Longitudinal adjustment device and vehicle seat

Abstract

To provide a vehicle seat using an electrically driven longitudinal adjustment device having an integrated motor-gear unit.SOLUTION: The invention relates to a longitudinal adjustment device (110), comprising at least one rail arrangement (112) and a drive device (118) therefor, the rail arrangement (112) having a first rail and a second rail guided movably on the first rail, the drive device (118) having at least one motor (118.1), a gear unit (118.2) supported in the second rail, a spindle with a spindle thread, and a spindle bearing, the gear unit (118.2) having a drive worm and a worm wheel, the spindle being of fixed design and being supported in the spindle bearing and connected to the first rail, and the worm wheel being supported in the gear housing, on the one hand via an axial ball bearing and on the other hand via an axial bearing bush, in an axially resilient manner in the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a longitudinal adjustment device (also referred to as a longitudinal adjustment device for short), and in particular to a seat for a motor vehicle. The present invention also relates to a seat for a vehicle. [Background technology]

[0002] Patent Document 1 discloses a longitudinal adjuster, particularly for a vehicle seat. The longitudinal adjuster has at least one rail arrangement formed from a first rail and a second rail longitudinally movable relative to the first rail, the rails engaging with each other to form an internal channel. A spindle nut supported by the second rail and a spindle operatively connected to the spindle nut are disposed in the internal channel, and a gear drivable by a motor and interacting with the spindle is disposed at one end of the first rail. At the front end of the spindle, the spindle is supported in the gear, and at the rear end of the spindle, the spindle is supported in a rotary bearing of the first rail. Patent Document 2 discloses a further longitudinal adjuster including a gear unit and a gear wheel axially and elastically supported relative to a gear housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] German Patent Application Publication No. 102017218492 [Patent Document 2] International Publication No. 2023 / 062567 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem that the present invention aims to solve is to improve longitudinal adjustment devices of the type mentioned at the beginning, in particular to propose an electrically operable longitudinal adjustment device with an integrated motor-gear unit, and to provide a corresponding vehicle seat. [Means for solving the problem]

[0005] According to the present invention, the first-mentioned problem is solved by a longitudinal adjustment device having the features of claim 1. According to the present invention, the second-mentioned problem is solved by a vehicle having the features of claim 11.

[0006] The longitudinal adjustment device according to the present invention comprises at least one rail arrangement and one drive for said rail arrangement, said rail arrangement comprising a first rail and a second rail movably guided on said first rail, said drive comprising at least one motor, a gear unit supported on said second rail, a spindle having a spindle screw, and a spindle bearing, said gear unit comprising a drive worm drivable by said motor, a worm wheel operatively connected (particularly meshing) with said drive worm, and a gear unit operatively connected to said worm wheel (particularly meshing) with said drive worm. the spindle is of fixed design, is supported on the spindle bearing and is connected to the first rail, the drive worm, the worm wheel (also called spiral gear or gear wheel) and the spindle nut are supported in a gear housing, the worm wheel and / or the spindle nut being supported (in particular rotatably supported) in the gear housing axially elastically and axially via at least one axial ball bearing on the one hand and via an axial bearing bush on the other hand.

[0007] Alternatively, two axial ball bearings may be provided, for example, arranged on either side of the worm wheel (also called worm gear) and / or spindle nut.

[0008] Here, the worm wheel may, for example, be operatively connected to a spindle nut, which in turn is operatively connected (particularly meshed) with the spindle. The worm wheel and spindle nut may, for example, form a single component. Alternatively, the spindle nut may be of separate design, and the worm wheel operatively connected (particularly kinematically coupled or coupled to rotate together) with the spindle nut.

[0009] In other words, the worm wheel can simultaneously form a spindle nut, for example, the worm wheel has outer worm teeth and an inner nut thread as the spindle nut.

[0010] In particular, the drive worm may have first teeth (in particular worm teeth or a first toothed portion). The worm wheel may have second teeth (in particular worm wheel teeth or a second toothed portion). The first teeth are designed as external teeth on the drive worm. The second teeth are designed as external teeth on the worm wheel. The first teeth and the second teeth form a gear wheel pair for the drive device.

[0011] When the worm wheel and the spindle nut are coupled together, the worm wheel has an internal thread (also referred to as an internal nut thread), particularly a trapezoidal thread, which engages with the external spindle thread of the spindle. When the drive worm is driven by the motor, the drive worm, the worm wheel driven by the drive worm, and consequently the spindle nut rotate. The positioning of the worm wheel, which is simultaneously designed as the spindle nut, is achieved by a radial bearing assembly (particularly by at least one radial bearing bushing). In addition, the worm wheel can be supported on a fixed spindle that is non-rotatably mounted on the vehicle. The rotational movement of the worm wheel and consequently the spindle nut causes the spindle nut, and thus the worm wheel, to move along the longitudinal axis of the spindle (also referred to as the spindle axis). This allows longitudinal adjustment along the longitudinal axis of the fixed spindle in a simple manner.

[0012] In particular, the drive worm is rotatable about a first axis, for example about a drive shaft or a first gear axis, and the worm wheel meshing with the drive worm is rotatable about a second axis, for example about an output shaft or a second gear axis, and in particular, the first axis extends perpendicular to the second axis.

