Circuit board for stator winding with integrated fixing structure

Abstract

A stator of an electric motor includes a stator core having a plurality of teeth. A printed circuit board (PCB) is fixed relative to the stator and includes a plurality of solder structures defined within a surface of the printed circuit board. A winding set is disposed on the teeth. The winding set includes at least one wire that is wrapped around the teeth to at least partially define a stator pole. Each wire of the winding set includes opposite ends that are attached to the printed circuit board at a dedicated solder structure of the plurality of solder structures.

Description

TECHNICAL FIELD

[0001] The present invention relates generally to electric motors, and more specifically to a securing structure for maintaining the positioning of stator windings of an electric motor. BACKGROUND

[0002] Conventional electric motors typically include a stator having windings that extend around the teeth of a stator core. These conductors are connected to a controller via a printed circuit board. The entire assembly is then overmolded or encased within a plastic material to form a stator structure for the electric motor. These conventional electric motors include intermediate conductive elements between the magnet wire and the printed circuit board controller. These intermediate conductive elements, commonly referred to as terminals, require specific components, such as the terminals themselves, as well as manufacturing processes to electrically connect the terminals to the magnet wire. Additional manufacturing processes are also required to electrically connect the terminals to the printed circuit board. SUMMARY

[0003] According to one aspect of the present invention, a stator of an electric motor includes a stator core having a plurality of teeth. A printed circuit board (PCB) is fixed relative to the stator and includes a plurality of solder structures defined within a surface of the printed circuit board. A winding set is disposed on the teeth. The winding set includes at least one conductor that is wrapped around the teeth to at least partially define a stator pole. Each conductor of the winding set includes opposite ends that are attached to the printed circuit board at dedicated solder structures of the plurality of solder structures.

[0004] According to another aspect of the present invention, a stator of an electric motor includes a stator core having a plurality of teeth. A printed circuit board (PCB) is attached to the stator core and has a plurality of solder structures defined therein. A winding set is comprised of at least one conductor. Each conductor of the at least one conductor extends from a first end attached to a first solder structure of the plurality of solder structures, around at least a portion of the plurality of teeth, and to a second end attached to a second solder structure of the plurality of solder structures. Each conductor is a continuous conductor segment that does not have an intermediate terminal.

[0005] According to another aspect of the present invention, an electric motor includes a printed circuit board. A conductor securing structure is positioned adjacent to the printed circuit board. A stator includes a plurality of poles. A conductor extends from a first end attached to the printed circuit board at a first solder pad, through a first portion of the conductor securing structure, around at least a portion of a pole of the plurality of poles, through a second portion of the conductor securing structure, and to a second end attached to the printed circuit board at a second solder pad. The conductor includes a continuous and uninterrupted conductor.

[0006] By studying the following description, claims and drawings, those skilled in the art will understand and appreciate these and other aspects, objects and features of the invention. Attached Figure Description

[0007] In the attached diagram:

[0008] Figure 1 It is a perspective view of the stator of an electric motor, including aspects of the soldering structure for attaching the windings to a printed circuit board;

[0009] Figure 2 yes Figure 1 An enlarged perspective view of the welded structure;

[0010] Figure 3 It is a perspective view of the stator and printed circuit board and shows the configuration of the solder structure;

[0011] Figure 4 yes Figure 1 Exploded perspective view of the stator;

[0012] Figure 5 yes Figure 1 The side front view of the stator shows the conductors in the welding position within the conductor assembly; and

[0013] Figure 6 yes Figure 1 The image shows a top view of the stator and illustrates the connection between the conductors in the conductor assembly and the dedicated solder pads. Detailed Implementation

[0014] For the purposes of this description, the terms “up,” “down,” “right,” “left,” “back,” “front,” “vertical,” “horizontal,” and their derivatives should be used interchangeably with those of the present invention. Figure 1 The orientation is related to the present invention. However, it should be understood that various alternative orientations may be employed, except as expressly specified otherwise. It should also be understood that the specific apparatus and processes shown in the drawings and described in the following specification are merely exemplary embodiments of the inventive concepts defined in the appended claims. Therefore, unless otherwise expressly stated in the claims, the specific dimensions and other physical characteristics relating to the embodiments disclosed herein should not be considered limiting.

