IN WHEEL AXIAL FLUX YOKELESS OUTRUNNER ELECTRIC MOTOR PROVIDING CABLES AND COOLING INTERNALLY

Abstract

An electric motor including a stator between a first and second rotor. The stator and the rotors are mounted to non-rotating shaft. The stator includes a plurality of windings and the first and second rotors include a plurality of magnets on a side thereof facing the stator. An opening internal to the electric motor is to provide cables and cooling to the stator. A hub is secured to opposite side of the first rotor as the plurality of magnets and rotates with rotation of the rotors. The hub includes a plurality of bolts extending therefrom to mount a rim thereto by placing the bolts through aligned holes in the rim. The motor is mounted in each wheel assembly of an electric automobile so that each wheel thereof is controlled by its own motor.

Claims

1. An electric motor comprising: a non-rotating shaft; a stator having a plurality of windings, wherein the stator is connected to the non-rotating shaft; a first rotor located on a first side of the stator having a plurality of magnets facing the stator, wherein the first rotor is secured to the non-rotating shaft via a bearing; a second rotor located on a second side of the stator having a plurality of magnets facing the stator, wherein the second rotor is secured to the non-rotating shaft via a bearing; an opening internal to the electric motor to provide cables and cooling to the stator; and a hub secured to opposite side of the first rotor as the plurality of magnets, wherein the hub includes a plurality of bolts extending therefrom to mount a rim thereto by placing the bolts through aligned holes in the rim.

2. The electric motor of claim 1, further comprising at least one of a first metal plate secured to opposite side of the first rotor as the plurality of magnets, wherein the hub is secured to the first plate; and a second metal plate secured to opposite side of the second rotor as the plurality of magnets.

3. The electric motor of claim 1, wherein the motor is mounted in a wheel assembly of an electric automobile.

4. The electric motor of claim 1, wherein a radius of the first and second rotors is greater than a radius of the stator and a connection means secures the first and the second rotors.

5. The electric motor of claim 1, wherein the opening is formed within the non-rotating shaft.

6. The electric motor of claim 1, wherein the non-rotating shaft is a shaft like protrusion extending from the stator and the opening is within the shaft like protrusion.

7. The electric motor of claim 1, wherein the stator includes a hollow shaft like protrusion extending toward the second rotor, wherein the shaft like protrusion is larger than the non-rotating shaft, wherein the non-rotating shaft passes through the shaft like protrusion, and wherein the opening is between the hollow shaft like protrusion and the non-rotating shaft.

8. An electric motor comprising: a hollow shaft; a stator having a plurality of windings, wherein the stator is connected to the hollow shaft; cables and cooling for the stator routed through the hollow shaft; a first rotor located on a first side of the stator having a plurality of magnets facing the stator, wherein the first rotor is secured to the hollow shaft via a bearing; a second rotor located on a second side of the stator having a plurality of magnets facing the stator, wherein the second rotor is secured to the hollow shaft via a bearing; and a hub secured to opposite side of the first rotor as the plurality of magnets, wherein the hub includes a plurality of bolts extending therefrom to mount a rim thereto by placing the bolts through aligned holes in the rim.

9. The electric motor of claim 8, further comprising at least one of a first metal plate secured to opposite side of the first rotor as the plurality of magnets, wherein the hub is secured to the first plate; and a second metal plate secured to opposite side of the second rotor as the plurality of magnets.

10. The electric motor of claim 8, wherein the motor is mounted in a wheel assembly of an electric automobile.

11. The electric motor of claim 8, wherein a radius of the first and second rotors is greater than a radius of the stator and a connection means secures the first and the second rotors.

12. The electric motor of claim 8, wherein the hollow shaft is a shaft like protrusion extending from the stator.

13. An electric automobile comprising a chassis; and a plurality of wheel assemblies to receive a plurality of rims and an associated plurality of tires mounted to the rims; a plurality of electric motors, wherein an electric motor is housed within each of the plurality of wheel assemblies, wherein the electric motors include: a non-rotating shaft; a stator having a plurality of windings, wherein the stator is connected to the non-rotating shaft; a first rotor located on a first side of the stator having a plurality of magnets facing the stator, wherein the first rotor is secured to the non-rotating shaft via a bearing; a second rotor located on a second side of the stator having a plurality of magnets facing the stator, wherein the second rotor is secured to the non-rotating shaft via a bearing; an opening internal to the electric motor to provide cables and cooling to the stator; and a hub secured to opposite side of the first rotor as the plurality of magnets, wherein the hub includes a plurality of bolts extending therefrom to mount a rim thereto by placing the bolts through aligned holes in the rim.

