Shaft assembly having a shaft rotatably supported relative to a flange component, speed reducer having the shaft assembly, and extruder having the speed reducer with the shaft assembly

Abstract

The present invention relates to a shaft assembly, a reducer having the shaft assembly, and an extruder having a reducer with the shaft assembly, wherein the shaft assembly comprises a shaft (13) supported so as to be rotatable relative to a flange component (7), a sleeve (8) being inserted onto the shaft and connected in a non-rotatable manner, the flange component comprising a first annular groove and a second and / or third annular groove coaxially oriented with the first annular groove, a sealing component or respective sealing components being arranged in the second and / or third annular groove, the respective sealing components respectively comprising a base ring (3), the base ring being surrounded by a corresponding outer ring (4) in the circumferential direction, the base ring being in contact with the sleeve, and the outer ring being in contact with the wall of the second annular groove, and a guide ring (6) for centering the sleeve being arranged in the first annular groove.

Description

Technical Field

[0001] The invention relates to a shaft assembly, a speed reducer having the shaft assembly and an extruder having the speed reducer having the shaft assembly. The shaft assembly has a shaft which is supported so as to be rotatable relative to a flange component. Background Art

[0002] As is known, shaft sealing rings are used to seal the reducer shaft.

[0003] A stuffing box for sealing shafts with large runout errors is known from DE 38 21 971 A1 as the closest prior art.

[0004] A radial sealing device for use in a radial pump is known from EP 1 893 898 A1. Summary of the invention

[0005] It is therefore an object of the present invention to improve the sealing in shaft arrangements with high pressure differences.

[0006] According to the invention, this object is achieved with respect to the shaft assembly according to the features specified in claim 1 and with respect to the reducer or extruder according to the features specified in claim 15 .

[0007] In the case of a shaft assembly having a shaft which is rotatably mounted relative to a flange part, an essential feature of the invention is that a sleeve is pushed onto the shaft and connected to the shaft in a rotationally fixed manner, in particular in a materially and forcefully locked manner.

[0008] The flange component has a first annular groove and a second annular groove and / or a third annular groove coaxially oriented with the first annular groove.

[0009] A sealing component is arranged in the second annular groove and / or the third annular groove, or a sealing component is arranged in the second annular groove and / or the third annular groove respectively;

[0010] The corresponding sealing components respectively have a base ring, which is radially surrounded by the corresponding outer ring, the base ring is in contact with the sleeve, and the outer ring is in contact with the wall of the second annular groove,

[0011] A guide ring for centering the sleeve is arranged in the first annular groove.

[0012] In particular, the guide ring is in contact with both the sleeve and the wall of the annular groove.

[0013] The advantage here is that the shaft is aligned coaxially with the base ring by means of the guide ring and the operating conditions of the base ring are thus kept as constant as possible. In this way, sealing is achieved even with high pressure differences. The base ring is in contact with the sleeve and is pressed by the outer ring against the sleeve, since the outer ring is elastically tensioned, in particular elastically pretensioned, and the base ring is thus compressed by the outer ring against the sleeve.

[0014] In an advantageous embodiment, the guide ring is supported on the wall of the first annular groove and there is sliding contact between the guide ring and the sleeve towards the sleeve. The advantage here is that, although the guide ring can also rotate relative to the flange part and / or relative to the sleeve, the guide ring mainly serves as a centering part for the sleeve or an additional bearing for centering the sleeve, so that the base ring works effectively under operating conditions that are as constant as possible.

[0015] In an advantageous embodiment, the outer ring is designed as an O-ring. This has the advantage that a simple and inexpensive embodiment can be achieved.

[0016] In an advantageous embodiment, the base annular surface contacts the sleeve.

[0017] In particular, the contact surface of the sleeve and the base ring is a cylinder circumference section, and / or the base ring is made of polyethylene, in particular made of polyethylene with ultra-high molecular weight. Advantageously, the centering of the sleeve coaxially with the annular groove and / or the base ring can be realized in a simple manner.

