Sealing arrangement for sealing a rolling bearing for a bicycle bottom bracket

Abstract

The invention relates to a sealing arrangement for sealing a rolling bearing for a bottom bracket of a bicycle, particularly an electrically driven bicycle, characterized in that at least one dynamic seal is attached to an inner angled ring (3) which is non-rotatably connected to a rotating inner bearing ring (4), and which is formed by at least two sealing lips (17, 18) against a static outer angled ring (6) which is connected to a stationary outer bearing ring (7), the latter forming an annular sealing disc on an axially outer leg (15) for sealing the rolling bearing to the environment. The invention further relates to a rolling bearing with such a sealing arrangement. The invention also relates to a bottom bracket arrangement for supporting a crankshaft (5) of a bicycle, particularly an electrically driven bicycle, with at least one such rolling bearing.

Description

[0001] The invention relates to a sealing arrangement for sealing a roller bearing for a bottom bracket of a bicycle, in particular an electrically driven bicycle. The invention further relates to a roller bearing with such a sealing arrangement. The invention further relates to a bottom bracket assembly for supporting a pedal crankshaft of a bicycle, in particular an electrically driven bicycle, with at least one such roller bearing.

[0002] DE 10 2015 216 168 B3 discloses a bottom bracket assembly for a bicycle. This assembly features axially spaced roller bearings, each secured to the bicycle frame by means of roller bearing outer rings. A bottom bracket spindle is inserted into the roller bearing inner rings. An additional external sealing ring is arranged between the roller bearing outer ring and the roller bearing inner ring, at least on one end face of the roller bearing.

[0003] The invention is therefore based on the object of proposing a sealing arrangement, a rolling bearing and a bottom bracket arrangement of the aforementioned type, which enable a low-friction, high-performance sealing of the bearing and a simple and cost-effective manufacture and assembly in a structurally simple manner.

[0004] The problem is solved by the features of claim 1 and alternatively by the features of claim 8 or 9. Further advantageous and claimed embodiments emerge from the respective subclaims, the description, and the drawings.

[0005] Thus, a sealing arrangement for sealing a rolling bearing for a bottom bracket of a bicycle, in particular an electrically driven bicycle, is proposed. The sealing arrangement comprises at least one dynamic seal, which is attached to an inner angle ring that is rotationally fixedly connected to a rotating bearing inner ring and is sealingly applied with at least two sealing lips to a stationary outer angle ring that is connected to a stationary bearing outer ring. This outer angle ring forms an annular sealing disc on an axially outer leg for sealing the rolling bearing from the environment.

[0006] In this way, a low-friction, high-performance seal can be realized that is easy to manufacture and install.

[0007] Furthermore, manufacturing limitations in the design of the outer angle ring are avoided. This allows the outer angle ring, particularly on the axially outer leg, to form a radially elongated sealing disc, which, for example, forms a labyrinth seal with a very high sealing effect for sealing the rolling bearing axially on the outside.

[0008] This allows for a high-performance seal for a bicycle's bottom bracket, which prevents water and dirt particles from penetrating the bottom bracket even when riding off-road.

[0009] The sealing arrangement is therefore particularly advantageous for sealing a rolling bearing for a bottom bracket of an electrically powered bicycle, such as an e-bike or a pedelec.

[0010] The proposed sealing arrangement is also simple and cost-effective to manufacture. In particular, the angle rings can be manufactured from sheet metal in a lightweight and simple manner, particularly by punching and bending. For assembly, the angle rings can be simply pressed into the rolling bearing. Furthermore, the seal with at least two sealing lips can be cost-effectively attached to the inner angle ring, for example, by injection molding.

[0011] Preferably, at least one static seal with at least one sealing lip is attached to the outer side of the axially outer leg of the outer angle ring, such that it can be applied to a stationary component with at least one sealing lip to seal the bearing seat of the bearing outer ring. This reliably prevents corrosion of the surfaces machined to produce the bearing seat.

