WO2019114592A1

WO2019114592A1 - Through-shaft miniature hub motor for electric bicycle

Info

Publication number: WO2019114592A1
Application number: PCT/CN2018/119421
Authority: WO
Inventors: 严振华
Original assignee: 天津迪思科博科技发展有限公司
Priority date: 2017-12-13
Filing date: 2018-12-05
Publication date: 2019-06-20

Abstract

A through-shaft miniature hub motor for an electric bicycle, comprising a stator (2) and a rotor (3), a dual-stage speed reduction mechanism being fixed to the rotor (3); a first sun gear (5) of the dual-stage speed reduction mechanism is fixed to the rotor (3), and the first sun gear (5) meshes with a first planet gear (6), the first planet gear (6) being supported on a first planet gear shaft (9) by means of a bearing; a second sun gear (11) is fixed on a first planet frame (10), the second sun gear (11) meshing with a second planet gear (12), and the first and second planet gears (6, 12) meshing with an inner gear ring (7); the second planet gear (12) is supported on a second planet gear shaft (14) by means of a bearing, and an inner ring of a second planet frame (15) is supported on a main shaft (1) by means of a bearing, while an outer ring is supported on an outer casing (19) by means of a bearing; a one-way clutch is fixed on the second planet frame (15), and the second planet frame (15) forms a through-shaft dual-stage speed reduction power output mechanism. The beneficial effects are as follows: the through-shaft dual-stage speed reduction power output mechanism reduces the size of the diameter of a motor, and the through-shaft may also be used to overcome the defects in a split half-axis structure; and the noise from the motor vibrating is reduced.

Description

Through-shaft miniature hub motor for electric bicycle

Technical field

The invention belongs to the field of electric bicycles, and in particular relates to a through-shaft micro-hub motor of an electric bicycle.

Background technique

At present, the development trend of electric bicycle hub motors is miniaturization. A common method for miniaturization is to use a double planetary gear reduction structure. That is, the sun gear meshes with the large gear of the double planetary gear, and the double planetary gear pinion meshes with the inner ring gear. If the size of the motor is small, it is necessary to further increase the reduction ratio, that is, the number of sun gears needs to be reduced, but the sun gear is limited by the diameter of the main shaft (the main shaft passes through the sun gear). The proposed solution is to use a half shaft (one shaft). In the second, that is, divided into the left half axis and the right half axis, the sun gear is not limited by the diameter of the main shaft, and the sun gear can be made smaller than the main shaft, thereby increasing the reduction ratio. A retarding hub motor is disclosed in the patent document publication number CN201710112694, comprising: a left half shaft and a right half shaft disposed coaxially; a hub that is sleeved outside the left and right axles by a first support bearing; a rotor and a stator in the hub, wherein the stator is fixed to the left half shaft; a flywheel connected to the outside of the right half shaft through the second support bearing; a one-way clutch coaxially arranged with the right half shaft, the one-way clutch including the mutual coupling a clutch inner ring and a clutch outer ring, wherein the inner clutch ring is fixed to the hub, an inner ring gear is integrally formed on the outer ring of the clutch; and a planetary gear speed reduction mechanism connected between the rotor and the inner ring gear; the inner ring of the clutch is integrally formed The ratchet, the flywheel is provided with a pawl connected to the ratchet and a pawl spring connected to the pawl, the ratchet, the pawl and the pawl spring cooperate to form a ratchet pawl one-way clutch. If the hub motor of this type is limited in size by the overall size, the semi-axle method has disadvantages such as high processing precision, high assembly difficulty, high production cost, and poor reliability with respect to the through shaft. The applicant of the present invention discloses a micro-hub motor including a main shaft, a stator, a rotor, a motor casing, an inner ring gear, an eccentric shaft and a planetary gear, and the internal ring gear meshes with the planetary gear, the planet, in the patent document publication No. 107017733A. The gear center hole is supported on the eccentric shaft by the planetary gear support bearing, and the eccentric shaft is supported on the main shaft through the eccentric shaft support bearing and the rotor bearing, the planetary gear has a T-shaped stepped shaft structure, and the gear disc and the pin shaft disc form an integral planet The pin and pin end face are evenly distributed with a plurality of pin shafts, and the left side of the spindle shaft is connected with a stop turntable, and the end surface of the stop turntable is evenly distributed with a plurality of countersunk holes, and the turntable is inserted through the counterbore with a pin-constrained disc, and the pin shaft is constrained. The front end surface of the disc is provided with a stud corresponding to the counterbore position, and the stud of the pin constraining disc is inserted into the counterbore of the stop disc to form a coupling, and the pin constraining disc is provided with a plurality of pin holes on the back side of the disc, and the pin shaft The hole is inserted into the pin shaft of the pinion disc of the planetary gear. The invention realizes the goal of a through-shaft micro-motor with an outer diameter of the motor of φ65-70 mm. Production technology has found that the technology still has shortcomings. When the planetary gear meshes with the inner ring gear, a radial force is generated. The eccentric shaft supported by the bearing on the main shaft increases the radial force, which causes the noise to be large when the motor is working. This is a problem that the designer does not want to have. Designers need to address a more complete miniature hub motor that can be miniaturized and adopts a through-axis approach.

