Patent Description:
Currently, motors of most high speed blenders in the market each generally has only one output shaft with a stirring blade fitted on. As rotation speed of the stirring blade increases, noise produced during the operation of a high speed blender also increases.

During a long period of research and development, inventors of the present disclosure found that using a counter-rotating motor as a motor of the high speed blender can make stirring blades mounted to two output shafts counter-rotate relative to each other, thereby improving the stirring effect and producing less noise. At present, in a traditional counter-rotating motor, a brush and a slip ring are used to drive two rotating shafts to rotate in opposite directions. However, noise generated by the brush is high and wear to the brush is serious, thus affecting motor life. In a two-rotor permanent magnet motor, two inverters are used to control two sets of stator and rotor for counter-rotation. In this configuration, although the brush is eliminated, the inverters are costly, complicated to control, and take up a lot of space.

<CIT> relates generally to electrical machines, such as asynchronous induction machines used in water turbines. <CIT>relates generally to a motor driving apparatus. <CIT> relates generally to a double-stator/double-rotor type motor and a direct drive apparatus for a washing machine using the double-stator/double-rotor type motor.

The present disclosure provides a high speed blender comprising a counter-rotating motor to solve technical problems of high noise made by the counter-rotating motor and complicated control in related art.

The counter-rotating motor includes a stator, an inverter, an inner rotor and an outer rotor.

The stator includes an outer winding and an inner winding. A phase sequence of the outer winding is reverse to a phase sequence of the inner winding.

The inverter is connected in parallel with the outer winding and the inner winding and configured to supply an excitation current to the outer winding and the inner winding synchronously.

The inner rotor is arranged at an inner side of the inner winding and configured to rotate in a first direction by an action of the inner winding.

The outer rotor is arranged at an outer side of the outer winding and configured to rotate in a second direction opposite to the first direction by an action of the outer winding.

The outer winding may include a three-phase winding. The inner winding may include a three-phase winding. A phase sequence of the three-phase winding in the outer winding may be reverse to a phase sequence of the three-phase winding in the inner winding.

The outer winding may include a plurality of three-phase windings. The inner winding may include a plurality of three-phase windings. Each three-phase winding of the outer winding may have a same phase sequence. Each three-phase winding of the inner winding may have a same phase sequence.

Each three-phase winding may include an A-phase winding, a B-phase winding, and a C-phase winding. The A-phase winding, B-phase winding, and C-phase winding of the inner winding may be sequentially arranged in a counterclockwise direction. The A-phase winding, B-phase winding, and C-phase winding of the outer winding may be sequentially arranged in a clockwise direction.

The inverter may include a first current output terminal, a second current output terminal, and a third current output terminal. The A-phase winding of the outer winding and the A-phase winding of the inner winding may be connected in parallel to the first current output terminal. The B-phase winding of the outer winding and the B-phase winding of the inner winding may be connected in parallel to the second current output terminal. The C-phase winding of the outer winding and the C-phase winding of the inner winding may be connected in parallel to the third current output terminal.

One of the inner rotor and the outer rotor may be a first squirrel cage rotor. The other of the inner rotor and the outer rotor may be a second squirrel cage rotor, a permanent magnet rotor, or a reluctance rotor.

The inverter may be configured to perform a closed-loop vector control of the second squirrel cage rotor, permanent magnet rotor, or reluctance rotor. The first squirrel cage rotor may be configured to automatically operate in a V/F open-loop control mode.

The stator may include an inner stator, and an outer stator that is disposed on a periphery of the inner stator. The inner winding may be arranged on the inner stator. The outer winding may be arranged on the outer stator.

The counter-rotating motor may further include a magnetic barrier. The magnetic barrier may be disposed between the outer stator and the inner stator and may be configured to magnetically isolate the outer winding from the inner winding.

The high speed blender may further include a first blade and a second blade. The first blade may be connected to the inner rotor. The second blade may be connected to the outer rotor such that the first blade and the second blade can counter-rotate relative to each other.

In the present disclosure, the counter-rotating motor may include an inner winding and an inner rotor matched with each other and an outer winding and an outer rotor matched with each other. In addition, one inverter may be configured to control the outer winding and the inner winding synchronously. In this way, the brush can be eliminated, the noise can be reduced, the motor life can be increased, and since two inverters are not required, the cost can be lower and the control can be simpler.

