LINEAR DRIVE, LONGITUDINAL ADJUSTMENT UNIT OF A SEAT AND MOTOR VEHICLE

Description

[0001] The present invention relates to a linear drive with the features of claim 1, a longitudinal adjustment unit for a seat with the features of claim 22 and a motor vehicle with the features of claim 23.

[0002] Linear actuators are known in various configurations from the prior art and are widely used as longitudinal adjustment units for adjusting the position of a seat in motor vehicles. Longitudinal adjustment units typically interact with a lower rail fixed to a chassis and an upper rail arranged within it, the upper rail being movable by the longitudinal adjustment unit and coupled to the seat. In the prior art, the adjustment of the upper rail by the longitudinal adjustment unit is typically achieved by means of a spindle arranged within the upper rail and supported at its respective first and second ends.

[0003] Such longitudinal adjustment units are known, for example, from DE 36 40 197 A1, DE 42 08 948 C2, DE 196 42 655 C2, DE 198 15 283 A1, DE 10 2004 013 009 A1 and DE 10 2006 052 936 A1.

[0004] Further information can be found in the publications JP 2022 143 776 A and WO 2020 24 52 52 A1.

[0005] Due to the high demands placed on a linear actuator, which, in addition to its adjustment function as a longitudinal adjustment unit, must also guarantee crash safety, such linear actuators exhibit different designs that require different manufacturing methods and processes. It has been shown that backlash-free linear movement is only achievable with considerable effort and that adjusting the breaking loads is complex. Furthermore, existing longitudinal adjustment units are only of limited use in the implementation of novel seating concepts in vehicles.

[0006] This is where the present invention comes in.

[0007] The invention is based on the objective of proposing an improved linear drive that advantageously eliminates the disadvantages known from the prior art. Furthermore, a linear drive with a particularly compact design is preferred, which in particular enables virtually backlash-free linear movement with a simultaneously variable and adjustable breaking load. In addition, the proposed linear drive should be capable of achieving a high adjustment speed.

[0008] These tasks are solved by a linear drive with the features of claim 1, a longitudinal adjustment unit with the features of claim 22, and a motor vehicle with the features of claim 23.

[0009] The linear drive according to the invention, comprising the features of claim 1, has at least one rail oriented along a longitudinal axis and at least one cam forming a toothed profile. The at least one cam preferably lies in an associated plane of the rail and comprises two opposing profile surfaces. Furthermore, the linear drive has at least one slide and a drive shaft. The at least one slide is movable transversely to the longitudinal axis and engages in the at least one cam, wherein the at least one slide is drivenly coupled to the drive shaft such that the at least one slide can perform at least one cyclic movement during one revolution of the drive shaft and can thereby alternately slide against the opposing profile surfaces in the at least one cam to generate a thrust in one direction of the longitudinal axis.

[0010] The present invention is based on the idea that the at least one slide engages in the at least one cam having a toothed profile. The at least one slide preferably engages in the cam such that the slide is always positively locked in the cam along its longitudinal axis and, during movement in one direction along the longitudinal axis, alternately slides against and pushes against the opposite profile surfaces of the toothed profile. The slide can thus ensure backlash-free linear movement in both directions oriented along the longitudinal axis.

[0011] Furthermore, the proposed linear drive can be easily extended along its longitudinal axis compared to prior art linear drives with a spindle, without altering its fracture behavior. For example, the rail can either be replaced with a longer one, or several rails, even of different lengths, can be joined together along the longitudinal axis.

[0012] A further development of the present invention provides that the linear drive has at least two sliders which engage in the at least one cam and that the engagement of the at least two sliders in the at least one cam is with a phase shift.

[0013] The phase shift between the at least two sliders can be achieved in various ways. For example, as will be described in detail later, the at least two sliders can engage in different cams, with the tooth profiles of the at least two cams being offset along the longitudinal axis, or by deflecting the at least two sliders transversely to the longitudinal axis via the drive shaft at different angles of rotation. This phase-shifted engagement of the at least two sliders allows for particularly smooth movement along the longitudinal axis. Simultaneously, the breaking load of the linear drive can be easily dimensioned by using a corresponding number of sliders engaging in the cams.

[0014] Furthermore, it has proven advantageous if the tooth profile of the guide has a zigzag or wavy shape. The two opposing profile surfaces can have any number of teeth, each formed from a rising and a falling tooth flank, with the point or section between two adjacent tooth flanks being referred to here as the transition. Preferably, the transitions of two opposing profile surfaces of a guide are arranged approximately transversely to the longitudinal axis and in alignment.

[0015] According to a further development of the present invention, the distance between the opposing profile surfaces is constant or uniform. The distance between the opposing profile surfaces is preferably measured transversely to the longitudinal axis.

