JP2001140996A - Cycloidal speed reduction type electric wheel motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cycloidal speed reduction type electric wheel motor capable of achieving the high speed reduction effect by a simple structure. SOLUTION: An output shaft of a motor attached to a hub is eccentrically provided, one cycloidal gear is provided on an eccentric shaft sleeve, a rotary needle fixing ring is fixed to one side of the motor, a rotary needle of an inner ring and the cycloidal gear are meshed with each other, the number of rotary needles is increased more one pitch than the number of cycloidal gear circular arcs so that the cycloidal gear may revolve in the rotary needle fixing ring in the eccentrically meshed state when the motor drives the cycloidal gear. When the cycloidal gear is rotated, it is rotated at specified angles in the opposite direction since the number of teeth is relatively small. By the angle of the rotation, the hub of the hub motor is driven, and therefore, the high speed reduction effect can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cycloid reduction type electric wheel motor, and more particularly to a cycloid reduction type electric wheel motor which can be directly mounted on the center of a wheel and drives and rotates an electric wheel. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cycloid reduction type electric wheel motor capable of obtaining a high reduction ratio effect with a simple reduction structure of a motor and extending a service life of the reduction structure.

[0002]

2. Description of the Related Art The structure of a conventional electric hub motor is shown in FIG.
, A hub 10, a motor case 20,
Stator ring 30, rotor disk 40, fixed shaft 50
And the planetary reduction gear device 60. The main purpose of such a hub motor is to install it directly in the center of the wheel,
The hub 10 is rotated by the motor structure of the motor case 20, the stator ring 30, and the rotor disk 40 to directly rotate the wheels. Since the output rotation speed of the rotor disk 40 is too high, it is necessary to drive and rotate the hub 10 after deceleration. In a well-known reduction gear system, the planetary reduction gear device 60 is provided, and the three planetary gears 60 of the planetary reduction gear device 60 are mounted on the output shaft 401 of the rotor disk 40.
1 is revolved in one internal gear 602, thereby obtaining a deceleration effect and transferring power to one planetary frame 603 to the hub 10.
It is a method of rotating by transmitting it. However, gear transmission has a number of disadvantages, summarized below. 1. The transmission utilizing the meshing of the gears generates a frictional motion in the pitch circle diameter portion, so that the mounting error must be very small, and a large amount of lubricating oil is used. If the mounting error of the gear was excessive or the amount of oil was insufficient, the tooth surface of the gear was cut off (portion A in FIG. 3), and if severe, the tooth surface was lost (portion B in FIG. 3). Therefore, the service life of the gear was not long. 2. When the gear rotates, an impact phenomenon is extremely likely to occur, and in a long time, the corner of the tooth tip is worn (part C in FIG. 3), and the tooth is torn due to continuous impact (part D in FIG. 3).
Was easily formed. All of these drawbacks are found in gears that are replaced during equipment maintenance. 3. When the gears are used as a reduction mechanism, the reduction ratio of the meshing of the two gears is not large and generally does not exceed 1:10 (this is due to consideration of the finite use range in design), and therefore the intermediate gear If the reduction ratio is not added, the effect of the high reduction ratio cannot be achieved. For example, when the reduction ratio is 1:20,
It is necessary to use several gears as multi-stage reduction,
The speed reduction mechanism of such a design is considerably heavy and complicated,
A situation in which the reduction mechanism became larger than the motor itself often occurred. Such a reduction mechanism is also found in a well-known electric hub motor (see FIG. 4). That is, one drive gear 604 ′ is provided on the output shaft 401 ′ of the rotor disk 40, and further, the drive gear 604 ′ and one large gear are provided. Gear 60
5 'is meshed, and a small gear 606' is provided at the center of one side of the large gear 605 '. This small gear 606' is meshed with a driven gear 607 'which is the last gear. The internal structure of such an electric hub motor is complicated and its thickness and weight are increased, so that it is not suitable for mounting on a light electric bicycle.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the electric hub motor reduction mechanism using gears, the present inventor intends to provide a kind of cycloid reduction electric wheel motor. It achieves a high reduction ratio with a simple reduction mechanism and has no drawbacks of gear damage, which increases the service life of the entire electric hub motor.

