Ergometer with constant torques electrodynamic hysteresis coupling - using ferromagnetic, low permeability high coercive force, hysteresis material and directly-driven coupler

摘要

An ergometer with a pedal operated drive and an associated braking device working electrodynamically generates full braking torque at the very low revolution rates required for medical applications. A hyoteresic coupling brake contains a first coupling component not directly driven by the drive system having an associated defined magnetic field generator. This produces a braked relative motion opposed to the drive. A directly driven coupling component arranged opposite the first consists of hysteresis material easily demagnetised by the field generated by the first coupling component magnetic field generator. The hysteresis, material is a ferromagnetic of chrome-cobalt or nickel-aluminium type, pref. an istropic ferromagnetic with a comparatively low initial permeability, e.g. about 10, and high coercive field strength, e.g. between 100 and 400 Oersted.