Motor capable of preventing electric corrosion of bearing
By reducing the surface area of the bearing sleeve and reducing the capacitance, the problem of shaft corrosion in brushless DC motors is solved, voltage reduction and noise suppression are achieved, and the stability of the motor is improved.
Patent Information
- Application Number
- CN202421345159.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-13
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2034-06-13
AI Technical Summary
When using a brushless DC motor, the bearing electrical corrosion caused by the potential difference caused by inverter switching is difficult to effectively solve this problem.
By reducing the surface area of the bearing sleeve, the capacitance between the first bearing and the second bearing inner and outer rings is reduced, thereby reducing the voltage and avoiding shaft corrosion. The specific implementation method is to set up an eccentric bearing sleeve and set a positioning structure on its outer periphery, so that the plastic-sealed end cap and the bearing sleeve are closely combined to form an integrated injection molded structure.
It effectively reduces the voltage between the bearing sleeves and avoids the axial corrosion. At the same time, the damping characteristics of the plastic-sealed end cap suppress high-frequency noise and improves the stability of the motor.
Smart Images
Figure CN222691494U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of motors, and more specifically to a motor capable of preventing electrical corrosion of bearings. Background Art
[0002] At present, as the household motor industry tends to develop high-efficiency motors, brushless DC motors have become the mainstream, and the motor uses PWM (Pulse Width Modulation, which is a very effective technology that uses the digital output of a microprocessor to control analog circuits. It is widely used in many fields from measurement, communication to power control and conversion.) The application of variable frequency control is also increasing. Under such conditions, the problem of electrical corrosion of motor bearings (abbreviated as shaft corrosion) has become a problem that needs attention. The potential difference between the inner and outer rings of the bearing caused by the switching of the inverter is called shaft voltage (also called bearing voltage). If the shaft voltage is too large, the bearing lubricant will be directly damaged, causing current to run on the bearing, resulting in bearing corrosion.
[0003] In order to solve the problem of shaft corrosion, the commonly used solution is to balance the potential difference between the front and rear bearings by connecting the front and rear cover. The front and rear cover are connected by spot welding or soldering the lead wires and terminals. The lead wires are often fixed on the surface of the outer ring of the stator core, fixed with tape and then sealed. However, there is a risk of the lead wires being exposed and damaged during the stator sealing process, making the connection unstable, thus causing shaft corrosion.
[0004] Therefore, how to solve the problem of shaft electrical corrosion of motors is an urgent problem to be solved by those skilled in the art. Utility Model Content
[0005] In view of this, the purpose of the utility model is to provide a motor that prevents bearing electrocorrosion, by reducing the surface area of the bearing sleeve to reduce the capacitance, thereby reducing the voltage between the inner and outer rings of the first bearing and the second bearing to avoid shaft electrocorrosion.
[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0007] A motor for preventing bearing electrical corrosion, comprising:
[0008] A rotating shaft, a rotor is arranged on the outer periphery of the rotating shaft, the rotor rotates synchronously with the rotating shaft, and a first bearing and a second bearing are arranged at both ends of the rotating shaft;
[0009] The bearing sleeve is arranged on the outer periphery of the first bearing and the second bearing, the bearing sleeve is a cylindrical hollow structure, the bearing sleeve is an eccentric bearing sleeve, and a positioning structure is arranged on the outer periphery of the eccentric bearing sleeve;
[0010] The plastic-encapsulated stator is arranged on the outer periphery of the rotor, and the plastic-encapsulated stator is rotatably connected to the rotor;
[0011] The plastic-sealed end cover is sleeved on the bearing sleeve of the first bearing.
[0012] Preferably, the plastic-sealed end cover and the bearing sleeve of the first bearing are an integral injection-molded structure.
[0013] Preferably, the positioning structure is a boss, which is arranged along the axial direction of the bearing sleeve, and the inner periphery of the plastic-sealed end cover is provided with a groove that cooperates with the boss.
[0014] Preferably, the positioning structure is an open groove, which is arranged along the axial direction of the bearing sleeve, and the inner periphery of the plastic-sealed end cover is provided with a protrusion that cooperates with the open groove.
[0015] Preferably, the positioning structure is a polygonal structure arranged on the outer periphery of the bearing sleeve.
