Gas spring-assisted spindle drive device

Abstract

The invention relates to a gas spring-assisted spindle drive device for opening and closing a pivotable flap (VF) of a vehicle, comprising a drive device (2) comprising a drive housing (3) and a drive unit (4) arranged in the drive housing (3), a lifting device (5) which can be driven by means of the drive device (2) via a rotatable spindle rod (13), comprising a lifting housing (6) and a lifting element arranged in the lifting housing (6) designed as a spindle nut (17), wherein the spindle nut (17) and the spindle rod (13) are engaged via a threaded connection (T), wherein the lifting housing (6) comprises a gas spring assembly (10), which gas spring assembly (10) has a pressurized pressure chamber (D) filled with a fluid (F), wherein a guide tube (19) is arranged in the lifting housing (6), and wherein the spindle nut (17) is rigidly connected to the guide tube (19).A spindle drive device which is reliable, compact and quiet is characterized by the fact that the lifting housing (6) can be extended telescopically from the drive housing (3) and that the lifting housing (6) can be retracted telescopically into the drive housing (3).

Description

[0001] The present invention relates to the field of electrical actuators and concerns a gas spring-assisted spindle drive device for opening and closing a pivoting flap of a vehicle.

[0002] Electrically driven spindle drive devices are known in practice, which in particular contain a helical compression spring. The helical compression spring is commercially manufactured from a steel alloy. Here, the helical compression spring is generally pre-tensioned in the opening direction of a vehicle hatch within a housing of the spindle drive device. This compressed arrangement of the helical compression spring in the housing of the spindle drive device is referred to as the initial position, whereby potential energy of the compressed helical compression spring is stored in the housing of the spindle drive device.

[0003] The helical compression spring assists in the opening movement of a vehicle hatch, such as a tailgate, thus avoiding the need for costly, energy-intensive electric motors. This allows for the integration of less powerful and more compact electric motors into spindle drive units. When the hatch closes, its own weight partially acts on the helical compression spring. This weight compresses the spring, allowing it to return to its initial position within the spindle drive unit housing.

[0004] A problem with commercially available spindle drive devices is the complex installation of the helical compression spring into the spindle drive housing during production. Furthermore, spindle drive devices with an integrated helical compression spring tend to generate unwanted noises, such as clicking and / or rattling, when the vehicle hatch is opened or closed. These noises, caused by the helical compression spring, can arise, for example, from lateral displacement of the spring under load within the spindle drive housing. Additionally, metallic helical compression springs represent a significant cost factor in the production of spindle drive devices.

[0005] Gas spring-assisted spindle drive devices are known in practice that completely eliminate the use of helical compression springs, particularly for the reasons mentioned above. In these devices, the helical compression spring is replaced by an inert gas, such as nitrogen, within the housing of the spindle drive device. However, a problem with commercially available gas spring-assisted spindle drive devices is the sealing, especially of moving components.

[0006] WO 2017 / 197 543 A1 discloses a gas spring-assisted spindle drive device for opening and closing a pivoting flap of a vehicle, comprising a drive device, comprising a drive housing and a drive unit arranged in the drive housing, a lifting device driven by the drive device via a rotatable spindle rod, comprising a lifting housing and a lifting element designed as a spindle nut arranged in the lifting housing, wherein the spindle nut and the spindle rod are engaged via a threaded connection, wherein the lifting housing comprises a gas spring assembly, which gas spring assembly has a pressurized pressure chamber filled with a fluid, wherein a guide tube is arranged in the lifting housing, wherein the spindle nut is rigidly connected to the guide tube, wherein the lifting housing is telescopically extendable from the drive housing, and wherein the lifting housing is telescopically retractable into the drive housing.

[0007] CN 206 190 101 U discloses a gas spring-assisted spindle drive device for opening and closing a pivoting flap of a vehicle, comprising a drive device, comprising a drive housing and a drive unit arranged in the drive housing, a lifting device which can be driven by means of the drive device via a rotatable spindle rod, comprising a lifting housing and a lifting element arranged in the lifting housing in the form of a spindle nut, wherein the spindle nut and the spindle rod are engaged via a threaded connection, wherein the lifting housing comprises a gas spring assembly, which gas spring assembly has a pressurized pressure chamber filled with a fluid, wherein a guide tube is arranged in the lifting housing, wherein the spindle nut is rigidly connected to the guide tube.

[0008] DE 10 2023 101 994 A1 discloses a gas spring-assisted spindle drive device for opening and closing a pivoting flap of a vehicle, comprising a drive device, comprising a drive housing and a drive unit arranged in the drive housing, a lifting device which can be driven by means of the drive device via a rotatable spindle rod, comprising a lifting housing and a lifting element designed as a spindle nut arranged in the lifting housing, wherein the spindle nut and the spindle rod are engaged via a threaded connection, wherein the lifting housing comprises a gas spring arrangement, which gas spring arrangement has a pressurized pressure chamber filled with a fluid, wherein a guide tube is arranged in the lifting housing, and wherein the spindle nut is rigidly connected to the guide tube.

[0009] DE 10 2014 114 737 A1 discloses a gas spring-assisted spindle drive device for opening and closing a pivoting flap of a vehicle, comprising a drive device, comprising a drive housing and a drive unit arranged in the drive housing, a lifting device which can be driven by means of the drive device via a rotatable spindle rod, comprising a lifting housing and a lifting element designed as a spindle nut arranged in the lifting housing, wherein the spindle nut and the spindle rod are engaged via a threaded connection, wherein the lifting housing comprises a gas spring arrangement, which gas spring arrangement has a pressurized pressure chamber filled with a fluid, wherein a guide tube is arranged in the lifting housing, and wherein the spindle nut is rigidly connected to the guide tube.

[0010] A disadvantage of this design is that the spindle rod, on its side facing the drive unit, is sealed against the pressure chamber by several sealing elements, and that dynamic sealing elements, such as rod seals, are particularly susceptible to increased wear. Furthermore, the sealing elements in contact with the spindle rod can impair its rotation due to, for example, seal abrasion, which could also reduce the sealing effectiveness of the elements.

[0011] Therefore, there is a need for a gas spring-assisted spindle drive device which solves the sealing problem in particular, thereby ensuring an increased product lifespan of the gas spring-assisted spindle drive device.

[0012] The present invention is therefore based on the technical problem of providing a spindle drive device that is reliable, compact and quiet.

[0013] According to the invention, this problem is solved by a gas spring-assisted spindle drive device according to an independent claim.

[0014] Further advantageous embodiments are specified in the dependent claims.

