Motor rotor structure

Abstract

The utility model discloses a motor rotor structure, which comprises a rotor assembly and a rotating shaft, the rotor assembly comprises a rotor iron core sleeved on the rotating shaft and magnetic steel clamped in a magnetic groove on the outer wall of the rotor iron core, and a plurality of airflow holes are arranged in the rotor iron core. The motor rotor structure is characterized in that a rotor core is arranged in the rotor assembly, so that air flow can pass through the interior of the rotor core when the motor runs, the outer wall of the rotor assembly is coated with a shell, so that the magnetic steel is fixedly connected with the rotor core, and the motor rotor structure is good in heat dissipation performance and stable in running.

Description

Technical Field

[0001] The utility model relates to the technical field of motor rotors, and particularly relates to a motor rotor structure. Background Art

[0002] At present, most automobile enterprises in the automobile market use brushed DC motors for the air compressors of air suspension systems. This motor can be electrically connected to the battery with the help of a relay. When starting, a very high starting current will appear, which will cause a temporary voltage drop of the battery, resulting in unstable voltage. The voltage fluctuation will cause the operation of other electrical appliances to be unstable and the operation of the motor itself to be unstable, resulting in current fluctuation and speed change, and the non-optimal operation state of the motor, which will cause wear of the carbon brushes, generate electromagnetic sparks while generating noise, and cause electromagnetic interference to in-vehicle electronic instruments and affect their normal work. At the same time, the brushed DC motor has defects such as low working efficiency, high power consumption, short service life, and high noise, which will affect the comfort and satisfaction of customers with the product.

[0003] If the brushed motor is replaced with a traditional brushless motor, its rotor usually bonds the magnetic steel to the surface of the rotor core with high-strength and high-temperature resistant structural glue and uses it after complete curing. Then, balance baffles can be added at both ends of the rotor core as needed to perform balance process treatment to reduce rotor vibration and thus reduce noise. Then, a stainless steel sheath can be added to the outer surface of the rotor magnetic steel as needed to prevent the magnetic steel bonding from loosening due to centrifugal force or high-temperature baking during long-term operation of the whole machine.

[0004] The above rotor, especially when applied to the field of air compressors of automobile air suspension systems, has the following defects: when the air compressor works continuously and the temperature of the motor rises, it is difficult for the heat of the rotor to dissipate, which will cause the phenomenon of magnetic steel demagnetization; moreover, the continuous high-intensity work of the rotor will cause problems in the reliability, vibration and noise of the motor. Therefore, the utility model aims to provide a motor rotor structure with good heat dissipation performance and stable operation. Content of the Utility Model

[0005] For this reason, the utility model provides a motor rotor structure to solve the above defects in the prior art.

[0006] A motor rotor structure includes a rotor assembly and a rotating shaft. The rotor assembly includes a rotor core sleeved on the rotating shaft and magnetic steel clamped and installed in a magnetic groove on the outer wall of the rotor core. A plurality of air flow holes are formed in the rotor core so that air flow can pass through the inside of the rotor core when the motor operates. The outer wall of the rotor assembly is covered with a housing to tightly connect the magnetic steel and the rotor core.

[0007] Preferably, the housing includes a first end, a second end, and a connecting sleeve connecting the first end and the second end. The first end and the second end are configured at both ends of the rotor core, and through holes communicating with the air flow holes are provided on the first end and the second end.

[0008] Preferably, a plurality of convex ribs are annularly arranged on the outer side surfaces of the first end and the second end, so as to accelerate the air flow on the side of the through holes when the motor operates.

[0009] Preferably, a wind blade structure is installed on the rotating shaft on one side of the housing.

[0010] Preferably, a plurality of the air flow holes penetrate through the rotor core in an annular array, and the air flow holes are all arranged parallel to the central axis of the rotating shaft.

[0011] Preferably, the housing is constructed on the surface of the rotor assembly by injection molding.

[0012] Preferably, the number of the magnetic slots is 4, 6 or 8.

[0013] Preferably, a groove is provided on the outer wall of the rotor core between two adjacent magnetic slots.

[0014] Preferably, the housing is injection-molded with PPS material.

[0015] Preferably, a thermal barrier coating treatment is performed on the shaft end of the rotating shaft.

