Transmission mechanism and seat driver

Abstract

The utility model discloses a transmission mechanism and a seat driver, the transmission mechanism comprises a bevel gear set mounted on a box body, and the bevel gear set comprises an input bevel gear corresponding to an input end and an output bevel gear corresponding to an output end; the input bevel gear is suitable for being in transmission connection with a rotating device, the output bevel gear is suitable for being in threaded connection with a long screw through the center, and the input bevel gear is parallel to the output bevel gear. The seat driver comprises the transmission mechanism. The device has the beneficial effects that the input bevel gear and the output bevel gear are arranged in parallel, so that in the advancing process of the seat, the axial component force generated by meshing of the bevel gear set and the axial component force applied to the output bevel gear by a long screw rod through thread fit can be balanced; therefore, abrasion of the output end of the bevel gear set can be effectively reduced, the service life is prolonged, and the stability of the seat in the advancing process can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of automobile parts, and in particular to a transmission mechanism and a seat driver. Background Art

[0002] The horizontal driving machine (HDM) of the car seat is one of the key moving parts of the car seat position adjustment system. Commonly used car seat drivers generally include a gearbox, a lead screw and a nut assembly. A worm gear is set in the gearbox. The motor is decelerated by the gearbox and then cooperates with the lead screw through the nut assembly. Then, the linear movement of the driver along the lead screw is realized by the rotation of the nut assembly around the lead screw.

[0003] With the development of new energy vehicle technology, the adjustment range of electric seats is gradually increasing to meet the needs of users. For long-distance seat adjustment, traditional car seat horizontal actuators cannot meet the requirements of height, strength, accuracy and motion stability. Therefore, how to improve the existing seat actuator to overcome the above problems is an urgent problem to be solved by those skilled in the art. Utility Model Content

[0004] One of the purposes of the present application is to provide a transmission mechanism that can solve at least one of the defects in the above-mentioned background technology.

[0005] Another object of the present application is to provide a seat driver that can solve at least one of the defects in the above-mentioned background technology.

[0006] In order to achieve at least one of the above-mentioned purposes, the technical solution adopted in the present application is: a transmission mechanism, including a helical gear group installed on a housing, the helical gear group including an input helical gear corresponding to the input end and an output helical gear corresponding to the output end; the input helical gear is suitable for transmission connection with a rotating device, the output helical gear is suitable for threaded connection with a long screw through a center, and the input helical gear is parallel to the output helical gear.

[0007] Preferably, a rotating sleeve is integrally formed in the center of the output helical gear along the axial direction, and the rotating sleeve cooperates with the long screw rod through a threaded section arranged on the inner wall and performs self-locking.

[0008] Preferably, both ends of the rotating sleeve are mounted on the box body via sliding sleeves, and the sleeve and the box body are matched via a limiting structure so that when the output bevel gear rotates, the sleeve remains stationary relative to the box body.

[0009] Preferably, the rotating sleeve cooperates with an inner hole with a circular cross-section arranged at the center of the shaft sleeve, and the cross-sectional shape of the outer contour of the shaft sleeve is non-circular, so that the shaft sleeve cooperates with the box body to form the limiting structure.

[0010] Preferably, the inner hole of the shaft sleeve is stepped so that the shaft sleeve can respectively cooperate with the rotating sleeve and the long screw through the inner hole.

[0011] Preferably, the input bevel gear is rotatably mounted on the housing via an integrally formed third rotating shaft, a gasket is sleeved on the third rotating shaft, and the gasket is suitable for synchronously rotating with the input bevel gear via a limiting structure.

[0012] Preferably, a buckle is vertically arranged on the side of the gasket, and when the gasket is sleeved on the third rotating shaft, the buckle is suitable for extending between two adjacent teeth on the input bevel gear to form a limiting structure.

[0013] Preferably, the helical gear set also includes at least one transition helical gear parallel to the output helical gear, and the transition helical gear is meshed between the input helical gear and the output helical gear; from the input end to the output end of the helical gear set, the pitch circle diameters of the input helical gear, the transition helical gear and the output helical gear increase successively, and the axes of the input helical gear, the transition helical gear and the output helical gear are located in the same plane.

[0014] Preferably, a first rotating shaft made of metal is integrally injection-molded at the center of the transition helical gear that directly meshes with the output helical gear, and a protrusion is radially arranged on the first rotating shaft inside the transition helical gear.

[0015] A seat driver comprises the above-mentioned transmission mechanism.

