An automatic internal variable-speed hub drive device

Abstract

The present invention relates to the technical field of transmissions, and particularly to a hub drive device with automatic internal variable speed. It includes a hub housing, a freehub body, an automatic internal variable speed unit, a planetary gear transmission unit, a clutch, and a support main shaft. The automatic internal variable speed unit includes an outer ring, a middle ring, an inner ring, a first internal gear ring, and a second internal gear ring. The clutch includes a first one-way clutch, a second one-way clutch, a third one-way clutch, a second centrifugal one-way clutch, and a third centrifugal one-way clutch. The hub housing is connected to the automatic internal variable speed unit, the automatic internal variable speed unit meshes with the planetary gear transmission unit, the freehub body and the planetary gear transmission unit are integrated or fixedly connected, and the clutch is arranged inside the automatic internal variable speed unit or between the planetary gear transmission unit and the hub housing. The present invention adopts a modular automatic internal variable speed unit, mainly using a compound differential clutch unit and a planetary speed change mechanism, so as to realize variable speed transmission with three gears and more gears.

Description

Technical Field

[0001] The present invention relates to the technical field of transmissions, and particularly to a hub drive device with automatic internal speed change. Background Art

[0002] Automatic transmissions are widely used in the fields of automotive gearboxes and bicycle transmissions. However, due to different requirements, there are significant structural differences. Currently, there are multiple speed transmission devices on the market, with different structural implementations, specifically as follows:

[0003] Traditional manual internal three-speed hub:

[0004] As Figure 1 shown, it is a classic manual internal three-speed hub on the market. Its core uses a first-stage planetary gear transmission and four one-way clutches in combination. Shifting is controlled manually by an axial shift lever, and this moving mechanism controls the disengagement and engagement of the core gears. There are two one-way clutches C1 / C4 between the pedal input freewheel and the internal gear ring of the internal speed change unit and the pedal planetary carrier. In addition, there are two one-way clutches C2 / C3 connecting the internal gear ring and the pedal planetary carrier to the output hub respectively. The opening and closing of the one-way clutches are controlled by different axial positions of the shift lever (the locking or release of the clutch pawl is achieved by the torque of the torsion spring, and different positions of the shift lever give different torsional spaces to the clutch pawl). Its shifting strategy is shown in Figure 1 .

[0005] In summary, the disadvantages of the prior art are as follows:

[0006] Traditional bicycle internal transmissions are operation-based transmissions that require external force intervention for control (moving or rotating gears). Although there are also automatic internal speed changes on the market, their structures are complex and redundant, not compact enough, with poor packaging integration, and complex assembly. Generally, they are rarely integrated with hub reduction motors. For existing formed internal transmissions, under the condition of the same number of gears, the structure is more complex. Summary of the Invention

[0007] The present invention provides a hub drive device with automatic internal speed change, aiming to propose a new drive structure and differential clutch control strategy, which can achieve automatic three-speed or multi-speed transmission, and at the same time solve problems such as complex structure and low integration of existing transmissions.

[0008] The present invention provides a hub drive device with automatic internal speed change, including a hub housing, a freehub body, an automatic internal speed change unit, a planetary gear transmission unit, a clutch, and a support main shaft. The automatic internal speed change unit includes an outer ring, a middle ring, an inner ring, a first internal gear ring, and a second internal gear ring. The clutch includes a first one-way clutch, a second one-way clutch, a third one-way clutch, a second centrifugal one-way clutch, and a third centrifugal one-way clutch. The hub housing is connected to the outer ring. The second centrifugal one-way clutch is arranged between the outer ring and the middle ring. The second one-way clutch is arranged between the middle ring and the first internal gear ring. The third centrifugal one-way clutch is arranged between the middle ring and the inner ring. The third one-way clutch is arranged between the inner ring and the second internal gear ring. The planetary gear transmission unit is installed on the support main shaft. The first internal gear ring and the second internal gear ring are respectively meshed with the planetary gear transmission unit. The freehub body and the planetary gear transmission unit are an integral body or fixedly connected. The first one-way clutch is arranged between the planetary gear transmission unit and the hub housing.

[0009] As a further improvement of the present invention, the planetary gear transmission unit includes a first sun gear, a second sun gear, a plurality of first planetary gears, a plurality of second planetary gears, and a variable-speed planetary carrier. The support main shaft is installed on the axis of the variable-speed planetary carrier. The variable-speed planetary carrier is provided with a plurality of pin shafts. The first planetary gears and the second planetary gears are rotatably connected to the pin shafts. The plurality of first planetary gears and the plurality of second planetary gears are evenly distributed around the axis of the variable-speed planetary carrier. The first sun gear and the second sun gear are fixedly connected to the support main shaft. The first internal gear ring and the second internal gear ring are respectively meshed with the first planetary gears and the second planetary gears. The first planetary gears, the second planetary gears are meshed with the first sun gear and the second sun gear. The first one-way clutch is arranged between the variable-speed planetary carrier and the hub housing. The freehub body is fixedly connected to the variable-speed planetary carrier.