[0016] According to a further development of the present invention, the at least one cam is formed as a groove or opening in the at least one rail. The groove or opening is preferably formed on a main surface, also called cam surface, of the rail and preferably has a constant groove depth.

[0017] According to the invention, the respective slide comprises at least one pin, preferably at least two pins, wherein the at least one pin engages in the cam. The at least one pin projects from a base body of the slide and extends in an axis transverse to the longitudinal axis and transverse to the axis along which the at least one slide performs the cyclic and linear movement. If, according to a preferred embodiment, two or more pins are provided on the at least one slide, the distance between the pins of the respective slide corresponds to the distance between the adjacent teeth of the tooth profile.

[0018] Furthermore, it has proven advantageous if the at least one pin has at least one friction surface that can come into effective contact with the opposing profile surfaces to generate thrust. The friction surface of the pin can come into surface contact or line contact with the respective profile surface.

[0019] It can also be advantageous if at least one pin has a coating that has improved friction properties and allows for smooth rubbing against the opposing profile surfaces.

[0020] According to a preferred embodiment of the present invention, the at least one friction surface corresponds to the shape of a tooth root between two adjacent teeth, whereby the at least one friction surface of the at least one slider is in operative contact with two immediately adjacent tooth flanks of one of the opposing profile surfaces.

[0021] Furthermore, it is according to the invention if the distance between the opposing profile surfaces of the cam corresponds approximately to the distance between two diametrically opposed sides of the at least one pin. In the case that two or more sliders are provided, it can be advantageous if the distance between two diametrically opposed sides of the respective at least one pin is slightly smaller than the distance between the opposing profile surfaces, thereby avoiding unwanted friction or jamming of the pin in the cam.

[0022] Furthermore, a further development of the present invention provides that the at least one pin has a cuboid, rhombus, or cylindrical cross-section. In particular, it is preferred that the at least one pin has a cuboid or rhombus shape, thereby achieving a planar contact between the respective profile surface and the at least one pin.

[0023] Furthermore, according to a preferred further development, it has proven advantageous if the respective slide and / or the cam is symmetrically designed.

[0024] Furthermore, it has proven advantageous if the drive shaft is arranged outside the track. Preferably, the track lies in the plane of the rail, with the drive shaft arranged either along or parallel to a normal vector of the plane of the rail, or in a plane parallel to and spaced apart from the plane of the rail along its longitudinal axis.

[0025] Furthermore, it has proven advantageous to provide at least two cams, each with at least one slide engaging in it. The at least two cams can be formed on a single rail, extending parallel and spaced apart along the longitudinal axis, or they can be formed on two rails arranged parallel and spaced apart along the longitudinal axis. Preferably, the at least two cams are arranged symmetrically to the drive shaft.

[0026] A preferred embodiment of the present invention provides that the at least two backdrops are each arranged in a rail plane, wherein the at least two rail planes are arranged parallel and spaced apart.

[0027] It has also proven advantageous if the respective rail has a guide on each of two opposing main surfaces, or if at least two rails are provided, and each of the at least two rails has at least one guide.

[0028] The at least one cam can be arranged on a side facing towards or away from a rotational axis of the drive shaft, whereby combinations with at least two cams are conceivable, in which one of the cams is arranged on the side facing the drive shaft and the other cam is arranged on the side away from the drive shaft.

[0029] A further development of the present invention provides that the drive shaft comprises at least one guide element that dictates the cyclic movement of the at least two slides during the rotation of the drive shaft. The guide element can, for example, be formed by a crankshaft or camshaft, and the respective slide can have contact surfaces that interact with the guide element. In the simplest case, the slide can have a recess or opening in which the at least one guide element of the drive shaft can come into operative contact with the contact surfaces of the slide.

[0030] A further development of the present invention provides that the at least one guide means is designed such that the respective slider can perform an approximately linear movement between the turning points of the cyclic movement. Such a guide means can, for example, be formed from an approximately heart-shaped guide means, which is known, for example, from EP 3 980 668.

[0031] Furthermore, it has proven advantageous to have a housing, and to mount the drive shaft and at least one slider movably to the housing transversely to the longitudinal axis. The housing can, for example, be supported against the rail and can, for example, be coupled to the seat in a vehicle.

[0032] A further advantageous embodiment of the present invention provides for a drive, wherein the drive drives the at least one drive shaft. In particular, it is preferred if the drive is an electric drive, and if a transmission, preferably a reduction transmission, is provided between the drive and the drive shaft.

[0033] According to a preferred embodiment of the present invention, the drive is arranged between at least two slides. For example, it is advantageous if the drive is arranged in the longitudinal axis between at least two slides or if the drive is arranged transversely to the longitudinal axis between at least two slides.

