Harmonic speed reduction built-in motor

Abstract

The utility model belongs to the technical field of power-assisted bicycles, and particularly relates to a harmonic speed reduction built-in motor. In order to overcome the defect of poor heat dissipation of an existing mid-motor adopting a harmonic speed reducer, the utility model adopts the following technical scheme that the harmonic speed reduction mid-motor comprises a machine body; the first end cover is fixedly connected with the machine body; the second end cover is fixedly connected with the machine body; the motor comprises a stator assembly and a rotor assembly; the harmonic reducer comprises an input disc connected with the rotor assembly, a flexible bearing connected with the input disc, a flexible gear connected with the flexible bearing, a rigid gear fixed to a machine body and an output disc connected with the flexible gear. Wherein the harmonic reducer, the machine body and the second end cover define an oil storage chamber, and the oil storage chamber is filled with cooling lubricating oil. The beneficial effects of the utility model are that the formed oil storage chamber is filled with cooling lubricating oil, and the cooling lubricating oil lubricates the movable contact part, thereby reducing the friction, improving the efficiency, and greatly improving the overall heat dissipation performance of the motor at the same time.

Description

Technical Field

[0001] The utility model belongs to the technical field of assisted bicycles, and particularly relates to a harmonic reduction mid-motor. Background Art

[0002] The assisted bicycles sold on the market mainly fall into two types: traditional hub motors and mid-motors. The mid-motor is installed in the middle of the frame, and the power generated by the rotation of the motor is transmitted to the rear wheel through a chain or a belt, thereby driving the vehicle forward. The mid-motor has the following advantages: installed in the central position of the frame, it makes the front and rear center of gravity of the vehicle more balanced, and has good stability during driving; compared with the hub motor, the mid-motor has a greater torque, uses air cooling or oil cooling for heat dissipation, has a fast speed increase and is more powerful when climbing slopes; the layout of the mid-motor does not occupy the space of the rear wheel of the vehicle, and the rear wheel hub of the assisted bicycle can be freely selected, making the body design more flexible.

[0003] For existing mid-motors, multi-stage gears or planetary gears are mostly used for transmission, which results in a large volume, low transmission efficiency, and the appearance is mostly square. A decorative cover needs to be set when matching with the whole vehicle. Therefore, a mid-motor using a harmonic reducer has emerged. However, new problems have also arisen, such as: 1. The heat dissipation condition of the harmonic reducer is poor; 2. The flexspline has a deformed part and a rigid connection part, and the rigid connection part is usually arranged radially, resulting in a large axial dimension of the harmonic reducer; 3. The layout and connection structure of the motor, harmonic reducer, clutch, torque sensor, etc. are not reasonable enough, resulting in a large axial dimension. Summary of the Invention

[0004] Aiming at the deficiency of poor heat dissipation in the existing mid-motor using a harmonic reducer, the utility model provides a harmonic reduction mid-motor to improve the heat dissipation performance. Further, the relevant structure of the harmonic reducer is improved to reduce the axial dimension of the harmonic reducer; the layout and connection structure of each component of the mid-motor are improved to reduce the volume of the whole mid-motor.

[0005] To achieve the above object, the utility model adopts the following technical scheme: a harmonic reduction mid-motor, the harmonic reduction mid-motor includes:

[0006] A body;

[0007] A first end cover fixedly connected to the body;

[0008] A second end cover fixedly connected to the body;

[0009] A motor including a stator assembly and a rotor assembly;

[0010] A harmonic reducer including an input disk connected to the rotor assembly, a flexible bearing connected to the input disk, a flexspline connected to the flexible bearing, a rigid ring fixed on the body, and an output disk connected to the flexspline;

[0011] Among them, the harmonic reducer, the fuselage, and the second end cover enclose an oil storage chamber, the oil storage chamber is filled with cooling lubricating oil, and the flexible bearing is located in the oil storage chamber.

