A continuously variable speed device for a hub motor

Abstract

The present application belongs to the technical field of electric bicycles, and specifically relates to a continuously variable transmission device for a hub motor, comprising a main shaft, a motor assembly, a hub, a planetary gear assembly, and a flywheel; the hub, the planetary gear assembly, and the flywheel are sequentially sleeved on the main shaft, the planetary gear assembly including at least a first planetary gear and a second planetary gear connected to each other along its axial direction, the first planetary gear and the second planetary gear each including an outer ring gear, a sun gear, planetary gears, and a planetary carrier; one end of the sun gear of the first planetary gear extends into the interior of the hub and is connected to the motor assembly; the planetary carrier of the first planetary gear passes through its planetary gears, one end of the planetary carrier of the first planetary gear is connected to the hub, and the other end is connected to the sun gear of the second planetary gear; one end of the planetary carrier of the second planetary gear is connected to its planetary gears, and the other end is connected to the flywheel. The present application couples the power of the flywheel and the motor to the wheel through the hub, realizing power assistance and continuously variable transmission functions, and can achieve a large speed ratio and high speed and low torque of the motor assembly, which is conducive to lightweighting of the mechanism.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric bicycles, and in particular relates to a continuously variable speed device of a hub motor. Background Art

[0002] The motor of a typical power-assisted bicycle is mounted on the center axle or rear wheel hub, with a manually adjustable transmission mounted on the flywheel of the rear wheel hub. A motor mounted on the center axle, located at the front of the transmission, has a long transmission path and low efficiency, but the motor speed ratio is adjustable. A motor mounted on the wheel hub, located at the rear of the transmission, has a short transmission path and high efficiency, but the motor speed ratio is not adjustable. The transmission has multiple gears mounted on the flywheel, and the gears are shifted by moving the chain with a shift fork. The transmission is exposed to the air, and the gear oil is cross-contaminated by the environment. Dust and sand on the gears affect transmission efficiency.

[0003] Patent CN201410145608.3 discloses an electric bicycle hub motor device, the technical solution of which is to integrate the transmission and motor into the wheel hub at the same time, and use a planetary mechanism (WW type) to couple the power of the motor and flywheel to the wheel, thus achieving power assistance and stepless speed change functions. Figure 1 The electric bicycle hub motor assembly includes a stator A1, a rotor A2, a wheel hub A3, planetary gears A4 and A5, a planetary carrier A6, a flywheel A7, a sun gear A8 and A9, and a main shaft A10. The stator A1, rotor A2, planetary gears A4 and A5, planetary carrier A6, sun gears A8 and A9, and main shaft A10 are mounted within the wheel hub A3. The flywheel A7 is mounted outside the wheel hub A3, and the wheel hub A3 is rotatably connected to the main shaft A10.

[0004] Planetary gear 1 A4 and planetary gear 2 A5 are integrated and coaxially mounted on planetary carrier A6. Planetary carrier A6 is connected to hub A3 and outputs power. Stator A1 is fixed to main shaft A10. Sun gear 1 A8 is connected to rotor A2 and meshes with planetary gear 1 A4. Sun gear 2 A9 is connected to flywheel 1 A7 and meshes with planetary gear 2 A5. The transmission relationship of this planetary mechanism is determined by the following formula:

[0005]

[0006]

[0007] Among them, n s1 、 n s2 are the rotational speeds of sun gear 1 A8, planet carrier A6, and sun gear 2 A9, respectively, and are also the rotational speeds of rotor A2, hub A3, and flywheel 1 A7; k0 is the speed ratio of the planetary gear assembly consisting of planet gear 1 A4, planet gear 2 A5, and planet carrier A6; These are the number of teeth of sun gear 1 A8, sun gear 2 A9, planet gear 1 A4 and planet gear 2 A5 respectively.

[0008] This technical solution has the following problems: 1. The sun gear A8 and the sun gear A9 rotate in the same direction relative to the planet carrier A6. According to mechanical principles, the WW type planetary mechanism of this technical solution is a positive mechanism. The transmission efficiency of the whole vehicle is low, and the load of each component increases, resulting in increased friction and wear during operation, affecting the life of the components and increasing maintenance costs. 2. Due to the structural constraints between the planetary gear groups, generally According to formula (1) and formula (2), k0≤5, and when n s2 =0, That is, the maximum speed ratio from the motor to the wheel is equal to 5. Since the maximum speed ratio is small, the motor speed is low and the torque is large. According to the formula, the total torque of the motor is Where: L is the length of the motor rotor; D is the diameter of the motor rotor; A is the current flowing through the unit width; B is the radial magnetic flux density; It can be seen that D 2 L is proportional to the volume of the motor rotor. The torque is determined by the rotor volume and load (the load is related to A and B). The total volume of the motor is determined by the torque. Therefore, as the motor torque increases, the motor volume also increases. This results in a bulky overall structure of the electric bicycle hub motor and increases the drive load of the motor. Therefore, a speed change device for power-assisted bicycles that can address existing problems is needed.

