Plastic-coated outer ring insulation bearing and its processing method

Abstract

This invention relates to an outer ring plastic-coated insulated bearing and its processing method, belonging to the field of insulated bearings. This technical solution adopts an integrated injection-molded plastic-coated structure. Compared with traditional plasma spraying coatings, the insulation layer has a larger thickness, higher density, and is more resistant to breakdown and wear, unaffected by assembly wear, and its insulation performance does not degrade over long-term use, fundamentally solving the problem of bearing electro-corrosion. Simultaneously, the mechanical interlocking structure formed by the dustproof groove, annular groove, and plastic-coated insulation layer of the metal outer ring significantly improves the bonding strength of the plastic-coated layer, avoiding the risks of slippage, axial movement, and peeling off. It can adapt to complex operating conditions such as high-frequency forward and reverse rotation and high-speed rotation of motors. Furthermore, this technical solution adopts a process route of segmented processing of the groove before and after plastic coating. Rough grinding before plastic coating allows for deformation allowance to accommodate injection molding thermal deformation, while fine grinding and ultra-precision machining after plastic coating correct all errors, solving the industry pain points of poor groove precision, high vibration, and high noise in traditional processes.

Description

Technical Field

[0001] This invention relates to the field of insulating bearing technology, and in particular to an outer ring plastic-coated insulating bearing and its processing method. Background Technology

[0002] During the operation of electrical equipment such as electric drives for new energy vehicles, industrial variable frequency motors, wind power equipment, rail transit, and servo electrical control systems, shaft currents and induced voltages are inevitably generated inside the equipment. When the current passes through the rolling contact surface inside the bearing, it can cause local high temperatures and arc discharge, leading to irreversible damage such as pitting corrosion, material ablation, and fatigue spalling in the bearing raceway. Ultimately, this results in bearing seizure, abnormal noise, and failure, significantly shortening the overall service life of the equipment. Currently, the mainstream insulated bearing solutions in the industry are divided into three categories: ceramic rolling element insulation, plasma-sprayed ceramic coating insulation, and outer ring plastic-coated insulation. Among them, ceramic rolling element bearings offer the best protection, but their high manufacturing cost makes large-scale industrial adoption difficult. Plasma-sprayed ceramic coatings are thin and have poor toughness, making them prone to cracking and peeling due to impacts. Furthermore, the probability of insulation failure after assembly wear is high, and the stability of mass production is difficult to guarantee. Outer ring plastic-coated insulated bearings, with their comprehensive advantages of thick insulation layer, high toughness, moderate cost, and good protection, have become the most promising and affordable alternative to ceramic rolling element bearings.

[0003] However, existing plastic-coated insulated bearings still have some technical defects: On the one hand, the traditional plastic coating process requires the bearing end face as the axial positioning reference, which means that plastic coating can only be applied to the outer circle of the outer ring and one side end face. In extreme cases, the shaft current can break down the air along the uncoated end face and form a circuit with the bearing housing, which still poses a risk of electrolytic corrosion. On the other hand, the industry generally adopts a process route that completes the groove grinding and ultra-precision machining in one go before plastic coating. During the subsequent high-temperature injection molding process, the bearing outer ring is subjected to high-temperature heating, cooling contraction and injection pressure, which will produce irreversible thermal deformation and residual stress deformation. This directly leads to out-of-tolerance groove roundness and profile deviation. The final finished bearing has large vibration, high noise and insufficient rotational accuracy, which cannot meet the requirements of high-precision motors and high-speed equipment. At the same time, the bonding force between the plastic coating layer and the metal outer ring is insufficient, and long-term operation is prone to slippage and delamination problems. Moreover, the outer diameter and width of the plastic coating layer often cannot meet the universal interchangeability requirements of P0 class bearings. Summary of the Invention

