Stepping motor split stator assembly

Abstract

This utility model discloses a split stator assembly for a stepper motor, including a stator core and a coil assembly mounted on the stator core. The stator core is composed of two stator lamination units with identical structures. Each stator lamination unit is formed by stacking multiple stator laminations of the same shape. The stator laminations have slots to form stator slots for embedding the coil assembly. After the coil assembly is installed in the stator slots of the two stator lamination units, they are symmetrically spliced ​​together along one side of the slot opening to form the motor stator, which is fixed inside the motor housing. By designing the stator core of the stepper motor as two parts, and splicing the two parts to form the motor stator, each part of the stator core is composed of multiple non-enclosed stator laminations stacked together. This facilitates the direct horizontal linear movement of the coil assembly into the stator slot, eliminating the need for vertical movement to the central cavity area of ​​the stator core and then horizontal movement, thus improving the assembly of the coil assembly.

Description

Technical Field

[0001] This disclosure relates to the field of stepper motor technology, and more particularly to a separate stator assembly for a stepper motor. Background Technology

[0002] A stepper motor is an electric motor that converts electrical pulse signals into corresponding angular or linear displacement. Each input pulse causes the rotor to rotate by an angle or move forward a step; its output pulse is proportional to the number of input pulses, and its rotational speed is proportional to the pulse frequency. The stator of a conventional stepper motor is typically composed of multiple stacked stator laminations. These laminations are made of silicon steel strip, which is punched into closed-loop stator laminations using a high-pressure punching die. Within the stacked stator laminations, forming the stator core, multiple stator slots are formed on the inner side to accommodate coil assemblies. The central area formed by these slots serves as the central cavity for installing individual coil assemblies. When installing coil assemblies, one coil assembly is inserted vertically downwards into the central cavity, and the insertion port of the coil assembly must be pre-adjusted to align with the corresponding stator slot. Then, the coil assembly is moved horizontally into the stator slot. The central cavity area also serves as the mounting location for the motor rotor. Due to limited space in this area, the coil assemblies must be installed one by one. This coil assembly process involves component handling in both vertical and horizontal dimensions. Automated assembly equipment requires corresponding mechanisms for each dimension. Manual assembly also presents challenges. The motor's overall size is small, and the central cavity area is enclosed, requiring individual coil assembly. The limited space makes sidewall interference a possibility. Therefore, existing stepper motors need to be optimized and improved. Utility Model Content

[0003] In view of this, this disclosure proposes a split stator assembly for a stepper motor to overcome the shortcomings of the prior art and make assembly simpler and more convenient.

[0004] According to one aspect of this disclosure, a split stator assembly for a stepper motor is provided, including a stator core and a coil assembly mounted on the stator core. The stator core is composed of two stator lamination units with the same structure. Each stator lamination unit is formed by stacking multiple stator laminations of the same shape. The stator laminations are provided with slots to form stator slots for embedding the coil assembly. After the coil assembly is installed in the stator slots of the two stator lamination units, they are symmetrically spliced ​​together along one side of the slot opening to form a motor stator, which is fixed inside the motor housing.

[0005] Furthermore, the coil assembly includes an insulating support, a coil, and a power-connecting pin. The insulating support has a hollow tube with openings at both ends. The front and rear ends of the hollow tube have a front convex edge and a rear convex edge extending vertically around the outer walls of the openings at the front and rear ends of the hollow tube, respectively. The coil is wound around the outer wall of the hollow tube between the front convex edge and the rear convex edge. The rear side of the rear convex edge has rearward protrusions on both sides of the port at the rear end of the hollow tube. The power-connecting pin is located inside the protrusion, and the upper and lower ends of the power-connecting pin extend out from the upper and lower ends of the protrusion, respectively.

