CN118004323A - Central power device for coaxial bicycle - Google Patents

Abstract

The invention relates to a coaxial bicycle middle power device, which is characterized in that a hollow shaft motor and a speed reducing structure are arranged in a motor seat, the output end of the speed reducing structure is connected with a one-way bearing seat of a chain disc seat through a one-way bearing, the motor seat is pivoted with a crank shaft of the one-way bearing seat through another one-way bearing, the two one-way bearings are opposite in installation direction and positioned at different inner and outer sides of the one-way bearing seat, and a strain gauge is arranged on the crank shaft, so that the strain gauge can directly obtain torque change of the crank shaft by matching and conducting an annular conductive track group combined with a spring sheet group on a control circuit board in the motor seat, and the power transmission path of pedal and electric assistance is divided into inner and outer sides by virtue of the way that the one-way bearing is arranged at different inner and outer sides of the one-way bearing seat, thus avoiding interference between transmission structures.

Description

Central power device for coaxial bicycle

Technical Field

The invention relates to a power device of a bicycle; in particular to a coaxial type bicycle central power device.

Background

The power device of the existing bicycle, for example, the patent of the certificate number I646016, the patent of the certificate number M437304, the patent of the built-in power output mechanism of the electric bicycle, and the patent of the certificate number M472666, the patent of the pedal force sensing mechanism of the electric bicycle, are all provided with a power-assisted motor on the bicycle, and the torque of the pedal force of a user is sensed by a sensing element such as a strain gauge, so as to determine the torque of the motor for outputting power assistance to a crank shaft.

The power device of the bicycle can sense the torsion of the user stepping on the bicycle to drive the bicycle to advance by means of the strain gauge, but because the position of the strain gauge is a sleeve around the fluted disc or the crank shaft, the stepping action of the user cannot be reflected in real time during measurement, the torque change of the crank shaft due to the stepping force cannot be obtained, the problem that auxiliary power is delayed during motor power output can be solved, and the smooth feeling of the bicycle user during riding is affected.

Disclosure of Invention

Therefore, the present invention provides a coaxial bicycle central power device, wherein strain gauges are arranged on the surface of a crank shaft, and elastic sheet sets and annular conductive track sets are respectively arranged between two control circuit boards with opposite surfaces in the process of relative rotation to conduct electricity, so that torque data measured by the strain gauges are transmitted to the control circuit boards, and the effect of controlling a motor to output auxiliary power by using real-time torque data is achieved.

The present invention provides a power device for a coaxial bicycle, comprising a motor seat, a hollow shaft motor, a deceleration structure, a chain disk driving assembly, a crank shaft and a signal transmission assembly, wherein an axis is defined in the axis of the motor seat. The hollow shaft motor is arranged in the motor seat and is provided with a hollow shaft at a position corresponding to the axial lead. The speed reducing structure is arranged in the motor seat, two sides in opposite directions are respectively provided with an input end and an output end, the input end is combined with the hollow shaft, the output end is provided with a sleeve, and the speed reducing structure is provided with a shaft hole at a position corresponding to the shaft axis. The chain disk driving assembly is provided with a one-way bearing seat and is provided with a first pipe section, a second pipe section and a middle section for connecting the first pipe section and the second pipe section, and the outer diameter of the first pipe section is smaller than the inner diameter of the second pipe section; the outer circumferential surface of the first pipe section is sleeved with a first one-way bearing, the first one-way bearing is embedded in the inner circumferential surface of the sleeve, the inner circumferential surface of the second pipe section is embedded with a second one-way bearing with the steering direction opposite to that of the first one-way bearing, and the second pipe section is combined with a chain disc seat.

The crank shaft is pivoted through the hollow shaft, the shaft hole and the one-way bearing seat along the shaft axis, two ends of the crank shaft are pivoted through two sides of the motor seat, one side of the crank shaft is provided with a wheel part with a larger diameter, the wheel part is embedded in the inner peripheral surface of the second one-way bearing, the other side of the crank shaft is provided with a groove, and a strain gauge is combined with the inner surface of the groove. The signal transmission assembly is provided with a rotary seat which is sleeved and combined with the part of the crankshaft provided with or adjacent to the groove, the rotary seat is provided with a ring part, a circuit board electrically connected with the strain gauge is combined with the ring part, a control circuit board electrically connected with the hollow shaft motor is fixedly arranged in the motor seat in a mode of being opposite to the circuit board surface, one of the circuit board and the control circuit board is provided with an elastic sheet group, the surface of the other one is provided with an annular conductive track group, and the elastic sheet group elastically abuts against the annular conductive track group in a direction parallel to the axis so as to electrically connect the circuit board and the control circuit board.