In order to make the technical solution described in the embodiments of the present disclosure more clear, the drawings used for the description of the embodiments will be briefly described. Apparently, the drawings described below are only for illustration but not for limitation. It should be understood that, one skilled in the art might acquire other drawings based on these drawings, without paying any creative efforts.

Technical solutions of the embodiments of the present disclosure may be clearly and comprehensively described by referring to accompanying figures of the embodiments. Obviously, embodiments to be described are only a part of, but not all of, the embodiments of the present disclosure. Any ordinary skilled person in the art may obtain other embodiments based on the embodiments of the present disclosure without any creative work, and the other embodiments should be included in the scope of the present disclosure.

As shown in <FIG>, a counter-rotating motor includes a stator <NUM>, an inverter <NUM>, an inner rotor <NUM> and an outer rotor <NUM>. The stator <NUM> may include an outer winding <NUM> and an inner winding <NUM>. A phase sequence of the outer winding <NUM> is reverse to a phase sequence of the inner winding <NUM>. The inverter <NUM> is connected in parallel with the outer winding <NUM> and the inner winding <NUM> to supply an excitation current to the outer winding <NUM> and the inner winding <NUM> synchronously. The inner rotor <NUM> is arranged at an inner side of the inner winding <NUM> and configured to rotate in a first direction by an action of the inner winding <NUM>. The outer rotor <NUM> is arranged at an outer side of the outer winding <NUM> and configured to rotate in a second direction opposite to the first direction by an action of the outer winding <NUM>.

The counter-rotating motor <NUM> may include an inner winding <NUM> and an inner rotor <NUM> matched with each other and an outer winding <NUM> and an outer rotor <NUM> matched with each other. In addition, one inverter <NUM> may be configured to control the outer winding <NUM> and the inner winding <NUM> synchronously. In this way, the brush can be eliminated, the noise can be reduced, and the motor life can be increased, and since two inverters are not required, the cost can be lower and the control can be simpler.

One of the inner rotor <NUM> and the outer rotor <NUM> may be a first squirrel cage rotor, and the other of the inner rotor <NUM> and the outer rotor <NUM> may be a second squirrel cage rotor, a permanent magnet rotor, or a reluctance rotor. The inverter <NUM> may be configured to perform a closed-loop vector control of the second squirrel cage rotor, permanent magnet rotor, or reluctance rotor. The first squirrel cage rotor may be configured to automatically operate in a V/F open-loop control mode. Specifically, the closed-loop vector control means that rotation speed and torque of the motor may be controlled separately, and output voltages may be generated to match different loads in response to received feedback signals. A V/F open-loop control means that a ratio of output voltage V to operating frequency F may be a constant value, and a feedback signal may not be received, thus the output voltage may not be affected by the load.

For example, the outer rotor <NUM> may be a first squirrel cage rotor and the inner rotor <NUM> may be a permanent magnet rotor. A permanent magnet <NUM> may be embedded within or attached to a surface of the permanent magnet rotor. The inverter <NUM> may perform a closed-loop vector control of the permanent magnet rotor such that the first squirrel cage rotor can automatically operate in the V/F open-loop control mode. For example, in other examples, the inner rotor <NUM> may be a first squirrel cage rotor and the outer rotor <NUM> may be a second squirrel cage rotor. The inverter <NUM> may perform the closed-loop vector control of the second squirrel cage rotor such that the open-loop V/F control of the first squirrel cage rotor can be achieved.

One of the inner rotor <NUM> and the outer rotor <NUM> may be the first squirrel cage rotor, so as to overcome the disadvantage that two rotors in a dual rotor motor with dual permanent magnet rotors, dual reluctance rotors or a permanent magnet rotor and a reluctance rotor must be controlled separately by two inverters, thus realizing the control of the two rotors, the inner rotor <NUM> and the outer rotor <NUM>, by one inverter <NUM>.

The outer winding <NUM> and the inner winding <NUM> may each include a three-phase winding. A phase sequence of the three-phase winding in the outer winding <NUM> may be reverse to a phase sequence of the three-phase winding in the inner winding <NUM>, such that the inner rotor <NUM> corresponding to the inner winding <NUM> and the outer rotor <NUM> corresponding to the outer winding <NUM> may rotate in opposite directions.

