Insulation coating apparatus for outer ring of bearing and insulation coating method using same

Abstract

The present invention relates to an insulation coating apparatus for an outer ring of a bearing and an insulation coating method using same, and more specifically to an insulation coating apparatus for an outer ring of a bearing and an insulation coating method using same, in which air and an insulation liquid are sprayed, so as to be altered by time period, along the outer circumferential surface and lateral periphery of an outer ring of a bearing while the bearing is rotated, and thus a strong adhesive force may be imparted between the surface of the outer ring of the bearing and an insulation coating film, thereby enabling the insulation coating film to maintain adhesion without peeling off when the bearing is driven.

Description

Insulating coating device for bearing outer ring and insulating coating method using the same

[0001] The present invention relates to an insulation coating device for a bearing outer ring and an insulation coating method using the same, which provides a strong adhesive force between the surface of a bearing outer ring and an insulating coating film so that the insulating coating film does not peel off during bearing operation and can maintain adhesion, and also provides uniformity in the thickness of the insulating coating film so as to prevent deposition of various impurities, and improves the durability of the bearing through a top coating layer, and based on the above improvements, satisfies various physical properties such as withstand voltage, heat resistance, oil resistance, peel strength, and pencil hardness of the insulation-coated bearing.

[0002] Generally, bearings are installed between rotating and non-rotating elements to facilitate the rotation of the rotating element. They are components that support the rotating shaft. Bearings are broadly categorized into ball bearings, slide bearings, rolling bearings, and bushing bearings, depending on their type and form, as well as their purpose and function.

[0003] Bearings are manufactured from high-strength metals like steel and are widely used in electrical applications such as motors. The current induced by the motor causes electrical erosion of the bearing surface, shortening its lifespan and potentially leading to motor or generator failure. The most economical solution to this problem is to provide insulation that blocks the flow of electricity or current through the bearing.

[0004] For example, a method is proposed in which a film is coated which can be bonded or sintered to the outer surface of the bearing outer ring, and the film, through its low thermal conductivity and high electrical resistance, insulates the outer ring, and thus the bearing, and the bearing structural members mounted on the inner surface, from the structural members supported on the outer surface of the outer ring.

[0005] However, the film coating for insulation as described above is expensive, there is a risk of damage such as peeling or tearing during use, and there is a problem that fixing the film to the outer ring is not easy.

[0006] To address the above issues, a resin-based insulated bearing was proposed. However, it is vulnerable to mechanical deformation and has very low thermal conductivity, which hinders heat dissipation from the bearing, causing the bearing temperature to rise, reducing the lifespan of the bearing itself and frequently causing thermal deformation of the resin-based insulator. This causes shaft misalignment and can lead to bearing damage.

[0007] Another method involves metal oxide ceramic coating using plasma spraying. While ceramics harden the surface of the bearing outer ring, providing wear resistance and good insulation, they are brittle and easily break during bearing assembly, electrical equipment operation, or external impact. Furthermore, their microporous nature allows moisture to easily penetrate in humid environments, reducing their electrical insulation performance. Furthermore, increasing the thickness of the insulating film to enhance the insulation performance of ceramic insulating coatings is extremely difficult, limiting their potential. Furthermore, thicker coatings lead to significant increases in cost, necessitating large-scale facility investment.

[0008] Therefore, there is a need to develop a technology that provides strong adhesion between the surface of the bearing outer ring and the insulating coating, thereby enabling adhesion to be maintained during bearing operation.

[0009] The present invention is intended to solve the above-mentioned problems, and the object of the present invention is to provide a strong adhesive force between the surface of the bearing outer ring and the insulating film by spraying air and insulating liquid at different times along the outer surface and side periphery of the bearing outer ring while rotating the bearing, so that the insulating film does not peel off and the adhesion is maintained during bearing operation.

[0010] In addition, the present invention aims to prevent the phenomenon of impurities such as sludge being deposited on the bearing by forming an insulating film with a uniform thickness on the surface of the bearing outer ring according to an insulating coating method.

[0011] In addition, the present invention aims to provide lubricity by forming an insulating film on the surface of the outer ring of a bearing and then applying a transparent silicone resin to form a top coating layer, thereby preventing destruction of the insulating film during bearing operation and thereby increasing the durability of the bearing and extending its lifespan.

[0012] In addition, the present invention aims to satisfy various physical properties of an insulating coating bearing, such as withstand voltage, heat resistance, oil resistance, peel strength, and pencil hardness.