[0016] The utility model has the following advantages:

[0017] (1) In the rotor structure of the utility model, a plurality of air flow holes are provided on the rotor core, so that air can pass through the inside of the rotor core, and convex ribs or wind blade structures capable of stirring the air on the side of the air flow holes are constructed at one end or both ends of the rotor assembly to promote gas flow. When the motor operates, the heat generated by the compressor is blown away, thereby reducing the heat of the brushless motor, effectively preventing the demagnetization problem of the magnetic steel, and at the same time improving the duty cycle of the air compressor; Secondly, due to the provision of the air flow holes, the weight of the rotor core can be reduced, the moment of inertia is reduced, and the starting performance of the brushless motor is improved;

[0018] (2) In addition, by forming a housing on the outside of the rotor assembly through an injection molding process, the rotor core and the magnetic steel are combined into a whole, preventing the magnetic steel from being damaged and broken due to collision during the production process, and effectively preventing the magnetic steel from loosening due to centrifugal force; The housing is injection-molded integrally, and there is no need to provide balance baffles commonly used in rotor manufacturing at both ends of the rotor core. The convex ribs and the housing are integrally formed, saving manufacturing costs; The housing and its accessories do not need to be arranged on the rotor assembly in a mechanically matching manner, which can reduce the vibration during rotor operation, thereby reducing noise. Brief Description of the Drawings

[0019] Figure 1 is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0020] Figure 2 is a schematic diagram of the structure of the rotor assembly of the present utility model sleeved on the rotating shaft;

[0021] Figure 3 is a schematic diagram of the structure of the rotor assembly of the present utility model;

[0022] Figure 4 is a schematic diagram of the cross-sectional structure of the present utility model;

[0023] Figure 5 is a schematic diagram of the structure of another embodiment of the present utility model.

[0024] In the figure:

[0025] 1 - rotating shaft; 2 - rotor assembly; 3 - housing; 4 - blade structure; 5 - bearing; 10 - central axis; 201 - rotor core; 202 - magnetic slot; 203 - magnetic steel; 204 - air flow hole; 205 - sleeve hole; 206 - groove;

[0026] 301 - connecting sleeve; 302 - first end; 303 - second end; 304 - through hole; 305 - protruding rib. Detailed Description of the Embodiment

[0027] In order to make the technical means, creative features, achieved purposes and effects of the present utility model easy to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0028] The motor rotor structure of the embodiment of the present utility model can be installed, for example, in household appliances such as air conditioners, air purifiers or refrigerators, and can be used as a driving source for fans or pumps; or, the motor rotor structure of the embodiment of the present utility model can be used as a driving source for industrial equipment, for example, the driving force of a sorting machine or a vehicle air compressor; it should be emphasized that the motor rotor structure of the present utility model can be used for other purposes, for example, according to other preferred embodiments of the present utility model, the rotor structure can be installed in office automation equipment, medical equipment, and automobiles as power.

[0029] Such as Figures 1 to 5As shown in the figure, the present utility model provides a motor rotor structure, which includes a rotor assembly 2 and a rotating shaft 1. The rotor assembly 2 includes a rotor core 201 sleeved on the rotating shaft 1 and a permanent magnet 203 clamped and installed in a magnetic slot 202 on the outer wall of the rotor core 201. In the prior art, the magnetic slots 202 are arranged in a circular array on the outer wall of the rotor core 201. And in the embodiment of the present utility model, the rotor can be an inner rotor structure. The number of the magnetic slots 202 is preferably 4, 6 or 8, and a reasonable slot-pole matching structure such as six slots and four poles, nine slots and six poles, twelve slots and eight poles is preferably adopted.

[0030] The outer wall of the rotor assembly 2 is coated with a housing 3 to tightly connect the permanent magnet 203 and the rotor core 201. Preferably, the housing 3 is constructed on the surface of the rotor assembly 2 by injection molding. The housing 3 is preferably made of PPS (polyphenylene sulfide) material when injection molding. PPS plastic (polyphenylene sulfide) is a thermoplastic special engineering plastic with excellent comprehensive performance. Its prominent features are high temperature resistance, corrosion resistance and superior mechanical properties. The material used for injection molding can also be modified PPS plastic. By selecting the injection molding material, the processing efficiency of the motor rotor can be further improved and the performance of the housing 3 can be enhanced.

[0031] In the embodiment of the present utility model, the shaft end of the rotating shaft 1 is treated with a thermal barrier coating. The rotating shaft 1 is matched with an eccentric wheel (not shown in the figure) having a certain eccentric distance. During operation, the temperature of the air compressor will be very high, and the surface of the cylinder head may reach 150 degrees or even 180 degrees; the heat inside the air compressor will be conducted to the motor structure through the combination of the eccentric wheel and the rotating shaft, causing the temperature inside the motor to rise, and even possibly causing the demagnetization of the rotor permanent magnet. To avoid this phenomenon, a thermal barrier coating process is performed on the output shaft part of the rotating shaft 1 to reduce the heat conducted from the air compressor to the motor through the combination of the eccentric wheel and the rotating shaft, reduce the temperature rise of the motor (the temperature reduction effect is 10%-15%), and to a certain extent avoid the demagnetization failure of the permanent magnet 203 caused by being in a high temperature state for a long time; at the same time, the temperature resistance grade of the permanent magnet 203 can be reduced to save the cost of the permanent magnet.

