WO2024021788A1

WO2024021788A1 - Mid-drive motor and electric bicycle

Info

Publication number: WO2024021788A1
Application number: PCT/CN2023/094854
Authority: WO
Inventors: 黄玮; 范清泉; 刘海量; 王洪晓
Original assignee: 广东威灵电机制造有限公司
Priority date: 2022-07-29
Filing date: 2023-05-17
Publication date: 2024-02-01
Also published as: CN115042908B; CN115042908A

Abstract

A mid-drive motor (100), comprising a housing (101), a crank shaft (102), a power output member (201), an electric motor (202), a gear reduction mechanism (203), a first one-way clutch (204) and a second one-way clutch (205), wherein the housing (101) is configured to fixedly connect to a frame (103); the crank shaft (102) penetrates the housing (101) and is rotationally connected to the housing (101); the crank shaft (102) is configured to connect to a pedal crank (105); the pedal crank (105) is connected to a pedal (106); and the first one-way clutch (204) is arranged between the power output member (201) and the crank shaft (102). Further provided is an electric bicycle. The mid-drive motor and the electric bicycle can achieve the technical effects of a simple structure and a small size.

Description

Mid-motor and electric bicycles

Cross-references to related applications

This application is filed based on the Chinese patent application with application number: 202210907717.9 and the filing date is July 29, 2022, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated into this application as a reference.

Technical field

This application relates to the technical field of electric bicycles, particularly to mid-mounted motors and electric bicycles.

Background technique

Among related technologies, in power-assisted electric bicycles, how to achieve small size and high power, and how to perfectly integrate the core components of electric power assist into the bicycle frame has always been the focus of design and development. In the related art, the one-way clutch of the motor assist part of the mid-mounted motor is arranged on the gear transmission assembly. This arrangement increases the overall size of the gear, and its structure and assembly form are complicated.

Contents of the invention

This application aims to solve at least one of the technical problems existing in the prior art. To this end, this application proposes a mid-mounted motor that can reduce the overall size of the gear transmission assembly.

This application also proposes an electric bicycle with the above-mentioned mid-mounted motor.

A mid-mounted motor according to the first embodiment of the present application includes: a housing, a crankshaft, a power output member, a motor, a gear reduction mechanism and a second one-way clutch; the crankshaft is rotationally connected to the housing; the The power output member is connected to the crankshaft through a transmission assembly, and the transmission assembly includes a first one-way clutch; the motor is installed in the housing; the gear reduction mechanism is connected to the output end of the motor, and the The gear reduction mechanism includes an output shaft and an output gear. The output gear is provided on the output shaft. The output shaft is provided with an inner hole. The power output member is inserted through the inner hole; the second one-way clutch Connect the output gear and the power output member; wherein the second one-way clutch includes a second inner ring, a second clutch assembly and a second outer ring, and the second clutch assembly is located in the inner hole, Part of the power output member is configured as the second inner ring, and part of the output shaft is configured as the second outer ring.

The mid-mounted motor according to the embodiment of the present application has at least the following beneficial effects: the overall size of the output gear is the largest among all the gears of the gear reduction mechanism, and the second one-way clutch is arranged in the inner hole of the output shaft, which can reasonably Utilizing the inner hole space of the output shaft, there is no need to additionally increase the size of the gear, and the power output member and the output shaft are used as the second inner ring and the second outer ring of the second one-way clutch respectively, that is, compared with the general single To the clutch, the inner and outer rings are reduced, which can reduce the overall size of the gear transmission assembly.

According to some embodiments of the present application, the first one-way clutch includes a first inner ring, a first clutch assembly and a first outer ring. The first outer ring is fixedly connected to the crankshaft. The first clutch The assembly is located between the first inner ring and the first outer ring. The transmission assembly includes a torque detection device. The torque detection device includes a torque sensing sleeve and a torque sensor. The torque sensing sleeve is connected to the first The inner ring, the power output member, and the torque sensor are fixed to the housing.

According to some embodiments of the present application, the torque detection device includes a shielding cover, and the shielding cover is provided on the outer periphery of the torque sensor.

According to some embodiments of the present application, the torque sensor includes a coil holder, the coil holder is fixed to the housing, and the coil holder is provided with an induction coil.

According to some embodiments of the present application, the mid-mounted motor includes a cadence sensor. The cadence sensor includes a detection component and a target component. The target component is fixed to the first outer ring, and the detection component is fixed to the first outer ring. on the coil holder.