[0016] Compared with the prior art, the beneficial effects of this application are:

[0017] By arranging the input helical gear and the output helical gear in parallel, the axial force component generated by the meshing of the helical gear group and the axial force component applied to the output helical gear by the long screw through threaded cooperation can be balanced during the movement of the seat, thereby effectively reducing the wear on the output end of the helical gear group to increase its service life and improving the stability of the seat during movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0019] Figure 2 It is a schematic diagram of the decomposed state of the utility model.

[0020] Figure 3 This is a schematic diagram of the internal structure of the first half box in the utility model.

[0021] Figure 4 It is a structural schematic diagram of the first gasket in the utility model.

[0022] Figure 5 It is a structural schematic diagram of the second shaft sleeve in the utility model.

[0023] Figure 6 It is a structural schematic diagram of the helical gear set in the utility model.

[0024] Figure 7 It is a schematic diagram of the front view structure of the cooperation between the helical gear set and the long screw in the utility model.

[0025] Figure 8 It is a structural schematic diagram of the output helical gear in the utility model.

[0026] Fig. 9 It is a partial structural schematic diagram of the installation of the output helical gear in the utility model.

[0027] Fig.10 It is a schematic diagram of the matching structure between the first transition bevel gear and the first rotating shaft in the utility model.

[0028] Fig.11 It is a partial structural schematic diagram of the installation of the first transition helical gear in the utility model.

[0029] Fig.12 It is a partial structural schematic diagram of the installation of the second transition helical gear in the utility model.

[0030] Fig.13 It is a schematic diagram of the matching structure of the input helical gear and the first gasket in the utility model.

[0031] Fig.14 It is a partial structural schematic diagram of the installation of the input helical gear in the utility model.

[0032] In the figure: drive shaft 01, long screw 02, housing 1, first half housing 11, second half housing 12, limiting groove 110, bevel gear set 2, rotating sleeve 20, threaded section 201, output bevel gear 21, first transition bevel gear 22, first rotating shaft 23, protrusion 231, second transition bevel gear 24, second rotating shaft 25, input bevel gear 26, third rotating shaft 27, spline groove 270, first sleeve 31, first gasket 32, groove 320, buckle 321, second gasket 33, second sleeve 34, inner hole 340, limiting portion 341, plane bearing 35. DETAILED DESCRIPTION

[0033] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0034] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present application.

[0035] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0036] The terms "including" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0037] One aspect of the present application provides a seat drive, such as Figure 1 and Figure 2As shown, it includes a long screw 02, a rotating device (not shown) and a helical gear box as a transmission mechanism. The long screw 02 can be fixedly installed on the vehicle to serve as a travel adjustment guide rail for the seat. In order to adapt to the current development of new energy technologies, the length of the long screw 02 can be designed to be more than 1m. The helical gear box is used to support the seat (not shown) and drive it to move. The two ends of the helical gear box are respectively provided with an input end and an output end. Specifically, it can be regarded as the input end is located at the upper part of the helical gear box, and the output end is located at the lower part of the helical gear box. The helical gear box can be threadedly matched with the long screw 02 through the output end at the lower part. The rotating device is installed on the upper part of the helical gear box and connected to the input end of the helical gear box; the helical gear box can move along the axis of the long screw 02 under the drive of the rotating device, thereby driving the seat connected to the helical gear box to move accordingly. When designing a helical gearbox, the extension directions of the input and output ends of the helical gearbox can be designed to be parallel, so that the axial force component generated by the helical tooth meshing during the movement of the helical gearbox can be balanced with the axial force component generated by the long screw 02 and the threaded fit of the output end of the helical gearbox.

[0038] It should be known that for the existing seat driver, such as the solution disclosed in the publication number CN112937384A, entitled "A Lengthened and Strengthened Seat Driver", the reduction box of the seat driver at least includes a worm wheel and a worm; the worm can be connected with the rotating device, and the worm wheel can be threaded with the screw, and then the worm wheel can drive the entire reduction box to move along the axial direction of the screw by rotating around the screw under the drive of the worm. It is well known to those skilled in the art that the transmission direction of the worm wheel and the worm is vertical, that is, the axial component of the force acting on the worm generated when the worm wheel and the worm are matched will be perpendicular to the axial component of the force generated by the threaded matching of the worm wheel and the screw, and the reduction box will be subjected to two vertical destabilizing forces during the process of moving, one of which is parallel to the moving direction, and the other is perpendicular to the moving direction. Then, when the reduction box reaches the set position, the above two destabilizing forces will impact the two vertical directions of the reduction box, causing the reduction box to vibrate in both mutually perpendicular directions, thereby affecting the stability of the seat adjustment. In the long run, the wear of the worm wheel and worm in the reduction box will increase, thereby reducing the service life.