[0015] According to the invention, a gas spring-assisted spindle drive device for opening and closing a pivoting flap of a vehicle is provided.The spindle drive device comprises a drive device comprising a drive housing and a drive unit arranged in the drive housing, a lifting device which can be driven by means of the drive device via a rotatable spindle rod, comprising a lifting housing and a lifting element designed as a spindle nut arranged in the lifting housing, wherein the spindle nut and the spindle rod are engaged via a threaded connection, wherein the lifting housing comprises a gas spring assembly, which gas spring assembly has a pressurized pressure chamber filled with a fluid, wherein a guide tube is arranged in the lifting housing, and wherein the spindle nut is rigidly connected to the guide tube, wherein the lifting housing can be extended telescopically from the drive housing, and wherein the lifting housing can be retracted telescopically into the drive housing.The gas spring-assisted spindle drive device is characterized by the fact that the spindle nut comprises an annular adapter part. This adapter part has a first side and an opposing second side, wherein the first side of the adapter part faces the pressure chamber, and the second side of the adapter part engages with the spindle nut. Advantageously, the spindle nut is connected to the adapter, for example, via a push-fit connection, providing a positive and force-fit connection. Furthermore, the adapter advantageously facilitates the alignment of the spindle nut within the stroke housing, thus preventing misalignment or tilting of the spindle nut during the connection process.One advantage is that the relatively large inner circumference of the lifting housing provides a larger surface area at the bottom for the compressed fluid, allowing for the generation of higher pressure forces to reliably open a vehicle hatch. Another advantage is that the telescopic lifting housing has no penetration or rod passage with a dynamic rod seal. The movable lifting housing is sealed to the outside environment solely by a static seal. Static seals are generally easier to install and also increase the service life of the gas spring-assisted spindle drive device.

[0016] According to the invention, a gas spring-assisted spindle drive device for opening and closing a pivoting flap of a vehicle is provided. The spindle drive device comprises a drive device comprising a drive housing and a drive unit arranged in the drive housing, a lifting device which can be driven by the drive device via a rotatable spindle rod, comprising a lifting housing and a lifting element designed as a spindle nut arranged in the lifting housing, wherein the spindle nut and the spindle rod are engaged via a threaded connection, wherein the lifting housing comprises a gas spring assembly, which gas spring assembly has a pressurized pressure chamber filled with a fluid, wherein a guide tube is arranged in the lifting housing, wherein the lifting housing and the guide tube are rigidly and fluid-tightly connected to each other in a connecting section, wherein the spindle nut is rigidly connected to the guide tube.wherein the lifting housing can be extended telescopically from the drive housing, and wherein the lifting housing can be retracted telescopically into the drive housing. The gas spring-assisted spindle drive device is characterized in that a first static sealing element is arranged between the lifting housing and the guide tube within the connecting section, that the lifting housing has a radially circumferential constriction, that the guide tube has a radially circumferential expansion, and that the first static sealing element is arranged between the constriction of the lifting housing and the expansion of the guide tube. The deformations of the lifting housing and the deformations of the guide tube are designed as a type of radial sealing groove. The static sealing element is arranged in this sealing groove in a captive and crimped manner.so that the static sealing element ensures a very good seal against the pressure chamber. To guarantee the seal of the pressure chamber, a simple static sealing element, e.g., an O-ring, is advantageously used between the stroke housing and the guide tube. The guide tube is advantageously permanently or securely connected to the stroke housing, for example, via a crimp connection or an interference fit. Alternatively, the guide tube is bonded to the stroke housing, e.g., via a weld or with the aid of an adhesive. Furthermore, in this alternative embodiment, the spindle nut is firmly connected to the guide tube, e.g., via a crimp connection or an interference fit. Thus, the stroke housing and the guide tube can advantageously be moved simultaneously in an axial direction via the spindle nut.

[0017] In this context, a fluid is a gas, a liquid, or a supercritical fluid. Furthermore, any mixture or solution of the aforementioned different media is also considered, and these mixtures and solutions are likewise grouped under the general term "fluid."

[0018] Advantageously, the spindle nut and the spindle rod are arranged outside the pressure chamber. This arrangement offers the advantage that the drive unit, as well as the bearing and braking elements of the spindle rod, are fluid-tight and separated from the pressure chamber. This also advantageously prevents any gas-soluble lubricating oils and greases, as well as any gas-soluble adhesives, from coming into contact with the fluid in the closed pressure chamber. The drive unit, comprising an electric motor, a circuit board, cables and electrical connections, as well as the bearing and braking elements of the spindle rod, can thus be arranged and configured independently of the pressure chamber within the gas spring-assisted spindle drive unit.

[0019] Advantageously, the lifting housing and the spindle nut are permanently and fluid-tightly connected in a joint section. The spindle nut is advantageously permanently connected to the lifting housing, for example, via a crimp connection. The term "permanently" means that this connection would have to be destroyed to separate the spindle nut and the lifting housing. Furthermore, the spindle nut is arranged in an opening area of ​​the lifting housing, where at least part of the lifting housing material exhibits plastic deformation. This plastically deformed material of the lifting housing engages the spindle nut in a force-fit and form-fit manner. Alternatively, the spindle nut is materially bonded to the lifting housing, for example, via a weld or with the aid of an adhesive.Certain crimping tools can also create at least a partially metallurgical crimp connection between the spindle nut and the stroke housing, thus enabling a metallurgical connection between the spindle nut and stroke housing without the use of high temperatures, as would be the case, for example, in a welding process. Advantageously, it is possible to drive the spindle nut axially by rotating the spindle rod, which in turn reliably moves the stroke housing axially.

[0020] Preferably, the guide tube is arranged at least partially between the adapter part and the spindle nut. The guide tube, which is rigidly arranged in the lifting housing, has a first end and a second end, the second end of the guide tube being connected to the spindle nut via a push-fit connection, providing a positive and frictional fit. Advantageously, the spindle nut serves as a second bearing element for the guide tube, resulting in a compact configuration of the gas spring-assisted spindle drive device. This allows the lifting housing and the guide tube to be moved simultaneously in an axial direction via the spindle nut.

[0021] It is particularly advantageous that at least one first static sealing element is arranged between the adapter part and the spindle nut. Advantageously, the spindle nut has at least one first radial groove in which a simple static seal, e.g., an O-ring, is inserted. Here, the first static sealing element is compressed between the adapter part and the spindle nut in the manner of a piston seal, thus achieving a very good seal of the pressure chamber.

