Hub driving device with automatic internal speed change function

Abstract

The invention relates to the technical field of transmissions, in particular to a hub driving device with an automatic internal speed change function. The invention relates to an automatic inner speed changing device which comprises a hub shell, a tower footing, an automatic inner speed changing unit, a planetary gear transmission unit, a clutch and a supporting main shaft. The automatic inner speed changing unit comprises an outer ring, a middle ring, an inner ring, a first inner gear ring and a second inner gear ring. The clutches comprise the first one-way clutch, the second one-way clutch, the third one-way clutch, the second centrifugal one-way clutch and the third centrifugal one-way clutch, the hub shell is connected with the automatic inner speed change unit, and the automatic inner speed change unit is meshed with the planetary gear transmission unit. The tower footing and the planetary gear transmission unit are integrated or fixedly connected, and the clutch is arranged in the automatic inner speed change unit or arranged between the planetary gear transmission unit and the hub shell. The modularized automatic inner speed change unit is adopted, and the composite differential clutch unit and the planetary speed change mechanism are mainly adopted, so that speed change transmission of three gears and more gears is achieved.

Description

Technical Field

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

[0002] Automatic transmissions are widely used in automobile transmissions and bicycle transmissions, but the requirements are different and the structures are very different. Currently, there are multi-speed transmissions on the market, which are different in structure, specifically: Traditional manual internal three-speed hub: like Figure 1 As shown in the figure, it is a classic manual internal three-speed hub on the market. The core adopts a primary planetary gear transmission and four one-way clutches. The gear shifting adopts a manually controlled axial shift lever. The mobile mechanism controls the disengagement and closing of the core gear. There are two one-way clutches C1 / C4 between the pedal input tower base and the inner gear ring of the internal speed unit and the pedaling planetary carrier, and the inner gear ring and the pedaling planetary carrier are respectively connected to the output hub with two one-way clutches C2 / C3. The opening and closing of the one-way clutch is controlled by different axial positions of the shift lever (the locking or releasing of the clutch ratchet is achieved by the torsion of the torsion spring, and different positions of the shift lever give different torsional spaces to the clutch ratchet). Its shifting strategy is shown in Figure 1 .

[0003] In summary, the shortcomings of the prior art are: Traditional bicycle internal transmissions are operational transmissions that require external force intervention to control (move or rotate gears). There are also automatic internal transmissions on the market, but their structures are complex and redundant, not compact enough, and their packaging is not highly integrated. They are complex to assemble and are rarely integrated with hub reduction motors. Existing internal transmissions have a more complex structure under the same gear conditions. Summary of the invention

[0004] The present invention provides a wheel hub drive device with automatic internal speed change, aiming to propose a new drive structure and differential clutch control strategy, which can realize automatic three-speed or multi-speed transmission and solve the problems of complex structure and low integration of existing transmissions.

[0005] The present invention provides a wheel hub driving device with automatic internal speed change, comprising a wheel hub shell, a freewheel base, an automatic internal speed change unit, a planetary gear transmission unit, a clutch, and a supporting main shaft. The automatic internal speed change unit comprises an outer ring, a middle ring, an inner ring, a first inner gear ring, and a second inner gear ring. The clutch comprises 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 wheel hub shell 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 inner gear ring, the third centrifugal one-way clutch is arranged between the middle ring and the inner ring, and the third one-way clutch is arranged between the inner ring and the second inner gear ring. The planetary gear transmission unit is installed on the supporting main shaft, the first inner gear ring and the second inner gear ring are respectively meshed with the planetary gear transmission unit, the freewheel base and the planetary gear transmission unit are an integral whole or fixedly connected, and the first one-way clutch is arranged between the planetary gear transmission unit and the wheel hub shell.

[0006] 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 speed planetary rotating frame. The supporting main shaft is installed on the axis of the speed planetary rotating frame. The speed planetary rotating frame is provided with a plurality of pins. The first planetary gear and the second planetary gear are rotatably connected on the pins. The plurality of the first planetary gears and the plurality of the second planetary gears are evenly distributed along the axis of the speed planetary rotating frame. The first sun gear and the second sun gear are fixedly connected to the supporting main shaft. The first inner ring gear and the second inner ring gear are respectively meshed with the first planetary gear and the second planetary gear. The first planetary gear, the second planetary gear and the first sun gear and the second sun gear are meshed. The first one-way clutch is arranged between the speed planetary rotating frame and the hub shell. The tower base is fixedly connected to the speed planetary rotating frame.

