DRIVE UNIT FOR A SLIDING DOOR

Description

[0001] The invention relates to a drive unit for a sliding arrangement. The sliding arrangement is designed as a sliding door. Furthermore, the invention relates to the sliding door including the drive unit.

[0002] The sliding assemblies considered here comprise at least one leaf, namely a door leaf, or are connected to a door leaf. The leaf is displaced horizontally by means of the sliding assembly. The sliding assembly typically comprises a continuously rotating drive belt. The leaf is attached to the drive belt and can thus be moved. A corresponding prior art assembly is disclosed in DE 10 2006 058 653 A1 and also US 3 834 081 A. Furthermore, EP 1 887 177 A2 discloses a garage drive assembly with a belt tensioning device.

[0003] It is an object of the present invention to provide a drive unit for a sliding arrangement which is as compact as possible, easy to install and can be operated with little maintenance.

[0004] The problem is solved by the features of independent claims 1 and 13. The dependent claims contain advantageous embodiments of the invention.

[0005] The invention comprises a sliding door according to claim 1, which comprises the drive unit described below, a substructure for attaching the tensioning device, a counter roller, and the drive belt. The drive belt runs around the deflection roller of the drive unit and around the counter roller.

[0006] The invention discloses a drive unit for a sliding arrangement according to claim 13.

[0007] The sliding arrangement is designed as a sliding door.

[0008] The drive unit comprises a carriage designed for linearly movable mounting relative to a substructure of the sliding assembly. This substructure of the sliding assembly is, for example, a rail to which the drive unit is mounted. The substructure can be fixed, for example, to a wall or a door frame, or can be arranged in a fixed location. Alternatively, however, it is also possible for the substructure to be located on another leaf, and for the drive unit shown here, including the drive belt, to be used to move two leaves synchronously with each other. In general terms, the present invention refers to the substructure being arranged on a "supporting structure." This supporting structure is, for example, the wall, a door frame, or the other leaf.

[0009] The drive unit also includes a deflection pulley. The deflection pulley is located on the carriage and is rotatable about a roller axis. The roller axis is designed to deflect the drive belt of the sliding assembly. The drive belt is, for example, a toothed belt.

[0010] The deflection roller can be motor-driven. Preferably, however, an opposing roller of the sliding assembly, referred to here as the counter-roller, is motor-driven. For this purpose, the sliding assembly can comprise an electric motor. Furthermore, it is also possible for neither roller to be motor-driven. This is particularly the case when the drive unit is used to move two leaves synchronously with each other, with one of the leaves being manually operated by a user.

[0011] The drive unit further comprises a tensioning device used to tension the drive belt. This tensioning device comprises a shaft with an external thread. The shaft is rotatable about a shaft axis. Furthermore, a first shaft receptacle with an internal thread is provided for receiving the external thread of the shaft. The shaft is inserted into the first shaft receptacle, with the internal thread of the first shaft receptacle engaging the external thread of the shaft.

[0012] The clamping device comprises a second shaft mount designed to accommodate the shaft in a linearly movable manner. The shaft is inserted into this second shaft mount and is linearly movable relative to the second shaft mount. The linear movement occurs, in particular, parallel to the shaft axis.

[0013] The tensioning device comprises a compression spring. The compression spring is arranged between the second shaft support and a spring stop on the shaft. This spring stop on the shaft is a fixed element mounted on the shaft. One end of the compression spring rests against this spring stop. The other end of the compression spring rests against the second shaft support. When the distance between the spring stop and the second shaft support decreases, the compression spring is compressed, exerting a force on the shaft and the second shaft support.

[0014] The shaft is designed to tension the drive belt by increasing the distance between the first shaft holder and the second shaft holder. To do this, the shaft is rotated around its shaft axis using a tool. The external thread of the shaft rotates relative to the internal thread of the first shaft holder, causing the shaft to move relative to the first shaft holder. With the correct direction of rotation, the distance between the first shaft holder and the spring stop increases, so that the pressing force on the second shaft holder is increased via the spring, thereby increasing the distance between the two shaft holders. This rotation of the shaft axis is continued until the desired tension on the drive belt is achieved.