[0010] As a further improvement of the present invention, the diameter of the first internal gear ring is larger than that of the second internal gear ring. The diameter of the first planetary gear is larger than that of the second planetary gear. The diameter of the first sun gear is smaller than that of the second sun gear.

[0011] As a further improvement of the present invention, when the hub speed is in the low-speed riding state, when the hub speed is in the low-speed state, the second centrifugal one-way clutch and the third centrifugal one-way clutch are both in the disengaged state. The first one-way clutch is locked. The power input by pedaling is transmitted to the hub housing through the freehub body and the variable-speed planetary carrier and output. The pedaling speed is the same as the speed of the hub housing.

[0012] As a further improvement of the present invention, when the hub speed is in the medium-speed state, the second centrifugal one-way clutch is locked, and the third centrifugal one-way clutch is disengaged. The power input by pedaling drives the first planetary gear through the bottom bracket and the variable-speed planetary carrier to output the first internal gear ring. When the speed of the first internal gear ring exceeds the pedaling speed, the first one-way clutch is disengaged, and the second one-way clutch is locked. The power of the first internal gear ring is transmitted to the hub housing output through the second one-way clutch and the second centrifugal one-way clutch.

[0013] As a further improvement of the present invention, when the hub speed is in the high-speed state, the second centrifugal one-way clutch is in the locked state, and the third centrifugal one-way clutch also starts to enter the locked state. The power input by pedaling drives the first planetary gear and the second planetary gear through the bottom bracket and the variable-speed planetary carrier to output the first internal gear ring and the second internal gear ring. When the speed of the second internal gear ring exceeds the speed of the first internal gear ring and the pedaling speed, the first one-way clutch and the second one-way clutch are disengaged, and the third one-way clutch is locked. The power of the second internal gear ring is transmitted to the hub housing output through the third one-way clutch, the third centrifugal one-way clutch, and the second centrifugal one-way clutch.

[0014] As a further improvement of the present invention, the automatic internal variable-speed hub drive device further includes bearings. A bearing is connected between the variable-speed planetary carrier and the support main shaft, and a bearing is connected between the hub housing and the variable-speed planetary carrier.

[0015] As a further improvement of the present invention, the automatic internal variable-speed hub drive device further includes a reduction motor. The reduction motor includes a motor-side main shaft, a motor drive unit, and a motor transmission unit. The motor drive unit and the motor transmission unit are installed on the motor-side main shaft. One end of the motor-side main shaft is butted against the support main shaft. The clutch further includes a fourth one-way clutch. The motor drive unit is connected to the motor transmission unit. The support main shaft is provided with a main shaft end cover, and the fourth one-way clutch is arranged between the motor transmission unit and the main shaft end cover.

[0016] As a further improvement of the present invention, the motor drive unit includes a motor-side planetary carrier and a planetary reduction assembly. The planetary reduction assembly includes a plurality of motor-side planetary gears, a motor-side internal gear ring, and a motor-side sun gear. The motor drive unit includes a motor rotor. The motor-side sun gear is movably connected to the motor-side main shaft, and the motor rotor is connected to the motor-side sun gear. A plurality of the motor-side planetary gears are rotatably mounted on the motor-side planetary carrier and are evenly distributed around the axis of the motor-side planetary carrier. The motor-side internal gear ring is fixedly connected to the hub housing. The motor-side internal gear ring meshes with the motor-side planetary gears, and the motor-side planetary gears mesh with the motor-side sun gear. The fourth one-way clutch is disposed between the motor-side planetary carrier and the spindle end cover.

[0017] As a further improvement of the present invention, when torque is generated during pedaling, the motor drive unit is activated, the fourth one-way clutch is locked, and the power of the motor rotor is transmitted to the hub housing through the motor-side sun gear, the motor-side planetary gears, and the motor-side internal gear ring. At low speeds, the rotation speed of the motor rotor matches the speed of the hub housing. At medium and high speeds, the rotation speed of the motor rotor and the speed of the hub housing match the reduction ratio of the planetary reduction assembly. When coasting or when the motor drive unit stops, the fourth one-way clutch disengages.

[0018] The beneficial effects of the present invention are as follows:

[0019] (1) Improve the riding experience. Especially when the wheel speed is relatively high, this transmission can enable the rider to maintain a lower pedaling frequency and can automatically adjust and match the pedaling frequency according to the riding speed.