[0012] In this way, a sealing arrangement is achieved that is integrated into the rolling bearing and simultaneously seals the bearing seat of the rolling bearing.

[0013] The proposed sealing arrangement is flexibly adaptable to the operating conditions. It can be used with just the dynamic seal or without the static seal. Alternatively, it can be used with both the dynamic seal and the static seal.

[0014] Furthermore, the static seal can be positioned as desired on the outside of the axially outer leg of the outer angle ring and can be designed with any number of sealing lips, so that a particularly simple adaptation of the design to the installation conditions is possible.

[0015] It is further advantageous if, preferably on the axially outer leg, at least one annular axial contact surface is formed next to the static seal for an assembly tool for pressing the outer angle ring into the rolling bearing. This reliably prevents damage to the static seal during assembly.

[0016] The proposed sealing arrangement, comprising the angle rings and seals, can be preassembled as a sealing package and can be precisely pressed into the rolling bearing to the required length in a single step. In addition to the static seal, the sealing disc preferably features two annular axial contact surfaces for an assembly tool.

[0017] In a further preferred embodiment of the invention, the outer angle ring on the axially outer leg forms a labyrinth seal radially inward with the inner angle ring for sealing the rolling bearing from the environment.

[0018] Preferably, the outer angle ring on the axially outer leg forms a sealing disc that extends radially inward. This allows the labyrinth seal to be designed with a very narrow radial sealing gap and a very high sealing effect.

[0019] In this way, a low-friction, high-performance seal can be created from a combination of a lip seal and a labyrinth seal, which is easy to manufacture and install.

[0020] In addition, it is possible to provide a grease barrier, preferably in an annular space delimited by the sealing lips and the axially outer leg or the sealing disc of the outer angle ring, by which the sealing effect is further increased.

[0021] It is also advantageous if the inner angle ring preferably forms a radial sealing gap of the labyrinth seal with the outer diameter of a cylindrical leg and the inner diameter of the sealing disc on the outer angle ring.

[0022] The sealing disc of the outer angle ring can be designed with any leg length, so that an arrangement with a radial sealing gap with a specifically minimum gap width between the outer angle ring and the inner angle ring is possible, which increases the sealing effect of the labyrinth seal formed between them.

[0023] A further preferred embodiment provides that the inner angle ring forms a sealing disc on an axially inner leg. The dynamic seal is preferably attached to the sealing disc. In this way, the inner angle ring seals the rolling bearing axially on the inside with the sealing disc and the dynamic seal attached to the sealing disc and resting against the outer angle ring.

[0024] In a further development of the invention, the dynamic seal is applied with at least one first sealing lip in the axial direction to a first sealing surface and with at least one second sealing lip in the radial direction to a second sealing surface on the outer angle ring.

[0025] Preferably, the dynamic seal is applied with at least one first sealing lip in the axial direction to a first sealing surface formed on the outer angle ring on the inside of the sealing disc.

[0026] A further preferred embodiment of the invention provides that the dynamic seal is sealingly applied with at least one second sealing lip in the radial direction to a second sealing surface formed on the outer angle ring on the inner diameter of a cylindrical leg thereof.

[0027] The object of the invention is also achieved by a rolling bearing with a sealing arrangement as described above. This results in the advantages already described above.

[0028] The object of the invention is further achieved by a bottom bracket assembly for supporting a pedal crankshaft of a bicycle, in particular an electrically driven bicycle, with at least one rolling bearing with a sealing arrangement as described above. This results in the advantages already described above; in particular, the proposed bottom bracket assembly is particularly advantageous for use in electrified bicycles such as e-bikes and pedelecs, or also in electrified cargo bikes.

[0029] Thus, preferably in the aforementioned bottom bracket arrangement, the pedal crank shaft is arranged in a motor housing so as to be drivably connected to an electric motor and is guided with its axial ends through the motor housing to the outside for connection to the pedal cranks.

[0030] Preferably, the pedal crankshaft is supported in the area of ​​the passage directly via a previously described rolling bearing in a bearing seat in the motor housing.

