CN114408084A - Mid-mounted motor and electric bicycle - Google Patents

Abstract

The invention discloses a middle-mounted motor and an electric bicycle, wherein the middle-mounted motor comprises a shell, a torque sensing pedal shaft, a power output part, a motor and a multi-stage planetary reduction mechanism, wherein the torque sensing pedal shaft is rotationally connected with the shell; the moment induction pedal shaft is connected to the power output part through a first overrunning clutch; the motor is arranged on the shell; the multi-stage planetary reduction mechanism is connected to the output end of the motor and is connected to the power output part through a second overrunning clutch. Through adopting multistage planet reduction gears for put motor shape rule in, the outward appearance is whole with moment response pedal axle central symmetry, compact structure, and the reduction ratio is big, satisfies whole car outward appearance demand. And the moment induction pedal shaft and the multi-stage planetary reduction mechanism are respectively connected to the power output part through the first overrunning clutch and the second overrunning clutch, so that manpower and motor power can be simultaneously input, and the independent input is not influenced mutually.

Description

Mid Motor & Electric Bike

technical field

The invention relates to the technical field of power-assisted electric bicycles, in particular to a mid-mounted motor and an electric bicycle.

Background technique

Nowadays, the problem of urban road congestion is becoming more and more serious and the concept of ecological protection is more and more respected. Many people are turning to bicycles to travel, and bicycles are also generally favored by young people for leisure travel. In order to make travel more comfortable, convenient and fast, it has become a trend to improve bicycles into electric or power-assisted bicycles.

In related technologies, in the field of power-assisted electric bicycles, how to achieve small size and high power, and how to perfectly integrate the core components of electric power assistance into the bicycle frame has always been the focus of design and development. At present, most of the mid-mounted motors have irregular shapes and large volumes, which are difficult to meet the appearance requirements of the vehicle.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a mid-mounted motor, which is small in size and high in power, and meets the appearance requirements of the entire vehicle.

The present invention also provides an electric bicycle with the above-mentioned central motor.

The mid-mounted motor according to the embodiment of the first aspect of the present invention includes a housing, a torque-sensing pedal shaft, a power output, a motor and a multi-stage planetary reduction mechanism, the torque-sensing pedal shaft is rotatably connected to the housing, and Connected to the power output member through a first overrunning clutch; the motor is mounted on the housing; the multi-stage planetary reduction mechanism is connected to the output end of the electric motor, and is connected to the power output through a second overrunning clutch pieces.

The central motor according to the embodiment of the present invention has at least the following beneficial effects: by adopting a multi-stage planetary deceleration mechanism, the central motor has a regular shape, the overall appearance is symmetrical with the center of the torque-sensing pedal shaft, the structure is compact, and the reduction ratio is large, which satisfies the Appearance requirements of the vehicle. In addition, the torque-sensing pedal shaft and the multi-stage planetary reduction mechanism are respectively connected to the power output through the first overrunning clutch and the second overrunning clutch, so that the human power and the motor power can be input at the same time, and they have no influence on each other when they are input independently.

According to some embodiments of the present invention, the multi-stage planetary reduction mechanism includes a primary planetary reduction system and a secondary planetary reduction system, and the primary planetary reduction system includes a first sun gear, a first ring gear, and a first planetary gear , The first planet carrier, the first sun gear is connected to the output end of the motor, the first ring gear is fixed on the casing; the two-stage planetary deceleration system includes a second sun gear, a second ring gear, The second planetary gear and the second planetary carrier, the second sun gear is fixedly connected to the first planetary carrier, the second ring gear is fixed to the outer casing, and the second planetary carrier is overrun by the second A clutch is connected to the power take-off.

According to some embodiments of the present invention, the first sun gear, the first ring gear and the first planet gear are all straight teeth or all helical teeth.

According to some embodiments of the present invention, the second sun gear, the second ring gear and the second planetary gear are all straight teeth or all helical teeth.

According to some embodiments of the present invention, the first overrunning clutch is a sprag type, a roller type or a ratchet type.

According to some embodiments of the present invention, the second overrunning clutch is of sprag type, roller type or ratchet type.

According to some embodiments of the present invention, the torque sensing pedal shaft includes a torque detection device and a pedal shaft, the torque detection device includes a torque sensing sleeve and a torque sensor, the torque sensor is mounted on the housing, and the torque One end of the induction sleeve is fixedly connected with the pedal shaft, and the other end is connected with the power output member through the first overrunning clutch.