Summary of the invention

The object of the present invention is to overcome the deficiencies of the above-mentioned technologies, and to provide a through-shaft micro-hub motor for an electric bicycle. Under the premise that the main shaft adopts a through shaft, the diameter of the motor casing is less than 74 mm, and the vibration noise of the motor is greatly reduced. .

In order to achieve the above object, the present invention adopts the following technical solution: a through-shaft micro-hub motor of an electric bicycle, comprising a main shaft, a stator, a rotor, a casing, an internal ring gear and a planetary gear, wherein the stator is coupled with the main shaft, the outer casing and The end cover is supported on the main shaft by the end cover supporting bearing and the outer casing supporting bearing, wherein the rotor is fixed with a double-stage speed reducing mechanism, and the double-stage speed reducing mechanism includes first and second sun gears, first and second planets a wheel, first and second planet carriers and a one-way clutch, wherein the first sun gear is fixed to the rotor, the first sun gear is meshed with the first planet gear, and the first planet gear is supported by the first planet gear support bearing at the first On the first planetary axle of the planet carrier, the first planetary gear meshes with the inner ring gear; the first planet carrier is fixed with the second sun gear, the second sun gear meshes with the second planetary gear, and the second planetary gear and the inner gear a ring meshing, the second planet gear being supported on a second planet gear axle of the second planet carrier by a second planet gear support bearing, the inner ring of the second planet carrier being supported on the spindle by a second planet carrier inner support bearing The outer ring is supported on the outer casing by the outer support bearing of the second planet carrier, and the second planet carrier is fixed with a one-way clutch, and constitutes a through-shaft two-stage deceleration power output mechanism.

The inner circumference of the second planet carrier is evenly distributed with the ratchet teeth of the one-way clutch, the inner ring of the one-way clutch is fixed on the main shaft, the inner ring of the one-way clutch is provided with a jack groove, and the jack is provided with a jack to form an integrated planet. One-way clutch structure.

The one-way clutch uses a pawl type one-way clutch or a wedge type one-way clutch.

The number of the first and second planetary wheels is 3-5 each.

Advantageous Effects: Compared with the prior art, the through-shaft two-stage speed-regulating power output mechanism of the invention can not only ensure the diameter reduction of the motor, but also adopt a through-shaft method to avoid the processing existing in the split-type half-axis structure. The precision requirements are high, the assembly is difficult, and the production cost is high; more importantly, the structure can greatly reduce the motor vibration noise through the floating connection of the first planet carrier and the double-stage speed reduction mechanism.

DRAWINGS

Figure 1 is a schematic view of the structure of the present invention;

2 is a schematic structural view of the one-way clutch of FIG. 1.

In the figure: 1, main shaft, 2, stator, 3, rotor, 4, rotor support bearing, 5, first sun gear, 6, first planetary gear, 7, inner ring gear, 8, first planetary gear support bearing, 9. First planetary axle, 10, first planet carrier, 11, second sun gear, 12, second planet gear, 13, second planetary gear support bearing, 14, second planetary axle, 15, second planet carrier , 15-1, ratchet, 16, second planet carrier outer support bearing, 17, second planet carrier inner support bearing, 18, one-way clutch inner ring, 18-1, jack, 19, housing, 20, housing Support bearings, 21, end cover, 22, end cover support bearings, 23, jin.

Detailed ways

The specific embodiments of the present invention are described in detail below in conjunction with the preferred embodiments.

Referring to the drawings in detail, the present embodiment provides a through-shaft micro-hub motor for an electric bicycle, comprising a main shaft 1, a stator 2, a rotor 3, a casing 19, an internal ring gear 7, an end cover 21 and planetary gears, and the stator Bonded with the main shaft, one end of the outer casing is connected to the end cover, and the outer casing and the end cover are supported on the main shaft through the end cover support bearing 22 and the outer casing support bearing 20. The rotor is supported on the main shaft by the rotor support bearing 4, and the rotor is fixed with double a stage reduction mechanism comprising first and

second sun gears

5, 11, first and

second planet gears

6, 12, first and

second planet carriers

10, 15, and a one-way clutch, said first The sun gear is fixed to the rotor, the first sun gear meshes with the first planet gear, and the first planet gear is supported by the first planet gear support bearing 8 on the first planet gear shaft 9 of the first planet carrier, the first planet gear and the inner The ring gear is meshed; the first planet carrier is fixed with a second sun gear, the second sun gear meshes with the second planet gear, the second planet gear meshes with the ring gear, and the second planet gear is supported by the second planet gear The bearing 13 supports the second planetary axle 1 of the second planet carrier 4, the inner ring of the second planet carrier is supported on the main shaft by the second carrier inner support bearing 17, and the outer ring is supported on the outer casing by the second carrier outer support bearing 16, and the second planet carrier is fixed One-way clutch and constitutes a through-shaft two-stage deceleration power output mechanism. The number of the first planetary gear and the second planetary gear is 3-5 each. This embodiment uses five.

