Nut transmission structure and electric side opening door driving mechanism

Abstract

A nut-driven structure includes a drive wheel, a large screw cap, a small screw cap, a ball nut, and a lead screw. The drive wheel has an axially oriented mounting hole. The large and small screw caps are both annular and coaxially mounted at both ends of the mounting hole, respectively, and are circumferentially fixed relative to the drive wheel. The inner annular wall of the large and small screw caps is spherical, and their spherical surfaces mate to form a ball-and-socket structure. The outer circumferential wall of the ball nut is spherical and movably connected within the ball-and-socket structure. The outer circumferential wall of the ball nut has an axially extending elongated groove. The large screw cap has a limiting pin that slides into the elongated groove. The ball nut has a threaded hole, and the lead screw is threaded into the threaded hole. This design features separate large and small screw caps, simplifying the assembly process. Since both the large and small screw caps are circumferentially fixed relative to the drive wheel, it avoids noise or wear and loosening problems caused by the deflection of the large and small screw caps, thus improving practicality. An electric side-opening door drive mechanism is also provided.

Description

Technical Field

[0001] This utility model relates to the technical field of automotive parts, specifically to a nut transmission structure and an electric side-opening door drive mechanism. Background Technology

[0002] As a core component enabling automatic door opening and closing, the electric actuator of a car door is becoming increasingly widespread as technology matures. The typical working principle of an electric actuator is to convert the rotational power of a drive motor into the linear motion of a lead screw via a screw-nut pair, which in turn drives the door to open or close.

[0003] However, considering the diverse usage scenarios of automobiles, when using electric actuators to open and close car doors on slopes, rough roads, etc., the lead screw not only needs to extend and retract linearly, but also needs to be able to swing within a certain angle range.

[0004] Patent CN221761703U proposes a drive mechanism for an electric side-opening door. It uses a pad assembly with a ball-and-socket structure inside the screw cap assembly, allowing the spherical nut to have a certain swing angle. However, this design requires assembling the pad assembly and screw cap assembly after the drive wheel and screw cap assembly are completed, making assembly cumbersome. Furthermore, the pad assembly may deflect relative to the screw cap assembly, causing abnormal noise. Utility Model Content

[0005] The purpose of this invention is to solve the problem that in the existing electric actuator, the assembly of the liner assembly and the screw cap assembly must be completed after the assembly of the transmission wheel and the screw cap assembly is completed. The assembly is relatively complicated, and the liner assembly may deflect relative to the screw cap assembly, causing abnormal noise.

[0006] To solve the above problems, this utility model provides a nut transmission structure, including a transmission wheel, a large screw cap, a small screw cap, a ball nut, and a lead screw. The transmission wheel has an axial mounting hole. The large and small screw caps are both annular and coaxially mounted at both ends of the mounting hole and circumferentially fixed relative to the transmission wheel. The inner diameter of the large screw cap gradually decreases away from the small screw cap, making its inner ring wall spherical. The inner diameter of the small screw cap also gradually decreases away from the large screw cap, making its inner ring wall spherical. The spherical surfaces of the large and small screw caps come into contact to form a ball-and-socket structure. The outer circumferential wall of the ball nut is spherical and movably connected within the ball-and-socket structure. The outer circumferential wall of the ball nut has an axially extending elongated groove. The large screw cap has a limiting pin that slides into the elongated groove. The ball nut has a screw hole, and the lead screw is screwed into the screw hole.

[0007] In the above scheme, the transmission wheel receives the rotational power input from the outside. The rotational power is transmitted to the ball nut via the large screw cap and the limiting pin. The ball nut then converts the rotational power into the linear extension and retraction motion of the lead screw. Simultaneously, due to the movable fit between the spherical surfaces of the large and small screw caps and the ball nut, both the ball nut and the lead screw can swing within a certain angle. Furthermore, the above scheme designs separate large and small screw caps. During installation, the large screw cap is first installed to one end of the assembly hole, then the ball nut is inserted, and finally the small screw cap is installed to the other end of the assembly hole to complete the assembly. Compared with existing technologies, this simplifies the assembly steps. Moreover, both the large and small screw caps are circumferentially fixed relative to the transmission wheel, avoiding abnormal noise or wear and loosening problems caused by the deflection of the large and small screw caps, thus possessing better practicality.

[0008] In an improved embodiment, the mounting hole is provided with several raised key blocks on the side near the small screw cap, and the outer ring side of the small screw cap is provided with a keyway for the key blocks to engage, thereby achieving circumferential fixation between the small screw cap and the mounting hole through the engaging action of the key blocks and the keyway.