[0015] like Figures 1-6As illustrated, reference numeral 10 generally refers to a printed circuit board (PCB) incorporated within the motor 12. The PCB 10 is positioned relative to the stator 14 in a fixed location such that various controls 16 for operating the components of the stator 14 can be fixed thereto during operation of the motor 12. Depending on various aspects of the device, the stator 14 for the motor 12 comprises a stator core 18 having a plurality of teeth 20. The PCB 10 is fixed relative to the stator core 18 and includes a plurality of solder structures 22 defined within a surface 24 of the PCB 10. A winding set 26 is disposed on the teeth 20 of the stator core 18. The winding set 26 includes at least one conductor 28 wound around the teeth 20 of the stator core 18 to at least partially define a plurality of stator poles 30 of the stator 14. Typically, the winding set 26 includes multiple conductors 28, each wound around a respective tooth 20 of the stator core 18 in a predetermined configuration. Each conductor 28 of the winding assembly 26 is attached to the opposite end 32 of the PCB 10 at a dedicated solder structure 34 of a plurality of solder structures 22. Using the solder structure 34, each of the various conductors 28 can be mounted on the stator 14 and the PCB 10 as a single and continuous conductor segment 28. By using single and continuous conductors 28, intermediate terminals and other electrical junctions are not included within the conductors 28 of the winding assembly 26.

[0016] like Figures 1-6 As illustrated, a plurality of solder structures 22 are defined near the edge 50 of the PCB 10. Each solder structure 22 may include a retaining notch 52 defined within the edge surface 54 of the PCB 10. Each retaining notch 52 is generally aligned with a corresponding tin-plated solder pad 56 that receives the corresponding end 32 of each conductor 28 of the winding set 26. The retaining notch 52 and the corresponding solder pad 56 cooperate to form at least a portion of each corresponding solder structure 22 of the PCB 10. In some aspects, the number of solder structures 22 may correspond to the number of conductors 28 of the winding set 26. It is also contemplated that the PCB 10 may include a predetermined number of solder structures 22 to accommodate various conductors 28 and various winding sets 26.

[0017] Refer again Figures 1-6 The tin-plated solder pads 56 are pre-tinned during the manufacturing of the PCB 10. As various circuit systems are printed on the substrate material 70 of the PCB 10, the various solder pads 56 of the multiple solder structures 22 are also positioned in specific locations on the PCB 10. Typically, the pre-tinned solder pads 56 are pre-tinned during the surface mount technology (SMT) process of manufacturing the PCB 10. With this configuration, each retaining recess 52 is aligned with the pre-tinned solder pad 56, allowing the end 32 of each conductor 28 of the winding assembly 26 to be placed within the retaining recess 52, and then ready for soldering when each conductor 28 is temporarily fixed to the PCB 10.

[0018] The use of multiple solder joints 22 is intended to assist in the accurate placement of the relative ends 32 of each conductor 28 of the winding assembly 26. This helps prevent conductor 28 crossing and other inaccuracies that could lead to short circuits and other structural and electrical defects within the stator core 18. This configuration also provides a feedback mechanism that informs the manufacturer that the PCB 10 has been accurately positioned relative to the various conductors 28 of the winding assembly 26 on the stator core 18. In this manner, retaining notches 52 assist in at least temporarily securing the relative ends 32 of each conductor 28 of the winding assembly 26. The various retaining notches 52 are configured to extend more than 180 degrees around the insulation layer 78 of at least one conductor 28 of the winding assembly 26. By extending more than 180 degrees around the insulation layer 78 of each conductor 28, each retaining notch 52 provides a clamping or other similar securing engagement for securing at least one conductor 28 in the solder position 100. This solder position 100 positions the conductors 28 of the winding assembly 26 in a location that facilitates stripping to expose the internal conductors 80. Once stripped, the inner conductor 80 can be easily folded at the retaining notch 52 to engage the pre-tinned solder pad 56. Once in this position, soldering operations can be performed to attach the conductor 80 of the wire 28 to the corresponding solder pad 56. These operations are facilitated by holding the end 32 of each wire 28 within the retaining notch 52. This holding feature allows for the use of a hands-free system for stripping and soldering the wires 28.

[0019] The operations of placing the wire 28 within the retaining recess 52, stripping the wire 28, folding the wire 28, and soldering the wire 28 to the solder pad 56 can be performed manually using hand-operated tools, or by automated or robotic mechanisms, or a combination of manual and automated processes. The soldering structure 22 provides an integrated guide for positioning the wire 28 during assembly and manufacturing and also helps protect the wire 28 during use.