[0013] The present invention relates to a device for insulating a bearing outer ring, comprising: a housing having a predetermined space and a hood; a jig installed inside the housing and rotating, in which a bearing (B) is inserted and placed; and a pair of nozzles installed at a predetermined distance from the jig on one side of the jig, the nozzles including an air nozzle and an insulating liquid nozzle for spraying air and an insulating liquid toward the bearing, respectively; wherein the jig is a circular jig and is rotated while the inner surface of the bearing is in close contact with the outer surface of the jig and fixed thereto, so that the outer surface and the side periphery of the bearing outer ring can be coated, and the pair of nozzles are installed so as to be inclined downward in the direction of the jig.

[0014] In addition, the present invention provides an insulation coating method using the insulation coating device for the outer ring of a bearing as described above, comprising: a first step of mounting a bearing on a jig and then rotating the jig at a speed of 20 to 50 rpm to rotate the bearing 10 to 100 times per minute; a second step of forming an insulation film on the outer ring of the bearing by spraying air and an insulation liquid, respectively, using a pair of nozzles including an air nozzle and an insulation liquid nozzle onto the rotating bearing, and then drying and curing the same; And a third step of forming a top coating layer by laminating a transparent silicone resin on the surface of the insulating film to protect the insulating film; wherein the second step comprises an initial air spraying time section for spraying air, a mixed spraying time section for simultaneously spraying air and an insulating liquid after the air spraying time section, and a later air spraying time section for spraying air after the mixed spraying time section, wherein air is sprayed for 1 to 5 seconds in the initial air spraying time section, air and insulating liquid are sprayed for 20 to 200 seconds in the mixed spraying time section, and air is sprayed for 1 to 5 seconds in the later air spraying time section, and the initial air spraying time section, the mixed spraying time section, and the later air spraying time section are continuously repeated a plurality of times, and then drying and curing are performed.

[0015] According to the present invention as a means for solving the above problem, by spraying air and insulating liquid at different times along the outer surface and side periphery of the bearing outer ring while rotating the bearing, a strong adhesive force is provided between the surface of the bearing outer ring and the insulating film, so that the insulating film does not peel off during bearing operation and the adhesion is maintained.

[0016] In addition, since an insulating film is formed with a uniform thickness on the surface of the bearing outer ring according to the insulating coating method of the present invention, there is an effect of preventing impurities such as sludge from being deposited on the bearing.

[0017] In addition, the present invention forms an insulating film on the surface of the outer ring of the bearing, and then forms a top coating layer by applying a transparent silicone resin, thereby not only imparting lubricity, but also preventing destruction of the insulating film during bearing operation, thereby increasing the durability of the bearing and extending its lifespan.

[0018] In addition, the present invention has the effect of satisfying various physical properties such as voltage resistance, heat resistance, oil resistance, peel strength, and pencil hardness of an insulating coating bearing based on the above effects.

[0019] Figure 1 is an actual photograph of a bearing that can be applied to an insulation coating device for a bearing outer ring according to the present invention and an insulation coating method using the same.

[0020] Figure 2 is a front view of an insulating coating device for a bearing outer ring according to the present invention.

[0021] Figure 3 is a side view of an insulating coating device for a bearing outer ring according to the present invention.

[0022] Figure 4 is a real photograph of an insulating coating device for a bearing outer ring according to the present invention.

[0023] Figure 5 is a block diagram illustrating a coating status inspection unit of an insulation coating device for a bearing outer ring according to the present invention.

[0024] Figure 6 is a block diagram illustrating a state judgment unit of an insulation coating device for a bearing outer ring according to the present invention.

[0025] Figure 7 is a block diagram illustrating a judgment module of an insulation coating device for a bearing outer ring according to the present invention.

[0026] Figure 8 is a process flow diagram showing an insulation coating method according to the present invention.

[0027] Figure 9 is a test report measuring the physical properties of an insulating coating bearing according to the present invention.

[0028] <Description of drawing symbols>

[0029] 100: Housing

[0030] 200: Jig

[0031] 300: Nozzle

[0032] 310: Air nozzle

[0033] 320: Insulating fluid nozzle

[0034] 400: Coating status inspection unit

[0035] 41: Sensor module

[0036] 42: Status judgment unit

[0037] 421: Learning Module

[0038] 422: Judgment Module

[0039] 422-1: Coating status information storage unit

[0040] 422-2: Change value calculation section

[0041] 422-3: Judgment Results Derivation Department

[0042] 43: Central Control Center

[0043] B: Bearing

[0044] S10: Stage 1

[0045] S20: Stage 2

[0046] S30: Stage 3

[0047] The present invention relates to an insulation coating device for a bearing outer ring, comprising: a housing having a predetermined space and a hood; a jig installed inside the housing and rotating, in which a bearing (B) is inserted and placed; and a pair of nozzles installed at a predetermined distance from the jig on one side of the jig, the nozzles including an air nozzle and an insulating liquid nozzle for spraying air and an insulating liquid toward the bearing, respectively; wherein the jig is a circular jig and is rotated while the inner surface of the bearing is in close contact with the outer surface of the jig and fixed thereto, so that the outer surface and the side periphery of the bearing outer ring can be coated, and the pair of nozzles are installed to be inclined downward in the direction of the jig, thereby providing the best mode for carrying out the invention.

