CN115102352A

CN115102352A - Micro-specific limited angle torque motor

Info

Publication number: CN115102352A
Application number: CN202210604174.3A
Authority: CN
Inventors: 申志刚; 张永辉; 程明科; 龙军
Original assignee: Shaanxi Chaolun Electromechanical Technology Co ltd
Current assignee: Shaanxi Chaolun Electromechanical Technology Co ltd
Priority date: 2022-05-30
Filing date: 2022-05-30
Publication date: 2022-09-23

Abstract

The invention provides a micro-specific limited-angle torque motor which is used for solving the technical problems of low torque density and large torque fluctuation of the existing motor. The motor comprises a stator and a rotor, wherein the rotor coaxially penetrates through the inside of the stator; the stator comprises an iron core and a winding, the iron core comprises an iron core body and tooth poles, the tooth poles are uniformly and fixedly connected with the inner circle of the iron core body along the radial direction of the iron core body, a stator slot is formed between every two adjacent tooth poles, and the winding is wound on the tooth poles; the windings are distributed in the stator slots according to a certain rule; the rotor comprises magnetic poles and a rotating shaft, the magnetic poles are fixedly connected with the rotating shaft, and the number of the magnetic poles is equal to that of the stator slots. The output torque of the micro specific limited angle torque motor is far higher than that of the traditional limited angle torque motor, the output torque characteristic is excellent, the rotor inertia is small, and the requirement of a high-precision motor is met.

Description

Micro-specific limited angle torque motor

Technical Field

The invention relates to the field of small and special motors, in particular to a limited-angle torque motor.

Background

With the development of permanent magnet materials and power electronic driving devices, permanent magnet type limited-angle torque motors gradually become hot points of research of people, and particularly in the fields of aerospace and the like with extremely strict requirements on the size, weight, reliability and the like of the motors, the permanent magnet type limited-angle torque motors are more prominent.

Nowadays, the limited-angle torque motor products at home and abroad are mainly divided into a tooth-slot-free limited-angle torque motor and a tooth-slot-type limited-angle torque motor, wherein the tooth-slot-free limited-angle torque motor accounts for most of the products, and the products are widely applied to position following systems. Compared with a tooth groove type structure, the tooth groove-free limited corner torque motor has the advantages that the equivalent air gap is larger, the magnetic load is relatively lower, and the tooth groove effect does not exist, so that excellent torque characteristics can be obtained, and a relatively larger operation interval is provided; but also has the fatal defect of low moment density, so that the motor is difficult to be applied to occasions with strict requirements on volume and weight. The tooth-slot type limited-rotation-angle torque motor has higher torque density, but also has the problems that the torque characteristic caused by magnetic circuit saturation is nonlinear, the torque fluctuation in the operation range caused by the tooth-slot effect is large, and the motor works unstably.

Disclosure of Invention

The invention provides a micro specific limited angle torque motor for solving the technical problems of low torque density and large torque fluctuation of the existing limited angle torque motor.

The micro specific limited angle torque motor is characterized by comprising a stator and a rotor, wherein the rotor coaxially penetrates through the inside of the stator; the stator comprises an iron core and a winding; the iron core comprises an iron core body and tooth poles, and the tooth poles are uniformly and fixedly connected with the inner circle of the iron core body along the radial direction of the iron core body; the winding is wound on the gear pole; stator slots are formed between every two adjacent tooth poles, wherein the windings are distributed in the stator slots according to a certain rule; the rotor comprises magnetic poles and a rotating shaft, the magnetic poles are fixedly connected with the rotating shaft, and the number of the magnetic poles is equal to that of the stator slots.

Further, the motor is a concentrated winding limited angle torque motor with a 2-pole and 2-slot structure.

Further, the motor further comprises a shell, a first end cover and a second end cover; the stator is coaxially and fixedly connected with the shell; one end of the rotor is connected with the first end cover, and the other end of the rotor is connected with the second end cover; the first end cover and the second end cover are respectively fixedly connected with two ends of the shell; one end of the rotor is provided with a positioning ring, the positioning ring is coaxially sleeved with the rotor, and the positioning ring is clamped with the first end cover.

Further, the rotor further comprises a first end ring and a second end ring; the first end ring is fixedly connected with one end of the magnetic pole, and the second end ring is fixedly connected with the other end of the magnetic pole; the positioning ring is movably connected with the first end ring.

