Kardankreuz

Kardankreuz, or Cardan cross, is the cross-shaped internal component at the heart of a Cardan universal joint. It provides a four-armed pivot that connects two yokes carried on adjacent shafts, allowing angular misalignment while transmitting rotational power. The cross is typically made of hardened steel. Each of its four arms carries a trunnion that fits into bearings or bushings within the corresponding yoke, enabling smooth rotation about two perpendicular axes. The Cardan cross is mounted inside the joint with lubrication to reduce wear and ensure durability.

In operation, the input shaft and output shaft rotate together, but when the shafts are not collinear, the joint introduces a non-uniform output speed, a phenomenon commonly referred to as the Cardan effect or non-constant velocity transmission. The velocity fluctuations are most noticeable at larger misalignment angles.

To achieve a constant-velocity drive, two Cardan joints can be used in series with equal angles and proper phase alignment (typically 90 degrees apart). This arrangement cancels out the speed fluctuations of the individual joints.

Applications and maintenance: Kardankreuze are widely used in automotive drive shafts, industrial machinery, agricultural and marine transmissions, and other systems where shafts must connect at an angle. Regular maintenance includes proper lubrication, seal inspection, and monitoring for wear or corrosion. Excessive angle, misalignment, or wear can increase vibration, noise, and the likelihood of joint failure.