[0009] The existing technology also has the following problems: the central axis motor can only output power in one direction. If the central axis motor is driven to rotate by the wheel, the pedals will be separated from the feet, which violates the riding habits of bicycles and causes safety problems. Ordinary hub motors can realize coasting feedback power generation, but they cannot change speed, and the vehicle performance is poor. The transmission configured in the central axis motor and ordinary hub motor system is exposed to the air, and the gear oil is cross-contaminated with the environment. The gears are contaminated with dust and mud, which affects the transmission efficiency. When the transmission in the hub motor of the prior art is coasting feedback power generation, the foot needs to apply force to keep the flywheel speed at zero, which violates the riding habits of bicycles and is likely to cause safety problems. Summary of the Invention

[0010] In response to the defects of the existing technology, the present invention proposes a continuously variable transmission device for a hub motor. The planetary gear assembly used couples the power of the flywheel (the flywheel is the input end) and the motor, and outputs it to the wheel through the hub (the hub is the output end). The speed of the wheel is determined by the flywheel speed and the motor speed. It can simultaneously realize power assistance and continuously variable transmission functions, can achieve a large speed ratio, high speed and small torque of the motor assembly, and is conducive to lightweighting of the mechanism.

[0011] In order to achieve the technical purpose of the present invention, the present invention will adopt the following technical solutions:

[0012] A continuously variable transmission device for a hub motor includes a main shaft, a motor assembly, a wheel hub, a planetary gear assembly, a flywheel, a first one-way clutch, and a second one-way clutch; the wheel hub, the planetary gear assembly, and the flywheel are sequentially sleeved on the main shaft, and the motor assembly is sleeved on the main shaft and located inside the wheel hub;

[0013] The planetary gear assembly includes at least a first planetary gear and a second planetary gear connected to each other along its axial direction. The first planetary gear and the second planetary gear each include an outer ring gear, a sun gear located at the center of the outer ring gear, a plurality of planetary gears located between the outer ring gear and the sun gear, and a planetary carrier. One end of the sun gear of the first planetary gear extends into the interior of the wheel hub and is connected to the motor assembly. The planetary carrier of the first planetary gear passes through the planetary gears inside the first planetary gear, one end of the planetary carrier of the first planetary gear is connected to the wheel hub, and the other end is connected to the sun gear of the second planetary gear. One end of the planetary carrier of the second planetary gear is connected to the planetary gears inside the second planetary gear, and the other end is connected to the flywheel. The outer ring gear of the first planetary gear is fixedly connected to the outer ring gear of the second planetary gear.

[0014] One-way clutch 1 is connected to the sun gear of the second planetary gear and the planet carrier of the second planetary gear respectively, and one-way clutch 2 is connected to the flywheel and the main shaft respectively;

[0015] One-way clutch 1 is used for the starting condition of the hub motor continuously variable transmission device. Under the starting condition, one-way clutch 2 is not installed or is in a disengaged state. One-way clutch 2 is used for the coasting feedback power generation condition of the hub motor continuously variable transmission device. Under the coasting feedback power generation condition, one-way clutch 1 is not installed or is in a disengaged state.

[0016] Furthermore, the power assist ratio λ of the hub motor continuously variable transmission device is determined by the following formula:

[0017]

[0018] Where: λ represents the power ratio; P MG Indicates the input power of the motor component; P FW Indicates the input power of the flywheel; T MG Indicates the torque of the motor assembly; T FW Indicates the torque of the flywheel; n MG Indicates the speed of the motor assembly; n FW represents the speed of the flywheel; k represents the total speed ratio of the planetary gear assembly.

[0019] Furthermore, the total speed ratio k of the planetary gear assembly is determined by the following formula:

[0020] k=k1+k1 / k2

[0021] Where: k1 represents the speed ratio of the first planetary gear set; k2 represents the speed ratio of the second planetary gear set.

