Gearbox with a shaft, at least one first bearing, a housing part and a cover

Description

[0001] The invention relates to a transmission with a shaft, at least one first bearing, a housing part and a cover.

[0002] A gearbox is known from CN 2 07 278 846 U. It is known that a shaft in the gearbox is rotatably mounted via bearings housed in a housing part of the gearbox.

[0003] DE 29 23 507 A1 discloses a device for grinding machines for material containing lignocellulose.

[0004] From WO 2015 / 185 484 A1 a device for lubricating a rolling bearing of an electric motor is known.

[0005] From CN 1 06 641 203 A1 a sealing arrangement for a rotatably mounted shaft of a gearbox is known.

[0006] From the CN 207 111 896 U a sealing arrangement is known. A sealed bearing arrangement is known from CN 207 278 846 U.

[0007] From the CN 203 685 659 U A bearing arrangement with labyrinth seal is known.

[0008] From the CN 206 889 640 U The closest state of the art is a sealing arrangement with a labyrinth seal. A transmission is known from WO 2020 / 192 964 A1.

[0009] The invention is therefore based on the object of designing a transmission that is environmentally friendly.

[0010] According to the invention, the object is achieved in the transmission according to the features specified in claim 1.

[0011] Important features of the invention in the transmission with a shaft, at least one first bearing, a housing part and a cover, wherein the shaft is rotatably mounted at least via the first bearing, wherein the first bearing has an inner ring which is pushed onto the shaft, wherein the cover is connected to the housing part, in particular by means of screws, wherein the shaft has a threaded area onto which a nut is screwed, in particular for adjusting a bearing tension, wherein a spacer sleeve and a disk are arranged between the nut and the inner ring, wherein the largest outer diameter of the disk is greater than the largest outer diameter of the spacer sleeve, wherein the largest radial distance of the disk relative to the axis of rotation of the shaft is greater than the largest radial distance of the spacer sleeve relative to the axis of rotation of the shaft, and / or wherein the radial distance area covered by the disk and relative to the axis of rotation of the shaft contains the radial distance area covered by the spacer sleeve, in particular.

[0012] The advantage of this is that it enables friction-free sealing on the output side of the gearbox. This means that the gearbox can be designed with low power loss, which conserves resources, particularly energy consumption, and protects the environment. It also prevents lubricating oil from leaking out, which likewise conserves and protects the environment. This is because the disc prevents oil escaping from the first bearing from spreading towards the shaft, thus causing it to flow away through the channel. It also prevents oil from adhering to the shaft and flowing out to the output side. This is because when the shaft rotates and thus also the disc which is connected to the shaft in a rotationally fixed manner, the disc acts as a centrifugal edge and centrifuges the oil away in such a way that the centrifuged oil is guided along the inner wall of the cover to the channel and from there returned to the oil sump.When not rotating, the disc acts as a drip edge and thus ensures the supply to the channel and thus the return to the oil sump.

[0013] Therefore, energy and material emissions are reduced or prevented, which protects the environment.

[0014] The interposition of a spacer sleeve between the disc and the inner ring of the first bearing allows the disc to be very narrow, thus with low mass and thus a low moment of inertia, and the spacer sleeve to have a very small outer diameter. This allows the oil flowing out of the first bearing to collect in the axial area between the disc and the inner ring and then flow from this annular area down through the channel to the oil sump in the interior area.

[0015] Thus, the bearing tension is generated and / or fixed by the nut screwed onto the shaft, with the disc being clamped in place as the bearing tension is generated. In other words, screwing the nut onto the shaft not only generates the bearing tension but also the fastening force for the disc. At higher bearing tension, the disc is also held more firmly than at lower bearing tension.

[0016] True containment here means containment as a true subset. Thus, the radial clearance range covered by the spacer sleeve is a true subset of the radial clearance range covered by the disk, relative to the shaft's rotational axis.

[0017] In an advantageous design, the washer is arranged axially between the nut and the spacer sleeve. This is advantageous because the nut presses directly on the washer, which then transmits the force to the inner ring via the spacer sleeve.

[0018] In an advantageous embodiment, the spacer sleeve rests against the inner ring of the first bearing. The advantage here is that pressure is exerted on the inner ring essentially only in the axial direction.

[0019] In an advantageous embodiment, the spacer sleeve is arranged axially between the disk and the inner ring of the first bearing. This has the advantage that the oil collects in the axial area covered by the spacer sleeve and then flows away via the channel.

