Roller, driving device and preparation method thereof

Abstract

The invention provides a driving device which comprises a shell, a driving assembly and an output assembly, at least part of the driving assembly is located in the shell, the driving assembly is connected with the output assembly, the output assembly comprises a sleeve, a pin roller and a lead screw, the sleeve is in threaded fit with the pin roller, and the pin roller is in threaded fit with the lead screw. The pin roller is in threaded fit with the lead screw, at least part of the pin roller is made of a plastic material, the pin roller comprises a threaded section, a first tooth part and a second tooth part, in the radial direction of the pin roller, the addendum circle diameter of the first tooth part is Dm1, the addendum circle diameter of the second tooth part is Dm2, the addendum circle diameter of the threaded section is Dm3, and Dm3 is larger than Dm1 or larger than Dm2. In addition, the invention further provides a roller and a preparation method of the roller.

Description

Technical Field

[0001] This application relates to the field of mechanical transmission components, and in particular to a roller, a drive device, and a method for manufacturing the same. Background Technology

[0002] The rollers in the related technology include a threaded section and two teeth. The sleeve is part of the drive device. The threaded section is located between the two teeth. The teeth mesh with the corresponding tooth bodies inside the sleeve. The teeth of the two teeth correspond to each other in the axial direction of the roller, and the tooth grooves correspond to each other in the axial direction of the roller. This means that the two teeth and the tooth bodies simultaneously enter or disengage. However, in general, when the precision is not high, there will be a gap when one tooth of a tooth meshes with the tooth body and the next tooth meshes with the tooth body. Especially at high speed, there is a possibility of impact during gear meshing, which affects the transmission stability and requires high precision of the teeth. Summary of the Invention

[0003] This application provides a roller with reduced machining accuracy requirements.

[0004] This application provides a roller, including a threaded section, a first tooth portion, and a second tooth portion. The threaded section is located between the first tooth portion and the second tooth portion. The first tooth portion includes a first tooth along the circumferential direction of the roller and has a first tooth groove located between two adjacent first teeth. The second tooth portion includes a second tooth along the circumferential direction of the roller and has a second tooth groove located between two adjacent second teeth. Along the axial direction of the roller, the first tooth and the second tooth are misaligned.

[0005] In the roller provided in this application, the first tooth portion and the second tooth portion are misaligned, which means that along the axial direction of the roller, the portion of the first tooth corresponds to the second tooth groove, and the portion of the second tooth corresponds to the first tooth groove, so as to reduce the machining accuracy requirements.

[0006] This application provides a driving device, including a housing, a driving assembly, and an output assembly. The driving assembly is at least partially located within the housing and is connected to the output assembly. The output assembly includes a sleeve, a roller, and a lead screw. The sleeve is threadedly engaged with the roller, and the roller is threadedly engaged with the lead screw. The roller includes a threaded section, a first tooth portion, and a second tooth portion. The threaded section is located between the first tooth portion and the second tooth portion. The first tooth portion includes a first tooth along the circumferential direction of the roller and has a first tooth groove located between two adjacent first teeth. The second tooth portion includes a second tooth along the circumferential direction of the roller and has a second tooth groove located between two adjacent second teeth. The first tooth and the second tooth are misaligned along the axial direction of the roller.

[0007] By using a roller with the first and second teeth misaligned, one end of the tooth can disengage while the other end engages, which can significantly improve the smooth operation of the roller, reduce the precision requirements of the first and second teeth, and improve transmission stability.

[0008] This application also provides a preparation method, providing a mold for preparing rollers, the mold having an inlet and a forming cavity, the inlet communicating with the forming cavity, the mold including a threaded raceway, a first toothed track and a second toothed track, the threaded raceway being located between the first toothed track and the second toothed track, the forming cavity being located between the threaded raceway, the first toothed track and the second toothed track; material is poured in from the inlet and flows into the forming cavity, the material forms a roller in the mold, the material forms a threaded segment in the threaded raceway, the material forms a first tooth in the first toothed track, the material forms a second tooth in the second toothed track, the first tooth includes a first tooth along the circumferential direction of the roller, the first tooth has a first tooth groove located between two adjacent first teeth, the second tooth includes a second tooth along the circumferential direction of the roller, the second tooth has a second tooth groove located between two adjacent second teeth, along the axial direction of the roller, the first tooth and the second tooth are misaligned; demolding, the mold is disassembled and detached to obtain the roller.

