Brushless DC motor

Abstract

A brushless DC motor is disclosed that includes a shaft, a rotor, and a stator assembly disposed about the rotor. A plurality of windings are supported on the stator. The circuit board is attached to an end of the stator and includes a plurality of slots in which the winding portions are received. One or more strain relief protrusions extend from the stator proximate at least one of the plurality of slots to abut at least a portion of the winding wound thereon.

Description

Technical Field

[0001] The present disclosure relates to electric motors, and more particularly to a brushless direct current (BLDC) motor, a stator suitable for use with the motor, a tool for using the motor, and a method of making the motor. Background Art

[0002] The battery-operated motor in a power tool is typically arranged to rotate a shaft to which the tool is attached, relying on electromagnetic interactions that occur between the windings and permanent magnets in the motor. In a permanent magnet brushed DC motor, the windings are wound around a magnetizable core (rotor) that rotates within a fixed permanent magnet (stator). The windings receive current via brushes and a commutator, and are therefore referred to as brushed DC motors.

[0003] In an alternative arrangement, namely a brushless DC motor, the stator windings surround an internal permanent magnet rotor. Brushless DC motors are typically more durable than brushed motors, with higher speed and torque capabilities. In addition, brushless DC motors typically produce less noise and have a longer lifespan.

[0004] In a brushless DC motor, the switching of current in windings around the stator drives the rotation of the rotor and attached shaft. Injecting current into successive stator coils creates varying electromagnetic poles around the stator circumference. These varying magnetic poles of the stator coils are sequentially energized to attract opposite magnetic poles on the rotor, thereby generating torque and rotation of the motor shaft, which in turn is used to drive the driven member of the power tool.

[0005] As is known in the art, in the operation of a brushless DC motor, it is critical to ensure that the rotating magnetic poles produced by energizing the stator coils are synchronized with the rotating magnetic poles of the rotor. Typically, sensors (e.g., Hall Effect sensors) mounted on a sensor board attached to the stator are arranged to detect the position of the rotor poles relative to the coil windings. The detected position is then provided to the motor controller circuit for controlling the current flowing to the stator coils. Typically, the wires from the stator coils are passed through slots in the sensor board to the power supply, and a ball of solder is used to secure the wires in the slots.

[0006] Unfortunately, in many cases, due to the different vibration frequencies inherent in the stator body and the sensor plate during operation, the wires of the stator coils may fatigue at the slots due to long-term operation, resulting in eventual failure of the motor.

[0007] It is an object of the present disclosure to provide an alternative arrangement which addresses or at least partially ameliorates the above-mentioned disadvantages or at least provides the public with further choices. Summary of the invention

[0008] The features and advantages of the present disclosure will be set forth in the following description, and in part will become apparent from the description, or may be learned by practicing the principles disclosed herein. The features and advantages of the present disclosure may be realized and obtained by the instruments and combinations particularly pointed out in the appended claims.

[0009] According to a first aspect of the present disclosure, there is provided a brushless DC motor comprising an elongated motor shaft, a rotor comprising a plurality of magnets fixed around the elongated motor shaft, a stator assembly arranged around the rotor, the stator assembly comprising a plurality of windings supported on the stator, a circuit board attached to an end of the stator, the circuit board comprising a plurality of slots therein for receiving winding portions, wherein one or more strain relief protrusions may extend from the stator proximate to at least one of the plurality of slots to abut against at least a portion of the windings wound thereon.

[0010] A portion of one or more strain relief tabs may extend radially outwardly relative to the elongated motor shaft and be positioned offset in a path between the slot and a corresponding winding of the stator assembly received therein.

[0011] A portion of the one or more strain relief tabs may extend downwardly and toward an end of the stator.

[0012] One or more strain relief tabs may extend from the end of the stator in an L-shape.

[0013] Alternatively, one or more strain relief protrusions may extend from an end of the stator in at least a partial U-shape.

[0014] The circuit board may be attached to the end of the stator by fasteners disposed proximate and between a pair of adjacent slots of the plurality of slots.

[0015] Fasteners may be positioned equidistantly around the circuit board to attach the circuit board to the stator.

[0016] Optionally, the fastener is a screw.

[0017] The circuit board may be attached to the end of the stator by three equidistant screws disposed between adjacent slots located at the periphery of the circuit board.

[0018] Optionally, the circuit board is a sensor board.

