Insulation and bypass composite shaft body structure for preventing electric corrosion of bearing
By introducing a composite structure of insulating bushing and conductive ring into the motor bearing structure, cutting off and bypass shaft current, the bearing electrical corrosion problem of large explosion-proof motors in the inverter power supply is solved, and cost-effective dual protection is achieved.
Patent Information
- Application Number
- CN202422080699.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-08-27
AI Technical Summary
In the prior art, in medium and large explosion-proof motors powered by inverters, bearings are prone to electrocorrosion due to induced voltage, and insulated bearings are costly and incomplete in specifications, and there is still a risk of electrocorrosion when the insulation measures fail.
The composite structure of an insulating bushing and conductive ring is adopted to cut off the shaft current loop and bypass the shaft current through the bypass member when the insulation fails to occur, forming a double protection.
Without insulated bearings, reliable protection of bearings is achieved, electrical corrosion is avoided, costs are reduced, and suitable for explosion-proof motors, with controllable delivery cycles.
Smart Images
Figure CN223124697U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of motors, in particular to an insulating and bypass composite shaft structure for preventing bearing electrolytic corrosion, which is applicable to medium and large explosion-proof motors powered by frequency converters. Background Art
[0002] Due to factors such as alternating magnetic flux, static charge accumulation, and asymmetry generated during motor manufacturing, an induced voltage will be generated on the motor shaft. Especially when powered by a frequency converter, due to the action of high-frequency switching, high-frequency harmonic components will be generated at the motor input end, thereby generating an induced voltage on the motor shaft. Once the induced voltage accumulates to a level sufficient to break down the oil film of the rolling bearing, it will discharge through the circuit with the least resistance, forming an axial current, causing electrolytic corrosion of the rolling bearing balls and raceways to form pits. At the same time, the high-speed rotating bearing will cover the entire bearing raceway with electrolytic corrosion pits in a short time, ultimately causing the bearing to fail.
[0003] Generally speaking, engineers will use insulated bearings to cut off the axial current circuit to prevent bearing electrolytic corrosion and failure. However, insulated bearings have disadvantages such as high cost, incomplete specifications, and long delivery times. Therefore, other insulation measures need to be taken. But when the insulation measures fail (such as reduced insulation resistance caused by moisture, oil contamination, conductive dust, etc.), there is still a possibility of electrolytic corrosion of the bearing raceway. At the same time, due to the particularity of explosion-proof motors, the insulation measures will also be restricted to a certain extent. Summary of the Invention
[0004] To solve the above technical problems, the purpose of the utility model is to provide an insulating and bypass composite shaft structure for preventing bearing electrolytic corrosion, which includes a motor shaft, a bearing, a bearing housing, and a bearing cover component. The bearing, the bearing housing, and the bearing cover component are fixedly installed at the end of the shaft body of the motor shaft. An insulating component is fixedly installed between the bearing housing and the bearing, and an equipotential bypass component is fixedly installed at the bearing position of the bearing cover component.
[0005] Preferably, the bearing cover component includes an outer bearing cover and an inner bearing cover, and the outer bearing cover, the inner bearing cover, and the bearing housing together form a cavity for accommodating the bearing.
[0006] Preferably, the insulating component includes an insulating bushing, and the insulating bushing is fixedly installed between the bearing housing and the bearing.
[0007] Preferably, the insulating component further includes two insulating pads, and the two insulating pads are respectively fixedly installed between the outer bearing cover and the outer ring of the bearing and between the inner bearing cover and the outer ring of the bearing.
[0008] Preferably, the equipotential bypass component includes a conductive ring, and the conductive ring is fixedly installed between the inner bearing cover and the motor shaft.
[0009] Preferably, the bodies of the outer bearing cover and the inner bearing cover both have a rabbet plane.
[0010] With the above solution, the utility model has at least the following advantages:
[0011] The technical solution of this application can adopt insulation measures suitable for explosion-proof motors without using insulated bearings. At the same time, when the insulation measures fail, the bearings can still be protected to prevent the occurrence of electric corrosion of the bearing raceway by shaft current.
[0012] Specifically, the technical solution of this application adopts insulation measures to cut off the shaft current circuit and uses equipotential measures to bypass the bearings. When the insulation fails, the shaft current can pass through the bypass without passing through the bearings, thereby protecting the bearings; similarly, when the bypass fails, the insulation measures can still play a protective role, with a dual effect to ensure the reliability of the bearings during use and avoid the occurrence of electric corrosion of the bearing raceway by shaft current.
[0013] The above description is only an overview of the technical solution of the utility model. In order to be able to more clearly understand the technical means of the utility model and can be implemented according to the content of the description, the following takes the preferred embodiments of the utility model and combines with the drawings to describe in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show a certain embodiment of the utility model, so it should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.
[0015] Figure 1 is a schematic structural diagram of an insulation and bypass composite shaft structure for preventing bearing electric corrosion of this application;
[0016] Figure 2 is Figure 1 a partial enlarged schematic view of
[0017] Figure 3 is Figure 1 a partial enlarged schematic view of
[0018] In the figure: 1 motor shaft, 2 bearing, 3 bearing housing, 4 bearing cover, 5 bearing inner cover, 6 insulating bushing, 7 insulating pad, 8 conductive ring. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] The following combines the drawings and embodiments to further describe in detail the specific implementation manners of the utility model. The following embodiments are used to illustrate the utility model, but not to limit the scope of the utility model.