[0020] In an advantageous embodiment, the bearing tension of the bearing arrangement of the shaft having the first bearing is adjusted by means of the nut, in particular wherein the bearing arrangement has a second bearing. It is advantageous in this case that the bearing tension provided in the bearing can be adjusted by means of the nut screwed onto the shaft. The nut preferably has means for force-fittingly clamping the nut on the threaded area of ​​the shaft. This prevents the nut from being screwed back on and fixes the bearing tension. For this purpose, the nut has slots and / or grooves on its outer side and on its inner side, so that axially directed screws passed through these press areas of the nut towards one another and in the process cause the clamping of the nut on the screw thread to create a fixation.

[0021] The disc extends into an annular space, which is connected via a channel to an interior area of ​​the transmission, in particular to a geared part and the interior area of ​​the transmission comprising an oil sump. The advantage of this is that the oil escaping from the first bearing is diverted via the channel and returned to the oil sump. Because the oil flowing through the channel flows along the cover, cooling of the cover and thus also of the parts connected to the cover is achieved.

[0022] In an advantageous embodiment, the annular space is defined by the first bearing, in particular by the inner ring, the rolling elements, and the outer ring of the first bearing, as well as by the nut, the washer, the spacer sleeve, and the cover. This allows for simple manufacturing by forming a recess in the cover.

[0023] According to the inventionthe channel includes a first spatial area, in particular a recess, which is delimited by the cover, a drain plug and the housing part, and a second spatial area which passes through the housing part and opens into the interior area of ​​the transmission on the one hand and into the first spatial area on the other hand, The first space area flows into the annular space area. The advantage here is that simple production is possible through appropriate shaping of the cover and the housing part.

[0024] In an advantageous embodiment, an annular gap is formed between the nut and the cover, in particular, with the nut being connected to the shaft in a rotationally fixed manner. It is advantageous that the nut is connected to the shaft in a rotationally fixed manner, and the cover is connected to the housing part in a rotationally fixed manner.

[0025] In an advantageous embodiment, a ring is placed on the shaft and connected to the shaft in a force-locking manner, in particular by thermal shrink-fitting. The nut is arranged axially, in particular in the axial direction and / or in the direction of the shaft's rotational axis, between the ring and the first bearing. The advantage here is that the ring can be easily connected to the shaft in an oil-tight manner.

[0026] In an advantageous embodiment, a labyrinth disc is connected to the ring, particularly by means of screws. In particular, its circumferential annular grooves, aligned coaxially with the shaft's rotational axis, together with corresponding circumferential annular grooves on the cover, aligned coaxially with the shaft's rotational axis, form a labyrinth gap. This is advantageous in that it increases protection against oil leakage. This improves environmental protection, i.e., the protection of the gearbox's environment against the escape of noise, energy, or substances, especially oil.

[0027] In an advantageous embodiment, a main chamber and two chambers spaced from the main chamber are formed between the ring and the cover, The main chamber is arranged axially between the two chambers, and an annular gap is formed between the ring and the cover, connecting the main chamber to the two chambers. The advantage here is that a pressure reduction can be achieved.

[0028] In an advantageous embodiment, a protrusion, in particular a local maximum of the outer diameter of the ring, which depends on the axial position, is formed on the ring, wherein the elevation extends into the main chamber, in particular wherein the axial region covered by the main chamber encompasses and / or actually contains the axial region covered by the elevation. This is advantageous in that it allows for the centrifugation of any escaping oil.

[0029] The main chamber is connected to the channel, so that this separated oil is also returned to the oil sump. This also improves environmental protection.

[0030] In an advantageous embodiment, a laminar ring is arranged between the labyrinth seal and the ring. This provides a further improved seal. This also improves environmental protection. The seal is constructed in layers. Any oil that, contrary to expectations, overcomes the disk axially toward the output will at least be thrown off at the raised portion in the main chamber. If, contrary to expectations, this does not happen, the oil is held back by the laminar ring, and if this cannot be achieved, by the labyrinth seal.

[0031] In an advantageous design, the radial wall thickness of the nut is greater than the radial wall thickness of the spacer sleeve. This saves material and maximizes the area for oil drainage.

[0032] In an advantageous embodiment, the laminar ring, which consists in particular of three pieces, is arranged in a circumferential annular groove of the labyrinth disc, in particular with the radially outer surface of the laminar ring contacting the cover. This is advantageous in that a particularly effective seal can be achieved. This improves environmental protection.

