Linear bearing for a linear actuator

Abstract

The invention relates to a linear bearing (2) for a linear actuator (1), with an outer tube (11) extending along a movement axis (4) and an end assembly (14; 15) which comprises the one end sleeve (41; 81), a connecting piece (22; 72), a fastening adapter (91; 92; 93), a first annular seal (61) and a second annular seal (62), wherein the connecting piece (22; 72) has a coupling section (24; 74) for a stationary coupling to the outer tube (11), a support section (25; 75) for contact with an inner surface (18) of the outer tube (11) and / or an inner surface (94) of the fastening adapter (91; 92; 93) and a connecting section (27; 77) for receiving the end sleeve (41; 81), wherein the annular seals (61, 62) in Annular gaps (62, 63) between the end sleeve (41; 81) and the fastening adapter (91; 92; 93) orare received between the fastening adapter (91; 92; 93) and the outer tube (11), and wherein an actuator rod (5) is mounted in the outer tube (11) for linear movement.

Description

The invention relates to a linear bearing for a linear actuator.A linear actuator can be designed, for example, as a pneumatic cylinder, as an electric motor with a flanged threaded spindle arrangement or as an electrical linear direct drive and serves for providing a linear actuating movement. This adjusting movement is usually provided by an actuator rod which is held in a bearing housing in a linearly movable manner and which is coupled to a drive component. Depending on the embodiment of the linear actuator, this drive component is, for example, a working piston of a pneumatic cylinder or a threaded nut or a threaded spindle of a threaded spindle drive or a rotor of an electrical linear direct drive.Such a linear actuator comprises an assembly referred to as a linear bearing, with which a linearly movable guide for the actuator rod is ensured and which is also designed for fixing the linear actuator, for example, on a machine frame.DE 31 32 430 A1 discloses a working cylinder for pneumatic or hydraulic working media, having a cylinder which is closed at the end by cylinder covers and in which a piston controlled by limit switches is guided such that it can be moved to and fro, at least one of the cylinder covers being traversed in the longitudinal direction of the cylinder by a stop body which can be adjusted to and fro and can be fixed in the respective position, the end face of which body protruding into the facing working space is designed as a stop surface for the piston and which contains a control valve which controls a control line and the valve body of which protrudes from the stop surface.DE 19 32 116 A discloses a moving cylinder device having a cylinder and a piston rod projecting from the one end of the cylinder and where the cylinder is pivotable about an axis located at the end where the piston rod projects and intersecting the cylinder axis, having a continuous pivot pin having a transverse bore for the piston rod.The object of the invention is to provide a linear bearing with which a compact design for the linear actuator can be realized.This object is achieved for a linear bearing of the type mentioned at the beginning in that the linear bearing has an outer tube extending along an axis of movement and an end assembly, wherein the end assembly is arranged at an end region of the outer tube and comprises a terminating sleeve, a connecting piece, a fastening adapter, a first ring seal and a second ring seal, wherein the connecting piece has a coupling section which is designed for a fixed coupling of the connecting piece to the outer tube or to an inner tube arranged in the outer tube and which is adjoined by a carrier section which is designed for bearing against an inner surface of the outer tube and / or an inner surface of the fastening adapter, wherein a connecting section which is designed for receiving the terminating sleeve is arranged adjacent to the carrier section, wherein the first annular seal is accommodated in a first annular gap between the terminating sleeve and the fastening adapter, and wherein the second annular seal is accommodated in a second annular gap between the fastening adapter and the outer tube, and wherein an actuator rod is mounted in the outer tube so as to be linearly movable along the movement axis which the end assembly is capable of moving.The outer tube forms, on the one hand, a sheath for the drive component in order to protect the latter from environmental influences and also serves as a mechanical connecting element, via which a force transmission is made possible between the drive component and the components of the end assembly, in particular the fastening adapter. The outer tube extends, preferably with a constant profile, along an axis of movement along which a relative movement of the drive rod with respect to the outer tube is provided. By way of example, the outer tube is designed as a circular cylindrical tube, wherein in this case the axis of movement is formed by the central axis of the outer tube.The outer tube has an end region at each of opposite ends, wherein an end assembly is arranged at at least one of the end regions, with which end assembly different functions for the linear bearing are realized. A first function