[0020] Typically, the pre-tinned material of the solder pads 56 is solder paste 90 applied during the SMT process. These solder pads 56 are positioned to align with various retaining recesses 52 to at least temporarily hold the positioning of the conductors 28 of the winding assembly 26 in the soldering position 100. Other solder pads 56 may be positioned around the PCB 10 to receive other conductors 28 of the winding assembly 26, as well as other data and electrical connections extending from the PCB 10 to other locations of the motor 12, controllers operating in conjunction with the motor 12, or other similar mechanisms. Various selective soldering processes can be utilized when the various conductors 28 of the winding assembly 26 are soldered to the pre-tinned solder pads 56. These selective soldering processes can be implemented to provide accurate solder, thereby minimizing the use of soldering material and other electrical and material resources. This process also minimizes conductor crossings 28 so that each conductor 28 of the winding assembly 26 is accurately positioned within the PCB 10 and also soldered to the appropriate pre-tinned solder pad 56.

[0021] Refer again Figures 1-6 The stator 14 for the electric motor 12 includes a stator core 18 having a plurality of teeth 20. A PCB 10 is attached to the stator core 18 and includes a plurality of solder structures 22 defined therein. A winding set 26 is composed of at least one conductor 28, each of which extends from a first end 130 of a first dedicated solder structure 118 attached to the plurality of solder structures 22. Each conductor 28 extends around at least a portion of the plurality of teeth 20 of the stator core 18. A second end 132 of each conductor 28 is attached to a second dedicated solder structure 120 of the plurality of solder structures 22. As previously discussed, each conductor 28 of the winding set 26 is a continuous conductor segment 28 without intermediate terminals. Therefore, compared to processes that include intermediate terminals, the process of mounting the windings to the stator core 18 and then attaching those windings to the PCB 10 can be performed in a less complex manner.

[0022] Refer again Figures 1-6The stator core 18 may include various covers 110 or other similar structures, which may include alignment towers 112. These alignment towers 112 are typically aligned with corresponding fixing recesses 52 of a plurality of welding structures 22. These alignment towers 112 may include internal conductor receiving channels 114 that receive conductors 28 of the winding assembly 26. Using these alignment towers 112, the various conductors 28 of the winding assembly 26 can be guided from the stator teeth 20 of the stator core 18, and the conductors can be specifically guided to engage with dedicated fixing recesses 52 of dedicated welding structures 34. Similarly, by using the alignment towers 112 in conjunction with the plurality of welding structures 22, each conductor 28 of the winding assembly 26 can be specifically oriented and precisely positioned within a specific location on the PCB 10 to enable precise selective soldering processes. Furthermore, the alignment towers 112 in conjunction with the fixing recesses 52 can be used to protect the conductors 28 during use of the stator core 18.

[0023] By using multiple soldering structures 22 on the PCB 10, which include fixing notches 52 and pre-plated solder pads 56, at least one conductor 28 of the winding set 26 can be in the form of a continuous conductor 28 without intermediate terminals. Therefore, a single continuous conductor 28 can be incorporated into the stator 14 for use as a conductor 28 in the winding set 26 of the stator 14. Using this configuration, each conductor 28 of the winding set 26 can be a single continuous conductor 28 extending from a first dedicated soldering structure 118 on the PCB 10, surrounding various teeth 20 of the stator core 18, and then reaching a second dedicated soldering structure 120 on the PCB 10. By using segments of continuous conductor 28 for the winding set 26, various winding processes of the winding set 26 can be completed with minimal resources. Furthermore, since no intermediate terminals are used within the conductors 28 of the winding set 26, the likelihood of manufacturing defects or tolerances affecting the performance of various components of the motor 12 is reduced.

[0024] In conventional electric motors, the intermediate terminal located between the magnetic wires and the printed circuit board controller requires additional components, at least in the form of the intermediate terminal itself and other connecting parts. Additional manufacturing processes are also required in these conventional motors to electrically connect the intermediate terminal to each magnetic wire and the printed circuit board controller. This applies to each wound coil in a conventional motor. These added components and processes can stress the magnetic wires and other components of the conventional motor, potentially leading to material fatigue or failure in the magnetic wires, solder joints, and other locations.

