CN111585412A

CN111585412A - DC motor with constant voltage brush

Info

Publication number: CN111585412A
Application number: CN202010627723.XA
Authority: CN
Inventors: 俞晓
Original assignee: Individual
Current assignee: LESHAN DONGCHUAN MACHINERY CO LTD
Priority date: 2020-07-01
Filing date: 2020-07-01
Publication date: 2020-08-25
Anticipated expiration: 2040-07-01
Also published as: CN111585412B

Abstract

The invention relates to the technical field of motors. The direct current motor comprises a base body fixedly arranged on an installation frame, wherein a sliding hole extending along the length direction of the base body is formed in the end face, facing one end of a commutator, of the base body, and a carbon brush matched with the sliding hole is arranged in the outer end of the sliding hole; the carbon brush is characterized in that a driving block matched with the sliding hole is further arranged in the sliding hole, an electromagnet and a permanent magnet are respectively arranged on the surfaces, opposite to the carbon brush, of the driving block, the electromagnet is opposite to the permanent magnet, and the electromagnet and the permanent magnet are mutually repelled in a power-on state. The invention can really ensure the constant-voltage contact between the electric brush and the commutator, and has the advantages of high response speed and flexible and convenient control.

Description

DC motor with constant voltage brush

Technical Field

The invention relates to the technical field of motors, in particular to a direct current motor with a constant-voltage electric brush.

Background

A dc motor is a kind of motor widely used in daily production and life, and generally includes a housing, a stator, a rotor, a commutator, and brushes, and the stator generally employs a permanent magnet or a directional electromagnetic coil set, which is fixedly installed in the housing to provide a magnetic motive force for the rotor. The rotor is generally formed of a plurality of sets of electromagnetic coils and a magnetic core wound thereon, and interacts with the stator when excited to form a rotational force. The commutator is mounted on the rotor, and is generally formed into a ring shape by multiple segments of circular arc-shaped conductive sheets, and is conducted with the electromagnetic coil on the rotor and connected with a power supply through a brush. The DC motor has the characteristics of good starting and speed regulating performance, wide and smooth speed regulating range, strong overload capacity, small influence of electromagnetic interference and the like. However, in actual production and life, we also find that the existing direct current motor has the following problems.

1. The conventional brush is disposed on the mounting bracket and is pressed into contact with the commutator by a spring. However, since the commutator rotates at a high speed with the rotor, there is a wear between the brush and the commutator. When the pressure generated by the spring is overlarge, the abrasion between the electric brush and the commutator is increased, the electric brush is excessively abraded, and the service life of the electric brush is influenced. When the pressure is too small, the stable contact between the electric brush and the commutator cannot be ensured, the phenomena of arc discharge and ignition are caused, the motor is easily burnt out, and the maintenance of the stable working condition of the motor is not facilitated. Therefore, how to ensure that the pressure between the brush and the commutator is always kept at a proper constant pressure is a great problem which cannot be solved in the field.

2. The traditional commutator is an annular structure formed by multiple sections, a gap position between two adjacent sections forms a commutation area of the commutator, but due to the existence of the gap, the edge of the gap has large abrasion on the electric brush in the process that the commutator continuously rotates and is in contact with the electric brush, so that the electric brush is abraded too fast, and the contact between the electric brush and the commutator is unstable.

3. In order to adapt to underwater working conditions, the existing motor must ensure the sealing property of the shell of the motor so as to prevent water from permeating into the motor and damaging electrical components. The conventional method in the prior art is to add various sealing rings on a rotor part of a motor, and for normal underwater operation, the performance of the sealing rings is enough to ensure the reliability of dynamic sealing and static sealing of the motor, and the normal operation of the motor is not influenced. However, for deep water and ultra-deep water operation, due to the fact that external water pressure is increased, the sealing reliability of a conventional sealing ring cannot be guaranteed, particularly the sealing reliability of a rotor part cannot be guaranteed, and for a small motor, mechanical sealing cannot be adapted in consideration of the machinability of each part, so that a special motor rotor waterproof structure is needed to improve the overall underwater operation performance of the motor.

