The next larger joint corres-ponding to Point P is d1 = 28

Example 2:

Transmitted torque M = 23 Nm
Speed n= 2300 rpm
Working angle ß= 18°
Correction factor k= 1.43
Reference torque
M = 1.43 x 23 Nm = 33 Nm
Intersection P1 is derived from 33 Nm and 2300 rpm (corresponding to a reference output N = 8.3 kW).
The next larger joint corres-ponding to Point P1 is d1 = 32

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