Specifically, a main object of the present invention is to provide a kind of cycloid reduction type electric wheel motor, in which an output shaft of a hub motor is provided eccentrically, and one cycloid sleeve is provided on an eccentric shaft sleeve. Gears are separately provided, and a rotating needle fixing ring is separately fixed to one side of the motor, and the rotating needle of the inner ring is engaged with the cycloid gear, and the number of rotating needles is increased by one pitch or more than the number of arc grooves of the cycloid gear. When the motor drives the cycloid gear, the cycloid gear revolves around the eccentric engagement ring in the rotating needle fixing ring, and when the cycloid gear revolves around one revolution, the number of teeth is relatively small, so the angle is in the opposite direction. By rotating, the hub of the hub motor is driven by the rotation angle to achieve a high-magnification deceleration effect, and its structure is simple.

Another object of the present invention is to provide a kind of cycloid reduction type electric wheel motor, which comprises:
It comprises two, symmetrically and eccentrically mounted cycloidal gears, which rotate together in one rotary needle fixing ring, thereby balancing the internal rotary center of gravity.

Another object of the present invention is to provide a kind of cycloid reduction type electric wheel motor, which comprises:
The cycloid gear reduction power is transmitted to one clutch, the belt is driven by the clutch to transmit the power to the wheels, and the cycloid reduction electric wheel motor can be installed at any position on the frame.

[0007]

According to a first aspect of the present invention, there is provided a hub, which is attached to a hollow case at the center of a wheel of an electric vehicle, and the hub and the motor for rotating the wheels in unison with the hub. An electric motor mounted inside,
One output shaft is extended from the center of one side surface, a single stage eccentric shaft is provided at the front end of the output shaft, and the hub, the fixed shaft, which is provided with a through-hole penetrating in the axial direction at the center of the output shaft. It is a circular shaft laid across the wheel end of the wheel fork of the electric vehicle, the shaft is fixed to the above-mentioned motor, the fixed shaft is a cycloid reduction mechanism, and a rotating needle fixing ring, a cycloid gear and a reduction gear Wherein the rotating needle fixing ring comprises a number of rotating needles arranged on the circumference of the inner ring surface of the circular ring, on average, so as to exhibit an axial direction, the cycloidal gear having a disk shape and a rotating needle having a diameter. Smaller than the inner ring surface diameter of the fixing ring, a plurality of arc tooth grooves are provided on the circumference, one or more transmission holes are provided at appropriate positions on the board surface, one hole is provided at the center, and the rotating means is fitted. And the speed reducer has a disk shape, At least one pin is provided at an appropriate position on the side panel surface, the pin corresponds to the transmission hole of the above-mentioned cycloid gear, a convex shaft is formed at the center of the panel surface on the other side of the reduction plate, and the center is formed in the center in the axial direction. The above-mentioned cycloid reduction mechanism, which is provided with one through hole penetrating therethrough, is provided such that the rotating needle fixing ring is fixed to a side of the output shaft of the motor so that the rotating needle fixing ring surrounds the output shaft. The cycloid gear is fixed to the eccentric shaft in front of the output shaft of the motor with rotating means, the cycloid gear is mounted on the eccentric shaft in front of the output shaft of the motor with rotating means, and the cycloid gear is eccentric. The reduction gear is engaged with the rotation needle of the rotation needle fixing ring, the reduction gear is coupled to the hub with its convex axis, the motor is encapsulated inside the hub, and the pin of the reduction gear is biased to each transmission hole of the cycloid gear. Is inserted into the Jo,
The fixed shaft passes through the through-hole of the output shaft of the motor and the through-hole of the speed reducer, the motor is fixed to the shaft of the fixed shaft, and the motor and the rotating needle fixing ring on one side thereof are in a state where they cannot rotate. ,
A cycloid reduction electric wheel motor characterized in that the output shaft is capable of slightly driving a cycloid gear, a speed reducer and a hub. The invention according to claim 2 is that the hub has one circular ring sandwiched between two disk covers arranged opposite to each other, and a plurality of hook holes are provided on average around the two disk covers. One clutch is fixed in the center of the disk cover, and one bearing is laid in the center of the other disk cover,
A screw portion is provided at each of both ends of the fixed shaft and is provided for attachment to the end of the wheel fork of the electric vehicle. A groove or a hole for passing an electric wire is provided at one end of the fixed shaft, and one side of the speed reducer is provided. The cycloid reduction electric wheel motor according to claim 1, wherein the convex shaft of the disk surface is inserted into a hole of a clutch at the center of the disk cover, and the reduction gear drives and rotates the hub by the clutch. The invention according to claim 3 is that a plurality of wave-shaped teeth are formed directly on the inner ring surface of the rotating needle fixing ring, two cycloidal gears are provided in the rotating needle fixing ring, and the waves around the cycloidal gear are also provided. Shaped teeth are formed to smoothly engage and disengage with the rotating needle fixing ring, and the two cycloidal gears are both mounted on the eccentric shaft of the motor, so that the eccentric positions of the two cycloidal gears are opposite to each other. The cycloid reduction electric wheel motor according to claim 1, wherein one equilibrium state is obtained by this. According to a fourth aspect of the present invention, there is provided a cycloid reduction type electric wheel motor according to the first aspect, wherein a balance sheet is fixed to one side of the cycloid gear to prevent generation of noise and vibration during rotation. And

