Driving device for electric sliding rail and automobile seat

Abstract

The utility model relates to the technical field of electric sliding rails, and discloses a driving device for an electric sliding rail and an automobile seat, the driving device comprises a first screw rod and a second screw rod, the external threads of the first screw rod and the second screw rod are opposite in screwing direction; the reduction gearbox module comprises a box body, a driving worm, a first driven worm gear and a second driven worm gear; the first driven worm gear and the second driven worm gear are provided with a first threaded hole and a second threaded hole respectively, the thread turning direction of the first threaded hole is opposite to that of the second threaded hole, the first threaded hole is arranged on the first lead screw in a sleeving mode, and the second threaded hole is arranged on the second lead screw in a sleeving mode. The driving worm is located between the first driven worm gear and the second driven worm gear. Power is input from the driving worm, the driving worm gear rotates to drive the first driven worm gear and the second driven worm gear to synchronously and reversely rotate, and the reduction gearbox module slides along the first lead screw and the second lead screw. The driving device has the advantages of being high in strength, good in stability, light in weight and small in rail type section.

Description

A drive mechanism for electric slide rails and an automobile seat Technical Field

[0001] This utility model relates to the field of electric slide rail technology, and in particular to a drive device for electric slide rails and an automobile seat. Background Technology

[0002] Electric sliding rails are typically used at the bottom of car seats. They can drive the car seat to move back and forth inside the car to adjust the seat's position.

[0003] Existing electric sliding rails for car seats typically use a lead screw structure for transmission and locking. The motor drive is transmitted to the lead screw through a single-stage worm gear reducer to achieve seat fore-and-aft adjustment. A Tr8 lead screw is generally sufficient for most needs. However, with the development of automobiles, car seats are increasingly offering large-travel adjustments, and some rear seats integrate the seat belt into the seat (i.e., ABTS seats). This places increasingly higher demands on the strength of the electric sliding rails.

[0004] To meet the demands of extended electric adjustment for car seats, the application of electric long slide rails has gradually increased. Early electric long slide rails used a gear and rack, cable-driven stepped locking system to address the issue of extended adjustment. However, the locking strength of stepped locking during adjustment posed safety hazards. To ensure both transmission and locking, some electric long slide rails adopted the traditional lead screw structure. However, to meet the strength requirements of ABTS seats, the lead screw specifications were too large, generally needing to reach Tr12. This resulted in a large gearbox, high Z-axis height, and large rail cross-section. Consequently, a dual-lead screw drive solution emerged, using two lead screws arranged side-by-side, rotating synchronously to drive the gearbox. This structure is compact and small in size. However, in existing dual-lead screw drive long slide rails, where the two long lead screws act as the driving components to move the gearbox, insufficient strength and unstable fixation are prone to problems during use. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the existing technology, the technical problem to be solved by this utility model is to provide a drive device for electric slide rails and a car seat that has high strength, good stability, light weight and small rail cross-section.

[0006] The technical solution adopted by this utility model to solve its technical problem is to propose a driving device for electric slide rails, comprising:

[0007] The first lead screw and the second lead screw are parallel and spaced apart, and the external threads on the first lead screw and the second lead screw have opposite directions;

[0008] The gearbox module, mounted on the first and second lead screws, includes a housing, a driving worm gear, and a first and second driven worm gear, both meshing with the driving worm gear; wherein...

[0009] Both the first driven worm gear and the second driven worm gear are disposed in the housing and are respectively provided with a first threaded hole and a second threaded hole. The first threaded hole and the second threaded hole have opposite thread directions. The first threaded hole is sleeved on the first lead screw and is threadedly engaged with the first lead screw; the second threaded hole is sleeved on the second lead screw and is threadedly engaged with the second lead screw.

[0010] The driving worm gear is rotatably disposed on the housing and is located between the first driven worm gear and the second driven worm gear;

[0011] Power is input from the driving worm gear, and the rotation of the driving worm gear drives the first driven worm gear and the second driven worm gear to rotate synchronously and in opposite directions, and the gearbox module slides along the first lead screw and the second lead screw.

