Centrally-arranged motor transmission system and centrally-arranged motor

Abstract

The utility model relates to a centrally-mounted motor transmission system and a centrally-mounted motor, the centrally-mounted motor transmission system comprises a center shaft structure, a motor assembly and a speed reduction assembly, and the speed reduction assembly is arranged between the motor assembly and the center shaft structure; wherein an output gear is arranged on the middle shaft structure, a first clutch is arranged between the output gear and the middle shaft structure, a second clutch is arranged in the speed reduction assembly, and the first clutch is configured to transmit power to the output gear in a one-way mode from the middle shaft; the second clutch is configured to perform one-way transmission of power from the motor assembly to the middle shaft structure; in the power-assisted mode and the full-automatic mode, the motor drives the crank to rotate, so that discomfort to a rider is avoided; and the specific mounting positions of the first clutch and the second clutch are favorable for improving the compactness of the structure and improving the bearing moment, so that the running state between the clutch and the corresponding connecting structure is better.

Description

Technical Field

[0001] The utility model belongs to the technical field of riding equipment, and specifically relates to a mid-mounted motor transmission system and a mid-mounted motor. Background Art

[0002] The mid-mounted motor is the driving motor of an electric power-assisted bicycle. It is installed in the middle of the vehicle body, that is, the motor at the pedal position. The motor is connected to the vehicle body and is connected to the wheel of the bicycle through a chainring and a rack to transmit power.

[0003] The mid-mounted motor includes human-powered riding mode, fully automatic riding mode, and power-assisted riding mode. When the bike is electrically driven, the motor body is used to transmit power to the chainring through gear transmission. At this time, the chainring is required to rotate, but the crank cannot rotate with it, otherwise it will cause injury or discomfort to the rider. When the bike is driven by human power without electricity, the crank is pressed, the clutch is locked, and the chainring rotates. At this time, the motor must be disconnected in the gear transmission link to prevent the motor from entering the power generation mode, which makes riding very strenuous and damages electronic devices. Summary of the invention

[0004] The purpose of the utility model is to provide a mid-mounted motor transmission system and a mid-mounted motor, so as to solve the problem of one-way transmission of power of riding equipment in human riding mode, fully automatic riding mode and power-assisted riding mode in the prior art, so as to avoid the crank rotating when the motor is driven, causing discomfort to the rider, or damaging the motor in the human-driven mode.

[0005] In order to achieve the above-mentioned utility model purpose, the utility model adopts the following technical solutions:

[0006] In one aspect, the utility model provides a mid-mounted motor transmission system, comprising:

[0007] The middle shaft structure comprises a middle shaft and a sleeve member, wherein the middle shaft is used to be connected with a crank to bear the riding force, and the sleeve member is sleeved on the outer side of the middle shaft;

[0008] A motor assembly, comprising a motor body, wherein a motor shaft is formed on the motor body;

[0009] A reduction assembly, which is arranged between the motor assembly and the middle shaft structure;

[0010] Among them, an output gear is arranged on the middle shaft structure, a first clutch is arranged between the output gear and the middle shaft structure, a second clutch is arranged in the deceleration assembly, the first clutch is configured to transmit power from the middle shaft to the output gear in one direction; the second clutch is configured to transmit power from the motor assembly to the middle shaft structure in one direction.

[0011] In some embodiments of the present application, the output gear is a cantilever structure, the first end of the output gear is connected to the central shaft through a support bearing, and the second end of the output gear extends to the outside of the sleeve member and forms a gap between the output gear and the sleeve member.

[0012] In some embodiments of the present application, a positioning portion extending radially outward is formed on the outer wall of the sleeve member, an annular accommodating cavity is formed between the positioning portion and the inner wall of the output gear, and the first clutch is disposed in the accommodating cavity.

[0013] In some embodiments of the present application, the reduction assembly includes a primary reduction assembly and a secondary reduction assembly;

[0014] The primary reduction assembly comprises a primary reduction shaft, a first transmission gear plate and a second transmission gear plate, wherein the first transmission gear plate and the second transmission gear plate are arranged on the primary reduction shaft at intervals;

[0015] The secondary reduction assembly comprises a secondary reduction shaft, a third transmission gear plate and a fourth transmission gear plate, wherein the third transmission gear plate and the fourth transmission gear plate are arranged on the secondary reduction shaft at intervals;

[0016] Among them, an input gear is formed on the motor shaft, the input gear is connected to the first transmission gear plate, the second transmission gear plate is connected to the third transmission gear plate, the output gear is connected to the fourth transmission gear plate, and the second clutch is arranged between the third transmission gear plate and the secondary reduction shaft.