The outer winding <NUM> and the inner winding <NUM> may each include a plurality of three-phase windings. Each three-phase winding of the outer winding <NUM> may have a same phase sequence. Each three-phase winding of the inner winding <NUM> may have a same phase sequence. In this way, the inner rotor <NUM> corresponding to the inner winding <NUM> or the outer rotor <NUM> corresponding to the outer winding <NUM> can continuously rotate in a same direction.

Specifically, the three-phase winding may include an A-phase winding, a B-phase winding, and a C-phase winding. An A-phase winding <NUM>, a B-phase winding <NUM>, and a C-phase winding <NUM> in the inner winding <NUM> may be sequentially arranged in a counterclockwise direction, and an A-phase winding <NUM>, a B-phase winding <NUM>, and a C-phase winding <NUM> in the outer winding <NUM> may be sequentially arranged in a clockwise direction. In other examples, the A-phase winding <NUM>, B-phase winding <NUM>, and C-phase winding <NUM> in the inner winding <NUM> may also be sequentially arranged in a clockwise direction, and the A-phase winding <NUM>, B-phase winding <NUM>, and C-phase winding <NUM> in the outer winding <NUM> may be sequentially arranged in the counterclockwise direction, without limitation herein.

The inverter <NUM> may include a first current output terminal <NUM>, a second current output terminal <NUM>, and a third current output terminal <NUM>. The A-phase winding of the outer winding <NUM> and the A-phase winding of the inner winding <NUM> may be connected in parallel to the first current output terminal <NUM>, the B-phase winding of the outer winding <NUM> and the B-phase winding of the inner winding <NUM> may be connected in parallel to the second current output terminal <NUM>, and the C-phase winding of the outer winding <NUM> and the C-phase winding of the inner winding <NUM> may be connected in parallel to the third current output terminal <NUM>. In this way, the inverter <NUM> can precisely control each three-phase winding of the inner winding <NUM>, and the control of the three-phase winding of the outer winding <NUM> can be automatically achieved at the same time.

The stator <NUM> may include an inner stator <NUM>, and an outer stator <NUM> that is disposed on a periphery of the inner stator <NUM>. The inner winding <NUM> may be arranged on the inner stator <NUM>, and the outer winding <NUM> may be arranged on the outer stator <NUM>. The counter-rotating motor <NUM> may further include a magnetic barrier <NUM>. The magnetic barrier <NUM> may be disposed between the outer stator <NUM> and the inner stator <NUM> and may be configured to magnetically isolate the outer winding <NUM> from the inner winding <NUM>. The magnetic barrier <NUM> can be configured to magnetically isolate the outer winding <NUM> from the inner winding <NUM>, thus avoiding the magnetic field interference between the outer winding <NUM> and the inner winding <NUM> that may affect normal operation of the counter-rotating motor <NUM>.

Specifically, a power source (not shown) may supply power to the outer winding <NUM> and the inner winding <NUM> through the inverter <NUM> at the same time. The inner winding <NUM> may generate a first magnetic field in response to the excitation current to drive the permanent magnet rotor to rotate in the first direction. For example, the first direction may be the clockwise direction, a voltage and frequency of the inner winding <NUM> may gradually increase, and a rotation speed of the permanent magnet rotor may gradually increase accordingly. The inverter <NUM> can precisely control a rotation speed or torque of the permanent magnet rotor by precisely controlling an output voltage, output current and output frequency of the inner winding <NUM>, thereby achieving a closed-loop vector control of the inner winding <NUM>. At the same time, the outer winding <NUM>, which is connected to the inverter <NUM> in parallel with the inner winding <NUM>, may also receive an excitation current to generate a second magnetic field. Since the phase sequence of the outer winding <NUM> is reverse to the phase sequence of the inner winding <NUM>, the first squirrel cage rotor may be driven by the outer winding <NUM> to rotate in the second direction opposite to the first direction, for example, the second direction may be counterclockwise direction. A voltage and frequency of the outer winding <NUM> can gradually increase, and a rotation speed of the first squirrel cage rotor can gradually increase accordingly. Since a ratio of the output voltage to the output frequency is a constant when the closed-loop vector control of the inner winding <NUM> by the inverter <NUM> is achieved, the first squirrel cage rotor may automatically operate in the V/F open-loop control mode. When a load on the first squirrel cage rotor is larger, the first squirrel cage rotor may run at a lower rotation speed than a magnetic field synchronous speed through its own control, thereby generating a rotation difference. In this way, an asynchronous electromagnetic torque matching the load may be generated and risk of out of synchronization may be avoided.

