Busbar unit and motor
A busbar unit is arranged on an axial end portion of a stator and electrically connected with a plurality of coil wire terminals arranged to project in an axial direction above the axial end portion of the stator. The busbar unit includes a plurality of busbars each including a body portion defined by an electrically conductive wire having an annular or “C” shape, the body portion being arranged around an axis of the stator; a holder member arranged on the axial end portion of the stator to hold the busbars; and a plurality of terminal members each including a busbar connection portion connected with the body portion of one of the busbars, and a coil connection portion connected with one of the coil wire terminals.
1. A busbar unit arranged on an axial end portion of a stator, and electrically connected with a plurality of coil wire terminals arranged to project in an axial direction above the axial end portion of the stator, the busbar unit comprising:
a plurality of busbars each including a body portion defined by an electrically conductive wire having an annular or “C” shape;
a holder member arranged on the axial end portion of the stator to hold the busbars; and
a plurality of terminal members each including a busbar connection portion connected with the body portion of one of the busbars and a coil connection portion connected with one of the coil wire terminals; wherein
the holder member is defined by a plurality of annular holders placed one upon another in the axial direction, each of the holders including an accommodating groove in an annular shape or in a “C” shape arranged to separately accommodate and hold the body portion of a separate one of the busbars and a lead groove arranged to accommodate and hold an external connection portion of the each of the busbars to allow the external connection portion to be drawn from the accommodating groove in a radial direction.
2. The busbar unit according to claim 1 , wherein the external connection portion is defined by an electrically conductive wire continuous and integral with the body portion, and arranged to be electrically connected with an external power supply.
3. The busbar unit according to claim 2 , wherein each of the busbars is defined by a bare electric wire.
4. The busbar unit according to claim 1 , wherein the external connection portion of each of the busbars extends in the axial direction after extending from the accommodating groove in the radial direction.
5. The busbar unit according to claim 4 , wherein
the lead groove of each of the holders is arranged to extend radially inward from the accommodating groove and then extend in the axial direction; and
an inner circumferential surface of each of the holders includes a vertical lead groove defined therein correspondingly to the lead groove of a different one of the holders, and arranged to accommodate and hold the external connection portion extending through the lead groove of the different holder to allow the external connection portion to be drawn in the axial direction.
6. The busbar unit according to claim 4 , wherein each of the busbars is defined by a bare electric wire.
7. The busbar unit according to claim 1 , wherein each of the holders has an identical configuration.
8. The busbar unit according to claim 7 , wherein the holders are placed one upon another such that the accommodating grooves of the respective holders do not have opening surfaces thereof facing each other.
9. The busbar unit according to claim 1 , wherein the holders are placed one upon another such that the accommodating grooves of the respective holders do not have opening surfaces thereof facing each other.
10. The busbar unit according to claim 9 , wherein each of the busbars is defined by a bare electric wire.
11. The busbar unit according to claim 1 , wherein each of the holders includes a first annular surface and a second annular surface, the first annular surface including a plurality of raised portions defined therein, the second annular surface including a plurality of recessed portions defined therein to have the raised portions of a different one of the holders fitted therein.
12. The busbar unit according to claim 1 , wherein
each of the terminal members is defined by a single piece of plate material; and
each of the terminal members includes a plate-shaped joining portion arranged to extend continuously between the busbar connection portion and the coil connection portion, the joining portion being bent in a plate thickness direction thereof.
13. The busbar unit according to claim 12 , wherein each of the busbars is defined by a bare electric wire.
14. The busbar unit according to claim 1 , wherein each of the busbars is defined by a bare electric wire.
15. A motor comprising:
the busbar unit of claim 1 ; and
a stator including a plurality of coils and a plurality of coil wire terminals arranged to project therefrom in an axial direction; wherein
the busbar unit is arranged on an axial end portion of the stator, and the terminal members of the busbar unit are connected with the coil wire terminals of the stator.
16. The motor according to claim 15 , wherein the coil wire terminals are arranged at regular intervals in a circumferential direction about an axis of the stator.
17. The motor according to claim 15 , further comprising:
a neutral point busbar defined by an electrically conductive wire having an annular or a “C” shape; and
a groove portion defined in the axial end portion of the stator and arranged to hold the neutral point busbar; wherein
the coils of the stator are connected in a star configuration;
the coil wire terminals include a neutral point terminal; and
the terminal members include a neutral point terminal member arranged to connect the neutral point busbar and the neutral point terminal to each other.