Electrically conductive seal ring and method of making same, bearing

Abstract

The application discloses a conductive sealing ring, a manufacturing method thereof and a bearing. The conductive sealing ring is arranged in a bearing with an inner ring and an outer ring, and comprises a first conductor extending in a circumferential direction, a rubber part extending in the circumferential direction, a second conductor and a conductive elastic part. The first conductor comprises a fixed area for fixing the first conductor on one side of the rubber part and a conductive area for interference contact with the outer ring. The second conductor is fixed on the other side of the rubber part and is in interference contact with the inner ring. A groove is arranged between the conductive area of the first conductor and the second conductor. The conductive elastic part is arranged in the groove and is in interference contact with the first conductor and the second conductor. The conductive sealing ring can electrically connect the inner ring and the outer ring of the rolling bearing, lead out the current between the inner ring and the outer ring of the bearing, effectively prevent the rolling bearing from being electrically eroded, reduce the cost and ensure the stability and reliability of the bearing operation.

Description

Technical Field

[0001] This invention relates to the field of bearing seals, and particularly to conductive seals for bearings, methods for manufacturing the same, and bearings. Background Technology

[0002] Rolling bearings are increasingly widely used, such as in new energy vehicle drive motor bearings, variable frequency motor bearings, variable speed motor bearings, commutator motor bearings, automotive alternator bearings, and wind turbine generator bearings. In these applications, positive and negative charges are generated on the inner and outer rings of the bearing during operation, creating a potential difference between them. Furthermore, bearings, strictly speaking, do not operate at a constant speed. Even bearings with nominally constant operating speeds experience rapid speed changes during startup and shutdown. Moreover, the three main components of a bearing—the outer ring, inner ring, and rolling elements—operate at different speeds; for example, the rolling elements rotate much faster than the inner ring. This speed variation also leads to the generation of a potential difference.

[0003] These positive and negative charges are separated by the lubricating oil film in the bearing most of the time and cannot conduct. They can only accumulate more and more, and become stronger and stronger. When the potential difference is too large, the positive and negative charges will conduct instantly and discharge suddenly. The electric spark will oxidize and burn the lubricating oil film. Even the instantaneous high temperature can damage the bearing raceway surface and rolling element surface, causing the "electrolytic corrosion" phenomenon of the bearing.

[0004] Please see Figure 1 The diagram shows a known generator assembly 100, which includes a frequency converter 101, a stator module 102, a rotor module 103, a generator main shaft 104, and rolling bearings 105 mounted at both ends of the generator main shaft 104. Figure 1 In the diagram, only a partial sectional view of the rolling bearings 105 at both ends of the generator main shaft 104 is shown, with different sections cut off at each end. Each rolling bearing 105 includes an outer ring 1051 on the outer side, an inner ring 1052 on the inner side, multiple rolling elements 1053 between the outer and inner rings 1051 and 1052, a cage 1054 securing the rolling elements 1053, and sealing rings 1055 on both sides of the bearing. The rolling bearing 105 further contains lubricating oil or grease for lubrication, and the sealing rings 1055 seal the lubricating oil or grease within the bearing to prevent leakage.

[0005] Please refer to the following: Figure 1 and Figure 2 , Figure 2The diagram further illustrates the lubricating oil or grease between the inner ring 1052 and the outer ring 1051 of the rolling bearing 105 and the rolling element 1053, wherein the lubricating oil or grease forms a lubricating film 1056 within the rolling bearing 105.