When the crank is used, the crank is arranged on a bicycle, when a user steps on the pedal to rotate the crank shaft through the crank, the crank shaft can drive the second one-way bearing to rotate together with the one-way bearing seat and the chain disc seat by the inner side of the second pipe section through the wheel part of the crank shaft, the rotary seat and the circuit board can be driven to rotate together with the crank shaft along with the relatively fixed control circuit board, the strain gauge on the surface of the crank shaft senses the torque when the crank shaft is stressed in real time, the friction contact transmission of the annular conductive track group on the surface of the circuit board is realized through the elastic sheet group, the data of the torque is immediately transmitted to the control circuit board, the hollow shaft motor is judged and controlled to output electric auxiliary assistance through the torque, and the output end of the speed reduction structure drives the first one-way bearing to rotate together with the one-way bearing seat and the chain disc seat by the outer side of the first pipe section through the speed reduction structure, so that the effect of driving the bicycle forward by manpower in cooperation with electric auxiliary power is achieved.

The invention has the advantages that the strain gauge is arranged on the surface of the crank shaft, can sense and acquire the torque generated when the crank shaft is stressed in real time, and transmits the torque data to the control circuit board, so that the coaxial bicycle mid-mounted power device can immediately control the hollow shaft motor to output power when needed, and the riding feeling of a user is smoother. In addition, the elastic sheet group and the annular conductive track group can be respectively arranged on the control circuit board and the opposite surfaces of the circuit board in a radial manner, so that the volume occupied by the control circuit board and the circuit board along the axial line L direction is small, and the axial length of the power device in the coaxial bicycle can be reduced.

Drawings

Fig. 1 is a perspective view of a preferred embodiment of the present invention.

Fig. 2 is an exploded view of the above preferred embodiment of the present invention.

Fig. 3 is an exploded view of another angle of the above preferred embodiment of the present invention.

Fig. 4 is an exploded view of the deceleration construction of the above preferred embodiment of the present invention.

Fig. 5 is an exploded view of the signal transmission device according to the above preferred embodiment of the present invention.

Fig. 6 is a front view of the above preferred embodiment of the present invention.

Fig. 7 is a sectional view in the direction 7-7 of fig. 6.

Fig. 8 is a cross-sectional view of the hollow shaft motor and reduction configuration of fig. 7.

Fig. 9 is a side view of the above preferred embodiment of the present invention.

Fig. 10 is a sectional view taken along the direction 10-10 of fig. 9.

Fig. 11 is an exploded view of a hollow shaft and a drive gear of another preferred embodiment of the present invention.

Fig. 12 is an exploded view of the other angle of fig. 11.

Detailed Description

In order to more clearly illustrate the present invention, preferred embodiments are described in detail below with reference to the accompanying drawings. Referring to fig. 1 to 5, a coaxial bicycle center power device 100 according to a preferred embodiment of the present invention includes a motor base 10, a hollow shaft motor 20, a decelerating structure 30, a chain drive assembly 40, a crank shaft 50, and a signal transmission assembly 60, wherein:

The motor seat 10 is a transversely disposed cylinder and has a motor seat tube 12, the motor seat tube 12 has a right end edge and a left end edge, the right end edge of the motor seat tube 12 is combined with a circular front cover 14, a right spacer ring 141 and a right bearing 142 are respectively embedded at the left and right sides of the inner peripheral surface of the front cover 14, a rear cover 16 is combined at the left end edge of the motor seat tube 12, a left bearing seat 161 is provided in the middle of the rear cover 16, a left bearing 162 is embedded at the left bearing seat 161, an axial lead L is defined at the axial center of the motor seat 10, and the axial lead L passes through the centers of the left bearing 162 and the right bearing 142.

The hollow shaft motor 20 is disposed in the motor seat 10, specifically, the hollow shaft motor 20 is disposed at the left side in the motor seat tube 12, and the hollow shaft motor 20 is provided with a driven hollow shaft 22 at a position corresponding to the axis L. The deceleration structure 30 is disposed in the motor housing 10, specifically, the deceleration structure 30 is disposed on the right side in the motor housing tube 12, two opposite sides of the deceleration structure 30 each have an input end 32 and an output end 34, the input ends 32 are combined with the hollow shaft 22 of the hollow shaft motor 20, the output ends 34 have a sleeve 341, and referring to fig. 6 and 7, the deceleration structure 30 has a shaft hole H at a position corresponding to the shaft axis L, and the shaft hole H is communicated with the interior of the hollow shaft 22.

