Sealing arrangement with flange part and rotatably mounted shaft
Patent Information
- Application Number
- EP2023794331
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-11-17
- Filing Date
- 2023-10-23
- Publication Date
- 2025-09-24
AI Technical Summary
Existing sealing systems for electric motors are inadequate in maintaining a secure seal under both static and dynamic conditions, particularly in reducing frictional torque and ensuring effective sealing against dust and water ingress.
A sealing arrangement featuring a flange part and a rotatably mounted shaft, where a sealing ring is non-positively connected to the shaft and a wear ring is clamped into the flange part, with a sealing lip directed radially inward, supported by an unstiffened area that can elastically deform under centrifugal force, reducing pressure and friction during rotation.
This configuration provides a high-pressure seal at rest while minimizing frictional torque during operation, maintaining effective sealing against dust and water ingress with reduced relative speed exposure, and allowing for cost-effective and easy manufacturing.
Smart Images
Figure 1.1
Abstract
Description
[0001] Sealing arrangement with flange part and rotatably mounted shaft
[0002] Description:
[0003] The invention relates to a sealing arrangement with a flange part and a rotatably mounted shaft.
[0004] It is common knowledge that electric motors are sealed from the environment.
[0005] DE 196 52 000 A1 discloses a semi-integrated sealing system as the closest state of the art.
[0006] A rolling bearing is known from DE 11 2015 002 746 T5.
[0007] A sealing system is known from JP S62-156667 U.
[0008] A shaft seal with a shaft sealing ring is known from DE 10 2018 122 000 A1.
[0009] A shaft seal is known from DE 23 22 458 A.
[0010] A shaft seal is also known from DD 62 972 A1.
[0011] A seal is known from US 2 509 461 A.
[0012] The invention is therefore based on the object of improving the sealing of an electric motor.
[0013] According to the invention, the object is achieved in the sealing arrangement according to the features specified in claim 1.
[0014] Important features of the invention in the sealing arrangement with flange part and rotatably mounted shaft are that a sealing ring is placed on the shaft and / or is non-positively and / or non-rotatably connected to the shaft, wherein the shaft projects through a bore in the flange part, wherein a split ring is received in the bore of the flange part and / or is clamped into the bore and / or is non-positively connected to the flange part, wherein a sealing lip of the sealing ring seals radially inwardly towards a running surface formed on the split ring, in particular wherein the sealing lip is held by an axially projecting support region of the sealing ring which is less stiffened than the rest of the sealing ring, in particular is not stiffened.
[0015] The advantage here is that the sealing ring is arranged on the shaft, yet the sealing lip presses radially inward against the running surface. The projecting support of the sealing lip is important for this. This is because the support, i.e. the second leg section of the sealing ring that acts as the support area for the sealing lip, protrudes between the leg sections of the split ring and can therefore be elastically deflected, particularly by centrifugal force. This allows a reduction in the contact pressure depending on the speed. When the shaft is stationary, a high contact pressure can be achieved, thus ensuring good sealing.
[0016] In an advantageous embodiment, the split ring has a first leg region, in particular one that runs continuously in the circumferential direction, wherein the split ring has a second leg region, in particular one that runs continuously in the circumferential direction, wherein the first leg region of the split ring is arranged radially inside the second leg region of the split ring and is connected to the second leg region of the split ring via a yoke region of the split ring. The advantage here is that simple production as a rubber-coated or overmolded sheet metal part is possible. The split ring is therefore simple and cost-effective to produce. In addition, it seals well against the bore because its elastic surface material conforms to the bore.
[0017] In an advantageous embodiment, the sealing ring has a first leg region, in particular one which runs continuously in the circumferential direction, wherein the sealing ring has a second leg region, in particular one which runs continuously in the circumferential direction, wherein the first leg region of the sealing ring is arranged radially inside the second leg region of the sealing ring and is connected to the second leg region of the sealing ring via a yoke region of the split ring. The advantage here is that the U-shaped cross-section enables the sealing lip to work towards the sealing seat of the sealing ring. This is because the second leg region enables a cantilevered mount of the sealing lip and an interposition of the running surface between the two leg regions of the sealing ring.In this way, although the sealing lip is radially spaced from the sealing seat of the sealing ring formed on the shaft, it still allows the sealing lip to be aligned with the sealing seat. The interposed, smooth, exposed metallic running surface of the stiffening part of the split ring has only a slightly larger diameter than the sealing seat and therefore only slightly increases the relative speed. However, in contrast to an alignment of the sealing lip radially outward, the relative speed is much lower.
