Motor cover plate assembly and stepping motor using same

Abstract

The utility model discloses a motor cover plate assembly and a stepping motor using the motor cover plate assembly, and the motor cover plate assembly comprises a cover plate body which is provided with an assembly hole at the center; the assembly hole is at least provided with an inner hole opening facing the motor inner cavity. The fixing plug is suitable for being fixed in the assembly hole; wherein the hardness of a material for manufacturing the fixing plug is smaller than that of a material for manufacturing the cover plate body; the side end face, facing the motor inner cavity, of the fixing plug is flush with an inner hole opening. Or the side end face, facing the inner cavity of the motor, of the fixing plug protrudes out of the opening of the inner hole so that the fixing plug can partially stretch into the inner cavity of the motor. According to the utility model, the use performance of the whole stepping motor can be optimized.

Description

Technical Field

[0001] The utility model relates to the technical field of stepper motors, in particular to a motor cover assembly and a stepper motor using the same. Background Art

[0002] The rotor assembly of the small stepper motor generally used in the prior art is generally installed on the central axis inside the motor housing. The bottom of the rotor assembly is supported by a spring sheet, and the top of the rotor assembly is limited by a cover plate, so that the rotor assembly can run relatively stably in the center of the stator.

[0003] Furthermore, the rotor assembly includes a magnetic ring and a rotor shaft tooth that is an integral structure with the magnetic ring, wherein the shaft tooth is made of plastic, and the head end face of the shaft tooth made of this material abuts against the inner surface of the cover plate. Under this structure, with the long-term operation of the motor, on the one hand, there is a problem of large relative wear between the head end face of the rotor shaft tooth and the inner surface of the cover plate; on the other hand, the friction between the head end face of the rotor shaft tooth and the mating surface of the cover plate produces abnormal noise, and the torque performance is attenuated.

[0004] In view of the above situation, in order to reduce the friction between the head end face of the rotor shaft tooth and the mating surface of the cover plate, the announcement number CN217789416U discloses a rotor assembly, a motor and a household appliance, which adds an annular boss to the head end face of the shaft tooth for contacting and mating with the cover plate of the motor. The end face of the shaft tooth and the cover plate are separated by a corresponding distance through the annular boss to prevent the contact and friction between the end face of the shaft tooth and the cover plate from generating motor friction noise and increasing mechanical losses.

[0005] For the above-mentioned public technology, it is found through actual research and use that it still has the following problems:

[0006] There is contact wear between the annular boss made of plastic and the cover plate made of metal. When the annular boss is worn, the gap between the rotor assembly and the cover plate becomes larger, which may cause axial movement of the rotor assembly during operation.

[0007] In addition, during the production process, after the metal cover and the casing are riveted together, the central axis extends into the center hole of the cover to achieve a rigid connection with the cover. Under this structure, when there is a processing error, the central axis will be squeezed and deformed.

[0008] In summary, in view of the above-mentioned problems existing in the current use of stepper motors, their structure needs to be further optimized. Utility Model Content

[0009] The first purpose of the utility model is to provide a motor cover assembly to solve the technical problem of optimizing its overall structure.

[0010] The second purpose of the utility model is to provide a stepping motor to solve the technical problem of optimizing the performance of the overall stepping motor.

[0011] The motor cover assembly of the utility model is realized as follows:

[0012] A motor cover assembly, applicable to a motor, comprising:

[0013] The cover body has an assembly hole formed at the center thereof; the assembly hole at least has an inner hole opening facing the inner cavity of the motor; and

[0014] A fixing plug adapted to be fixed in the assembly hole; wherein

[0015] The hardness of the material used to make the fixing plug is less than the hardness of the material used to make the cover plate body;

[0016] The side end surface of the fixing plug facing the inner cavity of the motor is flush with the inner hole opening; or

[0017] The side end surface of the fixing plug facing the inner cavity of the motor protrudes from the inner hole opening so that the fixing plug partially extends into the inner cavity of the motor.

[0018] In an optional implementation of the present invention, the fixing plug is made of plastic material, and the cover plate body is made of metal material.

[0019] In an optional implementation of the present invention, the assembly hole is a through hole or a countersunk hole; and

[0020] The fixing plug is transitionally matched with the assembly hole.