of the end assembly, in particular of the closing sleeve, is on the one hand to close off the end face of the outer tube and on the other hand to provide a through-opening for the actuator rod, so that the latter can carry out the desired relative movement with respect to the outer tube. A further function of the end assembly, which is substantially perceived by the fastening adapter, is the provision of at least one fastening surface, by means of which a mechanical coupling of the fastening adapter to a further component, such as a machine frame, can be realized.In order to ensure advantageous coupling of the fastening adapter to the outer tube, the end assembly comprises a connecting piece which is designed for fixed attachment to the outer tube. For this purpose, the connecting piece comprises a coupling section which is connected to the outer tube in a force-fitting and / or form-fitting manner either directly or with the interposition of a further component such as, for example, an inner tube arranged in the outer tube and / or which allows at least a force introduction from the end assembly onto the outer tube and a force dissipation from the outer tube onto the end assembly. Depending on the configuration of the linear bearing, it can be provided that an inner tube is arranged in the outer tube, wherein it can be provided in this case that the connecting piece with the coupling section is fixed to the inner tube and only an indirect connection to the outer tube exists.The coupling section is adjoined along the movement axis by a carrier section which is designed for bearing against an inner surface of the outer tube and / or against an inner surface of the fastening adapter. It is preferably provided that an outer surface of the carrier section abuts both the inner surface of the outer tube and the inner surface of the fastening adapter and thus ensures advantageous support for the fastening adapter. The carrier section is adjoined along the movement axis by a connecting section which is designed for receiving and in particular for fixing the terminating sleeve. It is advantageous if the coupling section, the carrier section and the connecting section are each configured with constant profiling and are arranged as a row along the movement axis. It is particularly advantageous if the connecting piece comprises the coupling section, the carrier section and the connecting section in one piece.In order to enable the linear bearing to be adapted to different use conditions, it is provided that the fastening adapter is designed as a separate component which can be replaced in a simple manner. This results in a first annular gap and a second annular gap between the fastening adapter and the end sleeve and between the fastening adapter and the outer tube. Both the first annular gap and the second annular gap cannot be configured in a manner which, even in the case of a highly precise and therefore costly production of the terminating sleeve, of the fastening adapter and of the outer tube, would exclude the penetration of contaminants and liquids into the respective first and second annular gap in the practical use of the linear bearing, this applies in particular if the linear actuator with the associated linear bearing is used in the field of food technology or pharmacy, where frequent cleaning processes are carried out, in particular using high-pressure water cleaners, water striking the linear bearing at up to 100 bar and temperatures of virtually 100 degrees Celsius. In order to be able to ensure an advantageous sealing effect for the first annular gap and the second annular gap, a first annular seal is arranged in the first annular gap and a second annular seal is arranged in the second annular gap. The ring seals are configured in such a way that they can compensate geometric deviations between the end sleeve and the fastening adapter or between the fastening adapter and the outer tube and thus ensure an adequate sealing effect despite relatively low quality requirements for those surfaces which delimit the respective ring gaps.Furthermore, it is provided that the components of the end assembly which is assigned to a first end region of the outer tube are traversed by the actuator rod which is mounted in the outer tube such that it can move linearly. If a further end assembly should be assigned to a second end region of the outer tube, the latter is usually not penetrated by the actuator rod and is for this reason configured differently at least with regard to the terminating sleeve.The actuator rod is designed for coupling to a drive component which can be accommodated in the outer tube and which is provided for introducing movement forces onto the actuator rod. If the linear actuator is designed as a pneumatic cylinder, the drive component is formed by a pneumatic piston, also referred to as a working piston, which can be accommodated in the outer tube in a sealing manner such that it can move linearly, for example, and which forms at least one variable-size working space, preferably two variable-size working spaces, with the outer tube and can apply the desired movement force by applying pressure to at least one working space. If the linear actuator is designed as a threaded spindle drive, the drive component