Fluid circulation pump with synchronous motor, equipped with heating means of the fluid, in particular for washing machines

A fluid circulation pump with synchronous motor, equipped with fluid heating means, said fluid circulation pump comprising:

• a stator equipped with pole shoes with corresponding windings;
• a rotor equipped with a permanent magnet that is rotation-driven by an electromagnetic field generated by the stator;
• a magnetic flux sensor of said rotor;
• and
• a control unit equipped with drawing means to draw by a signal provided from said magnetic flux sensor, at least one parameter of an operating fluid, and comparing means to compare this parameter with a reference value and to output an electric signal to be used to cut off a power supply of said fluid heating means upon reaching a threshold of said at least one parameter,
• wherein said at least one parameter of said operating fluid is drawn from a presence of the operating fluid in said fluid circulation pump,
• wherein said control unit comprises a memory portion wherein correlation experimental data between the values of an operating variable of the synchronous motor and the values corresponding to a pump flow rate are stored, said operating variable of the synchronous motor being the measure of a load or lag angle Θ representing the phase displacement between a voltage applied across the synchronous motor and a counter electromotive force caused by a sum of effects of a stator flux and of a flux induced by a rotor permanent magnet rotation, drawn by the magnetic flux sensor, and
• wherein the fluid presence in said fluid circulation pump is detected by an output signal of said control unit being proportional to said measure of the load or lag angle Θ and to the pump flow rate.

A fluid circulation pump with synchronous motor, equipped with fluid heating means, said pump comprising:

• a stator equipped with pole shoes with corresponding windings;
• a rotor equipped with a permanent magnet that is rotation-driven by an electromagnetic field generated by the stator;
• a magnetic flux sensor of said rotor, wherein said magnetic flux sensor is an analogue Hall sensor;
• and
• a control unit equipped with drawing means to draw, by the signal provided from said magnetic flux sensor, at least one parameter of an operating fluid, and comparing means to compare this parameter with a reference value and to output an electric signal to be used to cut a power supply of said fluid heating means off upon reaching a threshold of said parameter,
• wherein said drawing means comprise a device that is capable of drawing a temperature value of said operating fluid from a sinusoidal signal coming from said analogue Hall sensor;
• wherein said comparing means comprise an analogue digital comparator allowing a temperature and/or a fluid presence to be compared with the reference value and an output signal being capable to interrupt the power supply of said fluid heating means to be generated upon exceeding said reference value;
• and
• wherein said output signal of said comparing means is a digital signal and operates on a switch inserted on a power supply line to said fluid heating means.