[0048] Here, the insulation coating device of the bearing outer ring may further include a coating status inspection unit for inspecting the coating status of the bearing outer ring; wherein the coating status inspection unit may include: a sensor module including a laser echo sensor; a status determination unit for determining a thickness deviation of the coating layer based on coating status information sensed by the sensor module; and a central control unit for notifying workers and managers of the coating status determination information determined by the status determination unit.

[0049] At this time, the state judgment unit may include a learning module that stores and learns coating state information sensed by the sensor module for a certain period of time; and a judgment module that compares the coating state information learned by the learning module with the coating state information generated in real time by the sensor module to determine a thickness deviation of the coating layer; and the judgment module may include a coating state information storage unit in which the learned coating state information and the coating state information generated in real time are stored; a change value calculation unit that calculates a change value by substituting the learned coating state information and the coating state information generated in real time; and a judgment result derivation unit that substitues the change value into previously learned coating state classification information to determine a thickness deviation of the coating layer.

[0050] In addition, the present invention provides an insulation coating method using the insulation coating device for the outer ring of a bearing as described above, comprising: a first step of mounting a bearing on a jig and then rotating the jig at a speed of 20 to 50 rpm to rotate the bearing 10 to 100 times per minute; a second step of forming an insulation film on the outer ring of the bearing by spraying air and an insulation liquid, respectively, using a pair of nozzles including an air nozzle and an insulation liquid nozzle onto the rotating bearing, and then drying and curing the same; And a third step of forming a top coating layer by laminating a transparent silicone resin on the surface of the insulating film to protect the insulating film; wherein the second step comprises an initial air spraying time section for spraying air, a mixed spraying time section for simultaneously spraying air and an insulating liquid after the air spraying time section, and a later air spraying time section for spraying air after the mixed spraying time section, and wherein air is sprayed for 1 to 5 seconds in the initial air spraying time section, air and insulating liquid are sprayed for 20 to 200 seconds in the mixed spraying time section, and air is sprayed for 1 to 5 seconds in the later air spraying time section, and the initial air spraying time section, the mixed spraying time section, and the later air spraying time section are continuously repeated a plurality of times, and then drying and curing are performed, which is the best mode for carrying out the invention.

[0051] And in the second step, the air and the insulating liquid can be individually sprayed at a volume ratio of 1 to 10:90 to 99 from each of the air nozzle and the insulating liquid nozzle during the mixing injection time section.

[0052] In addition, the second step is performed so that the thickness of the final insulating film is coated to be 10 to 100 ㎛ after the initial air injection time section, the mixed injection time section, and the late air injection time section are continuously repeated multiple times, and the drying is performed at 50 to 70°C for 5 to 15 minutes, and the curing is performed at 160 to 180°C for 5 to 15 minutes.

[0053] In addition, the residual insulating liquid that was not coated on the outer ring of the bearing and fell during the spraying process in the second step can be recovered and reused during the mixing spraying time period.

[0054] Meanwhile, in the third step, the top coating layer can be formed to a thickness of 1 to 100 μm.

[0055] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. In addition, the terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular includes the plural unless specifically stated otherwise.

[0056] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Meanwhile, schematic and detailed descriptions of the configurations, operations, and effects readily apparent to those skilled in the art will be briefly or omitted, focusing on the details relevant to the present invention.

[0057] FIG. 1 is a real photograph of a bearing that can be applied to an insulation coating device for a bearing outer ring according to the present invention and an insulation coating method using the same, FIG. 2 is a front view of an insulation coating device for a bearing outer ring according to the present invention, FIG. 3 is a side view of an insulation coating device for a bearing outer ring according to the present invention, FIG. 4 is a real photograph of an insulation coating device for a bearing outer ring according to the present invention, FIG. 5 is a block diagram illustrating a coating status inspection unit of an insulation coating device for a bearing outer ring according to the present invention, FIG. 6 is a block diagram illustrating a status judgment unit of an insulation coating device for a bearing outer ring according to the present invention, FIG. 7 is a block diagram illustrating a judgment module of an insulation coating device for a bearing outer ring according to the present invention, FIG. 8 is a process flow diagram showing an insulation coating method according to the present invention, and FIG. 9 is a test report measuring the physical properties of an insulation-coated bearing according to the present invention.