According to some embodiments of the present invention, the central motor includes a cadence detection device, and the cadence detection device is connected to the housing for detecting the pedaling frequency of the torque-sensing pedal shaft.

The electric bicycle according to the embodiment of the second aspect of the present invention includes the mid-mounted motor of the embodiment of the first aspect of the present invention.

The electric bicycle according to the embodiment of the present invention has at least the following beneficial effects: by using the central motor of the first aspect of the present invention, the overall shape is regular, the overall appearance is symmetrical with the center of the torque-sensing pedal shaft, the structure is compact, and the speed is reduced. The ratio is large to meet the appearance requirements of the vehicle. In addition, the torque-sensing pedal shaft and the multi-stage planetary reduction mechanism are respectively connected to the power output through the first overrunning clutch and the second overrunning clutch, so that the human power and the motor power can be input at the same time, and they have no influence on each other when they are input independently.

According to some embodiments of the present invention, the electric bicycle includes a crankset connected to the power take-off.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, wherein:

1 is a schematic diagram of a mid-mounted motor according to an embodiment of the present invention;

2 is a schematic diagram of a one-stage planetary reduction system of the multi-stage planetary reduction mechanism shown in FIG. 1;

3 is a schematic diagram of a two-stage planetary reduction system of the multi-stage planetary reduction mechanism shown in FIG. 1;

FIG. 4 is a schematic diagram of an electric bicycle according to an embodiment of the present invention.

Reference number:

100, the central motor; 101, the housing; 102, the motor; 103, the first sun gear; 104, the first ring gear; 105, the first planetary gear; 106, the first planetary shaft; 107, the first planet carrier; 108 109, the second ring gear; 110, the second planetary gear; 111, the second planetary shaft; 112, the second planetary carrier; 113, the pedal shaft; 114, the torque sensing sleeve; 115, the torque sensor ; 116, the first overrunning clutch; 117, the second overrunning clutch; 118, the power output; 119, the crankset; 120, the cadence detection device;

401, frame; 402, wheel; 403, pedal crank; 404, pedal; 405, chain; 406, flywheel.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention.

In the description of the present invention, it should be understood that the azimuth description, such as the azimuth or position relationship indicated by up, down, front, rear, left, right, etc., is based on the azimuth or position relationship shown in the drawings, only In order to facilitate the description of the present invention and simplify the description, it is not indicated or implied that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

In the description of the present invention, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, exceeding, etc. are understood as not including this number, above, below, within, etc. are understood as including this number. If it is described that the first and the second are only for the purpose of distinguishing technical features, it cannot be understood as indicating or implying relative importance, or indicating the number of the indicated technical features or the order of the indicated technical features. relation.

In the description of the present invention, unless otherwise clearly defined, words such as setting, installation, connection should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

Power-assisted electric bicycles have developed for more than 20 years since the first product was put on the market, and now they have formed a huge industry. Electric bicycles are not only used as means of transportation, but also as sports tools are favored by the majority of cycling enthusiasts.

Power-assisted electric bicycle is a new type of two-wheeled vehicle, which belongs to a kind of bicycle. It uses battery as auxiliary power source, is equipped with motor, and has power auxiliary system, which can realize the integration of human riding and motor-assisted driving. .

In the field of power-assisted electric bicycles, the motor installation positions are mainly divided into two types, one is the middle position, that is, the motor is installed in the middle position of the body, that is, the motor in the five-way position, which is called the middle motor. The central motor is connected to the frame, and is connected to the rear wheel through a chain to transmit power. At the same time, pedals are installed on both sides of the motor. When the motor has no power supply, riders can use pedals to achieve manual riding. The resistance is no different from a normal bike.

The other is installed in the hub of the bicycle, called a hub motor. Compared with in-wheel motors, mid-mounted motors have greater advantages in terms of technology and performance. For example, the advantage of a mid-mounted motor is that it can keep the front and rear weight balance of the vehicle as much as possible without affecting the action of the shock absorber. The motor will also bear less road impact, and the ultra-high degree of integration can reduce unnecessary exposure of wires Therefore, it is better than the models with in-wheel motors in terms of off-road handling, stability, and passability.

In the related art, since most of the mid-mounted motors adopt the unfolding gear transmission reduction mechanism, the unfolded gear transmission reduction mechanism can be understood as the distribution of the shafts of the unfolded gear transmission reduction mechanism is unfolded step by step, Tiled cascade. The multi-stage unfolding gear transmission reduction mechanism is gradually arranged according to the external meshing of a pair of gears, and the structure is relatively simple. That is to say, the structural feature of the unfolding gear transmission reduction mechanism is that the axes of all the shafts equipped with gears are all distributed on one plane, and the input shaft and the output shaft are not coaxial. Regular, bulky, it is difficult to meet the needs of the appearance of the vehicle.