4. The existing motor is mainly cooled by air through blowing a cooling fan arranged in the existing motor to cool the rotor, and for underwater operation, the traditional air cooling cannot be matched, and the existing motor can only cool the motor by making the shell sealing performance of the motor and naturally cooling the shell by water. However, the heat exchange in the cooling mode is mainly concentrated on the outer surface of the shell, the cooling speed is slow, and the cooling mode is not suitable for some high-speed motors, so how to optimize the heat dissipation structure of the motor is also a big problem in the field.

Disclosure of Invention

The invention aims to provide a direct current motor with a constant voltage brush, which can ensure the stable pressure of the brush.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows: a DC motor with constant voltage brush comprises a housing, a pair of stators fixed on the inner wall of the housing, and a rotating shaft installed between the pair of stators; an installation frame is arranged on the inner wall of the shell corresponding to one end of the rotating shaft, and an electric brush is arranged on the installation frame; a section of the rotating shaft between the stators is provided with a rotor consisting of a magnetic core and an electromagnetic coil, and the electromagnetic coil is wound on the magnetic core; a commutator is arranged on the rotating shaft at a position opposite to the electric brush, the commutator is electrically connected with the electromagnetic coil, and the electric brush is in contact with the commutator;

the electric brush comprises a base body fixedly arranged on the mounting frame, a sliding hole extending along the length direction of the base body is arranged on the end face of one end, facing the commutator, of the base body, and a carbon brush matched with the sliding hole is arranged in the outer end of the sliding hole; the surface of the driving block, which is opposite to the carbon brush, is provided with an electromagnet and a permanent magnet respectively, the electromagnet is opposite to the permanent magnet, and the electromagnet and the permanent magnet repel each other in a power-on state; the hole bottom of the sliding hole is sequentially provided with a pressure sensor, a sliding plate and a supporting spring from inside to outside, the pressure signal acquisition end of the pressure sensor faces the sliding plate and is in contact with the sliding plate, and two ends of the supporting spring are fixedly connected with the sliding plate and the driving block respectively.

Preferably, the driving block is in a cap shape, and one end of the supporting spring is located in the driving block.

Preferably, the end face of one end of the carbon brush, which is located in the sliding hole, is provided with a conductive column, and the conductive column is connected with a wiring terminal arranged on the shell through a conductive copper wire.

Preferably, mounting bracket and pedestal are made by conducting material, it leads electrical pillar to set up on the mounting bracket, it is connected with the binding post that sets up on the shell through electrically conductive copper line to lead electrical pillar.

Preferably, one end of the base body facing the commutator is also provided with a limit cap, the limit cap is in threaded connection with the base body, and the center of the limit cap is provided with a guide hole; the carbon brush is T-shaped, and the outer end of the carbon brush is matched with the guide hole and penetrates through the guide hole.

Preferably, except for the opposite surfaces of the electromagnet and the permanent magnet, the other surfaces of the electromagnet and the permanent magnet are provided with anti-interference coatings.

Preferably, a set of opposite and vertical sliding grooves is formed in the side wall of the sliding hole, sliding blocks matched with the sliding grooves are arranged on the side wall of the carbon brush, and the sliding blocks are located in the sliding grooves.

Preferably, a silver plating layer is disposed on an inner wall of the sliding hole.

Preferably, a stepped installation cavity for the rotating shaft to penetrate out is formed in the end face of the shell, the installation cavity is composed of a large-size section and a small-size section, a bearing is arranged in the large-size section, the rotating shaft is located in the bearing, and the small-size section and the rotating shaft form clearance fit; a sealing disc is further arranged on the rotating shaft on the outer side of the bearing, the outward disc surface of the sealing disc is a slope surface, and the sealing disc is located in the large-size section; still be provided with the one deck sealing washer in the jumbo size section, the outer edge of sealing washer is fixed on the inner wall of jumbo size section to form airtight cooperation, the one side of sealing washer is attached on the domatic of sealed dish, the lateral wall of sealed dish, sealing washer, jumbo size section, the outer terminal surface of jumbo size section enclose into high-pressure seal chamber jointly, still be provided with the inflation inlet with the inside intercommunication of high-pressure seal chamber in the jumbo size section, the inflation inlet passes through the trachea and is connected with external air supply.

Preferably, an air pressure sensor for detecting air pressure in the high-pressure sealing cavity is further arranged on the inner wall of the outer end of the large-size section.