[0007] As a further improvement of the present invention, the diameter of the first inner gear ring is greater than the diameter of the second inner gear ring, the diameter of the first planetary gear is greater than the diameter of the second planetary gear, and the diameter of the first sun gear is smaller than the diameter of the second sun gear.

[0008] As a further improvement of the present invention, when the hub speed is in a low-speed riding state, when the hub speed is in a low-speed state, the second centrifugal one-way clutch and the third centrifugal one-way clutch are both in a separated and disengaged state, the first one-way clutch is locked, and the pedaling input power is transmitted to the hub shell output through the tower base and the speed-changing planetary carrier, and the pedaling speed is the same as the speed of the hub shell.

[0009] As a further improvement of the present invention, when the hub speed is in a medium speed state, the second centrifugal one-way clutch is locked, the third centrifugal one-way clutch is separated and disengaged, and the power input by pedaling drives the first planetary gear through the tower base and the speed change planetary carrier to output the first inner ring gear. When the speed of the first inner ring gear exceeds the pedaling speed, the first one-way clutch is separated, the second one-way clutch is locked, and the power of the first inner ring gear is transmitted to the hub shell output through the second one-way clutch and the second centrifugal one-way clutch.

[0010] As a further improvement of the present invention, when the hub speed is in a high-speed state, the second centrifugal one-way clutch is in a locked state, and the third centrifugal one-way clutch also begins to enter a locked state, and the power input by pedaling drives the first planetary gear and the second planetary gear through the tower base and the speed-changing planetary carrier to output the first inner ring gear and the second inner ring gear. When the speed of the second inner ring gear exceeds the speed of the first inner ring gear and the pedaling speed, the first one-way clutch and the second one-way clutch are separated and disengaged, and the third one-way clutch is locked. The power of the second inner ring gear is transmitted to the hub shell output through the third one-way clutch, the third centrifugal one-way clutch, and the second centrifugal one-way clutch.

[0011] As a further improvement of the present invention, the automatic internal speed-changing wheel hub driving device further comprises a bearing, a bearing is connected between the speed-changing planetary rotating frame and the supporting main shaft, and a bearing is connected between the wheel hub shell and the speed-changing planetary rotating frame.

[0012] As a further improvement of the present invention, the wheel hub drive device with automatic internal speed change also 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 connected to the supporting main shaft, the clutch also includes a fourth one-way clutch, the motor drive unit is connected to the motor transmission unit, the supporting 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.

[0013] As a further improvement of the present invention, the motor transmission unit includes a motor side planetary carrier, a planetary reduction assembly, the planetary reduction assembly includes multiple motor side planetary gears, a motor side inner ring gear, 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, the motor rotor is connected to the motor side sun gear, multiple 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 inner ring gear is fixedly connected to the hub shell, the motor side inner ring gear is meshed with the motor side planetary gears, the motor side planetary gears are meshed with the motor side sun gear, and the fourth one-way clutch is arranged between the motor side planetary carrier and the main shaft end cover.

[0014] As a further improvement of the present invention, when pedaling generates torque, the motor transmission unit starts, the fourth one-way clutch is locked, and the power of the motor rotor is transmitted to the hub shell through the motor side sun gear, the motor side planetary gear, and the motor side inner ring gear. At low speed, the rotation speed of the motor rotor matches the speed of the hub shell, and at medium and high speeds, the rotation speed of the motor rotor and the speed of the hub shell match the reduction ratio of the planetary reduction assembly; when coasting or the motor transmission unit stops, the fourth one-way clutch is separated and disengaged.