[0017] In some embodiments of the present application, a stepped mating surface is formed on the secondary reduction shaft, one end of the third transmission gear plate is connected to the secondary reduction shaft, and an installation gap is formed between the other end and the secondary reduction shaft, and the second clutch is arranged in the installation gap.

[0018] In some embodiments of the present application, an external spline is formed on the central shaft, an internal spline is formed in the sleeve member, and the sleeve member is fixed to the central shaft by means of a spline connection.

[0019] In another aspect, the utility model further proposes a mid-mounted motor, which comprises an outer shell and any one of the above-mentioned mid-mounted motor transmission systems arranged in the outer shell.

[0020] In some embodiments of the present application, two connecting holes are formed on both sides of the outer shell, and the two ends of the central axis extend corresponding to the connecting holes for connecting the crank; a first bearing portion and a second bearing portion are also provided between the central axis structure and the connecting holes.

[0021] In some embodiments of the present application, the output gear is further formed with an outer connecting section, and the outer connecting section extends out of the adjacent connecting hole for connecting to the crankset.

[0022] In some embodiments of the present application, the outer shell includes a first shell and a second shell, an installation cavity is formed between the first shell and the second shell, a support member is arranged in the installation cavity along a direction perpendicular to the center line of the motor shaft, and the support member divides the installation cavity into a motor cavity and a transmission cavity.

[0023] In some embodiments of the present application, the motor body is located in the motor cavity, the reduction assembly is located in the motor cavity, a first penetrating connecting portion is formed on the support member, and the motor shaft passes through the first connecting portion to connect with the reduction assembly.

[0024] Compared with the prior art, the advantages and positive effects of the utility model are:

[0025] The mid-mounted motor transmission system involved in the present application is provided with a first clutch between the output gear and the middle shaft structure, and the first clutch is configured to transmit power from the middle shaft to the output gear in one direction; a second clutch is provided in the reduction assembly, and the second clutch is configured to transmit power from the motor assembly to the middle shaft structure in one direction, so as to meet the riding requirements of the riding device in different states, avoid the motor driving the crank to rotate in the power-assisted mode and the fully automatic mode, and cause discomfort to the rider, which is conducive to reducing resistance;

[0026] The first clutch is arranged in the annular accommodating cavity surrounded by the sleeve member and the output gear, and the second clutch is arranged between the second transmission gear plate and the secondary reduction shaft. The first clutch and the second clutch are respectively cantilevered for force, which is beneficial to improve their force characteristics and increase fatigue lightness. The specific installation positions of the first clutch and the second clutch are beneficial to improve the compactness of the structure and increase the bearing torque, so that the operating state between the clutch and the corresponding connection structure is better.

[0027] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1It is a structural schematic diagram of the mid-mounted motor transmission system proposed by the utility model;

[0030] Figure 2 It is a schematic diagram of the connection between the middle shaft structure and the secondary reduction assembly;

[0031] Figure 3 It is a schematic diagram of the structure of the second clutch and the secondary reducer;

[0032] Figure 4 It is a schematic diagram of the cross section of the central axis structure;

[0033] Figure 5 It is a schematic diagram of the connection between the middle shaft and the sleeve member;

[0034] Figure 6 1 is a schematic diagram of the sleeve member structure;

[0035] Figure 7 It is a schematic diagram of the connection between the mid-mounted motor, the crank and the chainring;

[0036] Figure 8 It is a schematic diagram of the mid-mounted motor structure;

[0037] Fig. 9 It is a plan view of the mid-mounted motor;

[0038] Fig.10 yes Fig. 9 AA section diagram in;

[0039] In the figure,

[0040] 10. outer shell; 11. first shell; 12. second shell; 13. support member; 1301. first connecting portion; 14. magnetic braided plate;

[0041] 20. Tooth plate;

[0042] 30. Crank;

[0043] 100. Central axis structure;

