Hub unit for an electrically propelled two-wheeled vehicle having a sealed cable guide

Abstract

The present invention relates to a hub unit (1) for an electrically propelled two-wheeled vehicle (100), comprising: an electric motor (2) which is arranged around an axis of rotation in an inner region (3) of the hub unit in order to propel the electrically propelled two-wheeled vehicle; a radial bearing (4); a cable guide (10) having a sealing element (11); and a cable (5) which emerges from the hub unit and is designed to electrically connect the electric motor to an electrical energy store, wherein the sealing element circumferentially encloses the cable in order to seal the inner region of the hub unit, and wherein the sealing element is arranged axially outside the radial bearing.

Description

[0001] R.415565

[0002] - 1 -

[0003] Description

[0004] title

[0005] Hub unit for an electrically powered two-wheeler with sealed cable routing

[0006] State of the art

[0007] The present invention relates to a hub unit for an electrically powered two-wheeler and the associated electrically powered two-wheeler.

[0008] Typically, the battery of hub motors for e-bikes is located outside the motor on the bicycle frame. This necessitates routing cables from the frame into the motor. Sealing this interface between the cable and the hub is a critical point for water ingress. Current technologies use silicone sealant, among other methods. However, this seal is unreliable and difficult to achieve with consistent process reliability. Alternatively, current technologies use a connector from the hub motor that engages with a corresponding interface in the frame. This solution is significantly more expensive than a cable. Ideally, a hub unit for electrically powered two-wheelers, such as e-bikes, would provide the most cost-effective and reliable sealing possible for the cable connection to the hub unit.

[0009] Disclosure of the invention

[0010] The hub unit according to the invention, comprising the features of claim 1, and the associated electrically driven two-wheeler, comprising the features of claim 12, have the advantage that a reliable and cost-effective seal between the cable and the hub unit is enabled. According to the invention, this is achieved by the hub unit having an R.415565

[0011] - 2 -

[0012] The system comprises an electric motor arranged around a rotational axis within the hub unit to power the electrically driven two-wheeler. The electrically driven two-wheeler also includes a radial bearing, a cable guide with a sealing element, and a cable exiting the hub unit to connect the electric motor to an electrical energy storage device. The sealing element circumferentially encloses the cable to seal the interior of the hub unit. Furthermore, the sealing element is positioned axially outside the radial bearing. This axial positioning eliminates the need for a seal within the narrow radial area of ​​the bearing, thus providing more space. The sealing element enables a cost-effective and reliable seal between the cable and the interior of the hub unit.The radial bearing is preferably a rolling bearing. The sealing element is preferably designed as an elastomer seal.

[0013] The dependent claims describe preferred embodiments of the invention.

[0014] Preferably, a longitudinal axis of the sealing element is arranged at an angle > 45°, particularly perpendicular, to the axis of rotation. This allows the cable to be aligned within the cable tray. Furthermore, this reduces forces on the sealing element.

[0015] A ring-shaped sealing element is also preferred. This allows the sealing element to be easily attached to the cable and to reliably seal it.

[0016] The cable guide preferably incorporates a torque support to counteract the motor torque of the hub unit against the bicycle frame. This allows for a simple and cost-effective method of torque support between the motor and the bicycle frame.

[0017] More preferably, the hub unit comprises a hollow support shaft to which an inner ring of the radial bearing and the cable guide are attached, the hollow support shaft having a recess for the cable to guide the cable axially to the axis of rotation between the radial bearing and the hollow support shaft. Thus, reliable cable guidance can be ensured by the R.415565

[0018] - 3 -

[0019] The electric motor is located inside the hub unit, between the radial bearing and the hollow support axle, through to the sealing element and out of the hub unit.

[0020] The cable guide of the hub unit preferably comprises a sleeve element and a cover element, with the sealing element arranged adjacent to the sleeve element and the cover element. This improves the manufacturability and assembly of the cable guide. The sleeve element is preferably arranged in the direction of the hub unit, while the cover element is arranged in the direction of the electric motor frame. Furthermore, the sealing element is preferably arranged between the sleeve element and the cover element.