[0015] The beneficial effects of the present invention are: (1) Improve the riding experience. Especially when the wheel speed is high, the transmission allows the rider to maintain a lower cadence and can automatically adjust the cadence to match the riding speed; (2) Modular automatic internal transmission unit, mainly using an integrated compound differential clutch unit, which can achieve transmission of three or more gears; (3) The integrated wheel hub reduction motor and automatic internal speed change unit have a more compact structure and can achieve a larger gear shift, thus realizing a more compact electric power-assisted bicycle transmission structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a traditional manual internal three-speed hub transmission configuration and shift strategy diagram; Figure 2 It is an overall structural diagram of the wheel hub drive device with automatic internal speed change of the present invention; Figure 3 It is a structural cross-sectional view of the wheel hub drive device with automatic internal speed change of the present invention; Figure 4 It is a structural diagram of the speed change side of the wheel hub drive device with automatic internal speed change of the present invention; Figure 5 It is a structural cross-sectional view of the speed-changing side of the wheel hub drive device with automatic internal speed change of the present invention; Figure 6is a structural cross-sectional view of the automatic internal speed change unit of the present invention; Figure 7 It is a connection structure diagram of the speed-changing planetary carrier, the planetary gear and the tower base in the present invention; Figure 8 It is an exploded view of the structure of the supporting main shaft, the first sun gear and the second sun gear in the present invention; Fig. 9 It is a transmission configuration and shifting strategy diagram of the wheel hub drive device with automatic internal speed change of the present invention; Fig.10 It is a comparison diagram of the matching of the riding cadence speed and the wheel speed between the wheel hub drive device with automatic internal speed change of the present invention and the traditional unit without internal speed change. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0018] like Figures 4 to 6 As shown, the present invention relates to an application of an automatic internal speed change unit 4 in an electric power-assisted bicycle hub motor, specifically an automatic internal speed change hub drive device, comprising a hub shell 1, a freewheel base 2, an automatic internal speed change unit 4, a planetary gear transmission unit 5, a clutch, and a support spindle 3. The automatic internal speed change unit 4 comprises an outer ring 41, a middle ring 42, an inner ring 43, a first inner gear ring 44, and a second inner gear ring 45. The clutch comprises 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 shell 1 is connected to the outer ring 41, and the second clutch 43 is connected to the outer ring 41. The 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 inner 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 inner gear ring 45, the planetary gear transmission unit 5 is installed on the supporting main shaft 3, the first inner gear ring 44 and the second inner gear ring 45 are respectively meshed with the planetary gear transmission unit 5, the tower base 2 and the planetary gear transmission unit 5 are a whole or fixedly connected, and the first one-way clutch 61 is arranged between the planetary gear transmission unit 5 and the hub shell 1.

[0019] The first one-way clutch 61, the second one-way clutch 62, and the third one-way clutch 63 are common 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 the automatic internal speed change unit 4 is the use of an automatically controllable centrifugal clutch, which is integrated with the common one-way clutch between the inner gear ring and the wheel hub of the internal speed change unit. The automatically controllable centrifugal clutch can be automatically closed and disconnected according to the different wheel hub speeds. When a person steps on the speed change planetary rotating frame 55 fixedly connected to the tower base 2, different inner gear rings will have different speed outputs, so that the speed of human riding and the output speed of the wheel hub have the best match.

[0020] The working principle of the one-way clutch is based on the locking mechanism of the wedge. The one-way clutch consists of an outer ring, an inner ring, a retaining frame and a wedge. When the inner ring is fixed, when the outer ring rotates in a certain direction, the wedge is designed not to lock and the outer ring can rotate freely; however, when the outer ring rotates in the opposite direction, the wedge is designed to lock and the outer ring cannot rotate, thereby achieving the function of the one-way clutch.

[0021] The wedge block is designed not to lock because when the wedge block rotates on the outer ring, the wedge block is passively tilted, leaving a certain space gap between the inner and outer rings so that there is no wedge connecting the inner and outer rings; otherwise, the wedge block will combine the inner and outer rings, thereby achieving the purpose of clutch.