[0044] 110, middle shaft; 111, first shaft section; 112, second shaft section; 113, clearance; 114, external spline;

[0045] 120, sleeve member; 121, first connecting section; 122, second connecting section; 123, positioning portion; 124, internal spline;

[0046] 130. output gear; 131. external connecting section;

[0047] 140, first clutch;

[0048] 150. Support bearing;

[0049] 161, a first bearing portion; 162, a second bearing portion;

[0050] 200, secondary reduction assembly; 210, third transmission gear plate; 220, fourth transmission gear plate; 230, second clutch; 240, secondary reduction shaft;

[0051] 300, motor assembly; 310, motor body; 320, motor shaft; 321, input gear;

[0052] 330, first bearing member; 340, third bearing member; 350, second bearing member; 351, sealing member; 360, permanent magnetic steel; 370, buffer member;

[0053] 400, primary reduction assembly; 410, second transmission gear plate; 420, first transmission gear plate; 430, primary reduction shaft. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0055] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not 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 should not be understood as a limitation on the present application.

[0056] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0057] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0058] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0059] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0060] The mid-mounted motor is the driving motor of an electric power-assisted bicycle, which is installed in the middle of the vehicle body, that is, at the pedal position.

[0061] The motor is connected to the vehicle body and is connected to the wheel of the bicycle through a toothed plate 20 and a rack to transmit power.

[0062] The present application proposes a mid-mounted motor transmission system and a mid-mounted motor, wherein the mid-mounted motor is used in a power-assisted bicycle. The mid-mounted motor indirectly estimates the work power of the rider according to the pedaling speed of the rider, and then controls the motor power-assisting power.

[0063] refer to Figure 1-Figure 3 The central axis motor transmission system includes a central axis structure 100, a motor assembly 300 and a reduction assembly.

[0064] The middle shaft structure 100 includes a middle shaft 110 and a sleeve member 120 . The sleeve member 120 is sleeved on the outer side of the middle shaft 110 .

[0065] The outer shell 10 has an installation cavity formed therein for installing the motor assembly 300 , the reduction assembly and the central shaft structure 100 .

[0066] The motor assembly 300 includes a motor body 310 fixed in the installation cavity. A motor shaft 320 is formed on the motor body 310. The motor shaft 320 is the output shaft of the motor body 310 and is connected to the reduction assembly for transmitting the power of the motor body 310 to the central axis structure 100 through the reduction assembly.

[0067] The reduction assembly is connected between the motor assembly 300 and the middle shaft structure 100 , and transmits the rotation output from the motor assembly 300 to the middle shaft structure 100 after reducing the speed, thereby assisting the rider in riding.

[0068] Specifically, the reduction assembly includes a primary reduction assembly 400 and a secondary reduction assembly 200 .

[0069] The primary reduction assembly 400 includes a primary reduction shaft 430 , a first transmission gear plate 420 , and a second transmission gear plate 410 . The first transmission gear plate 420 and the second transmission gear plate 410 are arranged on the primary reduction shaft 430 at intervals.

[0070] The secondary reduction assembly 200 includes a secondary reduction shaft 240 , a third transmission gear plate 210 , and a fourth transmission gear plate 220 . The third transmission gear plate 210 and the fourth transmission gear plate 220 are arranged on the secondary reduction shaft at intervals.

[0071] The rotation axes of the primary reduction shaft 430 and the secondary reduction shaft 240 are parallel to the rotation axis of the central shaft 110 , and both ends of the primary reduction shaft 430 and the secondary reduction shaft 240 are rotatably connected to the outer shell 10 .

[0072] Among them, an input gear 321 is formed on the motor shaft 320, the input gear 321 is connected to the first transmission gear plate 420, the second transmission gear plate 410 is connected to the third transmission gear plate 210, and an output gear 130 is arranged on the middle shaft 110, and the output gear 130 is connected to the fourth transmission gear plate 220.

[0073] Specifically, the size of the first transmission gear plate 420 is larger than that of the second transmission gear plate 410, and the size of the third transmission gear plate 210 is larger than that of the fourth transmission gear plate 220. After the output gear 130 is decelerated by the primary reduction assembly 400 and the secondary reduction assembly 200, it drives the central axis structure 100 to rotate.

[0074] refer to Figure 4 Specifically, the output gear 130 is connected to the central shaft 110 through a support bearing 150 .