[0006] Furthermore, the stator lamination is provided with a first slot and a second slot. The bottom center of the first slot and the second slot are respectively provided with a first stator tooth and a second stator tooth extending towards their opening direction. A connecting portion is provided on the adjacent side of the first slot and the second slot. A middle protrusion extends from the inner side of the connecting portion. A first outer splicing portion and a second outer splicing portion are respectively provided on the side of the first slot and the second slot that are far apart. The inner side of the first outer splicing portion and the second outer splicing portion are respectively provided with a first side protrusion and a second side protrusion. When two stator lamination units are symmetrically spliced, the first outer splicing portions of the two stator lamination units are joined together, and the second outer splicing portions of the two stator lamination units are joined together. The width of the splicing of the two first side protrusions and the width of the splicing of the two second side protrusions are the same as the width of the first stator tooth, the second stator tooth, and the middle protrusion.

[0007] Furthermore, when the two stator lamination units are spliced ​​together to form the motor stator, the front ends of the first stator tooth, the second stator tooth, the middle convex edge, the two first side convex edges, and the two second side convex edges of the stator laminations are respectively stacked to form magnetic pole surfaces. The magnetic pole surfaces are evenly distributed on a circumference at 45° intervals. The coil groups assembled by the first stator tooth and the second stator tooth of the two stator lamination units respectively form four coil groups whose central axes are evenly distributed at a 90° angle.

[0008] Furthermore, positioning holes are provided on the rear side of the stator lamination corresponding to the connecting part and the first outer splicing part and the second outer splicing part.

[0009] Furthermore, the stator laminations are integrally stamped from silicon steel sheets.

[0010] Furthermore, the insulating bracket is made of engineering plastic, and the power connection pins are integrally formed with the engineering plastic through an insert molding process.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: This technical solution designs the stepper motor stator core as consisting of two parts, which are spliced ​​together to form the motor stator. Each part of the stator core is composed of multiple non-enclosed stator laminations stacked together. Existing traditional stator laminations are enclosed designs, while the non-enclosed design of this solution allows the coil assembly to move directly horizontally into the stator slots, eliminating the need for vertical movement to the central cavity of the stator core followed by horizontal movement. Therefore, this design is more conducive to coil assembly. Furthermore, this stepper motor is applicable to the automotive industry, such as in throttle actuators and grille actuators. By setting four sets of coils evenly distributed at 90° intervals, the central magnetic rotor is in a state of force balance between the natural magnetic field and the driving magnetic field, resulting in more stable and smoother operation and more uniform output torque. Attached Figure Description

[0012] The accompanying drawings, which are included in and form part of this specification, illustrate exemplary embodiments, features, and aspects of this disclosure together with the specification and serve to explain the principles of this disclosure.

[0013] Figure 1 This is a schematic diagram of the stator lamination structure of this utility model.

[0014] Figure 2 This is a schematic diagram of the stator core structure of this utility model.

[0015] Figure 3 This is an exploded view of the coil assembly structure of this utility model.

[0016] Figure 4 This is a schematic diagram of the coil assembly of this utility model along the straight direction of the stator slot.

[0017] Figure 5 This is a front view of the stator lamination unit structure of this utility model.

[0018] Figure 6 The main view of the motor stator is shown below, which consists of two stator units assembled with coil groups according to this utility model.

[0019] Figure 7 The left view shows the motor stator composed of two stator units assembled with coil groups according to this utility model.

[0020] The following are explanations of the reference numerals in the attached figures: 1. Stator lamination; 101. Positioning hole; 11. First slot; 111. First stator tooth; 12. Second slot; 121. Second stator tooth; 13. Connecting part; 131. Middle convex edge; 14. First outer splicing part; 141. First side convex edge; 15. Second outer splicing part; 151. Second side convex edge; 2. Coil assembly; 21. Insulating bracket; 211. Hollow tube part; 212. Front convex edge part; 213. Rear convex edge part; 2131. Protrusion part; 22. Coil; 23. Power connection pin. Detailed Implementation

[0021] The technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this disclosure.