Furthermore, a positioning lug is arranged on the positioning ring, a positioning table is arranged on the first end cover, and a positioning groove is arranged on the positioning table; the positioning lug is clamped with the positioning groove.

Furthermore, a first positioning hole is formed in the machine shell, and a second positioning hole is also formed in the first end cover; the first positioning hole and the second positioning hole are coaxial and are far away from the central axis of the rotor.

Furthermore, two mutually symmetrical limiting tables are axially arranged on the inner side of the iron core body, and the limiting tables are perpendicular to the central line of the tooth pole.

Furthermore, a first process groove is formed in the limiting table and used for positioning the limiting table and the iron core body.

Furthermore, a second process groove is axially formed in one end, far away from the iron core body, of the tooth pole, and the second process groove is used for positioning the connection between the tooth pole and the iron core body.

Further, the tines are pointed tines.

Compared with the prior art, the invention has the following beneficial effects:

the micro-specific limited angle torque motor does not need a chute to additionally reduce tooth spaces, reduces the influence of torque fluctuation, and improves the full rate of the slot and the electric load of the motor; meanwhile, the output torque of the micro specific limited angle torque motor is far higher than that of the traditional limited angle torque motor, the output torque characteristic is excellent, the rotor inertia is small, and the requirement of a high-precision motor is met.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of a micro-characteristic limited angle motor according to the present invention;

FIG. 2 is a schematic diagram of a winding coil connection of an embodiment of a micro characteristic limited angle motor of the present invention;

FIG. 3 is a schematic diagram of a stator structure of an embodiment of a micro specific limited angle motor according to the present invention;

FIG. 4 is a schematic view of the structure in the direction A of FIG. 3;

FIG. 5 is a schematic diagram of a second end cap of an embodiment of a micro special limited angle motor according to the present invention;

FIG. 6 is a schematic view of the structure in the direction B in FIG. 5;

FIG. 7 is a schematic view of a rotor structure of a micro characteristic limited angle motor according to an embodiment of the present invention;

FIG. 8 is a schematic view of the structure in the direction C of FIG. 7;

FIG. 9 is a cross-sectional view of the structure taken along line D-D of FIG. 7;

FIG. 10 is a schematic view of a first end cap of an embodiment of a micro unique limited angle motor according to the present invention;

FIG. 11 is a schematic view of the structure in the direction E of FIG. 10;

fig. 12 is a schematic view of a housing structure of an embodiment of a micro specific limited angle motor of the present invention;

fig. 13 is a schematic structural diagram of an iron core body of an embodiment of a micro characteristic limited angle motor according to the present invention;

FIG. 14 is a schematic view of the structure in the direction F in FIG. 13;

fig. 15 is a schematic structural diagram of a tooth pole of a micro characteristic limited angle motor according to an embodiment of the present invention.

The reference numbers are as follows:

1-motor, 2-stator, 21-iron core, 22-winding, 24-tooth pole, 241-second process groove, 25-iron core body, 251-limiting table, 2511-first process groove, 3-rotor, 31-rotating shaft, 32-magnetic pole, 33-positioning ring, 331-positioning lug, 34-first end ring, 35-second end ring, 4-machine shell, 41-first positioning hole, 5-first end cover, 51-positioning table, 511-positioning groove, 52-second positioning hole, 6-second end cover and 61-wire outlet hole.

Detailed Description

To make the objects, advantages and features of the present invention more apparent, a micro characteristic limited angle torque motor of the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments, wherein the drawings are in simplified form and are not to precise scale, so as to facilitate and clearly illustrate the objects of the present embodiment.

As shown in fig. 1 to 15, a micro characteristic limited angle torque motor 1 of the present invention includes: the stator 2 and the rotor 3, the rotor 3 coaxially penetrates through the stator 2; the stator 2 includes a core 21 and a winding 22; the iron core 21 comprises an iron core body 25 and a tooth pole 24, wherein the tooth pole 24 is uniformly and fixedly connected with the inner circle of the iron core body 25 along the radial direction of the iron core body 25; the winding 22 is wound on the gear pole 24; stator slots 23 are formed between two adjacent tooth poles 24, wherein the windings 22 are distributed in the stator slots 23 according to a certain rule; the rotor 3 comprises magnetic poles 32 and a rotating shaft 31, the magnetic poles 32 are fixedly connected with the rotating shaft 31, and the number of the magnetic poles 32 is equal to that of the stator slots 23.