[0022] The working principle of the automatic centrifugal one-way clutch is that the special-shaped wedges are evenly distributed between the outer ring and the inner ring, and the retaining frame and the strip spring keep the wedges in a certain position (the center of gravity of the wedges is located on the contact line between the wedges and the inner and outer rings). Considering the combined force of the centrifugal torque (generated by different speeds, wedge mass and centrifugal radius) and the spring torque, the wedges and the inner ring are disengaged or locked, thereby realizing the function of the automatic centrifugal one-way clutch; the wedges can be pre-designed to lock at a specified speed.

[0023] 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 speed-changing planetary rotating frame 55. The supporting main shaft 3 is installed on the axis of the speed-changing planetary rotating frame 55. The speed-changing planetary rotating frame 55 is provided with a plurality of pins 56. The first planetary gear 53 and the second planetary gear 54 are rotatably connected to the pins 56. The plurality of first planetary gears 53 and the plurality of second planetary gears 54 are evenly distributed along the axis of the speed-changing planetary rotating frame 55. The first sun gear 51 and the second sun gear 52 are fixedly connected to the supporting main shaft 3. The first inner gear ring 44 and the second inner gear ring 44 are 45 are respectively meshed with the first planetary gear 53 and the second planetary gear 54, the first planetary gear 53, the second planetary gear 54 are meshed with the first sun gear 51, the second sun gear 52, the first one-way clutch 61 is arranged between the speed planetary rotating frame 55 and the hub shell 1, the freewheeling base 2 is fixedly connected to the speed planetary rotating frame 55, the freewheeling base 2 and the speed planetary rotating frame 55 can be an integral structure formed in one piece, or the freewheeling base 2 and the speed planetary rotating frame 55 can be two independent parts, which are fixedly connected together by fasteners. The effect to be achieved by the two connection structures is to enable the freewheeling base 2 and the speed planetary rotating frame 55 to rotate synchronously.

[0024] The transmission configuration and shifting strategy of the wheel hub drive are as follows: Fig. 9 The basic principle is to utilize the basic characteristics of planetary gear transmission. Through the three basic components of the sun gear, the planetary carrier, and the inner ring gear, when the sun gear is fixed, the planetary carrier is used as the input, and the inner ring gear will be accelerated to output; when there are two groups / levels of such planetary transmissions, the core problem is how to solve the "logical and sequential" output. Therefore, two groups of automatically controllable centrifugal clutches and two groups of ordinary one-way clutches are used in combination to solve the problem of logical and sequential hub output.

[0025] The position on the supporting main shaft 3 connected with the sun gear is a flat shaft 31 structure, and the corresponding first sun gear 51 and second sun gear 52 are provided with a flat hole 57 in the center, and the first sun gear 51 and second sun gear 52 are fixedly connected to the flat shaft 31 position in the middle of the supporting main shaft 3 through the flat hole 57. The first planetary gear 53 and the second planetary gear 54 can rotate relatively on the pin 56, and the first inner gear ring 44 and the second inner gear ring 45 can also rotate relatively, so that the first sun gear 51, the first planetary gear 53, and the first inner gear ring 44 form an independent gear transmission structure, and the second sun gear 52, the second planetary gear 54, and the second inner gear ring 45 form another independent gear transmission structure.

[0026] The diameter of the first inner gear ring 44 is greater than that of the second inner 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. The design of the size can make the transmission ratio of the transmission structure composed of the first sun gear 51, the first planetary gear 53, and the first inner gear ring 44 greater than the transmission ratio directly achieved by the speed change planetary carrier 55, and the transmission ratio of the transmission structure composed of the second sun gear 52, the second planetary gear 54, and the second inner gear ring 45 greater than the transmission ratio of the transmission structure composed of the first sun gear 51, the first planetary gear 53, and the first inner gear ring 44, thereby achieving three different automatic speed change effects.

[0027] The hub drive device of automatic internal speed change also includes a bearing 58, a bearing 58 is connected between the speed change planetary carrier 55 and the supporting main shaft 3, and a bearing 58 is connected between the hub shell 1 and the speed change planetary carrier 55. Through the bearing 58, the speed change planetary carrier 55 can rotate freely around the supporting main shaft 3, and the hub shell 1 can also rotate automatically around the speed change planetary carrier 55, so as to cooperate with the state of each clutch to realize the switching transmission of different gears.