[0018] In an advantageous embodiment, the guide ring contacts the sleeve in a manner similar to that of a ring.

[0019] Especially, the contact surface of sleeve and guide ring is a cylinder circumference section. Advantage is that, can realize the effective centering of sleeve.

[0020] In an advantageous design, the guide ring is made of a harder material than the base ring. Advantageously, the guide ring centers the sleeve coaxially and therefore keeps the running conditions of the base ring constant.

[0021] In an advantageous embodiment, the contact surface between the sleeve and the guide ring is wider in the axial direction than the contact surface between the sleeve and the base ring. This has the advantage that the forces required for centering can be effectively conducted away.

[0022] In an advantageous design, the first annular groove is smaller in radial direction than the second annular groove. The advantage here is that the guide ring is wider in the axial direction than in the radial direction. Therefore, centering can be effectively performed by the guide ring.

[0023] In an advantageous embodiment, the first annular groove is arranged in the axial direction between the second annular groove and the third annular groove. This has the advantage that the spacing from the first annular groove to the other two annular grooves is very small, so that the centering by means of the guide ring is effective for both base rings. In this case, the axial spacing between the first annular groove and the second annular groove and / or the third annular groove is smaller than the inner radius of the guide ring, in particular smaller than half the diameter of the annular opening of the guide ring.

[0024] In an advantageous embodiment, a V-ring is received on the sleeve on the side of the second annular groove facing away from the first annular groove, the sealing lip of the V-ring being in contact with the flange part.

[0025] In particular, the V-ring is spaced apart from the annular grooves in the axial direction. This has the advantage that the material conveyed by the extruder screw, which is connected to the shaft in a rotationally fixed manner via the extruder screw coupling, does not penetrate, or only insignificantly, into the sealing area between the flange part and the sleeve. The V-ring is arranged here so that the material is blocked outside the sealing area when there is a pressure drop toward the sealing area. If, in another operating state, there is a negative pressure or vacuum in the area where the material is located, then although the V-ring is open, the seal by means of the two sealing components arranged in the second annular groove and the third annular groove is sufficient to prevent lubricating oil from being sucked from the reducer into the area of ​​the material.

[0026] In an advantageous embodiment, the flange part is connected to a housing part which is designed in one piece or in multiple pieces and in which at least one bearing which rotatably supports the shaft is accommodated.

[0027] The minimum distance between the individual annular grooves and the bearing measured in the axial direction is greater than half the inner diameter of the bearing, in particular greater than half the inner diameter of the inner ring of the bearing resting on the shaft. The advantage here is that, although the shaft is supported, the sleeve is pushed onto the protruding end region of the shaft and connected thereto, so that the sleeve is oriented coaxially with the base ring by centering via the guide ring and, despite an outer diameter of the sleeve of more than 100 mm, the radial runout of the sleeve is less than one percent.

[0028] In an advantageous embodiment, the base ring in the relaxed state has on its inner side a surface section which corresponds to the cylindrical circumference and whose axial width is in particular greater than half the maximum diameter of the ring cross section. This has the advantage that a flat contact with the sleeve can be implemented, i.e. no point contact, and thus a high degree of protection and / or a high sealing performance can be achieved.

[0029] In an advantageous embodiment, the outer ring, the V-ring and / or the guide ring are made of FKM, ie in particular fluorocarbon rubber.

[0030] In particular, the material of the V-ring has a lower hardness than the material of the outer ring and the material of the guide ring.

[0031] In particular, the material of the base ring has a higher hardness than the material of the base ring, the material of the guide ring and / or the material of the V-ring.

[0032] And / or the sleeve is made of hardened steel. This has the advantage that inexpensive materials can be used. The sleeve can be made of finely machined hardened steel and thus achieve good sealing conditions. Since the guide ring is harder than the base ring, centering can be achieved via the guide ring, while the base ring only needs to be made of a material that only results in a very low friction coefficient in the material pairing with the sleeve material. In addition, the outer ring is made of an elastic material, so that the base ring is compressively prestressed and thus pressed onto the sleeve.