[0025] Refer again Figures 1-6The electric motor 12 includes a PCB 10 and a wire fixing structure positioned near the PCB 10 in the form of a soldering structure 22. The stator 14 of the electric motor 12 includes a plurality of magnetic poles. Each of these magnetic poles includes various wires 28 constituting a winding set 26 of the stator 14 of the electric motor 12. The wires 28 extend from a first end 130, which is attached to the PCB 10 at a solder pad 56 of a first dedicated soldering structure 118. The wires 28 then extend through a first portion of the wire fixing structure, generally in the form of a fixing notch 52. The wires 28 extend around at least a portion of one of the magnetic poles to form various windings. The wires 28 extend to a second portion of the wire fixing structure, which includes a second fixing notch 52. Each of the fixing notches 52 is defined within an edge 50 of the body of the PCB 10, as discussed herein. The wires 28 include a second end 132, which is attached to the PCB 10 at a solder pad 56 of a second dedicated soldering structure 120. The wires 28 include a continuous and uninterrupted conductor 80 without intermediate terminals.

[0026] Refer again Figures 1-6 The first and second solder pads 56 are positioned adjacent to corresponding fixing recesses 52 of the conductor fixing structure. These fixing recesses 52 are defined within the edge 50 of the PCB 10. In operation, the corresponding fixing recesses 52 are configured to selectively fix the first end 130 and the second end 132 of the conductor 28 in a soldering position 100 relative to the PCB 10. This soldering position 100 ( Figure 5 The feature shown is that the first end 130 and the second end 132 of the conductor 28 are oriented to allow for the stripping and soldering of the conductor 28, while the first end 130 and the second end 132 of the conductor 28 are in soldering position 100. In other words, soldering position 100 positions each of the first end 130 and the second end 132 of the conductor 28 in a configuration generally perpendicular to the PCB 10. From this positioning, the first end 130 and the second end 132 of the conductor 28 are easily accessible for stripping the insulation layer 78 of the conductor 28 and exposing the inner conductor 80. This conductor 80 can then be easily bent and attached to the corresponding solder pad 56 to complete the mounting of the conductor 28 of the winding assembly 26.

[0027] Refer again Figures 1-6The continuous conductors 28 of the winding assembly 26, along with the retaining notch 52 and pre-tinned solder pads 56, form strain relief features. These strain relief features are used to limit material stresses experienced within the conductors 28, the PCB 10, and other components of the motor 12 during manufacturing and use. The stator 14 of the motor 12 is constructed in a novel way by directly connecting the conductors 28 of the stator core 18 to the PCB 10 (without using intermediate terminals), thereby forming integrated strain relief within these components. As discussed herein, features located within and near the edge 50 of the PCB 10—generally in the form of retaining notches 52 and pre-tinned solder pads 56—form strain relief features. These strain relief features are used to clamp the insulation layer 78 of the conductors 28 while the mechanically stripped and exposed inner conductors 80 of the conductors 28 are soldered to the pre-tinned solder pads 56 on the PCB 10. The retaining notch 52 also provides a guide around which the conductors 28 can be bent to solder the conductors 80 of the conductors 28 to the solder pads 56.

[0028] The PCB 10 utilizes multiple solder structures 22, fixing notches 52, and pre-plated solder pads 56 to provide an integrated strain relief feature that minimizes the stress applied to the various conductors 28 of the winding assembly 26 during the manufacture of the motor 12. These strain relief features minimize the risk of breakage and other damage at solder joints or fatigue of the conductors 28 of the winding assembly 26 and other components of the motor 12.

[0029] The PCB 10, which includes the solder structure 22, can be used in a variety of electric motors. Such motors may include, but are not limited to, brushless DC motors, synchronous A / C motors, switched reluctance motors, synchronous reluctance motors, and other similar motor applications utilizing the stator 14 and winding set 26.

[0030] It should be understood that changes and modifications may be made to the foregoing structure without departing from the concept of the invention, and it should also be understood that such concept is intended to be covered by the appended claims unless the wording of those claims expressly states otherwise.

Claims

1. A stator of an electric motor, the stator comprising: a stator core having a plurality of teeth; a printed circuit board (PCB) fixed relative to the stator and containing a plurality of solder structures defined within a surface of the printed circuit board; a winding set disposed on the teeth, wherein the winding set contains at least one wire that is wrapped around the teeth to at least partially define a stator pole, wherein each wire of the winding set contains opposite ends that are attached to the printed circuit board at a dedicated solder structure of the plurality of solder structures; wherein the dedicated solder structure is defined at an edge of the printed circuit board, and wherein each solder structure contains a securing notch defined within the edge of the printed circuit board; and wherein the stator core contains an alignment tower aligned with a respective securing notch of the plurality of solder structures.