[0019] According to a second aspect of the present disclosure, there is provided a brushless DC motor, the brushless DC motor comprising an elongated motor shaft, a rotor comprising a plurality of magnets fixed around the elongated motor shaft, a stator assembly arranged around the rotor, the stator assembly comprising a plurality of windings supported on the stator, wherein the stator may include a mounting portion for receiving a fastener engaged with a circuit board, the mounting portion may be disposed between a pair of adjacent windings extending from the stator. Optionally, a circuit board is attached to an end of the stator, the circuit board comprising a plurality of slots for receiving winding portions therein.

[0020] Each of the mounting portions may receive a screw therein.

[0021] The brushless DC motor may further include one or more strain relief protrusions extending from the stator proximate at least one slot of the plurality of slots to abut against at least a portion of the winding wound thereon.

[0022] Optionally, the circuit board is a sensor board.

[0023] According to a third aspect of the present disclosure, there is provided a stator for a brushless DC motor, the stator comprising one or more strain relief protrusions arranged to extend from ends of the stator adjacent to one or more corresponding slots of a circuit board to which the stator can engage, the one or more strain relief protrusions abutting against at least a portion of one of a plurality of windings wound thereon.

[0024] One or more strain relief protrusions may extend radially outward from the stator and offset from a path between one or more corresponding slots and corresponding windings wound around the stator when assembled.

[0025] A portion of the one or more strain relief tabs may extend downwardly and toward an end of the stator.

[0026] One or more strain relief tabs may extend from the end of the stator in an L-shape.

[0027] Alternatively, one or more strain relief protrusions may extend from an end of the stator in at least a partial U-shape.

[0028] Optionally, the stator includes mounting portions for receiving fasteners that engage the circuit board, and each of the mounting portions may be disposed between a pair of adjacent windings extending from the stator.

[0029] The mounting portion may receive a screw therein.

[0030] Optionally, the circuit board is a sensor board.

[0031] According to a fourth aspect of the present disclosure, there is provided a stator for a brushless DC motor, the stator comprising: a mounting portion for receiving a corresponding fastener engaged with a circuit board, the mounting portion being disposed between a pair of adjacent windings extending from the stator.

[0032] The mounting portion may receive a screw therein.

[0033] Optionally, the circuit board is a sensor board.

[0034] According to a fifth aspect of the present disclosure, an electrical appliance or a tool is provided, the electrical appliance or the tool comprising the stator as described above or the motor as described above.

[0035] According to a sixth aspect of the present disclosure, there is provided a method of manufacturing a brushless DC motor as described above, wherein one or more of the plurality of windings are at least partially wound around a strain relief protrusion.

[0036] Optionally, the circuit board is attached to the stator by a plurality of fasteners, wherein each fastener is disposed on the circuit board proximate to and between a pair of slots to receive the winding therethrough.

[0037] According to a seventh aspect of the present disclosure, there is provided a method of manufacturing a stator as described above, wherein one or more windings of the plurality of windings are at least partially wound around the strain relief protrusion.

[0038] Optionally, the circuit board is attached to the stator by a plurality of fasteners, wherein each fastener is disposed on the circuit board proximate to and between a pair of slots to receive the winding therethrough.

[0039] The object of the present disclosure is to solve or at least partially ameliorate some of the above-mentioned problems of current approaches. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to describe the manner in which the above and other advantages and features of the present disclosure can be obtained, the principles briefly described above will be described in more detail by referring to the specific embodiments of the present disclosure shown in the accompanying drawings. It should be understood that these drawings only depict exemplary embodiments of the present disclosure and therefore should not be considered to limit the scope of the present disclosure. The principles of this article are described and explained in more detail by using the accompanying drawings.

[0041] The preferred embodiments of the present disclosure will be further explained in detail below by way of examples and with reference to the accompanying drawings, in which

[0042] In the figure:

[0043] Figure 1A Depicted is an exploded perspective view of the various components of a brushless DC motor according to conventional design.

[0044] Figure 1B Depicted is a perspective view of a Hall sensor plate and stator of a conventional brushless DC motor assembly.

[0045] Figure 1C An enlarged perspective view depicting the disconnection between the stator wires and the circuit board.

[0046] Figure 2A An exploded perspective view of various components of a brushless DC motor with an improved design according to an embodiment of the present invention is depicted.

