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CN-122009376-A - Electric power-assisted continuously variable transmission

CN122009376ACN 122009376 ACN122009376 ACN 122009376ACN-122009376-A

Abstract

The application belongs to the technical field of bicycle electric power-assisted continuously variable transmissions, in particular to an electric power-assisted continuously variable transmission and a control method thereof, wherein the electric power-assisted continuously variable transmission comprises a manpower input member, a planetary gear assembly, a motor and an output member, the manpower input member is in transmission connection with a planet carrier, the output member is in transmission connection with a gear ring, the motor drives a sun gear through a first transmission branch provided with a first one-way clutch, the output component is driven by a second transmission branch provided with a second one-way clutch, and the manpower is transmitted to the gear ring in the first rotation direction and separated in the opposite direction through a third one-way clutch by a third transmission branch formed by the planetary rows, so that the motor can selectively participate in the speed regulation of the planetary rows or directly drive the output component, and the manpower can be output through the planetary rows and block the reverse return. The application realizes continuous and smooth stepless speed change and power coupling output on the premise of keeping the compact and closed structure, reduces drag loss and impact, and improves transmission efficiency and riding comfort.

Inventors

  • Zhang Ruchu

Assignees

  • 上海楚才斯盛科技合伙企业(有限合伙)

Dates

Publication Date
20260512
Application Date
20260225

Claims (10)