According to some embodiments of the present application, the gear reduction mechanism includes an input shaft and an input gear, the motor includes a rotor assembly, and the input gear and the rotor assembly are installed on the input shaft.

According to some embodiments of the present application, the input shaft is provided with a first bearing, a second bearing and a third bearing, the input gear is located between the first bearing and the third bearing, and the rotor assembly Located between the second bearing and the third bearing.

According to some embodiments of the present application, the gear reduction mechanism is a two-stage reduction gear set or a three-stage reduction gear set.

According to some embodiments of the present application, the motor includes a stator assembly, the stator assembly includes a winding, and the winding uses a conductor with a non-circular cross-section.

According to some embodiments of the present application, the mid-mounted motor includes an angle sensor for detecting the rotation speed of the motor, and the angle sensor is arranged in the gear reduction mechanism.

According to some embodiments of the present application, the power output member is provided with a fourth bearing. The fourth bearing is located on an end side of the second one-way clutch and is used to support the output shaft. The fourth bearing It includes an outer raceway, a rolling assembly and an inner raceway, part of the power output member is configured as the inner raceway, and part of the output shaft is configured as the outer raceway.

An electric bicycle according to a second embodiment of the present application includes the mid-mounted motor of the first embodiment of the present application.

The electric bicycle according to the embodiment of the present application has at least the following beneficial effects: by using the mid-mounted motor of the first embodiment of the present application, the inner hole space of the output shaft can be reasonably utilized without additionally increasing the size of the gear. And the power output part and the output shaft are respectively configured as the second inner ring and the second outer ring of the second one-way clutch. That is, compared with the general one-way clutch, the inner ring and the outer ring are reduced, and the gear transmission assembly can be reduced. overall size.

Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.

Description of drawings

The present application will be further described below in conjunction with the accompanying drawings and examples, wherein:

Figure 1 is a schematic diagram of an electric bicycle according to an embodiment of the present application;

Figure 2 is a schematic diagram of a mid-mounted motor according to an embodiment of the present application;

Figure 3 is an A-A cross-sectional view of the mid-mounted motor shown in Figure 2;

Figure 4 is a schematic diagram of the gear reduction mechanism and transmission assembly shown in Figure 3;

Figure 5 is a B-B cross-sectional view shown in Figure 4;

Figure 6 is a C-C cross-sectional view shown in Figure 4;

FIG. 7 is an exploded view of the power output member, the second one-way clutch and the output gear shown in FIG. 6 .

Reference signs:

100. Mid-mounted motor; 101. Housing; 102. Crankshaft; 103. Frame; 104. Wheel; 105. Pedal crank; 106. Pedal; 107. Chain; 108. Drive sprocket;

201. Power output part; 202. Motor; 203. Gear reduction mechanism; 204. First one-way clutch; 205. Second one-way clutch; 206. First housing; 207. Second housing; 208. First End cover; 209, second end cover; 210, input shaft; 211, input gear; 212, first intermediate shaft; 213, primary driven gear; 214, secondary driving gear; 215, second intermediate shaft; 216 , secondary driven gear; 217, third-stage driving gear; 218, output shaft; 219, output gear; 220, first bearing; 221, second bearing; 222, third bearing; 223, electrical control component; 224, Angle sensor magnetic ring; 225, cadence sensor; 226, torque detection device; 227, detection component; 228, target component; 229, torque sensing sleeve; 230, torque sensor; 231, strain gauge; 232, shielding cover; 233. Coil holder; 234. Fourth bearing; 235. Stator assembly; 236. Rotor assembly; 237. Induction coil;

601. Second clutch component; 602. Inner hole; 603. Rolling component.

Detailed ways

The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and cannot be understood as limiting the present application.

In the description of this application, it should be understood that the orientation descriptions involved, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc. are based on the orientation or positional relationship shown in the drawings, and are only In order to facilitate the description of the present application and simplify the description, it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present application.

In the description of this application, several means one or more, plural means two or more, greater than, less than, exceeding, etc. are understood to exclude the original number, and above, below, within, etc. are understood to include the original number. If there is a description of first and second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the order of indicated technical features. relation.

In the description of this application, unless otherwise explicitly limited, words such as setting, installation, and connection should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meaning of the above words in this application in conjunction with the specific content of the technical solution.

