CN212022888U

CN212022888U - Chain wheel direct-drive type middle shaft transmission mechanism

Info

Publication number: CN212022888U
Application number: CN202020760205.0U
Authority: CN
Inventors: 温群峰
Original assignee: Suzhou Shengyi Motor Co ltd
Current assignee: Suzhou Shengyi Motor Co ltd
Priority date: 2020-05-09
Filing date: 2020-05-09
Publication date: 2020-11-27
Anticipated expiration: 2030-05-09

Abstract

The utility model discloses a chain wheel directly drives formula axis drive mechanism, include: the middle shaft is used for mounting a crank and a pedal to bear the riding pedaling force; the main chain wheel transmits pedal force to a driving chain wheel of the electric bicycle through a sleeved chain; the motor core is arranged in the shell together with the middle shaft and comprises a stator, a rotor and a core shaft which is used for outputting power and is parallel to the middle shaft; the machine core shaft is connected with the rotor through a first one-way clutch, the main toothed disc is directly fixed on the machine core shaft, and the middle shaft is in transmission connection with the machine core shaft through a gear transmission mechanism. The utility model relates to an anti-conventional design, with main fluted disc snap-on at the core axle of motor core for mechanism overall structure is compacter, and the volume is littleer, and transmission efficiency is higher.

Description

Chain wheel direct-drive type middle shaft transmission mechanism

Technical Field

The utility model relates to a chain wheel directly drives formula axis drive mechanism.

Background

The middle shaft transmission mechanism is a general name of a whole set of power mechanism including a motor, a middle shaft, a clutch, a speed reducing mechanism, a torque sensor and a chain wheel. The structure forms of the middle shaft transmission mechanism in the prior art are various, and the final transmission efficiency and the whole volume of the mechanism are different due to different structures.

A middle shaft transmission mechanism widely applied in the industry of the electric bicycle at present is in a side hanging mode, a middle shaft of the middle shaft transmission mechanism is arranged in parallel with an output shaft of a motor, and a middle shaft sleeve for arranging the middle shaft is led out of a shell so as to be inserted into a frame five-way pipe of a universal specification on the market, so that the motor does not need to be matched with a special hanging bracket, can be matched with frames of most specifications on the market, and has good adaptability.

As is well known, in the existing inherent structural form of the middle shaft transmission mechanism, a chain wheel is usually fixed with a middle shaft, the power at the motor end is decelerated by a deceleration mechanism, transmitted to the middle shaft by a one-stage or multi-stage transmission gear, transmitted to the chain wheel by the middle shaft, and finally transmitted to a rear wheel to drive the electric bicycle to run by the chain wheel; when the bicycle is ridden, the force of the pedal of a person is transmitted to the middle shaft through the crank, then transmitted to the chain wheel, and finally transmitted to the rear wheel driving electric bicycle through the chain by the chain wheel to run.

However, in practice, the above-mentioned inherent design of the bottom bracket bearing drive increasingly suffers from the following disadvantages:

1) the power output of the motor is transmitted through the speed reducing mechanism and also transmitted to the chain wheel through the middle one-stage or multi-stage gear transmission mechanism, so that the transmission loss is large, and the transmission efficiency cannot be effectively improved all the time;

2) the larger size of the crankset coupled with its geared design with the central shaft and the interior leads to an overall structure that cannot be further compacted, but the crankset cannot be made smaller because it is directly mounted on the central shaft, the specifications being designed according to the transmission ratio and the human pedaling rate, which is not desirable or permissible in design if the crankset is made smaller, which may increase the human pedaling rate.

Therefore, a chain wheel direct-drive type middle shaft transmission mechanism with a more compact structure, a smaller volume and higher transmission efficiency is urgently needed in the industry.

Disclosure of Invention

The utility model discloses the purpose is: the chain wheel direct-drive type middle shaft transmission mechanism is more compact in structure, small in size and high in transmission efficiency.

The technical scheme of the utility model is that: a chain wheel direct drive type middle shaft transmission mechanism comprises:

the middle shaft is used for mounting a crank and a pedal to bear the riding pedaling force;

the main chain wheel transmits pedal force to a driving chain wheel of the electric bicycle through a sleeved chain;

the motor core is arranged in the shell together with the middle shaft and comprises a stator, a rotor and a core shaft which is used for outputting power and is parallel to the middle shaft;

the machine core shaft is connected with the rotor through a first one-way clutch, the main toothed disc is directly fixed on the machine core shaft, and the middle shaft is in transmission connection with the machine core shaft through a gear transmission mechanism.