  1. 1. An electrically assisted continuously variable transmission, comprising: a human input member; The planet row assembly (2) comprises a sun gear, a planet carrier, a gear ring and a plurality of planet gears which are meshed with each other; a motor (4); an output member (6); a first transmission branch connecting the output of the motor (4) with the sun gear of the planetary gear set (2), and provided with a first one-way clutch (3), the first one-way clutch (3) being configured to allow only the torque of the motor (4) to be transmitted to the sun gear along the first transmission branch and to be separated when transmitted in the reverse direction; A second transmission branch connecting the output of the motor (4) with the output member (6), and provided with a second one-way clutch (5), the second one-way clutch (5) being configured to allow only torque of the motor (4) to be transmitted to the output member (6) along the second transmission branch and to be separated upon reverse transmission; A third transmission branch arranged between the manual input member and the output member (6) via the planetary gear set (2), and provided with a third one-way clutch (7), the third one-way clutch (7) being configured to allow torque to rotate through the third transmission branch and drive the output member (6) via a ring gear of the planetary gear set (2) when the manual input member is driven in a first rotational direction, and to disengage when the manual input member is driven in a second rotational direction opposite to the first rotational direction, so as to decouple the manual input member from the output member (6); wherein the manual input member is in transmission connection with the planet carrier of the planet row assembly (2), and the output member (6) is in transmission connection with the gear ring of the planet row assembly (2).
  2. 2. The electrically assisted continuously variable transmission according to claim 1, wherein the electrically assisted continuously variable transmission is a centrally disposed electrically assisted continuously variable transmission, and is integrally disposed in a five-way position of a bicycle frame, wherein the human input member is a center shaft (1), the electrically assisted continuously variable transmission further comprises a housing (9) and a countershaft assembly (8), wherein the housing (9) is fixedly mounted on the bicycle frame, the center shaft (1) is rotatably connected with the housing (9) through a bearing, wherein the planetary gear assembly (2) is fixedly connected with the center shaft (1) through a planet carrier, wherein the planetary gear assembly (2), the motor (4), the first one-way clutch (3), the second one-way clutch (5), the third one-way clutch (7) and the countershaft assembly (8) are disposed inside the housing (9), wherein the countershaft assembly (8) comprises a countershaft input gear (80), a countershaft (81), a first output gear (82) and a second countershaft output gear (83), wherein the countershaft (81) is rotatably connected with the housing (9), and wherein the countershaft (81) is fixedly connected with the input gear (80) so as to be coaxially disposed with the countershaft (80), the second auxiliary shaft output gear (83) is coaxially arranged with the auxiliary shaft (81), and is sleeved on the auxiliary shaft (81) through the second one-way clutch (5).
  3. 3. The electrically assisted continuously variable transmission according to claim 2, wherein the planetary row assembly (2) further comprises a planetary row input gear (220) and a coupling gear (200), the electric machine (4) is provided with a motor output gear (410) which meshes with a countershaft input gear (80), the first countershaft output gear (82) is in driving connection with the sun gear of the planetary row assembly (2) via the planetary row input gear (220), and the second countershaft output gear (83) is in driving connection with the ring gear of the planetary row assembly (2) and the output member (6) via the coupling gear (200).
  4. 4. The electric power assisted continuously variable transmission according to claim 1, wherein the electric power assisted continuously variable transmission is a hub, is arranged at a hub position of a rear wheel of a bicycle and is integrated in the hub, the manual input member is a flywheel (100) arranged on a main shaft (101), the main shaft (101) is fixed on a rear fork of a frame, the output member (6) is rotationally connected with the main shaft (101) through a bearing, the flywheel (100) is sleeved on the main shaft (101) and is rotationally connected with the main shaft (101) through a bearing, a planet carrier of the planet row assembly (2) is fixedly connected with the flywheel (100), and a gear ring of the planet row assembly (2) is fixedly connected with the output member (6).
  5. 5. The electrically assisted continuously variable transmission according to claim 4, further comprising a transmission mechanism (10) disposed between the motor (4) and the planetary row assembly (2), the motor (4), the first one-way clutch (3), the second one-way clutch (5), the third one-way clutch (7) and the transmission mechanism (10) being disposed inside the output member (6) housing.
  6. 6. The electrically assisted continuously variable transmission according to claim 5, wherein said transmission mechanism (10) comprises a transmission sun gear (11), a plurality of transmission planetary gears (12), a transmission ring gear (13), a transmission planet carrier (14) and a transmission mechanism auxiliary shaft (15), a plurality of said transmission planetary gears (12) are mounted to said transmission planet carrier (14) and mesh with said transmission sun gear (11), said transmission ring gear (13) meshes with said plurality of transmission planetary gears (12), said transmission planet carrier (14) is fixedly connected with said main shaft (101), and said transmission ring gear (13) is fixedly connected with said transmission mechanism auxiliary shaft (15).
  7. 7. The electrically assisted continuously variable transmission according to claim 6, characterized in that the first one-way clutch (3) is provided between the variator layshaft (15) and the sun gear of the planetary gear assembly (2), with an inner race of the first one-way clutch (3) being connected with the sun gear of the planetary gear assembly (2) and an outer race being connected with the variator layshaft (15), the second one-way clutch (5) is provided between the variator layshaft (15) and the output member (6), with an inner race of the second one-way clutch (5) being connected with the variator layshaft (15) and an outer race being connected with the output member (6), and the third one-way clutch (7) being provided between the flywheel (100) and the ring gear of the planetary gear assembly (2).
