CN210643897U

CN210643897U - Motor and floor sweeping robot adopting same

Info

Publication number: CN210643897U
Application number: CN201920610839.5U
Authority: CN
Inventors: 王圣平; 魏明辉; 王立磊
Original assignee: Shenzhen Debao Motor Co ltd; Guangdong Bona Robot Co ltd
Current assignee: Shenzhen Debao Motor Co.,Ltd.; Guangzhou Keyu Robot Co Ltd
Priority date: 2019-04-28
Filing date: 2019-04-28
Publication date: 2020-06-02
Anticipated expiration: 2029-04-28

Abstract

The utility model discloses a motor and a sweeping robot adopting the motor, and the motor is characterized by comprising a magnet, a brush arm, a carbon element, a rotating shaft, a commutator and a coil; the carbon essence is fixed on the brush arm, the coil is fixed in the pivot, the commutator surface is fluted, the commutator includes insulating part and conductive part, the conductive part covers the surface at insulating part, the carbon essence with the conductive part contacts, the external diameter of conductive part is 3.8 ~ 4.2 mm. The utility model has the advantages that: because the outer diameter of the conductive part of the commutator is properly increased, carbon powder attached to the groove of the commutator due to continuous abrasion can be thrown away more easily in the using process, so that the risk of short circuit caused by the fact that the commutator is blocked by the carbon powder is reduced, the motor is prevented from being burnt out due to violent increase of the current of the motor, and the service life of the motor is prolonged.

Description

Motor and floor sweeping robot adopting same

Technical Field

The utility model belongs to the motor field especially relates to the inside motor of mobile robot.

Background

Because of the continuous improvement of the requirements of people on life convenience, the intelligent robot is more and more popular with users in the world, and various types and functional intelligent robots such as a floor sweeping robot, a mowing robot and a water and medicine spraying robot are in endless.

The running life of a wheel set motor of a 500-model household sweeper in the current market is about 800 hours. The reason for the short life is, first: the rubber core commutator with the outer diameter of 3.3mm is used in the motor. Because of the problems of the size structure and the material of the commutator, when the motor runs for a long time, the carbon powder is excessively accumulated. Because the carbon fine powder contains copper powder, the copper powder has the possibility of connecting and conducting the commutator copper sheets (the copper sheets are insulated from each other). Therefore, the motor is short-circuited, the current of the motor is increased violently, and the motor is burnt out, so that the service life of the motor is shortened. Secondly, the method comprises the following steps: dry-pressed ferrite magnets are used inside the motor. The central value of the magnetic flux density of the magnet is 350 gauss, and the central value is lower, so that the torque of the motor needs to be increased to meet the load requirement of the sweeper, and the enameled wire with the wire diameter of 0.15 is selected for the motor winding. Therefore, the starting current of the motor is about 1.3A, so that the starting current is large, the motor reversing spark is large due to large current, the carbon abrasion is aggravated, and the service life of the motor is short.

The utility model has the following contents:

for solving the technical problem in the background art, the utility model provides a technical scheme as follows:

a motor comprises a magnet, a brush arm, a carbon powder, a rotating shaft, a commutator and a coil;

the carbon essence is fixed on the brush arm, the coil is fixed in the pivot, the commutator surface is fluted, the commutator includes insulating part and conductive part, the conductive part covers the surface at insulating part, the carbon essence with the conductive part contacts, the external diameter of conductive part is 3.8 ~ 4.2 mm.

Further, in order not to short the conductive portion even if a small amount of carbon powder is accumulated in the groove, in an optimized solution of the present embodiment, the groove is disposed on the insulating portion, the conductive portion is two or more conductive sheets, and the groove separates the conductive sheets.

Further, in order to prevent fine carbon powder attached to the surface of the commutator from being easily stuck in the groove, in an optimized scheme of the embodiment, the width of the groove is 0.33-0.40 mm.

