Worm gear linear driving structure and worm gear linear driving module

Abstract

The invention provides a worm gear linear driving structure. The worm gear linear driving structure comprises an inner spiral tooth component, a rod piece, a plurality of worm gear sets and a pre-pressing piece set. The inner spiral tooth component is provided with an inner hole extending in the axial direction, and a spiral tooth structure is arranged on the inner circumferential face of the inner spiral tooth component. The rod piece is arranged in the inner hole in a penetrating mode and extends in the axial direction. The worm gear sets are arranged in the inner hole and arranged between the inner spiral tooth component and the rod piece. Each worm gear set comprises at least one worm gear, a tooth structure is arranged on the peripheral face of the worm gear, the tooth line of the tooth structure is meshed with the tooth line of the spiral tooth structure in a crossed mode, and the worm gear is in friction contact with the peripheral face of the rod piece. The pre-pressing piece set is arranged on the radial outer side of the worm wheel set and used for applying pre-pressing force to the worm wheel set, so that static friction force is formed between the worm wheel and the rod piece. When the inner spiral tooth component is driven to rotate, the worm gear can be driven to rotate, and the rod piece is pushed to move in the axial direction through the worm gear. When the rod piece bears reverse external force exceeding the static friction force, the rod piece slides relative to the worm gear set.

Description

Technical Field

[0001] The present invention relates to a drive structure, and more particularly to a worm gear linear drive structure and a worm gear linear drive module that combine a worm gear and an internal helical gear structure to achieve conversion between rotational drive and linear motion. Background Art

[0002] Existing linear actuators, such as screw and nut mechanisms, are widely used in industrial automation, precision machinery, and robotics. However, these structures still face technical limitations in terms of reverse drive capability, overload protection, and stroke design flexibility.

[0003] For example, when a screw mechanism is subjected to reverse external forces, it is limited by the helix angle and friction. If the external force exceeds the load limit, it can easily lead to thread damage, structural failure, or reverse load on the motor. Furthermore, the difficulty and high cost of manufacturing the internal threads of the nut also adversely affect the design of the stroke length.

[0004] Some linear drive devices utilize friction wheel structures. However, these designs are often simplified and lack comprehensive friction adjustment and control mechanisms. This can lead to transmission failure or poor positioning due to insufficient friction under normal driving or high-load conditions. They also lack effective overload protection, making it difficult to respond to overloads caused by adverse external force input.

[0005] In view of this, there is an urgent need for a new linear drive structure that can effectively solve the above problems and combine reverse overload protection, stroke freedom and manufacturing efficiency to meet the requirements of modern equipment for reliability, flexibility and application diversity. Summary of the Invention

[0006] The object of the present invention is to provide a worm gear linear drive structure and a worm gear linear drive module.

[0007] To solve the above problems, the present invention provides a worm gear linear drive structure, characterized by comprising:

[0008] An internal helical tooth component has an inner hole extending in the axial direction, and an inner peripheral surface of the inner hole is provided with a helical tooth structure;

[0009] a rod member, passing through the inner hole and extending along the axial direction;

[0010] a plurality of worm gear assemblies disposed in the inner hole and arranged between the internal helical tooth member and the rod, each worm gear assembly comprising at least one worm wheel, the outer circumference of the worm wheel being provided with a tooth structure, the tooth trace of the tooth structure being cross-engaged with the tooth trace of the helical tooth structure, and the outer circumference of each worm wheel being in frictional contact with the outer circumference of the rod; and

[0011] A pre-compression component set is arranged on the radial outer side of the plurality of worm gear sets and is used for applying pre-compression force to each of the worm gear sets.

[0012] The worm gear linear drive structure further comprises:

[0013] a main bearing disposed on the inner circumferential surface of at least one end portion of the internal helical tooth member;

[0014] a fixing frame, disposed on an axially outer side of the main bearing, the fixing frame having a penetrating inner hole; and

[0015] a sliding bushing assembled in the inner hole of the fixing frame, the sliding bushing having a through hole;

[0016] The rod is further inserted into the main bearing, the inner hole of the fixing frame and the insertion hole of the sliding bushing.