[0022] Furthermore, the rotational speed relationship between the motor assembly, the wheel hub, and the flywheel of the in-wheel motor continuously variable transmission device is determined by the following formula:

[0023] n MG +k*n FW =(1+k)n W

[0024] Where: n MG Indicates the speed of the motor assembly; n FW Indicates the speed of the flywheel; n W Indicates the rotational speed of the wheel hub.

[0025] Furthermore, the torque relationship between the motor assembly, the wheel hub, and the flywheel of the in-wheel motor continuously variable transmission device is determined by the following formula:

[0026] T MG :T FW :T W =1:k:(k+1)

[0027] Where: T MG Indicates the torque of the motor assembly; T FW Indicates the torque of the flywheel; T W Indicates the torque of the wheel hub.

[0028] Furthermore, the first planetary gear and the second planetary gear constitute a power split device, and the power flow of the power split device of the hub motor continuously variable transmission device is determined by the following formula:

[0029] P W =P MG +P FW

[0030] Where: P W Indicates the output power of the hub; P MG Indicates the input power of the motor component; P FW Represents the input power to the flywheel.

[0031] Furthermore, the motor assembly includes a motor rotor and a motor stator; the motor stator is sleeved and fixed on the main shaft, and the motor rotor is connected to the sun gear of the first planetary gear.

[0032] Furthermore, the center holes of the planetary wheels of the first planetary row are provided with bearings, and the planetary carrier of the first planetary row has a plurality of planetary wheel columns, which are cylindrical rods, and the plurality of planetary wheel columns respectively pass through the center holes of the planetary wheels of the first planetary row;

[0033] The planetary gears and the planetary carrier of the second planetary gear set have the same connection structure as the planetary gears and the planetary carrier of the first planetary gear set.

[0034] Furthermore, it also includes a brake; the brake is connected to the outer gear ring of the first planetary gear and the outer gear ring of the second planetary gear;

[0035] The brake is used for high-speed pure human riding conditions of the hub motor continuously variable transmission device. Under high-speed pure human riding conditions, the one-way clutch 1 and the one-way clutch 2 are not installed or are in a disengaged state.

[0036] Furthermore, the one-way clutch 1 and the one-way clutch 2 are overrunning clutches.

[0037] The beneficial effects of the present invention are:

[0038] First, the planetary mechanism of the present invention achieves a higher speed ratio than a single planetary gear by introducing a second planetary gear and connecting it to the first planetary gear in a special way, and there is no power ring between the planetary gears; the planetary mechanism achieves a dual benefit of a high speed ratio from the motor to the wheel and a high speed ratio from the flywheel to the wheel through a special connection with the motor, flywheel, and wheel hub; according to the formula n MG +k*n FW =(1+k)n W The principle of the hub motor continuously variable transmission device of this embodiment is determined by the motor speed and the flywheel speed, which can achieve continuous stepless adjustment; according to the formula According to the principle, for a planetary mechanism with a speed ratio of k, its λ matches the speed ratio of the motor assembly and the flywheel, which can adjust the power assist ratio λ under different road conditions and accelerations;

[0039] Second, in a preferred embodiment, the dual planetary gear mechanism of the present invention increases the motor speed and reduces the motor torque, thereby reducing the motor size and facilitating a lightweight structure. The dual planetary gears of the present invention are both NGW-type planetary gears, which are negative-sign mechanisms. There are no power rings between the planetary gears, resulting in high transmission efficiency. This effectively solves the problems of large motor size, bulky mechanism, and low transmission efficiency in the prior art.

[0040] Third, in a preferred embodiment, the present invention has a coasting feedback power generation function. A one-way clutch is added between the flywheel and the main shaft. In the coasting condition, the motor applies negative torque, and the flywheel is reversely locked by the main shaft. The motor feedback power generation does not affect riding habits.

[0041] Fourth, in a preferred embodiment, the present invention has a two-speed pure human-powered function, with a low-speed gear ratio of 1 and a high-speed gear ratio of k2+1. A one-way clutch 1 is provided between the second planetary carrier and the second sun gear. When the flywheel speed exceeds the hub speed, the one-way clutch 1 engages, providing a low-speed pure human-powered riding without motor assistance.

[0042] Fifth, in a preferred embodiment, the present invention provides a brake on the ring gear of the dual planetary gear set to increase the high gear for pure human-powered riding. When the speed limit of the motor-assisted vehicle is reached, the brake is engaged, the motor idles, and the bicycle can continue to ride by inputting power through the flywheel.