[0075] In order to make the structure compact, the first clutch 140 uses a wedge block or a retaining frame clutch. This clutch has a compact structure and transmits large torque, but has high requirements on the matching structure and must ensure that the coaxiality of the rolling track of the first clutch 140 is high.

[0076] In order to solve the above problem, a positioning portion 123 extending radially outwardly along the sleeve member 120 is further formed on the outer wall of the second connecting section 122 , and an annular accommodating inner cavity is formed between the positioning portion 123 and the inner wall of the output gear 130 .

[0077] The first clutch 140 is installed in the accommodating inner cavity. The first clutch 140 is positioned along its radial direction on both sides by the sleeve member 120 and the output gear 130 respectively. Along its radial direction, it is positioned at both ends by the positioning portion 123 and the support bearing 150 respectively, which can effectively improve the coaxiality of the rolling track of the first clutch 140.

[0078] That is, the outer raceway of the first clutch 140 is the inner race of the output gear 130 , and the inner raceway of the first clutch 140 is the outer wall of the central shaft 110 .

[0079] Since the first clutch 140 is cantilevered, the supporting pressure of the output gear 130 is relatively large. The length of the supporting bearing 150 between the output gear 130 and the central shaft 110 is designed to be relatively large to reduce the cantilever size of the output gear 130 and achieve effective support for the supporting bearing 150.

[0080] The support bearing 150 is selected from at least two deep groove ball bearings, needle bearings, sliding bearings, etc. arranged in parallel to increase the effective length of the entire support bearing 150.

[0081] The support bearing 150 is a self-lubricating dynamic bearing, and the dimensional tolerance is controlled through processing to ensure a compact structure, strong load-bearing capacity, not prone to damage, and self-lubricating properties to avoid abnormal friction noise.

[0082] In the secondary reduction assembly 200 , a second clutch 230 is disposed between the third transmission gear plate 210 and the secondary reduction shaft 240 , and the second clutch 230 is configured to transmit power from the third transmission gear plate 210 to the secondary reduction shaft in a one-way manner.

[0083] The second clutch 230 is also cantilevered. Specifically, a stepped mating surface is formed on the secondary reduction shaft 240. One end of the third transmission gear plate 210 is connected to the secondary reduction shaft 240, and an installation gap is formed between the other end and the secondary reduction shaft 240. The second clutch 230 is located in the installation gap.

[0084] The second clutch 230 is supported by the third transmission sprocket 210. The inner diameter of the third transmission sprocket 210 cooperates with the small gap 113 on the axial surface of the fourth transmission sprocket 220. This can ensure that when the second clutch 230 is in an idling state, the relative rotation is not stuck, and when the second clutch 230 is subjected to unbalanced force, the coaxiality is controlled by the third transmission sprocket 210 and the fourth transmission sprocket 220, so that the clutch raceway is always in a good coaxiality.

[0085] In addition, in order to improve the end surface friction during relative rotation, a wear-resistant smooth plastic gasket is added between the fourth transmission gear plate 220 and the second clutch 230 to prevent abnormal friction noise.

[0086] The second clutch 230 is a self-lubricating bearing to ensure that the second clutch 230 and the third transmission gear plate 210 and the fourth transmission gear plate 220 are in a grease environment, so that various operating conditions are better.

[0087] refer to Figure 4 The output gear 130 is also formed with an outer connecting section 131 , which extends out of an adjacent connecting hole for connecting to the crankset 20 .

[0088] The mid-mounted motor transmission system includes the following three riding modes: human riding mode, fully automatic riding mode and power-assisted riding mode.

[0089] Riders can switch and choose among these three riding modes according to their actual needs. The power-assisted riding mode is favored by many riders for its healthy and long-endurance power-assisted riding characteristics.

[0090] refer to Figure 1 , Figure 2 , combined with the three riding states, the specific transmission process of the first clutch 140 and the second clutch 230 is described in detail:

[0091] In the human riding mode, the crank 30 is connected to the middle shaft 110, the middle shaft 110 and the sleeve member 120 rotate synchronously, and the output gear 130 is locked and driven by the first clutch 140. The output gear 130 is externally connected to the chainring 20, and the chainring 20 is connected to drive the bicycle to move forward.