[0004] The purpose of this invention is to provide an outer ring plastic-coated insulated bearing and its processing method to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a plastic-coated insulating bearing with an outer ring, comprising: The inner ring has an inner groove machined on its outer surface; The outer metal ring has an outer channel on its inner surface that is coaxial with the inner channel and matches the cross-sectional profile. The outer circular surface of the outer ring has at least one continuous annular groove. The two outer ring axial end faces have annular dustproof grooves near the inner diameter side. These grooves are located on the radially outer side of the inner ring and form an annular rolling element receiving space between them and the inner ring. Multiple rolling elements are evenly distributed within the rolling element receiving space and simultaneously roll in contact with the inner and outer grooves; A cage is fitted between the inner ring and the outer metal ring, and has pockets corresponding to the number of rolling elements to separate all the rolling elements at equal intervals along the circumferential direction. A plastic-coated insulating layer is integrally injection molded on the outside of the metal outer ring, completely covering the entire outer circular surface of the metal outer ring and the two complete axial end faces of the outer ring; In this process, the molten plastic of the plastic-coated insulation layer is embedded inside the annular groove and the dustproof groove during injection molding. After cooling and solidification, it forms a mechanical interlocking structure between the plastic and the metal. The plastic portion embedded in the annular groove restricts the axial movement of the plastic-coated insulation layer relative to the outer metal ring, and the plastic portion embedded in the dustproof groove restricts the circumferential rotation and axial peeling of the plastic-coated insulation layer relative to the outer metal ring.

[0006] In some embodiments, the inner ring, the cage, the outer metal ring, and the plurality of rolling elements are arranged coaxially nested.

[0007] In some embodiments, when the plastic-coated insulating layer is injection molded, the inner diameter surface of the outer metal ring is used as the radial positioning reference, and the groove surfaces of the dustproof grooves at both ends are used as the axial positioning reference.

[0008] In some embodiments, the number of the annular slots is one or two arranged in parallel.

[0009] In some embodiments, the plastic-coated insulation layer is made of modified polyphenylene sulfide (PPS) insulating plastic, wherein the resistivity of the modified PPS insulating plastic is not less than 1.0 × 10⁻⁶. 16 Ω / cm, breakdown voltage not less than 25kV / cm.

[0010] In some embodiments, the thickness of the plastic-coated insulation layer is 0.4-0.6 mm, the depth of the annular groove is 0.4-0.6 mm, and the finished precision grade of the outer ring plastic-coated insulated bearing is not lower than P6 grade.

[0011] In some embodiments, the outer channel is pre-machined with a finishing allowance of 0.08-0.12mm during rough grinding before plastic coating, in order to compensate for thermal deformation and stress deformation generated during injection molding and plastic coating.

[0012] Secondly, the present invention provides a method for processing an outer ring plastic-coated insulated bearing, the method being applied to the aforementioned outer ring plastic-coated insulated bearing, the method comprising: S1. Pre-treatment of outer ring blank: After forging, annealing and precision turning, the bearing steel blank is subjected to quenching and tempering heat treatment to eliminate processing stress and ensure the hardness of the base material and structural stability. S2. Rough grinding before plastic coating: The machining steps are to grind the axial end faces of the two outer rings, rough grind the outer groove, and grind the inner diameter surface in sequence. S3, Integrated Injection Molding and Coating: The pre-treated metal outer ring is placed in a special coating mold. The inner diameter surface of the metal outer ring is used as the radial positioning reference, and the groove surfaces of the dustproof grooves at both ends are used as the axial positioning reference for clamping. Insulating engineering plastic melt is injected into the mold so that the plastic melt completely covers the outer circular surface of the metal outer ring and the axial end faces of the two outer rings, and is embedded in the annular groove and dustproof groove. After cooling, an integral plastic coating insulation layer is formed. S4. Finishing after plastic coating: The machining process of grinding the axial end faces of the two insulation layers, the outer circular surface of the insulation layer, the fine grinding of the outer groove, and the ultra-fine grinding of the outer groove are carried out in sequence. S5. Bearing assembly: The machined plastic-coated outer ring is assembled with the inner ring, cage, and rolling elements to obtain the finished plastic-coated insulated bearing.

[0013] In some implementations, during step S2, when grinding the axial end faces of the two outer rings, the parallelism error of the two end faces is ensured to be no greater than 0.003 mm.

[0014] In some embodiments, during step S4, when grinding the axial end faces of the two insulating layers and the outer circular surface of the insulating layer, the end face warping deformation caused during the plastic coating process is corrected, and the perpendicularity error between the outer circular surface of the insulating layer and the axial end faces of the two insulating layers is not greater than 0.003 mm. During fine grinding of the outer groove, the machining allowance reserved during rough grinding is removed, and the groove roundness deviation and contour deviation generated during injection molding and overmolding are corrected. After ultra-precision external channeling, the surface roughness Ra of the external channel is no greater than 0.04 μm.