[0034] Furthermore, the present invention relates to a longitudinal adjustment unit with a linear drive according to the invention.

[0035] Another aspect of the present invention relates to a motor vehicle with at least one such linear drive according to the invention.

[0036] An exemplary embodiment of the invention and further developments of the present invention are described in detail below with reference to the accompanying drawings. The drawings show: Figure 1 shows a perspective view of a first embodiment of a linear drive with a rail oriented along a longitudinal axis, a slider engaging in the cam, and a drive shaft with a drive by which the slider is movable transversely to the longitudinal axis. Figure 2 shows a top view of the linear drive according to... Figure 1 Figure 3 shows a sectional view along the section line AA in Figure 2 Figure 4 shows a side view of the slides of the linear actuator according to Figure 1Figure 5 shows a perspective view of a second embodiment of the linear drive, Figure 6 shows a top view of the linear drive according to Figure 5 Figure 7 shows two highly simplified views of a slide according to Figure 5 Figure 8 shows a perspective view of a third embodiment of the linear drive, and Figure 9 shows a simplified perspective view of the slides and the drive unit according to Figure 8 Figure 10 is a sectional view of the linear drive according to Figure 8, Figure 11 is a perspective view of a fourth embodiment of the linear drive, Figure 12 is a side view of the linear drive according to Figure 11 Figure 13 shows a section created along the section line B - B in Figure 12 Figure 14 shows a sectional view along the section line A - A according to Figure 12 Figure 15 shows two representations of the slides and the drive mechanism according to Figure 11Figure 16 shows a perspective view of a fourth embodiment of the linear drive, and Figure 17 shows a simplified perspective view of the slides of the linear drive with the drive shaft according to Figure 16 Figure 18 is a sectional view of the linear drive according to Figure 16, Figure 19 is a perspective view of a fifth embodiment of the linear drive, Figure 20 is a sectional view of the linear drive according to Figure 19, Figure 21 is a simplified perspective view of the slides of the linear drive with the drive shaft according to Figure 19 Figure 22 shows a perspective view of a sixth embodiment of the linear drive, and Figure 23 shows a simplified sectional view of the linear drive transverse to the longitudinal axis. Figure 22 Figure 24 shows a simplified sectional view parallel to the longitudinal axis of the linear drive according to Figure 22Figure 25 shows a perspective view of a seventh embodiment of the linear drive, and Figure 26 shows a simplified perspective view of the linear drive according to Figure 25 Figure 27 shows a simplified sectional view transverse to the longitudinal axis of the linear drive according to Figure 25 Figure 28 shows a simplified sectional view of the linear drive according to Figure 25 with a slider that engages in the track's cam, Figure 29 a simplified sectional view of the linear drive analogous to Figure 28 , wherein the drive shaft has undergone a quarter turn counterclockwise about its axis of rotation, Figure 30a a crankshaft or camshaft of the drive shaft according to the embodiments according to the Figures 1-29 Figure 30: Detailed view of a rail according to the Figures 1-29 , Figure 31a a further development of the crankshaft or camshaft of the drive shaft, and Figure 31 a detailed representation of the rail for a crankshaft or camshaft according to Figure 31a.

[0037] Identical or functionally equivalent parts or features are identified by the same reference numerals in the detailed description of the figures below. Furthermore, not all identical or functionally equivalent parts or features in the figures are assigned a reference number.

[0038] Figure 1 Figure 1 shows an exemplary simplified and perspectively depicted design of a linear drive 1 which can be used, for example, in a longitudinal adjustment unit 2 for a (not shown) seat of a (not shown) motor vehicle.

[0039] The linear drive 1 according to Figure 1 The system comprises a rail 10 oriented along a longitudinal axis L, at least one slider 30 movable transversely to the longitudinal axis L, and at least one driveable drive shaft 50. The drive shaft 50 is rotatable in a rotational axis X.

[0040] The at least one rail 10 is oriented along the longitudinal axis L, where, for example, the longitudinal axis L can be defined by a vehicle longitudinal axis of the motor vehicle. The rail 10 has at least one cam 20 forming a tooth profile 21, which comprises two opposing profile surfaces 25, 26.

[0041] The at least one rail 10 is preferably cuboid in cross-section. The groove or opening is preferably formed on a main surface, which is hereinafter referred to as the cam surface 11, of the rail 10.

[0042] The backdrop surface 11 preferably spans a rail plane E which is oriented parallel to the longitudinal axis L.

[0043] The cam 20, designed as a groove or opening, extends in the direction of the normal vector into the rail 10, after which the opposing profile surfaces 25, 26 are arranged parallel to the normal vector.

[0044] Scenery 20 preferably has a constant scene depth.

