Structure for improving abnormal electromagnetic noise of brush motor

Abstract

The utility model provides a structure for improving electromagnetic noise and abnormal noise of a brush motor, relates to the field of brush motors, and adopts the following scheme that the structure comprises a motor body, the motor body comprises a rotor mechanism and a shell mechanism, the rotor mechanism comprises a rotor iron core, a motor shaft and two magnets, the motor shaft comprises a long shaft section, a shaft body section and a short shaft section, the long shaft section, the shaft body section and the short shaft section are fixedly connected in sequence, the rotor iron core is fixedly arranged on the outer side of the shaft body section in a sleeving mode, and a first bearing is arranged on the outer side of the long shaft section. The motor shaft is arranged to be the section difference shaft, the diameter of the long shaft section is smaller than that of the shaft body section, so that the first bearing can be in interference fit with the shaft body section to form a close-fitting side, and the problems of motor shaft bending and bearing deformation caused by long-distance interference of the long shaft end are solved; the second bearing can pass through the short shaft end in a sliding fit mode and is in close fit with the shaft body section, and therefore the abnormal noise problem of the ball bearing is greatly reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a brushed motor technical field especially relates to a brushed motor improves electromagnetic noise abnormal sound structure. BACKGROUND

[0002] With the development of new energy electric vehicles, in order to better drive, ride comfortable experience, will request the component system of personnel position close, noise is small, and cannot have abnormal sound, and cannot cause human ear ear feeling discomfort, and because the new energy electric vehicle is high in performance price ratio, requires the low price of spare part, brushed DC motor is a kind of motor that current commutation is realized by brush and commutator, and the micro brushed motor of 395 in the automobile central screen driving motor is often selected in market, the price can satisfy the low requirement of car factory, but cannot completely satisfy the requirement of low noise, no abnormal sound, in the production process, there will be about 20% motor noise exceeds, abnormal sound problem.

[0003] When the motor shaft of the existing micro brushed motor is interference fit and press-fitted with the inner hole of the micro bearing, the ball bearing abnormal sound problem is often generated, and the proportion of ball bearing abnormal sound is as high as 5% to 10%, therefore we propose a kind of brushed motor improves electromagnetic noise abnormal sound structure to solve this problem. SUMMARY

[0004] In order to solve the above problems, the utility model provides a kind of brushed motor improves electromagnetic noise abnormal sound structure to more exactly solve the above-mentioned problems.

[0005] The utility model is realized by the following technical schemes:

[0006] The utility model provides a kind of brushed motor improves electromagnetic noise abnormal sound structure, including motor body, the motor body includes rotor mechanism and shell mechanism, the rotor mechanism includes rotor iron core, motor shaft and two magnet, the motor shaft includes long shaft section, shaft body section and short shaft section, the long shaft section, shaft body section and short shaft section are sequentially fixedly connected, the rotor iron core is fixedly covered in the outside of shaft body section, the outside of long shaft section is provided with bearing one, the inner hole of bearing one is fixedly connected with the outside of shaft body section, the outside of short shaft section is provided with bearing two, the inner hole of bearing two is slidably connected with the outside of shaft body section.

[0007] Further, the diameter of the long shaft section is less than the diameter of the shaft body section, and the diameter of the shaft body section is greater than the diameter of the short shaft section.

[0008] Further, the shell mechanism includes a shell and a rear cover, the shell and the rear cover are both provided with a protruding portion, the bearing one is arranged at the protruding portion on the shell and the outer ring of the bearing one is glued and fixedly connected with the shell, and the bearing two is arranged at the protruding portion on the rear cover and the outer ring of the bearing two is slidably connected with the rear cover.

[0009] Further, the connecting part of the long shaft section, the shaft body section and the short shaft section is smooth transition, and the mutually faraway end of the shaft body section and the short shaft section is provided as a round corner.

[0010] Further, the outer side of the long shaft section and the short shaft section is provided as a slide surface, and the outer side of the long shaft section and the short shaft section is treated by nitriding.

[0011] Further, the outer side of the rotor core is provided with a plurality of positioning ribs, the two ends of the magnet are movably abutted with the corresponding two positioning ribs respectively, and a gap exists between the magnet and the rotor core.

[0012] Further, the magnet is fixedly installed on the outer side of the rotor core, the cross section of the magnet is arc-shaped, and the magnet adopts an eccentric structure.

[0013] Further, the two magnets are centrally symmetrically arranged, and the included angle between the two pole center lines of the magnet is 144-145 degrees.

[0014] The beneficial effects of the utility model are:

[0015] 1. the motor shaft is provided as a stepped shaft, the diameter of the long shaft section is smaller than the diameter of the shaft body section, bearing one can be in interference fit with the shaft body section to form a tight fit side, the problem of motor shaft bending and bearing deformation caused by long shaft end long distance interference is reduced, the diameter of the shaft body section is larger than the diameter of the short shaft section, bearing two can be in slip fit through the short shaft end and the shaft body section to form a tight fit, thereby the problem of ball bearing abnormal sound is greatly reduced.