1 to 4 , the following describes how the mid-mounted motor 100 and the electric bicycle according to the embodiment of the present invention solve the above problems.

1 , it can be understood that the central motor 100 of the embodiment of the present invention includes a casing 101, a pedal shaft 113, a power output member 118, a first overrunning clutch 116, a motor 102, a second overrunning clutch 117 and multiple Stage planetary reduction mechanism. The housing 101 is used to be fixedly connected to the frame 401 so as to ensure the stability of the entire central motor 100 .

The pedal shaft 113 passes through the casing 101 and is rotatably connected with the casing 101 , and the first overrunning clutch 116 is disposed between the power output member 118 and the pedal shaft 113 . The pedal shaft 113 is used to connect the pedal crank 403 , and the pedal crank 403 is connected to the pedal 404 . When the cyclist steps on the pedal 404, the pedal shaft 113 is driven to rotate by the pedal crank 403, the first overrunning clutch 116 works, and the human power is transmitted to the power output member 118 through the first overrunning clutch 116, and then the pedal is driven. The power is transmitted to the wheels 402 and finally drives the wheels 402 to rotate.

The motor 102 is fixedly connected to the housing 101, so that the motor 102 can provide power stably, so as to achieve the function of assisting. The multi-stage planetary reduction mechanism is connected to the output end of the motor 102 , and the second overrunning clutch 117 is arranged between the output end of the multi-stage planetary reduction mechanism and the power output member 118 . The power of the motor 102 is transmitted to the multi-stage planetary deceleration mechanism, and the second overrunning clutch 117 works, thereby transmitting the power of the motor 102 to the wheels 402, and finally driving the wheels 402 to rotate.

The planetary reduction mechanism is a power transmission mechanism that uses the speed converter of the gear to reduce the number of revolutions of the motor to the required number of revolutions and obtain a larger torque. The gear with a small number of teeth on the transmission shaft of the planetary reduction mechanism meshes with the large gear on the output shaft to achieve the purpose of deceleration. The planetary reduction mechanism is small in size, light in weight, high in carrying capacity, long in service life, stable in operation and low in noise. It has the characteristics of power splitting and multi-tooth meshing. In addition, the planetary reduction mechanism can achieve that the input shaft and the output shaft are coaxial, and the multi-stage planetary reduction mechanism can achieve a larger reduction ratio.

The central motor 100 in the embodiment of the present invention adopts a multi-stage planetary reduction mechanism, so that the central motor 100 has a regular shape, a compact structure, and a large reduction ratio, which meets the appearance requirements of the whole vehicle. The whole machine has the characteristics of small structure size, large output torque, large speed ratio, high efficiency, safe and reliable performance.

In addition, by using the first overrunning clutch 116, when the motor 102 outputs power and the rider does not pedal, the phenomenon that the pedal shaft 113 causes magnetic resistance or mechanical resistance to the multi-stage planetary reduction mechanism is eliminated, thereby making the It is guaranteed that no additional resistance will be added to the motor 102 when the rider is not pedaling. By using the second overrunning clutch 117, when the motor 102 stops running, the phenomenon that the motor 102 and the multi-stage planetary deceleration mechanism cause magnetic resistance or mechanical resistance to the pedal shaft 113 is eliminated, thereby ensuring that the motor 102 does not provide assistance when the motor 102 does not assist. Will add extra resistance to the cyclist.

It can be understood that, when the pedal shaft 113 is driven to rotate forward by manpower, and the motor 102 does not provide power to the power output member 118 , the pedal shaft 113 can drive the first overrunning clutch 116 to work, and the manpower is transmitted through the first overrunning clutch 116 . When the power output member 118 reaches the power output member 118, the second overrunning clutch 117 is idling, and the human power does not affect the multi-stage planetary deceleration mechanism, so that the power output member 118 is driven to rotate by a human foot pedal. In addition, when the rider stops pedaling or rotates the pedal 404 in the reverse direction, the pedal shaft 113 rotates in the reverse direction relative to the first overrunning clutch 116 at this time, that is, the pedal shaft 113 does not move toward the power output member 118 at this time. transmit power. In addition, when the motor 102 outputs power and the cyclist is not pedaling, the motor 102 rotates in the forward direction and is delivered to the power output member 118. At this time, the first overrunning clutch 116 is idling, and the motor 102 does not affect the pedaling. Axle 113. That is, when the human power drives the pedal shaft 113 to rotate in the forward direction, the first overrunning clutch 116 provides power to the power output member 118. When the human power drives the pedal shaft 113 to rotate in the reverse direction or does not rotate relative to it, the pedal shaft 113 and the first An overrunning clutch 116 rotates relatively, that is, the pedal shaft 113 does not transmit resistance to the power output member 118 .

