Gear box structure of adaptive double-screw long slide rail

Abstract

The utility model belongs to gear box field provides a kind of gear box structure of adaptable double screw rod long slide rail, comprising: shell, be equipped with parallel and interval first screw rod and second screw rod, the external thread rotation direction of first screw rod and second screw rod is opposite;Driving worm and the first driven worm wheel, second driven worm wheel being engaged with the driving worm, are all arranged in the shell, and the first driven worm wheel and the second driven worm wheel are respectively equipped with first threaded hole and second threaded hole.Compared with prior art, the utility model has the advantages that through the transmission structure of sealing element cooperation double worm wheel, double screw rod, the strength of engagement structure is guaranteed, and the transmission efficiency is improved;Meanwhile, sealing element is used to cooperate the oil sealing washer on the screw rod and the shell side wall to form independent oil storage chamber, so that the lubricating grease is effectively retained in the screw rod movement area, the friction and abrasion between the screw rod and worm wheel are significantly reduced, the service life is prolonged, and the transmission noise is effectively inhibited.

Description

Technical Field

[0001] This utility model belongs to the field of gearboxes, specifically relating to a gearbox structure that can be adapted to a double lead screw long slide rail. Background Technology

[0002] With the increasing demand for intelligent and comfortable vehicles, electrically adjustable seats have become a standard feature in mid-to-high-end models. Among them, the seat horizontal slide rail, as the core actuator, directly affects user experience and driving safety in terms of its driving and locking performance.

[0003] Currently, most mainstream electric long sliding rails on the market adopt a single lead screw drive structure. This means that a worm gear reducer drives a lead screw, which in turn moves the seat along the rail and achieves mechanical locking. However, the single lead screw solution has significant limitations: to meet the high locking strength required by regulations (usually above 60kN), a large-diameter, large-lead lead screw (such as the Tr14 specification) must be used, resulting in an increase in the rail cross-sectional size and overall weight, which is not conducive to the lightweight design of the vehicle. At the same time, single-point drive is prone to uneven force distribution, off-center loading, or even jamming under long-stroke conditions, affecting the smoothness and durability of operation. On the other hand, the existing gearbox structure is relatively simple and lacks an oil reservoir design. This causes the lead screw to wear faster due to insufficient lubrication during long-term operation, producing abnormal noise or even functional failure. In addition, the compact space inside the gearbox makes it impossible to accommodate an oil reservoir structure within the limited space, ultimately affecting the service life of the overall structure. Utility Model Content

[0004] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a gearbox structure that is simple in structure, has good stability, ensures overall strength, and meets lubrication requirements, and is compatible with double lead screw long slide rails.

[0005] The objective of this utility model can be achieved by addressing the following technical problem: proposing a gearbox structure that can be adapted to a double lead screw long slide rail, comprising: a housing, and a first lead screw and a second lead screw arranged in parallel and spaced apart, wherein the external threads on the first lead screw and the second lead screw have opposite directions;

[0006] The driving worm and a first driven worm wheel and a second driven worm wheel, both meshing with the driving worm, are both disposed within the housing. The first driven worm wheel and the second driven worm wheel are respectively provided with a first threaded hole and a second threaded hole. The threads of the first threaded hole and the second threaded hole have opposite directions. The first threaded hole is sleeved on the first lead screw and threadedly engaged with the first lead screw; the second threaded hole is sleeved on the second lead screw and threadedly engaged with the second lead screw; the driving worm is located between the first driven worm wheel and the second driven worm wheel.

[0007] The sealing element and the oil sealing gasket are provided. The ends of the first driven worm gear and the second driven worm gear are both connected to the sealing element. The oil sealing gasket is sleeved on the first lead screw or the second lead screw and connected to the side wall of the housing to form an oil storage chamber between the oil sealing gasket and the sealing element. The first lead screw and the second lead screw both pass through the corresponding oil storage chamber.

[0008] In the aforementioned gearbox structure adaptable to a double lead screw long slide rail, the sealing element is a plastic bushing, and the end circumferences of the first driven worm gear and the second driven worm gear are both formed with diamond knurling. The plastic bushing is fitted and covers the diamond knurling by a tangential injection molding process.