[0045] The backdrop 20 according to the detailed illustration in Figure 30b includes the two opposing profile surfaces 25, 26, which are at a permanent distance A1, see Figure 2 , to form the tooth profile 21 with a plurality of teeth 22 extending in a zigzag or wave-like pattern. A zigzag-shaped backdrop 20 is shown in detail in Figure 30b shown and a wave-shaped backdrop 20 is detailed in Figure 30b The distance A1 can also be referred to as the groove width of the backdrop 20.

[0046] The two opposing profile surfaces 25, 26 of the guide 20 are therefore oriented essentially perpendicular to the rail plane E. The teeth 22 have symmetrical flanks 25a, 25b, 26a, 26b that extend on both sides between the tooth tip and tooth root. Two adjacent tooth tips are arranged at a tooth spacing A2, or the length of a tooth 22 along its longitudinal axis corresponds to the tooth spacing A2.

[0047] The tooth profile 21 can, among other things, Figures 1 and 2 can be removed, extending completely along the longitudinal axis L over the rail 10.

[0048] The embodiments shown in the accompanying figures depict at least two slides 30, although it should be noted that a single slide 30 is sufficient to generate a thrust in a direction L1 or L2 of the longitudinal axis L.

[0049] The two sliders 30 of a linear drive 1 can, as in the exemplary embodiments Figures 1-21 The two models shown are essentially identical in construction.

[0050] The respective slide 30 is coupled to the driven drive shaft 50 in such a way that the respective slide 30 performs at least one cyclic movement during one revolution of the drive shaft 50.

[0051] The slide 30 can have an opening 35 or a recess. The opening 35 or the recess preferably extends in the axis of rotation X and can have a width B2 and a height H2.

[0052] To generate the thrust in one direction along the longitudinal axis L, the slide 30 engages in the cam 20 of the rail 10. For this purpose, the slide 30 can include a friction surface 33 which is designed to be in operative contact with the opposing profile surfaces 25, 26. As in Figure 3As can be seen, the friction surface 33 can be formed on a pin 32 which engages the cam 20 from a base body 31 of the slider 30 transversely to the longitudinal axis L and perpendicular to the rail plane E.

[0053] The pin 32 can have a cuboid, rhomboid or round cross-section and can be formed integrally with the base body 31 or attached to, in particular inserted into, the base body 31 of the slide 30.

[0054] How Fig. 3 As can be seen, pin 32 has a width B1, measured perpendicular to the longitudinal axis L. Preferably, the width B1 corresponds approximately to the distance A1 between the two profile surfaces 25, 26, i.e., B1 ≈ A1.

[0055] The friction surface 33 can have a surface with improved friction properties to reduce the friction between the cam 20 and the slide 30. Preferably, the friction surface 33 comprises a coating that promotes smooth friction against the opposing profile surfaces 25, 26.

[0056] The slide 30, in particular the pin 32 of the slide 30, is preferably positively locked in the longitudinal axis L between two opposing profile surfaces 25, 26. The positive locking in the longitudinal axis L between the slide 30 and the cam 20 can block unwanted movement or free play of the linear drive 1.

[0057] The coupling between the drive shaft 50 and the respective slide 30 can be effected in different ways, whereby, according to the embodiments presented here, the coupling can be effected by means of guide elements 52 that interact with the slide 30. The slide 30 can have at least one contact surface 42 that interacts with the guide element 52.

[0058] The command tool 52 can, for example, be used as described in the accompanying documentation. Figures 1-29 is shown as a camshaft disc 53 of a crankshaft or camshaft, and engage in the opening 35 or recess of the slide 30 and cooperate there with slide guide 42.

[0059] The drive shaft 50 can be driven by the drive 60, wherein the drive 60 is preferably an electric drive which is further preferably coupled to the drive shaft 50 via a (not shown) gearbox.

[0060] The guide means 52 or the camshaft disc 53 according to the embodiment shown in the Figure 1 as well as in the following exemplary embodiments, detailed in Figure 30a It is depicted and can be described as essentially heart-shaped.

[0061] The guide element 52 or the camshaft disc 53 has, according to the detailed illustration in Figure 30aA contact surface 54 is formed, which is located at a distance in the direction of rotation from an axis of rotation X of the drive shaft 50. The distance between the contact surface 54 and the axis of rotation X changes in the direction of rotation such that the distance increases predominantly linearly in one direction of rotation in at least a first half and decreases linearly in the direction of rotation in at least a second half. The contact surface 54 extends approximately in a spiral shape in each half, and the contact surface 54 is preferably designed such that the distance between two diametrically opposed sides, measured across the axis of rotation X, is approximately constant.