Of course, the motor core can adopt an inner rotor outer stator or an outer rotor inner stator in any form, and the utility model discloses do not have the limit to this.

Further, in the utility model discloses in gear drive includes first drive gear, second drive gear and idler, and first drive gear passes through second one way clutch and links to each other with the axis, and second drive gear is fixed or integrated into one piece is in on the core axle, the idler pivot is installed in the casing, and this idler all meshes with first drive gear and second drive gear.

Still further, the utility model discloses in still including installing epaxial torque sensor, this torque sensor is known magnetic ring hall formula sensor, it is including fixing epaxial deformation axle sleeve and fixing on the casing and be located deformation axle sleeve outlying hall element support, be fixed with the response magnetic ring position sleeve on the deformation axle sleeve, be fixed with the response magnetic ring along the circumference on this response magnetic ring position sleeve, and be fixed with on the hall element support with response magnetic ring complex hall element, hall element is connected with electric bicycle's the controller that is used for driving motor core moving is electric, and warp the axle sleeve with pass through between the first transmission gear the second one way clutch links to each other.

For the installation form of the torque sensor, the utility model can also adopt another scheme, namely the torque sensor is arranged at the position of the idler pulley, the idler pulley comprises a sensor deformation bracket arranged in the shell, the idler pulley is pivoted and installed on the sensor deformation bracket, simultaneously, a strain gauge and a PCB electrically connected with the strain gauge are fixed on the sensor deformation bracket, and the PCB is electrically connected with a controller of the electric bicycle for driving the movement of the motor to run; and the centers of the first transmission gear, the second transmission gear and the idler gear are distributed in a triangular shape.

Furthermore, in the present invention, the first one-way clutch is a one-way needle bearing, and the second one-way clutch is a ratchet and pawl mechanism.

Furthermore, the diameter of the first transmission gear is larger than that of the idle gear, and the diameter of the second transmission gear is smaller than or equal to that of the idle gear.

Furthermore, the utility model discloses in still include the pivot and locate on the casing and be used for strutting an at least supplementary chain wheel of chain.

Further, in the utility model discloses in casing is stretched out to core axle one end, mills on it to have and supplies main chain wheel cover to establish the step portion that supports and lean on, and this end is opened has axial screw hole simultaneously, and same chain wheel screw cooperation is very convenient with locking main chain wheel, and main chain wheel's installation location.

The utility model discloses the theory of operation as follows:

motor core operating condition, people trample and make torque sensor produce the sensing signal, and the operation of driving motor core with the help of first one way clutch's effect, the core axle is output the moment of torsion under the rotor drives, transmits to the main chain wheel on, and main chain wheel transmits the moment of torsion to electric bicycle's drive sprocket through the chain on, and the drive electric bicycle advances. Under the state, due to the action of the second one-way clutch, a first transmission gear in the gear transmission mechanism is disengaged from the middle shaft, and the middle shaft is prevented from rotating along with the middle shaft.

The person rides and tramples operating condition, and the foot is incessantly trampled the pedal on the crank, and the moment of torsion passes through on axis and the second one way clutch of interlock transmit to first drive gear, transmits to the core axle through idler and second drive gear again on, because the effect of first one way clutch, core axle and rotor throw off to it is rotatory to drive main chain wheel, and last main chain wheel is on the same drive sprocket that transmits the moment of torsion to electric bicycle through the chain, and the drive electric bicycle advances.

The utility model has the advantages that:

1) the utility model relates to an anti-conventional design fixes the main fluted disc at the core axle of motor core, and the power take off of motor core need not like conventional technique and transmits to main fluted disc again through reduction gears and middle one-level or multistage gear drive mechanism, reduction transmission loss that can be very big effectively promotes transmission efficiency.

2) The utility model discloses in with main chain wheel snap-on at the core axle of motor core, rather than in the epaxial, the speed that the specification of main chain wheel no longer receive transmission speed ratio and people to trample requires the restriction like this, can further change the small-size. And after the size of the main gear disc is changed to be small, the structural design of the whole middle shaft transmission mechanism is more compact, and the volume of the shell part can be made smaller.