[0012] In the harmonic reduction in - center motor of the present utility model, the harmonic reducer, the fuselage, and the second end cover enclose an oil storage chamber (also with the help of a sealing bearing, etc.), the oil storage chamber is filled with cooling lubricating oil, and the cooling lubricating oil lubricates between the flexspline and the circular spline, between the flexible bearing and the flexspline, inside the flexible bearing, and between the flexspline and the output disk, reducing friction and improving efficiency. At the same time, when the harmonic reducer rotates, it stirs the cooling lubricating oil, which can greatly increase the overall heat dissipation performance of the motor. The cooling lubricating oil has a cooling function and a lubricating function.

[0013] As an improvement, a first sealing bearing is provided between the input disk and the fuselage in the radial direction, a second sealing bearing is provided between the input disk and the output disk in the radial direction, and a third sealing bearing is provided between the second end cover and the output disk in the radial direction. The fuselage, the input disk, the first sealing bearing, the output disk, the second sealing bearing, the second end cover, and the third sealing bearing enclose the oil storage chamber.

[0014] As an improvement, the inner side of the flexspline includes a smooth section adapted to the flexible bearing and an internal - tooth section adapted to the output disk. The wall thickness of the smooth section is smaller than that of the internal - tooth section, and the output disk has external teeth adapted to the internal - tooth section. The flexspline with this structure has a small axial dimension.

[0015] As an improvement, the input disk includes a first mounting portion and a second mounting portion distributed axially. The inner side of the first mounting portion cooperates with the rotor assembly, the outer side of the first mounting portion cooperates with the first sealing bearing. The cross - section of the second mounting portion is generally U - shaped and the opening faces the output disk. The second mounting portion has a bearing groove, the second sealing bearing is located in the bearing groove, the output disk has a bearing - mating portion located in the bearing groove, and the lower end of the second mounting portion extending radially outward towards the output disk forms a first limiting convex portion.

[0016] As an improvement, the fuselage includes an outer - layer axial portion on the outermost layer, a radial portion radially extending from the inner side of the axial annular portion, an inner - layer axial portion extending from the inner end of the radial portion, and a bearing mounting portion extending from the inner - layer axial portion. A support bearing for supporting the input disk is provided in the bearing mounting portion.

[0017] As an improvement, the inner side of the output disc includes a bearing fitting portion located outside the second sealing bearing and a first abutting portion axially abutting against the second sealing bearing, and the output disc forms a second abutting portion axially abutting against the third sealing bearing; a second limiting convex portion extends radially downward from the lower end of the output disc.

[0018] As an improvement, the motor further includes a main shaft, both ends of the main shaft extend out of the first end cover and the second end cover, and two clutch assemblies are provided on the main shaft.

[0019] As an improvement, the fuselage and the first end cover form a motor installation chamber, and the rotor assembly and the stator assembly are arranged in the motor installation chamber.

[0020] As an improvement, a torque sensor is provided on the main shaft, the harmonic reduction in - center motor further includes a controller, the torque sensor is electrically connected to the controller, and the controller is electrically connected to the stator assembly.

[0021] As an improvement, the fuselage and the first end cover are connected by a plurality of circumferential threaded parts; the fuselage and the second end cover are connected by a plurality of circumferential threaded parts; the fuselage, the first end cover and the second end cover enclose a containing chamber.

[0022] The beneficial effects of the harmonic reduction in - center motor of the present utility model are as follows: Its harmonic reducer, fuselage and second end cover enclose an oil storage chamber (also with the help of sealing bearings, etc.), the oil storage chamber is filled with cooling lubricating oil, and the cooling lubricating oil lubricates between the flexspline and the circular spline, between the flexure bearing and the flexspline, inside the flexure bearing, and between the flexspline and the output disc, reducing friction and improving efficiency. At the same time, when the harmonic reducer rotates, it stirs the cooling lubricating oil, which can greatly increase the overall heat dissipation performance of the motor. Description of the Drawings

[0023] Figure 1 is a schematic structural diagram of the harmonic reduction in - center motor according to Embodiment 1 of the present utility model.