[0020] (2) The modular automatic internal transmission unit mainly adopts an integrated compound differential clutch unit, which can achieve three or more gears of transmission.

[0021] (3) The integrated hub reduction motor and the automatic internal transmission unit have a more compact structure and can achieve a larger gear shift, realizing a more compact transmission structure for an electric assist bicycle. Description of the Drawings

[0022] Figure 1 is a diagram of the traditional manual internal three-speed hub transmission configuration and shifting strategy;

[0023] Figure 2 is the overall structure diagram of the automatic internal transmission hub drive device of the present invention;

[0024] Figure 3 is the structural cross-sectional view of the automatic internal transmission hub drive device of the present invention;

[0025] Figure 4 is the structural diagram of the transmission side in the automatic internal transmission hub drive device of the present invention;

[0026] Figure 5 It is a structural sectional view of the speed-changing side in the hub drive device with automatic internal speed change of the present invention;

[0027] Figure 6 It is a structural sectional view of the automatic internal speed change unit in the present invention;

[0028] Figure 7 It is a connection structure diagram of the speed-changing planetary carrier, planetary gears, and freehub body in the present invention;

[0029] Figure 8 It is an exploded view of the structure supporting the main shaft, first sun gear, and second sun gear in the present invention;

[0030] Figure 9 It is a transmission configuration and shift strategy diagram of the hub drive device with automatic internal speed change of the present invention;

[0031] Figure 10 It is a comparison diagram of the hub drive device with automatic internal speed change of the present invention and a traditional hub without an internal speed change unit in terms of the matching of cycling cadence speed and wheel speed. Detailed implementation manners

[0032] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] As Figures 4 to 6 shown, the present invention relates to the application of an automatic internal speed change unit 4 in an electric assist bicycle hub motor, specifically to a hub drive device with automatic internal speed change, which includes a hub housing 1, a freehub body Z2, an automatic internal speed change unit 4, a planetary gear transmission unit 5, a clutch, and a supporting main shaft 3. The automatic internal speed change unit 4 includes an outer ring 41, a middle ring 42, an inner ring 43, a first internal gear ring 44, and a second internal gear ring 45. The clutch includes a first one-way clutch 61, a second one-way clutch 62, a third one-way clutch 63, a second centrifugal one-way clutch 64, and a third centrifugal one-way clutch 65. The hub housing 1 is connected to the outer ring 41. The second centrifugal one-way clutch 64 is arranged between the outer ring 41 and the middle ring 42. The second one-way clutch 62 is arranged between the middle ring 42 and the first internal gear ring 44. The third centrifugal one-way clutch 65 is arranged between the middle ring 42 and the inner ring 43. The third one-way clutch 63 is arranged between the inner ring 43 and the second internal gear ring 45. The planetary gear transmission unit 5 is installed on the supporting main shaft 3. The first internal gear ring 44 and the second internal gear ring 45 are respectively meshed with the planetary gear transmission unit 5. The freehub body 2 and the planetary gear transmission unit 5 are an integral body or fixedly connected. The first one-way clutch 61 is arranged between the planetary gear transmission unit 5 and the hub housing 1.

[0034] The first one-way clutch 61, the second one-way clutch 62, and the third one-way clutch 63 are ordinary one-way clutches, and the second centrifugal one-way clutch 64 and the third centrifugal one-way clutch 65 are automatically controllable centrifugal clutches. The core of this automatic internal speed change unit 4 is the adoption of an automatically controllable centrifugal clutch, which is integrated between the internal gear ring and the hub of the internal speed change unit together with the ordinary one-way clutch. According to the different speeds of the hub, the automatically controllable centrifugal clutch can be automatically closed and disconnected. When a person pedals the variable-speed planetary carrier 55 fixedly connected to the tower base 2, different internal gear rings will have different speed outputs, so that the speed of human-powered riding and the speed output of the hub have an optimal match.

[0035] The working principle of the one-way clutch is based on the locking mechanism of the wedge block. The one-way clutch consists of an outer ring, an inner ring, a cage, and wedge blocks. When the inner ring is fixed, when the outer ring rotates in a certain direction, the wedge blocks are designed not to lock, and the outer ring can rotate freely; however, when the outer ring rotates in the reverse direction, the wedge blocks are designed to lock, and the outer ring cannot rotate, thus realizing the function of one-way clutch.

[0036] The wedge blocks are designed not to lock because when the outer ring rotates, the wedge blocks are tilted passively, creating a certain space gap between the inner and outer rings, so that there is no connection between the inner and outer rings by the wedge blocks; on the contrary, the wedge blocks will connect the inner and outer rings; thus achieving the purpose of clutch.

