CN114394191A

CN114394191A - Power assisting device, middle-arranged motor and electric bicycle

Info

Publication number: CN114394191A
Application number: CN202111544308.9A
Authority: CN
Inventors: 范清泉; 何潇; 刘海量; 王洪晓
Original assignee: Guangdong Welling Motor Manufacturing Co Ltd; Welling Wuhu Motor Manufacturing Co Ltd
Current assignee: Guangdong Welling Motor Manufacturing Co Ltd; Welling Wuhu Motor Manufacturing Co Ltd
Priority date: 2021-12-16
Filing date: 2021-12-16
Publication date: 2022-04-26

Abstract

The invention discloses a power assisting device, a middle motor and an electric bicycle, wherein the power assisting device comprises: a housing, a speed reduction system and a motor; the speed reducing system comprises an input shaft, an intermediate shaft, an output shaft, a planetary gear mechanism, a first gear speed reducing mechanism and a second gear speed reducing mechanism, wherein a sun gear is fixed on the input shaft, an inner gear ring is fixed on the shell, and a planet carrier is rotationally connected with the input shaft; the first gear reduction mechanism comprises a first driving wheel and a first driven wheel, the first driving wheel is fixed on the planet carrier, and the first driven wheel is fixed on the intermediate shaft; the second gear reduction mechanism comprises a second driving wheel and a second driven wheel, the second driving wheel is fixed on the intermediate shaft, and the second driven wheel is fixed on the output shaft. By adding the motor and the speed reducing system, larger power can be provided under the working condition with larger gradient, so that the rider can be helped to cross the hillside. And, the deceleration system has tertiary speed reduction, makes the noise greatly reduced to improve the comfort of riding.

Description

Power assisting device, middle-arranged motor and electric bicycle

Technical Field

The invention relates to the technical field of electric bicycles, in particular to a power assisting device, a middle motor and an electric bicycle.

Background

The common bicycles are driven by manpower, and common people are difficult to drive for a long distance and a long time and to reach a hillside with a large gradient, so that the use and the development of the bicycles are limited. In the related art, the electric power-assisted bicycle also has the advantage that auxiliary power is provided by adding a motor, and when a low-power motor is used, the provided power cannot meet the use requirement of a large slope. When a high-power motor is used, the noise is very high in the process of power transmission due to the high rotating speed of the motor, and the riding comfort is greatly reduced.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides the power assisting device which can provide extra power to assist driving, greatly reduce noise and improve riding comfort.

The invention also provides a middle motor with the power assisting device and an electric bicycle.

According to an embodiment of the first aspect of the invention, the booster includes: a housing, a speed reduction system and a motor; the speed reducing system comprises an input shaft, an intermediate shaft, an output shaft, a planetary gear mechanism, a first gear speed reducing mechanism and a second gear speed reducing mechanism, wherein the input shaft, the intermediate shaft and the output shaft are all rotationally connected to the shell; the first gear reduction mechanism comprises a first driving wheel and a first driven wheel, the first driving wheel is fixed on the planet carrier, and the first driven wheel is fixed on the intermediate shaft; the second gear speed reducing mechanism comprises a second driving wheel and a second driven wheel, the second driving wheel is fixed on the intermediate shaft, and the second driven wheel is fixed on the output shaft; the motor is used for driving the input shaft to rotate.

The power assisting device provided by the embodiment of the invention has at least the following beneficial effects: by adding the motor and the speed reducing system, larger power can be provided under the working condition with larger gradient, so that the rider can be helped to cross the hillside. And, the deceleration system has tertiary speed reduction, makes the noise greatly reduced to improve the comfort of riding.

According to some embodiments of the invention, the first drive pulley is disposed on an outer peripheral side of the carrier.

According to some embodiments of the invention, the planet carrier is connected to the input shaft by a bushing or a bearing.

According to some embodiments of the invention, at least one of the planet wheel, the first driving wheel, the first driven wheel, the second driving wheel and the second driven wheel is made of plastic.

According to some embodiments of the invention, the two gears that mesh with each other are of different materials.