[0016] Preferably, the positioning structure is an annular groove provided on the outer periphery of the bearing sleeve, and the inner diameter of the annular groove is smaller than the outer diameter of the annular groove.
[0017] Preferably, the outer circumferential surface of the plastic-sealed end cover is interference-fitted with the inner circumferential surface of the plastic-sealed stator, and a stress release groove is circumferentially provided on the outer circumferential surface of the plastic-sealed end cover.
[0018] Preferably, a staggered rib structure is provided on the top end surface of the plastic-sealed end cover.
[0019] Preferably, the bottom end surface of the outer ring of the plastic-sealed end cover is provided with a positioning platform extending along its axial direction, and the top end surface of the inner ring of the plastic-sealed stator is provided with a positioning groove matching with the positioning platform.
[0020] Preferably, the positioning groove is provided with a glue filling port communicated with the positioning groove.
[0021] The motor for preventing bearing electrocorrosion provided by the utility model comprises a rotating shaft, a first bearing, a second bearing, a bearing sleeve, a plastic-sealed stator and a plastic-sealed end cover. Specifically, a rotor which rotates synchronously with the rotating shaft is provided on the outer periphery of the rotating shaft, the plastic-sealed stator is provided on the outer periphery of the rotor and is rotatably connected with the rotor, a magnetic field is generated when the plastic-sealed stator is energized to drive the rotor to rotate, thereby driving the rotating shaft to rotate synchronously, a first bearing and a second bearing are provided at both ends of the rotating shaft, the bearing sleeve is provided on the outer periphery of the first bearing and the second bearing, that is, the inner rings of the first bearing and the second bearing are fixed to the rotating shaft, the outer rings of the first bearing and the second bearing are fixed to the bearing platform, the plastic-sealed end cover is sleeved on the bearing sleeve of the first bearing, the plastic-sealed end cover has a certain damping characteristic to suppress high-frequency noise, the bearing sleeve is a cylindrical hollow structure, the bearing sleeve is an eccentric bearing sleeve and a positioning structure is provided on the outer periphery of the eccentric bearing sleeve, by such arrangement, the surface area of the bearing sleeve is reduced to reduce the capacitance, thereby reducing the voltage between the inner and outer rings of the first bearing and the second bearing to avoid the occurrence of shaft electrocorrosion. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.
[0023] Figure 1 A cross-sectional view of a motor for preventing bearing electrocorrosion provided by the utility model;
[0024] Figure 2 A schematic diagram of the structure of the first bearing sleeve provided by the utility model;
[0025] Figure 3 A schematic diagram of the structure of a second bearing sleeve provided by the utility model;
[0026] Figure 4 A schematic diagram of the structure of a third bearing sleeve provided by the utility model;
[0027] Figure 5 A schematic diagram of the structure of a fourth bearing sleeve provided by the utility model;
[0028] Figure 6 A schematic diagram of the structure of a fifth bearing sleeve provided by the utility model;
[0029] Figure 7 The present invention is a schematic structural diagram of a motor for preventing electrical corrosion of bearings provided by the present invention.
[0030] Reference numerals:
[0031] 1- Rotating shaft;
[0032] 2- rotor;
[0033] 3- first bearing;
[0034] 4- second bearing;
[0035] 5-bearing sleeve;
[0036] 6- Positioning structure;
[0037] 7- plastic-sealed stator, 71- positioning groove, 72- glue filling port;
[0038] 8- plastic sealing end cover, 81- stress release groove, 82- dislocation rib structure, 83- positioning platform;
[0039] 9-Annular groove. DETAILED DESCRIPTION
[0040] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0041] The core of the utility model is to provide a motor that prevents bearing electrocorrosion, by reducing the surface area of the bearing sleeve 5 to reduce capacitance, thereby reducing the voltage between the inner and outer rings of the first bearing 3 and the second bearing 4 to avoid shaft electrocorrosion.
[0042] Please refer to Figure 1 , Figure 2 and Figure 3 A motor for preventing bearing electrocorrosion includes a rotating shaft 1, a rotor 2, a first bearing 3, a second bearing 4, a bearing sleeve 5, a positioning structure 6, a plastic-sealed stator 7 and a plastic-sealed end cover 8.
