LOW-VOLTAGE MOTOR AND METHOD FOR MAKING THE SAME

• US 20180233987A1
• Filed: 12/22/2016
• Published: 08/16/2018
• Est. Priority Date: 12/22/2016
• Status: Active Application

• Current Assignee: General Dynamics OTS Incorporated (General Dynamics Corporation)
• Original Assignee: General Dynamics OTS Incorporated (General Dynamics Corporation)
• Inventors: Steinbach, Russell
• Application Number:
  US15/388,088
• Publication Number:
  US 20180233987A1
• Time in Patent Office: Days
• CPC Class Codes: H02K 1/16 Stator cores with slots for windings
• CPC Class Codes: H02K 1/27 Rotor cores with permanent magnets
• CPC Class Codes: H02K 2203/03 Machines characterised by the wiring boards, i.e. printed circuit boards or similar structures for connecting the winding terminations
• CPC Class Codes: H02K 3/04 Windings characterised by the conductor shape, form or construction, e.g. with bar conductors
• CPC Class Codes: H02K 3/47 Air-gap windings, i.e. iron-free windings
• CPC Class Codes: H02K 3/50 Fastening of winding heads, equalising connectors, or connections thereto
• CPC Class Codes: H02K 5/225 Terminal boxes or connection arrangements specially adapted for submersible motors H02K5/132
• CPC Class Codes: H05K 1/14 Structural association of two or more printed circuits providing electric connection to or between printed circuits H05K1/11, H01R12/00
• CPC Class Codes: H05K 1/145 Arrangements wherein electric components are disposed between and simultaneously connected to two planar printed circuit boards, e.g. Cordwood modules
• CPC Class Codes: H05K 1/184 Components including terminals inserted in holes through the printed circuit board and connected to printed contacts on the walls of the holes or at the edges thereof or protruding over or into the holes
• CPC Class Codes: H05K 2201/10242 Metallic cylinders small solder preforms other than balls H05K2203/0415
• CPC Class Codes: H05K 2201/10303 Pin-in-hole mounted pins

Abstract

Embodiments of the present disclosure relate to a low-voltage motor. The low-voltage motor includes a housing, a rotor disposed within the stator, and a stator disposed within the housing. The stator includes a first circuit board; and a second circuit board, and a number of single-turn coils. The first circuit board and the second circuit board each have a number of plated through-openings and wirings formed therein. The number of single-turn coils are formed by the wirings of the first circuit board, the wirings of the second circuit board, and conductive rods disposed in the plated through-openings.

Claims

1. A low-voltage motor, comprising:

a housing;

a rotor; and

a stator disposed within the housing, the rotor being disposed within the stator, and the stator comprising;

a first circuit board; and

a second circuit board, wherein the first circuit board and the second circuit board each have;

a number of plated through-openings and wirings formed therein; and

a number of single-turn coils formed by the wirings of the first circuit board, the wirings of the second circuit board, and conductive rods disposed in the plated through-openings.

2. The low-voltage motor according to claim 1, wherein the first circuit board has a number of first wirings formed therein and a number of first plated through-openings formed therein, wherein the second circuit board has a number of second wirings formed therein and a number of second plated through-openings formed therein, and wherein each single-turn coil comprises:

a first conductive rod being disposed in one of the first plated through-openings and one of the second plated through-openings;

a second conductive rod being disposed in another one of the first plated through-openings and another one of the second plated through-openings; and

the first conductive rod being connected to the second conductive rod by one of the first wirings and the second wirings.

3. The low-voltage motor according to claim 1, wherein the stator has a fill factor that is greater than or equal to sixty-five percent.

4. The low-voltage motor according to claim 1, wherein each of the single-turn coils consists of a single conductive loop.

5. The low-voltage motor according to claim 4, wherein each of the single-turn coils consists of only one conductor on each side of the single-turn coil, and wherein the low-voltage motor comprises two or more phase windings, wherein each phase winding comprises a plurality of the single-turn coils connected together.

6. The low-voltage motor according to claim 1, wherein each of the conductive rods is made from a wire conductor having a substantially circular cross-section.