According to some embodiments of the present invention, the planet wheel, the inner gear ring, and the second driven wheel are made of plastic, and the sun wheel, the first driving wheel, the first driven wheel, and the second driving wheel are made of metal.

According to some embodiments of the invention, the electric machine includes a stator fixed to the housing and a rotor fixed to the input shaft.

According to some embodiments of the invention, the stator comprises windings, the windings being of aluminium wire with a non-circular cross-section.

According to some embodiments of the invention, the aluminum wire has a square cross-section.

The centrally-mounted motor according to the embodiment of the second aspect of the invention comprises the power assisting device according to the embodiment of the first aspect of the invention.

The centrally-mounted motor provided by the embodiment of the invention at least has the following beneficial effects: by adopting the power assisting device disclosed by the embodiment of the first aspect of the invention, larger power can be provided under the working condition with larger gradient, so that a rider can be helped to cross a hillside. And, the deceleration system has tertiary speed reduction, makes the noise greatly reduced to improve the comfort of riding.

The electric bicycle according to the embodiment of the third aspect of the present invention includes the center-set motor according to the embodiment of the second aspect of the present invention.

The electric bicycle provided by the embodiment of the invention at least has the following beneficial effects: by adopting the middle-mounted motor of the embodiment of the second aspect of the invention, larger power can be provided under the working condition with larger gradient, so that a rider can be helped to cross a hillside. And, the deceleration system has tertiary speed reduction, makes the noise greatly reduced to improve the comfort of riding.

According to some embodiments of the invention, the electric bicycle comprises a sprocket to which the output shaft is connected.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The invention is further described with reference to the following figures and examples, in which:

FIG. 1 is a schematic diagram of a booster according to an embodiment of the present invention;

FIG. 2 is a schematic view of a power assist device according to an embodiment of the present invention;

FIG. 3 is an axial view of the planetary gear mechanism shown in FIG. 2;

fig. 4 is a parallel axis structure in the related art.

Reference numerals:

101. a housing; 102. an input shaft; 103. an intermediate shaft; 104. an output shaft; 105. a motor; 106. a sun gear; 107. a planet wheel; 108. an inner gear ring; 109. a planet carrier; 110. a first drive wheel; 111. a first driven wheel; 112. a second drive wheel; 113. a second driven wheel; 114. a stator; 115. a rotor; 116. a sprocket;

401. a first gear; 402. a second gear.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does 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 description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

The power assist device, the center motor 105, and the electric bicycle according to the embodiment of the present invention will be described with reference to fig. 1 to 4.

It will be appreciated that the various components of FIG. 1 are shown in a simplified pattern to facilitate understanding by those skilled in the art, e.g., gears are shown in the "I" pattern and shafts are shown in the "I" pattern.

Referring to fig. 1, the power assisting apparatus according to the embodiment of the present invention includes a housing 101, an input shaft 102, an intermediate shaft 103, an output shaft 104, a motor 105, a sun gear 106, a planetary gear 107, an annular gear 108, a planetary carrier 109, a first driving wheel 110, a first driven wheel 111, a second driving wheel 112, and a second driven wheel 113, wherein the motor 105, the sun gear 106, the planetary gear 107, the annular gear 108, the planetary carrier 109, the first driving wheel 110, the first driven wheel 111, the second driving wheel 112, and the second driven wheel 113 are all located in the housing 101, and the input shaft 102, the intermediate shaft 103, and the output shaft 104 are rotatably connected to the housing 101.

The input shaft 102, the intermediate shaft 103 and the output shaft 104 are sequentially arranged along the radial direction, the motor 105, the sun gear 106 and the planet carrier 109 are sequentially arranged on the input shaft 102 along the axial direction, and the first driving wheel 110 is fixedly connected to the planet carrier 109 to keep rotating coaxially with the planet carrier 109; the ring gear 108 is fixed on the housing 101, and the first driven wheel 111 and the second driving wheel 112 are sequentially arranged on the intermediate shaft 103 along the axial direction; a second driven wheel 113 is arranged on the output shaft 104.

