Abstract The invention relates to centrifuging devices, and particularly to the acceleration thereof to a design speed. In order to prevent imbalance (U) of the device exceeding a permitted maximum value (U m ) during acceleration, the imbalance (U) is monitored and acceleration (α) controlled as a function of temporal changes in the imbalance (U). Acceleration n/ t may be controlled in relation to the difference (ΔU) between the measured imbalance (U) and the maximum value (U m ), in relation to the rate of change (β) of the measured imbalance, or to maintain the imbalance (U) between upper (U 1 ) and lower (U 2 ) threshold values at or below the maximum value (U m ). Acceleration to the design speed can thus be accomplished with minimum delay and variation with reference to operating criteria of the device.
A method for controlling the acceleration to design speed of a centrifuging device subject to variable imbalance, the method comprising the steps of measuring the imbalance as the device is accelerated; limiting speed changes of the device to a positive range of acceleration values including zero; and regulating acceleration of the device within that range solely as a function of the difference between the measured imbalance and a threshold value, whereby the acceleration period is kept short while avoiding excessive imbalance.
Claim 2
Independent Claim
81 words
A method for controlling the acceleration to design speed of a centrifuging device subject to variable imbalance, the method comprising the steps of measuring the imbalance as the device is accelerated; limiting speed changes of the device to a positive range of acceleration values including zero; and regulating acceleration of the device within that range solely as a function of the difference between the measured imbalance and a threshold value, whereby the acceleration period is kept short while avoiding excessive imbalance.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the threshold value is the maximum permissible imbalance value.
Claim 4
Dependent Claim
17 words
A method according to claim 1 wherein the acceleration of the device reduces as does said difference.
Claim 5
Dependent Claim
33 words
A method according to claim 1 wherein initial acceleration of the device is carried out independantly of any imbalance up to a predetermined speed, imbalance being subsequently monitored and acceleration being accordingly controlled.
Claim 6
Dependent Claim
21 words
A method according to claim 1 wherein imbalance is measured as a function of the deflection of the device during rotation.
Claim 7
Dependent Claim
25 words
A method according to claim 1 wherein imbalance is measured as a function of the forces occurring on at least one bearing of the device.
Claim 8
Dependent Claim
17 words
A method according to claim 6 wherein said at least one bearing includes an hydrostatic support piston.
Claim 9
Dependent Claim
19 words
A method according to claim 1 wherein said device is a centrifuge drum which rotates about a horizontal axis.
Claim 10
Dependent Claim
23 words
A method according to claim 1 wherein said device is a centrifuge drum of a washing machine which rotates about a horizontal axis.