[0092] The output gear 130 is meshed with the fourth transmission gear plate 220 to drive the fourth transmission gear plate 220 to rotate. In order to prevent power from being transmitted to the motor assembly 300, the second clutch 230 is in an idling state to ensure that power can only be transmitted here.

[0093] In the fully automatic riding mode, power is emitted from the motor assembly 300 and transmitted to the third transmission sprocket 210 through the input gear 321 on the motor shaft 320 , the first transmission sprocket 420 , and the second transmission sprocket 410 .

[0094] In this state, the second clutch 230 is in working state. Under the action of the second clutch 230, the third transmission sprocket 210 drives the fourth transmission sprocket 220 to rotate, thereby driving the output gear 130 to rotate, and finally driving the chainring 20 to rotate, so that the bicycle moves forward.

[0095] At this time, from the output gear 130 to the middle shaft 110, the first clutch 140 is in the idling direction, that is, the power is not transmitted to the middle shaft 110, the middle shaft 110 does not rotate, and the crank 30 will not be driven to rotate, and the pedal does not produce any action.

[0096] In the power-assisted riding mode, the bicycle is first driven by human power, from the crank 30 to the middle shaft 110, the first clutch 140 is locked, and the power is transmitted to the output gear 130. At this time, the output gear 130 rotates to drive the chainring 20 to rotate, and the bicycle moves forward.

[0097] A torque detection device and a cadence detection device are also provided on the middle shaft structure 100. The torque detection device and the cadence detection device detect the torque and cadence data and control the motor body to start rotating and outputting.

[0098] The power of the motor body is transmitted to the third transmission gear plate 210 via the input gear 321 on the motor shaft 320 , the first transmission gear plate 420 , and the second transmission gear plate 410 .

[0099] In this state, the second clutch 230 is in working state. Under the action of the second clutch 230, the third transmission sprocket 210 drives the fourth transmission sprocket 220 to rotate, thereby driving the output gear 130 to rotate, and finally driving the chainring 20 to rotate, so that the bicycle moves forward.

[0100] In this state, human and electric power work simultaneously, reducing the requirements on human ability and improving the riding experience.

[0101] refer to Figure 5 , Figure 6 In some embodiments of the present application, the middle shaft 110 includes at least a first shaft section 111 and a second shaft section 112 arranged along its own axis. The middle shaft 110 is used to connect with the crank 30 of the bicycle to withstand the pedaling force.

[0102] The sleeve member 120 is formed with a first connecting section 121 and a second connecting section 122 along its axial direction. The first connecting section 121 is fixedly connected to the first shaft section 111 of the central axis 110. The position of the second connecting section 122 corresponds to the second shaft section 112 of the central axis 110. A gap 113 is formed between the second connecting section 122 and the second shaft section 112.

[0103] That is, the central axis 110 and the sleeve member 120 are connected and fixed via the first connecting section 121 and the first shaft section 111, a gap 113 is formed between the second shaft section 112 of the central axis 110 and the second connecting section 122 of the sleeve member 120, and the outer wall of the second shaft section 112 does not contact the inner wall of the second connecting section 122.

[0104] In some embodiments of the present application, in order to form an annular gap 113 between the second connecting segment 122 and the second shaft segment 112, the inner diameter of the second connecting segment 122 is larger than the inner diameter of the first connecting segment 121, and the outer diameter of the first shaft segment 111 is equal to the outer diameter of the second shaft segment 112.

[0105] That is, in this embodiment, the outer diameter dimensions of the first shaft segment 111 and the second shaft segment 112 are consistent, the inner diameter dimension of the first connecting segment 121 is adapted to the outer diameter dimensions of the first shaft segment 111 and the second shaft segment 112, and the inner diameter dimension of the second connecting segment 122 is larger than the outer diameter dimensions of the first shaft segment 111 and the second shaft segment 112. Then, in this state, in the connected state, a gap 113 can be formed between the second shaft segment 112 and the second connecting segment 122.

[0106] In other embodiments, the outer diameter of the first shaft segment 111 is greater than the outer diameter of the second shaft segment 112 , and the inner diameter of the first connecting segment 121 is equal to the outer diameter of the second connecting segment 122 .