[0006] Because filter 101 does not completely filter out electromagnetic waves, residual voltage is generated. This residual voltage is generated along the axial direction of the generator main shaft 104 and acts on the inner ring 1052 and the outer ring 1051 of the rolling bearing 105. Since the lubricating film between the rolling element 1053 and the inner ring 1052 or the outer ring 1051 cannot conduct current, and the resistance of the lubricating film 1056 is very high, these positive and negative charges are separated by the lubricating film most of the time and cannot conduct. They can only accumulate more and more, becoming stronger and stronger. However, because the thickness of the lubricating film of the rolling bearing is between nanometer and micrometer scales, once the potential difference is too large, the positive and negative charges will conduct instantaneously, suddenly generating a spark discharge, thereby forming a closed circuit between the generator main shaft 104 and the rolling bearing 105 and generating shaft current. The conductive electrical spark discharge burns the lubricating film 1056, oxidizing or even charring the lubricating oil or grease, and causing pitting and corrugated bumps on the raceways of the inner ring 1051 and outer ring 1052 of the rolling bearing 105. Because the lubricating film is charred, its lubrication performance and dielectric strength are reduced, increasing noise and vibration, severely affecting the smoothness and reliability of the rolling bearing's operation. The "electro-erosion" damage to the rolling bearing raceway leads to premature bearing failure.

[0007] To prevent bearing damage, one method is to contain the shaft current, that is, to insulate the rolling bearing from external residual voltage. Insulated bearings can be used, typically where at least one of the three main components of a rolling bearing—the outer ring, inner ring, or rolling elements—is made entirely of insulating ceramic material or has at least one coated with insulating ceramic material. However, ceramic materials and insulating coatings are very expensive, and their low manufacturing efficiency and precision limit their engineering applications.

[0008] Therefore, a better solution is needed to prevent spark discharge from damaging the bearings, while also avoiding excessive increases in bearing costs. Summary of the Invention

[0009] One objective of this invention is to provide a conductive sealing ring and its manufacturing method, as well as a bearing. The conductive sealing ring can electrically connect the inner and outer rings of a rolling bearing, thereby discharging the current acting between the inner and outer rings of the bearing and effectively preventing electrolytic corrosion of the rolling bearing, reducing costs, and ensuring the smooth operation and reliability of the bearing.

[0010] Other aspects and advantages of the present invention can be further understood from the technical features disclosed herein.

[0011] One aspect of this invention proposes the following technical solution:

[0012] A conductive sealing ring is disposed within a bearing having an inner ring and an outer ring. It includes a first conductor extending circumferentially, a rubber component extending circumferentially, a second conductor, and a conductive elastic component. The first conductor includes a fixing area for fixing the first conductor to one side of the rubber component and a conductive area in interference contact with the outer ring. The second conductor is fixed to the other side of the rubber component and in interference contact with the inner ring. A groove is provided between the conductive area of ​​the first conductor and the second conductor. The conductive elastic component is disposed within the groove and in interference contact with both the first and second conductors.

[0013] Optionally, according to one aspect of the present invention, the first conductor includes a first conductive portion, a second conductive portion connected to the first conductive portion, and a third conductive portion bent out from the second conductive portion.

[0014] Optionally, according to one aspect of the present invention, the inner and outer sides of the third conductive portion of the first conductor and the outer side of the lower half of the second conductive portion together constitute the fixing area of ​​the first conductor, and an adhesive is sprayed on the fixing area before the first conductor is fixed to the rubber part.

[0015] Optionally, according to one aspect of the present invention, the inner and outer sides of the first conductive portion, the inner side of the second conductive portion, and the outer side of the upper half of the second conductive portion together constitute the conductive region of the first conductive body.

[0016] Optionally, according to one aspect of the present invention, the rubber part is a vulcanized rubber body, including a circumferentially extending main body portion and a circumferentially extending extension portion bent out from the main body portion.

[0017] Optionally, according to one embodiment of the present invention, the second conductor is a carbon sheet.

[0018] Optionally, according to one aspect of the present invention, the carbon sheet is a plurality of carbon sheets evenly spaced along the circumference of the rubber part.

[0019] Optionally, according to one aspect of the present invention, the conductive elastic element is a plurality of springs, each spring being disposed corresponding to one of the carbon sheets.

[0020] In another aspect, the present invention provides a bearing comprising the conductive sealing ring described in any of the above-mentioned technical solutions.

[0021] Another aspect of the present invention provides a method for manufacturing a conductive sealing ring, comprising:

[0022] Step 1: Spray the adhesive onto the fixing area of ​​the first conductor;

[0023] Step 2: Place the first conductor and the second conductor into the mold environment where the rubber part is to be vulcanized;

[0024] Step 3: Vulcanize and mold the rubber part;

[0025] Step 4: Install and secure the conductive elastic element into the groove of the sealing ring and make interference contact with the first conductor and the second conductor.