[0018] The advantage is that it can be easily manufactured as a rubberized or overmolded sheet metal part. This makes the sealing ring simple and cost-effective to produce. Furthermore, it seals well against the shaft, as its elastic surface material conforms to the shaft.
[0019] In an advantageous embodiment, the first leg region of the split ring projects into the space between the first leg region of the sealing ring and the second leg region of the sealing ring, in particular such that the first leg region of the split ring is arranged radially between the first leg region of the sealing ring and the second leg region of the sealing ring, in particular wherein the axial region covered by the first leg region of the split ring overlaps the axial region covered by the first leg region of the sealing ring and / or the axial region covered by the second leg region of the sealing ring. It is advantageous in this case that the sealing lip works radially inwardly against the running surface.In an advantageous embodiment, the second leg region of the sealing ring, in particular comprising the support region and the sealing lip, projects into the spatial region between the first leg region of the split ring and the second leg region of the split ring, in particular such that the first leg region of the sealing ring is arranged radially between the first leg region of the split ring and the second leg region of the split ring, in particular wherein the axial region covered by the second leg region of the sealing ring overlaps the axial region covered by the first leg region of the split ring and / or the axial region covered by the second leg region of the split ring. The advantage here is that the sealing lip is directed radially inward against the running surface and thus does not work radially outward, but radially inward, i.e. is exposed to a lower speed.
[0020] In an advantageous embodiment, each of the leg regions of the split ring and the sealing ring is designed to be completely, in particular uninterrupted, circumferential. It is advantageous that both rings are designed as rotating bodies.
[0021] In an advantageous embodiment, the sealing ring is made of a rubber or plastic, particularly NBR. This allows for cost-effective production.
[0022] In an advantageous embodiment, the stiffening part of the split ring is rubberized and / or overmolded with a plastic, with the exception of the running surface for the sealing lip of the sealing ring. It is advantageous that a metallic running surface is provided.
[0023] In an advantageous embodiment, a stiffening part, particularly realized as a one-piece and / or single-piece sheet metal part, is arranged in the split ring, which stiffens the first leg region of the split ring, the second leg region of the split ring, and the yoke region of the split ring. The advantage here is that cost-effective production is achievable. In an advantageous embodiment, a stiffening part, particularly realized as a one-piece and / or single-piece sheet metal part, is arranged in the sealing ring, which stiffens the first leg region of the sealing ring and the yoke region of the sealing ring, but in particular not the second leg region of the sealing ring. The advantage here is that cost-effective production is possible.
[0024] In an advantageous embodiment, a stiffening part, particularly realized as a one-piece and / or single-part sheet metal part, is arranged in the sealing ring. This stiffening part stiffens the first leg region of the sealing ring and the yoke region of the sealing ring and is spaced apart from the second leg region of the sealing ring. Advantageously, the sealing ring can be designed to be dimensionally stable, while the second leg region is not stiffened and is thus elastically deformable.
[0025] In an advantageous embodiment, each leg region is spaced apart from all other leg regions. This advantageously allows the leg regions to be arranged in a nested manner.
[0026] In an advantageous embodiment, the first leg region of the split ring is spaced from the shaft, with the yoke region of the split ring projecting radially inward beyond the first leg region of the split ring. Advantageously, the first leg region may extend between the leg regions of the sealing ring, and the yoke region is widened, sealing off the shaft except for a gap for objects larger than the gap width.
[0027] In an advantageous embodiment, the first leg region of the split ring is spaced from the shaft, wherein the yoke region of the split ring projects radially inward beyond the first leg region of the split ring such that the radial spacing region covered by the first leg region of the split ring is contained in and / or encompassed by the radial spacing region covered by the yoke region of the split ring. It is advantageous in this case that the yoke region projects radially towards the shaft, wherein a gap remains between the yoke region of the split ring and the shaft. In an advantageous embodiment, the yoke region of the sealing ring is slipped and / or clamped onto the shaft and / or is non-positively connected to the shaft. It is advantageous in this case that the sealing ring is mounted tightly against the shaft and simple production is enabled.
[0028] In an advantageous embodiment, the split ring limits the sealing ring axially, particularly in the axial direction. This allows for easy installation.
[0029] In an advantageous embodiment, the first leg region of the sealing ring borders the yoke region of the split ring and / or is positioned against the yoke region of the split ring. This allows for simple manufacturing by pushing the two rings axially toward each other until they stop during assembly.
[0030] In an advantageous embodiment, the running surface is formed on the stiffening part of the split ring. This provides a smooth metallic running surface for the sealing lip.