[0033] In an advantageous embodiment, at least one screw is guided through the labyrinth disc and is screwed into a threaded hole in the ring, The area covered by the screw in the axial direction overlaps the area covered by the main chamber in the axial direction, in particular, the head of the screw pressing the labyrinth disc toward the cover. The advantage here is that the screw can be made of a material with a lower density than the material of the ring. This allows for a lower moment of inertia than with a shorter screw and threaded hole.

[0034] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0035] The invention will now be explained in more detail with reference to schematic illustrations; Figure 1 a region of a transmission according to the invention is shown in longitudinal section.

[0036] As in the Figure 1 As shown, a shaft 9, in particular solid shaft or hollow shaft, is rotatably mounted via bearings which are accommodated in a housing part 15.

[0037] The shaft 9 is preferably a drive shaft of the gearbox and protrudes from the housing comprising the housing part 15.

[0038] The inner ring 1 of a first of the bearings is pushed onto the shaft and is non-positively connected to the shaft 15.

[0039] The bearings are designed as angular contact bearings, in particular as double bearings or double-row bearings.

[0040] To adjust the bearing tension, a nut 4 is screwed onto the shaft 9, which presses on the inner ring 1 via a spacer sleeve 2 placed on the shaft 9 and arranged axially between the inner ring 1 of the first bearing and the nut 4 and a disk 3 also placed on the shaft 9 and arranged between the nut 4 and the spacer sleeve 2, in particular and thus causes the bearing tension.

[0041] The disc 3 extends radially further than the nut 4 and the spacer sleeve 2. The disc 3 thus covers a radial distance range that includes the radial distance range covered by the nut 4, and / or the disc 3 covers a radial distance range that includes the radial distance range covered by the spacer sleeve. This radial protrusion of the disc 3 prevents the oil lubricating the rolling element from flowing from the inner ring 1 to the nut 4.

[0042] The nut 4 can be designed as a clamping nut, wherein it has at least one circumferential groove and / or slot on its radial outer side and on its radial inner side, and screws which press axially spaced apart axial areas towards each other by the groove or slot. Thus, a locking or

[0043] Fixation is possible on the screw thread area of ​​the shaft 9 onto which the nut 4 is screwed.

[0044] To cover the first bearing, a cover 12 is connected to the housing part 15. The radial clearance area covered by the cover 12 contains the radial clearance area covered by the first bearing, in particular by its outer ring, rolling elements, and inner ring 1.

[0045] The cover 12 is tightly connected to the housing part 15 by means of screws and a sealing means, in particular a flat seal and / or an O-ring.

[0046] The radial distance, the axial direction and the circumferential direction always refer to the axis of rotation of shaft 9.

[0047] The disc 3 projects radially into a recess of the cover 12, which is delimited by the cover 12, the spacer sleeve 2, the housing part 15 and the first bearing, in particular by the inner ring 1, the outer ring and the rolling elements of the first bearing.

[0048] The oil escaping from the first bearing enters this chamber-like recess and is returned to the transmission's oil sump via a channel. The channel consists of a recess 13, which is formed in the cover 12, particularly from the underside of the cover 12, and a recess 14, which is formed in the housing part 15. This recess 14 extends continuously through the housing part and thus opens into the interior of the transmission, particularly in such a way that the oil can be returned to the transmission's oil sump.

[0049] A drain plug screwed into a threaded hole in the housing part 15 extending from the environment through the housing part 15 closes the recess 14 to the environment.

[0050] A drain plug screwed into a threaded hole in the cover 12, which extends from the outside through the cover 12, seals the recess 13 from the outside. This allows oil accumulating in the recesses 13 and 14 to be easily drained during maintenance.

[0051] The disc 3 is clamped between the nut 4 and the spacer sleeve 2. Since the disc 3 protrudes radially from the spacer sleeve and is arranged on the side of the spacer sleeve 2 facing away from the first bearing, the oil escaping from the first bearing is held back by the nut 4 and drained to the oil sump via the downward-leading channel.

[0052] The disc 3, like the nut 4 and the spacer sleeve 2, is connected to the shaft 9 in a rotationally fixed manner. Thus, any oil that may be present on the disc 3 is thrown off, particularly due to centrifugal force.

[0053] There is a narrow gap between the nut 4 and the housing part 12. However, a labyrinth seal 6 and a laminar ring 8 are arranged for sealing on the output side. Furthermore, a ring 5 is arranged between these seals and the nut 4.

