초록 ▼

In order to determine an imbalance of a rotor caused to turn by means of a driving arrangement, imbalance-produced deflections or accelerations of the driving arrangement, spring-loaded with respect to a stationary housing, are determined and relayed as an electrical signal to an evaluation device.

In order to determine an imbalance of a rotor caused to turn by means of a driving arrangement, imbalance-produced deflections or accelerations of the driving arrangement, spring-loaded with respect to a stationary housing, are determined and relayed as an electrical signal to an evaluation device. The sensor may be, for example, a piezoelectric crystal for detection of accelerations of the drive unit caused by imbalance or a path sensor for detection of deflections of the drive unit relative to the housing as a result of imbalance. The signal is evaluated as a function of the rotary speed of the rotor by means of an adaptive band filter. The method is especially suitable for determination of imbalance during operation of laboratory centrifuges, where an imbalance can occur, for example, from breakage of test tubes.

대표청구항 ▼

A method for determining an imbalance of a rotor caused to rotate by means of a rotor driving arrangement, said method comprising the steps of: a) connecting movement sensor means for generating an electrical signal corresponding to a selected movement of said rotor driving arrangement to said rotor

A method for determining an imbalance of a rotor caused to rotate by means of a rotor driving arrangement, said method comprising the steps of: a) connecting movement sensor means for generating an electrical signal corresponding to a selected movement of said rotor driving arrangement to said rotor driving arrangement; b) relaying said electrical signal to signal evaluation means for determining when said movement exceeds a predetermined value indicating rotor imbalance; c) generating an electrical control signal corresponding to the speed of said rotor; d) relaying said electrical control signal to said signal evaluation means to thereby permit said electrical signal generated by said movement sensor means to be evaluated as a function of rotor speed; e) relaying said electrical control signal to an adaptive band pass filter, said electrical control signal being utilized as the center frequency for said adaptive band pass filter, said adaptive band pass filter generating a signal amplitude; f) relaying said signal amplitude to a rectifier for transformation into a rectified voltage value; g) relaying said rectified voltage value to a differential element whereas a trigger signal is transmitted to a warning- or to switching-off unit in response to a predetermined change in rectified voltage value.