[0012] Furthermore, the first driven worm gear and the second driven worm gear have the same direction of tooth rotation.

[0013] Furthermore, the driving worm gear is made of metal, the first driven worm wheel and the second driven worm wheel are both made of plastic, and the first lead screw and the second lead screw are both made of metal.

[0014] Furthermore, one end of the first driven worm gear is provided with a first metal nut that is integral with or separate from it, and the internal thread direction of the first metal nut is the same as the internal thread direction of the first threaded hole.

[0015] One end of the second driven worm gear is provided with a second metal nut that is integral with or separate from it, and the internal thread of the second metal nut is in the same direction as the internal thread of the second threaded hole.

[0016] Furthermore, when the first driven worm gear is normally engaged with the first lead screw, the internal thread of the first metal nut does not contact the external thread of the first lead screw; when the second driven worm gear is normally engaged with the second lead screw, the internal thread of the second metal nut does not contact the external thread of the second lead screw.

[0017] Furthermore, when the first driven worm gear wears down or the external load increases to a preset value, the first metal nut can engage with the first lead screw;

[0018] When the second driven worm gear wears out or the external load increases to a preset value, the second metal nut can engage with the second lead screw.

[0019] Furthermore, both the first driven worm gear and the second driven worm gear have rubber washers at one end;

[0020] When the first driven worm gear and the second driven worm gear are installed in the housing, they can respectively compress the rubber gaskets on themselves.

[0021] Furthermore, the housing is provided with a first mounting cavity and a second mounting cavity, and the first driven worm gear and the second driven worm gear are respectively installed in the first mounting cavity and the second mounting cavity;

[0022] The length of the first mounting cavity along the axial direction of the first driven worm gear is greater than the length of the second mounting cavity along the axial direction of the second driven worm gear; or, the length of the first mounting cavity along the axial direction of the first driven worm gear is less than the length of the second mounting cavity along the axial direction of the second driven worm gear.

[0023] Furthermore, the active worm gear is arranged perpendicular to the first driven worm wheel and the second driven worm wheel, and one end of the active worm gear is provided with a slot for connecting a power component;

[0024] Both ends of the driving worm gear, both ends of the first driven worm wheel, and both ends of the second driven worm wheel are provided with bushings, which are fitted to the housing through the bushings.

[0025] This utility model also proposes a car seat, wherein the bottom of the car seat is provided with an electric slide rail, and the aforementioned drive device is configured on the electric slide rail.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] In this invention, the driving worm gear in the gearbox module is positioned between the first driven worm wheel and the second driven worm wheel. Through the engagement of the driving worm gear, the first and second driven worm wheels rotate simultaneously in opposite directions. The thread direction of the first threaded hole of the first driven worm wheel is opposite to that of the second threaded hole of the second driven worm wheel, and the external threads of the first and second lead screws are also opposite. Therefore, the first and second driven worm wheels move in the same direction along the first and second lead screws, meaning the gearbox module moves in the same direction. The drive device, through the cooperation of the double lead screws and the gearbox, achieves high locking strength while occupying little Z-axis space, having a small rail cross-section, and being lightweight. Power is input from the driving worm gear, which engages and drives the first and second driven worm wheels, while the first and second lead screws do not need to move, effectively improving the working stability of the electric slide rail. The first and second lead screws are also less prone to deformation and bending.

[0028] In this invention, the driving worm gear is made of metal, the first driven worm wheel and the second driven worm wheel are made of plastic, and the first lead screw and the second lead screw are made of metal. This ensures that during transmission, each meshing stage is between metal and plastic, which can avoid transmission friction noise and absorb vibration.

