Wheel unit for a bicycle and bicycle

Abstract

Wheel unit (20) for a bicycle (1), wherein the wheel unit (20) comprises a hub (22), a brake disc (21) and a measuring element (2), - wherein the measuring element (2) is set up to determine a rotational speed of the wheel (25) of the bicycle (1), - wherein the measuring element (2) and the brake disc (21) are arranged on the hub (22), - wherein the measuring element (2) is arranged directly adjacent to the brake disc (21), - wherein the measuring element (2) has a mounting area (3) and a plurality of spaced-apart uniform signal transmitters (6, 6a), - wherein the mounting area (3) is connected to the signal transmitters (6, 6a), - wherein each signal transmitter (6, 6a) defines a signal path (7) with a signal path length, - wherein the signal transmitters (6, 6a) are arranged radially around the mounting area (3) and radially around a central axis (M) of the measuring element (2), - wherein uniform material-free windows (12) are arranged between the signal transmitters (6, 6a), characterized in that the measuring element (2) is designed as a circular ring segment, - wherein a circular arc of the circular ring segment is bounded by two limit signal transmitters (6a), which are uniformly designed to match the other signal transmitters (6), - wherein a dimension (A) of a material-free area (8) between the two limit signal transmitters (6a) is larger than the sum of the dimensions of two material-free windows (12).

Description

[0001] The present invention relates to a wheel unit for a bicycle and a bicycle.

[0002] In the area of ​​bicycles that are at least temporarily powered by muscle power, such as pedelecs and e-bikes, it is necessary to determine the rotational speed of a wheel of such vehicles in order to be able to draw conclusions about the speed of the bicycle.

[0003] DE 10 2022 202 716 A1 relates to a measuring ring element for a measuring system for a bicycle for determining the rotational speed of a wheel of the bicycle. The measuring ring element, which is designed to be arranged on the wheel of the bicycle, has a plurality of spaced-apart signal generators. Each signal generator defines a signal path with a signal path length, wherein the signal generators are arranged radially around a central axis of the measuring ring element. The measuring ring element has a calibration element, wherein the calibration element is formed as a material-free recess in the measuring ring element, wherein the calibration element is arranged between two signal generators.

[0004] EP 3 176 064 B1 relates to a wheel unit for a bicycle, comprising a hub and a rim arranged to be rotatable about a rotational axis. The hub and the rim are connected to each other by spokes. A brake disc and a sensor rim with a sensing area are arranged on the hub, and the sensor rim is arranged adjacent to the brake disc.

[0005] From EP 3 590 812 A1, an incremental measuring path system for a bicycle with a manipulation protection for determining a rotational speed of a wheel of the bicycle relative to a fixed point on the bicycle is known.

[0006] EP 2 557 004 A2 shows an arrangement of a brake disc and a sensor disc on a two-wheeled vehicle, including bicycles at least indirectly. The brake disc is combined with a sensor disc to detect, for example, the rotational speed. The sensor disc is regularly perforated. The two discs are designed to be at least partially directly adjacent to one another.

[0007] The present invention is based on the prior art and is based on the object of proposing a wheel unit which is improved compared to the prior art.

[0008] Based on the aforementioned object, the present invention proposes a wheel unit having the features of claim 1 and a bicycle having the features of claim 4. Further advantageous embodiments and developments emerge from the subclaims.

[0009] A wheel unit for a bicycle has a hub, a brake disc, and a measuring element. The measuring element is designed to determine a rotational speed of the bicycle wheel. The measuring element and the brake disc are arranged on the hub. The measuring element is arranged directly adjacent to the brake disc. The measuring element has a mounting area and a plurality of spaced-apart, uniform signal sensors. The mounting area is connected to the signal sensors. Each signal sensor defines a signal path with a signal path length. The signal sensors are arranged radially around the mounting area and radially around a central axis of the measuring element. Uniform, material-free windows are arranged between the signal sensors. The measuring element is designed as a circular ring segment. An arc of the circular ring segment is delimited by two limit signal sensors, which are designed uniformly to the other signal sensors.A dimension of a material-free area between the two limit signal devices is larger than the sum of the dimensions of two material-free windows.

[0010] "Bicycle" refers to a vehicle that is at least temporarily powered by human power. In particular, bicycles in the context of this application include bicycles with electric or auxiliary drive systems, such as e-bikes, pedelecs, speed pedelecs, velomobiles, cargo bikes, etc. Bicycles can be single-track, double-track, or multi-track vehicles.