[0021] Preferably, the cover element incorporates the torque support. The cover element is preferably designed to rest directly against the frame and can thus easily support the motor torque against the frame. The torque support is preferably positively engaged. Furthermore, the torque support is preferably designed as a web extending perpendicular to the axis of rotation.

[0022] The cover element is preferably attached to the hollow support axle. It is attached primarily using countersunk screws. This allows the cover element to be attached to the hub unit in a space-saving manner and to reliably transmit the motor torque to the frame. The cover element preferably has conical recesses for the countersunk screws, enabling a positive fit to the hollow support axle. The hollow support axle is a static component of the hub unit.

[0023] The sleeve element preferably has a first flange region and the cover element a second flange region, wherein the first flange region and the second flange region are arranged sealed against each other. The flange regions can be manufactured cost-effectively and allow the cover element to be arranged on the sleeve element in a sealed manner with respect to the interior of the hub unit. A gasket is preferably arranged between the first flange region and the second flange region for sealing purposes. The gasket can be a separate R.415565

[0024] - 4 -

[0025] be a component or be integrated into the sleeve element or the lid element in a 2K injection molding process.

[0026] Preferably, a sealing cap is arranged adjacent to the cable guide and the cable itself. This sealing cap is designed to seal the contact area between the first flange region, the second flange region, and the cable to the interior. Without the sealing cap, contaminants can penetrate the interior of the hub unit through the area between the cable and the seal between the flange regions. The sealing cap improves the seal to the interior. The sealing cap can either form the sealing element itself or be arranged in addition to the sealing element.

[0027] Preferably, the cable guide has a clamping area adjacent to the sealing element to secure the cable. This provides strain relief for the cable in addition to the pure sealing function.

[0028] Preferably, the cable guide is axially sealed and arranged on an inner ring of the radial bearing. This ensures a space-saving arrangement and prevents dirt from penetrating the interior of the hub unit between the cable guide and the inner ring.

[0029] Furthermore, the invention relates to an electrically powered two-wheeler comprising a hub unit as previously described. The hub unit according to the invention allows for a reduction in the cost of the electrically powered two-wheeler while ensuring a reliable seal between the cable and the interior of the hub unit. The electrically powered two-wheeler can be, for example, an e-scooter, an electric bicycle, or an electric motorcycle.

[0030] Brief description of the drawings

[0031] A preferred embodiment of the invention is described in detail below with reference to the accompanying drawings. The drawing shows:

[0032] Figure 1 shows a perspective view of a hub unit according to a first embodiment of the invention, R.415565

[0033] - 5 -

[0034] Figure 2 shows a sectional view of an electric bicycle with a

[0035] Hub unit according to the first embodiment of the invention,

[0036] Figure 3 shows a perspective view of a lid element of the

[0037] Hub unit according to the first embodiment of the invention and

[0038] Figure 4 shows a perspective view of a hub unit according to a second embodiment of the invention.

[0039] Embodiments of the invention

[0040] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0041] The following describes in detail a hub unit 1 and an electrically driven two-wheeler 100 with reference to Figures 1 to 3.

[0042] Figure 1 shows a perspective view of the hub unit 1 for an electrically driven two-wheeler 100 in the form of an e-bike. The hub unit 1 has a housing 8 in the interior 3 of which an electric motor 2 (shown in Figure 2) is arranged to drive the electrically driven two-wheeler 100. The hub unit 1 is arranged around a rotational axis XX and has a radial bearing 4, which supports a static part relative to a rotating part of the hub unit 1.

[0043] Along the axis of rotation XX, axially outside the radial bearing 4, the hub unit has a cable guide 10 with a sealing element 11, from which a cable 5 emerges. The cable 5 is configured to electrically connect the electric motor 2 to an electrical energy storage device of the electrically driven two-wheeler 100. Furthermore, signals for controlling the electric motor 2 can be transmitted via the cable 5.