[0031] Important features of the drive component, particularly an electric motor or transmission, with the aforementioned sealing arrangement are that the sealing ring is located in the interior of the drive component and that the split ring, together with the flange part, forms the housing, particularly for the drive component. The advantage here is that an improved seal is achieved, which generates less frictional torque during operation and provides reliable sealing when stationary.
[0032] 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. The invention will now be explained in more detail with reference to schematic illustrations:
[0033] Figure 1 shows a sealing arrangement according to the invention for an electric motor in a sectional view.
[0034] In Figure 2, a first area Z of Figure 1 is shown enlarged.
[0035] In Figure 3, a second area Y of Figure 1 is shown enlarged.
[0036] As shown in the figures, the electric motor has a sealing arrangement against dust and / or water.
[0037] The shaft 1, which functions as a rotor shaft, is rotatably mounted, in particular relative to the stator housing of the electric motor, in particular via bearings accommodated in flange parts.
[0038] A first flange part 2 is arranged stationary, in particular connected in a rotationally fixed manner to the stator housing of the electric motor.
[0039] The flange part 2 has a through hole through which the shaft 1 protrudes.
[0040] A split ring 22 is accommodated in the bore and clamped, thus being elastically preloaded. The split ring 22 preferably presses against the wall of the bore, as it is elastically shrunk into the bore.
[0041] A gap area is formed between the split ring and the shaft 1, extending completely around the circumference. Thus, no friction occurs between the split ring 22 and the shaft 1.
[0042] The split ring has a stiffening part 30. The stiffening part 30 is preferably a rotating body created by rotating a U-shaped region, wherein the U is open in the axial direction. In particular, the two legs of the U-shaped region are each formed as a hollow cylinder and connected to each other via a yoke.
[0043] The stiffening part 30 can be produced by forming a piece of sheet metal. In particular, the stiffening part 30 is designed as a single piece and / or in one piece.
[0044] The stiffening part 30 is rubberized or overmolded with a plastic, in particular NBR, to form the split ring 22, wherein a surface area of the metallic stiffening part 30 acting as a running surface for a sealing lip 23 of the sealing ring 20 is uncovered, in particular without rubberization and without covering by plastic.
[0045] The sealing ring 20 is pushed onto the shaft 1 and is connected to the shaft in a force-locking manner, in particular by shrinking.
[0046] The sealing ring 20 is designed as a rotational body which is formed by rotation of a generating U-shaped region, in particular wherein this mathematically conceived rotation takes place around the axis of rotation of the shaft.
[0047] The U is open opposite to the axial direction, in particular inversely to the U-shaped area of the split ring 22.
[0048] The sealing ring 20 thus has a first, radially inner leg region, which rests on the shaft 1, and a second, radially outer leg region, which is designed as a support region 21 for the sealing lip of the sealing ring 20.
[0049] The two leg regions are connected via a high region of the sealing ring 20. Thus, the first leg region is spaced radially from the second leg region. The first leg region is arranged radially inside the second leg region.
[0050] The radial direction, the axial direction, and the circumferential direction are always relative to the rotational axis of the shaft 1. Preferably, the first leg region of the sealing ring 20 is less extended in the axial direction than the second leg region of the sealing ring 20.
[0051] Furthermore, a sheet metal part acting as a stiffening part is preferably also arranged in the sealing ring.
[0052] The conical section allows the first leg section to be designed with a tapered wall thickness toward the yoke area. This allows elastic deformation with low forces. The end section of the first leg section, which encompasses the sealing lip 23, has a thicker wall thickness and therefore a correspondingly large mass.
[0053] When the shaft 1 is not rotating, the sealing lip 23 is pressed by elastic preload onto the area of the split ring 22 that functions as a running surface.
[0054] During rotational movement, however, the centrifugal force reduces this elastic pressure and thus reduces the frictional force. With a sufficiently thin wall thickness and material selection, it is even possible to lift the sealing lip 23 from the sealing surface.
[0055] The radially inner leg region of the split ring 22 projects into the U of the sealing ring 20, i.e., radially between the leg regions of the sealing ring 20. In this way, a labyrinth channel 31 is formed, which further complicates the penetration of dirt, dust, and / or water.
[0056] The area covered in the axial direction by the radially inner leg of the split ring 22 overlaps with the area covered in the axial direction by the first and / or second leg area of the sealing ring 20.
[0057] The radial distance area covered by the split ring 22 overlaps with the radial distance area covered by the sealing ring 20. The radial distance area covered by the yoke area of the sealing ring 20 includes the radial distance area covered by the radially inner leg area of the split ring 22.