[0043] Sixth, in a preferred implementation, the two-speed manual function of the present invention can also provide a limp home function for the system. When the power-assist system fails, the system can be ridden manually to avoid stalling.

[0044] Seventh, the planetary gear mechanism of the present invention is enclosed in a housing and mounted on the main shaft, which can eliminate chain drive and adopt belt drive or enclosed shaft drive, thereby avoiding cross contamination between the transmission system and the environment and improving transmission efficiency during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a structural diagram of a hub motor continuously variable transmission device in the prior art;

[0046] Figure 2 A schematic structural diagram of a hub motor continuously variable transmission device according to embodiment 1 of the present invention;

[0047] Figure 3 This is a power-assisted operating condition vector diagram of the in-wheel motor continuously variable transmission device according to embodiment 1 of the present invention;

[0048] Figure 4 2 is a schematic structural diagram of a hub motor continuously variable transmission device according to embodiment 2 of the invention;

[0049] Figure 5 This is a vector diagram of the starting operating condition of the in-wheel motor continuously variable transmission device according to embodiment 2 of the present invention;

[0050] Figure 6 This is a coasting feedback operating condition vector diagram of the in-wheel motor continuously variable transmission device according to embodiment 2 of the present invention;

[0051] Figure 7 This is a vector diagram of a high-speed, unassisted operating condition of the in-wheel motor continuously variable transmission device according to embodiment 2 of the present invention.

[0052] Among them, A1-stator; A2-rotor; A3-hub; A4-planet gear one; A5-planet gear two; A6-planet carrier; A7-flywheel one; A8-sun gear one; A9-sun gear two; A10-main shaft one; 1-main shaft; 2-motor assembly; 20-motor rotor; 21-motor stator; 3-hub; 4-first planetary row; 40-first ring gear; 41-first planetary gear; 42-first sun gear; 43-first planetary carrier; 5-second planetary row; 50-second ring gear; 51-second planetary gear; 52-second planetary carrier; 53-second sun gear; 6-flywheel; 7-one-way clutch one; 8-one-way clutch two; 9-brake. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the technical solution of the present application, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0054] The terms "up", "down", "left", "right", "front", and "back" in this application are based on the positional relationships shown in the accompanying drawings. The corresponding positional relationships may vary depending on the drawings, and should not be construed as limiting the scope of protection.

[0055] In this application, the terms "installed," "connected," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, integral connection, mechanical connection, electrical connection, or mutual communication. They can also be directly connected or indirectly connected through an intermediate medium. They can also refer to internal communication between two components or interaction between two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0056] Example 1:

[0057] See the instructions attached Figure 2 A continuously variable transmission device for a hub motor includes a main shaft 1, a motor assembly 2, a hub 3, a planetary gear assembly, and a flywheel 6. The main shaft 1 passes through the hub 3 and is rotationally connected to the hub 3. The motor assembly 2 is mounted inside the hub 3. The interior of the planetary gear assembly is provided with multiple rows of planetary gear mechanisms meshing along their axial direction. The planetary mechanism has at least two rows, namely a first planetary gear 4 and a second planetary gear 5. The planetary gear assembly is sleeved on the main shaft 1 and is located on one side of the hub 3. The first planetary gear 4 is connected to the motor assembly 2, and the second planetary gear 5 is connected to the flywheel 6. The first planetary gear 4 and the second planetary gear 5 are connected to each other. The motor assembly 2 and the flywheel 6 drive the planetary gear assembly to rotate, thereby driving the hub 3 to rotate.

[0058] The motor assembly 2 includes a motor rotor 20 and a motor stator 21; the first planetary row 4 includes a first ring gear 40, a first planetary gear 41, a first sun gear 42 and a first planetary carrier 43; the second planetary row 5 includes a second ring gear 50, a second planetary gear 51, a second planetary carrier 52 and a second sun gear 53.

[0059] The first planetary gear row 4 is mounted on the main shaft 1 via a first sun gear 42 and a first planet carrier 43. The second planetary gear row 5 is mounted on the main shaft 1 via a second planet carrier 52 and a second sun gear 53. There are multiple first planetary gears 41, with the first sun gear 42 located at the center of the first ring gear 40. The multiple first planetary gears 41 are evenly distributed between the first sun gear 42 and the first ring gear 40, and mesh with both the external teeth of the first sun gear 42 and the internal teeth of the first ring gear 40. The first planetary gear carrier 43 has multiple planetary gear posts, which pass through the multiple first planetary gears 41. One end of the first planetary gear carrier 43 is fixed to one side of the hub 3, and the other end is fixedly connected to the second sun gear 53.