[0044] The cable guide 10 has a sleeve element 13 and a cover element 14, wherein the sealing element 11 is located between the sleeve element 13 and the R.415565

[0045] - 6 -

[0046] The lid element 14 is arranged. The sealing element 11 forms a longitudinal axis LL, the longitudinal axis LL being arranged at a 90° angle a to the rotation axis XX. Furthermore, the longitudinal axis LL intersects the rotation axis XX.

[0047] The cable guide 10 is attached to the hub unit 1 by means of countersunk screws 15, which connect the cover element 14 to a hollow support shaft 6. The cover element 14 presses the sleeve element 13 axially against an inner ring 4a of the radial bearing 4. A seal 9 is arranged between the sleeve element 13 and the inner ring 4a of the radial bearing 4 to prevent the ingress of contaminants between the sleeve element 13 and the radial bearing 14 into the interior 3 of the hub unit 1.

[0048] The cover element 14 has a torque support 12 to support a motor torque of the hub unit 1 on a bicycle frame 50 (shown in Figure 2). The torque support 12 extends parallel to the longitudinal axis LL of the sealing element 10 and can enable a positive-locking force transmission between the hub unit 1 and the bicycle frame 50.

[0049] Adjacent to the sealing element 11, the cable guide 10 between the sleeve element 13 and the cover element 14 has a clamping area 18 to secure the cable 5 and create a tensile load. In the clamping area 18, the sleeve element 13 and the cover element 14 directly contact the sheath of the cable 5. The clamping area 18 is arranged axially outside the sealing element 11 along the longitudinal axis LL.

[0050] Figure 2 shows a sectional view through the hub unit 1 and the adjacent bicycle frame 50 as part of the electrically powered two-wheeler 100. The hub unit 1 is attached to the bicycle frame 50 by means of a thru-axle 51, the thru-axle 51 extending coaxially to the axis of rotation XX through the hub unit 1.

[0051] Adjacent to the plug-in shaft 51 is the support hollow shaft 6, which is a non-rotating component and is attached to the inner ring 4a of the radial bearing 4 and the cable guide 10. The support hollow shaft 6 has a recess 7 in which the cable 5 runs axially to the axis of rotation XX between the R.415565

[0052] - 7 -

[0053] The cable is guided by radial bearing 4 and the hollow support shaft 6. The cable 5 has no sheathing within the recess 7 to save space.

[0054] The cover element 14 lies flush against the bicycle frame 50. This allows for an additional friction-based torque transmission from the electric motor 2 to the bicycle frame 50.

[0055] The electric motor 2 preferably comprises a rotor and a stator, the stator preferably being connected directly or indirectly to the hollow support shaft 6. The rotor is preferably connected to the housing 8 of the hub unit 1 and transmits the torque of the electric motor 2 to the tire. The housing 8 is rotatably mounted on an outer ring 4b of the radial bearing 4, which is designed as a sealed deep groove ball bearing.

[0056] The sleeve element 13 has a first flange region 16, and the cover element 14 has a second flange region 17, with the first flange region 16 abutting the second flange region 17. A seal 9 is arranged between the first flange region 16 and the second flange region 17, which prevents the ingress of dirt into the interior 3 of the hub unit 1. The sealing element 11 is shown in an annular form and surrounds the cable 5 circumferentially. The outer surface of the sealing element 11 abuts the sleeve element 13 and the cover element 14. Adjacent to the sealing element 11, the sleeve element 13 and the cover element 14 have a shoulder directed towards the longitudinal axis LL, whereby the sleeve element 13 and the cover element 14 clamp the sheath of the cable 5 and form the clamping area 18.

[0057] Figure 3 shows a perspective view of the cover element 14 as seen from the interior area 3 of the hub unit 1. The cover element 14 is preferably a formed sheet metal component.

[0058] The cover element 14 has conical recesses 19 in which the countersunk screws 15 can be arranged for connection to the hollow support shaft 6. The conical recesses 19 can form an improved positive fit to the hollow support shaft 6 in order to transmit a motor torque from the electric motor 2, which is transmitted via the hollow support shaft 6, by means of the R.415565

[0059] - 8 -

[0060] Torque support 12 on the bicycle frame 50 of the electrically powered two-wheeler 100 to support.