can optionally be designed as a threaded spindle or threaded nut. In one embodiment of the drive component as a threaded spindle, a rotatable coupling with the drive rod is preferably provided, wherein the threaded spindle is set in rotation by a motor, in particular an electric motor, and is supported on a threaded nut fixed in a fixed position in the outer tube. In one embodiment of the drive component as a threaded nut, it is provided that this threaded nut is accommodated in the outer tube in a linearly movable and rotationally fixed manner and is traversed by a threaded spindle which is mounted rotatably and otherwise fixed in the outer tube and is driven by a motor, in particular an electric motor.Advantageous further developments of the invention are the subject matter of the dependent claims.It is expedient if the first annular gap is bounded by an axial end face of the connecting piece and by a first axial end face of the fastening adapter and / or if the second annular gap is bounded by a second axial end face of the fastening adapter and by an axial end face of the outer tube, wherein the first annular seal and the second annular seal are each produced from a plastic material, in particular a rubber-elastic material. Preferably, the axial end face of the connecting piece and the first axial end face of the fastening adapter are each designed as planar surfaces, in particular as annular surfaces, and are arranged opposite one another. Particularly preferably, these planar surfaces are arranged in planes parallel to one another and oriented transversely to the movement axis. This applies in the same way to the second axial end face of the connecting piece and the axial end face of the outer tube. The first ring seal and the second ring seal are preferably formed with a rectangular or square profile and are compressed in the axial direction along the movement axis during the assembly of the end assembly, in particular by screwing the end sleeve onto the connecting piece, in order to ensure the desired sealing contact with the respective axial end face. The first ring seal and the second ring seal are preferably produced from a plastic material which does not lose its sealing effect even when a water jet, which exits from a nozzle of a high-pressure cleaner at a pressure of 100 bar and which has a temperature of approximately 100 degrees Celsius, impinges and ensures reliable sealing of the respective ring gap.It is advantageous if a guide sleeve is arranged on an inner surface of the connecting piece, which guide sleeve is designed for a sliding guide of the actuator rod. The guide sleeve is preferably produced from a metallic material, for example brass or bronze, or from a plastic material, in particular from the group of the polyoxymethylenes (POM) or the polyetheretherketones (PEEK), and ensures low-play and low-friction guidance of the actuator rod.In a further development of the invention, it is provided that the connecting section of the connecting piece is provided with an external thread and that the terminating sleeve has a tubular fastening section which engages with an internal thread in the external thread of the connecting piece and which abuts with an outer surface against the inner surface of the fastening adapter.In a further embodiment of the invention, it is provided that a circumferential radial groove is formed on an inner surface of the connecting piece, in which groove a shaft sealing ring is accommodated, which is formed for a sealing contact on the first connecting piece and on an outer surface of the actuator rod. With this shaft sealing ring, through which the actuator rod passes, a spatial separation between an interior space bounded by the outer tube and a surrounding area of the linear bearing is ensured. The shaft sealing ring is preferably made at least in regions from a rubber-elastic material and rests sealingly on the actuator rod by means of at least one encircling sealing lip, preferably by means of two sealing lips arranged at a distance from one another along the movement axis. Furthermore, the shaft sealing ring is held in a fixed and sealing manner in the circumferential radial groove of the connecting piece.It is preferably provided that the fastening adapter is formed from the group: fastening ring with axially aligned threaded bores, fastening ring with pivot bearing pins arranged on both sides and aligned radially, fastening ring with feet. A configuration of the fastening adapter as a fastening ring with axially aligned threaded bores is of interest in particular if the linear bearing is to be fixed with a vertical alignment of the movement axis relative to a fastening surface of a machine frame. In this case, an outer diameter of the fastening ring is selected to be greater than an outer diameter of the outer tube, whereby an annular end face of the fastening ring can be placed against the fastening surface. For the fixation of such a fastening ring, it can be provided that the fastening surface is traversed by bores which are aligned parallel to the movement axis and in which fastening screws can be received which can engage in the axially aligned threaded bores in the circular ring-shaped end face of the fastening ring. Alternatively, the fastening ring is