[0016] 2. by setting the magnet as an eccentric structure, the position relationship of the magnetic pole relative to the stator tooth can be changed, the magnetic flux density changes more smoothly and continuously, and the uneven air gap is formed between the magnet and the rotor core, in the traditional concentric structure, the difference of the air gap width under different angles is very small, by using the uneven air gap characteristics, the torque fluctuation caused by the uniform air gap change is reduced, the motor tooth slot torque is reduced, and the motor noise is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 a cross-sectional structure schematic view of a motor body of a brush motor structure for improving electromagnetic noise and abnormal sound is provided for the utility model;

[0018] Figure 2 a front view structure schematic view of a rotor mechanism of a brush motor structure for improving electromagnetic noise and abnormal sound is provided for the utility model;

[0019] Figure 3 a plane structure schematic view of a motor shaft of a brush motor structure for improving electromagnetic noise and abnormal sound is provided for the utility model;

[0020] Figure 4 The utility model provides a kind of magnet of the structure of improving electromagnetic noise abnormal sound of brush motor improves the plane structure schematic diagram of magnet.

[0021] Reference signs are as follows:

[0022] In the drawing: 1, motor body;2, rotor mechanism;3, rotor core;4, motor shaft;5, magnet;6, long shaft section;7, shaft body section;8, short shaft section;9, bearing one;10, bearing two;11, shell;12, rear cover;13, protruding portion. Specific embodiments

[0023] In order to more clearly and completely illustrate the technical scheme of the utility model, the utility model is further described below in combination with the drawings.

[0024] Please refer to Figures 1-4 The utility model provides a kind of structure of improving electromagnetic noise abnormal sound of brush motor, including motor body 1, motor body 1 includes rotor mechanism 2 and shell mechanism, rotor mechanism 2 includes rotor core 3, motor shaft 4 and two magnets 5, motor shaft 4 includes long shaft section 6, shaft body section 7 and short shaft section 8, long shaft section 6, shaft body section 7 and short shaft section 8 are fixedly connected in turn, rotor core 3 is fixedly covered in the outside of shaft body section 7, the outside of long shaft section 6 is provided with bearing one 9, the inner hole of bearing one 9 is fixedly connected with the outside of shaft body section 7, the outside of short shaft section 8 is provided with bearing two 10, the inner hole of bearing two 10 is tightly connected with the outside of shaft body section 7.

[0025] In the embodiment, the diameter of long shaft section 6 is less than the diameter of shaft body section 7, and the diameter of shaft body section 7 is greater than the diameter of short shaft section 8.

[0026] In the embodiment, the shell mechanism includes shell 11 and rear cover 12, the protruding portion 13 is arranged on the shell 11 and the rear cover 12, the bearing one 9 is arranged on the protruding portion 13 of the shell 11, and the outer ring of the bearing one 9 is glued and fixedly connected with the shell 11, and the bearing two 10 is arranged on the protruding portion 13 of the rear cover 12, and the outer ring of the bearing two 10 is slidingly connected with the rear cover 12.

[0027] It should be noted that the motor shaft 4 is provided as a stepped shaft, the inner hole of the bearing one 9 is fixedly connected with the outside of the shaft body section 7, which is a tight fitting side, the bearing one 9 on the tight fitting side is firmly installed on the stepped shaft by interference fit, which can withstand working load and transmit torque;The inner hole of bearing two 10 is fixedly connected with the outside of shaft body section 7, which is also a tight fitting side.

[0028] It is to be noted that the bearing one 9 and the bearing two 10 are respectively slidably fitted through the long shaft section 6 and the short shaft section 8 and tightly fitted with the shaft body section 7, so as to reduce the stress concentration caused by the interference fit, and help to prevent abnormal sound generated between the bearing, the shell 11 and the rear cover 12. Through the tight fitting of the bearing one 9 and the tight fitting of the bearing two 10, the shaft bending of the motor shaft 4 and the deformation of the bearing caused by the long-distance interference are reduced, so as to greatly reduce the abnormal sound problem of the ball bearing.

[0029] In the embodiment, the connection parts of the long shaft section 6, the shaft body section 7 and the short shaft section 8 are smoothly transitioned, the mutually faraway ends of the shaft body section 7 and the short shaft section 8 are respectively provided as a round corner, and the bearing one 9 and the bearing two 10 are respectively provided as a ball bearing. The round corner is helpful to guide the ball bearing to smoothly slide into the correct position, and can also reduce the potential damage to the ball bearing in the assembly process. The chamfering can limit the ball bearing.