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS.
The cycloid reduction type electric wheel motor of the present invention includes a hub 1, a motor 2, a fixed shaft 3, and a cycloid reduction mechanism 4.
It is composed of

The hub 1 is attached to a hollow case at the center of the wheel of an electric vehicle, and two disk covers 11 and 11 ′ arranged opposite to each other are formed with one circular ring 12 interposed therebetween. A plurality of hook holes 111, 111 ′ are provided on the periphery of the disc cover 11, 11 ′ on average and are engaged with the spokes of the wheel of the electric vehicle, or are provided directly around the hub 1 of the tire. The wheels are driven and rotated by the hub 1, and one clutch 13 is fixed to the center of one of the disk covers 11 (the clutch 13 is a commercially available drum clutch, transcendental clutch, ball type, rotating column type, or Another type of clutch which can be used alternatively) is provided with one bearing 14 at the center of another disk cover 11 '.

The motor 2 is an electric motor mounted inside the hub 1, which is a DC electric motor or an AC electric motor, and has one output shaft 2 from the center of one side.
1 is extended, and a single-stage eccentric shaft 22 is attached to the front end of the output shaft 21.
Is provided, and a through hole 211 penetrating in the axial direction is provided at the center of the output shaft 21.

The fixed shaft 3 is a circular shaft laid across the end of the wheel fork of the electric vehicle. Screws 31 and 31 'are provided at both ends of the fixed shaft 3, and the fixed shaft 3 is used for screwing. Are fixed to the motor 2 described above, and a groove 32 is provided in the shaft body at one end, and the groove 32 is provided in the axial direction.

The cycloid reduction mechanism 4 is composed of a rotating needle fixing ring 41, a cycloid gear 42 and a speed reducer 43, of which the rotating needle fixing ring 41 is a circular ring 4
There are provided a plurality of rotating needles 412 arranged on the circumference of the inner ring surface of the eleventh surface so as to have an axial direction, and the rotating needles 412 are jointly connected to one circular support piece 413 with one end face.

The cycloid gear 42 has a disk shape and a diameter smaller than the diameter of the inner ring surface of the rotary needle fixing ring 41. A plurality of arc tooth grooves 4 are formed on the circumference of the cycloid gear 42.
21 are provided, and a plurality of convex teeth 422 are formed on the circumference of the cycloid gear 42 so that the cycloid gear 4
When one or more transmission holes 423 are provided at eccentric positions on the surface of the second board, and a plurality of transmission holes 423 are provided, the transmission holes 423 have an equiangular average distribution, and one hole is provided at the center of the cycloid gear 42. The rotating means 424 is fitted, the rotating means 424 is a bearing or a self-lubricating bearing 432 made of a self-lubricating material, and a balance sheet 425 is provided on an edge portion of one side surface of the cycloid gear 42. .

The speed reducer 43 has a disk shape, and at least one pin 431 is provided at an appropriate position on one side surface of the speed reducer 43. The pins 431 correspond to the transmission holes 423 of the cycloid gear 42 described above. A self-lubricating bearing 432 is provided around the outer periphery of the pin 431, a convex shaft 433 is formed at the center of the other side of the speed reduction plate 43, and a through hole 434 is formed through the center of the shaft 433 to fit the bearing 436. Is provided.

