Device for fastening and electrically connecting a circuit board to a motor

1. A motor assembly comprising:

a motor including:

a rotor, and

a stator coil disposed alongside the rotor;

a printed circuit board (PCB) configured to control electric coil-powering current to the coil to electromagnetically urge the rotor to rotate, the PCB having a top surface facing away from the stator coil;

a PCB housing that encapsulates the PCB, wherein the PCB housing includes a top housing layer overlying the PCB and a bottom housing layer underlying the PCB;

top, middle and bottom apertures that respectively extend through the top housing layer, the PCB and the bottom housing layer;

an electrically-conductive PCB contact on the PCB's top surface adjacent the middle aperture;

an electrically-conductive fastener that secures the PCB to the motor, the fastener including:

a head structure located in the top aperture, that engages a top surface of the PCB contact,

a shank structure that extends from the head structure, through the middle and bottom apertures, and into the motor, and

a screw thread, on the shank structure, that threadedly engages the motor; and

a fastener-to-coil conductor in the motor that electrically connects the shank structure to the coil;

for the coil-powering current to flow from the PCB contact, through the fastener's head structure and through the shank structure to the fastener-to-coil conductor in the motor to power the coil.

2. The motor assembly of claim 1 , wherein the rotor is configured to rotate about a rotational axis, and wherein the PCB is on the rotational axis and above the stator coil.

3. The motor assembly of claim 1 , wherein:

the stator coil is one of multiple stator coils disposed alongside the rotor;

each of the top, middle and bottom apertures is one of multiple respective top, middle and bottom apertures that respectively extend through the top housing layer, the PCB and the bottom housing layer;

the PCB contact is one of multiple electrically-conductive PCB contacts, each PCB contact being on the PCB's top surface and adjacent a respective one of the middle apertures;

the fastener is one of multiple electrically-conductive fasteners that secure the PCB to the motor, each fastener including:

a head structure located in the top aperture, that engages a top surface of a respective one of the PCB contacts,

a shank structure that extends from the head structure, through the respective middle and bottom apertures, and into the motor, and

a screw thread, on the shank structure, that threadedly engages the motor; and

the fastener-to-coil conductor is one of multiple fastener-to-coil conductors in the motor, each fastener-to-coil conductor electrically connecting the shank to at least one of the stator coils;

for, with respect to each fastener, coil-powering current to flow from the respective PCB contact, through the fastener's head structure and through the shank structure to the respective fastener-to-coil conductor in the motor to power the respective stator coil.

4. The motor assembly of claim 3 , further comprising, for each of the fasteners, a spacer that is sandwiched between the PCB housing and the motor to space the PCB housing away from the motor to define a gap between the PCB housing and the motor, to enable fluid to flow into and out of the gap to cool the PCB.

5. The motor assembly of claim 4 , wherein the motor assembly is located in a fuel tank, to enable fuel in the tank to flow into and out of the gap to cool the PCB.

6. The motor assembly of claim 1 , wherein the fastener is a screw.

7. The motor assembly of claim 1 , wherein the fastener-to-coil conductor includes an electrical terminal that is in the motor and that contains a threaded bore into which the screw thread is threadedly engaged, for the coil-powering current to flow from the top surface of the PCB contact, through the fastener's head structure and through the shank structure to the threaded electrical terminal to power the coil.

8. The motor assembly of claim 1 , further comprising a sealing plug, located in the top aperture and above the fastener head, that seals the top aperture to prevent fluid from contacting the fastener's head structure.

9. The motor assembly of claim 1 , wherein the PCB housing is in direct contact with the electrical devices of the PCB.

10. The motor assembly of claim 1 , wherein the motor assembly is brushless.

11. The motor assembly of claim 1 , wherein all rotating parts of the motor assembly are encased in a common motor housing.

12. The motor assembly of claim 1 , wherein the PCB contact surrounds the middle aperture.

13. The motor assembly of claim 1 , wherein the fastener-to-coil conductor in the motor is spaced away from the PCB, to form a gap that is spanned by the fastener shank and located between the PCB and the fastener-to-coil conductor.

14. The motor assembly of claim 13 , wherein the gap spanned by the fastener shank includes (i) the bottom housing layer and (ii) a fluid-flow space for fluid to flow in and out of.

15. The motor assembly of claim 1 , further comprising:

a liquid pump that is driven by motor, and

a housing that houses the rotor, the stator coil and the pump.

16. The motor assembly of claim 15 , wherein the rotor rotates about a rotational axis, and wherein the coil is located axially between the PCB and the pump.

17. The motor assembly of claim 15 , further comprising:

an opening that extends through the top housing layer, the PCB and the bottom housing layer; and

an outlet stem projecting from the motor and through the opening;

wherein the pump is configured to pump the liquid to flow through a passage between the rotor and the stator coil and out of the motor through the outlet stem.