[0054] This ring 5 has an annular groove whose groove base has a radially outward-facing elevation. This annular groove is thus manufactured such that the groove depth has a local minimum in the axial direction. This enables the oil to be thrown off, as the elevation acts as a throwing edge. The thrown-off oil is thrown into a main chamber 10, which is circumferentially formed by a circumferentially extending inner groove in the cover 12.

[0055] A further inner groove is provided axially in front of and behind this inner groove, forming corresponding chambers 11, each of which is bounded by the cover 12 and the shaft 9. These chambers 11 serve to reduce pressure.

[0056] The main chamber 10 is connected to the channel at its end region facing the drain plug 16 by a recess extending through the cover 12, which opens into the recess 13 on the one hand and into the main chamber 10 on the other. This recess is preferably designed as a stepped bore, in particular radially directed.

[0057] The main chamber 10 together with the chambers 11 is arranged axially between the laminar ring 8 and the nut 4.

[0058] The labyrinth seal is formed from the cover 12 and the labyrinth disc 7. The labyrinth disc 7 has circumferentially encircling annular grooves arranged concentrically and spaced apart from one another with respect to the rotational axis of the shaft 9. These annular grooves are open towards the cover 12. A labyrinth seal is formed by corresponding annular grooves formed on the cover 12, which also circumferentially encircle, concentrically and spaced apart from one another with respect to the rotational axis of the shaft 9. The labyrinth seal extends in the radial direction, because the annular grooves of the cover 12 each cover the same axial area. Likewise, the annular grooves formed on the labyrinth disc 7 each cover an identical further axial area, which, however, overlaps the axial area covered by the annular grooves of the cover 12.

[0059] The laminar ring 8, preferably consisting of three pieces, is arranged in a circumferential annular groove of the labyrinth disc 7. The radially outer surface of the laminar ring 8 contacts the cover 12.

[0060] Ring 5 is non-positively mounted and / or connected to shaft 9. To achieve this, a temperature difference is created during production, and the sliding of ring 5 is carried out with this temperature difference. This shrinking process creates a non-positive connection between ring 5 and shaft 9.

[0061] The labyrinth disc 7 is connected to the ring 5 by means of screws. For this purpose, the screws are screwed into the respective threaded holes in the cover 12 with their threaded portions, and the screw head of the respective screw protruding through the labyrinth disc 7 presses the labyrinth disc 7 toward the cover 12. In particular, the threaded holes and the screws are aligned in the axial direction.

[0062] The cover 12 is attached to the housing part 15 by means of screws.

[0063] The chambers 11 together have a smaller volume than the main chamber 10.

[0064] The chambers 11 are each formed by a circumferentially encircling groove, in particular an inner groove, formed in the cover 12. The main chamber 10, in contrast, is formed by an annular groove, having the elevation, encircling the circumferential direction, formed in the shaft 9, and another circumferentially encircling groove, in particular an inner groove, formed in the cover 12. The area covered in the axial direction by the further groove comprises the area covered in the axial direction by the annular groove formed in the shaft 9.

[0065] In further embodiments according to the invention, the bearings are not designed as angular contact bearings, but as roller bearings or other rolling bearings that are lubricated by means of the oil from the interior of the gearbox. List of reference symbols

[0066] 1 Inner ring of the first bearing 2 Spacer sleeve 3 Disc 4 Nut, especially clamping nut 5 Ring 6 Labyrinth seal 7 Labyrinth disc 8 Laminar ring 9 Shaft, especially solid shaft or hollow shaft 10 Main chamber 11 Chamber 12 Cover 13 Recess in cover 12 14 Recess in housing part 15 15 Housing part 16 Drain plug 17 Drain plug

