Belt transmission mid-motor of power-assisted bicycle

Abstract

A power-assisted bicycle belt transmission middle motor comprises a shell, a power mechanism, a belt, a transmission wheel, a support flange, a chain wheel and a middle shaft, the shell is provided with a through hole allowing the middle shaft to penetrate through, and the power mechanism, the belt, the transmission wheel and the support flange are located in the shell. The chain wheel and the transmission wheel are connected with the bracket flange through bolts; the belt sleeves the transmission wheel and the output end of the power mechanism, and the power mechanism drives the transmission wheel through the belt to drive the chain wheel to rotate; according to the electric bicycle, when the motor is not supplied with electricity, a rider treads the pedals to shorten a transmission structural chain, and compared with an electric bicycle, the electric bicycle saves more labor during riding, can achieve large torque output in a small space, has good load distribution capacity and is more stable and reliable in the transmission process.

Description

Technical Field

[0001] The utility model relates to the field of power-assisted bicycles, in particular to a belt-driven mid-mounted motor for power-assisted bicycles. Background Art

[0002] Bicycles are the most economical and convenient means of transportation for people and have been widely used by urban and rural residents. Bicycle structural technology includes many aspects, among which mechanical transmission technology is one of the most important factors. With the advancement of science and technology and the improvement of people's quality of life, people's requirements for traditional bicycles have also increased, resulting in the emergence of electric bicycles. Electric bicycles are usually equipped with battery-driven parts and human-driven parts. The human-driven part consists of pedals, cranks, chainrings and axles. People pedal to drive the cranks, which in turn drives the chainrings to rotate, and finally drives the rear wheel to rotate through the chain and flywheel to provide power and complete the entire transmission chain of the bicycle.

[0003] The existing electric bicycles are equipped with a battery drive part, which increases the transmission structure of the gear disk and makes the entire transmission chain bloated and complicated. Although the battery drive part can help the rider save energy, when the battery is exhausted, the increase in the transmission structure will increase the force, and the transmission will also rotate with the output end of the driven motor. In addition, the internal structure of the motor is wrapped with a lot of copper wire, and there will be a noticeable sense of drag when riding. When the rider uses human power to drive, he needs to exert more effort than an ordinary bicycle, which affects the riding experience. It is laborious and not suitable for long-distance riding. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a belt-driven mid-mounted motor for a power-assisted bicycle, which can effectively solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above problems, the technical solution adopted by the utility model is: a belt-driven mid-mounted motor for a power-assisted bicycle, comprising a shell, a power mechanism, a belt, a transmission wheel, a bracket flange, a chainring and a central axis, the shell being provided with a through hole for the central axis to pass through, wherein the power mechanism, the belt, the transmission wheel and the bracket flange are located inside the shell, and is characterized in that the chainring is connected to the transmission wheel through the bracket flange, and the chainring and the transmission wheel are both bolted to the bracket flange; the belt is sleeved on the output end of the transmission wheel and the power mechanism, and the power mechanism drives the transmission wheel to rotate through the belt.

[0006] As a further preferred embodiment of the present utility model, the power mechanism includes a positioning shaft, a stator, a rotating drum and a planetary transmission mechanism; both ends of the positioning shaft are clamped with the inner wall of the shell; the stator is sleeved on the positioning shaft, and the stator is located inside the rotating drum; a plurality of groups of rotor coils are embedded in the inner wall of the rotating drum, and a bearing is provided in the middle of the rotating drum to be sleeved with the positioning shaft, and the outer side of the middle of the rotating drum is connected to one side of the planetary transmission mechanism; the other side of the planetary transmission mechanism is sleeved with a belt, and the planetary transmission mechanism is provided with a bearing to be sleeved with the positioning shaft.

[0007] As a further preferred embodiment of the present invention, the planetary transmission mechanism includes a sun gear, a planetary gear, a planetary carrier and an inner gear ring; the sun gear is bolted to the rotating drum; the inner gear ring is sleeved on the inner wall of the shell; the planetary carrier is mounted on the positioning shaft through a bearing, and an output wheel is provided in the middle of one side of the planetary carrier; the output wheel is sleeved with a belt; the planetary gear is mounted on the other side of the planetary carrier, and the planetary gear is meshed and connected with the sun gear and the inner gear ring respectively.

