A pump is driven by a compact electric motor in which a coil is disposed in a ring form around and along a stator core which has a plurality of claw magnetic poles that extend alternately from both ends of one member of the stator core toward the end of the other member thereof. A stator core can be made from a compressed powder core by molding with resin, with the molded portion able to serve as a partition separating pump and motor units.
1. An electric pump mounted in a vehicle, comprising:
an electric motor and a pump structural body,
said electric motor including:
a stator comprising a stator core and a stator coil, and
a rotor constituted so that different magnetic poles are formed in the circumferential direction alternatively, and supported rotatably;
wherein said stator core having a plurality of first claw magnetic poles and a plurality of second claw magnetic poles, each of said plurality of first and second claw magnetic poles extending from an axial end of said core toward the other end of said core, and each of said plurality of first and second claw magnetic poles being formed alternatively in the circumferential direction;
said stator coil wound inside said core in a ring form, said stator coil generating different magnetic poles on said first and second claw magnetic poles upon being energized;
said plurality of first and second claw magnetic poles comprise a claw part which counters a rotor perimeter side and a claw base arranged at both sides of the rotor in the direction along in a rotation axis direction of said stator coil, respectively;
said plurality of first and second claw magnetic poles have a thickness in a direction of a path of the tip part of said claw part is less than a thickness in the direction of a rotation axis of said claw base; and
said pump structural body adapted to discharge a flowing medium as a rotational force is given to said pump structural body by said rotor.
2. The electric pump of claim 1 , wherein
wherein said core is formed to include a single phase, and
wherein magnetic field deviation portions are provided on said first and second claw magnetic poles to deviate a magnetic field in one circumferential direction.
3. The electric pump of claim 2 , wherein
said magnetic field deviation portions are provided so that one circumferential side of said first and second claw magnetic poles is farther from said magnetic pole member than the other circumferential side thereof.
4. The electric pump of claim 1 , wherein
said core is formed to include a plurality of phases.
5. An electric pump adapted to discharge a cooling medium, the electric pump comprising:
an electric motor having
a coil wound in a ring form;
a core formed of a claw part and a claw base along said coil in a tubular form so that different magnetic poles are formed alternately in a circumferential direction of said core as said coil is energized wherein a thickness of the claw base in a rotation direction of said core is greater than a thickness of said claw part in a direction transverse to the rotation direction; and
a magnetic pole member opposed to said magnetic pole forming portions of said core and relatively rotatable with said core so that different magnetic poles are formed in the circumferential direction; and
a pump structural body disposed adjacent to at least one end of said core and magnetic pole member so that said pump structural body discharges a cooling medium as a rotational force is given to said pump structural body by said core or magnetic pole member.
6. The electric pump of claim 5 ,
wherein said core and said magnetic pole member are housed in a motor housing; and
wherein one axial end of said motor housing serves also as a pump housing adapted to house said pump structural body.
7. The electric pump of claim 5 , wherein
the side end portion of said pump structural body disposed along the inner periphery of said motor housing is in close contact with said core.
8. The electric pump of claim 5 , wherein
a rotation stop mechanism is provided between the side end portion of said pump structural body disposed along the inner periphery of said motor housing and said core to restrict the relative rotation of said core.
9. The electric pump of claim 8 , wherein
said rotation stop mechanism comprises a projected portion on one side and a recessed portion on the other side.
10. The electric pump of claim 8 , wherein
wherein said cores are formed to include a plurality of phases; and
wherein said rotation stop mechanism is provided on said core for each phase.
11. The electric pump of claim 5 , wherein
bearings for said magnetic pole member are disposed along the inner periphery of said magnetic pole member.
12. An electric pump adapted to discharge a liquid, the electric pump comprising:
an electric motor having
a coil wound in a ring form;
a stator core formed of a claw part and a claw base along said coil in a tubular form and made from a compressed powder core so that different magnetic poles are formed alternately in the circumferential direction as said coil is energized, said core having a molded portion, formed by molding a non-magnetic material, at least on the inner periphery thereof wherein a thickness of the claw base in a rotation direction of said core is greater than a thickness of said claw part in a direction transverse to the rotation direction;
a rotor opposed to said magnetic pole forming portions of said stator core so that different magnetic poles are formed in the circumferential direction, with said rotor rotating in a liquid; and
a pump structural body adapted to discharge liquid as a rotational force is imparted to said pump structural body by said rotor.
13. The electric pump of claim 12 , wherein
said non-magnetic material is a resin material.
14. The electric pump of claim 12 , wherein
said molded portion is provided over the entire inner periphery of said stator core.
15. The electric pump of claim 12 , wherein
said non-magnetic material and said magnetic pole are formed alternately on the inner peripheral surface of said stator core.
16. The electric pump of claim 12 ,
wherein said stator core is formed to include a plurality of phases; and
wherein said molded portion is formed on said core for each phase.
17. The electric pump of claim 12 , wherein
channels are provided on said molded portion.
18. The electric pump of claim 17 , wherein
said channels are formed radially.
19. The electric pump of claim 17 , wherein
said stator cores are formed to include a plurality of phases, wherein
said molded portion is formed on said core for each phase, and wherein
a channel is provided between said phases.
20. The electric pump of claim 17 , wherein
said channel is formed at the center of said magnetic pole.
21. The electric pump of claim 1 , wherein said stator core is divided into two side portions.
22. The electric pump of claim 1 , wherein said stator core is a compressed powder core.
23. The electric pump of claim 1 , wherein an opening defined by the claw part and the claw base is a large opening.