TWI565197B - Motor reducer - Google Patents

Description

Motor reducer

The invention relates to a combined technology of a motor and a gear reduction mechanism, and more particularly to a motor reducer.

The gear motor is an integrated electric drive that is easy to install and configure in combination with an electric motor and gear reduction mechanism. For power tools, electric machines, electrical appliances, etc., in the case of relatively low shaft speeds, or low speeds and high torques, the motor reducer can greatly reduce the configuration size and configuration cost of the motor and gear reduction mechanism.

The motor reducer allows the motor to provide a large torque output with low horsepower, such as lifts, winches, jacks and robots, which can be lifted, for example, by a motor reducer; in addition, through a motor reducer The drive is for example a micro clock running.

The use of a conventional motor reducer is also disclosed in, for example, U.S. Patent Publication Nos. 6,196,347, 6, 276, 072, </ RTI> </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> which teaches the use of a motor reducer as a driver on a bicycle to facilitate easing of the rider. Physical load when stepping.

Moreover, it is known that the method of assembling the gear reduction mechanism in the motor reducer is usually to arrange a small gear on the motor spindle to engage the drive gear or the gear train to obtain a deceleration output, or to assemble a motor spindle. The worm is de-engaged to drive a worm wheel to obtain a deceleration output, or a deceleration output is provided by coaxially arranging a planetary gear train coaxially on one side of the motor spindle as disclosed in the above-mentioned U.S. Patent Nos. 6,196,347, 6, 062,072, and 6, 257, 957; Patent discloses a motor reducer configuration technology with a single-stage reduction output, the US Patent No. 6,296,072, 6, 257, 957 teaches a motor reducer configuration technique with a two-stage deceleration output. However, the overall volume of these conventional motor reducers is too large, especially in the axial length of the motor spindle, which is obviously too space-consuming, and during installation, the axial length of the motor spindle is limited. It is not appropriate for equipment that has a design need for miniaturization and refinement.

Further, in order to reduce the overall size of the motor reducer, a flat motor reducer (Planetary Gear Train Pancake Motor) has been disclosed, see http://www.haydonkerk.com/LinearActuatorProducts/StepperMotorLinearActuators/RotaryStepperMotors/PancakeRotaryMotors/PlanetaryPancakeMotors /tabid/107/Default.aspx#ballbearing), which teaches that a rotor of a hollow motor is connected to a sun gear, and then other components of the planetary gear train are integrated into the center of the hollow motor to make only a single order. Flat motor reducer with reduced ratio output. Wherein, the inner ring gear (or the ring inner gear or the ring gear, that is, the outer periphery of the planetary gear and the meshing planetary gear) in the planetary gear train is disposed on the inner side of the motor rotor and fixed to the motor. The outer casing, this structural configuration, simply combines the conventional planetary gear train into the interior of the hollow motor. Although the axial length of the motor spindle can be reduced, for the overall volume of the motor reducer, only the motor The axial length of the mandrel is transferred to the radial width around the motor mandrel. The absolute value of the overall configuration space and volume is not reduced, and even the problem of the number and cost of the parts is increased, and the technology can only be implemented. The first-order deceleration is the fault.

In addition, in U.S. Patent No. 6,296,072, 6, 257, 957, the teaching of the application of two planetary gears and two sun gears respectively to drive transmission to produce a two-stage reduction ratio transmission output, however, for reducing the overall volume of the motor reducer, No technical teaching has been produced.

In addition, it should be further explained that the general knowledge will be based on the technical implications of the above-mentioned flat motor reducer, the hollow motor A planetary gear train that only implements a first-order deceleration is replaced by a planetary gear train that can implement a two-stage reduction ratio as taught by the U.S. Patent No. 6,296,072, 6, 257, 957, in which case, there is still a motor rotor that drives the planetary gear train or its ring. A number of technical issues, such as the operation of the gears and how to effectively reduce the configuration space of the planetary gear train with the two-stage deceleration function, have yet to be overcome. Therefore, the combination of the above-mentioned conventional technologies obviously has technical difficulties, and it is not easy to replace or transfer. And know.

In view of this, the object of the present invention is to provide a motor reducer for improving the conventional motor reducer having a first-order and two-stage deceleration output, and the overall configuration space and volume are difficult to be effectively reduced.