[0008] As a further preferred embodiment of the present invention, a notch is provided on the inner wall of the planetary carrier, and the output wheel and the notch form a closed chamber; a ball and a spring are installed in the notch, and the spring is located on one side of the ball; a sliding connection is formed between the outer wall on one side of the output wheel and the ball.

[0009] As a further preferred solution of the utility model, there are three of each of the notch, ball and spring, which are arranged in corresponding combinations and at intervals on the inner ring of the planet carrier and cooperate with the output wheel to form a one-way clutch.

[0010] As a further preferred solution of the utility model, the central shaft is provided with a one-way bearing sleeved with a bracket flange.

[0011] Compared with the prior art, the utility model provides a belt-driven mid-mounted motor for a power-assisted bicycle, which has the following beneficial effects:

[0012] The utility model can shorten the transmission structure chain by the rider stepping on the pedals when the motor has no power supply. Compared with an electric bicycle, riding is more labor-saving, a large torque output can be achieved in a smaller space, and it has a better load distribution capability, making it more stable and reliable during the transmission process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the utility model;

[0014] Figure 2 It is a schematic diagram of the structural section of the utility model;

[0015] Figure 3 It is a schematic diagram of the power drive structure;

[0016] Figure 4 This is a schematic cross-sectional view of the power drive structure;

[0017] Figure 5 It is a schematic diagram of the structure of the power drive part;

[0018] Figure 6 This is a schematic diagram of the human-driven structure;

[0019] Figure 7 This is a schematic cross-section diagram of a human-driven structure;

[0020] Among them: 1. Shell; 2. Power mechanism; 2-1. Positioning shaft; 2-2. Stator; 2-3. Drum; 2-31. Rotor coil; 2-4. Planetary transmission mechanism; 2-41. Sun gear; 2-42. Planetary gear; 2-43. Planet carrier; 2-44. Internal gear ring; 3. Belt; 4. Drive wheel; 5. Bracket flange; 6. Chainring; 7. Middle shaft; 8. Output wheel; 9. Notch; 10. Ball; 11. Shrapnel; 12. One-way bearing; 13. Bearing. DETAILED DESCRIPTION

[0021] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0023] In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel options. Taking "A and / or B" as an example, it includes option A, or option B, or a option in which both A and B are satisfied.

[0024] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0025] Reference Figure 1-7The utility model provides a belt-driven mid-mounted motor for an assistive bicycle, comprising a housing 1, a power mechanism 2, a belt 3, a transmission wheel 4, a bracket flange 5, a chainring 6 and a central axis 7, wherein the housing 1 is provided with a through hole for the central axis 7 to pass through, wherein the power mechanism 2, the belt 3, the transmission wheel 4 and the bracket flange 5 are located inside the housing 1, and is characterized in that the chainring 6 is connected to the transmission wheel 4 through the bracket flange 5, and the chainring 6 and the transmission wheel 4 are both bolted to the bracket flange 5; the belt 3 is sleeved on the output end of the transmission wheel 4 and the power mechanism 2, and the power mechanism 2 drives the transmission wheel 4 through the belt 3 to drive the chainring 6 to rotate.

[0026] As a further preferred embodiment of the present utility model, the power mechanism 2 includes a positioning shaft 2-1, a stator 2-2, a rotating drum 2-3 and a planetary transmission mechanism 2-4; both ends of the positioning shaft 2-1 are clamped with the inner wall of the shell 1; the stator 2-2 is sleeved on the positioning shaft 2-1, and the stator 2-2 is located inside the rotating drum 2-3; the inner wall of the rotating drum 2-3 is inlaid with a plurality of groups of rotor coils 2-31, the rotor coils 2-31 are arranged around the stator 2-2, and a bearing 13 is provided in the middle of the rotating drum 2-3 to be sleeved with the positioning shaft 2-1, and the outer side of the middle of the rotating drum 2-3 is connected to one side of the planetary transmission mechanism 2-4; the other side of the planetary transmission mechanism 2-4 is sleeved with the belt 3, and the planetary transmission mechanism 2-4 is provided with a bearing 13 to be sleeved with the positioning shaft 2-1.

