Black Decker Inc.

Daniel F Heck

Colin M Crosby

Ryan F Schroeder

Barak N Gohn

Stephen P Osborne

William D Spencer

Michael D Grove

Michael P Sikora

Connor T Mohan

Christian B Rogerson

James R Clarke

Nicholas J Lowe

Jarrett A Dunston

William M Spencer

Stephen P Osbourne

A brushless direct-current (BLDC) motor for a power tool includes a rotor assembly and a stator assembly including stator windings. A ratio of a motor size (Km) constant of the motor to an electrical envelope of the motor including electrical parts of the motor is greater than approximately 850 (N·m/√W)/m{circumflex over ( )}3. A ratio of a motor size (Km) constant of the motor to a magnetic envelope of the motor including stator core and windings is greater than approximately 980 (N·m/√W)/m{circumflex over ( )}3.

Brushless DC motor having high power density for power tool

A brushless direct-current (BLDC) motor for a power tool includes a rotor assembly; a stator assembly including a stator having stator teeth forming slots therebetween and stator windings wound around the stator teeth; stator terminals extending substantially parallel to the longitudinal axis from the stator assembly and being substantially aligned with centerlines of the slots of the stator assembly; and a circuit board mounted on the stator terminals adjacent the stator assembly. The circuit board includes conductive traces facilitating a one of a delta or a series connection between the stator windings. An end insulator is provided at an axial end of the stator to electrically insulate the stator from the stator windings, the end insulator including support members to support the stator terminals relative to the stator assembly. The circuit board is mounted and fastened to the support members.

Brushless DC motor with circuit board for winding interconnections

A brushless direct-current (BLDC) motor includes a stator assembly and a rotor assembly including a rotor supporting permanent magnets rotatable relative to the stator assembly. The stator assembly includes a stator comprising a stator core and stator teeth radially extending from the stator core and defining slots therebetween. A first set of stator windings is wound on the stator teeth, and a second set of stator windings is also wound on the stator teeth such that, on each stator tooth, the first and second windings are provided in an electrically parallel configuration.

Brushless DC motor with stator teeth having multiple parallel sets of windings

An electric motor is provided including: a stator, an armature rotatably received within the stator and having an armature shaft on which a commutator is mounted, and a brush assembly. The brush assembly defines a first side facing the stator and a second side. The brush assembly includes a brush card mount having openings, brushes in sliding contact with the commutator, and thermally-conductive brush holders that support the brushes. Each brush holder includes a base piece disposed between the first side of the brush assembly and the stator, and a main piece including a brush-holder portion and two side flat portions. The brush-holder portion is axially received through a brush card mount opening from the first side of the brush assembly and protrude over the second side to house a brush. The two side flat portions are axially sandwiched between the base piece and the brush card mount.

Brush assembly having multi-piece brush holders for an electric motor, brush holder main piece with flat portions between base piece and brush card mount

An electric motor is provided including: a stator, an armature rotatably received within the stator and having an armature shaft on which a commutator is mounted, and a brush assembly. The brush assembly defines a first surface facing the stator and a second surface opposite the first surface. The brush assembly includes a brush card mount having openings, brushes in sliding contact with the commutator to supply electric current to the commutator, and thermally-conductive brush holders that house the brushes. Each of the brush holders includes a base portion disposed substantially along a same plane as a surface of the brush card mount to form the first surface of the brush assembly, and a main portion protruding from the base portion through a respective opening of the brush card mount to house a respective brush at least partially over the second surface of the brush assembly.

Brush assembly with brush card mount with brush holders having base and main portion pieces

An electric motor is provided including a stator, an armature rotatably received within the stator and having an armature shaft on which a commutator is mounted, and a brush assembly. The brush assembly includes a planar portion disposed around the commutator and accommodating a plurality of brushes, a bridge portion disposed at an end of the commutator and extending from the planer portion via two or more legs, and metal routing(s) disposed on or within the bridge portion to electrically couple the brushes.

Brush assembly with bridge and leg portions with metal routing

An electric motor is provided including a stator and an armature rotatably received within the stator, the armature having an armature shaft on which a commutator is mounted. The motor also includes a brush assembly having a brush card mount disposed around the commutator, a brush holder mounted on a surface of the brush card mount, and a brush disposed within the brush holder in sliding contact with the commutator to supply electric current to the commutator. A torsion spring is secured to the brush card mount adjacent the brush holder, the spring having a leg arranged to engage the back surface of the brush. A spring stop post is disposed proximate an outer periphery of the brush card mount to limit an outward movement of the leg of the spring away from the back surface of the brush.

Spring post for brush card for a power tool

An electric motor includes a stator, a shaft rotatable with respect to the stator, and a lamination stack mounted on the shaft and having radially extending teeth forming slots therebetween. An end insulator is provided at an end of the lamination stack having forming slots therebetween. Motor coils are wound in the lamination stack slots and the end insulator slots. A fan having blades attached to a fan ring and mounted to an end of the lamination stack. The fan ring includes longitudinally-extending tongues arranged to be mounted at the end of the lamination stack and the end insulator includes longitudinally-extending notches corresponding to the tongues of the fan ring to allow the tongues to be in direct contact with the end of the lamination stack.

Power tool having improved motor fan assembly

An electric motor is provided including a stator assembly having a stator body and magnets attached to an inner surface of the stator body via an adhesive, and an armature rotatably received within the stator assembly and having an armature shaft on which a commutator is mounted. A brush assembly is provided including a brush card mount disposed around the commutator and a mating housing longitudinally extending from the brush card mount. The mating housing includes a cylindrical wall and a mating surface formed substantially perpendicularly to an inner surface of the cylindrical wall and arranged to mate with an end surface of the stator body. The mating surface of the mating housing includes posts longitudinally extending along the inner surface of the cylindrical wall and recessed surfaces formed therebetween, the posts being mounted on the end surface of the stator body.

Growing community of inventors

Baltimore, MD, United States of America

Daniel F Heck