Stator assembly for a brushless motor in a power tool

Patent metadata

Field	Value
Publication number	US-10056806-B2
Application number	US-201113704033-A
Country	US
Kind code	B2
Filing date	Jun 14, 2011
Priority date	Jun 14, 2010
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A power tool includes a brushless DC motor having a stator and a rotor pivotably arranged inside the stator, the stator including a first winding, a second winding, and a third winding. Each winding is arranged at at least two opposite poles connected together. The stator windings may be connected in a delta configuration by electrically coupling adjacent terminals of the first and second windings, second and third windings, and third and first windings at three connection points. A baffle may be provided in parallel and adjacent to the stator, the baffle including at least one conductive routing or stamping to facilitate electrically coupling the first, second, and third windings in at least one of a delta or a wye configuration.

First claim

The invention claimed is:

1. A power tool comprising a housing and a brushless DC motor housed inside the housing, the motor comprising:
a stator having a lamination stack defining a plurality of poles, the stator comprising a first winding, a second winding, and a third winding, each said winding arranged at at least two opposite poles of the plurality of poles;
a rotor pivotably arranged inside the stator and having a rotor shaft;
a fan disposed on the rotor shaft to rotate therewith and including a plurality of blades facing the stator; and
a baffle having a substantially planar body arranged in parallel and adjacent to the stator between the stator and the fan, the baffle including a front face facing an axial end of the stator proximate ends of the first, second, and third windings, a through-hole through which the rotor shaft extends, and at least one conductive routing or stamping electrically coupled to the ends of the first, second, and third windings from the front face of the baffle, the at least one conductive routing or stamping comprising three discrete metallic bodies disposed around the through-hole at three sides of the baffle, each discrete metallic body being electrically connected at two nodes to adjacent ends of the first and second windings, the first and third windings, or the first and third windings, to connect the first, second, and third windings in a delta configuration.

2. The power tool of claim 1 , wherein the baffle comprises a plurality of terminals corresponding to and electrically connected to a plurality of winding terminals of the stator.

3. The power tool of claim 2 , wherein each of the three discrete metallic bodies is arranged on the front face of the baffle between two of the plurality of terminals to electrically connect the two baffle terminals.

4. The power tool of claim 1 , further comprising a bus bar arranged on an outer surface of the stator and coupled to the first, second, and third windings to supply electric power from a power source to the first, second, and third windings.

5. The power tool of claim 4 , wherein the baffle further comprises a protruding portion to enclose the wiring connections from the bus bar to the first, second, and third windings.

6. The power tool of claim 1 , wherein the conductive routing or stamping is adhesively connected or stamped to the front face of the baffle.

7. A brushless electric motor comprising:
a stator having a lamination stack defining a plurality of poles, the stator comprising a first winding, a second winding, and a third winding, each said winding arranged at at least two opposite poles of the plurality of poles;
a rotor pivotably arranged inside the stator and having a rotor shaft;
a fan disposed on the rotor shaft to rotate therewith and including a plurality of blades facing the stator; and
a baffle having a substantially planar body arranged in parallel and adjacent to the stator between the stator and the fan, the baffle including a front face facing an axial end of the stator proximate ends of the first, second, and third windings, a through-hole through which the rotor shaft extends, and at least one conductive routing or stamping electrically coupled to the ends of the first, second, and third windings from the front face of the baffle, the at least one conductive routing or stamping comprising three discrete metallic bodies disposed around the through-hole at three sides of the baffle, each discrete metallic body being electrically connected at two nodes to adjacent ends of the first and second windings, the first and third windings, or the first and third windings, to connect the first, second, and third windings in a delta configuration.

8. The brushless electric motor of claim 7 , wherein the baffle comprises a plurality of terminals corresponding to and electrically connected to a plurality of winding terminals of the stator.

9. The brushless electric motor of claim 8 , wherein each of the three discrete metallic bodies is arranged on the front face of the baffle between at least two of the plurality of terminals to electrically connect the two terminals.

10. The brushless electric motor of claim 7 , further comprising a bus bar arranged on an outer surface of the stator and coupled to the first, second, and third windings to supply electric power from a power source to the first, second, and third windings.

11. The brushless electric motor of claim 10 , wherein the baffle further comprises a protruding portion to enclose the wiring connections from the bus bar to the first, second, and third windings.

12. The brushless electric motor of claim 7 , wherein the conductive routing or stamping is adhesively connected or stamped to the front face of the baffle.

13. A power tool comprising a housing and a brushless DC motor housed inside the housing, the motor comprising:
a stator having a lamination stack defining a plurality of poles, the stator comprising a plurality of windings, each said winding arranged at at least two opposite poles of the plurality of poles;
a rotor pivotably arranged inside the stator and having a rotor shaft;
a plurality of conductive terminals, each conductive terminal having at least a portion arranged substantially along an outer longitudinal surface of the lamination stack, the longitudinal surface of the lamination stack being parallel to the rotor shaft, the plurality of conductive terminals being electrically coupled to the plurality of windings to supply power from a power source to the plurality of windings; and
a baffle having a substantially planar body arranged in parallel and adjacent to an axial end of the stator substantially perpendicularly to the plurality of conductive terminals, the baffle including a front face facing the axial end of the stator proximate ends of the plurality of windings, and at least one conductive routing or stamping arranged to make electrical contacts with one or two ends of each of the plurality of windings from the front face of the baffle to connect the plurality of windings in at least one of a delta or a wye configuration,
wherein the baffle further comprises a protruding portion longitudinally extending over the plurality of conductive terminals to enclose wiring connections between the plurality of conductive terminals and the plurality of windings.

14. The power tool of claim 13 , wherein the at least one conductive routing or stamping comprises a metallic portion being electrically connected at three nodes to the ends of the plurality of windings to commonly connect the plurality of windings in a wye configuration.

15. The power tool of claim 13 , wherein the at least one conductive routing or stamping comprises three discrete metallic portions arranged at three sides of the baffle, each discrete metallic portion being electrically connected at two nodes to adjacent ends of two of the plurality of windings to connect the plurality of windings in a delta configuration.

16. The power tool of claim 13 , further comprising a fan disposed on the rotor shaft to rotate therewith and including a plurality of blades facing the stator.

17. The power tool of claim 16 , wherein the baffle is arranged between the stator and the fan and comprises a through-hole through which the rotor shaft extends.

18. The power tool of claim 13 , wherein the conductive routing or stamping is adhesively connected or stamped to the front face of the baffle.

19. The power tool of claim 13 , wherein the baffle comprises a plurality of baffle terminals protruding longitudinally from the fro

Assignees

• Hatfield Eric E
• Ortt Earl M
• Black & Decker Inc

Inventors

• Hatfield Eric E
• Ortt Earl M

Classifications

• H02K2203/09

  Machines characterised by wiring elements other than wires, e.g. bus rings, for connecting the winding terminations · CPC title

• H02K2203/03

  Machines characterised by the wiring boards, i.e. printed circuit boards or similar structures for connecting the winding terminations · CPC title

• H02K21/16

  having annular armature cores with salient poles (with homopolar co-operation H02K21/20) · CPC title

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• H02K11/30

  Structural association with control circuits or drive circuits · CPC title