CN214626540U - 48-slot three-phase concentrated winding type permanent magnet motor - Google Patents
48-slot three-phase concentrated winding type permanent magnet motor Download PDFInfo
- Publication number
- CN214626540U CN214626540U CN202120711904.0U CN202120711904U CN214626540U CN 214626540 U CN214626540 U CN 214626540U CN 202120711904 U CN202120711904 U CN 202120711904U CN 214626540 U CN214626540 U CN 214626540U
- Authority
- CN
- China
- Prior art keywords
- winding
- rotor
- permanent magnet
- slot
- phase
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000004804 winding Methods 0.000 title claims abstract description 98
- 238000009826 distribution Methods 0.000 claims abstract description 7
- 238000004080 punching Methods 0.000 claims description 23
- 239000011810 insulating material Substances 0.000 claims description 4
- 230000015572 biosynthetic process Effects 0.000 claims 2
- 238000004519 manufacturing process Methods 0.000 abstract description 6
- 238000005516 engineering process Methods 0.000 abstract description 2
- 230000002349 favourable effect Effects 0.000 abstract description 2
- 230000001174 ascending effect Effects 0.000 abstract 1
- 230000007704 transition Effects 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 239000000696 magnetic material Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910000976 Electrical steel Inorganic materials 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000003475 lamination Methods 0.000 description 2
- 229910001004 magnetic alloy Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000011295 pitch Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Landscapes
- Iron Core Of Rotating Electric Machines (AREA)
- Permanent Magnet Type Synchronous Machine (AREA)
Abstract
The utility model discloses a winding formula permanent-magnet machine is concentrated to 48 grooves three-phase, it includes stator core and rotor, the first-class angle annular of stator core is provided with 8 wire casings that can supply the rule, adjacent two be formed with the wire winding tooth between the wire casing, the rotor with be formed with annular air gap between the stator core, the rotor towards annular air gap 'S the annular evenly is provided with 46 or 50N polarity and S polarity distribution' S magnetic pole in turn on the surface, every around being equipped with the concentrated winding of setting for the number of turns, adjacent eight on the wire winding tooth concentrated winding series each other forms a coil assembly, and conformal one has six coil assembly, relative distribution are in 180 ascending two of side coil assembly becomes single phase winding, conformal one-phase winding. The utility model discloses under the prerequisite of equal overall dimension size, improved the output torque and the output of motor greatly, simplified the wire winding technology, be favorable to improving wire winding efficiency, reduced the cost of manufacture.
Description
[ technical field ] A method for producing a semiconductor device
The utility model belongs to the technical field of permanent-magnet machine, especially, relate to a winding formula permanent-magnet machine is concentrated to 48 groove three-phases.
[ background of the invention ]
In the application fields of mechanical arms, robots, unmanned planes and the like, three-phase permanent magnet motors with high power density and large output torque need to be used, and the output torque and the output power are expected to be as large as possible under the condition of the smallest external dimension as possible.
At present, a 36-slot 42-pole design scheme is commonly used, as shown in fig. 1-2, that is, 36 slots for wire insertion are formed in the circumferential direction of a stator core, two sides of one coil are distributed in two adjacent slots to form a concentrated winding (that is, the number of cross slots is 1, the coil is concentrated and wound on one tooth), 42 magnetic poles are uniformly distributed in the circumferential direction of a motor rotor, and the three-phase coil concentrated winding is wound as shown in fig. 2. Taking a U-phase winding of three-phase windings as an example, the U-phase winding is composed of 12 coils/teeth of #35, #36, #5, #6, #11, #12, #17, #18, #23, #24, #29 and #30, and every two coils are adjacent and divided into 6 groups. After winding 1 group (2 teeth) in winding, a 'tooth crossing' operation is performed to wind the next group of coils across 4 tooth pitches, 5 times of 'tooth crossing' transition operations are performed in the middle, and a plurality of 'tooth crossing transition lines' are distributed on the circumference of the stator.