[0015] The compression spring is preferably designed as a spiral spring and is mounted on the shaft. This ensures secure positioning of the compression spring between the second shaft mount and the spring stop. Preferably, the drive unit includes an indicator device for indicating the tension of the drive belt. The indicator device has a first indicator element on the shaft and a second indicator element. The second indicator element is arranged stationary relative to the second shaft mount. In particular, the second indicator element is connected to the carriage, in particular the second shaft mount, or is formed integrally therewith.

[0016] Initially, at the beginning of assembly of the drive unit, the two indicator elements are as far apart as possible. By tensioning the drive belt—i.e., by rotating the shaft and thus increasing the distance between the two shaft mounts—the two indicator elements move toward each other until a predefined and desired drive belt tension is reached.

[0017] The first indicator element is preferably located at or on the spring stop. Particularly preferably, the shaft has a groove at the spring stop into which the first indicator element, in particular a rubber ring, is inserted. The first indicator element, in particular the rubber ring, is particularly colored.

[0018] The second display element preferably comprises a frame that is firmly attached to the carriage. This frame particularly preferably has a fastening section that is attached, for example, clipped, to the second shaft mount. The frame preferably comprises a window. The window is, in particular, slit-shaped. The first display element is visible through the window when the desired voltage is set.

[0019] In particular, the second display element, preferably designed as a window, is located in front of the shaft and thus in front of the first display element with respect to the installation position of the drive unit. This allows the installer to see the display device from the front during assembly.

[0020] The shaft axis preferably intersects the roller axis. This ensures that the force is transmitted between the clamping unit and the roller as directly as possible and with as little leverage as possible, thus preventing, for example, tilting of the linearly movable carriage.

[0021] Furthermore, it is preferably provided that the deflection pulley is defined by two opposing end faces. These end faces are perpendicular to the pulley axis. The drive belt runs between the two end faces. The shaft axis preferably runs between these two end faces, preferably centrally between these two end faces. This design also ensures that the force is transmitted between the pulley and the tensioning device as directly as possible and with as little leverage as possible, thus preventing, for example, tilting of the carriage in its linear movement.

[0022] According to the invention, the drive unit comprises a support for fixed mounting on the substructure. The carriage is mounted on the support for linear movement. One of the two shaft mounts, preferably the first shaft mount with the internal thread, is fixedly mounted on the support.

[0023] The support is preferably formed as a one-piece component. For example, the support is a bent sheet metal. The support preferably has a support wall that is connected to the substructure. Furthermore, the support preferably has a support base that extends, in particular, perpendicular to the support wall. In the installed position of the drive unit, the support base preferably extends vertically. The support base preferably supports the first shaft holder and the linearly movable carriage.

[0024] The first shaft receptacle is preferably a 90° bent area of ​​the support base.

[0025] The carrier preferably comprises at least one slot. The carriage preferably comprises at least one sliding foot that is inserted in the slot of the carrier for linear movement.

[0026] According to the invention, at least one fixing element, for example a screw, is provided to secure the carriage to the support. This fixing element preferably also extends through the at least one slot in the support. The fixing element makes it possible to block the linear movement of the carriage relative to the support, so that the carriage is fixedly attached to the support. This fixing is particularly useful when the desired tension of the drive belt has been set.

[0027] The support, in particular the support base, preferably has a recess through which the display device is visible. This recess allows the installer to see the two display elements of the display device. In particular, the two display elements are arranged relative to the recess in such a way that it is visible through the recess how the first display element moves toward the second display element.

[0028] The drive unit shaft is preferably located between the drive belt. The drive belt is deflected by 180° at the idler pulley, so that the drive belt has two parallel and counter-rotating sections. The shaft is preferably located between these two counter-rotating sections. In particular, the shaft axis runs between the two end faces of the pulley. This results in a very compact design of the drive unit and the entire sliding assembly. Furthermore, it ensures the most direct power transmission possible between the pulley and the tensioning device.