[0058] First, referring to FIGS. 1 to 7, the insulation coating device for a bearing outer ring according to the present invention includes a housing (100), a jig (200), and a pair of nozzles (300).

[0059] The above housing (100) is provided with a certain space in which a bearing (B) can be positioned and a hood capable of recovering coating liquid, etc.

[0060] The above jig (200) is installed inside the housing (100) and rotates, and the bearing (B) is fitted and placed in the circular jig (200), so that the inner surface of the bearing (B) is fixed in close contact with the outer surface of the jig (200) so that the jig can rotate, thereby allowing the outer surface and side perimeter of the outer ring of the bearing (B) to be coated.

[0061] The above pair of nozzles (300) are installed at a position spaced apart from the jig (200) at one side of the jig (200), and include an air nozzle (310) and an insulating liquid nozzle (320) to spray air and insulating liquid, respectively, toward the bearing (B).

[0062] Here, the above pair of nozzles (300) are installed so as to be inclined downward in the direction of the jig (200).

[0063] Meanwhile, the insulation coating device for the bearing outer ring according to the present invention may further include a coating status inspection unit (400) for inspecting the coating status of the bearing outer ring.

[0064] More specifically, the coating status inspection unit (400) according to the present invention is a means for sensing coating status information, determining the status of the thickness deviation of the coating layer, etc. based on artificial intelligence based on the sensed coating status information, and notifying the worker or manager of this.

[0065] For this purpose, the coating status inspection unit (400) includes a sensor module (41), a status judgment unit (42), and a central control unit (43).

[0066] The above sensor module (41) includes a laser echo sensor that senses the coating state of the bearing outer ring.

[0067] The above laser echo sensor is a sensor that receives a specific reflected echo when a laser beam is incident on a specific object and then collides with the object and is reflected. Since the laser beam has different echo wave characteristics depending on the coating state of each object, i.e., thickness deviation, etc., it is used as a sensor for sensing the coating state of the bearing outer ring in the present invention.

[0068] The above-described state judgment unit (42) receives the coating state information sensed by the sensor module (A41) and determines the thickness deviation of the coating layer based on the received coating state information. More specifically, the coating state information sensed by the sensor module (41) for a certain period of time is stored and learned through the learning module (421), and the coating state information learned by the learning module (421) and the coating state information generated in real time by the sensor module (41) are compared by the judgment module (422) to determine the thickness deviation of the coating layer.

[0069] To this end, the judgment module (422) stores the learned coating status information and the real-time generated coating status information through the coating status information storage unit (422-1), calculates a change value by substituting the learned coating status information and the real-time generated coating status information through the change value calculation unit (422-2), and determines the thickness deviation of the coating layer by substituting the change value into the previously learned coating status classification information through the judgment result derivation unit (422-3).

[0070] Here, the coating status classification information is information learned in advance to classify and judge the status as A when the range of the change value is A according to the change value, for example, information that classifies the status as ‘thickness deviation occurrence status’ when the change value is ‘+5’.

[0071] Meanwhile, the learning module (421) and judgment module (422) can utilize known artificial intelligence (AI) modules. In other words, the construction of an AIoT (Artificial Intelligence of Things)-based system is possible through the fusion of the various sensors and artificial intelligence modules.

[0072] Here, the artificial intelligence module may be a CNN (Convolutional Neural Networks) model including an Inception module in a GAP (Global Average Pooling) layer.

[0073] The AI ​​module can learn the weights of multiple inputs through deep learning to produce desired data. Furthermore, various AI network models can be utilized for this learning, including Recurrent Neural Networks (RNNs), Deep Neural Networks (DNNs), and Dynamic Recurrent Neural Networks (DRNNs).

[0074] Here, RNN is a deep learning technique that considers current and past data simultaneously, and a recurrent neural network (RNN) refers to a neural network in which the connections between the units that make up the artificial neural network form a directed cycle. Furthermore, various methods can be used to construct a recurrent neural network (RNN), for example, a fully recurrent network (FRN), a Hopfield network, an Elman network, an Echo state network (ESN), a Long short term memory network (LSTM), a Bi-directional RNN, a Continuous-time RNN (CTRNN), a Hierarchical RNN, and a Secondary RNN are representative examples. In addition, methods such as gradient descent, Hessian Free Optimization, and the Global Optimization Method can be used to train a recurrent neural network (RNN).

[0075] Furthermore, conventional CNNs suffer from processing speed and computational complexity. The present invention requires repetitive computations using immediate additional data, requiring a more lightweight algorithm. Therefore, the CNN model can incorporate a GAP (Global Average Pooling) layer and an Inception module. CNNs typically stack numerous convolutional layers, resulting in a large number of filters. A larger number of filters means a greater number of feature maps, meaning the CNN's dimensionality is very large.