[0107] That is, in this embodiment, the inner diameters of the first connecting segment 121 and the second connecting segment 122 are equal and matched with the outer diameter of the first shaft segment 111, and the outer diameter of the second shaft segment 112 is smaller than the inner diameter of the second connecting segment 122. In this case, a gap 113 can also be formed between the second shaft segment 112 and the second connecting segment 122.

[0108] In other embodiments, the inner diameter of the first connecting segment 121 is smaller than the inner diameter of the second connecting segment 122 , the outer diameter of the first shaft segment 111 is larger than the inner diameter of the second shaft segment 112 , and the inner diameter of the first connecting segment 121 matches the outer diameter of the first shaft segment 111 .

[0109] In this case, a gap 113 may also be formed between the second shaft segment 112 and the second connecting segment 122 .

[0110] The first shaft section 111 and the first connecting section 121 are connected by interference fit.

[0111] Specifically, an external spline 114 is formed on the first shaft segment 111 , an internal spline 124 is formed in the first connecting segment 121 , and the first connecting segment 121 is fixed to the first shaft segment 111 by means of a spline connection.

[0112] In the specific transmission process, the sleeve member 120 and the middle shaft 110 realize torque transmission through the first connecting section 121 and the first shaft section 111. Due to the gap 113 formed between the second connecting section 122 and the second shaft section 112, the friction between the sleeve member 120 and the middle shaft 110 is reduced, the deformation loss is reduced, and the detection accuracy of parameters such as torque and pedaling frequency is greatly improved.

[0113] In this manner, the cantilever force is applied between the central axis 110 and the sleeve member 120 , and the force state is poor, which may easily lead to poor coaxiality between the central axis 110 and the sleeve member 120 or the sleeve member 120 falling off.

[0114] In order to ensure fatigue life, when subjected to stress, the spline connection between the center shaft 110 and the sleeve member 120 must be strong enough, the spline interference must be controlled, and the connection length between the inner spline 124 and the outer spline 114 should be 1 / 4 to 1 / 2 of the entire stress length to ensure the strength of the connection.

[0115] refer to Figure 7-10 The mid-mounted motor involved in the application also includes an outer shell 10 , and the motor assembly 300 , the reduction assembly and the above-mentioned central axis structure 100 are installed in the outer shell 10 .

[0116] Two connecting holes are formed on both sides of the outer shell 10, and corresponding connecting holes extend from both ends of the middle shaft 110 for connecting the crank 30; a first bearing portion 161 and a second bearing portion 162 are also provided between the middle shaft structure 100 and the connecting holes.

[0117] Next, the specific connection between the outer shell 10 and the motor assembly 300 is described in detail:

[0118] The outer shell 10 includes a first shell 11 and a second shell 12 , and the first shell 11 and the second shell 12 are detachable by mechanical connection.

[0119] An installation cavity is formed between the first shell 11 and the second shell 12 , in which a support member 13 is arranged along a direction perpendicular to the center line of the motor shaft 320 . The support member 13 can be arranged on the first shell 11 or on the second shell 12 .

[0120] For the convenience of processing, the support member 13 is manufactured and processed separately, and is connected to the first shell 11 or the second shell 12 by fasteners or the like.

[0121] A motor cavity is formed between the support member 13 and the first shell 11 , and the motor body 310 is located in the motor cavity.

[0122] A transmission cavity is formed between the support member 13 and the second housing 12 , and the first reduction assembly and the second reduction assembly are both disposed in the transmission cavity.

[0123] Both ends of the primary reduction shaft 430 and the secondary reduction shaft 240 are rotatably connected to the second housing 12 and the support member 13 respectively.

[0124] A penetrating first connecting portion 1301 is formed on the support member 13 , and the motor shaft 320 passes through the first connecting portion 1301 , and two ends of the motor shaft 320 are respectively connected to the first shell 11 and the second shell 12 .

[0125] The bottom of the motor shaft 320 passes through the motor body and is connected to the first housing 11 .

[0126] Connecting recesses are formed on the inner surfaces of the first housing 11 and the second housing 12 , respectively. Both ends of the motor shaft 320 are connected to the first housing 11 and the second housing 12 through the first bearing member 330 and the second bearing member 350 , respectively.

[0127] Specifically, a first bearing seat is disposed in the connecting recess of the first shell 11 , a second bearing seat is disposed in the connecting recess of the second shell 12 , and a third bearing seat is disposed on the first connecting portion 1301 .

