Hub drive unit and bicycle

Abstract

The utility model relates to a kind of hub drive units (1) for electric bicycle (100), the electric bicycle is especially electrically assisted bicycle, super electrically assisted bicycle or electric bicycle, the hub drive unit has housing unit (10), with torque weight ratio coefficient, wherein, the torque weight ratio coefficient is in the range of 14.9 to 25, preferably in the range of 16.0 to 21.0, particularly preferably 18.0, wherein, the outer diameter (20) of the housing unit is in the range of 102mm to 115mm, preferably in the range of 105mm to 113mm, particularly preferably 110mm.

Description

Technical Field

[0001] This utility model relates to a hub drive unit and a bicycle having a hub drive unit. Background Technology

[0002] Hub drive units enable electric motor assistance on bicycles, making it easier to ride on steep slopes and long distances. Because the hub drive unit is mounted in the wheel hub, this increases the wheel's weight and, in addition to its bulky appearance, can potentially affect the bicycle's handling. Nevertheless, hub drive units are popular in e-bikes because they offer the possibility of propelling the bicycle efficiently and in a space-saving manner. Common models typically involve a trade-off between weight and appearance. Utility Model Content

[0003] The objective of this invention is to further improve upon existing hub drive units, thereby providing an optimized hub drive unit with high driving performance.

[0004] This utility model proposes a hub drive unit for an electric bicycle, particularly an electric-assisted bicycle (Pedelec), a high-speed electric-assisted bicycle (S-Pedelec), or an e-bike. The hub drive unit has a housing unit and a torque-to-weight ratio coefficient, wherein the torque-to-weight ratio coefficient is in the range of 14.9 to 25, preferably in the range of 16.0 to 21.0, and particularly preferably 18.0, and wherein the outer diameter of the housing unit is in the range of 102 mm to 115 mm, preferably in the range of 105 mm to 113 mm, and particularly preferably 110 mm.

[0005] In contrast, the hub drive unit according to this invention has the following advantages: the hub drive unit has a housing unit with a specific outer diameter and a torque-to-weight ratio coefficient (hereinafter referred to as the "coefficient"). This outer diameter is in the range of 102 mm to 115 mm, preferably in the range of 105 mm to 113 mm, and particularly preferably 110 mm. This provides a particularly compact hub drive unit.

[0006] The housing unit of the hub drive unit includes components that constitute the electric drive mechanism of an electric bicycle. Specifically, an electric motor is arranged inside the housing unit. In addition to the rider's muscle force, this electric motor generates an auxiliary driving force to propel the vehicle. This electric motor can be implemented as an internal rotor motor or an external rotor motor. Furthermore, a transmission device is arranged within the housing unit. This transmission device is used to adapt the speed of the electric motor to the rotation of the wheel, especially to achieve efficient driving. This transmission device is preferably implemented as a planetary gear transmission. Additionally, the housing unit may contain sensors. For example, a temperature sensor for monitoring the temperature of the electric motor can be arranged inside the housing unit. In particular, at least one wire can pass through the housing unit, wherein this at least one wire can, for example, conduct current and signals. This passage can particularly occur at the axial center of the hub drive unit, and preferably the at least one wire can pass through the housing unit eccentrically, for example, near the edge region of the shaft or axle of the hub drive unit.

[0007] The housing unit has a base that is at least partially cylindrical or has at least one cylindrical segment. The housing unit comprises multiple housing components connected to each other, for example, by bolts. In particular, the housing unit has means for supporting the spokes, which are preferably arranged on the cylindrical segment, and more preferably on its circumferential surface. These means are spaced apart axially, respectively arranged in the edge region along the central axis of the first housing component, which defines the axial extension direction of the hub drive unit. This central axis defines a rotational reference for the hub drive unit. Preferably, the means for supporting the spokes are arranged on the axial ends of the circumferential surface.

[0008] The housing unit is preferably configured such that its radial extension dimension is small, and more preferably larger than its axial extension dimension. The outer diameter and the aforementioned radial extension dimension of the housing unit are determined in a region with a constant diameter, particularly between the devices for supporting the spokes. The outer diameter is preferably determined in a cylindrical section of the housing unit, and is particularly selected such that it does not include devices for supporting the spokes. In particular, the outer diameter of the housing unit is the diameter formed by the housing of the motor and / or transmission device.

[0009] In a preferred embodiment of the hub drive unit, the outer diameter is in the range of 102 mm to 115 mm, preferably in the range of 105 mm to 113 mm, and particularly preferably 110 mm. This results in an advantageous overall appearance for the electric bicycle.

[0010] To characterize a hub drive unit, the torque-to-weight ratio (Drehmoment-zu-Gewicht-Faktor) can be used. This ratio is derived by dividing the output torque of the hub drive unit by its weight. In other words, the torque-to-weight ratio of a hub drive unit is an important parameter indicating how much torque the hub drive unit can generate relative to its weight. A high torque-to-weight ratio means that the drive unit has high power relative to its weight, which is crucial for the efficiency and performance of an electric bicycle.

