CN107947494A - A kind of electromechanical mixing of fixed brush formula is without arc commutating dc motor - Google Patents

Abstract

The invention discloses a fixed brush type electromechanical hybrid arcless commutation direct current motor, comprising: a stator, a rotor and a reversing device; the rotor is rotatably arranged in the space surrounded by the stator, and the reversing device is arranged on the rotor and the stator Between; the stator of the fixed brush electromechanical hybrid arcless commutation DC motor is a pair of permanent magnet poles, and the rotor is an m-phase armature winding in a star connection; the gas of the fixed brush electromechanical hybrid arcless commutation DC motor The gap magnetic field and electromotive force are trapezoidal waves, and the armature current is a square wave; the reversing device includes electronic parts and mechanical parts; the mechanical part of the reversing device includes brushes and commutators. According to their different composition methods, there can be p groups There are two structures of commutator segments and p-group brushes. The invention overcomes the shortcomings of the existing electromechanical hybrid arcless commutation multiphase direct current square wave motor, especially the problems of dynamic balance and maintenance inconvenience caused by rotating brushes.

Description

A fixed brush electromechanical hybrid arcless commutated DC motor

technical field

The invention relates to the technical field of motor design and manufacture, in particular to a fixed brush electromechanical hybrid arcless commutated DC motor.

Background technique

At present, both brushed DC motors with mechanical commutation and brushless DC motors with electronic commutation are widely used in the prior art. Sparks are almost unavoidable in mechanical commutation, and arcs are likely to occur; although electronic commutators have no sparks, they increase system costs and complicate control. Therefore, Chinese invention patent CN106685148A and Chinese invention patent CN206294034U "An electromechanical hybrid arcless commutation multi-phase DC square wave motor" propose an electromechanical hybrid commutation arcless DC motor, which uses mechanical and electronic hybrid commutation It does not require additional controllers and power electronic converters, and solves the problems of arcing and sparks in traditional mechanical commutation devices. However, the brushes and the rotor of the hybrid commutated DC motor rotate together, and there is a dynamic balance problem after the brushes are worn out, and it is inconvenient to maintain and replace the brushes. In addition, the commutator of the hybrid commutated DC motor is composed of a power commutator segment and a freewheeling commutator segment, and the two commutator segments with different sizes increase the manufacturing cost.

In the prior art, there is an urgent need for a fixed brush electromechanical hybrid arcless commutated DC motor to overcome the above defects, avoid the generation of sparks or arcs, and the problems of inconvenient dynamic balance and maintenance.

Contents of the invention

In order to overcome the shortcomings of the existing DC electromechanical, the present invention proposes a fixed brush electromechanical hybrid arcless commutation DC motor. The fixed brush hybrid DC motor does not have dynamic balance problems, and the maintenance and replacement of the brushes are convenient. .

In order to achieve the above object, the present invention provides the following technical solutions:

The first solution is a fixed brush electromechanical hybrid arcless commutated DC motor, which includes: a stator, a rotor and a reversing device; the rotor is rotatably arranged in the space surrounded by the stator, and the reversing device It is arranged between the rotor and the stator; the stator of the fixed brush type electromechanical hybrid arcless commutated DC motor is p pairs of permanent magnet poles, and the rotor is an m-phase armature winding connected in star shape The air-gap magnetic field and the electromotive force of the fixed brush type electromechanical hybrid arcless commutation DC motor are trapezoidal waves, and the armature current is a square wave; the reversing device includes an electronic part and a mechanical part; The mechanical part includes brushes and commutators;

The brushes include power positive brushes, forward freewheel brushes, power negative brushes and reverse freewheel brushes, and the power supply positive brushes, forward freewheel brushes, power negative brushes and reverse The freewheeling brush is fixed on the stator side according to the position of the magnetic pole, and the positive pole brush of the power supply is placed at the center line of the N pole; the position of the forward freewheeling brush lags behind the center line of the N pole by 60° electrical angle, 60°/p mechanical Angle; the negative electrode brush of the power supply is placed on the center line of the S pole; the position of the reverse freewheeling brush lags behind the center line of the S pole by 60° electrical angle, 60°/p mechanical angle;

The commutator is fixed on the rotor side and rotates together with the rotor; the commutator includes p commutator segment groups, each of which is composed of m-phase commutator segments, passing through each other The mica sheets are insulated and arranged in a circle; the armature winding of each phase is connected to the p commutation segments belonging to the phase; the commutation segments of each pole and each phase plus its front and rear insulating mica sheets are 360°/m electrical angle, 360°/(pm) mechanical angle; under the same pole, the commutator segments of each phase have a mutual difference of 360°/m electrical angle, 360°/(pm) mechanical angle; under different poles, the commutator segments belonging to the same phase have a mutual difference of 360° ° electrical angle, 360°/p mechanical angle.