3) The main chain wheel needs to design the chain wheel connecting sleeve to assemble with the middle shaft and the internal gear transmission mechanism in the conventional technology, and the utility model provides a main chain wheel installs very conveniently simply, can improve assembly efficiency to owing to also cancelled the chain wheel connecting sleeve, reduced spare part, further simplified the structure, so also reduced manufacturing cost simultaneously.

4) The utility model provides an in the mechanism, torque sensor both can install epaxially and can install in idler wheel department, and it is nimble more convenient to install, can effectively utilize and optimize axis drive mechanism inner structure, improves production efficiency, reduction in production cost.

Drawings

The invention will be further described with reference to the following drawings and examples:

FIG. 1 is a cross-sectional view of an embodiment of the present invention;

FIG. 2 is a side view of the outer chain wheel of the housing of the embodiment of FIG. 1 (with the drive sprocket on the rear of the electric bicycle);

fig. 3 is a front view of a torque sensor according to another embodiment of the present invention (including its positional relationship with the first drive gear, the second drive gear, and the idler gear).

Wherein: 1. a middle shaft; 2. a crank; 3. a master chain wheel; 4. a chain; 5. a drive sprocket; 6. a stator; 7. a rotor; 8. a machine core shaft; 8a, an axial threaded hole; 9. a first one-way clutch; 10. a housing; 11. a first drive gear; 12. a second transmission gear; 13. an idler pulley; 14. a deformable shaft sleeve; 15. a Hall element support; 16. an induction magnetic ring; 17. a Hall element; 18. a second one-way clutch; 19. a sensor deformation support; 20. a strain gauge; 21. a PCB board; 22. an auxiliary chain wheel; 23. an induction magnetic ring positioning sleeve; 24. a chain wheel screw.

Detailed Description

Example 1: the present invention provides a specific embodiment of the chain wheel direct-drive middle shaft transmission mechanism, which is shown in fig. 1-2, and the detailed structure thereof is as follows:

the structure of the chain wheel direct drive type middle shaft transmission mechanism mainly comprises a middle shaft 1, a crank 2, a main chain wheel 3, a motor core, a first one-way clutch 9, a shell 10, a gear transmission mechanism, a torque sensor, a second one-way clutch 18 and an auxiliary chain wheel 22.

First, as shown in fig. 1, the housing 10 is constituted by an upper housing and a lower housing integrally connected to each other, and is integrally fixed to a frame (not shown) of the electric bicycle. The middle shaft 1 is installed in the lower housing of the housing 10 by a plurality of bearings (not shown) as in the conventional art, and both ends of the middle shaft 1 are used for installing the crank 2 and the pedals (not shown) to bear the riding pedaling force.

The motor core and the first clutch 9 are both arranged in the upper shell of the shell 10, wherein the motor core 8 is in the form of an outer rotor and an inner stator and consists of a stator 6, a rotor 7 and a core shaft 8, and two ends of the core shaft 8 are assembled in the upper shell of the shell 10 by adopting bearings. The first one-way clutch 9 is a one-way needle bearing which is sleeved on the machine core shaft 8, and the rotor 7 is fixed with the outer ring of the first one-way clutch 9. One end of the machine core shaft 8 extends out of the shell 10 to fix the main chain wheel 3, a step part for the main chain wheel 3 to be sleeved and abutted against is milled on the machine core shaft, meanwhile, the end is provided with an axial threaded hole 8a, and the same chain wheel screw 24 is matched to lock the main chain wheel 3, as shown in figure 1. The main chain wheel 3 transmits a pedaling force to a driving sprocket 5 installed at the rear of the frame of the electric bicycle through a sheathing chain 4, as shown in fig. 2.

Still referring to fig. 2, two auxiliary crankshafts 22 are pivotally mounted on the lower housing of the housing 10 symmetrically on the upper and lower sides of the central shaft 1 for expanding the chain 4, so as to transmit torque better and avoid interference between the chain 4 and the crank 2.

Referring back to fig. 1, the central shaft 1 in this embodiment is in transmission connection with the spindle shaft 8 through a gear transmission mechanism.

The gear transmission mechanism is composed of a first transmission gear 11, a second transmission gear 12 and an idler gear 13, wherein the first transmission gear 11 is connected with a middle shaft 1 through a second one-way clutch 18, the second transmission gear 12 is integrally formed on a machine core shaft 8, the idler gear 13 is pivotally installed in a shell 10, and the idler gear 13 is meshed with the first transmission gear 11 and the second transmission gear 12.