As shown in fig. 2, the distribution of each phase winding coil over the circumference exhibits: every two adjacent coils are divided into 6 groups; two groups need to be connected by a cross-tooth transition line which spans 4 tooth pitches. The winding structure has the following defects: 1) the continuity of winding operation is poor, the winding machine needs to pause for 5 times and execute 5 times of 'tooth crossing' transition operation in the middle of winding, and when the tooth crossing transition operation is performed, the mechanical action is slow, the operation time is wasted, and the production efficiency is low; 2) the number of turns of the coil which can be embedded is reduced because the tooth crossing transition lines occupy other slot spaces and interfere the winding of the coil, and meanwhile, the adjacent tooth crossing transition lines are crossed and overlapped at the end part of the coil, so that the height of the end part of the coil is raised, the copper amount for the coil is increased (cost is increased) and the phase resistance of the motor is increased, the cost is increased due to the increase of the copper amount for the coil, the loss of the motor is increased due to the increase of the phase resistance of the motor, the efficiency is reduced, the output torque of the motor is reduced, the output power of the motor is reduced, and the like.
Therefore, it is necessary to provide a new 48-slot three-phase concentrated winding type permanent magnet motor to solve the above problems.
[ Utility model ] content
The utility model discloses a main aim at provides a winding formula permanent-magnet machine is concentrated to 48 groove three-phases under the prerequisite of equal overall dimension size, has improved the output torque and the output of motor greatly, has simplified wire winding technology, is favorable to improving wire winding efficiency, has reduced the cost of manufacture.
The utility model discloses a following technical scheme realizes above-mentioned purpose: the utility model provides a 48 winding formula permanent-magnet machine is concentrated to groove three-phase, its includes stator core and rotor, the equidistance annular is provided with 8 wire casings that can supply the rule on the stator core, adjacent two be formed with the winding tooth between the wire casing, the rotor with be formed with annular air gap between the stator core, the rotor towards the annular air gap on the surface the annular evenly be provided with 46 or 50 magnetic poles that N polarity and S polarity distribute in turn, every around being equipped with the concentrated winding of setting for the number of turns on the winding tooth, adjacent eight concentrate the winding and establish ties each other and form a coil group, the conformal one has six the coil group, relative distribution is two in 180 orientation the coil group constitutes single phase winding, the conformal three-phase winding.
Furthermore, two edges of each coil in the concentrated winding are respectively embedded in the wire slots corresponding to two sides of the winding teeth.
Further, the rotor is arranged on the periphery of the stator core to form an outer rotor motor.
Further, the rotor is arranged in the inner ring of the stator core to form an inner rotor motor.
Furthermore, the rotor comprises a rotor punching sheet, and 46 or 50 permanent magnets embedded or attached to the rotor punching sheet, wherein an N/S magnetic pole alternate distribution structure is formed on one side of each permanent magnet facing the annular air gap.
Further, the surface of the wire groove is coated with an insulating material layer.
Further, two coil groups in the same single phase winding are connected in series or in parallel.
Furthermore, a plurality of accommodating grooves are formed in the rotor punching sheet, and the permanent magnets are embedded in the accommodating grooves.
Furthermore, the permanent magnet is composed of two permanent magnet sheets and is embedded in the rotor punching sheet in a V shape; or consists of three rows of permanent magnet sheets, and the permanent magnet sheets are embedded in the rotor punching sheet in a semi-concave arc shape.
Furthermore, the permanent magnets are radially and radially embedded in the rotor punching sheet.
Compared with the prior art, the utility model relates to a winding formula permanent-magnet machine is concentrated to 48 groove three-phases's beneficial effect lies in: the output torque and the output power of the motor can be obviously increased, the winding process of the motor is simple, the cost is low, and the winding efficiency is high; through actual measurement, the cogging torque of the motor is small, the performance of the motor can be obviously improved, and the motor has obvious economic benefit.