[0047] Figure 2B An exploded perspective view of various components of a brushless DC motor with an improved design according to another embodiment of the present invention is depicted.

[0048] Figure 2C Depicted Figure 2A or Figure 2B A perspective view of the Hall sensor board and stator.

[0049] Figure 2D Depicted Figure 2A An enlarged perspective view of an exemplary strain relief protrusion and end retention member of a stator.

[0050] Figure 2E Depicted Figure 2B An enlarged perspective view of an exemplary strain relief protrusion and end retention member of a stator.

[0051] Figure 2F Depicted Figure 2A An enlarged perspective view of an exemplary fastener, a sensor plate, a portion of a winding, and a stator.

[0052] Figure 3A A schematic side view of an exemplary strain relief tab is depicted.

[0053] Figure 3B Depicted is a schematic side view of an alternative exemplary strain relief tab.

[0054] Figure 4A A schematic diagram of an exemplary tool in which a brushless DC motor is provided is depicted.

[0055] Figure 4B Depicted Figure 4A An enlarged schematic diagram of a brushless DC motor. DETAILED DESCRIPTION

[0056] A number of different embodiments of the present disclosure are discussed in detail below. Although specific embodiments are discussed, it should be understood that this is done for illustrative purposes only. Those skilled in the relevant art will recognize that other components and configurations may be used without departing from the scope of the present disclosure.

[0057] The disclosed technology addresses the need in the art for an improved brushless DC motor that solves or at least ameliorates some of the deficiencies of the prior art.

[0058] Figure 1A Depicted is an exploded perspective view of the various components of a brushless DC motor according to conventional design.

[0059] like Figure 1A As depicted in the illustrated embodiment of the present disclosure, the front cover 102 receives the front coil retainer 104, in which the stator laminations 106 and the insulating paper 108 are also received. The stator assembly 110 includes the front coil retainer 104, the rear coil retainer 105, and the stator lamination assembly 106, and the winding 112. The stator 111 includes the front coil retainer 104, the rear coil retainer 105, and the stator laminations 106.

[0060] A printed circuit board (PCB) 114 (typically having a Hall Effect type sensor) is attachable to the rear coil retainer 105 of the stator 111 via fasteners 116. Typically, but not exclusively, such fasteners may be screws or the like that engage into corresponding threaded portions included in the rear coil retainer 105. Typically, these screws extend through holes 117 (not shown) in the circuit board 114, the specific location of which may be determined based on the design of the circuit.

[0061] The rotor assembly 130 (including magnets 128 arranged around an elongated shaft 134 and rotor lamination stack 131) is supported by various components at the front of the motor. Typically, these components include wave washers 118, ball bearings 120, 126, front balancing washers 122, and rubber rings 124, although other arrangements may be used. The rotor assembly 130 is also supported at the rear of the motor by a rear balancing washer 132.

[0062] exist Figure 1A In the depicted conventional motor 100, the rotor assembly 130, the elongated shaft 134, and the stator assembly 110 are thus received and supported between the front cover 102 and the rear cover 136, secured together by screws or other fasteners 138. It should be understood that, although not depicted, other arrangements of prior art brushless motors that do not include the front cover 102 and the rear cover 136 are also used.

[0063] Figure 1B Depicted Figure 1AFIG. 1 is an enlarged perspective view of a Hall sensor plate and stator of a conventional brushless DC motor assembly. For ease of reference, the enlarged view depicts a conventional arrangement of a brushless DC motor, wherein a winding 112 is received in a slot 115 of a printed circuit board 114.

[0064] It will be appreciated that the ends 113 of the windings 112 have been truncated in the figures, with these ends ultimately being connected to a motor controller (not shown) for connection to a power source.

[0065] As depicted, ends 113 of windings 112 are supported on stator 111 and extend directly above through corresponding slots 115 defined in circuit board 114. Typically, the windings are secured in the slots with a blob of solder (not shown).

[0066] Reference now Figure 1C , depicting an enlarged perspective view of the disconnection between the stator wire and the circuit board. The winding end 113 has been sheared off from another portion of the winding (not shown for clarity) that is held in place in a slot 115 of the PCB 114 by a small amount of solder.

[0067] Figure 2A Depicted is an exploded perspective view of the various components of a brushless DC motor of an improved design according to an embodiment of the present invention. Note that this arrangement includes a pair of end caps for securing components of the motor.