And as shown in fig. 1 specifically, the utility model discloses in install magnetic ring hall's torque sensor on axis 1, this kind of torque sensor is including fixing epaxial deformation axle sleeve 14 in 1 and fixing on casing 10 and lieing in deformation axle sleeve 14 outlying hall element support 15, be fixed with response magnetic ring position sleeve 23 on the deformation axle sleeve 14, be fixed with response magnetic ring 16 along the circumference on this response magnetic ring position sleeve 23, and be fixed with on the hall element support 15 and respond to magnetic ring 16 complex hall element 17, hall element 17 is connected with electric bicycle's the controller (omitted in the figure) electricity that is used for driving motor core moving to warp axle sleeve 14 one end with pass through between the first drive gear 11 second one way clutch 18 links to each other. The second one-way clutch 18 is a known ratchet and pawl mechanism, a ratchet is fixed on the deformation sleeve 14, and a pawl matched with the ratchet is formed on the inner periphery of the first transmission gear 11. Meanwhile, a plurality of bearings (not labeled in the figure) are also arranged between the first transmission gear 11 and the middle shaft 1 in the embodiment.

The first transmission gear 11 in this embodiment has a larger diameter than the idler gear 13, while the second transmission gear 12 has a smaller diameter than the idler gear 13.

The utility model discloses the theory of operation as follows:

when the motor core works, a person treads a pedal on the crank 2, the middle shaft 1 is stressed to enable the deformation shaft sleeve 14 to be twisted, the Hall element 17 induces magnetic flux change, an induction signal is emitted to the controller, the controller drives the motor core to operate, the core shaft 8 outputs torque under the driving of the rotor 7 under the action of the first one-way clutch 9 and transmits the torque to the main chain wheel 3, and the main chain wheel 3 transmits the torque to the driving chain wheel 5 of the electric bicycle through the chain 4 to drive the electric bicycle to move. In this state, the first transmission gear 11 is disengaged from the bottom bracket axle 1 due to the action of the second one-way clutch 18 (ratchet and pawl disengagement), preventing the bottom bracket axle 1 from following.

The person rides and tramples the operating condition, the foot is incessantly trampled the pedal on the crank 2, the moment of torsion is transmitted to the first drive gear 11 through axis 1 and second one way clutch 18 of interlock, transmit to the core axle 8 through idler 13 and second drive gear 12 again, because the effect of first one way clutch 9, core axle 8 and rotor 7 disengage, thus drive main chain wheel 3 and rotate, main chain wheel 3 transmits the moment of torsion to the driving sprocket 5 of electric bicycle through chain 4 equally at last, drive electric bicycle advances.

Example 2: the structure of the present embodiment is different from that of embodiment 1 in that a torque sensor is not installed on the middle shaft 1, but is installed at the idle wheel 13, and the torque sensor is specially designed and comprises a sensor deformation bracket 19 fixed in the housing 10, the idle wheel 13 is pivotally installed on the sensor deformation bracket 19, meanwhile, a strain gauge 20 and a PCB 21 electrically connected with the strain gauge 20 are fixed on the sensor deformation bracket 19, and the PCB 21 is electrically connected with a controller of the electric bicycle for driving the motor core to operate; and the centers of the first transmission gear 11, the second transmission gear 12 and the idle gear 13 are distributed in a triangular shape as shown in fig. 3. The second one-way clutch 18 in this embodiment is also a known ratchet and pawl mechanism in which the ratchet is directly fixed to the central shaft and the first transmission gear 11 is formed with a pawl on its inner periphery that engages with the ratchet. The rest of the structure of this embodiment is the same as embodiment 1, and can be seen from the structures in fig. 1 and 2.

The working principle is also slightly different due to the variation of the position and structure of the torque sensor:

the motor core operating condition, the people tramples the pedal on the crank 2, axis 1 atress rotates, drive first drive gear 11 through second one way clutch 18 of interlock and rotate, drive idler 13 again and rotate, and idler 13 atress makes the foil gage 20 on the sensor deformation support 19 warp and produces the sensing signal and deliver to the controller, make the controller drive motor core operation, with the help of the effect of first one way clutch 9, machine dabber 8 is output the moment of torsion under the drive of rotor 7, transmit to on main chain wheel 3, main chain wheel 3 transmits the moment of torsion to electric bicycle's drive sprocket 5 through chain 4, drive electric bicycle marchs. After the machine core shaft 8 rotates, the idle gear 13 and the first transmission gear 11 are driven to rotate reversely through the second transmission gear 12, so that the second one-way clutch 18 is disengaged, and further the first transmission gear 11 is disengaged from the middle shaft 1.