Further, in order to reduce the temperature-affected variation degree of the shape and volume of the commutator, in an optimized scheme of the embodiment, the commutator insulating part is made of bakelite, and the thermal expansion coefficient of the bakelite is 1.5-2.5 (× 10)^-5/℃)。

Further, in order to reduce the heat caused by friction and reduce unnecessary wear, in an optimized scheme in the embodiment, the roundness of the commutator is not more than 0.006mm, and the roughness is not more than 2.0 μm.

Further, in order to reduce the heat caused by friction and reduce unnecessary wear, in an optimized scheme of the embodiment, the magnets are wet-pressed ferrite magnets, and the central magnetic flux density is 400-480 gauss.

Preferably, the wet-pressed ferrite magnets have a central magnetic flux density of 460 gauss in an optimized version of the present embodiment, taking into account both the overall volume of the machine and the required magnetic flux.

Further, in order to reduce the starting spark and increase the resistance, in an optimized scheme of the embodiment, the coil is formed by winding a enameled wire, and the wire diameter of the enameled wire is 0.13-0.15 mm.

In order to increase centrifugal force and reduce accumulation of carbon powder in a commutator groove and not to increase the whole volume of the motor too much, the outer diameter of the conductive part is 4.0 mm.

The utility model also provides a robot of sweeping floor, the robot of sweeping floor includes: the machine comprises a machine body and/or a driving wheel set and/or a rolling brush and/or an edge brush and/or a suction fan and/or a laser radar, wherein the driving wheel set and/or the rolling brush and/or the edge brush and/or the suction fan and/or the laser radar adopts the motor.

The utility model has the advantages that: because the outer diameter of the conductive part of the commutator is properly increased, carbon powder attached to the groove of the commutator due to continuous abrasion can be thrown away more easily in the using process, so that the risk of short circuit caused by the fact that the commutator is blocked by the carbon powder is reduced, the motor is prevented from being burnt out due to violent increase of the current of the motor, and the service life of the motor is prolonged.

Description of the drawings:

in order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic view of the motor of the present invention;

FIG. 2 is an exploded view of the motor of the present invention;

fig. 3 is an enlarged view of a first view of the motor commutator of the present invention;

fig. 4 is an enlarged view of a second view of the electrode commutator of the present invention;

fig. 5 is a cross-sectional view of the motor commutator of the present invention;

fig. 6 is a first schematic view of a second embodiment of the present invention;

fig. 7 is a second schematic view of a second embodiment of the present invention.

The specific implementation mode is as follows:

in order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings. For convenience of explanation, the present embodiment uses directional terms such as left, right, inner, and outer, but this does not limit the scope of the present invention.

The roundness mentioned in the application refers to the degree that the cross section of the workpiece is close to a theoretical circle, when the difference between the maximum radius and the minimum radius is 0, the roundness is 0, and the measuring tool is a roundness meter and is used for measuring the roundness of the annular workpiece.

The roughness referred to in this application means: surface roughness (roughness) refers to the roughness of the machined surface with small pitches and minute peaks and valleys. The distance between two wave crests or two wave troughs (wave distance) is very small (below 1 mm), and the micro geometrical shape error belongs to. The smaller the surface roughness, the smoother the surface.

In a first embodiment exemplified in the present application, as shown in fig. 1 to 2, there is provided a motor 1 for a small-sized mobile robot for home use, which includes a housing 1, a magnet 2, a brush arm 3, a carbon 4, a top cover 5, a shaft 6, a commutator 7, and a coil 8. Top cap 5 and shell 1 constitute the outside of motor jointly, the inside rotor and the stator of mainly dividing into of motor, wherein, magnetite 2 divide into N, S two, fix and provide the permanent magnetic field inside the motor, carbon essence 4 is fixed on brush arm 3, brush arm 3 is fixed inside the motor, coil 8 is formed and fix on pivot 6 by the winding of enamel covered wire 81, as shown in fig. 2, pivot 6 has three

axle branch

61, 3 sections coil 8 twine respectively and fix on three axle branch 61, there is the electric current to pass through in the enamel covered wire 81 after the motor circular telegram, according to the left-hand rule, the power that coil 8 received forms a moment, make the pivot rotate.