[0017] In the worm gear linear drive structure, at least a portion of the outer circumference of the rod has a smooth surface for frictional contact with each of the worm gears.

[0018] In the worm gear linear drive structure, the rod has a circular, elliptical or polygonal geometric cross-section.

[0019] The worm gear linear drive structure, wherein each worm gear assembly further comprises:

[0020] a retaining member having a main body and two pairs of end portions extending from both sides of the main body, each end portion being provided with a through hole, and a spacing space being formed between each pair of end portions, each worm gear being disposed in the spacing space;

[0021] at least one worm gear shaft, passing through the through hole of the retaining member and penetrating the corresponding worm gear; and

[0022] At least two worm gear bearings are respectively disposed in the inner hole of the worm gear and sleeved on the worm gear shaft.

[0023] In the worm gear linear drive structure, the outer peripheral surface of each worm gear forms a concave profile, and the shape of the concave profile corresponds to the outer peripheral profile of the rod.

[0024] In the worm gear linear drive structure, the pre-pressing component assembly includes a plurality of torsion plates, each of which is provided with a hook portion.

[0025] The worm gear linear drive structure is characterized in that the multiple torsion plates are stacked into a torsion plate group, each of which is arranged on two adjacent retaining members and is clamped on the radial outside of the two retaining members through the hook portion to apply pre-pressure to the two retaining members.

[0026] A worm gear linear drive module, characterized by comprising:

[0027] The worm gear linear drive structure described above;

[0028] a housing defining a receiving space in which the worm gear linear drive structure is disposed;

[0029] a stator fixedly disposed in the housing and disposed around the outer side of the internal helical tooth member to drive the internal helical tooth member to rotate; and

[0030] A flange cover is fixedly arranged on one end of the shell.

[0031] A worm gear linear drive module, characterized by comprising:

[0032] The worm gear linear drive structure described above;

[0033] a housing defining a receiving space in which the worm gear linear drive structure is disposed;

[0034] a stator fixedly disposed in the housing;

[0035] a rotor disposed in a space surrounded by the stator and capable of rotating relative to the stator;

[0036] a rotor structure, one end of which is coupled to the rotor, and the other end of which is coupled to the internal helical tooth member; and

[0037] An end cover is fixedly arranged on one end of the shell.

[0038] When the internal helical toothed member is driven to rotate, its helical teeth mesh with those of the worm gear, driving the worm gear to rotate synchronously. Frictional contact between the worm gear and the outer circumference of the rod converts rotational torque into axial linear movement of the rod. Furthermore, if the rod is subjected to a reverse external force that exceeds the static friction set by the preload assembly, the rod will slip relative to the worm gear, thereby blocking the transmission of excessive reaction force and preventing damage to the worm gear, internal helical toothed member, or other drive components due to overload, thereby improving the durability and operational safety of the entire drive structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1A FIG. 1 is an exploded schematic diagram of the main components of the worm gear linear drive structure according to the first embodiment of the present invention.

[0040] Figure 1B This is a schematic exploded view of the worm gear assembly and pre-compression member assembly of the worm gear linear drive structure according to the first embodiment of the present invention.

[0041] Figure 2A FIG1 is a cross-sectional view of the worm gear linear drive structure in an assembled state according to the first embodiment of the present invention.

[0042] Figure 2B FIG. 1 is a schematic cross-sectional view of a worm gear linear drive structure according to a first embodiment of the present invention.

[0043] Figure 3A for Figure 2B Schematic cross-sectional view along BB.

[0044] Figure 3B for Figure 2B Schematic cross-sectional view along AA.