Claims

1. A gear unit having a shaft (9), at least a first bearing, a housing part (15) and a cover (12), wherein the shaft (9) is rotatably mounted at least via the first bearing, wherein the first bearing has an inner ring (1) which is pushed onto the shaft (9), wherein the cover (12) is connected to the housing part (15), wherein the shaft (9) has a threaded region onto which a nut (4) is screwed, which nut adjusts the bearing tension, wherein between the nut (4) and the inner ring (1) there are arranged a spacer sleeve (2) and a disc (3), - wherein the greatest external diameter of the disc (3) is greater than the greatest external diameter of the spacer sleeve (2), - wherein the greatest radial distance of the disc (3) related to the rotational axis of the shaft (9) is greater than the greatest radial distance of the spacer sleeve (2) related to the rotational axis of the shaft (9), wherein - the radial distance region covered by the disc (3) and related to the rotational axis of the shaft (9) contains the radial distance region covered by the spacer sleeve (2), wherein the nut (4) presses onto the inner ring (1) via the spacer sleeve (2), placed onto the shaft (9) and arranged axially between the inner ring (1) of the first bearing and the nut (4), and via the disc (3), likewise placed onto the shaft (9) and arranged between the nut (4) and the spacer sleeve (2), wherein the disc (3) projects into an annular spatial region connected via a channel to an inner-space region of the gear unit, and characterised in that the channel comprises - a first spatial region bounded by the cover (12), a drain screw (16) and the housing part (15), - and a second spatial region which passes through the housing part (15) and on the one hand issues into the inner-space region of the gear unit and on the other hand issues into the first spatial region, wherein the first spatial region issues into the annular spatial region.

2. A gear unit according to claim 1, characterised in that the disc (3) is arranged axially between the nut (4) and the spacer sleeve (2).

3. A gear unit according to any one of the preceding claims, characterised in that the spacer sleeve (2) rests against the inner ring (1) of the first bearing.

4. A gear unit according to any one of the preceding claims, characterised in that the spacer sleeve (2) is arranged axially between the disc (3) and the inner ring (1) of the first bearing.

5. A gear unit according to any one of the preceding claims. characterised in that the bearing tension of the bearing arrangement, having the first bearing, of the shaft (9) is adjusted by means of the nut (4).

6. A gear unit according to claims 5, characterised in that the bearing arrangement has a second bearing.

7. A gear unit according to any one of the preceding claims, characterised in that the annular spatial region is bounded by the first bearing, in particular by the inner ring (1), the rolling bodies and the outer ring of the first bearing, as well as by the nut (4), the disc (3), the spacer sleeve (2) and the cover (12).

8. A gear unit according to any one of the preceding claims, characterised in that an annular gap is formed between the nut (4) and the cover (12), in particular wherein the nut (4) is connected to the shaft (9) in a rotationally-fixed manner.

9. A gear unit according to any one of the preceding claims, characterised in that a ring (5) is placed onto the shaft (9) and is connected to the shaft (9) in a force-locked manner, in particular is connected by being shrunk on thermally, wherein the nut (4) is arranged axially, therefore in an axial direction, between the ring (5) and the first bearing.

10. A gear unit according to any one of the preceding claims, characterised in that connected to the ring (5), in particular by means of screws, there is a labyrinth disc (7), in particular the annular grooves of which, encircling in a circumferential direction and oriented coaxially with the rotational axis of the shaft (9), together with corresponding annular grooves, made in the cover (12), encircling in a circumferential direction and oriented coaxially with the rotational axis of the shaft (9), form a labyrinth gap.

11. A gear unit according to any one of the preceding claims, characterised in that a main chamber (10) and two chambers (11) spaced apart from the main chamber (10) are formed between the ring (5) and the cover (12), wherein the main chamber (10) is arranged axially between the two chambers (11), wherein an annular gap is formed between the ring (5) and the cover (12) and connects the main chamber (10) to the two chambers (11).

12. A gear unit according to any one of the preceding claims, characterised in that there is a protrusion on the ring (5), in particular a local maximum of the external diameter, dependent on the axial position, of the ring (5), wherein the protrusion projects into the main chamber (10), in particular wherein the axial region covered by the main chamber (10) comprises the axial region covered by the protrusion.

13. A gear unit according to any one of the preceding claims, characterised in that a laminar ring (8) is arranged between the labyrinth seal (6) and the ring (5), in particular in such a manner that the seal is constructed in layers, and / or in that the radial wall thickness of the nut (4) is greater than the radial wall thickness of the spacer sleeve (2).

14. A gear unit according to any one of the preceding claims, characterised in that the laminar ring (8), in particular consisting of three pieces, is arranged in an annular groove, encircling in a circumferential direction, of the labyrinth disc (7), in particular wherein the radially outer surface of the laminar ring (8) contacts the cover (12).

15. A gear unit according to any one of claims 12 - 14, characterised in that at least one screw is guided through the labyrinth disc (7) and is screwed into a tapped bore of the ring (5), wherein the region covered in an axial direction by the screw overlaps with the region covered in an axial direction by the main chamber (10), in particular wherein the material of the screw has a lower density than the material of the ring (5), in particular wherein the head of the screw presses the labyrinth disc (7) towards the cover (12).