[0037] The working principle of the automatic centrifugal one-way clutch is that special-shaped wedge blocks are evenly distributed between the outer ring and the inner ring, and the cage and the strip spring keep the wedge blocks in a certain position (the center of gravity of the wedge blocks is located on the contact line between the wedge blocks and the inner and outer rings). Considering the resultant moment of its centrifugal moment (generated by different speeds, the mass of the wedge blocks, and the centrifugal radius) and the spring moment, the wedge blocks are disengaged or locked with the inner ring, thus realizing the function of the automatic centrifugal one-way clutch; the wedge blocks can be pre-designed so that the wedge blocks lock at a specified speed.

[0038] The planetary gear transmission unit 5 includes a first sun gear 51, a second sun gear 52, a plurality of first planetary gears 53, a plurality of second planetary gears 54, and a variable-speed planetary carrier 55. The support main shaft 3 is installed on the axis of the variable-speed planetary carrier 55. The variable-speed planetary carrier 55 is provided with a plurality of pin shafts 56. The first planetary gears 53 and the second planetary gears 54 are rotatably connected to the pin shafts 56. The plurality of first planetary gears 53 and the plurality of second planetary gears 54 are evenly distributed around the axis of the variable-speed planetary carrier 55. The first sun gear 51 and the second sun gear 52 are fixedly connected to the support main shaft 3. The first internal gear ring 44 and the second internal gear ring 45 are respectively meshed with the first planetary gears 53 and the second planetary gears 54. The first planetary gears 53, the second planetary gears 54 are meshed with the first sun gear 51 and the second sun gear 52. The first one-way clutch 61 is arranged between the variable-speed planetary carrier 55 and the hub housing 1. The tower base 2 is fixedly connected to the variable-speed planetary carrier 55. The tower base 2 and the variable-speed planetary carrier 55 can be an integrally formed integral structure, or the tower base 2 and the variable-speed planetary carrier 55 can be two independent parts, which are fixedly connected together by fasteners. The effect achieved by the two connection structures is that the tower base 2 and the variable-speed planetary carrier 55 can rotate synchronously.

[0039] The transmission configuration and shifting strategy of this hub drive device are as Figure 9 , and the basic principle is to utilize the basic characteristics of planetary gear transmission. Through three basic components: the sun gear, the planetary carrier, and the internal gear ring. When the sun gear is fixed, if the planetary carrier is used as the input, the internal gear ring will be output with acceleration; when there are two sets / stages of such planetary transmissions, the core problem is how to solve the "logical and sequential" output. Therefore, a combination of two sets of automatically controllable centrifugal clutches and two sets of ordinary one-way clutches is used to solve the problem of logical and sequential hub output.

[0040] The position on the support main shaft 3 where it is connected to the sun gear is a flat shaft 31 structure. Corresponding flat holes 57 are provided in the centers of the first sun gear 51 and the second sun gear 52. The first sun gear 51 and the second sun gear 52 are fixedly connected to the position of the flat shaft 31 in the middle of the support main shaft 3 through the flat holes 57. The first planetary gears 53 and the second planetary gears 54 can rotate relative to each other on the pin shafts 56, and the first internal gear ring 44 and the second internal gear ring 45 can also rotate relative to each other, so that the first sun gear 51, the first planetary gears 53, and the first internal gear ring 44 form an independent gear transmission structure, and the second sun gear 52, the second planetary gears 54, and the second internal gear ring 45 form another independent gear transmission structure.

[0041] The diameter of the first internal gear ring 44 is greater than that of the second internal gear ring 45, the diameter of the first planetary gear 53 is greater than that of the second planetary gear 54, and the diameter of the first sun gear 51 is smaller than that of the second sun gear 52. Such a design of the size can make the transmission ratio achieved by the transmission structure composed of the first sun gear 51, the first planetary gear 53, and the first internal gear ring 44 greater than the transmission ratio directly achieved by the transmission of the variable-speed planetary carrier 55, and the transmission ratio achieved by the transmission structure composed of the second sun gear 52, the second planetary gear 54, and the second internal gear ring 45 is greater than the transmission ratio achieved by the transmission structure composed of the first sun gear 51, the first planetary gear 53, and the first internal gear ring 44, thereby realizing three different automatic transmission effects.

[0042] The hub drive device with automatic internal transmission further includes a bearing 58. A bearing 58 is connected between the variable-speed planetary carrier 55 and the support main shaft 3, and a bearing 58 is also connected between the hub housing 1 and the variable-speed planetary carrier 55. Through the bearing 58, the variable-speed planetary carrier 55 can rotate freely around the support main shaft 3, and the hub housing 1 can also rotate automatically around the variable-speed planetary carrier 55, so as to cooperate with the states of each clutch to realize the switching transmission of different gears.