[0045] Figure 4A FIG1 is a schematic diagram of the worm gear linear drive structure according to the first embodiment of the present invention when the rod is subjected to a reverse external force input.

[0046] Figure 4B FIG1 is a schematic diagram of the worm gear linear drive structure according to the first embodiment of the present invention, in a state where the rod member is in a friction sliding state relative to the worm gear assembly.

[0047] Figure 5 FIG. 4 is a cross-sectional schematic diagram of a worm gear linear drive module according to a second embodiment of the present invention.

[0048] Figure 6 FIG. 4 is a cross-sectional schematic diagram of a worm gear linear drive module according to a third embodiment of the present invention.

[0049] Description of reference numerals: worm gear linear drive structure 1; internal helical tooth member 10; inner hole 100; helical tooth structure 100t; rod 20; smooth surface 20s; worm gear assembly 30; retainer 301; body 301b; end 301e; through hole 301h; spacing space 301p; worm wheel 302; tooth structure 302t; recessed portion profile 302c; inner hole 302h; worm wheel shaft 303; worm wheel bearing 304; preload Component group 40; torque plate 401; hook 402; torque plate group 401g; main bearing 50; fixing frame 60; inner hole 60h; sliding bushing 70; through hole 70h; worm gear linear drive modules 2, 3; housing 80, 80′; through holes 80h, 80h′, 83h, 92h; accommodating spaces AS, AS′; stators 81, 81′; flange cover 83; rotor 90; rotor structure 91; end cover 92; external force F. DETAILED DESCRIPTION

[0050] The structural and functional characteristics of the worm gear linear drive structure and module proposed in the present invention will be described based on the preferred embodiments shown in the accompanying drawings.

[0051] See also Figure 1A 、 Figure 1B 、 Figure 2A and Figure 2BThe first embodiment of the present invention provides a worm gear linear drive structure 1, comprising: an internal helical tooth component 10, a rod 20, a plurality of worm gear sets 30 and a pre-loaded component set 40. The structure and configuration relationship of each component will be described in sequence below.

[0052] like Figure 1A 、 Figure 2A and Figure 2B As shown, the internal helical tooth member 10 is a cylindrical (hollow cylindrical) structure and defines an inner hole 100 extending along the axial direction. The inner circumference of the internal helical tooth member 10 is provided with a helical tooth structure 100t.

[0053] The rod 20 is inserted into the inner hole 100 of the internal helical tooth member 10 and extends along the axial direction. The rod 20 can adopt a circular, elliptical, square or polygonal cross-section according to design requirements.

[0054] like Figure 2B As shown, at least a portion of the outer circumference of the rod 20 is provided with a smooth surface 20s.

[0055] like Figure 2A and Figure 2B As shown, the plurality of worm gears 30 are disposed in the inner hole 100 of the internal helical tooth member 10 and arranged between the internal helical tooth member 10 and the rod 20 .

[0056] like Figure 1B As shown, each worm gear assembly 30 includes a retaining member 301, at least one worm gear 302, at least one worm gear shaft 303, and at least two worm gear bearings 304. This embodiment is described using three worm gear assemblies 30, each worm gear assembly 30 including two worm gears 302, two worm gear shafts 303, and four worm gear bearings 304 as an example.

[0057] The retaining member 301 comprises a main body 301b and two pairs of end portions 301e extending from the main body 301b. Each end portion 301e has a through hole 301h, and a space 301p is defined between the opposing end portions 301e. Two worm gears 302 are respectively disposed in the spaces 301p corresponding to the opposing end portions 301e.

[0058] like Figure 1B As shown, the worm wheel 302 is cylindrical, and a tooth structure 302t is provided on the outer peripheral surface.

[0059] like Figure 1B and Figure 2AAs shown, the outer circumference of the worm wheel 302 further forms a recessed profile 302c. The shape of the recessed profile 302c corresponds to the outer circumference of the rod 20, thereby enabling close contact with the rod 20. In this embodiment, the tooth structure 302t of the worm wheel 302 is composed of two rows of racks spaced apart along the circumference, with the recessed profile 302c formed between the two rows of racks.