[0011] The measuring element is arranged and mounted directly on the brake disc, with no gap between the brake disc and the measuring element. No spacers or intermediate layers are provided. The brake disc and the measuring element are arranged together on the hub coaxially to the rotational axis of the bicycle wheel, with the central axis of the measuring element coaxial to the rotational axis.

[0012] The wheel unit also has spokes and a rim, which are connected to each other in the usual way. The spokes are also connected to the hub in the usual way. When the wheel unit is used in a bicycle, the brake disc is positioned closer to the spokes of the bicycle wheel than the measuring element. This means that the arrangement sequence, starting from the bicycle wheel, is from the inside out: spokes – brake disc – measuring element. The brake disc and measuring element are arranged on the hub in such a way that, when the wheel unit is used in a bicycle, rotation of the brake disc and the measuring element around the rotation axis is possible.

[0013] When used with a bicycle wheel unit, the brake disc allows one of the wheels to be slowed down. During braking, the brake pads of a bicycle disc brake caliper press against the brake disc, creating friction and slowing the rotation of the corresponding wheel. Disc brakes offer several advantages over rim brakes on bicycles, including greater braking power, better controllability of braking force, and less susceptibility to weather conditions.

[0014] The measuring element is designed to determine the rotational speed of the bicycle wheel when the wheel unit is used in a bicycle. The measuring element is used in an incremental measuring system on the bicycle.

[0015] The measuring element can preferably be formed entirely from a metallic material. Alternatively, the measuring element can be formed at least partially from a plastic material, a fiber-reinforced plastic composite material, or another suitable material. Alternatively, the measuring element can be assembled from different materials; for example, the mounting area can be formed from a first material, e.g., a fiber-reinforced plastic composite material, and a signal area from a second material, e.g., a metallic material.

[0016] The measuring element has a mounting area that is used to connect to the brake disc. The mounting area therefore has holes, for example, so that the measuring element can be joined to the brake disc, for example, by screwing it.

[0017] The measuring element has the signal range, which is directly connected to the mounting area. The signal range is defined by the plurality of uniform signal transmitters spaced apart from one another. The two limit signal transmitters are also signal transmitters that are no different from the other signal transmitters. The only special feature of the limit signal transmitters is their arrangement at the two ends of the sensor range. The signal transmitters are arranged radially around the mounting area and radially around a central axis of the measuring element. Each signal transmitter has and defines a signal path with an arc-shaped dimension. Each signal path has a signal path length. The signal path length directly influences the resolution of the sensor signal, which is caused by tapping the signal path. Each signal transmitter is preferably made of a magnetic material.Alternatively, each signal generator can be made of a non-magnetic material. The respective signal path of the individual signal generators can be tapped using a sensor element if the measuring element is used in a bicycle's measuring system. The sensor element can be designed, for example, as a magnetic, inductive, capacitive, or optical sensor, a Hall sensor, or an ultrasonic sensor. Overall, the sensor element and the signal generators must be selected so that they are compatible with each other, so that the sensor element can detect the signal generators and tap the signal paths. For example, a Hall sensor is compatible with a signal generator made of magnetic material.

[0018] The measuring element is flat, meaning it extends in a single plane and has no offsets or elevations. The signal transmitters are arranged in the same plane as the mounting area and do not protrude from this plane.

[0019] The uniform material-free windows are arranged between the signal sensors. This means that the signal sensors are arranged equidistant from one another. The two limit signal sensors that delimit the measuring element are not arranged equidistant from one another because the measuring element is designed as a circular ring segment. This means that the sensor area does not form a full circle, which can also be referred to as a ring, but only a partial circle. This creates a slot or gap. The arcuate dimension of the material-free area between the two limit signal sensors is larger than the sum of the arcuate dimensions of two material-free windows. For example, the dimension of the material-free area can be larger than the sum of the dimensions of three material-free windows. Preferably, the dimension can be as large as the sum of the dimensions of two material-free windows and a single signal path.

[0020] The advantage of this shape of the measuring element compared to a full circle is that the weight of the measuring element can be significantly reduced because less material is used. This leads to an increase in overall performance and efficiency when the wheel unit is used in a bicycle. The lower material usage also reduces costs. A further advantage is that the measuring element in the shape of a circular ring segment can be more easily mounted on the brake disc and hub because it takes up less space and is more flexible to handle. This simplifies installation and maintenance. Another advantage is that the design of the measuring element in the shape of a circular ring segment significantly improves heat dissipation compared to a full circle. When the bicycle brakes, the brake disc of the wheel unit heats up, and the heat is transferred to the measuring element.This leads to deformation of the measuring element. The circular ring segment design reduces the coverage of the brake disc. In addition, the surface area of ​​the measuring element is larger. This allows the heat from the wheel unit caused by braking to be dissipated more effectively, which improves the service life of the measuring element and the brake disc, and thus of the entire wheel unit. Overheating during braking is also better prevented than with a full circle design. In addition, the asymmetrical design of the measuring element in the area of ​​the wide slot and the associated double webs at the ends of the measuring element prevent natural vibrations excited by the brake disc during braking, thus improving acoustics.