In order to achieve the above object and solve the problem, the present invention provides a first preferred embodiment, the technical means comprising: configured in a casing used as a fixed end: a hollow motor having an inner ring rotor, The rotor is provided with a hollow annular hole, the center of the annular hole accommodating a power output shaft pivotally connected to the casing, the periphery of the rotor is provided with a plurality of driving elements for driving the rotor to rotate; a planetary gear system is disposed at An annular hole of the rotor and surrounding a periphery of the output shaft, the planetary gear set includes: a sun gear set having a first sun gear and a second sun gear in a concentric series, the first sun gear being fixed to In the casing, the second sun gear is fixed on the output shaft; a plurality of planetary gear sets are respectively arranged at equal intervals on the outer periphery of the sun gear set, and the planetary gear sets respectively have a coaxial pivot and a series of a planetary gear and a second planetary gear, the first planetary gear meshes with the first sun, the second planetary gear meshes with the second sun gear; and an annular inner tooth surface is formed at the An inner wall of the sub-machine; wherein the rotor is coupled to the plurality of first planetary gears via an internal tooth surface, driving the plurality of first planetary gears to rotate synchronously with the second planetary gear and revolving around the sun gear set to generate a a first-order deceleration output, the plurality of second planetary gears meshingly coupled to the second sun gear fixed on the output shaft, driving the output shaft to generate a second-order deceleration output.

In the above first embodiment, the method further includes: The number of teeth of the first sun gear and the second sun gear is different.

The first planetary gear has a different modulus from the second planetary gear.

The plurality of driving elements include a magnet fixed to an outer wall of the rotor, and a stator disposed at a periphery of the magnet and fixed in the casing.

A planetary gear disc is disposed on each of the two sides of the plurality of planetary gear sets, and the planetary gear disc restrains each of the plurality of planetary gear sets from revolving around the sun gear set in synchronization with each of the second planetary gears.

The first planetary gear of the plurality of planetary gear sets is coaxially pivotally coupled to the second planetary gear on a planetary gear shaft, and the disk surfaces of the two planetary gear disks provide double-end equal intervals of the plurality of planetary gear shafts fixed.

According to the above first embodiment of the present invention, the technical idea and effect of the invention is that the rotor of the motor is modified to have an annular internal tooth surface to replace the ring gear which is indispensable in the conventional planetary gear train (or Internal gear) to reduce the number of parts and effectively reduce the overall configuration space and volume of the motor reducer. In addition, the relative arrangement characteristics of the gears with the two-stage deceleration output in the sun gear set and the planetary gear set can not only greatly increase the reduction ratio in the effective space, but also further simplify the mechanism and reduce the overall speed of the motor reducer. The space and volume are configured to meet the installation requirements of miniaturized and refined equipment.

The present invention also includes providing a second preferred embodiment, the difference between the technical means and the first embodiment described above is that the inner wall of the motor rotor does not form an internal tooth surface to transmit power to the plurality of first planetary gears, Rather, it is changed to two planetary gear discs fixed to both sides of the rotor. On the one hand, the plurality of planetary gear sets can be restrained to be equally spaced on the outer periphery of the sun gear set, and on the other hand, the rotor can be The two planetary gear plates transmit power to the plurality of first planetary gears, so that the utility of the single-stage deceleration output can be obtained.

In the above second embodiment, further comprising the double side wall surface of the rotor and the end edges of the two planetary gear discs respectively interacting The plurality of teeth are fitted to each other and fixed. Apart from this, the technical features of the above second embodiment are as large as those of the first embodiment.

According to the second embodiment of the present invention, the technical creativity and effect is that the rotor of the motor is fixed integrally with the existing planetary gear plate of the planetary gear train to transmit the first-order deceleration output instead of the conventional planetary gear. The ring gear (or internal gear), which is indispensable in the system, can be configured to reduce the number of parts and effectively reduce the overall configuration space and volume of the motor reducer. In addition, the configuration features of the related gears of the two-stage deceleration output can produce the benefits of increasing the reduction ratio, simplifying the mechanism, reducing the configuration space and volume, and the like, which is the same as that described in the first embodiment, and will not be described again.

Further, details of the related art to which the present invention may be implemented will be explained in the following embodiments and drawings.

