An outer rotor middle-mounted driving motor for an electric bicycle

Abstract

The utility model discloses an electric bicycle outer rotor middle -mounting drive motor, including the casing, be provided with the rotor in the inner side of casing, be provided with permanent magnet on the inner side wall of rotor, and be provided with stator in the inner side of rotor, be provided with copper wire winding group on the stator, still be provided with gear set in the inner side of casing, gear set interrelated setting in the side of rotor, the utility model sets up gear set, and gear set includes the internal gear and planetary nylon wheel, and simultaneously internal gear is linked with the casing, and planetary nylon wheel is linked with sun gear, can drive planetary nylon wheel rotation under the condition that rotor rotates, under the condition that wheel speed ratio increases, and then increase the output torque of output main shaft, and the low -speed start of electric bicycle is convenient, set up transmission board, and a plurality of planetary nylon wheels are installed through bearing and are connected in the support shaft of transmission board, and simultaneously transmission board is set on output main shaft, therefore, can control output main shaft rotation under the action of transmission board, realizes the transmission of power.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to an external rotor mid-drive motor for electric bicycles. Background Technology

[0002] DC motors, as a traditional type of motor, are widely used in various production and daily life applications, such as power tools, household appliances, industrial robots, and electric bicycles.

[0003] Currently, commonly used DC motors include a stator and a rotor. The stator includes the frame, main poles, commutating poles, and brush assembly. The frame is the outer frame of the DC motor, made of cast steel or thick steel plate. It is located on the outermost side of the motor, serving as the mechanical support for the entire motor and also part of the magnetic circuit, bearing the magnetic flux generated by the magnetic field windings. The main poles consist of the main pole core and the excitation coil. The main pole core is usually made of 1.0-1.5 mm thick steel plate, and the excitation coil is formed by winding insulated copper wire. The commutating poles generally consist of a core and windings. The core is mostly machined from a single piece of steel, although in large DC motors it is sometimes made of stacked steel sheets. The windings are usually made of round or flat copper wire with a large cross-section. The brush assembly includes the brushes and brush holders. Brushes are generally made of graphite and copper powder, pressed and sintered, and placed in brush holders. Springs press them against the surface of the commutator. The brush assembly is fixed to the stator and maintains sliding contact with the rotating commutator, used to introduce or extract DC voltage and current. The rotor section includes the armature core, armature windings, commutator, and shaft. The armature core, located at the center of the rotor, is fitted onto the shaft and is part of the main magnetic circuit of the DC motor. Its slots house the armature windings. The armature windings, placed in the slots of the armature core, are key components for converting mechanical energy into electrical energy. When current flows through them, they generate electromagnetic torque; when they move in a magnetic field, they generate induced electromotive force. The commutator is a cylinder made of many insulated wedge-shaped commutator segments (copper sheets), connected to the shaft by a key, and mounted at one end of the rotor, connected to the end of the armature windings. The shaft runs through the center of the rotor, supporting the armature core, commutator, and other components, and outputting the motor's mechanical energy to an external load or inputting mechanical energy from an external source to rotate the motor.

[0004] As described above, the rotor is located inside the stator, meaning the rotor is situated inside the stator. This causes heat generated during rotor rotation to accumulate inside the motor, resulting in poor heat dissipation and impacting the motor's efficiency and lifespan. Furthermore, this structural distribution leads to lower output torque, which is detrimental to starting and driving devices such as electric bicycles. Utility Model Content

[0005] The purpose of this invention is to provide an external rotor mid-drive motor for electric bicycles, which aims to improve the problem that the output torque of DC motors is relatively small and not conducive to starting under load.

[0006] This utility model is implemented as follows: an external rotor mid-drive motor for electric bicycles includes a housing, a rotor disposed inside the housing, a permanent magnet disposed on the inner wall of the rotor, a stator disposed inside the rotor, and a copper wire winding disposed on the stator; a gear set is also disposed inside the housing, the gear set is connected and disposed on the side of the rotor, and an output main shaft is disposed through the middle of the gear set.