[0029] Preferably, at least one driver is arranged on the drive belt, which is designed for attachment to a wing of the sliding assembly. Furthermore, the sliding assembly preferably comprises at least one wing that is attached to the driver.

[0030] In the sliding arrangement, the shaft axis preferably runs horizontally and / or parallel to the drive belt. The roller axis preferably runs vertically.

[0031] Preferably, the substructure has a rear wall. This rear wall is designed for attachment to the supporting structure. This supporting structure is, as already described, for example, a wall, a door frame, or another leaf. By attaching the rear wall of the substructure to the supporting structure, the substructure is stationary relative to the supporting structure.

[0032] The rear wall preferably comprises at least one fastening element designed to secure the sliding assembly to the supporting structure. This fastening element is, for example, a hole through which, in particular, a screw can be inserted.

[0033] Furthermore, it is preferably provided that the deflection roller is arranged between the rear wall and the support base. Particularly preferably, the roller axis is perpendicular to the rear wall. In particular, the roller axis is aligned horizontally when the sliding arrangement is installed. Accordingly, the rear wall extends, in particular, vertically when the sliding arrangement is installed. The at least one fastening element, designed as a hole, preferably extends parallel to the roller axis, so that a screw or other element can be inserted into the hole parallel to the roller axis.

[0034] Furthermore, it is preferably provided that the shaft is arranged between the rear wall and the support base.

[0035] In particular, the arrangement of the deflection pulley and / or the shaft between the rear wall and the support base results in not only the compact design of the sliding arrangement but also good accessibility of the clamping device for the fitter.

[0036] The substructure preferably comprises a side wall in addition to the rear wall. The rear wall and side wall are preferably perpendicular to each other. The side wall is preferably used to attach the support, in particular the support wall. The support wall is particularly preferably screwed to the side wall of the substructure, with the screw(s) used particularly preferably extending perpendicular to the roller axis and perpendicular to the shaft axis.

[0037] As already described, the second display element preferably comprises a frame. This frame essentially comprises at least two regions. One region is designed as a fastening section and serves to fasten the frame, for example, to the carriage, in particular to the second shaft mount. InThe window is formed in the other area of ​​the frame. Furthermore, it has already been described that the support base can have a recess through which the window and the first display element are visible.

[0038] The support base is preferably visible from the front in the installed position. This makes the recess visible from the front.

[0039] In In a preferred embodiment, the shaft is arranged between the area of ​​the frame with the window and the rear wall. As a result, the first display element, particularly when arranged on the shaft, is visible through the window. The first display element can be visible from the front through the window and / or through the recess.

[0040] Furthermore, it is preferably provided that the shaft is arranged between the area of ​​the support base with the recess and the rear wall. This also ensures that the area of ​​the frame with the window, and thus also the shaft with the first display element, are clearly visible through the recess.

[0041] It is particularly preferred that the area of ​​the frame with the window and / or the area of ​​the support base with the recess are formed parallel to the rear wall. In In the installation position of the drive unit or the entire sliding arrangement, the area of ​​the support base with the recess and the area of ​​the frame with the window and the rear wall are preferably parallel to each other and in particular vertical.

[0042] Furthermore, it is preferably provided that the support base comprises a first side and a second side opposite the first side. The first side faces the rear wall; thus, it faces the rear wall. In particular, the first side faces rearward in the installed position. The second side faces away from the rear wall. In particular, the second side faces forward in the installed position. In particular, both sides of the support base are parallel to each other and perpendicular to the roller axis.

[0043] A shoulder is preferably formed on the at least one fixing element used for the fixed attachment of the carriage to the carrier. This shoulder is designed to introduce a torque into the fixing element or to otherwise set and / or release the fixing element; i.e., to actuate the fixing element. In particular, the shoulder is a tool shoulder. Particularly preferably, the shoulder is designed as an external or internal hexagon.