The beneficial effects of the invention are concentrated and expressed as follows: the constant-voltage contact between the electric brush and the commutator can be really ensured, the response speed is high, and the control is flexible and convenient. Specifically, during the use process of the electric brush, the carbon brush can slide up and down in the sliding hole and is driven by the electromagnet on the driving block to be pressed on the commutator at a constant pressure. The carbon brush is directly pressed on the commutator through the spring in the traditional mode, but along with the abrasion of the carbon brush and the elastic fatigue of the spring, the pressure of the spring on the carbon brush can change, and the change of the pressure can cause the contact pressure of the carbon brush and the commutator to be too large or too small, so that the carbon brush and the commutator cannot reach the optimal contact pressure. The invention generates repulsion force to the permanent magnet through the electromagnet and drives the carbon brush to move through the permanent magnet. Due to the relationship of the force and the reaction force being equal, the repulsive force between the electromagnet and the permanent magnet (the pressure detected by the pressure sensor) is substantially the contact pressure between the carbon brush and the commutator. According to the invention, the contact pressure is controlled by the electromagnet, and the contact pressure can be quickly and accurately changed by changing the repulsion force of the electromagnet, so that the carbon brush and the commutator reach the optimal contact working condition, and the device has the advantages of simple operation, extremely high response speed and convenience in control.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the mounting of the brushes;

FIG. 3 is an enlarged view of portion B of FIG. 2;

FIG. 4 is a schematic diagram of a preferred embodiment of the structure shown in FIG. 3;

FIG. 5 is a schematic structural view of a commutator;

FIG. 6 is an enlarged view of portion C of FIG. 1;

FIG. 7 is a view from direction A-A of the structure shown in FIG. 1;

FIG. 8 is a schematic cross-sectional view of a spindle;

FIG. 9 is a schematic structural view of an end face of a rotating shaft;

fig. 10 is a schematic structural view of the heat dissipation fin.

Detailed Description

The motor shown in fig. 1 to 10 is the same as the conventional dc motor in that it also includes a housing 1, a pair of stators 2 fixedly provided on the inner wall of the housing 1, and a rotating shaft 3 installed between the pair of stators 2. The inner wall of the shell 1 corresponding to one end of the rotating shaft 3 is provided with a mounting frame 4, as shown in fig. 1, the inner wall of the shell 1 at the left end of the rotating shaft 3 is provided with the mounting frame 4, and the mounting frame 4 is provided with an electric brush 5. And a section of the rotating shaft 3 between the stators 2 is provided with a rotor 6 consisting of a magnetic core and an electromagnetic coil, and the electromagnetic coil is wound on the magnetic core. After the rotor 6 is energized, the rotor 6 is influenced by the magnetic force of the stator 2 and continues to rotate within the housing 1. A commutator 7 is arranged on the position, opposite to the electric brush 5, of the rotating shaft 3, the commutator 7 is electrically connected with the electromagnetic coil, and the electric brush 5 is in contact with the commutator 7.

Compared with the traditional direct current motor, the motor of the invention has great optimization and improvement in aspects of service life, stability, waterproofness, heat dissipation and the like, and the optimization and improvement in various aspects of the invention are systematically explained by combining drawings.

From the aspect of the electric brush, the traditional motor has the defects that the pressure is unstable in the contact process of the electric brush and the commutator 7 due to the structural defects of the electric brush, the optimal matching between the electric brush and the commutator 7 cannot be realized, the abrasion is serious, and the stability is insufficient. For this purpose, as shown in fig. 2 to 4, the brush 5 of the present invention includes a base 8 fixedly disposed on the mounting frame 4, a sliding hole 9 extending along a length direction of the base 8, that is, extending in an up-down direction in fig. 3, is disposed on an end surface of the base 8 facing to one end of the commutator 7, a carbon brush 10 adapted to the sliding hole 9 is disposed in an outer end of the sliding hole 9, and the size and shape of the carbon brush 10 are matched with the sliding hole 9 to ensure stable and smooth sliding of the carbon brush 10. In addition, in order to further improve the sliding stability of the carbon brush 10, a set of opposite and vertical sliding grooves 20 may be provided on the side wall of the sliding hole 9, a sliding block 21 that is matched with the sliding grooves 20 may be provided on the side wall of the carbon brush 10, and the sliding block 21 is located in the sliding groove 20. The stable sliding of the carbon brush 10 is achieved by positioning and guiding the slider 21 through the sliding groove 20.

