Closed type horizontal driver for car seat

Abstract

The utility model provides a closed horizontal driver of car seat, including the reduction gearbox of left, right box body buckle into and form the cavity, the both ends of reduction gearbox are equipped with the bearing hole, be equipped with worm and worm wheel in the cavity, worm wheel center is equipped with the screw thread, reduction gearbox corresponds to the closed state of worm position, worm wheel both ends are equipped with the support cylinder, worm wheel outer cylinder wall middle section position is equipped with worm wheel tooth, the bearing hole includes first, second support hole and the inner inclined surface at the junction of both, the second support hole inner wall is equipped with the circumferential positioning groove, still including the wear ring of each support cylinder outside, the wear ring includes first, second support part and the outer inclined surface at the junction of both, the second support part is equipped with the circumferential positioning convex, the wear ring still includes the support washer, first support part is equipped with a plurality of circumferential direction interval arrangement's through groove, the utility model has the advantages of small work noise, simple structure, long service life.

Description

Technical Field

[0001] This utility model relates to the field of automotive parts, specifically to a closed-type automotive seat horizontal actuator. Background Technology

[0002] The fore-and-aft adjustment of electric seats relies on a horizontal actuator. Existing horizontal actuators use a worm gear to reduce speed and then cooperate with a lead screw to achieve displacement. Since the load is applied to the worm gear when the gearbox is working, and the axial support of the worm gear depends on the gearbox, there will inevitably be friction between the end of the worm gear and the inner wall of the gearbox. In particular, due to production cost considerations, the worm gear teeth are cut through the gearbox. Under the premise of controlling the size of the gearbox, when the worm gear is subjected to axial load, the worm gear teeth are prone to scraping against the inner wall of the gearbox, which increases the friction during operation, accelerates the wear of the gearbox, and also easily accumulates heat, increases operating noise, and shortens the life of the gearbox.

[0003] To address the aforementioned issues, the applicant invented a horizontal drive box for automotive seats (application number: 201920319262.2), aiming to achieve long service life and low operating noise. After the product was launched on the market, customer feedback indicated that although the wear resistance of the wear ring has been improved, the wear ring still experiences significant workload for vehicles where the seats automatically reset upon power-on or power-off. In particular, when the lead screw vibrates during rotation, the lead screw teeth are prone to scraping against the inner hole of the wear ring, generating debris that gets crushed into the threaded mating surface, causing noise and wear. Therefore, further improvements to the wear ring are urgently needed.

[0004] The applicant filed an application on September 15, 2020, and published it on April 13, 2021, for a mid-mounted automotive seat horizontal drive with patent number CN202022018223.4. The drive includes a reduction gearbox consisting of left and right housings. The reduction gearbox contains a worm gear and a worm shaft. The worm gear has a lead screw thread at its center. Lead screw holes are located on both sides of the reduction gearbox. The worm gear includes worm gear teeth located in the middle section and shoulders located at both ends of the worm gear. A gasket is fitted onto the shoulder, and a positioning ear is provided on the gasket. A wear-resistant ring is provided on the side of the gasket facing away from the worm gear teeth. The wear-resistant ring includes a radial support ring supported between the outer cylindrical wall of the shoulder and the inner wall of the lead screw hole, and a sealing ring concentrically connected to the radial support ring. An axial support ring is provided between the gasket and the inner wall of the reduction gearbox, which connects to the radial support ring. The diameter of the axial support ring is larger than that of the radial support ring, and the outer diameter of the radial support ring is larger than that of the sealing ring. The end face of the sealing ring is flush with the opening of the lead screw hole.