10‧‧‧Chassis

11, 12‧‧‧ cover

11a‧‧‧ Rib ring

13‧‧‧ housing room

14‧‧‧Axis hole

20‧‧‧Motor

21, 210‧‧‧ rotor

211, 361‧‧‧ teeth

22‧‧‧ring hole

23‧‧‧Output shaft

23a‧‧‧Bolt

24‧‧‧ ring magnet

24a, 24b‧‧‧Fixed ring

25‧‧‧ Stator

30‧‧‧ planetary gear train

31‧‧‧Sun Gear Set

32‧‧‧First sun gear

33‧‧‧second sun gear

34‧‧‧ planetary gear set

34a‧‧‧First planetary gear

34b‧‧‧Second planetary gear

34c‧‧‧ planetary gear shaft

35‧‧‧ internal tooth surface

36, 360‧‧‧ planetary gear plate

36a‧‧‧Axis hole

36b‧‧‧Perforation

36c‧‧‧ balls

37‧‧‧ sleeve

38‧‧‧ screws

39‧‧‧Spiral sleeve

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exploded perspective view of a first embodiment of the present invention.

Figure 2 is a front elevational view of Figure 1 assembled.

Figure 3 is a cross-sectional view taken along line A-A of Figure 2;

Figure 4 is a cross-sectional view taken along line B-B of Figure 2;

Figure 5 is a perspective partial exploded view of a second embodiment of the present invention.

Figure 6 is a cross-sectional view showing a second embodiment of the present invention.

First, please refer to FIG. 1 to FIG. 4 to disclose the configuration details of the first preferred embodiment of the present invention. The motor reducer provided by the present invention has a structure including a casing 10, a motor 20 and a planet. Gear train 30.

It can be seen from FIG. 1 and FIG. 3 that the casing 10 is formed by combining two disk-shaped casing covers 11 and 12 with respect to a screw group, so that an accommodation chamber 13 is formed inside the casing 10. The casing 10 is a fixed end of the motor reducer, and includes a device for mounting the motor reducer to a power demand having a deceleration output, and when the motor 20 and the planetary gear train 30 are disposed in the accommodation chamber 13, the machine Shell 10 can provide absolute Good assembly fixation.

The motor 20 is a hollow motor and is a power source of the motor reducer. The motor 20 is composed of an inner annular rotor 21 having a hollow annular hole 22, the center of the annular hole 22 accommodating a power output shaft 23 pivotally connected to the casing 10, the casing 10 The center of the two disc-shaped casing covers 11, 12 respectively form a shaft hole 14, which provides one end or both ends of the output shaft 23 to the outside, and the output shaft 23 can output a power supply device end of a predetermined reduction ratio.

In addition, the motor 20 is further configured to include a plurality of driving elements disposed on a periphery of the rotor 21, the plurality of driving elements including a ring magnet 24 disposed on an outer wall of the rotor 21, and a periphery disposed on the magnet 24 and The annular stator 25 is fixed in the casing; wherein the magnet 24 is covered by the double-side annular fixing rings 24a, 24b and is fixed between the rotor 21 and the stator 25. According to Ampere's law, the stator in the motor drive element can be energized and subjected to the magnetic field of the magnet 24 to further drive the rotor 21 to generate a rotation motion to generate a power source of the motor 20.

The configuration details of the planetary gear train 30 described above are also seen in FIGS. 1 and 3, including the entire planetary gear train 30 being disposed within the annular bore 22 of the rotor 21 and surrounding the periphery of the output shaft 23. Specifically, the planetary gear train 30 includes a sun gear set 31, a plurality of planetary gear sets 34, and an annular internal tooth surface 35.

The sun gear set 31 has a first sun gear 32 and a second sun gear 33. The second sun gear 33 is fixed to the shaft wall of the output shaft 23; in practice, the shaft wall of the output shaft 23 is formed with a bolt groove 23a, and the second sun gear 33 is axially fixed and integrated. When the second sun gear 33 rotates, the output shaft 23 rotates synchronously, and the first sun gear 32 is fixed in the casing 10; in practice, the side cover 11 of the casing 10 is adjacent to the output shaft 23, The urging and output shaft 23 is concentrically formed to form a rib ring 11a, and the first sun gear 32 is assembled in a close fitting manner. The rib ring 11a is further fixed in the casing 10. According to this implementation, the first sun gear 32 and the second sun gear 33 can be arranged in a concentric arrangement; the concentric series means that the first sun gear 32 and the second sun gear 33 are arranged in series. On the same axis, the second sun gear 33 fixed to the output shaft 23 is movable, and the first sun gear 32 fixed in the casing 10 is stationary, and further, the first sun fixed. The gear 32 only guides the second planetary gear with its circumferential tooth surface (described in detail later).