[ description of the drawings ]
Fig. 1 is a schematic structural diagram of a 36-slot 42-pole three-phase motor in the prior art;
fig. 2 is a schematic diagram of a winding structure of a 36-slot 42-pole three-phase motor in the prior art;
fig. 3 is a schematic structural diagram of a 48-slot 46 pole in a first embodiment of the present invention;
fig. 4 is a schematic structural diagram of a 48-slot 50 electrode according to a first embodiment of the present invention;
fig. 5 is a schematic view of a winding structure of an external rotor motor according to an embodiment of the present invention;
fig. 6 is a schematic structural view of an inner rotor motor according to an embodiment of the present invention;
fig. 7 is a schematic view of a winding structure of an inner rotor motor according to an embodiment of the present invention;
fig. 8 is a schematic view of a partial structure of a second rotor according to an embodiment of the present invention;
fig. 9 is a second partial schematic structural view of a second rotor according to a second embodiment of the present invention;
fig. 10 is a third schematic view of a partial structure of a second rotor according to the second embodiment of the present invention;
fig. 11 is a fourth schematic view of a partial structure of a second rotor according to an embodiment of the present invention;
fig. 12 is a fifth schematic view of a partial structure of a second rotor according to an embodiment of the present invention;
the figures in the drawings represent:
10048 groove three-phase concentrated winding type permanent magnet motor;
1, a stator core, 11 wire slots and 12 wire winding teeth; 2, a rotor, 21, a rotor punching sheet and 22 permanent magnets; 3, concentrated winding; 4 coil groups.
[ detailed description ] embodiments
The first embodiment is as follows:
referring to fig. 3 to 5, the present embodiment is a 48-slot three-phase concentrated winding type permanent magnet motor 100, which includes a stator core 1 and a rotor 2, wherein 48 slots 11 for wire insertion are annularly disposed on the stator core 1 at equal angles, winding teeth 12 are formed between two adjacent slots 11, an annular air gap is formed between the rotor 2 and the stator core 1, 46 or 50 magnetic poles with N-polarity and S-polarity alternately distributed are annularly and uniformly disposed on a surface of the rotor 2 facing the annular air gap, a set number of turns of concentrated windings 3 are wound on each winding tooth 12, the concentrated windings 3 on eight adjacent winding teeth 12 are connected in series to form one coil group 4, six coil groups 4 are formed in total, and two coil groups 4 relatively distributed in a 180 ° direction form a single phase winding, and form a three-phase winding.
Two edges of each coil in the concentrated winding 3 are respectively embedded in the wire slots 11 on two sides of the corresponding winding teeth 12, the number of the cross slots of the concentrated winding 3 is 1, and the coils are intensively wound on one winding tooth 12.
Referring to fig. 5, taking the U phase of the three-phase winding as an example, the U-phase winding is composed of only two coil groups, each group of 8 coils is closely adjacent, i.e. 17# -24 #, # 41- #48, only 1 tooth-crossing action needs to be performed in the middle, thereby greatly reducing the time extension caused by the tooth-crossing operation, improving the production efficiency of the winding, reducing the interference of the less tooth-crossing transition lines on the windings in other slots, reducing the cross overlapping parts of the coil ends, leading the arrangement of the wires in the slots to be more beautiful and obtaining higher slot filling rate.
Meanwhile, due to the increase of the number of the slots and the number of the magnetic poles, compared with a 36-slot scheme, the tooth width of the stator punching sheet in the 48-slot scheme is reduced, so that the height of the end coil of the 48 slots is reduced compared with that of the 36-slot scheme; the reduction of the height of the end coil brings the reduction of the axial size of the motor; and the copper loss at the end part of the motor is reduced, the output power of the motor is increased, and the efficiency is improved.