A power-assisted electric bicycle is a new type of two-wheeled vehicle, which is a type of bicycle. It uses a battery as an auxiliary power source, is equipped with a motor, and has a power assist system. It can realize the integration of human riding and motor-assisted new transportation. .

In the field of power-assisted electric bicycles, there are two main types of motor installation positions. One is mid-mounted, that is, the motor is installed in the middle of the body, that is, the motor at the bottom bracket position is called a mid-mounted motor. Referring to Figure 1, it can be understood that an electric bicycle includes a frame 103, wheels 104, pedal cranks 105, pedals 106, a chain 107, a driving sprocket 108 and a mid-mounted motor 100. The mid-mounted motor 100 is connected to the bicycle. The frame 103 is connected, and is connected to the rear wheel through a chain 107 to transmit power. At the same time, pedals 106 are installed on both sides of the mid-mounted motor 100. When the mid-mounted motor 100 has no power supply, the rider can use the pedals to To achieve human-powered riding, the resistance is no different from that of a normal bicycle.

The other is installed in the wheel hub of the bicycle, called a hub motor. Compared with hub motors, mid-mounted motors have greater advantages in technology and performance. For example, the advantage of a mid-mounted motor is that it can maintain the front and rear weight balance of the vehicle as much as possible without affecting the shock absorber action. The motor will also bear less road impact, and its ultra-high degree of integration can reduce unnecessary exposure of wire pipes. , so it is better than cars equipped with in-wheel motors in terms of off-road handling, stability, and passability. In the related art, in most mid-mounted motors, the one-way clutch of the motor assist part is arranged on the intermediate gear of the gear transmission assembly. This arrangement increases the overall size of the intermediate gear, and its structure and assembly form are more complicated.

The following describes how the mid-mounted motor 100 and the electric bicycle according to the embodiment of the present application solve the above problems with reference to FIGS. 2 to 7 .

Referring to Figures 2 and 3, it can be understood that the mid-mounted motor 100 in the embodiment of the present application includes a housing 101, a crankshaft 102, a power output part 201, a motor 202, a gear reduction mechanism 203, and a first one-way clutch 204 and the second one-way clutch 205. The housing 101 is used to be fixedly connected to the frame 103 to ensure the stability of the entire mid-mounted motor 100.

The crankshaft 102 is passed through the housing 101 and is rotationally connected with the housing 101. The crankshaft 102 is used to connect the foot crank 105, and the foot crank 105 is connected to the foot pedal 106. The first one-way clutch 204 is provided between the power output member 201 and the crankshaft 102 . When the rider steps on the pedal 106, the pedal crank 105 drives the crank shaft 102 to rotate, the first one-way clutch 204 works, and the human power is transmitted to the power output member 201 through the first one-way clutch 204, thereby turning the pedal The power is transmitted to the wheel 104, and finally drives the wheel 104 to rotate.

The motor 202 is fixedly connected to the housing 101 so that the motor 202 can stably provide power to achieve the power-assisting effect. The gear reduction mechanism 203 is connected to the output end of the motor 202, and the second one-way clutch 205 is disposed between the output end and the power output member 201. The power of the motor 202 is transmitted to the gear reduction mechanism 203, and the second one-way clutch 205 operates, thereby transmitting the power of the motor 202 to the wheel 104, and finally drives the wheel 104 to rotate.

In addition, by using the first one-way clutch 204, when the motor 202 outputs power and the rider does not pedal, the phenomenon of magnetic resistance or mechanical resistance caused by the crankshaft 102 to the gear reduction mechanism 203 is eliminated, thereby enabling the It is guaranteed that no additional resistance will be added to the motor 202 when the rider does not have pedals. By using the second one-way clutch 205, when the motor 202 stops running, the phenomenon of magnetic resistance or mechanical resistance caused by the motor 202 and the gear reduction mechanism 203 to the crankshaft 102 is eliminated, thereby ensuring that no power is generated when the motor 202 is not assisting. Adds extra resistance to the rider.