[0009] In the aforementioned gearbox structure adaptable to a double lead screw long slide rail, the sealing element includes a metal washer and a plastic bushing, which are sequentially connected to the ends of the first driven worm gear or the second driven worm gear.

[0010] In the aforementioned gearbox structure that can be adapted to a double lead screw long slide rail, an oil inlet is provided on the housing, and the plastic bushing and the oil sealing gasket are spaced apart and together with the housing form an oil storage chamber that communicates with the oil inlet.

[0011] In the aforementioned gearbox structure adaptable to a double lead screw long slide rail, the plastic bushing forms an extension plate with an oil inlet along its axial direction. The extension plate is connected to the oil sealing gasket, and the extension plate, the oil sealing gasket, and the first driven worm gear or the second driven worm gear together form an oil storage chamber that communicates with the oil inlet.

[0012] In the aforementioned gearbox structure adaptable to a double lead screw long slide rail, when the first driven worm gear is normally meshed with the first lead screw, or when the second driven worm gear is normally meshed with the second lead screw, the plastic bushing does not contact the external thread of the first lead screw or the second lead screw.

[0013] In the gearbox structure adapted to a double lead screw long slide rail described above, the housing is provided with a first receiving cavity and a second receiving cavity, and the first driven worm gear and the second driven worm gear are respectively installed in the first receiving cavity and the second receiving cavity;

[0014] The width of the first receiving cavity along the radial direction of the first driven worm wheel is greater than the width of the second receiving cavity along the radial direction of the second driven worm wheel; or the width of the first receiving cavity along the radial direction of the first driven worm wheel is less than the width of the second receiving cavity along the radial direction of the second driven worm wheel.

[0015] In the aforementioned gearbox structure adaptable to a double lead screw long slide rail, both the first driven worm gear and the second driven worm gear are made of metal, while the driving worm is made of plastic.

[0016] In the gearbox structure adapted to a double lead screw long slide rail described above, when the plastic bushing is in active engagement with the first lead screw or the second lead screw, there is no contact between the first driven worm gear and the first lead screw, or between the second driven worm gear and the second lead screw.

[0017] When the plastic bushing wears or the external load increases to a preset value, the first driven worm gear meshes with the first lead screw, or the second driven worm gear meshes with the second lead screw.

[0018] In the aforementioned gearbox structure that can be adapted to a double lead screw long slide rail, the first driven worm gear and the second driven worm gear rotate in opposite directions.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The gearbox structure of this utility model that can be adapted to a double lead screw long slide rail uses a sealing element in conjunction with the transmission structure of double worm gear and double lead screw to ensure the strength of the meshing structure and improve the transmission efficiency. At the same time, the sealing element, together with the oil sealing gasket sleeved on the lead screw and the side wall of the housing, forms an independent oil storage chamber, so that the lubricating grease is effectively retained in the movement area of ​​the lead screw, which significantly reduces the friction and wear between the lead screw and the worm gear, extends the service life, and effectively suppresses transmission noise.

[0021] (2) In this solution, the plastic bushing is used as a functional component to mesh with the lead screw, while the metal worm wheel is used as a strength component and does not mesh. When the strength requirement is met, the plastic bushing fails first and then the metal worm wheel plays a strength role. This ensures the strength of the worm wheel and reduces friction loss, effectively improving the transmission efficiency.

[0022] (3) The diamond knurling provides a large contact surface area and mechanical interlocking force. Combined with the tangential injection molding process, it makes the plastic bushing and the metal worm gear extremely strong, which simplifies the assembly process and enhances the adaptability and reliability of the product. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this application;

[0024] Figure 2 This is a schematic diagram of the installation structure of the driving worm, the first driven worm wheel, and the second driven worm wheel within the housing;

[0025] Figure 3 This is an exploded view of the area between the plastic bushing and the driven worm gear.

[0026] Figure 4 yes Figure 1 Exploded view after removing the first / second lead screw;

[0027] Figure 5 yes Figure 1 A schematic diagram of the cross-section at point AA;

[0028] Figure 6 This is a schematic diagram of the structure when the oil inlet is located on the casing;

[0029] Figure 7 yes Figure 6 A schematic diagram of the cross-section at point BB;

[0030] Figure 8 This is a schematic diagram of the structure of the first and second receiving cavities.