[0005] While the aforementioned patent solved a series of technical problems, the product has gradually revealed its shortcomings with the development of new energy vehicles. Because new energy vehicles eliminate the engine, their interior quietness is far superior to that of gasoline vehicles, making the operating noise of the electric seats, which was previously masked by engine noise, easily noticeable. This is because the gearbox has an open structure corresponding to the worm gear, making it prone to noise leakage. Furthermore, the internal worm gear structure uses a helical tooth structure. To prevent wear on the wear ring from the helical tooth end face, additional shims are added for isolation, making the overall structure more complex (the front and back of the shims must be distinguished during assembly). The locating ears of the shims are fixed to the worm gear teeth by bending. During operation, the shims rotate with the worm gear and slide relative to the wear ring to prevent the worm gear teeth from scratching the wear ring. However, under the action of friction, the positioning ear is easily dislodged from the tooth groove of the worm gear. Specifically, during operation (forward), one side of the worm gear pad (A) is squeezed, while the other side pad (B) is in a non-squeezed state, causing a gap between the pad (B) and the worm gear, resulting in relative circumferential displacement. This causes the positioning ear of the pad (B) to be misaligned with the worm gear tooth at a certain angle. Although this misalignment will not immediately cause the positioning ear to separate from the worm gear tooth, it will squeeze the positioning ear of the pad (B) when the seat moves in the opposite direction. After repeated reciprocating motion, the positioning ear of the pad (B) will gradually become flat and eventually completely separate from the worm gear tooth. Moreover, during the squeezing, the flatness of the pad (B) corresponding to the positioning ear position will exceed the tolerance due to the bending effect, thereby aggravating the scratching and wear of the wear ring. Utility Model Content

[0006] Based on the above problems, the purpose of this utility model is to provide a closed car seat leveling drive with low operating noise, simple structure, and long service life.

[0007] To address the above problems, the following technical solution is provided: a closed-type automotive seat horizontal actuator, comprising a reduction gearbox formed by a left and right housing fastened together to form a cavity; the reduction gearbox has bearing holes at both ends located between the fastening surfaces of the left and right housings and connected to the cavity; the cavity contains a worm gear and a worm wheel concentrically arranged with the bearing holes, the worm wheel having a lead screw thread at its center; the reduction gearbox is closed corresponding to the worm gear position; the worm wheel has extended support cylinders at both ends; the worm wheel has worm gear teeth meshing with the worm gear at the middle section of its outer cylindrical wall, with the ends of the worm gear teeth spaced apart from the end face of the worm wheel; the bearing holes are sequentially arranged as first support holes from the orifice towards the cavity. The system includes a first support hole and a second support hole with an inner diameter larger than the first support hole. The junction of the first support hole and the second support hole is transitioned by an inner inclined surface. The inner wall of the second support hole is provided with a circumferential positioning groove. The system also includes a wear-resistant ring fitted around each support cylinder. The wear-resistant ring includes a first support portion adapted to the first support hole, a second support portion adapted to the second support hole, and an outer inclined surface located between the first support portion and the second support portion and adapted to the inner inclined surface. The second support portion is provided with a circumferential positioning protrusion adapted to the circumferential positioning groove. The wear-resistant ring also includes a support washer located between the end face of the worm gear and the cavity. The first support portion is provided with a plurality of through slots opened along its axial direction and spaced apart in the circumferential direction.

[0008] The present invention is further configured such that the circumferential positioning groove is located between the fastening surfaces of the left and right housings; the circumferential positioning protrusion is connected to the second support part, and one end of it is connected to the support washer.

[0009] The present invention is further configured such that the wear-resistant ring is made of polyoxymethylene (POM) or polybutylene terephthalate (PBT).

[0010] The present invention is further configured such that the worm shaft axis and the worm wheel axis are arranged at a 90-degree angle; the two ends of the worm are respectively rotatably engaged with the left housing and the right housing, and one end is provided with a torsion part.

[0011] The present invention is further provided that the side walls of the left and right housings corresponding to the positions at both ends of the worm gear are provided with outwardly protruding support protrusions.

[0012] The present invention is further provided that the two ends of the gearbox are provided with shock-absorbing rubber sleeves; the shock-absorbing rubber sleeves are provided with through holes corresponding to the bearing holes.

[0013] The present invention is further configured to include a seat screw that passes through the gearbox and is adapted to the screw thread.

[0014] The present invention is further configured such that the left housing and the right housing are connected and fixed by bolts, the left housing is provided with a recess for accommodating a nut, and the right housing is provided with a screw hole for cooperating with a screw rod.

[0015] The present invention is further configured such that the left box body has a positioning protrusion on the side facing the fastening surface, and the right box body has a positioning recess that matches the positioning protrusion on the side facing the fastening surface.