[0015] The beneficial effects of the technical solution provided by this invention include at least the following: This technical solution adopts an integrated injection molding and coating structure. Compared with traditional plasma spraying coatings, the insulation layer is thicker, denser, more resistant to breakdown and wear, unaffected by assembly wear, and its insulation performance does not degrade over long-term use. It can completely block the shaft current path, fundamentally solving the problem of bearing electro-corrosion. At the same time, the mechanical interlocking structure formed by the dustproof groove, annular groove, and plastic-coated insulation layer of the metal outer ring significantly improves the bonding strength of the plastic coating layer, avoiding the risks of slippage, axial movement, and peeling off. It can adapt to complex working conditions such as high-frequency forward and reverse rotation and high-speed rotation of motors. In addition, this technical solution adopts a process path of segmented processing of grooves before and after plastic coating. The process involves rough grinding before plastic coating to allow for deformation allowance to accommodate injection molding heat deformation, followed by fine grinding and ultra-precision machining after plastic coating to correct all errors. This solves the industry pain points of poor channel precision, high vibration, and high noise in traditional processes, enabling the finished bearings to achieve a precision of P5 / P6 level. Moreover, the plastic-coated insulation layer has multiple properties such as insulation, shock absorption, noise reduction, and wear resistance, which can effectively reduce equipment vibration transmission, improve equipment operating stability, significantly extend bearing life, and is suitable for automated mass production. The product scrap rate is low, and the production cost is far lower than that of ceramic rolling element insulated bearings and plasma sprayed insulated bearings, making it highly adaptable to the market and valuable for industrialization. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0017] Figure 1 A schematic diagram of the structure of an outer ring plastic-coated insulated bearing provided by an exemplary embodiment of the present invention is shown.

[0018] Figure 2 This diagram illustrates the structure of the metal outer ring and the plastic-coated insulating layer of an outer ring plastic-coated insulating bearing provided by an exemplary embodiment of the present invention.

[0019] In the picture: 1. Inner circle; 2. Cage; 3. Metal outer ring; 31. Outer circular surface of the outer ring; 32. Annular groove; 33. Axial end face of the outer ring; 34. Dustproof groove; 35. Inner diameter surface; 36. Outer channel; 4. Plastic-coated insulation layer; 41. Outer circular surface of the insulation layer; 42. Axial end face of the insulation layer; 5. Rolling element. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In this specification, identical components are represented by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions towards or away from a specific component. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this specification, "multiple" means two or more.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This diagram illustrates the structure of an outer ring plastic-coated insulated bearing provided in an exemplary embodiment of the present invention. Figure 2This diagram illustrates the structure of a metal outer ring and a plastic-coated insulating layer of an outer ring plastic-coated insulating bearing provided by an exemplary embodiment of the present invention. The outer ring plastic-coated insulating bearing includes: an inner ring 1 with an inner groove machined on its outer surface; a metal outer ring 3 with an outer groove 36 coaxial with the inner groove and matching its cross-sectional profile on its inner surface; at least one continuous annular groove 32 formed on the outer circular surface 31 of the outer ring; annular dustproof grooves 34 formed on the two axial end faces 33 of the outer ring near the inner diameter side, located radially outside the inner ring 1 and forming an annular rolling element receiving space between them; a plurality of rolling elements 5 evenly distributed within the rolling element receiving space, simultaneously rolling in contact with the inner groove and the outer groove 36; and a cage 2, which... Located between the inner ring 1 and the outer metal ring 3, it has pockets corresponding to the number of rolling elements 5 to separate all the rolling elements 5 at equal intervals along the circumferential direction; the plastic-coated insulating layer 4 is integrally injection molded on the outside of the outer metal ring 3, completely covering the entire outer circumferential surface 31 of the outer metal ring 3 and the two complete axial end faces 33 of the outer ring; wherein, the plastic melt of the plastic-coated insulating layer 4 is embedded in the interior of the annular groove 32 and the dustproof groove 34 during injection molding, and after cooling and solidification, it forms a mechanical interlocking structure between plastic and metal. The plastic part embedded in the annular groove 32 restricts the axial movement of the plastic-coated insulating layer 4 relative to the outer metal ring 3, and the plastic part embedded in the dustproof groove 34 restricts the circumferential rotation and axial peeling of the plastic-coated insulating layer 4 relative to the outer metal ring 3.