[0044] Preferably, the attachment point of at least one fixing element, in particular all fixing elements, is arranged on the second side of the support base and / or the fixing element is aligned perpendicular to the rear wall. This ensures that the fixing element is easily accessible. This makes it easier for the installer to fix the carriage in its tensioned position when tensioning the drive belt.

[0045] The shaft comprises a tool attachment, wherein the tool attachment corresponds to the attachment of the fixing element.

[0046] The invention will now be described in more detail using an exemplary embodiment. In the following: Fig. 1 shows a sliding arrangement according to the invention with a drive unit according to the invention according to an exemplary embodiment, Fig. 2 shows a side view of the drive unit according to the invention according to the exemplary embodiment, Fig. 3 shows a bottom view of the drive unit according to the invention according to the exemplary embodiment, Fig. 4 shows individual components of the drive unit according to the invention according to the exemplary embodiment, Fig. 5 shows a perspective view of the sliding arrangement according to the invention with the drive unit according to the invention according to the exemplary embodiment, and Fig. 6 shows a further view of the sliding arrangement according to the invention with the drive unit according to the invention according to the exemplary embodiment.

[0047] In the following, a sliding arrangement 50 with drive unit 1 is described in detail using the Fig. 1 to 6 explained. Fig. 1 shows the drive unit 1 with purely schematically illustrated components of the sliding arrangement 50. In the Fig. 2 to 4 only the drive unit 1 is shown. The Fig. 5 and 6 show the sliding arrangement 50 with drive unit 1 taking into account several details of a substructure 51.

[0048] In addition to the drive unit 1, the sliding assembly 50 includes the substructure 51 to which the drive unit 1 is mounted. Furthermore, a drive belt 52 is provided, which runs around a deflection pulley 11 of the drive unit 1 and a counter pulley (not shown).

[0049] It is shown purely schematically that a driver 53 is arranged on the drive belt 52. A wing 54 is attachable or attached to this driver 53 and is horizontally displaceable via the drive belt 52. The sliding assembly 50 can be designed as a movement unit for a sliding door, to which the wing 54 can be attached. Alternatively, the sliding assembly 50 can comprise the wing 54 and be designed as a sliding door. The representation of the wing 54 in Figure 1 is to be seen purely schematically, since the wing 54 is preferably arranged perpendicular to the roller axis 41. Thus, contrary to the illustration of the Figure 1 out of the drawing layer.

[0050] The drive unit 1, according to the Fig. 1 to 4 , comprises a support 2. The support 2 comprises a support base 3, which is connected, in particular manufactured integrally, to a support wall 4. The support wall is immovably attached to the substructure 51.

[0051] There are slots 5 and a recess 6 in the support base 3.

[0052] The drive unit 1 further comprises a carriage 10. The carriage 10 has sliding feet 12. One or more sliding feet 12 are guided for linear movement in a slot 5. Furthermore, fixing elements 13 in the form of screws are provided, which protrude through the slots 5 and serve to fix the carriage 10 relative to the carrier 2.

[0053] On the carriage 10 is a deflection pulley 11, which guides the drive belt 52 between two opposite end walls 14. The deflection pulley 11 is rotatable relative to the carriage 10 about a roller axis 41. The carriage 10 is linearly movable perpendicular to the roller axis 41 and parallel to a shaft axis 40.

[0054] The drive unit 1 further comprises a clamping device 20. This clamping device 20 comprises a shaft 21 that is rotatable about the shaft axis 40. The shaft 21 has, in the given order, a tool attachment 22, a portion with an external thread 23, a spring stop 24, a spring portion 25, a sliding portion 26, and a pull-out protection device 27. The tool attachment 22 is designed, for example, as a polygon, so that the shaft 21 can be rotated using a corresponding tool.

[0055] Furthermore, the clamping device 20 comprises a first shaft receptacle 28 with an internal thread. In the illustrated embodiment, the first shaft receptacle 28 is stationary relative to the substructure 51. For this purpose, the first shaft receptacle 28 is an integral part of the support 2. The shaft 21 is inserted into the first shaft receptacle 28, with the external thread 23 of the shaft 21 engaging the internal thread of the first shaft receptacle 28.

