CN212861775U - Electric bicycle propulsion system and electric bicycle - Google Patents

Abstract

The utility model provides an electric bicycle propulsion system and electric bicycle, including motor element, drive assembly and casing, the motor element includes motor and motor shaft, the drive assembly includes transmission shaft, driven wheel and drive sprocket, the distance of motor shaft and transmission shaft to the bicycle front wheel is less than the distance of bicycle axis to the bicycle front wheel, the casing is used for detachably fixing on the bicycle frame; the transmission shaft is arranged above the motor shaft in parallel, one end of the transmission shaft is connected with the driven wheel, the other end of the transmission shaft is connected with the transmission chain wheel, the driven wheel is meshed with an output wheel at the output end of the motor shaft, and the transmission chain wheel is meshed with a transmission chain of a bicycle to drive the transmission chain to transmit motor power. The utility model discloses propulsion system detachably installs on bicycle frame, compact structure, and can provide bigger thrust-weight ratio.

Description

Electric bicycle propulsion system and electric bicycle

Technical Field

The utility model belongs to the technical field of electric bicycle, concretely relates to electric bicycle propulsion system and electric bicycle.

Background

The electric bicycle is a novel two-wheeled vehicle, and can realize a vehicle integrating manual riding and motor boosting. Under the premise of not changing the special property of riding, the riding is easier, and the requirements of outing, outdoor sports and the like can be better met while the daily commuting purpose is met. The electric bicycle may be powered by an internal combustion engine or an electric motor integrated to the bicycle, or by an internal combustion engine or an electric motor integrated to the bicycle. The auxiliary power can supplement or replace the driving force generated by the bicycle rider.

The prior power-assisted bicycle is divided into a hub motor driving mode and a central system driving mode; in the former, a motor is added on the wheel, but the mass of the motor is large, so that the rotational inertia is large, and when the bicycle does not need to be ridden with assistance, a large inertial load needs to be overcome. Therefore, the riding effect is poor; the latter overcomes the disadvantage, but the centrally-mounted system usually needs to specially design the bicycle frame, and needs to make the bicycle power assisting system and the whole bicycle be designed integrally. In the prior art, a motor used by the power-assisted bicycle must be small and light, so that overweight or inconvenient use of the bicycle can be avoided. The use of small motors generally enables such compactness and lightness, but the power generated by small motors is limited. The traditional transmission system is limited by the sum of transmission torque and cannot be matched with a motor with higher rated power for use. As a result, many motors are often unable to fully reach their rated power.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the mid-set system drive mode of prior art will be solved and the bicycle frame of special design often needs, needs the integrative design of bicycle propulsion system and whole car for transmission system is subject to transmission torque's total, can't cooperate the problem of using with the bigger motor of rated power.

The utility model provides an electric bicycle propulsion system, including motor element, drive assembly and casing, motor element includes motor and motor shaft, drive assembly includes transmission shaft, driven wheel and drive sprocket, the distance of motor shaft and transmission shaft to the bicycle front wheel is less than the distance of bicycle crank axle to the bicycle front wheel, motor element, transmission shaft and driven wheel all set up in the casing, the casing is used for detachably fixing on the bicycle frame;

the transmission shaft parallel arrangement is in motor shaft top, the one end of transmission shaft with be connected from the driving wheel, from the driving wheel with the output wheel meshing of motor shaft output, the other end of transmission shaft with drive sprocket connects, drive sprocket sets up the casing outside, drive sprocket is used for meshing in order to drive chain conveying motor power with the drive chain of bicycle.

Furthermore, the shell is provided with at least one support bracket, and the support bracket is used for fixedly connecting the shell with the frame.

Preferably, the motor shaft comprises a middle shaft section, a transmission shaft section and an output shaft section which are coaxially arranged, and a clutch bearing is arranged between the middle shaft section and the output shaft section and is used for selectively connecting or disconnecting the output shaft section and the middle shaft section.

Preferably, the drive assembly further comprises an engagement element disposed between the drive shaft and the driven wheel, the engagement element for controlling engagement or disengagement of the driven wheel with the drive shaft.