[0013] The fact that the worm wheel and / or spindle nut are supported axially elastically allows for particularly efficient rail drives (drive devices for rail arrangements) with low friction losses. For example, the worm wheel and / or spindle nut can be supported axially elastically and / or with axial tolerance compensation in a gear housing by a composite bearing. The composite bearing consists of at least one spring-loaded axial ball bearing (a combination of a spring washer and an axial ball bearing) (e.g., two axial ball bearings combined with two spring washers) and an axial bearing bush (e.g., an axial plain bearing).

[0014] An axial ball bearing is understood to mean in particular a ball cage ring with balls. The conventional annular washers between which the ball cage ring is usually arranged are eliminated. The axial ball bearing, and thus the ball cage ring, is preferably arranged directly between the worm wheel / spindle nut and the spring washer.

[0015] Advantageous embodiments, which can be used individually or in combination with one another, form the subject matter of the dependent claims.

[0016] It is also possible to use, for example, a standard axial ball bearing as the axial ball bearing, and an axial bearing bush with an integrated spring element can be provided instead of the spring washer on the opposite side of the axial ball bearing or standard axial ball bearing for a spring action that provides zero play.

[0017] For example, the spring washer may be arranged axially between the gear housing and the axial ball bearing, and in the axial direction the spring washer may for example abut against the gear housing on the one hand and against the contact surface of the axial ball bearing on the other hand.

[0018] The axial ball bearing may be arranged axially between the spring washer and the worm wheel and / or spindle nut, for example, and may contact the spring washer on one side and a raceway on the worm wheel and / or spindle nut on the other side.

[0019] In addition, the axial bearing bush may be designed, for example, as an angle bearing bush. The axial bearing bush may have, for example, a cylindrical radial bearing portion (in particular a radial plain bearing) and, adjacent to said portion, an axial bearing portion in the form of an annular disk. The axial bearing portion may be designed, for example, as an axial annular collar (in particular an axial plain collar bearing) facing radially inward.

[0020] Additionally, for example, a radial bearing bush can be provided in the end region of the worm wheel and / or spindle nut facing the axial ball bearing. The radial bearing bush can be designed, for example, as a hollow cylindrical radial plain bearing. In this case, the radial bearing bush can have a radially protruding portion, for example, so that it is firmly supported against rotation in the gear housing. In other words, the radial bearing bush includes a plain bearing for the worm wheel and / or spindle nut on the inside and a detent on the outside for non-rotatable support of the radial bearing bush in the gear housing.

[0021] In addition, the axial bearing bush may have radially protruding portions, for example, so that it is firmly supported against rotation in the gear housing: in other words, on the inside and at the end, the axial bearing bush comprises in each case a plain bearing for the worm wheel and / or the spindle nut, and on the outside, a detent for non-rotatable support of the axial bearing bush in the gear housing.

[0022] In the region of the drive screw, both the radial and axial bearing bushes may have an outwardly narrowing region to allow for play or clearance between the drive worm and the radial and axial bearing bushes, each narrowing region being a radially decreasing region that terminates in a tapered portion axially facing towards the drive screw.

[0023] The worm wheel and / or worm wheel teeth of the spindle nut may further protrude radially beyond the cylindrical nut portion, which is particularly designed as a sliding portion (e.g., sliding surface) for support in the radial and / or axial bearing bushing.

[0024] The object is further achieved according to the invention by a vehicle seat having a longitudinal adjustment device as described above.

[0025] Additionally, another longitudinal adjustment device can be provided that has the same rail arrangement and is of the same structure or identical to the one described above and equipped with the same drive (especially a direct drive), whereby undesired asynchronous adjustment of the second rail of one rail arrangement of one longitudinal adjustment device with the second rail of the other rail arrangement of the other longitudinal adjustment device can be at least partially compensated for by the axial play.

[0026] In another alternative, to avoid undesired asynchronous adjustments, one drive can guide one of the second rails under control with respect to its rotational speed (in particular under speed and / or position control), while the other second rail has end stops spaced apart more than the end stops of the preceding second rail. In this way, it can be ensured, for example, that only the preceding second rail (in particular only the controlled second rail) moves up to or hits its end stops, and that the vehicle seat does not rotate about its vertical axis when it reaches a stop position relative to its end stop, even if the other second rail moves ahead or behind.

[0027] The advantages achieved by the invention are in particular that a highly efficient, and in particular low-friction, worm wheel and / or spindle nut support, or at least a worm wheel and / or spindle nut support that compensates for different adjustment behaviors in some one or more areas, is made possible by a spindle bearing with axial play and / or by an arrangement of end stops (in particular a short distance from the associated end stop of a leading rail compared to a larger distance from its end stop of a trailing or following rail). The combination of axial play and multiple end stops allows for optimal adjustment with a high degree of comfort. [Brief explanation of the drawings]

[0028] The invention will be described in more detail below with reference to advantageous exemplary embodiments shown in the drawings, but the invention is not limited to these exemplary embodiments.

