Axial brushless DC motor

Patent metadata

Field	Value
Publication number	US-10658902-B2
Application number	US-201816206499-A
Country	US
Kind code	B2
Filing date	Nov 30, 2018
Priority date	Feb 10, 2015
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

An axial brushless DC motor comprising a stator, a rotor including a magnet, a sleeve bushing extending through the stator and including a pair of opposed distal collars, a motor shaft extends through the sleeve bushing, and a pair of opposed bearings are seated in the respective pair of collars and mount the shaft and a rotor for rotation relative to the sleeve bushing and the stator. The bearings are adapted for thrust, radial support/self-alignment, and angular adjustment of the motor shaft. In one embodiment, a stator overmold member includes a central tube that defines the sleeve bushing and includes a stator shorting ring. In one embodiment, a metal pole piece is seated in a cup-shaped magnet with a rim and the magnetic flux travels through the rim of the magnet and through a magnetic flux sensor.

First claim

We claim:

1. An axial brushless DC motor comprising:
a stator including a plurality of coils;
a rotor including a disc-shaped base and a disc-shaped magnet defining an interior and coupled to the disc-shaped base, each of the disc-shaped base and the disc-shaped magnet defining a through-aperture;
an elongate sleeve extending through the stator, the sleeve defining an interior through-aperture and a distal collar;
a stator over mold member surrounding and enveloping the exterior side surfaces of the coils of the stator and including a central elongated hollow tube defining the sleeve and the interior through-aperture and the distal collar of the sleeve, the stator over mold member further including an upper peripheral collar defining an interior receptacle, the disc-shaped magnet being seated in the interior receptacle of the stator over mold member and surrounded by the upper peripheral collar of the stator over mold member, the disc-shaped pole piece being seated in the interior of the disc-shaped magnet;
an elongate shaft extending through the interior through-aperture of the disc-shaped base, the disc-shaped magnet, and the sleeve of the stator over mold member; and
a bearing in the distal collar of the elongate sleeve of the stator over mold member for allowing the rotation of the shaft relative to the sleeve and the stator.

2. The axial brushless DC motor of claim 1 , wherein the stator over mold member defines a housing for the rotor.

3. The axial brushless DC motor of claim 1 , further comprising a stator shorting ring including respective terminals coupled to the respective coils.

4. The axial brushless DC motor of claim 1 , wherein the plurality of coils are arranged in respective pairs of coils connected in parallel.

5. The axial brushless DC motor of claim 1 , wherein the plurality of coils are arranged in respective pairs of coils connected in series.

6. The axial brushless DC motor of claim 1 , wherein the magnet is the form of a cup and the base defines a disc-shaped pole piece seated in the interior of the cup.

7. The axial brushless DC motor of claim 1 further comprising a magnetic flux sensor, the magnet of the rotor including a rim and adapted to generate a magnetic flux, the magnetic flux being adapted to travel through the rim of the magnet and the magnetic flux sensor.

8. The axial brushless DC motor of claim 1 wherein the magnet is in the form of a cup including the rim and defining a receptacle for the base defining a metal pole piece, the metal pole piece defining a notch in a peripheral region thereof located adjacent the rim of the magnet for enhancing the density of the magnetic flux in the region of the rim of the magnet and the magnetic flux sensor.

9. An axial brushless DC motor comprising:
a stator including a plurality of coils;
a stator over mold member surrounding and enveloping the exterior side surfaces of the coils of the stator and including a central elongated hollow tube defining an interior elongate through-aperture, the stator over mold member further including an upper peripheral collar defining an interior receptacle;
a rotor including a magnet seated in the interior receptacle defined by the stator over mold member and surrounded by the upper peripheral collar of the stator over mold member;
an elongate shaft extending through the through-aperture of the tube of the stator over mold member; and
the magnet being in the form of a cup including a base and a peripheral lip together defining a receptacle for a disc-shaped pole piece, the disc-shaped pole piece being separate from the magnet, the base of the magnet defining a through-hole and the disc-shaped pole piece defining a through-hole and seated against the base of the cup and surrounded by the peripheral lip of the magnet, the elongate shaft extending through the through-hole in the base of the magnet and the disc-shaped pole piece respectively.

Assignees

• Cts Corp

Inventors

• King Yulanda Y H W
• Kolberg David
• Cors Douglas E
• Calkins Scott
• Andrina Eric
• Wolschlager Kevin C
• Stewart William S

Classifications

• H02K3/522

  for generally annular cores with salient poles · CPC title

• H02K5/1735

  radially supporting the rotary shaft at only one end of the rotor (H02K5/1737 takes precedence) · CPC title

• H02K7/083 Primary

  radially supporting the rotary shaft at both ends of the rotor (H02K7/086, H02K7/09 take precedence) · CPC title

• F16C33/585

  of raceways, e.g. ribs to guide the rollers · CPC title

• F16C2380/26

  Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators · CPC title