[0031] In the diagram, 1 represents the first lead screw;

[0032] 2. Second lead screw;

[0033] 3. Housing; 30. Upper housing; 31. Lower housing; 310. First receiving cavity; 311. Second receiving cavity; 32. Driving worm gear; 320. Slot; 33. First driven worm wheel; 330. First threaded hole; 34. Second driven worm wheel; 340. Second threaded hole; 341. Diamond knurling; 35. Seal; 350. Plastic bushing; 350a. Extension plate; 351. Metal washer; 36. Oil sealing washer; 360. Oil storage chamber; 37. Oil inlet. Detailed Implementation

[0034] 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.

[0035] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention 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 indication will also change accordingly.

[0036] Example 1:

[0037] like Figures 1 to 8As shown, this utility model discloses a gearbox structure adaptable to a double lead screw long slide rail, comprising: a housing 3, with a first lead screw 1 and a second lead screw 2 arranged parallel and spaced apart, the external threads on the first lead screw 1 and the second lead screw 2 having opposite directions of rotation; a driving worm gear 32 and a first driven worm wheel 33 and a second driven worm wheel 34, both meshing with the driving worm gear 32, both disposed within the housing 3; the first driven worm wheel 33 and the second driven worm wheel 34 are respectively provided with a first threaded hole 330 and a second threaded hole 340, the threads of the first threaded hole 330 and the second threaded hole 340 having opposite directions of rotation, the first threaded hole 330 being sleeved on the first lead screw 1. The first lead screw 1 is threadedly engaged with the second lead screw 2; the second threaded hole 340 is fitted onto the second lead screw 2 and threadedly engaged with the second lead screw 2; the driving worm gear 32 is located between the first driven worm wheel 33 and the second driven worm wheel 34; the sealing element 35 and the oil sealing gasket 36 are provided, and the ends of the first driven worm wheel 33 and the second driven worm wheel 34 are connected to the sealing element 35. The oil sealing gasket 36 is fitted onto the first lead screw 1 or the second lead screw 2 and connected to the side wall of the housing 3, so as to form an oil storage chamber 360 between the oil sealing gasket 36 and the sealing element 35. The first lead screw 1 and the second lead screw 2 both pass through the corresponding oil storage chamber 360.

[0038] During operation, power (such as a motor) is input from the driving worm gear 32. The rotating driving worm gear 32 simultaneously meshes with the first driven worm wheel 33 and the second driven worm wheel 34 located on both sides of it. Since the driving worm gear 32 is located between the two worm wheels, its rotation will drive the first driven worm wheel 33 and the second driven worm wheel 34 to rotate synchronously and in opposite directions (i.e., one rotates counterclockwise and the other rotates clockwise). The entire gearbox structure (except for the first lead screw 1 and the second lead screw 2) slides along the axis of the first lead screw 1 and the second lead screw 2. Since the external threads of the first lead screw 1 and the second lead screw 2 have opposite directions, and correspondingly, the internal threads of the first threaded hole 330 on the first driven worm wheel 33 and the second threaded hole 340 on the second driven worm wheel 34 have opposite directions, the first driven worm wheel 33 and the second driven worm wheel 34 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, ultimately realizing the motion transmission and locking functions. This embodiment achieves high locking strength by utilizing the synergistic effect of a single worm gear, double worm wheels, and double lead screws (i.e., ensuring the meshing structure is maintained only in the strength section (i.e., the transmission meshing section), thus improving overall strength and transmission efficiency). This ensures the stability of the structure during operation, and the first lead screw 1 and the second lead screw 2 are not easily deformed or bent. Furthermore, this embodiment has a seal 35 installed at the end of each driven worm wheel, which, together with an oil sealing washer 36, is fitted onto the lead screw and fixed to the side wall of the housing 3. This allows the seal 35 and the oil sealing washer 36 to create an oil storage port (i.e., an oil storage chamber 360) within a limited space, ensuring the lubrication needs of the worm wheels during operation. During assembly, the injected lubricating grease is confined within this oil storage chamber 360, ensuring that the first / second worm wheels and the first / second lead screw 2 are always in a lubricated environment during meshing transmission. This provides continuous and sufficient lubrication, and the grease is less likely to leak, reducing wear on the friction pairs, extending service life, and effectively suppressing transmission noise.