[0128] A first bearing component 330 is disposed between the first bearing seat and the motor shaft 320 , a second bearing component 350 is connected between the second bearing seat and the motor shaft 320 , and a third bearing component 340 is disposed between the third bearing seat and the motor shaft 320 .

[0129] The second bearing member 350 and the third bearing member 340 are both connected to the motor shaft 320 and are disposed at both ends of the input gear 321 , thereby optimizing the forces on both sides of the input gear 321 .

[0130] The first bearing member 330 and the second bearing member 350 are disposed on both sides of the motor body to jointly support the operation of the motor.

[0131] Bearings are arranged on both sides of the motor body and both sides of the input gear 321, forming a symmetrical support, improving the overall force environment, and greatly improving the selection and life of the bearings.

[0132] The input gear 321 is integrally formed with the motor shaft 320 , and the input gear 321 is meshed with the first transmission gear plate 420 to achieve torque transmission.

[0133] Since the motor shaft 320 is a rotating body with a relatively high rotation speed, the first bearing component 330 and the third bearing component 340 are interference fit with the motor shaft 320, the second bearing component 350 is gap fit with the motor shaft 320, and the second bearing component 350 is interference fit with the second bearing seat.

[0134] The second bearing member 350 cooperates with the motor shaft 320 gap 113, having the following advantages;

[0135] First, it is easy to assemble. During installation, the motor assembly 300 is first installed in the outer shell 10, and then the first-stage reduction assembly 400 is installed. At this time, the installation path of the first-stage reduction assembly 400 can easily interfere with the position of the second bearing member 350 and cannot be installed. Therefore, the second bearing member 350 is designed to cooperate with the gap 113. After the first-stage reduction assembly 400 is installed, the second bearing member 350 is assembled to solve the interference problem.

[0136] Second, the first bearing component 330, the second bearing component 350 and the third bearing component 340 have very high requirements on the coaxiality of the connecting holes on the motor shaft 320 and the outer shell 10. After installation, if the coaxiality does not meet the standard, the bearings will be stuck and subjected to lateral force, resulting in bearing damage. Changing the second bearing component 350 to a gap 113 can increase the coaxiality tolerance and reduce the processing difficulty.

[0137] Third, the second bearing member 350 is interference fit with the second bearing seat of the upper shell, and can be installed once when the upper shell is installed, which simplifies the installation steps and avoids the second bearing member 350 being out of position and causing abnormal noise during operation.

[0138] In other embodiments, due to the gap 113 between the second bearing component 350 and the motor shaft 320 , abnormal wear and damage may occur to the inner ring of the bearing. To solve this problem, a sealing portion 351 is provided between the second bearing component 350 and the motor shaft 320 .

[0139] An inwardly recessed sealing groove is formed on the motor shaft 320 . The sealing portion 351 is a sealing ring. Part of the sealing portion 351 is installed in the sealing groove.

[0140] The sealing portion 351 is an O-ring, and the diameter of the sealing ring is larger than the sum of the groove depth of the sealing groove and the fitting clearance 113 with the motor shaft 320. After the bearing is installed, the sealing portion 351 is in a compressed state, providing a radial clamping effect on the second bearing component 350, so that the motor shaft 320 and the inner diameter of the second bearing component 350 are in a relatively static state, thereby improving the bearing life.

[0141] For multiple installations, due to the influence of cumulative errors, the motor shaft 320 needs to be made to fit with the gap 113, but the gap 113 will cause the outer ring of the third bearing component 340 to loosen and run in circles, and the bearing will be worn and damaged.

[0142] To solve this problem, an annular limiting portion extending toward the center of the first connecting portion 1301 is formed above the first connecting portion 1301, the third bearing member 340 is located below the limiting portion, and a buffer member 370 is provided between the third bearing member 340 and the limiting portion.

[0143] The buffer member 370 is a corrugated gasket, and the gasket is wavy.

[0144] The gap 113 reserved between the third bearing component 340 and the support component 13 will compress the buffer component 370. At this time, the buffer component 370 will generate a pre-pressure to eliminate the axial movement of the third bearing component 340 and solve the problem of outer ring looseness.

