Abstract: A fluid pump includes a pump casing, a motor connected to the pump casing, and an impeller driven by the motor. The motor includes a housing and a stator arranged in the casing. The housing is made of a non-magnetic material. The stator includes a stator iron core and a plurality of windings wound on the stator iron core. The motor further includes a sleeve having a cylindrical main body and a flange extending radially outwards from one end of the main body and fixed to the housing. An annular space is jointly bounded by the sleeve and the housing to accommodate the stator. A part of inner surface of the housing and a part of bottom surface of the flange facing the annular space are coated with a metal coating for electromagnetic wave shielding.

Abstract: A fluid pump includes a pump casing, a motor connected to the pump casing, and an impeller driven by the motor. The motor includes a housing and a stator arranged in the casing. The housing is made of a non-magnetic material. The stator includes a stator iron core and a plurality of windings wound on the stator iron core. The motor further includes a sleeve having a cylindrical main body and a flange extending radially outwards from one end of the main body and fixed to the housing. An annular space is jointly bounded by the sleeve and the housing to accommodate the stator. A part of inner surface of the housing and a part of bottom surface of the flange facing the annular space are coated with a metal coating for electromagnetic wave shielding.

Abstract: The present invention relates to a control technology of a three-phase DC motor. In order to resolve a problem in the prior art that the good current closed-loop control has not been realized on a three-phase square-wave brushless DC motor, the present invention provides a brushless DC motor control system, wherein cathodes of freewheel diodes D1, D3 and D5 are independent of input terminals of their respective switch tubes and connected in parallel to a sampling coil L1, and anodes of freewheel diodes D4, D6 and D2 are independent of output terminals of their respective switch tubes and connected in parallel to a sampling coil L2. The present invention can use a single resultant current sensor to completely and continuously sample the three-phase current existing during the motor is on and performs current freewheel, and perform the continuous closed-loop control on the three-phase current with a single current closed-loop regulator, thereby increasing dynamic and static indexes of the motor significantly.

Abstract: A hall rotary transformer comprises a rotary transformer stator (1), linear Hall components (3), a PCB (4) and a permanent magnet magnetic ring (5). A ring shape soft iron core (2) is installed on the PCB (4). Plural grooves (8) are uniformly distributed inside the peripheral surface of the ring shape soft iron core (2) and have the same number as the linear Hall components (3). Every linear Hall component (3) is installed in its corresponding groove (8) and soldered on the PCB (4). The magnetic sensitive surface of each linear Hall component (3) is aligned with the magnetic pole surface of the permanent magnet magnetic ring (5) each other. A Hall rotation angle encoder is made of the Hall rotary transformer.

Abstract: A hall rotary transformer comprises a rotary transformer stator (1), linear Hall components (3), a PCB (4) and a permanent magnet magnetic ring (5). A ring shape soft iron core (2) is installed on the PCB (4). Plural grooves (8) are uniformly distributed inside the peripheral surface of the ring shape soft iron core (2) and have the same number as the linear Hall components (3). Every linear Hall component (3) is installed in its corresponding groove (8) and soldered on the PCB (4). The magnetic sensitive surface of each linear Hall component (3) is aligned with the magnetic pole surface of the permanent magnet magnetic ring (5) each other. A Hall rotation angle encoder is made of the Hall rotary transformer.

Abstract: The present invention relates to a control technology of a three-phase DC motor. In order to resolve a problem in the prior art that the good current closed-loop control has not been realized on a three-phase square-wave brushless DC motor, the present invention provides a brushless DC motor control system, wherein cathodes of freewheel diodes D1, D3 and D5 are independent of input terminals of their respective switch tubes and connected in parallel to a sampling coil L1, and anodes of freewheel diodes D4, D6 and D2 are independent of output terminals of their respective switch tubes and connected in parallel to a sampling coil L2. The present invention can use a single resultant current sensor to completely and continuously sample the three-phase current existing during the motor is on and performs current freewheel, and perform the continuous closed-loop control on the three-phase current with a single current closed-loop regulator, thereby increasing dynamic and static indexes of the motor significantly.