[0024] Figure 2 is an exploded view of the harmonic reduction in - center motor according to Embodiment 1 of the present utility model.

[0025] Figure 3 is a sectional view of the harmonic reduction in - center motor according to Embodiment 1 of the present utility model.

[0026] Figure 4 is a schematic structural diagram of the harmonic reduction in - center motor according to Embodiment 1 of the present utility model (the black - block part is the oil storage chamber, and only the lower - half part of the oil storage chamber is marked as a black block).

[0027] Figure 5 is a partial sectional view of the harmonic reduction in - center motor according to Embodiment 1 of the present utility model.

[0028] Figure 6 It is an exploded view of the harmonic reducer of the harmonic reduction mid-mounted motor in the first embodiment of the present utility model.

[0029] Figure 7 and Figure 8 are schematic structural diagrams of different angles of the fuselage, the first end cover and the second end cover of the harmonic reduction mid-mounted motor in the first embodiment of the present utility model.

[0030] In the figure, 1 is the fuselage; 11 is the outer axial part; 12 is the radial part; 13 is the inner axial part; 14 is the bearing mounting part; 15 is the mounting seat;

[0031] 2 is the first end cover;

[0032] 3 is the second end cover;

[0033] 4 is the motor; 41 is the stator assembly; 42 is the rotor assembly;

[0034] 5 is the harmonic reducer; 51 is the input disk; 511 is the first mounting part; 512 is the second mounting part; 513 is the bearing groove; 514 is the first limiting convex part; 52 is the flexible bearing; 53 is the flexspline; 54 is the rigid ring; 55 is the output disk; 551 is the bearing mating part; 552 is the first abutting part; 553 is the second abutting part; 554 is the second limiting convex part; 56 is the first sealed bearing; 57 is the second sealed bearing; 58 is the third sealed bearing;

[0035] 6 is the main shaft;

[0036] 7 is the torque sensor;

[0037] 8 is the bi-directional clutch;

[0038] 9 is the controller;

[0039] R is the oil storage chamber. Specific embodiments

[0040] The technical solutions of the embodiments of the present invention are explained and described below. However, the following embodiments are only the preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation manners without creative efforts all fall within the protection scope of the present invention.

[0041] See Figures 1 to 8 , for the harmonic reduction mid-mounted motor of the embodiment of the present utility model, the harmonic reduction mid-mounted motor includes:

[0042] The fuselage;

[0043] The first end cover, fixedly connected to the fuselage;

[0044] The second end cover, fixedly connected to the fuselage;

[0045] The motor, including a stator assembly and a rotor assembly;

[0046] The harmonic reducer, including an input disk connected to the rotor assembly, a flexible bearing connected to the input disk, a flexspline connected to the flexible bearing, a rigid gear fixed on the fuselage, and an output disk connected to the flexspline;

[0047] Wherein, the harmonic reducer, the fuselage and the second end cover enclose an oil storage chamber, the oil storage chamber is filled with cooling lubricating oil, and the flexible bearing is located in the oil storage chamber.

[0048] In the harmonic reduction in - center motor of the present utility model, the harmonic reducer, the fuselage and the second end cover enclose an oil storage chamber (also with the help of a sealing bearing, etc.), the oil storage chamber is filled with cooling lubricating oil, the cooling lubricating oil lubricates between the flexspline and the rigid gear, between the flexible bearing and the flexspline, inside the flexible bearing, and between the flexspline and the output disk, reducing friction and improving efficiency. At the same time, when the harmonic reducer rotates, it stirs the cooling lubricating oil, which can greatly increase the overall heat dissipation performance of the motor. The cooling lubricating oil has a cooling function and a lubricating function.