[0039] In the present embodiment, a helical gearbox is directly used for speed reduction, and the extension directions of the input end and the output end of the helical gearbox are parallel to each other, that is, the input end and the output end of the helical gearbox are located in the same plane. Furthermore, when the helical gearbox moves along the long screw 02, the helical gears in the helical gearbox can generate a first axial force component in a single direction by mutual meshing, and the first axial force component is parallel to the axial direction of the long screw 02. At the same time, the threaded cooperation between the long screw 02 and the output end of the helical gearbox can generate a second axial force component parallel to the axial direction of the long screw 02. Those skilled in the art can balance the first axial force component and the second axial force component with each other through the structural design of the helical gearbox, thereby effectively reducing the shutdown impact of the helical gearbox in the direction of travel to improve the stability of seat adjustment.

[0040] In layman's terms, compared with the aforementioned prior art, this embodiment does not generate destabilizing force perpendicular to the travel direction during the movement of the helical gear box; and the destabilizing force perpendicular to the travel direction in the aforementioned prior art is reversed to be parallel to the travel direction, and then balanced with the destabilizing force generated by the original threaded fit, thereby avoiding the vibration of the helical gear box in the directions on both sides during the movement, and can also weaken the vibration of the helical gear box in the travel direction, which can effectively improve the stability of seat adjustment.

[0041] At the same time, for the aforementioned prior art, since the input and output ends of the reducer are vertical, the rotating device used to drive the reducer to move will be installed on the side of the reducer that deviates from the moving direction, which will cause the entire mass distribution of the reducer to be uneven. As a result, during the movement of the reducer, the reducer will also cause corresponding vibrations due to the uneven mass, and in the long run, it will also cause increased wear on one side of the reducer, further shortening its service life.

[0042] After the helical gearbox is adopted in this embodiment, the technicians in this field can design to evenly distribute the mass of the helical gearbox to both sides along the axial direction of the long screw 02, that is, the torques formed from the center of gravity of both sides of the helical gearbox to the long screw 02 are basically equal in magnitude and opposite in direction, so that the balance of gravity can be achieved. And after the rotating device is installed on the helical gearbox, the mass of the rotating device can also be basically evenly distributed, thereby avoiding or greatly reducing the vibration of the helical gearbox caused by uneven mass during the movement.

[0043] It is understandable that the specific structure and working principle of the rotating device are well-known technologies to those skilled in the art, so they will not be elaborated in detail here; common rotating devices include motors and motors. The output end of the rotating device can be connected to the input end of the bevel gear box through the installed drive shaft 01. The specific structure and working principle of the long screw 02 are well-known to those skilled in the art, so they will not be elaborated in detail here; in order to ensure the safety and stability of the seat adjustment, the long screw 02 generally adopts a metal rod, and the long screw 02 made of metal can meet the long-stroke stiffness requirements of the seat adjustment.

[0044] Another aspect of the present application provides a transmission mechanism, such as Figure 1 , Figure 2 and Figure 6 As shown, the transmission mechanism includes a helical gear set 2 that can be installed in the housing 1, and the helical gear set 2 and the housing 1 can cooperate to form a helical gear box. The housing 1 includes a first half housing 11 and a second half housing 12, and the first half housing 11 and the second half housing 12 are connected by fasteners to facilitate the installation of the helical gear set 2. The helical gear set 2 includes an output helical gear 21 corresponding to the output end, and an input helical gear 26 corresponding to the input end. The helical gear set 2 can be threadedly matched with the long screw 02 through the output helical gear 21 to form a thread self-locking. The input helical gear 26 is splined to the drive shaft 01 installed at the output end of the rotating device. In a specific example, a spline groove 270 is provided at the center of the input helical gear 26, and the drive shaft 01 is the corresponding spline shaft. The parallel arrangement of the input end and the output end of the helical gear set 2 is achieved by installing the input helical gear 26 and the output helical gear 21 in parallel.

[0045] It is understandable that in order to reduce the weight of the helical gear box, the input helical gear 26 can be made of plastic material, such as polyetheretherketone (PEEK). Since the input helical gear 26 is the first-stage input, it is directly driven by the rotating device. Therefore, in order to ensure the rotation stability of the input helical gear 26, it can be rotatably installed on the box body 1 through a metal sleeve, that is, a first sleeve 31.

[0046] At the same time, the output helical gear 21 is threadedly matched with the long screw 02 through the centrally arranged threaded segment 201, and the thread rotation direction of the long screw 02 is opposite to that of the output helical gear 21, so that the axial component force generated by the meshing of the helical gears in the helical gear box can be balanced with the axial component force generated by the threaded matching of the long screw 02.