In this embodiment, the rotor 2 is disposed on the outer periphery of the stator core 1, and constitutes an outer rotor motor. The outermost circle of the outer rotor motor is a rotor punching sheet 21, which is made of a material with good magnetic conductivity (such as #8 steel, #10 steel, silicon steel sheet, soft magnetic alloy and the like) and is used for providing a circulation loop of a permanent magnet magnetic field. The inner wall of the rotor punching sheet 21 is next to 46 or 50 permanent magnets 22 which are uniformly distributed, the size, the dimension and the material grade of the permanent magnets are completely the same, and the magnetic pole directions are uniformly distributed at N/S intervals. The permanent magnet 22 is adhered to the surface of the inner ring of the rotor punching sheet 21 through glue and is solidified with the rotor punching sheet 21 to form a magnetic steel body, namely the rotor 2, and the magnetic steel body rotates around the central axis. An air layer (called as air gap) is arranged between the inner ring of the magnetic steel body and the periphery of the stator core 1, the stator core 1 is made of materials with good magnetic conductivity (such as silicon steel sheets, soft magnetic alloy and the like), and a mode of laminating sheets is usually adopted to reduce eddy current loss. The stator core 1 is provided with 48 slots 11 at uniform intervals in the circumferential direction to form a structure in which 48 slots are spaced apart, and after the surfaces of all the slots 11 are covered with an insulating material (slot insulation), each tooth is wound with a coil as shown in fig. 5. 2 sides of the coil span in the adjacent wire slots 11 (two sides of the coil are intensively wound on 1 winding tooth 12, which is called as 'concentrated winding'), 48 coils are divided into 3 groups of phase windings according to the diagram shown in fig. 5, each phase winding is composed of 16 concentrated windings 3 in total of 2 groups of coil groups 4, 8 concentrated windings 3 in each group of coil groups 4 are connected in series, and 2 groups of coil groups 4 can be connected in series or in parallel. The 3 phase windings can be connected into a star connection method or a triangle connection method according to the connection mode, and finally the U, V, W phase winding connector lug of the three-phase motor is led out and obtained.
In the embodiment of the external rotor motor, the external diameter of the motor rotor is 110mm, the lamination thickness of the stator punching sheet is 20mm, the 48-slot three-phase concentrated winding type permanent magnet motor 100 and a traditional 36-slot prototype are manufactured in a trial mode respectively, the used magnetic material marks are the same, the motor driving conditions are completely the same, the coils in the motor slots are fully wound as much as possible, and the no-load rotating speeds of the motors are guaranteed to be equal. Through prototype testing and comparison, the 48-slot design scheme has the following significant advantages compared with the 36-slot design scheme:
1) under the same motor rotating speed, the output power and the output torque of the motor are increased by 15 to 20 percent in the same ratio;
2) the highest efficiency of the motor is improved by 8%;
3) the resistance of the motor wire is reduced by 10%;
4) the cogging torque is reduced to 15 percent of the original torque;
5) the height of the coil end is reduced by 30%;
6) the axial size of the motor is reduced by 3 mm;
7) the stator winding manufacturability is improved, the winding arrangement is beautiful, and the production efficiency is high.
The 48-slot three-phase concentrated winding type permanent magnet motor 100 has the advantages that: the output torque and the output power of the motor can be obviously increased, the winding process of the motor is simple, the cost is low, and the winding efficiency is high; through actual measurement, the cogging torque of the motor is small, the performance of the motor can be obviously improved, and the motor has obvious economic benefit.
Example two:
referring to fig. 6 to 12, the structure principle of the present embodiment is the same as that of the first embodiment, and the difference is: the rotor 2 is arranged in the inner ring of the stator core 1 to form an inner rotor motor.