[0049] Embodiment 1

[0050] See Figures 1 to 8 , for the harmonic reduction in - center motor of Embodiment 1 of the present utility model, the harmonic reduction in - center motor includes:

[0051] The fuselage 1;

[0052] The first end cover 2, fixedly connected to the fuselage 1;

[0053] The second end cover 3, fixedly connected to the fuselage 1;

[0054] The motor 4, including a stator assembly 41 and a rotor assembly 42;

[0055] The harmonic reducer 5, including an input disk 51 connected to the rotor assembly 42, a flexible bearing 52 connected to the input disk 51, a flexspline 53 connected to the flexible bearing 52, a rigid gear 54 fixed on the fuselage 1, and an output disk 55 connected to the flexspline 53;

[0056] Wherein, the harmonic reducer 5, the fuselage 1 and the second end cover 3 enclose an oil storage chamber R, the oil storage chamber R is filled with cooling lubricating oil, and the flexible bearing 52 is located in the oil storage chamber R.

[0057] In this embodiment, the fuselage 1 and the first end cover 2 are connected by a plurality of circumferential threaded members. The fuselage 1 is a metal fuselage 1. A plurality of mounting ears are formed on the fuselage 1. Threaded holes are provided in the mounting ears. The first end cover 2 forms a plurality of mounting seat ears, and through holes are provided in the mounting seat ears. A plurality of screws pass through the through holes of the mounting seat ears of the first end cover 2 and then are screwed into the threaded holes of the mounting ears of the fuselage 1.

[0058] In this embodiment, the fuselage 1 and the second end cover 3 are connected by a plurality of circumferential threaded members. A plurality of mounting ears are formed on the fuselage 1. Threaded holes are provided in the mounting ears. The second end cover 3 forms a plurality of mounting seat ears, and through holes are provided in the mounting seat ears. A plurality of screws pass through the through holes of the mounting seat ears of the second end cover 3 and then are screwed into the threaded holes of the mounting ears of the fuselage 1.

[0059] In this embodiment, the fuselage 1, the first end cover 2 and the second end cover 3 enclose a receiving chamber. The first end cover 2 is generally U-shaped. The axial dimension of the first end cover 2 is larger than that of the second end cover 3. A pair of mounting seats for mounting the entire mid-mounted motor are further formed on the first end cover 2 and the fuselage 1, and axial through holes are provided in the mounting seats.

[0060] In this embodiment, a first sealed bearing 56 is provided between the input disk 51 and the fuselage 1 in the radial direction, a second sealed bearing 57 is provided between the input disk 51 and the output disk 55 in the radial direction, a third sealed bearing 58 is provided between the second end cover 3 and the output disk 55 in the radial direction. The fuselage 1, the input disk 51, the first sealed bearing 56, the output disk 55, the second sealed bearing 57, the second end cover 3 and the third sealed bearing 58 enclose the oil storage chamber R.

[0061] In this embodiment, the inner side of the flexspline 53 includes a smooth section adapted to the flexure bearing 52 and an internal tooth section adapted to the output disk 55. The wall thickness of the smooth section is smaller than that of the internal tooth section. The output disk 55 has external teeth adapted to the internal tooth section. With this structure of the flexspline 53, the axial dimension of the flexspline 53 is small, and further the size of the entire harmonic reducer 5 can be made smaller.

[0062] In this embodiment, the input disk 51 includes a first mounting portion 511 and a second mounting portion 512 that are axially distributed. The inner side of the first mounting portion 511 cooperates with the rotor assembly 42, the outer side of the first mounting portion 511 cooperates with the first sealing bearing 56. The cross-section of the second mounting portion 512 is generally U-shaped and the opening faces the output disk 55. The second mounting portion 512 has a bearing groove 513, the second sealing bearing 57 is located in the bearing groove 513. The output disk 55 has a bearing mating portion 551 located in the bearing groove 513. The lower part of the second mounting portion 512 extends radially outward towards one end of the output disk 55 to form a first limiting convex portion 514. The rotor assembly 42 and the input disk 51 are engaged. The outer ring of the second sealing bearing 57 abuts against the bearing groove 513 of the input disk 51. There is an axial gap between the input disk 51 and the output disk 55, and this gap is radially connected. The flexible bearing 52 and the flexspline 53 are in contact with each other only in a small section in the circumferential direction, so the cooling lubricating oil can flow between the axial two sides of the flexible bearing 52 and the flexspline 53. There is also a gap between the flexspline 53 and the steel gear, so the cooling lubricating oil can also flow between the axial two sides of the flexspline 53 and the steel gear.