[0043] Specifically, a rotor 2 that rotates synchronously with the rotating shaft 1 is provided on the outer periphery of the rotating shaft 1, a plastic-sealed stator 7 is provided on the outer periphery of the rotor 2 and is rotatably connected with the rotor 2, a magnetic field is generated when the plastic-sealed stator 7 is energized to drive the rotor 2 to rotate, thereby driving the rotating shaft 1 to rotate synchronously, a first bearing 3 and a second bearing 4 are provided at both ends of the rotating shaft 1, a bearing sleeve 5 is provided on the outer periphery of the first bearing 3 and the second bearing 4, that is, the inner rings of the first bearing 3 and the second bearing 4 are fixed to the rotating shaft 1, and the outer rings of the first bearing 3 and the second bearing 4 are fixed to the bearing platform, a plastic-sealed end cover 8 is sleeved on the bearing sleeve 5 of the first bearing 3, and the plastic-sealed end cover 8 has a certain damping characteristic to suppress high-frequency noise, the bearing sleeve 5 is a cylindrical hollow structure, the bearing sleeve 5 is an eccentric bearing sleeve, and a positioning structure 6 is provided on the outer periphery of the eccentric bearing sleeve, so as to reduce the surface area of the bearing sleeve 5 to reduce the capacitance, thereby reducing the voltage between the inner and outer rings of the first bearing 3 and the second bearing 4 to avoid the occurrence of shaft electrical corrosion.
[0044] In the motor that prevents bearing electrocorrosion by adopting the above-mentioned arrangement, the bearing sleeve 5 has a simple structure and a small surface area, and the capacitance can be reduced to reduce the shaft voltage.
[0045] In the above embodiment, the plastic-sealed end cover 8 and the bearing sleeve 5 of the first bearing 3 are an integral injection-molded structure.
[0046] It should be noted that the bearing sleeve 5 and the plastic end cover 8 can be integrally plastic-molded, and the spring ejector on the injection mold will form an axial positioning hole on the plastic end cover 8. The plastic end cover 8 after injection molding will form an anti-overflow boss structure on the inner ring of the plastic end cover 8 under the action of the injection mold. In practical applications, the bearing sleeve 5 and the plastic end cover 8 can also be separately molded, and the bearing sleeve 5 is subsequently riveted or embedded in the plastic end cover 8.
[0047] Among them, the bearing sleeve 5 can be made of metal material or non-metallic plastic material, and the plastic end cover 8 can be made of BMC, PBT, PPS and other materials. Compared with the original iron end cover, the plastic end cover 8 has smaller capacitance and smaller shaft voltage. There is no restriction on the material of the bearing sleeve 5 and the plastic end cover 8, as long as the above-mentioned technical effect can be achieved.
[0048] In the first embodiment, the positioning structure 6 is a boss such as Figure 2 As shown, the boss is arranged along the axial direction of the eccentric bearing sleeve, and the inner periphery of the plastic-sealed end cover 8 is provided with a groove matching with the boss.
[0049] It can be understood that the bearing sleeve 5 and the plastic-sealed end cover 8 are fixed to each other through the cooperation of the boss and the groove. In practical applications, there is no limit on the number of bosses, which can be one or more. When there are more than one boss, there is no limit on the distance between two adjacent bosses, as long as the above-mentioned technical effect can be achieved.
[0050] There is no restriction on the specific setting of the boss. The boss may be flush with only one end of the bearing sleeve 5, or may not be flush with both ends of the bearing sleeve 5. The bosses may be flush or staggered, and there is no restriction on this.
[0051] In the second embodiment, the positioning structure 6 is an open groove such as Figure 3 As shown, the opening groove is arranged along the axial direction of the eccentric bearing sleeve, and the inner periphery of the plastic-sealed end cover 8 is provided with a protrusion that matches the opening groove.
[0052] It should be noted that the bearing sleeve 5 and the plastic-sealed end cover 8 are fixed together by the cooperation of the opening grooves and the protrusions. In practical applications, there is no restriction on the number of opening grooves, which can be one or more. When there are more than one opening grooves, there is no restriction on the distance between two adjacent opening grooves, as long as the above-mentioned technical effect can be achieved.