[0058] Preferably, the sealing lip 23 is undulating in the circumferential direction. In particular, the axial position of the sealing lip is a periodic, particularly non-vanishing, function of the circumferential angle in the circumferential direction. This, for example, sinusoidal shape achieves a pumping effect and thus increased sealing.
[0059] Preferably, the support region 21 has an inner cone on its radial inner side, in particular with a radially inward, conical inner side.
[0060] As can be seen from the figures, the sealing lip 23 seals according to the invention in a radially inward direction towards the running surface formed on the split ring, although the sealing ring is connected to the shaft in a rotationally fixed manner and thus the bore radially surrounds and / or encloses the sealing ring 20. The running surface is therefore located radially inside the sealing lip 20. This results in the axially projecting holder, in particular the support area 23, for the sealing lip 23, wherein the lack of stiffening of the projecting holder enables elastic deformation of the holder under the action of the centrifugal force generated during rotational movement, which causes a reduction in the pressure force of the sealing lip 23 against the running surface or even causes the sealing lip 23 to lift off the running surface.
[0061] In further embodiments according to the invention, the sealing ring 20 also has a U-shaped cross-section with a half-plane whose normal direction is aligned parallel to the axis of rotation of the shaft and which is limited by circumferential angle values between 0° and 180°. The sealing ring 20 is created by a mathematically conceived rotation of the U-shaped cross-section, in particular as a rotating body.
[0062] Accordingly, the split ring 22 also has a U-shaped cross-section with a half-plane whose normal direction is aligned parallel to the shaft's axis of rotation and which is limited by circumferential angle values between 0° and 180°. The split ring 22 is created by a mathematically conceived rotation of the U-shaped cross-section, in particular as a rotating body.
[0063] The radially inner leg region of the split ring 22 projects into the U-shape, in particular into the U-shaped cross section, of the sealing ring 20. Accordingly, the radially inner leg region of the sealing ring 20 projects into the U-shape, in particular into the U-shaped cross section, of the sealing ring 20.
[0064] The U-shapes are thus designed to be open in opposite directions to each other. The overmolded stiffening part in the sealing ring 20 is designed with an L-shaped cross-section, so that only the yoke area and the radially inner leg area of the sealing ring 20 are supported and stiffened by a metallic stiffening part. The radially outer leg area of the sealing ring 20 is not stiffened and can therefore be deflected by even a slight centrifugal force, in particular radially outward from the running surface on the split ring 22, and lifted off, in particular from the metallic stiffening part.
[0065] According to the invention, the sealing lip is pressed tightly against the shaft 1 when the shaft 1 is at rest. Since the split ring 22 lies tightly against the flange part 2 and the sealing ring 20 lies tightly against the shaft 1, the shaft 1 is sealed against the flange part and the shaft 1 is held with high static friction. In particular, the associated static torque is lower than the starting torque or moving-off torque of the electric motor. When the shaft 1 rotates, the sealing lip is pressed less against the shaft 1 or even lifted off. This then results in lower or even zero friction. The sealing effect is nevertheless maintained because the pumping effect of the sealing lip increases with increasing speed, in particular because the axial position of the sealing lip 23, particularly on the running surface, is a periodic function of the circumferential angle.
[0066] In contrast to sealing ring 20, both leg regions and the yoke region of split ring 22 are stiffened by means of the metallic stiffening part. As mentioned above, only the radially inner leg region and the yoke region of sealing ring 20 are stiffened.
[0067] In the bore, the yoke area of the split ring 22 together with the gap area, in particular the annular gap formed between shaft 1 and split ring 22, covers the entire radial area between shaft 1 and flange part 2.
[0068] The radial distance area covered by the gap area is encompassed by the radial distance area covered by the radially inner leg area of the sealing ring 20.
[0069] In further embodiments according to the invention, the yoke region of the split ring 22, in contrast to Figures 2 and 3, is axially widened in its region adjacent to the shaft 1 such that the sealing ring 20 is axially delimited by the split ring 22, in particular by its yoke region. This enables simplified assembly.
[0070] 1 Shaft 2 Flange part
[0071] 20 sealing ring
[0072] 21 Load-bearing area with inner cone
[0073] 22 split ring
[0074] 23 Sealing lip 30 Reinforcing part
[0075] 31 Labyrinth Corridor
Claims
Patent claims:
1. Sealing arrangement with a flange part and a rotatably mounted shaft, characterized in that a sealing ring is placed on the shaft and / or is non-positively and / or non-rotatably connected to the shaft, the shaft protruding through a bore in the flange part, a split ring being received in the bore of the flange part and / or being clamped into the bore and / or being non-positively connected to the flange part, a sealing lip of the sealing ring sealing radially inwardly directed towards a running surface formed on the split ring, in particular the sealing lip being held by an axially projecting support region of the sealing ring which is less stiffened than the rest of the sealing ring, in particular is not stiffened.