[0043] Figure 9 Cc- is the fourth one-way clutch 66 of the motor-side planetary carrier 91; C2’- is the second centrifugal one-way clutch 64 between the outer ring 41 and the middle ring 42, C3’- is the third centrifugal one-way clutch 65 between the middle ring 42 and the inner ring 43, C1- is the first one-way clutch 61 between the variable-speed planetary carrier 55 and the hub housing 1, C2- is the second one-way clutch 62 between the first internal gear ring 44 and the middle ring 42, C3- is the third one-way clutch 63 between the second internal gear ring 45 and the inner ring 43; C2’ and C2- can realize the first-stage planetary transmission, and C3’ and C3- can realize the second-stage planetary transmission; C1, C2’, C2, C3’, C3, and the variable-speed planetary carrier 55 can realize the change of three transmission ratios.

[0044] The clutch combination of this hub drive device is called a compound differential clutch. The use of two-stage planetary gears and the clutch combination can achieve three pedaling speeds matching the hub speed change. Specifically as follows:

[0045] When the hub speed is in the low-speed state, both the second centrifugal one-way clutch 64 and the third centrifugal one-way clutch 65 are in the disengaged state. Since the pedaling speed is greater than the speed of the hub housing 1 during low-speed starting, the first one-way clutch 61 is locked, and the power input by pedaling is transmitted to the hub housing 1 through the tower base 2 and the variable-speed planetary carrier 55 for output, and the pedaling speed is the same as the speed of the hub housing 1.

[0046] When the hub speed is relatively low, the second centrifugal one-way clutch 64 and the third centrifugal one-way clutch 65 are both disengaged. That is, at this time, the first internal gear ring 44, the second internal gear ring 45 and the hub housing 1 are disengaged. At this time, when a person rides a bicycle, through the freehub body 2 and the transmission planetary carrier 55, the planetary gears drive the internal gear rings to rotate idly, without power output. Since the hub speed is lower than the pedaling speed, the first one-way clutch 61 locks, and the power of the person is transmitted to the end cover 11 of the hub housing 1 through this clutch, and the two have the same speed.

[0047] When the hub speed is in the medium-speed state, the second centrifugal one-way clutch 64 locks, and the third centrifugal one-way clutch 65 disengages. The power input by pedaling drives the first planetary gear 53 through the freehub body 2 and the transmission planetary carrier 55 to output the first internal gear ring 44. When the speed of the first internal gear ring 44 exceeds the pedaling speed, the first one-way clutch 61 disengages, and the second one-way clutch 62 locks. The power of the first internal gear ring 44 is transmitted to the hub housing 1 through the second one-way clutch 62 and the second centrifugal one-way clutch 64 for output.

[0048] When the hub speed is in the medium-speed state, the second centrifugal one-way clutch 64 locks. At this time, the third centrifugal one-way clutch 65 does not work and is in a disengaged state. At this time, when a person rides a bicycle, through the freehub body 2 and the transmission planetary carrier 55, the first planetary gear 53 is driven to output the first internal gear ring 44. Since the speed of the first internal gear ring 44 exceeds the pedaling speed, the first one-way clutch 61 disengages, and the second one-way clutch 62 locks, and the riding power is directly output through the closed second centrifugal one-way clutch 64.

[0049] When the hub speed is in the high-speed state, the second centrifugal one-way clutch 64 is in a locked state, and the third centrifugal one-way clutch 65 locks. The power input by pedaling drives the first planetary gear 53 and the second planetary gear 54 through the freehub body 2 and the transmission planetary carrier 55 to output the first internal gear ring 44 and the second internal gear ring 45. When the speed of the second internal gear ring 45 exceeds the speed of the first internal gear ring 44 and the pedaling speed, the first one-way clutch 61 and the second one-way clutch 62 disengage, and the third one-way clutch 63 locks. The power of the second internal gear ring 45 is transmitted to the hub housing 1 through the third one-way clutch 63, the third centrifugal one-way clutch 65 and the second centrifugal one-way clutch 64 for output.

[0050] When the hub speed is in the high-speed state, the third centrifugal one-way clutch 65 starts to lock, and at this time, the second centrifugal one-way clutch 64 is still in operation and in the locked state. At this time, the rider's pedaling drives the first planetary gear 53 and the second planetary gear 54 through the freehub body 2 and the transmission planetary carrier 55 to output the internal gear ring. Since the speed of the second internal gear ring 45 exceeds that of the first internal gear ring 44 and the pedaling speed, the first one-way clutch 61 and the second one-way clutch 62 disengage, and the third one-way clutch 63 locks, directly outputting the riding power through the locked third centrifugal one-way clutch 65 and the second centrifugal one-way clutch 64.