Further, the output wheel is arranged on the output shaft section of the motor shaft, the diameter of the output wheel is smaller than that of the driven wheel, and the driven wheel and the output wheel are meshed for increasing the torque provided for the transmission chain wheel in a rotating mode.

The utility model also provides an electric bicycle, which comprises an inverted triangle frame, a transmission system and the propulsion system, wherein the propulsion system is detachably fixed on the frame, a middle shaft is arranged at the vertex angle of the frame, and the transmission system comprises a crank shaft, two crank arms, a chain wheel and a transmission chain;

the crank shaft is coaxially sleeved in the middle shaft, the chain wheel is coaxially arranged at one end of the crank shaft, and the chain wheel and the transmission chain wheel are connected with the rear chain wheel of the bicycle through the transmission chain and transmit power.

Further, still include front wheel, front wheel fork, rear wheel and rear wheel fork, the frame is including the connection horizontal pole, cushion connecting rod and the front fork connecting rod that connect gradually, the cushion connecting rod is used for being connected with the rear wheel through the rear wheel fork, the front fork connecting rod is used for being connected with the front wheel through the front wheel fork.

Further, the middle shaft is in a hollow tubular shape and is arranged at the vertex angle of an inverted triangle formed at the joint of the cushion connecting rod and the front fork connecting rod.

Preferably, the transmission system further comprises a flywheel disposed between the crank shaft and the crankset for controlling engagement or disengagement of the crankset with or from the crank shaft.

Further, the transmission system further comprises a reversing gear, the reversing gear is arranged between the chain wheel and the rear chain wheel, the reversing gear is meshed with the transmission chain and arranged below the transmission chain, and the reversing gear is used for preventing the transmission chain from loosening.

Implement the embodiment of the utility model provides a, following beneficial effect has:

(1) the utility model discloses propulsion system is provided with solitary casing, installs the frame through support holder detachably on, can install on non-electric bicycle on need not to destroy or revise original non-electric bicycle's geometric structure and ergonomic's basis, for transmission system replenishment power, can repack non-electric bicycle into electric bicycle.

(2) The utility model discloses propulsion system sets up the place ahead of crank axle, can reduce the pressure of being used in the crank epaxial, can adopt the bigger motor of power, applys bigger moment and/or improvement rotational speed to the rear wheel.

(3) The utility model discloses electric bicycle integrates motor element and crank axle and crank arm with clutch bearing and flywheel respectively between for motor and transmission system can independent operation each other, nimble control.

(4) The utility model discloses propulsion system compares and puts motor system in the current, compact structure, and can provide bigger thrust-weight ratio.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of a propulsion system according to embodiment 1 of the present invention;

FIG. 2 is a schematic view of the other side of the propulsion system of embodiment 1 of the present invention;

fig. 3 is a perspective view of a propulsion system according to embodiment 1 of the present invention;

fig. 4 is another perspective view of a propulsion system according to embodiment 1 of the present invention;

fig. 5 is a cross-sectional view of a propulsion system according to embodiment 1 of the present invention;

figure 6 is a perspective view of a propulsion system geared embodiment of embodiment 2 of the present invention;

FIG. 7 is a perspective view of the propulsion system of FIG. 6 shown from the side of the housing;

FIG. 8 is a view of the propulsion system of FIG. 6 shown from the other side of the housing;

figure 9 is a side view of a propulsion system geared embodiment of the present invention embodiment 2;

figure 10 is a perspective view of a propulsion system belt drive embodiment of embodiment 2 of the present invention;

fig. 11 is a perspective view of a pushing system chain drive embodiment of embodiment 2 of the present invention;

FIG. 12 is another perspective view of the pushing system of FIG. 8;

fig. 13 is a side view of the electric bicycle according to embodiment 3 of the present invention;

fig. 14 is another structure of the electric bicycle frame according to embodiment 3 of the present invention;

fig. 15 is a sectional view of a crankshaft and a flywheel according to embodiment 3 of the present invention;

figure 16 is a partially exploded view of the propulsion system of the present invention.