[0060] like Figure 1B As shown, the worm gear bearing 304 is disposed within the inner hole 302h of the worm gear 302, while the worm gear shaft 303 is sequentially inserted through the retaining member through-hole 301h, the worm gear bearing 304, and the interior of the worm gear 302. The combination of the worm gear shaft 303 and the worm gear bearing 304 can firmly support and position the worm gear 302, ensuring its stable rotation during operation.

[0061] See also Figure 1B 、 Figure 2B 、 Figure 3A and Figure 3B As shown. Figure 1B 、 Figure 3A and Figure 3B As shown, each pre-compression member assembly 40 is disposed radially outward of the three worm gear assemblies 30 and is disposed between two adjacent retaining members 301 to apply pre-compression force to each worm gear assembly 30. Thus, the radial pre-compression force applied by the pre-compression member assembly 40 on the retaining members 301 can press each worm gear 302 toward the rod 20, thereby forming a stable and controllable static friction force between the worm gear 302 and the rod 20.

[0062] In this embodiment, three groups of pre-pressing member sets 40 , each group including a plurality of torsion plates 401 , are used as examples for description.

[0063] like Figure 1B As shown, each pre-pressing component group 40 includes a plurality of torsion plates 401. Each torsion plate 401 is generally sheet-shaped and has a hook portion 402. Figure 1B and Figure 3A As shown, the torque plates 401 are stacked in groups to form a plurality of torque plate groups 401g. Each torque plate group 401g is arranged between two pairs of ends on the corresponding two retaining members 301, and is clamped to the radial outer sides of the two retaining members 301 through the hooks 402 to apply pre-pressure to the retaining members 301.

[0064] like Figure 3A and Figure 3B As shown, by the preload applied by each torsion plate group 401g, each worm gear group 30 is able to withstand radial preload, and the preload is then transmitted to the worm gear 302, so that the worm gear 302 is pressed toward the rod 20, thereby forming a stable static friction contact between the worm gear 302 and the rod 20, ensuring that the power of the internal helical tooth component 10 during rotation is smoothly transmitted to the rod 20.

[0065] In addition, by selecting torsion plates 401 with different elastic coefficients or stacking numbers, the preload can be adjusted, thereby controlling the strength of the static friction between the worm gears 302 and the rod 20 to meet different driving requirements.

[0066] Furthermore, in order to make the friction force more flexible and precise, the friction force between the worm gear 302 and the rod 20 can be adjusted in the following manner in this embodiment:

[0067] First, by adjusting the interference amount of the torsion plate 401 (for example, selecting a torsion plate of different thickness or adjusting the degree of compression during assembly), the preload applied by the preload assembly 40 to the worm gear 302 can be changed, thereby indirectly changing the friction between the worm gear 302 and the rod 20.

[0068] Furthermore, the rod 20 may be surface treated, such as applying a coating, changing the material, or adjusting the surface roughness, to change the friction coefficient of the rod 20 surface, thereby adjusting the static friction between the worm gear 302 and the rod 20 .

[0069] The design of the preload assembly 40 of the present invention is not limited to the torsion plate 401 disclosed above. Other elastic members with similar functions, such as ring-shaped or other elastic members, may also be used. Any method that can apply appropriate preload to each worm gear assembly 30 to establish static friction between the worm gear 302 and the rod 20 is a feasible embodiment of the present invention.

[0070] like Figure 1A and Figure 2B As shown, the worm gear linear drive structure 1 further includes at least one main bearing 50, at least one fixing bracket 60, and at least one sliding bushing 70. This embodiment is described by taking two main bearings 50, two fixing brackets 60, and two sliding bushings 70 as an example.