14. The electric automobile of claim 13, wherein the electric motors further includes at least one of a first metal plate secured to opposite side of the first rotor as the plurality of magnets, wherein the hub is secured to the first plate; and a second metal plate secured to opposite side of the second rotor as the plurality of magnets.

15. The electric automobile of claim 13, wherein a radius of the first and second rotors is greater than a radius of the stator and a connection means secures the first and the second rotors.

16. The electric automobile of claim 13, wherein the opening is formed within the non-rotating shaft.

17. The electric automobile of claim 13, wherein the non-rotating shaft is a shaft like protrusion extending from the stator and the opening is within the shaft like protrusion.

18. The electric automobile of claim 13, wherein the stator includes a hollow shaft like protrusion extending toward the second rotor, wherein the shaft like protrusion is larger than the non-rotating shaft, wherein the non-rotating shaft passes through the shaft like protrusion, and wherein the opening is between the hollow shaft like protrusion and the non-rotating shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The features and advantages of the various embodiments will become apparent from the following detailed description in which:

[0012] FIG. 1 illustrates an example radial flux electric motor.

[0013] FIG. 2 illustrates an example axial flux electric motor.

[0014] FIG. 3 illustrates a cross sectional view of an example axial flux electric motor.

[0015] FIG. 4 illustrates a cross sectional view of an example yokeless axial flux electric motor.

[0016] FIG. 5 illustrates a cross sectional view of an example axial flux yokeless motor.

[0017] FIG. 6 illustrates an electric automobile utilizing an inrunner axial flux yokeless electric motor (such as that illustrated in FIG. 5).

[0018] FIG. 7 illustrates a cross sectional view of an example outrunner axial flux yokeless motor, according to one embodiment.

[0019] FIG. 8 illustrates a cross sectional view of an example outrunner axial flux yokeless motor, according to one embodiment.

[0020] FIG. 9 illustrates a cross sectional view of an example outrunner axial flux yokeless motor, according to one embodiment.

[0021] FIG. 10 illustrates a cross sectional view of an example outrunner axial flux yokeless outrunner motor providing cooling and cabling within the motor footprint (such as those illustrated in FIGS. 7-9) being utilized in a wheel assembly, according to one embodiment.

DETAILED DESCRIPTION

[0022] The size of the axial flux motors may enable the motors to be utilized within a wheel assembly so that each wheel is provided with its own motor. In such an arrangement, the rotors may be utilized to directly turn the wheel instead of utilizing the shaft and possibly a gear box. Utilizing the rotors to directly rotate the wheel, and not utilizing a gear box, means that the motor needs to operate at the desired speed as the speed is not altered by the gear box. A configuration that utilizes the rotors to turn the wheels is often referred to as outrunner since the rotors can be accessed external to the motor.

[0023] FIG. 7 illustrates a cross sectional view of an example outrunner axial flux yokeless motor 700. The motor 700 includes a stator 710 and a pair of rotors 720 mounted on a shaft (non-rotating) 730. The rotors 720 include bearings 725 so that when they rotate, they can rotate around the shaft 730 without moving the shaft 730. The stator 710 includes windings 712, and the rotors 720 include magnets 722 facing the stator 710. The polarity of the magnets 722 alternates on each rotor 720 and also between each rotor 720. According to one embodiment, the rotors 720 may be slightly larger than the stator 710 so that the rotors 720 can be connected to one another with a connection means 790 (e.g., casing, rods) to ensure all the mechanical motion is available to be transferred. The connection means 790 is illustrated as connecting the tops and bottoms of the rotors 720 in cross sectional view, but is in no way intended to be limited thereto.

[0024] As the rotors 720, and possibly the connection means 790, are rotating, the power and cooling cannot be provided via an external means. As the shaft 730 is not rotating but is rather stationary, the shaft 730 may be hollow to allow cables and cooling 740 to traverse therein. The stator 710 and the shaft 730 may have openings 735 in alignment with each other that enable the cables and cooling 740 to be received by the stator 710.