Referring to fig. 1-3 and 6 and 7, the chain drive assembly 40 includes a one-way bearing seat 42, a first one-way bearing 44, a second one-way bearing 46, and a chain plate seat 48. The unidirectional bearing seat 42 is a pipe body surrounding the axis L, and the unidirectional bearing seat 42 has a first pipe section 421, a second pipe section 422, and a middle section 423 connecting the first pipe section 421 and the second pipe section 422; the outer diameter of the first pipe section 421 is smaller than the inner diameter of the second pipe section 422, and at least a portion of the outer circumferential surface of the second pipe section 422 is embedded and combined with the inner circumferential surface of the right bearing 142.

The first one-way bearing 44 is sleeved and fixed on the outer peripheral surface of the first pipe section 421, the first one-way bearing 44 is embedded and combined with the inner peripheral surface of the sleeve 341 of the speed reducing structure 30, the right spacing ring 141 is arranged between the outer peripheral surface of the sleeve 341 and the inner peripheral surface of the front cover 14, and the speed reducing structure 30 can drive the one-way bearing seat 42 to rotate by the sleeve 341 of the output end 34 through the first one-way bearing 44; the second one-way bearing 46 is embedded and combined with the inner peripheral surface of the second pipe section 422, the second one-way bearing 46 is installed in the opposite direction to the first one-way bearing 44, and the chain wheel seat 48 is combined with the second pipe section 422 of the one-way bearing seat 42 to provide chain wheel combination of the bicycle.

The crank axle 50 is pivoted through the centers of the hollow axle 22, the axle hole H and the unidirectional bearing seat 42 along the axle axis L, so that the crank axle 50 can rotate freely relative to the hollow axle motor 20, the chain wheel driving assembly 40 and the chain wheel driving assembly 40, the right end of the crank axle 50 is pivoted through the center of the front cover 14, the left end of the crank axle 50 is pivoted through the left bearing 162 embedded in the middle of the rear cover 16, and a crank joint portion 52 is formed at each of the left and right ends of the crank axle 50 penetrating out of the motor seat 10, for providing crank and pedal joint of a bicycle.

One side of the crank axle 50, for example, in the preferred embodiment, a wheel portion 54 having a larger diameter than that of the other portion is provided on the right side of the crank axle 50 corresponding to the second one-way bearing 46, and the wheel portion 54 is embedded in the inner circumferential surface of the second one-way bearing 46, so that when a user drives the crank axle 50 to rotate by driving the pedal, the crank axle 50 can drive the one-way bearing seat 42 and the chain seat 48 to rotate by the wheel portion 54 through the second one-way bearing 46, and the chain mounted on the chain seat 48 normally operate. The other side of the crankshaft 50 opposite to the direction, for example, in the preferred embodiment, has a groove 56 on the left side of the crankshaft 50, the groove 56 is disposed on the crankshaft 50 at a position between the hollow shaft motor 20 and the rear cover 16, and a strain gauge 561 is coupled to the inner surface of the groove 56.

Referring to fig. 2,3, 5 and 7, the signal transmission assembly 60 includes a rotary base 62, a circuit board 64 and a control circuit board 66. The rotary seat 62 is a disc body, and the rotary seat 62 is sleeved and combined with the part of the crankshaft 50 with the groove 56 to be fixed in a mode that the rotary seat 62 is screwed or pressed on the crankshaft 50 by a fixing piece, the rotary seat 62 is provided with a ring part 621, and the surface of the ring part 621 is perpendicular to the axis L; in other preferred embodiments, the rotary base 62 may be configured to be fixed around the portion of the crankshaft 50 adjacent to the recess 56. The circuit board 64 is coupled to the surface of the ring 621 and is electrically connected to the strain gauge 561 by connecting wires to the circuit board 64 and the strain gauge 561. The control circuit board 66 is fixed in the motor seat 10 in a face-to-face manner with the circuit board 64, specifically, as in the preferred embodiment, the control circuit board 66 is fixed on the inner surface of the rear cover 16, and a fixed interval is provided between the control circuit board 66 and the circuit board 64.

The control circuit board 66 is electrically connected with the hollow shaft motor 20, and is configured to receive the signal of the torque of the crankshaft 50 measured in real time by the strain gauge 561, and then intelligently judge to control the hollow shaft motor 20 to output electric power; the control circuit board 66 is provided with a spring plate group 661, and the surface of the circuit board 64 is provided with an annular conductive track group 641 taking the axis L as the center, the spring plate group 661 elastically abuts against the annular conductive track group 641 in a direction parallel to the axis L, so that the circuit board 64 and the control circuit board 66 can still maintain an electric connection state when rotating face to face with the axis L as the rotation center, and signals of the torque of the crankshaft 50 measured by the strain gauge 561 in real time can be transmitted and fed back to the control circuit board 66 through the circuit board 64, the annular conductive track group 641 and the spring plate group 661. In addition, the control circuit board 66 and the circuit board 64 are in a ring-shaped board structure, so that the elastic sheet set 661 and the ring-shaped conductive track set 641 are respectively arranged on opposite surfaces of the control circuit board 66 and the circuit board 64 in a radial direction, the volume occupied by the structure between the control circuit board 66 and the circuit board 64 along the axial line L direction is small, and the axial length of the power device 100 in the coaxial bicycle is reduced.