[0068] Similar to Figure 1A The depicted arrangement shows a front cover 202 that receives a front coil retainer 204 in which a stator lamination 206 and insulating paper 208 are also received. A stator assembly 210 includes a front coil retainer 204, a rear coil retainer 205 and a stator lamination 206 of a stator 211, and a winding 212. The stator 211 includes a front coil retainer 204, a rear coil retainer 205 and a stator lamination 206.

[0069] A printed circuit board 214 (typically having a Hall Effect type sensor) is attachable to the rear coil retainer 205 of the stator 211 via fasteners 216. Such fasteners may be screws or the like that engage into corresponding threaded portions included in the rear coil retainer 205. The screws extend through holes 217 (not shown) in the circuit board 214.

[0070] The rotor assembly 230 (including magnets 228 and rotor laminations 231 arranged around shaft 234) is supported by various components at the front side of the motor. Typically, these components include wave washers 218 (not shown), ball bearings 220, 226 (not shown), front balancing washers 222, and rubber rings 224, although other arrangements may be used. The rotor assembly 230 is also supported at the rear of the motor by a rear balancing washer 232.

[0071] exist Figure 2A In the depicted motor 200 , the rotor assembly 230 , shaft 234 , and stator 211 are thus received and supported between the front cover 202 and the rear cover 236 , secured together by screws or other fasteners 238 .

[0072] Figure 2B An exploded perspective view of various components of a brushless DC motor with an improved design according to another embodiment of the present invention is depicted.

[0073] basically, Figure 2B The depicted embodiments are Figure 2A The illustrated embodiment is identical except for the absence of the end cap members 202, 236 and the changes in the shape of the strain relief tabs 250, which will be described in further detail below.

[0074] Figure 2C Depicted Figure 2A and / or Figure 2B A magnified perspective view of the Hall sensor plate and stator of the brushless DC motor assembly.

[0075] As can be seen from the enlarged view, the winding 212 is received in the slot 215 of the printed circuit board 214. (For the purpose of clarity, some reference numbers of certain slots / windings have been omitted.) It should be understood that the ends of the winding 212 have been truncated in the figure, and ultimately these ends are connected to the motor controller (not shown) for connection to a power source.

[0076] As depicted, the winding 212 is supported on the stator 211 and passes from the stator around a strain relief tab 250 formed on the rear coil retainer 205. As shown, the strain relief tab 250 extends or protrudes outwardly away from the elongated shaft 234 (not shown), such as FIG. 2D to FIG. 2F As shown in more detail in FIG.

[0077] The strain relief tabs 250 are arranged so that the path of the windings 212 when exiting the stator assembly 210 when assembled is not directly through the slots 215 of the circuit board 214 as in conventional prior art arrangements. Instead, in an arrangement according to the present disclosure, the windings exit the stator, bend and bear against the strain relief tabs to rest around the tabs, and then extend upward through the slots 215 of the circuit board 214.

[0078] Thus, when the motor is manufactured, the windings are at least partially wrapped around the strain relief member 250 .

[0079] During operation, the positioning of the strain relief member 250 relative to the slots and windings on the stator means that the forces caused by the difference in vibration frequency of the stator and circuit board no longer act only on the solder joints, but on the strain relief tabs. The windings have the ability to deform and move slightly around the strain relief member 250. This increases the life of the motor because fatigue in the windings is avoided.

[0080] Figure 2D An enlarged perspective view of an exemplary strain relief member and end retention member of a stator is depicted.

[0081] As depicted, the strain relief protrusion can be a generally L-shaped arrangement with a first body portion 252 extending in a direction parallel to the longitudinal axis of the elongated shaft; and an arm portion 254 extending radially outward from the elongated shaft. This arrangement is particularly suitable for smaller motors or shorter motors where the stator winding coils have a smaller diameter.

[0082] Figure 2E An enlarged perspective view of an exemplary strain relief projection of a stator (which is U-shaped in this arrangement) is depicted.

[0083] Figure 2F A perspective view of an exemplary sensor plate 214 and an end of the stator 211 , particularly the rear coil retainer 205 , is depicted.

[0084] In the depicted embodiment, three equally spaced apertures 217 are provided between each pair of adjacent slots 215 located at the periphery of the sensor board 214, which receive the windings of the stator. As shown, there are three fasteners (in this case screws) 216 configured to engage the sensor board 214 with the stator 211. The slots 215 in the circuit board 214 are located on either side of the apertures 217 for the screws 216.