And a driving block 11 matched with the sliding hole 9 is further arranged in the sliding hole 9, and the driving block 11 is used for driving the carbon brush 10 to move and applying pressure to the carbon brush. Compared with the traditional mode of directly connecting through a spring, the surfaces of the driving block 11, which are opposite to the carbon brush 10, are respectively provided with the electromagnet 12 and the permanent magnet 13, the electromagnet 12 is opposite to the permanent magnet 13, and the electromagnet 12 and the permanent magnet 13 repel each other in an electrified state. That is, the polarity of the electromagnet 12 is opposite to that of the permanent magnet 13 in the normal energization state, and a thrust can be applied to the permanent magnet 13 after the activation, and it is expected that the thrust applied thereto is controllable in the case of changing the energization current of the electromagnet 12. The bottom of the sliding hole 9 is sequentially provided with a pressure sensor 14, a sliding plate 15 and a supporting spring 16 from inside to outside, a pressure signal acquisition end of the pressure sensor 14 faces the sliding plate 15 and is in contact with the sliding plate 15, and two ends of the supporting spring 16 are fixedly connected with the sliding plate 15 and the driving block 11 respectively. The pressure sensor 14 is used to collect the force exerted by the drive block 11 on the pressure sensor 14 via the support spring 16 and the slide plate 15,

in the use process of the brush of the invention, the carbon brush 10 can slide up and down in the sliding hole 9 and is driven by the electromagnet 12 on the driving block 11 to be pressed on the commutator 7 with constant pressure. The conventional method presses the carbon brush 10 directly against the commutator 7 by the spring, but as the carbon brush 10 is worn and the spring is elastically fatigued, the pressure of the spring against the carbon brush 10 varies, and the variation of the pressure may cause the contact pressure between the carbon brush 10 and the commutator 7 to be too large or too small, so that the optimal contact pressure cannot be achieved between the carbon brush 10 and the commutator 7. In the invention, the electromagnet 12 generates repulsion to the permanent magnet 13, and then the permanent magnet 13 drives the carbon brush 10 to move. The repulsive force between the electromagnet 12 and the permanent magnet 13 (the pressure detected by the pressure sensor 14) is substantially the contact pressure between the carbon brush 10 and the commutator 7 due to the relationship of the force and the reaction force being equal. According to the invention, the contact pressure is controlled by the electromagnet 12, and the contact pressure can be quickly and accurately changed by changing the repulsive force of the electromagnet 12, so that the carbon brush 10 and the commutator 7 reach the optimal contact working condition, the operation is simple, the current can be changed by changing the electrified current of the electromagnet 12, the response speed is very high, and the control is convenient.

In order to improve the stability of the installation of the supporting spring 16 and the stability of the movement of the driving block 11, the driving block 11 is in a cap shape, one end of the supporting spring 16 is positioned in the driving block 11, and the specific fixed connection mode can adopt bonding, clamping and the like.

The invention relates to a connection mode of a carbon brush 10 and a wiring terminal 17, which mainly comprises the following two modes, wherein a conductive column is arranged on the end face of one end of the carbon brush 10, which is positioned in a sliding hole 9, and the conductive column is connected with the wiring terminal 17 arranged on a shell 1 through a conductive copper wire. This configuration is simpler and more intuitive and is relatively less costly, but it should be done without affecting the normal motion of the driving block 11 and the carbon brush 10 when conducting the wiring of the conductive copper wires. Two mounting bracket 4 and pedestal 8 are made by conducting material, it leads electrical pillar to set up on mounting bracket 4, it is connected with the binding post 17 that sets up on shell 1 through electrically conductive copper line to lead electrical pillar. That is to say, under this kind of mode, its circuit switches on the relation and is carbon brush 10, pedestal 8, mounting bracket 4, wire, binding post 17 in proper order, and this kind of scheme is owing to need not to set up on carbon brush 10 and leads electrical pillar, and the whole of carbon brush 10 is changed more swiftly convenient, but nevertheless the important electric connection contact between guaranteeing carbon brush 10 and the pedestal 8, in order to ensure to switch on, for this reason, can also be provided with the silver-plated layer on the inner wall of sliding hole 9, in order to increase electric conductivity. Meanwhile, since the base body 8 and the carbon brush 10 are made of conductive materials, in order to reduce electromagnetic interference, the surfaces of the electromagnet 12 and the permanent magnet 13 are provided with anti-interference coatings except for the opposite surfaces. As shown in fig. 3, that is, the electromagnet 12 is coated with the interference preventing coating except for the lower surface and the permanent magnet 13 except for the upper surface.