Specifically, as shown in fig. 1, due to the limitation of the structure of the motor 1 of the present invention, the outer diameter of the motor casing 4 is not greater than 22mm, and a commercially available adhesive, such as DG-3S glue, can be used to adhere the stator 2 to the inner wall of the casing 3 through a special tool, so as to ensure that the stator 2 is assembled with the casing 4 without deformation. The rotor 3 is coaxial with the stator 2, and the distance between the rotor and the stator 2 is an air gap, when the stator 2 is electrified, air gap magnetic flux is generated between the stator 2 and the rotor 3. The stator 2 can adopt a tooth-slot type structure, is similar to a traditional permanent magnet brushless direct current motor, and has smaller air gap and higher air gap flux density, so the torque density of the tooth-slot type limited-rotation-angle torque motor is generally higher than that of a tooth-slot type limited-rotation-angle torque motor; the motor stator 2 and the rotor 3 are cylindrical structures, the rotor 2 is generally a surface-mounted structure, and can also adopt a built-in structure, and the winding 22 is in a single-phase, single-layer or distributed winding form. The winding 22 of the present embodiment is a single-phase, double-layer, concentrated winding, the pitch of the winding 22 is an integer, and the coils of the winding 22 are connected in series.

As shown in fig. 3 and 4, in order to improve the torque density of the motor 1, the winding 22 needs to be provided with more wires as much as possible to improve the slot fullness, a conventional iron core is adopted, and the stator 2 with high slot fullness cannot be realized in the process, in the invention, the winding 22 is firstly nested on the tooth pole 24, and the tooth pole 24 can be provided with an installation slot on the premise of ensuring the rigidity of the iron core body 25, the shape of the installation slot is not limited, the shape of the connection end of the tooth pole 24 and the iron core body 25 is matched with that of the installation slot, or the iron core body 25 is cylindrical, the iron core body 25 is arc-shaped, the connection end of the tooth pole 24 and the iron core body 25 is also arc-shaped, and then the tooth pole 24 and the iron core body 25 are fixedly connected in a bonding or clamping manner.

As a preferable scheme, due to the limitation of the volume of the motor, the embodiment preferentially adopts a bonding mode to fixedly connect the tooth pole 24 and the iron core body 25, and this mode solves the problem that the micro-special torque motor cannot achieve the process assembly with the requirement of high slot filling rate.

As shown in fig. 1 and 2, U + and U-are motor lead-out wires, i and ii are motor stator coils, a is a coil head, and b is a coil tail; when the red outgoing line is connected with the positive electrode of the power supply, and the black outgoing line is connected with the negative electrode of the power supply, the rotating shaft 31 of the motor 1 rotates clockwise from the zero position to the constant torque angle of the motor 1, the power supply is generally supplied by an inverter with 12V, 24V or 36V, and the matching can be performed according to the actual requirements, for example, the aerospace power supply is 28V, which is not limited in this embodiment. Meanwhile, the direction of the current of the winding opposite to each permanent magnetic pole face is the same, and when the winding 22 of the stator 2 is electrified with the current in a certain direction, the rotor 3 can rotate to a certain side under the action of ampere force; when the current direction changes, the rotation direction of the rotor 3 also changes correspondingly; when the power supply is cut off, the rotor 3 is restored to the initial position after being subjected to the reluctance torque.

In a conventional tooth-groove type limited-angle torque motor, due to the action of tooth-groove torque, torque fluctuation still exists in electromagnetic torque in a constant torque interval, the amplitude of the tooth-groove torque is generally reduced by increasing the number of stator grooves 23, and then the torque fluctuation is reduced, wherein the number of the grooves of the stator grooves 23 is generally an integral multiple of the number of poles of magnetic poles of the rotor 3 which is greater than or equal to 2. In addition, the number of poles of the rotor 3 is not excessive, because the constant torque section of the motor 1 is also reduced along with the increase of the number of poles, and in order to reduce the influence of the cogging torque on the constant torque section of the limited-angle torque motor, the embodiment preferentially adopts a micro-special concentrated winding limited-angle torque motor, the number of poles of the rotor 3 is equal to the number of slots of the stator 2, namely 2 poles and 2 slots, and also 4 poles and 4 slots, and the like, and the winding type is different from the conventional tooth slot type structure, and can be a single-phase or double-layer concentrated winding, and because of adopting the double-layer winding, the stator slot 23 can be provided with more conducting wires, so that the electric load of the motor 1 is far higher than that of the limited-angle motor in the prior art, the torque of the motor 1 is improved, and the constant-angle range is large, and the torque can reach 50Nm at most.

