Vehicle door drive mechanism
The integrated rotating component and adjustment mechanism in the vehicle door drive mechanism address unstable gear rotation and oscillation issues, ensuring stable operation and reduced noise by using a spherical surface engagement and laser welding.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KIEKERT AG
- Filing Date
- 2025-11-05
- Publication Date
- 2026-05-15
AI Technical Summary
Existing vehicle door mechanisms with separated worm gear and nut caps face issues of unstable gear rotation due to machining and assembly errors, leading to noise and excessive oscillation clearance.
A vehicle door drive mechanism with an integrated first rotating component, a ball nut, and a ball nut socket, featuring a spherical surface engagement and an adjustment device to adjust clearance, stabilized by laser welding, ensuring stable gear rotation and reduced oscillation.
The solution provides stable gear rotation and minimizes excessive oscillation clearance, enhancing the operation stability and reducing noise in vehicle doors.
Smart Images

Figure CN2025132611_15052026_PF_FP_ABST
Abstract
Description
VEHICLE DOOR DRIVE MECHANISMTechnical Field
[0001] The present application belongs to the technical field of vehicles, and in particular to a vehicle door drive mechanism.Background Art
[0002] Electric tailgates and electric sliding doors are now widely used in vehicles. With the rapid development of automotive intelligence and electrification, electric door opening mechanisms are also being applied to vehicle side doors. These mechanisms utilize motors as power sources, and power is transmitted through corresponding transmission mechanisms, thereby realizing opening and closing of the vehicle side doors.
[0003] For example, Chinese Utility Model Patent CN218912621U discloses an electric side door opening drive mechanism, which includes a worm gear housing assembly, a worm assembly, a motor assembly, a worm gear nut assembly, a mounting base assembly, a lead screw assembly, and a lead screw casing. The worm assembly is rotatably mounted within the worm gear housing assembly, an output end of the motor assembly is connected to the worm assembly, the worm gear nut assembly includes a worm gear matching with the worm assembly, the mounting base assembly and the lead screw casing are respectively connected to two sides of the worm gear housing assembly, the worm gear nut assembly is rotatably connected between the worm gear housing assembly and the mounting base assembly, the lead screw assembly includes a lead screw movably threaded to the worm gear nut assembly, and the lead screw has one end located in the lead screw casing and the other end extending to the mounting base assembly.
[0004] However, in this solution, the worm gear and nut caps supporting a bearing are components separated from each other, and two nut caps are provided. In this way, during assembly, due to machining and assembly errors, it is difficult to ensure that the worm gear and the nut caps of the final product rotate about the same center, resulting in unstable gear rotation, which affects operation and generates noise. In addition, excessive clearance between the nut caps and a ball nut may also cause excessive oscillation clearance of the door.Summary
[0005] In order to solve the above problems or other problems at least to some extent, the present application proposes the following solution.
[0006] A vehicle door drive mechanism includes:
[0007] a transmission mechanism, having a lead screw, a first rotating component and a ball nut, where the ball nut is arranged inside the first rotating component and can rotate with the first rotating component, the screw being threadedly engaged with the ball nut, and one end of the lead screw being connected to the vehicle door; and
[0008] a power source, where the power source outputs power to the transmission mechanism;
[0009] where the first rotating component is a hollow integral piece, and has a first part, a second part and a third part arranged in sequence along its axial direction, the first part being supported by a first bearing, the third part being supported by a second bearing, the second part having an external toothed portion on its radial outside, and the external toothed portion receiving power from the power source.
[0010] According to one aspect of the present application, the second part has a spherical surface on its radial inner side engaged with the outer surface of the ball nut, and the area of the spherical surface of the second part is less than half of the area of the outer surface of the ball nut.
[0011] According to one aspect of the present application, a ball nut socket is provided inside the first rotating component, the ball nut socket is engaged with the outer surface of the ball nut, and the spherical inner surface of the ball nut socket is arranged opposite to the spherical surface of the second part.
[0012] According to one aspect of the present application, an adjustment device is provided inside the first rotating component, and the adjustment device is arranged adjacent to the ball nut socket and is used to adjust the clearance between the ball nut socket and the ball nut.
[0013] According to one aspect of the present application, the adjustment device has an external threaded portion and is threadedly engaged with the inner surface of the first rotating component.