In addition to the above arrangement of the preferred embodiment, the elastic sheet set 661 is disposed on the control circuit board 66, the annular conductive track set 641 is disposed on the circuit board 64, the elastic sheet set 661 may be disposed on the circuit board 64, and the annular conductive track set 641 centered on the axis L may be disposed on the surface of the control circuit board 66, at this time, the elastic sheet set 661 still elastically abuts against the annular conductive track set 641 in a direction parallel to the axis L, so that the circuit board 64 and the control circuit board 66 can still maintain an electrically connected state when rotating face-to-face with the axis L as a rotation center.

When the preferred embodiment of the present invention is used, the power device 100 is mounted on the five-way pipe of the bicycle frame, the crank and pedal are combined by the crank combining parts 52 at the left and right ends of the crank shaft 50, the chain plate of the bicycle is sleeved and combined around the chain plate seat 48 for fixing, and the chain is arranged between the chain plate and the flywheel of the rear wheel of the bicycle. The above preferred embodiments of the present invention are used in two ways, namely, manual and electric auxiliary power. When a user steps on and rotates the crank axle 50, please refer to fig. 6 to 7, the crank axle 50 is rotated to rotate the second one-way bearing 46 by the wheel 54, the second one-way bearing 46 drives the second pipe section 422 of the one-way bearing seat 42 from inside to rotate the one-way bearing seat 42 and the chain wheel seat 48 together, and the chain and flywheel are driven to rotate, so that the bicycle is driven to advance.

Referring to fig. 2 to 3, 5 and 7, in the case of electric auxiliary power, when a user steps on the crankshaft 50 to rotate, the rotary base 62 and the circuit board 64 rotate together with the crankshaft 50, so that the control circuit board 66 relatively fixed to the motor base 10 rotates, the strain gauge 561 also senses the stress of the crankshaft 50 to generate torque in real time, and transmits signals to the circuit board 64. The elastic sheet set 661 is in friction contact with the annular conductive track set 641 on the surface of the circuit board 64, so that the circuit board 64 and the control circuit board 66 can be kept in electrical connection although relatively rotated, a torque signal measured by the strain gauge 561 is continuously transmitted to the control circuit board 66, the control circuit board 66 continuously receives a signal of the torque of the crankshaft 50 measured by the strain gauge 561 in real time, and the magnitude of the torque is used for judging and controlling the magnitude of the electric auxiliary power assistance output by the hollow shaft motor 20.

When the hollow shaft motor 20 outputs the electric auxiliary power, the hollow shaft 22 drives the input end 32 of the speed reducing structure 30, the output end 34 drives the first one-way bearing 44 to rotate after the speed is reduced by the speed reducing structure 30, the first one-way bearing 44 drives the first pipe section 421 of the one-way bearing seat 42 from the outside, so that the one-way bearing seat 42 and the chain plate seat 48 rotate together, and the chain and the flywheel are driven to rotate, thereby driving the bicycle to advance, so that the hollow shaft motor 20 can quickly respond to the torque of the crank shaft 50 to output the electric auxiliary power in real time, and the riding feeling of a user is smoother. In addition, when the unidirectional bearing seat 42 and the chain plate seat 48 are driven to rotate by manpower or electric auxiliary power, the unidirectional bearing seat 42 is driven to rotate by a second unidirectional bearing 46 arranged on the inner peripheral surface of the unidirectional bearing seat 42, or the unidirectional bearing seat 42 is driven to rotate by a first unidirectional bearing 44 arranged on the outer peripheral surface of the unidirectional bearing seat 42, so that the force transmission path of the manpower and the electric auxiliary power is divided into the inner side and the outer side of the unidirectional bearing seat 42, and mutual interference of transmission structures among different powers can be avoided.

The construction of the above preferred embodiment is further described. Referring to fig. 7 and 8, a first bearing 51 is disposed between the crankshaft 50 and the inner peripheral surface of the hollow shaft 22, a second bearing 53 is disposed between the crankshaft 50 and the hole wall of the shaft hole H, and a third bearing 55 is disposed between the crankshaft 50 and the inner peripheral surface of the first pipe section 421 of the unidirectional bearing seat 42, so that the crankshaft 50 can pivot through the centers of the hollow shaft 22, the shaft hole H and the unidirectional bearing seat 42 along the axis L, and the first bearing 51, the second bearing 53 and the third bearing 55 are sliding bearings in the preferred embodiment.