[0060] There are multiple second planetary gears 51, and the second sun gear 53 is located at the center of the second ring gear 50. The multiple second planetary gears 51 are evenly distributed between the second sun gear 53 and the second ring gear 50, and at the same time mesh with the outer teeth of the second sun gear 53 and the inner teeth of the second ring gear 50. The second ring gear 50 and the first ring gear 40 are fixedly connected along the axial direction. The second planetary carrier 52 has multiple planetary gear columns, and the multiple planetary gear columns of the second planetary carrier 52 respectively pass through the multiple second planetary gears 51 and are rotatably connected to the second planetary gears 51. One side of the second planetary carrier 52 is fixedly connected to the flywheel 6, and a chain is installed on the periphery of the flywheel 6.

[0061] Specifically, the center holes of the first planetary gear 41 and the second planetary gear 51 have bearings, and the multiple planetary gear columns of the first planetary carrier 43 and the second planetary carrier 52 are cylindrical rods, and the multiple planetary gear columns of the first planetary carrier 43 and the second planetary carrier 52 pass through the bearings of the center holes of the first planetary gear 41 and the second planetary gear 51 respectively.

[0062] Furthermore, the motor stator 21 is sleeved on the main shaft 1 and fixed thereto, and one end of the first sun gear 42 extends into the interior of the hub 3 and is connected to the motor rotor 20. One end of the hub 3 is sleeved around the periphery of the main shaft 1 and is rotationally connected to the main shaft 1, and the other end of the hub 3 is sleeved around the periphery of the first sun gear 42 and is rotationally connected to the first sun gear 42.

[0063] Preferably, a speed sensor is installed on the flywheel 6 or the central axis of the bicycle. The speed sensor is connected to the control system of the power-assisted bicycle through a signal line, and the motor assembly 2 is electrically connected to the control system of the power-assisted bicycle. The speed sensor feeds back the speed of the flywheel 6 to the control system of the power-assisted bicycle, and the control system then controls the speed of the motor assembly 2.

[0064] It should be noted that in this embodiment, the planetary gear assembly is located outside the hub 3 and is mounted on the main shaft 1 via a sealed housing. The flywheel is located outside the housing and driven by a chain, thereby preventing cross-contamination between the transmission and the environment and improving transmission efficiency during use. In another embodiment, the chain drive of the flywheel 6 is eliminated and a belt drive or a sealed shaft drive is adopted to further improve transmission efficiency and reduce environmental pollution.

[0065] The first planetary gear 4 and the second planetary gear 5 of this embodiment are both negative-sign mechanisms, which can improve the transmission efficiency of the hub motor continuously variable transmission device.

[0066] Specifically, according to the working principle of the first planetary gear 4 and the second planetary gear 5, the rotational speed relationship of the motor assembly 2, the hub 3 and the flywheel 6 of the hub motor continuously variable transmission device is determined by the following formula:

[0067] n MG +k*n FW =(1+k)n W (1)

[0068] Where: n MG Indicates the speed of the motor assembly 2; n FW represents the speed of flywheel 6 and n W Indicates the rotation speed of the hub 3.

[0069] The torque relationship between the motor assembly 2, the wheel hub 3 and the flywheel 6 of the wheel hub motor continuously variable transmission device is determined by the following formula:

[0070] T MG :T FW :T W =1:k:(k+1) (2)

[0071] Where: T MG Represents the torque of the motor assembly 2; T FW represents the torque of the flywheel 6; T W Indicates the torque of the hub 3.

[0072] The speed ratio relationship between the motor assembly 2, the wheel hub 3 and the flywheel 6 of the wheel hub motor continuously variable transmission device is determined by the following formula:

[0073] k=k1+k1 / k2 (3)

[0074] Wherein: k1 represents the speed ratio of the first planetary gear 4; k2 represents the speed ratio of the second planetary gear 5; and k represents the total speed ratio of the planetary gear assembly.

[0075] Based on the above formula, in this embodiment, k1=5, k2=1.6, then k=8.125; n MG +8.125n FW =9.125nW , T MG :T FW :T W =1:8.125:9.125, when n FW =0, the speed ratio between the hub 3 and the motor assembly 2 is a maximum of 9.125.