[0024] In this embodiment, the inner ring 1 and the outer metal ring 3 are coaxially nested, and the outer groove 36 matches the inner groove, providing a stable rolling track for the rolling element 5; the annular groove 32 and the dustproof groove 34 provide fitting and positioning for the plastic-coated insulation layer 4, preventing the insulation layer from shifting; the cage 2 evenly separates the rolling elements 5 through pockets, reducing friction and improving operational stability; the plastic-coated insulation layer 4 fully covers the outer metal ring 3, blocking shaft current and preventing electrolytic corrosion, and its melt is embedded in the annular groove 32 and the dustproof groove 34 to form a mechanical interlock, respectively suppressing axial movement, circumferential rotation and axial peeling, strengthening the bonding strength, taking into account insulation stability, structural robustness and operational reliability, and adapting to high-speed and high-frequency operating conditions.

[0025] In some embodiments, see Figure 1 and Figure 2 The inner ring 1, cage 2, metal outer ring 3, and multiple rolling elements 5 are coaxially nested. During injection molding of the plastic-coated insulating layer 4, the inner diameter surface 35 of the metal outer ring 3 is used as the radial positioning reference, and the groove surfaces of the dustproof grooves 34 at both ends (…) Figure 2 Plane A in the diagram serves as the axial positioning reference. The number of annular grooves 32 is one or two arranged in parallel.

[0026] In this embodiment, the inner ring 1, cage 2, metal outer ring 3, and rolling element 5 are coaxially nested to ensure that all rotating parts share the same rotation center, avoiding additional vibration and uneven wear caused by eccentric operation; with the inner diameter surface 35 of the metal outer ring 3 as the radial reference, the groove surface of the dustproof groove 34 ( Figure 2 The dual positioning system with plane A as the axial reference in the middle gets rid of the limitations of traditional end face positioning; the annular slot 32 adopts a choice of one or two parallel arrangements. A single slot is suitable for small size and low load scenarios to simplify processing, while the double slot further enhances the axial anti-detachment capability for large size and high speed working conditions.

[0027] In some embodiments, see Figure 1 and Figure 2 The plastic-coated insulation layer 4 is made of modified polyphenylene sulfide (PPS) insulating plastic, and the resistivity of the modified PPS insulating plastic is not less than 1.0 × 10⁻⁶. 16 The withstand voltage is Ω / cm, and the breakdown voltage is not less than 25kV / cm. The thickness of the plastic-coated insulation layer 4 is 0.4-0.6mm, the depth of the annular groove 32 is 0.4-0.6mm, and the finished precision grade of the outer ring plastic-coated insulated bearing is not less than P6 grade. The outer groove 36 has a finishing allowance of 0.08-0.12mm reserved during rough grinding before plastic coating to compensate for thermal deformation and stress deformation generated during injection molding and plastic coating.

[0028] In this embodiment, the plastic-coated insulation layer 4 is made of modified PPS material with a particle size of 1.0 × 10⁻⁶. 16 With a resistivity above Ω / cm and a breakdown voltage above 25kV / cm, it can stably block shaft current for a long time in harsh environments such as alternating high and low temperatures, oil contamination, and humidity, eliminating the risk of electrolytic corrosion failure. An insulation layer thickness of 0.4-0.6mm ensures sufficient insulation margin, avoiding a decrease in load-bearing capacity due to an excessively thin outer groove bottom. The annular groove 32 has a depth of 0.4-0.6mm, matching the insulation layer thickness, ensuring full plastic fitting and a strong interlocking. The outer groove 36 has a 0.08-0.12mm machining allowance to compensate for injection molding thermal deformation and residual stress. Combined with subsequent precision grinding and ultra-precision processes, the finished bearing achieves a stable precision of P6 grade or higher, meeting the requirements of high-precision motors and high-speed equipment.