[0022] According to a particularly preferred embodiment, a sealing unit with a first side and a second side facing away from the first side is arranged in the guide tube, wherein preferably only the first side of the sealing unit is in contact with the pressurized fluid, and wherein the guide tube is advantageously displaceable in the axial direction relative to the sealing unit. The sealing unit advantageously separates the pressurized pressure chamber filled with fluid from the drive housing in a pressure-tight and fluid-tight manner. The drive housing has an internal pressure that corresponds to the ambient pressure outside the spindle drive device. Furthermore, the sealing unit thus separates the pressure chamber from the spindle nut and the spindle rod in a pressure-tight and fluid-tight manner.Because the guide tube is movable relative to the sealing unit, a defined volume within the pressure chamber can be advantageously adjusted via the sealing unit. When the lifting housing extends from the drive housing—i.e., when a vehicle hatch is opened—the sealing unit releases some of the internal volume of the guide tube, allowing the pressurized fluid within the guide tube to expand. When the vehicle hatch is closed—i.e., when the lifting housing retracts into the drive unit—the sealing unit forces almost all of the fluid out of the internal volume of the guide tube, resulting in compression of the fluid within the pressure chamber and thus allowing potential energy to be stored in the gas spring assembly.

[0023] Advantageously, the sealing unit incorporates a dynamic seal. The sealing unit has at least one outwardly sealing dynamic sealing element, similar to a piston seal, to create a pressure-tight and fluid-tight seal between the pressure chamber and the drive housing. This sealing element advantageously provides a dynamic seal against an inner running surface of the guide tube and a static seal against a groove base of the sealing unit. To allow the guide tube to slide smoothly along the sealing unit, its inner running surface must be polished smooth. The surface finish of the inner running surface of the guide tube is preferably less than 0.3 µm (Ra). This is typically achieved by honing an inner surface of the guide tube. Furthermore, the mean roughness value (Ra) describes the surface roughness.A smoothly polished inner surface is therefore a prerequisite for a functioning dynamic seal, ensuring that the sealing material is not damaged when the guide tube is moved, thus allowing for smooth and quiet movement. This results in a long service life for the dynamic seal of the sealing unit. Alternatively, the sealing unit can incorporate multiple dynamic sealing elements to prevent tilting of the unit within the guide tube.

[0024] Preferably, the sealing unit separates the pressurized pressure chamber and the spindle nut with the engaged spindle rod from each other in a fluid-tight and pressure-tight manner. Advantageously, the spindle nut and the spindle rod are arranged entirely outside the pressure chamber, so that the pressurized fluid cannot influence any lubrication of the spindle-spindle nut drive. Greases and oils can dissolve into a pressurized fluid, so that a fluid could extract lubricants from the surface of the spindle nut and / or the spindle rod and distribute these lubricants arbitrarily within a space. This is advantageously prevented, among other things, by the sealing unit.

[0025] According to an advantageous embodiment, the spindle rod has a first end face, which faces the second side of the sealing unit, preferably with the second side of the sealing unit being in contact with the first end face of the spindle rod. Advantageously, the first end face of the spindle rod is designed as an end stop with respect to the sealing unit. An internal pressure prevailing within the pressure chamber presses the second side of the sealing unit against the first end face of the spindle rod. Thus, the first end face of the spindle rod blocks further displacement of the sealing unit in one direction towards the drive device. Consequently, the internal volume of the pressure chamber can be adjusted via the position of the first end face of the spindle rod.

[0026] The second side of the sealing unit preferably has a first centering element, wherein the first end face of the spindle rod preferably has a corresponding second centering element, and wherein the first centering element of the sealing unit and the second centering element of the spindle rod are expediently inserted into one another. To prevent undesirable tilting of the sealing unit when the guide tube is displaced relative to the sealing unit, the sealing unit is advantageously connected to the spindle rod at a free end of the spindle rod via a plug connection. Furthermore, the sealing unit connected to the spindle rod serves as a bearing element, so that the spindle rod is arranged concentrically and coaxially in the guide tube.

[0027] Preferably, the lifting housing has a single base. Advantageously, the base of the lifting housing is arranged in a direction away from the drive device, so that the closed base faces outwards towards the environment. This arrangement of the lifting housing has the advantage, firstly, that the telescopic lifting housing has an attractive appearance from the outside, and secondly, it advantageously ensures that in the event of an undesired seal failure, components remain within the spindle drive device. In this way, the risk of injury from potentially flying components due to a sudden release of the fluid is completely avoided. Thus, the gas spring-assisted spindle drive device addresses relevant safety aspects.

[0028] Advantageously, the lifting housing includes an internal alignment element, which is arranged coaxially with respect to the lifting housing and is located centrally on the base of the lifting housing. The base of the lifting housing advantageously offers sufficient space for the arrangement of further components, which, for example, play a load-bearing role as bearing elements.

[0029] According to a preferred embodiment, the alignment element has an opening for pressure equalization. To ensure a uniform distribution of the fluid within the pressure chamber, the fluid can flow freely through a pressure equalization channel of the alignment element, thus maintaining a constant internal pressure within the pressure chamber.

[0030] Preferably, the guide tube is connected to the alignment element, at least partially, via a plug connection. Advantageously, a first end of the guide tube is connected to the alignment element, so that the alignment element acts as a first bearing element and the spindle nut as an opposing second bearing element, positioning the guide tube coaxially and concentrically within the stroke housing. The guide tube is thus advantageously clamped immovably and rigidly between the alignment element and the spindle nut within the stroke housing.

[0031] Preferably, a gas- and fluid-tight plug is arranged in the base of the stroke housing. A fluid can be filled into the pressure chamber through an opening in the base of the stroke housing. This opening is advantageously sealed gas- and fluid-tight after filling with fluid by means of a static plug, so that no fluid can flow outwards through the base of the stroke housing to the environment.

[0032] According to an advantageous embodiment, the drive housing has a first connection element, and the lifting housing expediently has a second connection element opposite it. Advantageously, the gas spring-assisted spindle drive device can be mounted in a vehicle via the first and second connection elements. For this purpose, the first connection element, which is associated with the drive housing, is advantageously articulated to the vehicle body. The second connection element, which is associated with the lifting housing, is articulated to a pivotable flap, e.g., a tailgate, of the vehicle. The first connection element is preferably designed as a first ball socket. The second connection element is preferably designed as a second ball socket.Ball sockets are characterized by the fact that a simple, articulated connection can be made quickly and securely.

[0033] In an advantageous embodiment, the spindle rod can be coupled to the drive unit via a magnetic coupling. The magnetic coupling advantageously comprises a pressure-tight and fluid-tight partition, allowing the spindle rod to be driven contactlessly by the drive unit. The partition advantageously protects the drive unit from any fluids, thus ensuring an improved service life for the spindle drive device.