[0009] In an improved embodiment, the outer ring of the small screw cap is polygonal in shape, and the shape of the side of the mounting hole near the small screw cap is adapted to the shape of the outer ring of the small screw cap, thereby achieving better circumferential fixing between the small screw cap and the mounting hole.

[0010] In an improved embodiment, the large screw cap has a radially penetrating insertion hole. The end of the insertion hole facing the drive wheel is closed by the wall of the mounting hole. The limiting pin is cylindrical, with one end inserted into the insertion hole and the other end extending out of the insertion hole and slidingly inserted into the elongated groove. The length of the elongated groove limits the swing range of the ball nut, and the cylindrical shape of the limiting pin reduces the contact area with the elongated groove, thus reducing wear.

[0011] In an improved embodiment, there are two elongated slots symmetrically distributed on both sides of the ball nut, and two limiting pins are slidably inserted into the two elongated slots respectively, so that the large screw cap can more stably transmit rotational power to the ball nut through the two limiting pins.

[0012] In an improved design, the outer ring side of the large screw cap is provided with multiple circumferentially distributed toothed grooves. The transmission wheel is made of plastic and is connected to the outer ring side of the large screw cap through a plastic coating process. The plastic coating process not only makes the processing of the transmission wheel more convenient and ensures a tight and noiseless connection between the transmission wheel and the large screw cap, but also allows the mounting hole of the transmission wheel to enter the toothed groove of the large screw cap during the plastic coating process, achieving better circumferential fixation between the large screw cap and the mounting hole. Since the rotational power of the ball nut is transmitted by the large screw cap through the limiting pin, the large screw cap can withstand a greater load after adopting this structure, ensuring the stability of power transmission between the transmission wheel and the large screw cap.

[0013] This utility model also provides an electric side-opening door drive mechanism, including the nut transmission structure as described above, and further including a housing, a motor and a worm gear. The nut transmission structure is located inside the housing. The transmission wheel is a worm gear and is rotatably connected to the housing through a bearing. The motor is installed inside the housing and its output end is connected to the worm gear. The worm gear meshes with the transmission wheel. The housing has an opening for the extension and retraction of the lead screw.

[0014] In the above solution, the housing can be installed on the car door, and the lead screw at the opening of the housing can be hinged to the car body. When the motor drives the transmission wheel to rotate through the worm gear, the lead screw can extend and retract from the opening of the housing, realizing the opening and closing of the car door relative to the car body. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a nut drive structure;

[0016] Figure 2 For along Figure 1 Cross-sectional view of section AA in the middle;

[0017] Figure 3 For along Figure 1 Cross-sectional view of the BB section line;

[0018] Figure 4 For along Figure 3 A cross-sectional view of the CC section line;

[0019] Figure 5 for Figure 3 A magnified view of a portion of region D in the middle;

[0020] Figure 6 A schematic diagram of a small screw cap for a nut-driven structure;

[0021] Figure 7 A schematic diagram of a transmission wheel in a nut-driven structure;

[0022] Figure 8 This is a schematic diagram of a ball nut with a nut drive structure.

[0023] Explanation of reference numerals in the attached figures.

[0024] 1. Drive wheel; 11. Assembly hole; 12. Key block; 2. Large screw cap; 21. Limit pin; 22. Tooth groove; 23. Insertion hole; 3. Small screw cap; 31. Keyway; 4. Ball nut; 41. Long groove; 42. Screw hole; 5. Lead screw; 6. Housing; 61. Motor; 62. Worm gear; 63. Bearing. Detailed Implementation

[0025] It should be understood by those skilled in the art that the following embodiments are merely illustrative of the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0026] In the following description of the embodiments, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0027] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] Please see Figures 1-8 The present invention provides a nut transmission structure comprising a transmission wheel 1, a large screw cap 2, a small screw cap 3, a ball nut 4, and a lead screw 5. The transmission wheel 1 has an axially oriented mounting hole 11. The large screw cap 2 and the small screw cap 3 are both annular and coaxially mounted at both ends of the mounting hole 11 and circumferentially fixed relative to the transmission wheel 1. The inner diameter of the large screw cap 2 gradually decreases in the direction away from the small screw cap 3, making the inner annular wall of the large screw cap 2 spherical. The inner diameter of the small screw cap 3 gradually decreases in the direction away from the large screw cap 2, making the inner annular wall of the small screw cap 3 spherical. The spherical surfaces of the large screw cap 2 and the small screw cap 3 are joined together to form a ball-and-socket structure. The outer peripheral wall of the ball nut 4 is spherical and is movably connected within the ball-and-socket structure. The outer peripheral wall of the ball nut 4 has an axially extending elongated groove 41. The large screw cap 2 has a limiting pin 21 that slides into the elongated groove 41. The ball nut 4 has a screw hole 42, and the lead screw 5 is screwed into the screw hole 42.