[0022] Please refer to Figures 1 to 7 This is a specific embodiment of a split stator assembly for a stepper motor disclosed in this solution. The split stator assembly includes a stator core and a coil group 2 installed on the stator core. The stator core is composed of two stator lamination units with the same structure. Each stator lamination unit is formed by stacking multiple stator laminations 1 of the same shape. Each stator lamination 1 has two slots forming two stator slots for embedding the coil group 2. After the coil group 2 is installed in the stator slots of the two stator lamination units, they are symmetrically spliced ​​along one side of the slot to form the motor stator, which is fixed inside the motor housing. The stator core of the stepper motor is designed to consist of two parts, which are spliced ​​together to form the motor stator. Each part of the stator core is formed by stacking multiple non-enclosed stator laminations 1. Compared to the existing traditional closed-type stator laminations, the open-type stator laminations 1 in this design allow the coil assembly 2 to be directly moved horizontally into the stator slots without needing to move vertically to the central cavity of the stator core and then horizontally. Therefore, this design is more conducive to the assembly of the coil assembly 2.

[0023] Please refer to Figures 3 to 5The coil assembly 2 includes an insulating support 21, a coil 22, and a power-connecting pin 23. The insulating support 21 has a hollow tube 211 with openings at both ends. A front convex edge 212 and a rear convex edge 213 extend vertically along the outer walls of the openings at the front and rear ends of the hollow tube 211, respectively. The coil 22 is wound around the outer wall of the hollow tube 211 between the front convex edge 212 and the rear convex edge 213. The rear side of the rear convex edge 213 has rearwardly protruding protrusions 2131 on both sides corresponding to the rear end port of the hollow tube 211. The power-connecting pin 23 is located inside the protrusions 2131, with its upper and lower ends extending out from the upper and lower ends of the protrusions 2131, respectively. The coil 22 is made of enameled wire and is wound using a separate insulating support 21. The preferred insulating bracket 21 is made of engineering plastic, and the hollow tube 211, the front protruding edge 212, the rear protruding edge 213, and the protrusion 2131 are integrally injection molded. The power connection pin 23 is integrally molded with the engineering plastic using an insert molding process.

[0024] Please refer to Figures 1 to 7Specifically, the stator lamination 1 is provided with a first slot 11 and a second slot 12. A first stator tooth 111 and a second stator tooth 121 extend from the bottom center of the first slot 11 and the second slot 12 towards their opening direction, respectively. A connecting portion 13 is provided on the adjacent side of the first slot 11 and the second slot 12. A central protruding edge 131 extends from the inner side of the connecting portion 13. A first outer splicing portion 14 and a second outer splicing portion 15 are provided on the side of the first slot 11 and the second slot 12 that are far apart from each other, respectively. The inner sides of the first outer splicing portion 14 and the second outer splicing portion 15 respectively extend with a first side protrusion 141 and a second side protrusion 151. When the two stator lamination units are symmetrically spliced, the first outer splicing portions 14 of the two stator lamination units are joined together, and the second outer splicing portions 15 of the two stator lamination units are joined together. The width of the splicing of the two first side protrusions 141 and the width of the splicing of the two second side protrusions 151 are the same as the width of the first stator tooth 111, the second stator tooth 121, and the middle protrusion 131. When the two stator lamination units are spliced ​​together to form the motor stator, the front ends of the first stator tooth 111, the second stator tooth 121, the middle protrusion 131, the two first side protrusions 141, and the two second side protrusions 151 of the stator lamination 1 form magnetic pole surfaces. The magnetic pole surfaces are evenly distributed at 45° intervals on a circumference. The central axes of the four coil groups 2 set on the stator slots of the two stator lamination units are evenly distributed at a 90° angle, forming a uniform driving magnetic field of four coils. Specifically, the four coil groups 2 are evenly arranged with their central axes in a 90° clamp and fixed inside the stator core. The input and output wires of the coils 22 in each coil group 2 are soldered to the upper end of the power-connecting pin 23, and the lower end of the power-connecting pin 23 is connected to the PCB board of the stepper motor. Each coil group 2 is connected in series with the coil group 2 on the opposite side through the PCB board, forming a loop in pairs to generate excitation. When a sinusoidal wave drive signal with a 90-degree phase is applied, the coils 22 generate magnetism and form a closed magnetic field with the stator core. As the drive waveform signal runs, the magnetic field changes, driving the motor rotor to rotate.

