Mid-mounted motor transmission mechanism, electric power-assisted bicycle driving system and electric power-assisted bicycle

Abstract

The present invention relates to the technical field of electric power-assisted vehicles, and in particular to a mid-mounted motor transmission mechanism, an electric power-assisted vehicle driving system and an electric power-assisted vehicle. The mid-mounted motor transmission mechanism includes a central shaft, an input gear, an output gear, a clutch and a central shaft support bearing, wherein the input gear is used to mesh with the output gear of the reducer, and the output gear is used to transmit power to the crankset; the clutch is sleeved on the central shaft and is connected to the central shaft by transmission; the output gear is sleeved on the clutch and is connected to the clutch by transmission; the stepped mating surfaces of the central shaft support bearing and the central shaft are respectively located at both ends of the output gear, which are used to limit the output gear; by fixing the input gear on the central shaft, and limiting the output gear by using the stepped mating surface on the central shaft and the central shaft support bearing, the input gear and the output gear can be positioned without increasing the size of the central shaft, thereby ensuring accurate positioning and reducing transmission noise.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power-assisted vehicles, and in particular to a mid-mounted motor transmission mechanism, an electric power-assisted vehicle driving system and an electric power-assisted vehicle. Background Art

[0002] Electric power-assisted bicycles can be driven by human power and electric power, and can provide corresponding electric power support in different proportions according to the strength of the rider's pedaling. The electric power of electric power-assisted bicycles usually includes two forms. One is to use the hub motor to achieve electric power. The hub motor is to integrate the motor into the hub drum. After power is turned on, the motor converts electrical energy into mechanical energy, thereby driving the wheels to rotate; the other is to use the mid-mounted motor to achieve electric power. The mid-mounted motor needs to transmit the power output of the motor to the output shaft of the electric power-assisted bicycle through the transmission mechanism, and then transmit the power to the chain plate through the output shaft, and finally transmit the power of the chain plate to the wheel through the chain to realize the wheel rotation.

[0003] like Figure 1 As shown, the existing mid-mounted motor transmission mechanism includes a central shaft 1', an input gear 2', an output gear 3' and a clutch 4', wherein the input gear 2' is connected to the central shaft 1' through the clutch 4', the output gear 3' is integrally formed with the central shaft 1', the reducer input gear 100' is matched with the output end of the central motor, and the power of the central motor is transmitted to the input gear 2' through the reducer output gear (not shown in the figure), and then the central shaft 1' is driven to rotate through the clutch 4' and the output gear 3' is driven to rotate, and finally the power is output to the toothed disc to realize the electric drive of the electric power-assisted vehicle. In the process of transmitting power (torque and speed), the input gear 2' will generate radial force, tangential force and axial force, wherein the radial force and circumferential tangential force are mainly supported and borne by the cylindrical mating surface of the clutch 4 and the central shaft 1', and the axial force is mainly borne by the stepped mating surface of the central shaft 1', and these forces will be transmitted to the shaft section of the output gear 3', and the radial force, tangential force and axial force existing in the shaft section of the output gear 3' are borne by the bearings arranged at both ends thereof.

[0004] The design of the above-mentioned central motor transmission mechanism has the following problems: 1) When the clutch 4' uses a wedge-type clutch, the clutch 4' does not have a centering function, and the centering of the input gear 2' is mainly played by the cylindrical mating surface of the middle shaft 1', and the relative movement between the input gear 2' and the middle shaft 1' easily causes the wear of the cylindrical mating surface of the middle shaft 1', thereby further causing problems such as inaccurate positioning of the input gear 2', high vibration and noise. 2) When the clutch 4' uses an integrated clutch, under the condition of transmitting the same torque, the size of the integrated clutch is much larger than that of the wedge-type clutch, and there is a possibility of interference with the reducer input gear 100'. If the clutch 4' is to avoid the interference with the reducer input gear 100', the length of the middle shaft 1' needs to be increased, so that the size of the entire mechanism is larger and cannot meet the requirements of the installation space.

[0005] Therefore, a mid-mounted motor transmission mechanism is urgently needed to solve the above problems. Summary of the invention

[0006] The first object of the present invention is to provide a mid-mounted motor transmission mechanism, which can realize the positioning of the transmission gear without increasing the overall size of the mechanism, ensure the accurate positioning of the transmission gear, and reduce the transmission noise.

