based on limits of Mass Acceleration
When Cardan Shaft (Universal Joint
Shaft) are operated at any angle
greater than zero, the center
section of the universal joint shaft
always run irregularly, being
accelerated and de-accelerated twice
in every revolution. The maximum
valves of mass acceleration torque
arising here are dependent on the
operating speed and angle of
and upon the moment of inertia of
the cardan shaft section (RPM X
To ensure smooth running of the
universal joint, especially at
idling speed, the mass acceleration
torque must not be allowed to exceed
the limits shown in Table 1.
Limit based on Lateral Critical
In applications where long
lengths of shafts are required, the
speed is restricted by the lateral
critical speed of the center
section. This speed is a function of
the center tube diameter wall
thickness, and the effective length.
The maximum operating speed must be
less than the lateral critical speed
Nc shown in Table 2.
Allowable Operating Speed = NC x
In many applications, operation
at 1/2 critical speed will also
create unacceptable vibration. For
these applications the operating
speed should be 8% above or below
50% of the maximum indicated.
For flange-to-flange lengths
greater than shown, or if allowable
speed is exceeded, contact CARDAN
All standard universal joints
under 300 RPM are supplied
unbalanced. Between 300-850 RPM they
are balanced if required. Consult
factory for further information.
Over 850 RPM all universal joints
are normally supplied balanced.
Please consult the factory for
special balancing requirements.