Meanwhile, in order to prevent the carbon brush 10 from protruding excessively, as shown in fig. 4, a limiting cap 18 is further disposed at one end of the base body 8 facing the commutator 7, the limiting cap 18 is in threaded connection with the base body 8, and a guide hole 19 is disposed in the center of the limiting cap 18. The carbon brush 10 is in a T shape, and the outer end of the carbon brush 10 is matched with the guide hole 19 and penetrates through the guide hole 19. The design of the limiting cap 18 can limit the limit position of the carbon brush 10 at the lower part, and prevent the carbon brush from falling out.

In the aspect of the commutator 7, the conventional commutator 7 is formed by cutting a copper ring to form a gap, so that the current direction is exchanged in the rotating process, but the copper ring is subjected to cutting, has high stress in the cutting process and is easy to generate micro deformation, and the micro deformation is fatal to the commutator 7 rotating at high speed, so that the abrasion of the electric brush 5 is increased, and the stability of the contact between the electric brush 5 and the commutator 7 is influenced. To this end, the present invention has solved the above problems by improving the overall structure of the commutator 7, and as shown in fig. 5, the commutator 7 according to the present invention includes an insulating mounting ring 22 disposed around the shaft 3, and the insulating mounting ring 22 is made of an insulating material, typically high-strength resin, which is used as a mounting base for the commutator 7.

The commutator 7 further comprises a plurality of pairs of fan-shaped conductive frames 23 which are uniformly arranged on the insulating mounting ring 22 in an annular mode, the conductive frames 23 are preferably copper frames, and copper alloy frames with better mechanical performance can be selected while the conductive performance is guaranteed. The inner end of the conductive frame 23 is fixedly connected with the insulating mounting ring 22 and the rotating shaft 3 through an insulating bolt 24 to form the fixation of the conductive frame 23. In order to improve the installation accuracy of the conductive frame 23, a positioning groove is arranged at a position of the insulating installation ring 22 opposite to the inner end of the conductive frame 23, and the inner end of the conductive frame 23 is arranged in the positioning groove. The structure of constant head tank is comparatively simple, only need ensure its shape unanimous with the inner of electrically conductive frame 23, guarantee electrically conductive frame 23 the accurate installation can. The region between the conductive frames 23 is filled with insulating resin 25, and the outer end face of each conductive frame 23 and the outer surface of the insulating resin 25 together constitute a circular ring-shaped contact surface which is in contact with the brush 5.

The commutator 7 of the invention is composed of an insulating mounting ring 22, a conductive frame 23 and insulating resin 25 filled in the gap of the conductive frame 23, the conductive frame 23 can be uniformly opened and independently processed without the traditional cutting procedure aiming at the gap, so that the accuracy of the conductive frame 23 is better, and the roundness of the whole commutator 7 can be ensured by matching positioning and mounting. Meanwhile, the insulating resin 25 filled in the gaps of the conductive frames 23 can also ensure the stability of the conductive frames 23, prevent the commutator 7 from deforming and further ensure the roundness of the commutator 7, so that the commutator 7 always has a better contact surface in the process of contacting the conductive frames 23, and the abrasion caused by insufficient surface roundness is reduced.

As for the connection of the conductive frame 23 and the electromagnetic coil on the rotor 6, the invention adopts the mode that the inner surface of the outer end of the conductive frame 23 is provided with the binding posts 26, and each conductive frame 23 is connected with the electromagnetic coil through each binding post 26. Of course, the terminal 26 can be mounted at other positions of the conductive frame 23, as long as the structure is reasonable. In addition, in order to further improve the structural strength of the conductive frame 23, the corner parts on both sides of the outer end of the conductive frame 23 are arc-shaped, and the arc-shaped structure makes the transition of the corner parts smoother, facilitates the adhesion of the insulating resin 25, and has higher structural strength. On the basis, a transverse plate 27 is arranged between two sides of the middle part of the conductive frame 23, so that the stability of the conductive frame 23 can be further improved.