[0028] Fig. 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 speed-changing planetary carrier 55 and the hub shell 1, C2- is the second one-way clutch 62 between the first inner gear ring 44 and the middle ring 42, and C3- is the third one-way clutch 63 between the second inner 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 speed-changing planetary carrier 55 can realize the change of three-stage transmission ratio.

[0029] The clutch combination of the hub drive is called a compound differential clutch. The use of a two-stage planetary gear and clutch combination can achieve three gears of pedaling speed to match the hub speed when it changes. The details are as follows: When the hub speed is in a low speed state, the second centrifugal one-way clutch 64 and the third centrifugal one-way clutch 65 are both in a separated and disengaged state. Since the pedaling speed is greater than the speed of the hub shell 1 when starting at a low speed, the first one-way clutch 61 is locked, and the pedaling input power is transmitted to the hub shell 1 output through the tower base 2 and the speed planetary carrier 55, and the pedaling speed is the same as the speed of the hub shell 1.

[0030] When the wheel hub speed is low, the second centrifugal one-way clutch 64 and the third centrifugal one-way clutch 65 are both separated, that is, at this time, the first inner ring gear 44, the second inner ring gear 45 and the hub shell 1 are separated. At this time, the person's riding drives the planetary gears through the tower base 2 and the speed planetary carrier 55 to make the inner ring gear idle, and there is no power output. Since the rotation speed of the hub is lower than the pedaling speed, the first one-way clutch 61 plays a locking role, and the person's power is transmitted to the end cover 11 of the hub shell 1 through the clutch, and the two have the same speed.

[0031] When the hub speed is in a medium speed state, the second centrifugal one-way clutch 64 is locked, and the third centrifugal one-way clutch 65 is separated and disengaged. The power input by pedaling drives the first planetary gear 53 through the tower base 2 and the speed planetary carrier 55 to make the first inner ring gear 44 output. When the speed of the first inner ring gear 44 exceeds the pedaling speed, the first one-way clutch 61 is separated, and the second one-way clutch 62 is locked. The power of the first inner ring gear 44 is transmitted to the hub shell 1 through the second one-way clutch 62 and the second centrifugal one-way clutch 64 for output.

[0032] When the hub speed is in the medium speed state, the second centrifugal one-way clutch 64 plays a locking role. At this time, the third centrifugal one-way clutch 65 does not work and is in a separated state. At this time, the person's riding drives the first planetary gear 53 through the tower base 2 and the speed planetary carrier 55 to make the first inner ring gear 44 output. Since the speed of the first inner ring gear 44 exceeds the pedaling speed, the first one-way clutch 61 is separated, and the second one-way clutch 62 plays a locking role, and the riding power is directly output through the closed second centrifugal one-way clutch 64.

[0033] When the hub speed is in a high-speed state, the second centrifugal one-way clutch 64 is in a locked state, and the third centrifugal one-way clutch 65 is locked. The power input by pedaling drives the first planetary gear 53 and the second planetary gear 54 through the tower base 2 and the speed-changing planetary carrier 55 to output the first inner ring gear 44 and the second inner ring gear 45. When the speed of the second inner ring gear 45 exceeds the speed of the first inner ring gear 44 and the pedaling speed, the first one-way clutch 61 and the second one-way clutch 62 are separated, and the third one-way clutch 63 is locked. The power of the second inner ring gear 45 is transmitted to the hub shell 1 for output through the third one-way clutch 63, the third centrifugal one-way clutch 65, and the second centrifugal one-way clutch 64.

[0034] When the hub speed is at a high speed, the third centrifugal one-way clutch 65 begins to play a locking role. At this time, the second centrifugal one-way clutch 64 is still working and is in a locked state. At this time, the person's riding drives the first planetary gear 53 and the second planetary gear 54 through the tower base 2 and the speed planetary carrier 55 to make the inner ring output. Since the speed of the second inner ring 45 exceeds the first inner ring 44 and the pedaling speed, the first one-way clutch 61 and the second one-way clutch 62 are separated, and the third one-way clutch 63 plays a locking role, and the riding power is directly output through the locked third centrifugal one-way clutch 65 and the second centrifugal one-way clutch 64.