It can be understood that when the motor 102 rotates in the forward direction, the power output member 118 can be driven to rotate in the forward direction through the second overrunning clutch 117 . In addition, when the pedal shaft 113 drives the power output member 118 to rotate, and the motor 102 does not provide assistance to the power output member 118, the second overrunning clutch 117 is idling at this time, that is, the power output member 118 can be relatively opposite to the second overrunning clutch. The rotation of 117 does not affect the rotation of the pedal shaft 113 . When the rotation direction of the motor 102 relative to the second overrunning clutch 117 is reversed, the motor 102 also does not transmit power to the power output member 118 at this time. That is, the electric motor 102 provides power to the power output member 118 through the second overrunning clutch 117 when the electric motor 102 rotates in the forward direction with respect to the second overrunning clutch 117, and when the electric motor 102 rotates in the reverse direction with respect to the second overrunning clutch 117 or does not rotate relatively , the motor 102 and the second overrunning clutch 117 rotate relatively, that is, the motor 102 does not transmit resistance to the power output member 118 .

It should be noted that, when the pedal shaft 113 rotates in the forward direction and/or the motor 102 rotates in the forward direction and drives the power output member 118, the electric bicycle is in a forward state at this time.

It can be understood that, the first overrunning clutch 116 may be of sprag type, roller type or ratchet type. The second overrunning clutch 117 can also be of a sprag type, roller type or ratchet type.

A one-way clutch locks a working part so that it can only rotate in one direction. That is, when the pedal 404 is rotated forward by the human power, the wheel 402 is driven to rotate forward, so that the bicycle moves forward. However, the wheels 402 do not reverse when the pedals 404 are reversed.

An overrunning clutch is a kind of clutch that automatically engages and disengages by using the speed change or rotation direction change of the driving part and the driven part. When the driving member drives the driven member to rotate together, it is called the combined state; when the driving member and the driven member are disengaged and rotate at their respective speeds, it is called the overrunning state.

The overrunning clutch is a special mechanical clutch, which is automatically combined or disengaged by the change of the relative movement speed or the change of the rotation direction of the main and driven parts in the mechanical transmission. The driving element can only rotate the driven element from a single direction. If the driving element changes direction, the driven element will automatically disengage without transmitting power, so it is also called a one-way clutch or one-way bearing. Generally, it is selected according to the overrunning speed, so it is collectively referred to as an overrunning clutch.

The overrunning clutch has the following functions:

a. Realize fast and slow speed conversion and overtaking functions in rapid feed machinery.

b. Realize the indexing function of step gap movement and precise positioning.

c. When it is used in conjunction with ball screws or other components, it can prevent reverse rotation and achieve self-locking and backstop functions.

Commonly used overrunning clutches include ratchet overrunning clutches, roller overrunning clutches and sprag overrunning clutches. Wedge block overrunning clutch is usually divided into contact type wedge block overrunning clutch, non-contact wedge block overrunning clutch and two-way wedge block overrunning clutch.

Non-contact wedge block overrunning clutch is composed of outer ring, inner ring, wedge block, fixed retaining ring, retaining ring, end cover, bearing and retaining ring. When running at low speed, the wedge is kept in contact with the inner ring under the action of the spring. When the speed exceeds a certain limit, the centrifugal moment of the eccentric wedge overcomes the spring and other resistance moments, so that the wedge is radially separated from the working surface of the inner ring. Open to form a small gap, thus avoiding friction and wear, and the clutch can work without contact. When in use, the inner ring is installed on the high-speed shaft, the outer ring is set on the two bearings of the inner ring, and is fastened together by screws and two end covers; the raceway between the inner ring working surface and the outer ring is fixed by a wedge block , It consists of a fixed retaining ring, a bearing and a retaining ring. The reset torsion springs are respectively on the cylinders at both ends of the wedge block. One end of the torsion spring is inserted into the small opening of the wedge block section, and the other end rests on the retaining pin. The fixed retaining ring connects the inner ring and the The wedge device is connected together, and the outer ring is connected with the flange by screws.