2. Sealing arrangement according to claim 1, characterized in that the split ring has a first leg region, in particular one which runs continuously in the circumferential direction, wherein the split ring has a second leg region, in particular one which runs continuously in the circumferential direction, wherein the first leg region of the split ring is arranged radially inside the second leg region of the split ring and is connected to the second leg region of the split ring via a yoke region of the split ring.
3. Sealing arrangement according to one of the preceding claims, characterized in that the sealing ring has a first leg region, in particular one which runs continuously in the circumferential direction, wherein the sealing ring has a second leg region, in particular one which runs continuously in the circumferential direction, wherein the first leg region of the sealing ring is arranged radially inside the second leg region of the sealing ring and is connected to the second leg region of the sealing ring via a yoke region of the split ring.
4. Sealing arrangement according to one of the preceding claims, characterized in that the first leg region of the split ring projects into the space between the first leg region of the sealing ring and the second leg region of the sealing ring, in particular so that the first leg region of the split ring is arranged radially between the first leg region of the sealing ring and the second leg region of the sealing ring, in particular wherein the axial region covered by the first leg region of the split ring overlaps the axial region covered by the first leg region of the sealing ring and / or the axial region covered by the second leg region of the sealing ring.
5. Sealing arrangement according to one of the preceding claims, characterized in that the second leg region of the sealing ring, in particular comprising the support region and the sealing lip, projects into the spatial region between the first leg region of the split ring and the second leg region of the split ring, in particular so that the first leg region of the sealing ring is arranged radially between the first leg region of the split ring and the second leg region of the split ring, in particular wherein the axial region covered by the second leg region of the sealing ring overlaps the axial region covered by the first leg region of the split ring and / or the axial region covered by the second leg region of the split ring.
6. Sealing arrangement according to one of the preceding claims, characterized in that each of the leg regions of the split ring and the sealing ring is formed to be completely, in particular uninterrupted, circumferential in the circumferential direction.
7. Sealing arrangement according to one of the preceding claims, characterized in that the sealing ring is made of a rubber or a plastic, in particular NBR, and / or that the stiffening part of the split ring is rubberized and / or overmolded with a plastic with the exception of the running surface for the sealing lip of the sealing ring.
8. Sealing arrangement according to one of the preceding claims, characterized in that a stiffening part, particularly realized as a one-piece and / or one-part sheet metal part, is arranged in the split ring, which stiffens the first leg region of the split ring, the second leg region of the split ring and the yoke region of the split ring.
9. Sealing arrangement according to one of the preceding claims, characterized in that a stiffening part, in particular realized as a one-piece and / or one-part sheet metal part, is arranged in the sealing ring, which stiffens the first leg region of the sealing ring and the yoke region of the sealing ring, but in particular not the second leg region of the sealing ring and / or that a stiffening part, in particular realized as a one-piece and / or one-part sheet metal part, is arranged in the sealing ring, which stiffens the first leg region of the sealing ring and the yoke region of the sealing ring and is spaced from the second leg region of the sealing ring.
10. Sealing arrangement according to one of the preceding claims, characterized in that each leg region is spaced from all other leg regions.
11. Sealing arrangement according to one of the preceding claims, characterized in that the first leg region of the split ring is spaced from the shaft, wherein the yoke region of the split ring projects radially inward beyond the first leg region of the split ring, and / or that the first leg region of the split ring is spaced from the shaft, wherein the yoke region of the split ring projects radially inward beyond the first leg region of the split ring such that the radial spacing region covered by the first leg region of the split ring is contained in and / or encompassed by the radial spacing region covered by the yoke region of the split ring.
12. Sealing arrangement according to one of the preceding claims, characterized in that the yoke region of the split ring is plugged and / or clamped onto the shaft and / or is non-positively connected to the shaft.
13. Sealing arrangement according to one of the preceding claims, characterized in that the split ring delimits the sealing ring axially, in particular in the axial direction, and / or that the first leg region of the sealing ring adjoins the yoke region of the split ring and / or is positioned against the yoke region of the split ring.
14. Sealing arrangement according to one of the preceding claims, characterized in that the running surface is formed on the stiffening part of the split ring.
15. Drive component, in particular electric motor or transmission, with a sealing arrangement according to one of the preceding claims, characterized in that the sealing ring is arranged in the interior of the drive component and the split ring together with the flange part forms the housing, in particular for the drive component.