It can be understood that when the crankshaft 102 is driven by human power to rotate forward, and the motor 202 does not provide assistance to the power output member 201, the crankshaft 102 can drive the first one-way clutch 204 to work, and the human power is transmitted through the first one-way clutch 204. When the power output member 201 is reached, the second one-way clutch 205 is idling at this time, and human power does not affect the gear reduction mechanism 203, so that the power output member 201 is driven to rotate by human pedaling. In addition, when the rider stops pedaling or rotates the pedal 106 in the opposite direction, the crankshaft 102 rotates in the opposite direction relative to the first one-way clutch 204, that is, the crankshaft 102 does not transmit power to the power output member 201 at this time. power. In addition, when the motor 202 outputs power but the rider does not pedal, the motor 202 rotates in the forward direction and delivers it to the power output member 201. At this time, the first one-way clutch 204 is idling and the motor 202 does not affect the crank. Axis 102. That is, when manpower drives the crankshaft 102 to rotate in the forward direction, power is provided to the power output member 201 through the first one-way clutch 204. When manpower drives the crankshaft 102 to rotate in the reverse direction or there is no relative rotation, the crankshaft 102 and the first unit The relative rotation to the clutch 204 means that the crankshaft 102 does not transmit resistance to the power output member 201 .

It can be understood that when the motor 202 rotates in the forward direction, the second one-way clutch 205 can drive the power output member 201 to rotate in the forward direction. In addition, when the crankshaft 102 drives the power output member 201 to rotate, and at the same time the motor 202 does not provide assistance to the power output member 201, the second one-way clutch 205 is idling at this time, that is, the power output member 201 can rotate relative to the second one-way clutch 205 at this time. The rotation of the clutch 205 does not affect the rotation of the crankshaft 102. When the rotation direction of the motor 202 is reversed relative to the second one-way clutch 205, the motor 202 does not transmit power to the power output member 201 at this time. That is, when the motor 202 rotates in the forward direction relative to the second one-way clutch 205, it provides assistance to the power output member 201 through the second one-way clutch 205. When the motor 202 rotates in the reverse direction relative to the second one-way clutch 205 or does not During relative rotation, the motor 202 and the second one-way clutch 205 rotate relatively, that is, the motor 202 does not transmit resistance to the power output member 201.

It should be noted that when the crankshaft 102 rotates in the forward direction and/or the motor 202 rotates in the forward direction and drives the power output member 201, the electric bicycle is in a forward state at this time.

Referring to FIG. 3 , it can be understood that the housing 101 includes a first housing 206 , a second housing 207 , a first end cover 208 and a second end cover 209 . The material of the housing 101 may be aluminum alloy, magnesium alloy, or magnesium-aluminum alloy. The first end cover 208 is located at the left rear position of the first housing 206, so that the left rear portion of the first housing 206 and the first end cover 208 together define a first cavity for accommodating the motor 202. The second end cover 209 Located in the left half of the second housing 207 and between the first housing 206 and the second housing 207 , the second end cover 209 and the second housing 207 together form a second housing for accommodating the gear reduction mechanism 203 . cavity, the crankshaft 102 penetrates the first housing 206 and the second housing 207, the first one-way clutch 204 is located at one end of the crankshaft 102 close to the first housing 206, and the second one-way clutch 205 is located at the end of the crankshaft 102 close to the first housing 206. One end of the second housing 207. The first end cover 208 and the first housing 206 are fixed to each other by bolts, the second end cover 209 and the second housing 207 are fixed to each other by bolts, and the first housing 206 and the second housing 207 are fixed to each other by bolts. A sealing member is arranged between the first housing 206 and the second housing 207, and the sealing members are used to seal each other. The seal is a flat seal made of non-metallic material.

It can be understood that the motor 202 is in the form of an outer stator and an inner rotor, including a stator assembly 235 and a rotor assembly 236 . The stator assembly 235 is arranged in the first housing 206 , the rotor assembly 236 is arranged on the inner circumference of the stator assembly 235 , and the rotor assembly 236 is connected to the gear reduction mechanism 203 . The winding of the stator assembly 235 usually uses round wire winding, and the winding slot fill rate of the round wire winding is low. Under the condition that the volume of the stator assembly 235 remains unchanged, the power density and efficiency of the mid-mounted motor 100 are both low. The mid-mounted motor 100 is used in electric bicycles to accelerate the consumption of battery life, so there is a great demand for improving the energy efficiency of the motor 202.