With reference of <FIG>, in another example, the counter-rotating motor <NUM> may include a stator <NUM> structured as a single unit. The inner winding <NUM> may be arranged in an inner ring of the stator <NUM> and the outer winding <NUM> may be arranged on an outer ring of the stator <NUM>. The inner winding <NUM> and the outer winding <NUM> may be precisely controlled to avoid the interference between the inner winding <NUM> and the outer winding <NUM>. A control method in this example may be more complicated than the above example of a counter-rotating motor <NUM> with a magnetic barrier <NUM>, but structure of the counter-rotating motor <NUM> may be simpler.

Referring to <FIG>, in an embodiment of the present disclosure, a high speed blender may include a counter-rotating motor <NUM>, a first blade <NUM>, and a second blade <NUM>. Structure of the counter-rotating motor <NUM> is described in the above embodiments and will not be described herein. The first blade <NUM> may be connected to the inner rotor <NUM>, and the second blade <NUM> may be connected to the outer rotor <NUM>. In this way, the first blade <NUM> and the second blade <NUM> can counter-rotate relative to each other.

In detail, the high speed blender may further include a base <NUM>, a first output shaft <NUM>, a second output shaft <NUM>, and a cup <NUM>. The cup <NUM> may be arranged on the base <NUM> and define a receiving chamber <NUM>. The counter-rotating motor <NUM> may be arranged in the base <NUM>. The first output shaft <NUM> and the second output shaft <NUM> may penetrate through the base <NUM>. The second output shaft <NUM> may be nested in the first output shaft <NUM>. The first output shaft <NUM> may be fixedly connected to the inner rotor <NUM> and the first blade <NUM>. The second output shaft <NUM> may be fixedly connected to the outer rotor <NUM> and the second blade <NUM>. In this way, the first blade <NUM> may rotate with the inner rotor <NUM> and the second blade <NUM> may rotate with the outer rotor <NUM> such that the first blade <NUM> and the second blade <NUM> may counter-rotate relative to each other, and a relative rotation speed between the first blade <NUM> and the second blade <NUM> can reach twice the speed of a single blade. In this way, food received in the receiving chamber <NUM> can be better processed. In other embodiments, a plurality of blades may be arranged on the first output shaft <NUM> and the second output shaft <NUM>, without limitation herein.

The counter-rotating motor <NUM> of the high speed blender in the embodiments of the present disclosure may include an inner winding <NUM> and an inner rotor <NUM> matched with each other and an outer winding <NUM> and an outer rotor <NUM> matched with each other. In addition, one inverter <NUM> may be configured to control the outer winding <NUM> and the inner winding <NUM> synchronously. In this way, the brush can be eliminated, the noise can be reduced, the motor life can be increased, and since two inverters are not required, the cost can be lower and the control can be simpler. A blade <NUM> may be connected to the inner rotor <NUM> and another blade <NUM> to the outer rotor <NUM>, such that a relative rotation speed between the two blades <NUM>, <NUM> can reach twice the speed of a single blade, thereby processing efficiency can be improved without increasing noise.

Claim 1:
A high speed blender comprising a counter-rotating motor (<NUM>), comprising:
a stator (<NUM>), comprising an outer winding (<NUM>) and an inner winding (<NUM>), wherein a phase sequence of the outer winding (<NUM>) is reverse to a phase sequence of the inner winding (<NUM>);
an inverter (<NUM>), connected in parallel with the outer winding (<NUM>) and the inner winding (<NUM>) and configured to supply an excitation current to the outer winding (<NUM>) and the inner winding (<NUM>) synchronously;
an inner rotor (<NUM>), arranged at an inner side of the inner winding (<NUM>) and configured to rotate in a first direction by an action of the inner winding (<NUM>);
an outer rotor (<NUM>), arranged at an outer side of the outer winding (<NUM>) and configured to rotate in a second direction opposite to the first direction by an action of the outer winding (<NUM>).