[0011] The weight of the hub drive unit is composed of multiple components. Here, the total weight specifically includes the individual weights of the electric motor, the flywheel system of the Kassette, the end caps, and the motor-side cables. This weight does not include, in particular, fixed components such as shafts, especially the plug shafts.

[0012] In other words, the hub drive unit should be understood as a mechanical unit that, once manufactured, can be delivered to the wheel manufacturer for integration into the wheel. Specifically, in the context of weight, the hub drive unit as a mechanical unit should also be understood as other components required for its operation, such as control units. However, these other components are not included in the weight calculation and are not further factored into the torque-to-weight ratio coefficient.

[0013] The outer diameter of the hub drive unit can affect the torque-to-weight ratio coefficient, and an increase in the outer diameter can negatively impact this coefficient. As the outer diameter increases, more powerful motors and transmission components can be used, which negatively affects weight, coefficient, and appearance. The desired output torque of the hub drive unit can be achieved, in particular, by adjusting the diameter and / or axial length of the motor, especially the number of windings.

[0014] Preferably, the maximum torque of the hub drive unit is 45 Nm. The torque generated by the electric motor is enhanced by the mechanical transmission ratio of the transmission device. In particular, this maximum torque is determined at a certain operating point of the electric motor. In particular, the maximum torque is determined by the design of the electric motor. In particular, the maximum torque is reached at very low speeds or immediately after coming to a stop. This torque is particularly proportional to the electric motor current flowing through the windings. Therefore, at low speeds, the current can be maximized.

[0015] This torque acts specifically on the shaft of the drive unit. The sprocket fixed to the shaft transmits the torque, especially by means of connecting elements, such as a chain or belt drive.

[0016] Preferably, the weight of the hub drive unit is equal to or less than 2.5 kg.

[0017] Preferably, the hub drive unit has a shaft for supporting the hub drive unit on the frame of the electric bicycle, wherein the shaft is implemented as a 12mm-steckachse. In particular, the shaft has threads of M12 x 1mm, M12 x 1.25mm, M12 x 1.5mm, or M12 x 1.75mm. The portion of the shaft passing through the hub drive unit is configured to be fixed to and / or particularly supported on the frame. Specifically, the shaft supports the hub drive unit, wherein the hub drive unit rotates at least partially about the shaft. The shaft is particularly designed to ensure a strong and reliable connection between the hub drive unit and the frame. For example, the shaft is fixed to the frame by passing the shaft along its central axis through or into the hub drive unit, particularly a hollow shaft in the hub drive unit, and a recess provided for this purpose in the frame of the electric bicycle. The detachable connection between the axle and the frame component can be established using suitable fastening elements, such as nuts or quick-clamping devices. In a preferred embodiment using a 12mm plug-in axle, the plug-in axle is directly or indirectly threaded to the frame component. Plug-in axles are well known to those skilled in the art, for example, for mounting wheels to bicycle frames or for mounting hub drives to bicycle frames.

[0018] Preferably, the maximum length of the shaft member does not exceed 148 mm. This maximum length is specifically defined as the length determined from the outer end where the M12 thread originates to the contact surface of the bolt head of the plug shaft 2 in the axial extension direction along the central axis, wherein the contact surface of the bolt head is supported on the vehicle frame member.

[0019] Preferably, the hub drive unit has a shaft that at least partially supports the housing unit, wherein the housing unit and the shaft are arranged such that the housing unit and the shaft have a first distance between 13 mm and 17 mm, preferably between 14 mm and 16 mm, and particularly preferably 15.25 mm. This first distance is specifically the distance obtained from a first end face of the hub drive unit to the end face of the shaft in the axial extension direction of the hub drive unit. The end faces of the hub drive unit and the shaft are particularly and substantially parallel. The end faces of the hub drive unit and the shaft are particularly and substantially perpendicular to the central axis. In other words, the shaft can extend beyond the housing unit, wherein this extension defines the first distance.

[0020] Preferably, the housing unit is configured to meet the IP67 protection rating. IP67 protection rating is an international classification of protection ratings that specifically indicates the level of protection against dust and water ingress into electrical equipment. The definition of IP67 protection rating is specified in standard IEC 60529, which defines international standards for protection against foreign matter and water ingress into electrical equipment.

[0021] Preferably, the hub drive unit is implemented without sensors. More preferably, "sensorless" means an implementation without rotor position sensors. In the case of a hub drive unit without rotor position sensors, this specifically means that the electric motor does not have a dedicated device or sensor to determine the precise position of the rotor. Here, "dedicated" specifically refers to the specific application of the sensing device used to determine the rotor position. In particular, this allows for the realization of a particularly compact hub drive unit with fewer components.