[0076] Furthermore, the first planetary gear 4 and the second planetary gear 5 of this embodiment form a power split device, and the power flow of the power split device is determined by the following formula:

[0077] P W =P MG +P FW (4)

[0078] Where: P W Indicates the output power of hub 3; P MG Represents the input power of the motor assembly 2; P FW Represents the input power of the flywheel 6.

[0079] By adjusting the power ratio of the wheel hub motor continuously variable transmission device to adapt to different road conditions, combined with the above formulas (1)-(4), the power ratio of the wheel hub motor continuously variable transmission device is determined by the following formula:

[0080]

[0081] Where: λ represents the assist ratio.

[0082] The working principle of the hub motor continuously variable transmission device is explained below by taking an electric power-assisted bicycle under low-speed and low-load conditions as an example.

[0083] See the instructions attached Figure 3 , Figure 3 Here, MG represents motor assembly 2, W represents wheel hub 3, FW represents flywheel 6, S1 represents first sun gear 42, C1 represents first planetary carrier 43, R1 represents first ring gear 40, S2 represents second sun gear 53, C2 represents second planetary carrier 52, and R2 represents second ring gear 50. Operating Condition 1 is a low-speed balanced operating condition. As the rider's pedaling frequency increases, the speed of flywheel 6 increases, and the control system detects the acceleration intention and increases the speed of motor assembly 2, accelerating the bicycle. Operating Condition 2 is when the rider's pedaling frequency stabilizes, and motor assembly 2 no longer increases, maintaining the current speed.

[0084] The structure of this embodiment can achieve a large speed ratio, high speed and small torque of the motor assembly 2, which is conducive to lightweighting of the mechanism; according to the formula n MG +k*n FW =(1+k)n WThe hub speed of the hub motor continuously variable transmission device of this embodiment is determined by the motor speed and the flywheel speed, which can achieve continuous stepless adjustment; according to the power ratio According to the principle, for a planetary mechanism with a speed ratio of k, its λ matches the speed ratio of the motor assembly 2 and the flywheel 6. By controlling the speed ratio of the motor assembly 2 and the flywheel 6, the power assist ratio λ under different road conditions and accelerations can be adjusted.

[0085] Example 2:

[0086] See the instructions attached Figure 4 This embodiment includes all the structures of embodiment 1, and also includes a one-way clutch 1 7, a one-way clutch 2 8 and a brake 9.

[0087] One-way clutch 1 7, one-way clutch 2 8, and brake 9 employ conventional structures, with one-way clutch 1 7 and one-way clutch 2 8 employing overrunning clutches. One-way clutch 1 7 is connected to the second sun gear 53 and the second planetary carrier 52, respectively, while one-way clutch 2 8 is connected to the flywheel 6 and the main shaft 1, respectively. Because the second ring gear 50 and the first ring gear 40 are fixedly connected axially, the brake 9 is connected to both the first and second ring gears 40 and 50. The brake 9 is connected to the power-assisted bicycle's control system via a signal line, receiving control commands from the control system and actuating accordingly.

[0088] The in-wheel motor continuously variable transmission device of this embodiment has at least three functions: a low-speed gear for pure human-powered riding, coasting feedback power generation, and a high-speed gear for pure human-powered riding. A one-way clutch 1 (7) is added between the second planetary carrier 52 and the second sun gear 53 to enhance the low-speed gear for pure human-powered riding, improving starting response. A one-way clutch 2 (8) is added between the second planetary carrier 52 and the main shaft 1 to enable coasting feedback power generation. Brakes 9 are added to the first and second ring gears 40 and 50 to provide a high-speed gear for pure human-powered riding, addressing the requirement in some countries or regions to limit motor torque output when the vehicle speed exceeds a certain limit.

[0089] The one-way clutch 1 7 , the one-way clutch 2 8 and the brake 9 are independent of each other. According to the actual needs of the user, one or more functions can be achieved by installing the one-way clutch 1 7 , the one-way clutch 2 8 and the brake 9 respectively.

[0090] The following further illustrates this embodiment by introducing different working conditions:

[0091] See the instructions attached Figure 5 , which is the starting condition of the hub motor continuously variable transmission device. In this condition, the hub motor continuously variable transmission device is equipped with a one-way clutch 7, the one-way clutch 7 is working, the one-way clutch 2 8 is not installed or is in an overrunning and disengaged state, and the brake 9 is not installed or is not engaged.