Wherein the reference numerals in the figures correspond to: 100-propulsion system, 1-motor assembly, 11-motor, 111-rotor, 112-stator, 12-motor shaft, 121-output shaft section, 122-intermediate shaft section, 123-drive shaft section, 13-output wheel, 14-clutch bearing, 2-drive assembly, 21-drive shaft, 22-driven wheel, 23-drive sprocket, 24-engagement element, 3-housing, 31-support bracket, 4-frame, 41-middle shaft, 42-connecting cross bar, 43-cushion connecting bar, 44-front fork connecting bar, 5-drive system, 51-crank shaft, 52-chain wheel, 53-drive chain, 54-flywheel, 55-reversing gear, 56-crank arm, 6-rear sprocket, 7-front wheel, 71-front fork, 8-rear wheel, 81-rear fork, 131-output pulley, 221-driven pulley, 132-output sprocket, 222-driven sprocket.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. The terms "upper", "lower", "front", "rear", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. In the embodiment of the present invention, the direction of the front wheel of the bicycle is "front", and the direction of the rear wheel of the bicycle is "rear".

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

It should be noted that "electrically powered" is understood to mean that the bicycle can be partially or completely powered by the electric motor, or if desired, can be completely powered by the pedal. The bicycle can be configured in many different ways as long as it remains at least partially powered by the electric propulsion system, and the electric bicycle can be assembled as a road or city bicycle, or a mountain bike.

Example 1

As shown in fig. 1-5, embodiment 1 of the present invention provides an electric bicycle propulsion system, including motor element 1, drive assembly 2 and casing 3, motor element 1 includes motor 11 and motor shaft 12, drive assembly 2 includes transmission shaft 21, follows driving wheel 22 and drive sprocket 23, motor shaft 12 and transmission shaft 21 are less than the distance of bicycle axis 41 to the bicycle front wheel to the distance of bicycle front wheel, motor element 1, transmission shaft 21 and follow driving wheel 22 all set up in casing 3, casing 3 is used for detachably fixing on the bicycle frame.

The transmission shaft 21 is arranged above the motor shaft 12 in parallel, one end of the transmission shaft 21 is connected with the driven wheel 22, the driven wheel 22 is meshed with the output wheel 13 at the output end of the motor shaft 12, the other end of the transmission shaft 21 is connected with the transmission chain wheel 23, the transmission chain wheel 23 is arranged on the outer side of the shell 3, and the transmission chain wheel 23 is used for being meshed with a transmission chain of a bicycle to drive the transmission chain to transmit motor power. The diameter of the output wheel 13 is smaller than the diameter of the driven wheel 22, which engages with the output wheel for rotationally increasing the torque supplied to the drive sprocket.

Specifically, referring to fig. 1 and 2, in an embodiment of the present invention, the motor 11 of the propulsion system 100 generates a driving force, assists the rider, and powers the bicycle. The motor 11 may be any suitable motor that converts electrical energy into mechanical motion. The motor 11 may be provided with a circuit or electronic chip for controlling the power it applies and the operation itself. In the embodiment of the present invention, the motor assembly 1 and the transmission assembly 2 are disposed in the housing 3, and the housing 3 can protect the motor assembly from the influence of debris, moisture and natural factors. Specifically, at least one support bracket 31 is disposed on the housing 3, and the support bracket 31 is used for fixedly connecting the housing 3 with a vehicle frame. The support bracket 31 secures the housing 3 to the vehicle frame at a distance from the bottom bracket 41. The support bracket 31 is removable and the support bracket 31 is typically mounted on a seat connecting rod 43 or a front fork connecting rod 44 of the bicycle frame 4.

Specifically, the motor 11 includes a rotor 111 and a stator 112, the rotor 111 rotates within the stator 112, and the motor shaft 12 rotates with the rotor 111. The motor shaft 12 outputs the rotary mechanical motion generated by the motor 11, the motor shaft 12 includes a middle shaft section 122, a transmission shaft section 123 and an output shaft section 121 which are coaxially arranged, the output wheel 13 is arranged on the output shaft section 121 of the motor shaft 12, and the transmission chain wheel 23 is arranged on the transmission shaft section 123. The intermediate shaft segment 122, the transmission shaft segment 123 and the output shaft segment 121 may be segmented or may be an integral shaft manufactured in one piece. In practice, the output of the motor 11 may rotate at a speed ranging from about 0 rpm to about 5,200 rpm, although other reasonable speeds and ranges of speeds are also within the scope of the present disclosure.