[0062] By means of the drive coupling of the at least one slide 30 with the drive shaft 50, the respective slide 30 is set into at least a linear and cyclical motion transverse to the longitudinal axis during one revolution of the drive shaft 50, wherein the cyclical motion of the respective slide 30 takes place in the plane of the rail E or parallel to the plane of the rail E. The double arrow in Figure 3 This is intended to illustrate the cyclic movement in the rail plane E or parallel to the rail plane E of the slide 30.

[0063] During the cyclic movement of the at least one slide 30, the slide 30 alternately slides against the opposite profile surfaces 25, 26 to generate the thrust in the longitudinal axis L. In other words, the slide 30 moves about the axis of rotation X transversely to the longitudinal axis L for at least one revolution of the drive axis 50. This interaction is used, for example, in the Figures 28 and 29 depicted, whereby in Figure 29the drive shaft 50 compared to the illustration in Figure 28 has completed a quarter turn around the axis of rotation X counterclockwise.

[0064] A complete cycle of movement, starting from an initial position, comprises movement in a first direction Y1 and a change of movement to a second direction Y2 at a turning point. The movement in the second direction Y2 continues until the next turning point. Finally, the movement returns to the initial position.

[0065] With further reference to the Figures 28 and 29The figure shows how the slide 30, to generate a thrust in a first direction L1 along the longitudinal axis L, slides along the flank 25a of the profile surface 25 in the first direction Y1 and along the flank 26a of the profile surface 26 in the second direction Y2. At the respective turning point, the slide 30 preferably engages in a transition of the respective profile surface designed as a tooth root 27, 28, wherein the slide 30 is positively locked in the longitudinal axis L against one of the two opposing profile surfaces 25, 26, i.e. 25a and 25b or 26a and 26b.

[0066] To generate a thrust in a second direction L2 opposite to the first direction L1, the slide 30 pushes off in the first direction Y1 on the flank 25b of the profile surface 25 and in the second direction Y2 on the flank 26b of the profile surface 26.

[0067] In the accompanying embodiments, the linear drive 1 has two slides 30. From the Figures 1 to 3 It is immediately apparent that the two slides 30 are spaced apart from each other along the longitudinal axis L. The slides 30 engage with the cam 20 at a distance A3, where the distance A3 is measured parallel to the longitudinal axis L.

[0068] The two sliders 30 engage in the cam 20 at a phase offset, the phase offset φ preferably being chosen such that the two sliders 30 are not at an inflection point at the same time, or that the two sliders 30 do not engage in the tooth bases 27, 28 at the same time.

[0069] The phase shift φ of the movement of the slides 30 can be determined by the guide means 52, for which, for example, the camshaft discs 53 on the drive shaft 50 are arranged at different angles around the axis of rotation X. In the following figures, the angle is approximately 90°, resulting in a phase shift φ of one quarter of the cycle length, i.e., φ = 1 / 4. The following relationship applies to the slide gap A3: A3 = n x A2 + φ x A2, where n is a natural integer, i.e., 0, 1, 2, 3, ..., and A2 is the length of a tooth 22 or the tooth spacing. In the illustrated embodiment, the slide gap A3 = 1 / 4 A2.

[0070] Preferably, the phase offset φ between the at least two sliders is 0 < φ < 0.5 and 0.5 < φ < 1, whereby, in the case that more than two sliders may be provided, the phase offset between two of the three sliders may also be φ = 0, φ = 0.5 or φ = 1 as well as a multiple thereof.

[0071] In the first embodiment according to the Figures 1 to 4 The two sliders 30 are arranged on one side of the drive shaft to the drive 60. In the embodiment shown there, each slider 30 has a single pin 32.

[0072] The second embodiment according to the Figures 5-7 differs from the first embodiment according to Figures 1-3 in the design and arrangement of the slides 30.

[0073] How Figure 5 The linear drive 1 has two slides 30, which are arranged on both sides of the drive 60 in the axis of rotation X of the drive shaft. The two slides 30 can be identical in design.

[0074] The two sliders 30, or rather the pins 32 of the two sliders 30, are arranged at a pin spacing A3, whereby the following relationship also applies to the pin spacing A3: A3 = nx A2 + φ x A2

[0075] The sliders 30 can be arranged on a common drive shaft 50, or on two different drive shafts 50, wherein the rotation of the drive shaft 50 is preferably synchronized.

[0076] The rotation axes X of the drive shaft 50 or drive shafts 50 are parallel to the longitudinal axis L of the linear drive 1.

[0077] Furthermore, in particular the Figures 5 and 7 It can be deduced that each slide 30 comprises three pins 32, which are arranged at a constant pin spacing A4 in the orientation of the longitudinal axis L. The three pins 32 are arranged on the base body 31 above a cantilevered pin carrier 34. The pin spacing A4 corresponds to the distance A2, i.e., the distance between two adjacent tooth tips or the length of a tooth 22 in the longitudinal axis L.