[0145] In other embodiments, a permanent magnet 360 is also embedded in the top end face of the motor shaft 320. The magnet is radially magnetized and has NS poles on the circular cross section. It is reliably bonded to the shaft. A magnetic braiding plate 14 is installed on the shell. When the motor rotates, the magnetic braiding plate 14 rotates relative to the magnet, sensing the frequency of the change of the magnetic poles of the magnet and calculating the motor speed.

[0146] The magnetic plate 14 is connected to the main control board, and transmits the speed signal to the main control board in real time to complete the closed-loop control of the motor speed.

[0147] The above is only a specific implementation method of the utility model, but the protection scope of the utility model is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the utility model should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A mid-mounted motor transmission system, characterized in that: include: The middle shaft structure comprises a middle shaft and a sleeve member, wherein the middle shaft is used to be connected with a crank to bear the riding force, and the sleeve member is sleeved on the outer side of the middle shaft; A motor assembly, comprising a motor body, wherein a motor shaft is formed on the motor body; A reduction assembly, which is arranged between the motor assembly and the middle shaft structure; Among them, an output gear is arranged on the middle shaft structure, a first clutch is arranged between the output gear and the middle shaft structure, a second clutch is arranged in the deceleration assembly, the first clutch is configured to transmit power from the middle shaft to the output gear in one direction; the second clutch is configured to transmit power from the motor assembly to the middle shaft structure in one direction.

2. The mid-mounted motor transmission system according to claim 1, characterized in that: The output gear is a cantilever structure, the first end of the output gear is connected to the central shaft through a support bearing, and the second end of the output gear extends to the outside of the sleeve member and forms a gap with the sleeve member.

3. The mid-mounted motor transmission system according to claim 1, characterized in that: A positioning portion extending radially outward is also formed on the outer wall of the sleeve member, and an annular accommodating inner cavity is formed between the positioning portion and the inner wall of the output gear, and the first clutch is arranged in the accommodating inner cavity.

4. The mid-mounted motor transmission system according to claim 1, characterized in that: The deceleration assembly includes a primary deceleration assembly and a secondary deceleration assembly; The primary reduction assembly comprises a primary reduction shaft, a first transmission gear plate and a second transmission gear plate, wherein the first transmission gear plate and the second transmission gear plate are arranged on the primary reduction shaft at intervals; The secondary reduction assembly comprises a secondary reduction shaft, a third transmission gear plate and a fourth transmission gear plate, wherein the third transmission gear plate and the fourth transmission gear plate are arranged on the secondary reduction shaft at intervals; Among them, an input gear is formed on the motor shaft, the input gear is connected to the first transmission gear plate, the second transmission gear plate is connected to the third transmission gear plate, the output gear is connected to the fourth transmission gear plate, and the second clutch is arranged between the third transmission gear plate and the secondary reduction shaft.

5. The mid-mounted motor transmission system according to claim 4, characterized in that: A stepped mating surface is formed on the secondary reduction shaft, one end of the third transmission gear plate is connected to the secondary reduction shaft, and an installation gap is formed between the other end and the secondary reduction shaft, and the second clutch is arranged in the installation gap.

6. A mid-mounted motor, characterized in that: It comprises an outer shell and a mid-mounted motor transmission system according to any one of claims 1 to 5 arranged in the outer shell.

7. The mid-mounted motor according to claim 6, characterized in that: Two connecting holes are formed on both sides of the outer shell, and two ends of the central axis extend out corresponding to the connecting holes for connecting the crank; a first bearing portion and a second bearing portion are also provided between the central axis structure and the connecting holes.

8. The mid-mounted motor according to claim 7, characterized in that: The output gear is also formed with an outer connecting section, which extends out of the adjacent connecting hole and is used for connecting to the crankset.

9. The mid-mounted motor according to claim 6, characterized in that: The outer shell includes a first shell and a second shell, an installation cavity is formed between the first shell and the second shell, a support member is arranged in the installation cavity along a direction perpendicular to the center line of the motor shaft, and the support member divides the installation cavity into a motor cavity and a transmission cavity.

10. The mid-mounted motor according to claim 9, characterized in that: The motor body is located in the motor cavity, the reduction assembly is located in the motor cavity, a first connecting portion is formed on the support member, and the motor shaft passes through the first connecting portion to be connected with the reduction assembly.

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