[0056] Furthermore, the clamping device 20 comprises a second shaft receptacle 29, which is linearly movable relative to the substructure 51. For this purpose, the second shaft receptacle 29 is designed as an integral component of the carriage 10. The shaft 21 is inserted with its sliding area 26 into the second shaft receptacle 29, so that the shaft 21 is linearly movable relative to the second shaft receptacle 29 parallel to the shaft axis 40. To prevent the shaft 21 from sliding out of the second shaft receptacle 29, a pull-out protection device 27 in the form of a retaining ring is provided at the end of the shaft 21.

[0057] The tensioning device 20 further comprises a compression spring 15. The compression spring 15 is inserted into the spring region 25. One end of the compression spring 15 is supported on the second shaft receptacle 29 and thus on the carriage 10. The other end of the compression spring 15 rests against the spring stop 24 on the shaft 21.

[0058] In Fig. 2The compression spring 15 is hidden. This illustration clearly shows that the shaft 21 is not in contact with the second shaft mount 29, but rather that the carriage 10 is linearly movable relative to the shaft 21. Only the compression spring 15 transfers the force from the shaft 21 or the spring stop 24 to the carriage 10 when the drive belt 52 is tensioned.

[0059] As in particular the Figs. 3 and 4 As can be seen, the drive unit 1 has a display device 30. This display device 30 comprises a first display element 31 and a second display element 32. The first display element 31 is formed on the shaft 21. In the illustrated embodiment, the shaft 21 has a groove at the spring stop 24 in which a colored rubber ring is seated.

[0060] The second display element 32 includes a window 34 through which the first display element 31 is visible when the voltage is correctly set. The window 34 is slit-shaped.

[0061] In particular, the recess 6 in the support base 3 is provided for this purpose, so that the fitter can see both the window 34 and the first display element 31 from the front.

[0062] In the embodiment shown, the second display element 32 comprises a frame 33 in which the window 34 is recessed.

[0063] The frame 33 is clipped onto the second shaft holder 29 and is therefore stationary relative to the carriage 10.

[0064] In The following is based on the Fig. 5 and 6The sliding assembly 50 with drive unit 1 is described in more detail, taking into account details of the substructure 51. The two figures show that the substructure 51 comprises a rear wall 55 and a side wall 57. The rear wall 55 is substantially perpendicular to the roller axis 41. The side wall 57 is substantially parallel to the roller axis 41 and parallel to the shaft axis 40. The rear wall 55 is vertically aligned in the installed position and is located on a supporting structure.

[0065] The side wall 57 is preferably aligned horizontally in the installed position. The side wall 57 can face the ceiling of a room. In Figure 6 The wing 54, not shown, is attached to the left. A rail protrudes from the rear wall 55 for the sliding arrangement of the wing 54. The rail is aligned parallel to the side wall 57. The rail can accommodate a carriage as a driver 52, to which the wing 54 can be attached.

[0066] The rear wall 55 is used to attach the substructure 51 to a supporting structure. For this purpose, the rear wall 55 comprises several fastening elements 56, here designed as through holes. These through holes extend parallel to the roller axis 41, so that screws can be inserted into the fastening elements 56 parallel to the roller axis 41 to screw the rear wall 55 to the supporting structure.

[0067] The side wall 57 is used to attach the support 2, here the support wall 4. The support 2, in particular the support wall 4, is fastened to the side wall 57 of the substructure 51 with support fastening elements 58, in particular in the form of screws. These support fastening elements 58 in the form of screws preferably extend perpendicular to the side wall 57 and / or perpendicular to the roller axis 41.

[0068] The Fig. 5 and 6show that the deflection pulley 11 and the shaft 21 are located between the support base 3 and the rear wall 55 of the substructure 51. Accordingly, the drive belt 52 also runs between the support base 3 and the rear wall 55.

[0069] This arrangement allows the tool attachment 22 on the shaft 21 to be easily accessible from the front by the fitter.