[0035] In summary, the structure of the scheme and the state of the matched clutch can obtain the speed change function at different wheel hub speeds. The core unit of the internal three-speed change is a differential clutch unit that encapsulates two centrifugal one-way clutches and a common one-way clutch, and an inner gear ring connected to each one-way clutch. Fig.10 As shown, low speed refers to the interval where the wheel speed is lower than 22.5 km / h, medium speed refers to the interval where the wheel speed is between 22.5 and 30 km / h, and high speed refers to the interval where the wheel speed is higher than 30 km / h. At medium and high speeds, when the wheel speed is the same, the wheel hub drive device containing the automatic internal transmission unit 4 of the present invention has a lower riding cadence speed than the traditional wheel hub drive device without an internal transmission unit, and riding is more labor-saving.

[0036] like Figure 2 and Figure 3 As shown, the wheel hub drive device with automatic internal speed change also 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, and one end of the motor-side main shaft 7 is connected to the supporting main shaft 3. The clutch also includes a fourth one-way clutch 66. The motor drive unit 8 is connected to the motor transmission unit 9, and the supporting main shaft 3 is provided with a main shaft end cover 32. The fourth one-way clutch 66 is arranged between the motor transmission unit 9 and the main shaft end cover 32.

[0037] The motor transmission unit 9 includes a motor-side planetary carrier 91, a planetary reduction assembly, a plurality of motor-side planetary gears 92, a motor-side inner ring gear 93, and a motor-side sun gear 94 in the planetary reduction assembly. 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. The motor rotor 81 is connected to the motor-side sun gear 94. A 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 inner ring gear 93 is fixedly connected to the wheel hub shell 1. The motor-side inner ring gear 93 is meshed with the motor-side planetary gears 92. The motor-side planetary gears 92 are meshed with the motor-side sun gear 94. The fourth one-way clutch 66 is arranged between the motor-side planetary carrier 91 and the main shaft end cover 32.

[0038] The motor side planetary carrier 91 adopts a motor side compound double planetary gear structure, each compound double planetary gear is coaxially fixedly connected by a large gear and a small gear, the large gears of multiple motor side compound double planetary gears are meshed with the motor side sun gear 94, and the small gears of multiple motor side compound double planetary gears are meshed with the motor side inner gear ring 93. When the motor rotor 81 rotates, the power is transmitted to the hub shell 1 through the motor side sun gear 94, the large gear of the motor side compound double planetary gear, the small gear of the motor side compound double planetary gear, and the motor side inner gear ring 93 in sequence.

[0039] When pedaling generates torque, the motor transmission unit 9 starts, the fourth one-way clutch 66 is locked, and the power of the motor rotor 81 is transmitted to the hub shell through the motor-side sun gear 94, the motor-side planetary gear 92, and the motor-side inner ring gear 93. At low speeds, the rotation speed of the motor rotor 81 matches the speed of the hub shell 1, and at medium and high speeds, the rotation speed of the motor rotor 81 and the speed of the hub shell 1 match the reduction ratio of the planetary reduction assembly; when coasting or the motor transmission unit 9 stops, the fourth one-way clutch 66 is separated and disengaged.

[0040] Figure 2 and Figure 3 The left side of the middle is a common reduction motor, which adopts a planetary reduction transmission scheme of a composite double planetary gear, and the right side is an automatic internal speed change unit 4, both of which are integrated in the output hub shell 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 power-assisted bicycles. It is a new hybrid power transmission system that is mainly driven by motors and supplemented by human riding.