[0009] Rollers with phase misalignment of the first and second tooth sections are prepared by using a mold. The first and second tooth paths in the mold are misaligned, which reduces the precision requirements and facilitates demolding. Attached Figure Description

[0010] Figure 1 This is a three-dimensional structural diagram of a roller according to this application;

[0011] Figure 2 Is it like this? Figure 1 A three-dimensional structural diagram of the roller at another angle;

[0012] Figure 3 Is it like this? Figure 1 A planar anatomical diagram of the first tooth of the roller shown;

[0013] Figure 4 This is a schematic projection of the first tooth and the second tooth of this application;

[0014] Figure 5 Is it like this? Figure 2 A magnified schematic diagram of a portion of the roller structure shown;

[0015] Figure 6 This is a partial planar sectional view of the drive device of this application;

[0016] Figure 7This is a three-dimensional structural diagram of the mold for preparing rollers according to this application.

[0017] Figure 8 Is it like this? Figure 7 A schematic diagram of the first toothed groove of the mold shown.

[0018] Figure 9 Is it like this? Figure 7 A schematic diagram of the first and second toothed tracks of the mold shown for demolding.

[0019] Figure 10 Is it like this? Figure 9 A cross-sectional view of the first and second toothed passages of the mold shown for demolding.

[0020] Figure 11 Is it like this? Figure 7 A schematic cross-sectional view of the mold shown.

[0021] Figure 12 Is it like this? Figure 7 A three-dimensional structural diagram of one side of the thread raceway shown.

[0022] Figure 13 Is it like this? Figure 12 A three-dimensional structural diagram of the other side of the thread raceway shown;

[0023] Figure 14 Is it like this? Figure 7 A schematic diagram showing the projection of both sides of the thread raceway.

[0024] Figure 15 Is it like this? Figure 7 A three-dimensional structural diagram of the first tooth channel is shown;

[0025] Figure 16 Is it like this? Figure 7 The diagram shows a three-dimensional structure of the second tooth channel. Detailed Implementation

[0026] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0027] It should be understood that the described embodiments are merely some embodiments of this application, and not all embodiments. All other technical solutions obtained by those skilled in the art based on the technical solutions in this application without creative effort are within the scope of protection of this application.

[0028] The technical solutions described in this application should be understood by those skilled in the art. For example, directional descriptions such as "front," "back," "left," "right," "up," and "down" are only used to describe the relationship between objects and are not substantive limitations. "Multiple" means at least two or more.

[0029] This application provides a roller, which is an important component of the roller screw and an essential part of a drive device, with wide applications. In related drive devices, a housing, a drive assembly, and an output assembly are included. The drive assembly is at least partially located in the housing and connected to the output assembly. The drive assembly drives the axial movement of the output assembly's screw, thereby driving the operation of an external drive device. In this embodiment, the output assembly is a roller screw, a mechanical transmission device that can convert rotary motion into linear motion. The three main components of a roller screw are the screw, the sleeve, and the roller assembly. Generally, the rotary motion of the screw or sleeve is converted into the linear motion of the sleeve and screw through the planetary motion of the rollers. The roller assembly includes multiple rollers and a cage to prevent the rollers from deviating from their rotational trajectory. Roller screws include upright and reverse types. In this embodiment, the output assembly uses an upright roller screw. Taking a lead screw as an example, the difference between the upright and reverse types is that when the sleeve is rotated to move the lead screw, it is called a reverse roller lead screw, and when the lead screw is rotated to move the sleeve, it is called an upright roller lead screw. The roller in the related technology includes a threaded section and two teeth. The threaded section is located between the two teeth, and the two teeth are located at the two ends of the threaded section. The teeth include teeth, and there is a tooth groove between two adjacent teeth. In the related technology, the teeth of the two teeth correspond to each other along the roller axis, and the tooth grooves correspond to each other along the roller axis, which means that the two teeth are not misaligned. The roller generally meshes with the corresponding tooth body of the sleeve. The two teeth without misalignment means that they enter or disengage simultaneously. However, in general, when the precision is not high, there will be a gap when one tooth of the tooth meshes with the tooth body and the next tooth meshes with the tooth body. Especially at high speed, there is a possibility of impact in gear meshing, which affects the rotation (transmission) stability.

