Power tool and method of forming coil in power tool motor

Patent metadata

Field	Value
Publication number	US-10720822-B2
Application number	US-201715609501-A
Country	US
Kind code	B2
Filing date	May 31, 2017
Priority date	Jul 29, 2016
Publication date	Jul 21, 2020
Grant date	Jul 21, 2020

Abstract

In a brushless motor comprising a stator core having a plurality of teeth that protrude therefrom in radial directions, a front insulator which is attached to the stator core and which has a plurality of insulating portions that protrude therefrom along the direction of protrusion of the respective teeth, and a plurality of coils formed by magnet wire wound about each of the insulating portions at the respective teeth, a top face of the respective insulating portions of the front insulator is provided in advance with a deformable rib which is capable of being deformed by tension of the magnet wire wound thereabout, and the magnet wire is wound about the deformable rib to form the coils as the deformable rib is made to deform in correspondence to the external shape of the magnet wire.

First claim

What is claimed is:

1. A method of forming a coil in a power tool motor, the power tool motor comprising a stator core having a plurality of teeth that protrude therefrom in radial directions; an insulator which is attached to the stator core and which has a plurality of insulating portions that protrude therefrom along the direction of protrusion of the respective teeth; and a plurality of coils formed by wire wound about each of the insulating portions at the respective teeth, the method comprising:
providing at least a portion of a surface about which the wire is wound at the respective insulating portions in advance with a deformable portion which is capable of being deformed by tension of the wire wound thereabout; and
winding the wire about the deformable portion to form the coils as the deformable portion is made to deform in correspondence to the external shape of the wire;
wherein the deformable portion is a deformable rib provided in erect fashion along the direction of protrusion of the insulating portion.

2. The method of forming a coil in a power tool motor according to claim 1 , wherein the deformable rib is provided to be paired in erect fashion such that there is prescribed spacing therebetween in a direction crossing the protrusion of the insulating portion.

3. The method of forming a coil in a power tool motor according to claim 2 , wherein a recess, at which a wall thickness of the insulating portion is less than at a portion outside of the deformable ribs, is formed between the deformable ribs.

4. The method of forming a coil in a power tool motor according to claim 2 , wherein cross-sectional shapes of the deformable ribs are such that angular portions at which corners are apparent are formed at mutually outward sides at the top ends thereof, and radiused portions at which edges are not apparent are formed at mutually inward sides at the top ends thereof.

5. The method of forming a coil in a power tool motor according to claim 1 , wherein the deformable rib is formed in such fashion that thickness thereof gradually increases as progress is made in a direction in which the wire is neatly wound thereover.

6. The method of forming a coil in a power tool motor according to claim 1 , wherein the deformable portion is a thin-walled portion provided at the surface about which the wire is wound.

7. The method of forming a coil in a power tool motor according to claim 6 , wherein the thin-walled portion is formed from a resin material which is different from that of the insulating portions.

8. The method of forming a coil in a power tool motor according to claim 1 , wherein the insulator is one of two thereof that are attached to two ends of the stator core, and the deformable portion is at least provided at one of the two insulators.

9. A power tool motor comprising:
a stator core having a ring and a plurality of teeth that protrude radially inward from the ring;
an insulator that (1) is attached to the stator core and (2) has a plurality of insulating portions that protrude radially inward from the ring; and
a plurality of coils formed by wire (1) wound about each of the insulating portions at the teeth and (2) having a cross-sectional shape; wherein:
at least a portion of surfaces about which the wire is wound at the insulating portions has a deformable portion which is capable of being deformed by tension of the wire wound thereabout; and
the coils are formed by winding the wire around the each of the insulating portions such that (1) a portion of the deformable portions deforms in correspondence to an external shape of the wire as the wire is wound about the each of the insulating portions and (2) the wire maintains the cross-sectional shape.

10. A power tool,
the power tool being equipped with a drive source in the form of a motor comprising a stator core having a plurality of teeth that protrude therefrom in radial directions; an insulator which is attached to the stator core and which has a plurality of insulating portions that protrude therefrom along the direction of protrusion of the respective teeth; and a plurality of coils formed by wire wound about each of the insulating portions at the respective teeth;
wherein at least a portion of a surface about which the wire is wound at the respective insulating portions of the insulator is provided with a deformable rib which is capable of being deformed by tension of the wire wound thereabout and which is provided in erect fashion along the direction of protrusion of the insulating portions; and
wherein the coils are formed in a state such that a portion of the deformable rib at which the wire is wound thereabout has been made to deform in correspondence to the external shape of the wire.

11. The power tool according to claim 10 , wherein the deformable rib is provided to be paired in erect fashion such that there is prescribed spacing therebetween in a width direction of the insulating portion.

12. A power tool,
the power tool being equipped with a drive source in the form of a motor comprising a stator core having a plurality of teeth that protrude therefrom in radial directions; an insulator which is attached to the stator core and which has a plurality of insulating portions that protrude therefrom along the direction of protrusion of the respective teeth; and a plurality of coils formed by wire wound about each of the insulating portions at the respective teeth;
wherein at least a portion of a surface about which the wire is wound at the respective insulating portions of the insulator is provided with a deformable portion which is capable of being deformed by tension of the wire wound thereabout and which is formed in such fashion that thickness thereof gradually increases as progress is made in a direction in which the wire is neatly wound thereover; and
wherein the coils are formed in a state such that a portion of the deformable portion at which the wire is wound thereabout has been made to deform in correspondence to the external shape of the wire.

Assignees

• Makita Corp

Inventors

• Niwa Akira

Classifications

• B25F5/02

  Construction of casings, bodies or handles {(B25F5/006, B25F5/008 take precedence)} · CPC title

• H02K3/325 Primary

  for windings on salient poles, such as claw-shaped poles · CPC title

• H02K3/522 Primary

  for generally annular cores with salient poles · CPC title

• H02K9/06

  with fans or impellers driven by the machine shaft · CPC title

• H02K29/08

  using magnetic effect devices, e.g. Hall-plates, magneto-resistors (H02K29/12 takes precedence) · CPC title