[0034] According to the invention, a gas spring-assisted spindle drive device for opening and closing a pivoting flap of a vehicle is provided.The spindle drive device comprises a drive device comprising a drive housing and a drive unit arranged in the drive housing, a lifting device which can be driven by means of the drive device via a rotatable spindle rod, comprising a lifting housing and a lifting element designed as a spindle nut arranged in the lifting housing, wherein the spindle nut and the spindle rod are engaged via a threaded connection, wherein the lifting housing comprises a gas spring assembly, which gas spring assembly has a pressurized pressure chamber filled with a fluid, wherein a guide tube is arranged in the lifting housing, wherein the spindle nut is rigidly connected to the guide tube, wherein the guide tube is telescopically extendable from the lifting housing, and wherein the guide tube is telescopically retractable into the lifting housing.The spindle drive device is characterized by the fact that the spindle rod can be coupled to the drive unit via a magnetic coupling, and that a completely closed partition wall provides a fluid-tight seal between the drive unit and the pressure chamber. An advantage is that the partition wall between the drive unit and the pressure chamber has no penetrations, thus preventing fluid from the pressure chamber from coming into contact with sensitive electrical components, particularly a circuit board of the drive unit. Furthermore, the magnetic coupling advantageously includes a pressure-tight and fluid-tight partition wall, allowing the spindle rod to be driven contactlessly by the drive unit. The partition wall advantageously protects the drive unit from any fluids, thereby ensuring an extended service life for the spindle drive device.

[0035] According to a preferred embodiment, the drive housing has a first connection element, and the guide tube has an opposing second connection element. Advantageously, the gas spring-assisted spindle drive device can be mounted in a vehicle via the first and second connection elements. For this purpose, the first connection element, which is associated with the drive housing, is advantageously articulated to the vehicle body. The opposing second connection element, which is associated with the guide tube, is articulated to a pivotable flap, e.g., a tailgate, of the vehicle. The first connection element is preferably designed as a first ball socket. The second connection element is preferably designed as a second ball socket.Ball sockets are characterized by the fact that a simple, articulated connection can be made quickly and securely.

[0036] The following advantages, further developments and properties refer back to all previous articles according to the invention.

[0037] Advantageously, the spindle rod has an external thread, and the spindle nut has a corresponding internal thread. The spindle nut and the spindle rod are threaded together. Advantageously, the spindle nut can be displaced along the spindle rod via a robust threaded connection, whereby a 360° rotation of the spindle rod in any direction causes the spindle nut to move axially by a precisely defined amount. Displacement via a threaded connection is also advantageously extremely precise, so that the displacement path of the spindle nut is precisely defined along the thread pitch. Furthermore, unwanted slippage of the spindle nut is prevented by the meshing thread connection. Alternatively, the spindle nut can have an external thread, and the spindle rod a corresponding internal thread.

[0038] Preferably, the spindle nut can be displaced axially without rotation. Advantageously, wear can be reduced by displacing the spindle nut linearly along the spindle rod without rotation. Any components connected to the spindle nut, especially the guide tube, can also be displaced without rotation, thereby reducing wear, particularly on dynamic seals.

[0039] Preferably, the guide tube is arranged coaxially with respect to a longitudinal axis of the lifting housing. This advantageously optimizes the use of the available space within the lifting housing. Furthermore, it advantageously ensures stable, precise, and therefore reliable movement of the vehicle flap, since, among other things, the spindle rod is at least partially located within the guide tube.

[0040] In a preferred embodiment, the stroke housing and guide tube are designed as hollow cylinders, and the guide tube is arranged concentrically within the stroke housing. This advantageously optimizes the use of available space, resulting in a compact spindle drive device. Furthermore, a rounded geometry is beneficial for use with pressurized containers to prevent stress concentrations in the container wall material. Additionally, circular cross-sections can be effectively sealed using standardized sealing elements, such as O-rings.

[0041] Advantageously, a longitudinally extending annular gap is formed between the lifting housing and the guide tube. This annular gap serves as a storage location where the compressed fluid is predominantly located in the initial position of the spindle drive device. The potential energy of the fluid can be preset via the geometry of the annular gap. In this way, a compact spindle drive device is provided that can be preset to individual requirements.

[0042] In an advantageous embodiment, the spindle rod is arranged coaxially with respect to a longitudinal axis of the guide tube. This advantageously optimizes the use of available space. Furthermore, a stable, precise, and therefore reliable movement of the vehicle flap is advantageously ensured, since the spindle rod is arranged at least partially within the guide tube.

[0043] Advantageously, the spindle rod includes a guide element, which is arranged inside the guide tube. The spindle rod is advantageously supported at its first free end by a bearing element within the guide tube, thus ensuring precise positioning of the spindle rod.

[0044] Preferably, the spindle rod is made of a steel alloy and / or an aluminum alloy, and preferably the spindle nut is made of a steel alloy and / or an aluminum alloy. An advantage is that a particularly stable threaded connection is generated between the spindle nut and the spindle rod when both components are made of a metallic material. This ensures reliable, stable, and durable movement of the vehicle hatch by means of the spindle drive device.

[0045] In a preferred embodiment, the spindle rod and / or the spindle nut has a friction-reducing coating. Advantageously, the external thread of the spindle rod or the internal thread of the spindle nut is coated with polytetrafluoroethylene (PTFE). This eliminates the need for lubricants such as greases or oils. A PTFE coating advantageously improves running and sliding properties, ensuring quiet and low-maintenance operation of the spindle drive device. Furthermore, other components, particularly the stroke housing and the guide tube, can be coated with friction-reducing materials, such as PTFE, to reduce the friction of moving elements, thus ensuring smooth and quiet movement. Alternatively, other coating materials, such as molybdenum disulfide, graphite, or silicone, can be used instead of PTFE.

[0046] Further features and advantages of the present invention will become apparent from the following drawings and embodiments, which serve to explain the invention in more detail by way of example, without limiting the invention to these.

[0047] The invention is explained in more detail below with reference to the accompanying drawings. Fig. Figure 1 shows a sectional view of a first embodiment of a spindle drive device according to the invention a) in a retracted position (starting position) and b) in an extended position (positioning position). Fig. 2 shows a) an enlarged view I from Fig. 1a; and b) an enlarged view II from Fig. 1a; and c) an enlarged view III from Fig. 2b; and d) a perspective view of an alignment element. Fig. Figure 3 shows a sectional view of a further embodiment of a spindle drive device according to the invention a) in a retracted position (starting position) and b) an enlarged view in an extended position (positioning position). Fig. Figure 4 shows a) a sectional view of a further embodiment of a spindle drive device according to the invention; and b) an enlarged view IV from Fig. 4a. Fig. Figure 5 shows a) a sectional view of a further embodiment of a spindle drive device according to the invention; and b) an enlarged view V from Fig. 5a. Fig. Figure 6 shows a) a sectional view of a further embodiment of a spindle drive device according to the invention; and b) an enlarged view VI from Fig. 6a.

[0048] Fig. 1a and Fig. Figures 1b show a sectional view along a longitudinal axis A of a first preferred embodiment of a gas spring-assisted spindle drive device 1.

[0049] The spindle drive device 1 is in Fig. 1a is shown in a retracted starting position. Furthermore, the spindle drive device 1 is shown in Fig. 1b shown in an extended position.