[0047] It should be known that the threaded section 201 at the center of the output bevel gear 21 has the same threaded direction as the long screw 02, and the threaded direction of the threaded section 201 corresponding to the center of the output bevel gear 21 is also opposite to that of the output bevel gear 21. In order to ensure the stability of the bevel gearbox in adjusting the seat, the threaded fit between the long screw 02 and the output bevel gear 21 can be self-locking; the specific structure and working principle of the screw self-locking are well-known technologies to those skilled in the art, so they will not be elaborated in detail here.

[0048] For ease of understanding, the following Figure 7 The transmission process of the output helical gear 21 is analyzed in detail. Assuming that the rotation direction of the output helical gear 21 is left-handed, the rotation direction of the long screw 02 and the threaded segment 201 at the center of the output helical gear 21 are both right-handed. When the output helical gear 21 rotates in the direction indicated by the corresponding dotted arrow, the entire helical gear box can move in the direction indicated by the dotted arrow a along the long screw 02 through the thread cooperation between the long screw 02 and the threaded segment 201.

[0049] The movement of the helical gearbox can be regarded as the push of the long screw 02 on the helical gearbox. When the helical gearbox moves in the direction a, i.e., to the left, the threaded section 201 can slide against the right side of the external thread groove on the long screw 02. When the prior art is adopted, the long screw 02 can generate a leftward axial support force F4 on the output helical gear 21, and the magnitude of the axial support force F4 is mainly affected by the load; accordingly, the output helical gear 21 can exert an axial pressure F4′ in the opposite direction on the long screw 02, and theoretically F4′=F4.

[0050] In this embodiment, the direction of the axial thrust F3 exerted on the output helical gear 21 when the upper helical gear and the output helical gear 21 are meshed can be determined by the rotation direction and the rotation direction of the output helical gear 21. The axial thrust F3 is in the same direction as the axial component force F4. Then, the output helical gear 21 will tend to move to the left through the axial thrust F3 driven by the upper helical gear, which will weaken the axial pressure exerted by the output helical gear 21 on the long screw 02, that is, F4′=F4-F3. Compared with the prior art, the helical gear box and the corresponding structural design of this embodiment can effectively reduce the axial pressure exerted by the output helical gear 21 on the long screw 02, thereby reducing the friction to increase the service life of the helical gear box, and at the same time, it can also weaken the impact force generated by the helical gear box during the travel and stop process to improve the stability of the seat adjustment.

[0051] It should be known to those skilled in the art that, due to the long length of the long screw 02, when the helical gear box moves on the long screw 02, the lighter the weight of the helical gear box, the smaller the gravity generated, and thus the smaller the bending degree of the long screw 02. Therefore, in this embodiment, the lighter the weight of the helical gear box, the more stably the helical gear box can move on the long screw 02. Based on this, in this embodiment, the output helical gear 21 can be made of plastic material, and the specific material can be determined according to the transmission strength.

[0052] In this embodiment, if the thread segment 201 is directly set on the output bevel gear 21, the extension length of the thread segment 201 is equal to the thickness of the output bevel gear 21, so that the matching length between the output bevel gear 21 and the long screw 02 is shorter, which may affect the travel stability of the bevel gear box. Figure 6 , Figure 8 and Fig. 9 As shown, a rotating sleeve 20 is integrally formed along the axial direction at the center of the output helical gear 21 , and the rotating sleeve 20 cooperates with the long screw 02 through a threaded section 201 arranged on the inner wall.

[0053] It can be understood that the rotating sleeve 20 can extend on both sides of the output helical gear 21, and the threaded segments 201 are arranged on the rotating sleeve 20 with equal length, that is, the distance between the ends of the rotating sleeves 20 on both sides is equal to the length of the threaded segments 201. Then, by matching the threaded segments 201 with the long screw 02, the matching length can be effectively increased to ensure the travel stability of the helical gear box. Specifically, the magnitude of the meshing force between the threaded segments 201 and the long screw 02 can be basically regarded as constant, and will not increase significantly with the increase in the length of the threaded segments 201; then, by increasing the matching length of the threaded segments 201 and the long screw 02, the magnitude of the meshing force corresponding to the unit length can be effectively reduced. And the rotating sleeve 20 can also be used for the rotational installation of the output helical gear 21, so that part of the meshing force distributed on the rotating sleeve 20 can be transmitted to the housing 1 through the contact between the rotating sleeve 20 and the housing 1, thereby effectively reducing the transmission vibration of the output helical gear 21 to reduce noise.

