Brushless motor and fuel pump having a terminal structure for reducing tensile forces between stator coils
Relay terminals, which are formed integrally with a W-phase terminal, a V-phase terminal and a U-phase terminal provided radially outside bobbins, connect stator coils and the W-phase terminal, the V-phase terminal and the U-phase terminal. Second connection parts of the relay terminals connected to the coils are provided radially inside the W-phase terminal, the V-phase terminal and the U-phase terminal. Thus distances between the second connection part and the inner wall surface of a housing are increased to maintain insulation between the relay terminals and the housing. Thus the relay terminals are protected from breakage.
1. A brushless motor comprising:
a stator including a plurality of stator cores formed of a magnetic material, a plurality of stator coils wound about the stator cores, a plurality of bobbins covering the stator cores to insulate the stator coils from the stator cores, power supply terminals provided radially outside the bobbins to receive electric power from an external side, and relay terminals connecting electrically the power supply terminals and the stator coils, the stator generating a rotating magnetic field when power supply to the stator coils is controlled; and
a rotor provided radially inside the stator and magnetized to opposite magnetic poles alternately in a circumferential direction to be rotated by the rotating magnetic field generated by the stator,
wherein the relay terminals include, respectively, first connection parts, which are connected electrically to the power supply terminals, and second connection parts, which are connected electrically to the first connection parts and the stator coils,
wherein each of the second connection parts is provided radially inside the power supply terminal, formed in a U-shape opening in a radially outward direction, and provided at a position adjacent to the power terminals in a circumferential direction, and
wherein each of the second connection parts is connected electrically within the respective U-shaped opening to a corresponding coil of the plurality of stator coils at a coil end of the corresponding coil, and each of the second connection parts in connected electrically within the respective U-shaped opening to another corresponding coil of the plurality of stator coils at a coil end of the other corresponding coil, and the corresponding coil and the other corresponding coil extend in different directions from the respective U-shape opening.
2. The brushless motor according to claim 1 , wherein:
each of the second connection parts is provided at a position, to which tensile forces of at least two of the stator coils are exerted and at which a resultant force of the tensile forces in a radially inward direction is reduced.
3. The brushless motor according to claim 2 , wherein:
the relay terminals are formed integrally with the power supply terminals, respectively.
4. The brushless motor according to claim 2 , wherein:
the power supply terminal includes a connector connection part, which is connectable to an external connector and located radially inside the first connection part.
5. The brushless motor according to claim 1 , wherein:
the relay terminals are formed integrally with the power supply terminals, respectively.
6. The brushless motor according to claim 1 , wherein:
the power supply terminal includes a connector connection part, which is connectable to an external connector and located radially inside the first connection part.
7. A fuel pump for suctioning fuel in a fuel tank mounted in a vehicle and discharging the fuel, the fuel pump comprising:
the brushless motor according to claim 1 ;
a pump unit including a rotary member, which is coupled to the rotor of the motor to pressurize the fuel;
an inlet port for introducing the fuel from the fuel tank into the pump unit; and
an outlet port for outwardly discharging the fuel pressurized by the pump unit.
8. The brushless motor according to claim 1 , wherein:
the relay terminals are formed integrally with the power supply terminals, respectively; and
the power supply terminal includes a connector connection part, which is connectable to an external connector and located radially inside the first connection part.
9. The brushless motor according to claim 1 , wherein:
each of the second connection parts is provided at a substantially intermediate position of tensile forces of the corresponding coil and the other corresponding coil.
10. The brushless motor according to claim 1 , wherein:
the first connection part does not block the U-shape opening.
11. The brushless motor according to claim 1 , wherein each of the second connection parts connects two coil ends of the plurality of stator coils within the U-shape opening.