[0050] The spindle drive device 1 is designed as an electrically driven actuator for opening and closing a pivoting flap VF of a vehicle. Furthermore, the spindle drive device 1 has a cylindrical outer shell Z with longitudinal axis A, comprising a first connecting element 11 designed as a first ball socket and an opposing second connecting element 12 designed as a second ball socket. The longitudinal axis A coincides with a central axis of the spindle drive device 1.

[0051] In this embodiment, the first connecting element 11 is pivotally coupled to a vehicle frame VB of a vehicle, and the second connecting element 12, opposite the first connecting element 11, is pivotally coupled to a pivotable vehicle flap VF or vehicle door of the vehicle. For clarity, the vehicle frame VB and the vehicle flap VF are shown schematically as dashed lines. The spindle drive device 1 preferably serves to open, hold, and close the vehicle flap VF or vehicle door of the vehicle. For clarity, a vehicle is not shown.

[0052] Furthermore, the spindle drive device 1 comprises a drive device 2 with a hollow cylindrical drive housing 3 and a lifting device 5 with a hollow cylindrical lifting housing 6. A drive unit 4 is also arranged in the drive housing 3 of the drive device 2, wherein the drive unit 4 is preferably an electric motor. The drive housing 3 and the lifting housing 6 are preferably made of stainless steel.

[0053] As in Fig. 1a and Fig. As can be seen in Figure 1b, the lifting housing 6 can be extended telescopically from the drive housing 3 to reach an active positioning position of the spindle drive device 1. Furthermore, the lifting housing 6 can be retracted telescopically into the drive housing 3 to return to a resting starting position of the spindle drive device 1.

[0054] Furthermore, the lifting device 5 has a lifting element designed as a spindle nut 17 with an internal thread 18, which spindle nut 17 is fixedly connected to the lifting housing 6 and fluid-tightly connected to the lifting housing 6 via a first static seal 22 with the aid of an adapter 28. The lifting housing 6 has a first end 6a, which is directed outwards away from the drive device 2. A base 7 of the lifting housing 6 is located at the first end 6a of the lifting housing 6, and the second connecting element 12 is also connected to the first end 6a of the lifting housing 6. The spindle nut 17 is preferably made of stainless steel.

[0055] Furthermore, the lifting housing 6 has a second end 6b opposite the first end 6a, in which the spindle nut 17 is arranged. Here, the spindle nut 17 is fixedly and permanently connected to the lifting housing 6 in a connecting section C via a crimp connection. The spindle nut 17 is arranged coaxially with respect to the longitudinal axis A and concentrically with respect to an inner circumference of the hollow cylindrical lifting housing 6. The crimp connection comprises plastic deformation of at least a section of a radially circumferential edge of the second end 6b of the lifting housing 6, wherein at least section of the material at the edge of the lifting housing 6 is crimped, thus forming the second end 6b of the lifting housing 6 as a kind of collar.

[0056] In the retracted starting position of the spindle drive device 1 according to Fig. In 1a, the lifting housing 6 is predominantly arranged within the drive housing 3, with only the first end 6a of the lifting housing 6 and the second connecting element 12 protruding outwards from the drive housing 3. The lifting housing 6 is arranged concentrically with respect to the drive housing 3 and coaxially with respect to the longitudinal axis A within the drive housing 3.

[0057] Furthermore, a spindle rod 13 rotatable about a rotational axis and having an external thread 14 is arranged in the lifting housing 6. This spindle rod 13 is arranged coaxially with respect to the longitudinal axis A, with the axis of rotation of the spindle rod 13 coinciding with the longitudinal axis A. The spindle rod 13 is preferably made of stainless steel.

[0058] Here, the spindle rod 13 can be driven into a rotatable motion in a clockwise or counterclockwise direction via the drive unit 4 of the drive device 2 and a coupling device. The internal thread 18 of the spindle nut 17 and the corresponding external thread 14 of the spindle rod 13 are in meshing engagement, allowing the spindle nut 17 and the lifting housing 6, which is rigidly connected to the spindle nut 17, to be displaced axially along the longitudinal axis A without rotation by rotating the spindle rod 13. Thus, the spindle nut 17 is connected to the spindle rod 13 via a positive-locking threaded connection T.

[0059] Furthermore, a hollow cylindrical guide tube 19 is arranged coaxially with respect to the longitudinal axis A in the lifting housing 6, wherein the guide tube 19 and an inner wall 6i of the lifting housing 6 form an annular gap 20. The guide tube 19 is also arranged concentrically with respect to the lifting housing 6. The guide tube has a first end 19a and an opposite second end 19b. Here, the first end 19a of the guide tube 19 is connected to an alignment element 8 on the base 7 of the lifting housing 6 via a plug connection, and the second end 19b of the guide tube 19 is rigidly connected to the spindle nut 17. The guide tube 19 is thus clamped in the lifting housing 6 between the spindle nut 17 and the base 7 of the lifting housing 6, and is arranged immovably and non-rotatably with respect to the axis of rotation or longitudinal axis A. The guide tube 19 is preferably made of stainless steel.

[0060] Furthermore, the lifting device 5 in the lifting housing 6 comprises a gas spring assembly 10, which gas spring assembly 10 has a pressure chamber D filled with a fluid F and operating under pressure p. Here, and preferably, the fluid F contains predominantly gaseous nitrogen, wherein the pressure chamber D operating under pressure p is in Fig. Figure 1 is schematically represented by several circular symbols. The amount of fluid F filled into pressure chamber D always remains constant, while the internal volume of pressure chamber D is variable.

[0061] In the retracted starting position of the spindle drive device 1 according to Fig. 1a The fluid F is in a compressed state predominantly in the annular gap 20 between the stroke housing 6 and the guide tube 19, wherein the fluid F is fluidically connected via a pressure equalization channel 8d of the alignment element 8 and can flow freely through the pressure equalization channel 8d, so that a homogeneous pressure p in the pressure chamber D can be quickly set. In the retracted starting position, the spindle drive device 1 has a higher potential energy due to the fluid F compressed in the pressure chamber D compared to the extended position of the spindle drive device 1, since in the extended position of the spindle drive device 1 the internal volume of the pressure chamber D is larger than the internal volume of the pressure chamber D in the starting position.

[0062] In the extended position of the spindle drive device 1 according to Fig. 1b the fluid F is in an expanded state, wherein the fluid F remains in the annular gap 20 between the stroke housing 6 and the guide tube 19. Furthermore, the fluid F flows in the extended position of the spindle drive device 1 according to Fig. 1b also into the guide tube 19, so that the fluid F can spread almost within the entire stroke housing 6. In the extended position, due to the increase in the internal volume of the pressure chamber D, the spindle drive device 1 thus has a reduced potential energy due to the expanded fluid F.