[0033] In an advantageous embodiment, the shaft and the sleeve are implemented together as a single component, ie, are implemented in one piece, in particular are formed integrally. The advantage here is that the number of components can be reduced.

[0034] An important feature of a reducer with a shaft assembly or an extruder with a reducer with a shaft assembly is that the extruder screw is connected to the shaft in a rotationally fixed manner via an extruder screw coupling, in particular by means of a plug-in toothing. This has the advantage that the extruder including the extruder screw can be operated alternately under vacuum and under overpressure. In both operating conditions, the area of ​​the material conveyed by the extruder screw is sealed relative to the interior of the reducer.

[0035] Further advantages are given by the dependent claims. The invention is not limited to the feature combinations of the claims. For a person skilled in the art, other reasonable combinations of the claims and / or the features of the individual claims and / or the features of the description and / or the features of the drawings are apparent, in particular from the objectives proposed and / or from a comparison with the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention is described in detail below according to the accompanying drawings:

[0037] Figure 1 An oblique view shows a drive of an extruder with an extruder screw coupling 2, which has a reduction gear 1 driven by an electric motor;

[0038] Figure 2 A section through the output region of the extruder with one of the extruder screw couplings 2 is shown. DETAILED DESCRIPTION

[0039] As shown in the figures, the individual extruder screw couplings 2 are connected to the shaft 13 in a form-fitting manner, in particular by means of a plug toothing 11 .

[0040] The extruder screw coupling 2 is axially limited by the cover plate 12 , which is limited by the screw head of the screw, which is screwed into the axial threaded hole of the shaft 13 .

[0041] A sleeve 8 made of hardened steel is placed on the axially protruding sleeve section of the extruder screw coupling 2. Advantageously, friction can be reduced in this way. The sleeve is pressed onto the shaft 13 and glued.

[0042] The shaft 13 is connected to the extruder screw coupling 2 in a rotationally fixed manner. The shaft 13 is rotatably supported via a bearing 14, which is preferably designed to be untensioned. Here, the bearing 14 is accommodated in a bearing flange 16, in particular a housing part.

[0043] The bearing flange 16 is detachably connected to the housing part 10 , which is detachably connected to the flange part 7 .

[0044] Accommodated in the bearing flange 16 is a shaft sealing ring 15 , the sealing lip of which runs on a second sleeve made of hardened steel which is connected to the shaft 13 and which is in turn pressed onto the shaft 13 and adhesively bonded.

[0045] The bearing 14 is arranged on the side facing away from the sealing ring 15 in the axial direction and is therefore arranged in the inner space of the reducer 1 which is at least partially filled with lubricating oil and in which toothed parts meshing with each other are also arranged.

[0046] The housing parts are connected to each other in a sealing manner to form the housing of the reducer 1 .

[0047] Although the shaft sealing ring 15 acts as an oil seal to protect the interior of the reducer, a very high pressure is still set on the extruder screw side and, depending on the operating state, even a vacuum is set.

[0048] Therefore, a V-ring is accommodated on the sleeve 8, the sealing lip of which presses against the finely machined annular surface of the flange part 7. The flange part has two circumferential annular grooves.

[0049] A sealing assembly is accommodated in each of the two annular grooves, which has a base ring 3, which is surrounded in the circumferential direction by an outer ring 4. The outer ring 4 is preferably made of a first plastic and is preferably formed as an O-ring. The outer ring 4 is preferably connected to the base ring 3 in a material-locking manner and is elastically deformed so that the outer ring is pressed against the wall of the annular groove. In this way, the outer ring 4 seals between the base ring 3 and the wall of the annular groove.