[0054] In this embodiment, Figure 2 and Fig. 9As shown, the rotating sleeves 20 at both ends of the output helical gear 21 are sleeved with shaft sleeves and plane bearings 35. For the convenience of subsequent distinction, the shaft sleeve sleeved on the rotating sleeve 20 can be defined as the second shaft sleeve 34. The second shaft sleeve 34 is rotatably matched with the rotating sleeve 20 through the inner hole 340. The second shaft sleeve 34 is sleeved with the housing 1 through the outer wall and the rotational freedom of the second shaft sleeve 34 in the circumferential direction is limited by the limiting structure, so that when the output helical gear 21 rotates, the rotating sleeve 20 can rotate along the inner hole 340 of the second shaft sleeve 34, thereby avoiding direct contact between the rotating sleeve 20 and the housing 1, which can effectively reduce the wear of the rotating sleeve 20. The plane bearing 35 is installed between the second shaft sleeve 34 and the end face of the output helical gear 21, and then during the rotation of the output helical gear 21, the plane bearing 35 can ensure the smooth rotation of the output helical gear 21, and transmit the axial thrust of the output helical gear 21 to the housing 1 through the second shaft sleeve 34, so as to ensure the rotation stability of the output helical gear 21.

[0055] It should be known that the processing accuracy of the housing 1 is generally relatively low. If the output bevel gear 21 is directly rotatably installed with the housing 1 through the rotating sleeve 20, a large friction force will be generated when the output bevel gear 21 rotates, causing the rotating sleeve 20 to wear more and easily generate a large noise. The processing accuracy of the sleeve is relatively high and it is convenient to process. By installing the second sleeve 34 in the housing 1 and rotatably installing the output bevel gear 21 on the second sleeve 34 through the rotating sleeve 20, the rotation smoothness of the output bevel gear 21 can be effectively improved and wear and noise can be reduced. Of course, in order to ensure the smooth rotation of the output bevel gear 21, the second sleeve 34 needs to remain stationary relative to the housing 1, that is, the freedom of the second sleeve 34 in the circumferential direction needs to be limited by a limit structure. Under the condition of meeting the processing accuracy and strength, the second sleeve 34 is also made of plastic material.

[0056] It is understandable that there are many specific structures for the limiting structure between the second sleeve 34 and the housing 1. For the convenience of understanding, for example, the cross-sectional shape of the inner hole 340 of the second sleeve 34 is circular to ensure that the rotating sleeve 20 can be stably rotated and installed, and the cross-sectional shape of the outer contour of the second sleeve 34 is non-circular, and then when installed with the corresponding matching groove in the housing 1, the required limiting structure can be formed, thereby limiting the rotational freedom of the second sleeve 34. For the convenience of understanding, a specific example can be used to illustrate.

[0057] Specifically, Figure 3 , Figure 5 and Fig. 9As shown, the second sleeve 34 includes a cylindrical portion and a limiting portion 341 arranged in a stepped manner. The limiting portion 341 can be used to abut against one side of the plane bearing 35, and part of the side edge of the limiting portion 341 is convex. Correspondingly, a matching hole with a circular cross section is provided in the box body 1, and a limiting groove 110 is provided on the side corresponding to the part of the matching hole of the limiting portion 341. The limiting groove 110 is used to engage with the convex position of the limiting portion 341 to form a limiting structure.

[0058] In this embodiment, Figure 5 and Fig. 9 As shown, the inner hole 340 of the second sleeve 34 is stepped, so that the second sleeve 34 cooperates with the rotating sleeve 20 and the long screw 02 respectively through the inner hole 340, thereby ensuring that the long screw 02 and the output bevel gear 21 remain concentric through the second sleeve 34, thereby further improving the walking quality of the output bevel gear 21 to reduce vibration and noise.

[0059] Specifically, Figure 2 , Fig.13 and Fig.14 As shown, the center of the input bevel gear 26 is integrally injection molded at both ends to form an axially extending rotating shaft. For the convenience of subsequent distinction, the rotating shaft can be defined as a third rotating shaft 27; the spline groove 270 can be formed at the center of the third rotating shaft 27. The third rotating shaft 27 at both ends of the input bevel gear 26 is sleeved with a first shaft sleeve 31, so the input bevel gear 26 can be rotatably installed on the first shaft sleeve 31 fixedly installed on the housing 1 through the third rotating shaft 27. The first shaft sleeve 31 made of metal can reduce the radial wear of the third rotating shaft 27 to reduce the generation of noise.