[0063] The pressure p in the compressed state is according to Fig. 1a of the spindle drive device 1 preferably between 10 bar and 230 bar, wherein a pressure p here and preferably is about 80 bar at an ambient temperature of 25°C (standard temperature) according to the retracted starting position of the spindle drive device 1 shown in Fig. 1a.

[0064] Furthermore, the pressure p in the pressure chamber D depends on the ambient temperature due to the material properties of the fluid F, with a temperature range between -30°C and +80°C being considered an operating range for the spindle drive device 1. Within this operating range, at an ambient temperature between -30°C and +80°C, the pressure p increases by approximately 3% to 4% when the ambient temperature rises by approximately 10°C. However, if the ambient temperature falls by approximately 10°C, the pressure p decreases by approximately 3% to 4%.

[0065] The tightness of the pressure chamber D is ensured by several elements. Firstly, the first static sealing element 22, which is associated with the spindle nut 17, prevents fluid F from escaping within the connection section C between the spindle nut 17 and an inner wall 6i of the stroke housing 6. Secondly, another static sealing element, which is arranged in the base 7 of the stroke housing 6, prevents fluid F from escaping from the stroke housing 6 to the outside.

[0066] Furthermore, the guide tube 19 comprises a cylindrical sealing unit 25, which sealing unit 25 also serves as a guide element 16 for the spindle rod 13 in a region of a first end face 13a of the spindle rod 13, wherein the spindle rod 13 is arranged at least partially in the sealing unit 25 via a plug connection. The cylindrical sealing unit 25 is arranged coaxially with respect to the longitudinal axis A and concentrically with respect to an inner wall 19i of the guide tube within the guide tube 19.

[0067] Fig. Figure 2a shows an enlarged section I from Fig. Figure 1a shows an enlarged view of the connection section C of the crimp connection between the stroke housing 6 and the spindle nut 17. The spindle nut 17 has a first side 17a and an opposing second side 17b, with the first side 17a of the spindle nut 17 facing the pressure chamber D.

[0068] Furthermore, the first side 17a of the spindle nut 17 rests section by section on an end face of the guide tube 19 at the second end 19b of the guide tube 19, with the annular adapter 28 also resting on the first side 17a of the spindle nut 17, so that the guide tube 19 is enclosed without play by both the spindle nut 17 and the adapter 28. In a region of the inner wall 6i of the stroke housing 6, the adapter 28 and the spindle nut 17 form a first radially circumferential U-shaped sealing groove G1, in which the first static sealing element 22 is arranged. The first static sealing element 22 is an O-ring. Thus, the first static sealing element 22 is clamped between the inner wall 6i of the stroke housing 6 and the first sealing groove G1.

[0069] Furthermore, connection section C includes according to Fig. 2a Optionally, a second static sealing element 29 is arranged in a second radially circumferential U-shaped sealing groove G2. The second static sealing element 29, which here is an O-ring, is thus clamped between the spindle nut 17, the adapter 28, and the guide tube 19.

[0070] Fig. 2b shows an enlarged section II from Fig. Figure 1a shows an enlarged view of the cylindrical sealing unit 25. The sealing unit 25 has a first side 25a and a second side 25b opposite the first side 25a, with the first side 25a of the sealing unit 25 facing the pressure chamber D. Thus, the first side 25a of the sealing unit 25 is in contact with the fluid F.

[0071] Furthermore, the sealing unit 25 comprises two dynamic sealing elements 26 in the form of a piston seal, which fit tightly against an inner wall 19i of the guide tube 19, so that the sealing element 25 separates the pressurized pressure chamber D from the spindle rod 13 and the spindle nut 17 in a fluid-tight and pressure-tight manner. The fluid F thus has no contact with the threaded connection T of the spindle nut 17 and the spindle rod 13. The entire spindle nut-spindle rod threaded connection and the entire drive device 2 are located in a pressure-free space.

[0072] Furthermore, the sealing unit 25 has a first centering element 27 designed as a blind hole, which faces the end face 13a of the spindle rod 13. The spindle rod 13 has a corresponding second centering element 15, which is arranged in the first centering element 27 of the sealing unit 25. For this purpose, the first centering element 27 is arranged coaxially with respect to the longitudinal axis A. A disk 21 is also located flat on a base 25c of the first centering element 27, with the disk 21 in contact with the end face 13a of the spindle rod 13 on its side facing away from the base 25c.

[0073] Furthermore, in Fig. Figure 2b shows more clearly that the guide tube 19 is coupled to the alignment element 8 at its first end 19a via a plug connection. The alignment element 8 is positioned coaxially with respect to the longitudinal axis A on the base 7 of the stroke housing 6 within the pressure chamber D. Thus, the alignment element 8 is clamped between the base 7 of the stroke housing 6 and the first end 19a of the guide tube. Consequently, the guide tube 19 has two bearing sections. Firstly, the first end 19a of the guide tube 19 is supported in the alignment element 8, and secondly, the second end 19b of the guide tube 19, opposite the first end 19a, is supported in the spindle nut 17, with the guide tube 19 being rigidly arranged within the stroke housing 6.

[0074] Fig. Figure 2c shows an enlarged section III from Fig. Figure 2b shows an enlarged representation of the first centering element 27 of the sealing unit 25 and the second centering element 15 of the spindle rod 13, which is in contact with the first centering element 27. The first end face 13a of the spindle rod 13 rests on the disk 21, which disk 21 is made of polytetrafluoroethylene (PTFE).

[0075] Furthermore, the second centering element 15 of the spindle rod 13 has a convex outer surface S to ensure a reduced point contact area with an inner wall of the first centering element 27 of the sealing unit 25 in order to reduce friction between the first centering element 27 of the sealing unit 25 and the second centering element 15 of the spindle rod 13.

[0076] Fig. Figure 2d shows a perspective view of a single, one-piece, hollow cylindrical alignment element 8 with a first inner diameter 8c for receiving the guide tube 19. This alignment element 8 can be arranged in a region of the base 7 of the lifting housing. The alignment element 8 has a circular contact surface 8a on which a front face of the first end 19a of the guide tube 19 can be arranged. The first end 19a of the guide tube can be inserted into the alignment element 8 without play.

[0077] Furthermore, the alignment element 8 has an outer surface m from which several support elements 8b, designed as centering means, extend outwards. Here, and preferably, the alignment element 8 comprises three support elements 8b. The support elements 8b of the alignment element 8 can be brought into contact with the inner wall 6i and the bottom 7 of the lifting housing 6 within the lifting housing 6, so that the alignment element 8 can be arranged centered and coaxial with respect to the longitudinal axis A and concentrically within the lifting housing 6. Furthermore, on a side facing away from the support surface 8a, the alignment element 8 has several openings, each of which serves as a pressure equalization channel 8d for the pressure chamber D in the lifting housing 6.

[0078] The one-piece alignment element 8 is here and preferably made of a plastic by means of an injection molding process.