[0041] The starting and working process of the motor: it matches the pedaling speed of the person at the same time, and meets the riding speed requirement of the wheel hub from low speed to high speed; when starting at low speed, the torque signal is mainly generated by the pedaling of the person, and the same speed is also given to the freehub 2 and the wheel hub shell 1. At this moment, the control system controls the motor to match the appropriate torque and speed, so that the input of the rider and the assistance of the motor are perfectly unified. As the riding speed increases, the speed of the motor gradually increases. The speed of the motor and the speed of the wheel hub shell 1 meet the fixed reduction ratio of the planetary reduction assembly on the left, providing the main power source for riding; and at medium and high speeds, the automatic transmission unit on the right allows the person's riding speed to be appropriately reduced, so as to obtain a better riding experience at medium and high speeds; After the motor is started, the motor side planetary gear 92, the motor side inner gear ring 93, and the motor side sun gear 94 of the left planetary reduction assembly are always in meshing working state, the fourth one-way clutch 66 is always in meshing and locking, the motor side planetary carrier 91 is fixed to the main shaft end cover 32, and the motor rotor 81 transmits power to the hub shell 1 through the planetary reduction assembly; unless the motor stops assisting and coasting, the fourth one-way clutch 66 is separated and disengaged, at which time the motor side planetary carrier 91 is separated from the main shaft end cover 32, and the motor side planetary carrier 91 can rotate freely. The working state of the one-way device and planetary gear of the right automatic internal transmission unit 4 is as mentioned above and will not be described again.

[0042] The automatic internal speed change unit 4 is integrated with the wheel hub reduction motor in the application of electric bicycles. The automatic internal speed change unit 4 mainly realizes automatic adjustment of different gears through the logical combination of controllable centrifugal one-way clutch, one-way clutch and planetary gear transmission system. When the wheel hub speed is different, the automatic one-way clutch in different positions is closed or opened, so that the riding frequency with a stable speed can be matched with it, so as to obtain a better riding experience; the core of the design is that the two-stage planetary inner gear ring and the complex combination of one-way clutch are integrated together to form a compound differential clutch that can obtain multi-stage speed change. The clutch unit is composed of two controllable centrifugal one-way clutches and two ordinary clutches. The outer ring 41 of the clutch unit is connected to the hub shell 1, and the inner ring 43 is respectively connected to the outer wall of the inner gear ring of the two-stage planet. The two-stage planetary gears share the same speed planetary carrier 55. The center distances of the two-stage planetary gears are the same, and the sun gears are fixedly connected to the fixed support main shaft 3. The number of teeth of the planetary gear transmission is designed to meet special conditions. The speed planetary carrier 55 and the input tower base 2 are as a whole, and there is an ordinary one-way clutch between the component and the end cover 11 of the hub shell 1.

[0043] The advantages of the wheel hub drive device with automatic internal speed change of the present invention are as follows: (1) Since human power has a certain riding speed range, people will feel uncomfortable and tired beyond this range. Therefore, this device improves the riding experience. Especially when the wheel speed is high, the device can enable the rider to maintain a low pedaling frequency. It can automatically match the riding frequency according to the wheel speed (hub speed) to meet the best human riding characteristics.

[0044] (2) The automatic internal transmission unit 4 adopts a compound differential clutch, namely an automatic centrifugal one-way clutch and a common one-way clutch, to realize conditional logic opening or closing, control the multi-stage planetary transmission, realize three-speed transmission, and can also be expanded to realize more speed transmission, thereby realizing the modular design of a multi-speed transmission.

[0045] (3) The automatic internal speed change unit 4 is integrated in the wheel hub reduction motor, and the composite clutch and the inner gear ring are assembled into one body, which has the advantages of integration and unitization.

[0046] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A wheel hub drive device with automatic internal speed change, characterized in that: It includes a hub shell, a freehub, an automatic internal speed change unit, a planetary gear transmission unit, a clutch, and a supporting main shaft. The automatic internal speed change unit includes an outer ring, a middle ring, an inner ring, a first inner gear ring, and a second inner 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 shell 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 inner gear ring, the third centrifugal one-way clutch is arranged between the middle ring and the inner ring, and the third one-way clutch is arranged between the inner ring and the second inner gear ring. The planetary gear transmission unit is installed on the supporting main shaft, the first inner gear ring and the second inner gear ring are respectively meshed with the planetary gear transmission unit, the freehub and the planetary gear transmission unit are an integral whole or fixedly connected, and the first one-way clutch is arranged between the planetary gear transmission unit and the hub shell.