[0085] It should be noted that the apertures for the fasteners of the circuit board 214 may be defined proximate to and between the slots of the circuit board in conjunction with the strain relief tabs extending from the stator described herein.

[0086] Alternatively, an aperture 217 for a fastener for the circuit board 214 can be defined proximate to and between each pair of slots of the circuit board, as an alternative to the strain relief tabs extending from the stator described herein. In either arrangement, the location of the aperture proximate to the slots 215 reduces the forces and displacements on the windings by minimizing the moments generated by the difference in relative vibrations of the stator assembly 210 and the circuit board 214.

[0087] Figure 3A A schematic side view of an exemplary strain relief tab is depicted.

[0088] As depicted, the winding includes an end portion 213 that contacts the strain relief tab 250. In particular, as depicted, the strain relief tab can be a generally L-shaped arrangement with a first body portion 252 extending in a direction parallel to the longitudinal axis of the elongated shaft and an arm portion 254 extending radially outward from the elongated shaft. This arrangement is particularly suitable for smaller motors in which the stator winding coils have a small diameter and in which end caps are not applied. Typically, although not exclusively, such smaller motors can have a diameter of the stator lamination 206 that is less than 38 mm.

[0089] Figure 3B Depicted is a schematic side view of an alternative exemplary strain relief tab.

[0090] As depicted, the winding includes an end portion 213 that contacts the strain relief tab 250. In particular, as depicted, the strain relief tab can be a generally U-shaped arrangement with a first body portion 252 extending in a direction parallel to the longitudinal axis of the elongated shaft and an arm portion 254 extending radially outward from the elongated shaft. A second body portion 256 extends generally downward from the arm portion 254 in a direction arranged generally parallel to the elongated axis. This arrangement is particularly suitable for larger diameter motors or longer motors where the stator winding coils have a larger diameter and where end caps may not be suitable because the additional body portion 256 provides additional fixation for the windings wound therethrough.

[0091] It should be understood by those skilled in the art that although Figure 3A and Figure 3B The windings are all depicted as being disposed at or near the junction of the arm and the body portion of the strain relief protrusion, but other arrangements in which the windings abut the body portion and are spaced further from the junction of the arm and body portion are possible without departing from the scope of the present disclosure.

[0092] Figure 4A An exemplary tool is depicted in which a brushless DC motor is provided, and Figure 4B An enlarged portion thereof is depicted.

[0093] As depicted, tool 310 is an exemplary drill head that includes a motor 320 including a stator assembly 330 and a rotor assembly 340 and a circuit board 350 (not shown) constructed as described above. It should be understood that other tools provided with similar motors, such as power saws, blowers, etc., may also be used without departing from the scope of the present disclosure.

[0094] The arrangement of the circuit board aperture and strain relief member together or alone can demonstrate an increase in the life of a brushless DC micro motor (e.g., from 30mm to 60mm in diameter). However, it should be understood that the teachings of the present disclosure are not limited to this application and are applicable for use with larger motors.

[0095] The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the present disclosure as defined in the appended claims.

[0096] Although various examples and other information are used to explain aspects within the scope of the appended claims, in such examples, limitations to the claims should not be implied based on specific features or arrangements, because ordinary technicians will be able to use these examples to derive a variety of implementations. Further, although some topics may have been described in language specific to examples of structural features and / or method steps, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the features or actions described. For example, such functions may be distributed differently or performed in components other than those identified herein. Instead, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims.

Claims

1. A brushless DC motor, comprising: An elongated motor shaft; a rotor including a plurality of magnets secured about the elongated motor shaft; a stator assembly disposed about the rotor, the stator assembly comprising a plurality of windings supported on a stator; a circuit board attached to an end of the stator, the circuit board including a plurality of slots for receiving winding portions therein, wherein one or more strain relief protrusions extend from the stator proximate at least one slot of the plurality of slots to abut against at least a portion of a winding wound thereon.

2. The brushless DC motor according to claim 1, wherein: A portion of the one or more strain relief projections extends radially outwardly relative to the elongated motor shaft and is positioned offset in a path between a slot and a corresponding winding of the stator assembly received therein.