[0076] Handling high-dimensional data requires a large number of parameters capable of handling that dimensionality. However, too many parameters can lead to overfitting during training. Therefore, a method is needed to reduce the dimensionality by reducing the number of parameters used in the filter. The layer in CNNs that performs this role is the pooling layer.

[0077] GAP solves this problem by extracting a representative value (average) from each feature and transferring it directly to the classification stage. Consequently, it maintains the spatial information contained in previous feature maps while directly linking them to categories, resulting in a confidence map (= feature map) that identifies which parts of the resulting feature map played a key role in classifying the corresponding class. Because it does not require separate parameter optimization, it not only reduces computational complexity but also prevents overfitting.

[0078] The Inception architecture adds a smaller neural network within a neural network, called an Inception module. The Inception module can reduce the feature map through 1x1 convolution, making it effective in terms of processing speed and computational complexity.

[0079] Accordingly, the above artificial intelligence module can be applied with a CNN model including an Inception module in the GAP (Global Average Pooling) layer.

[0080] The central control unit (43) above notifies workers and managers of the coating status judgment information judged by the status judgment unit (42), and can notify workers and managers through wireless communication terminals. In the case of wireless communication, Bluetooth, ZigBee, UWB (Ultra WideBand) or Wi-Fi can be applied.

[0081] Accordingly, the present invention senses coating status information, determines the status of the coating layer thickness deviation, etc. based on artificial intelligence based on the sensed coating status information, and notifies the worker or manager of the same, thereby more efficiently implementing uniformity of the thickness of the insulating coating on the surface of the bearing outer ring.

[0082] Next, referring to Fig. 8, the insulation coating method according to the present invention will be described as follows. In the first step (S10), a bearing (B) is placed inside a housing (100) and then rotated.

[0083] To form an insulating film, a bearing is prepared, and the bearing (B) is placed on a jig (200) that can rotate and is installed inside a housing (100) that has a certain space and a hood.

[0084] Here, the jig (200) is a circular jig (200) that rotates, and the inner surface of the bearing (B) is fixed in close contact with the outer surface of the jig (200) so that it can rotate, thereby allowing the outer surface and side periphery of the outer ring of the bearing (B) to be coated.

[0085] With regard to the rotation speed of the jig (200), it is desirable to adjust it to an appropriate range depending on the size (or diameter) of the bearing or the outer ring of the bearing (B), and it is desirable to rotate the bearing (B) mounted on the jig (200) at a speed of 20 to 50 rpm in order to form a uniform insulating film on the surface of the outer ring of the bearing (B).

[0086] When the bearing (B) rotates at a speed of less than 20 rpm, there is a disadvantage in that it takes a long time to form an insulating film because the bearing (B) rotates too slowly, and in addition, the insulating liquid does not coat the surface of the outer ring of the bearing (B) and flows down, making it impossible to achieve efficiency in terms of the production process.

[0087] If the bearing (B) rotates at a speed exceeding 50 rpm, a mismatch is bound to occur between the speed at which the bearing (B) rotates and the speed at which the air and insulating liquid are sprayed, making it impossible to form an insulating film of uniform thickness, and as a result, it becomes impossible to provide insulating performance to the bearing (B).

[0088] Alternatively, the rotation speed of the bearing (B) may be 10 to 100 times per minute. If it is less than 10 times, the rotation speed of the bearing (B) is low, which is inefficient for the process, and if it exceeds 100 times, a uniform insulating film is not formed on the outer surface and side of the outer ring of the rotating bearing (B), which is not desirable.

[0089] For reference, in the first step, after placing the bearing (B) inside the housing (100) and before rotating it, a removable release film or the like is attached to the remaining parts of the bearing (B) except for the outer ring of the bearing (B) on which the insulating film is to be formed, thereby preventing the phenomenon of the insulating liquid splashing on parts other than the outer ring.

[0090] Step 2 (S20) sprays air and insulating liquid onto the rotating bearing (B) to form an insulating film on the outer surface and side of the outer ring of the bearing.

[0091] In order to perform the second step, a nozzle (300) including an air nozzle (310) and an insulating liquid nozzle (320) is installed at a position spaced apart from the jig (200) on one side of the jig (200) inside the housing (100) that has been treated in a clean state. These nozzles (300) may be installed as a pair so as to increase the spraying efficiency in the direction of the bearing (B) that is rotated by the jig (200). Since the pair of nozzles (300) are installed at an angle toward the jig (200) at positions spaced apart from each other, it is easy to form a uniform insulating film on the outer surface and side of the outer ring of the bearing (B).