[0070] Furthermore, the recess 6 in the support base 3 faces forward, so that the area of ​​the frame 33 with the window 34 is clearly visible from the front through the recess 6. The first display element 31 on the shaft 21 is visible through this window 34.

[0071] Fig. 6clarifies that the fixing elements 13 each have a shoulder 42, here designed as an external hexagon. This shoulder 42 is located on the lower side (second side) of the support base 3. This allows the fitter to easily access the shoulders 42 of the fixing elements 13 from the front. The shaft 21 comprises a tool shoulder 22, wherein the tool shoulder 22 corresponds to the shoulder 42 of the fixing element 13. This allows the fitter to use the same tool for rotating the shaft 21 and thus for tensioning the drive belt 52 as for rotating the fixing element and thus for fastening the carriage 10 to the support 2.

[0072] During assembly, the installer can first attach the pre-assembled drive unit 1 to the substructure 51. For this purpose, the support 2 is attached to the substructure using the support fastening element 58. The support 2 is attached to the substructure 51 in such a way that the drive belt 52 is pre-tensioned. The support 2 can be arranged at various locations in a groove of the side wall 57.

[0073] The technician can then, without changing position, place a tool on the tool attachment 22 of the shaft 21 and rotate the shaft 21 until the first indicator element 31 appears in the window 34. This sets the correct tension. While rotating the shaft 21, the technician can see the window 34 through the recess 6 without changing position. The technician can see through the recess 6 how the first indicator element 31 moves toward the window 34.

[0074] Now, without changing position, the fitter can use the same tool to position the tool on the attachment 42. Using the locking screw 13, the carriage 10 can now be secured in the adjusted position relative to the carrier 2. This ensures that the drive belt 52 remains tensioned with the correct force. List of reference symbols

[0075] 1 Drive unit 2 Support 3 Support base 4 Support wall 5 Slots 6 Recess 10 Carriage 11 Deflection pulley 12 Sliding feet 13 Fixing elements 14 End walls 15 Compression spring 20 Clamping device 21 Shaft 22 Tool attachment 23 External thread 24 Spring stop 25 Spring area 26 Sliding area 27 Pull-out protection 28 First shaft holder 29 Second shaft holder 30 Indicator device 31 First indicator element 32 Second indicator element 33 Frame 34 Window 40 Shaft axis 41 Roller axis 42 Attachment 50 Sliding assembly 51 Substructure 52 Drive belt 53 Driver 54 Wing 55 Rear wall 56 Fastening element 57 Side wall 58 Support fastening element

Claims

1. A sliding door comprising a drive unit (1), wherein the drive unit (1) comprises: • a carriage (10) which is designed for linearly-movable mounting relative to a substructure (51) of the sliding door, • a deflection roller (11) rotatable about a roller axis (41) on the carriage (10) for deflecting a drive belt (52) of the sliding door, • and a tensioning device (20) comprising ∘ a shaft (21) rotatable about a shaft axis (40) with an external thread (23), ∘ a first shaft receiver (28) with an internal thread for receiving the external thread (23) of the shaft (21), ∘ a second shaft receiver (29) for receiving the shaft (21) in a linearly-movable manner, ∘ a compression spring (15) between the second shaft receiver (29) and a spring stop (24) arranged stationary on the shaft (21), ∘ a carrier (2) for stationary mounting on the substructure (51), wherein the carriage (10) is supported on the carrier (2) so as to be linearly movable and wherein one of the two shaft receivers (28, 29), preferably the first shaft receiver (28), is arranged stationary on the carrier (2), ∘ at least one fixing element (13) for immovably fixing the carriage (10) to the carrier (2), ∘ wherein the shaft (21) is arranged for tensioning the drive belt (52) by increasing the distance between the first shaft receiver (28) and the second shaft receiver (29), wherein the sliding door comprises the substructure (51), a counter roller and a drive belt (52), wherein the drive belt (52) runs circumferentially around the deflection roller (11) and the counter roller.