[0016] The present invention is further provided that the side walls of the left and right housings corresponding to the worm gear positions are provided with outwardly protruding clearance protrusions.

[0017] The beneficial effects of this utility model are: 1. Setting the gearbox in a closed configuration corresponding to the worm gear position effectively blocks the noise generated when the worm and worm wheel mesh. Adding grease reduces grease loss and further absorbs sound through the grease. The circumferential positioning groove and circumferential positioning protrusion provide circumferential constraint for the wear ring. The wear ring and support cylinder are matched, allowing the support cylinder to rotate relative to the wear ring and provide radial support. Axial support is achieved by using a support washer to separate the worm wheel end face from the inner wall of the cavity. This is because the worm wheel teeth were not drilled through along its axial direction. Therefore, the smoothness of the worm gear end face is preserved, which reduces wear when it rubs against the support washer; the first support and the second support can achieve two-stage support, which is beneficial to improve coaxiality and stability, and the outer inclined surface can adapt to the inner inclined surface when subjected to the axial force of the worm gear to achieve a better centering effect, that is, the larger the force, the better the centering effect; the through groove can provide better adaptability for the first support during assembly, and can capture hair, dust and debris when they adhere to the seat screw, reducing or avoiding the possibility of them getting caught in the screw thread; 2. The support protrusion improves the support effect on both ends of the worm gear while ensuring that the wall thickness of the left and right housings is not too thick. 3. The clearance protrusion provides installation space for the worm gear inside the cavity, making the overall volume of the gearbox more compact, reducing unnecessary internal space, and improving overall rigidity. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model.

[0019] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the gearbox of this utility model.

[0020] Figure 3 This is a schematic diagram of the exploded three-dimensional structure of this utility model.

[0021] The labels in the diagram have the following meanings: 10-Gearbox; 11-Left housing; 111-Recess; 112-Positioning protrusion; 12-Right housing; 121-Screw hole; 122-Positioning recess; 13-Cavity; 14-Bearing hole; 141-First support hole; 142-Second support hole; 1421-Circumferential positioning groove; 143-Inner inclined surface; 15-Support protrusion; 16-Leanback protrusion; 20-Worm; 21-Torsion part; 30-Worm wheel; 31-Screw thread; 32-Support cylinder; 33-Worm wheel tooth; 40-Wear ring; 41-First support part; 411-Through groove; 42-Second support part; 421-Circumferential positioning protrusion; 43-Outer inclined surface; 44-Support washer; 50-Seat screw; 60-Shock-absorbing rubber sleeve; 61-Through hole; 70-Bolt; 71-Nut; 72-Screw. Detailed Implementation

[0022] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0023] refer to Figures 1 to 3 ,like Figures 1 to 3 The diagram illustrates a closed-type automotive seat horizontal actuator, comprising a reduction gearbox 10 formed by the fastening of a left housing 11 and a right housing 12 to create a cavity 13. The reduction gearbox 10 has bearing holes 14 at both ends, located between the fastening surfaces of the left housing 11 and the right housing 12 and connected to the cavity 13. The cavity 13 contains a worm gear 20 and a worm wheel 30 concentrically arranged with the bearing holes 14. The worm wheel 30 has a screw thread 31 at its center. The reduction gearbox 10 is closed relative to the position of the worm gear 20. The worm wheel 30 has extended support cylinders 32 at both ends. A worm wheel tooth 33, meshing with the worm gear 20, is located in the middle section of the outer cylindrical wall of the worm wheel 30, with the ends of the worm wheel teeth 33 spaced apart from the end face of the worm wheel 30. The bearing holes 14, from the opening towards the cavity 13, are sequentially configured as a first support hole 141 and a hole with an inner diameter larger than the first support hole 141. The second support hole 142 is provided, and the junction of the first support hole 141 and the second support hole 142 is transitioned by an inner inclined surface 143. The inner wall of the second support hole 142 is provided with a circumferential positioning groove 1421. It also includes a wear-resistant ring 40 sleeved on each support cylinder 32. The wear-resistant ring 40 includes a first support part 41 adapted to the first support hole 141, a second support part 42 adapted to the second support hole 142, and an outer inclined surface 43 located between the first support part 41 and the second support part 42 and adapted to the inner inclined surface 143. The second support part 42 is provided with a circumferential positioning protrusion 421 adapted to the circumferential positioning groove 1421. The wear-resistant ring 40 also includes a support washer 44 located between the end face of the worm gear 30 and the cavity 13. The first support part 41 is provided with a plurality of through grooves 411 opened along its axial direction and spaced apart in the circumferential direction.