[0020] SeeFigures 1 to 3 , in a preferred embodiment of the present utility model, an insulating and bypass composite shaft structure for preventing bearing electrolytic corrosion includes a motor shaft 1, a bearing 2, a bearing housing 3 and a bearing cover member. The bearing 2, the bearing housing 3 and the bearing cover member are fixedly installed at the end of the shaft body of the motor shaft 1. An insulating member is fixedly installed between the bearing housing 3 and the bearing 2, and an equipotential bypass member is fixedly installed at the position of the bearing 2 on the bearing cover member.
[0021] Preferably, the bearing cover member includes an outer bearing cover 4 and an inner bearing cover 5. The outer bearing cover 4, the inner bearing cover 5 and the bearing housing 3 together form a cavity for accommodating the bearing 2.
[0022] Preferably, the insulating member includes an insulating bushing 6, and the insulating bushing 6 is fixedly installed between the bearing housing 3 and the bearing 2.
[0023] The insulating bushing 6 and the bearing housing 3 are in interference fit to ensure that the insulating bushing 6 is reliably fixed on the bearing housing 3, avoiding loosening after long-term use of the motor, and ensuring the reliability of the insulation measures to the greatest extent to cut off the shaft current loop.
[0024] Preferably, the insulating member further includes two insulating pads 7, and the two insulating pads 7 are respectively fixedly installed between the outer bearing cover 4 and the outer ring of the bearing 2 and between the inner bearing cover 5 and the outer ring of the bearing 2.
[0025] The two insulating pads 7 can cooperate with the insulating bushing 6 to act together, so that insulation measures are adopted between the bearing 2 and the bearing housing 3 and the bearing cover member, reliably cutting off the shaft current loop.
[0026] Preferably, the equipotential bypass member includes a conductive ring 8, and the conductive ring 8 is fixedly installed between the inner bearing cover 5 and the motor shaft 1.
[0027] The conductive ring 8 can serve the purpose of bypassing. When used in cooperation with the insulating member, it forms a double insurance to protect the bearing 2 to the greatest extent during use and avoid the occurrence of electrolytic corrosion on its raceway. In actual use, if the motor is a non-explosion-proof motor, the conductive ring 8 can be set between the outer bearing cover 4 and the motor shaft 1. Further, the conductive ring 8 itself can be replaced by a grounding brush with the same function.
[0028] Preferably, the cover bodies of the outer bearing cover 4 and the inner bearing cover 5 both have a spigot plane.
[0029] Insulating materials can be inlaid on the spigot plane. Such a structure can replace the two insulating pads 7. By means of the insulating materials on the spigot plane cooperating with the insulating bushing 6, the two act together to insulate the outer ring of the bearing 2.
[0030] In summary, compared with the traditional insulating bearing, the insulating component and the equipotential bypass component of the technical solution of the present application have significantly reduced costs, are not restricted by incomplete market specifications, and have a controllable delivery cycle;
[0031] At the same time, compared with a single insulating measure, the technical solution of the present application also adds a bypass function, so that even if either the insulating measure or the bypass function fails during use, the bearing 2 can still be correspondingly protected;
[0032] The installation position of the conductive ring 8 of the technical solution of the present application is flexible. When the motor is an explosion-proof motor, it can be installed on the bearing inner cover 5, and when the motor is a non-explosion-proof motor, it can be installed on the bearing outer cover 4.
[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.
Claims
1. An insulating and bypass composite shaft structure for preventing bearing electro-erosion, characterized in that: It includes a motor shaft (1), bearings (2), a bearing housing (3) and a bearing cover component. The bearings (2), the bearing housing (3) and the bearing cover component are fixedly installed at the end of the shaft body of the motor shaft (1). An insulating component is fixedly installed between the bearing housing (3) and the bearings (2). An equipotential bypass component is fixedly installed at the bearings (2) on the bearing cover component.
2. The insulating and bypass composite shaft structure for preventing electric corrosion of bearings according to claim 1, wherein: The bearing cover component includes an outer bearing cover (4) and an inner bearing cover (5). The outer bearing cover (4), the inner bearing cover (5) and the bearing housing (3) together form a cavity for accommodating the bearings (2).
3. An insulating and bypass composite shaft structure for preventing bearing electro-erosion according to claim 1 or 2, characterized in that: The insulating component includes an insulating bushing (6), and the insulating bushing (6) is fixedly installed between the bearing housing (3) and the bearings (2).
4. An insulating and bypass composite shaft structure for preventing electric corrosion of bearings according to claim 1 or 2, characterized in that: The insulating component further includes two insulating pads (7), and the two insulating pads (7) are respectively fixedly installed between the outer bearing cover (4) and the outer ring of the bearings (2) and between the inner bearing cover (5) and the outer ring of the bearings (2).
5. An insulating and bypass composite shaft structure for preventing bearing electrolytic corrosion according to claim 1, characterized in that: The equipotential bypass component includes a conductive ring (8), and the conductive ring (8) is fixedly installed between the inner bearing cover (5) and the motor shaft (1).
6. An insulating and bypass composite shaft structure for preventing bearing electrolytic corrosion according to claim 1 or 2, characterized in that: The cover bodies of the outer bearing cover (4) and the inner bearing cover (5) both have a rabbet plane.