[0030] To solve the above problems, the following will refer to Figures 1 to 16 This application may be described in whole or in part by way of the content of this document.

[0031] Please refer to the following first. Figure 1 and Figure 2As shown, this application provides a roller including a threaded section 1, a first toothed portion 2, and a second toothed portion 3. The threaded section 1 is located between the first toothed portion 2 and the second toothed portion 3. One end of the threaded section 1 is connected to the first toothed portion 2, and the other end of the threaded section 1 is connected to the second toothed portion 3. The connection can be direct or indirect. For example, the threaded section 1 and the first toothed portion 2 can be directly connected, or the threaded section 1 and the first toothed portion 2 can be connected indirectly through a groove or a third part. The first toothed portion 2 includes a first tooth 21 along the circumferential direction of the roller 100 and a first tooth groove 22 located between two adjacent first teeth 21. The second toothed portion 3 includes a second tooth 31 along the circumferential direction of the roller 100 and a second tooth groove 31 located between two adjacent second teeth 31. Along the axial direction of the roller 100, the first tooth 21 and the second tooth 31 are staggered, that is, the second tooth 31 part corresponds to the first tooth groove 22. The tooth 21 portion corresponds to the second tooth groove 32, and the first tooth 21 portion may correspond to the second tooth 31 portion. In other words, in the roller 100 provided in this application, the second tooth 31 corresponds to the first tooth groove 22 along the axial direction of the roller 100, and the first tooth 21 corresponds to the second tooth groove 32 along the axial direction of the roller 100. This means that the first tooth portion 2 and the second tooth portion 3 are phase-shifted. The purpose is that when the roller with the phase shift is applied to the drive device, it can ensure that one end of the tooth disengages while the other end of the tooth engages, which can ensure the smooth operation of the planetary gear part and not affect the operation of the product, thereby improving the rotation (transmission) stability. In related technologies, if the first tooth 21 and the second tooth 31 are not phase-shifted along the axial direction of the roller 100, but are correspondingly set, then a high precision requirement is required when manufacturing the roller. However, in this embodiment, the first tooth 21 and the second tooth 31 have a phase difference, that is, they are phase-shifted, which reduces the machining precision requirement.

[0032] For details, please refer to Figure 3 and Figure 4 As shown, the plane perpendicular to the central axis C of the roller 100 is defined as the projection plane Q. Along the axial direction of the roller 100, the orthographic projection of the first tooth 21 on the projection plane Q is the first tooth projection Q1, and the orthographic projection of the second tooth 31 on the projection plane Q is the second tooth projection Q2. The first tooth projection Q1 and the second tooth projection Q2 are misaligned. In addition, the misalignment of the first tooth projection Q1 and the second tooth projection Q2 also means that the first tooth 21 and the second tooth 31 have a phase difference, that is, there is a phase difference (misaligned teeth). On the one hand, it facilitates the forming and demolding of the first tooth 21 and the second tooth 31, and there is no need for excessively high precision requirements when designing the first tooth 21 and the second tooth 31. On the other hand, it can ensure that one end of the tooth disengages while the other end of the tooth engages, which can ensure the smooth operation of the planetary gear part and not affect the operation of the product, thereby improving the rotation (transmission) stability.