[0014] According to one aspect of the present application, the adjustment device has a welding portion, and the adjustment device and the inner surface of the first rotating component are connected by laser welding after being adjusted in place.
[0015] According to one aspect of the present application, the power source is a motor, and the motor is engaged with the external toothed portion through a worm.
[0016] According to one aspect of the present application, the outer surface of the ball nut is provided with a plurality of recessed portions.
[0017] According to one aspect of the present application, the ball nut has two planes parallel to each other and parallel to the axis of an internal threaded hole of the ball nut, and a rhombus-shaped protrusion viewed in a direction perpendicular to the plane is respectively provided on each plane, and a limit portion abutting against the protrusion on each side is provided in the radial inside of the first rotating component.
[0018] According to one aspect of the present application, the surface of the protrusion viewed in a direction perpendicular to the plane on which the protrusion is located and the spherical surface portion of the ball nut are on the same sphere.
[0019] According to the present application, the gear rotation is stable to achieve steady operation, and the clearance between the ball nut socket and the ball nut can be adjusted to avoid the excessive oscillation clearance of the vehicle door.
[0020] Other advantageous features and advantages of the present application will be described in detail below with reference to the drawings.Brief Description of the Drawings
[0021] Fig. 1 shows a front view of a vehicle door drive mechanism according to the present application.
[0022] Fig. 2 shows a partial view of a transmission mechanism of the vehicle door drive mechanism according to the present application.
[0023] Fig. 3 shows a front view of a first rotating component of the vehicle door drive mechanism according to the present application.
[0024] Fig. 4 shows a sectional view of the first rotating component and a nut of the vehicle door drive mechanism according to the present application.
[0025] Fig. 5 shows a partial sectional view of the transmission mechanism of the vehicle door drive mechanism according to the present application.
[0026] Fig. 6 shows a perspective view of the first rotating component and the nut of the vehicle door drive mechanism according to the present application.
[0027] Fig. 7 shows a sectional view of the first rotating component of the vehicle door drive mechanism according to the present application.
[0028] Fig. 8 shows a perspective view of the nut of the vehicle door drive mechanism according to the present application.
[0029] Fig. 9 shows a perspective view of a ball nut socket and the nut of the vehicle door drive mechanism according to the present application.Detailed Description of Embodiments
[0030] Embodiments of the present application are described below with reference to the drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand and implement the present application. However, it will be apparent to those skilled in the art that the present application may be implemented without some of these specific details. In addition, it should be understood that the present application is not limited to the particular embodiments described. Instead, it is contemplated that the present application can be implemented by any combination of the features and elements described below, regardless of whether they relate to different embodiments. Thus, the following aspects, features, embodiments and advantages are merely illustrative and should not be considered as elements or limitations of the claims, unless otherwise explicitly recited in the claims.
[0031] The description of the orientations that may be used in the following description, such as "left" , "right" , "upper" , "lower" , unless otherwise explicitly stated, is only for ease of description, and is not intended to form any limitation on the technical solutions of the present application. In addition, the terms such as "first" and "second" are used below to describe elements in the present application, and these terms are only used to distinguish the individual elements and are not intended to limit the nature, sequence, order or number of these elements.
[0032] Fig. 1 shows a front view of a vehicle door drive mechanism according to the present application. In Fig. 1, the vehicle door drive mechanism includes a transmission mechanism 100 and a power source 200. The transmission mechanism 100 is connected to a vehicle door connecting component 300 on a vehicle door. Power generated by the power source 200 is transmitted through the transmission mechanism 100 to the vehicle door connecting component 300, thereby driving the vehicle door to move. Specifically, the power source 200 outputs rotation power, the power source 200 is connected to a worm, and the transmission mechanism 100 includes a gear connected to the worm. A nut capable of rotating with the gear is arranged inside the gear, the nut is provided with an internal thread on the inner side, the internal thread is further connected to a lead screw 102, and the lead screw 102 is connected to the vehicle door connecting component 300. Thus, the rotation power from the power source is transmitted through the worm, the gear, the nut, and the lead screw, and then converted into a reciprocation of the lead screw along its own axis, thereby driving the vehicle door to open and close.