[0051] In summary, the structure in this solution and the states of the matched clutches can achieve the variable-speed function at different hub speeds. The core unit of this internal three-speed is a differential clutch unit encapsulating two centrifugal one-way clutches and a common one-way clutch, and the internal gear rings respectively connected to the one-way clutches. As Figure 10 shown, the low speed refers to the range where the wheel speed is lower than 22.5 km / h, the medium speed refers to the range where the wheel speed is between 22.5 and 30 km / h, and the high speed refers to the range where the wheel speed is higher than 30 km / h. At medium and high speeds, when reaching the same wheel speed, the hub drive device with the automatic internal variable-speed unit 4 of the present invention has a lower pedaling speed than the traditional hub drive device without an internal variable-speed unit, making cycling more labor-saving.

[0052] As Figure 2 and Figure 3 shown, the hub drive device with automatic internal variable speed further includes a reduction motor, which includes a motor-side main shaft 7, a motor drive unit 8, and a motor transmission unit 9. The motor drive unit 8 and the motor transmission unit 9 are installed on the motor-side main shaft 7. One end of the motor-side main shaft 7 is butted against the support main shaft 3. The clutch further includes a fourth one-way clutch 66. The motor drive unit 8 is connected to the motor transmission unit 9. The support main shaft 3 is provided with a main shaft end cover 32, and the fourth one-way clutch 66 is arranged between the motor transmission unit 9 and the main shaft end cover 32.

[0053] The motor drive unit 9 includes a motor-side planetary carrier 91 and a planetary reduction assembly. The planetary reduction assembly includes a plurality of motor-side planetary gears 92, a motor-side internal gear ring 93, and a motor-side sun gear 94. The motor drive unit 8 includes a motor rotor 81. The motor-side sun gear 94 is movably connected to the motor-side main shaft 7, and the motor rotor 81 is connected to the motor-side sun gear 94. The plurality of motor-side planetary gears 92 are rotatably mounted on the motor-side planetary carrier 91 and are evenly distributed around the axis of the motor-side planetary carrier 91. The motor-side internal gear ring 93 is fixedly connected to the hub housing 1. The motor-side internal gear ring 93 meshes with the motor-side planetary gears 92, and the motor-side planetary gears 92 mesh with the motor-side sun gear 94. The fourth one-way clutch 66 is disposed between the motor-side planetary carrier 91 and the spindle end cover 32.

[0054] The motor-side planetary carrier 91 adopts a motor-side compound double planetary gear structure. Each compound double planetary gear is coaxially and fixedly connected by a large gear and a small gear. The large gears of the plurality of motor-side compound double planetary gears mesh with the motor-side sun gear 94, and the small gears of the plurality of motor-side compound double planetary gears mesh with the motor-side internal gear ring 93. When the motor rotor 81 rotates, the power is sequentially transmitted to the hub housing 1 through the motor-side sun gear 94, the large gears of the motor-side compound double planetary gears, the small gears of the motor-side compound double planetary gears, and the motor-side internal gear ring 93.

[0055] When torque is generated during pedaling, the motor drive unit 9 is activated, and the fourth one-way clutch 66 is locked. The power of the motor rotor 81 is transmitted to the hub housing through the motor-side sun gear 94, the motor-side planetary gears 92, and the motor-side internal gear ring 93. At low speeds, the rotation speed of the motor rotor 81 matches the speed of the hub housing 1. At medium and high speeds, the rotation speed of the motor rotor 81 and the speed of the hub housing 1 match the reduction ratio of the planetary reduction assembly. When coasting or when the motor drive unit 9 stops, the fourth one-way clutch 66 disengages.

[0056] Figure 2 and Figure 3 On the left side in the [description] is a common reduction motor, which adopts a planetary reduction drive scheme with compound double planetary gears. On the right side is the automatic internal speed change unit 4. The two are integrated in the output hub housing 1. The left side adopts a planetary reduction drive unit driven by a common motor, and the right side is a speed change unit with an internal automatic three-speed change as the core, which is suitable for the field of electric assist bicycles. It is a new hybrid drive system that is mainly driven by a motor and supplemented by human pedaling.

[0057] Starting and operating process of the motor: It simultaneously matches the pedaling speed of the user to meet the requirement of the riding speed of the wheel hub ranging from low speed to high speed. When starting at low speed, the torque signal is mainly generated by the user pedaling the foot pedal, and the same speed is also given to the tower base 2 and the wheel hub housing 1. At this moment, the control system controls the motor to match the appropriate torque and speed, making the input of the rider and the assistance of the motor perfectly integrated. As the riding speed increases, the speed of the motor also gradually increases. The speed of the motor and the speed of the wheel hub housing 1 satisfy the fixed reduction ratio of the left planetary reduction assembly, providing the main power source for riding. At medium and high speeds, the automatic transmission unit on the right allows the riding speed of the user to be appropriately reduced, providing a better riding experience at medium and high speeds.