The inner rotor motor integrally moves the stator to the outermost side and the rotor to the inside of the motor. The outermost side is a motor stator core 1, which is made of laminated sheet soft magnetic materials like the outer rotor, and is uniformly provided with 48 wire grooves 11 in the inner circumferential direction to form a structure with 48 tooth spaces alternating, and the openings of the wire grooves 11 are arranged on the inner circumferential surface of the stator core 1. Also after the surface of the wire groove 11 is covered with an insulating material (groove insulation), each winding tooth 12 is coil-wound as shown in fig. 7, and the coil is arranged and connected in a manner similar to the outer rotor solution (abbreviated here). Between the inner surface of the stator core 1 and the outer surface of the rotor 2, an air layer (referred to as an air gap) is spaced, and similarly, the magnetic steel body is also composed of a rotor punching sheet 21 (soft magnetic material) and permanent magnets 22, but the rotor structure may have various forms according to the arrangement mode of the permanent magnets 22, for example, but not limited to, the following: as shown in fig. 8, the permanent magnets 22 are uniformly arranged on the outer peripheral surface of the rotor sheet 21, and thus are called a "surface-mount" rotor structure; the permanent magnet 22 in fig. 9 is a rectangular block structure embedded in the rotor punching sheet 21; in fig. 10, the permanent magnet 22 is composed of 2 rectangular permanent magnets and is embedded into the rotor punching sheet 21 in a V shape; in fig. 11, the permanent magnet 22 is embedded in the rotor punching sheet 21 from 3 rectangular permanent magnets; in fig. 12, permanent magnets 22 are radially embedded in rotor lamination 21. Whatever the configuration of the rotor structure, it is required that 46 or 50 magnetic poles with alternate N/S magnetic field polarities are formed on the circumferential surface of the rotor on the side facing the air gap.
What has been described above are only some embodiments of the invention. For those skilled in the art, without departing from the inventive concept, several modifications and improvements can be made, which are within the scope of the invention.
Claims (10)
1. The utility model provides a winding formula permanent-magnet machine is concentrated to 48 groove three-phases which includes stator core and rotor, its characterized in that: stator core is the equidistance annular be provided with 8 wire casings that can supply the rule, adjacent two be formed with the winding tooth between the wire casing, the rotor with be formed with annular air gap between the stator core, the rotor faces annular air gap' S the surperficial annular evenly is provided with 46 or 50 magnetic poles that N polarity and S polarity distribute in turn, every around being equipped with the concentrated winding of setting for the number of turns on the winding tooth, adjacent eight concentrated winding is established ties each other and is formed a coil assembly, and the conformal formation has six coil assembly, relative distribution is two in 180 orientation the coil assembly forms single looks winding, and the conformal formation three-phase winding.
2. A 48-slot three-phase concentrated winding permanent magnet machine according to claim 1, wherein: two edges of each coil in the concentrated winding are respectively embedded in the wire grooves corresponding to two sides of the winding teeth.
3. A 48-slot three-phase concentrated winding permanent magnet machine according to claim 1, wherein: the rotor is arranged on the periphery of the stator core to form an outer rotor motor.
4. A 48-slot three-phase concentrated winding permanent magnet machine according to claim 1, wherein: the rotor is arranged in the inner ring of the stator core to form an inner rotor motor.
5. A48-slot three-phase concentrated winding permanent magnet machine according to claim 3 or 4, characterized in that: the rotor comprises a rotor punching sheet and 46 or 50 permanent magnets embedded or attached to the rotor punching sheet, and an N/S magnetic pole alternate distribution structure is formed on one side, facing the annular air gap, of each permanent magnet.
6. A 48-slot three-phase concentrated winding permanent magnet machine according to claim 1, wherein: the surface of the wire groove is coated with an insulating material layer.
7. A 48-slot three-phase concentrated winding permanent magnet machine according to claim 1, wherein: two coil groups in the same single phase winding are connected in series or in parallel.
8. A48-slot three-phase concentrated winding permanent magnet machine according to claim 5, characterized in that: the rotor punching sheet is internally provided with a plurality of accommodating grooves, and the permanent magnets are embedded in the accommodating grooves.