2. The wheel hub drive device with automatic internal speed change according to claim 1, characterized in that: 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 speed planetary rotating frame. The supporting main shaft is installed on the axis of the speed planetary rotating frame. The speed planetary rotating frame is provided with a plurality of pins. The first planetary gear and the second planetary gear are rotatably connected to the pins. The plurality of the first planetary gears and the plurality of the second planetary gears are evenly distributed along the axis of the speed planetary rotating frame. The first sun gear and the second sun gear are fixedly connected to the supporting main shaft. The first inner ring gear and the second inner ring gear are respectively meshed with the first planetary gear and the second planetary gear. The first planetary gear, the second planetary gear and the first sun gear and the second sun gear are meshed. The first one-way clutch is arranged between the speed planetary rotating frame and the hub shell. The tower base is fixedly connected to the speed planetary rotating frame.

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

4. The wheel hub drive device with automatic internal speed change according to claim 2, characterized in that: When the wheel hub speed is in a low speed state, the second centrifugal one-way clutch and the third centrifugal one-way clutch are both in a separated and disengaged state, the first one-way clutch is locked, and the pedaling input power is transmitted to the wheel hub shell output through the tower base and the speed change planetary carrier, and the pedaling speed is the same as the speed of the wheel hub shell.

5. The wheel hub drive device with automatic internal speed change according to claim 2, characterized in that: When the wheel hub speed is in a medium speed state, the second centrifugal one-way clutch is locked, the third centrifugal one-way clutch is separated and disengaged, and the power input by pedaling drives the first planetary gear through the tower base and the speed change planetary carrier to make the first inner ring gear output; when the speed of the first inner ring gear exceeds the pedaling speed, the first one-way clutch is separated, the second one-way clutch is locked, and the power of the first inner ring gear is transmitted to the wheel hub shell output through the second one-way clutch and the second centrifugal one-way clutch.

6. The wheel hub drive device with automatic internal speed change according to claim 2, characterized in that: When the wheel hub speed is in a high-speed state, the second centrifugal one-way clutch is in a locked state, and the third centrifugal one-way clutch also begins to enter a locked state, and the power input by pedaling drives the first planetary gear and the second planetary gear through the tower base and the speed-changing planetary carrier to output the first inner ring gear and the second inner ring gear. When the speed of the second inner ring gear exceeds the speed of the first inner ring gear and the pedaling speed, the first one-way clutch and the second one-way clutch are separated and disengaged, and the third one-way clutch is locked. The power of the second inner ring gear is transmitted to the wheel hub shell output through the third one-way clutch, the third centrifugal one-way clutch, and the second centrifugal one-way clutch.

7. The wheel hub drive device with automatic internal speed change according to claim 2, characterized in that: It also includes bearings, wherein the bearings are connected between the speed-changing planetary rotating frame and the supporting main shaft, and the bearings are connected between the wheel hub shell and the speed-changing planetary rotating frame.

8. The wheel hub drive device with automatic internal speed change according to claim 1, characterized in that: It also includes a reduction motor, which 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, and one end of the motor-side main shaft is connected to the supporting main shaft. The clutch also includes a fourth one-way clutch. The motor drive unit is connected to the motor transmission unit, and the supporting main shaft is provided with a main shaft end cover. The fourth one-way clutch is arranged between the motor transmission unit and the main shaft end cover.

9. The wheel hub drive device with automatic internal speed change according to claim 8, 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 inner ring gear, 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 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 inner ring gear is fixedly connected to the wheel hub shell, the motor side inner ring gear is meshed with the motor side planetary gears, the motor side planetary gears are meshed with the motor side sun gear, and the fourth one-way clutch is arranged between the motor side planetary carrier and the main shaft end cover.

10. The wheel hub drive device with automatic internal speed change according to claim 9, characterized in that: When torque is generated by pedaling, the motor transmission unit starts and the fourth one-way clutch is locked. The power of the motor rotor is transmitted to the hub shell through the motor-side sun gear, the motor-side planetary gear and the motor-side inner ring gear. At low speed, the rotation speed of the motor rotor matches the speed of the hub shell. At medium and high speeds, the rotation speed of the motor rotor and the speed of the hub shell match the reduction ratio of the planetary reduction assembly. When coasting or the motor transmission unit stops, the fourth one-way clutch is separated and disengaged.

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