[0021] In an optional implementation of the present invention, the assembly hole is a through hole or a countersunk hole; and

[0022] The fixing plug is bonded and fixed in the assembly hole.

[0023] In an optional implementation of the present invention, the assembly hole includes a small inner diameter hole and a large inner diameter hole that are integrally connected; wherein

[0024] The large inner diameter hole is located on the side facing the inner cavity of the motor; and

[0025] The fixing plug comprises a small outer diameter column adapted to a small inner diameter hole and a large outer diameter ring adapted to a large inner diameter hole;

[0026] A central hole adapted to communicate with the inner cavity of the motor is provided at least at the center of the large outer diameter ring.

[0027] In an optional implementation of the present invention, a chamfer is formed on an opening edge of the central hole facing the inner cavity of the motor.

[0028] In an optional implementation of the utility model, an injection gate with an opening facing away from the large outer diameter is also formed in the small outer diameter column; and

[0029] A barrier portion is formed between the injection gate and the center hole.

[0030] The stepping motor of the utility model is realized as follows:

[0031] A stepper motor comprises: a motor housing, a motor cover assembly which cooperates with the motor housing to form a motor inner cavity, and a rotor assembly arranged in the motor inner cavity; wherein

[0032] The rotor assembly comprises a rotor body and a central shaft used in conjunction with each other; one end of the central shaft is inserted into a fixing plug; and

[0033] The rotor body is provided with a shaft tooth portion at one end facing the fixing plug;

[0034] The fixing plug is suitable for abutting against the shaft tooth portion to form a barrier between the shaft tooth portion and the side end surface of the cover plate body facing the inner cavity of the motor.

[0035] In an optional implementation of the present invention, the side end surface of the fixing plug facing the inner cavity of the motor is suitable for fully covering the side end surface of the shaft tooth portion facing the fixing plug.

[0036] In an optional implementation of the present invention, the side end surface of the fixing plug facing the inner cavity of the motor is suitable for partially covering the side end surface of the shaft tooth portion facing the fixing plug.

[0037] By adopting the above technical scheme, the utility model has the following beneficial effects: the motor cover plate assembly of the utility model and the stepper motor using the same, through a fixing plug provided on the cover plate body, and the fixing plug is suitable for abutting against the shaft tooth portion of the rotor assembly to form a barrier between the shaft tooth portion and the side end surface of the cover plate body facing the inner cavity of the motor, and the hardness of the material made of the fixing plug is less than the hardness of the material made of the cover plate body. Under this structure, not only can the wear on the shaft tooth portion be reduced, but the fixing plug is suitable for abutting against the shaft tooth portion, which can also limit the axial movement of the rotor body in the inner cavity of the motor, thereby reducing the noise during motor operation, making the rotor assembly run more stably and reliably, reducing torque performance attenuation, and extending the overall service life of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is an exploded schematic diagram of the rotor assembly and the motor cover assembly of the stepper motor of the utility model;

[0039] Figure 2 It is a cross-sectional structural schematic diagram of the stepping motor of the utility model;

[0040] Figure 3It is a cross-sectional schematic diagram of the rotor assembly and the motor cover assembly of the stepper motor of the utility model in a matching state;

[0041] Figure 4 It is a schematic diagram of the overall structure of the fixing plug of the stepping motor of the utility model;

[0042] Figure 5 It is a cross-sectional structural schematic diagram of a fixing plug of a stepping motor of the utility model;

[0043] Figure 6 It is a schematic diagram of the cooperation between the middle hole and the middle axis of the fixing plug of the stepping motor of the utility model;

[0044] Figure 7 It is a cross-sectional schematic diagram of the motor cover assembly of the stepper motor of the utility model.

[0045] In the figure: cover body 1, assembly hole 11, small inner diameter hole 111, large inner diameter hole 112, fixing plug 2, small outer diameter column 21, large outer diameter ring 22, middle hole 221, injection molding gate 222, baffle 223, fillet K, chamfered corner M, rotor body 31, middle axis 32, shaft tooth portion 33, motor housing 4, motor inner cavity 41, spring sheet 5. DETAILED DESCRIPTION

[0046] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments and in conjunction with the accompanying drawings.