When the main motor is started, it drives the main deceleration high-speed shaft extension to drive the inner ring and the module device to rotate together to generate centrifugal force, which forms a torque on the support point of the wedge, the direction of which is opposite to the torque applied to the module by the torsion spring. The tendency of the outer ring to come out of contact; when the torque generated by the centrifugal force of the wedge is not enough to overcome the torque applied by the torsion spring to the wedge, the wedge and the working surface of the inner ring are in contact with each other, and relative sliding friction occurs with the outer ring. As the rotational speed increases, the centrifugal force of the wedge increases. When the rotational speed of the inner ring reaches or exceeds the minimum non-contact rotational speed of the clutch, the torque generated by the centrifugal force of the wedge increases to be greater than the torque applied to the module by the torsion spring, forcing the wedge to deflect. It is out of contact with the outer ring to realize the frictionless and non-contact rotation of the clutch, and the follower is no longer driven to rotate at this time.

The directional clutch can only transmit torque in one direction, and can be automatically disengaged when reversed. Among them, the most widely used is the roller oriented clutch. It is mainly composed of star wheel, outer ring, spring ejector rod and roller. The function of the spring is to press the rollers into the wedge-shaped groove of the star wheel, so that the rollers connect with the star wheel and the outer ring.

Both the roller and the outer circle of the roller overrunning clutch can be used as the driving wheel. When the planetary gear is the driving member and rotates forward, the rollers are wedged in the groove by the friction force, thus driving the outer circle to rotate together, and the clutch is in the engaged state. When the planetary gear is reversed, the rollers are pushed to the wider part of the groove under the action of friction, and are no longer wedged in the groove, and the clutch is in a disengaged state. If the planetary wheel is still rotating forward, and the outer ring can obtain a speed from another kinematic chain in the same direction as the planetary wheel, but at a higher speed than the planetary wheel, the clutch is still in a disengaged state.

The ratchet mechanism (ratchet and pawl) is a one-way intermittent motion mechanism composed of a ratchet and a pawl. Ratchet mechanisms are used in bicycles for one-way drive.

The ratchet mechanism consists of an active swing rod, a pawl, a ratchet wheel, a non-return pawl and a rack. The driving element is hollowly sleeved on the driven shaft fixedly connected with the ratchet wheel, and is connected with the rotating pair for driving the pawl. When the driving member rotates in the forward direction, the driving pawl is inserted into the tooth slot of the ratchet, so that the ratchet rotates through a certain angle. At this time, the non-return pawl slides on the tooth back of the ratchet. When the driving member rotates in the reverse direction, the non-return pawl prevents the reverse rotation of the ratchet wheel, but the driving pawl can slide over the tooth back of the ratchet wheel, so the ratchet wheel is stationary at this time. Therefore, when the driving member performs continuous reciprocating swing, the ratchet performs a one-way intermittent movement.

The ratchet teeth are usually one-way teeth, and the pawl is hinged on the rocker. When the rocker rotates forward, the driving pawl is inserted into the ratchet teeth to push the ratchet to rotate in the same direction; when the rocker rotates in the reverse direction, the pawl is in The ratchet wheel slides over, and the ratchet wheel stops turning. In order to ensure that the ratchet is not reversed, anti-reverse pawls are often installed on the fixed member. The reciprocating swing of the rocker can be realized by a crank-rocker mechanism, a gear mechanism and a swinging oil cylinder. When transmitting a small amount of power, an electromagnet is also used to directly drive the pawl. The angle each time the ratchet turns is called the stroke. The size of the stroke can be adjusted by changing the structural parameters of the drive mechanism or the position of the gear shield, or it can be adjusted during operation. If it is desired to adjust the precision higher than the angle corresponding to one ratchet, a multi-pawl ratchet mechanism can be used.

Ratchet mechanisms can be classified into tooth-type ratchet mechanisms and friction-type ratchet mechanisms according to their structural forms. Among them, the friction ratchet mechanism replaces the pawl in the toothed ratchet mechanism with an eccentric sector wedge, and replaces the ratchet with toothless friction.

The ratchet mechanism can be divided into external meshing ratchet mechanism and internal meshing ratchet mechanism according to the meshing method. The pawls or wedges of the external ratchet mechanism are installed outside the ratchet, while the pawls or wedges of the internal ratchet mechanism are all inside the ratchet. The external meshing ratchet mechanism is widely used due to its convenient processing, installation and maintenance. The internal meshing ratchet mechanism is characterized by compact structure and small external dimensions.