[0031] Preferably, a sealing arrangement as described above with a sealing disc is provided to seal the respective rolling bearing from the environment.

[0032] Preferably, at least one static seal is attached to the outside of the sealing disc, which is applied with at least one sealing lip to the inside of the motor housing and seals the bearing seat of the bearing outer ring.

[0033] In a simple and cost-effective way, sealing the roller bearing simultaneously seals the bearing seat of the roller bearing and the interior of the motor housing. Sealing the bearing seat reliably prevents corrosion of the surfaces machined to produce the bearing seat. Furthermore, both the bottom bracket and the electric motor in the motor housing, which drives the crankshaft, can be protected from environmental influences.

[0034] In addition, the static seal can be positioned as desired on the outside of the sealing disc, depending on the installation conditions, in particular the design of the motor housing.

[0035] Preferably, the inner bearing ring of the rolling bearing with the inner diameter is arranged in a rotationally fixed manner on the outer diameter of the pedal crankshaft.

[0036] Further claimed features of the invention will become apparent from the following description and the drawings, which further explain the present invention. They show: Fig. 1 a sectional partial view of a sealing arrangement according to the invention for sealing a rolling bearing for a bottom bracket of a bicycle and of a rolling bearing according to the invention with such a sealing arrangement, Fig. 2 a bottom bracket assembly according to the invention with a sealing arrangement and a rolling bearing made of Fig. 1 in installation position on an electrically powered bicycle, Fig. 3 a partial sectional view of the bottom bracket assembly from Fig. 2.

[0037] The figures illustrate various views of a sealing arrangement according to the invention for sealing a rolling bearing for a bottom bracket of a bicycle, in particular an electrically driven bicycle. These illustrations also illustrate the rolling bearing and bottom bracket assembly according to the invention.

[0038] The sealing arrangement comprises a dynamic seal 1 and preferably a static seal 2. The dynamic seal 1 is mounted on an inner angle ring 3, which, as a race, is directly connected in a rotationally fixed manner to a rotating bearing inner ring 4 of the rolling bearing. The static seal 2 is mounted on a static outer angle ring 6, which is directly connected to the stationary bearing outer ring 7 of the rolling bearing.

[0039] The proposed sealing arrangement can be flexibly adapted to the operating conditions. It can be used with only the dynamic seal 1 or without the static seal 2. Alternatively, it can be used with the dynamic seal 1 and the static seal 2.

[0040] The roller bearing serves as a bottom bracket for supporting a bicycle crankshaft 5. The bearing axis 26 is indicated by a dashed line. The bearing inner ring 4 is arranged coaxially with the inner diameter, i.e., the inner circumference, of the bicycle crankshaft 5 and is rotationally fixed to the outer diameter, i.e., the outer circumference. The bearing outer ring 7 of the roller bearing is arranged stationary in a bearing seat 8 of a stationary housing 9.

[0041] The sealing arrangement and the rolling bearing are particularly advantageous for use in a bottom bracket assembly in an electrically powered bicycle, in particular an e-bike, a pedelec, or a cargo bike, but also in a conventional bicycle. The housing 9 is preferably designed as a bottom bracket housing or motor housing, which accommodates the crankshaft 5, the bottom bracket, and, if appropriate, the electric motor (not shown) driving them, and, if appropriate, a transmission.

[0042] The rolling bearing is designed as a deep groove ball bearing with an extended rim 10, 11 on the bearing rings 4, 7 in the axially outer direction relative to the axial inner side for accommodating the sealing arrangement according to the invention. The latter serves to seal the rolling bearing on its axial outer side from the environment. On the axial inner side facing away from this, the rolling bearing is shielded from the interior of the bottom bracket by the rolling element cage 12. The pedal crankshaft 5 is preferably mounted via two rolling bearings 33, 34 in the bottom bracket or motor housing 9 ( Fig. 3), of which only one in Fig. 1 is shown.