[0029] It is worth mentioning that the present invention also provides a method for processing an outer ring plastic-coated insulated bearing, the method being applied to the aforementioned outer ring plastic-coated insulated bearing, the method comprising: Step S1, outer ring blank pretreatment: After forging, annealing and precision turning, the bearing steel blank is subjected to quenching and tempering heat treatment to eliminate processing stress and ensure the hardness and structural stability of the base material.

[0030] In this embodiment, forging refines the grains of bearing steel through plastic deformation, optimizes the internal metal flow line distribution, and significantly improves the fatigue strength and impact toughness of the material; annealing eliminates residual stress generated during forging, reduces the hardness of the material, and gives the blank good machinability, making it easy to obtain regular dimensions by precision machining; quenching and tempering heat treatment gives the outer metal ring 3 a uniform tempered martensitic structure, ensuring high hardness of HRC60-65 while also having excellent dimensional stability, and eliminating the processing stress of the blank.

[0031] Step S2, rough grinding before plastic coating: The following processing steps are performed in sequence: grinding the axial end faces 33 of the two outer rings, rough grinding the outer groove 36, and grinding the inner diameter surface 35.

[0032] In one example, when grinding the two outer ring axial end faces 33, ensure that the parallelism error of the two end faces is no greater than 0.003mm.

[0033] In this embodiment, the axial end face 33 of the outer ring is ground and the parallelism is strictly controlled to be ≤0.002mm, providing a high-precision axial reference for all subsequent processing steps; the rough grinding of the outer groove 36 does not directly form the final size, but reserves the deformation compensation amount required for subsequent finishing, which is the essential difference from the traditional one-time groove processing process; the inner diameter surface 35 is ground to obtain a high-precision cylindrical surface, which serves as the radial positioning reference for subsequent injection molding and coating, ensuring the coaxiality of the metal outer ring 3 and the coating mold.

[0034] Step S3, Integrated Injection Molding and Coating: Place the pre-treated metal outer ring 3 in a special coating mold, using the inner diameter surface 35 of the metal outer ring 3 as the radial positioning reference, and the groove surfaces of the dustproof grooves 34 at both ends ( Figure 2 The mold is clamped with plane A as the axial positioning reference, and insulating engineering plastic melt is injected into the mold so that the plastic melt completely covers the outer circular surface 31 of the outer ring 3 and the two outer ring axial end faces 33, and is embedded in the annular groove 32 and the dustproof groove 34. After cooling, an integral plastic-coated insulating layer 4 is formed.

[0035] In this embodiment, a dual-reference clamping scheme is adopted, with radial positioning on the inner diameter surface 35 and axial positioning on the dustproof groove 34. This eliminates the obstruction of the plastic-coated area by the traditional end-face positioning, achieving full coverage of the outer circular surface 31 of the metal outer ring 3 and the two axial end faces 33 without any dead angles, thus structurally blocking all possible paths of shaft current. Under high pressure, the molten plastic fully fills the internal space of the annular groove 32 and the dustproof groove 34, and after cooling and solidification, it forms a three-dimensional mechanical interlocking structure. Compared with simple interface bonding, the bonding strength is increased by more than 3 times, preventing the plastic-coated insulation layer 4 from slipping and peeling under high-speed rotation and high-frequency forward and reverse rotation conditions.

[0036] Step S4, finishing after plastic coating: The following machining processes are performed in sequence: grinding the axial end faces 42 of the two insulating layers, the outer circular surface 41 of the insulating layer, fine grinding the outer groove 36, and ultra-fine grinding the outer groove 36.

[0037] In one example, when grinding the two axial end faces 42 and the outer circular face 41 of the insulation layer, the end face warping deformation caused during the plastic coating process is corrected, and the perpendicularity error between the outer circular face 41 of the insulation layer and the two axial end faces 42 of the insulation layer is not greater than 0.003mm; when fine grinding the outer channel 36, the finishing allowance reserved by the rough grinding is removed, and the channel roundness deviation and contour deviation caused during the injection molding and plastic coating process are corrected; after ultra-fine grinding of the outer channel 36, the surface roughness Ra of the outer channel 36 is not greater than 0.04μm.