It can be understood that the stator assembly 235 includes windings and a stator core. The stator core is generally cut from silicon steel sheets, and the cut silicon steel sheets are processed into a wound stator core. In order to improve the utilization of silicon steel sheets When cutting, you need to design the cutting method in advance. If the teeth of the stator core are equipped with tooth boots, when cutting the stator core, you must design the cutting method according to the tooth boots. But no matter what, Optimization, in the case of toothed shoes, the material utilization rate of silicon steel sheets can only reach 70% at most, and it is difficult to further improve it. The stator core in the embodiment of the present application adopts the tooth portion of the toothless shoe to optimize the cutting method and thereby improve the material utilization rate of the silicon steel sheet.

It can be understood that the tooth portion is set in a straight tooth shape, and the winding does not need to be wound on the tooth portion. The winding can be completed externally using tooling, and the operating space is large, which can effectively increase the winding slot full rate. In addition, the winding uses aluminum conductors with non-circular cross-sections, such as square-section aluminum conductors, while the teeth adopt a straight tooth-shaped structure, such as the cross-section of the teeth is also square. The aluminum conductors of the winding match the shape of the teeth, and the aluminum conductors are tight Fitting to the outer wall of the tooth portion allows the aluminum conductors to be arranged more closely, thus increasing the winding slot fullness ratio of the stator assembly 235 . Therefore, the motor 202 adopts the flat wire process, which improves the power density and efficiency of the mid-mounted motor 100 while keeping the volume of the stator assembly 235 unchanged. The mid-mounted motor 100 is used in electric vehicles, which helps to improve the endurance of electric vehicles. .

Referring to Figure 3, it can be understood that the gear reduction mechanism 203 is a parallel shaft reduction gear set, which is arranged parallel to the crankshaft 102 in the housing 101. According to different speed ratio requirements, it can be a two-stage reduction gear set, or It can be a three-stage reduction gear set.

Referring to FIG. 3 , it can be understood that the gear reduction mechanism 203 is a three-stage reduction gear set. The three-stage reduction gear set includes an input shaft 210 , an input gear 211 , a first intermediate shaft 212 , a first-level driven gear 213 , and a second-level driven gear 213 . The first-stage driving gear 214, the second intermediate shaft 215, the second-stage driven gear 216, the third-stage driving gear 217, the output shaft 218, the output gear 219 and multiple sets of bearing groups. The input shaft 210 rotates with the rotor assembly 236 and is arranged parallel to the axis of the crankshaft 102 and the input gear 211 is arranged on the input shaft 210 . The first intermediate shaft 212 is arranged parallel to the axis of the crankshaft 102. The primary driven gear 213 is arranged on the first intermediate shaft 212, meshes with the input gear 211, and has a greater number of teeth than the input gear 211. The driving gear 214 is arranged on the first countershaft 212 . The second intermediate shaft 215 is arranged parallel to the axis of the crankshaft 102 . The secondary driven gear 216 is arranged on the second intermediate shaft 215 , meshes with the secondary driving gear 214 , and has more power than the secondary driving gear 214 . The third-stage driving gear 217 is arranged on the second countershaft 215. The output shaft 218 rotates coaxially with the power output member 201. The output gear 219 is arranged on the output shaft 218, meshes with the third-stage driving gear 217, and has a greater number of teeth than the third-stage driving gear 217. Multiple sets of bearing sets support the input shaft 210, the first intermediate shaft 212, the second intermediate shaft 215, and the output shaft 218 in such a manner that they can rotate around their axes.

It can be understood that the material of the gear reduction mechanism 203 can be all steel. The primary driven gear 213 and the secondary driven gear 216 can also be a combination of steel and plastic materials, and can adopt a plastic-coated structure or a nested structure.

It can be understood that the input gear 211 and the input shaft 210 can be of an integrated structure, the first intermediate shaft 212 and the secondary driving gear 214 can be of an integrated structure, and the primary driven gear 213 can be splined or interference-fitted. The second intermediate shaft 215 and the third-stage driving gear 217 can be an integrated structure, and the secondary driven gear 216 can be fixed on the second intermediate shaft 215 through splines or interference fit. On the other hand, the output gear 219 and the output shaft 218 may be of an integrated structure. The input shaft 210 and the rotor assembly 236 may be connected together by a spline or an interference fit.

It can be understood that when the gear reduction mechanism 203 is a secondary reduction gear set, the secondary reduction gear set includes an input shaft 210, an input gear 211, a first intermediate shaft 212, a primary driven gear 213, a secondary driving gear 214, Output shaft 218, output gear 219 and multiple bearing sets.