[0047] Embodiment 1:

[0048] See also Figures 1 to 7 As shown, this embodiment provides a motor cover assembly suitable for a motor, comprising: a cover body 1 and a fixing plug 2 suitable for fixing on the cover body 1. Here, for example, a conventionally shaped motor is optionally used. Generally, the cover body 1 adopts a circular or approximately circular structure, and an assembly hole 11 is formed at the center of the cover body 1.

[0049] Furthermore, the assembly hole 11 of this embodiment at least has an inner hole opening toward the motor inner cavity 41, and the fixing plug 2 is also matched with the assembly hole 11 from the inner hole opening. The assembly hole 11 here can be a through hole or a countersunk hole, and this embodiment does not make an absolute limitation on this.

[0050] In terms of materials, the hardness of the material used to make the fixing plug 2 is less than the hardness of the material used to make the cover body 1; for example, the fixing plug 2 is made of plastic material, such as but not limited to polyoxymethylene (POM) or nylon (PA) in wear-resistant plastics, and the cover body 1 is made of metal material. Based on this situation, in one embodiment, the fixing plug 2 is transitionally matched with the assembly hole 11; in another embodiment, the fixing plug 2 is bonded and fixed in the assembly hole 11.

[0051] Next, an optional implementation is described in detail with reference to the accompanying drawings.

[0052] First, the assembly hole 11 includes a small inner diameter hole 111 and a large inner diameter hole 112 that are connected in one piece; wherein the large inner diameter hole 112 is located on the side facing the motor inner cavity 41. Correspondingly, the fixing plug 2 includes a small outer diameter column 21 adapted to the small inner diameter hole 111 and a large outer diameter ring 22 adapted to the large inner diameter hole 112. The design of the small outer diameter column 21 matching the small inner diameter hole 111 and the large outer diameter ring 22 matching the large inner diameter hole ensures that the fixing plug 2 will not fall off the cover body 1 due to collision or falling during the production, transportation and use of the motor, thereby improving the stability of the motor during storage and use.

[0053] In a specific optional implementation here, the corner seam formed at the junction between the small outer diameter column 21 and the large outer diameter ring 22 is a rounded corner K, and the corners of the small inner diameter hole 111 and the large inner diameter hole 112 that match it are rounded corners K with a larger radius. The design of the matching surfaces with rounded corners K allows workers to press the fixing plug 2 into the cover plate more smoothly during production and assembly, thereby improving the efficiency of motor assembly. The design of rounded corners K makes it easier to demold the fixing plug 2 during injection molding production, thereby improving the efficiency of parts production. At the same time, the design of rounded corners K can also reduce the contact area between the fixing plug 2 and the assembly hole 11, thereby reducing the friction between the two when they match, making it easier for workers to assemble.

[0054] Furthermore, a middle hole 221 suitable for connecting to the motor inner cavity 41 is provided at least at the center of the large outer diameter ring 22. The middle hole 221 here can also partially extend into the small outer diameter column 21. The middle hole 221 is mainly used to match with the central axis 32 of the motor. In this regard, in order to improve the smoothness of the assembly process between the middle hole 221 and the central axis 32, a chamfer M can be formed on the edge of the opening of the middle hole 221 facing the motor inner cavity 41, so that the fixing plug 2 is easier to press into the central axis 32 in actual production and assembly, thereby reducing the occurrence of extrusion deformation of the central axis 32 and improving production efficiency and qualified rate.

[0055] Secondly, it should be noted that in this embodiment, the axial length of the small outer diameter column 21 can be selected to be larger than the axial length of the large outer diameter ring 22. Of course, the two can also have the same axial length, and this embodiment does not make an absolute limitation on this.

[0056] In addition, taking the fixing plug 2 made of plastic material as an example, in order to facilitate the injection molding of the fixing plug 2, an injection gate 222 with an opening facing away from the large outer diameter is formed in the small outer diameter column 21; and a blocking portion 223 is formed between the injection gate 222 and the middle hole 221.

[0057] The blocking portion 223 is designed here mainly because a small amount of grease will gradually overflow from the driving gear along the central axis 32 during long-term operation of the motor, polluting the external environment of the motor. With the fixing plug 2 under this structure, the grease overflowing along the central axis 32 will be retained in the central hole 221, thereby preventing the grease from overflowing.