The plurality of planetary gear sets 34 described above may be implemented in six groups and disposed at equal intervals in the periphery of the sun gear set 31; the equally spaced manner is implemented by using two planetary gear plates 36, and A planetary gear disc 36 is disposed on each of the two planetary gear sets, and the plurality of planetary gear sets 34 are restrained by the two planetary gear discs 36 at intervals of the same arc of the same circumference. The periphery of the sun gear set 31.

Each of the planetary gear sets 34 includes a first planetary gear 34a and a second planetary gear 34b, and the first planetary gear 34a and the second planetary gear 34b are integrated by a planetary gear shaft 34c; further A bearing or a bushing is disposed on the planetary gear shaft 34c so as to integrate the first planetary gear 34a and the second planetary gear 34b in a coaxial manner, and the two planetary gears 36 are on the disk surface. The shaft holes 36a are provided at equal intervals to be equal to the number of the planetary gear sets 34 for providing the double ends of the planetary gear shafts 34c to be integrally fixed in the shaft holes 36a.

In addition, please refer to FIG. 1 and FIG. 4 to illustrate that a plurality of perforations 36b are equally spaced apart on the disk surface of the two planetary gear plates 36, and each of the two planetary gear plates 36 is perforated. A sleeve 37 is also disposed between the 36bs for facilitating the insertion of a set of screws 38 into the sleeve 37 in the perforations 36b of the disk faces on each side, and a set of threaded sleeves in the through-holes 36b of the other side of the disk. 39 implanting the sleeve 37, the screw 38 and the nut 39 are relatively screwed, and thus the two planetary gear discs 36 can position the respective planetary gear sets 34 in the planetary gear train 30 by the spacing of the sleeves 37. Integral; in addition, two planetary gears Between the disk 36 and the inner walls of the two disk-shaped casing covers 11, 12 of the casing 10, balls 36c serving as bearings are disposed so that the two planetary gear plates 36 can flexibly rotate within the casing 10; The two planetary gear discs 36 can restrain the first planetary gears 34a of the plurality of planetary gear sets 34 from revolving around the sun gear set 31 in synchronization with the respective second planetary gears 34b.

Further, as shown in FIG. 2, the first planetary gear 34a is in contact with the first sun gear 32, and the second planetary gear 34b is in contact with the second sun gear 33, so that the first planetary gear 34a The second planetary gear 34b can be freely rotated (ie, synchronously rotated) synchronously on the planetary gear shaft 34c, thereby synchronously revolving around the sun gear set 31; in addition, the first planetary gear 34a and the second planetary gear The 34b can also be integrally formed in a tandem form, and pivotally coupled to the planetary gear shaft 34c to synchronously rotate and revolve around the sun gear set 31.

The annular inner tooth surface 35 is formed on the inner wall of the annular rotor 21 such that the rotor 21 can be engaged with the plurality of first planetary gears 34a via the inner tooth surface 35; wherein, it must be noted that the inner teeth Face 35 is not in contact with second planet gear 34b. With this design, the integrated rotor 21 can be converted into a ring gear (or internal gear) in the planetary gear train 30; in other words, the present invention is a ring gear (or internal gear) necessary for the rotor 21 and the planetary gear train 30. The members are integrated to omit the necessary ring gear (or internal gear) member in the planetary gear train 30, so that the space around the output shaft 23 of the motor reducer can be effectively reduced.

In addition, the present invention can further configure the first sun gear 32 and the second sun gear 33 with different numbers of teeth; in other words, the first sun gear 32 has A teeth number, the second sun gear 33 has B teeth number, and the A teeth number ≠B number of teeth. Furthermore, the present invention can further configure the first planetary gear 34a and the second planetary gear 34b of the synchronous rotation (including the rotation and the bypass sun gear set 31) to have different modulus; in other words, One planetary gear 34a has an A modulus, the second planetary gear 34b has a B modulus, and the A modulus ≠B modulus.