[0027] As a further preferred embodiment of the present invention, the planetary transmission mechanism 2-4 includes a sun gear 2-41, a planetary gear 2-42, a planetary carrier 2-43 and an inner gear ring 2-44; the sun gear 2-41 is bolted to the rotating drum 2-3; the inner gear ring 2-44 is sleeved on the inner wall of the housing 1; the planetary carrier 2-43 is installed on the positioning shaft 2-1 through a bearing 13, and an output wheel 8 is provided in the middle of one side of the planetary carrier 2-43; the output wheel 8 is sleeved on the belt 3; the planetary gear 2-42 is installed on the other side of the planetary carrier 2-43, and the planetary gear 2-42 is meshed and connected with the sun gear 2-41 and the inner gear ring 2-44 respectively.

[0028] The planetary gears 2-42 are provided with 3 or more, which are arranged in a circular pattern and are all installed on the planetary carrier 2-43. When the sun gear 2-41 rotates, the planetary gears 2-42 are driven to rotate. Since the position of the inner ring 2-44 is fixed, the planetary gears 2-42 will revolve around the sun gear 2-41 at the same time according to the transmission of force. When the planetary gears 2-42 revolve, they will drive the planetary carrier 4-3 to rotate, output torque, so that the bicycle can obtain electric power assistance, and riding is more labor-saving.

[0029] As a further preferred embodiment of the present invention, a slot 9 is provided on the inner wall of the planetary carrier 2-43, and the output wheel 8 and the slot 9 form a closed chamber; a ball 10 and a spring 11 are installed in the slot 9, and the spring 11 is located on one side of the ball 10; a sliding connection is formed between the outer wall on one side of the output wheel 8 and the ball 10.

[0030] As a further preferred embodiment of the present invention, three grooves 9, balls 10 and springs 11 are provided, which are arranged in corresponding combinations and spacings on the inner ring of the planetary carrier 2-43, and cooperate with the output wheel 8 to form a one-way clutch; when the planetary carrier 2-43 actively rotates, the balls 10 are in a downhill state on the output wheel 8, and the space at the downhill place is narrow. The balls 10 are stuck and locked, so that when the planetary carrier 2-43 actively rotates, it will drive the output wheel 8 to rotate and output torque. On the contrary, when the output wheel 8 outputs with an opposite force, the balls 10 are in an uphill state on the output wheel 8, and the space at the uphill place is wider, and the output wheel 8 will not drive the planetary carrier 2-43 to rotate, thereby cutting off the torque transmission, shortening the transmission chain, and making active riding more labor-saving.

[0031] As a further preferred embodiment of the present invention, the middle shaft 7 is provided with a one-way bearing 12 which is sleeved with the bracket flange 5. The middle shaft 7 is a torque sensing middle shaft with a built-in strain gauge. When riding, the greater the induced deformation of the strain gauge, the greater the pedaling force, and the smaller the deformation, the opposite is true. Signal transmission is performed to control the output power of the motor.

[0032] A wire unwinding bin and a control circuit board are also provided inside the housing 1; the control circuit board is connected to the power mechanism 2 via a wire.

[0033] As a specific embodiment of the utility model: when the rider is riding, the middle shaft 7 drives the bracket flange 5 to rotate the chainring 6 through the action of the one-way bearing 12. Due to the action of the one-way clutch of the planetary transmission mechanism 2-4 combination, the force will not continue to be transmitted to the power mechanism 2 behind. When the rider actively exerts force, the transmission chain is reduced, making riding easier and more labor-saving;

[0034] Due to the rotation of the middle shaft 7 during riding, when the induced deformation of the strain gauge is greater, it means that the pedaling force is greater, and the smaller the deformation is, the opposite is true. According to the signal transmission, the power mechanism 2 is operated;

[0035] When the power mechanism 2 is working, the magnetic field change of the stator 2-2 is controlled by the current, so that the drum 2-3 can rotate, and the sun gear 2-41 can rotate at the same time. Through the transmission of the sun gear 2-41, the planetary gear 2-42 makes a circular motion around the sun gear 2-41, and the planetary gear 2-42 then transmits the force to the planetary carrier 2-43, so that the planetary carrier 2-43 rotates. Due to the action of the one-way clutch, the planetary carrier 2-43 will drive the output wheel 8 to output, and then transmit it to the transmission wheel 4 through the belt 3, so that the toothed disc 6 rotates, and the torque is further increased through the planetary transmission mechanism 2-4, so that the rider can ride more easily and labor-saving, and a large torque output can be achieved in a small space. The use of multiple planetary gears 2-42 for simultaneous transmission has a good load distribution ability, making it more stable and reliable during the transmission process. According to needs, the above-mentioned installation, setting, provision or connection methods include but are not limited to screws, riveting, welding or socketing, fixing and other methods for installation, setting or connection, and the installation, setting or connection method is selected according to the needs of the working scenario.