It can be understood that the overall size of the output gear 219 is larger than the primary driven gear 213 and the secondary driven gear 216. Therefore, the diameter of the inner hole 602 of the output shaft 218 can also be made larger than the first intermediate shaft 212 and the second intermediate shaft 212. The diameter of the shaft hole of the intermediate shaft 215 is large, and the second one-way clutch 205 is arranged in the inner hole 602 of the output shaft 218, which can effectively utilize the space of the inner hole 602 of the output shaft 218, and at the same time reduce the size of the primary driven gear 213 and The overall size of the secondary driven gear 216 can thereby reduce the overall size of the gear transmission assembly.

Referring to FIG. 3 , it can be understood that the plurality of bearing sets include a first bearing 220 , a second bearing 221 and a third bearing 222 . The first bearing 220 is fixed to the second housing 207 and is mounted on the input shaft 210 Axially, the first bearing 220 is arranged on a different side from the motor 202 , that is, the first bearing 220 is arranged on the front side of the input shaft 210 . The second bearing 221 is fixed to the input shaft 210 , and is arranged on the same side as the motor 202 in the axial direction of the input shaft 210 , that is, the second bearing 221 is arranged on the rear side of the input shaft 210 . The third bearing 222 is fixed to the input shaft 210 and is arranged between the first bearing 220 and the second bearing 221 in the axial direction of the input shaft 210 . In related technologies, the shaft where the output of the motor 202 is located generally has two support bearings arranged at both ends. There is no auxiliary support in the middle of the shaft where the output of the motor 202 is located. In this way, the shaft where the output of the motor 202 is located will bear a large bending moment, which is not conducive to the control of vibration and noise. . In the embodiment of the present application, two support bearings and an auxiliary support bearing are arranged on the output shaft of the motor 202, that is, the first bearing 220 and the second bearing 221 are respectively arranged at both ends of the input shaft 210. The second bearing 221 serves as a support bearing, and a third bearing 222 is arranged in the middle of the input shaft 210. The third bearing 222 serves as an auxiliary support bearing, which can well support the motor 202 and provide support for gear transmission, which is beneficial to the control of vibration and noise.

The second bearing 221 and the third bearing 222 may be ball bearings, and the first bearing 220 may be a needle roller bearing or a cylindrical roller bearing. The second bearing 221 and the third bearing 222 can stably support the rotation of the input shaft 210 and the rotor assembly 236, while the addition of the first bearing 220 can stably support the rotation of the input gear 211.

Referring to Figure 3, it can be understood that the mid-mounted motor 100 also includes an electrical control component 223 and an angle sensor magnetic ring 224. The angle sensor magnetic ring 224 is arranged on the gear reduction mechanism 203, rotates together with the rotor assembly 236, and electrically The angle sensor on the control component 223 is used to detect the rotation speed and position of the motor 202 . The electrical control component 223 is disposed around the circumference of the input shaft 210 and the crankshaft 102 for controlling the motor 202 .

Referring to FIGS. 3 to 5 , it can be understood that the mid-mounted motor 100 also includes a transmission assembly. The power output member 201 is connected to the crankshaft 102 through the transmission assembly. The transmission assembly is arranged in the housing 101 . The transmission assembly is arranged in the housing 101 . One end of the crankshaft 102 is arranged on a side away from the drive sprocket 108 , and the transmission assembly is rotatable around the crankshaft 102 . The transmission assembly includes a first one-way clutch 204, a cadence sensor 225 and a torque detection device 226. The first one-way clutch 204 is arranged at one end of the transmission assembly and is connected to the crankshaft 102 in the housing 101; cadence The pedaling sensor 225 is arranged at one end of the transmission assembly and is connected to the first one-way clutch 204 in the housing 101 for detecting the rotation speed and steering of the crankshaft 102; the torque detection device 226 is arranged at the other end of the transmission assembly. The first one-way clutch 204 is connected to the housing 101 for detecting the torque generated on the crankshaft 102 .

Specifically, the first one-way clutch 204 is arranged on the transmission assembly and is arranged on a side further away from the drive sprocket 108 than the torque detection device 226. The drive sprocket 108 is located on the side where the power output member 201 is located. The one-way clutch 204 transmits the rotational force of the crankshaft 102 in the first rotational direction (the direction in which the electric power-assisted bicycle is forwarded) to the drive sprocket 108 without transmitting the rotational force of the crankshaft 102 in the opposite direction to the first rotational direction. Drive sprocket 108. The first one-way clutch 204 may be splined to the crankshaft 102 and the torque detection device 226 .