[0033] The transmission mechanism 100 has a housing 101 for accommodating a part of transmission components. Furthermore, a flexible guard 103 is provided on a side opposite the housing 101, and may, for example, have a corrugated structure, with one end fixed to the lead screw 102 and the other end fixed to the housing 101. Thus, it is possible to prevent the lead screw 102 from coming into contact with the outside and also prevent foreign objects from entering the inside of the housing 101. The housing 101 may be of a one-piece structure or a multi-piece structure. Fig. 1 further shows two threaded connectors for fixing the entire power source 200 and transmission mechanism 100 to the vehicle door.
[0034] The power source 200 is preferably a motor, and the gear may be a worm gear or a helical gear.
[0035] Fig. 2 shows a partial view of a transmission mechanism of the vehicle door drive mechanism according to the present application. Fig. 3 shows a front view of a first rotating component of the vehicle door drive mechanism according to the present application. The first rotating component 104 acts as a rotating member, having two sides supported on the housing 101 by a first bearing 103 and a second bearing 105 respectively. The lead screw 102 passes through the inside of the first rotating component 104 and is connected to a nut within the first rotating component 104.
[0036] Fig. 4 shows a sectional view of the first rotating component and a nut of the vehicle door drive mechanism according to the present application. Fig. 5 shows a partial sectional view of the transmission mechanism of the vehicle door drive mechanism according to the present application. Fig. 6 shows a perspective view of the first rotating component and the nut of the vehicle door drive mechanism according to the present application. As shown in Figs. 4 to 6, the first rotating component 104 may be divided into three parts along the direction of its own axis, i.e., a first part 1041 configured to be engaged with the first bearing 103, the second part 1042 configured to be connected to the worm and a nut 108 and the third part 1043 configured to support the second bearing 103, respectively. In order to solve the problem of unstable gear rotation caused by machining and assembly errors in the prior art, the first rotating component 104 is formed as an integral piece, that is, the first part 1041, the second part 1042, and the third part 1043 form an integrated structure.
[0037] Further, the second part 1042 is provided with an external toothed portion engaged with the worm on the outer peripheral surface, and is provided with a structure of a spherical surface inside to facilitate the engagement with the outer surface of the ball nut 108. In addition, a ball nut socket 107 is provided opposite the structure, and the ball nut socket 107 has a spherical surface which is engaged with the outer surface of the ball nut. Thus, the two structures arranged axially adjacent to each other can accommodate and be in close engagement with the ball nut.
[0038] Further, as a further improvement of the present application, an adjustment device 106 is provided on one side of the ball nut socket 107, and the adjustment device 106 is arranged radially inside the first rotating component 104, and partially overlaps axially with the first part 1041. An internal thread is provided on an inner peripheral surface of the first part 1041, and an external thread is provided on an outer peripheral surface of the adjustment device 106, so that the adjustment device 106 can be threadedly connected to the first part 1041 and can move axially. Thus, during assembly, the ball nut 108 is mounted onto the first rotating component 104 before the ball nut socket 107 is mounted, the adjustment device 106 is then screwed into the internal thread of the first part 1041, and the ball nut socket 107 is fixed to a proper position by screwing. Thus, a clearance between the ball nut socket and the ball nut can be adjusted by means of the adjustment device, thereby avoiding the excessive oscillation clearance of the vehicle door.
[0039] As a further improvement, after the adjustment device 106 is arranged in place, the adjustment device 106 can be welded to the first part 1041 by laser welding, so that the two are fixed together. In Fig. 5, the welding position is indicated by the arrow and the letter L. Thus, the ball nut socket can be prevented from loosening when subjected to a large axial force.
[0040] Fig. 7 shows a sectional view of the first rotating component of the vehicle door drive mechanism according to the present application. Fig. 8 shows a perspective view of the nut of the vehicle door drive mechanism according to the present application. As shown in Fig. 8, the ball nut 108 has a body 1081, and a threaded hole is provided inside the body 1081 to be connected to the lead screw 102. The threaded hole defines the axis of the body 1081. The body 1081 has a spherical surface to match with the spherical inner surface of the second part 1042 and the spherical inner surface of the ball nut socket 107.
[0041] The spherical surface of the body 1081 is further provided with a plurality of recessed portions 1082. The plurality of recessed portions 1082 may be arranged regularly substantially, for example, they may be arranged in m rows and n columns in an m × n form. For example, the recessed portions shown in Fig. 8 are arranged in 8 rows and 2 columns. In Fig. 8, 4 rows and 2 columns of recessed portions can be viewed, and other 4 rows and 2 columns of recessed portions are provided on the other side. The recessed portions 1082 can store a lubricant, thereby alleviating the wear between the outer surface of the ball nut, and the spherical inner surface of the second part 1042 and the spherical inner surface of the ball nut socket 107.