According to the above configuration details, so that when the driving element of the motor 20 drives the rotor 21 to rotate, the power of the rotor 21 can drive the plurality of first planetary gears 34a having the A modulus via the internal tooth surface 35, In order for the rotational speed of the rotor 21 to thereby obtain a first-order deceleration output. Since the first planetary gear 34a and the second planetary gear 34b are coaxially arranged in series, when the first planetary gear 34a is driven by the rotor 21, the second planetary gear 34b is rotatable in synchronization with the first planetary gear 34a (including rotation) And around the sun gear set 31 revolutions). The first-stage deceleration output is transmitted to the first sun gear 32 and the second sun gear 33 in the sun gear set 31 via the plurality of sets of planetary gear sets 34; in the process of transmitting the first-order deceleration output, The first sun gear 32 having the A-number of teeth is engaged by the plurality of first planetary gears 34a having the A-modulus, and the second sun having the B-number of teeth is engaged by the plurality of second planetary gears 34b having the B-modulus The gear 33; wherein, since the first sun gear 32 has been fixed in the casing 10 and does not rotate, the second sun gear 33 having the B number of teeth generates a lowering ratio of the second planetary gear 34b. Further, the first planetary gear 34a that is synchronously rotated and revolved with the second planetary gear 34b is restrained, and the second sun gear 33 fixed to the output shaft 23 via the second planetary gear 34b is driven to drive the output shaft 23 to generate the second The step-down output is used to supply equipment with reduced speed requirements; moreover, the present invention can also obtain the final reduction ratio output according to the following formula:

On the other hand, please refer to FIG. 5 and FIG. 6 together to disclose the configuration details of the second preferred embodiment provided by the present invention. The difference between the structural configuration and the first embodiment described above is that the motor rotor The inner wall of the 210 does not form an inner tooth surface, but the double side wall surfaces of the rotor 210 are respectively formed with an annular portion 211, and the corresponding end sides of the two planetary gear discs 360 are also shaped. The teeth 361 are formed in an annular shape so that the teeth 361 of the two planetary gear discs 360 can engage with the tooth portions 211 of the double side wall surfaces of the rotor 210 so as to facilitate the two planetary gear discs 360 The fixed combination is integrated on both sides of the rotor 210, except that the configuration of the second embodiment is as large as the first embodiment. Wherein, the engagement of the tooth portions 211 and 361 with each other is only a configuration example of the present invention which is less space-consuming, and the other includes the method of screwing or bolting, and the same can be used for two planetary gears. The disk 360 is fixedly coupled to the two sides of the rotor 210. These techniques are all within the scope of application of the present invention and are also known.

According to the configuration details of the second embodiment described above, the two planetary gear discs 360 also follow the rotation when the rotor 210 rotates, so that the power of the rotor 210 can be transmitted to the plurality of first planetary gears 34a via the two planetary gear discs 360. To obtain a single-stage deceleration output to the output shaft 23 to supply the demand of the equipment end. The deceleration effect that can be produced by this design is based on the design of the tooth difference between the two sets of sun gears, which can achieve a higher reduction ratio than the conventional planetary gear set.

In summary, it should be readily understood that the two-stage deceleration output of the present invention includes the first-order and second-order or only single-stage reduction ratio output after the rotation of the motor rotor, which is particularly feasible; Among them, the structural arrangement of the rotor power transmitted to the planetary gear train, the sun gear set and even the output shaft can not only greatly increase the reduction ratio in the effective space, but also contribute to the simplification of the mechanism. The overall configuration space and volume of the motor reducer are more compact, to supply the installation requirements of miniaturized and refined equipment.

However, the above embodiments are merely illustrative of preferred embodiments of the invention, but are not to be construed as limiting the scope of the invention. Therefore, the present invention should be based on the content of the claims defined in the scope of the patent application.

10‧‧‧Chassis

11, 12‧‧‧ cover

13‧‧‧ housing room

14‧‧‧Axis hole

20‧‧‧Motor

21‧‧‧Rotor

22‧‧‧ring hole

23‧‧‧Output shaft

23a‧‧‧Bolt

24‧‧‧ ring magnet

24a, 24b‧‧‧Fixed ring

25‧‧‧ Stator

30‧‧‧ planetary gear train

31‧‧‧Sun Gear Set

32‧‧‧First sun gear

33‧‧‧second sun gear

34‧‧‧ planetary gear set

34a‧‧‧First planetary gear

34b‧‧‧Second planetary gear

34c‧‧‧ planetary gear shaft

35‧‧‧ internal tooth surface

36‧‧‧ planetary gear disc

36a‧‧‧Axis hole

36b‧‧‧Perforation

36c‧‧‧ balls

37‧‧‧ sleeve

38‧‧‧ screws

39‧‧‧Spiral sleeve

Claims (12)