[0063] In this embodiment, the fuselage 1 includes an outer axial portion 11 on the outermost layer, a radial portion 12 radially extending from the inner side of the axial annular portion, an inner axial portion 13 extending from the inner end of the radial portion 12, and a bearing mounting portion 14 extending from the inner axial portion 13. A support bearing for supporting the input disk 51 is provided in the bearing mounting portion 14.

[0064] In this embodiment, the inner side of the output disk 55 includes a bearing mating portion 551 located outside the second sealing bearing 57, a first abutting portion 552 axially abutting against the second sealing bearing 57. The output disk 55 forms a second abutting portion 553 axially abutting against the third sealing bearing 58 and a mating portion cooperating with the inner ring of the third sealing bearing 58; the lower end of the output disk 55 extends radially to form a second limiting convex portion 554.

[0065] In this embodiment, the motor 4 further includes a main shaft 6. Both ends of the main shaft 6 extend out of the first end cover 2 and the second end cover 3. Two clutch assemblies are provided on the main shaft 6. The two clutch assemblies include a first clutch assembly for foot clutch and a second clutch assembly for the chainring. The two clutch assemblies are radially distributed and located radially inside the harmonic reducer 5.

[0066] In this embodiment, the accommodation chamber includes a motor 4 installation chamber formed by the fuselage 1 and the first end cover 2. The rotor assembly 42 and the stator assembly 41 are provided in the motor 4 installation chamber.

[0067] In this embodiment, the accommodation chamber includes the harmonic reduction chamber formed by the fuselage 1 and the second end cap 3.

[0068] In this embodiment, a torque sensor 7 is provided on the main shaft 6. The torque sensor 7 is located in the middle of the main shaft 6. The torque sensor 7 is located radially inside the rotor shaft of the rotor assembly 42 of the motor 4.

[0069] In this embodiment, the harmonic reduction in-wheel motor further includes a controller 9. The torque sensor 7 is electrically connected to the controller 9, and the controller 9 is electrically connected to the stator assembly 41.

[0070] In this embodiment, the structure of the harmonic reducer 5 is different from that in the prior art, but the basic principle is the same.

[0071] The beneficial effects of the harmonic reduction in-wheel motor of the first embodiment of the present invention are as follows: Its fuselage 1, input disk 51, first sealing bearing 56, output disk 55, second sealing bearing 57, second end cap 3 and third sealing bearing 58 enclose an oil storage chamber R. The oil storage chamber R is filled with cooling lubricating oil. The cooling lubricating oil lubricates the moving contact parts between the flexspline 53 and the circular spline, between the flexure bearing 52 and the flexspline 53, inside the flexure bearing 52, and between the flexspline 53 and the output disk 55, reducing friction and improving efficiency. At the same time, when the harmonic reducer 5 rotates, it stirs the cooling lubricating oil, which can greatly increase the overall heat dissipation performance of the motor 4; teeth are formed on the inner side of the flexspline 53 to cooperate with the output disk 55, and the axial dimension of the harmonic reducer 5 is small; the rotor of the rotor assembly 42 of the motor 4 meshes with the input disk 51; the overall structure of the in-wheel motor is compact.

[0072] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the content described in the above specific implementation manner. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. Harmonic reduction in - center motor, characterized in that: The harmonic reduction center motor includes: a body (1); a first end cover (2) fixedly connected to the body (1); a second end cover (3) fixedly connected to the body (1); a motor (4) including a stator assembly (41) and a rotor assembly (42); a harmonic reducer (5) including an input disk (51) connected to the rotor assembly (42), a flexible bearing (52) connected to the input disk (51), a flexspline (53) connected to the flexible bearing (52), a rigid ring (54) fixed on the body (1), and an output disk (55) connected to the flexspline (53); wherein, the harmonic reducer (5), the body (1) and the second end cover (3) enclose an oil storage chamber (R), the oil storage chamber (R) is filled with cooling lubricating oil, and the flexible bearing (52) is located in the oil storage chamber (R).