provided with radially oriented pivot bearing pins arranged on both sides, which can engage in corresponding bearing bushes on a machine frame in order to be able to ensure a pivotable mounting of the linear bearing with a pivot axis oriented transversely to the movement axis. In a further alternative embodiment, the fastening ring is provided with one or more feet, wherein the respective foot has a bearing surface which is designed for bearing on a fastening surface of a machine frame and the surface normal of which is oriented transversely to the movement axis. This makes it possible to fix the linear bearing on a machine frame with a parallel alignment of the movement axis with respect to the fastening surface.It is expedient if a circumferential radial groove is formed on an inner surface of the end sleeve, in which groove a shaft sealing ring is accommodated, which is formed for a sealing contact on the end sleeve and on an outer surface of the actuator rod. With this shaft sealing ring, through which the actuator rod passes, an intermediate space, which extends between the connecting piece and the end sleeve, is sealed off from the environment of the linear bearing, wherein this intermediate space is located upstream of the interior space, which is bounded by the outer tube. This achieves a double seal between the interior and the environment. The shaft sealing ring is preferably made at least in regions from a rubber-elastic material and rests sealingly on the actuator rod by means of at least one encircling sealing lip, preferably by means of two sealing lips arranged at a distance from one another along the movement axis. Furthermore, the shaft sealing ring is held in a fixed and sealing manner in the circumferential radial groove of the closing sleeve.In an advantageous development of the invention, it is provided that the one outer surface of the outer tube and one outer surface of the fastening adapter and one outer surface of the first ring seal and one outer surface of the second ring seal and one outer surface of the closing sleeve each have the same profile in a projection plane oriented transversely to the movement axis. This ensures a smooth outer surface for the linear bearing in the region of the end assembly, so that no undesired undercuts or other depressions are present, which would make a cleaning process for this outer surface more difficult.In a further embodiment of the invention, it is provided that the outer tube is provided with an end assembly at opposite end regions. It is preferably provided that the two end assemblies each have the same components (end sleeve, connecting piece, fastening adapter, ring seals), wherein these components can have differing geometric configurations depending on the configuration of the linear actuator for which the linear bearing is configured. This applies in particular to the end sleeves of the two end assemblies, which differ considerably from one another since only one of the two end sleeves is traversed by the actuator rod, while this is not the case with the other end sleeve.It is preferably provided that in one of the two end assemblies the closing sleeve has a fastening flange or is designed for coupling a fastening flange, wherein the fastening flange is designed for fixing a drive motor. This is the end sleeve which is not traversed by the actuator rod, wherein the fastening flange can optionally be formed integrally with the end sleeve or can be coupled, in particular screwed, to the end sleeve.An advantageous embodiment of the invention is shown in the drawing. The following shows: FIG. 1 shows a perspective illustration of a linear actuator realized as a threaded spindle drive with an electric motor and a linear bearing, FIG. 2 shows a purely schematic sectional illustration of a front end region of the linear bearing according to FIG. 1, FIG. 3 shows a purely schematic sectional illustration of a rear end region of the linear bearing according to FIG. 1 FIG. 4 shows a perspective and schematic illustration of an annularly designed fastening adapter, FIG. 5 shows a perspective and schematic illustration of a fastening ring with feet, and FIG. 6 shows a perspective and schematic illustration of an annularly designed fastening adapter with laterally protruding pivot bearing pins.A linear actuator 1 shown only schematically in FIG. 1 comprises a linear bearing 2 and an electric motor 3. The threaded spindle interacts with a threaded nut, likewise not shown, which is held in the linear bearing 2 in a linearly movable and rotationally fixed manner and which is coupled to an actuator rod 5 which passes through the linear bearing 2 on the end face. The actuator rod 5 is, purely by way of example, of circular cylindrical design and extends along the movement axis 4. According to the illustration in FIG. 1, the actuator rod 5 is in a first functional position, which is also referred to as the retracted position, and, starting from this first functional position, can be transferred along the movement axis 4 in the direction of the symbolically drawn movement arrow 6 into a second functional position, which is not illustrated and is also referred to as the extended position.The linear bearing 2 comprises an outer tube 11, which is purely exemplarily