[0026] The conductive sealing ring and its manufacturing method provided by this invention, along with a bearing, allow current from the inner ring of the bearing to be conducted to the outer ring of the bearing via a second conductor, a conductive elastic element, and the conductive area of ​​the first conductor on the conductive sealing ring. Therefore, since the current is conducted out of the bearing through the conductive sealing ring, no current acts on the rolling elements of the bearing or the lubricating film between the rolling elements and the raceway. Consequently, almost no spark discharge occurs on the lubricating film between the rolling elements and the raceway, thus avoiding bearing damage and effectively preventing electrical erosion, ensuring smooth and reliable bearing operation. The manufacturing process of the conductive sealing element is relatively simple and does not use expensive raw materials, therefore the conductive sealing ring is inexpensive, saving costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a known generator device.

[0028] Figure 2 for Figure 1 A partial schematic diagram of the rolling bearings in a generator unit.

[0029] Figure 3 This is a perspective view of a conductive sealing ring according to one aspect of the present invention.

[0030] Figure 4 for Figure 3 A partially enlarged sectional view of the conductive sealing ring cut into the second conductor and the conductive elastic element.

[0031] Figure 5 This is a perspective view of the conductive elastic element of the conductive sealing ring of the present invention.

[0032] Figure 6 This is a flowchart illustrating the manufacturing process of the conductive sealing ring of the present invention.

[0033] Figure 7 This is a cross-sectional schematic diagram of the conductive sealing ring of the present invention working inside the bearing.

[0034] The reference numerals in the above figures are explained as follows:

[0035] Generator unit 100, frequency converter 101

[0036] Stator module 102 Rotor module 103

[0037] Generator main shaft 104, rolling bearing 105

[0038] Outer ring 1051, 34; Inner ring 1052, 32

[0039] Rolling element 1053, cage 1054

[0040] 1055 sealing ring, 1056 lubricating film

[0041] Conductive sealing ring 200 First conductor 21

[0042] First conductive part 211 Second conductive part 212

[0043] Third conductive part 213 Rubber part 22

[0044] Main body 221 Extension 222

[0045] Second conductor 23, conductive elastic element 24

[0046] Tank 25 Detailed Implementation

[0047] The following description of embodiments is based on the accompanying drawings and is used to illustrate specific embodiments in which the present invention can be implemented. Directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "top," and "bottom," are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrating and understanding the present invention, and not for limiting the present invention. Furthermore, the embodiments described in the specific embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0048] Please see Figures 3 to 5This is a conductive sealing ring 200 according to one embodiment of the present invention, used for sealing rolling bearings. It includes a first conductor 21, a rubber component 22, a plurality of second conductors 23, and a plurality of conductive elastic components 24. The first conductor 21 is a circumferentially extending annular ring located at the outermost edge of the conductive sealing ring 200. In this embodiment, the first conductor 21 may be a metal insert, including a first conductive portion 211, a second conductive portion 212 connected to the first conductive portion 211, and a third conductive portion 213 bent out from the second conductive portion 212. The rubber component 22 is a vulcanized rubber body, including a circumferentially extending main body portion 221 and a circumferentially extending extension portion 222 bent out from the main body portion 221. In this embodiment, the plurality of second conductors 23 are plurality of conductive carbon sheets, uniformly distributed and embedded in the extension portion 222 of the rubber component 22 along the circumferential direction, with the lower ends of the second conductors 23 exposed above the main body portion 221 of the rubber component 22. The conductive elastic element 24 is preferably a wave spring 24, but it can also be other elastic elements with conductive properties. After the rubber part 22 is vulcanized, the plurality of conductive elastic elements 24 are uniformly and interference-fittedly installed between each second conductor 23 and the first conductor 21.