As shown in FIGS. 6 and 7, the cycloid reduction type electric wheel motor composed of the above components has the rotating needle fixing ring 41 in which the output shaft 2 of the motor 2 is balanced.
1, a rotating needle fixing ring 41 is disposed just around the output shaft 21. The cycloid gear 42 is mounted on the eccentric shaft 22 at the front end of the output shaft 21 with its central rotating means 424, so that the cycloid gear 42 is eccentrically installed and can engage with the rotating needle 412 of the rotating needle fixing ring 41. It is. The speed reducer 43 has a convex shaft 433 on one side thereof and a clutch 1 of the disk cover 11.
3, the hub 1 is formed by two disk covers 11 and 11 ′ sandwiching the circular ring 12 in opposition to each other,
And the motor 2 is coated inside the
Of the self-lubricating bearing 43 is inserted into each transmission hole 423 on the surface of the cycloid gear 42 in an eccentric manner.
2 and the hole wall of the transmission hole 423 contact at only one point. However, the fixed shaft 3 penetrates through the clutch 13 and the bearing 14 of the two disk covers 11 and 11 ′, the through hole 211 at the center of the output shaft 21 of the motor 2, and the through hole 43
4, the motor 2 is fixed to the shaft of the fixed shaft 3. Motor 2 and rotating needle fixing ring 4 on one side thereof
1 forms an unrotatable state, and the output shaft 21 slightly rotates the cycloid gear 42, the speed reducer 43 and the hub 1,
Thus, the cycloid reduction type electric wheel motor of the present invention is constituted.

The cycloid reduction type electric wheel motor of the present invention can be screwed to the fork end of the wheel of the electric vehicle with the fixed shaft 3, so that when the motor 2 starts, the eccentric shaft 22 drives the cycloid gear 42. The eccentric rotation in the rotating needle fixing ring 41 causes the cycloid gear 42 to mesh with the rotating needle fixing ring 41, and thus, when the cycloid gear 42 rotates in the opposite direction, the engagement between the tooth groove 421 and the rotating needle 412 causes the cycloid to rotate. The gear 42 rotates in the forward direction by deceleration, and the effect of the deceleration rotation drives and rotates the speed reduction plate 43 (see FIGS. 8 to 12), whereby the hub 1 also generates the rotation speed after deceleration and causes the wheels to rotate. Rotate and march.

The deceleration effect will be described in more detail. As shown in FIG. 8, there are a total of 18 rotary needles 412 of the rotary needle fixing ring 41 and the cycloid gear 4
2 has 17 teeth, and when the eccentric shaft 22 of the motor 2 drives the cycloid gear 42 to rotate to the left, the cycloid gear 42 rotates in the opposite direction, that is, of the cycloid gear 42 originally meshed with A. When the tooth groove 421 separates and moves to the left (FIGS. 9 to 11), and the cycloid gear 42 revolves around the circumference by being driven by the eccentric shaft 22, the rotation of the cycloid gear 42 and the rotating needle 412 of the rotating needle fixing ring 41 is reduced. Because there is one pitch difference, the cycloid gear 42
Twelve 1-pitch angle rotations (see FIG. 12)
When the eccentric shaft 22 of the motor 2 rotates 18 turns, the cycloid gear 42 rotates only once, and its reduction ratio is 1:18.
It is apparent that a well-known reduction gear has a high reduction effect. In addition, since there is no need to reduce the speed in several stages, the structure is simpler than a known structure using a reduction gear. When the cycloid gear 42 rotates, the transmission hole 423
By driving the pin 431 of the speed reduction plate 43, the speed reduction plate 43 is rotated at a reduced speed.
To rotate the wheels of the electric vehicle. In this way, the overall reduction mechanism is considerably simplified and the reduction ratio is increased, and when taken together, the cycloid reduction electric wheel motor of the present invention can solve many of the disadvantages of the gear reduction described above.

As shown in FIGS. 13 and 14, the present invention is also possible in a form in which two cycloidal gears 42 are provided in a rotating needle fixing ring 41, in which case two cycloidal gears 42, 42 'are provided. Are combined with the eccentric shaft 22 of the motor 2 and two cycloid gears 42,
The eccentric position of 42 'is set in the opposite direction, thereby obtaining an equilibrium state and preventing the occurrence of vibration due to the rapid rotation of the cycloid reduction type electric wheel motor. Naturally, in order to achieve balanced noise and vibration free during high-speed rotation, it is also possible to bond the load-corrected weight balance to make the rotation smooth.