[0033] Please see Figure 3 and Figure 4 Defined on the same projection plane Q, the projection of the first tooth 2 onto the projection plane Q is tooth projection Q3, and the axis of the tooth projection is C1. The line connecting the tooth tip projection of one of the first tooth projections Q1 to the axis C1 is O1, and the line connecting the tooth tip projection of the adjacent first tooth projection Q1 to the axis C1 is O2. The angle between O1 and O2 is T°. On the same projection plane Q, take one point of the tooth tip projection of the first tooth projection Q1 as A, and take a point at the relative position of the tooth tip projection of the second tooth projection Q2 as B. The relative positions here should be understood as follows: if the first tooth 21 and the second tooth 31 are not misaligned, the projections Q1 and Q2 of the first tooth are overlapping. In the case of no misalignment, point A on the first tooth projection Q1 and point B on the second tooth projection Q2 are also overlapping points. The line connecting A to the axis C1 is A1, and the line connecting B to the axis C1 is B1. There is an angle θ between A1 and B1, where 0° < θ < T°. A preferred solution is 0° < θ ≤ 1 / 2 T°. Figure 4 In this embodiment, θ is 1 / 2T°, where T° depends on the actual number of teeth on the roller 100. A larger number of teeth results in a smaller T°, and a smaller number of teeth results in a larger T°. In this embodiment, θ is 1 / 2T° to ensure that the second tooth 31 is aligned with the center of the first tooth groove 22 along the axial direction of the roller 100. From a projection perspective, the projection Q2 of the second tooth is located in the middle of two adjacent projections Q1 of the first tooth. That is, the distance between the projection Q2 of the second tooth and the projections Q1 of one side and the projections Q1 of the first tooth on the other side are approximately the same. This further ensures that one end of the tooth disengages while the other end engages, guaranteeing smooth operation of the planetary gear. If the distance between the projection Q2 of the second tooth and the projection Q1 of one side is greater than or less than the distance to the projection Q1 of the first tooth on the other side, then one end of the tooth may disengage while the other end either does not engage or has already engaged. Of course, this must be based on the actual tooth meshing design; therefore, a certain range of error is within the allowable range. Please refer to [link to relevant documentation]. Figure 3 and Figure 4 In terms of tooth pitch, the tooth pitch of two adjacent first teeth 21 is L, and the tooth pitch of the first tooth 21 and the second tooth 31 is M, where M≥0.4L. In other words, as the optimal tooth pitch, the tooth pitch of the first tooth 21 and the second tooth 31 is not less than 80% of half a tooth pitch L. This design can further optimize and improve the transmission stability of the misaligned teeth and the drive device.

[0034] Please refer to it again. Figure 1 and Figure 2The first tooth portion 2 includes a plurality of first teeth 21 and a first shaft portion 23. The first teeth 21 are connected to the first shaft portion 23. The plurality of first teeth 21 are distributed circumferentially along the first shaft portion 23 and extend axially along the first shaft portion 23. The first teeth 21 are radially protruding from the surface of the first shaft portion 23. The second tooth portion 3 includes a plurality of second teeth 31 and a second shaft portion 33. The second teeth 31 are connected to the second shaft portion 33. The plurality of second teeth 31 are distributed circumferentially along the second shaft portion 23 and extend axially along the second shaft portion 23. The first teeth 21 are radially protruding from the surface of the first shaft portion 23. The shaft portion 33 extends axially, and the second tooth 31 protrudes radially from the surface of the second shaft portion 33. In other words, multiple first teeth 21 are radially distributed along the circumference of the first tooth portion 2. The first tooth 21 protrudes radially along the first tooth portion 2, and the protrusion of the first tooth 21 extends axially along the first tooth portion 2 to form a convex ridge. Similarly, the second tooth 31 also has such a structure. However, the teeth of rollers in current related technologies have a radially radial disordered tooth structure, and such a tooth structure can generally only be formed by rolling. The manufacturing process is relatively complicated and difficult. However, the first tooth 21 and the second tooth 31 in this embodiment adopt a spline-like structure and are straight teeth, which can reduce the manufacturing difficulty. They can be manufactured by rolling, milling, injection molding, powder metallurgy, etc. For example, in the injection molding process, using the structure of the first tooth 21 and the second tooth 31 in this embodiment, the mold can be removed along the axial direction of the roller during demolding. The molded object can be taken out without damaging the mold, and the mold can be reused. The details will be further described in the process section below. Of course, in some other embodiments, helical teeth can be used, but helical teeth are difficult to control during demolding. In addition, in this embodiment, the number of teeth of the first tooth 21 and the second tooth 31 are equal, that is, the number of teeth of the two tooth parts is equal, so as to ensure that the tooth angle is consistent, which is beneficial to processing. If the number of teeth is not equal, the tooth pitch and tooth width of the part with fewer teeth are larger, which is not conducive to processing and transmission.