[0021] Furthermore, the dimensions of a material-free area can define a calibration distance for tamper detection. The material-free area thus represents a "non-signal section" due to the missing signal sensor(s). The calibration section has a calibration distance length. This ensures that a single rotation of the bicycle wheel can be reliably detected in a simple manner. The size of the material-free area prevents incorrect detection of a window between two signal sensors as the dimension of the material-free area.

[0022] When the wheel unit is used on a bicycle, the sensor element measures the signal paths of the sensor transmitters during wheel rotation, and the calibration distance is also detected by the sensor element. Based on the measured signal paths, the wheel's rotational speed can be determined. During a complete rotation of the bicycle wheel—and thus during a complete rotation of the measuring element—the material-free area passes the sensor element exactly once. This makes it possible to determine an actual full rotation of the wheel. Manipulation of the measurement signal and / or faulty transmission of the measurement signal can thus be counteracted.

[0023] A bicycle has at least one wheel unit, which was already described in the previous description. The bicycle also has the sensor element, which is fixed to a stationary component of the bicycle, so that the signal paths of the signal generators can be scanned using the sensor element. The sensor element and the measuring principle have already been described in the previous description. The wheel unit can be used, for example, for a front wheel or a rear wheel of the bicycle. The stationary component is defined here as a component that does not rotate when the bicycle is moving. For example, the stationary component can be part of the bicycle frame or a suspension fork, or it can be present as a separate mounting device, which is connected, for example, to the frame.The stationary component should be selected in such a way that the sensor element can be mounted in such a way that it can detect the signal generators and the calibration element unhindered during the rotation of the wheel.

[0024] The sensor element generates a sensor signal, which can be picked up at the sensor element. The sensor signal can then be evaluated, for example, using an evaluation device in a bicycle's control unit. The sensor signal is generated when the measuring element rotates with the bicycle wheel and the signal generators rotate past the sensor element, resulting in an interaction between the sensor element, the signal generators, and the calibration element.

[0025] Various embodiments and details of the invention are described in more detail with reference to the figures explained below. They show, by way of example: Fig. 1 a schematic representation of a measuring element according to an embodiment, Fig. 2 a schematic representation of a wheel unit with a measuring element according to the embodiment of Fig. 1, Fig. 3 a schematic representation of a bicycle with a wheel unit according to the embodiment of Fig. 2.

[0026] Fig. 1 shows a schematic representation of a measuring element 2 according to an exemplary embodiment. The measuring element 2 is designed as a circular ring segment. The measuring element 2 has a sensor region 10 and a mounting region 3. The mounting region 3 is directly connected to the sensor region 10. The measuring element 2 is flat. The measuring element 2 has a plurality of bores 11 in the mounting region 3, which serve to connect the measuring element 2 to a brake disc in a snug manner. For example, this connection can be made by screwing. The measuring element 2 also has a plurality of webs 5 on the mounting region 3. These webs 5 are not part of the sensor region 10.

[0027] The measuring element 2 has several signal transmitters 6, 6a, all of which are uniformly designed. The signal transmitters 6, 6a are arranged radially around a geometric center axis M of the measuring element 2 and radially around the mounting area 3. Each signal transmitter 6, 6a has and defines a signal path 7 with a dimension. Each signal path 7 has a signal path length.

[0028] Between two signal sensors 6 located directly next to each other, a material-free window 12 is arranged, with all material-free windows 12 being uniformly shaped. Between the two limit signal sensors 6a is a material-free area 8 having a dimension A. This dimension A defines a calibration section 9, which can be used to detect errors in the detection of the rotation speed or tampering. The dimension A of the material-free area 8 is as large as the combined dimensions of two windows 12 and one signal sensor 6. The measuring element 2 shown has a total of 55 uniform signal sensors 6, 6a, including the two limit signal sensors 6a. The two limit signal sensors 6a delimit the circular arc of the circular ring segment. The positions of the signal sensors 6, 6a are subject to a regular angular division across the circular arc of the measuring element 2.This angular pitch is: 360° / (number of signal heads + number of signal heads missing due to the circular segment shape). The angular pitch is thus α = 360° / 56 = 6.43°. This means that each signal head 6, 6a is offset by 6.43° from the previous signal head 6, 6a, except for the two signal heads 6a between which the material-free area 8 is located.