Referring to fig. 1, it can be understood that the motor 105 includes a stator 114 and a rotor 115, the stator 114 is fixed to the housing 101, and the rotor 115 is fixed to the input shaft 102, such that rotation of the rotor 115 rotates the input shaft 102 to provide power to the input shaft 102. The sun gear 106 is fixed to the input shaft 102, and rotation of the input shaft 102 also causes the sun gear 106 to rotate together. The inner gear ring 108 is fixedly connected with the housing 101, the planet wheels 107 are meshed with the sun wheel 106 and the inner gear ring 108, and the planet wheels 107 are rotatably connected to the planet carrier 109, so that the rotation of the sun wheel 106 drives the planet carrier 109 to rotate. The first driving wheel 110 is fixedly connected to the planet carrier 109, and the rotation of the planet carrier 109 drives the first driving wheel 110 to rotate coaxially, i.e. the first driving wheel 110 also rotates around the input shaft 102. The first driven wheel 111 is fixed on the intermediate shaft 103, the first driven wheel 111 is engaged with the first driving wheel 110, and the rotation of the first driving wheel 110 drives the first driven wheel 111 to rotate together. The second driving wheel 112 is also fixed on the intermediate shaft 103, and the rotation of the intermediate shaft 103 also drives the second driving wheel 112 to rotate together. The second driven wheel 113 is fixed on the output shaft 104, the second driven wheel 113 is meshed with the second driving wheel 112, and the second driving wheel 112 rotates to drive the second driven wheel 113 to rotate, so as to drive the output shaft 104 to rotate, thereby realizing power output.

It is understood that since the first driving wheel 110 is coaxial with the input shaft 102, one shaft can be reduced relative to the parallel shaft structure, thereby reducing the number of parts, such as at least one shaft and two sets of bearings, and reducing the structural cost.

It is understood that the sun gear 106, the planet gears 107, the ring gear 108 and the planet carrier 109 constitute a planetary gear mechanism, and in the planetary gear mechanism, the planet carrier 109 has the equivalent number of teeth and satisfies: the number of teeth of the planet carrier 109 is equal to the number of teeth of the sun gear 106 plus the number of teeth of the ring gear 108, and the number of teeth of the sun gear 106 is less than the number of teeth of the ring gear 108 is less than the number of teeth of the planet carrier 109.

It will be appreciated that the planetary gear mechanism achieves a speed reduction effect in the case of movement of the ring gear 108 as a fixed member, the sun gear 106 as a driving member, and the carrier 109 as a driven member. The rotation direction of the carrier 109 is the same as the rotation direction of the sun gear 106, i.e., the rotation direction of the carrier 109 is the same as the rotation direction of the input shaft 102.

It can be understood that the first driven wheel 111 and the first driving wheel 110 form a first gear 401 speed reduction mechanism, and the number of teeth of the first driving wheel 110 is greater than that of the first driven wheel 111, so as to achieve the speed reduction effect. The rotation direction of the first driving pulley 110 is the same as the rotation direction of the carrier 109, the rotation direction of the first driven pulley 111 is opposite to the rotation direction of the first driving pulley 110, that is, the rotation direction of the first driven pulley 111 is opposite to the rotation direction of the input shaft 102, and the rotation direction of the intermediate shaft 103 is opposite to the rotation direction of the input shaft 102.

It can be understood that the second driven wheel 113 and the second driving wheel 112 form a second gear 402 speed reduction mechanism, and the number of teeth of the second driving wheel 112 is greater than that of the second driven wheel 113, so as to achieve the speed reduction effect. The rotation direction of the second driving pulley 112 is opposite to the rotation direction of the first driven pulley 111, the rotation direction of the second driven pulley 113 is opposite to the rotation direction of the second driving pulley 112, that is, the rotation direction of the second driven pulley 113 is the same as the rotation direction of the input shaft 102, and the rotation direction of the output shaft 104 is the same as the rotation direction of the input shaft 102.

It is understood that the planetary gear mechanism, the first gear 401 speed reduction mechanism, and the second gear 402 speed reduction mechanism constitute a speed reduction system. The purpose of speed reduction can be achieved if a planetary gear mechanism is used instead of the first gear 401 speed reduction mechanism and the second gear 402 speed reduction mechanism, but the use of multiple sets of planetary gear mechanisms makes the overall structure complicated and the cost is increased.