[0058] After the motor starts, the motor-side planetary gear 92, motor-side internal gear ring 93, and motor-side sun gear 94 of the left planetary reduction assembly are always in the meshing working state. The fourth one-way clutch 66 is always in the meshing and locking state. The motor-side planetary carrier 91 is fixed to the main shaft end cover 32. The motor rotor 81 transmits power to the wheel hub housing 1 through the planetary reduction assembly. Unless the motor stops assisting and coasting, the fourth one-way clutch 66 disengages. At this time, the motor-side planetary carrier 91 disengages from the main shaft end cover 32, and the motor-side planetary carrier 91 can rotate freely. The working states of the one-way clutch and planetary gears of the right automatic internal transmission unit 4 are as described above and will not be described again.

[0059] Application of the automatic internal transmission unit 4 integrated with the hub reduction motor on an electric bicycle. The automatic internal transmission unit 4 mainly realizes the automatic adjustment of different gears through the logical combination of a controllable centrifugal one-way clutch, a one-way clutch, and a planetary gear transmission system. When the hub speed is different, the automatic one-way clutches at different positions close or open, matching the riding cadence with a stable speed to obtain a better riding experience. The core of this design lies in integrating the internal gear rings of two-stage planets and a complex combination of one-way clutches to form a compound differential clutch unit that can obtain multiple gears. This unit is composed of two controllable centrifugal one-way clutches and two ordinary clutches. The outer ring 41 of this clutch unit is connected to the wheel hub housing 1, and the inner ring 43 is respectively connected to the outer walls of the internal gear rings of the two-stage planets. The two-stage planetary gears share the same variable-speed planetary carrier 55. The center distances of the two-stage planetary gears are the same, and the sun gears are both fixedly connected to the fixed support main shaft 3. The tooth number design of the planetary gear transmission needs to meet special conditions. The variable-speed planetary carrier 55 and the input tower base 2 are taken as a whole, and there is an ordinary one-way clutch between this component and the end cover 11 of the wheel hub housing 1.

[0060] Advantages of the hub drive device with automatic internal transmission of the present invention:

[0061] (1)Since human power has a certain range of cycling speeds, and people will feel discomfort and fatigue beyond this range, this device improves the cycling experience. Especially when the wheel speed is relatively high, the device can enable the cyclist to maintain a lower pedaling frequency. It can automatically match the cycling pedaling frequency according to the speed of the wheel (hub speed) to meet the best human-powered cycling characteristics.

[0062] (2)This automatic internal speed change unit 4 uses a compound differential clutch, namely an automatic centrifugal one-way clutch and a common one-way clutch, to achieve conditional logical opening or closing, control multi-stage planetary transmission, achieve three-speed transmission, and can also be extended to achieve more-speed variable transmission, realizing the modular design of a multi-speed transmission.

[0063] (3)This automatic internal speed change unit 4 is integrated in the hub reduction motor, with the compound clutch and the internal gear ring assembled into one body, having the advantages of integration and unitization.

[0064] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as belonging to the protection scope of the present invention.

Claims

1. An automatic internal variable speed hub drive device, characterized in that It includes a hub housing, a tower base, an automatic internal transmission unit, a planetary gear transmission unit, a clutch, and a support main shaft. The automatic internal transmission unit includes an outer ring, a middle ring, an inner ring, a first internal gear ring, and a second internal gear ring. The clutch includes a first one-way clutch, a second one-way clutch, a third one-way clutch, a second centrifugal one-way clutch, and a third centrifugal one-way clutch. The hub housing is connected to the outer ring. The second centrifugal one-way clutch is arranged between the outer ring and the middle ring. The second one-way clutch is arranged between the middle ring and the first internal gear ring. The third centrifugal one-way clutch is arranged between the middle ring and the inner ring. The third one-way clutch is arranged between the inner ring and the second internal gear ring. The planetary gear transmission unit is installed on the support main shaft. The first internal gear ring and the second internal gear ring are respectively meshed with the planetary gear transmission unit. The tower base and the planetary gear transmission unit are integrated or fixedly connected. The first one-way clutch is arranged between the planetary gear transmission unit and the hub housing; The planetary gear transmission unit includes a first sun gear, a second sun gear, a plurality of first planetary gears, a plurality of second planetary gears, and a variable-speed planetary carrier. The support main shaft is installed on the axis of the variable-speed planetary carrier. The variable-speed planetary carrier is provided with a plurality of pin shafts. The first planetary gears and the second planetary gears are rotatably connected to the pin shafts. The plurality of first planetary gears and the plurality of second planetary gears are evenly distributed around the axis of the variable-speed planetary carrier. The first sun gear and the second sun gear are fixedly connected to the support main shaft. The first internal gear ring and the second internal gear ring are respectively meshed with the first planetary gears and the second planetary gears. The first planetary gears, the second planetary gears are meshed with the first sun gear and the second sun gear. The first one-way clutch is arranged between the variable-speed planetary carrier and the hub housing. The tower base is fixedly connected to the variable-speed planetary carrier.