In actual production life, the motor needs to work under water or even in deep water, the traditional mode ensures the water resistance of the motor by improving the sealing performance of the whole machine casing of the equipment, but the mode is not directly opposite to the optimization and improvement of the motor, and cannot fundamentally solve the water resistance problem of the motor, and under some conditions, the layout rationality of the whole machine of the equipment is considered, the motor has to be directly positioned in the water body, so that the use requirement of the special occasion is met.

Referring to fig. 1 and 6, a stepped installation cavity for the shaft 3 to penetrate out is formed on the end surface of the housing 1, the installation cavity is composed of a large-size section 28 and a small-size section 29, a bearing 30 is arranged in the large-size section 28, the shaft 3 is located in the bearing 30, the shaft 3 is supported and limited, a clearance fit is formed between the small-size section 29 and the shaft 3, and the smaller the clearance is, the better the clearance is, the rotation of the shaft 3 is not influenced.

As shown in fig. 6, a sealing disc 31 is further disposed on the rotating shaft 3 outside the bearing 30, the outward disc surface of the sealing disc 31 is a slope, and the sealing disc 31 is located in the large-size section 28. Still be provided with one deck sealing washer 32 in the jumbo size section 28, the outer edge of sealing washer 32 is fixed on jumbo size section 28's inner wall to form airtight cooperation, the one side of sealing washer 32 is attached on sealed dish 31 domatic, after exerting pressure to sealing washer 32, it can be attached and form sealedly on sealed dish 31 domatic, of course sealing washer 32 preferably adopts the material that has high wear resistance to make, for example: the seal ring 32 is a wear-resistant silica gel seal ring. The sealing disc 31, the sealing ring 32, the side wall of the large-size section 28 and the outer end face of the large-size section 28 jointly enclose a high-pressure sealing cavity, the large-size section 28 is further provided with an inflation inlet 33 communicated with the inside of the high-pressure sealing cavity, and the inflation inlet 33 is connected with an external air source through an air pipe. The external air source can adopt an air compressor, a high-pressure air tank and the like.

According to the invention, high-pressure gas is continuously filled into the high-pressure sealing cavity through the external gas source, so that the high-pressure sealing cavity forms relative high pressure relative to the outside and the inside of the shell 1, and therefore, in a normal use state, the sealing ring 32 can be tightly attached to the slope surface of the sealing disc 31 to form primary sealing. Meanwhile, the outward only channel of the high-pressure gas in the high-pressure sealing cavity is a micro gap between the small-size section 29 of the installation cavity and the rotating shaft 3, and a trend of high-pressure gas outward discharge always exists in the micro gap, so that external water can be effectively prevented from entering the motor. In addition, the invention can adapt to underwater operation at different depths by changing the inflating pressure of the external air source, and has strong universality. In order to monitor the pressure in the high-pressure sealing cavity in real time, an air pressure sensor 34 for detecting the air pressure in the high-pressure sealing cavity is further arranged on the inner wall of the outer end of the large-size section 28.

Under the ordinary condition, the one end of pivot 3 is located shell 1, at this moment shell 1 only has one end design installation cavity, but outside shell 1 all will stretch out at the both ends of pivot 3 to when satisfying two-way transmission or other demands, also can shell 1's both ends all are provided with the installation cavity, shell 1 is worn out through two installation cavities respectively at the both ends of pivot 3, and the seal structure of two installation cavity departments is unanimous. At this time, in order to realize reasonable distribution of high-pressure gas, the inflation ports 33 on the large-sized sections 28 of the two installation cavities are respectively communicated with a distribution valve 35 through a branch gas pipe 0, and the distribution valve 35 is communicated with a main gas pipe 36.

As described above, in the case of meeting some special requirements, both ends of the rotating shaft 3 may extend out of the casing 1, and in the present invention, in order to improve the heat dissipation performance of the whole motor, as shown in fig. 1 and 7-10, both ends of the rotating shaft 3 extend out of the casing 1 and form an airtight connection with the casing 1, and the airtight connection manner may be referred to above. The rotating shaft 3 is a hollow shaft with one open end and one closed end, and a spiral pumping blade 37 is arranged inside the rotating shaft 3. On the end face of the closed end of the rotating shaft 3, a power output shaft 38 is coaxially and fixedly arranged, the power output shaft 38 and the rotating shaft 3 can be of an integrated structure, so that the connection strength is improved, on the basis, a plurality of triangular reinforcing plates 41 can be arranged between the side face of the power output shaft 38 and the end face of the rotating shaft 3, and the triangular reinforcing plates 41 are annularly and uniformly distributed around the power output shaft 38. Be the annular evenly to be provided with a plurality of through-holes 39 on the 3 terminal surfaces of pivot of power output shaft 38 week side, through-hole 39 can adopt round hole or elliptical aperture, nevertheless discharge from through-hole 39 for the inside air or the water of pivot 3 of being convenient for more, through-hole 39 is inner little, the outer end is big.