[0092] In detail, the second step can be performed by including an initial air injection time section in which air is sprayed, a mixed injection time section in which air and insulating liquid are sprayed simultaneously after the air injection time section, and a later air injection time section in which air is sprayed after the mixed injection time section.

[0093] In more detail, air is sprayed for 1 to 5 seconds in the initial air spray time section, air and insulating liquid are sprayed simultaneously for 20 to 200 seconds in the mixed spray time section, and air is sprayed for 1 to 5 seconds in the later air spray time section.

[0094] During the initial air spray time, fine dust, etc. on the outer ring of the bearing (B) can be removed by spraying air onto the bearing (B) for 1 to 5 seconds. If the spray time is less than 1 second, the time is too short to remove foreign substances on the surface of the outer ring of the bearing (B), and it is difficult to check the defect rate of the air spray, especially when the insulating liquid is sprayed during the mixed spray time. On the other hand, if the air is sprayed for more than 5 seconds, the air is supplied unnecessarily, which does not help in forming the insulating film. Preferably, the air is sprayed for 2 seconds.

[0095] In the mixed injection time section, air and insulating liquid are sprayed together from the air nozzle (310) and the insulating liquid nozzle (320), and the insulating liquid may be formed of an insulating resin containing polyhydroxy ether and a solvent. The insulating resin is not limited to the above composition, and various insulating resins capable of providing insulating performance to the bearing (B) may be used.

[0096] In particular, if air is not sprayed together during the mixing injection time, the dispersing power of the insulating liquid cannot be increased. If only the insulating liquid is sprayed without air, the insulating liquid will stick to the outer ring of the bearing (B) in a clumpy state, which can easily peel off from the surface of the outer ring of the bearing (B).

[0097] In the mixed injection time section, air and insulating liquid are sprayed at a volume ratio of 1 to 10: 90 to 99. If the air volume ratio is less than 1, the spraying force of the insulating liquid discharged from the insulating liquid nozzle (320) cannot be increased, resulting in poor coating properties along the outer surface and side of the outer ring of the bearing (B). If the air volume ratio exceeds 10 from the air nozzle (310), the insulating liquid discharged from the insulating liquid nozzle (320) adheres to the inner wall surface of the housing (100) in the form of fibers, resulting in a defective insulating film.

[0098] If the insulating liquid is sprayed at a volume ratio of less than 90, it is difficult to form a coating film that can provide sufficient insulating performance on the surface of the outer ring of the bearing (B). If the insulating liquid is sprayed at a volume ratio of more than 99, it is good for improving the insulating performance, but there is a disadvantage in that the insulating coating film is not formed uniformly.

[0099] However, as described above, air and insulating liquid can be individually sprayed at a volume ratio of 1 to 10:90 to 99 from each of the air nozzle (310) and the insulating liquid nozzle (320), but air and insulating liquid can also be sprayed by being mixed at a volume ratio of 1 to 10:90 to 99 from a single nozzle (300).

[0100] If the air and insulating liquid are sprayed for less than 20 seconds during the mixed spray time section, even if the spray process is repeated multiple times, empty spaces that are not sprayed may be created on the outer surface and side of the outer ring of the bearing (B), or the thickness of the insulating film may not be uniform, making it impossible to provide sufficient insulating performance to the bearing (B). If it exceeds 200 seconds, there is a risk that the air pressure supplied to the air nozzle (310) may be too strong, changing the direction in which the air is sprayed from the air nozzle (310). In order to achieve a uniform coating power of the insulating film, it is most preferable that the mixed spray time section be performed for 90 seconds.

[0101] During the post-air injection time period, air is sprayed for 1 to 5 seconds. If the air spray is sprayed for less than 1 second, it is not suitable for completing the process, and if it exceeds 5 seconds, the pressure of the sprayed air may cause damage to the insulating coating. As such, spraying air for less than 1 second or more than 5 seconds has no advantage in terms of the process, it is recommended to perform the post-air injection for 1 to 5 seconds, and most preferably, to complete the process stably, the post-air injection for 2 seconds.

[0102] It is preferable that the above initial air injection time section, mixed injection time section, and later air injection time section be performed repeatedly and continuously multiple times. If the initial air injection time section, mixed injection time section, and later air injection time section are performed only once, coating defects of the insulating film may occur. Therefore, it is preferable that the initial air injection time section, mixed injection time section, and later air injection time section be performed repeatedly and continuously multiple times in sequence so that the insulating film can be formed by laminating it in layers.

[0103] The thickness of the final insulating film can be up to 100 ㎛ or less. For example, the initial air injection time section, the mixed injection time section, and the late air injection time section can be sequentially repeated 10 times to form a thickness of several ㎛ (e.g., 10 ㎛) for each repetition, and a solid insulating film with a thickness of up to 100 ㎛ or less can be formed using a laminated coating method.