[0053] There is no restriction on the specific setting of the opening grooves. The opening grooves may be flush with only one end of the bearing sleeve 5, or may not be flush with both ends of the bearing sleeve 5. The opening grooves may be flush with each other or offset with each other. There is no restriction on this.
[0054] In the third embodiment, the positioning structure 6 is a polygonal structure on the outer periphery of the eccentric bearing sleeve. Figure 4 shown.
[0055] It is understandable that the outer surface of the eccentric bearing sleeve is set to a polygonal structure to achieve fixation between the bearing sleeve 5 and the plastic-sealed end cover 8. There is no restriction on the specific number of sides of the polygon as long as the above-mentioned technical effect can be achieved.
[0056] Please refer to Figure 5 The positioning structure 6 is an annular groove 9 on the outer periphery of the eccentric bearing sleeve, and the inner diameter of the annular groove 9 is smaller than the outer diameter of the annular groove 9 .
[0057] It should be noted that the eccentric bearing sleeve can achieve anti-torsion effect. An annular groove 9 is provided on the outer periphery of the eccentric bearing sleeve to realize the fixation between the bearing sleeve 5 and the plastic-sealed end cover 8. The cross-sectional shape of the annular groove 9 along the axial direction of the bearing sleeve 5 is set to an inverted trapezoidal structure to facilitate the fixation between the bearing sleeve 5 and the plastic-sealed end cover 8. However, in actual applications, there is no restriction on the cross-sectional shape of the annular groove 9 along the axial direction of the bearing sleeve 5, as long as the above-mentioned technical effect can be achieved.
[0058] Among them, in this embodiment, the distance that the eccentric bearing sleeve deviates from the center is 0-0.3mm, preferably 0.1mm, but in practical applications, there is no limitation to this, as long as the above technical effects can be achieved.
[0059] Please refer to Figure 6 and Figure 7 The outer circumferential surface of the plastic-sealed end cover 8 is interference-fitted with the inner circumferential surface of the plastic-sealed stator 7 , and a stress release groove 81 is circumferentially provided on the outer circumferential surface of the plastic-sealed end cover 8 .
[0060] It is understandable that when the plastic-encapsulated stator 7 and the outer ring of the plastic-encapsulated end cover 8 are fixed by interference fit, it is necessary to provide a stress release groove 81 on the outer ring of the plastic-encapsulated end cover 8 .
[0061] There is no limitation on the number and shape of the stress release grooves 81 , as long as the above-mentioned technical effects can be achieved.
[0062] As a preferred embodiment, a dislocation rib structure 82 is provided on the top surface of the plastic-sealed end cover 8 .
[0063] It should be noted that the surface of the plastic-sealed end cover 8 is provided with a dislocation rib structure 82 to suppress noise.
[0064] In the above case, the outer ring bottom end surface of the plastic-sealed end cover 8 is provided with a positioning platform 83 extending along its axial direction, and the inner ring top end surface of the plastic-sealed stator 7 is provided with a positioning groove 71 matching with the positioning platform 83 .
[0065] It can be understood that when installing the plastic-sealed end cover 8, the positioning platform 83 of the plastic-sealed end cover 8 is first aligned with the positioning groove 71 of the plastic-sealed stator 7, and then the plastic-sealed end cover 8 is pressed downward along the axial direction of the rotating shaft 1 until the positioning platform 83 is completely abutted against the positioning groove 71 to achieve the positioning of the plastic-sealed end cover 8 and the plastic-sealed stator 7.
[0066] There is no limitation on the number and shape of the positioning platforms 83 as long as the above-mentioned technical effects can be achieved.
[0067] In the above embodiment, the positioning groove 71 is provided with a glue injection port 72 which is in communication with the positioning groove 71 .
[0068] It should be noted that when the plastic-encapsulated end cap 8 is connected to the plastic-encapsulated stator 7 , the positioning platform 83 is placed in the positioning groove 71 , and glue is poured into the positioning groove 71 through the glue pouring port 72 , so that the plastic-encapsulated end cap 8 is fixedly connected to the plastic-encapsulated stator 7 .
[0069] The motor for preventing bearing electrocorrosion provided in the present application can be applied to the fields of household or commercial air conditioning, HVAC, refrigeration and cold chain.