[0029] In this invention, a first metal nut and a second metal nut are respectively provided at one end of the first driven worm gear and the second driven worm gear. Under normal circumstances, the first metal nut does not contact the first lead screw and the second metal nut does not contact the second lead screw. Only when the first driven worm gear and the second driven worm gear are worn or the external load increases, will the first metal nut engage with the first lead screw and the second metal nut engage with the second lead screw to ensure strength.

[0030] In this invention, the first mounting cavity and the second mounting cavity have unequal lengths, one being larger and the other smaller. After the gearbox is assembled, the first driven worm gear and the second driven worm gear are fitted tightly, one with a tight fit and the other with a loose fit (i.e., axially floating), to avoid jamming. Furthermore, each of the first and second driven worm gears has a rubber washer at one end. During assembly, the rubber washer can be compressed, and after assembly, it can be tightened, ensuring convenient assembly. Attached Figure Description

[0031] Figure 1 is a schematic diagram of the drive device of this utility model;

[0032] Figure 2 is a schematic diagram of the structure after removing the upper shell from Figure 1;

[0033] Figure 3 is an exploded view of the gearbox module;

[0034] Figure 4 is a schematic diagram of the gearbox module after the housing has been removed;

[0035] Figure 5 is a planar schematic diagram of Figure 4.

[0036] In the picture:

[0037] 1. First lead screw;

[0038] 2. Second lead screw;

[0039] 3. Gearbox module; 30. Housing; 30A. Upper shell; 30B. Lower shell; 301. First mounting cavity; 302. Second mounting cavity; 31. Driving worm gear; 310. Slot; 32. First driven worm wheel; 320. First threaded hole; 321. First metal nut; 33. Second driven worm wheel; 330. Second threaded hole; 331. Second metal nut; 34. Rubber washer; 35. Bushing; 36. Metal washer. Detailed Implementation

[0040] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0041] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0042] Furthermore, in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0043] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0044] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0045] As shown in Figures 1-5, a drive device for an electric slide rail according to this embodiment mainly includes: a first lead screw 1, a second lead screw 2, and a reduction gearbox module 3. The reduction gearbox module 3 mainly includes: a housing 30, a driving worm gear 31, a first driven worm wheel 32, a second driven worm wheel 33, a rubber washer 34, a bushing 35, and a metal washer 36. The first lead screw 1 and the second lead screw 2 are arranged parallel and spaced apart, and the external threads on the first lead screw 1 and the second lead screw 2 have opposite directions of rotation. The gearbox module 3 is mounted on the first lead screw 1 and the second lead screw 2, and includes a housing 30, a driving worm gear 31, and a first driven worm wheel 32 and a second driven worm wheel 33, both meshing with the driving worm gear 31. The first driven worm wheel 32 and the second driven worm wheel 33 are both disposed within the housing 30 and are respectively provided with a first threaded hole 320 and a second threaded hole 330. The threads of the first threaded hole 320 and the second threaded hole 330 have opposite directions. The first threaded hole 320 is fitted onto the first lead screw 1 and threadedly engages with it. The second threaded hole 330... The hole 330 is fitted onto the second lead screw 2 and threadedly engages with it. The driving worm gear 31 is rotatably mounted on the housing 30 and positioned between the first driven worm wheel 32 and the second driven worm wheel 33, i.e., the first driven worm wheel 32 and the second driven worm wheel 33 are located on opposite sides of the driving worm gear 31. During use, power is input from the driving worm gear 31, and the rotation of the driving worm wheel drives the first driven worm wheel 32 and the second driven worm wheel 33 to rotate synchronously and in opposite directions. The reduction gearbox module 3 slides along the first lead screw 1 and the second lead screw 2. The motion transmission and locking functions are achieved through the engagement of the first threaded hole 320 of the first driven worm wheel 32 and the second threaded hole 330 of the second driven worm wheel 33 with the first lead screw 1 and the second lead screw 2, respectively.