[0025] A hub 750 is mounted to one of the rotors 720 with, for example, bolts 755. However, the manner in which the hub is secured to the rotor is not limited thereto. The hub 750 includes bolts 760 extending therefrom in alignment with holes in a rim. The hub 750 is utilized to mount the rim of the wheel onto the vehicle. The hub 750 is illustrated as being mounted external to the shaft 730 so no bearings are needed. However, the hub 750 is not limited thereto. Rather, the hub 750 could be located on and rotate around the shaft 730 utilizing bearings without departing the current scope. Furthermore, the size of the hub 750 is illustrated as being smaller than the size of the rotor 720 but is not limited thereto. Rather, the size of the various components is limited by the size of the wheel assembly.

[0026] According to one embodiment, the motor 700 may also include a plate (e.g., iron, steel) mounted to one of the rotors 720 or a plate mounted to each of the rotors 720 to provide support and/or protection for the motor (e.g., act as a housing). The plate(s) could be connected to the rotor(s) 720 with, for example, bolts, but is not limited thereto. The hub 750 may act as a plate on the one side of the motor 700. Alternatively, a plate could be mounted to the rotor 720 and the hub 750 could be mounted to the plate.

[0027] FIG. 8 illustrates a cross sectional view of an example outrunner axial flux yokeless motor 800. The motor 800 is similar to the motor 700 of FIG. 7 except that the stator 710 includes a centrally located shaft like protrusion 810 extending therefrom in each direction in place of the shaft 730. The rotors 720 may be mounted on the protrusion 810 with bearings 725 to enable the rotors 720 to rotate therearound. One end of the protrusion 810 includes a centrally formed opening 812. The protrusion also includes an opening 814 into the stator 710. Like the hollow shaft 730, the openings 812, 814 in the protrusion 810 may be utilized to route the cables and cooling 740 to the stator 710.

[0028] As illustrated, the motor 800 includes a plate 820 acting as a housing on one side of the motor 800 (side facing wheel). The motor is not limited to a single plate on the wheel side. Rather, a plate could be located on both sides or only the non-wheel side without departing from the current scope. The plate is mounted to the rotor 720 with bolts 825. The manner in which the plate 820 is mounted to the rotor 720 is not limited thereto. As illustrated, the plate 820 is larger than the rotor 720 and is mounted on the protrusion 810 with bearings so that it rotates therearound. The size of the plate 820 is not limited thereto and the plate need not be mounted on the protrusion 810. The hub 755 is mounted to the plate 820. As with FIG. 7, the hub 750 is illustrated as being mounted external to the shaft 730 and as being smaller than the size of the rotor 720 but is not limited thereto.

[0029] FIG. 9 illustrates a cross sectional view of an example outrunner axial flux yokeless motor 900. The motor 900 is similar to the motor 800 of FIG. 8 except the stator 710 includes a hollow shaft like protrusion 910 that only extends in one direction (away from wheel assembly). The protrusion 910 extends over one end of a shaft (possibly solid) 920. One rotor 720 (one facing away from wheel assembly) is mounted to the protrusion 910 and one rotor 720 (one facing wheel assembly) is mounted to the shaft 920. An open area between the protrusion 910 and the shaft 920 is utilized to route the cables and cooling 740 to the stator 710.

[0030] As illustrated, the hub 750 is mounted on the shaft 920 with bearings 930 so that it rotates therearound. The configuration of the motor with regard to providing a housing and means for mounting the rim is in no way intended to be limited to that illustrated.

[0031] FIG. 10 illustrates a cross sectional view of an example outrunner axial flux yokeless outrunner motor providing cooling and cabling within the motor footprint (such as those illustrated in FIGS. 7-9) being utilized in a wheel assembly. The cables and the cooling are provided to the motor in and/or around the shaft in some fashion.

[0032] Although the disclosure has been illustrated by reference to specific embodiments, it will be apparent that the disclosure is not limited thereto as various changes and modifications may be made thereto without departing from the scope. The various embodiments are intended to be protected broadly within the spirit and scope of the appended claims.