Specifically, the embodiment of the utility model provides a, transmission assembly 2 can convey the produced drive power of motor 11 to the bicycle rear wheel for electric drive power can assist and ride passerby's propulsion bicycle. The driven wheel 22 in the transmission assembly 2 is engaged with the output wheel 13 of the motor, the motor 11 drives the motor shaft 12 and the output wheel 13 to rotate, the driven wheel 22 is driven to rotate, the driven wheel 22 is arranged on the transmission shaft 21, and therefore the transmission chain wheel 23 on the other end of the transmission shaft 21 is driven to rotate. The motor 11, the motor shaft 12, the output wheel 13, the driven wheel 22 and the transmission shaft 21 are all arranged in the shell 3, the transmission chain wheel 23 is arranged outside the shell 3, and the transmission chain wheel 23 is arranged on the same side of the bicycle chain wheel 52 and the rear chain wheel 6. The drive sprocket 23 is another rotatable component that engages the drive chain 53. The driving sprocket 23 can drive the driving chain 53, and can also be driven by the driving chain 53 to rotate. This function allows the drive sprocket 23 to transmit the power output of the motor 11 to the drive chain 53 and ultimately to the rear wheel of the bicycle.

In the embodiment of the utility model, the passerby can choose whether to use the auxiliary power of motor. The rider may selectively disengage the motor 11 via the propulsion system 100 to no longer provide motive power to the rear wheels. Specifically, as shown in fig. 5, a clutch bearing 14 is disposed between the intermediate shaft segment 122 and the output shaft segment 121, and the clutch bearing 14 is used for selectively engaging or disengaging the output shaft segment 121 and the intermediate shaft segment 122. For example, when the bicycle is on a downhill slope, the motor 11 is not required to provide additional driving force. The rider can control the disengagement of the intermediate shaft section 122 from the output shaft section 121 by means of the clutch bearing 14, in which case the motor 11 no longer drives the output wheel 13 in rotation, the motor 11 is idle and the driven wheel 22 is indirectly driven by the transmission chain 53. When the motor shaft 12 is an integrally formed integral shaft, the clutch bearing 14 is used to engage or disengage the motor shaft 2.

In other embodiments, as shown in fig. 5, an engaging element 24 may also be provided in the transmission assembly 2, said engaging element 24 being provided between the transmission shaft 21 and the driven wheel 22 for controlling the engagement or disengagement of said driven wheel 22 with said transmission shaft 21. The engagement element 24 is a flywheel, ratchet or clutch bearing. Specifically, the engagement element 24 is used to select the use of the driving force assist of the motor 11, or the forward movement only through the pedal plate of the bicycle, as with the clutch bearing 14. When the transmission shaft 21 is controlled to be separated from the driven pulley 22 by the engaging element 24, the pedal applies force to rotate the transmission sprocket 23 without rotating the driven pulley 22 and the motor shaft 12 together, and the provision of the engaging element 24 helps to reduce the number of rotating parts. In practical application, the motor accidentally rotates to increase resistance and generate a magnetic field to limit the rotation of the rotor and prevent the bicycle from advancing. The engagement element 24 helps to ensure that the rider can step the bicycle smoothly and continue to apply force to the pedals without engaging or moving the mechanical reduction gearing arrangement. It is also possible to slide downhill without having to bring the crankshaft to rotation.

In an embodiment of the present invention, the propulsion system 100 provides power assist to the bicycle to assist the rider in propelling the bicycle forward. The propulsion system may be the sole power, or part of the power, for propelling the bicycle forward. In addition, the propulsion system can be separated, so that the propulsion system does not provide power, and the bicycle can be used as a non-motorized bicycle. The propulsion system is an electric system, and the motor provides a rotary power output. The propulsion system may also be powered by other suitable technologies, such as electrochemical cells or electrical storage devices. The propulsion system may optionally employ a regenerative circuit for charging. In most devices, the driving force generated by the propulsion system acts on the rear wheel of the bicycle. The propulsion system of the utility model is relatively small and light, so that the propulsion system can be installed on the frame. The propulsion system will typically be mounted to the seat connecting rod 43 or the front fork connecting rod 44 of the bicycle frame, but may be mounted elsewhere on the frame.