[0039] The sealing element 35 is a plastic bushing 350. The end circumferences of the first driven worm gear 33 and the second driven worm gear 34 are both formed with diamond knurling 341. The plastic bushing 350 is fitted and covered on the diamond knurling 341 by a tangential injection molding process.

[0040] like Figure 2 and Figure 3As shown, diamond-shaped knurling 341 (i.e., a cross-grid texture) is pre-machined on the outer circumferential surface of the ends of the first driven worm gear 33 and the second driven worm gear 34 to form a mechanical interlocking surface with a high coefficient of friction. Combined with the tangential injection molding design of the plastic bushing 350 (i.e., the two curved surfaces smoothly transition in a tangential manner), the plastic bushing 350 is tightly wrapped in the knurled area to form a plastic bushing 350 seal 35 integrated with the end of the worm gear. Its inner wall is completely embedded in the groove of the diamond knurling 341, so that the plastic bushing 350 forms a mechanical interlocking structure after injection molding. This eliminates the traditional assembly operation process, greatly enhances the bonding strength between the two, and avoids loosening, falling off, or rotational misalignment that may occur during vibration, temperature change, or long-term operation in traditional press-fitting or bonding methods.

[0041] The seal 35 includes a metal washer 351 and a plastic bushing 350, which are sequentially connected to the ends of the first driven worm gear 33 or the second driven worm gear 34.

[0042] like Figure 2 and Figure 4 As shown, the seal 35 in this embodiment can also adopt a composite sealing structure of metal gasket 351 and plastic bushing 350, which takes into account both mechanical strength and sealing performance: metal gasket 351 provides structural support and pressure resistance, while plastic bushing 350 provides good sealing and wear resistance. This combined structure can adapt to the use requirements of higher loads or harsher working conditions, further improving the stability and reliability of the gearbox in complex environments.

[0043] The housing 3 has an oil inlet 37. The plastic bushing 350 and the oil sealing gasket 36 are spaced apart and together with the housing 3 form an oil storage chamber 360 that is connected to the oil inlet 37.

[0044] like Figure 6 and Figure 7 As shown, in this embodiment, an oil inlet 37 is directly opened on the housing 3. Through the spaced arrangement of plastic bushings 350 and oil sealing gaskets 36, together with the cavity inside the housing 3, an oil storage chamber 360 is formed that communicates with the oil inlet 37. This allows users to perform convenient lubrication and maintenance without disassembling the gearbox, ensuring that the transmission pair is in a good lubrication state for a long time, effectively avoiding wear or jamming caused by dry friction, and improving the continuity and safety of equipment operation.

[0045] When the first driven worm gear 33 is normally engaged with the first lead screw 1, or when the second driven worm gear 34 is normally engaged with the second lead screw 2, the plastic bushing 350 does not contact the external thread of the first lead screw 1 or the second lead screw 2.

[0046] In this embodiment, stepped holes are provided in the first driven worm gear 33 and the second driven worm gear 34, such as... Figure 5As shown, section D1 is the meshing section (i.e., the first / second threaded hole 340), and sections D2 on both sides are non-meshing sections. This means that while ensuring the overall meshing strength, the integrated first / second driven worm gear 34 reduces worm gear friction loss and improves transmission efficiency by meshing in the middle section and not meshing on both sides.

[0047] When the plastic bushing 350 is engaged with the first lead screw 1 or the second lead screw 2, there is no contact between the first driven worm gear 33 and the first lead screw 1, or between the second driven worm gear 34 and the second lead screw 2. When the plastic bushing 350 is worn or the external load increases to a preset value, the first driven worm gear 33 engages with the first lead screw 1, or the second driven worm gear 34 engages with the second lead screw 2.

[0048] like Figure 6 and Figure 7 As shown, this embodiment can also employ a meshing design of worm gear / plastic bushing 350, specifically, as... Figure 7 As shown, with the plastic bushing 350 connected to the end of the first / second driven worm gear 34, the plastic bushing 350 can then function as a component to mesh with the lead screw (i.e., Figure 7 The D3 section shown is the meshing section; the metal worm gear, as a strength component, does not mesh (i.e., Figure 7 The D4 section shown is the non-meshing section. It relies on the bushings on both sides to cooperate with the first / second lead screw 2 through threaded engagement. Under the condition of strength requirement (i.e., wear of plastic bushing 350 or increase of external load), after the bushing fails first, the first / second driven worm gear 34 can play a strength role, thereby ensuring the reliability and stability of the overall transmission. This structure can also ensure the strength of the first / second driven worm gear 34 while reducing friction loss, thereby improving transmission efficiency and service life.