Referring to fig. 2 to 3 and fig. 5 and 7, the rotary seat 62 has a cylindrical portion 622, the cylindrical portion 622 is sleeved on the portion of the crankshaft 50 where the groove 56 is disposed, the cylindrical portion 622 is fixed to the crankshaft 50 by screwing or pressing the fixing member through the cylindrical portion 622 onto the crankshaft 50, the annular portion 621 is circumferentially combined around the cylindrical portion 622, the circuit board 64 is an annular circuit board, when the circuit board 64 is combined with the surface of the annular portion 621, the circular portion 622 is circumferentially combined with the cylindrical portion 622, the groove 56 is an annular groove circumferentially combined around the crankshaft 621, a through hole 623 is formed at a position of the cylindrical portion 622 corresponding to the groove 56, and an opening 624 connected with the through hole 623 is formed at the annular portion, and wires connected between the circuit board 64 and the strain gauge 561 are electrically connected with the circuit board 64 by passing through the through hole 623 to the opening 624; in other preferred embodiments, the opening 624 may be omitted such that the wires pass through the through hole 623 before being connected to the circuit board 64.

The elastic sheet set 661 includes four elastic sheets 662 linearly arranged along the radial direction of the crank shaft 50, the annular conductive track set 641 is provided with four circles of annular conductive tracks 642 with diameters from small to large in cooperation with the number of the plurality of elastic sheets 662, and the plurality of elastic sheets 662 elastically abut against the conductive tracks 642 respectively. In other preferred embodiments, the spring plate set 661 may include other numbers of spring plates 662, where the plurality of conductive tracks 642 of the annular conductive track set 641 are sized to fit the same number as the diameters of the plurality of spring plates 662.

In order to enhance the conductive effect between the circuit board 64 and the control circuit board 66, in the preferred embodiment, the control circuit board 66 is further configured as an annular circuit board with the same area as the first unidirectional bearing 44, and a plurality of the spring plate groups 661 are disposed on the control circuit board 66 in an arrangement manner surrounding the axis L, for example, in the preferred embodiment, two more spring plate groups 661 are disposed in addition to the original spring plate groups 661, and the number of the spring plates 662 included in each spring plate group 661 is the same as the arrangement manner of the plurality of spring plates 662, so that each spring plate group 661 can elastically abut against the annular conductive track group 641 in the same manner, and each conductive track 642 can simultaneously electrically connect the spring plates 662 with the same arrangement order of the plurality of spring plate groups 661, for example, the same conductive track 642 in the preferred embodiment is simultaneously contacted with three spring plates 662 with the same arrangement order.

The hollow shaft motor 20 is coaxial with the speed reducing structure 30, the unidirectional bearing seat 42 and the crank shaft 50, the hollow shaft motor 20 has a housing 24, the housing 24 is fixedly disposed in the motor seat tube 12 of the motor seat 10, the hollow shaft 22 is pivoted at a position of the axial center of the housing 24, a stator 26 is fixedly disposed around the housing 24, and a rotor 28 is fixedly coupled to the outer peripheral surface of the hollow shaft 22. The hollow shaft 22 has a large diameter portion 221 having an inner diameter larger than that of the other portion at one end thereof facing the speed reducing structure 30, the inner circumferential surface of the large diameter portion 221 has a circular shape, and a plurality of key grooves 222 are formed around and spaced apart from the inner circumferential surface of the large diameter portion 221.

Referring to fig. 4, 7 and 9-10, the speed reducing structure 30 is a planetary gear reducer and has an inner gear ring 36, the inner gear ring 36 is fixedly disposed in the motor housing tube 12 of the motor housing 10, the inner gear ring 36 is screwed to the right end surface of the housing 24 of the hollow shaft motor 20, a first-order planetary gear carrier 361 and a second-order planetary gear carrier 362 are disposed on the left side and the right side in the inner gear ring 36, one side surface of the first-order planetary gear carrier 361 facing away from the second-order planetary gear carrier 362 is combined with a plurality of first-order planetary gears 363 on the left side surface in a manner of encircling the axis L, the outer sides of the plurality of first-order planetary gears 363 are meshed with the inner gear ring 36, a plurality of second-order planetary gears 364 are combined between the right side surface and the second-order planetary gear carrier 362 in a manner of encircling the axis L, the outer sides of the plurality of second-order planetary gears 364 are meshed with the inner gear ring 36 in a manner of encircling the axis L, and the inner gear ring 341 extends from the right side surface of the sun gear carrier 341 to the right side surface of the sleeve 341.