[0078] The number of pins 32 on each slide 30 can be chosen arbitrarily. By appropriately selecting the number of pins 32, the breaking load of the linear drive 1 can be dimensioned. The pin spacing A4 can also be varied, preferably being a single or multiple of the tooth spacing A2.

[0079] The third embodiment, which is described in the Figures 8-10 The embodiment shown can be considered a combination of the previously described embodiments, with the difference that two rails 10 are arranged parallel to and spaced apart from each other along the longitudinal axis L, and each of the two sliders 30 engages in one of the rails 10. The sliders 30, the drive shaft 50 with the guide means 52, and the drive 60 are arranged between the two rails 10, with the cam surfaces 11 of the two rails 10 facing each other.

[0080] The respective slide 30 is analogous to the slide 30 according to Figure 6 formed and each has three pins 32 arranged along the longitudinal axis L at a pin spacing A4.

[0081] The pin carrier 34 is diamond-shaped, with the middle pin 32 being arranged centrally on the pin carrier 34 and centrally to the base body 31.

[0082] The two sliders 30 engage – as already described in detail in connection with a previous embodiment – ​​in the respective cam of the rail 10 at a phase shift, the phase shift in the illustrated embodiment being according to the Figures 8-10 due to an angular misalignment between the guide means 52 or the camshaft discs 53 - as particularly in Figure 9 The depicted representation is realized. Accordingly, the tooth profiles 21 of the two rails 10 formed by the cams 20 are in the same phase or are mirrored in line.

[0083] A fourth embodiment can be the Figures 11-15 can be extracted. The fourth embodiment is similar to the first embodiment according to the Figures 1-4 However, with the difference that two rails 10 are arranged parallel and spaced apart along the longitudinal axis L, and that each of the sliders 30 engages in the respective rail 10. Furthermore, the cam surfaces 11 with the cams 20 are arranged on the side of the rail 10 facing away from the axis of rotation X.

[0084] The respective slider 30 can be described as T-shaped and the pins 32 are arranged transversely to the longitudinal axis on opposite sides on a pin carrier 34, with the pins 32 protruding on the side of the pin carrier 34 facing the axis of rotation X.

[0085] A fifth embodiment can be the Figures 16-18 can be extracted. The fifth embodiment is similar to the fourth embodiment according to the Figures 11-15, however, with the difference that the respective slider 30 engages in one of the two rails 10, and that the respective slider 30 has three pins 32 along the longitudinal axis L, which are arranged at the pin spacing A4.

[0086] The respective slider 30 can be described as L-shaped and the three pins 32 are arranged in the longitudinal axis L on the pin carrier 34, with the pins 32 protruding on the side of the pin carrier 34 facing the axis of rotation X.

[0087] A sixth embodiment can be Figures 19-21 can be taken.

[0088] The sixth embodiment is similar to the fourth embodiment according to the Figures 11-15However, with the difference that the two sliders 30 are arranged on opposite sides of the drive 60 along the longitudinal axis L, and that each slider 30 has three pins 32 that engage in the respective rail 10. In total, each slider 30 thus has six pins 32.

[0089] The respective slider 30 can be described as T-shaped and the six pins 32 are arranged in two rows in the longitudinal axis L, each row being for one of the rails 10, on the pin carrier 34, with the pins 32 protruding on the side of the pin carrier 34 facing the axis of rotation X.

[0090] A seventh embodiment can be the Figures 22-24 It can be deduced that in this embodiment the axis of rotation X of the drive shaft 50 is oriented transversely to the longitudinal axis L.

[0091] Along the longitudinal axis L, as in the previously described embodiments, two rails 10 are arranged parallel and spaced apart from each other, with the respective cam 20 being arranged in the respective rail 10 on the side facing away from the drive 60.

[0092] The rail planes E of the two rails 10 lie within each other; however, according to a further development (not shown), they can also be arranged parallel and spaced apart. It is also possible that the guides 20 are arranged on the side of the rails 10 facing the drive 60.

[0093] Unlike the previously described embodiments, the two slides 30 are not identical in construction. To illustrate this, the following is shown in the Figures 22-24For clarity, one of the slides 30 is designated with the reference symbol 30' to highlight the different design of the slides 30 in the figures. Unlike the slide 30, the slide 30' may have a pin carrier 34 that projects from the base body 31 of the slide 30' in the direction of the rail 10 along the axis of rotation X.

[0094] It should be noted here that the cams 10 can also be arranged on the side of the rails 10 facing the drive 60. Furthermore, the rail planes E of the rails 10 can be parallel and spaced apart, preferably such that the sliders 30 can lie in a common plane.