[0046] When an electric slide rail is applied to a car seat, the car seat is mounted on the electric slide rail, which drives the car seat to move back and forth inside the vehicle. The electric slide rail is equipped with the drive device of this embodiment, such as a motor, which drives the driving worm gear 31 to rotate. The driving worm gear 31 simultaneously meshes with the first driven worm wheel 32 and the second driven worm wheel 33, causing the first driven worm wheel 32 and the second driven worm wheel 33 to rotate synchronously in opposite directions, i.e., one rotates counterclockwise and the other clockwise. Since the external threads of the first lead screw 1 and the second lead screw 2 have opposite directions of rotation, and correspondingly, the internal threads of the first threaded hole 320 on the first driven worm wheel 32 and the second threaded hole 330 on the second driven worm wheel 33 have opposite directions of rotation, the first driven worm wheel 32 and the second driven worm wheel 33 will move in the same direction along the first lead screw 1 and the second lead screw 2, thereby causing the car seat to move back and forth.

[0047] In this embodiment, the driving worm gear 31 in the gearbox module 3 is positioned between the first driven worm wheel 32 and the second driven worm wheel 33. The driving worm gear 31 engages and drives the first driven worm wheel 32 and the second driven worm wheel 33 to rotate simultaneously in opposite directions. The thread direction of the first threaded hole 320 of the first driven worm wheel 32 is opposite to the thread direction of the second threaded hole 330 of the second driven worm wheel 33. Furthermore, the external threads of the first lead screw 1 and the second lead screw 2 also have opposite directions. Therefore, the first driven worm wheel 32 and the second driven worm wheel 33 move in the same direction along the first lead screw 1 and the second lead screw 2, meaning the gearbox module 3 moves in the same direction. The drive device, through the cooperation of the double lead screws and the gearbox, can achieve the requirement of high locking strength, and occupies little Z-axis space, has a small rail cross-section, and is lightweight. Power is input from the driving worm gear 31, which meshes with the first driven worm wheel 32 and the second driven worm wheel 33. The first lead screw 1 and the second lead screw 2 do not need to move, which can effectively improve the working stability of the electric slide rail. The first lead screw 1 and the second lead screw 2 are not easily deformed or bent.

[0048] Since the first driven worm gear 32 and the second driven worm gear 33 mesh with the same driving worm 31, the worm gear teeth of the first driven worm gear 32 and the second driven worm gear 33 in this embodiment have the same helix direction. Furthermore, the driving worm 31 is perpendicular to the first driven worm gear 32 and the second driven worm gear 33, and one end of the driving worm 31 is provided with a slot 310 for connecting a power component. This slot 310 is a rectangular slot or a directional slot, facilitating the rotation of the motor's output shaft, which in turn drives the driving worm 31 to rotate, thus transmitting torque.

[0049] Specifically, in this embodiment, the driving worm gear 31 is made of metal, while the first driven worm wheel 32 and the second driven worm wheel 33 are both made of plastic. Therefore, the metal driving worm gear 31 meshes with the plastic first driven worm wheel 32 and the plastic second driven worm wheel 33. The first lead screw 1 and the second lead screw 2 are both made of metal. Therefore, the plastic first driven worm wheel 32 meshes with the metal first lead screw 1, and the plastic second driven worm wheel 33 meshes with the metal second lead screw 2. In actual use, ensuring that each meshing stage involves both metal and plastic avoids transmission friction noise and absorbs vibration.

[0050] More specifically, in this embodiment, one end of the first driven worm gear 32 is provided with a first metal nut 321, which is integrally or separately disposed with it. The internal thread direction of the first metal nut 321 is the same as the internal thread direction of the first threaded hole 320. One end of the second driven worm gear 33 is provided with a second metal nut 331, which is integrally or separately disposed with it. The internal thread direction of the second metal nut 331 is the same as the internal thread direction of the second threaded hole 330. Preferably, the first metal nut 321 is integrally injection molded with the first driven worm gear 32, and the second metal nut 331 is preferably integrally injection molded with the second driven worm gear 33.

