Electric fluid pump with improved rotor unit, rotor unit therefor and methods of construction thereof

1. An electric fluid pump, comprising:

a stator unit configured to generate a magnetic field in response to a control signal;

a rotor unit received within said stator unit, said rotor unit being configured to rotate about a central rotor axis in response to the magnetic field generated at said stator unit; and

a control apparatus for supplying the control signal to energize the stator unit;

wherein the rotor unit includes a plurality of magnets contained in a two-piece carrier assembly having first and second carrier members axially fixed to one another by a bond joint, wherein said first carrier member defines a plurality of hub pockets, wherein said second carrier member defines a plurality of retainer pockets in alignment with said hub pockets to define a plurality of magnet retention pockets each defined by one of said hub pockets and one of said retainer pockets, wherein said plurality of magnets are received in said magnet retention pockets, wherein said first and second carrier members have tapered surfaces, wherein said magnets have tapered surfaces, wherein said tapered surfaces of said first and second carrier members are engaged with said tapered surfaces of said magnets to bias said magnets radially inwardly wherein said first and second carrier members each have generally planar faces extending substantially transversely to said rotor axis and a plurality of circumferentially spaced lug segments extending outwardly from said faces, said lug segments on said first carrier member being bonded to said lug segments on said second carrier member, and wherein a plurality of said lug segments have at least partially melted ribs forming a bond joint being said bonded lug segments.

2. The electric fluid pump of claim 1 wherein said rotor unit includes a metal tubular member extending in coaxial relation about said central rotor axis, said magnets being biased by said tapered surfaces into engagement with an outer surface of said metal tubular member.

3. The electric fluid pump of claim 2 wherein one of said first and second carrier members has a tubular boss segment, said metal tubular member being disposed over said tubular boss segment.

4. The electric fluid pump of claim 3 wherein said first and second carrier members each have generally planar faces extending substantially transversely to said rotor axis and a plurality of circumferentially spaced lug segments extending outwardly from said faces, said lug segments on said first carrier member being bonded to said lug segments on said second carrier member.

5. The electric fluid pump of claim 4 wherein said magnets are contained between said lug segments.

6. The electric fluid pump of claim 1 wherein said magnets are contained between said lug segments.

7. The electric fluid pump of claim 6 wherein said magnets having opposite sidewalls engaged with said planar faces.

8. The electric fluid pump of claim 7 wherein said planar faces have at least partially deformed ribs engaging said magnets.

9. The electric fluid pump of claim 1 wherein said lug segments are generally T-shaped, each lug segment having a radially extending leg portion and a pair of circumferentially extending arm portions.

10. The electric fluid pump of claim 9 wherein said arm portions have said tapered surfaces engaged with said magnets to bias said magnets radially inwardly.

11. The electric fluid pump of claim 10 wherein each of said magnets having a pair of said tapered surfaces engaged with said surfaces of said arm portions.

12. An electric fluid pump, comprising:

a pump housing;

a stator unit disposed in said pump housing and configured to generate a magnetic field in response to a control signal;

a rotor unit also being disposed in said pump housing and received within said stator unit, said rotor unit being configured to rotate about a central rotor axis in response to the magnetic field generated at said stator unit, wherein said rotor unit includes a plurality of magnets being axially and circumferentially retained in a carrier assembly for conjoint rotation therewith about said rotor axis, and wherein said carrier assembly includes a first carrier member and second carrier member each including a plate for biasing said plurality of magnets in opposing axial directions, wherein said first carrier member includes a plurality of lug segments positioned in circumferentially spaced relationship with one another and defining a plurality of hub pockets circumferentially therebetween, wherein said second carrier member includes a plurality of lug segments positioned in circumferentially spaced relationship with one another and in alignment with said lug segments of said first carrier member and defining a plurality of retainer pockets circumferentially therebetween and in alignment with said hub pockets, wherein said plurality of magnets are received in said hub and retainer pockets such that said plurality of magnets are positioned circumferentially between said lug segments of said first and second carrier members, and wherein at least one partially deformed crush rib is disposed on at least one of said carrier member plates and axially biasing a corresponding one of said plurality of magnets; and

said lug segments of said first and second carrier members axially fixed to one another by a bond joint.

13. The electric fluid pump of claim 12 wherein said first and second carrier members have tapered surfaces, wherein said magnets have tapered surfaces, and wherein said tapered surfaces of said first and second carrier members are engaged with said tapered surfaces of said magnets to bias said magnets radially inwardly.

14. The electric fluid pump of claim 13 wherein said lugs are generally T-shaped, each lug having a radially extending leg portion and a pair of circumferentially extending arm portions.

15. The electric fluid pump of claim 14 wherein said arm portions of said circumferentially adjacent lugs are circumferentially spaced to define openings therebetween exposing said magnets to said pump housing.

16. The electric fluid pump of claim 13 wherein said lugs each define a mounting surface including at least one partially melted welding rib sonically-welded to said second carrier member.

17. The electric fluid pump of claim 12 wherein a radial outer surface of each of said magnets is substantially radially aligned with a radial outer surface of each of said lug segments.

18. An electric fluid pump, comprising:

a stator unit configured to generate a magnetic field in response to a control signal;

a rotor unit received within said stator unit, said rotor unit being configured to rotate about a central rotor axis in response to the magnetic field generated at said stator unit; and

a control apparatus for supplying the control signal to energize the stator unit;

wherein the rotor unit includes a plurality of magnets contained in a two-piece carrier assembly having first and second carrier members axially fixed to one another by a bond joint, wherein said first carrier member defines a plurality of hub pockets, wherein said second carrier member defines a plurality of retainer pockets in alignment with said hub pockets to define a plurality of magnet retention pockets each defined by one of said hub pockets and one of said retainer pockets, wherein said plurality of magnets are received in said magnet retention pockets, wherein said first and second carrier members have tapered surfaces, wherein said magnets have tapered surfaces, wherein said tapered surfaces of said first and second carrier members are engaged with said tapered surfaces of said magnets to bias said magnets radially inwardly, wherein said first and second carrier members each have generally planar faces extending substantially transversely to said rotor axis and a plurality of circumferentially spaced lug segments extending outwardly from said faces, said lug segments on said first carrier member being bonded to said lug segments on said second carrier member, wherein said magnets are contained between said lug segments, wherein said magnets having opposite sidewalls engaged with said planar faces, and wherein said planar faces have at least partially deformed ribs engaging said magnets.