[0022] This utility model also relates to an electric bicycle having a hub drive unit according to the foregoing embodiments. Attached Figure Description

[0023] Figure 1 The illustration shows a bicycle, particularly a bicycle powered by muscle force and electric motor force, which has a hub drive unit. Figure 2 One embodiment of the hub drive unit is shown in a side view, and Figure 3 An embodiment of the hub drive unit is shown in an isometric view.

[0024] The same elements or elements with the same function are given the same reference numerals in the drawings. Detailed Implementation

[0025] Figure 1A simplified schematic diagram of an electric bicycle 100 is shown, which has a drive unit 1. The electric bicycle 100 has a front wheel 115 and a rear wheel 116, which correspondingly have a front hub 130 and a rear hub 140. The rear wheel 116 is driven by means of a connecting element 101, in particular a chain, through the rider's pedaling force on the pedal 108 and by means of the hub drive unit 1. For this purpose, the pedal 108 is connected to a crank 119, which is in turn connected to different ends of a pedal axle 103. The hub drive unit 2 is arranged on the rear hub 12 and configured to assist the rider's torque. The torque introduced to the crank 119 is transmitted to the connecting element 101 by means of a sprocket 107, which directly engages with the rear wheel 116 to drive the electric bicycle 100. The frame components 102 of the electric bicycle 100 specifically include a seatpost 106, seat brace 104, downtube 111, toptube 110, steering tube 112, and chain brace 105, which are inseparably connected to each other, for example, by welding. Furthermore, the electric bicycle 100 has a steering unit 120. An input device 10 is schematically shown, which, like the user display 122 and braking device 121, is fixed to the steering unit 120. The hub drive unit 1 is connected to and powered by a battery module 109 via a cable (shown in the diagram). Additionally, Figure 1 The gear shifting device 102 is schematically shown. The electric bicycle control unit 124, which is shown, is fixed to the chain brace and is connected to the hub drive unit 2 via at least one wire 14.

[0026] exist Figure 2 The image shows a preferred embodiment of a hub drive unit 1 in a side view. The housing unit 10 of the hub drive unit 1 includes components that constitute the electric drive mechanism of the electric bicycle 100. Specifically, an electric motor (not shown) is arranged inside the housing unit 10. This electric motor is arranged in a first housing member 15, particularly on the side of the housing member 15 opposite to the housing wall 16. In addition to the rider's muscle force, the electric motor generates an auxiliary driving force to propel the electric bicycle 100. The electric motor can be implemented as an internal rotor motor or an external rotor motor, wherein an internal rotor motor is used in a preferred embodiment. The housing unit 10 has a substantially cylindrical base, wherein at least one segment 23 of the cylindrical base extends cylindrically along a circumferential surface 11. Devices 13 for supporting spokes (not shown) are mounted on the first housing member 15, particularly on the circumferential surface 11. These devices 13 are arranged axially spaced apart, respectively arranged in the edge regions of the first housing member 15 along the central axis 30. The axial extension dimension of the housing member 15 is preferably smaller than the radial extension dimension of the housing member 15. The outer diameter 20 of the housing unit 10, and especially the outer diameter of the housing component 15, is determined within a region with a constant diameter of 110 mm, preferably section 23, such that the device 13 for supporting the spokes is not included.

[0027] Figure 2 The diagram illustrates a first pitch 22, defined along the axial extension direction of the central axis 30, from the first end face 32 of the hub drive unit 1 to the end face 31 of the shaft 3. In a preferred embodiment, the first pitch 22 is 15.25 mm, but it can also be defined as being in the range of 13 mm to 17 mm, preferably 14 mm to 16 mm. The end face 32 of the hub drive unit 1 and the end face 31 of the shaft 3 are arranged substantially parallel to each other and, in particular, perpendicular to the central axis 30. The shortened pitch 22 can result in a larger housing component 15. The axially extended housing component 15 is suitable for accommodating a more powerful electric motor, and thus provides a more powerful hub drive unit 1.

[0028] To characterize the hub drive unit 1, a torque-to-weight ratio coefficient can be used. This coefficient is specifically derived by dividing the output torque of the hub drive unit by the weight of the hub drive unit 1. The preferred embodiment shown has a diameter of 110 mm, a weight of 2.5 kg, and a maximum torque of 45 Nm. This results in a torque-to-weight ratio coefficient of (45 / 2.5) = 18, which provides a compact and performance-optimized hub drive unit 1 with an outer diameter of 110 mm.