Referring to FIGS. 1 and 4 , it can be understood that the central motor 100 according to the embodiment of the present invention further includes a crankset 119 , the crankset 119 is connected to the power output member 118 , and the crankset 119 is used to connect a transmission connection such as a chain 405 . It is connected to the flywheel 406 through the chain 405, so as to transmit the assisting effect to the wheel 402, thereby providing the assisting effect.

1 , it can be understood that the central motor 100 in the embodiment of the present invention further includes a torque detection device, which is connected to the pedal shaft 113 and is used to detect the torque acting on the pedal shaft 113 . When the pedal shaft 113 receives the force of the pedal, the torque applied to the pedal shaft 113 can be detected by the torque detection device.

It can be understood that the mid-mounted motor 100 further includes a controller, and the controller is electrically connected to the torque detection device. The torque detection device can send the detected torque data to the controller. In addition, the controller is electrically connected to the motor 102, and the controller can control the motor 102 to operate according to the received torque data, and then control the motor 102 to provide power assistance to assist riding.

Referring to FIG. 1 , it can be understood that the torque detection device includes a torque sensing sleeve 114 and a torque sensor 115 , one end of the torque sensing sleeve 114 is fixedly connected to the pedal shaft 113 , and one end is connected to the power output member 118 through the first overrunning clutch 116 . The torque sensor 115 is installed on the housing 101 by sensing, and the human input parameters are obtained by sensing the state of the torque sensing sleeve 114 .

It can be understood that the central motor 100 further includes a cadence detection device 120 connected to the housing 101 , and the cadence detection device 120 is used to detect the pedaling frequency of the pedal shaft 113 . The cadence detection device 120 generally adopts a cadence sensor, which can send the detected pedaling frequency data to the controller.

It can be understood that the multi-stage planetary deceleration mechanism may be a two-stage planetary deceleration mechanism, or a three-stage planetary deceleration mechanism, a four-stage planetary deceleration mechanism, etc. The following takes the two-stage planetary deceleration mechanism as an example for description.

1 , it can be understood that the two-stage planetary reduction mechanism includes a first-stage planetary reduction system and a two-stage planetary reduction system. The input end of the first-stage planetary reduction system is connected to the output end of the motor 102, and the The output end is connected to the input end of the secondary planetary reduction system, and the output end of the secondary planetary reduction system is connected to the second overrunning clutch 117 .

Referring to FIG. 2 , it can be understood that the one-stage planetary reduction system includes a first sun gear 103 , a first ring gear 104 , a first planetary gear 105 , and a first planet carrier 107 , wherein the first sun gear 103 is used as an input The terminal is connected to the output terminal of the motor 102, so that the motor 102 can drive the first sun gear 103 to rotate. The first ring gear 104 is fixed on the casing 101 , and the first planet carrier 107 is used as an output end and is connected to the input end of the secondary planetary reduction system, so that power can be transmitted to the secondary planetary reduction system through the first planet carrier 107 .

It should be noted that, in some embodiments, the first sun gear 103 may also be used as the input end, the first planet carrier 107 may be fixed on the housing 101, and the first ring gear 104 may be used as the output end.

Referring to FIG. 2 , it can be understood that the one-stage planetary reduction system further includes a first planetary shaft 106 , and the first planetary gear 105 is rotatably connected to the first planetary carrier 107 through the first planetary shaft 106 , that is, the first planetary shaft 106 fixedly connected to the first planet carrier 107, and the first planetary gear 105 is rotatably connected to the first planetary shaft 106; or, the first planetary shaft 106 is rotatably connected to the first planetary carrier 107, and the first planetary gear 105 is fixedly connected to the first planetary shaft shaft 106 . The first planetary gear 105 meshes with the first sun gear 103 and at the same time meshes with the first ring gear 104. When the motor 102 is running, the first planetary gear 105 and the first planet carrier 107 can be driven to rotate in turn by the first sun gear 103 , and then drive the secondary planetary deceleration system to rotate in the forward direction through the first planet carrier 107 .

In this embodiment, the first sun gear 103 and the first planetary gear 105 are both set as spur gears. Correspondingly, the first ring gear 104 is also provided with straight teeth. It should be understood that in other embodiments, the first sun gear 103 and the first planetary gear 105 are set with helical gears, and correspondingly, the first ring gear 104 is also set with helical gears. Among them, the setting of the helical teeth can make the first-stage planetary deceleration system bear a larger load, improve the overload capacity of the first-stage planetary deceleration system, reduce noise and make the movement more stable.