It can be understood that the power of the motor 105 is amplified in a first stage by the sun gear 106, the planet gear 107 and the ring gear 108, amplified in a second stage by the first driving wheel 110 and the first driven wheel 111, amplified in a third stage by the second driving wheel 112 and the second driven wheel 113, and amplified in three stages by the third power, which greatly improves the dynamic property of the whole vehicle.

It should be noted that if the first gear 401 reduction mechanism is used to achieve primary power amplification, the planetary gear mechanism is used to achieve secondary power amplification, and the second gear 402 reduction mechanism is used to achieve tertiary power amplification, the ring gear 108 needs to be fixed, which results in a complex structure of the housing 101. If the first gear 401 reduction mechanism is used to achieve primary power amplification, the second gear 402 reduction mechanism is used to achieve secondary power amplification, and the planetary gear mechanism is used to achieve tertiary power amplification, the overall size will increase, as the output shaft 104 is generally thicker, causing the planetary gear mechanism to increase in size, which in turn will increase the overall size.

It will be appreciated that in order to improve the load carrying capacity of the power assist device, the power assist device of the embodiments of the present invention employs a planetary gear mechanism instead of a parallel shaft structure. As shown in fig. 3, the embodiment of the present invention shown in the figure is a planetary gear mechanism, in which a sun gear 106 and an inner gear ring 108 can be coaxially arranged, a required radial space is small, and a plurality of planet gears 107 are provided, so that the torque of the sun gear 106 can be distributed to a plurality of positions, the bearing capacity of the sun gear 106 is improved, the radial size of the sun gear 106 can be reduced under the same bearing capacity, the radial size of the inner gear ring 108 is reduced, and the radial size of the whole mechanism is reduced. As shown in fig. 4, a prior parallel shaft structure is shown, which includes a first gear 401 and a second gear 402, the first gear 401 and the second gear 402 are respectively disposed on two parallel shafts, that is, the first gear 401 and the second gear 402 are arranged in parallel, and the radial space occupied by the parallel shaft structure is larger than that of the planetary gear mechanism in order to realize a certain speed ratio.

Referring to fig. 1 and 2, it can be understood that the first driving wheel 110 is disposed on the outer periphery of the planet carrier 109, that is, the first driving wheel 110 is an outer ring gear formed on the outer periphery of the planet carrier 109, so that the coaxiality of the first driving wheel 110 and the planet carrier 109 can be ensured from the aspect of machining accuracy, the transmission accuracy can be improved, and the gear wear can be reduced. And one part can be reduced, so that the management and assembly links of materials are correspondingly reduced, and the effect of reducing the cost is achieved.

Referring to fig. 1 and 2, it will be appreciated that the planet carrier 109 is rotatably connected to the input shaft 102. In a typical planetary gear reduction structure, the planet carrier 109 is spaced from the shaft, i.e., the planet carrier 109 is not connected to the shaft. In the present embodiment, the first driven wheel 111 is engaged with the first driving wheel 110, and the first driving wheel 110 is fixedly connected to the planet carrier 109, so that the planet carrier 109 is subjected to a radial force exerted by the first driven wheel 111 and the first driving wheel 110, the radial force may cause instability of the planet carrier 109, and may also affect the cooperation between the planet wheel 107 and the sun wheel 106 and the ring gear 108, so that the planet wheel 107, the sun wheel 106 and the ring gear 108 are unevenly stressed, that is, a local stress is too large, which may aggravate local wear of the gears. In the embodiment of the present invention, the planet carrier 109 is rotatably connected to the input shaft 102, and the planet carrier 109 can be supported by the input shaft 102, so that the planet carrier 109 is more stable, and the influence of the radial force exerted by the first driven wheel 111 and the first driving wheel 110 on the planet wheels 107 is also reduced.

It will be appreciated that the planet carrier 109 may be connected to the input shaft 102 by conventional means such as bushings or bearings to reduce wear of the planet carrier 109 and allow smoother rotation. The lining is a matching part used outside a mechanical part to achieve the functions of sealing, wear protection and the like, and is a ring sleeve playing a role of a gasket. The main function of the bearing is to support the mechanical rotator, reduce the friction coefficient in the movement process and ensure the rotation precision.