[0035] Please refer to it again. Figure 2 This is a planar sectional view of the roller structure in this embodiment. Along the radial direction of the roller 100, the tip circle diameter of the first tooth 2 is D. m1 The tip circle diameter of the second tooth 3 is D. m2 The tip circle diameter of thread segment 1 is D. m3 , where D m3 >D m1 =D m2 ,from Figure 2As can be seen, its roller structure is a convex middle section and concave ends. This structure facilitates demolding. In other words, the molds at both ends can be removed first, and then the mold in the middle section can be removed along the axial direction of the roller structure. If the roller structure is designed with a concave middle section and convex ends, the mold in the middle section cannot be effectively removed after removing the molds at both ends, unless the mold in the middle section is destroyed. However, once the mold in the middle section is destroyed, it becomes impossible to use that mold to make standard parts, or multiple identical molds need to be made, thus increasing costs and requiring higher precision. In addition, in this embodiment, the radial dimensions of the first tooth 2 and the second tooth 3 are the same, that is, the first tooth 2 and the second tooth 3 are at the same height. This is more conducive to manufacturing and considering the corresponding structure of the sleeve, if one is higher and the other lower, it will be more complicated to manufacture the sleeve. Furthermore, although the first tooth 2 and the second tooth 3 are lower than the radial dimension of the threaded section 1, they cannot be too low, because if they are too low, they will not be able to effectively mesh with the sleeve, resulting in problems with the transmission of the component. Please refer to [further details omitted]. Figure 5 As shown, thread segment 1 includes a thread tooth 11, which includes a crest 12 and a root 13. Along the radial direction of the roller 100, the outer diameter of the root 13 is D. mb The outer diameter of tooth crest 12 is D. ma , where D ma >D mb D mb =nD m1 =nD m2 The optimal size is defined as 0.7≤n≤1, meaning that the tip circle diameter of the first tooth section 2 and the second tooth section 3 cannot be too low. If it is too low, it will not be able to effectively mesh with the lead screw or sleeve. Therefore, the size within the range of 0.7≤n≤1 is the optimal solution.

[0036] Furthermore, in this embodiment, the first tooth 2 and / or the second tooth 3 are involute gear structures, and the first tooth 2 and / or the second tooth 3 have a long involute profile. The advantage of using an involute gear structure is that it can improve the transmission stability of the component.

[0037] This embodiment also provides a driving device; please refer to [link / reference]. Figure 6 As shown, Figure 6This is a schematic diagram of a partial structure of the drive device. The drive device includes a housing 6, a drive assembly 7, and an output assembly 8. The drive assembly 7 is at least partially located within the housing 6 and is connected to the output assembly 8. The output assembly 8 includes a sleeve 81, a roller 100, and a lead screw 82. The sleeve 81 is threadedly engaged with the roller 100, and the roller 100 is threadedly engaged with the lead screw 82. The roller 100 includes a threaded section 1, a first tooth 2, and a second tooth 3. The threaded section 1 is located between the first tooth 2 and the second tooth 3. The first tooth 2 includes a first tooth 21 along the circumference of the roller 100. The first tooth 2 has a first tooth... The first tooth groove 22 is located between two adjacent first teeth 21. The second tooth portion 3 includes a second tooth 31. Along the circumference of the roller 100, the second tooth portion 3 has a second tooth groove 32, which is located between two adjacent second teeth 31. In the axial direction of the roller 100, the first teeth 21 and the second teeth 31 are staggered. The roller 100 adopts a phase-staggered arrangement of the first tooth portion 2 and the second tooth portion 3. When the roller 100 is engaged with the sleeve 81, it can ensure that one end of the tooth disengages while the other end of the tooth engages, which can ensure the smooth operation of the roller and improve the output rotation stability of the drive device.