[0024] In the above structure, the gearbox 10 is set as a closed type corresponding to the position of the worm 20, which can effectively block the noise generated when the worm 20 meshes with the worm wheel 30. After adding grease, on the one hand, the loss of grease can be reduced, and on the other hand, the grease can further absorb sound. The circumferential positioning groove 1421 and the circumferential positioning protrusion 421 are adapted to provide circumferential constraint for the wear ring 40. The wear ring 40 is adapted to the support cylinder 32, so that the support cylinder 32 rotates relative to the wear ring 40 and provides radial support for it. The axial support is separated from the end face of the worm wheel 30 and the inner wall of the cavity 13 by the support washer 44. Since the worm wheel 30 does not follow its axis when the worm wheel teeth 33 are opened. The through-cut design maintains the smoothness of the worm gear 30 end face, reducing wear when it rubs against the support washer 44. The first support 41 and the second support 42 provide two-stage support, which helps improve coaxiality and stability. The outer inclined surface 43 can adapt to the inner inclined surface 143 when subjected to the axial force of the worm gear 30, resulting in a better centering effect. The larger the force, the better the centering effect. The through groove 411 provides better fit for the first support 41 during assembly and captures hair, dust, and debris adhering to the seat screw 50, reducing or avoiding the possibility of them getting caught in the screw thread 31.

[0025] In this embodiment, the circumferential positioning groove 1421 is located between the mating surfaces of the left box 11 and the right box 12; the circumferential positioning protrusion 421 is connected to the second support part 42, and one end of it is connected to the support washer 44.

[0026] In the above structure, the left box 11 and the right box 12 can be clamped and fixed when they are fastened together; the circumferential positioning protrusion 421 is connected to the second support part 42, and one end of it is connected to the support washer 44, which can improve the overall connection strength.

[0027] In this embodiment, the wear-resistant ring 40 is made of polyoxymethylene (POM) or polybutylene terephthalate (PBT).

[0028] In the above structure, the wear-resistant ring 40 is preferably made of polybutylene terephthalate (PBT).

[0029] In this embodiment, the axis of the worm 20 is arranged at a 90-degree angle to the axis of the worm wheel 30; the two ends of the worm 20 are respectively rotatably engaged with the left housing 11 and the right housing 12, and one end is provided with a torsion part 21.

[0030] In this embodiment, the left housing 11 and the right housing 12 are provided with outwardly protruding support protrusions 15 on the side walls corresponding to the positions at both ends of the worm gear 20.

[0031] In the above structure, the support effect on both ends of the worm gear 20 is improved while ensuring that the wall thickness of the left housing 11 and the right housing 12 is not too thick.

[0032] In this embodiment, the gearbox 10 is provided with shock-absorbing rubber sleeves 60 at both ends; the shock-absorbing rubber sleeves 60 are provided with through holes 61 corresponding to the bearing holes 14.

[0033] In the above structure, the shock-absorbing rubber sleeve 60 provides shock absorption and also has a good sound absorption effect when the gearbox 10 is installed and in operation.

[0034] In this embodiment, a seat screw 50 is also included, which passes through the gearbox 10 and is adapted to the screw thread 31.

[0035] In the above structure, the gearbox 10 moves along the seat lead screw 50 during operation.

[0036] In this embodiment, the left housing 11 and the right housing 12 are connected and fixed by bolts 70. The left housing 11 is provided with a recess 111 for accommodating the nut 71, and the right housing 12 is provided with a screw hole 121 for cooperating with the screw 72.

[0037] In the above structure, the recess 111 can effectively hide the nut 71, reduce the overall volume of the gearbox 10, and the bolt 70 connection also makes it easier for the OEM to refurbish and maintain the gearbox 10.