  8. 8. The electrically-assisted continuously variable transmission according to claim 1, characterized in that it has a pure manual mode, a power split assist mode, and a parallel assist mode, and the following power transmission paths are formed by engagement and overrunning disengagement cooperation of the first one-way clutch (3), the second one-way clutch (5), and the third one-way clutch (7), respectively: in the pure manual mode, the motor (4) does not output driving torque, the first one-way clutch (3) and the second one-way clutch (5) are in an overrunning separation state, the torque of the manual input member is unidirectionally transmitted to the gear ring through the third one-way clutch (7) of the third transmission branch, and the gear ring drives the output member (6); In the power split assisting mode, the torque of a motor (4) is transmitted to a sun gear of a planetary gear set (2) through a first transmission branch and a first one-way clutch (3), the torque of a manual input member is input to a planet carrier of the planetary gear set (2) through a third transmission branch, and the motor torque and the manual torque are output by a gear ring of the planetary gear set (2) and drive an output member (6) after being coupled in the planetary gear set (2), wherein the second one-way clutch (5) is in an overrunning separation state so as to block the power transmission of the motor (4) to the output member (6) through a second transmission branch; In the parallel power assisting mode, the torque of the motor (4) is transmitted to the output member (6) through the second transmission branch and the second one-way clutch (5), and meanwhile, the torque of the manual input member is transmitted to the gear ring of the planet row assembly (2) through the third transmission branch and the third one-way clutch (7) in a one-way mode and drives the output member (6), so that parallel driving of the manual branch and the motor branch to the output member (6) is formed.
  9. 9. The electrically assisted continuously variable transmission according to claim 1, wherein the planetary gear assembly (2) comprises two stages of mutually coupled planetary gear rows, namely a first planetary gear row assembly (2-1) and a second planetary gear row assembly (2-2), the first planetary gear row assembly (2-1) comprises a first sun gear, a first planet carrier, a first gear ring and a plurality of first planet gears which are mutually meshed, the second planetary gear row assembly (2-2) comprises a second sun gear, a second planet carrier, a second gear ring and a plurality of second planet gears which are mutually meshed, the output shaft of the first transmission branch connecting motor (4) and the first sun gear of the first planetary gear row assembly (2-1), the output shaft of the second transmission branch connecting motor (4) and an output member (6), the third transmission branch being arranged between a human input member and an output member (6) via the second planetary gear row assembly (2-2), wherein the human input member is fixedly connected with the second planet carrier, the first planetary gear ring gear (6) is arranged on the first one-way clutch (3) and the second one-way clutch (5); The first gear ring is in transmission connection with the second gear ring or the second sun gear, the first gear ring and the second gear ring drive the output member (6) together, and the first planet carrier is in transmission connection with the second sun gear, and the first gear ring and the second sun gear drive the output member (6) together, and the first planet carrier is in transmission connection with the second gear ring when in transmission connection with the second sun gear.
  10. 10. A control method of an electrically assisted continuously variable transmission according to any one of claims 1 to 9, characterized in that the control method comprises: Step 1, acquiring the running condition information of the whole vehicle; When judging that the working conditions currently belong to starting, low-speed and/or medium-small load demand working conditions based on the operation working condition information, controlling a motor to output and drive a first one-way clutch to be closed according to the direction of a first transmission branch, inputting motor power into a sun gear of a planetary gear assembly through the first transmission branch, separating a second one-way clutch, cutting off direct transmission of the motor power to an output member, simultaneously allowing a manpower input member to input the manpower power into the planetary gear assembly through a fixedly connected planet carrier, enabling the motor power and the manpower power to be split in the planetary gear assembly and synthesized at a gear ring, and outputting the motor power and the manpower power through the gear ring and the output member connected with the gear ring to form a power splitting power assisting mode; When the current low-speed and high-load demand working condition is judged based on the operation working condition information, controlling the motor to output and drive the second one-way clutch to be closed according to the direction of the second transmission branch, directly inputting and outputting the motor power through the second transmission branch, separating the first one-way clutch, cutting off the input of the motor power to the sun wheel, simultaneously allowing the human input component to input and output the human power to the sun wheel through the third one-way clutch and the gear ring of the planet row assembly, and enabling the motor power and the human power to be combined and output in parallel at the output component to form a parallel power assisting mode; Step 4, when the current electric power which is not needed or the electric quantity of the storage battery is lower than a preset threshold value based on the operation condition information, controlling the motor to stop outputting so that the output shaft of the motor is in an idle state, and only allowing the manpower input member to drive the output member through the planet carrier and/or the third one-way clutch to form a pure manpower riding mode; And 5, repeatedly executing the step 1 in real time, and switching among a power splitting power assisting mode, a parallel power assisting mode and a pure manpower mode according to the updated operation condition information.