[0060] In this embodiment, since the end face of the input bevel gear 26 has no step design, the end face of the input bevel gear 26 can be formed into a milling cutter-like structure through the gear teeth, and then when the input bevel gear 26 rotates, the end face of the input bevel gear 26 may aggravate the wear of the contact surface with the first sleeve 31, thereby increasing the axial clearance. Figure 2 , Fig.13 and Fig.14 As shown, a gasket can be sleeved on the third rotating shaft 27, and for the convenience of subsequent distinction, the gasket can be defined as a first gasket 32. The first gasket 32 ​​can rotate synchronously with the input bevel gear 26 through a limiting structure, and then the end surface of the input bevel gear 26 and the end surface of the first shaft sleeve 31 can be transitioned through the first gasket 32, and then the wear of the first shaft sleeve 31 can be effectively reduced, so as to reduce or avoid the tendency of the axial clearance of the input bevel gear 26 to increase.

[0061] It is understandable that, in order to further reduce the friction between the first sleeve 31 and the first gasket 32, a wear-resistant coating can be added to the end face of the first gasket 32 ​​to reduce wear. The specific structure and working principle of the wear-resistant coating are well-known technologies for those skilled in the art. A common wear-resistant coating can be a PTFE coating. The specific thickness of the first gasket 32 ​​can be obtained by calculating the dimension chain by those skilled in the art. In order to ensure that the input helical gear 26 can rotate smoothly, there is a certain axial clearance between the first gasket 32 ​​and the first sleeve 31. The specific clearance value can be determined according to actual needs. For example, the axial clearance can be 0.05 to 0.13 mm. Too small an axial clearance will cause a large friction between the first gasket 32 ​​and the first sleeve 31 to affect the rotation of the input helical gear 26. Too large an axial clearance will cause the input helical gear 26 to have an axial wobble, which is easy to generate a large noise during the rotation process.

[0062] It can also be understood that there are many specific structures of the limiting structure for the synchronous rotation of the first gasket 32 ​​and the input bevel gear 26; specifically, the limiting structure can be arranged between the first gasket 32 ​​and the third rotating shaft 27, and in one specific example, the matching cross-section of the first gasket 32 ​​and the third rotating shaft 27 is non-circular. The limiting structure can also be arranged between the first gasket 32 ​​and the input bevel gear 26; in one specific example, the first gasket 32 ​​can be engaged with the end face of the input bevel gear 26 through a vertically extending buckle 321; in another specific example, the first gasket 32 ​​can be engaged between two adjacent teeth of the input bevel gear 26 through a vertically extending buckle 321.

[0063] It should be known that both of the above two implementations of the limiting structure can meet the needs of this application. For the convenience of the subsequent description, the subsequent content will be described by taking the limiting structure disposed between the first gasket 32 ​​and the input bevel gear 26 as an example. The specific number of the buckles 321 on the first gasket 32 ​​can be one or more, and can be selected according to actual needs. For the convenience of understanding, a specific example will be described in detail below with reference to the accompanying drawings.

[0064] Specifically, Figure 4 and Fig.13 As shown, a pair of grooves 320 are arranged at intervals along the circumferential direction on the outer side of the first gasket 32, and the segment of the first gasket 32 ​​between the two grooves 320 can be bent in a direction perpendicular to the end face of the first gasket 32 ​​to obtain the required buckle 321. Therefore, when the first gasket 32 ​​is sleeved on the third rotating shaft 27, the buckle 321 can extend between two adjacent teeth on the input helical gear 26, and then when the input helical gear 26 rotates, the first gasket 32 ​​is driven to rotate synchronously with the input helical gear 26 through the abutment between the tooth side and the buckle 321.

[0065] In this embodiment, Figure 2 , Figure 6 as well as Fig.10 As shown, the helical gear set 2 further includes at least one transition helical gear parallel to the output helical gear 21 and the input helical gear 26, and the transition helical gear is meshed between the input helical gear 26 and the output helical gear 21. From the input end to the output end of the helical gear set 2, the pitch circle diameters of the input helical gear 26, the transition helical gear, and the output helical gear 21 increase in sequence, thereby meeting the height requirements of the helical gear box through the design of the transition helical gear while meeting the transmission ratio requirements.