The second solution is a fixed brush electromechanical hybrid arcless commutated DC motor, which includes: a stator, a rotor and a reversing device; the rotor is rotatably arranged in the space surrounded by the stator, and the reversing device It is arranged between the rotor and the stator; the stator of the fixed brush type electromechanical hybrid arcless commutated DC motor is p pairs of permanent magnet poles, and the rotor is an m-phase armature winding connected in star shape The air-gap magnetic field and the electromotive force of the fixed brush type electromechanical hybrid arcless commutation DC motor are trapezoidal waves, and the armature current is a square wave; the reversing device includes an electronic part and a mechanical part; The mechanical part includes p brush sets and commutators;

Each brush group includes: positive pole brush of power supply, forward freewheeling brush, negative pole brush of power supply and reverse freewheeling brush; said positive pole brush of power supply, forward freewheeling brush, negative pole of power supply The brushes and reverse freewheeling brushes are fixed on the stator side according to the position of the magnetic poles, and each brush group corresponds to a pair of magnetic poles; the positive pole brush of the power supply is placed at the center line of the N pole; The position of the brush lags behind the center line of the N pole by 60° electrical angle, 60°/p mechanical angle; the negative brush of the power supply is placed at the center line of the S pole; the position of the reverse freewheeling brush lags behind the center line of the S pole by 60° electrically Angle, 60°/p mechanical angle;

The commutator is fixed on the rotor side and rotates together with the rotor; the commutator is composed of m-phase commutation segments, which are insulated from each other by mica sheets and arranged in a circle; the armature windings of each phase It is connected to a commutator piece belonging to the phase; the electrical angle and mechanical angle of each phase commutator piece plus its front and rear insulating mica pieces are 360°/m, and the electrical angle and mechanical angle of each phase commutator piece are also Both are 360°/m.

Preferably, the two structures of the p group of commutator segments and the p group of brushes are exactly the same in the case of a pair of magnetic poles.

Preferably, the electronic part of the commutation means is the same for any number of pole pairs.

Preferably, the electronic part includes one or more sets of freewheeling buffer circuits, wherein each set of freewheeling buffer circuits includes a buffer capacitor and two forward and reverse freewheeling bridge arms, and each freewheeling bridge arm is composed of three diodes Composition; all the positive pole brushes of the power supply are connected to the positive pole of the DC power supply, all the negative pole brushes of the power supply are connected to the negative pole of the DC power supply, all the forward freewheeling brushes and all the reverse freewheeling brushes are connected to the forward and reverse freewheeling brushes respectively midpoint of the bridge arm.

The beneficial effects of the present invention are:

1) The commutation device includes one or p brush sets, one of which is composed of the positive pole brush of the power supply, the forward freewheeling brush, the negative pole brush of the power supply and the reverse freewheeling commutation brush. The brushes are fixed on the stator side according to the magnetic pole position, so maintenance and replacement are easy, and the manufacture and assembly of the brush holder is simple.

2) The commutator includes one or p commutator segment groups, one of which consists of m-phase commutator segments. The number of commutator segments is small and the size is the same, so it is easy to manufacture and the cost is low.

3) The commutator is fixed on the rotor side and rotates with the rotor. The commutator has uniform quality and is not easy to wear, so there is no problem of rotating dynamic balance.

4) There are two structures of p-paired pole motors: p-group brushes and p-group commutator segments, which can be selected according to the actual application, but the two structures are exactly the same in the case of a pair of magnetic poles.

Description of drawings

Fig. 1 is the electrical connection diagram of the fixed brush type electromechanical hybrid arcless commutation DC motor of the present invention in the form of three-phase pair.

Fig. 2 is a structural diagram of a fixed brush electromechanical hybrid arcless commutated DC motor of the present invention in the form of a three-phase pair.

Fig. 3 is the electric connection diagram of the three-phase two-pole form of the fixed brush electromechanical hybrid arcless commutated DC motor adopting two sets of commutator segments in the present invention.

Fig. 4 is a structural diagram of a three-phase, two-pole form of a fixed-brush electromechanical hybrid arcless commutated DC motor adopting two sets of commutator segments in the present invention.