The input end 32 of the speed reducing structure 30 has a transmission gear 32A as a sun gear, and the shaft hole H of the speed reducing structure 30 is a position passing through the centers of the transmission gear 32A, the first-stage carrier 361 and the second-stage carrier 362. The right half of the transmission gear 32A is engaged with the inner sides of the plurality of first planetary gears 362, the left half of the transmission gear 32A extends into the large diameter portion 221 of the hollow shaft 22, a key block 223 is embedded in each of the plurality of key grooves 222, and the inner sides of the plurality of key blocks 223 are embedded around the transmission gear 32A to fix the hollow shaft 22 to the input end 32 of the speed reduction structure 30.

The transmission gear 32A of the input end 32 is coupled to the large diameter portion 221 of the hollow shaft 22 by being fitted with a plurality of key blocks 223 at the left half portion thereof, except for the above-described preferred embodiment. Referring to fig. 11 and 12, in another preferred embodiment of the present invention, instead of the key groove 222, the inner circumferential surface of the large diameter portion 221 may be changed from a circular shape to a hexagonal shape, the driving gear 32A may be provided with only a right half portion, and a collar 32B may be provided corresponding to the large diameter portion 221, the collar 32B may be a hexagonal ring body having an outer circumferential surface matching with a wall surface of the caulking groove 221B, the collar 32B may be concentrically coupled to a side wall of the driving gear 32A, and an outer diameter of the collar 32B may be smaller than a diameter of the driving gear 32A, and the driving gear 32A may be fitted into the caulking groove 221B with the collar 32B, so that the hollow shaft 22 may be coupled to the input end 32.

In the above-described preferred embodiment, the caulking groove 221B may be a non-circular caulking groove such as a square, a pentagon, or a circular shape having two opposite parallel surfaces on opposite sides thereof, in addition to the hexagonal caulking groove, and the transmission gear 32A may be coupled to the hollow shaft 22 by inserting the transmission gear 32A into the caulking groove 221B by inserting the insertion ring 32B into the transmission gear 32A by using the insertion ring 32B concentrically coupled to the side wall of the transmission gear 32A as a ring body having an outer circumferential surface engaged with the wall surface of the caulking groove 221B.

The transmission gear 32A in the above preferred embodiment is coupled to the hollow shaft 22 by penetrating the left half portion thereof into the large diameter portion 221, and the transmission gear 32A in the other preferred embodiment is coupled to the hollow shaft 22 by penetrating the large diameter portion 221 with the nesting ring 32B connected to the side wall thereof. The drive gear 32A axially coupled to the hollow shaft 22 can be provided with a smaller diameter size than the prior art of crimping the gear around the motor shaft (hollow shaft 22), with the drive gear 32A having a smaller number of teeth when the teeth are of comparable size. When the reduction ratio of the planetary reducer (reduction structure 30) is the same in the inner ring gear 36, the reduction ratio is determined by the number of teeth of the sun gear (transmission gear 32A): the fewer the number of teeth of the sun gear, the higher the reduction ratio, and the higher the number of teeth of the sun gear, the fewer the reduction ratio. Since the transmission gear 32A of the present invention described above has fewer teeth, the reduction ratio of the reduction structure 30 can be improved.

Referring to fig. 2 to 3 and 7, the front cover 14 is a ring body and has an inner diameter slightly smaller than that of the motor seat tube 12, the unidirectional bearing seat 42 is disposed on the inner side of the front cover 14, and a portion of the second tube segment 422 extends rightward beyond the surrounding area of the front cover 14, a convex ring portion 424 is disposed on the portion of the second tube segment 422 extending beyond the front cover 14, and the right bearing 142 is disposed on the outer peripheral surface of the second tube segment 422 and is located on the left side of the convex ring portion 424. The sprocket seat 48 is a hat-shaped disc body and is screwed and coupled to the convex ring portion 424 of the second pipe section 422 by an inner peripheral edge, the outer peripheral surface of the sprocket seat 48 has a threaded portion 481, a blocking edge 482 is formed at a left end of the threaded portion 481, a sprocket gasket 483 is disposed to abut against a right side of the blocking edge 482, and a pressing ring 484 is screwed on the threaded portion 481.