[0104] In addition, in the second stage, the residual insulating liquid that is not coated on the outer ring of the bearing (B) by spraying can be collected using a spatula or the like and recovered by the insulating liquid nozzle (320) to be reused during the mixing spraying time period. This can improve the situation in which expensive insulating liquid is discarded without being coated on the outer ring of the bearing (B), thereby minimizing the process cost.

[0105] After this process, drying is performed at 50 to 70℃ for 5 to 15 minutes and curing is performed at 160 to 180℃ for 5 to 15 minutes. If the drying temperature is less than 50℃ or less than 5 minutes, the solvent contained in the insulating liquid cannot be 100% volatilized, and if drying is performed at more than 70℃, the solvent in the insulating liquid may volatilize, generating bubbles, which may cause defects in the insulating film, and drying for more than 15 minutes is not desirable as it reduces production efficiency. If curing is performed at less than 160℃ or less than 5 minutes, the strength of the insulating film cannot be obtained, and if it exceeds 180℃ or more than 15 minutes, the insulating film is over-cured, which eventually causes defects in the insulating film.

[0106] Step 3 (S30) is to laminate a top coating layer that protects the insulating film by applying transparent silicone resin to the surface of the insulating film.

[0107] This step is a process that can be performed additionally. That is, after forming an insulating film with a thickness of up to 100㎛ on the surface of the outer ring of the bearing (B), and then stabilizing the insulating film through a drying and hardening process, a top coating layer made of transparent silicone resin is laminated and formed on the surface of the insulating film, thereby imparting lubrication due to the properties of silicone and improving the durability of the bearing (B).

[0108] In other words, by forming an insulating film and a silicone top coating layer on the surface of the outer ring of the bearing (B), and by imparting lubrication by the properties of the transparent silicone resin itself through the top coating layer, the durability of the bearing (B) can be increased by primarily preventing destruction of the insulating film on the surface of the outer ring of the bearing (B) when the bearing (B) is driven.

[0109] In the case of the top coating layer, transparent silicone resin can be formed by a doctor blade method, spray coating method, or spin coating method, but is not limited to the above methods, and various coating methods that can form a laminate of transparent silicone resin on the surface of the insulating film can be used.

[0110] The thickness of the top coating layer applied to the surface of the insulating film by the above method can be formed to a thickness of 1 to 100 ㎛. If the thickness of the top coating layer is less than 1 ㎛, lubrication cannot be provided to the outer ring of the bearing (B), and thus the durability of the bearing (B) cannot be increased. On the other hand, if the thickness of the top coating layer exceeds 100 ㎛, although it is good for protecting the insulating film, there is a disadvantage in that the thickness of the top coating layer becomes too thick, making it difficult to drive the bearing (B), so it is important to form the top coating layer so that it does not exceed 100 ㎛.

[0111] Meanwhile, the properties of the bearing (B) formed with an insulating film by the above coating method were measured, and this is confirmed by Fig. 9. To summarize, the measurement results for the withstand voltage, heat resistance, oil resistance, peel strength, and pencil hardness of the insulating coating bearing to which the present invention is applied are as shown in [Table 1] below.

[0112] Test Item Method Test Result Unit Thickness KS B 201386.3㎛ Withstand Voltage KS C 21275500V or higher - Heat Resistance KS C IEC 60068-2-2 No higher - Oil Resistance KS M ISO 1817 No higher - Peeling Strength KS M ISO 24090 Grade Pencil Hardness KS M ISO 151844H-

[0113] That is, the present invention sprays air and insulating liquid along the outer surface and side periphery of the bearing outer ring by changing the spray time interval while rotating the bearing (B), thereby providing a strong adhesive force between the surface of the outer ring of the bearing (B) and the insulating coating, so that the insulating coating does not peel off when the bearing (B) is driven and the adhesion is maintained, and further, since the insulating coating is formed on the surface of the outer ring of the bearing (B) with a uniform thickness, the phenomenon of impurities such as sludge being deposited on the bearing (B) can be prevented, and further, after forming the insulating coating on the surface of the outer ring of the bearing (B) by applying a transparent silicone resin to form a top coating layer, not only can lubrication be provided, but also the destruction of the insulating coating film in the first place when the bearing (B) is driven can be prevented, thereby increasing the durability of the bearing and extending its lifespan, and based on this, the present invention can satisfy various physical properties such as withstand voltage, heat resistance, oil resistance, peel strength, and pencil hardness for the insulating-coated bearing as shown in [Table 1] above.