embodied as a circular cylindrical sleeve and is provided with a first end assembly 14 at a first end region 12 and with a second end assembly 15 at a second end region 13. The first end assembly 14 is shown in more detail in FIG. 2, and the second end assembly 15 is shown in more detail in FIG. 3.Purely by way of example, the two end assemblies 14, 15 are each equipped with a fastening adapter 91, which is illustrated in more detail in FIG. 5. Each of the fastening adapters 91 can be individually exchanged for another fastening adapter 92, 93 shown in FIGS. 4 and 6, in order to enable an advantageous fastening of the linear bearing 2 to a machine frame, which is not shown in any more detail.The fastening adapters 91 shown in FIG. 1 allow, for example, the linear actuator 1 to be fixed on a planar surface of a machine frame or machine frame, not shown in detail, wherein this surface is symbolized by the plane 7 shown in dashed lines.By way of example, the linear actuator 1 can be used to move a machine component, not shown, along the movement axis 4 relative to the machine frame, likewise not shown. For this purpose, with the aid of the actuator rod 5, which is connected to the electric motor via the threaded nut, not shown, and the associated threaded spindle, an extension movement and a retraction movement can be provided, in which a conversion of a rotational movement of a drive shaft of the electric motor into the desired linear movement of the actuator rod takes place.In another embodiment of a linear actuator, not shown, the actuator rod can be connected to a pneumatic piston of a pneumatic linear drive, which together with the outer tube delimits at least one variable-size working space and can carry out a movement along the movement axis 4 by applying an overpressure to this working space. In a further embodiment of a linear actuator, not shown, the actuator rod can be connected to a rotor of an electrodynamic linear direct drive, which can be acted upon by magnetic forces along the movement axis by an electrical coil arrangement assigned to the outer tube, in order thereby to bring about the desired movement of the actuator rod.As can be seen from the illustration of FIG. 2, which shows the first end assembly 14 in detail, the first end assembly 14 comprises a first terminating sleeve 41, a first connecting piece 22, a first annular seal 61 and a second annular seal 62. Purely by way of example, in the case of the linear actuator 1 designed as a threaded spindle drive, an inner tube 16 is arranged coaxially with the outer tube 11, which inner tube is provided, at an end region facing the first connecting piece 22, with an internal thread 17 which engages in an external thread 23 of the first connecting piece 22, which is formed at a coupling section 24 of the first connecting piece 22. By means of this threaded connection, the inner tube 16 can support the connecting piece 22 and take over the predominant part of the dissipation of forces acting on the connecting piece 22. A carrier section 25 follows the coupling section 24 along the movement axis 4, which carrier section is designed, purely by way of example, for bearing against an inner surface 18 of the outer tube 11 and against an inner surface 94 of the fastening adapter 91. Purely by way of example, the carrier section 25 is provided with a circular cylindrical outer surface 26 in order to ensure as extensive a contact as possible on the inner surfaces 18 and 94 and thus an advantageous support of the outer tube 11 and of the fastening adapter 91.Arranged adjacent to the carrier section 25 is a connecting section 27 which is provided with an external thread 28 which is provided for engaging an internal thread 29 formed on the first terminating sleeve 41. This ensures reliable fixing of the first end sleeve 41 from the connecting piece 22.Thus, the connecting piece 22 ensures a coupling between the inner tube 16, the outer tube 11, the fastening adapter 91 and the first closing sleeve 41 both in the axial direction and in the radial direction.For guiding the actuator rod 5, the connecting piece 22 is provided with a through bore 29 which is arranged coaxially with the outer surface 26 and in which a guide sleeve 30 is accommodated. The guide sleeve 30 forms a slide bearing for the actuator rod 5, which is formed purely by way of example from a circular cylindrical tube 8 and a closure piece 9 screwed into the tube 8 at the end. Furthermore, adjacent to the through contact 29 for the guide sleeve 30, a radial groove 31 which extends outwards in the radial direction is introduced into the connecting portion 27 and is bounded in the axial direction by a radially inwardly projecting annular collar 32. The radial groove 31 is designed to receive a shaft sealing ring 33, which in the radial direction sealingly abuts in the groove base 34 of the radial groove 31 as well as on the outer surface of the actuator rod 5. Furthermore, the shaft sealing ring 33 is designed to sealingly abut an axially aligned end face 35 of the connecting piece 22.The connecting piece 22 can be made of a metallic material, in particular a stainless steel, or of a high-strength plastic. The guide sleeve 30 is preferably made of POM or PEEK, but alternatively can also be made of a