[0038] In this embodiment, the axial end face 42 and the outer circular face 41 of the insulation layer are first ground to correct the end face warping and outer circle eccentricity caused during injection molding, and the perpendicularity is controlled to be ≤0.003mm, so that the installation dimensions of the plastic-coated outer ring fully meet the universal interchangeability requirements of standard bearings; then the outer groove 36 is finely ground to remove the allowance reserved by rough grinding, and to correct the groove roundness and contour deviation caused by injection molding thermal deformation and residual stress; finally, the outer groove 36 is ultra-fine ground to reduce the surface roughness to Ra≤0.04μm, forming a uniform cross oil storage pattern, which significantly reduces friction wear and operating noise, and makes the bearing accuracy stably reach P6 level or above.

[0039] Step S5, Bearing Assembly: The finished plastic-coated outer ring is assembled with the inner ring 1, cage 2, and rolling elements 5 to obtain the finished plastic-coated insulated bearing.

[0040] In this embodiment, the finished plastic-coated outer ring is assembled with the inner ring 1, cage 2, and rolling elements 5 according to strict radial clearance requirements; the cage 2 evenly separates the rolling elements 5 along the circumference to prevent them from colliding and rubbing against each other during operation; the cleanliness is strictly controlled during the assembly process to avoid hard impurities from entering the bearing and causing premature wear; finally, through multiple performance tests, the finished bearing is ensured to meet the stringent requirements of high-end electrical equipment.

[0041] In summary, this technical solution adopts an integrated injection-molded coating structure. Compared with traditional plasma spraying coatings, the insulation layer has a larger thickness, higher density, and is more resistant to breakdown and wear. It is unaffected by assembly wear, and its insulation performance does not degrade over long-term use. It can completely block the shaft current path, fundamentally solving the problem of bearing electro-corrosion. Simultaneously, the mechanical interlocking structure formed by the dustproof groove, annular groove, and plastic-coated insulation layer of the metal outer ring significantly improves the bonding strength of the plastic coating layer, avoiding the risks of slippage, axial movement, and peeling off. It can adapt to complex operating conditions such as high-frequency forward and reverse rotation and high-speed rotation of motors. Furthermore, this technical solution uses segmented processing of the grooves before and after the plastic coating. The process route, through rough grinding before plastic coating to allow for deformation allowance to accommodate injection molding heat deformation, and fine grinding and ultra-precision machining after plastic coating to correct all errors, solves the industry pain points of poor channel precision, high vibration, and high noise in traditional processes, enabling the finished bearing precision to reach P5 / P6 level. Moreover, the plastic coating insulation layer has multiple properties such as insulation, shock absorption, noise reduction, and wear resistance, which can effectively reduce equipment vibration transmission, improve equipment operation stability, significantly extend bearing service life, adapt to automated mass production, have a low product scrap rate, and have production costs far lower than ceramic rolling element insulated bearings and plasma sprayed insulated bearings, with extremely strong market adaptability and industrialization promotion value.

[0042] In the embodiments disclosed in this invention, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments disclosed in this invention according to the specific circumstances.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A bearing with a plastic-coated outer ring and insulation, characterized in that, include: The inner ring (1) has an inner groove machined on its outer surface; The outer metal ring (3) has an outer groove (36) on its inner surface that is coaxial with the inner groove and matches the cross-sectional profile. The outer circular surface (31) of the outer ring has at least one continuous annular groove (32). The two outer ring axial end faces (33) near the inner diameter side have annular dustproof grooves (34) which are located on the radial outer side of the inner ring (1) and form an annular rolling element receiving space between them. Multiple rolling elements (5) are evenly distributed within the rolling element receiving space and simultaneously roll in contact with the inner channel and the outer channel (36); A retainer (2) is fitted between the inner ring (1) and the outer metal ring (3), and has pockets corresponding to the number of rolling elements (5) to separate all the rolling elements (5) at equal intervals along the circumferential direction. A plastic-coated insulating layer (4) is integrally injection molded on the outside of the metal outer ring (3), which completely covers the entire outer circular surface (31) of the metal outer ring (3) and the two complete axial end faces (33) of the outer ring. During injection molding, the molten plastic of the plastic-coated insulation layer (4) is embedded inside the annular groove (32) and the dustproof groove (34). After cooling and solidification, it forms a mechanical interlocking structure between the plastic and the metal. The plastic part embedded in the annular groove (32) restricts the axial movement of the plastic-coated insulation layer (4) relative to the metal outer ring (3), and the plastic part embedded in the dustproof groove (34) restricts the circumferential rotation and axial peeling of the plastic-coated insulation layer (4) relative to the metal outer ring (3).