[0029] [Figure 1] 1 shows a schematic representation of a vehicle seat having a longitudinal adjustment device (also called a longitudinal adjuster). [Figure 2] 1 shows a plan view of a rail arrangement with a drive for a longitudinal adjustment device according to the invention; [Figure 3] 1 shows a perspective view of a rail arrangement with a drive for a longitudinal adjustment device according to the invention; [Figure 4] 4 shows a perspective view of a rail arrangement with a drive according to FIG. 3 without an upper rail. [Figure 5] 4 shows a perspective view of the drive unit according to FIG. 3 without the rail arrangement. [Figure 6] 6 shows a cross section through the gear unit of the drive along line VI in FIG. 5. [Figure 7] 7 shows an enlarged partial view of the cross section shown in FIG. 6 in the contact area between the axial ball bearing and the spring washer. [Figure 8] 1 shows another cross section through the drive and gear unit. [Figure 9] 1 shows a perspective view of a drive and a gear unit with a retaining clamp. [Figure 10] 1 shows a perspective view of the drive and a perspective view of the gear unit without the retaining clamp. [Figure 11] FIG. 1 shows a perspective cross section through the drive and gear unit without the retaining clamp. [Figure 12] FIG. 1 shows a perspective view of the drive and gear unit without the retaining clamp and gear housing. [Figure 13] 1 shows a perspective view of a drive device and a gear unit with a spindle. [Figure 14] FIG. 1 shows a perspective view of a worm wheel with a spindle nut having a grooved race for an axial ball bearing. [Figure 15]FIG. 2 shows a cutaway view of the gear housing of the gear unit. DETAILED DESCRIPTION OF THE INVENTION

[0030] In all the figures, corresponding parts are designated by the same reference numerals.

[0031] The vehicle seat 100, which is shown diagrammatically in FIG. 1 according to the prior art, will be described below using three mutually perpendicular spatial directions. In the case of the vehicle seat 100 installed in a vehicle, the longitudinal direction x extends substantially horizontally, preferably parallel to the vehicle longitudinal direction, which corresponds to the normal driving direction of the vehicle. The transverse direction y, which extends perpendicular to the longitudinal direction x, is likewise aligned horizontally in the vehicle and extends parallel to the vehicle transverse direction. The vertical direction z extends perpendicular to the longitudinal direction x and perpendicular to the transverse direction y. In the case of the vehicle seat 100 installed in a vehicle, the vertical direction z preferably extends parallel to the vehicle vertical axis.

[0032] The position and direction indices used, such as front, rear, up, down, etc., refer to the line of sight of an occupant seated in a normal seating position in the vehicle seat 100, which is installed in the vehicle with the seat back 104 upright in an in-use position suitable for carrying a person and facing the direction of travel in a normal manner. However, the vehicle seat 100 can also be installed or moved in a different orientation, for example transverse to the direction of travel. Unless otherwise stated, the vehicle seat 100 is configured with mirror symmetry about a plane extending perpendicular to the transverse direction y.

[0033] The seat back 104 may be pivotally arranged on the seat component 102 of the vehicle seat 100. To this end, the vehicle seat 100 may optionally include a fitting 106, in particular an adjustment fitting, a rotation fitting, a latch fitting, or a tilt fitting.

[0034] The positional and directional designations used, such as radial, axial, and circumferential, refer to the axis of rotation 108 of the fitting 106. Radial means perpendicular to the axis of rotation 108. Axial means in the direction of or parallel to the axis of rotation 108.

[0035] The vehicle seat 100 may optionally include a longitudinal adjustment device 110. The longitudinal adjustment device 110 includes, for example, a rail arrangement 112 (also referred to as a rail pair) having a first rail element 114 and a second rail element 116. The first rail element 114 is adjustable in the longitudinal direction x relative to the second rail element 116. The first rail element 114 is fixed to the seat component 102. The second rail element 116 is fixed to a structural element of the vehicle, such as the vehicle floor. For each vehicle seat 100, the longitudinal adjustment device 110 may include two rail arrangements 112 that can be synchronously adjusted by a drive device 118 (shown in FIG. 2 ). Alternatively, each rail arrangement 112 may include an associated drive device 118. If the vehicle seat 100 is designed as a bench seat with multiple seating surfaces, more than two rail arrangements 112 can be provided, for example, three, four, five or six rail arrangements 112. The rail arrangements 112 can be arranged parallel to one another and can be adjusted synchronously by one drive device 118 or by multiple drive devices 118.

[0036] An upper rail 114 (also referred to as a seat rail) is connected to the vehicle seat 100 for adjustment. The longitudinal adjustment devices 110, and in particular its rail device 112, can be adjusted synchronously with one another via flexible shafts, in particular by electric motors. Like the vehicle seat 100, the rail arrangement 112 is aligned in the direction of travel or longitudinal direction x.

[0037] For the sake of clarity, the first rail element 114 will be referred to in the following as the upper rail 114. This upper rail 114 (also referred to as the running rail) is assigned to the vehicle seat 100 and is configured to support the vehicle seat 100. The second rail element 116 will be referred to in the following as the lower rail 116. The lower rail 116 is fixedly connected, and for example to the floor of the vehicle.

[0038] Figure 2 shows a plan view of a rail arrangement 112 having a drive 118 for a longitudinal adjustment device 110 according to the present invention. Figure 3 shows a perspective view of a rail arrangement 112 having a drive 118 for a longitudinal adjustment device 110.

[0039] The rail arrangement 112 has a drive 118 for adjusting the upper rail 114 relative to the lower rail 116. The drive 118 has at least one motor 118.1 and one gear unit 118.2. The drive 118 is designed as a direct drive.

[0040] The gear unit 118.2 is at least partially disposed in a cavity 120 formed between the upper rail 114 and the lower rail 116 (shown in FIG. 2).

[0041] The motor 118.1 is arranged perpendicular to the longitudinal direction x and is connected to a gear unit 118.2. The motor 118.1 can be arranged below the seat component 102 (shown in FIG. 1) by means of a motor holder (not shown). The motor 118.1 can, for example, be directly connected to the upper rail 114 and held by a motor holder, in particular a plastic holder.

[0042] The gear unit 118.2 projects at least partially through a rail aperture 114.1 in the upper rail 114 and projects upwardly from or through it in the vertical direction z.