[0092] At the moment of starting, the speed of the second planetary carrier 52 is greater than the speed of the second sun gear 53, and the one-way clutch 7 is engaged, so that the second planetary carrier 52 and the second sun gear 53 are fixedly connected. The first planetary gear 4 and the second planetary gear 5 are both in a locked state. The flywheel 6 connected to the second planetary carrier 52 and the hub 3 connected to the first planetary carrier 43 realize direct power transmission. At this time, the total speed ratio k of the planetary gear assembly is 1, and the speeds of the motor assembly 2, the hub 3 and the flywheel 6 are all the same.

[0093] In working condition 1, the motor assembly 2 recognizes that the bicycle is in the starting state through the control system, and the motor assembly 2 immediately enters the power-assist mode. The speed of the motor assembly 2 increases, which drives the speed of the wheel hub 3 to increase. When the speed of the wheel hub 3 is greater than the speed of the flywheel 6, the one-way clutch 7 is automatically disengaged, causing the first planetary gear 4 and the second planetary gear 5 to enter the power split mode. The wheel hub 3 is driven by the power of the motor assembly 2 and the flywheel 6.

[0094] See the instructions attached Figure 6 , which is the coasting feedback power generation condition of the hub motor continuously variable transmission device. In this condition, the hub motor continuously variable transmission device is equipped with a one-way clutch 2 8, the one-way clutch 2 8 is engaged, the one-way clutch 1 7 is not installed or is in the overrunning separation state, and the brake 9 is not installed or not engaged.

[0095] Operating condition 1 is riding at a certain speed, with motor assembly 2 in the power-assisted state. When deceleration is required, the rider stops pedaling, the speed of flywheel 6 reaches zero, and the bicycle enters a coasting state. After motor assembly 2 gradually changes from positive torque to zero torque, motor assembly 2 enters an idling state. When motor assembly 2 applies negative torque, it drags flywheel 6 backward, causing flywheel 6 to reverse, and one-way clutch 2 8 engages, locking flywheel 6 to spindle 1. At this point, motor assembly 2 generates electricity to recover the bicycle's kinetic energy.

[0096] In working condition 2, due to the action of the one-way clutch 2 8, the flywheel 6 and the main shaft 1 are locked, and the pedals will not be driven to reverse. Therefore, the feedback power generation process does not affect the rider's control intention and does not affect riding safety.

[0097] See the instructions attached Figure 7 , which is a high-speed pure human riding condition of the hub motor continuously variable transmission device. The hub motor continuously variable transmission device in this condition is equipped with a brake 9, the brake 9 is engaged, and the one-way clutch 1 7 and the one-way clutch 2 8 are not installed or are in an overrunning and disengaged state.

[0098] Operating condition 1 is riding under power-assisted operation at a certain speed. In operating condition 2, when the vehicle speed reaches the power-assisted limit threshold, the control system controls the engagement of brake 9, stopping the rotation of first and second ring gears 40 and 50. The control system also controls the unloading and idling of motor assembly 2, cutting off the power transmission between motor assembly 2 and first sun gear 42. The power from the rider pedaling is transmitted to flywheel 6 and input into second planetary gear set 5. Flywheel 6 then drives first planetary gear set 4 and motor assembly 2 to idle, transmitting the power to wheel hub 3 through first planetary carrier 43.

[0099] The above is only an embodiment of the present invention, and common sense such as the specific structure and characteristics of the scheme are not described in detail here. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claim involved.