[0038] Because the roller 100 adopts a structure with a convex middle section and concave ends, in order to enable the sleeve 81 and the roller 100 to cooperate, the sleeve 81 includes a threaded sleeve portion 811 and a toothed sleeve portion 812. Along the radial direction of the sleeve 81, the wall thickness of the threaded sleeve portion 811 is less than the wall thickness of the toothed sleeve portion 812. The threaded sleeve portion 811 has an internal thread 8111, and the threaded section 1 has an external thread 15, which is threadedly engaged with the internal thread 8111. The toothed sleeve portion 812 includes a first tooth body 8121 and a second tooth body 8122. The tooth body 8121 meshes with the first tooth portion 2, and the second tooth body 8122 meshes with the second tooth portion 3. The external thread 13 is located between the first tooth body 8121 and the second tooth body 8122. Of course, in some other embodiments, the sleeve 81 may not adopt the above structure. The wall thickness of the threaded sleeve portion 811 and the toothed sleeve portion 812 may be the same. However, a third adapter may be provided between the first tooth 21 and the second tooth 31 and the toothed sleeve portion 812 for meshing connection, such as an internal gear ring and an external gear ring.

[0039] Furthermore, the drive assembly in the drive device includes a stator 71 and a rotor 72. The stator 71 includes a stator core 711, a coil winding 712, and an insulator 713. The insulator 713 covers at least a portion of the outer wall of the stator core 711, and the coil winding 712 is wound around the insulator 713. The rotor 72 includes a magnet 721, which is attached to the outer wall of the sleeve 81. The outer side of the stator 71 is connected to the inner wall of the housing 6. The stator 71 is distributed circumferentially along the sleeve 81. The magnet 721 is located between the stator 71 and the sleeve 81. The drive assembly 7 drives the sleeve 81 to rotate through the magnetic force of the stator 71 and the rotor 72. Since the magnet is attached to the outer wall of the sleeve 81, the sleeve 81 is rotated. In this embodiment, the sleeve rotates, which drives the lead screw to move axially. Other details will not be elaborated further. The sleeve 81 itself also serves as a magnetic conductor.

[0040] In addition, the drive device provided in this embodiment can be applied to fields such as automotive steering motors, actuators, and collaborative equipment. That is, the drive device mainly converts rotary motion into linear motion. It can be applied as long as the equipment requires a motion conversion method, and its application is quite wide.

[0041] Furthermore, this embodiment also provides a method for preparing rollers, including:

[0042] A mold 4 for preparing roller 100 is provided. The mold 4 has an inlet 44 and a forming cavity. The inlet 44 is connected to the forming cavity P. The mold 4 includes a threaded raceway 41, a first toothed track 42 and a second toothed track 43. The threaded raceway 41 is located between the first toothed track 42 and the second toothed track 43. The forming cavity P is located between the threaded raceway 41, the first toothed track 42 and the second toothed track 43.

[0043] Material is poured in from inlet 44 and flows into forming cavity P. The material forms rollers 100 in mold 4, and threaded segments 1 in threaded raceways 41. Material forms first teeth 2 in first toothed raceways 42 and second teeth 3 in second toothed raceways 43. One end of threaded segment 1 is connected to the first tooth 2, and the other end is connected to the second tooth 3. Along the circumference of rollers 100, the first tooth 2 includes a first tooth 21 and a first tooth groove 22 located between two adjacent first teeth 21. The second tooth 3 includes a second tooth 31. Part 3 has a second toothed groove 32, which is located between two adjacent second teeth 31. The second teeth 31 correspond to the first toothed groove 22 along the axial direction of the roller 100, and the first teeth 21 correspond to the second toothed groove 32 along the axial direction of the roller 100. The material can be plastic or metal. If plastic is used, it is injection molding; if metal is used, it is powder metallurgy. In general, the material is first melted or heat-treated and then poured into the molding cavity of the mold. After molding, a series of processing steps such as demolding are performed.

[0044] Demolding involves separating the mold 4 to obtain roller 100. Roller 100 is then refined through processes such as polishing, grinding, oxidation, and plating. Oxidation and plating are used to enhance the rigidity of the roller and prevent deformation during assembly or operation, which could lead to component failure. Polishing and grinding make the roller surface relatively smooth, reducing roughness and minimizing precision and meshing issues.