In addition, because the number of poles is equal to the number of slots, only one cogging torque period exists in one electromagnetic torque period, and the constant torque interval of the limited-angle torque motor is located at a position with a small cogging torque value, so that the cogging torque amplitude basically has no influence on the constant torque interval. Compared with the conventional tooth slot type structure, the concentrated winding limited corner torque motor has higher power density under the condition that the volume of the motor 1 is the same because the number of slots is relatively less, the utilization rate of the slot area is higher, and the winding coefficient is higher than that of the distributed winding. Meanwhile, the concentrated winding is adopted, so that the winding is convenient to coil, and the end part length of the concentrated winding is smaller than that of the distributed winding, thereby effectively reducing the utilization rate of copper and further reducing the copper consumption of the winding 22.

The micro-specific limited-angle torque motor has the advantages that tooth grooves are not required to be additionally reduced by the aid of the inclined grooves, the influence of torque fluctuation is reduced, the full rate of the grooves and the electric load of the motor are improved, the output torque of the limited-angle torque motor is far higher than that of a traditional limited-angle torque motor, the output torque characteristic is excellent, the inertia of a rotor is small, and the requirement of a high-precision motor is met.

In the present embodiment, as shown in fig. 1, fig. 2, fig. 3, fig. 4, and fig. 9, the motor 1 is a concentrated winding limited angle torque motor with a 2-pole and 2-slot structure.

Specifically, the pole-slot coordination of the motor 1 of the present embodiment is 2 poles and 2 slots, the winding type is different from the conventional tooth-slot structure, and is a single-phase, double-layer, concentrated winding, and the rotor structure is identical to the conventional tooth-slot structure. The constant rotation angle interval is 30-35 degrees, the torque fluctuation is small in the constant rotation angle range, the motor 1 is small in number of grooves, the utilization rate of the groove area is large, meanwhile, the concentrated winding coefficient is higher than that of distributed windings, the power density is high, the utilization rate of copper can be effectively reduced, and therefore copper consumption of the windings is reduced.

In this embodiment, as shown in fig. 1, 5, 6 and 7, the motor further includes a housing 4, a first end cover 5 and a second end cover 6; the stator 2 is coaxially and fixedly connected with the shell 4; one end of the rotor 3 is connected with the first end cover 5, and the other end of the rotor is connected with the second end cover 6; the first end cover 5 and the second end cover 6 are respectively fixedly connected with two ends of the shell 4; one end of the rotor 3 is provided with a positioning ring 33, the positioning ring 33 is coaxially sleeved with the rotor 3, and the positioning ring 33 is clamped with the first end cover 5.

Specifically, to facilitate assembly of the motor 1, one end of the rotor 3 is provided with a positioning ring 33, and the positioning ring 33 is in clearance fit with the rotor 3, is clamped with the first end cover 4, and can rotate circumferentially so as to adjust a relative position with the first end cover 4, ensure an assembly position of the rotor 3 and the first end cover 4, and further improve torque angle accuracy of the motor 1 of the present invention. The rotor 3 is installed with the first end cover 5 and the second end cover 6 through the bearing housing under pressure, so that the positions of the first end cover 5, the second end cover 6 and the bearing housing are not changed when the rotor rotates, and meanwhile, the first end cover 5, the second end cover 6 and the machine shell 4 are connected through bolts or bonding modes according to the structure and the application occasions of the motor 1.

In order to connect a power supply with the motor 1, the second end cover 6 is further provided with a wire outlet hole 61, the wire outlet hole 61 is used for leading the motor 1 to be led out, and the lead wire can be provided with a wiring port, so that the reliability of power supply connection is improved.

In the present embodiment, as shown in fig. 7, the rotor 3 further includes a first end ring 34 and a second end ring 35; the first end ring 34 is fixedly connected with one end of the magnetic pole 32, the second end ring 35 is fixedly connected with the other end of the magnetic pole 32, and the positioning ring 33 is movably connected with the first end ring 34.

Specifically, the rotor 3 further includes a first end ring 34 and a second end ring 35, the first end ring 34 and the magnetic pole 32 can be fixedly connected through bonding, the bonding agent adopts fixing glue commonly used for motors, the positioning ring 33 is in clearance fit with the first end ring 34, the degree of unbalance of the rotor 3 is reduced, and torque fluctuation of the motor is reduced.

