Stator assembly, electric pump having stator assembly, and method for manufacturing stator assembly

An electric pump, comprising:

• a stator assembly,
• a housing,
• a rotor assembly, and
• an electric control board,
• wherein the housing forms an inner cavity, the rotor assembly and the stator assembly are arranged in the inner cavity, the rotor assembly and the stator assembly are separated from each other by the housing, the stator assembly is arranged around the rotor assembly, the electric control board is arranged to be electrically connected to the stator assembly, and the stator assembly, comprising:
• a stator core, and
• a winding,
• wherein the stator core comprises teeth and a yoke, and the yoke comprises an inner circumferential surface and an outer circumferential surface, and the teeth are arranged and distributed along the inner circumferential surface or the outer circumferential surface of the yoke,
• wherein the stator core is formed by stacked silicon steel sheets, and each of the teeth comprises a neck and a tip, and two ends of the neck are respectively connected to the yoke and the tip,
• wherein the neck comprises a winding portion that provides support for the winding, and the neck comprises a first stacking portion, a second stacking portion, a first plane portion and a second plane portion, and the first stacking portion and the second stacking portion are arranged opposite to each other, the first plane portion and the second plane portion are arranged opposite to each other, and the first stacking portion and the second stacking portion are formed by stacking silicon steel sheets of the neck,
• wherein in a stacking direction of the neck, the first plane portion and the second plane portion are outer surfaces of silicon steel sheets located at two terminal ends of the neck;
• wherein in the stacking direction of the silicon steel sheets of the neck, and from the first plane portion and/or the second plane portion to the middle of the winding portion in a height direction, the widths of the silicon steel sheets gradually increase to allow the first stacking portion and the second stacking portion to be in an arc-like shape;
• wherein a furthest distance from the first stacking portion to the second stacking portion is a first distance (W), a distance between the first plane portion and the second plane portion is a second distance (H), and the ratio of the second distance to the first distance is greater than or equal to ½ and smaller than or equal to 1,
• wherein the tip comprises a first terminal end, a second terminal end, and a magnet collecting surface, and the magnet collecting surface collects a magnetic field, the first terminal end and the second terminal end are located at two ends of the magnet collecting surface, and the first terminal end is arranged to be flush with the first plane portion of the neck,
• wherein each of the teeth and the yoke are assembled to be fixed, and a stacking direction of silicon steel sheets of the yoke is same with the stacking direction of the silicon steel sheets of each of the teeth,
• the tip comprises a first portion and a second portion which are aligned in an axis direction of the yoke, and the first portion is connected directly to the neck and the second portion is not directly connected to the neck,
• the first plane portion of the neck is arranged to be flush with the first portion of the tip, and the second portion of the tip is arranged to protrude out of the second plane portion of the neck.

A method for manufacturing a stator assembly, wherein:

• the stator assembly comprises:
• a stator core, and
• a winding,
• wherein the stator core comprises teeth and a yoke, and the yoke comprises an inner circumferential surface and an outer circumferential surface, and the teeth are arranged and distributed along the inner circumferential surface or the outer circumferential surface of the yoke,
• wherein the stator core is formed by stacked silicon steel sheets, and each of the teeth comprises a neck and a tip, and two ends of the neck are respectively connected to the yoke and the tip,
• wherein the neck comprises a winding portion that provides support for the winding, and the neck comprises a first stacking portion, a second stacking portion, a first plane portion and a second plane portion, and the first stacking portion and the second stacking portion are arranged opposite to each other, the first plane portion and the second plane portion are arranged opposite to each other, and the first stacking portion and the second stacking portion are formed by stacking silicon steel sheets of the neck,
• wherein the tip comprises a first terminal end, a second terminal end, and a magnet collecting surface, and the magnet collecting surface collects a magnetic field, the first terminal end and the second terminal end are located at two ends of the magnet collecting surface, and the first terminal end is arranged to be flush with the first plane portion of the neck,
• wherein each of the teeth and the yoke are assembled to be fixed, and a stacking direction of silicon steel sheets of the yoke is same with the stacking direction of the silicon steel sheets of each of the teeth,
• the tip comprises a first portion and a second portion which are aligned in an axis direction of the yoke, and the first portion is connected directly to the neck and the second portion is not directly connected to the neck,
• the first plane portion of the neck is arranged to be flush with the first portion of the tip, and the second portion of the tip is arranged to protrude out of the second plane portion of the neck,
• a forming process of the stator assembly comprises:
• forming a yoke comprises blanking a plurality of first silicon steel sheets of the yoke and stacking and riveting the plurality of first silicon steel sheets,
• forming teeth comprises blanking a plurality of second silicon steel sheets of a neck and the first portion of the tip and stacking and riveting the plurality of second silicon steel sheets, and blanking a plurality of third silicon steel sheets of the second portion of the tip and stacking the plurality of third silicon steel sheets on the plurality of second silicon steel sheets and riveting the plurality of third silicon steel sheets to the plurality of the second silicon steel sheets,
• forming a stator core comprises injection molding the yoke and the teeth by an insulating layer.