The utility model discloses propulsion system 100 compares and puts motor system in the current, compact structure, and can provide bigger thrust-weight ratio. The propulsion system is independently arranged on the frame and keeps a distance with a middle shaft of the frame. The utility model discloses propulsion system can install on the non-electric bicycle, for transmission system provides supplementary power, need not to destroy or modify original non-electric bicycle's geometric structure and ergonomic. The propulsion system may also be used as a retrofit to convert a non-electric bicycle into an electric bicycle. In the conventional electric propulsion system, the propulsion system must be installed in the middle shaft of the bicycle frame, so that a specific matched bicycle frame configuration is required or the bicycle frame is specially designed, and the original geometric structure of the bicycle is often adversely affected.

Example 2

Referring to fig. 6-12, the transmission assembly 2 of the propulsion system of embodiment 2 of the present invention is a modification of embodiment 1, and as shown in fig. 6-9, the motor output wheel 13 and the driven wheel 22 are in helical gear transmission. Specifically, the output wheel 13 and the driven wheel 22 are gears meshed with each other, and the output wheel 13 is meshed with the driven wheel 22 and drives the driven wheel 22 to rotate. In the reverse direction, the driven wheel 22 can rotate the output wheel 13.

As shown in fig. 10, in some embodiments, the motor assembly 1 and the transmission assembly 2 are driven by a belt. Specifically, an output pulley 131 is disposed on the output shaft segment 121 of the motor shaft 12, a driven pulley 221 is disposed at one end of the transmission shaft 21 in the same direction as the output shaft segment 121, and the output pulley 131 and the driven pulley 221 are rotatably connected by a belt. The output pulley 131 rotates to drive the belt to move, thereby rotating the driven pulley 221. In the reverse direction, the driven pulley 221 can rotate the output pulley 131.

In other embodiments, as shown in fig. 11, the motor assembly 1 and the transmission assembly 2 are driven by sprockets. Specifically, the output shaft segment 121 of the motor shaft 12 is provided with an output sprocket 132, one end of the transmission shaft 21 in the same direction as the output shaft segment 121 is provided with a driven sprocket 222, and the output sprocket 132 and the driven sprocket 222 are connected through a chain. The output sprocket 132 rotates to drive the chain motion, thereby causing the driven sprocket 222 to rotate. In the opposite direction, the driven sprocket 222 can rotate the output sprocket 132. Also shown in fig. 11 and 12 is the engagement element 24 within the driven sprocket 222 so that the rider can step the bicycle without the assistance of a motor.

As can be seen from the above, the transmission assembly 2 of the present invention can adopt different transmission modes to transmit the driving force of the motor 11 to the rear wheel 8. Whatever the transmission mode, the transmission assembly 2 can multiply the torque generated by the motor 11 and transmit the multiplied torque to the driven wheel 22, then to the transmission chain wheel 23, to the transmission chain 53 and finally to the rear wheel 8. Multiplication of this torque can be achieved by changing the diameter or transmission ratio between the output wheel 13 and its driven wheel 22 which rotates. In some embodiments, the driven wheel 22 may be larger in diameter than the output wheel 13. For example, as shown in FIG. 6, where the drive assembly uses helical gears, the ratio of the driven wheel 22 to the output wheel 13 may be 1: 4. That is, if the motor 11 rotates the motor shaft 12 at about 1,200 revolutions per minute, the output wheel 13 will also rotate at about 1,200 revolutions per minute, and the driven wheel 22 will rotate at about 300 revolutions per minute. If motor 11 causes motor shaft 12 to rotate at a torque of about 15 foot pounds, output wheel 13 will also rotate at a torque of about 15 foot pounds, and the driven wheel will rotate at a torque of about 60 foot pounds. Other components of the transmission assembly may also be modified to increase torque or increase rotational speed. In some embodiments, the diameter of the drive sprocket 23 can be modified to increase the torque or increase the rotational speed.