2. The sliding door according to claim 1, wherein one of the two shaft receivers (28, 29), preferably the first shaft receiver (28), is designed for stationary mounting relative to the substructure (51), and wherein the other of the two shaft receivers (28, 29), preferably the second shaft receiver (29), is arranged on the carriage (10).

3. The sliding door according to one of the preceding claims, wherein the compression spring (15), designed as a spiral spring, is fitted on the shaft (21).

4. The sliding door according to one of the preceding claims, comprising a display device (30) for displaying the tension of the drive belt (52) with a first display element (31) on the shaft (21) and a second display element (32), which is arranged stationary relative to the second shaft receiver (29).

5. The sliding door according to claim 4, wherein the second display element (32) comprises a frame (33) with a window (34), in particular a slit-shaped window, through which the first display element (31) is visible at a certain setting of the tension.

6. The sliding door according to one of the preceding claims, wherein the shaft axis (40) intersects the roller axis (41).

7. The sliding door according to one of the preceding claims, wherein the deflection roller (11) is delimited by two opposing end faces (14) and the shaft axis (40) runs between the two end faces (14).

8. The sliding door according to one of claims 4 or 5, wherein the carrier (2) has a recess (6) through which the display device (30) is visible.

9. The sliding door according to one of the preceding claims, wherein the shaft (21) is arranged between the drive belt (52).

10. The sliding door according to one of the preceding claims, wherein the substructure (51) comprises a rear wall (55) with at least one fastening element (56) for fastening the sliding door to a carrying structure, wherein the deflection roller (11) is arranged between the rear wall (55) and the carrier base (3), and wherein the roller axis (41) is preferably aligned perpendicular to the rear wall (55).

11. The sliding door according to one of the preceding claims, wherein the shaft (21) is arranged between the region of the frame (33) with the window (34) and the rear wall (55) and / or wherein the shaft (21) is arranged between the region of the carrier base (3) with the recess (6) and the rear wall (55); in particular wherein the region of the frame (33) with the window (34) and / or the region of the base (3) with the recess (6) is / are formed parallel to the rear wall (55).

12. The sliding door according to one of the preceding claims, wherein the carrier base (3) comprises a first side and a second side opposite the first side, wherein the first side faces the rear wall (55) and the second side faces away from the rear wall (55), wherein a projection (42) for actuating the fixing element (13) is arranged on the second side and / or the fixing element (13) is aligned with the rear wall (55).

13. A drive unit (1) for a sliding door, comprising: • a carriage (10) which is designed for linearly-movable mounting relative to a substructure (51) of the sliding door, • a deflection roller (11) rotatable about a roller axis (41) on the carriage (10) for deflecting a drive belt (52) of the sliding door, • and a tensioning device (20) comprising ∘ a shaft (21) rotatable about a shaft axis (40) with an external thread (23), ∘ a first shaft receiver (28) with an internal thread for receiving the external thread (23) of the shaft (21), ∘ a second shaft receiver (29) for receiving the shaft (21) in a linearly-movable manner, ∘ a compression spring (15) between the second shaft receiver (29) and a spring stop (24) arranged stationary on the shaft (21), ∘ a carrier (2) for stationary mounting on the substructure (51), wherein the carriage (10) is supported on the carrier (2) so as to be linearly movable and wherein the first shaft receiver (28) is arranged stationary on the carrier (2), ∘ at least one fixing element (13) for immovably fixing the carriage (10) to the carrier (2), ∘ wherein the shaft (21) is arranged for tensioning the drive belt (52) by increasing the distance between the first shaft receiver (28) and the second shaft receiver (29).

14. The drive unit according to claim 13, comprising a display device (30) for displaying the tension of the drive belt (52) with a first display element (31) on the shaft (21) and a second display element (32), which is arranged stationary relative to the second shaft receiver (29).

15. The drive unit according to claim 14, wherein the second display element (32) comprises a frame (33) with a window (34), in particular a slit-shaped window, through which the first display element (31) is visible at a certain setting of the tension.