[0066] It should be known that the reduction ratio of the helical gearbox is mainly determined by the pitch circle diameter between the input helical gear 26 and the output helical gear 21; that is, when the reduction ratio is determined, the pitch circle diameters of the input helical gear 26 and the output helical gear 21 have been determined; the number of transition helical gears will not affect the reduction ratio, and it is only necessary to ensure that the pitch circle diameter of the transition helical gear is smaller than the pitch circle diameter of the output helical gear 21 to minimize the overall size of the helical gearbox. The specific number and structural size of the transition helical gears can be determined according to the height requirements of the seat drive. For example Figure 6 and Figure 7 As shown, there are two transition bevel gears, namely the first transition bevel gear 22 and the second transition bevel gear 24. The first transition bevel gear 22 is meshed with the output bevel gear 21 and the second transition bevel gear 24 respectively, and the second transition bevel gear 24 can also be meshed with the input bevel gear 26. Then the bevel gears from the input end to the output end of the bevel gear box are the input bevel gear 26, the second transition bevel gear 24, the first transition bevel gear 22 and the output bevel gear 21 in sequence, and the pitch circle diameters of the four bevel gears are also increased in sequence.

[0067] It should also be known that, in order to further reduce the weight of the helical gear box, the first transition helical gear 22 and the second transition helical gear 24 are both made of plastic material, such as POM or PA66. Since the strength of PA66 will be weakened after absorbing water, POM is preferably used for the first transition helical gear 22 and the second transition helical gear 24 in this embodiment. Since the output torque is related to the output speed, considering that the output torques of the first transition helical gear 22 and the second transition helical gear 24 are different, combined with cost considerations, the materials used for the first transition helical gear 22 and the second transition helical gear 24 can be different, such as the second transition helical gear 24 using POM100AL and the first transition helical gear 22 using POM 100P.

[0068] It is understandable that if Figure 7As shown, the transmission analysis of the helical gear set 2 is continued based on the transmission analysis process of the aforementioned output helical gear 21. In the figure, the direction indicated by the dotted arrow is the rotation direction of each helical gear, and the direction indicated by the dotted arrow is the axial thrust direction. From right to left, the rotation direction of the input helical gear 26 is counterclockwise, the rotation direction of the second transition helical gear 24 is clockwise, the rotation direction of the first transition helical gear 22 is counterclockwise, and the rotation direction of the output helical gear 21 is clockwise. Accordingly, the input helical gear 26 can apply a leftward axial thrust F1 to the second transition helical gear 24, and the second transition helical gear 24 can apply a leftward axial thrust F2 to the first transition helical gear 22. Since the directions of the axial thrusts F1 and F2 are the same as the axial thrust F3, the above analysis process shows that the axial pressure F4′=F4-F3-F2-F1 applied by the output bevel gear 21 to the long screw 02 can be obtained, and the axial pressure applied by the output bevel gear 21 to the long screw 02 can be further reduced to improve the stability of seat adjustment.

[0069] In this embodiment, Figure 2 , Figure 6 , Fig.10 and Fig.11 As shown, the transition helical gear directly meshing with the output helical gear 21, that is, the first transition helical gear 22, is integrally molded with a first rotating shaft 23 made of metal at its center, and a rod section connecting the first rotating shaft 23 and the first transition helical gear 22 is provided with a protrusion 231 in the radial direction, and the protrusion 231 is located in the first transition helical gear 22. By the cooperation between the protrusion 231 and the first transition helical gear 22, the stable connection between the first rotating shaft 23 and the first transition helical gear 22 in the axial direction can be ensured and the thickness of the first transition helical gear 22 in the radial direction can be reduced.

[0070] It is understandable that the structure of the protrusion 231 can be an arc-shaped protrusion, a conical protrusion or a rectangular protrusion, etc., as long as it can be abutted against the first transition bevel gear 22 in the axial direction. The number of the protrusions 231 can be one or more, which can be determined according to actual needs, for example Fig.10 As shown, the cross section of the protrusion 231 is rectangular and the number is one. At the same time, by setting the protrusion 231, the thickness of the first transition bevel gear 22 in the radial direction can be reduced, thereby reducing the radial deformation of the first transition bevel gear 22 after injection molding to reduce the noise generated during the rotation process.

[0071] It should be known that the first transition bevel gear 22 is closest to the output bevel gear 21, so the pitch circle diameter of the first transition bevel gear 22 is larger than that of the second transition bevel gear 24 and the input bevel gear 26. If the first rotating shaft 23 is a straight rod structure, the first transition bevel gear 22 is thicker in the radial direction. Those skilled in the art should know that the injection molding of plastic products has a shrinkage rate; the thicker the thickness of the injection molded product, the greater the shrinkage after injection molding. Therefore, the thickness of the first transition bevel gear 22 in the radial and axial directions can be reduced by providing a protrusion 231, thereby weakening the influence of the shrinkage rate on the product shape accuracy to improve the meshing quality of the first transition bevel gear 22.