[0049] Typically, to ensure that the first conductor 21 is firmly bonded to the rubber component 22, the first conductor 21 must be immersed in a rubber container for a period of time. However, after immersion, the entire surface of the first conductor 21 will be covered with a layer of adhesive, causing the first conductor 21 to become non-conductive. To ensure the conductivity of the first conductor 21, it is necessary to partially spray the first conductor 21 with a special adhesive.

[0050] Please see Figure 6 The method for manufacturing the conductive sealing ring 200 includes the following steps:

[0051] Step 1: Spray the adhesive onto the fixing area B of the first conductor 21; that is, spray the adhesive onto the inner and outer surfaces of the third conductive part 213 of the first conductor 21 and the outer surface of the lower half of the second conductive part 212, i.e., the outer surface at the location where the second conductive part 212 and the third conductive part 213 are connected. Please refer to... Figure 7 The inner and outer surfaces of the third conductive part 213 and the outer surface of the lower half of the second conductive part 212 together constitute the fixed area B shown by the short dotted line in the figure, and together form the fixed area B of the first conductor 21.

[0052] Step 2: Place the first conductor 21 and the second conductor 23 into the mold environment where the rubber part 22 is to be vulcanized; wherein, the second conductor 23 consists of multiple second conductors, which are vertically and evenly spaced in the mold, and the second conductive part 212 of the first conductor 21 is placed parallel to the multiple second conductors 23, and the bending direction of the third conductor 213 is oriented towards the second conductor 23.

[0053] Step 3: Vulcanize and mold the rubber part 22. After the rubber part 22 is vulcanized, the plurality of second conductors 23 are evenly arranged and embedded into the extension portion 222 of the rubber part 22. The fixing area B of the first conductor 21, that is, the inner and outer sides of the third conductor portion 213 and the outer side of the lower part of the second conductor portion 212, are bonded and fixed to the main body portion 222 of the rubber part 22. At this time, the area of ​​the first conductor 21 other than the fixing area B, that is, the inner and outer sides of the first conductor portion 211, the inner side of the second conductor portion 212, and the outer side of the upper half of the second conductor portion 212, together constitute the conductive area C of the first conductor 21 as shown by the long dotted line in the figure. The conductive area C has electrical conductivity because it is not coated with adhesive. At this time, a groove 25 extending circumferentially is formed between the inner side surface of the second conductor 23 and the inner side surface of the second conductive part 212 of the first conductor 21, and the bottom of the groove 25 is the inner surface of the main body part 221 of the rubber part 22.

[0054] Step 4: Install and secure the conductive elastic element 24 into the groove 25 of the sealing ring 200, making it in interference contact with the first and second conductors. The conductive elastic element 24 comprises multiple conductive elastic elements, the number of which is the same as the number of second conductors 23. Each conductive elastic element 24 corresponds to one second conductor 23. One end of each conductive elastic element 24 is in interference contact with the inner surface of its corresponding second conductor 23, and the other end is in interference contact with the inner surface of the second conductive portion 212 of the first conductor 21, i.e., against the conductive area C of the first conductor 21, to ensure that current can be conducted between the second conductor 23, the conductive elastic element 24, and the first conductor 21. Furthermore, the conductive elastic element 24 can also be placed at the bottom of the groove 25. In this embodiment, one side of the outer circumference of the wave spring abuts against the rubber part 22 on the bottom surface of the groove 25 to ensure that the wave spring is securely installed in the sealing ring 200 and does not fall off.

[0055] Please see Figure 7The figure shows a cross-sectional view of the sealing ring 200 when it is working inside the bearing. The bearing has an inner ring 32 and an outer ring 34. The sealing ring 200 is installed between the inner ring 32 and the outer ring 34 of the bearing. The outer side of the first conductive portion 211 of the first conductor 21 is in interference contact with the inner side of the outer ring 34, and the lower end of the second conductor 23 is in interference contact with the inner side of the inner ring 32. A lubricating film formed by the bearing's lubricating oil or grease is distributed on one side of the outer side of the extension 222 of the rubber component 22.