3. The brushless DC motor according to claim 1 or claim 2, wherein: A portion of the one or more strain relief tabs extends downwardly and toward an end of the stator.

4. The brushless DC motor according to claim 1, wherein: The one or more strain relief tabs extend from an end of the stator in an L-shape.

5. The brushless DC motor according to claim 1, wherein: The one or more strain relief tabs extend from an end of the stator in at least a partial U-shape.

6. The brushless DC motor according to claim 1, wherein: The circuit board is attached to the end of the stator by fasteners disposed proximate to and between a pair of adjacent slots of the plurality of slots.

7. The brushless DC motor according to claim 6, wherein: The fasteners are positioned equidistantly around the circuit board to attach the circuit board to the stator.

8. The brushless DC motor according to claim 6 or claim 7, wherein: The fastener is a screw.

9. The brushless DC motor according to claim 6 or claim 7, wherein: The circuit board is attached to the end of the stator by three equidistant screws disposed between adjacent slots located at the periphery of the circuit board.

10. The brushless DC motor according to claim 1, wherein The circuit board is a sensor board.

11. A brushless DC motor comprising: An elongated motor shaft; a rotor including a plurality of magnets secured about the elongated motor shaft; a stator assembly disposed about the rotor, the stator assembly including a plurality of windings supported on a stator, wherein the stator includes a mounting portion for receiving a fastener engaged with a circuit board, the mounting portion being disposed between a pair of adjacent windings extending from the stator; A circuit board is attached to an end of the stator, the circuit board including a plurality of slots receiving winding portions therein.

12. The brushless DC motor according to claim 11, wherein: Each of the mounting portions is configured to receive a screw therein.

13. The brushless DC motor according to claim 11 or claim 12, further comprising: One or more strain relief tabs extend from the stator proximate at least one slot of the plurality of slots to abut against at least a portion of a winding wound thereon.

14. The brushless DC motor according to claim 11, wherein: The circuit board is a sensor board.

15. A stator for a brushless DC motor, the stator comprising One or more strain relief tabs are arranged to extend from an end of the stator proximate one or more corresponding slots of a circuit board to which the stator can be engaged, and the one or more strain relief tabs abut at least a portion of one of the plurality of windings wound thereon.

16. The stator according to claim 15, wherein: The one or more strain relief protrusions are configured to extend radially outward from the stator and offset from a path between the one or more corresponding slots and a corresponding winding wound around the stator when assembled.

17. A stator according to claim 15 or claim 16, wherein: A portion of the one or more strain relief tabs extends downwardly and toward an end of the stator.

18. The stator according to claim 15, wherein: The one or more strain relief tabs extend from an end of the stator in an L-shape.

19. The stator according to claim 15, wherein: The one or more strain relief tabs extend from an end of the stator in at least a partial U-shape.

20. The stator of claim 15, comprising mounting portions for receiving fasteners that engage a circuit board, each of the mounting portions being disposed between a pair of adjacent windings extending from the stator.

21. The stator according to claim 20, wherein: The mounting portion is configured to receive a screw therein.

22. The stator according to claim 15, wherein: The circuit board is a sensor board.

23. A stator for a brushless DC motor, the stator comprising: A mounting portion for receiving a corresponding fastener that engages a circuit board is disposed between a pair of adjacent windings extending from the stator.

24. The stator for a brushless DC motor according to claim 23, wherein: The mounting portion is configured to receive a screw therein.

25. The stator for a brushless DC motor according to claim 23, wherein: The circuit board is a sensor board.

26. An electrical appliance or tool comprising a stator according to claims 15 to 24 or a motor according to claims 1 to 14.

27. A method for manufacturing a brushless DC motor according to claim 1, wherein: One or more of the plurality of windings is wound at least partially around the strain relief tab.

28. A method for manufacturing a brushless DC motor according to claim 1, wherein: The circuit board is attached to the stator by a plurality of fasteners, wherein each fastener is disposed on the circuit board proximate to and between a pair of slots to receive a winding therethrough.

29. The method for manufacturing a stator according to claim 15, wherein: One or more of the plurality of windings is wound at least partially around the strain relief tab.

30. The method for manufacturing a stator according to claim 15, wherein: The circuit board is attached to the stator by a plurality of fasteners, wherein each fastener is disposed on the circuit board proximate to and between a pair of slots to receive a winding therethrough.

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