The above-mentioned embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention, which should not be construed as limiting the scope of the present invention. All modifications made according to the spirit of the main technical scheme of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A chain wheel direct drive type middle shaft transmission mechanism comprises:

the middle shaft (1) is used for mounting a crank (2) and pedals to bear the riding pedaling force;

the main chain wheel (3) transmits pedal force to a driving chain wheel (5) of the electric bicycle through a sleeved chain (4);

the motor core is arranged in the shell (10) together with the middle shaft (1) and comprises a stator (6), a rotor (7) and a core shaft (8) which is used for outputting power and is parallel to the middle shaft (1);

the gear transmission mechanism is characterized in that a machine core shaft (8) is connected with a rotor (7) through a first one-way clutch (9), a main chain wheel (3) is directly fixed on the machine core shaft (8), and a middle shaft (1) is in transmission connection with the machine core shaft (8) through a gear transmission mechanism.

2. The chain wheel direct drive type middle shaft transmission mechanism according to claim 1, characterized in that the gear transmission mechanism comprises a first transmission gear (11), a second transmission gear (12) and an idle gear (13), the first transmission gear (11) is connected with the middle shaft (1) through a second one-way clutch (18), the second transmission gear (12) is fixed on the machine core shaft (8) or integrally formed on the machine core shaft, the idle gear (13) is pivotally installed in the housing (10), and the idle gear (13) is meshed with both the first transmission gear (11) and the second transmission gear (12).

3. The chain wheel direct drive type middle shaft transmission mechanism according to claim 2, further comprising a torque sensor mounted on the middle shaft (1), the torque sensor comprises a deformation shaft sleeve (14) fixed on a middle shaft (1) and a Hall element support (15) fixed on a shell (10) and positioned at the periphery of the deformation shaft sleeve (14), wherein an induction magnetic ring positioning sleeve (23) is fixed on the deformation shaft sleeve (14), an induction magnetic ring (16) is fixed on the induction magnetic ring positioning sleeve (23) along the circumference, a Hall element (17) matched with the induction magnetic ring (16) is fixed on the Hall element bracket (15), the Hall element (17) is electrically connected with a controller of the electric bicycle for driving the motor core to run, and the deformation shaft sleeve (14) is connected with the first transmission gear (11) through the second one-way clutch (18).

4. The chain wheel direct drive type middle shaft transmission mechanism according to claim 2, further comprising a torque sensor arranged at the idle wheel (13), wherein the torque sensor comprises a sensor deformation bracket (19) arranged in the housing (10), the idle wheel (13) is pivotally mounted on the sensor deformation bracket (19), meanwhile, a strain gauge (20) and a PCB (21) electrically connected with the strain gauge (20) are fixed on the sensor deformation bracket (19), and the PCB (21) is electrically connected with a controller of the electric bicycle for driving the motor core to operate; and the centers of the first transmission gear (11), the second transmission gear (12) and the idle gear (13) are distributed in a triangular shape.

5. The chain wheel direct drive bottom bracket drive according to claim 2 or 3, characterized in that the first one-way clutch (9) is a one-way needle bearing and the second one-way clutch (18) is a ratchet-pawl mechanism.

6. The chain wheel direct drive bottom bracket shaft transmission according to claim 2, wherein the first transmission gear (11) has a larger diameter than the idle gear (13) and the second transmission gear (12) has a smaller diameter than the idle gear (13) or the same diameter as the idle gear (13).

7. The chain wheel direct drive bottom bracket bearing according to claim 1, further comprising at least one auxiliary chain wheel (22) pivotally mounted on the housing (10) for spreading the chain (4).

8. The chain wheel direct drive bottom bracket bearing transmission according to claim 1, wherein one end of the machine core shaft (8) extends out of the housing (10), a step part for the main chain wheel (3) to be sleeved and abutted is milled on the machine core shaft, meanwhile, the end is provided with an axial threaded hole (8 a), and the same chain wheel screw (24) is matched to lock the main chain wheel (3).