Example 3

As shown in fig. 13-15, embodiment 3 of the present invention provides an electric bicycle, including an inverted triangle frame 4, a transmission system 5 and the propulsion system 100 of embodiments 1 and 2, wherein the propulsion system 100 is detachably fixed on the frame 4, a middle axle 41 is disposed at a vertex angle of the frame 4, and the transmission system 5 includes a crank shaft 51, two crank arms 56, a chain wheel 52 and a transmission chain 53; the two ends of the crank shaft 51 are respectively connected with the crank arms 56, the crank shaft 51 is coaxially sleeved in the middle shaft 41, the chain wheel 52 is coaxially arranged at one end of the crank shaft 51, and the chain wheel 52 and the transmission chain wheel 23 are connected with the bicycle rear chain wheel 6 through the transmission chain 53 and transmit power. Specifically, both ends of the crank shaft 51 are connected to pedals through crank arms 56.

Specifically, the bicycle further comprises a front wheel 7, a front wheel fork 71, a rear wheel 8 and a rear wheel fork 81, the frame 4 comprises a connecting cross rod 42, a cushion connecting rod 43 and a front fork connecting rod 44 which are connected in sequence, the cushion connecting rod 43 is connected with the rear wheel 8 through the rear wheel fork 81, and the front fork connecting rod 44 is connected with the front wheel 7 through the front wheel fork 71. Specifically, the central shaft 41 is in a hollow tube shape, and the central shaft 41 is arranged at the vertex of an inverted triangle formed by connecting the cushion connecting rod 43 and the front fork connecting rod 44.

The frame constitutes the main body of the bicycle, providing structural support thereto. Figures 13 and 14 show two different configurations of the frame. For example, the frame shown in FIG. 13 is suitable for a "hard tail" bicycle without a suspension device, while the frame in FIG. 14 has a rear suspension system suitable for a mountain bicycle. In addition to the frame shown in the drawings, many other types of frames are also within the scope of the present disclosure.

Specifically, as shown in fig. 15, the transmission system 5 further includes a flywheel 54, and the flywheel 54 is provided between the crank shaft 51 and the crank arm 56 for controlling engagement or disengagement of the crank arm 56 with or from the crank shaft 51. Specifically, the flywheel 54 enables the crank axle 51 and the crank arm 56 to rotate separately, suitable for use by a rider downhill. On a downhill slope, the crank arm 56 is stationary and therefore does not rotate the crank shaft 51. At this time, the flywheel 54 can rotate the crankshaft 51 by itself, thereby driving the transmission chain 53 and the rear wheel 8. The clutch bearing 14 and the flywheel 54 according to the embodiment of the present invention may be any suitable devices satisfying the above functions, such as a ratchet bearing, a flywheel, or an overload clutch and other components. In addition, the integration of the clutch bearing 14 and flywheel 54 into the motor 11 and transmission 5, respectively, may make the overall propulsion system 100 more compact while reducing complexity.

Specifically, the transmission system further comprises a reversing gear 55, the reversing gear 55 is arranged between the chain wheel 52 and the rear chain wheel 6, the reversing gear 55 is arranged below the transmission chain 53 and meshed with the transmission chain 53, and the reversing gear 55 is used for reducing the loosening of the transmission chain 53. Specifically, the reversing gear 55 is a sprocket with a housing. When the drive chain 53 is wound around the rear sprocket, the reverse gear 55 is used to keep the upper and lower chains of the drive chain 53 rotating around the rear sprocket of the bicycle parallel, reducing the looseness of the drive chain 53.

In an embodiment of the present invention, a switch for controlling the motor of the propulsion system is disposed on the handlebar of the bicycle. When the motor 11 is used to assist in driving the bicycle, the clutch bearing 14 can be activated by activating a switch on the handlebar. The output shaft section 121 of the motor shaft 12 is coupled to the intermediate shaft section 122 via the clutch bearing 14, so that the motor 11 rotates the output wheel 13. The output wheel 13 drives the driven wheel 22 to rotate, so that the torque generated by the motor 11 can be multiplied. This multiplied torque is transmitted through the drive shaft 21 to the drive sprocket 23. The drive sprocket 23 will then transmit this multiplied torque to the drive chain 53, and the drive chain 53 will transmit the torque to the rear wheel 8. When the motor 11 is not used for auxiliary driving, the switch needs to be triggered again, and the output shaft section 121 of the motor shaft 12 is separated from the middle shaft section 122 through the clutch bearing 14. At this point, the rider may power the transmission 5 by pedaling the pedals.