[0025] The stepper motor made from the stator assembly of this embodiment is used in the automotive field, such as automotive damper actuators and air intake grille actuators. By setting the central axis of the four sets of coil groups 2 to be evenly distributed at 90°, the magnet rotor at the center position is in a state of force balance in the natural magnetic field and the driving magnetic field, making the operation more stable and smooth, and the output torque is also uniform.

[0026] Please refer to Figure 1 , Figure 5 The stator lamination unit, consisting of stator laminations 1 and coil assembly 2, is positioned and fixed inside the motor housing. Positioning holes 101 are provided on the rear sides of the stator laminations corresponding to the connecting portion 13, the first outer splicing portion 14, and the second outer splicing portion 15. Positioning posts corresponding to these holes 101 are provided on the motor housing to achieve stator installation and fixation. Preferably, the stator lamination 1 is integrally stamped from silicon steel sheet.

[0027] The parts not described in detail in this technical solution specification are obvious to those skilled in the art and can be supplemented and improved based on existing technical knowledge. At the same time, those skilled in the art should understand that the above embodiments are merely preferred embodiments of this utility model. For those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A split stator assembly for a stepper motor, comprising a stator core and a coil assembly mounted on the stator core, characterized in that, The stator core is composed of two stator lamination units with the same structure. Each stator lamination unit is formed by stacking multiple stator laminations of the same shape. The stator laminations have slots to form stator slots for embedding coil groups. After the coil groups are installed in the stator slots of the two stator lamination units, they are symmetrically spliced ​​together along one side of the slot opening to form the motor stator, which is fixed inside the motor housing.

2. The stepper motor split stator assembly according to claim 1, characterized in that, The coil assembly includes an insulating support, a coil, and power-connecting pins. The insulating support has a hollow tube with openings at both ends. The front and rear ends of the hollow tube have a front convex edge and a rear convex edge extending vertically around the outer walls of the openings at the front and rear ends of the hollow tube, respectively. The coil is wound around the outer wall of the hollow tube between the front convex edge and the rear convex edge. The rear side of the rear convex edge has rearward protrusions on both sides of the port at the rear end of the hollow tube. The power-connecting pins are located inside the protrusions, and the upper and lower ends of the power-connecting pins extend out from the upper and lower ends of the protrusions, respectively.

3. The stepper motor split stator assembly according to claim 2, characterized in that, The stator laminations are provided with a first slot and a second slot. The bottom center of the first slot and the second slot are respectively provided with a first stator tooth and a second stator tooth extending towards their opening direction. A connecting portion is provided on the adjacent side of the first slot and the second slot. A middle protrusion extends forward from the inner side of the connecting portion. A first outer splicing portion and a second outer splicing portion are respectively provided on the side of the first slot and the second slot that are far apart. The inner side of the first outer splicing portion and the second outer splicing portion are respectively provided with a first side protrusion and a second side protrusion. When two stator lamination units are symmetrically spliced, the first outer splicing portions of the two stator lamination units are joined together, and the second outer splicing portions of the two stator lamination units are joined together. The width of the splicing of the two first side protrusions and the width of the splicing of the two second side protrusions are the same as the width of the first stator tooth, the second stator tooth, and the middle protrusion.

4. The stepper motor split stator assembly according to claim 3, characterized in that, When the two stator lamination units are spliced ​​together to form the motor stator, the front ends of the first stator tooth, the second stator tooth, the middle convex edge, the two first side convex edges, and the two second side convex edges of the stator laminations are formed to form magnetic pole surfaces. The magnetic pole surfaces are evenly distributed on a circumference at 45° intervals. The coil groups assembled by the first stator tooth and the second stator tooth of the two stator lamination units respectively form four coil groups whose central axes are evenly distributed at a 90° angle.

5. The stepper motor split stator assembly according to claim 3, characterized in that, Positioning holes are provided at the rear positions of the corresponding connecting parts of the stator laminations and the first and second outer splicing parts.

6. The stepper motor split stator assembly according to claim 1, characterized in that, The stator laminations are integrally stamped from silicon steel sheets.

7. The stepper motor split stator assembly according to claim 2, characterized in that, The insulating bracket is made of engineering plastic, and the power connection pins are integrally formed with the engineering plastic through an insert molding process.

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