[0007] The second object of the present invention is to provide an electric power-assisted bicycle driving system, which, by applying the above-mentioned mid-mounted motor transmission mechanism, has a compact structure, a small overall size, and low power transmission noise.

[0008] The third object of the present invention is to provide an electric power-assisted vehicle, which, by applying the above-mentioned electric power-assisted vehicle driving system, has the advantages of compact structure, small overall size, and low power transmission noise.

[0009] In order to achieve the above objectives, the following technical solutions are provided:

[0010] In a first aspect, a mid-mounted motor transmission mechanism is provided, comprising:

[0011] a center shaft, on which a stepped mating surface is provided;

[0012] An input gear, coaxially and fixedly connected to the middle shaft, and the input gear is used to mesh with the output gear of the reducer;

[0013] A clutch, sleeved on the middle shaft and drivingly connected to the middle shaft;

[0014] An output gear, which is sleeved on the clutch and is transmission-connected to the clutch, and is used to transmit power to the crankset;

[0015] The middle shaft support bearing and the stepped matching surface are respectively located at both ends of the output gear and are used to limit the output gear.

[0016] As an optional solution of the mid-mounted motor transmission mechanism, the mid-mounted motor transmission mechanism further includes a gasket, which is arranged between the mid-shaft support bearing and the output gear.

[0017] As an optional solution of the central motor transmission mechanism, the central motor transmission mechanism further includes a first limit bearing, and the first limit bearings are respectively arranged at both ends of the clutch.

[0018] As an optional solution for the central motor transmission mechanism, the first limit bearing is located between the output gear and the central shaft.

[0019] As an optional solution of the central motor transmission mechanism, the central motor transmission mechanism further includes a retaining spring, and the retaining spring is arranged between the first limit bearing close to the stepped matching surface and the clutch.

[0020] As an optional solution for the central motor transmission mechanism, a limiting groove is provided on the inner wall of the output gear, and the retaining spring is accommodated in the limiting groove.

[0021] As an optional solution for the central motor transmission mechanism, the input gear and the central shaft are an integrally formed structure.

[0022] As an optional solution for the central motor transmission mechanism, the input gear and the stepped mating surface are arranged at a distance, and the distance is used to accommodate the reducer input gear.

[0023] In a second aspect, an electric power-assisted bicycle driving system is provided, comprising a mid-mounted motor, a reducer and the mid-mounted motor transmission mechanism as described above.

[0024] In a third aspect, an electric power-assisted vehicle is provided, comprising the electric power-assisted vehicle driving system as described above.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The central motor transmission mechanism provided by the present invention comprises a central shaft, an input gear, an output gear, a clutch and a central shaft support bearing, wherein the input gear is used to mesh with the output gear of the reducer, and the output gear is used to transmit power to the crankset; a stepped mating surface is provided on the central shaft; the input gear is coaxially fixedly connected with the central shaft; the clutch is sleeved on the central shaft and is transmission-connected with the central shaft; the output gear is sleeved on the clutch and is transmission-connected with the clutch; the central shaft support bearing and the stepped mating surface are respectively located at both ends of the output gear, and are used to limit the output gear. The central motor transmission mechanism is achieved by fixing the input gear on the central shaft, the output gear is transmission-connected with the central shaft through the clutch, and the output gear is limited by the stepped mating surface on the central shaft and the central shaft support bearing, so that the input gear and the output gear can be positioned without increasing the size of the central shaft, thereby ensuring accurate positioning and reducing transmission noise.

[0027] The electric power-assisted bicycle driving system provided by the present invention has a compact structure, a small overall size, and low power transmission noise by applying the above-mentioned mid-mounted motor transmission mechanism.

[0028] The electric power-assisted vehicle provided by the present invention has the advantages of compact structure, small overall size, low power transmission noise, etc. by applying the above-mentioned electric power-assisted vehicle driving system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0030] Figure 1 It is a cross-sectional schematic diagram of a central motor transmission mechanism in the prior art;

[0031] Figure 2 A schematic diagram of the structure of a mid-mounted motor transmission mechanism provided in an embodiment of the present invention;

[0032] Figure 3 A cross-sectional view of a mid-mounted motor transmission mechanism provided by an embodiment of the present invention;

[0033] Figure 4 An exploded schematic diagram of a mid-mounted motor transmission mechanism provided in an embodiment of the present invention.