[0095] With reference to the accompanying Figure 24It is further evident that each slide 30, 30' has two pins 32, 32'. It is emphasized that the number of pins 32, 32' of each individual slide 30, 30' can be chosen arbitrarily. The pins 32, 32' of each slide 30, 30' are arranged along the longitudinal axis L at a pin spacing A4. The pin spacing A4 essentially corresponds to the tooth spacing A2, which describes the distance between two adjacent tooth tips.

[0096] Furthermore, the Figure 24 It can be deduced that the pins 32 of the slider 30 and the pins 32' of the slider 30' are arranged offset from each other in the longitudinal axis L by an offset ΔL, the offset ΔL being correlated with the phase offset in the cyclic movement between the two sliders 30 and 30'.

[0097] The phase shift φ of the movement of the slides 30, 30' can also be predetermined in this embodiment, as previously described, by the guide means 52. As in particular the Figure 24 As can be seen, the camshaft discs 53 are arranged on the drive shaft 50 rotated at different angles around the axis of rotation X. In this specific embodiment, the angle is approximately 90°, resulting in a phase shift φ of one quarter of the cycle length, i.e., φ = 1 / 4.

[0098] The following relationship applies to the offset ΔL: ΔL = φ x A2. In the illustrated embodiment, the slider spacing ΔL = ¼ A2. Preferably, the phase offset φ between the at least two sliders 30, 30' is: 0 < φ < 0.5 and 0.5 < φ < 1. If more than two sliders 30, 30' are provided, the phase offset φ between two of the three sliders 30, 30' can also be φ = 0, φ = 0.5, or φ = 1, as well as multiples thereof.

[0099] The eighth embodiment of a linear drive 1 is described in the Figures 25-29 depicted, whereby in Figure 25 The linear drive 1 is used in a longitudinal adjustment unit 2, for example, of a motor vehicle.

[0100] The linear drive 1 according to this embodiment is designed in accordance with embodiment 7 in such a way that the axis of rotation X of the drive shaft 50 is arranged transversely to the longitudinal axis L.

[0101] The linear drive 1 comprises two rails 10 arranged parallel to each other and spaced apart along the longitudinal axis. Each rail 10 includes – as previously described in detail – a cam 10, which is arranged in the respective cam surface 11 of the respective rail 10 in a rail plane E. The two cam surfaces 11 of the two rails 10 face each other, and two slides 30, 30' are arranged in a space between the rails 10, each engaging with one of the cams 20.

[0102] The linear drive 1 can, as exemplified in the Figures 25-27 The figure shows a housing 40, referred to as a whole. The housing 40 can be made up of multiple parts and can accommodate the slides 30 completely or partially, and can furthermore provide a linear guide 42 for the at least one slide 30. The linear guide 42 holds the at least one slide 30 in a linear guide transverse to the longitudinal axis L.

[0103] Furthermore, the housing 40 can have support means 44 which are configured to support the housing 40, in particular the Figures 26 and 27 can be removed, to support at least one rail 10 or the two rails 10.

[0104] The housing 40 can also have receptacles in which bearings 56 for the drive shaft 50 are held supported.

[0105] The sliders 30, 30' are designed analogously to the sliders according to embodiment 7, wherein in this embodiment the sliders 30, 30' each have nine pins 32, which are arranged in the longitudinal axis at a pin spacing A4. The pins 32, 32' of the slider 30 and the slider 30' are arranged in the longitudinal axis at an offset ΔL and the cyclic movement of the two sliders 30, 30' takes place with a phase offset φ, as already described previously.

[0106] The longitudinal adjustment unit 2 according to Figure 25The system can comprise two linear drives 1, wherein the drive shaft 50 of each linear drive 1 can be driven by a common drive 60. For example, both linear drives 1 can have a common drive shaft 50, thus enabling synchronization of the linear drives 1.

[0107] Figure 31 Figure 1 shows a further development of the rail 10 and an associated guide element 52 or a camshaft disk 53. The cam 20 of the rail 10 is, as previously described, wave-shaped, whereby the wave shape can be more precisely described as a sine wave. A pin 32, preferably round in cross-section, engages in such a cam 20. Reference symbol list

[0108] 1 Linear drive 2 Longitudinal adjustment unit 10 Rail 11 Slide surface 20Circuit 21Tooth profile 22Tooth 25Profile surface 25aTooth flank 25bTooth flank 26Profile surface 26aTooth flank 26bTooth flank 27Tooth root 28Tooth root 30Slide 31Base body of 30 32Pin 33Friction surface 34Pin carrier 35Opening 40Housing 42Slide guide 44Support means 50Drive shaft 52Guide means 53Camshaft disc 54Contact surface 60Drive A1 Spacing A2 Tooth spacing A3 Slider spacing A4 Pin spacing B1 Width of 32 B2 Width of 35 E Rail plane H1 Height L Longitudinal axis ΔL Offset X Rotation axis of 50