It can be understood that the sun gear 106, the ring gear 108, the planet carrier 109 and the first driving wheel 110 are coaxially arranged, and the sun gear 106, the ring gear 108, the planet carrier 109 and the first driving wheel 110 which are coaxially arranged enable each part of the middle motor 105 to be arranged more compactly, so that the axial size of the input shaft 102 can be reduced, the treading width value can be conveniently set to a proper value, the transverse distance between two feet of an electric bicycle using the middle motor 105 can be reduced, the force of a user can be favorably exerted, the windward area can be reduced, and the wind resistance can be reduced.

In the existing gear meshing structure, a metal gear is usually meshed with a metal gear, such as low-carbon steel and low-carbon steel, and due to the limitation of manufacturing cost and process, the noise generated by the meshing of the metal gear and the metal gear is relatively large. The plastic gear and the metal gear which are engaged with each other in the embodiment of the present invention can significantly reduce the peak noise value, for example, the planet gear 107 in the embodiment of the present invention uses a plastic material, the first driving wheel 110 uses a plastic material, the sun gear 106 uses a metal material, the inner gear ring 108 uses a metal material, the first driven wheel 111 uses a metal material, the second driving wheel 112 uses a metal material, and the second driven wheel 113 uses a metal material, so that the decibel value can be reduced by 15dB through tests.

Of course, other embodiments may be adopted, for example, the planet wheels 107 are made of plastic material, the ring gear 108 is made of plastic material, the second driven wheel 113 is made of plastic material, the sun wheel 106 is made of metal material, the first driving wheel 110 is made of metal material, the first driven wheel 111 is made of metal material, and the second driving wheel 112 is made of metal material.

It is understood that at least one of the planetary gear 107, the first driving wheel 110, the first driven wheel 111, the second driving wheel 112 and the second driven wheel 113 is made of plastic. Plastic gear and metal gear meshing compare metal gear and metal gear meshing can the greatly reduced noise to promote the comfort of riding.

It will be appreciated that the two gears which mesh with each other are of different materials. For example, the first driving wheel 110 and the first driven wheel 111 are made of different materials, specifically, the first driving wheel 110 is made of a plastic material, and the first driven wheel 111 is made of a metal material, so that the noise can be greatly reduced due to the meshing of a plastic gear and a metal gear, and the riding comfort is improved. In another embodiment, the first driving wheel 110 is made of a plastic material, and the first driven wheel 111 is also made of a plastic material, but the plastic material of the first driving wheel 110 is different from the plastic material of the first driven wheel 111, so that the problem of serious abrasion caused by the same plastic material can be avoided.

It will be appreciated that in some embodiments, the planet gears 107 are arranged in a straight gear arrangement, and correspondingly, the sun gear 106 and the annulus gear 108 are also arranged in a straight gear arrangement. It will be appreciated that in other embodiments the planet gears 107 are arranged in a helical gear arrangement, and correspondingly the sun gear 106 and the annulus gear 108 are likewise arranged in a helical gear arrangement. The planet wheels 107 can bear larger load through the helical teeth, the overload capacity of the planet wheels 107 can be improved, noise is reduced, and movement is more stable.

It will be appreciated that in some embodiments, the first drive wheel 110 is provided as a spur gear arrangement and, correspondingly, the first driven wheel 111 is also provided as a spur gear arrangement. It should be appreciated that in other embodiments, the first driving wheel 110 is provided with a helical gear arrangement, and correspondingly, the first driven wheel 111 is also provided with a helical gear arrangement. The first driving wheel 110 and the first driven wheel 111 can bear larger load through the helical tooth arrangement, the overload capacity of the first driving wheel 110 and the first driven wheel 111 can be improved, noise is reduced, and movement is more stable.

It will be appreciated that in some embodiments, the second drive wheel 112 is provided as a spur gear arrangement and, correspondingly, the second driven wheel 113 is also provided as a spur gear arrangement. It should be appreciated that in other embodiments, the second drive wheel 112 is provided with a helical gear arrangement and correspondingly, the second driven wheel 113 is also provided with a helical gear arrangement. The second driving wheel 112 and the second driven wheel 113 can bear larger load through the arrangement of the helical teeth, the overload capacity of the second driving wheel 112 and the second driven wheel 113 can be improved, noise is reduced, and movement is more stable.