[0058] Regarding the injection gate 222 designed in this embodiment, the injection gate 222 of the fixed plug 2 is designed to be located at the center of the top of the part during processing, so that the plastic melt can reach various parts of the mold cavity more quickly when the part is injected. Since there is no matching requirement at the top of the fixed plug 2, it is easy to cut off the runner after injection molding, which simplifies the post-processing of the product, and can omit unnecessary surface treatment processes, resulting in high production efficiency. The distance from the center of the part to each part is roughly the same. When the injection is performed at the center, the plastic melt can reach various parts of the mold cavity more evenly and quickly.

[0059] In summary, the motor cover assembly of this embodiment is mainly used to form a match with the rotor assembly of the motor, and its specific implementation principle is described in Example 2.

[0060] Embodiment 2:

[0061] See also Figures 1 to 7 As shown, based on the motor cover assembly of Example 1, this embodiment provides a stepper motor, including: a motor housing 4, a motor cover assembly as in Example 1 that cooperates with the motor housing 4 to form a motor cavity 41, and a rotor assembly arranged in the motor cavity 41.

[0062] Specifically, a rotor assembly of mature technical means is given as an example, which generally includes a rotor body 31 and a central shaft 32 used in conjunction with each other; one end of the central shaft 32 is inserted into the fixing plug 2; and a shaft tooth portion 33 is provided at one end of the rotor body 31 facing the fixing plug 2. The central hole 221 of the fixing plug 2 and the central shaft 32 can be optionally matched with each other in a clearance, so that the central shaft 32 can be reduced from being squeezed when the motor cover assembly and the motor housing 4 are installed, resulting in deformation of the central shaft 32, so that the rotor body 31 can run more stably on the central shaft 32.

[0063] The rotor body 31 here can optionally adopt mature means in the prior art to form a support for the side end thereof facing away from the shaft tooth portion 33 through the spring sheet 5. And for the central axis 32, it can be fixed to the inner bottom wall of the motor inner cavity 41 by riveting, and the central hole 221 of the fixing plug 2 plays the role of supporting and positioning the central axis 32. At the same time, through the hollow design designed in the fixing plug 2, the other end of the central axis 32 is limited, so that the central axis 32 is positioned as far as possible at the center of the stepper motor, reducing the radial offset of the rotor during operation.

[0064] Based on the motor cover assembly used in this embodiment, the fixing plug 2 is suitable for abutting against the shaft tooth portion 33 to form a barrier between the shaft tooth portion 33 and the side end surface of the cover body 1 facing the motor inner cavity 41. Under this structure, it means that during the operation of the rotor assembly, it will not contact the cover body 1 itself, but will only cooperate with the fixing plug 2, so that the wear on the shaft tooth portion 33 can be reduced, thereby reducing the operating noise.

[0065] In order to meet the above usage requirements, this embodiment also makes the following designs:

[0066] In the first optional implementation, when the fixing plug 2 is assembled into the assembly hole 11 of the cover body 1, the side end surface of the fixing plug 2 facing the motor inner cavity 41 is flush with the inner hole opening. Under this structure, for the shaft tooth portion 33 abutting against the fixing plug 2, preferably, the side end surface of the fixing plug 2 facing the motor inner cavity 41 is suitable for fully covering the side end surface of the shaft tooth portion 33 facing the fixing plug 2, that is, the outer diameter of the large outer diameter ring 22 of the fixing plug 2 is greater than the outer diameter of the shaft tooth portion 33, or the outer diameter of the large outer diameter ring 22 of the fixing plug 2 is equal to the outer diameter of the shaft tooth portion 33, that is, as long as it is ensured that the shaft tooth portion 33 does not have direct contact with the cover body 1, the use requirements of this embodiment can be met.

[0067] In the second optional implementation, when the fixing plug 2 is assembled into the assembly hole 11 of the cover body 1, the side end surface of the fixing plug 2 facing the motor cavity 41 protrudes from the inner hole opening so that the fixing plug 2 partially extends into the motor cavity 41. Based on this situation, optionally, the side end surface of the fixing plug 2 facing the motor cavity 41 is suitable for fully covering the side end surface of the shaft tooth portion 33 facing the fixing plug 2, that is, the outer diameter of the large outer diameter ring 22 of the fixing plug 2 is greater than the outer diameter of the shaft tooth portion 33, or the outer diameter of the large outer diameter ring 22 of the fixing plug 2 is equal to the outer diameter of the shaft tooth portion 33. Also optionally, the side end surface of the fixing plug 2 facing the motor cavity 41 is suitable for partially covering the side end surface of the shaft tooth portion 33 facing the fixing plug 2, that is, taking the layout of the coaxially distributed shaft tooth portion 33 and the fixing plug 2 as an example, at this time, the outer diameter of the large outer diameter ring 22 of the fixing plug 2 is smaller than the outer diameter of the shaft tooth portion 33.