Claims

1. Linear drive (1), comprising - at least one rail (10), which is oriented along a longitudinal axis (L) and comprises at least one link (20) which forms a tooth profile (21) and which comprises two opposing profile surfaces (25, 26), - at least one slider (30), which is movable transversely to the longitudinal axis (L) and engages in the at least one link (20), and - a drive shaft (50), - wherein the at least one slider (30) is drivingly coupled to the drive shaft (50) in such a way that the respective slider (30) performs at least one cyclical movement in the course of one rotation of the drive shaft (50), and in the process can shift in the at least one link (20) for generating propulsion in a direction of the longitudinal axis (L), alternately at the opposing profile surfaces (25, 26), - wherein the respective slider (30) comprises at least one pin (32), characterised in that a spacing between the opposing profile surfaces (25, 26) of the link (20) approximately corresponds to the size of the at least one pin (32).

2. Linear drive (1) according to claim 1, characterised in that at least two sliders (30) are provided, and that the cyclical movement of the at least two sliders (30) occurs relative to the link (20) with a phase offset.

3. Linear drive (1) according to either claim 1 or claim 2, characterised in that the tooth profile (21) of the link (20) has a zigzag or corrugated course.

4. Linear drive (1) according to any of the preceding claims, characterised in that a spacing between the opposing profile surfaces (25, 26) remains the same.

5. Linear drive (1) according to any of the preceding claims, characterised in that the link (20) is configured as a groove or aperture in the at least one rail (10).

6. Linear drive (1) according to any of the preceding claims, characterised in that the respective slider (30) comprises at least two pins (32).

7. Linear drive (1) according to any of the preceding claims, characterised in that the at least one pin (32) comprises at least one friction surface (33), which can come into active contact on the opposing profile surfaces (25, 26) for generating a propulsion.

8. Linear drive (1) according to any of the preceding claims, characterised in that the at least one friction surface (33) corresponds to the shape of a tooth base (28) of the tooth profile (21).

9. Linear drive (1) according to any of the preceding claims, characterised in that the at least one pin (32) is dimensioned in such a way that opposing sides of the pin (32) are in active contact with opposing profile surfaces (25, 26).

10. Linear drive (1) according to any of the preceding claims, characterised in that the at least one pin (32) is configured to be square, rhomboid or cylindrical in cross-section.

11. Linear drive (1) according to any of the preceding claims, characterised in that the respective slider (30) and / or the link (20) is or are configured symmetrically.

12. Linear drive (1) according to any of the preceding claims, characterised in that the drive shaft (50) is arranged outside the link (20).

13. Linear drive (1) according to any of the preceding claims, characterised in that the drive shaft (50) is arranged in a plane in parallel with and spaced apart from the rail plane, or in that the drive shaft (50) is arranged in a plane in parallel with and spaced apart from a plane perpendicular to the rail plane.

14. Linear drive (1) according to any of claims 3 to 13 in combination with claim 2, characterised in that at least one second link (20) is provided and that at least one of the two sliders (30) engages in the second link (20).

15. Linear drive (1) according to claim 14, characterised in that the at least one second link (20) is arranged in the rail plane (E) or at least in a plane in parallel with the rail plane (E).

16. Linear drive (1) according to either claim 14 or claim 15, characterised in that the at least one second link (20) is arranged in a second rail (10).

17. Linear drive (1) according to any of claims 3 to 16 in combination with claim 2, characterised in that the drive shaft (50) includes a crankshaft or camshaft and comprises at least one guide means (52) which specifies the cyclical movement of the at least two sliders (30) during the rotation of the drive shaft (50).

18. Linear drive (1) according to claim 17, characterised in that the at least one guide means (52) is configured in such a way that the respective slider (30) performs an approximately linear movement between the turning points of the cyclical movement.

19. Linear drive (1) according to any of claims 3 to 18 in combination with claim 2, characterised in that a housing (40) is provided, and in that the drive shaft (50) and at least one of the at least two sliders (30) are held on the housing (40) in a manner mounted so as to be movable transversely to the longitudinal axis (L).

20. Linear drive (1) according to any of the preceding claims, characterised in that a drive (60) is provided, wherein the drive (60) drives the drive shaft (50).

21. Linear drive (1) according to claim 20, characterised in that the drive (60) is arranged between the at least two sliders (30), in the longitudinal axis (L).

22. Longitudinal adjustment unit (2) comprising a linear drive (1) according to any of the preceding claims.

23. Motor vehicle comprising a linear drive (1) according to any of the preceding claims 1 to 21.