In the related art, in the motor, the winding of the stator usually adopts the round wire winding, the winding slot full rate of the round wire winding is lower, and under the condition that the volume of the stator is not changed, the power density and the efficiency of the motor are both lower.

It can be understood that stator 114 includes winding and stator core, stator core generally adopts the silicon steel sheet to cut and forms, the silicon steel sheet that will cut out processes the stator core of coiling formula, in order to improve the utilization ratio of silicon steel sheet, need design the piece in advance and cut the mode when cutting, if stator core's tooth portion is provided with tooth boots, when cutting stator core, must go to design the piece and cut the mode according to tooth boots, but no matter how optimize, under the condition that has tooth boots, the material utilization ratio of silicon steel sheet also can only reach 70% at most, hardly further promote. The stator core of the embodiment of the invention adopts the tooth part without the tooth shoe, optimizes the splicing and cutting mode and further improves the material utilization rate of the silicon steel sheet.

The tooth part is arranged to be in the shape of straight teeth, the winding does not need to be wound on the tooth part, the winding can be completed by a tool outside, the operation space is large, and the full rate of the winding slot can be effectively improved. In addition, the winding adopts the aluminium wire of non-circular cross section, for example the aluminium wire of square cross section, and the tooth portion adopts straight tooth shape structure, for example the cross section of tooth portion is the square equally, the aluminium wire of winding matches the shape of tooth portion, the aluminium wire closely laminates at the outer wall of tooth portion, make aluminium wire arrange more closely, therefore improved stator 114's wire winding groove filling rate, under the unchangeable condition of stator 114's volume, the power density and the efficiency of motor 105 have been promoted, motor 105 is applied to electric bicycle, help promoting electric bicycle's duration.

The centrally-mounted motor 105 of the embodiment of the invention comprises the power assisting device of the embodiment of the invention. Due to all technical features of the power assisting device in the embodiment of the present invention, the beneficial effects of all the embodiments described above are also achieved, and are not described herein again.

It is understood that in some embodiments, the output shaft 104 serves as a pedal shaft, and the mid-motor 105 of the present embodiment further includes a power output member, a first one-way check device (not shown), and a second one-way check device (not shown), wherein the first one-way check device is disposed between the power output member and the pedal shaft. The power take off may include a sprocket 116 for connecting to a drive connection such as a chain and to the wheel via the chain to transmit the assistance to the wheel to provide the assistance. The pedal shaft is used for connecting a pedal crank, and the pedal crank is connected with a pedal. When the pedal is stepped on by the pedal, the pedal crank drives the pedal shaft to rotate, the first one-way check device works, the manpower is transmitted to the power output part through the first one-way check device, the pedal power is transmitted to the wheel, and finally the wheel is driven to rotate. A second one-way check device is provided between the second driven wheel 113 and the power output member. The power of the motor 105 is transmitted to the speed reducing system, the second one-way check device works, and then the power of the motor 105 is transmitted to the wheels, and finally the wheels are driven to rotate.

In addition, through using first one-way contrary device that ends, at motor 105 output power, and the personnel of riding do not have under the pedal condition, eliminated the phenomenon that the pedal axle caused magnetic resistance or mechanical resistance to speed reduction system, and then make and guarantee not to increase the extra resistance to motor 105 when the personnel of riding do not pedal. By using the second one-way check device, when the motor 105 stops operating, the phenomenon of magnetic resistance or mechanical resistance of the motor 105 and the speed reduction system to the pedal shaft is eliminated, and further extra resistance to the riding personnel is not increased when the motor 105 does not assist.