[0030] In the embodiment, the outer sides of the long shaft section 6 and the short shaft section 8 are respectively provided as a sliding surface, and the outer sides of the long shaft section 6 and the short shaft section 8 are respectively subjected to nitriding treatment. The nitriding treatment can form a hard and wear-resistant nitriding layer on the outer sides of the long shaft section 6 and the short shaft section 8, so as to improve the wear resistance of the long shaft section 6 and the short shaft section 8. The sliding surface setting reduces the static friction coefficient of the surface of the long shaft section 6 and the short shaft section 8, so as to reduce the energy loss and wear, and helps the bearing one 9 and the bearing two 10 to be installed in the appropriate position.

[0031] In the embodiment, the outer side of the rotor core 3 is provided with a plurality of positioning ribs, the two ends of the magnet 5 respectively abut against the corresponding two positioning ribs, and there is a gap between the magnet 5 and the rotor core 3. The magnet 5 is fixedly installed on the outer side of the rotor core 3, the cross section of the magnet 5 is arc-shaped, and the magnet 5 adopts an eccentric structure.

[0032] It is to be noted that the arc-shaped magnet 5 can help to form a more smooth and continuous magnetic field, and the outer side and the inner wall of the magnet 5 are respectively provided as an arc line. The centers of the two arc lines are different, that is, the magnet 5 is provided as an eccentric structure. By setting the magnet 5 as an eccentric structure, the positional relationship of the magnetic pole relative to the stator tooth can be changed, so that the magnetic flux density changes more smoothly and continuously. An uneven air gap is formed between the magnet 5 and the rotor core 3. In the traditional concentric structure, the difference in air gap width at different angles is very small. By using the uneven air gap feature, the torque fluctuation caused by the change of the uniform air gap is reduced, the motor tooth slot torque is reduced, and the motor noise is reduced.

[0033] In the embodiment, the two magnets 5 are centrally symmetrically arranged, and the included angle between the two magnetic pole center lines of the magnet 5 is set to 144 to 145 degrees.

[0034] It should be noted that, unlike the traditional inner and outer diameter concentric and the angle of the side is 135 magnet 5, the angle of the side is 144 to 145 degrees magnet 5 by adjusting the relative angle between the magnetic poles, can effectively reduce the harmonic components generated during the operation of the motor, thereby reducing noise, vibration, and improving efficiency, and make up for the lack of eccentric magnetic energy of the magnet 5, without affecting the electrical performance of the motor.

[0035] Of course, the utility model can also have other various implementation manners, based on the present embodiment, other implementation manners obtained by the ordinary skilled in the art without any creative labor all belong to the range protected by the utility model.

Claims

1. A structure for improving electromagnetic noise in a brushed motor, characterized in that, The device includes a motor body, which comprises a rotor mechanism and a housing mechanism. The rotor mechanism includes a rotor core, a motor shaft, and two magnets. The motor shaft includes a long shaft section, a shaft body section, and a short shaft section, which are sequentially and fixedly connected. The rotor core is fixedly sleeved on the outside of the shaft body section. A bearing is provided on the outside of the long shaft section, and the inner hole of the bearing is fixedly connected to the outside of the shaft body section. A bearing is provided on the outside of the short shaft section, and the inner hole of the bearing is fixedly connected to the outside of the shaft body section.

2. The structure for improving electromagnetic noise in a brushed motor according to claim 1, characterized in that, The diameter of the long axis segment is smaller than the diameter of the shaft body segment, and the diameter of the shaft body segment is larger than the diameter of the short axis segment.

3. The structure for improving electromagnetic noise in a brushed motor according to claim 1, characterized in that, The outer casing mechanism includes a housing and a rear cover. Both the housing and the rear cover are provided with protrusions. Bearing 1 is disposed on the protrusion on the housing and its outer ring is fixedly connected to the housing. Bearing 2 is disposed on the protrusion on the rear cover and its outer ring is slidably connected to the rear cover.

4. The structure for improving electromagnetic noise in a brushed motor according to claim 1, characterized in that, The connections between the long shaft segment, the shaft body segment, and the short shaft segment are all smoothly transitioned, and the ends of the shaft body segment and the short shaft segment that are far apart from each other are all rounded.

5. The structure for improving electromagnetic noise in a brushed motor according to claim 1, characterized in that, The outer sides of both the long and short shaft sections are provided with a smooth surface, and the outer sides of both the long and short shaft sections are nitrided.

6. The structure for improving electromagnetic noise in a brushed motor according to claim 1, characterized in that, The outer side of the rotor core is provided with several positioning ribs, and the two ends of the magnet are respectively in movable contact with the two corresponding positioning ribs, and there is a gap between the magnet and the rotor core.

7. The structure for improving electromagnetic noise in a brushed motor according to claim 1, characterized in that, The magnet is fixedly installed on the outside of the rotor core. The cross-section of the magnet is arc-shaped and the magnet adopts an eccentric structure.

8. The structure for improving electromagnetic noise in a brushed motor according to claim 1, characterized in that, The two magnets are arranged in a centrally symmetrical manner, and the included angle between the center lines of the two magnetic poles of the magnets is set to 144 degrees to 145 degrees.

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