[0061] Figure 4 shows a second embodiment of the hub unit 1 according to the invention, wherein the cover element 14 is omitted. The second embodiment is similar to the first embodiment and differs from it in particular in that the sealing element 11 is designed as a sealing cap 20.

[0062] The sealing cap 20 is arranged at the end of the cable guide 10 where the cable 5 exits the hub unit 1. The sealing cap 20 surrounds the end of the cable guide 10 axially and radially to the longitudinal axis LL, in particular to seal the area between the cable 5 and the seal 9 between the first flange region 16 and the second flange region 17. The sealing cap 20 is preferably made of a silicone material or an equivalent material. More preferably, the sealing cap 20 is arranged on the cable 5 before the cable is connected to the electric motor 2.

[0063] Thus, the hub unit 1 can be manufactured cost-effectively using the cable guide 10 according to the invention, with the sealing element 11 enabling a reliable seal between the cable 5 and the interior 3 of the hub unit 1. Furthermore, the torque support 12 integrated into the cable guide 10 and the clamping area 18 ensure reliable operation of the electrically driven two-wheeler 100.

Claims

R.415565 - 9 - Claims 1. Hub unit for an electrically powered two-wheeler, comprising: - an electric motor (2) arranged around a rotational axis (XX) in an inner area (3) of the hub unit (1) to drive the electrically driven two-wheeler (100), - a radial bearing (4), - a cable guide (10) with a sealing element (11) and - a cable (5) which exits from the hub unit (1) and is configured to electrically connect the electric motor (2) to an electrical energy storage device, - wherein the sealing element (11) circumferentially surrounds the cable (5) to seal the interior (3) of the hub unit, and - wherein the sealing element (11) is arranged axially outside the radial bearing (4).

2. Hub unit according to claim 1, wherein a longitudinal axis (LL) of the sealing element (11) is arranged at an angle (a) greater than 45°, in particular perpendicular, to the axis of rotation (XX).

3. Hub unit according to one of the preceding claims, wherein the sealing element (11) is annular.

4. Hub unit according to one of the preceding claims, wherein the cable guide (10) has a torque support (12) to support a motor torque of the hub unit (1) on a bicycle frame (50).

5. Hub unit according to one of the preceding claims, comprising a support hollow axle (6) to which an inner ring (4a) of the radial bearing (4) and the cable guide (10) are attached, wherein the support hollow axle (6) has a recess (7) for the cable (5) to guide the cable (5) axially to the R.415565 - 10 - to guide the axis of rotation (XX) between the radial bearing (4) and the hollow support axis (6).

6. Hub unit according to one of the preceding claims, wherein the cable guide (10) has a sleeve element (13) and a cover element (14), wherein the sealing element (11) is adjacent to the sleeve element (13) and the lid element (14) is arranged.

7. Hub unit according to claim 6, wherein the cover element (14) has the torque support (12).

8. Hub unit according to one of claims 5 to 7, wherein the cover element (14) is attached to the hollow support axis (6), in particular by means of countersunk screws (15).

9. Hub unit according to one of claims 6 to 8, wherein the sleeve element (13) has a first flange area (16) and the cover element (14) has a second flange area (17), wherein the first flange area (16) and the second flange area (17) are arranged sealed against each other.

10. Hub unit according to claim 9, wherein a sealing cap (20) is arranged adjacent to the cable guide (10) and to the cable (5), wherein the sealing cap (20) is configured to seal a contact area between the first flange area (16), the second flange area (17) and the cable (5) to the interior area (3).

11. Hub unit according to one of the preceding claims, wherein the cable guide (10) adjacent to the sealing element (11) has a clamping area (18) to fix the cable (5).

12. Hub unit according to one of the preceding claims, wherein the cable guide (10) is axially sealed on an inner ring (4a) of the radial bearing (4).

13. Electrically powered two-wheeler comprising a hub unit (1) according to one of the preceding claims.

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