[0051] In actual use, when the first driven worm gear 32 is normally engaged with the first lead screw 1, the internal thread of the first metal nut 321 does not contact the external thread of the first lead screw 1. When the second driven worm gear 33 is normally engaged with the second lead screw 2, the internal thread of the second metal nut 331 does not contact the external thread of the second lead screw 2. When the first driven worm gear 32 wears or the external load increases to a preset value, the first metal nut 321 can engage with the first lead screw 1. When the second driven worm gear 33 wears or the external load increases to a preset value, the second metal nut 331 can engage with the second lead screw 2. Specifically, this preset value can be selected according to actual needs.

[0052] In this embodiment, the internal thread profile of the first metal nut 321 is identical to that of the internal thread profile of the first threaded hole 320 of the first driven worm gear 32, except that the thread profile is thinner. Similarly, the internal thread profile of the second metal nut 331 is identical to that of the internal thread profile of the second threaded hole 330 of the second driven worm gear 33, except that the thread profile is thinner. Therefore, under normal circumstances, the first metal nut 321 does not contact the first lead screw 1, and the second metal nut 331 does not contact the second lead screw 2. Only when the first driven worm gear 32 and the second driven worm gear 33 are worn or the external load increases, will the first metal nut 321 engage with the first lead screw 1, and the second metal nut 331 engage with the second lead screw 2 to ensure strength. That is, only when higher strength is required, and the plastic tooth profiles of the first driven worm gear 32 and the second driven worm gear 33 are deformed, will the first metal nut 321 and the second metal nut 331 participate in ensuring strength.

[0053] In this embodiment, the housing 30 is provided with a first mounting cavity 301 and a second mounting cavity 302. For ease of assembly, the housing 30 includes an upper shell 30A and a lower shell 30B, which are detachably fixed together by bolts. A first driven worm gear 32 and a second driven worm gear 33 are respectively installed in the first mounting cavity 301 and the second mounting cavity 302. Specifically, the length (L1) of the first mounting cavity 301 along the axial direction of the first driven worm gear 32 is greater than the length (L2) of the second mounting cavity 302 along the axial direction of the second driven worm gear 33; or the length (L1) of the first mounting cavity 301 along the axial direction of the first driven worm gear 32 is less than the length (L2) of the second mounting cavity 302 along the axial direction of the second driven worm gear 33. In other words, the lengths of the first mounting cavity 301 and the second mounting cavity 302 are different, for example, one is 0.5 mm longer than the other. In the actual assembly process, the lengths of the first mounting cavity 301 and the second mounting cavity 302 are not equal, one is larger and the other is smaller. After the gearbox is assembled, the first driven worm gear 32 and the second driven worm gear 33 are tightly fitted and loosely fitted (i.e., axially floating) to avoid jamming.

[0054] Furthermore, a rubber washer 34 is provided at one end of both the first driven worm gear 32 and the second driven worm gear 33. When the first driven worm gear 32 and the second driven worm gear 33 are installed into the housing 30, the rubber washer 34 on each of them can be compressed. During assembly, the rubber washer 34 can be compressed, and after assembly, the rubber washer 34 can be tightened again to ensure convenient assembly. A metal washer 36 is provided on the outside of the rubber washer 34 to press the rubber washer 34 tightly. In addition, bushings 35 are provided at both ends of the driving worm 31, both ends of the first driven worm gear 32, and both ends of the second driven worm gear 33, and each is assembled to the housing 30 through the plastic bushing 35. After the bushings wear, they are easy to replace. The driving worm 31 is made of plastic or copper, and the bushings 35 at both ends of the first driven worm gear 32 and the second driven worm gear 33 are made of plastic.

[0055] During operation, the motor drives the driving worm gear 31 to rotate. The driving worm gear 31 meshes with the first driven worm wheel 32 and the second driven worm wheel 33, causing the first driven worm wheel 32 and the second driven worm wheel 33 to rotate synchronously in opposite directions. The first driven worm wheel 32 and the second driven worm wheel 33 mesh with the first lead screw 1 and the second lead screw 2 respectively, moving in the same direction along the first lead screw 1 and the second lead screw 2, thus causing the gearbox to move along the first lead screw 1 and the second lead screw 2. When the motor reverses, the gearbox moves in the opposite direction.