[0049] In this embodiment, the housing 3 is provided with a first receiving cavity 310 and a second receiving cavity 311. For ease of assembly, the housing 3 includes an upper housing 30 and a lower housing 31, which are detachably fixed together by bolts. A first driven worm gear 33 and a second driven worm gear 34 are respectively installed in the first receiving cavity 310 and the second receiving cavity 311. Wherein, as... Figure 8As shown, the width of the first receiving cavity 310 along the radial direction of the first driven worm wheel 33 is greater than the width of the second receiving cavity 311 along the radial direction of the second driven worm wheel 34; or the width of the first receiving cavity 310 along the radial direction of the first driven worm wheel 33 is less than the width of the second receiving cavity 311 along the radial direction of the second driven worm wheel 34. In other words, the distance (L1) between the center line of the first receiving cavity 310 and the center line of the lower housing 31 is greater than the distance (L2) between the center line of the second receiving cavity 311 and the center line of the lower housing 31, or the distance (L1) between the center line of the first receiving cavity 310 and the center line of the lower housing 31 is less than the distance (L2) between the center line of the second receiving cavity 311 and the center line of the lower housing 31. In the actual assembly process, the secondary mating groove of the gearbox is larger than the primary mating groove (i.e., when L1>L2, the first receiving cavity 310 is the secondary mating groove; conversely, when L1<L2, the second receiving cavity 311 is the secondary mating groove). This design makes the driving worm 32 tightly fitted with the driven worm wheel in the primary mating groove, and loosely fitted with the driven worm wheel in the secondary mating groove. This can absorb the tolerance clearance of the secondary worm wheel (i.e., the driven worm wheel in the secondary mating groove) during assembly / operation, ensuring that the gearbox as a whole will not experience jamming problems during operation.

[0050] refer to Figure 2 In the structure shown, since the first driven worm gear 33 and the second driven worm gear 34 mesh with the same driving worm 32, the first driven worm gear 33 and the second driven worm gear 34 rotate in opposite directions in this embodiment (that is, the driven worm gear and the lead screw are opposite, one turning left and the other right, to ensure that while the worm rotates in one direction, the two mechanisms move in the same direction). Furthermore, the driving worm 32 is perpendicular to the first driven worm gear 33 and the second driven worm gear 34, and one end of the driving worm 32 is provided with a slot 320 for connecting a power component. This slot 320 is a rectangular slot or a directional slot to facilitate the rotation of the motor's output shaft, which can drive the driving worm 32 to rotate and transmit torque.

[0051] Preferably, in this embodiment, the first driven worm gear 33 and the second driven worm gear 34 are both made of metal, and the driving worm 32 is made of plastic. The use of metal driven worm gears in conjunction with the lead screw ensures high strength and wear resistance; while the use of plastic material for the driving worm 32 can effectively absorb vibration, reduce noise and reduce overall weight.

[0052] Example 2:

[0053] The plastic bushing 350 forms an extension plate 350a with an oil inlet 37 along its axial direction. The extension plate 350a is connected to the oil sealing gasket 36, and the extension plate 350a, the oil sealing gasket 36, and the first driven worm gear 33 or the second driven worm gear 34 together form an oil storage chamber 360 that communicates with the oil inlet 37.

[0054] This second embodiment is a further improvement on the structure of the oil inlet 37 in the first embodiment above. Specifically, as follows: Figure 1 and Figure 5 As shown, since the upper housing 30 in the housing 3 can be quickly removed from the lower housing 31 by bolts, in this embodiment, the plastic bushing 350 is directly connected to the side wall of the housing 3 by an integrally formed extension plate 350a in conjunction with the oil sealing gasket 36. This allows the oil sealing gasket 36, the extension plate 350a, and the plastic bushing 350 to form the required oil storage chamber 360. This design does not require the housing 3 to cooperate, and the oil storage port can be made in a limited space. In actual use, after the user removes the upper housing 30, the lubricating grease can be injected into the formed oil chamber through the oil injection port 37, so that the lubricating grease can directly act on the meshing area of ​​the lead screw and worm gear, improving the lubrication efficiency. At the same time, the structure is compact, which is conducive to the miniaturization and lightweight design of the gearbox.