Referring to FIG. 3 , it can be understood that the two-stage planetary reduction system includes a second sun gear 108 , a second ring gear 109 , a second planetary gear 110 , and a second planet carrier 112 , wherein the second sun gear 108 is used as an input The end is fixedly connected to the first planet carrier 107 so that the first planet carrier 107 can drive the second sun gear 108 to rotate. For example, the second sun gear 108 and the first planet carrier 107 are fixedly connected by means of bolt connection, interference connection, welding, etc., or even directly processed into one body. The second ring gear 109 is fixed on the casing 101 , and the second planet carrier 112 is used as the output end, which is connected to the power output member 118 through the second overrunning clutch 117 . Further, the power can be transmitted to the power output member 118 through the second planet carrier 112 .

It should be noted that, in some embodiments, the second sun gear 108 may also be used as the input end, the second planet carrier 112 may be fixed on the housing 101 , and the second ring gear 109 may be used as the output end.

Referring to FIG. 3 , it can be understood that the secondary planetary reduction system further includes a second planetary shaft 111 , and the second planetary gear 110 is rotatably connected to the second planetary carrier 112 through the second planetary shaft 111 , that is, the second planetary shaft 111 is fixedly connected to the second planet carrier 112, and the second planetary gear 110 is rotatably connected to the second planetary shaft 111; or, the second planetary shaft 111 is rotatably connected to the second planetary carrier 112, and the second planetary gear 110 is fixedly connected to the second planetary shaft Axle 111. The second planetary gear 110 meshes with the second sun gear 108 and at the same time meshes with the second ring gear 109. When the motor 102 is running, the second planetary gear 110 and the second planet carrier 112 can be driven to rotate in turn by the second sun gear 108. , and then drive the power output member 118 to rotate in the forward direction through the second planet carrier 112 .

In this embodiment, both the second sun gear 108 and the second planetary gear 110 are set as spur gears. Correspondingly, the second ring gear 109 is also provided with straight teeth. It should be understood that in other embodiments, the second sun gear 108 and the second planetary gear 110 are set with helical gears, and correspondingly, the second ring gear 109 is also set with helical gears. Among them, the setting of the helical teeth can make the first-stage planetary deceleration system bear a larger load, improve the overload capacity of the first-stage planetary deceleration system, reduce noise and make the movement more stable.

It can be understood that the housing 101 , the pedal shaft 113 , the motor 102 , the first sun gear 103 , the first ring gear 104 , the first planetary gear 105 , the first planet carrier 107 , the second sun gear 108 , and the second ring gear 109. The second planetary wheel 110 , the second planet carrier 112 , and the power output member 118 are coaxially guaranteed by matching and bearings, so that the mid-mounted motor 100 can be made into a regular-shaped structure, with small size and high power, which is convenient to meet the requirements of the whole vehicle. Appearance requirements.

Referring to FIG. 4 , it can be understood that the electric bicycle of the embodiment of the present invention includes a frame 401, a wheel 402, a pedal crank 403, a pedal 404, a chain 405, a flywheel 406 and a central motor of the embodiment of the present invention 100. The arrangement of the frame 401 and the wheel 402 is in the prior art, and details are not described here. In addition, the central motor 100 is mounted on the frame 401, and can provide assistance to the electric bicycle when the electric bicycle is riding, thereby saving the riding force of the rider. Wherein, the central motor 100 can be connected to the wheel 402 through transmission connecting parts such as the chain 405 and the flywheel 406, so as to transmit the boosting action to the wheel 402, thereby providing the boosting action. The central motor 100 is connected to the pedal crank 403, and the pedal crank 403 is connected to the pedal 404, so that the rider can apply pedaling force, thereby driving the electric bicycle to move.

It should be noted that, when the electric bicycle is riding, the cyclist can provide pedaling force to drive the electric bicycle, and at the same time, the electric bicycle can also be powered by the mid-mounted motor 100 to assist in driving the electric bicycle. . The human power and the power of the motor 102 can be input independently or simultaneously.

When the auxiliary drive of the motor 102 is damaged or loses power, the pedal shaft 113 is driven to rotate forward by human power, the pedal shaft 113 drives the torque sensing sleeve 114 to rotate synchronously, the first overrunning clutch 116 works, and the human power is transmitted through the first overrunning clutch 116 When the power output member 118 reaches the power output member 118 , the second overrunning clutch 117 is idling, the manpower does not affect the second planet carrier 112 , and the power output member 118 outputs the manpower.