[0070] In summary, the motor for preventing bearing electrocorrosion provided by the utility model changes the capacitance by structural changes, thereby reducing the voltage between the inner and outer rings of the first bearing 3 and the second bearing 4. The plastic-sealed end cover 8 has a certain damping characteristic relative to the metal end cover, which can have a certain inhibitory effect on high-frequency noise and can shift the inherent value of the motor forward. The resonance noise in the high-frequency band is suppressed by shifting the resonance point of the motor. The bearing sleeve 5 cancels the original flange structure to reduce the surface area of the bearing sleeve 5, which is beneficial to the reduction of capacitance and the improvement of shaft voltage. In addition, the bearing sleeve 5 adopts a stretching structure, and the overall material utilization rate is higher than the original stamping structure, and the overall cost is lower.
[0071] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.
[0072] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.
[0073] The above is a detailed introduction to a motor for preventing bearing electrocorrosion provided by the utility model. This article uses specific examples to illustrate the principle and implementation method of the utility model. The description of the above embodiment is only used to help understand the method and core idea of the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.
Claims
1. A motor for preventing electrical corrosion of bearings, characterized in that: include: A rotating shaft (1), wherein a rotor (2) is provided on the outer periphery of the rotating shaft (1), the rotor (2) rotates synchronously with the rotating shaft (1), and a first bearing (3) and a second bearing (4) are provided at both ends of the rotating shaft (1); A bearing sleeve (5) is arranged on the outer periphery of the first bearing (3) and the second bearing (4); the bearing sleeve (5) is a cylindrical hollow structure; the bearing sleeve (5) is an eccentric bearing sleeve, and a positioning structure (6) is provided on the outer periphery of the eccentric bearing sleeve; A plastic-encapsulated stator (7) is arranged on the outer periphery of the rotor (2), and the plastic-encapsulated stator (7) is rotatably connected to the rotor (2); The plastic-sealed end cover (8) is sleeved on the bearing sleeve (5) of the first bearing (3).
2. The motor for preventing bearing electrical corrosion according to claim 1, characterized in that: The plastic sealed end cover (8) and the bearing sleeve (5) of the first bearing (3) are an integral injection-molded structure.
3. The motor for preventing bearing electrical corrosion according to claim 2, characterized in that: The positioning structure (6) is a boss, and the boss is arranged along the axial direction of the eccentric bearing sleeve. The inner circumference of the plastic sealed end cover (8) is provided with a groove that cooperates with the boss.
4. The motor for preventing bearing electrical corrosion according to claim 2, characterized in that: The positioning structure (6) is an open groove, the open groove is arranged along the axial direction of the bearing sleeve (5), and the inner periphery of the plastic sealed end cover (8) is provided with a protrusion that cooperates with the open groove.
5. The motor for preventing bearing electrical corrosion according to claim 2, characterized in that: The positioning structure (6) is a polygonal structure arranged on the outer periphery of the bearing sleeve (5).
6. The motor for preventing bearing electrical corrosion according to claim 2, characterized in that: The positioning structure (6) is an annular groove (9) provided on the outer periphery of the bearing sleeve (5), and the inner diameter of the annular groove (9) is smaller than the outer diameter of the annular groove (9).
7. The motor for preventing bearing electrocorrosion according to any one of claims 1 to 6, characterized in that: The outer circumferential surface of the plastic-sealed end cover (8) is interference-fitted with the inner circumferential surface of the plastic-sealed stator (7), and a stress release groove (81) is provided in the circumferential direction of the outer circumferential surface of the plastic-sealed end cover (8).
8. The motor for preventing bearing electrical corrosion according to claim 7, characterized in that: The top end surface of the plastic sealed end cover (8) is provided with a dislocation rib structure (82).
9. The motor for preventing bearing electrical corrosion according to claim 8, characterized in that: The outer ring bottom end surface of the plastic-sealed end cover (8) is provided with a positioning platform (83) extending along its axial direction, and the inner ring top end surface of the plastic-sealed stator (7) is provided with a positioning groove (71) matching with the positioning platform (83).
10. The motor for preventing bearing electrical corrosion according to claim 9, characterized in that: The positioning groove (71) is provided with a glue injection port (72) which is in communication with the positioning groove (71).