Fig. 5 is an electrical connection diagram of the three-phase two-pole form of the fixed brush electromechanical hybrid arcless commutated DC motor adopting two sets of brush structures of the present invention.

Fig. 6 is a structural diagram of a three-phase, two-pole form of a fixed-brush electromechanical hybrid arcless commutated DC motor adopting two sets of brushes in the present invention.

In the figure 1. Commutator, 2. C-phase commutator, 3. B-phase commutator, 4. A-phase commutator, 5. Power positive pole brush, 6. Forward freewheeling brush, 7. Power negative brush, 8. Reverse freewheeling brush, 9. Brush holder, 10. C phase commutator, 11. B phase commutator, 12. A phase commutator, 13. Power positive brush, 14. Forward freewheeling brush, 15. Power supply negative brush, 16. Reverse freewheeling brush.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below in conjunction with the drawings in the embodiments of the present invention. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of the invention. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

In a broad embodiment of the present invention: a fixed brush electromechanical hybrid arcless commutated direct current motor comprising: a stator, a rotor and a commutation device; the rotor is rotatably arranged in a space surrounded by the stator, The commutation device is arranged between the rotor and the stator; the stator of the fixed-brush electromechanical hybrid arcless commutated DC motor is p pairs of permanent magnet poles, and the rotor is m-phase star-connected Armature winding; the air-gap magnetic field and electromotive force of the fixed brush type electromechanical hybrid arcless commutated DC motor are trapezoidal waves, and the armature current is a square wave; the commutation device includes electronic parts and mechanical parts; the commutation The mechanical part of the commutator includes brushes and commutators;

The brushes include power positive brushes, forward freewheel brushes, power negative brushes and reverse freewheel brushes, and the power supply positive brushes, forward freewheel brushes, power negative brushes and reverse The freewheeling brush is fixed on the stator side according to the position of the magnetic pole, and the positive pole brush of the power supply is placed at the center line of the N pole; the position of the forward freewheeling brush lags behind the center line of the N pole by 60° electrical angle, 60°/p mechanical Angle; the negative electrode brush of the power supply is placed on the center line of the S pole; the position of the reverse freewheeling brush lags behind the center line of the S pole by 60° electrical angle, 60°/p mechanical angle;

The commutator is fixed on the rotor side and rotates together with the rotor; the commutator includes p commutator segment groups, each of which is composed of m-phase commutator segments, passing through each other The mica sheets are insulated and arranged in a circle; the armature winding of each phase is connected to the p commutation segments belonging to the phase; the commutation segments of each pole and each phase plus its front and rear insulating mica sheets are 360°/m electrical angle, 360°/(pm) mechanical angle; under the same pole, the commutator segments of each phase have a mutual difference of 360°/m electrical angle, 360°/(pm) mechanical angle; under different poles, the commutator segments belonging to the same phase have a mutual difference of 360° ° electrical angle, 360°/p mechanical angle.

In another broad embodiment of the present invention: a fixed brush electromechanical hybrid arcless commutated direct current motor comprising: a stator, a rotor and a commutation device; In the space, the commutation device is arranged between the rotor and the stator; the stator of the fixed brush type electromechanical hybrid arcless commutated DC motor is p pairs of permanent magnet poles, and the rotor is star-connected The m-phase armature winding; the air gap magnetic field and the electromotive force of the fixed brush type electromechanical hybrid arcless commutated DC motor are trapezoidal waves, and the armature current is a square wave; the commutation device includes electronic parts and mechanical parts; The mechanical part of the reversing device includes p brush sets and a commutator;

Each brush group includes: positive pole brush of power supply, forward freewheeling brush, negative pole brush of power supply and reverse freewheeling brush; said positive pole brush of power supply, forward freewheeling brush, negative pole of power supply The brushes and reverse freewheeling brushes are fixed on the stator side according to the position of the magnetic poles, and each brush group corresponds to a pair of magnetic poles; the positive pole brush of the power supply is placed at the center line of the N pole; The position of the brush lags behind the center line of the N pole by 60° electrical angle, 60°/p mechanical angle; the negative brush of the power supply is placed at the center line of the S pole; the position of the reverse freewheeling brush lags behind the center line of the S pole by 60° electrically Angle, 60°/p mechanical angle;

The commutator is fixed on the rotor side and rotates together with the rotor; the commutator is composed of m-phase commutation segments, which are insulated from each other by mica sheets and arranged in a circle; the armature windings of each phase It is connected to a commutator piece belonging to the phase; the electrical angle and mechanical angle of each phase commutator piece plus its front and rear insulating mica pieces are 360°/m, and the electrical angle and mechanical angle of each phase commutator piece are also Both are 360°/m.

