Patent ID: 7926313

Claim:
Device for detecting motions of a rotatable component of a domestic appliance that are caused by unbalance, said device having: a housing ( 2 ), a mass ( 14 ; M) which is movable in the housing ( 2 ) in dependence on motions of the rotatable component that are caused by unbalance, a spring arrangement ( 10 , 12 ; 22 ; F) acting upon the mass in order, in the idle state, to hold the mass ( 14 ; M) in an initial position, and a fluidic damping (D) acting upon the mass ( 14 ; M) in order to damp movements of the mass ( 14 ; M) out of the initial position, at least one of the spring arrangement ( 10 , 12 ; 22 ; F), the mass ( 14 ; M) and the damping (D) being so designed that, above a predefined frequency of motions of the rotatable component that are caused by unbalance of said component, movements of the mass ( 14 ; M) out of the initial position are substantially non-dependent on frequency, or frequency-dependent components of movements of the mass ( 14 ; M) out of the initial position are within a predefined range, said device further having a motion detection unit for detecting movements of the mass out of the initial position, the motion detection unit comprising a pressure sensor arrangement ( 42 ), wherein the device is fluidly coupled with the rotatable component by a fluid line, and wherein the ratio of spring constant of the spring arrangement and mass is selected such that the resonance frequency thereof lies in a lower end of a frequency range of unwanted motions of the rotatable component that are caused by the unbalance.