[0032] To improve the heat dissipation efficiency of the rotor structure, a plurality of air flow holes 204 are opened in the rotor core 201 so that air can flow through the inside of the rotor core 201 when the motor is running. Preferably, a plurality of the air flow holes 204 are arranged in a circular array and penetrate through the rotor core 201. This setting method is beneficial to the smooth flow of air.

[0033] Furthermore, a plurality of the air flow holes 204 are symmetrically distributed around the rotating shaft 1. In the embodiment of the present utility model, the number of the air flow holes 204 is four arranged in a circular array around the rotating shaft 1.

[0034] The number of the air flow holes 204 can be more or less, for example, the number of the air flow holes 204 is not limited to 2, 4, 6, 8, 10 or more.

[0035] In the embodiment of the present utility model, the air flow holes 204 are all parallel to the central axis 10 of the rotating shaft 1.

[0036] In order to improve the injection molding efficiency of the housing 3, a groove 206 is formed on the outer wall of the rotor core 201 between two adjacent magnetic slots 202 in the embodiment of the present utility model.

[0037] In one embodiment of the present utility model, the housing 3 includes a first end 302, a second end 303, and a connecting sleeve 301 connected between the first end 302 and the second end 303. The connecting sleeve 301 is preferably cylindrical. The first end 302 and the second end 303 are configured at both ends of the rotor core 201, and through holes 304 communicating with the air flow holes 204 are formed on the first end 302 and the second end 303 to improve the heat dissipation efficiency of the motor rotor structure.

[0038] In the embodiment of the present utility model, in order to further improve the heat dissipation efficiency of the motor rotor structure, a plurality of convex ribs 305 are annularly arranged on the outer side surfaces of the first end 302 and the second end 303. The convex ribs 305 are located on both sides of the through holes 304 so as to accelerate the air flow on the side of the through holes 304 when the motor runs. The convex ribs 305 are similar to the blades of an axial flow fan and play a role in stirring the air flow, so that the heat generated during the operation of the brushless motor can be timely transferred out from the through hole 304 part through the air flow hole 204. Since the heat is dissipated in time, the temperature of the brushless motor will not be too high during operation.

[0039] The plurality of convex ribs 305 are preferably integrally injection molded with the housing 3 on the outer side of the rotor assembly 2 to improve the production efficiency of the rotor structure.

[0040] In another embodiment of the present utility model, the plurality of convex ribs 305 for heat dissipation can be replaced with a wind blade structure 4 installed on the rotating shaft 1 on one side of the housing 3, which can also achieve a similar heat dissipation effect. The blades of the wind blade structure 4 are preferably inclined.

[0041] Bearings 5 are installed on both sides of the rotor assembly 2 on the rotating shaft 1, and the wind blade structure 4 is preferably arranged between one side bearing 5 and one side end of the housing 3.

[0042] When the motor rotor structure rotates in one direction, the fan blade structure 4 rotates with the rotating shaft 1 and generates negative pressure near the through hole 304, so that air passes through a plurality of air flow holes 204, accelerating the heat dissipation effect. The time interval of this cycle is short, and due to the limited interference between the air flow holes 204 and the fan blade structure 4, no large noise will be generated.

[0043] Furthermore, each air flow hole 204 has an arc-shaped edge part, and this setting method helps to reduce the interference between the air flow holes 204 and the fan blade structure 4 and reduce noise.

[0044] In the embodiment of the present utility model, the rotor core 201 is made of laminated silicon steel sheets (by processes such as riveting, laser welding, or resin bonding), the lamination coefficient is greater than 0.97; the original unbalance is less than 150 mg; the silicon steel sheet material is 50W470, 35W300, 35W310 or even better quality silicon steel sheets, and the surface is treated with rust prevention to prevent rusting, and the iron loss during operation is minimized as much as possible.