metallic material such as brass or bronze.The closing sleeve 41 serves for guiding the fastening adapter 91 and for fixing the fastening adapter 91 on the connecting piece 22, for which purpose the closing sleeve 41 is divided into a ring section 43 and a sleeve section 44. The ring section 43 has a radial groove 45 which extends outwards in the radial direction and which is bounded in the axial direction by a radially inwardly projecting ring collar 46. The radial groove 45 is designed to receive a shaft sealing ring 47, which in the radial direction sealingly abuts in the groove base 48 of the radial groove 45 and on the outer surface of the actuator rod 5. Furthermore, the shaft sealing ring 47 is designed to sealingly abut an axially aligned end face 49 of the end sleeve 41. Formed in the axial direction adjacent to the ring section 43 is the sleeve section 44, which is provided on the inner surface with the internal thread 42 and which has an outer surface 50 which is profiled in a circular manner, purely by way of example, and which is designed for planar contact with the inner surface 94 of the fastening adapter 91, which inner surface is likewise profiled in a circular manner. By way of example, an outer diameter of the sleeve section 44 and an inner diameter of the fastening adapter 91 are matched to one another in such a way that a transition fit (for example H7 / k6 according to DIN 7257) can be ensured thereby, in which the fastening adapter 91 can be pushed manually onto the sleeve section 42 by a user and is substantially free of play.In order to ensure a seal between the components of the first end assembly 14 and the outer tube 11, a first annular seal 61 is arranged in a first annular gap 63 which is formed between the terminating sleeve 41 and the fastening adapter 91. Furthermore, a second annular seal 62 is arranged in a second annular gap 64, which is formed between the fastening adapter 91 and the outer tube.The first ring seal 61 is clamped between an end face 51 of the end sleeve 41 and an oppositely arranged first end face 95 of the fastening adapter 91 during the mounting of the end sleeve 41 on the connecting piece 22. During the mounting of the closing sleeve 41 on the connecting piece 22, the second ring seal 62 is clamped between a second end face 96 of the fastening adapter 91 and an end face 19 of the outer tube 11.In order to enable the closing sleeve 41 to be screwed onto the connecting piece 22, the closing sleeve 41 is provided with wrenching surfaces 52 arranged in pairs and visible in FIG. 1. In order to ensure an advantageous sealing effect for the two ring seals 61, 62, it can be provided that the screwing process for the closing sleeve 41 onto the connecting piece 22 is carried out with a maximum torque, with which it is possible to prevent the ring seals 61, 62 from being pushed out of the respective ring gaps 63, 64.In the second end assembly 15 as shown in FIG. 3, the connector 72 is simpler in design than the connector 22 of the first end assembly 14. In the case of the connecting piece 72, a coupling section 74 is also formed to match the connecting piece 22 for connection to the inner tube 16. The coupling section 74 is adjoined by a carrier section 75, the outer surface 76 of which is designed to bear both on the inner surface 18 of the outer tube 11 and on the inner surface 94 of the fastening adapter 91. The connecting section 77 adjoining the latter is provided with an external thread 78 for fixing the terminating sleeve 81, which is fixed to the connecting section 77 with an internal thread 82. The first annular seal 61 is accommodated in the first annular gap 63 which extends between an end face 89 of the terminating sleeve 81 and the first end face 95 of the fastening adapter 91. The second annular seal 62 is accommodated in the second annular gap 64, which extends between the second end face 96 of the fastening adapter 91 and the opposite end face 19 of the outer tube 11.As can be seen from the illustration in FIG. 1, the closing sleeve 81 comprises a fastening flange 90, which is designed for fixing the electric motor 3 and which is provided purely by way of example with four axial bores, which are not illustrated and which are designed for receiving fastening screws 10 for fixing the electric motor 3 to the closing sleeve 81.As an alternative to the fastening adapter 91 shown in FIGS. 1 to 4, the linear actuator 1 can also be equipped with other fastening adapters that can be freely selected, of which further embodiments are shown purely by way of example in FIGS. 4 and 6. The fastening adapter 92 according to FIG. 4 is of annular design and has a larger outer diameter than the outer tube 11, so that end faces 97 and 98 oriented in the axial direction protrude beyond the outer tube 11 in the radial direction when the fastening adapter 92 is mounted, thus permitting use of screw fasteners which pass through the bores 99 formed in the end faces 97, 98 in the axial direction.The annularly designed fastening adapter 93 has pivot bearing pins 100 which are aligned transversely to the movement axis 4 and are purely exemplarily of circular cylindrical design and which, when received in bearing bushes not shown, enable a pivotable mounting of the linear actuator 1.