A motor reducer is disposed in a casing used as a fixed end, comprising: a hollow type motor having an inner annular rotor, the rotor providing a hollow annular hole, the center of the annular hole receiving a pivot a driving shaft connected to the casing, a peripheral of the rotor is provided with a plurality of driving elements for driving the rotor to rotate; a planetary gear train is disposed in the annular hole of the rotor and surrounds the periphery of the output shaft, the planetary gear The system includes: a sun gear set having a first sun gear and a second sun gear in a concentric series, the first sun gear being fixed in the casing, the second sun gear being fixed on the output shaft; The planetary gear sets are respectively disposed at equal intervals on the periphery of the sun gear set, and the planetary gear sets respectively have a first planetary gear and a second planetary gear that are coaxially pivoted and arranged in series, and the first planetary gears are engaged a first sun, the second planetary gear meshes with the second sun gear; and an annular internal tooth surface formed on an inner wall of the rotor; wherein the rotor is coupled to the plurality of teeth via the internal tooth surface a planetary gear driving the plurality of first planetary gears to rotate synchronously with the second planetary gears and revolving around the sun gear set to generate a first-order deceleration output, and the plurality of second planetary gears are coupled to each other by a transmission force A second sun gear on the shaft drives the output shaft to generate a second-order deceleration output. The motor reducer of claim 1, wherein the first sun gear and the second sun gear have different numbers of teeth. The motor reducer of claim 1 or 2, wherein the first planetary gear has a different modulus from the second planetary gear. The motor reducer of claim 1, wherein the plurality of driving elements comprise a magnet fixed to an outer wall of the rotor, and a The magnet is peripherally and fixed to the stator within the casing. The motor reducer of claim 1, wherein the two sides of the plurality of planetary gear sets are respectively disposed with a planetary gear disc, the planetary gear disc restraining each of the plurality of planetary gear sets The gear revolves around the sun gear set synchronously with each of the second planet gears. The motor reducer of claim 5, wherein the first planetary gear of the plurality of planetary gear sets is coaxially coupled to the second planetary gear on a planetary gear shaft, the two planetary gear wheels The disk surface provides double-ended equal spacing of the plurality of planet gear shafts. A motor reducer is disposed in a casing used as a fixed end, comprising: a hollow type motor having an inner annular rotor, the rotor providing a hollow annular hole, the center of the annular hole receiving a pivot a driving shaft connected to the casing, a peripheral of the rotor is provided with a plurality of driving elements for driving the rotor to rotate; a planetary gear train is disposed in the annular hole of the rotor and surrounds the periphery of the output shaft, the planetary gear The system includes: a sun gear set having a first sun gear and a second sun gear in a concentric series, the first sun gear being fixed in the casing, the second sun gear being fixed on the output shaft; a planetary gear set having a first planetary gear and a second planetary gear pivotally connected and arranged in series, the first planetary gears meshing with the first sun, and the second planetary gears are engaged with the second sun gear; And two planetary gear discs fixed to both sides of the rotor, and the plurality of planetary gear sets are respectively arranged at equal intervals on the periphery of the sun gear set; wherein the rotor passes through two rows The gear plate drives the plurality of planetary gear sets to rotate synchronously, driving the plurality of first planetary gears to rotate synchronously with the second planetary gears and revolving around the sun gear set to generate a first-order deceleration output, the plurality of second The second gear of the planetary gear is fixed to the output shaft The sun gear drives the output shaft to generate a single-stage deceleration output. The motor reducer of claim 7, wherein the first sun gear and the second sun gear have different numbers of teeth. The motor reducer of claim 7 or 8, wherein the first planetary gear has a different modulus from the second planetary gear. The motor reducer of claim 7, wherein the plurality of drive elements comprise a magnet disposed on an outer wall of the rotor, and a stator disposed on the periphery of the magnet and fixed in the casing. The motor reducer according to claim 7, wherein the double side wall surface of the rotor and the end edges of the two planetary gear discs are alternately formed to form a plurality of tooth portions that are engaged with each other and fixed. The motor reducer of claim 7 or 11, wherein the first planetary gear of the plurality of planetary gear sets is coaxially coupled to the second planetary gear on a planetary gear shaft, the two planets The disk surface of the gear plate provides double-end equal spacing of the plurality of planet gear shafts.