Rotationslack

Rotationslack is a term used to describe the presence of angular slack or backlash in a rotational system, resulting in a delay or mismatch between input rotation and the resulting output motion. It arises from elasticity and clearances in components such as gears, belts, couplings, shafts, and bearings, as well as from mounting tolerances and structural flex.

In practical engineering, rotationslack can be modeled as a torsional spring with deadband or backlash, producing a nonzero angular offset until the transmitted torque exceeds a threshold. In systems, it manifests as a phase lag, position error, or stick-slip behavior, particularly under changing loads or rapid direction changes.

Causes include gear tooth backlash, belt elongation, bearing play, shaft flex, and coupling compliance. Environmental factors such as temperature can alter clearances and stiffness, affecting the magnitude of rotationslack. The effect is often more pronounced during acceleration or deceleration and in high-precision or high-speed applications.

Effects of rotationslack include reduced control accuracy in servo and CNC systems, increased vibration and noise, and wear patterns that reflect cyclic loading. Diagnosis typically involves high-speed angular sensing, torque measurement, or strain sensing to distinguish rotationslack from other disturbances.

Mitigation and design approaches emphasize selecting low-backlash components, pretensioning belts, rigid or preloaded bearings, and stiff or carefully chosen couplings. Control strategies may include feedforward compensation, backlash modeling, and regular calibration. In precision machinery, rotationslack is a central consideration for achieving repeatable and predictable motion.

See also: backlash, hysteresis, deadband, stick-slip, torsional stiffness, gear lash.