The utility model discloses propulsion system and the arrangement of crank axle can reduce the pressure of being used in crank axle 51, can adopt the bigger motor of power, applys bigger moment and/or improvement rotational speed to the rear wheel, the embodiment of the utility model provides an in, motor power is about between 250W to 2,000W. For example, to propel a bicycle at a speed of about 2m/h, the motor 11 of the propulsion system 100 operates at about 900 revolutions per minute, and when the motor 11 operates at about 1,200 revolutions per minute, the bicycle speed is about 32 km/h. The present invention integrates the clutch bearing 14 and the flywheel 54 between the motor 11 and the crank shaft 51 and the crank arm 56, respectively, so that the motor 11 and the transmission system 5 can operate independently of each other.

The utility model discloses propulsion system 100 can install on non-electric bicycle 10, changes non-electric bicycle into electric bicycle to provide extra electric power, the auxiliary bicycle traveles. Specifically, the electric propulsion system 100 is mounted on the frame of a non-electric bicycle, and the axis of the transmission shaft 21 and the axis of the motor shaft 12 of the propulsion system 100 are both located in front of the axis of the bottom bracket 41. The propulsion system 100 is not mounted to the bottom bracket 41 and therefore does not change the geometry of the frame or its suspension system. A non-electric bicycle can be converted to an electric bicycle simply by connecting the existing drive train components of the non-electric bicycle to the propulsion system 100. In addition, because propulsion system 100 is mounted to the frame of the bicycle, the resulting load is distributed throughout the frame, and the crankshaft experiences reduced stress relative to a conventional mid-motor system in which the motor is coaxial with or replaces the crankshaft. If propulsion system 100 is removed from being mounted to frame 4, the bicycle can still be operated in the state before propulsion system 100 is mounted, without having to reconfigure its accessories. The removal of the conventional motor system with the motor coaxial with the crank shaft can render the bicycle unusable. As shown in fig. 16, the propulsion system 100 is mounted on the frame 4 of the bicycle with part of the housing 3 of the propulsion system removed and the propulsion system is spaced from the bottom bracket 41. The housing 3 is mounted to the frame 4 at the junction of the seat cushion connecting rod 43 and the front fork connecting rod 44 via the support bracket 31. The propulsion system 100 does not interfere with the drivetrain components that rotate about the bottom bracket center axis, and the propulsion system 100 is removed from the frame without adversely affecting the structural integrity of the frame or the operability of the bicycle.

The utility model discloses propulsion system 100 can integrate to current moped frame, only needs to change current transmission system's crank arm and chain etc. remains current transmission system's gear and other parts simultaneously, need not the axis of relocating. Thus, the existing frame geometry of the bicycle can be maintained unchanged. This design feature has many benefits, particularly for bicycles in which the frame and/or suspension geometry is carefully designed or specifically selected for a particular application. For example, the present propulsion system 100 can be integrated into a mountain bike frame equipped with a rear suspension without changing the frame or suspension geometry and without moving the bottom bracket, thus not changing the ride characteristics associated with the frame/rear suspension geometry. And the purchase of the traditional frame and the transmission system can be conveniently carried out, and the production cost is favorably reduced. The existing electric drive bicycle with the electric drive system arranged near the rear hub usually needs to replace the whole drive system and adjust the rear hub, so that a standard frame and the drive system cannot be used, and the production cost is increased.

The foregoing is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations are also considered as the protection scope of the present invention.