[0071] Two main bearings 50 are respectively disposed on the inner circumference of two opposite ends of the internal helical tooth member 10 to provide radial support required for the rotation of the internal helical tooth member 10 .

[0072] Two retaining brackets 60 are positioned axially outward of the two main bearings 50. One end of each retaining bracket 60 is inserted into the through-hole of the main bearing 50. The outer diameter of the end matches the inner diameter of the through-hole of the main bearing 50, thereby forming a fitting and positioning relationship. The retaining bracket 60 has a through-hole 60h. This hole 60h has a multi-segmented structure. The larger diameter section is used to assemble the sliding bushing 70, while the smaller diameter section is used to allow the rod 20 to pass through.

[0073] The two sliding bushings 70 are respectively assembled in the larger diameter section of the inner hole 60h of the two fixing frames 60, and each sliding bushing 70 is provided with a through hole 70h. The inner diameter of the through hole 70h matches the outer diameter of the rod 20, so that the rod 20 can be passed through and provide radial guidance and positioning effects during operation, thereby ensuring the stability and coaxial accuracy of the movement of the rod 20.

[0074] like Figure 2B As shown, when the internal helical tooth member 10 is driven to rotate, the helical tooth structure 100t on its inner circumference cross-engages with the outer circumferential tooth structure 302t of the worm gear 302, synchronously driving the worm gear 302 to rotate. During the rotation of the worm gear 302, the frictional contact between the worm gear 302 and the rod 20 effectively converts the rotational torque into thrust, pushing the rod 20 linearly in the axial direction.

[0075] like Figure 3A and Figure 3B As shown, the worm gears 302 of the three worm gear assemblies 30 are distributed in the circumferential direction along the outer circumference of the rod 20 and are stably and tightly attached to the outer circumference of the rod 20 under the radial preload applied by the preload assembly 40 .

[0076] like Figure 3B As shown, the shape of the concave profile 302 c on the outer peripheral surface of each worm wheel 302 corresponds to the outer peripheral profile of the rod 20 , so that the worm wheel 302 can form a more intimate and stable friction contact with the rod 20 through the concave profile when rotating.

[0077] See also Figure 4A and Figure 4B When the rod 20 is driven in the reverse direction by an external force F, if the external force F exceeds the static friction generated by the frictional contact between the rod 20 and the worm gear 302, relative sliding (slipping) will occur between the smooth surface 20s of the rod 20 and the worm gear 302.

[0078] In this embodiment, the worm gear linear drive structure is composed of an internal helical tooth component, a plurality of worm gear groups and a rod, and is supplemented by a pre-load component group to apply preload to the worm gear group to form a static friction force between the worm gear and the rod. When the internal helical tooth component is driven to rotate, its spiral tooth structure and the tooth structure of the worm wheel produce a cross-meshing effect, which can drive the worm wheel to rotate synchronously. When the worm wheel rotates, the friction contact formed by the concave profile provided on its outer peripheral surface and the outer peripheral profile of the rod converts the rotational torque into thrust, thereby driving the rod to produce linear movement in the axial direction. In addition, when the rod is subjected to a reverse external force and exceeds the static friction force formed between the worm wheel and the rod, the rod can slide (slip) relative to the worm wheel, thereby exerting an overload protection function. With this design, excessive reaction force can be prevented from being directly transmitted to the worm wheel, the internal helical tooth component and other drive components, avoiding component damage caused by excessive load, thereby improving the durability and operational safety of the overall drive system.

[0079] See also Figure 5 As shown, the second embodiment of the present invention provides a worm gear linear drive module 2 , which is based on the aforementioned worm gear linear drive structure 1 and further combines a rotation drive mechanism with a module packaging structure.

[0080] The worm gear linear drive module 2 includes the aforementioned worm gear linear drive structure 1 , a housing 80 , a stator 81 , and a flange cover 83 .

[0081] The housing 80 defines an accommodating space AS, and the worm gear linear drive structure 1 is disposed in the accommodating space AS.