[0079] Fig. 3a and Fig. Figures 3b each show a sectional view along the longitudinal axis A of a further embodiment of a gas spring-assisted spindle drive device 1'. Here, the spindle drive device 1' corresponds to... Fig. 3 essentially the spindle drive device 1 from Fig. 1.

[0080] Fig. Figure 3a shows the entire spindle drive device 1' in a retracted starting position, wherein in Fig. 3b only the lower section of the spindle drive device 1', which is assigned to the lower section of the vehicle flap VF, is shown enlarged in an extended position.

[0081] A difference of the spindle drive device 1' according to Fig. 3 regarding the spindle drive device 1 described above Fig. 1 consists in the fact that the first static sealing element 22 is arranged between the stroke housing 6 and the guide tube 19. The stroke housing 6 has a constriction 23 and the guide tube 19 has a widening 24. The stroke housing 6 and the guide tube 19 are firmly connected to each other via a crimp connection. Furthermore, the spindle nut 17 is firmly connected to the guide tube 19. Thus, in this embodiment of the spindle drive device 1' according to Fig. 3. An adapter can be dispensed with.

[0082] Furthermore, in Fig. 3b it can be seen that a plug 9 is arranged in the base 7 of the hub housing as a static seal.

[0083] Another difference of the spindle drive device 1' according to Fig. Section 3 consists in the fact that the spindle rod 13 has a guide element 16 at its end with the first end face 13a, which first end face 13a faces the pressure chamber D. The guide element 16 comprises an outer circumference of the spindle rod 13, such that the spindle rod 13 is arranged coaxially with respect to the longitudinal axis A inside the guide tube 19.

[0084] Fig. Figure 4a shows a sectional view along a longitudinal axis A of an alternative embodiment of a gas spring-assisted spindle drive device 1". Here, the spindle drive device 1" is in Fig. 4a shown in a partially extended position.

[0085] Fig. Figure 4b shows an enlarged section IV from Fig. 4a, in which a magnetic coupling M of a drive device 2 is shown.

[0086] The spindle drive device 1" comprises the drive device 2' with a hollow cylindrical drive housing 3 and a lifting device 5' with a hollow cylindrical lifting housing 6'. A drive unit 4 is arranged in the drive housing 3 of the drive device 2', wherein the drive unit 4 is an electric motor.

[0087] Furthermore, the lifting device 5' comprises a lifting element designed as a spindle nut 17 with an internal thread 18, which engages in the lifting housing 6' with a spindle rod 13 having an external thread 14. The spindle nut 17 and the spindle rod 13 are thus engaged with each other via a threaded connection T.

[0088] The drive device 2' has a magnetic coupling M, allowing the spindle rod 13 to be rotated clockwise or counterclockwise via the drive unit 4 without contact. Rotation of the spindle rod 13 displaces the spindle nut 17 axially along the longitudinal axis A without rotation, whereupon a guide tube 19', rigidly connected to the spindle nut 17, can be displaced axially along the longitudinal axis L. Furthermore, the guide tube 19' is connected at one end facing away from the drive device 2' to the second connecting element 12 in order to transmit a generated adjusting force to the openable vehicle flap VF.

[0089] Thus, the guide tube 19' can be extended telescopically out of the lifting housing 6' and retracted telescopically into the lifting housing 6' depending on the positioning of the spindle nut 17 within the lifting housing 6' of the lifting device 5'.

[0090] Furthermore, the spindle drive device 1'' comprises a gas spring assembly 10', which gas spring assembly 10' has a pressure chamber D' filled with a fluid F and operating under pressure p. Here, and preferably, the fluid F contains predominantly gaseous nitrogen, wherein the pressure chamber D' operating under pressure p is in Fig. Figure 4 is schematically represented by several circular symbols. The amount of fluid F filled into the pressure chamber D' always remains constant, while the internal volume of the pressure chamber D' is variable via the movable guide tube 19'.

[0091] The pressure chamber D' encompasses the entire stroke housing 6' and also an internal volume up to a partition wall W of the magnetic coupling M, which partition wall in Fig. 4b is shown enlarged.

[0092] Firstly, the pressure chamber D' is sealed on the side associated with the vehicle flap VF by a dynamic rod seal 30 and a static seal 31. Secondly, the partition W of the magnetic coupling M seals the pressurized fluid F from the drive unit 4. Thus, the pressure chamber D' extends from the connection element 12 to the partition W.

[0093] Fig. Figure 4b shows the drive unit 4 with a motor shaft 32 rotatable about the longitudinal axis A. The motor shaft 32 has a magnetic inner rotor IR, which is rigidly connected to the motor shaft 32 in a rotationally secure manner. The partition W is arranged between the inner rotor IR and an outer rotor OR, which is also rotatable about the longitudinal axis A. The inner rotor IR and the outer rotor are coupled to each other by a magnetic force. Thus, one rotation of the inner rotor IR causes a contactless rotation of the outer rotor OR, thereby defining a magnetic coupling M. A drive shaft 33 can then be driven via the outer rotor OR. This drive shaft is mechanically coupled to the spindle rod 13, allowing the spindle rod 13 to be set into a rotary motion about the longitudinal axis A.

[0094] Fig. 5 and Fig. 6 essentially correspond to the embodiment of the Fig. 4, wherein only one arrangement of the partition W of the magnetic coupling M is designed such that the drive unit 4, i.e., the electric motor, simultaneously forms the magnetic coupling M. In other words, it is not necessary to add an external inner rotor IR and an external outer rotor OR according to Fig. Figure 4 is omitted because the electric motor in the drive unit 4 already has an inner rotor IR and an outer rotor OR. More precisely, a simple electric motor consists of an external magnetic field generated by stators, in which an electromagnet (rotor) rotates. Repulsion of like magnetic poles and attraction of opposite magnetic poles cause the rotor to move. A commutator reverses the polarity of the rotor. Accordingly, a more compact drive device 2' can be provided.

[0095] The invention works as follows: To open a pivoting flap VF of a vehicle, e.g., a tailgate, from a retracted starting position using the spindle drive device 1, 1', the drive unit 4 first sets the spindle rod 13 into a rotational movement about the longitudinal axis A. This causes the spindle nut 17 to be displaced axially along the longitudinal axis A in a direction towards the flap VF, thereby extending the lifting housing 6, 6' or the guide tube 19' telescopically. The high-pressure fluid F, located in the pressure chamber D, D', assists the opening movement of the vehicle flap VF analogously to a compressed helical spring. When the vehicle flap VF is fully open, the spindle drive device 1, 1' is in an extended position, with the fluid F in an expanded state at a pressure p', where the pressure p' is lower than the pressure p in the compressed state.