[0050] The outer ring 4 thus fulfills the sealing function of an O-ring. Furthermore, the outer ring is also designed to be suitable for introducing compressive forces, ie, at all circumferential positions there is a force field of tensioning forces acting on the base ring 3 which is in particular the same and directed radially inwards.

[0051] The base ring 3 is abutted against the sleeve 8, and the contact area is not point contact in the axial direction, but line contact. For this reason, the base ring 3 has a cylindrical circumferential surface segment in the contact area as the inner surface contacting the sleeve 8. Therefore, when the shaft 13 is in rotational motion relative to the housing of the reducer, the base ring 3 will slide relative to the sleeve 8. In order to reduce friction loss, a suitable second material is appropriately selected as the material of the base ring 3. The second material is preferably plastic or rubber.

[0052] Although a brass ring coated with Teflon (ie in particular PTFE, ie in particular polytetrafluoroethylene) can also be used as base ring 3, a fiber composite is preferably used which also has a material which results in a very low coefficient of friction when paired with the sleeve 8, ie hardened steel.

[0053] The two annular grooves are spaced apart from each other in the axial direction. In each annular groove there is a seal having the described base ring 3 and an outer ring 4 which is connected to the base ring in a materially bonded manner and radially surrounds the respective base ring and is designed as an O-ring.

[0054] A further annular groove is embodied in the flange part 7 axially between the two annular grooves and preferably has a smaller radial extent than the two annular grooves, in which further annular groove the guide ring 6 is arranged.

[0055] The guide ring 6 is made of a second material, in particular plastic, which is harder than the first material.

[0056] Since the guide ring 6 bears flat against the sleeve 8 , the sleeve 8 together with the shaft 13 connected to the sleeve 8 can be centered.

[0057] Since the shaft 13 is supported in the reducer via its bearing 14 , the shaft end protruding from the reducer is slidably supported with the sleeve 8 arranged thereon by means of the guide ring 6 .

[0058] The guide ring 6 thus ensures that the sleeve 8 is centered relative to the receiving opening of the flange part 7, so that the base ring 3 does not have to absorb radial transverse impacts or transverse movements, but rather has operating conditions that are as constant as possible.

[0059] The V-ring 5 keeps dirt and material conveyed by the extruder screw away from the area of ​​the seal between the sleeve 8 and the flange part 7 .

[0060] The radial extent of the annular groove which accommodates the guide ring 6 is smaller than the radial extent of the individual annular grooves which accommodate the respective sealing components.

[0061] In a further embodiment according to the invention, the housing comprising the flange part 7, the housing part 10 and the bearing flange 16 is implemented from a relatively small number of parts in that the flange part 7 and the housing part 10 are implemented integrally, i.e. in one piece, and the bearing flange 16 is optionally also implemented from a single piece together with the flange part 7 and the housing part 10. In this way, simple production can be achieved, since fewer parts need to be handled.

[0062] The shaft assembly according to the invention can be used not only in reducers but also in other devices in which excellent sealing of areas with materials under high or low pressure is to be achieved and the shaft support is not preloaded and / or, in particular in the area of ​​the bearing receptacle of the bearing of the shaft 13 which is arranged closest to the seal, the shaft support is at a distance from the seal in the axial direction, i.e. in the direction of the axis of rotation of the shaft 13, that is greater than half the diameter of the shaft 13.

[0063] List of reference numerals:

[0064] 1 Reducer

[0065] 2 Extruder screw coupling

[0066] 3 base ring

[0067] 4 Outer ring

[0068] 5 V-ring

[0069] 6 Guide ring

[0070] 7 Flange parts, especially housing parts

[0071] 8 Sleeve

[0072] 9 Seals

[0073] 10 Housing parts

[0074] 11 Tooth, especially plug tooth

[0075] 12 Cover

[0076] 13 Axis

[0077] 14 Bearings, especially non-tensioned bearings

[0078] 15 Shaft sealing ring

[0079] 16 Bearing flange, especially housing parts

Claims

1. A shaft assembly comprising a shaft supported in a rotatable manner relative to a flange member, The sleeve (8) is sleeved on the shaft and connected to the shaft in a non-rotatable manner. It is characterized in that The flange component has a first annular groove and a second annular groove and / or a third annular groove coaxially oriented with the first annular groove, A sealing component or a respective sealing component is arranged in the second annular groove and / or the third annular groove. The corresponding sealing components respectively have a base ring, which is surrounded by a corresponding outer ring in the circumferential direction, the base ring is in contact with the sleeve, and the outer ring is in contact with the wall of the second annular groove and / or the third annular groove. A guide ring is arranged in the first annular groove for centering the sleeve. A V-ring is received on the sleeve on the side of the second annular groove facing away from the first annular groove, the sealing lip of the V-ring contacting the flange part, the V-ring (5) being used to keep dirt away from the area of ​​the seal between the sleeve (8) and the flange part (7), The flange part is connected to a housing part which is designed in one piece or in multiple pieces and in which at least one bearing which rotatably supports the shaft is accommodated. The smallest distance between the annular grooves and the bearing, measured in the axial direction, is greater than half the inner diameter of an inner ring of the bearing which lies against the shaft.

2. The shaft assembly according to claim 1, It is characterized in that The sleeve is connected to the shaft in a materially and force-fitting manner.

3. The shaft assembly according to claim 1, It is characterized in that The guide ring is in contact not only with the sleeve but also with the wall of the annular groove.

4. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The guide ring is supported on the wall of the first annular groove and there is a sliding contact between the guide ring and the sleeve facing the sleeve.

5. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The outer ring is embodied as an O-ring.

6. A shaft assembly according to any one of claims 1 to 3, It is characterized in that Base annular surface contact sleeve, That is, the contact surface between the sleeve and the base ring is the cylindrical circumferential surface segment, and / or the base ring is made of polyethylene, or the base ring is a brass ring coated with PTFE.

7. The shaft assembly according to claim 6, It is characterized in that The base ring is made of polyethylene having an ultra-high molecular weight.

8. The shaft assembly according to claim 6, It is characterized in that PTFE is Teflon.

9. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The guide ring contacts the sleeve. That is, the contact surface between the sleeve and the guide ring is the peripheral surface segment of the cylinder.

10. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The guide ring is made of a harder material than the base ring.

11. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The contact surface between the sleeve and the guide ring is wider in the axial direction than the contact surface between the sleeve and the base ring.

12. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The first annular groove has a smaller radial extent than the second annular groove.

13. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The first annular groove is arranged between the second annular groove and the third annular groove in the axial direction.

14. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The V-rings are spaced apart from the annular grooves in the axial direction.

15. A shaft assembly according to any one of claims 1 to 3, It is characterized in that In the relaxed state, the base ring has on its inner side a surface section which corresponds to a cylindrical circumferential surface and whose axial width is greater than half the maximum diameter of the ring cross section.

16. A shaft assembly according to any one of claims 1 to 3, It is characterized in that Outer ring, V-ring and / or guide ring made of FKM, The hardness of the material of the V-ring is lower than that of the material of the outer ring and the guide ring. The base ring material has a greater hardness than the outer ring material and / or the guide ring material and / or the V-ring material. and / or the sleeve is made of hardened steel.

17. The shaft assembly according to claim 16, It is characterized in that FKM is fluorocarbon rubber.

18. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The shaft and the sleeve are designed together as a single component, ie in one piece.

19. A shaft assembly according to any one of claims 1 to 3, It is characterized in that The shaft and the sleeve are integrally formed.

20. A speed reducer having a shaft assembly according to any one of claims 1 to 19.

21. An extruder comprising a speed reducer according to claim 20, in, The extruder screw coupling is connected to the shaft in a non-rotatable manner.

22. The extruder according to claim 21, It is characterized in that The extruder screw coupling is connected to the shaft by means of a plug-in toothing.

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