In the preferred embodiment, the shortest distance between the outer circumferential surface of the first pipe section 421 and the inner circumferential surface of the second pipe section 422 along the radial direction of the crank shaft 50 is equal to the shortest distance between the inner circumferential surface and the outer circumferential surface of the first unidirectional bearing 44 along the radial direction of the crank shaft 50, and is also equal to the shortest distance between the inner circumferential surface and the outer circumferential surface of the second unidirectional bearing 46 along the radial direction of the crank shaft 50, and the middle section 423 is a ring body extending from inside to outside and having a direction perpendicular to the axis L, and by virtue of the design that the first unidirectional bearing 44 and the second unidirectional bearing 46 adopt the same size parts and are arranged at the positions parallel to the left and right sides of the middle section 423, the types of the parts can be reduced, the diameter of the motor base 10 can be reduced, and the motor base 10 can be miniaturized.

The above description is only of the preferred embodiments of the present invention, and all equivalent changes in the specification and claims should be construed to be included in the scope of the present invention.

Description of the reference numerals

[ Invention ]

100: Central power device for coaxial bicycle

10: Motor seat

12: Motor seat tube

14: Front cover

141: Right spacer ring

142: Right bearing

16: Rear cover

161: Left bearing seat

162: Left bearing

20: Hollow shaft motor

22: Hollow shaft

221: Large diameter portion

221B: caulking groove

222: Key groove

223: Key block

24: Outer casing

26: Stator

28: Rotor

30: Speed reducing structure

32: Input terminal

32A: transmission gear

32B: nested ring

34: An output terminal

341: Casing pipe

36: Inner gear ring

361: First-order planet carrier

362: Second-order planetary gear carrier

363: First planetary gear

364: Second planetary gear

365: Sun gear

40: Chain disk driving assembly

42: Unidirectional bearing pedestal

421: First pipe section

422: Second pipe section

423: Middle section

424: Convex ring part

44: First one-way bearing

46: Second one-way bearing

48: Chain plate seat

481: Screw part

482: Stop edge

483: Chain plate gasket

484: Packing ring

50: Crank axle

51: First bearing

52: Crank joint

53: Second bearing

54: Wheel part

55: Third bearing

56: Groove

561: Strain gauge

60: Signal transmission component

62: Rotary seat

621: Ring part

622: Barrel part

623: Wearing mouth

624: An opening

64: Circuit board

641: Annular conductive track group

642: Conductive track

66: Control circuit board

661: Spring plate set

662: Spring plate

H: shaft hole

L: axial lead

Claims (11)

1. A coaxial bicycle center power device comprising:

A motor seat defining an axis on its axis;

the hollow shaft motor is arranged in the motor seat and is provided with a hollow shaft at a position corresponding to the axial lead;

the motor seat is provided with a hollow shaft, a motor shaft is arranged in the motor seat, a sleeve is arranged at the output end, and a shaft hole is arranged at the position corresponding to the shaft axis of the motor seat;

The chain disk driving assembly is provided with a one-way bearing seat and is provided with a first pipe section, a second pipe section and a middle section for connecting the first pipe section and the second pipe section, and the outer diameter of the first pipe section is smaller than the inner diameter of the second pipe section; a first one-way bearing is sleeved on the outer circumferential surface of the first pipe section, the first one-way bearing is embedded on the inner circumferential surface of the sleeve, a second one-way bearing with the direction opposite to that of the first one-way bearing is embedded on the inner circumferential surface of the second pipe section, and a chain disc seat is combined with the second pipe section;

The crank shaft is pivoted through the hollow shaft, the shaft hole and the one-way bearing seat along the shaft axis, two ends of the crank shaft are pivoted through two sides of the motor seat, one side of the crank shaft is provided with a wheel part with a larger diameter, the wheel part is embedded in the inner peripheral surface of the second one-way bearing, the other side of the crank shaft is provided with a groove, and a strain gauge is combined with the inner surface of the groove; and

The rotary seat is provided with a ring part, a circuit board electrically connected with the strain gauge is combined with the ring part, a control circuit board electrically connected with the hollow shaft motor is fixedly arranged in the motor seat in a mode of being opposite to the circuit board surface, one of the circuit board and the control circuit board is provided with an elastic sheet group, the surface of the other is provided with an annular conductive track group, and the elastic sheet group elastically abuts against the annular conductive track group in a direction parallel to the axis line to enable the two to be electrically connected.

2. The power device in a coaxial bicycle according to claim 1, wherein the spring plate group comprises a plurality of spring plates which are arranged in a straight line along the radial direction of the crank shaft, the annular conductive track group is provided with a plurality of circles of annular conductive tracks with diameters from small to large in cooperation with the number of the plurality of spring plates, and the plurality of spring plates respectively elastically lean against each conductive track.

3. The power device in a coaxial bicycle according to claim 2, wherein two identical spring plate groups are additionally arranged on the circuit board or the control circuit board provided with the spring plate groups, the spring plate groups comprise the same number of spring plates as the spring plate groups, the spring plate groups are arranged in a mode of encircling the axis line, and each conductive track is simultaneously contacted with each spring plate with the same arrangement sequence of the spring plate groups.