2, the preferred embodiment of the present invention is that the inner circumference of the second planet carrier is evenly distributed with the ratchet teeth 15-1 of the one-way clutch, and the one-way clutch inner ring 18 is fixed on the main shaft, the one-way clutch The inner ring is provided with a jacking groove 18-1, and the jack is provided with a jack 23 to constitute an integrated planetary carrier one-way clutch structure.

The one-way clutch adopts a pawl type one-way clutch or a wedge type one-way clutch, and the one-way clutch can also be formed into an integral unit, and is screwed on the inner circumference of the second planet carrier through the outer casing.

In this embodiment, the number of teeth of the two sun gears is Z1=20 teeth, the number of teeth of the planetary gears is Z2=20 teeth, and the number of teeth of the inner ring gear is Z3=60 teeth. In this embodiment, the sun gear is input and the ring gear is output. At this time, the reduction ratio is i=-[(Z3/Z1+1)*(Z3/Z1+1)-1]=-[(60/20+1)* (60/20+1)-1]=-15, achieve a higher reduction ratio with a small ring gear (60 mm diameter) and achieve miniaturization.

Working process and principle

The rotor rotating torque acts on the first planet gear and acts on the ring gear and the first planet carrier through the first planet gear. Since the number of teeth of the ring gear is three times the number of teeth of the sun gear (Z3=60, Z1=20), The torque generated by a planetary gear on the ring gear is three times the torque of the rotor; and according to the planetary deceleration formula i=Z3/Z1+1=60/20+1=4, the first planetary gear is produced on the first planet carrier. The torque is 4 times of the rotor torque; since the first planet carrier is fixed to the second sun gear, the same second sun gear produces a torque on the ring gear that is three times the torque of the second sun gear, that is, the rotor torque. 4x3 = 12 times. In the two-stage speed reduction mechanism of the present invention, the first planetary gear and the second planetary gear simultaneously generate torque to the ring gear, the magnitude of which is 3 times and 12 times of the rotor torque, respectively, and the total torque acting on the ring gear is 3 of the rotor torque. +12=15 times, which is the same as the reduction ratio. It is not difficult to conclude that the total load of the hub in this embodiment will be distributed to the first planetary gear and the second planetary gear, respectively carrying 20% and 80% of the total load, and the distributed load is advantageous for improving the load carrying capacity of the speed reduction mechanism.

When the electric drive is used, that is, when the planetary gear is used as the active member, the direction of the second planet carrier to rotate is opposite to the direction of rotation of the ring gear. At this time, the second planet carrier stops rotating under the action of the one-way clutch, and the planetary gear can drive the ring gear to transmit power. .

When the pure manpower rides, that is, when the motor rotor stops and the ring gear acts as the active member, the ring gear drives the planetary gear and the carrier to rotate, and the second planet carrier rotates in the same direction as the ring gear, and the one-way clutch slips. The two planet carriers are free to rotate, so that the rotor of the motor is not rotated, that is, electromagnetic damping is not generated, and riding is more brisk.

The detailed description of the through-shaft micro-hub motor of the electric bicycle of the above-mentioned reference embodiment is illustrative and not limiting, and several embodiments can be enumerated according to the limited scope, so that the invention is not deviated from the present invention. Changes and modifications under the general concept are intended to be within the scope of the invention.

Claims

A through-shaft micro-hub motor for an electric bicycle, comprising a main shaft, a stator, a rotor, a casing, an inner ring gear and a planetary gear, wherein the stator is coupled with a main shaft, and the outer casing and the end cover support the bearing and the outer casing support bearing through the end cover On the main shaft, the rotor is fixed with a two-stage speed reduction mechanism, and the two-stage speed reduction mechanism includes first and second sun gears, first and second planetary gears, first and second planet carriers, and a one-way clutch. The first sun gear is fixed to the rotor, the first sun gear is meshed with the first planet gear, and the first planet gear is supported on the first planet gear axle of the first planet carrier by the first planet gear support bearing, the first planet The wheel meshes with the ring gear; the first planet carrier is fixed with a second sun gear, the second sun gear meshes with the second planet gear, the second planet gear meshes with the ring gear, and the second planet gear passes the second The planetary wheel support bearing is supported on the second planetary axle of the second planet carrier, the inner ring of the second planet carrier is supported on the main shaft by the second carrier inner support bearing, and the outer ring is supported by the outer side of the second planet carrier support On the housing, a second carrier fixed to the one-way clutch, and constitute a double reduction through the shaft power output mechanism.
The through-shaft micro-hub motor of the electric bicycle according to claim 1, wherein the inner circumference of the second carrier is uniformly distributed with a ratchet of a one-way clutch, and a one-way clutch inner ring is fixed on the main shaft. The inner ring of the one-way clutch is provided with a jack groove, and the jack is provided with a kilogram to form a one-way clutch structure of the integrated planetary carrier.
The through-shaft type micro-hub motor of an electric bicycle according to claim 1 or 2, wherein the one-way clutch uses a pawl type one-way clutch or a wedge type one-way clutch.
The through-shaft type micro-hub motor of the electric bicycle according to claim 1, wherein the number of the first and second planetary wheels is 3-5 each.