[0038] In this embodiment, the left box 11 has a positioning protrusion 112 on the side facing the fastening surface, and the right box 12 has a positioning recess 122 that matches the positioning protrusion 112 on the side facing the fastening surface.

[0039] The above structure can improve the stability when the left box 11 and the right box 12 are fastened together, pre-positioning is performed before fixing with bolts 70, and it has a foolproof function during assembly.

[0040] In this embodiment, the left housing 11 and the right housing 12 are provided with outwardly protruding relief protrusions 16 on the side walls corresponding to the positions of the worm gear 30.

[0041] In the above structure, the clearance protrusion 16 is used to provide installation space for the worm gear 30 in the cavity 13, making the overall volume of the gearbox 10 more compact, reducing unnecessary internal space, and improving overall rigidity.

[0042] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model. These improvements and modifications assumed above should also be considered within the protection scope of the present utility model.

Claims

1. A closed-type automotive seat horizontal actuator, comprising a reduction gearbox formed by a left housing and a right housing fastened together to form a cavity, wherein the reduction gearbox has bearing holes at both ends located between the fastening surfaces of the left housing and the right housing and connected to the cavity; the cavity contains a worm gear and a worm wheel concentrically arranged with the bearing holes, the worm wheel having a lead screw thread at its center, characterized in that: The gearbox is closed at the worm position; the worm wheel has extended support cylinders at both ends, and worm wheel teeth that mesh with the worm are provided in the middle section of the outer cylindrical wall of the worm wheel, with the ends of the worm wheel teeth spaced apart from the end face of the worm wheel; the bearing holes are arranged sequentially from the orifice towards the cavity as a first support hole and a second support hole with an inner diameter larger than the first support hole, and the junction of the first support hole and the second support hole is transitioned by an inner inclined surface, and the inner wall of the second support hole is provided with a circumferential positioning groove; it also includes a wear-resistant ring fitted around each support cylinder, the wear-resistant ring including a first support part adapted to the first support hole, a second support part adapted to the second support hole, and an outer inclined surface located between the first support part and the second support part and adapted to the inner inclined surface, the second support part is provided with a circumferential positioning protrusion adapted to the circumferential positioning groove, the wear-resistant ring also includes a support washer located between the end face of the worm wheel and the cavity; the first support part is provided with several through slots opened along its axial direction and spaced apart in the circumferential direction.

2. The enclosed automotive seat horizontal actuator according to claim 1, characterized in that: The circumferential positioning groove is located between the fastening surfaces of the left and right housings; the circumferential positioning protrusion is connected to the second support part, and one end of it is connected to the support washer.

3. The enclosed automotive seat horizontal actuator according to claim 1, characterized in that: The wear-resistant ring is made of polyoxymethylene (POM) or polybutylene terephthalate (PBT).

4. The enclosed automotive seat horizontal actuator according to claim 1, characterized in that: The worm shaft axis is arranged at a 90-degree angle to the worm wheel axis; the two ends of the worm are respectively rotatably engaged with the left and right housings, and one end is provided with a torsion part.

5. A closed-type automotive seat horizontal actuator according to claim 4, characterized in that: The left and right housings have outwardly protruding support protrusions on their side walls corresponding to the positions at both ends of the worm gear.

6. The enclosed automotive seat horizontal actuator according to claim 1, characterized in that: The gearbox is provided with shock-absorbing rubber sleeves at both ends; the shock-absorbing rubber sleeves are provided with through holes corresponding to the bearing holes.

7. A closed-type automotive seat horizontal actuator according to claim 1 or 6, characterized in that: It also includes a seat screw that passes through the gearbox and is adapted to the screw thread.

8. The enclosed automotive seat horizontal actuator according to claim 1, characterized in that: The left and right housings are fixed together by bolts. The left housing has a recess for accommodating a nut, and the right housing has a screw hole for engaging with a screw rod.

9. A closed-type automotive seat horizontal actuator according to claim 1, characterized in that: The left housing has a positioning protrusion on the side facing the fastening surface, and the right housing has a positioning recess on the side facing the fastening surface that matches the positioning protrusion.

10. A closed-type automotive seat horizontal actuator according to claim 1, characterized in that: The left and right housings have outwardly protruding relief protrusions on their side walls corresponding to the worm gear positions.

Images