[0082] The stator 81 is a surrounding structure fixedly disposed in the housing 80 and arranged around the outer circumference of the internal helical tooth member 10. The stator 81 may include an electromagnetic coil assembly (not shown) that generates a magnetic field when energized to drive the internal helical tooth member 10 to rotate.

[0083] The flange cover 83 is mounted on one end of the housing 80 to enclose the accommodating space AS. The housing 80 and the flange cover 83 may respectively define through holes 80h and 83h, allowing the rod 20 to pass therethrough and extend axially to the exterior of the worm gear linear drive module 2 .

[0084] This embodiment builds upon the architecture of the first embodiment by adding a housing, stator, and flange cover to form a module. The stator surrounds the outer surface of the internal helical gear member. When energized, it generates a magnetic field that drives the internal helical gear member to rotate, while the aforementioned worm gear and rod friction drive mechanism generates linear motion of the rod.

[0085] See also Figure 6The third embodiment of the present invention provides a worm gear linear drive module 3 , which is similar to the worm gear linear drive module 2 of the second embodiment. The main difference is that this embodiment drives the internal helical tooth member 10 to rotate by another rotor 90 and a rotor structure 91 .

[0086] The worm gear linear drive module 3 includes: the aforementioned worm gear linear drive structure 1 , a housing 80 ′, a stator 81 ′, a rotor 90 , a rotor structure 91 , and an end cover 92 .

[0087] The housing 80 ′ defines an accommodating space AS′, and the aforementioned worm gear linear drive structure 1 is disposed in the accommodating space AS′.

[0088] The stator 81' is a wraparound structure fixedly disposed inside the housing 80'. The stator 81' may include an electromagnetic coil assembly (not shown) that generates a magnetic field when energized.

[0089] The rotor 90 is disposed in the space surrounded by the stator 81' and is rotatable relative to the stator 81'. The rotor 90 is an annular structure and is fixedly coupled to one end of the rotor structure 91 to form an integral rotation relationship.

[0090] The rotor structure 91 has a multi-stage stepped shape, with one end engaging and securing the rotor 90, while the other end is inserted into the end of the internal helical tooth member 10, thereby firmly coupling the rotor structure 91 to the internal helical tooth member 10. Furthermore, the rotor structure 91 has a through hole whose inner diameter matches the outer diameter of the rod 20, allowing the rod 20 to pass therethrough.

[0091] When rotor 90 is driven to rotate, it synchronously drives the rotor structure 91, to which it is fixed, to rotate. Through the connection between rotor structure 91 and internally helical member 10, internally helical member 10 also rotates. Internally helical member 10 further drives worm gear 302 through cross-engagement. The rotating worm gear 302, in turn, propels rod 20 axially through frictional contact between its outer circumference and rod 20, achieving both power transmission and linear drive.

[0092] The end cap 92 is fixedly mounted on one end of the housing 80' to enclose the accommodating space AS'. The housing 80' and the end cap 92 may be provided with through holes 80h' and 92h, respectively, to allow the rod 20 to pass therethrough and extend axially to the exterior of the worm gear linear drive module 3.

[0093] This embodiment realizes the driving of the internal helical tooth component by means of the design of the rotor and the rotor structure, and converts the rotational motion into the linear movement of the rod through the friction transmission mechanism between the worm gear and the rod, providing another modular design.

[0094] In summary, the worm gear linear drive structure and worm gear linear drive module disclosed in various embodiments of the present invention utilize a cross-meshing design between the internal helical toothed member and the worm gear, combined with the preload provided by the preload assembly to generate a friction transmission mechanism between the worm gear and the rod. This allows for efficient and stable conversion of rotational torque into linear movement of the rod, and automatically induces slippage when the rod is subjected to abnormal loads, preventing structural damage from overload. Furthermore, the second and third embodiments further integrate the stator or rotor drive mechanism directly into the housing, creating a modular structure. This not only helps improve system compactness but also provides diverse application flexibility to meet diverse application requirements.