As shown in fig. 3 to 5, the commutator 7 is divided into an insulating portion 71 and a conductive portion 72, the conductive portion 72 uniformly covers the surface of the insulating portion 71, the insulating portion 71 of the conventional motor commutator 7 is usually made of rubber-core nylon, and the thermal expansion coefficient is 8.0 × 10^-5The commutator insulating part 71 adopted in the embodiment is made of bakelite, the chemical name of which is phenolic plastic, and the expansion coefficient is 1.5-2.5 multiplied by 10^-5The commutator 7 made of the changed materials is more heat-resistant, and the expansion degree caused by heating is reduced, so that the roundness of the commutator 7 is ensured, the spark of the motor is not too large, and the wear degree of the motor is reduced.

After the rubber core commutator is changed into an electric wood commutator, the roundness of the commutator 7 is not more than 0.006mm, and the roughness is not more than 2.0 μm. The commutator 7 with such precision can further reduce the abrasion of the carbon 4 and prolong the service life of the motor. In order to achieve the precision, the surface machining process of the commutator 7 needs to be changed from polishing to lathe finish turning.

According to the working principle of the motor, the carbon 4 is a device for transmitting energy or signals between a fixed part and a rotating part of a motor or a generator or other rotating machinery, the carbon 4 is fixed on the brush arm 3, the brush arm 3 is fixed in the motor, the carbon 4 is in contact with a conductive part 72 of the commutator 7, the commutator 7 can rotate continuously when the motor is started, so the conductive part 72 can rub the carbon continuously, the carbon 4 is mainly made of graphite, impregnated graphite and metal (copper-containing and silver-containing) graphite, and the carbon 4 is easy to wear because the graphite is soft, and the carbon powder falling off from the carbon 4 can be attached to the surface of the commutator 7 after the motor is used for a period of time because the carbon is rubbed continuously. The insulating part 71 of the commutator is a similar cylinder, the conductive part 72 is three conductive sheets, the conductive sheets are copper sheets in the embodiment, the three copper sheets are not connected with each other, the copper sheets cover the surface of the insulating part 71, the surface of the insulating part 71 is provided with 3 grooves 73 which are uniformly distributed, the grooves 73 enable the copper sheets to be spaced from each other, and the insulating effect among the copper sheets can be better. However, since the carbon powder is conductive, when the carbon powder is accumulated to a certain degree, the copper sheets which should not be connected with each other are mutually short-circuited to form a ring fire, and the commutator 7 breaks down quickly.

The diameter of the cross section of the portion of the commutator 7 covered by the copper sheet is called as an outer diameter D, in this embodiment, the outer diameter D of the commutator is increased from the original 3.3mm to 4.0mm, and according to a calculation formula F of centrifugal force, m ω ^2r, where m is mass, ω is angular velocity, and 2r is the diameter, that is, the outer diameter D, it can be known that the centrifugal force is also increased when the outer diameter D is increased, and fine carbon powder attached to the surface of the commutator 7 can be thrown away more easily due to the increase of the centrifugal force, so that the accumulation of the fine carbon powder in the commutator groove 73 is reduced, and the short circuit caused by excessive accumulation of the fine carbon powder is avoided.

In this embodiment, the width W of the commutator groove 73 is increased by 0.3mm to 0.35mm adopted in this embodiment, the width W of the groove 73 is increased, carbon powder accumulated in the groove 73 is effectively reduced, and the risk that the carbon powder connects adjacent copper sheets is reduced, so that the short circuit phenomenon of the motor is avoided.

In the present embodiment, the depth of the commutator groove 73 is also increased appropriately, so that even if a small amount of carbon powder is accumulated in the groove, the adjacent copper sheets of the conductive part 72 on the surface of the commutator 7 are not connected by the carbon powder because the groove has a certain depth.