The cadence sensor 225 includes a detection component 227 and a target component 228. The target component 228 is arranged on the first one-way clutch 204 and closer to the torque detection device 226 side. The target component 228 is arranged in the axial direction of the crankshaft 102. On a different position from the torque detection device 226, the target component 228 can rotate together with the crankshaft 102; the detection component 227 is arranged on the torque detection device 226, which is arranged on the side of the target component 228, for detecting the rotation of the target component 228 speed and direction.

The torque detection device 226 includes a torque sensing sleeve 229 and a torque sensor 230. The torque sensing sleeve 229 rotates together with the crankshaft 102. The torque sensing sleeve 229 is provided with a strain gauge 231. The strain gauge 231 can reflect the deformation of the torque sensing sleeve 229; the torque sensor 230 is arranged on the outer circumference of the torque sensing sleeve 229 to detect the torque on the torque sensing sleeve 229. The torque detection device 226 also includes a shielding cover 232. The shielding cover 232 is arranged on the outer circumference of the torque sensing sleeve 229 to shield the interference of external signals on the torque sensor 230 to ensure signal detection accuracy.

The first one-way clutch 204 includes a first inner ring, a first clutch assembly and a first outer ring, the first outer ring is fixedly connected to the crankshaft 102, and the first clutch assembly is located between the first inner ring and the first outer ring, The torque sensing sleeve 229 connects the first inner ring and the power output member 201 , and the torque sensor 230 is fixed on the housing 101 . The first one-way clutch 204 is placed at the front end of the power output route. When the crankshaft 102 rotates reversely, it does not need to drive many parts to rotate together, and the inertia is small. That is, when the crankshaft 102 rotates reversely, only the first outer ring rotates together with the crankshaft 102, while the first inner ring and the torque sensing sleeve 229 can be in a stationary state.

The torque sensor 230 includes a coil holder 233 which is arranged on the outer circumference of the torque sensing sleeve 229 . The coil holder 233 is fixed to the housing 101 and is provided with an induction coil 237 . The target component 228 is fixed on the first outer ring, and the detection component 227 is fixed on the coil fixing base 233 . The coil holder 233, other components of the torque sensor 230 and the shielding cover 232 are fixed on the first housing 206 and can be in a stationary state.

A drive sprocket 108 is installed on one end of the power output member 201, and the power output member 201 and the drive sprocket 108 become part of the output assembly. The output assembly is arranged at an end of the crankshaft 102 away from the transmission assembly and can rotate around the crankshaft 102 . The power output member 201 is coaxially arranged with the crankshaft 102. One end of the power output member 201 can be connected to the torque sensing sleeve 229 through splines, and the other end can be connected to the drive sprocket 108 through splines, on the side closer to the drive sprocket 108. It is supported on the housing 101 by bearings.

The crankshaft 102 penetrates the housing 101 and is arranged parallel to the motor 202. The crankshaft 102 penetrates the transmission assembly and the power output member 201 . The crankshaft 102 is connected to the transmission assembly through splines, and transmits human-driven power to the drive sprocket 108; its side away from the sprocket 108 is supported on the housing 101 through bearings.

Referring to FIG. 3 , it can be understood that fourth bearings 234 are arranged at both ends of the second one-way clutch 205 to support the output shaft 218 so that the output shaft 218 can rotate around the axis of the power output member 201 . The fourth bearing 234 may be a needle roller bearing, a cylindrical roller bearing, or a ball bearing; in the embodiment shown in FIG. 7 , the fourth bearing 234 is a needle roller bearing, and the inner hole 602 of the output shaft 218 serves as the fourth bearing. The outer raceway of the bearing 234 and the outer circumference of the power output member 201 serve as the inner raceway of the fourth bearing 234. The rolling assembly 603 of the fourth bearing 234 is disposed between the output shaft 218 and the power output member 201, so that the fourth bearing 234 is not required. The bearing 234 is provided with two separate inner and outer steel rings, which can reduce the overall size of the gear transmission assembly.

It can be understood that the second one-way clutch 205 can be a sprag-type one-way clutch or a roller-type one-way clutch; in the embodiments shown in FIGS. 6 and 7 , the second one-way clutch 205 is a sprag. A one-way clutch can transmit the clockwise rotation force of the output shaft 218 to the power output member 201 as shown in the figure, but it cannot transmit the counterclockwise rotation force of the power output member 201 to the output shaft 218 as shown in the figure. This can avoid When the electric bicycle travels in the reverse direction, the output shaft 218 reversely drags the motor 202 through the gear reduction mechanism 203.