[0043] In this case, the motor 118.1 and the gear unit 118.2 are together mounted to the rail arrangement 112, in particular centrally across the length of the upper rail 114. In particular, the motor 118.1 and the gear unit 118.2 are mounted to the upper rail 114 and can move therewith during longitudinal adjustment.

[0044] Thus, at least the motor 118.1 is easy to replace or repair while in the installed state.

[0045] The gear unit 118.2 can be connected to the upper rail 114. This connection can be made in particular by friction and / or positive connection (e.g. by screw fastening), or materially (e.g. fastened by a welded seam) and / or positive connection (e.g. pressed in) so that high forces can be transmitted.

[0046] For example, in the case of friction-fit and form-fit connections, elastic inserts (e.g. rubber shims) can be provided, which by means of compressively loaded elastic inserts (e.g. rubber mounts) hold the gear unit 118.2 (also referred to as gear for short) in position on the upper rail 114 at an appropriate holding angle, without rattle and under preload. Nevertheless, the friction connection allows a compensating vertical movement of the gear unit 118.2 (and the motor 118.1 coupled to it) in the vertical direction z (also referred to as z-direction) in case there is a need to compensate for height tolerances of the spindle 118.5 (shown in FIG. 4 ) and the upper rail 114.

[0047] FIG. 4 shows a perspective view of a rail array 112 having a drive 118 and a lower rail 116 according to FIG. 3, but without the upper rail 114 of the rail array 112 shown in FIG.

[0048] The drive 118 is designed, for example, as a spindle drive and includes at least a motor 118.1, a gear unit 118.2, two spindle bearings 118.3, 118.4 fixed relative to the lower rail 116 (also called floor rail), and a spindle 118.5 with a spindle screw 118.6.

[0049] FIG. 5 shows a perspective view of the drive 118 according to FIG. 3 without the rail arrangement 112, i.e. without the upper rail 114 and the lower rail 116 (shown in FIG. 3).

[0050] The spindle 118.5 is of fixed design, supported in spindle bearings 118.3, 118.4, and rigidly connected to the lower rail 116 via said bearings. For example, on the one hand, the spindle 118.5 can be rigidly connected materially to one of the spindle bearings 118.3, 118.4 (in particular by a welded joint), and on the other hand, it can be connected to the other of the spindle bearings 118.3, 118.4 by a positive and frictional connection (for example by a threaded joint). In other words, the spindle 118.5 can be held in the spindle bearings 118.3, 118.4 in various ways and rigidly connected to the spindle bearings 118.3, 118.4. This allows the installation sequence to be optimized.

[0051] The first spindle bearing 118.3 can be designed, for example, as an L-profile. The second spindle bearing 118.4 can be designed, for example, as a U-profile or a bearing pedestal. The spindle bearings 118.3, 118.4 support the free spindle end of the spindle 118.5 and can be rigidly connected to the lower rail 116 in various ways, for example, via associated fastening lugs 118.31 or fastening surfaces 118.41, as in the examples described above.

[0052] The gear unit 118.2 (shown in FIG. 4) includes a gear holder 118.21 (particularly a U-shaped holding clamp), by which the gear unit 118.2 is held on the upper rail 114 by a positive and / or frictional connection. At a plurality of free clamping ends 118.211, the gear holder 118.21 has, for example, outer latching noses 118.24 for fastening the gear unit 118.2 to the adjustable upper rail 114. These free clamping ends 118.211 may, for example, be present within a hole pattern in the upper rail 114 and may be partially materially connected to the upper rail 114, for example, by a welded joint. Alternatively, they may be connected to each other without a material bond, and may absorb high longitudinal forces (particularly in a crash) because the latching noses 118.24 are locked within laterally associated hole patterns and are thus connected by a positive connection.

[0053] The gear holder 118.21 is configured to receive and hold the gear housing 118.22. The worm wheel 118.23 and spindle nut 118.230 are rotatably supported in the gear housing 118.22, where the spindle nut 123.230 is engaged with the spindle 118.5. For example, the gear housing 118.22 may be held in the gear holder 118.21 while being supported by a plurality of elastic inserts (not specifically shown, e.g., a plurality of rubber mounts).

[0054] In this case, the spindle 118.5 is fixedly supported by a through-opening 118.7 (also referred to as spindle opening) in the gear holder 118.21. In the gear housing 118.22, a spindle nut 123.230 runs on the spindle 118.5.

[0055] Here, the worm wheel 118.23 may, for example, be operatively connected to the spindle nut 123.230, which in turn is operatively connected to, and in particular meshes with, the spindle 118.5. The worm wheel 118.23 and the spindle nut 123.230 (shown in FIG. 14) may, for example, form a single component. Alternatively, the spindle nut 123.230 may be of separate design, and the worm wheel 118.23 may be operatively connected to, and in particular coupled in terms of movement or co-rotation with, the spindle nut 123.230.

[0056] In this case, the worm wheel 118.23 and / or the spindle nut 123.230 may be held in place in a frictional connection to the upper rail 114 (shown in FIG. 3) via the gear housing 118.22.

[0057] FIG. 6 shows a cross section through the gear unit 118.2 of the drive 118 along line VI in FIG.

[0058] The drive 118 may include, for example, a fixed spindle 118.5 (shown in FIG. 5), specifically a spindle 118.5 fixedly supported in the lower rail 116 (shown in detail in FIGS. 3 and 4).

