Laundry appliance
AssigneeFisher & Paykel Limited
InventorsGregory Raymond Collecutt, David Charles Rhodes
Life of this patent
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Abstract
A balancing system for a laundry appliance is disclosed, which is particularly suited to horizontal axis washing machines. The system includes force and acceleration transducers at each end of the drum, to detect the imbalance. Several algorithms are disclosed, which calculate the correction required to correct for the imbalance. The correction is implemented using a set of balancing chambers, at each end of the drum. The advantages include the traditional mechanical suspension to be dispensed with, and that the system is capable of adapting to different types of floors.
Claims13
A laundry appliance having a perforated drum for dehydrating a clothes load, an electric motor adapted to rotate said drum at speed thereby dehydrating the load and a system for compensating for imbalances of said drum and any load carried therein during dehydration of the load, said system comprising:
- at least one sensor located at more than one position on the drum spin axis for detecting rotational imbalance in the load,
- correction means for adding one or more masses to said drum,
- a digital processor which in use receives as inputs signals from said sensor, and programmed to calculate the value and position of one or more masses required to be added to the drum depending on at least said sensed imbalance and any past, current or future additions, said processor controlling such additions such that the resultant value and position is substantially similar to said modified value and position to correct the imbalance.
A laundry appliance having a perforated drum for dehydrating a clothes load, driving means adapted to rotate said drum at speed thereby dehydrating the load and a system for compensating for imbalances of said drum and any load carried therein during dehydration of the load, said system comprising:
- at least one sensor located at more than one position on the spin axis of said drum for detecting rotational imbalance in the load,
- correction means for adding two or more masses to said drum to correct for any imbalance caused by the rotation thereof, and
- a digital processor which in use receives as inputs signals from said sensor and programmed with software causing said processor to carry out the following steps:
- a) energising said electric motor to apply a first predetermined rate of rotation to said drum;
- b) energising said correction means to add at least one small imbalance to at least one end of said drum and storing the detected rotational imbalances at each end of said drum;
- c) determining the differential relationship between said at least one added imbalances' and said detected rotational imbalances' at each end of said drum, thereby estimating the value and position of one or more masses required to be added to the drum to correct the actual imbalance;
- and
- d) controlling additions of one or more masses to said drum by said correction means such that the resultant value and position of the added masses is substantially similar to the said estimated value and position to correct the imbalance.
A laundry appliance having a perforated drum for dehydrating a clothes load, driving means adapted to rotate said drum at speed thereby dehydrating the load and at least two independent systems for compensating for imbalances of said drum and any load carried therein during dehydration of the load, each said system comprising:
- at least one sensor located at one or more positions on the spin axis of said drum for detecting rotational imbalance in the load,
- a digital processor which in use receives as inputs signals from said sensor and programmed to estimate the value and position of one or more masses required to be added to the drum to correct the sensed imbalance,
- correction means for adding one or more masses to said drum, said processor in use controlling such additions such that the resultant value and position of the added masses is substantially similar as the said estimated value and position to correct the imbalance.
A laundry appliance having a perforated drum for dehydrating a clothes load, an electric motor adapted to rotate said drum at speed thereby dehydrating the load and a system for compensating for imbalances of said drum and any load carried therein during dehydration of the load, said system comprising:
- at least one sensor located at more than one position on the drum spin axis for detecting rotational imbalance in the load,
- correction means for adding one or more masses to said drum,
- a digital processor which in use receives as inputs signals from said sensor and adapted to energise said electric motor and said correction means and programmed with software causing said processor to carry out the following steps:
- 1) monitor the rotational imbalance based on the output of said sensor;
- 2) energise said electric motor to redistribute the load within said drum if said estimated imbalance is above a first predetermined threshold;
- 3) if said estimated imbalance is below said first predetermined threshold determine the value and position of one or more masses required to be added to the drum to correct the sensed imbalance;
- 4) if said estimated imbalance is below said first predetermined threshold energise said correction means such that the resultant value and position of any additions is substantially similar to the calculated value and position to correct the imbalance;
- and
- 5) energise said electric motor to apply a further faster rate of rotation to said drum so as to effectively dehydrate said load.
Dependencies are inferred from the claim text.