[0045] Furthermore, since it is necessary to prepare rollers with staggered tooth arrangement at both ends, the corresponding mold is also staggered. The first tooth path 42 includes a first tooth profile and has a first groove, which is located between two adjacent first tooth profiles. The second tooth path 43 includes a second tooth profile and has a second groove, which is located between two adjacent second tooth profiles. The second tooth profile corresponds to the first groove along the axial direction of the mold 4, and the first tooth profile corresponds to the second groove along the axial direction of the mold 4. The first tooth profile, the second tooth profile, the first groove, and the second groove are all located in the forming cavity. When the material is poured into the forming cavity, the material forms the first tooth in the first groove and the material forms the second tooth in the second groove.

[0046] Please see Figures 8 to 10 After the material is formed in the mold 4, the first toothed track 42 and the second toothed track 43 are simultaneously or sequentially separated from the threaded raceway 41. The first toothed track 42 moves out along the axial direction of the roller 100, and the first toothed track 42 separates from one end of the threaded raceway 41 and the first toothed track 42 separates from the first tooth 2. The second toothed track 43 moves out along the axial direction of the mold 4, and the second toothed track 43 separates from the other end of the threaded raceway 41 and the second toothed track 43 separates from the second tooth 3. The threaded raceway 41 is screwed out and separated along the helical direction of the threaded section 1, or the threaded raceway 41 is split and separated from the threaded section 1. Since the first tooth 21 and the second tooth 31 of the roller are designed as axially extended protruding structures, the mold only needs to be removed along the axial direction of the roller during demolding. The molded object can be taken out without damaging the mold, and the mold can be reused, which is convenient for demolding and facilitates the reuse of the mold.

[0047] To maintain the staggered positional relationship between the first tooth path 42 and the second tooth path 43 during the manufacturing process and prevent displacement, this embodiment adds a positioning component 5 to circumferentially limit the first tooth path 42 and the second tooth path 43. Specifically, the mold 4 includes the positioning component 5, which includes a first positioning groove 51, a first positioning element 52, a second positioning groove 53, and a second positioning element 54. The first positioning groove 51 is located at one end of the first tooth path 42 and the thread raceway 41, and the first positioning element 52 is located at the other end of the first tooth path 42 and the thread raceway 41. The second positioning groove 53 is located at the other end of the second tooth path 43 and the thread raceway 41. Firstly, the second positioning element 54 is located at the other end of the second toothed track 43 and the threaded raceway 41. When assembling the mold 4, the first toothed track 42 is assembled and connected to one end of the threaded raceway 41, and the first positioning element 52 is installed in the first positioning groove 51. The second toothed track 43 is assembled and connected to the other end of the threaded raceway 41, and the second positioning element 54 is installed in the second positioning groove 53. The mold 4 has a cylindrical structure. The plane perpendicular to the central axis C of the mold 4 is defined as the projection plane H. Along the axial direction of the mold 4, the orthographic projection of the first positioning groove 51 on the projection plane H is the first projection H1, and the orthographic projection of the second positioning groove 53 on the projection plane H is the second projection H2. The first projection H1 and the second projection H2 are misaligned.

[0048] The functions and structural principles of this invention have been demonstrated and explained in the embodiments.

[0049] Although this application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications or equivalent substitutions to this application, and all technical solutions and improvements that do not depart from the spirit and scope of this application should be covered within this application.

Claims

1. A driving device, characterized in that, The assembly includes a housing (6), a drive assembly (7), and an output assembly (8). The drive assembly (7) is at least partially located within the housing (6) and is connected to the output assembly (8). The output assembly (8) includes a sleeve (81), a roller (100), and a lead screw (82). The sleeve (81) is threadedly engaged with the roller (100), and the roller (100) is threadedly engaged with the lead screw (82). The roller (100) is at least partially made of plastic and includes a threaded section (1), a first tooth (2), and a second tooth (3). Along the radial direction of the roller (100), the tip circle diameter of the first tooth (2) is D. m1 The tip circle diameter of the second tooth (3) is D. m2 The tooth tip circle diameter of the threaded segment (1) is D. m3 , where D m3 >D m1 Or D m3 >D m2 .