[0059] The gear unit 118.2 supported on the upper rail 114 (shown in FIG. 3) can be designed as a worm-wheel gear. The gear unit 118.2 can include, for example, a drive worm 118.25 drivable by the motor 118.1 and having worm teeth 118.26 (also shown in FIG. 8), and a worm wheel 118.23 having worm wheel teeth 118.27 operatively connected (in particular meshing) with the worm teeth 118.26.

[0060] The drive worm 118.25, worm wheel 118.23, and spindle nut 123.230 are supported within the gear housing 118.22. If the worm wheel 118.23 and spindle nut 123.230 are designed as a single unit, worm wheel teeth 118.27 (also referred to as outer worm wheel teeth) that mesh with the drive worm 118.25 are provided on the outside of the spindle nut 123.230.

[0061] The worm wheel 118.23 and / or the spindle nut 123.230 are axially elastically and, in particular, rotatably supported in the gear housing 118.22 in the axial direction (in particular in the longitudinal direction x) via an axial ball bearing 118.28 on the one hand and an axial bearing bush 118.29 on the other hand.

[0062] The gear unit 118.2 is used to transmit the rotational motion obtained by the motor 118.1 (shown in FIG. 5) (particularly a micromotor) via the worm teeth 118.26 of the drive worm 118.25 and the worm wheel teeth 118.27 of the worm wheel 118.23 to the spindle nut 123.230, which engages with the spindle 118.5 via a trapezoidal thread 118.232. This converts the rotational motion of the drive worm 118.25 and the worm wheel 118.23 into linear motion of the spindle nut 123.230 along the spindle 118.5. In this case, the linear motion of the spindle nut 123.230 is transmitted to the upper rail 114 via the gear housing 118.22, and then to the seat component 102 (shown in FIG. 1) via the upper rail 114. As a result, the upper rail 114 and the sheet component 102 fastened thereto are moved linearly relative to the lower rail 116 along the fixed spindle 118.5.

[0063] In this case, the worm wheel 118.23 is supported on one side, in particular axially resiliently, relative to the gear housing 118.22, either directly or via a spindle nut 123.230, via at least one spring-loaded axial ball bearing 118.28 (in particular a combination of the axial ball bearing 118.28 and the spring washer 118.20). In the exemplary embodiment shown, the worm wheel 118.23 has a nut part (also referred to as spindle nut 123.230) with an internal trapezoidal thread 118.232, which engages with the spindle 118.5 (shown in Figures 4 or 5).

[0064] The zero axial play condition is achieved by the spring force of a spring washer 118.20 located between the axial ball bearing 118.28 (also called ball bearing ring) and the gear housing 118.22.

[0065] The fact that the worm wheel 118.23 and the integrated spindle nut 123.230 are axially elastically supported allows for a particularly efficient rail drive (= drive 118 for the radial arrangement 112) with low friction losses, since the load is mainly borne by the axial ball bearing 118.28. This is possible because the front seats are generally provided with a rail inclination. In this way, it is possible to ensure that the main load is always dissipated via the axial ball bearing 118.28 to the upper rail 114.

[0066] If loads are expected in both directions (especially in the longitudinal direction x), it is also possible to operate with two axial ball bearings 118.28, since otherwise the sliding friction of the variant with only one axial ball bearing 118.28 and one bearing bush (especially one axial bearing bush 118.29) would result in poor efficiency.

[0067] If two axial ball bearings 118.28 are provided, the axial ball bearings 118.28 may be arranged, for example, on either side of the spindle nut 123.230 (not shown in detail). The axial bearing bushes 118.29 are accordingly provided on either side of the spindle nut 123.230 and accordingly configured, for example, as only an L-shaped profile. In particular, the axial ball bearing 118.28 and the axial bearing bush 118.29 on the left side of the spindle nut 123.230 are also arranged and designed accordingly on the right side.

[0068] The variant with one axial ball bearing 118.28 represents a particularly low-cost variant of the drive 118, but has the disadvantage of reduced efficiency in the case of loads on the plain bearing (radial plain bearing part 118.83 shown in FIG. 7).

[0069] For example, the worm wheel 118.23 and the spindle nut 123.230 can be supported in the gear housing 118.22 elastically or in a manner that compensates for axial tolerances via a composite bearing consisting of a spring-loaded axial ball bearing 118.28 (a combination of a spring washer 118.20 and an axial ball bearing 118.28) and an axial bearing bush 118.29. The axial bearing bush 118.29 can be designed, for example, as an axial plain bearing and / or a radial plain bearing.

[0070] The worm wheel 118.23 with an axially elastically supported and integrated spindle nut 123.230 is understood in particular to mean a spiral gear with an integrated nut that is axially elastically preloaded or spring-loaded and thus supported without play in the gear housing 118.22. In particular, the worm wheel 118.23 with an integrated spindle nut 123.230 is axially elastically supported relative to the gear housing 118.22.

[0071] For this purpose, a spring washer 118.20 can be provided in the region of the axial ball bearing 118.28. Alternatively or additionally, the axial bearing bush 118.29 may include a spring element integrated in the region of said bush.

[0072] For example, the spring washer 118.20 may be arranged axially between the gear housing 118.22 and the axial ball bearing 118.28. On the one hand, the spring washer 118.20 abuts the gear housing 118.22 with its outer contact 118.201 in the axial direction, and on the other hand, the spring contact surface 118.281 contacts the axial ball bearing 118.28, thus making it possible to have an inner contact 118.202 with, for example, the balls 118.282 of the axial ball bearing 118.28. The lever arm between these contact areas and the free space between the gear housing 118.22 and the spring washer 118.20 behind the inner contact 118.202 (= ball contact) allow for spring deflection within the required axial tolerance compensation.