[0095] The above description has provided a detailed description of the present invention. However, the above description is merely a preferred embodiment of the present invention and should not limit the scope of the present invention. In other words, all equivalent variations and modifications based on the present invention should still fall within the scope of the present invention.

Claims

1. A worm gear linear drive structure, characterized in that: Include: An internal helical tooth component has an inner hole extending in the axial direction, and an inner peripheral surface of the inner hole is provided with a helical tooth structure; a rod member, passing through the inner hole and extending along the axial direction; a plurality of worm gear assemblies disposed in the inner hole and arranged between the internal helical tooth member and the rod, each worm gear assembly comprising at least one worm wheel, the outer circumference of the worm wheel being provided with a tooth structure, the tooth trace of the tooth structure being cross-engaged with the tooth trace of the helical tooth structure, and the outer circumference of each worm wheel being in frictional contact with the outer circumference of the rod; and A pre-compression component set is arranged on the radial outer side of the plurality of worm gear sets and is used for applying pre-compression force to each of the worm gear sets.

2. The worm gear linear drive structure according to claim 1, characterized in that: Also includes: a main bearing disposed on the inner circumferential surface of at least one end portion of the internal helical tooth member; a fixing frame, disposed on an axially outer side of the main bearing, the fixing frame having a penetrating inner hole; and a sliding bushing assembled in the inner hole of the fixing frame, the sliding bushing having a through hole; The rod is further inserted into the main bearing, the inner hole of the fixing frame and the insertion hole of the sliding bushing.

3. The worm gear linear drive structure according to claim 1, wherein: At least a portion of the outer circumference of the rod has a smooth surface for frictionally contacting the worm gears.

4. The worm gear linear drive structure according to claim 1, wherein: The rod has a circular, elliptical or polygonal geometric cross section.

5. The worm gear linear drive structure according to claim 1, wherein: Each worm gear assembly further comprises: a retaining member having a main body and two pairs of end portions extending from both sides of the main body, each end portion being provided with a through hole, and a spacing space being formed between each pair of end portions, each worm gear being disposed in the spacing space; at least one worm gear shaft, passing through the through hole of the retaining member and penetrating the corresponding worm gear; and At least two worm gear bearings are respectively disposed in the inner hole of the worm gear and sleeved on the worm gear shaft.

6. The worm gear linear drive structure according to claim 1, wherein: The outer peripheral surface of each worm wheel forms a concave profile, and the shape of the concave profile corresponds to the outer peripheral profile of the rod.

7. The worm gear linear drive structure according to claim 1, wherein: The pre-pressing component set includes a plurality of torsion plates, and each torsion plate is provided with a hook portion.

8. The worm gear linear drive structure according to claim 7, wherein: The plurality of torsion plates are stacked to form a torsion plate group. Each torsion plate group is arranged on two adjacent retaining members and is clamped on the radial outer sides of the two retaining members through the hook portion to apply pre-pressure to the two retaining members.

9. A worm gear linear drive module, characterized in that: Include: A worm gear linear drive structure as claimed in claim 2; a housing defining a receiving space in which the worm gear linear drive structure is disposed; a stator fixedly disposed in the housing and disposed around the outer side of the internal helical tooth member to drive the internal helical tooth member to rotate; and A flange cover is fixedly arranged on one end of the shell.

10. A worm gear linear drive module, characterized in that: Include: A worm gear linear drive structure as claimed in claim 2; a housing defining a receiving space in which the worm gear linear drive structure is disposed; a stator fixedly disposed in the housing; a rotor disposed in a space surrounded by the stator and capable of rotating relative to the stator; a rotor structure, one end of which is coupled to the rotor, and the other end of which is coupled to the internal helical tooth member; and An end cover is fixedly arranged on one end of the shell.

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