Description

Electric power-assisted continuously variable transmission Technical Field The application belongs to the technical field of electric-assisted continuously variable transmissions of bicycles, and particularly relates to an electric-assisted continuously variable transmission. Background Along with the continuous improvement of the requirements of people on green travel and energy conservation and environmental protection, the booster bicycle (also called as an electric booster bicycle) gradually becomes a main form of urban short-distance traffic due to the advantages of manpower driving and electric booster. The existing booster bicycle generally adopts a driving mode of a central motor or a hub motor, and realizes cooperative output by assisting manpower through the motor. In the existing structure, the rear wheel is mainly an external multi-stage cone pulley or a hub type transmission, is connected with a front fluted disc through a chain, and is shifted by a shifting fork mechanism. The structure can provide a certain speed ratio change, but has the defects that 1, the mechanisms such as a transmission chain, a cone pulley, a shifting fork and the like are exposed to the external environment, and are kept to run smoothly depending on lubricating oil, so that the lubricating oil is easy to leak and pollute the environment, 2, dust and sediment are easy to adhere to the surfaces of the chain and the cone pulley, so that the abrasion is aggravated, the transmission efficiency is reduced and the maintenance is frequent, 3, the mechanical speed change gear is limited, the speed ratio change is discrete, the stepless smooth speed regulation is difficult to realize, and the riding comfort is influenced. To overcome the above-mentioned problems, the prior art proposes to integrate the motor and the two-speed mechanical transmission inside the hub, so as to realize an electric drive system without exposed chain. Although the scheme improves the tightness and the attractiveness of the system, the motor has a limited speed ratio adjusting range because the motor is only provided with a two-gear mechanical speed change function, is difficult to adapt to variable working conditions, and has longer working time and lower efficiency under a low-speed high-load state. In addition, the scheme is also tried to improve the transmission performance by matching a centrally-mounted motor with a multi-gear hub speed change mechanism or arranging a composite planetary row structure in a hub, but the structures have the defects of 1. The structure is complex, the manufacturing precision requirement is high, the assembly space is limited, the lightweight design is not facilitated, 2. The power path is fixed, and the flexible distribution of manpower, motor and wheel inertia energy under different working conditions is lacked. In summary, in the prior art, no matter the scheme of external chain transmission and multistage cone pulley is adopted, or the scheme of integrating the motor and the two-gear mechanical transmission in the hub is adopted, or the scheme of using the middle motor to match with the flower drum type or compound planetary gear transmission mechanism is adopted, the comprehensive performances of compact and closed structure, high transmission efficiency, wide speed ratio range, flexible power distribution, easy manufacturing and assembly and the like cannot be simultaneously considered, so that an electric power-assisted stepless transmission capable of realizing wide speed ratio, continuous variable speed and power self-adaptive coupling and having high efficiency and low maintenance characteristics on the premise of keeping the compact and closed hub structure is needed. Disclosure of Invention Aiming at the technical problems that an external chain transmission and multistage cone pulley or hub speed change mechanism is easy to be worn by environmental pollution, frequent in maintenance, discrete in gear and difficult to smoothly and steplessly regulate speed, a two-gear integration scheme in a hub is limited in speed ratio range, a motor is low in low speed and high in load efficiency and inflexible in power distribution and the like, the application provides an electric power assisted stepless speed changer. In one aspect, the present application provides an electrically assisted continuously variable transmission comprising: a human input member; the planet row assembly comprises a sun gear, a planet carrier, a gear ring and a plurality of planet gears which are meshed with each other; A motor; An output member; a first transmission branch connecting the output of the motor with the sun gear of the planetary gear set, and provided with a first one-way clutch configured to allow only the torque of the motor to be transmitted to the sun gear along the first transmission branch and to be separated when transmitted reversely; A second transmission branch connecting the output of the motor with the output memb