[0073] The axial ball bearing 118.28 may be arranged, for example, axially between the spring washer 118.20 and the spindle nut 123.230. In the axial direction, for example, the axial ball bearing 118.28 can contact the spring washer 118.20 with its inner contact area 118.202 on the one hand, and roll on a raceway 118.231 on the spindle nut 123.230 on the other hand. In this case, the raceway 118.231 can be designed, for example, as an annular track groove, in particular as an annular groove in the end face, of the worm wheel 118.23 with the integrated spindle nut 123.230, facing the axial ball bearing 118.28.

[0074] It is also possible to use, for example, a standard axial ball bearing as the axial ball bearing 118.28. For the purpose of spring action to provide a zero-play condition, an axial bearing bushing 118.29 with an integrated spring element (not specifically shown) may be provided instead of the spring washer 118.20 on the opposite side of the axial ball bearing 118.28 or the standard axial ball bearing. For example, a plastic spring plate may be integrated. Alternatively, for example, the axial bearing bushing 118.29 may be a plastic bearing bushing with an integrally molded plastic spring element for axial force action, or a separate spring washer 118.20.

[0075] In addition, the axial bearing bush 118.29 can be designed, for example, as an angle bearing bush. The axial bearing bush 118.29 can have, for example, a cylindrical radial bearing portion 118.291 (in particular a radial plain bearing) and, adjacent to said portion, an axial bearing portion 118.292 in the form of an annular disk. The axial bearing portion 118.292 can be designed, for example, as an axial annular collar (in particular an axial plain collar bearing) facing radially inward.

[0076] Additionally, it is possible, for example, to provide a radial bearing bush 118.8 in the end region of the spindle nut 123.230 facing the axial ball bearing 118.28. The radial bearing bush 118.8 can be designed, for example, as a hollow cylindrical radial plain bearing. In this case, the radial bearing bush 118.8 can have, for example, a radially protruding portion 118.81 in order to firmly support the radial bearing bush 118.8 against rotation in the gear housing 118.22. In other words, the radial bearing bush 118.8 includes on the inside a plain bearing for the spindle nut 123.230 and on the outside a detent 118.9 for non-rotatable support of the radial bearing bush 118.8 in the gear housing 118.22.

[0077] In addition, the axial bearing bush 118.29 may have an additional radially protruding portion 118.293, for example, so as to be firmly supported against rotation in the gear housing 118.22. In other words, on the inside, in the radial bearing portion 118.291 and in the end axial bearing portion 118.292, the axial bearing bush 118.29 comprises a plain bearing for the worm wheel 118.23 with an integrated spindle nut 123.230 in each case, and on the outside, in the radially protruding portion 118.293, the axial bearing bush 118.29 comprises another detent 118.9 for non-rotatable support of the axial bearing bush 118.29 in the gear housing 118.22.

[0078] In the region of the drive screw 118.25, both the radial bearing bushing 118.8 and the axial bearing bushing 118.29 may have associated outwardly directed narrowing regions 118.82 and 118.294. The narrowing regions 118.82 and 118.294 respectively provide clearance between the drive worm 118.25 and the radial bearing bushing 118.8, and between the drive worm 118.25 and the axial bearing bushing 118.29. Each narrowing region 118.82, 118.294 is a radially decreasing region that terminates in an axially directed taper in the direction of the drive screw 118.25. This profile may also be described by a cylindrical subtractive solid having an axis identical to the axis of rotation of the drive worm 118.25.

[0079] The worm wheel teeth 118.27 of the spindle nut 123.230 may furthermore project radially beyond the cylindrical nut portion 118.233, which is designed in particular as a sliding portion (e.g., sliding surface) for support in the radial bearing bush 118.8 and / or the axial bearing bush 118.29.

[0080] Figure 7 shows an enlarged partial view of the cross section shown in Figure 6 at the contact area between the spring washer 118.20, with its outer contact portion 118.201 facing the gear housing 118.22 and its inner contact portion 118.202 facing the axial ball bearing 118.28, and the axial ball bearing 118.28. The balls 118.282 roll in the raceway 118.231 at the end of the spindle nut 123.230.

[0081] The radial bearing bush 118.8 includes, on the inside, a radial plain bearing portion 118.83 for the spindle nut 123.230 and, on the outside, a detent 118.9 with a radially protruding portion 118.81 for non-rotatable support of the radial bearing bush 118.8 in a corresponding housing recess 118.221 in the gear housing 118.22.

[0082] FIG. 8 shows another cross section through the drive device 118 with the motor 118.1 and the gear unit 118.2.

[0083] In the radial direction, the worm wheel 118.23 with an integrated spindle nut 123.230 designed as a drive nut and worm wheel teeth 118.27 designed as external teeth is held at an appropriate distance from the drive screw 118.25 and its worm teeth 118.26 at two points via a radial bearing bush 118.8 and an axial bearing bush 118.29 designed as, for example, plastic bushes.

[0084] The worm wheel 118.23 with its integral spindle nut 123.230 is supported at its end opposite the axial ball bearing 118.28 against the gear housing 118.22 (shown in FIG. 6) via an axial bearing bushing 118.29. The plastic axial bearing bushing 118.29 is non-rotatably supported within the gear housing 118.22 as described above with reference to FIGS. 6 and 7.