[0007] Preferably, the rotor is configured as a cylindrical structure, and the side of the rotor away from the gear set is configured as an opening; the outer diameter of the stator is smaller than the inner diameter of the rotor, and the stator is located inside the rotor.

[0008] Preferably, an inner tube is provided on the inner side of the rotor, the inner tube is positioned directly opposite the middle of the rotor, and a mounting hole is provided on the stator, the inner tube extends into the mounting hole, and a gap is formed between the inner tube and the mounting hole.

[0009] Preferably, the permanent magnet is a neodymium iron boron permanent magnet, and the stator is a silicon steel sheet core stator; the copper wire winding is located at the end of the stator.

[0010] Preferably, the gear set includes an internal gear and multiple planetary nylon wheels, all of which are disposed inside the internal gear and are meshed with the internal gear.

[0011] Preferably, the gear set also includes a transmission plate and multiple support shafts, with the multiple support shafts vertically arranged on the side of the transmission plate, and multiple planetary nylon wheels connected and sleeved on the support shafts through bearings.

[0012] Preferably, a sun gear is fixedly provided at the end of the rotor, the sun gear is meshed with the inner side of multiple planetary nylon gears, and the internal gear is fixedly installed on the housing.

[0013] Preferably, a channel is provided in the middle of the transmission plate, the output spindle is provided through the channel, and a sprocket can be provided at the end of the output spindle that protrudes from the housing.

[0014] Preferably, one end of the housing is set as an opening, and an end cap is provided at the opening of the housing by bolts.

[0015] Preferably, the output spindle is connected through the rotor and the housing via a bearing, and the end of the output spindle is inserted into the end cover via a bearing.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. This utility model is equipped with a gear set, which includes an internal gear and a planetary nylon wheel. The internal gear is connected to the housing, and the planetary nylon wheel is connected to the sun gear. When the rotor rotates, it can drive the planetary nylon wheel to rotate. With the increase of the wheel speed ratio, the output torque of the output main shaft is increased, which facilitates the low-speed start of the electric bicycle.

[0018] 2. This utility model is equipped with a transmission plate, and multiple planetary nylon wheels are connected and installed on the support shaft of the transmission plate through bearings. At the same time, the transmission plate is sleeved on the output spindle. Therefore, the rotation of the output spindle can be controlled under the action of the transmission plate to realize the transmission of power.

[0019] 3. In this utility model, the rotor is set as a cylindrical structure and the stator is set inside the rotor. Therefore, the generated heat is conducted through the shell, which changes the heat dissipation problem of the motor, thereby improving the efficiency and service life of the motor. Attached Figure Description

[0020] Figure 1 This is a first structural schematic diagram of the entire utility model;

[0021] Figure 2 This is a second structural schematic diagram of the entire utility model;

[0022] Figure 3 This is a schematic diagram of the gear set of this utility model;

[0023] Figure 4 This is a schematic diagram of the rotor and planetary nylon wheel of this utility model;

[0024] Figure 5 This is a first structural schematic diagram of the rotor and stator of this utility model;

[0025] Figure 6 This is a second structural schematic diagram of the rotor and stator of this utility model.

[0026] In the diagram: 1. Housing; 2. End cap; 3. Rotor; 31. Permanent magnet; 32. Sun gear; 33. Inner tube; 4. Stator; 41. Copper wire winding; 42. Mounting hole; 5. Gear set; 51. Internal gear; 52. Planetary nylon wheel; 53. Transmission plate; 54. Support shaft; 6. Output spindle; 61. Sprocket. Detailed implementation method:

[0027] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] The following description, in conjunction with the accompanying drawings and specific embodiments, provides further details:

[0029] Example 1

[0030] like Figure 1 , Figure 2 As shown, in order to improve the torque output of the motor and adapt to the starting conditions of an electric bicycle, this embodiment provides a new motor. The motor includes a housing 1, a rotor 3, a stator 4, a gear set 5, and an output shaft 6. One end of the housing 1 is open, and an end cover 2 is bolted to the opening of the housing 1. Therefore, the housing 1 and the end cover 2 together form the motor's support structure. The stator 4 is a silicon steel sheet core stator 4. The gear set 5, rotor 3, and stator 4 are all disposed within the space formed by the housing 1 and the end cover 2, with the rotor 3 and stator 4 positioned internally and externally. A permanent magnet 31 is disposed on the rotor 3, and a copper wire winding 41 is disposed on the stator 4. Therefore, when the copper wire winding 41 is energized, the permanent magnet 31 can be controlled to rotate, thereby driving the rotor 3 to rotate. Gear set 5 is located on the side of rotor 3 and is connected to rotor 3. Output shaft 6 passes through gear set 5. Therefore, the transmission of rotor 3 is transmitted to output shaft 6 via gear set 5, and the output torque of output shaft 6 is increased under the action of gear set 5. Installing a motor with the above structure on an electric bicycle can improve the starting thrust of the electric bicycle and provide support for transporting materials or carrying heavier passengers.

[0031] like Figure 3As shown, in order to increase the output torque of the output spindle 6 through the action of the gear set 5, the gear set 5 includes an internal gear 51 and multiple planetary nylon wheels 52. The multiple planetary nylon wheels 52 are all disposed inside the internal gear 51 and are evenly distributed along the circumference of the internal gear 51. Furthermore, the multiple planetary nylon wheels 52 are meshed with the internal gear 51. In addition, the internal gear 51 is fixedly mounted on the housing 1, and a transmission plate 53 and multiple support shafts 54 are provided on the sides of the multiple planetary nylon wheels 52. The multiple support shafts 54 are vertically arranged on the sides of the transmission plate 53. The multiple planetary nylon wheels 52 are connected and sleeved on the support shafts 54 through bearings. Therefore, when the planetary nylon wheels 52 revolve around their axes, they can drive the transmission plate 53 to rotate.

[0032] like Figure 3 As shown, in order to drive the output spindle 6 to rotate via the transmission plate 53, a channel is provided in the middle of the transmission plate 53, through which the output spindle 6 passes, so that the output spindle 6 and the transmission plate 53 are interference-fitted. Alternatively, components such as keys and pins can be added between the output spindle 6 and the transmission plate 53 to achieve synchronous rotation of the output spindle 6 and the transmission plate 53, so that the rotation of the transmission plate 53 can drive the output spindle 6 to rotate.

[0033] When the motor is used in an electric bicycle, a sprocket 61 is fitted onto the end of the output spindle 6 that protrudes from the housing 1.

[0034] like Figure 4 As shown, in order to drive the rotation of multiple planetary nylon wheels 52, a sun gear 32 is fixedly installed at the end of the rotor 3. The sun gear 32 is meshed with the inner side of the multiple planetary nylon wheels 52. Therefore, when the rotor 3 rotates, the rotation of multiple planetary nylon wheels 52 can be controlled to realize the transmission of power. The internal gear 51 is fixed on the housing, which increases the gear ratio and greatly improves the final output torque of the motor.

[0035] Example 2

[0036] like Figure 5 , Figure 6 As shown, based on Embodiment 1, in order to improve heat dissipation efficiency, the rotor 3 is configured as a cylindrical structure in this embodiment, and the side of the rotor 3 away from the gear set 5 is set as an opening. A permanent magnet 31, which is a neodymium iron boron permanent magnet 31, is provided on the inner wall of the rotor 3. The outer diameter of the stator 4 is smaller than the inner diameter of the rotor 3, and the stator 4 is located inside the rotor 3. Meanwhile, the copper wire winding 41 is located at the end of the stator 4. This configuration facilitates the rapid output of heat generated by the rotor 3 through the housing 1 to the motor, changing the situation where heat accumulates in the middle of the motor and is not conducive to dissipation, thereby improving the efficiency and service life of the motor.

[0037] like Figure 5As shown, an inner tube 33 is also provided on the inner side of the rotor 3. The inner tube 33 is positioned directly opposite the middle of the rotor 3. A mounting hole 42 is provided on the stator 4. The inner tube 33 extends into the mounting hole 42, and a gap is formed between the inner tube 33 and the mounting hole 42.