It can be understood that the pedal shaft is driven forward by the manpower and is rotated, and when motor 105 did not provide the helping hand to power take-off, the pedal shaft can drive the work of first one-way contrary device that ends, and the manpower transmits power take-off through first one-way contrary device that ends, and the one-way contrary device that ends of second idles this moment, and the manpower does not influence speed reduction system, realizes driving power take-off by the pedal manpower and rotates. In addition, when the rider stops pedaling or rotates the pedal in the reverse direction, the pedal shaft rotates in the reverse direction relative to the first one-way check device, and the pedal shaft does not transmit power to the power output part. In addition, when the motor 105 outputs power and the rider does not step on the pedal, the motor 105 rotates in the forward direction and is transmitted to the power output part, the first one-way check device idles, and the motor 105 does not affect the pedal shaft. When the pedal shaft is driven by manpower to rotate along the reverse direction or not to rotate relatively, the pedal shaft and the first one-way check device rotate relatively, namely, the pedal shaft does not transmit resistance to the power output part.

It will be appreciated that when the motor 105 is rotating in the forward direction, the power take-off can be driven to rotate in the forward direction by the second one-way check device. In addition, when the pedal shaft drives the power output element to rotate and the motor 105 does not provide assistance to the power output element, the second one-way check device idles, namely, the power output element can rotate relative to the second one-way check device at the moment, and the rotation of the pedal shaft is not influenced. When the rotation direction of the motor 105 relative to the second one-way check device is reverse, the motor 105 does not transmit power to the power output member at this time. That is, the motor 105 provides power to the power output member through the second one-way check device when rotating in the forward direction with respect to the second one-way check device, and the motor 105 and the second one-way check device rotate with respect to each other when the motor 105 rotates in the reverse direction with respect to the second one-way check device or does not rotate with respect to each other, that is, the motor 105 does not transmit resistance to the power output member.

It should be noted that, when the pedal shaft rotates in the forward direction and/or the motor 105 rotates in the forward direction and drives the power output member, the electric bicycle is in the forward traveling state.

It will be appreciated that the first one-way check means may be an overrunning clutch or a ratchet mechanism. The second one-way check device can also be an overrunning clutch or a ratchet mechanism.

The electric bicycle of the embodiment of the invention comprises the middle-mounted motor 105 of the embodiment of the invention. Due to all technical features of the mid-motor 105 according to the embodiment of the present invention, the beneficial effects of all the embodiments described above are also achieved, and are not described herein again.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. Booster unit, its characterized in that includes:

a housing;

the speed reducing system comprises an input shaft, an intermediate shaft, an output shaft, a planetary gear mechanism, a first gear speed reducing mechanism and a second gear speed reducing mechanism, wherein the input shaft, the intermediate shaft and the output shaft are all rotationally connected to the shell; the first gear reduction mechanism comprises a first driving wheel and a first driven wheel, the first driving wheel is fixed on the planet carrier, and the first driven wheel is fixed on the intermediate shaft; the second gear speed reducing mechanism comprises a second driving wheel and a second driven wheel, the second driving wheel is fixed on the intermediate shaft, and the second driven wheel is fixed on the output shaft;

and the motor is used for driving the input shaft to rotate.

2. The booster of claim 1 wherein the first drive pulley is disposed on an outer peripheral side of the carrier.

3. The booster of claim 1 wherein the planet carrier is connected to the input shaft by a bushing or bearing.

4. The booster of claim 1, wherein at least one of the planet wheel, the first drive wheel, the first driven wheel, the second drive wheel, and the second driven wheel is plastic.

5. A force assist arrangement according to claim 4 wherein the two intermeshing gears are of different materials.

6. The booster of claim 1, wherein the planet gears, the ring gear, and the second driven wheel are plastic, and the sun gear, the first driver, the first driven wheel, and the second driver are metal.

7. The booster of claim 1 wherein the motor comprises a stator and a rotor, the stator being secured to the housing and the rotor being secured to the input shaft.

8. The booster of claim 7 wherein the stator includes windings, the windings being formed of aluminum wire having a non-circular cross-section.

9. The force assist device of claim 8, wherein the aluminum wire has a square cross-section.

10. An electric motor built in, characterized by comprising the booster of any one of claims 1 to 9.

11. An electric bicycle comprising the mid-motor of claim 10.

12. The electric bicycle of claim 11, wherein the electric bicycle includes a sprocket to which the output shaft is connected.