Referring to FIG. 7 , it can be understood that the second one-way clutch 205 is a sprag-type one-way clutch. The second one-way clutch 205 includes a second inner ring, a second clutch assembly 601 and a second outer ring. The power output The component 201 is configured as a second inner ring, that is, an inner race. The output shaft 218 is configured as a second outer ring, that is, an outer race. The second clutch assembly 601 includes a cage, a wedge and other components. That is, compared with a general one-way clutch, the inner ring and outer ring are reduced, which can reduce the overall size of the gear transmission assembly.

The electric bicycle of the embodiment of the present application includes the mid-mounted motor 100 of all the above embodiments, and therefore also has all of its beneficial effects, which will not be described again here.

The embodiments of the present application have been described in detail above in conjunction with the accompanying drawings. However, the present application is not limited to the above-mentioned embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various embodiments can be made without departing from the purpose of the present application. Variety.

Claims

Mid-mounted motor, including:

shell;

a crankshaft, rotatably connected to the housing;

A power output member is connected to the crankshaft through a transmission assembly, and the transmission assembly includes a first one-way clutch;

A motor, installed in the housing;

A gear reduction mechanism is connected to the output end of the motor. The gear reduction mechanism includes an output shaft and an output gear. The output gear is provided on the output shaft. The output shaft is provided with an inner hole. The power output member Passed through the inner hole;

a second one-way clutch, connecting the output shaft and the power output member;

Wherein, the second one-way clutch includes a second inner ring, a second clutch assembly and a second outer ring, the second clutch assembly is located in the inner hole, and part of the power output member is configured as the second The inner ring and part of the output shaft are configured as the second outer ring.
The mid-mounted motor according to claim 1, wherein the first one-way clutch includes a first inner ring, a first clutch assembly and a first outer ring, and the first outer ring is fixedly connected to the crankshaft, The first clutch assembly is located between the first inner ring and the first outer ring. The transmission assembly includes a torque detection device. The torque detection device includes a torque sensing sleeve and a torque sensor. The torque sensing sleeve The first inner ring and the power output member are connected, and the torque sensor is fixed on the outer shell.
The mid-mounted motor according to claim 2, wherein the torque detection device includes a shielding cover, and the shielding cover is disposed around the outer periphery of the torque sensor.
The mid-mounted motor according to claim 2 or 3, wherein the torque sensor includes a coil holder, the coil holder is fixed to the housing, and the coil holder is provided with an induction coil.
The mid-mounted motor according to claim 4, wherein the mid-mounted motor includes a cadence sensor, the cadence sensor includes a detection component and a target component, and the target component is fixed to the first outer ring, The detection component is fixed on the coil holder.
The mid-mounted motor according to any one of claims 1 to 5, wherein the gear reduction mechanism includes an input shaft and an input gear, the motor includes a rotor assembly, and the input gear and the rotor assembly are installed on the the input shaft.
The mid-mounted motor according to claim 6, wherein a first bearing, a second bearing and a third bearing are provided on the input shaft, and the input gear is located between the first bearing and the third bearing. , the rotor assembly is located between the second bearing and the third bearing.
The mid-mounted motor according to any one of claims 1 to 7, wherein the gear reduction mechanism is a two-stage reduction gear set or a three-stage reduction gear set.
The mid-mounted motor according to any one of claims 1 to 8, wherein the motor includes a stator assembly, the stator assembly includes windings, and the windings adopt conductors with a non-circular cross-section.
The mid-mounted motor according to any one of claims 1 to 9, wherein the mid-mounted motor includes an angle sensor for detecting the rotation speed of the motor, and the angle sensor is arranged in the gear reduction mechanism.
The mid-mounted motor according to any one of claims 1 to 10, wherein the power output member is provided with a fourth bearing, the fourth bearing is located on an end side of the second one-way clutch and is used for Supporting the output shaft, the fourth bearing includes an outer raceway, a rolling assembly and an inner raceway, part of the power output member is configured as the inner raceway, and part of the output shaft is configured as the outer raceway.
An electric bicycle, comprising the mid-mounted motor according to any one of claims 1 to 11.