When the human foot pedal is driven to stand still or backward, and the motor 102 works, the power of the motor 102 is synchronously output by the first sun gear 103, and then transmitted to the second planet carrier 112 after being decelerated by the first-level planetary reduction system and the second-level planetary reduction system. The second overrunning clutch 117 works, and the power of the motor 102 is transmitted to the power output member 118 through the second overrunning clutch 117 . Power to the motor 102 is output by the power take-off 118 .

When the motor 102 works normally and the human power is normally pedal driven, the pedal shaft 113 is driven to rotate forward by the human power, the pedal shaft 113 drives the torque sensing sleeve 114 to rotate synchronously, and the torque sensor 115 senses the torque sensing sleeve 114. When the force is applied, the physical state occurs. In order to determine the magnitude of the human input, the motor 102 outputs corresponding power according to the magnitude of the human input, and is transmitted to the second planet carrier 112 after being decelerated by the first-level planetary deceleration system and the second-level planetary deceleration system. The human power and the power of the motor 102 are respectively transmitted to the power output member 118 through the first overrunning clutch 116 and the second overrunning clutch 117, and the power output member 118 outputs the human-machine hybrid power.

When the pedal shaft 113 is reversed, the torque sensing sleeve 114 rotates synchronously, the first overrunning clutch 116 is disengaged, no power is output, and the pedal shaft 113 and the torque sensing sleeve 114 rotate idly. When the motor 102 is reversed, the power of the motor 102 is synchronously output by the first sun gear 103, and then transmitted to the second planet carrier 112 after being decelerated by the first-stage planetary deceleration system and the second-stage planetary deceleration system, and the second overrunning clutch 117 is disengaged without power. output, the motor 102 is idling.

To sum up, the embodiments of the present invention provide an electric bicycle, which has a regular shape and conforms to the motion shape of a bicycle pedal. The structure is compact, and the power reduction ratio of the motor 102 is large.

The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and within the scope of knowledge possessed by those of ordinary skill in the art, various Variety.

Claims (10)

1. A central motor, characterized in that it includes: shell; power output; a torque-sensing pedal shaft, rotatably connected to the housing, and connected to the power output member through a first overrunning clutch; a motor, mounted on the housing; The multi-stage planetary reduction mechanism is connected to the output end of the motor, and is connected to the power output member through a second overrunning clutch. 2. The mid-mounted motor according to claim 1, wherein the multi-stage planetary reduction mechanism comprises: A one-stage planetary reduction system includes a first sun gear, a first ring gear, a first planetary gear, and a first planet carrier, the first sun gear is connected to the output end of the motor, and the first ring gear is fixed to the the shell; A two-stage planetary reduction system includes a second sun gear, a second ring gear, a second planet gear, and a second planet carrier, the second sun gear is fixedly connected to the first planet carrier, and the second ring gear is fixed In the casing, the second planet carrier is connected to the power output member through the second overrunning clutch. 3 . The mid-mounted motor according to claim 2 , wherein the first sun gear, the first ring gear and the first planetary gear are all straight teeth or all helical teeth. 4 . 4 . The mid-mounted motor according to claim 2 , wherein the second sun gear, the second ring gear and the second planetary gear are all straight teeth or all helical teeth. 5 . 5 . The mid-mounted motor according to claim 1 , wherein the first overrunning clutch is a wedge type, roller type or ratchet type structure. 6 . 6 . The mid-mounted motor according to claim 1 , wherein the second overrunning clutch is a sprag type, a roller type or a ratchet type. 7 . 7 . The central motor according to claim 1 , wherein the torque sensing pedal shaft comprises a torque detection device and a pedal shaft, the torque detection device comprises a torque sensing sleeve and a torque sensor, and the torque sensor Installed on the housing, one end of the torque sensing sleeve is fixedly connected with the pedal shaft, and the other end is connected with the power output member through the first overrunning clutch. 8 . The mid-mounted motor according to claim 1 , wherein the central motor comprises a cadence detection device, and the cadence detection device is connected to the housing for detecting the torque-sensing pedal shaft. 9 . pedaling frequency. 9. An electric bicycle, characterized in that it comprises the mid-mounted motor according to any one of claims 1 to 8. 10. The electric bicycle of claim 9, wherein the electric bicycle comprises a crankset connected to the power take-off.

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