2. The hub drive device with automatic internal speed change according to claim 1, characterized in that, The diameter of the first internal gear ring is larger than that of the second internal gear ring. The diameter of the first planetary gear is larger than that of the second planetary gear. The diameter of the first sun gear is smaller than that of the second sun gear.

3. The hub drive device with automatic internal speed change according to claim 1, characterized in that, When the hub speed is in the low-speed state, both the second centrifugal one-way clutch and the third centrifugal one-way clutch are in the disengaged state. The first one-way clutch is locked. The power input by pedaling is transmitted to the hub housing through the tower base and the variable-speed planetary carrier for output. The pedaling speed is the same as the speed of the hub housing.

4. The hub drive device with automatic internal speed change according to claim 1, characterized in that, When the hub speed is in the medium-speed state, the second centrifugal one-way clutch is locked, and the third centrifugal one-way clutch is disengaged. The power input by pedaling drives the first planetary gear through the tower base and the variable-speed planetary carrier to output the first internal gear ring. When the speed of the first internal gear ring exceeds the pedaling speed, the first one-way clutch is disengaged, the second one-way clutch is locked, and the power of the first internal gear ring is transmitted to the hub housing through the second one-way clutch and the second centrifugal one-way clutch for output.

5. The hub drive device with automatic internal speed change according to claim 1, characterized in that, When the hub speed is in the high-speed state, the second centrifugal one-way clutch is in the locked state, and the third centrifugal one-way clutch also begins to enter the locked state. The power input by pedaling is driven by the bottom bracket and the variable-speed planetary carrier to drive the first planetary gear and the second planetary gear to output the first internal gear ring and the second internal gear ring. When the speed of the second internal gear ring exceeds the speed of the first internal gear ring and the pedaling speed, the first one-way clutch and the second one-way clutch disengage and separate, and the third one-way clutch locks. The power of the second internal gear ring is transmitted to the hub housing output through the third one-way clutch, the third centrifugal one-way clutch, and the second centrifugal one-way clutch.

6. The hub drive device with automatic internal speed change according to claim 1, characterized in that, It further includes bearings. There is a bearing connected between the variable-speed planetary carrier and the support main shaft, and a bearing connected between the hub housing and the variable-speed planetary carrier.

7. The hub drive device with automatic internal speed change according to claim 1, characterized in that, It further includes a reduction motor. The reduction motor includes a motor-side main shaft, a motor drive unit, and a motor transmission unit. The motor drive unit and the motor transmission unit are installed on the motor-side main shaft. One end of the motor-side main shaft is butted against the support main shaft. The clutch further includes a fourth one-way clutch. The motor drive unit is connected to the motor transmission unit. The support main shaft is provided with a main shaft end cover, and the fourth one-way clutch is arranged between the motor transmission unit and the main shaft end cover.

8. The hub drive device with automatic internal speed change according to claim 7, characterized in that, The motor transmission unit includes a motor-side planetary carrier and a planetary reduction assembly. The planetary reduction assembly includes a plurality of motor-side planetary gears, a motor-side internal gear ring, and a motor-side sun gear. The motor drive unit includes a motor rotor. The motor-side sun gear can rotate freely on the motor-side main shaft. The motor rotor is fixedly connected to the motor-side sun gear. A plurality of the motor-side planetary gears are rotatably installed on the motor-side planetary carrier and are evenly distributed around the axis of the motor-side planetary carrier. The motor-side internal gear ring is fixedly connected to the hub housing. The motor-side internal gear ring meshes with the motor-side planetary gears, and the motor-side planetary gears mesh with the motor-side sun gear. The fourth one-way clutch is arranged between the motor-side planetary carrier and the main shaft end cover.

9. The hub drive device with automatic internal speed change according to claim 8, characterized in that, When torque is generated by pedaling, the motor transmission unit starts, the fourth one-way clutch locks, and the power of the motor rotor is transmitted to the hub housing through the motor-side sun gear, the motor-side planetary gears, and the motor-side internal gear ring. At low speeds, the rotation speed of the motor rotor matches the speed of the hub housing. At medium and high speeds, the rotation speed of the motor rotor and the speed of the hub housing match the reduction ratio of the planetary reduction assembly. When coasting or when the motor transmission unit stops, the fourth one-way clutch disengages and separates.

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