[0068] In summary, as long as it can be ensured that the shaft tooth portion 33 does not come into direct contact with the cover body 1 in the operating state, the use requirements of this embodiment are met, and this embodiment does not provide examples for optional implementations. That is, this embodiment forms a barrier between the shaft tooth portion 33 and the cover body 1 through the fixing plug 2, which can not only reduce the wear on the shaft tooth portion 33, but also the fixing plug 2 is suitable for contacting with the shaft tooth portion 33, which can also limit the axial movement of the rotor body 31 in the motor cavity 41, thereby reducing the noise during the operation of the stepper motor, making the rotor assembly run more stably and reliably, reducing the torque performance attenuation, and extending the overall service life of the stepper motor.

[0069] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0070] In the description of the present invention, it is necessary to understand that the terms indicating orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0071] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0072] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0073] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0074] In the present utility model, unless otherwise clearly specified and limited, the first feature being above or below the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being above, above, and above the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being below, below, and below the second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

Claims

1. A motor cover assembly, suitable for a motor, characterized in that: include: The cover body has an assembly hole formed at the center thereof; the assembly hole at least has an inner hole opening facing the inner cavity of the motor; and A fixing plug adapted to be fixed in the assembly hole; in The hardness of the material used to make the fixing plug is less than the hardness of the material used to make the cover plate body; The side end surface of the fixing plug facing the inner cavity of the motor is flush with the inner hole opening; or The side end surface of the fixing plug facing the inner cavity of the motor protrudes from the inner hole opening so that the fixing plug partially extends into the inner cavity of the motor.

2. The motor cover assembly according to claim 1, characterized in that: The fixing plug is made of plastic material, and the cover plate body is made of metal material.

3. The motor cover assembly according to claim 1 or 2, characterized in that: The assembly hole is a through hole or a countersunk hole; and The fixing plug is transitionally matched with the assembly hole.

4. The motor cover assembly according to claim 1 or 2, characterized in that: The assembly hole is a through hole or a countersunk hole; and The fixing plug is bonded and fixed in the assembly hole.

5. The motor cover assembly according to claim 1, characterized in that: The assembly hole includes a small inner diameter hole and a large inner diameter hole that are integrally connected; wherein The large inner diameter hole is located on the side facing the inner cavity of the motor; and The fixing plug comprises a small outer diameter column adapted to a small inner diameter hole and a large outer diameter ring adapted to a large inner diameter hole; A central hole adapted to communicate with the inner cavity of the motor is provided at least at the center of the large outer diameter ring.

6. The motor cover assembly according to claim 5, characterized in that: The opening edge of the middle hole facing the inner cavity of the motor is formed with a rounded corner.

7. The motor cover assembly according to claim 5 or 6, characterized in that: The small outer diameter column is also formed with an injection gate with an opening facing away from the large outer diameter; and A barrier portion is formed between the injection gate and the center hole.

8. A stepping motor, characterized in that: include: A motor housing, a motor cover assembly as claimed in any one of claims 1 to 7 which cooperates with the motor housing to form a motor inner cavity, and a rotor assembly disposed in the motor inner cavity; in The rotor assembly comprises a rotor body and a central shaft used in conjunction with each other; one end of the central shaft is inserted into a fixing plug; and The rotor body is provided with a shaft tooth portion at one end facing the fixing plug; The fixing plug is suitable for abutting against the shaft tooth portion to form a barrier between the shaft tooth portion and the side end surface of the cover plate body facing the inner cavity of the motor.

9. The stepper motor according to claim 8, characterized in that: The side end surface of the fixing plug facing the inner cavity of the motor is suitable for fully covering the side end surface of the shaft tooth portion facing the fixing plug.

10. The stepper motor according to claim 8, characterized in that: The side end surface of the fixing plug facing the inner cavity of the motor is suitable for partially covering the side end surface of the shaft tooth portion facing the fixing plug.

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