[0038] Example 3

[0039] like Figure 1 As shown, based on Embodiment 1 or 2, to ensure stable installation of the output spindle 6 and enhance its strength, the output spindle 6 is connected through the rotor 3 and housing 1 via bearings, and the end of the output spindle 6 is inserted into the end cover 2 via bearings. Compared to traditional toothed mid-drive motors that use multi-axis torque transmission, resulting in complex structures and high costs, this invention employs a through-shaft structure, which simplifies the motor structure and enhances the through-shaft load-bearing capacity.

[0040] In addition, a fan can be installed in the space formed by the housing 1 and the end cover 2 as needed, and connected to the output spindle 6, so that the air can be circulated under the action of the fan to achieve heat dissipation of the motor.

[0041] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An outer rotor center drive motor for an electric bicycle, characterized by, The device includes a housing (1), a rotor (3) is provided inside the housing (1), a permanent magnet (31) is provided on the inner wall of the rotor (3), and a stator (4) is provided inside the rotor (3), with a copper wire winding assembly (41) provided on the stator (4); a gear set (5) is also provided inside the housing (1), the gear set (5) is connected and provided on the side of the rotor (3), and an output main shaft (6) is provided through the middle of the gear set (5).

2. An electrically driven bicycle outer rotor center driving motor according to claim 1, characterized in that, The rotor (3) is configured as a cylindrical structure, and the side of the rotor (3) away from the gear set (5) is configured as an opening; the outer diameter of the stator (4) is smaller than the inner diameter of the rotor (3).

3. An electrically driven bicycle outer rotor center drive motor according to claim 2, characterized in that, An inner tube (33) is provided on the inner side of the rotor (3). The inner tube (33) is positioned opposite the middle of the rotor (3). A mounting hole (42) is provided on the stator (4). The inner tube (33) extends into the mounting hole (42), and a gap is formed between the inner tube (33) and the mounting hole (42).

4. An electrically driven bicycle outer rotor center driving motor according to claim 2, characterized in that, The permanent magnet (31) is a neodymium iron boron permanent magnet (31), and the stator (4) is a silicon steel sheet core stator (4); the copper wire winding (41) is located at the end of the stator (4).

5. An electrically driven bicycle outer rotor center driving motor according to claim 1, characterized in that, The gear set (5) includes an internal gear (51) and a plurality of planetary nylon wheels (52). The plurality of planetary nylon wheels (52) are all disposed on the inner side of the internal gear (51), and the plurality of planetary nylon wheels (52) are meshed with the internal gear (51).

6. An electrically driven bicycle outer rotor mid-drive motor according to claim 5, characterized in that, The gear set (5) also includes a transmission plate (53) and multiple support shafts (54). The multiple support shafts (54) are vertically arranged on the side of the transmission plate (53), and multiple planetary nylon wheels (52) are connected and sleeved on the support shafts (54) through bearings.

7. An electrically driven bicycle outer rotor mid-drive electric motor according to claim 6, wherein, A sun gear (32) is fixedly provided at the end of the rotor (3), the sun gear (32) is meshed with the inner side of a plurality of planetary nylon gears (52), and the internal gear (51) is fixedly installed on the housing (1).

8. The electric bicycle external rotor mid-drive motor according to claim 6, characterized in that, A channel is provided in the middle of the transmission plate (53), the output spindle (6) is provided through the channel, and a sprocket (61) may be provided at the end of the output spindle (6) that protrudes from the housing (1).

9. A mid-mounted external rotor drive motor for an electric bicycle according to claim 1, characterized in that, One end of the housing (1) is set as an opening, and an end cap (2) is provided at the opening of the housing (1) by bolts.

10. A mid-mounted external rotor drive motor for an electric bicycle according to claim 9, characterized in that, The output spindle (6) is connected through the rotor (3) and the housing (1) by a bearing, and the end of the output spindle (6) is inserted into the end cover (2) by a bearing.

Images