7. The low-voltage motor according to claim 1, wherein each of the conductive rods is made from a wire conductor having a substantially bar-shaped cross-section.

8. The low-voltage motor according to claim 1, wherein the single-turn coils form phase windings of the stator, and wherein phase-to-phase inductance of the phase windings measures between 250 nanohenries (nH) and 1 microhenries (μ

H), and wherein phase-to-phase resistance of the phase windings measures between 0.03 and 0.01 ohms.

9. The low-voltage motor according to claim 4, wherein stator of the low-voltage motor has a diameter between about 0.25 centimeters and 3.8 centimeters, and a length between 0.5 and 3.5 times the diameter.

10. The low-voltage motor according to claim 1, wherein the low-voltage motor is configured to be powered by a DC source having a DC voltage of between 4 and 20 volts DC.

11. The low-voltage motor according to claim 10, wherein DC power is converted to a variable current by a variable current source and supplied to motor commutation circuitry that is configured to drive the low-voltage motor, wherein the variable current has value between 0 and 100 amperes at a voltage between 0.1 and 6.0 volts.

12. The low-voltage motor according to claim 1, wherein the low-voltage motor is one of:

a Brushless Direct Current (BLDC) motor,

a Permanent Magnet Synchronous Machine (PMSM), and

a Variable Reluctance Stepper Motor (VRSM).

13. The low-voltage motor according to claim 1, wherein the low-voltage motor is a multi-phase motor, wherein the stator has multiple phases and multiple single-turn coils in each phase, and wherein the rotor comprises permanent magnets mounted on a shaft of the rotor and includes at least one pair of poles.

14. A method for making a low-voltage motor, the method comprising:

providing a first circuit board and a second circuit board each having a plurality of plated through-openings and wirings formed therein;

inserting a plurality of conductors into the plated through-openings of the first circuit board;

placing a back iron sleeve over the conductors;

inserting the plurality of conductors into the plated through-openings of the second circuit board;

terminating the plurality of the conductors, originating at the first circuit board, at the second circuit board to create a stator assembly; and

placing a motor housing over the stator assembly, wherein the stator assembly comprises a number of single-turn coils formed by the wirings of the first circuit board, the wirings of the second circuit board, and the conductors.

15. The method according to claim 14, wherein each of the conductors is inserted through one of the plated through-openings formed in the first circuit board, and terminated at the second circuit board, and wherein each single-turn coil comprises two of the conductors connected by one of the wirings, and

wherein a first group of the single-turn coils are connected by wirings to form a first stator phase winding, wherein a second group of the single-turn coils are connected by wirings to form a second stator phase winding, and wherein a third group of the single-turn coils are connected by wirings to form a third stator phase winding.

16. The method according to claim 14, wherein terminating the plurality of the single-turn coils at plated through-openings the second circuit board comprises:

inserting each of the plurality of the conductors into one of the plated through-openings formed in the second circuit board; and

soldering each of the plurality of the conductors to the second circuit board to create the stator assembly.

17. The method according to claim 14, further comprising:

potting the stator assembly.

18. The method according to claim 17, wherein potting the stator assembly comprises:

placing the stator assembly on a mandrel;

wherein placing the motor housing over the stator assembly comprises;

inserting the motor housing over the mandrel such that is surrounds and encases the stator assembly; and

depositing epoxy potting material over the stator assembly such the second circuit board is covered;

attaching a mandrel top piece to the mandrel to create a resulting assembly; and

heating the resulting assembly to cure the epoxy potting material such that the single-turn coils that are encased in the cured epoxy potting material.

19. The method according to claim 18, further comprising:

removing the mandrel and mandrel top piece from the resulting assembly after the epoxy potting material has cured to provide a completed stator assembly in which a stator is bonded into the motor housing.

20. The method according to claim 19 further comprising:

inserting a rotor into the completed stator assembly, wherein the rotor comprises a shaft having two ends;

placing bearings over the two ends of the shaft;

placing motor end caps over the two ends of the shaft;

securing the motor end caps to the motor housing; and

attaching a sensor magnet assembly at one end of the shaft of the rotor.