[0034] Reference numerals:

[0035] 100-reducer input gear; 200-reducer output gear;

[0036] 1-center axis; 11-step mating surface;

[0037] 2- Input gear;

[0038] 3- Output gear;

[0039] 4- Clutch;

[0040] 5-Middle shaft support bearing;

[0041] 6- first limit bearing;

[0042] 7-circlip;

[0043] 8- Gasket;

[0044] 9-Second limit bearing. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0046] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 or other connections; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In the present invention, 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.

[0048] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0049] The present embodiment provides an electric power-assisted bicycle driving system, including a mid-mounted motor, a reducer and a mid-mounted motor transmission mechanism. The reducer includes a reducer input gear 100 and a reducer output gear 200, the reducer input gear 100 is transmission-connected to the output end of the mid-mounted motor, and the reducer output gear 200 is used to transmit power to the mid-mounted motor transmission mechanism, and then the mid-mounted motor transmission mechanism transmits the power to the crankshaft to realize the electric drive of the electric power-assisted bicycle.

[0050] like Figure 2-Figure 4 As shown, the central motor transmission mechanism provided in this embodiment includes a central shaft 1, an input gear 2, an output gear 3, a clutch 4 and a central shaft support bearing 5, wherein the input gear 2 is used to mesh with the output gear 200 of the reducer, and the output gear 3 is used to transmit power to the crankset; a stepped mating surface 11 is provided on the central shaft 1; the input gear 2 is coaxially fixedly connected with the central shaft 1; the clutch 4 is sleeved on the central shaft 1 and is transmission-connected with the central shaft 1; the output gear 3 is sleeved on the clutch 4 and is transmission-connected with the clutch 4; the central shaft support bearing 5 and the stepped mating surface 11 are respectively located at both ends of the output gear 3, which are used to limit the output gear 3. The central motor transmission mechanism is configured such that the input gear 2 is fixed on the central shaft 1, the output gear 3 is transmission-connected with the central shaft 1 through the clutch 4, and the output gear 3 is limited by the stepped mating surface 11 on the central shaft 1 and the central shaft support bearing 5, so that the input gear 2 and the output gear 3 can be positioned without increasing the size of the central shaft 1, thereby ensuring accurate positioning and reducing transmission noise.

[0051] In normal operation, the input gear 2 receives power input from the output gear 200 of the reducer, the input gear 2 rotates and drives the clutch 4 to work, the clutch 4 then drives the output gear 3 to rotate, and the output gear 3 outputs power to the chainring through the gear matched with it. In the process of power transmission by the output gear 3, axial force will be generated, and the axial force can be borne by the stepped mating surface 11 and the middle shaft support bearing 5 to limit the output gear 3, ensure its accurate positioning, and reduce the power transmission noise.

[0052] Preferably, the input gear 2 and the stepped mating surface 11 are spaced apart, and the space is used to accommodate the reducer input gear 100, so as to fully utilize the layout space of the middle shaft 1 and reduce the size of the whole machine.

[0053] Exemplarily, the clutch 4 may be a wedge clutch, and the clutch 4 is a one-way clutch.

[0054] Preferably, the central motor transmission mechanism also includes a first limit bearing 6 and a second limit bearing 9, which are respectively arranged at the two ends of the clutch 4 to limit the clutch 4 axially. During the power transmission process of the output gear 3, radial force and tangential force will also be generated, wherein the radial force and tangential force are mainly borne by the first limit bearing 6 and the second limit bearing 9, and the clutch 4 does not need to bear them, so as to avoid the wedge block of the clutch 4 from being subjected to inconsistent force and inclination, resulting in eccentricity of the middle shaft 1 matched therewith, and causing the clutch 4 to work unsmoothly or fail to work. In addition, the axial force generated by the output gear 3 can be transmitted to the input gear 2 through the stepped mating surface 11, and does not need to be borne by the first limit bearing 6 and the second limit bearing 9, thereby reducing the working force of the first limit bearing 6 and the second limit bearing 9 and improving their service life.

[0055] Preferably, the first limit bearing 6 and the second limit bearing 9 are both located between the output gear 3 and the central shaft 1. That is, the first limit bearing 6 and the second limit bearing 9 are located inside the output gear 3 and outside the central shaft 1, and bearings with smaller outer diameters can be selected to meet the space layout requirements.