Claims

Linear bearing (2) for a linear actuator (1), having an outer tube (11) extending along a movement axis (4) and an end assembly (14; 15), wherein the end assembly (14; 15) is arranged at an end region (12, 13) of the outer tube (11) and comprises a terminating sleeve (41; 81), a connecting piece (22; 72), a fastening adapter (91; 92; 93), a first annular seal (61) and a second annular seal (62), wherein the connecting piece (22; 72) has a coupling section (24; 74) which is designed for a fixed coupling of the connecting piece (22; 72) to the outer tube (11) or to an inner tube (16) arranged in the outer tube (11) and on which a carrier section (25; 75,) which is designed for bearing against an inner surface (18) of the outer tube (11) and / or an inner surface (94) of the fastening adapter (91; 92; 93), wherein a connecting portion (27; 77) which is designed to receive the closing sleeve (41; 81) is arranged adjacent to the carrier portion (25; 75), wherein the first ring seal (61) is received in a first ring gap (62) between the closing sleeve (41; 81) and the fastening adapter (91; 92; 93), and wherein the second ring seal (62) is received in a second ring gap (64) between the fastening adapter (91; 92; 93) and the outer tube (11), and wherein an actuator rod (5) is mounted in the outer tube (11) such that it can move linearly along the movement axis (4) and passes through the end assembly (14; 15).Linear bearing (2) according to Claim 1, characterized in that the first annular gap (63) is delimited by an axial end face (35) of the connecting piece (22) and by a first axial end face (95) of the fastening adapter (91; 92; 93), and / or in that the second annular gap (64) is delimited by a second axial end face (96) of the fastening adapter (91; 92; 93) and by an axial end face (19) of the outer tube (11), wherein the first annular seal (61) and the second annular seal (62) are each produced from a plastics material.Linear bearing (2) according to Claim 1 or 2, characterized in that a guide sleeve (30) is arranged on an inner surface (29) of the connecting piece (22), said guide sleeve being designed for a sliding guide of the actuator rod (5).Linear bearing (2) according to Claim 1, 2 or 3, characterized in that the connecting section (27) of the connecting piece (22) is provided with an external thread (28), and in that the terminating sleeve (41; 81) has a tubular fastening section (44) which engages with an internal thread (42) in the external thread (28) of the connecting piece (22) and which bears with an outer surface (26) against the inner surface (94) of the fastening adapter (91; 92; 93).Linear bearing (2) according to Claim 1, 2, 3 or 4, characterized in that a circumferential radial groove (31) is formed on an inner surface of the connecting piece (22), in which groove a shaft sealing ring (33) is accommodated, which is formed for sealing contact on the connecting piece (22) and on an outer surface of the actuator rod (5).Linear bearing (2) according to one of the preceding claims, characterized in that the fastening adapter (91; 92; 93) is formed from the group: fastening ring (92) with axially aligned threaded bores (99), fastening ring (94) with pivot bearing pins (100) arranged on both sides and aligned radially, fastening ring (91) with feet.Linear bearing (2) according to one of the preceding claims, characterized in that a circumferential radial groove (45) is formed on an inner surface of the end sleeve (41), in which groove a shaft sealing ring (47) is accommodated, which is formed for sealing contact on the end sleeve (41) and on an outer surface of the actuator rod (5).Linear bearing (2) according to Claim 1, characterized in that adjoining outer surfaces of the outer tube (5), of the fastening adapter (91; 92, 93), of the first annular seal (61), of the second annular seal (62) and of the terminating sleeve (41) each have the same profiling in a projection plane aligned transversely with respect to the movement axis.Linear bearing (2) according to one of the preceding claims, characterized in that the outer tube (11) is provided with an end assembly (14, 15) in each case at mutually opposite end regions (12, 13).Linear bearing (2) according to Claim 9, characterized in that, in one of the two end assemblies (15), the terminating sleeve (81) has a fastening flange (90) or is designed for coupling a fastening flange, the fastening flange (90) being designed for fixing a drive motor (3).

Images