[0055] It should be noted that in this invention, 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 invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" 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 elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If 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 the present invention.

[0057] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A gearbox structure adaptable to a double lead screw long slide rail, characterized in that, include: The housing is equipped with a parallel and spaced first lead screw and a second lead screw, the external threads on the first lead screw and the second lead screw having opposite directions of rotation; The driving worm and a first driven worm wheel and a second driven worm wheel, both meshing with the driving worm, are both disposed within the housing. The first driven worm wheel and the second driven worm wheel are respectively provided with a first threaded hole and a second threaded hole. The threads of the first threaded hole and the second threaded hole have opposite directions. The first threaded hole is sleeved on the first lead screw and threadedly engaged with the first lead screw; the second threaded hole is sleeved on the second lead screw and threadedly engaged with the second lead screw; the driving worm is located between the first driven worm wheel and the second driven worm wheel. The sealing element and the oil sealing gasket are provided. The ends of the first driven worm gear and the second driven worm gear are both connected to the sealing element. The oil sealing gasket is sleeved on the first lead screw or the second lead screw and connected to the side wall of the housing to form an oil storage chamber between the oil sealing gasket and the sealing element. The first lead screw and the second lead screw both pass through the corresponding oil storage chamber.

2. The gearbox structure adaptable to a double lead screw long slide rail according to claim 1, characterized in that, The sealing element is a plastic bushing. Both the end circumferences of the first driven worm gear and the second driven worm gear are formed with diamond-shaped knurling. The plastic bushing is fitted and covers the diamond-shaped knurling by a tangential injection molding process.

3. The gearbox structure adaptable to a double lead screw long slide rail according to claim 1, characterized in that, The sealing element includes a metal washer and a plastic bushing, which are sequentially connected to the end of the first driven worm gear or the second driven worm gear.

4. A gearbox structure adaptable to a double lead screw long slide rail according to claim 2 or 3, characterized in that, The housing has an oil inlet, and the plastic bushing and the oil sealing gasket are spaced apart and together with the housing form an oil storage chamber that communicates with the oil inlet.

5. A gearbox structure adaptable to a double lead screw long slide rail according to claim 2 or 3, characterized in that, The plastic bushing forms an extension plate with an oil inlet along its axial direction. The extension plate is connected to the oil sealing gasket, and the extension plate, the oil sealing gasket, and the first driven worm gear or the second driven worm gear together form an oil storage chamber that communicates with the oil inlet.

6. A gearbox structure adaptable to a double lead screw long slide rail according to claim 2, characterized in that, When the first driven worm gear is normally engaged with the first lead screw, or when the second driven worm gear is normally engaged with the second lead screw, the plastic bushing does not contact the external thread of the first lead screw or the second lead screw.

7. A gearbox structure adaptable to a double lead screw long slide rail according to claim 1, characterized in that, The housing is provided with a first receiving cavity and a second receiving cavity, and the first driven worm gear and the second driven worm gear are respectively installed in the first receiving cavity and the second receiving cavity; The width of the first receiving cavity along the radial direction of the first driven worm wheel is greater than the width of the second receiving cavity along the radial direction of the second driven worm wheel; or the width of the first receiving cavity along the radial direction of the first driven worm wheel is less than the width of the second receiving cavity along the radial direction of the second driven worm wheel.

8. A gearbox structure adaptable to a double lead screw long slide rail according to claim 1, characterized in that, Both the first driven worm gear and the second driven worm gear are made of metal, while the driving worm is made of plastic.

9. A gearbox structure adaptable to a double lead screw long slide rail according to claim 2, characterized in that, When the plastic bushing is engaged with the first lead screw or the second lead screw, there is no contact between the first driven worm gear and the first lead screw, or between the second driven worm gear and the second lead screw. When the plastic bushing wears or the external load increases to a preset value, the first driven worm gear meshes with the first lead screw, or the second driven worm gear meshes with the second lead screw.

10. A gearbox structure adaptable to a double lead screw long slide rail according to claim 1, characterized in that, The first driven worm gear and the second driven worm gear rotate in opposite directions.

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