[0036] The above description is only a preferred embodiment of the utility model, and does not limit the patent scope of the utility model. All equivalent structural changes made by using the contents of the utility model specification and drawings under the utility model concept, or directly / indirectly used in other related technical fields are included in the patent protection scope of the utility model.

Claims

1. A belt-driven mid-mounted motor for an assistive bicycle, comprising a housing (1), a power mechanism (2), a belt (3), a transmission wheel (4), a bracket flange (5), a chainring (6) and a central shaft (7), wherein the housing (1) is provided with a through hole for the central shaft (7) to pass through, wherein the power mechanism (2), the belt (3), the transmission wheel (4) and the bracket flange (5) are located inside the housing (1), and characterized in that: The toothed disc (6) is connected to the transmission wheel (4) via a bracket flange (5), and the toothed disc (6) and the transmission wheel (4) are both bolted to the bracket flange (5); the belt (3) is sleeved on the transmission wheel (4) and the output end of the power mechanism (2), and the power mechanism (2) drives the transmission wheel (4) via the belt (3) to drive the toothed disc (6) to rotate.

2. The belt-driven mid-mounted motor for power-assisted bicycle according to claim 1, characterized in that: The power mechanism (2) comprises a positioning shaft (2-1), a stator (2-2), a rotating drum (2-3) and a planetary transmission mechanism (2-4); both ends of the positioning shaft (2-1) are clamped with the inner wall of the housing (1); the stator (2-2) is sleeved on the positioning shaft (2-1), and the stator (2-2) is located inside the rotating drum (2-3); a plurality of groups of rotor coils (2-31) are embedded on the inner wall of the rotating drum (2-3), and a bearing (13) is provided in the middle of the rotating drum (2-3) and sleeved with the positioning shaft (2-1), and the outer side of the middle of the rotating drum (2-3) is connected to one side of the planetary transmission mechanism (2-4); the other side of the planetary transmission mechanism (2-4) is sleeved with the belt (3), and the planetary transmission mechanism (2-4) is provided with a bearing (13) and sleeved with the positioning shaft (2-1).

3. The belt-driven mid-mounted motor for power-assisted bicycle according to claim 2, characterized in that: The planetary transmission mechanism (2-4) comprises a sun gear (2-41), planetary gears (2-42), a planetary carrier (2-43) and an inner gear ring (2-44); the sun gear (2-41) is bolted to the rotating drum (2-3); the inner gear ring (2-44) is sleeved on the inner wall of the housing (1); the planetary carrier (2-43) is mounted on the positioning shaft (2-1) through a bearing (13), and an output wheel (8) is provided in the middle of one side of the planetary carrier (2-43); the output wheel (8) is sleeved with a belt (3); the planetary gear (2-42) is mounted on the other side of the planetary carrier (2-43), and the planetary gear (2-42) is meshedly connected with the sun gear (2-41) and the inner gear ring (2-44) respectively.

4. The belt-driven mid-mounted motor for power-assisted bicycle according to claim 3, characterized in that: A notch (9) is provided on the inner wall of the planet carrier (2-43), and the output wheel (8) and the notch (9) form a closed chamber; a ball (10) and a spring sheet (11) are installed in the notch (9), and the spring sheet (11) is located on one side of the ball (10); and a sliding connection is formed between the outer wall on one side of the output wheel (8) and the ball (10).

5. The belt-driven mid-mounted motor for power-assisted bicycle according to claim 4, characterized in that: The notches (9), balls (10) and spring pieces (11) are each provided with three, which are arranged in corresponding combinations and at intervals on the inner ring of the planet carrier (2-43), and cooperate with the output wheel (8) to form a one-way clutch.

6. The belt-driven mid-mounted motor for power-assisted bicycle according to claim 1, characterized in that: The central shaft (7) is provided with a one-way bearing (12) which is sleeve-connected with the bracket flange (5).

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