[0043] The angle rings 3, 6 serve in particular as seal supports for the seals 1, 2. Sheet metal is preferably used as the material for the angle rings 3, 6, which makes them lightweight and easy to manufacture, particularly by punching and bending. The angle rings 3, 6 each have an L-shaped cross-sectional profile with two legs 13, 14 and 15, 16 arranged at right angles to each other.

[0044] To seal the rolling bearing from the environment, the outer angle ring 6 forms an axially outer annular sealing disc on an axially outer leg 15 facing the environment. The inner angle ring 3 forms an annular axially inner sealing disc on an axially inner leg 13 facing the interior of the bearing. The sealing discs 13, 15 are each designed as a flat annular disc and as an axial disc with their flat side surfaces aligned axially, i.e., in the direction of the bearing axis 26.

[0045] The outer angle ring 6 has a cylindrical leg 16, the free end of which extends axially inward. The outer angle ring 6 is pressed onto the inner diameter, i.e., the inner circumference, of the bearing outer ring 7 with the outer diameter of the cylindrical leg 14, i.e., the outer circumference of the cylindrical leg.

[0046] The inner angle ring 3 is designed with a cylindrical leg 14, the free end of which extends axially outward. The inner angle ring 3 is pressed onto the outer diameter, thus the outer circumference, of the bearing inner ring 4 for fastening purposes, using the inner diameter of the cylindrical leg 14, thus the inner circumference of the same.

[0047] The angle rings 3, 6 are arranged opposite one another, with their sealing discs 13 and 15, respectively, and with their cylindrical legs 14 and 16, respectively, and define an annular space located between them in a cassette-like manner. The inner angle ring 3, with the sealing disc 13, defines the annular space axially inward, and the outer angle ring 6, with the sealing disc 15, defines the annular space axially outward.

[0048] On the inner angle ring 3, the sealing disc 13 is aligned with its free end at its outer diameter in the radially outward direction. The dynamic seal 1 with two sealing lips 17, 18 is annularly mounted on the outer diameter of the sealing disc 13. The inner sides of the sealing disc 13 and the cylindrical leg 14, which border the annular space, as well as the axially outer end face of the latter, are each covered with sealing material for corrosion protection.

[0049] In addition, a grease barrier is preferably provided in the annular space between the sealing lips 17, 18, which further increases the sealing effect.

[0050] The static seal 2 with a sealing lip 19 is annularly attached to the outer angle ring 6 on the outside of the sealing disc 15 facing the environment. The seals 1, 2 are each vulcanized as an elastomer to the respective sealing discs 13 and 15, respectively.

[0051] The dynamic seal 1 is prestressed and sealed against the outer angle ring with its two sealing lips 17, 18. A first sealing lip 17 is in axial contact with a flat, annular first sealing surface 21 formed on the inner side of the sealing disc 15 on the outer angle ring 6.

[0052] The second sealing lip 18 engages in a radial direction on an annular second sealing surface 22 formed on the inner diameter of the cylindrical leg 14 on the outer angle ring 6.

[0053] The first sealing lip 17 tapers slightly in the axially outer direction, while the second sealing lip 18 widens slightly in the axially outer direction. This provides greater stability within the system and greater resistance to any water or dirt particles penetrating from the outside. Both sealing lips 17, 18 are designed with an overlength or overlap, as indicated, so that they each rest against the respective sealing surface 21, 22 under prestress.

[0054] On the outer angle ring 6, the annular sealing disc 15 extends with its free end at the inner diameter in the radially inner direction and forms a labyrinth seal 20 with the inner angle ring 3. A radial sealing gap 20 is formed between the inner diameter of the sealing disc 15 and the outer diameter of the cylindrical leg 16 of the inner angle ring 3. The radial gap width can be minimized by the radial leg length of the sealing disc 15, thus optimizing the sealing effect of the labyrinth seal 20. The sealing disc 15 forms a sealing disc that is elongated in the radially inner direction. In this way, the sealing disc 15 and the labyrinth seal 20 seal the rolling bearing axially from the outside to the environment.