[0029] Figure 3 An embodiment of the hub drive unit 1 is shown in an isometric diagram. Wires 14 extend from an electric motor (not shown), and these wires 14 are connected at least to the control unit 124. The wires 14 extend from the hub drive unit 1, particularly from the housing unit 10. The shaft 3 has a groove into which the wires 14 are embedded. The electric motor preferably has a stator anti-torsionally connected to the housing unit 10 and a rotor rotatably supported on the shaft 3. The stator and rotor constitute the electric motor. The hub drive unit 1 also has a transmission mechanism consisting of a planetary gear transmission to transmit the rotational motion of the rotor to the rear wheel 116 at varying speeds, and especially at reduced speeds.

[0030] The hub drive unit 1 also includes a shaft 2 for fixing to the frame member 102 of the electric bicycle 100, wherein the shaft is implemented as a 12mm plug-in shaft. Specifically, the plug-in shaft has an M12 thread, which can be implemented as M12 x 1mm, M12 x 1.25mm, M12 x 1.5mm, or M12 x 1.75mm. The shaft 2, which passes completely through the hub drive unit 1, is configured such that the shaft is fixed to the frame member 102 by means of its M12 thread. The shaft 2 supports the hub drive unit 1, which rotates at least partially about the shaft 2. The shaft 2 is designed to ensure a secure and reliable connection between the hub drive unit 2 and the frame member 102. In another embodiment, the shaft may also be equipped with a quick-clamping mechanism. Preferably, the maximum length of the shaft 2 is 148 mm, wherein the maximum length is defined as the length determined in the axial extension direction of the plug shaft 2 from the outer end where the M12 thread starts to the contact surface of the bolt head of the plug shaft 2.

[0031] Especially Figure 3 As can be seen, the end face 32 of the hub drive unit 1 has a fixing device 35, which is particularly suitable for accommodating at least a portion of the braking device 121 of the electric bicycle 100. In particular, the fixing device 35 has a threaded portion, which is suitable for accommodating a bolt (not shown) by means of which the brake disc can be fixed.

[0032] The hub drive unit 1 of the electric bicycle is implemented according to IP67, which means that it has a high protection level against dust and water intrusion. The IP67 classification of the hub drive unit 1 ensures that it operates reliably in harsh environments, such as heavy rain or muddy conditions, without allowing moisture or dirt to enter the housing unit 10 and adversely affect its performance or lifespan.

Claims

1. A hub drive unit (1) for an electric bicycle (100), characterized in that, The hub drive unit has a housing unit (10) and a torque-to-weight ratio coefficient, wherein the torque-to-weight ratio coefficient is in the range of 14.9 to 25, and wherein the outer diameter (20) of the housing unit is in the range of 102 mm to 115 mm.

2. The hub drive unit (1) according to claim 1, characterized in that, The maximum torque of the hub drive unit (1) is 45 Nm.

3. The hub drive unit (1) according to claim 1 or 2, characterized in that, The weight of the hub drive unit is equal to or less than 2.5 kg.

4. The hub drive unit (1) according to claim 1 or 2, characterized in that, The hub drive unit also has a shaft (2) for supporting the hub drive unit (1) on the frame member (102) of the electric bicycle (100), wherein the shaft (2) is implemented as a 12mm plug shaft.

5. The hub drive unit (1) according to claim 4, characterized in that, The maximum length of the shaft (2) shall not exceed 148 mm.

6. The hub drive unit (1) according to claim 1 or 2, characterized in that, The hub drive unit also has a shaft (3) configured to support the housing unit (10), wherein the housing unit (10) and the shaft (3) are arranged such that the housing unit and the shaft have a first distance between 13 mm and 17 mm.

7. The hub drive unit (1) according to claim 1 or 2, characterized in that, The housing unit (10) is configured to meet the IP67 protection rating.

8. The hub drive unit (1) according to claim 1 or 2, characterized in that, The hub drive unit (1) is implemented in a sensorless manner.

9. The hub drive unit (1) according to claim 8, characterized in that, The sensorless implementation is configured to not have a rotor position sensor assembly.

10. The hub drive unit (1) according to claim 1, characterized in that, The electric bicycles mentioned are electric-assisted bicycles, high-speed electric-assisted bicycles, or electric bicycles.

11. The hub drive unit (1) according to claim 1, characterized in that, The torque-to-weight ratio coefficient is in the range of 16.0 to 21.

0.

12. The hub drive unit (1) according to claim 1, characterized in that, The torque-to-weight ratio coefficient is 18.

0.

13. The hub drive unit (1) according to claim 1, characterized in that, The outer diameter (20) of the housing unit is in the range of 105 mm to 113 mm.

14. The hub drive unit (1) according to claim 1, characterized in that, The outer diameter (20) of the housing unit is 110 mm.

15. The hub drive unit (1) according to claim 6, characterized in that, The first spacing is between 14mm and 16mm.

16. The hub drive unit (1) according to claim 6, characterized in that, The first spacing is 15.25 mm.

17. A bicycle (100), characterized in that, The bicycle has a hub drive unit (1) according to any one of claims 1 to 16.

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