4. The center-mounted bicycle power device according to claim 1, wherein the rotary seat is provided with a barrel part, the barrel part is sleeved and fixed on the crank shaft, the ring part is combined around the barrel part, the circuit board is an annular circuit board and is sleeved around the barrel part, a through hole penetrates through the barrel part, an opening connected with the through hole penetrates through the ring part, and a wire is connected between the circuit board and the strain gauge and penetrates out from the through hole to the opening to be electrically connected with the circuit board.

5. The power device in a coaxial bicycle according to claim 1, wherein the motor seat is provided with a motor seat tube, the hollow shaft motor and the speed reducing structure are respectively embedded at the left side and the right side in the motor seat tube, a front cover is combined at the right end edge of the motor seat tube, a rear cover is combined at the left end edge of the motor seat tube, a left bearing seat is arranged in the middle of the rear cover, and a left bearing is embedded in the left bearing seat; the right and left ends of the crank shaft are pivoted through the center of the front cover and the left bearing, respectively.

6. The center-mounted power device of the coaxial bicycle according to claim 5, wherein the front cover is a ring body, and a right spacer ring and a right bearing are respectively embedded on the left side and the right side of the inner peripheral surface of the front cover; the right spacing ring is arranged between the outer peripheral surface of the sleeve and the inner peripheral surface of the front cover, at least part of the outer peripheral surface of the second pipe section is embedded and combined with the inner peripheral surface of the right bearing, the rest part of the second pipe section stretches out of the surrounding range of the front cover rightwards, a convex ring part is convexly arranged on the part of the second pipe section stretching out of the front cover towards the periphery, and the chain disc seat is a hat-shaped disc body and is combined with the convex ring part through an inner peripheral edge spiral lock.

7. The center-mounted bicycle power device according to claim 6, wherein the outer circumferential surface of the chain wheel seat is provided with a threaded portion, a blocking edge is formed at the left end of the threaded portion, a chain wheel gasket is arranged on the right side of the blocking edge in an abutting manner, and a pressing ring is screwed on the threaded portion.

8. The coaxial bicycle center power device according to claim 1, wherein the shortest distance between the outer peripheral surface of the first tube section and the inner peripheral surface of the second tube section along the radial direction of the crank shaft is equal to the shortest distance between the inner peripheral surface and the outer peripheral surface of the first one-way bearing along the radial direction of the crank shaft and is equal to the shortest distance between the inner peripheral surface and the outer peripheral surface of the second one-way bearing along the radial direction of the crank shaft.

9. The power device in a coaxial bicycle according to claim 1, wherein the hollow shaft forms a large diameter portion with an inner diameter larger than that of other portions at one end facing the speed reducing structure, a plurality of key grooves are formed in an inner peripheral surface of the large diameter portion, the speed reducing structure is a planetary gear reducer, the input end is a transmission gear, a part of the transmission gear extends into the large diameter portion of the hollow shaft, a key block is embedded in each of the plurality of key grooves, and inner sides of the plurality of key blocks are embedded around the transmission gear to be fixed.

10. The coaxial bicycle center power device according to claim 9, wherein the speed reducing structure has an inner gear ring fixedly arranged in the motor seat, a first-order planetary gear carrier and a second-order planetary gear carrier are respectively arranged at two sides of the inner gear ring, a plurality of first planetary gears are combined on one side surface of the first-order planetary gear carrier, which is away from the second-order planetary gear carrier, in a mode of encircling the axis, the outer sides of the plurality of first planetary gears are meshed with the inner gear ring, the inner sides of the plurality of first planetary gears are meshed with the other part of the transmission gears, a plurality of second planetary gears are combined on the other side surface of the first-order planetary gear carrier and the second-order planetary gear carrier in a mode of encircling the axis, the outer sides of the plurality of second planetary gears are meshed with the inner gear ring, the inner sides of the plurality of second planetary gears are meshed with a sun gear, and the sleeve is combined on the second-order planetary gear carrier in a concentric mode and protrudes out of the coverage range of the inner gear ring.

11. The power device in a coaxial bicycle according to claim 1, wherein the hollow shaft forms a large diameter part with an inner diameter larger than that of other parts at one end facing the speed reducing structure, a non-circular caulking groove is formed on the inner peripheral surface of the large diameter part, the speed reducing structure is a planetary gear reducer, the input end is a transmission gear, and the side wall of the transmission gear is concentrically combined with a caulking ring, so that the caulking ring is embedded in the caulking groove for fixing.