[0096] To close the open flap VF and thus return the spindle drive device 1, 1' from the extended position to the retracted starting position, the drive unit 4 sets the spindle rod 13 into a counter-rotating movement about the longitudinal axis A. This causes the spindle nut 17 to be moved axially back along the longitudinal axis A, causing the lifting housing 6, 6' or the guide tube 19' to retract telescopically. Furthermore, the weight of the vehicle flap VF assists in compressing the fluid F within the pressure chamber D, D'.

[0097] The invention has been explained above with reference to an exemplary embodiment in which the first connection element 11 is assigned to the drive device 2, and the second connection element 12 to the lifting device 5. It is understood that, alternatively, the first connection element 11 can be connected to the vehicle flap VF, and that the second connection element 12 can alternatively be connected to the vehicle frame VB, so that the spindle drive device can be used both as a gas spring and as a gas tension spring.

[0098] The invention has been explained above using an exemplary embodiment in which the spindle drive device serves to open and close a vehicle hatch. It is understood that the spindle drive device can also be used to open and close pivoting front doors, front door leaves, windows, skylights, roof hatches, garage doors, floor hatches, lift beds, as well as pivoting doors of kitchen cabinets and safes. Furthermore, the spindle drive device could be used as a height-adjustable positioning device for furniture such as tables, chairs, and beds, particularly for hospital or office furniture. It is also intended that the spindle drive device can be used as a positioning device in an exoskeleton, particularly for providing support in ergonomically unfavorable postures or when lifting or lowering heavy objects.

Claims

[1] Gas spring-assisted spindle drive device (1) for opening and closing a pivoting flap (VF) of a vehicle, comprising a drive device (2) comprising a drive housing (3) and a drive unit (4) arranged in the drive housing (3), a lifting device (5) which can be driven by means of the drive device (2) via a rotatable spindle rod (13), comprising a lifting housing (6) and a lifting element designed as a spindle nut (17) arranged in the lifting housing (6), wherein the spindle nut (17) and the spindle rod (13) are engaged via a threaded connection (T), wherein the lifting housing (6) comprises a gas spring assembly (10) which gas spring assembly (10) has a pressurized pressure chamber (D) filled with a fluid (F), wherein a guide tube (19) is arranged in the lifting housing (6), wherein the spindle nut (17) is rigidly connected to the guide tube (19), wherein the lifting housing (6) can be extended telescopically from the drive housing (3), and wherein the lifting housing (6) can be retracted telescopically into the drive housing (3), characterized by , that the spindle nut (17) comprises an annular adapter part (28), which adapter part (28) has a first side (28a) and an opposite second side (28b), that the first side (28a) of the adapter part (28) faces the pressure chamber (D), and that the second side (28b) of the adapter part (28) engages with the spindle nut (17). [2] Spindle drive device (1) according to claim 1, characterized by , that the spindle nut (17) is arranged outside the pressure chamber (D), and that the spindle rod (13) is arranged outside the pressure chamber (D). [3] Spindle drive device (1) according to claim 1 or 2, characterized by, that the stroke housing (6) and the spindle nut (17) are firmly and fluid-tightly connected to each other in a connecting section (C). [4] Spindle drive device (1) according to one of claims 1 to 3, characterized by , that the guide tube (19) is arranged at least sectionally between the adapter part (28) and the spindle nut (17), and that at least one first static sealing element (22) is arranged between the adapter part (28) and the spindle nut (17). [5] Gas spring-assisted spindle drive device (1') for opening and closing a pivoting flap (VF) of a vehicle, comprising a drive device (2) comprising a drive housing (3) and a drive unit (4) arranged in the drive housing (3), a lifting device (5) which can be driven by means of the drive device (2) via a rotatable spindle rod (13), comprising a lifting housing (6) and a lifting element designed as a spindle nut (17) arranged in the lifting housing (6), wherein the spindle nut (17) and the spindle rod (13) are engaged via a threaded connection (T), wherein the lifting housing (6) comprises a gas spring assembly (10) which gas spring assembly (10) has a pressurized pressure chamber (D) filled with a fluid (F), wherein a guide tube (19) is arranged in the lifting housing (6), wherein the lifting housing (6) and the guide tube (19) are firmly and fluid-tightly connected to each other in a connecting section (C), wherein the spindle nut (17) is firmly connected to the guide tube (19), wherein the lifting housing (6) can be extended telescopically from the drive housing (3), and wherein the lifting housing (6) can be retracted telescopically into the drive housing (3), characterized by , that a first static sealing element (22) is arranged between the lifting housing (6) and the guide tube (19) within the connecting section (C), that the hub housing (6) has a radially circumferential constriction (23), that the guide tube (19) has a radially circumferential widening (24), and that the first static sealing element (22) is arranged between the constriction (23) of the stroke housing (6) and the widening (24) of the guide tube (19). [6] Spindle drive device (1, 1') according to any one of claims 1 to 5, characterized by, that a sealing unit (25) with a first side (25a) and a second side (25b) facing away from the first side (25a) is arranged in the guide tube (19), that only the first side (25a) of the sealing unit (25) is in contact with the pressurized fluid (F), and that the guide tube (19) is displaceable in the axial direction relative to the sealing unit (25). [7] Spindle drive device (1, 1') according to claim 6, characterized by , that the sealing unit (25) has a dynamic seal (26). [8] Spindle drive device (1, 1') according to claim 6 or 7, characterized by , that the sealing unit (25) separates the pressurized pressure chamber (D) and the spindle nut (17) with the engaged spindle rod (13) from each other in a fluid-tight and pressure-tight manner. [9] Spindle drive device (1, 1') according to one of the preceding claims, characterized by, that the spindle rod (13) can be coupled to the drive unit (4) via a magnetic coupling (M). [10] Gas spring-assisted spindle drive device (1'', 1'''', 1'''') for opening and closing a pivoting flap (VF) of a vehicle, comprising a drive device (2') comprising a drive housing (3) and a drive unit (4) arranged in the drive housing (3), a lifting device (5') which can be driven by means of the drive device (2') via a rotatable spindle rod (13), comprising a lifting housing (6') and a lifting element designed as a spindle nut (17) arranged in the lifting housing (6'), wherein the spindle nut (17) and the spindle rod (13) are engaged via a threaded connection (T), wherein the lifting housing (6') comprises a gas spring assembly (10') which gas spring assembly (10') has a pressurized pressure chamber (D') filled with a fluid (F), wherein a guide tube (19') is arranged in the lifting housing (6'), wherein the spindle nut (17) is rigidly connected to the guide tube (19'), wherein the guide tube (19') can be extended telescopically from the lifting housing (6'), and wherein the guide tube (19') can be retracted telescopically into the lifting housing (6'), characterized by , that the spindle rod (13) can be coupled to the drive unit (4) via a magnetic coupling (M), and that a completely closed partition (W) separates the drive unit (4) from the pressure chamber (D') in a fluid-tight manner.

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