[0056] In this embodiment, there is a stepped hole in the output gear 3, and the aperture of the shaft section for assembling the first limit bearing 6 and the clutch 4 is larger than the aperture of the shaft section for assembling the second limit bearing 9. This design can limit the clutch 4 and ensure the structural strength of the output gear 3 while reducing the diameter of the output gear 3.

[0057] Exemplarily, different types of bearings can be selected for the first limiting bearing 6 and the second limiting bearing 9. In this embodiment, the first limiting bearing 6 located near the stepped mating surface 11 is a ball bearing, and the second limiting bearing 9 is a needle bearing.

[0058] Optionally, in order to limit the axial position of the clutch 4 , the central motor transmission mechanism further includes a retaining spring 7 , which is disposed between the first limiting bearing 6 close to the stepped mating surface 11 and the clutch 4 .

[0059] Optionally, a limiting groove is provided on the inner wall of the output gear 3, and the retaining spring 7 is accommodated in the limiting groove, so as to ensure that the relative position of the clutch 4 and the output gear 3 remains unchanged, thereby ensuring the power transmission effect.

[0060] Preferably, the central motor transmission mechanism further includes a gasket 8, which is disposed between the central shaft support bearing 5 and the output gear 3. By disposing the gasket 8 between the central shaft support bearing 5 and the output gear 3, the second limit bearing 9 and the output gear 3 can be axially limited to improve the transmission stability. In addition, the wear on the central shaft support bearing 5 can be reduced, and the service life of the components can be extended.

[0061] Optionally, the input gear 2 and the middle shaft 1 are an integrally formed structure, which can ensure coaxial transmission of the input gear 2 and the middle shaft 1 and accurate positioning of the input gear 2 to ensure transmission effect.

[0062] This embodiment also provides an electric power-assisted vehicle, including the above-mentioned electric power-assisted vehicle driving system. By applying the above-mentioned electric power-assisted vehicle driving system, the electric power-assisted vehicle has the advantages of compact structure and smaller size.

[0063] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A mid-mounted motor transmission mechanism, characterized in that: include: A central shaft (1) having a stepped mating surface (11) disposed thereon; An input gear (2) is coaxially fixedly connected to the middle shaft (1), and the input gear (2) is used to mesh with the output gear (200) of the reducer; A clutch (4) is sleeved on the middle shaft (1) and is drivingly connected to the middle shaft (1), the clutch (4) is a wedge-type clutch, and the clutch (4) is a one-way clutch; An output gear (3) is sleeved on the clutch (4) and is drivingly connected to the clutch (4), and the output gear (3) is used to transmit power to the crankset; The middle shaft support bearing (5) and the stepped matching surface (11) are respectively located at two ends of the output gear (3) and are used to limit the position of the output gear (3).

2. The mid-mounted motor transmission mechanism according to claim 1, characterized in that: The central motor transmission mechanism further comprises a gasket (8), wherein the gasket (8) is arranged between the central shaft support bearing (5) and the output gear (3).

3. The mid-mounted motor transmission mechanism according to claim 1, characterized in that: The central motor transmission mechanism further comprises a first limit bearing (6) and a second limit bearing (9), wherein the first limit bearing (6) and the second limit bearing (9) are respectively arranged at two ends of the clutch (4).

4. The mid-mounted motor transmission mechanism according to claim 3, characterized in that: The first limit bearing (6) and the second limit bearing (9) are both located between the output gear (3) and the central shaft (1).

5. The mid-mounted motor transmission mechanism according to claim 3, characterized in that: The central motor transmission mechanism further comprises a retaining spring (7), wherein the retaining spring (7) is arranged between the first limit bearing (6) and the clutch (4).

6. The mid-mounted motor transmission mechanism according to claim 5, characterized in that: A limiting groove is provided on the inner wall of the output gear (3), and the retaining ring (7) is accommodated in the limiting groove.

7. The mid-mounted motor transmission mechanism according to any one of claims 1 to 6, characterized in that: The input gear (2) and the central shaft (1) are an integrally formed structure.

8. The mid-mounted motor transmission mechanism according to claim 7, characterized in that: The input gear (2) and the stepped matching surface (11) are arranged at a distance, and the distance is used to accommodate the reducer input gear (100).

9. An electric power-assisted vehicle driving system, characterized in that: It comprises a mid-mounted motor, a reducer and a mid-mounted motor transmission mechanism as described in any one of claims 1-8.

10. An electric power-assisted vehicle, characterized in that: It comprises the electric power-assisted vehicle driving system as claimed in claim 9.

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