[0056] When residual voltage is applied to the inner ring 32 and outer ring 34 of the bearing, the resulting current is applied to the inner ring 32 of the bearing, such as... Figure 6 As indicated by the middle arrow, the current flows from the inner ring 32 of the bearing to the lower end of the second conductor 23, then through the second conductor 23 and from its inner surface to the conductive elastic element 24. From the conductive elastic element 24, the current flows to the inner wall of the second conductive portion 212 of the first conductor 21, entering the conductive area C of the first conductor. Finally, it is conducted through the first conductive portion 211 to the outer ring 34 and exits the bearing. Therefore, since the current is conducted out of the bearing via the conductive seal, no current acts on the rolling elements of the bearing or the lubricating film between the rolling elements and the raceway. Consequently, almost no spark discharge occurs on the lubricating film between the rolling elements and the raceway, thus preventing bearing damage. The conductive seal 200 has a relatively simple manufacturing process and does not use expensive raw materials, resulting in a low-cost conductive seal and cost savings.

[0057] The present invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above implementation methods is only for the purpose of helping to understand the technical solutions and core ideas of the present invention. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing implementation methods or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various implementation methods of the present invention.

Claims

1. An electrically conductive seal ring disposed in a bearing having an inner race and an outer race, characterized by: The conductive seal ring comprises a first electrically conductive body extending in a circumferential direction, a rubber member extending in a circumferential direction, a second electrically conductive body and an electrically conductive elastic member. The first electrically conductive body comprises a fixing area for fixing the first electrically conductive body on one side of the rubber member and an electrically conductive area in contact with the outer ring. The second electrically conductive body is fixed on the other side of the rubber member. The rubber member comprises a main body part extending in a circumferential direction and an extension part extending in a circumferential direction and bent from the main body part. The second electrically conductive body is a plurality of second electrically conductive bodies which are uniformly distributed on the extension part of the rubber member in a circumferential direction and the lower ends of the second electrically conductive bodies are exposed from the main body part of the rubber member and in contact with the inner ring. A groove is arranged between the electrically conductive area of the first electrically conductive body and the second electrically conductive body. The electrically conductive elastic member is arranged in the groove and in contact with the first electrically conductive body and the second electrically conductive body.

2. An electrically conductive sealing grommet as defined in claim 1, wherein: The first electrically conductive body comprises a first electrically conductive part, a second electrically conductive part connected to the first electrically conductive part and a third electrically conductive part bent from the second electrically conductive part.

3. An electrically conductive sealing grommet as defined in claim 2, wherein: The inner and outer sides of the third electrically conductive part of the first electrically conductive body and the outer side of the lower half of the second electrically conductive part jointly form a fixing area of the first electrically conductive body. Before the first electrically conductive body is fixed to the rubber member, the fixing area is sprayed with glue.

4. An electrically conductive sealing grommet as defined in claim 2, wherein: The inner and outer sides of the first electrically conductive part, the inner side of the second electrically conductive part and the outer side of the upper half of the second electrically conductive part jointly form an electrically conductive area of the first electrically conductive body.

5. A conductive sealing grommet as defined in claim 1, wherein: The rubber member is a vulcanized rubber body comprising a main body part extending in a circumferential direction and an extension part extending in a circumferential direction and bent from the main body part.

6. An electrically conductive sealing grommet as defined in claim 1, wherein: The second electrically conductive body is a carbon sheet.

7. An electrically conductive sealing grommet as defined in Claim 6, wherein, The carbon sheet is a plurality of carbon sheets uniformly and evenly arranged in a circumferential direction of the rubber member.

8. An electrically conductive sealing grommet as defined in claim 7, wherein, The electrically conductive elastic member is a plurality of springs, each of which is arranged corresponding to one of the carbon sheets.

9. A bearing characterized by: The conductive seal ring is provided.

10. A method of making the electrically conductive seal ring of claim 1, wherein, The conductive seal ring comprises: Step 1: spraying glue to the fixing area of the first electrically conductive body; Step 2: placing the first electrically conductive body and the second electrically conductive body into a mold environment in which the rubber member is to be vulcanized; Step 3: vulcanizing the rubber member; Step 4: installing and fixing the electrically conductive elastic member into the groove of the seal ring and in contact with the first electrically conductive body and the second electrically conductive body.

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