2. The outer ring plastic-coated insulated bearing according to claim 1, characterized in that, The inner ring (1), the cage (2), the metal outer ring (3), and the multiple rolling elements (5) are arranged coaxially and nested.

3. The outer ring plastic-coated insulated bearing according to claim 1, characterized in that, When the plastic-coated insulation layer (4) is injection molded, the inner diameter surface (35) of the outer metal ring (3) is used as the radial positioning reference, and the groove surface of the dustproof groove (34) at both ends is used as the axial positioning reference.

4. The outer ring plastic-coated insulated bearing according to claim 1, characterized in that, The number of the annular slots (32) is one or two arranged in parallel.

5. The outer ring plastic-coated insulated bearing according to claim 1, characterized in that, The plastic-coated insulation layer (4) is made of modified polyphenylene sulfide (PPS) insulating plastic, and the resistivity of the modified PPS insulating plastic is not less than 1.0 × 10⁻⁶. 16 Ω / cm, breakdown voltage not less than 25kV / cm.

6. The outer ring plastic-coated insulated bearing according to claim 1, characterized in that, The thickness of the plastic-coated insulation layer (4) is 0.4-0.6mm, the depth of the annular groove (32) is 0.4-0.6mm, and the finished precision grade of the outer ring plastic-coated insulating bearing is not lower than P6 grade.

7. The outer ring plastic-coated insulated bearing according to claim 1, characterized in that, The outer channel (36) has a finishing allowance of 0.08-0.12mm reserved during rough grinding before plastic coating, which is used to compensate for thermal deformation and stress deformation generated during injection molding and plastic coating.

8. A method for processing an outer ring plastic-coated insulated bearing, the method being applied to the outer ring plastic-coated insulated bearing according to any one of claims 1 to 7, characterized in that, The method includes: S1. Pre-treatment of outer ring blank: After forging, annealing and precision turning, the bearing steel blank is subjected to quenching and tempering heat treatment to eliminate processing stress and ensure the hardness of the base material and structural stability. S2. Rough grinding before plastic coating: The following processing steps are performed in sequence: grinding the axial end faces (33) of the two outer rings, rough grinding the outer groove (36), and grinding the inner diameter surface (35); S3, Integrated Injection Molding: The pre-treated metal outer ring (3) is placed in a special molding mold. The inner diameter surface (35) of the metal outer ring (3) is used as the radial positioning reference, and the groove surface of the dustproof groove (34) at both ends is used as the axial positioning reference for clamping. The insulating engineering plastic melt is injected into the mold so that the plastic melt completely covers the outer circle surface (31) of the metal outer ring (3) and the two outer ring axial end faces (33), and is embedded in the annular groove (32) and the dustproof groove (34). After cooling, an integral plastic insulation layer (4) is formed. S4. Finishing after plastic coating: The following processing steps are performed in sequence: grinding the axial end faces (42) of the two insulating layers, grinding the outer circular surface (41) of the insulating layer, grinding the outer groove (36) and the ultra-precision outer groove (36); S5. Bearing assembly: The finished plastic-coated outer ring is assembled with the inner ring (1), cage (2), and rolling elements (5) to obtain the finished plastic-coated insulated bearing.

9. The processing method of the outer ring plastic-coated insulated bearing according to claim 8, characterized in that, In step S2, when grinding the two outer ring axial end faces (33), ensure that the parallelism error of the two end faces is not greater than 0.003mm.

10. The processing method of the outer ring plastic-coated insulated bearing according to claim 8, characterized in that, In step S4, when grinding the two axial end faces (42) and the outer circular face (41) of the insulation layer, the end face warping deformation caused during the plastic coating process is corrected, and the perpendicularity error between the outer circular face (41) of the insulation layer and the two axial end faces (42) of the insulation layer is not greater than 0.003mm. When fine grinding the outer channel (36), remove the finishing allowance reserved by rough grinding and correct the channel roundness deviation and contour deviation generated during injection molding and encapsulation. After the ultra-precision outer channel (36), the surface roughness Ra of the outer channel (36) is no greater than 0.04 μm.

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