[0085] The axial ball bearing 118.28 (shown in FIG. 6) is arranged in the gear housing 118.22 to bear the main load in the case of a typical rail tilt of the front seat rail. In this case, the spring washer 118.20 (shown in FIG. 6) is pressed in response to the force, reducing the load on the axial bearing bush 118.29 (especially the plastic bush that contacts the end face) located on the opposite side.

[0086] In special cases, axial ball bearings 118.28 may be arranged on both sides of the worm wheel 118.23 and / or spindle nut 123.230 in order to obtain high efficiency in both adjustment directions and all possible rail inclinations. In both cases (one or two axial ball bearings 118.28), an advantageously relatively low-power motor 118.1 can be used.

[0087] Further efficiency improvements can be achieved by the bearing interface 118.11 of the motor shaft 118.12 in the gear housing 118.22. For example, the motor shaft 118.12 can be point-supported at one end in the gear housing 118.22 in a shaft bearing 118.222. The laterally supported motor shaft 118.12 can have a very small diameter.

[0088] The gear housing 118.22 may be manufactured from a die-cast material, in particular a zinc die-cast material, so that the gear housing 118.22 has low friction and very good bearing properties, and therefore the frictional work in the drive stage is significantly reduced.

[0089] The gear unit 118.2 may be vibrationally isolated from the upper rail 114 by a rubber element 118.220.

[0090] The motor 118.1 can be directly connected to the gear unit 118.2 (in particular the gear housing 118.22) via the adapter 118.13. Therefore, vibrations from the motor 118.1 and the gear unit 118.2 are only minimally transmitted to the upper rail 114. Furthermore, the gear unit 118.2, designed as a worm gear, operates smoothly due to its principle, which further helps to reduce noise levels.

[0091] 9 shows a perspective view of the drive 118 with a motor 118.1 and a gear unit 118.2. The gear unit 118.2 has a gear holder 118.21 designed as a holding clamp for fastening to the upper rail 114 (shown in FIG. 2).

[0092] Figure 10 shows a perspective view of the drive device 118 with the motor 118.1 and the gear unit 118.2, without the gear holder 118.21 (shown in Figure 9). The gear housing 118.22 is connected to the motor 118.1 (in particular its motor housing 118.14) by means of an adapter 118.13.

[0093] Another embodiment of the axial motor retention system is possible, for example, by a wire clip, which first pivots away laterally and then, after insertion of the motor 118.1 (with the drive worm 118.25 on the drive shaft or motor shaft 118.12), pivots to the position shown in Figure 10. In this case, such a wire clip also allows for spring-loaded retention in the axial direction, thus not allowing any play.

[0094] 11 shows a perspective cross-sectional view of the drive 118 with the motor 118.1 and the gear unit 118.2, without the gear holder 118.21 in the area of ​​the axial ball bearing 118.28. Above the axial ball bearing 118.28, the motor housing 118.14 and the gear housing 118.22 are additionally connected to one another, for example by a threaded connection with a fastening screw 122. The gear housing 118.22 is formed from two housing shells 118.223, 118.224, which are connected to one another below the axial ball bearing 118.28 by another fastening screw 122.

[0095] 12 shows a perspective view of the drive 118 with the motor 118.1 and the gear unit 118.2, without the gear holder 118.21 and the gear housing 118.22. The gear unit 118.2 is designed as a worm gear and has a drive worm 118.25. The drive worm 118.25 is driven by the motor 118.1 and engages with the worm wheel 118.23. On the one hand, an axial ball bearing 118.28 is arranged at one end of the worm wheel 118.23 and / or the spindle nut 123.230, and on the other hand, an axial bearing bush 118.29 is arranged at the other end. A spring washer 118.20 (particularly an annular spring washer) for axially elastic support of the worm wheel 118.23 with its integral spindle nut 123.230 within the gear housing 118.22 is arranged outside the axial ball bearing 118.28, as described above. In addition, a radial bearing bush 118.8 is arranged between the worm wheel teeth 118.27 and the axial ball bearing 118.28.

[0096] FIG. 13 shows FIG. 12 additionally with a spindle 118.5 fixedly arranged in the gear unit 118.2.

[0097] Figure 14 shows a perspective view of the worm wheel 118.23 with an integrated spindle nut 123.230. The outer worm wheel teeth 118.27 engage the drive worm 118.25, the internal trapezoidal thread 118.232 engages the spindle 118.5, the outer raceway 118.231 slides within the radial bearing bush 118.8 and the axial bearing bush 118.29, and the raceway 118.231 (also called running grooves) for the balls 118.282 of the axial ball bearing 118.28 (shown in Figure 13) extends around the end face to predetermine the running direction of the balls 118.282. The spring washer 118.20 alone cannot ensure this.

[0098] Figure 15 shows a cutaway view of the gear housing 118.22 of the gear unit 118.2. Figure 15 shows the gear housing 118.22 as an open housing with a top view of one of the housing shells. A drive worm 118.25 and spindle nut 123.230 are rotatably mounted within the gear housing 118.22 and are driven by the drive worm 118.25.

[0099] The gear unit 118.2 of FIG. 15 differs from the gear unit 118.2 according to FIG. 6 in that it includes two axial ball bearings 118.28 instead of the one axial ball bearing 118.28 shown in FIG.

[0100] Two axial ball bearings 118.28 are located on either side of the spindle nut 123.230. In addition, a spring washer 118.20 is disposed on each side of the spindle nut 123.230 between the respective axial ball bearing 118.28 and the gear housing 118.22.