[0072] At the same time, the output speed angle corresponding to the first transition bevel gear 22 has a larger desired output torque, and thus the axial thrust generated by the first transition bevel gear 22 is also larger. Therefore, through the setting of the protrusion 231, the axial connection stability between the first transition bevel gear 22 and the first rotating shaft 23 can also be guaranteed.

[0073] Specifically, Figure 2 and Fig.11 As shown, the first shaft sleeve 31 and the second gasket 33 are respectively sleeved on the first rotating shaft 23 corresponding to the two ends of the first transition bevel gear 22; the first shaft sleeve 31 is fixed in the housing 1, and the first transition bevel gear 22 is rotatably mounted on the first shaft sleeve 31 through the first rotating shaft 23, and then when the first transition bevel gear 22 rotates, the first transition bevel gear 22 can cooperate with the first shaft sleeve 31 through the second gasket 33 to reduce wear, thereby avoiding the first transition bevel gear 22 directly contacting the first shaft sleeve 31 through the end face. In order to further reduce wear, a wear-resistant coating, such as a PTFE coating, can be coated on the second gasket 33.

[0074] Specifically, Figure 2 and Fig.12 As shown, the center of the second transition bevel gear 24 is integrally molded with a second rotating shaft 25 made of metal, and the second rotating shaft 25 is a straight rod or has a structure similar to that of the first rotating shaft 23. The second transition bevel gear 24 can be directly mounted on the housing 1 through the second rotating shaft 25, or can be rotatably mounted on the first shaft sleeve 31 fixed on the housing 1 through the second rotating shaft 25. A second gasket 33 is also sleeved on the second rotating shaft 25, so that the end face of the second transition bevel gear 24 is matched with the housing 1 or the first shaft sleeve 31 through the second gasket 33. In order to further reduce wear, a wear-resistant coating, such as a PTFE coating, can be coated on the second gasket 33.

[0075] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A transmission mechanism, characterized in that: It includes a helical gear set installed on a box body, the helical gear set includes an input helical gear corresponding to the input end and an output helical gear corresponding to the output end; the input helical gear is suitable for transmission connection with a rotating device, the output helical gear is suitable for threaded connection with a long screw through the center, and the input helical gear is parallel to the output helical gear.

2. The transmission mechanism according to claim 1, characterized in that: A rotating sleeve is integrally formed in the center of the output helical gear along the axial direction. The rotating sleeve cooperates with the long screw rod through a threaded section arranged on the inner wall and performs self-locking.

3. The transmission mechanism according to claim 2, characterized in that: Both ends of the rotating sleeve are installed on the box body through sleeves that are slidably connected, and the sleeve and the box body are matched through a limiting structure so that when the output bevel gear rotates, the sleeve remains stationary relative to the box body.

4. The transmission mechanism according to claim 3, characterized in that: The rotating sleeve cooperates with an inner hole with a circular cross section set at the center of the shaft sleeve, and the cross-sectional shape of the outer contour of the shaft sleeve is non-circular, so that the shaft sleeve cooperates with the box body to form the limiting structure.

5. The transmission mechanism according to claim 4, characterized in that: The inner hole of the shaft sleeve is stepped so that the shaft sleeve can respectively cooperate with the rotating sleeve and the long screw through the inner hole.

6. The transmission mechanism according to claim 1, characterized in that: The input helical gear is rotatably mounted on the box body via an integrally formed third rotating shaft, a gasket is sleeved on the third rotating shaft, and the gasket is suitable for synchronously rotating with the input helical gear via a limiting structure.

7. The transmission mechanism according to claim 6, characterized in that: A buckle is vertically arranged on the side of the gasket. When the gasket is sleeved on the third rotating shaft, the buckle is suitable for extending between two adjacent teeth on the input helical gear to form the limiting structure.

8. The transmission mechanism according to any one of claims 1 to 7, characterized in that: The helical gear set also includes at least one transition helical gear parallel to the output helical gear, and the transition helical gear is meshed between the input helical gear and the output helical gear; from the input end to the output end of the helical gear set, the pitch circle diameters of the input helical gear, the transition helical gear and the output helical gear increase successively, and the axes of the input helical gear, the transition helical gear and the output helical gear are located in the same plane.

9. The transmission mechanism according to claim 8, characterized in that: A first rotating shaft made of metal is integrally injection-molded at the center of the transition helical gear that directly meshes with the output helical gear. The first rotating shaft is provided with a protrusion in the radial direction inside the transition helical gear.

10. A seat driver, characterized in that: It comprises the transmission mechanism described in any one of claims 1 to 9.

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