9. A 48-slot three-phase concentrated winding permanent magnet machine according to claim 8, wherein: the permanent magnet consists of two permanent magnet sheets and is embedded in the rotor punching sheet in a V shape; or consists of three rows of permanent magnet sheets, and the permanent magnet sheets are embedded in the rotor punching sheet in a semi-concave arc shape.
10. A 48-slot three-phase concentrated winding permanent magnet machine according to claim 8, wherein: the permanent magnets are radially and radially embedded in the rotor punching sheet.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202120711904.0U CN214626540U (en) | 2021-04-08 | 2021-04-08 | 48-slot three-phase concentrated winding type permanent magnet motor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202120711904.0U CN214626540U (en) | 2021-04-08 | 2021-04-08 | 48-slot three-phase concentrated winding type permanent magnet motor |
Publications (1)
Publication Number | Publication Date |
---|---|
CN214626540U true CN214626540U (en) | 2021-11-05 |
Family
ID=78400543
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202120711904.0U Active CN214626540U (en) | 2021-04-08 | 2021-04-08 | 48-slot three-phase concentrated winding type permanent magnet motor |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN214626540U (en) |
-
2021
- 2021-04-08 CN CN202120711904.0U patent/CN214626540U/en active Active
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2190103B1 (en) | Axial gap type coreless rotating machine | |
US20220094228A1 (en) | Axial flux electrical machine | |
WO2011017839A1 (en) | Broad-pole type square-wave three-phase brushless permanent magnet direct current motor and assembling method thereof | |
WO2013100803A1 (en) | Electromagnetic generator | |
CN111404290A (en) | Concentrated winding transverse flux permanent magnet synchronous motor | |
CN202085046U (en) | Axial magnetic field permanent magnetic brushless motor for smooth torque output | |
CN105391268A (en) | Cylinder-shaped primary permanent magnet type transverse flux linear motor | |
CN114726180A (en) | Wide-narrow stator pole axial flux switch reluctance motor and control method thereof | |
CN112968539A (en) | 48-slot three-phase concentrated winding type permanent magnet motor | |
JP5995883B2 (en) | Rotating electric machine stator | |
CN111211659B (en) | Stator modular annular winding dual-rotor permanent magnet motor | |
CN110492708B (en) | Laminated vernier motor | |
CN214626540U (en) | 48-slot three-phase concentrated winding type permanent magnet motor | |
CA3128290A1 (en) | Axial flux electrical machine | |
CN111817521A (en) | Axial magnetic field double-rotor AC motor | |
CN108390537A (en) | Non-overlapping winding bilateral exchange linear motor | |
CN103904796B (en) | Disc type electric machine | |
CN211429017U (en) | Stator core of motor | |
CN106936233B (en) | Stator module and external rotor motor | |
WO2022199144A1 (en) | Five-phase motors for servo systems | |
CN209402384U (en) | 10 pole three-phase permanent magnetic brushless motor of electric vehicle and 18 slot | |
CN209267289U (en) | A kind of brushed DC motor | |
CN209608411U (en) | A kind of stator module and big torque disc type electric machine for disc type electric machine | |
US20120025653A1 (en) | Aggregate magnetization skew in a permanent magnet assembly | |
CN110138112A (en) | motor for improving stability of cogging torque |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
GR01 | Patent grant | ||
GR01 | Patent grant | ||
TR01 | Transfer of patent right |
Effective date of registration: 20240712 Address after: No. 331, Affinity Road, Zhangpu Town, Kunshan City, Suzhou City, Jiangsu Province, 215300 Patentee after: Yiyuan Drive (Suzhou) Technology Co.,Ltd. Country or region after: China Address before: 3 / F, building C, 405 Jiande Road, Zhangpu Town, Kunshan City, Suzhou City, Jiangsu Province 215000 Patentee before: SUZHOU BONIU ELECTRIC Co.,Ltd. Country or region before: China |
|
TR01 | Transfer of patent right |