[0045] In the embodiment of the present utility model, the magnet 203 is made of high-strength neodymium iron boron material, which belongs to the "three highs" magnets (remanent magnetism, coercivity, magnetic energy product). The temperature resistance grade of the magnet can be selected as SH, UH or even higher. The magnet magnetization method can be radially magnetized, parallel magnetized or other magnetization processes (Halbach magnetization) according to actual needs. The surface of the magnet is treated with rust prevention, such as galvanizing, nickel plating, etc., to ensure no rust after the salt spray test required by customers;

[0046] In the embodiment of the present utility model, the material of the rotating shaft 1 is medium carbon steel (40Cr, 45#, etc.), and it is quenched and tempered to achieve the best compatibility of hardness and toughness; especially at the part connected to the compressor, the output shaft diameter of the rotating shaft is 10 mm - 12 mm, and local high-frequency quenching treatment is carried out, and the hardness is HRC50 - 60; to improve the anti-bending fatigue strength of the rotating shaft and reduce the risk of shaft bending and even shaft breakage to a certain extent.

[0047] In summary, the rotor structure of the present utility model opens a plurality of air flow holes 204 on the rotor core 201, so that air can pass through the inside of the rotor core 201, and a convex rib 305 or a fan blade structure 4 that can stir the air on the side of the air flow holes 204 is constructed at one end or both ends of the rotor assembly 2 to promote gas flow. When the motor operates, the heat generated by the compressor is blown away, thereby reducing the heat of the brushless motor, effectively preventing the demagnetization problem of the magnet 203, and at the same time improving the duty cycle of the air compressor; secondly, due to the opening of the air flow holes 204, the weight of the rotor core 201 can be reduced, the moment of inertia is reduced, and the starting performance of the brushless motor is improved;

[0048] In addition, by forming the housing 3 through an injection molding process outside the rotor assembly 2, the rotor core 201 and the permanent magnet 203 are combined into an integral whole, preventing the permanent magnet 203 from being damaged and fractured due to collision during the production process, and effectively preventing the permanent magnet 203 from loosening due to centrifugal force; the housing 3 is integrally formed by injection molding, eliminating the need to provide balance baffles commonly used in rotor manufacturing at both ends of the rotor core 201. The raised ribs 305 are integrally formed with the housing 3, saving manufacturing costs; the housing 3 and its accessories do not need to be arranged on the rotor assembly 2 in a mechanically matching manner, which can reduce the vibration during rotor operation, thereby reducing noise.

[0049] Although the present invention has been described in detail with general descriptions and specific embodiments above, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A motor rotor structure, comprising a rotor assembly (2) and a rotating shaft (1), wherein the rotor assembly (2) includes a rotor core (201) sleeved on the rotating shaft (1) and a magnetic steel (203) clamped and installed in a magnetic slot (202) on the outer wall of the rotor core (201), and is characterized in that: The outer wall of the rotor assembly (2) is covered with a housing (3) to tightly connect the permanent magnet (203) and the rotor core (201). A plurality of air flow holes (204) are formed in the rotor core (201) so that air flows through the inside of the rotor core (201) when the motor operates.

2. The structure of a motor rotor according to claim 1, wherein: The housing (3) includes a first end portion (302), a second end portion (303), and a connecting sleeve (301) connected between the first end portion (302) and the second end portion (303). The first end portion (302) and the second end portion (303) are constructed at both ends of the rotor core (201), and through holes (304) communicating with the air flow holes (204) are formed in the first end portion (302) and the second end portion (303).

3. The structure of an electric motor rotor according to claim 2, wherein: A plurality of convex ribs (305) are annularly arrayed on the outer side surfaces of the first end portion (302) and the second end portion (303) to accelerate the air flow on the side of the through holes (304) when the convex ribs (305) rotate during the operation of the motor.

4. A motor rotor structure according to claim 1 or 2, characterized in that: A wind blade structure (4) is installed on the rotating shaft (1) on one side of the housing (3).

5. A motor rotor structure according to claim 1, characterized in that: A plurality of the air flow holes (204) are annularly arrayed and penetrate through the rotor core (201), and the air flow holes (204) are all arranged parallel to the central axis (10) of the rotating shaft (1).

6. A motor rotor structure according to claim 1, characterized in that: The housing (3) is constructed on the surface of the rotor assembly (2) by injection molding.

7. A motor rotor structure according to claim 1, characterized in that: The number of the magnetic slots (202) is 4, 6, or 8.

8. A motor rotor structure according to claim 1, characterized in that: A groove (206) is formed in the outer wall of the rotor core (201) between two adjacent magnetic slots (202).

9. A motor rotor structure according to claim 6, characterized in that: The PPS material is used for injection molding the housing (3).

10. A motor rotor structure according to claim 1, characterized in that: The shaft end of the rotating shaft (1) is treated with a thermal barrier coating.

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