The invention overcomes the shortcomings of the existing electromechanical hybrid arcless commutation multiphase direct current square wave motor, especially the problems of dynamic balance and maintenance inconvenience caused by rotating brushes.

The detailed description is as follows according to accompanying drawings 1-6.

It should be emphasized that the following description is only exemplary and not intended to limit the scope of the invention and its application.

The electrical connection diagram of the embodiment of the three-phase one-pole fixed brush electromechanical hybrid arcless commutation DC motor as shown in FIG. 1 . Fig. 2 is a structural diagram of this embodiment. In the case of a pair of poles, there is only one set of commutator segments and brushes, so there is only one structure.

The commutator 1 is fixed on the rotor side and rotates with the rotor. The rotor armature is a star-connected three-phase symmetrical winding A, B, C. The commutator is composed of three-phase commutation segments, which are A-phase commutation segment 4, B-phase commutation segment 3 and C-phase commutation segment 2, which are insulated from each other by mica sheets and arranged in a circle. Each phase winding is connected to the commutator segment of the phase respectively. The electrical and mechanical angles of each phase commutator and its front and rear insulating mica sheets are 120°, and the electrical and mechanical angles between them are also 120°.

The positive brush 5 of the power supply, the forward freewheeling brush 6, the negative brush 7 of the power supply and the reverse freewheeling commutation brush 8 are fixed on the stator side according to the position of the magnetic pole: the positive brush 5 of the power supply is placed at the center line of the N pole, and the positive The position of the freewheeling brush 6 lags behind the centerline of the N pole by 60° in electrical and mechanical angles; the negative brush 7 of the power supply is placed on the centerline of the S pole, and the position of the reverse freewheeling brush 8 lags behind the centerline of the S pole by 60° in electrical angle and mechanical angles.

The electronic part of the commutation device is composed of a freewheeling buffer circuit, including a buffer capacitor C and two freewheeling bridge arms. The forward freewheeling bridge arm is composed of diodes D ₁ , D ₂ and D ₅ , and the reverse freewheeling bridge arm The bridge arm is composed of diodes D ₃ , D ₄ and D ₆ . The positive pole brush 5 of the power supply is connected to the positive pole U ₊ of the DC power supply, the negative pole brush 7 of the power supply is connected to the negative pole U _- of the DC power supply, the forward freewheeling brush 6 and the reverse freewheeling brush 8 are respectively connected to the forward and reverse freewheeling bridge arms midpoint.

The sliding contact between the brush and the commutator realizes the commutation of the armature winding, and the freewheeling buffer circuit ensures that no arc is generated during the commutation process.

When the DC motor runs in the direction shown by the arrow in Figure 1 and Figure 2, the windings of each phase are sequentially connected with the positive pole brush 5 of the power supply, the forward freewheeling brush 6, the negative pole brush 7 of the power supply and the reverse freewheeling current through the commutator piece. Brush 8 slides into contact, and again reaches the power positive pole brush 5 to start the next cycle. Take phase A as an example: assume that the phase A winding starts to enter the N pole at the initial moment, the phase A commutator segment 4 starts to contact the positive pole brush 5 of the power supply, and the phase A winding conducts forward; after running 60° in the forward direction, A The phase winding is under the center line of the N pole, and the A-phase commutator piece 4 begins to contact the forward freewheeling brush 6, but since the A-phase commutator piece 4 is still in contact with the positive pole brush 5 of the power supply, no freewheeling is performed; After running 120° electrical angle, the A-phase winding leaves the N pole, the A-phase commutator piece 4 is disconnected from the power positive pole brush 5, but still contacts with the forward freewheeling brush 6, and the A-phase winding starts to continue forward. After running in the forward direction for 180° electrical angle, the A-phase winding begins to enter the S pole, the A-phase commutator piece 4 is disconnected from the positive freewheeling brush 6, and starts to contact the negative pole brush 7 of the power supply, and the A-phase winding reverses In the same way, until the forward running of 300° electrical angle, the A-phase winding leaves the S pole, the A-phase commutator piece 4 is disconnected from the negative brush 7 of the power supply, and only when it is in contact with the reverse freewheeling brush 8 , A-phase winding starts reverse freewheeling.