[0031] In the above scheme, the transmission wheel 1 receives the rotational power input from the outside. The rotational power is transmitted to the ball nut 4 via the large screw cap 2 and the limiting pin 21. The ball nut 4 then converts the rotational power into the linear extension and retraction motion of the lead screw 5. At the same time, due to the movable fit between the spherical surfaces of the large screw cap 2 and the small screw cap 3 and the ball nut 4, both the ball nut 4 and the lead screw 5 can swing within a certain angle. Furthermore, the above scheme designs a split large screw cap 2 and a small screw cap 3. During installation, the large screw cap 2 is first installed to one end of the assembly hole 11, then the ball nut 4 is inserted, and finally the small screw cap 3 is installed to the other end of the assembly hole 11 to complete the assembly. Compared with the prior art, the assembly steps are simplified, and both the large screw cap 2 and the small screw cap 3 are circumferentially fixed relative to the transmission wheel 1, avoiding abnormal noise or wear and loosening problems caused by the deflection of the large screw cap 2 and the small screw cap 3, thus having better practicality.

[0032] Regarding the circumferential fixing of the small screw cap 3 relative to the transmission wheel 1, in this embodiment, several protruding key blocks 12 are provided on the side of the mounting hole 11 near the small screw cap 3, such as... Figure 2 As shown, there are two key blocks 12, which are spaced apart in the assembly hole 11. The outer ring side of the small screw cap 3 is provided with two keyways 31. The two key blocks 12 are respectively snapped into the two keyways 31, thereby realizing the circumferential fixation between the small screw cap 3 and the assembly hole 11.

[0033] In other embodiments, the outer ring of the small screw cap 3 can be designed as a polygon, for example, the outer ring of the small screw cap 3 can be quadrilateral, and the shape of the side of the mounting hole 11 near the small screw cap 3 can be adapted to the shape of the outer ring of the small screw cap 3, thereby achieving a better circumferential fixing effect between the small screw cap 3 and the mounting hole 11. Of course, the key block 12 and keyway 31 can also be omitted, and only the shape of the outer ring of the small screw cap 3 and the shape of the side of the mounting hole 11 near the small screw cap 3 can be designed as a polygon.

[0034] In this embodiment, the large screw cap 2 is provided with a radially penetrating insertion hole 23. One end of the insertion hole 23 facing the transmission wheel 1 is closed by the hole wall of the mounting hole 11. The limiting pin 21 is cylindrical and one end is inserted into the insertion hole 23, while the other end extends out of the insertion hole 23 and is slidably inserted into the elongated groove 41. The length of the elongated groove 41 limits the swing range of the ball nut 4, and the cylindrical shape of the limiting pin 21 can reduce the contact area with the elongated groove 41 and reduce wear.

[0035] Preferably, there are two elongated grooves 41 symmetrically distributed on both sides of the ball nut 4, and two limiting pins 21 are slidably inserted into the two elongated grooves 41 respectively, so that the large screw cap 2 can more stably transmit the rotational power to the ball nut 4 through the two limiting pins 21.

[0036] In this embodiment, the outer ring side of the large screw cap 2 is provided with multiple circumferentially distributed toothed grooves 22. The transmission wheel 1 is made of plastic and is connected to the outer ring side of the large screw cap 2 through a plastic coating process. The plastic coating process not only makes the processing of the transmission wheel 1 easier and ensures a tight and noiseless connection between the transmission wheel 1 and the large screw cap 2, but also allows the mounting hole 11 of the transmission wheel 1 to enter the toothed grooves 22 of the large screw cap 2 during the plastic coating process, achieving better circumferential fixation between the large screw cap 2 and the mounting hole 11. Since the rotational power of the ball nut 4 is transmitted by the large screw cap 2 through the limiting pin 21, the large screw cap 2 can withstand a greater load after adopting this structure, ensuring the stability of power transmission between the transmission wheel 1 and the large screw cap 2. In addition, both the large screw cap 2 and the small screw cap 3 are preferably made of metal, which has good wear resistance.