[0055] Accordingly, on the one hand, the inner angle ring 3 with the dynamic seal 1 as a lip seal adjacent to the outer angle ring 6 and, on the other hand, the outer angle ring 6 with the labyrinth seal 20 formed between it and the inner angle ring 3 forms a low-friction high-performance seal which keeps moisture and dirt particles out of the rolling bearing and the bottom bracket and motor housing 9 even when driving off-road.

[0056] The static seal 2 is attached to the flat axial outer side of the sealing disc 12 of the outer angle ring 5 and, with its annular sealing lip 16, rests in an axial direction under preload against a flat annular sealing surface 23 formed on the inside of the bottom bracket or motor housing 9. In this way, the static seal 2 seals the bearing seat 8 of the rolling bearing, thereby preventing corrosion of the surfaces machined to produce the bearing seat 8.

[0057] The static seal 2 can be positioned on the outer angle ring 6 over the entire radial length of the sealing disc 15 as desired to adapt to the installation conditions. Planar annular contact surfaces 24, 25 are provided on the sealing disc 15 in the radial direction next to the static seal 2, preferably on both sides thereof, aligned axially, for an assembly tool, such as a punch, for pressing the outer angle ring 6 into the rolling bearing. By placing the assembly tool on the contact surfaces 24, 25 next to the static seal 2, damage to the seal during assembly is avoided.

[0058] The proposed sealing arrangement can be preassembled as a sealing package with the angle rings 3, 6 and the seals 1, 2. It can be precisely pressed into the rolling bearing to the required length in a single step, thus achieving the required excess length and preload required for the sealing lip of the static seal 2 to seal against the sealing surface 23 on the bottom bracket or motor housing 9.

[0059] The bearing inner ring 4 is secured on its axially outer end face by a retaining element 27 on the pedal crankshaft 5 in the axially outer direction. The retaining element 27 can, for example, be designed as a retaining ring arranged in an annular groove 28 on the outer diameter of the pedal crankshaft 5. The bearing outer ring 7 is secured with its axially outer end face against a shoulder 29 formed on the bearing seat 8 on the housing 9. This simultaneously further seals the bearing seat 8 of the rolling bearing.

[0060] Fig. 2 and Fig. 3 show the proposed bottom bracket arrangement as an example in the installed position on an e-bike. Fig. Figure 2 shows the bottom bracket assembly with the bottom bracket and motor housing 9 connected to the bicycle frame 30. The crankshaft 5 is arranged transversely to the longitudinal axis of the e-bike and its axial ends extend through the bottom bracket and motor housing 9. It is connected at each of its axial ends to a crank 31, 32 of the e-bike. The output of the crankshaft 5 is via a sprocket 35.

[0061] Fig. Figure 3 shows the bottom bracket assembly in a partial cross-sectional view. The crankshaft 5 is supported at its axial end sections in the bottom bracket and motor housing 9 via a previously described roller bearing 33, 34. For this purpose, the outer diameter of the bearing outer ring 7 of the respective roller bearing 33, 34 is supported on the inner diameter of a bearing seat 8 on the inside of the bottom bracket and motor housing 9.

[0062] An electric motor 35 (not shown) and a gear 36 connected to it are arranged in the bottom bracket and motor housing 9. The e-bike is propelled by both the pedal cranks 31, 32 ( Fig. 2) and the pedal crankshaft 5 as well as via the electric motor 35.