[0029] Fig. 2 shows a schematic representation of a wheel unit 20 with a measuring element 2 according to the embodiment of Fig. 1. The wheel unit 20 and its individual components are shown in a highly simplified manner for clarity. The wheel unit 20 comprises a brake disc 21, a hub 22, and the measuring element 2 with the mounting area 3 and the signal area 10. The material-free area 8 is clearly visible.

[0030] The circular ring-segment-shaped measuring element 2 is mounted on the brake disc 21 by means of the mounting area 3, with the measuring element 2 resting directly on the brake disc 21. The brake disc 21 and the measuring element 2 are arranged together on the hub 22 and mounted thereon.

[0031] Fig. 3 shows a schematic representation of a bicycle with a wheel unit according to the embodiment of Fig.2. The wheel unit 20 is arranged on the rear wheel 25 of the bicycle 1, which is designed, for example, as an e-bike. The bicycle 1 has a sensor element 4, which is arranged on a stationary component 13 of the bicycle 1, so that the sensor element 4 does not rotate with the wheel 25. The sensor element 4 can be designed, for example, as a Hall sensor, and the signal generators of the measuring element 2 of the wheel unit 20 can be made of a magnetic material. The brake disc 21 is made of a metallic material. The other components of the disc brake, such as the brake pads and the brake caliper, are not shown.

[0032] When the bicycle 1 is moving and the wheels 25 are rotating, both the brake disc 21 and the measuring element 2 rotate with the wheel 25. The sensor element 4 detects the signal transmitters 6, 6a of the measuring element 2. The sensor element 4 taps the signal paths 7. From this, the rotational speed of the wheel 25 can be determined. If the material-free area 8 between the two limit signal transmitters 6a is detected due to the absence of a signal transmitter 6, a full rotation of the wheel 25 can be detected by sensors. Based on this, the sensor element 4 generates a sensor signal, which can be forwarded, for example, to a control unit of the bicycle 1.

[0033] The examples shown here are for illustrative purposes only. The angular pitch, the number of signal transmitters, the signal path lengths of the signal transmitters, and the dimensions of the material-free area can be adjusted as needed and to achieve the desired resolution. Reference symbol 1 bicycle 2 measuring element 3 Assembly area 4 Sensor element 5 bridge 6 signal generators 6a Limit signal transmitter 7 Signal path 8 material-free area 9 Calibration track 10 Signal range 11 Hole 12 windows 13 standing component 20 wheel unit 21 brake disc 22 Hub 25 wheels A Dimension M central axis 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 2022 202 716 A1

[0003] EP 3 176 064 B1

[0004] EP 3 590 812 A1

[0005] EP 2 557 004 A2

[0006]

Claims

[1] Wheel unit (20) for a bicycle (1), wherein the wheel unit (20) comprises a hub (22), a brake disc (21) and a measuring element (2), - wherein the measuring element (2) is arranged to determine a rotational speed of the wheel (25) of the bicycle (1), - wherein the measuring element (2) and the brake disc (21) are arranged on the hub (22), - wherein the measuring element (2) is arranged directly adjacent to the brake disc (21), - wherein the measuring element (2) has a mounting area (3) and a plurality of spaced-apart uniform signal transmitters (6, 6a), - wherein the mounting area (3) is connected to the signal transmitters (6, 6a), - wherein each signal generator (6, 6a) defines a signal path (7) with a signal path length, - wherein the signal transmitters (6, 6a) are arranged radially around the mounting area (3) and radially around a central axis (M) of the measuring element (2), - wherein uniform material-free windows (12) are arranged between the signal transmitters (6, 6a), characterized by that the measuring element (2) is designed as a circular ring segment, - wherein a circular arc of the circular ring segment is delimited by two limit signal transmitters (6a) which are designed uniformly to the other signal transmitters (6), - wherein a dimension (A) of a material-free area (8) between the two limit signal transmitters (6a) is larger than the sum of the dimensions of two material-free windows (12). [2] Wheel unit (20) according to claim 1, characterized by that the dimension (A) is as large as the sum of the dimensions of two material-free windows (12) and a signal path (7). [3] Wheel unit (20) according to one of the preceding claims, characterized by that the dimension (A) of the material-free area (8) defines a calibration section (9) for manipulation detection. [4] Bicycle (1) characterized byat least one wheel unit (20) according to one of the preceding claims, wherein the bicycle (1) has a sensor element (4) which is fixed to a stationary component (13) of the bicycle (1), so that the signal paths (7) of the signal transmitters (6, 6a) can be scanned by means of the sensor element (4).

Images