[0056] In this design, the drive device has high strength, good stability, and is lightweight with a small rail cross-section.

Claims

1. A drive device for an electric slide rail, characterized in that, include: The first lead screw and the second lead screw are parallel and spaced apart, and the external threads on the first lead screw and the second lead screw have opposite directions; A gearbox module, mounted on the first and second lead screws, includes a housing, a driving worm gear, and a first and second driven worm gear, both meshing with the driving worm gear. The first and second driven worm gears are both housed within the housing and have a first threaded hole and a second threaded hole, respectively. The threads of the first and second threaded holes have opposite directions. The first threaded hole is fitted onto the first lead screw and threadedly engages with it; the second threaded hole is fitted onto the second lead screw and threadedly engages with it. The driving worm gear is rotatably mounted on the housing and positioned between the first and second driven worm gears. Power is input from the driving worm gear, and its rotation drives the first and second driven worm gears to rotate synchronously and in opposite directions. The gearbox module slides along the first and second lead screws.

2. The drive device for an electric slide rail according to claim 1, characterized in that, The first driven worm gear and the second driven worm gear have the same direction of tooth rotation.

3. The drive device for an electric slide rail according to claim 1, characterized in that, The driving worm gear is made of metal, the first driven worm wheel and the second driven worm wheel are both made of plastic, and the first lead screw and the second lead screw are both made of metal.

4. The drive device for an electric slide rail according to claim 1 or 3, characterized in that, One end of the first driven worm gear is provided with a first metal nut that is integral with or separate from it, and the internal thread of the first metal nut is in the same direction as the internal thread of the first threaded hole; one end of the second driven worm gear is provided with a second metal nut that is integral with or separate from it, and the internal thread of the second metal nut is in the same direction as the internal thread of the second threaded hole.

5. The drive device for an electric slide rail according to claim 4, characterized in that, When the first driven worm gear is normally engaged with the first lead screw, the internal thread of the first metal nut does not contact the external thread of the first lead screw; when the second driven worm gear is normally engaged with the second lead screw, the internal thread of the second metal nut does not contact the external thread of the second lead screw.

6. The drive device for an electric slide rail according to claim 5, characterized in that, When the first driven worm gear wears down or the external load increases to a preset value, the first metal nut can engage with the first lead screw; when the second driven worm gear wears down or the external load increases to a preset value, the second metal nut can engage with the second lead screw.

7. The drive device for an electric slide rail according to claim 1, characterized in that, Both the first driven worm gear and the second driven worm gear have rubber washers at one end; when the first driven worm gear and the second driven worm gear are installed in the housing, the rubber washers on them can be compressed respectively.

8. The drive device for an electric slide rail according to claim 1 or 7, characterized in that, The housing is provided with a first mounting cavity and a second mounting cavity, and the first driven worm gear and the second driven worm gear are respectively installed in the first mounting cavity and the second mounting cavity; the length of the first mounting cavity along the axial direction of the first driven worm gear is greater than the length of the second mounting cavity along the axial direction of the second driven worm gear; or the length of the first mounting cavity along the axial direction of the first driven worm gear is less than the length of the second mounting cavity along the axial direction of the second driven worm gear.

9. The drive device for an electric slide rail according to claim 1, characterized in that, The driving worm is perpendicular to the first driven worm wheel and the second driven worm wheel, and one end of the driving worm is provided with a slot for connecting a power component; both ends of the driving worm, both ends of the first driven worm wheel and both ends of the second driven worm wheel are provided with bushings, and each bushing is fitted to the housing.

10. A car seat, characterized in that, The bottom of the car seat is provided with an electric slide rail, and the electric slide rail is equipped with a drive device as described in any one of claims 1-9.

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