2. The harmonic reduction center motor according to claim 1, characterized in that: A first sealing bearing (56) is provided between the input disk (51) and the body (1) in the radial direction, a second sealing bearing (57) is provided between the input disk (51) and the output disk (55) in the radial direction, a third sealing bearing (58) is provided between the second end cover (3) and the output disk (55) in the radial direction, and the body (1), the input disk (51), the first sealing bearing (56), the output disk (55), the second sealing bearing (57), the second end cover (3) and the third sealing bearing (58) enclose the oil storage chamber (R).

3. The harmonic reduction mid-mounted motor according to claim 2, wherein: The inner side of the flexspline (53) includes a smooth section adapted to the flexible bearing (52) and an internal tooth section adapted to the output disk (55), the wall thickness of the smooth section is smaller than that of the internal tooth section, the output disk (55) has external teeth adapted to the internal tooth section; there is an axial gap between the input disk (51) and the output disk (55).

4. The harmonic reduction mid-mounted motor according to claim 2, wherein: The input disk (51) includes an axially distributed first mounting portion (511) and a second mounting portion (512), the inner side of the first mounting portion (511) cooperates with the rotor assembly (42), the outer side of the first mounting portion (511) cooperates with the first sealing bearing (56), the cross section of the second mounting portion (512) is generally U-shaped and the opening faces the output disk (55), the second mounting portion (512) has a bearing groove (513), the second sealing bearing (57) is located in the bearing groove (513), the output disk (55) has a bearing mating portion (551) located in the bearing groove (513), and a first limiting convex portion (514) extends radially outward at one end of the lower part of the second mounting portion (512) facing the output disk (55).

5. The harmonic reduction mid-mounted motor according to claim 2, characterized in that: The body (1) includes an outer axial portion (11) at the outermost layer, a radial portion (12) radially extending from the inner side of the axial annular portion, an inner axial portion (13) extending from the inner end of the radial portion (12), and a bearing mounting portion (14) extending from the inner axial portion (13), and a support bearing for supporting the input disk (51) is provided in the bearing mounting portion (14).

6. The harmonic reduction in-wheel motor according to claim 2, wherein: The inner side of the output disk (55) includes a bearing mating portion (551) located outside the second sealed bearing (57) and a first abutting portion (552) axially abutting the second sealed bearing (57). The output disk (55) forms a second abutting portion (553) axially abutting the third sealed bearing (58). A second limiting convex portion (554) is formed by radially extending the lower end of the output disk (55).

7. The harmonic reduction center motor according to claim 1, characterized in that: The motor (4) further includes a main shaft (6). Both ends of the main shaft (6) extend out of the first end cover (2) and the second end cover (3). Two clutch assemblies are provided on the main shaft (6). The two clutch assemblies are radially distributed and located radially inside the harmonic reducer (5).

8. The harmonic reduction mid-mounted motor according to claim 7, wherein: A torque sensor (7) is provided on the main shaft (6). The harmonic reduction in-motor further includes a controller (9). The torque sensor (7) is electrically connected to the controller (9). The controller (9) is electrically connected to the stator assembly (41). The torque sensor (7) is located in the middle of the main shaft (6).

9. The harmonic reduction in-wheel motor according to claim 1, wherein: The fuselage (1) and the first end cover (2) form a motor (4) installation chamber. The rotor assembly (42) and the stator assembly (41) are arranged in the motor (4) installation chamber. The fuselage (1) and the second end cover (3) form a harmonic reduction chamber.

10. The harmonic reduction mid-mounted motor according to claim 1, wherein: The fuselage (1) and the first end cover (2) are connected by a plurality of circumferential threaded members. The fuselage (1) and the second end cover (3) are connected by a plurality of circumferential threaded members. Mounting seats for mounting the entire in-motor are formed on the first end cover (2) and the fuselage (1).

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