[0037] Example 2

[0038] Embodiment 2 of this utility model provides an electric side-opening door drive mechanism, including the nut transmission structure as in Embodiment 1, and also including a housing 6, a motor 61 and a worm gear 62. The nut transmission structure is located inside the housing 6. The transmission wheel 1 is a worm gear and is rotatably connected to the housing 6 through a bearing 63. The motor 61 is installed inside the housing 6 and its output end is connected to the worm gear 62. The worm gear 62 meshes with the transmission wheel 1. The housing 6 has an opening for the extension and retraction of the lead screw 5.

[0039] In the above scheme, the housing 6 can be installed to the car door, and the lead screw 5 located at the opening of the housing 6 can be hinged to the car body. When the motor 61 drives the transmission wheel 1 to rotate through the worm gear 62, the lead screw 5 can extend and retract from the opening of the housing 6 to realize the opening and closing of the car door relative to the car body.

[0040] It should be noted that in the description of this application, the terms "inner" and "outer," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application. All directional indications (such as up, down, left, right, front, back, inner, and outer) are only used to explain the relative positional relationships and movement between components in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0041] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0042] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A nut transmission structure, characterized in that, The assembly includes a drive wheel (1), a large screw cap (2), a small screw cap (3), a ball nut (4), and a lead screw (5). The drive wheel (1) has an axial mounting hole (11). The large screw cap (2) and the small screw cap (3) are both annular and are coaxially mounted at both ends of the mounting hole (11) and circumferentially fixed relative to the drive wheel (1). The inner diameter of the large screw cap (2) gradually decreases in the direction away from the small screw cap (3), making the inner annular wall of the large screw cap (2) spherical. The inner diameter of the small screw cap (3) gradually decreases in the direction away from the large screw cap (2). The inner ring wall of the small screw cap (3) gradually decreases in size, forming a spherical surface. The spherical surfaces of the large screw cap (2) and the small screw cap (3) come into contact with each other to form a ball-and-socket structure. The outer peripheral wall of the ball nut (4) is spherical and is movably connected within the ball-and-socket structure. The outer peripheral wall of the ball nut (4) is provided with an axially extending elongated groove (41). The large screw cap (2) is provided with a limiting pin (21) that slides into the elongated groove (41). The ball nut (4) is provided with a screw hole (42) and a screw rod (5) is screwed into the screw hole (42).

2. The nut transmission structure according to claim 1, characterized in that, The mounting hole (11) has several protruding key blocks (12) on the side near the small screw cap (3), and the outer ring side of the small screw cap (3) has a key groove (31) for the key blocks (12) to engage.

3. The nut transmission structure according to claim 1 or 2, characterized in that, The outer ring of the small screw cap (3) is polygonal in shape, and the shape of the side of the mounting hole (11) near the small screw cap (3) is adapted to the shape of the outer ring of the small screw cap (3).

4. The nut transmission structure according to claim 1, characterized in that, The large screw cap (2) is provided with a radially penetrating insertion hole (23). One end of the insertion hole (23) facing the transmission wheel (1) is closed by the hole wall of the assembly hole (11). The limiting pin (21) is cylindrical and one end is inserted into the insertion hole (23), while the other end extends out of the insertion hole (23) and is slidably inserted into the elongated groove (41).

5. The nut transmission structure according to claim 1, characterized in that, The elongated grooves (41) are two in number and symmetrically distributed on both sides of the ball nut (4), and the limiting pins (21) are two in number and are respectively slidably inserted into the two elongated grooves (41).

6. The nut transmission structure according to claim 4 or 5, characterized in that, The outer ring side of the large screw cap (2) is provided with multiple circumferentially distributed toothed grooves (22), and the transmission wheel (1) is made of plastic. The transmission wheel (1) is connected to the outer ring side of the large screw cap (2) through a plastic coating process.

7. An electric side-opening door drive mechanism, characterized in that, The nut transmission structure includes the nut transmission structure as described in any one of claims 1-6, and further includes a housing (6), a motor (61), and a worm (62). The nut transmission structure is located inside the housing (6). The transmission wheel (1) is a worm wheel and is rotatably connected to the housing (6) through a bearing (63). The motor (61) is installed inside the housing (6) and its output end is connected to the worm (62). The worm (62) meshes with the transmission wheel (1). The housing (6) has an opening for the extension and retraction of the lead screw (5).

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