Claims (10)

1. The electric bicycle propulsion system is characterized by comprising a motor assembly (1), a transmission assembly (2) and a shell (3), wherein the motor assembly (1) comprises a motor (11) and a motor shaft (12), the transmission assembly (2) comprises a transmission shaft (21), a driven wheel (22) and a transmission chain wheel (23), the distance from the motor shaft (12) and the transmission shaft (21) to a front wheel of a bicycle is smaller than the distance from a crank shaft (51) to the front wheel of the bicycle, the motor assembly (1), the transmission shaft (21) and the driven wheel (22) are all arranged in the shell (3), and the shell (3) is used for being detachably fixed on a frame;

transmission shaft (21) parallel arrangement is in motor shaft (12) top, the one end of transmission shaft (21) with follow driving wheel (22) and connect, follow driving wheel (22) with output wheel (13) the meshing of motor shaft (12) output, the other end of transmission shaft (21) with drive sprocket (23) are connected, drive sprocket (23) set up casing (3) outside, drive sprocket (23) are used for with the drive chain meshing of bicycle in order to drive chain transmission motor power.

2. An electric bicycle propulsion system according to claim 1, characterised in that the housing (3) is provided with at least one support bracket (31), the support bracket (31) being adapted to fixedly connect the housing (3) to the frame.

3. An electric bicycle propulsion system according to claim 1, characterized in that the motor shaft (12) comprises a coaxially arranged intermediate shaft section (122), a transmission shaft section (123) and an output shaft section (121), the output wheel (13) being arranged on the output shaft section (121) of the motor shaft (12), a clutch bearing (14) being arranged between the intermediate shaft section (122) and the output shaft section (121), the clutch bearing (14) being adapted to selectively engage or disengage the output shaft section (121) with or from the intermediate shaft section (122).

4. An electric bicycle propulsion system according to claim 1, characterised in that the transmission assembly (2) further comprises an engagement element (24), the engagement element (24) being arranged between the transmission shaft (21) and the driven wheel (22), the engagement element (24) being adapted to control the engagement or disengagement of the driven wheel (22) with the transmission shaft (21).

5. An electric bicycle propulsion system according to claim 1, characterised in that the diameter of the output wheel (13) is smaller than the diameter of the driven wheel (22), the driven wheel and output wheel engaging for increasing the torque provided to the drive sprocket in rotation.

6. An electric bicycle, characterized by comprising an inverted triangular frame (4), a transmission system (5) and a propulsion system (100) according to any one of claims 1-5, wherein the propulsion system (100) is detachably fixed on the frame (4), a middle shaft (41) is arranged at the top corner of the frame (4), and the transmission system (5) comprises a crank shaft (51), two crank arms (56), a chain wheel (52) and a transmission chain (53);

the bicycle chain wheel is characterized in that two ends of the crank shaft (51) are respectively connected with crank arms (56), the crank shaft (51) is coaxially sleeved in the middle shaft (41), the chain wheel (52) is coaxially arranged at one end of the crank shaft (51), and the chain wheel (52) and the transmission chain wheel (23) are connected with a bicycle rear chain wheel (6) through the transmission chain (53) and transmit power.

7. The electric bicycle of claim 6, further comprising a front wheel (7), a front wheel fork (71), a rear wheel (8) and a rear wheel fork (81), wherein the frame (4) comprises a connecting cross bar (42), a cushion connecting rod (43) and a front fork connecting rod (44) which are connected in sequence, the cushion connecting rod (43) is connected with the rear wheel (8) through the rear wheel fork (81), and the front fork connecting rod (44) is connected with the front wheel (7) through the front wheel fork (71).

8. The electric bicycle according to claim 6, wherein the middle shaft (41) is hollow and tubular, and the middle shaft (41) is arranged at the vertex angle of an inverted triangle formed by connecting the cushion connecting rod (43) and the front fork connecting rod (44).

9. An electric bicycle according to claim 6, characterized in that the transmission system (5) further comprises a flywheel (54), the flywheel (54) being arranged between the crank axle (51) and the crank arm (56) for controlling the engagement or disengagement of the crank arm (56) with the crank axle (51).

10. An electric bicycle according to claim 6, characterized in that the transmission system further comprises a reversing gear (55), the reversing gear (55) being arranged between the chain wheel (52) and the rear sprocket (6), the reversing gear (55) being in engagement with the drive chain (53) and being arranged below the drive chain (53), the reversing gear (55) being adapted to reduce drive chain loosening.

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