[0042] The body 1081 further has two planes parallel to each other and parallel to the axis of the body 1081. A protrusion 1083 is provided on each of the two planes. As shown in Fig. 7, after assembly, the protrusion 1083 is located between two limit portions inside the second part 1042 of the first rotating component 104, and the limit portions extend in the axial direction of the first rotating component. The protrusion 1083 is generally rhombic, with its longer diagonal parallel to the axis of the body 1081, viewed in a direction perpendicular to the plane on which it is located. Preferably, the surface of the protrusion 1083, viewed in the direction perpendicular to the plane on which it is located, and the spherical surface portion of the body 1081 are on the same sphere. Thus, during operation of the vehicle door drive mechanism, the ball nut 108 rotates in the rotational direction of the first rotating component 104 under the action between the protrusion 1083 and the two limit portions. However, the ball nut 108 can oscillate to a certain extent relative to the first rotating component 104 as the lead screw 102 oscillates along its own axis, causing the axis of the ball nut 108 to form a certain angle with the first rotating component 104.
[0043] Fig. 9 shows a perspective view of a ball nut socket and the nut of the vehicle door drive mechanism according to the present application. As shown in Fig. 9, the cylindrical adjustment device 106 is provided with recesses for avoiding the two limit portions and the protrusions 1083.
[0044] The foregoing descriptions are only exemplary implementations related to the spirit and principle of the present application. It can be understood by those skilled in the art that various changes can be made to the described examples without departing from the spirit and principles, and these changes and various equivalents are envisioned by the inventor and fall within the scope defined by the claims of the present application.
Claims
1.A vehicle door drive mechanism, comprising:a transmission mechanism, comprising a lead screw, a first rotating component and a ball nut, wherein the ball nut is arranged inside the first rotating component and can rotate with the first rotating component, the screw being threadedly engaged with the ball nut, and one end of the lead screw being connected to the vehicle door;a power source, wherein the power source outputs power to the transmission mechanism;characterized in that,the first rotating component is a hollow integral piece, and has a first part, a second part and a third part arranged in sequence along its axial direction, the first part being supported by a first bearing, the third part being supported by a second bearing, and the second part having an external toothed portion on its radial outside, and the external toothed portion receiving power from the power source.2.The vehicle door drive mechanism according to claim 1, characterized in that,the second part has a spherical surface on its radial inner side engaged with the outer surface of the ball nut, and the area of the spherical surface of the second part is less than half of the area of the outer surface of the ball nut.3.The vehicle door drive mechanism according to claim 2, characterized in that,a ball nut socket is provided inside the first rotating component, the ball nut socket is engaged with the outer surface of the ball nut, and the spherical inner surface of the ball nut socket is arranged opposite to the spherical surface of the second part.4.The vehicle door drive mechanism according to claim 3, characterized in that,an adjustment device is provided inside the first rotating component, and the adjustment device is arranged adjacent to the ball nut socket and is used to adjust the clearance between the ball nut socket and the ball nut.5.The vehicle door drive mechanism according to claim 4, characterized in that,the adjustment device has an external threaded portion and is threadedly engaged with the inner surface of the first rotating component.6.The vehicle door drive mechanism according to claim 5, characterized in that,the adjustment device has a welding portion, and the adjustment device and the inner surface of the first rotating component are connected by laser welding after being adjusted in place.7.The vehicle door drive mechanism according to any one of claims 1-6, characterized in that,the power source is a motor, and the motor is engaged with the external toothed portion through a worm.8.The vehicle door drive mechanism according to any one of claims 1 to 6, characterized in that,the outer surface of the ball nut is provided with a plurality of recessed portions.9.The vehicle door drive mechanism according to any one of claims 1 to 6, characterized in that,the ball nut has two planes parallel to each other and parallel to the axis of the internal threaded hole of the ball nut, and a rhombus-shaped protrusion viewed in a direction perpendicular to the plane is respectively provided on each plane, and a limit portion abutting against the protrusion on each side is respectively provided in the radial inside of the first rotating component.10.The vehicle door drive mechanism according to claim 9, characterized in that,the surface of the protrusion viewed in a direction perpendicular to the plane on which the protrusion is located and the spherical surface portion of the ball nut are on the same sphere.