According to the invention, the solid shaft of the traditional motor is optimized into a hollow shaft structure, and in the process of continuous rotation of the rotating shaft 3, the pumping blades 37 in the solid shaft can enable air flow or water to rapidly pass through, so that heat on the rotating shaft 3 is rapidly taken away, the rotor 6 is directly arranged on the rotating shaft 3 in a winding manner, and the improvement of heat dissipation of the rotating shaft 3 substantially improves the heat dissipation speed of the rotor 6. Compared with the traditional mode of air cooling and heat dissipation by adopting a fan, the invention has novel structure, directly dissipates heat of the motor rotor 6, has better heat dissipation effect, and is particularly suitable for being applied to high-speed motors with serious heat generation. Because the rotating shaft 3 is designed to be a hollow shaft and the pumping paddle 37 is designed in the rotating shaft, compared with a solid shaft, the rotating shaft 3 has the advantages of reduced weight, higher power conversion rate and poorer stability in the rotating process, and therefore, the rotating shaft 3 is also provided with the liquid-filled self-balancing device 40. The liquid-filled automatic balancing device 40 is composed of a rotary disc filled with part of liquid, the liquid is thrown to the outer edge of the rotary disc due to the action of inertial centrifugal force, a cavity is formed near the middle part, and when the liquid runs at the supercritical rotating speed, the eccentric mass is opposite to the axial bending direction of the rotating shaft 3, so that the liquid plays a role in attenuating the amplitude. This is widely used in more shafts 3 and will not be described in the present invention.

In addition, the present invention may further include a plurality of heat dissipation fins 42, as shown in fig. 7 and 10, the heat dissipation fins 42 are uniformly disposed on the surface of the housing 1, and the heat dissipation fins 42 are in a wave shape. Even, a plurality of radiating pipes 43 penetrating the upper and lower surfaces of the casing 1 may be further disposed on the casing 1, wherein the upper ends of the radiating pipes 43 are welded to the casing 1 without seams, and the lower ends of the radiating pipes extend out of the casing 1 and form an airtight fit with the casing 1. External air or water can directly flow through the radiating pipe 43, so that the inside of the motor is directly radiated, the air or water forms ascending convection after heat exchange, and the radiating speed is further improved. The heat dissipation pipes 43 are located at the left and right sides of the rotor 6, and in order to further increase the heat dissipation speed of the heat dissipation pipes 43, a plurality of heat dissipation fins 44 are uniformly arranged on the outer side walls of the heat dissipation pipes 43. Through the mutual combination of the heat dissipation fin plates 42, the heat dissipation fins 44 and the heat dissipation pipes 43, the three-dimensional heat dissipation performance of the motor is improved, and the motor runs more stably and efficiently. In consideration of the installation and placement of the motor, the bottom of the housing 1 is further provided with an inverted U-shaped support frame 45, and the support frame 45 can also play a role of being overhead, so that air flow or water can enter the radiating pipe 43 conveniently.

Claims

1. A direct current motor with constant voltage electric brushes comprises a shell (1), a pair of stators (2) fixedly arranged on the inner wall of the shell (1), and a rotating shaft (3) arranged between the pair of stators (2); a mounting rack (4) is arranged on the inner wall of the shell (1) corresponding to one end of the rotating shaft (3), and an electric brush (5) is arranged on the mounting rack (4); a section of the rotating shaft (3) between the stators (2) is provided with a rotor (6) consisting of a magnetic core and an electromagnetic coil, and the electromagnetic coil is wound on the magnetic core; a commutator (7) is arranged on the position, opposite to the electric brush (5), of the rotating shaft (3), the commutator (7) is electrically connected with the electromagnetic coil, and the electric brush (5) is in contact with the commutator (7);