In this embodiment, as shown in fig. 7, 8, 10 and 11, the positioning ring 33 is provided with a positioning protrusion 331, the first end cap 5 is provided with a positioning table 51, and the positioning table 51 is provided with a positioning groove 511; the positioning protrusion 331 is engaged with the positioning slot 511.

Specifically, in order to ensure the positions of the rotor 3 and the first end cover 5, the positioning lug 331 is arranged on the positioning ring 33, the positioning table 51 is arranged on the first end cover 5, the positioning lug 331 is preferably provided with a sector opening, the angle of the positioning lug 331 is determined according to the constant torque angle range of the motor 1, and the angle difference between the angle of the positioning groove 511 on the positioning table 51 and the angle of the positioning lug 331 is a constant torque angle, so that the torque output range of the motor is ensured, and the working reliability of the motor is improved.

In this embodiment, as shown in fig. 10, 11 and 12, the casing 4 is provided with a first positioning hole 41, and the first end cover 5 is further provided with a second positioning hole 52; the first positioning hole 51 and the second positioning hole 52 are coaxial and distant from the central axis of the rotor 3.

Specifically, in order to facilitate assembly of the motor 1, the housing 4 is provided with a first positioning hole 41, the first end cover 5 is provided with a second positioning hole 52, the first positioning hole 41 is disposed on an outer circle of the housing 4, the second positioning hole 52 is disposed on an inner circle of the first end cover 5, the first positioning hole 41 and the second positioning hole 52 have the same size and shape, and may be circular holes or semicircular holes, and are concentrically aligned, and in consideration of the processing technology, the semicircular holes are preferred in this embodiment. When the housing 4 is assembled with the first end cover 5, the first positioning hole 41 and the second positioning hole 52 can be used as marks of relative positions and as starting positions of torque angles, so that the accuracy of assembling the motor 1 is ensured.

In this embodiment, as shown in fig. 13 and 14, two mutually symmetrical limiting tables 251 are axially disposed inside the core body 25, and the limiting tables 251 are perpendicular to the center line of the tooth pole 24.

Specifically, the inner side of the iron core body 25 is further provided with symmetrically arranged limit tables 251 along the axial direction, the pair of limit tables 251 are symmetrically arranged with the center line of the tooth pole 24, and the limit tables 251 are integrally connected with the iron core body 25. After the stator 2 is electrified, the torque fluctuation of the motor 1 can be effectively reduced because the magnetic flux density of the tooth pole 24 is different from that of the limit table 251. Rectangular groove or trapezoidal groove that can set up on the iron core body 25 and be used for the positioning, for the reliability that improves tooth pole 24 and iron core body 25 joint, preferred trapezoidal groove. Compared with the welding method, the structure adopted by the embodiment avoids the deformation of the tooth pole 24 and the iron core body 25.

In this embodiment, as shown in fig. 14, a first process groove 2511 is provided on the limit table 251, and the first process groove 2511 is used for positioning the connection between the limit table 251 and the iron core body 25.

Specifically, the first process groove 2511 is formed in the limiting table 251, the first process groove 2511 is used for positioning the connection between the limiting table 251 and the iron core body 25, the shape of the first process groove 2511 is not limited, and the first process groove 2511 and the center of a rectangular groove or a trapezoidal groove which can be arranged on the iron core body 25 for assembly positioning need to be on the same plane, so that the assembly accuracy and reliability of the tooth pole 24 and the iron core body 25 are improved.

In this embodiment, as shown in fig. 15, a second process groove 241 is axially disposed at an end of the tooth pole 24 away from the core body 25, and the second process groove 241 is used for positioning the connection between the tooth pole 24 and the core body 25.

Specifically, a second process groove 241 is axially formed in one end of the tooth pole 24 away from the core body 25 to position the connection between the tooth pole 24 and the core body 25, and the shape of the second process groove 241 is not limited, but needs to be on the same plane as the center of a rectangular groove or a trapezoidal groove that can be formed in the core body 25 for assembly positioning, so as to improve assembly accuracy and reliability.

In this embodiment, the tooth pole 24 is a pointed tooth tip, as shown in FIG. 15.