[0114] The above description is merely an illustrative description of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention, but rather to illustrate it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

[0115] The present invention provides a method for spraying air and insulating liquid along the outer surface and side periphery of a bearing outer ring at different times while rotating the bearing, thereby providing a strong adhesive force between the surface of the bearing outer ring and the insulating film, thereby preventing the insulating film from peeling off and maintaining the adhesion during bearing operation. In addition, since the insulating film is formed on the surface of the bearing outer ring with a uniform thickness, it is possible to prevent impurities such as sludge from being deposited on the bearing. In addition, after forming the insulating film on the surface of the bearing outer ring, a transparent silicone resin is applied to form a top coating layer, thereby not only providing lubricity but also preventing primary destruction of the insulating film during bearing operation, thereby increasing the durability of the bearing and extending its lifespan. Based on this, the present invention is expected to be widely used in industry because it can satisfy various physical properties such as withstand voltage, heat resistance, oil resistance, peel strength, and pencil hardness for insulating-coated bearings.

Claims

1. In the insulation coating device of the bearing outer ring, A housing having a certain space and a hood; A jig installed inside the housing and rotating, and having a bearing fitted therein; and A pair of nozzles, which are installed at a certain distance from the jig on one side of the jig and spray air and insulating liquid toward the bearing side, including an air nozzle and an insulating liquid nozzle; The above jig is a circular jig that can be rotated while the inner surface of the bearing is fixed in close contact with the outer surface of the jig so that the outer surface and side perimeter of the bearing outer ring can be coated. An insulation coating device for a bearing outer ring, characterized in that the pair of nozzles are installed so as to be inclined downward in the direction of the jig.

2. In paragraph 1, Further comprising a coating status inspection unit for inspecting the coating status of the outer ring of the bearing; The above coating status inspection unit. A sensor module including a laser echo sensor that senses the coating state of the outer ring of the bearing; A status determination unit that determines the thickness deviation of the coating layer based on the coating status information sensed by the above sensor module; and An insulation coating device for a bearing outer ring, characterized in that it includes a central control unit that notifies workers and managers of the coating status judgment information judged by the above status judgment unit.

3. In paragraph 2, The above status judgment unit is, A learning module that stores and learns coating status information sensed by the sensor module over a certain period of time; and A judgment module that compares the coating status information learned by the learning module with the coating status information generated in real time by the sensor module to determine the thickness deviation of the coating layer; The above judgment module is, A coating status information storage unit in which the learned coating status information and the coating status information generated in real time are stored; A change value calculation unit that calculates a change value by inputting the learned coating status information and the real-time generated coating status information; and An insulation coating device for a bearing outer ring, characterized in that it includes a judgment result derivation unit that determines a thickness deviation of a coating layer by substituting the above change value into previously learned coating state classification information.

4. In the insulation coating method using the insulation coating device of the bearing outer ring according to Article 1, The first step is to place the bearing on the jig and then rotate the jig at a speed of 20 to 50 rpm to rotate the bearing 10 to 100 times per minute; A second step of forming an insulating film on the outer ring of the bearing by spraying air and insulating liquid using a pair of nozzles including an air nozzle and an insulating liquid nozzle onto the rotating bearing, and then drying and hardening the same; and A third step of laminating and forming a top coating layer to protect the insulating film by applying a transparent silicone resin to the surface of the insulating film; including, The second step above is, It includes an initial air injection time section for spraying air, a mixed injection time section for spraying air and insulating liquid simultaneously after the air injection time section, and a later air injection time section for spraying air after the mixed injection time section. In the initial air injection time section, air is sprayed for 1 to 5 seconds, in the mixed injection time section, air and insulating liquid are sprayed simultaneously for 20 to 200 seconds, and in the later air injection time section, air is sprayed for 1 to 5 seconds. An insulation coating method characterized in that the initial air injection time section, the mixed injection time section, and the late air injection time section are continuously repeated a number of times and then dried and cured.

5. In paragraph 4, The second step above is, An insulation coating method, characterized in that air and insulation are individually sprayed from each of the air nozzle and insulation nozzle at a volume ratio of 1 to 10:90 to 99 during a mixed spray time section.

6. In paragraph 4, The second step above is, After the above initial air injection time section, the above mixed injection time section, and the above late air injection time section are repeatedly performed multiple times in succession, the final insulating film is coated with a thickness of 10 to 100 μm. The above drying is performed at 50 to 70°C for 5 to 15 minutes. An insulation coating method, characterized in that the above curing is performed at 160 to 180°C for 5 to 15 minutes.

7. In paragraph 4, An insulation coating method characterized in that the residual insulating liquid that has fallen and not been coated on the outer ring of the bearing by spraying in the second step is recovered and reused during the mixing spraying time section.

8. In paragraph 4, The third step above is, An insulating coating method characterized in that the top coating layer is formed to have a thickness of 1 to 100 ㎛.

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