The sliding contact between the commutator plate and the brush realizes the commutation of the armature winding current. In one cycle, each phase winding has forward conduction, forward freewheeling, reverse conduction, reverse freewheeling and non-conduction after freewheeling. through five states.

When the number of pole pairs is greater than one, according to the composition of brushes and commutators, fixed brush electromechanical hybrid arcless commutated DC motors have two structures: p-group commutator segments and p-group brushes. Fig. 3 is an electrical connection diagram of an embodiment of a three-phase two-pole fixed brush electromechanical hybrid arcless commutated DC motor with two sets of commutator segments. Fig. 4 is a structural diagram of this embodiment.

The commutator 1 includes two commutator segment groups, one of which consists of three-phase commutator segments 2, 3, 4, and the other commutator segment group consists of three-phase commutator segments 10, 11, 12, They are insulated from each other by mica sheets and arranged in a circle. Each phase armature winding is connected to the two commutator segments belonging to the phase: A phase winding is connected to commutator segment 3 and commutator segment 11, B phase winding is connected to commutator segment 4 and commutator segment 12, and C phase winding Connect to commutator segment 2 and commutator segment 10. The commutation piece of each pole and each phase plus its front and rear insulating mica pieces is 120° electrical angle and 60° mechanical angle. Under the same pole, the commutation segments of each phase differ from each other by 120° electrical angle and 60° mechanical angle. Under different poles, the commutator segments belonging to the same phase have a mutual difference of 360° electrical angle and 180° mechanical angle.

The motor of the two groups of commutator segments has only four brushes, the positive pole brush 5 of the power supply, the forward freewheeling brush 6, the negative pole brush 7 of the power supply and the reverse freewheeling commutation brush 8. The brushes are fixed on the stator side according to the position of the magnetic poles: the positive pole brush of the power supply is placed at the center line of the N pole, and the position of the forward freewheeling brush lags behind the center line of the N pole by 60° electrical angle and 30° mechanical angle; the negative pole brush of the power supply is placed on the The position of the S pole center line, the position of the reverse freewheeling brush lags behind the S pole center line by 60° electrical angle and 30° mechanical angle. For two-pole motors, each brush has two positions to choose from, and the placement does not affect the commutation of the motor. As shown in Figure 4, the positive pole brush 5 and the negative pole brush 7 of the power supply can be placed under one pair of poles, and the forward freewheeling brush 6 and reverse freewheeling brush 8 can be placed under another pair of poles, so that Make the brushes more evenly distributed on the stator side.

Fig. 5 is an electrical connection diagram of an embodiment of a three-phase two-pole fixed brush electromechanical hybrid arcless commutated DC motor with two sets of brush structures. Fig. 6 is a structural diagram of this embodiment.

The motor contains two brush sets, one of which is composed of the positive pole brush 5 of the power supply, the forward freewheeling brush 6, the negative pole brush 7 of the power supply and the reverse freewheeling commutation brush 8, and the other brush set is composed of The positive electrode brush 13 of the power supply, the forward freewheeling brush 14, the negative electrode brush 15 of the power supply and the reverse freewheeling brush 16 are formed. The brushes are fixed on the stator side according to the position of the magnetic poles. One set of brushes corresponds to a pair of magnetic poles: the positive brush of the power supply is placed at the center line of the N pole, and the position of the forward freewheeling brush lags behind the center line of the N pole by 60° in electrical angle, 30° Mechanical angle: The negative brush of the power supply is placed on the center line of the S pole, and the position of the reverse freewheeling brush lags behind the center line of the S pole by 60° electrical angle and 30° mechanical angle.

The commutator is composed of three-phase commutation segments, which are insulated from each other by mica sheets and arranged in a circle. Each phase armature winding is connected to one commutator segment belonging to that phase. The electrical and mechanical angles of each phase commutator plus its front and rear insulating mica sheets are 120°, and the electrical and mechanical angles of each phase's commutator are also 120°.

Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that: they can still modify the technical solutions described in the aforementioned embodiments, or perform equivalent replacements for some of the technical features; and these The modification or replacement does not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (5)

1. A fixed brush electromechanical hybrid arcless commutation DC motor, characterized in that it comprises: a stator, a rotor and a reversing device; the rotor is rotatably arranged in the space surrounded by the stator, and the reversing device It is arranged between the rotor and the stator; the stator of the fixed brush type electromechanical hybrid arcless commutated DC motor is p pairs of permanent magnet poles, and the rotor is an m-phase armature winding connected in star shape The air-gap magnetic field and the electromotive force of the fixed brush type electromechanical hybrid arcless commutation DC motor are trapezoidal waves, and the armature current is a square wave; the reversing device includes an electronic part and a mechanical part; The mechanical part includes brushes and commutators; The brushes include power positive brushes, forward freewheel brushes, power negative brushes and reverse freewheel brushes, and the power supply positive brushes, forward freewheel brushes, power negative brushes and reverse The freewheeling brush is fixed on the stator side according to the position of the magnetic pole, and the positive pole brush of the power supply is placed at the center line of the N pole; the position of the forward freewheeling brush lags behind the center line of the N pole by 60° electrical angle, 60°/p mechanical Angle; the negative electrode brush of the power supply is placed on the center line of the S pole; the position of the reverse freewheeling brush lags behind the center line of the S pole by 60° electrical angle, 60°/p mechanical angle; The commutator is fixed on the rotor side and rotates together with the rotor; the commutator includes p commutator segment groups, each of which is composed of m-phase commutator segments, passing through each other The mica sheets are insulated and arranged in a circle; the armature winding of each phase is connected to the p commutation segments belonging to the phase; the commutation segments of each pole and each phase plus its front and rear insulating mica sheets are 360°/m electrical angle, 360°/(pm) mechanical angle; under the same pole, the commutator segments of each phase have a mutual difference of 360°/m electrical angle, 360°/(pm) mechanical angle; under different poles, the commutator segments belonging to the same phase have a mutual difference of 360° ° electrical angle, 360°/p mechanical angle. 2. A fixed brush electromechanical hybrid arcless commutated DC motor, characterized in that it comprises: a stator, a rotor and a reversing device; the rotor is rotatably arranged in the space surrounded by the stator, and the reversing device It is arranged between the rotor and the stator; the stator of the fixed brush type electromechanical hybrid arcless commutated DC motor is p pairs of permanent magnet poles, and the rotor is an m-phase armature winding connected in star shape The air-gap magnetic field and the electromotive force of the fixed brush type electromechanical hybrid arcless commutation DC motor are trapezoidal waves, and the armature current is a square wave; the reversing device includes an electronic part and a mechanical part; The mechanical part includes p brush sets and commutators; Each brush group includes: positive pole brush of power supply, forward freewheeling brush, negative pole brush of power supply and reverse freewheeling brush; said positive pole brush of power supply, forward freewheeling brush, negative pole of power supply The brushes and reverse freewheeling brushes are fixed on the stator side according to the position of the magnetic poles, and each brush group corresponds to a pair of magnetic poles; the positive pole brush of the power supply is placed at the center line of the N pole; The position of the brush lags behind the center line of the N pole by 60° electrical angle, 60°/p mechanical angle; the negative brush of the power supply is placed at the center line of the S pole; the position of the reverse freewheeling brush lags behind the center line of the S pole by 60° electrically Angle, 60°/p mechanical angle; The commutator is fixed on the rotor side and rotates together with the rotor; the commutator is composed of m-phase commutation segments, which are insulated from each other by mica sheets and arranged in a circle; the armature windings of each phase It is connected to a commutator piece belonging to the phase; the electrical angle and mechanical angle of each phase commutator piece plus its front and rear insulating mica pieces are 360°/m, and the electrical angle and mechanical angle of each phase commutator piece are also Both are 360°/m. 3. The fixed-brush electromechanical hybrid arcless commutated DC motor according to one of claims 1 or 2, characterized in that: the two structures of p-group commutator segments and p-group brushes are completely Same. 4. The fixed-brush electromechanical hybrid arcless commutated DC motor according to one of claims 1 or 2, characterized in that the electronic parts of the commutation device are the same for any number of magnetic pole pairs. 5. The fixed brush electromechanical hybrid arcless commutated DC motor according to claim 4, characterized in that: said electronic part includes one or more sets of freewheeling buffer circuits, wherein each set of freewheeling buffer circuits includes a Snubber capacitor and forward and reverse freewheeling bridge arms, each freewheeling bridge arm is composed of three diodes; all positive pole brushes of the power supply are connected to the positive pole of the DC power supply, all negative pole brushes of the power supply are connected to the negative pole of the DC power supply, and all positive pole brushes are connected to the negative pole of the DC power supply. The freewheeling brushes and all the reverse freewheeling brushes are respectively connected to the midpoints of the forward and reverse freewheeling bridge arms.