2. The driving device according to claim 1, characterized in that, The tip circle diameter D of the first tooth (2) m1 and the tip circle diameter D of the second tooth (3) m2 Consistent, where D m3 >D m1 =D m2 .

3. The driving device according to claim 1 or 2, characterized in that, The roller (100) is made of plastic. The threaded section (1) includes a threaded portion (11), which includes a crest (12) and a root (13). The outer diameter of the root (13) is D along the radial direction of the roller (100). mb The outer diameter of the tooth crest (12) is D. ma , where D ma >D mb D ma =D m3 D mb ≥D m1 Or D mb ≥D m2 .

4. The driving device according to claim 3, characterized in that, D mb =nD m1 =nD m2 ,0.7≤n≤1.

5. The driving device according to any one of claims 1 to 4, characterized in that, The first tooth portion (2) includes a plurality of first teeth (21) and a first shaft portion (23). The first teeth (21) are connected to the first shaft portion (23). The plurality of first teeth (21) are distributed circumferentially along the first shaft portion (23). The first teeth (21) extend axially along the first shaft portion (23). The first teeth (21) are radially protruding from the surface of the first shaft portion (23). The second tooth portion (3) includes a plurality of second teeth (31) and a second shaft portion (33). The second teeth (31) are connected to the second shaft portion (33). The plurality of second teeth (31) are distributed circumferentially along the second shaft portion (33). The second teeth (31) extend axially along the second shaft portion (33). The second teeth (31) are radially protruding from the surface of the second shaft portion (33).

6. The driving device according to claim 5, characterized in that, The number of teeth in the first tooth (21) is equal to the number of teeth in the second tooth (31).

7. The driving device according to claim 1, characterized in that, The first tooth (2) and / or the second tooth (3) are involute gear structures, and the first tooth (2) and / or the second tooth (3) have a long involute profile.

8. A roller, characterized in that, The roller (100) is at least partially made of plastic. The roller (100) includes a threaded section (1), a first tooth (2), and a second tooth (3). Along the radial direction of the roller (100), the tip circle diameter of the first tooth (2) is D. m1 The tip circle diameter of the second tooth (3) is D. m2 The tooth tip circle diameter of the threaded segment (1) is D. m3 , where D m3 >D m1 Or D m3 >D m2 .

9. A method for preparing a roller, characterized in that, include: A mold (4) for preparing rollers (100) is provided. The mold (4) has an inlet (44) and a forming cavity. The inlet (44) is located on the end side of the mold and communicates with the forming cavity (P). The mold (4) includes a threaded raceway (41), a first toothed track (42), and a second toothed track (43). The threaded raceway (41) is located between the first toothed track (42) and the second toothed track (43). The forming cavity (P) is located between the threaded raceway (41), the first toothed track (42), and the second toothed track (43). Plastic is injected from the inlet (44) and flows into the molding cavity (P), forming rollers (100) in the mold (4), forming threaded segments (1) in the threaded raceway (41), forming a first tooth (2) in the first toothed track (42), and forming a second tooth (3) in the second toothed track (43); Demolding involves first removing at least one of the first toothed passage (42) and the second toothed passage (43), then removing the threaded raceway (41) to obtain the roller (100). Along the radial direction of the roller (100), the tip circle diameter of the first tooth (2) is D. m1 The tip circle diameter of the second tooth (3) is D. m2 The tooth tip circle diameter of the threaded segment (1) is D. m3 , where D m3 >D m1 Or D m3 >D m2 .

10. The preparation method according to claim 9, characterized in that, After the plastic is formed in the mold (4), the first toothed track (42) and the second toothed track (43) are simultaneously or sequentially separated from the threaded raceway (41). The first toothed track (42) moves out along the axial direction of the roller (100), the first toothed track (42) separates from one end of the threaded raceway (41), the first toothed track (42) separates from the first tooth (2), the second toothed track (43) moves out along the axial direction of the mold (4), the second toothed track (43) separates from the other end of the threaded raceway (41), and the second toothed track (43) separates from the second tooth (3). The threaded raceway (41) is screwed out and disengaged along the helical direction of the threaded segment (1), or The thread raceway (41) is split and separated from the thread segment (1).

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