Further, the tooth profile of the tooth engaged with the rotary needle fixing ring 41 and the cycloid gear 42 of the present invention is not limited to the structure of the rotary needle 412 described above, and as shown in FIGS. A plurality of wave-shaped teeth 411A are formed directly on the inner ring surface of the fixed ring 41A, and correspondingly, the tooth shape around the cycloid gear 42 is also changed to the wave-shaped tooth 211.
1A, which can achieve more smooth engagement and disengagement movements. Therefore, the present invention can be easily implemented even if other well-known tooth shapes are adopted.

The present invention simplifies the structure of the electric vehicle reduction motor and is not restricted by the design principle of the gear reduction ratio. Therefore, the cycloid reduction type electric wheel motor of the present invention is not limited to being installed at the center of the wheel of the electric vehicle.
As shown in the figure, the structure of the hub 1 in the present invention is canceled and the motor 2, the fixed shaft 3 and the cycloid reduction mechanism 4 are slightly removed.
, And one protective cover 6 is added, and one drum type clutch 5 or another type of clutch is provided on the outside of the speed reduction plate 43 of the cycloid speed reduction mechanism 4, thereby providing the cycloid reduction type of the present invention. The electric wheel motor can be installed at an arbitrary position on the electric vehicle frame, and the effect of decelerating and driving the electric vehicle to march can be achieved. Since the drum type clutch 5 has a known structure, a detailed description is omitted.

[0021]

The cycloid reduction electric wheel motor of the present invention is a cycloid reduction electric wheel motor which can be directly mounted on the center of the wheel and drives and rotates the electric wheel. The electric wheel motor has a simple deceleration structure. It is possible to obtain a high reduction ratio effect and prolong the service life of the reduction structure. Therefore, it can be said that the present invention is an invention having practicality, novelty, and industrial value.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a known hub motor.

FIG. 2 is a view showing a state of engagement of a known planetary gear.

FIG. 3 is a three-dimensional display diagram of a defect easily generated in a known gear.

FIG. 4 is a structural sectional view of a known multi-stage reduction hub motor.

FIG. 5 is an exploded perspective view of the present invention.

FIG. 6 is a front sectional view after assembling of the present invention.

FIG. 7 is a side sectional view after assembling of the present invention.

FIG. 8 is a view showing a continuous operation operation of the cycloid reduction mechanism of the present invention.

FIG. 9 is a view showing a continuous operation operation of the cycloid reduction mechanism of the present invention.

FIG. 10 is a view showing a continuous operation operation of the cycloid reduction mechanism of the present invention.

FIG. 11 is a view showing a continuous operation operation of the cycloid reduction mechanism of the present invention.

FIG. 12 is a view showing a continuous operation operation of the cycloid reduction mechanism of the present invention.

FIG. 13 is an exploded perspective view of an embodiment provided with two cycloidal gears of the present invention.

FIG. 14 is a combined sectional view of an embodiment provided with two cycloidal gears of the present invention.

FIG. 15 is a cross-sectional view of another embodiment of the present invention.

16 is a front sectional view of the embodiment of FIG.

FIG. 17 is an exploded perspective view of still another embodiment of the present invention.

FIG. 18 is a local sectional view of the embodiment in FIG. 18;

19 is a view showing a state of attachment to a bicycle wheel in the embodiment of FIG. 18;

[Explanation of symbols]

Reference Signs List 10 hub 20 motor 30 stator ring 40 rotor disk 401, 401 ′ output shaft 50 fixed shaft 60 planetary reduction gear device 601 planetary gear 602 internal gear 603 planetary frame 604 ′ main driving gear 605 ′ large gear 606 ′ small gear 607 ′ driven gear DESCRIPTION OF SYMBOLS 1 Hub 11, 11 'Disk cover 12 Circular ring 111, 111'
Hook hole 13 Clutch 14 Bearing 2 Motor 21 Output shaft 22 Eccentric shaft 211 Through hole 3 Fixed shaft 31, 31 'Screw portion 32 Groove 4 Cycloid reduction mechanism 41 Rotating needle fixing ring 411 Circular ring 412 Rotating needle 413 Supporting pieces 42, 42' Cycloid gear 421 Tooth groove 422 Convex tooth 423 Transmission hole 424 Rotating means 425 Balance sheet 43 Reduction plate 431 Pin 432 Self-lubricating bearing 433 Convex shaft 434 Through hole 435 Bearing 41A Rotating needle fixing ring 411A Wave-shaped tooth 42A Cycloid gear tooth A 5 Clutch 51 Belt 6 Protective cover