[0063] The bottom bracket and motor housing 9 is sealed from the environment. At the passage of the pedal crankshaft 5, it is sealed from the environment by the rolling bearings 33, 34 with the proposed and previously described sealing arrangement. This protects the rolling bearings 33, 34, the electric motor, and the transmission in the bottom bracket and motor housing 9 from moisture and dirt particles from the environment. List of reference symbols 1 dynamic seal 2 static seal 3 inner angle ring 4 Bearing inner ring 5 Crankshaft 6 outer angle ring 7 Bearing outer ring 8 bearing seat 9 Housing, bottom bracket shell, motor housing 10 Board 11 Board 12 Rolling element cage 13 axially outer leg, sealing disc 14 cylindrical leg 15 axially inner leg, sealing disc 16 cylindrical leg 17 first sealing lip 18 second sealing lip 19 Sealing lip 20 Labyrinth seal, radial sealing gap 21 first sealing surface 22 second sealing surface 23 Sealing surface 24 contact surface 25 contact surface 26 bearing axis 27 Retaining element, retaining ring 28 ring groove 29 paragraph 30 bicycle frames 31 crank 32 crank 33 rolling bearings 34 rolling bearings 35 sprocket 36 electric motor 37 gearboxes QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2015 216 168 B3

[0002]

Claims

[1] Sealing arrangement for sealing a rolling bearing for a bottom bracket of a bicycle, in particular an electrically driven bicycle, characterized by in that at least one dynamic seal is mounted on an inner angle ring (3) which is connected in a rotationally fixed manner to a rotating bearing inner ring (4), said seal being sealingly applied by means of at least two sealing lips (17, 18) to a static outer angle ring (6) connected to a stationary bearing outer ring (7), the latter forming an annular sealing disc on an axially outer leg (15) for sealing the rolling bearing from the environment. [2] Sealing arrangement according to claim 1, characterized by that at least one static seal (2) is attached to the axially outer leg (15) of the outer angle ring (6) in such a way that it can be applied to a stationary component (9) with at least one sealing lip (19) for sealing the bearing seat (8) of the bearing outer ring (7). [3] Sealing arrangement according to claim 2, characterized by that the axially outer leg (15) forms on the outside, next to the static seal (2), at least one axial contact surface (24, 25) for an assembly tool for pressing the outer angle ring (6) into the rolling bearing. [4] Sealing arrangement according to one of claims 1 or 2, characterized by that the outer angle ring (3) on the axially outer leg (15) radially inside forms a labyrinth seal (20) with the inner angle ring (3) for sealing the rolling bearing axially outside. [5] Sealing arrangement according to one of claims 1 to 3, characterized by that the inner angle ring (3) forms an annular sealing disc on an axially inner leg (13) and seals the rolling bearing axially on the inside with the dynamic seal (1) attached to this and resting on the outer angle ring (6). [6] Sealing arrangement according to one of claims 1 to 4, characterized bythat the dynamic seal (1) is sealingly applied with at least one first sealing lip (17) in the axial direction to a first sealing surface (21) formed on the outer angle ring (6) on the inside of the axially outer leg (15). [7] Sealing arrangement according to one of claims 2 to 5, characterized by that the outer angle ring (6) has a cylindrical leg (16) for fastening to the bearing outer ring (7) and the dynamic seal (1) is sealingly applied with at least one second sealing lip (18) in the radial direction to a second sealing surface (22) formed on the inner diameter of the cylindrical leg (16). [8] Rolling bearing (33, 34) with a sealing arrangement according to one of the preceding claims. [9] Bottom bracket arrangement for supporting a pedal crankshaft (5) of a bicycle, in particular an electrically driven bicycle, with at least one rolling bearing (33, 34) according to claim 8. [10] Bottom bracket assembly according to claim 9, characterized by in that the pedal crankshaft (5) is arranged in a bottom bracket and motor housing (9) so as to be drivable and connected to an electric motor, and is guided with its axial ends through the bottom bracket and motor housing (9) to the outside for connection to pedal cranks (31, 32), and in the region of the lead-through is supported directly via a rolling bearing (33, 34) in a bearing seat (8) in the motor housing (9), and a sealing arrangement seals the rolling bearing (33, 34) from the environment, wherein at least one static seal (2) is attached to the outside of a sealing disc (15) connected to the bearing outer ring (7) of the rolling bearing (33, 34), which is applied with at least one sealing lip (19) to the inside of the motor housing (9) and seals the bearing seat (8) of the bearing outer ring (7) from the environment.

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