Claims

1. A hub motor continuously variable transmission device, comprising a main shaft (1), a motor assembly (2), a hub (3), a planetary gear assembly, a flywheel (6), a one-way clutch 1 (7) and a one-way clutch 2 (8); characterized in that: The wheel hub (3), the planetary gear assembly and the flywheel (6) are sequentially sleeved on the main shaft (1); the motor assembly (2) is sleeved on the main shaft (1) and is located inside the wheel hub (3); The planetary row assembly comprises at least a first planetary row (4) and a second planetary row (5) connected to each other along its axial direction, and the first planetary row (4) and the second planetary row (5) both comprise an outer ring gear, a sun gear located at the center of the outer ring gear, a plurality of planetary gears located between the outer ring gear and the sun gear, and a planetary carrier; one end of the sun gear of the first planetary row (4) extends into the interior of the wheel hub (3) and is connected to the motor assembly (2); the planetary carrier of the first planetary row (4) passes through the planetary gears inside the wheel hub (3), one end of the planetary carrier of the first planetary row (4) is fixed to one side of the wheel hub (3), and the other end is fixedly connected to the sun gear of the second planetary row (5); one end of the planetary carrier of the second planetary row (5) is connected to the planetary gears inside the wheel hub (3), and the other end is fixedly connected to the flywheel (6); the outer ring gear of the first planetary row (4) and the outer ring gear of the second planetary row (5) are fixedly connected; The one-way clutch 1 (7) is respectively connected to the sun gear of the second planetary gear (5) and the planetary carrier of the second planetary gear (5), and the one-way clutch 2 (8) is respectively connected to the flywheel (6) and the main shaft (1); The one-way clutch 1 (7) is used for the starting condition of the wheel hub motor continuously variable transmission device, and the one-way clutch 2 (8) is not installed or is in a disengaged state under the starting condition; the one-way clutch 2 (8) is used for the coasting feedback power generation condition of the wheel hub motor continuously variable transmission device, and the one-way clutch 1 (7) is not installed or is in a disengaged state under the coasting feedback power generation condition; The motor assembly (2) comprises a motor rotor (20) and a motor stator (21); the motor stator (21) is sleeved and fixed on the main shaft (1), and the motor rotor (20) is connected to the sun gear of the first planetary gear (4).

2. The in-wheel motor continuously variable transmission device according to claim 1, characterized in that: The power assist ratio λ of the wheel hub motor continuously variable transmission is determined by the following formula: Where: λ represents the power ratio; P MG represents the input power of the motor assembly (2); P FW represents the input power of the flywheel (6); T MG represents the torque of the motor assembly (2); T FW represents the torque of the flywheel (6); n MG Indicates the speed of the motor assembly (2); n FW represents the rotational speed of the flywheel (6); k represents the total speed ratio of the planetary gear assembly.

3. The in-wheel motor continuously variable transmission device according to claim 2, characterized in that: The total speed ratio k of the planetary gear assembly is determined by the following formula: k=k1+k1 / k2 Wherein: k1 represents the speed ratio of the first planetary gear (4); k2 represents the speed ratio of the second planetary gear (5).

4. The in-wheel motor continuously variable transmission device according to claim 3, characterized in that: The rotational speed relationship among the motor assembly (2), the wheel hub (3) and the flywheel (6) of the wheel hub motor continuously variable transmission device is determined by the following formula: n MG +k*n FW =(1+k)n W Where: n MG Indicates the speed of the motor assembly (2); n FW represents the speed of the flywheel (6); n W Indicates the rotational speed of the hub (3).

5. The in-wheel motor continuously variable transmission device according to claim 3, characterized in that: The torque relationship between the motor assembly (2), the wheel hub (3) and the flywheel (6) of the wheel hub motor continuously variable transmission device is determined by the following formula: T MG :T FW :T W =1:k:(k+1) Where: T MG represents the torque of the motor assembly (2); T FW represents the torque of the flywheel (6); T W Indicates the torque of the hub (3).

6. The in-wheel motor continuously variable transmission device according to claim 2, characterized in that: The first planetary gear (4) and the second planetary gear (5) form a power split device. The power flow of the power split device of the hub motor continuously variable transmission device is determined by the following formula: P W =P MG +P FW Where: P W Indicates the output power of the hub (3); P MG represents the input power of the motor assembly (2); P FW represents the input power of the flywheel (6).

7. The in-wheel motor continuously variable transmission device according to claim 1, characterized in that: The center holes of the planetary wheels of the first planetary row (4) are provided with bearings, and the planetary carrier of the first planetary row (4) has a plurality of planetary wheel columns, the plurality of planetary wheel columns are cylindrical rods, and the plurality of planetary wheel columns respectively pass through the center holes of the planetary wheels of the first planetary row (4); The planetary gears and the planetary carrier of the second planetary row (5) have the same connection structure as the planetary gears and the planetary carrier of the first planetary row (4).

8. The in-wheel motor continuously variable transmission device according to claim 1, characterized in that: It also includes a brake (9); the brake (9) is connected to the outer gear ring of the first planetary row (4) and the outer gear ring of the second planetary row (5); The brake (9) is used for a high-speed pure human-powered riding condition of a hub motor continuously variable transmission device, and under the high-speed pure human-powered riding condition, the one-way clutch 1 (7) and the one-way clutch 2 (8) are not installed or are in a separated state.

9. The in-wheel motor continuously variable transmission device according to claim 1, characterized in that: One-way clutch 1 (7) and one-way clutch 2 (8) adopt overrunning clutch.

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