2. The stator of claim 1, wherein each securing notch is aligned with a corresponding solder pad.

3. The stator of claim 2, wherein each corresponding solder pad is pre-tinned.

4. The stator of claim 2, wherein the corresponding solder pad is pre-tinned during a surface mount technology (SMT) process.

5. The stator of claim 1, wherein each alignment tower contains an internal channel that receives a wire that positions the at least one wire in alignment with the respective securing notch.

6. The stator of claim 2, wherein each securing notch of the plurality of solder structures is configured to position the at least one wire in a soldering position such that the at least one wire can be stripped and soldered to the solder pad while the at least one wire remains in the respective securing notch.

7. The stator of claim 6, wherein each securing notch is configured to extend more than 180 degrees around an insulation layer of the at least one wire to secure the at least one wire in the soldering position.

8. The stator of any one of claims 1-7, wherein the at least one wire is a continuous wire without an intermediate terminal.

9. The stator of claim 8, wherein the at least one wire extends from a first dedicated solder structure of the PCB, around the teeth of the stator core, and to a second dedicated solder structure of the PCB.

10. A stator of an electric motor, the stator comprising: a stator core having a plurality of teeth; a printed circuit board (PCB) attached to the stator core and having a plurality of solder structures defined therein; a winding set comprised of at least one wire, wherein each wire of the at least one wire extends from a first end attached to a first solder structure of the plurality of solder structures, around at least a portion of the plurality of teeth, and to a second end attached to a second solder structure of the plurality of solder structures, wherein each wire is a continuous wire segment without an intermediate terminal. wherein the plurality of solder structures are defined at an edge of the printed circuit board, and wherein each solder structure includes a securing notch defined within the edge of the printed circuit board; and wherein the stator core includes an alignment tower aligned with a respective securing notch of the plurality of solder structures.

11. The stator of claim 10, wherein each securing notch is aligned with a corresponding solder pad.

12. The stator of claim 11, wherein each corresponding solder pad is pre-tinned.

13. The stator of claim 11, wherein the corresponding solder pad is pre-tinned during surface mount technology (SMT).

14. The stator of claim 10, wherein each alignment tower includes an internal channel that positions the at least one wire in alignment with the respective securing notch.

15. The stator of claim 11, wherein the respective securing notch is configured to selectively secure a portion of the at least one wire in a soldering position relative to the corresponding solder pad, wherein the soldering position is characterized by the at least one wire being positioned to allow stripping and soldering while the at least one wire is in the soldering position.

16. The stator of claim 11, wherein each of the corresponding solder pads is incorporated within a respective solder structure of the plurality of solder structures.

17. The stator of claim 10, wherein each securing notch is configured to extend more than 180 degrees around an insulation layer of the at least one wire to secure the at least one wire in a soldering position.

18. The stator of any one of claims 10 to 17, wherein the at least one wire extends from a first dedicated solder structure of the PCB, around the teeth of the stator core, and to a second dedicated solder structure of the PCB.

19. An electric motor, comprising: a printed circuit board; a wire securing structure located proximate to the printed circuit board; a stator having a plurality of magnetic poles; a wire extending from a first end attached to the printed circuit board at a first solder pad, through a first portion of the wire securing structure, around at least a portion of the plurality of magnetic poles, through a second portion of the wire securing structure, and to a second end attached to the printed circuit board at a second solder pad, wherein the wire includes a continuous and uninterrupted conductor; wherein the wire securing structure is at least partially defined within an edge of the printed circuit board, and each of the first solder pad and the second solder pad is positioned proximate to a respective securing notch of the wire securing structure, the securing notch defined within an edge of the printed circuit board; and wherein the wire securing structure further includes an alignment tower positioned in alignment with the respective securing notch of the printed circuit board.

20. The electric motor of claim 19, wherein each alignment tower includes an internal channel that positions the wire in alignment with the respective securing notch.

21. The electric motor of claim 19, wherein the respective securing notches are configured to selectively secure the first and second ends of the wire in a soldering position relative to the printed circuit board, wherein the soldering position is characterized by the first and second ends of the wire being oriented to allow stripping and soldering of the wire when the first and second ends of the wire are in the soldering position.

22. The electric motor of claim 19, wherein each respective securing notch is configured to extend more than 180 degrees around an insulation layer of the wire to secure the wire in a soldering position.

23. The electric motor of any one of claims 19 to 22, wherein the first and second solder pads are pre-tinned.

24. The electric motor of any one of claims 19 to 22, wherein the first and second solder pads are pre-tinned during surface mount technology (SMT).

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