Claims (4)

[Claims] 1. An electric motor which is a hub and is attached to a hollow case at the center of a wheel of an electric vehicle, and is an electric motor which is an electric motor which is attached to the inside of the hub. One output shaft is extended from the center of the side surface, a one-stage eccentric shaft is provided at the front end of the output shaft, and the hub is provided with a through-hole penetrating in the axial direction at the center of the output shaft. It is a circular shaft laid across the wheel fork end of the electric vehicle, and the shaft is fixed to the aforementioned motor. The fixed shaft is a cycloid reduction mechanism, which is composed of a rotating needle fixing ring, a cycloid gear, and a reduction plate. The rotating needle fixing ring comprises a small number of rotating needles arranged on the circumference of the inner ring surface of the circular ring on the average, so as to exhibit an axial direction, and the cycloidal gear has a disk-like shape and a rotating needle fixing ring having a diameter. Inner ring surface straight Smaller than the diameter, multiple arc tooth grooves are provided on the circumference,
One or more transmission holes are provided at appropriate positions on the board surface, one hole is provided at the center, and a rotating means is fitted, and the speed reducer has a disk shape. One pin is provided, the pin corresponds to the transmission hole of the above-mentioned cycloid gear, a convex shaft is formed at the center of the board surface on the other side of the speed reduction plate, and one through hole penetrating in the axial direction is provided at the center. The cycloid reduction mechanism, comprising the above, wherein the rotating needle fixing ring is fixed to a side of the output shaft of the motor, the rotating needle fixing ring is fixed so as to surround the output shaft, and the cycloid gear rotates. Means are mounted on the eccentric shaft in front of the output shaft of the motor, and the cycloid gear is mounted on the eccentric shaft in front of the output shaft of the motor by the rotating means, so that the cycloid gear has an eccentric shape and the rotation of the rotating needle fixing ring. With a needle The reduction gear is engaged with the hub with its convex shaft, the motor is encapsulated inside the hub, the pins of the reduction gear are inserted eccentrically into each transmission hole of the cycloid gear, and the fixed shaft passes through the output shaft of the motor. The motor is fixed to the shaft of the fixed shaft, the motor and the rotating needle fixing ring on one side of the motor are fixed to the non-rotatable state, and the output shaft is slightly cycloid gear, A cycloid reduction type electric wheel motor, wherein a reduction gear and a hub can be driven to rotate. 2. The hub has one circular ring sandwiched between two disk covers disposed opposite to each other, and a plurality of hook holes are provided on the periphery of the two disk covers on average, and one disk is provided. One clutch is fixed at the center of the cover, and one bearing is provided at the center of the other disk cover.Screw portions are provided at both ends of the fixed shaft, so that it can be attached to the end of the electric vehicle wheel fork. A groove or a hole for passing an electric wire is provided at one end of the fixed shaft, and a convex shaft on one side of the speed reduction plate is inserted into a hole of a clutch in the center of the disk cover, and the speed reduction plate is connected to the hub by the clutch. The cycloid reduction type electric wheel motor according to claim 1, wherein the motor is driven to rotate. 3. A plurality of wave-shaped teeth are formed directly on an inner ring surface of the rotating needle fixing ring, two cycloid gears are provided in the rotating needle fixing ring, and the wave-shaped teeth are also provided around the cycloid gear. Is formed and smoothly engages and disengages with the rotating needle fixing ring, and the two cycloidal gears are both mounted on the eccentric shaft of the motor so that the eccentric positions of the two cycloidal gears are in opposite directions. The cycloid reduction type electric wheel motor according to claim 1, wherein one equilibrium state is obtained by this. 4. The cycloid reduction electric wheel motor according to claim 1, wherein a balance sheet is fixed to one side of the cycloid gear to prevent generation of noise and vibration during rotation.