[0101] Instead of the axial bearing bush 118.29 and radial bearing bush 118.8 shown in Figure 6, the design according to Figure 15 includes two radial bearing bushes 118.8 arranged between the spindle nut 123.230 and the gear housing 118.22. Each radial bearing bush 118.8 includes a radially protruding portion.

[0102] The construction and design of the axial ball bearing 118.28 and spring washer 118.20 are the same as the components described above and shown in FIG. [Explanation of symbols]

[0103] 100 Vehicle seats 102 Seat parts 104 seat back 106 Fitting 108 Rotational Axis 110 Longitudinal adjustment device 112 Rail Array 114 First rail element (upper rail) 114.1 Rail Aperture 116 Second Rail Element (Lower Rail) 118 Drive Unit 118.1 Motor 118.11 Bearing Interface 118.12 Motor shaft 118.13 Adapter 118.14 Motor housing 118.2 Gear units 118.20 Spring washer 118.201 Outer contacts 118.202 Inner contact 118.21 Gear holder 118.211 Clamp end 118.22 Gear housing 118.220 Rubber elements 118.221 Housing recess 118.222 Shaft bearing 118.223 Housing shell 118.224 Housing shell 118.23 worm wheel 123.230 Spindle nut 118.231 Racing surface 118.232 Trapezoidal thread 118.233 Nut part 118.24 Latching Nose 118.25 Drive worm 118.26 Worm teeth 118.27 Worm wheel teeth 118.28 Axial ball bearing 118.281 Spring contact surface 118.282 balls 118.29 Axial bearing bush 118.291 Radial bearing part 118.292 Axial bearing part 118.293 Radial projection 118.294 Narrow area 118.3 Spindle bearing (first spindle bearing) 118.31 Fastening legs 118.4 Spindle bearing (second spindle bearing) 118.41 Fastening surfaces 118.5 spindle 118.6 Spindle screw 118.7 Through openings 118.8 Radial Bearing Bush 118.81 Radial projection 118.82 Narrow area 118.83 Radial plain bearing part 118.9 Anti-rotation 120 cavity 122 Fastening screw VI line x Longitudinal direction y transverse direction z vertical direction

Claims

1. A longitudinal adjustment device (110) comprising at least: one rail array (112); one drive (118) for said rail arrangement (112); Including, The rail arrangement (112) includes a first rail and a second rail movably guided in the first rail; The drive device (118) comprises at least one motor (118.1), a gear unit (118.2) supported on the second rail, a spindle (118.5) having a spindle screw (118.6), and spindle bearings (118.3, 118.4); the gear unit (118.2) includes a drive worm (118.25) drivable by the motor (118.1), a worm wheel (118.23) operatively connected to the drive worm (118.25), and a spindle nut (123.230) operatively connected to the worm wheel (118.23); the spindle (118.5) is of fixed design, supported on the spindle bearings (118.3, 118.4) and connected to the first rail; The drive worm (118.25), the worm wheel (118.23), and the spindle nut (123.230) are supported in a gear housing (118.22); The worm wheel (118.23) and / or the spindle nut (123.230) are axially elastically supported in the gear housing (118.22) and axially supported on the one hand via at least one axial ball bearing (118.28) and on the other hand via an axial bearing bush (118.29), a longitudinal adjustment device (110).

2. 2. The longitudinal adjustment device (110) according to claim 1, wherein a spring washer (118.20) is arranged axially between the gear housing (118.22) and the axial ball bearing (118.28).

3. 3. The longitudinal adjustment device (110) according to claim 2, wherein the spring washer (118.20) axially abuts against the gear housing (118.22) on the one hand and against a spring contact surface (118.281) on the axial ball bearing (118.28) on the other hand.

4. 4. The longitudinal adjustment device (110) according to claim 2 or 3, wherein the axial ball bearing (118.28) is arranged axially between the spring washer (118.20) and the spindle nut (123.230) and / or the worm wheel (118.23).

5. 5. The longitudinal adjustment device (110) according to claim 1, wherein the axial ball bearing (118.28) is in axial contact with the spring washer (118.20) on the one hand and with the spindle nut (123.230) and / or with a raceway (118.231) on the worm wheel (118.23) on the other hand.

6. A longitudinal adjustment device (110) according to any one of claims 1 to 6, wherein the axial bearing bush (118.29) is designed as an angle bearing bush and has a cylindrical radial bearing portion (118.291) and an axial bearing portion (118.292) in the form of an annular disk adjacent to the radial bearing portion (118.291).

7. 7. The longitudinal adjustment device (110) according to any one of claims 1 to 6, wherein the radial bearing bush (118.8) is arranged in an end region of the spindle nut (123.230) facing the axial ball bearing (118.28).

8. 8. The longitudinal adjustment device (110) according to claim 7, wherein the radial bearing bush (118.8) has a radial protruding portion (118.81) for being firmly supported against rotation in the gear housing (118.22).

9. 9. The longitudinal adjustment device (110) according to any one of claims 1 to 8, wherein the axial bearing bush (118.29) has a radial protruding portion (118.293) so as to be firmly supported against rotation within the gear housing (118.22).

10. 10. The longitudinal adjustment device (110) according to any one of claims 1 to 9, wherein the motor (118.1) includes a motor shaft (118.12) that extends into the gear housing (118.22) and drives the drive worm (118.25) disposed within the gear housing (118.22).

11. A vehicle seat (100) comprising a longitudinal adjustment device (110) according to any one of claims 1 to 10.

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