Specifically, since the notch of the micro-specific limited angle torque motor is not too large, when the motor 1 is a conventional parallel tooth tip, a large part of the armature flux linkage passes through the stator yoke, the middle part of the stator tooth, and the tooth tip part, and is then closed through the notch. When the armature current is large, the nonlinearity of the core material can cause the tooth tip part to be seriously saturated, thereby causing the moment characteristic of the limited-rotation-angle torque motor to be poor. The equivalent slot opening width of the sharp-angled tooth point is larger than that of the parallel tooth point, so that the equivalent magnetic resistance at the slot opening is increased, and the purpose of reducing the magnetic flux leakage near the slot opening is achieved. The shape of the tooth pole with the sharp-angle tooth tip can enable the armature flux linkage to pass through the main magnetic circuit more, so that the saturation of the magnetic circuit of the tooth part is reduced.

It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.

While alternative embodiments of the present invention have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including alternative embodiments and all such alterations and modifications as fall within the true scope of the embodiments of the invention.

While the technical solutions provided by the present invention have been described in detail, the principles and embodiments of the present invention are described herein by using specific examples, and meanwhile, for a person skilled in the art, according to the principles and implementation manners of the present invention, the specific embodiments and application scope may be changed, and in conclusion, the content of the present description should not be construed as limiting the present invention.

Claims

1. A micro specific limited angle torque motor is characterized in that the motor comprises a stator (2) and a rotor (3), wherein the rotor (3) coaxially penetrates through the stator (2);

the stator (2) comprises an iron core (21) and a winding (22); the iron core (21) comprises an iron core body (25) and tooth poles (24), wherein the tooth poles (24) are uniformly and fixedly connected with the inner circle of the iron core body (25) along the radial direction of the iron core body (25); the winding (22) is wound on the tooth pole (24); stator slots (23) are formed between two adjacent tooth poles (24), wherein the windings (22) are distributed in the stator slots (23) according to a certain rule;

the rotor (3) comprises magnetic poles (32) and a rotating shaft (31), the magnetic poles (32) are fixedly connected with the rotating shaft (31), and the number of the magnetic poles (32) is equal to that of the stator slots (23).

2. A micro characteristic limited angle torque motor according to claim 1, wherein: the motor is a concentrated winding limited angle torque motor with a 2-pole and 2-slot structure.

3. A micro characteristic limited angle torque motor according to claim 1, wherein: the motor also comprises a shell (4), a first end cover (5) and a second end cover (6);

the stator (2) is coaxially and fixedly connected with the shell (4);

one end of the rotor (3) is connected with the first end cover (5), and the other end of the rotor is connected with the second end cover (6);

the first end cover (5) and the second end cover (6) are respectively fixedly connected with two ends of the shell (4);

one end of the rotor (3) is provided with a positioning ring (33), the positioning ring (33) is coaxially sleeved with the rotor (3), and the positioning ring (33) is connected with the first end cover (5) in a clamping mode.

4. A micro characteristic limited angle torque motor according to claim 1, wherein: the rotor (3) further comprises a first end ring (34) and a second end ring (35);

the first end ring (34) is fixedly connected with one end of the magnetic pole (32), and the second end ring (35) is fixedly connected with the other end of the magnetic pole (32);

the positioning ring (33) is movably connected with the first end ring (34).

5. A micro characteristic limited angle torque motor according to claim 3, wherein: a positioning lug (331) is arranged on the positioning ring (33), a positioning table (51) is arranged on the first end cover (5), and a positioning groove (511) is arranged on the positioning table (51);

the positioning convex block (331) is clamped with the positioning groove (511).

6. A micro characteristic limited angle torque motor according to claim 3, wherein: a first positioning hole (41) is formed in the shell (4), and a second positioning hole (52) is further formed in the first end cover (5);

the first positioning hole (51) and the second positioning hole (52) are coaxial and far away from the central axis of the rotor (3).

7. A micro characteristic limited angle torque motor according to claim 1, wherein: two mutually symmetrical limiting tables (251) are axially arranged on the inner side of the iron core body (25), and the limiting tables (251) are perpendicular to the central line of the tooth pole (24).

8. The micro characteristic limited angle torque motor according to claim 7, wherein: the limiting table (251) is provided with a first process groove (2511), and the first process groove (2511) is used for positioning connection between the limiting table (251) and the iron core body (25).

9. A micro characteristic limited angle torque motor according to claim 1, wherein: one end, far away from the iron core body (25), of the tooth pole (24) is provided with a second process groove (241) along the axial direction, and the second process groove (241) is used for positioning the connection between the tooth pole (24) and the iron core body (25).

10. A micro characteristic limited angle torque motor according to claim 1, wherein: the tooth pole (24) is a sharp-angled tooth tip.