The groove 73 of the commutator 7 is provided on the surface of the insulating portion 71, and the groove 73 is not covered with the conductive portion 72, so it can also be understood that the groove 73 is provided on the surface of the insulating portion 71 as well as on the surface of the commutator 7.

As shown in fig. 2, in the present embodiment, the magnet 2 of the motor is a wet-pressed ferrite magnet, and the magnetic flux density is 460 gauss, which is higher than that of the originally used dry-pressed ferrite magnet, so that the wire diameter of the enameled wire 81 is changed from 0.15mm to 0.14mm under the condition that the motor keeps the same torque, and the wire diameter here follows the industry standard and means the diameter of the enameled wire is not contained. The resistance value of the rotor is increased from 6.8 ohms to 7.5 ohms, and the starting current of the motor is reduced from 1.3A to 1.15A. Therefore, the starting spark of the motor is reduced, the burning of the internal parts of the motor is avoided, and the service life of the motor is prolonged.

As shown in fig. 6 and 7, in a second embodiment of the present application, there is provided a sweeping robot, including: the motor comprises a machine main body 100, a driving wheel group 101, a rolling brush 102, an edge brush 103, a suction fan (not shown in the figure), a laser radar (not shown in the figure) and the like, wherein the left and right driving wheel groups 101, the rolling brush 102 and the edge brush 103 are all arranged at the bottom of the machine main body, the laser radar is arranged at the top of the machine main body 100 and the suction fan is arranged inside the machine main body 100, and the left and right driving wheel groups 101, the rolling brush 102, the edge brush 103, the suction fan and the laser radar can all use the motor.

Compared with the prior art, the utility model provides a motor is when rated voltage is 15.0VDC, and load operation more than 1500 hours improves the life of motor greatly, and this kind of motor can be used in removing electrical apparatus, for example the robot of sweeping the floor, robot of mowing etc. can improve the life of these electrical apparatus by a wide margin.

Those of ordinary skill in the art will understand that: the above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A motor is characterized by comprising a magnet (2), a brush arm (3), a carbon powder (4), a rotating shaft (6), a commutator (7) and a coil (8);

carbon essence (4) are fixed on brush arm (3), coil (8) are fixed on pivot (6), commutator (7) surface is fluted (73), commutator (7) are including insulating part (71) and conductive part (72), conductive part (72) cover is on the surface of insulating part (71), carbon essence (4) with conductive part (72) contact, the external diameter (D) of conductive part (72) is 3.8 ~ 4.2 mm.

2. The machine according to claim 1, characterized in that the grooves (73) are arranged on the insulating part (71), the conducting parts (72) are two or more conducting strips, and the grooves (73) separate the conducting strips.

3. The machine according to claim 1, characterized in that the width (W) of the groove (73) is 0.33-0.40 mm.

4. The motor according to claim 1, wherein the insulating part (71) is made of bakelite having a thermal expansion coefficient of 1.5 to 2.5(× 10)^-5/℃)。

5. A machine as claimed in claim 1, characterized in that the commutator (7) has a roundness of not more than 0.006mm and a roughness of not more than 2.0 μm.

6. The motor according to claim 1, wherein the magnet (2) is a wet-pressed ferrite magnet having a central magnetic flux density of 400 to 480 gauss.

7. The electric machine of claim 6, wherein the wet-pressed ferrite magnets have a central flux density of 460 gauss.

8. The motor according to claim 1, wherein the coil (8) is formed by winding a enameled wire (81), and the wire diameter of the enameled wire (81) is 0.13-0.15 mm.

9. The machine according to claim 1, characterized in that the outer diameter (D) of the conductive part (72) is 4.0 mm.

10. The utility model provides a robot of sweeping floor which characterized in that: the robot of sweeping the floor includes: machine body (100) and/or drive wheel set (101) and/or roller brush (102) and/or side brush (103) and/or suction fan and/or lidar, said drive wheel set (101) and/or roller brush (102) and/or side brush (103) and/or suction fan and/or lidar employing an electric machine according to any of claims 1 to 9.