the method is characterized in that: the electric brush (5) comprises a base body (8) fixedly arranged on the mounting frame (4), a sliding hole (9) extending along the length direction of the base body (8) is formed in the end face, facing one end of the commutator (7), of the base body (8), and a carbon brush (10) matched with the sliding hole (9) is arranged in the outer end of the sliding hole (9); a driving block (11) matched with the sliding hole (9) is further arranged in the sliding hole (9), an electromagnet (12) and a permanent magnet (13) are respectively arranged on the surfaces, opposite to the carbon brush (10), of the driving block (11), the electromagnet (12) is opposite to the permanent magnet (13), and the electromagnet (12) and the permanent magnet (13) are mutually repelled in a power-on state; the sliding mechanism is characterized in that a pressure sensor (14), a sliding plate (15) and a supporting spring (16) are sequentially arranged at the bottom of the sliding hole (9) from inside to outside, a pressure signal acquisition end of the pressure sensor (14) faces the sliding plate (15) and is in contact with the sliding plate (15), and two ends of the supporting spring (16) are fixedly connected with the sliding plate (15) and the driving block (11) respectively.

2. The direct current motor having a constant voltage brush as claimed in claim 1, wherein: the driving block (11) is in a cap shape, and one end of the supporting spring (16) is positioned in the driving block (11).

3. The direct current motor having a constant voltage brush as claimed in claim 2, wherein: the end face, located at one end of the sliding hole (9), of the carbon brush (10) is provided with a conductive column, and the conductive column is connected with a wiring terminal (17) arranged on the shell (1) through a conductive copper wire.

4. The direct current motor having a constant voltage brush as claimed in claim 2, wherein: mounting bracket (4) and pedestal (8) are made by conductive material, it leads electrical pillar to set up on mounting bracket (4), it is connected with binding post (17) of setting on shell (1) through electrically conductive copper line to lead electrical pillar.

5. The direct current motor having a constant voltage brush as claimed in claim 4, wherein: a limiting cap (18) is further arranged at one end, facing the commutator (7), of the base body (8), the limiting cap (18) is in threaded connection with the base body (8), and a guide hole (19) is formed in the center of the limiting cap (18); the carbon brush (10) is T-shaped, and the outer end of the carbon brush (10) is matched with the guide hole (19) and penetrates through the guide hole (19).

6. The direct current motor having a constant voltage brush as claimed in claim 5, wherein: except the opposite surfaces of the electromagnet (12) and the permanent magnet (13), the other surfaces are provided with anti-interference coatings.

7. The direct current motor having a constant voltage brush as claimed in claim 6, wherein: the carbon brush is characterized in that a group of opposite and vertical sliding grooves (20) are formed in the side wall of the sliding hole (9), sliding blocks (21) matched with the sliding grooves (20) are arranged on the side wall of the carbon brush (10), and the sliding blocks (21) are located in the sliding grooves (20).

8. The direct current motor having a constant voltage brush as claimed in claim 7, wherein: and a silver plating layer is arranged on the inner wall of the sliding hole (9).

9. The direct current motor having a constant voltage brush as claimed in claim 8, wherein: a stepped installation cavity for the rotating shaft (3) to penetrate out is formed in the end face of the shell (1), the installation cavity is composed of a large-size section (28) and a small-size section (29), a bearing (30) is arranged in the large-size section (28), the rotating shaft (3) is located in the bearing (30), and the small-size section (29) and the rotating shaft (3) form clearance fit; a sealing disc (31) is further arranged on the rotating shaft (3) on the outer side of the bearing (30), the outward disc surface of the sealing disc (31) is a slope surface, and the sealing disc (31) is located in the large-size section (28); still be provided with one deck sealing washer (32) in jumbo size section (28), the outer edge of sealing washer (32) is fixed on the inner wall of jumbo size section (28) to form airtight cooperation, the one side of sealing washer (32) is attached on the domatic of sealed dish (31), the lateral wall of sealed dish (31), sealing washer (32), jumbo size section (28), the outer terminal surface of jumbo size section (28) enclose into high-pressure seal chamber jointly, still be provided with inflation inlet (33) with the inside intercommunication in high-pressure seal chamber on jumbo size section (28), inflation inlet (33) are connected with external air supply through the trachea.

10. The direct current motor having a constant voltage brush as claimed in claim 9, wherein: and an air pressure sensor (34) for detecting the air pressure in the high-pressure sealing cavity is also arranged on the inner wall of the outer end of the large-size section (28).