Eccentricity measurement system

Abstract

The present disclosure relates to an eccentricity measurement system, and more particularly, to an eccentricity measurement system configured to measure eccentricity generated in a motor rotor. The eccentricity measurement system of the present disclosure can include an eccentricity measurement sensor installed in a motor and configured to measure all of the tilting eccentricity, static eccentricity, and dynamic eccentricity of a rotor using a change in a magnetic field generated between the rotor and a stator, thereby overcoming the limitations of a reflective laser sensor method in the related art, reducing costs compared to a reflective laser sensor in the related art, detecting an eccentricity factor that most affects noise and vibration of a rotating device, and detecting defects in an initial stage of mass production.

Description

Technical Field

[0001] This disclosure relates to an eccentricity measurement system, and more specifically, to an eccentricity measurement system configured to measure the eccentricity generated in a motor rotor. Background Technology

[0002] Reflective laser displacement sensors are widely used to measure the rotor eccentricity of permanent magnet motors. This method measures changes in distance by directly illuminating the rotating shaft with a laser beam. It is intuitive, easy to understand, and applicable to various rotating devices. In addition, transmission micrometers or transmission 2D micrometers are also used in industrial settings.

[0003] However, when applying existing reflective laser displacement sensors to permanent magnet motors to measure the outer diameter of the rotor core (excluding the shaft), the sensor needs to be mounted outside the motor housing, and the surface of the rotor core needs to be illuminated with a laser beam. However, since the rotor core is covered by the stator within the motor structure, the laser beam cannot penetrate the rotor core, and measurement cannot be performed. In particular, there is a problem of difficulty in measuring static eccentricity because radial displacement at a single point cannot be measured.

[0004] Therefore, even for the portion of the shaft not covered by the stator core, at least two or more sensors need to be installed on opposite sides. In this case, the sensors may interfere with other external components, which imposes limitations on the sensor mounting structure and increases system cost.

[0005] Related technical documents

[0006] (Patent Document 1) Japanese Patent No. 6441757 "Eccentricity Direction Detection Device and Variable Gap Motor". Utility Model Content

[0007] This disclosure is made to address these problems and aims to provide an eccentricity measurement system comprising an eccentricity measurement sensor mounted in a motor and configured to measure the total tilt eccentricity, static eccentricity, and dynamic eccentricity of the rotor by using changes in the magnetic field generated between the rotor and stator. This overcomes the limitations of existing reflective laser sensor methods, reduces costs compared to existing reflective laser sensors, detects eccentricity factors that have the greatest impact on noise and vibration of rotating devices, detects defects in the early stages of mass production to prevent the shipment of potentially defective products, and measures eccentricity caused by wear, etc., after product durability testing or long-term vehicle operation to detect problems in advance and take preventative repair actions.

[0008] Using the aforementioned eccentricity measurement system, in the future application of eccentricity measurement systems to autonomous vehicles, it is possible to monitor the mechanical state of rotating devices. Furthermore, by applying the eccentricity measurement system to intelligent rotating device systems that can evaluate their state using pre-defined defect level indicators, the state of rotating devices can be identified in areas imperceptible to humans. In addition, the eccentricity measurement system can be applied in situations where the state of individual rotating devices is difficult to identify due to external vibrations or noise, enabling the eccentricity measurement system to be used for the pre-detection and resolution of problems in electric motors used in urban air mobility (UAM) aircraft.

[0009] To achieve the above objectives, one embodiment of this disclosure provides an eccentricity measurement system applied to a motor system including a stator and a rotor, and measuring the eccentricity of the rotor. The eccentricity measurement system includes: an eccentricity measuring portion that measures the presence or absence of rotor eccentricity by measuring changes in the magnetic field generated between the rotor and the stator; the eccentricity measuring portion including one or more eccentricity measuring sensors; and a sensing housing including: a surface in which the eccentricity measuring portion is embedded; and a central hole formed through the center of the sensing housing, wherein the rotational shaft of the rotor is fitted into the central hole; wherein the eccentricity measuring portion is coupled to a front surface of the sensing housing and includes a sensing plate disposed on one surface of the eccentricity measuring portion, such that the one or more eccentricity measuring sensors are embedded in the sensing plate; and wherein the one or more eccentricity measuring sensors include sensing terminals extending axially and electrically connected to the sensing plate.

[0010] Additionally, the eccentricity measurement section may further include: an external terminal electrically connected to one or more eccentricity measurement sensors and transmitting sensing information from the one or more eccentricity measurement sensors to the outside; and a circuit pattern printed on a surface of the eccentricity measurement section to electrically connect the external terminal and the one or more eccentricity measurement sensors.

[0011] Additionally, the circuit pattern may include: two power lines, each power line including a power terminal, the power terminal being connected to the sensing terminal of the one or more eccentricity measuring sensors and supplying power to the one or more eccentricity measuring sensors; and a signal line, the signal line including a signal output terminal, the signal output terminal being connected to the sensing terminal of the one or more eccentricity measuring sensors and outputting the sensing value of the one or more eccentricity measuring sensors. Each of the two power lines and the signal line may extend in the same direction, and the power terminal and the signal output terminal may be configured as two or more power terminals and two or more signal output terminals respectively disposed in the power lines and the signal lines and spaced apart from each other at a predetermined interval.

[0012] Additionally, the sensing housing may include: an annular central fixing portion having the central hole; a sensor fixing portion protruding radially outward from the central hole, wherein one or more eccentricity measuring sensors are embedded in the sensor fixing portion; a plate insertion slot recessed along the axial direction such that the sensing plate is inserted into the plate insertion slot; and an interference avoidance slot recessed in a cylindrical shape along the axial direction based on the apex of the plate insertion slot.

[0013] Additionally, the sensing housing may further include: a protective step portion disposed along the edge of the sensing housing and extending axially to a height equal to or greater than the height of the one or more eccentricity measuring sensors; and a plate-shaped potting portion covering and protecting one surface of the sensing plate and disposed inside the protective step portion, the height of the potting portion being equal to or greater than the height of the one or more eccentricity measuring sensors including the sensing terminals.

[0014] Additionally, the sensing housing may further include: a protective step portion disposed along the edge of the sensing housing and extending axially to a height equal to or greater than the height of the one or more eccentricity measuring sensors; and a retainer having a first surface covering and protecting one surface of the sensing plate, the retainer being disposed inside the protective step portion and including a sensor receiving groove protruding along the axial direction, such that the one or more eccentricity measuring sensors are received in the sensor receiving groove.

[0015] Additionally, the sensing housing may also include a capturing portion for fixing the position of the retainer. The capturing portion may include: a post that protrudes from the edge of the sensing housing along the axial direction; and a capturing step that protrudes radially from the distal end of the post and abuts the second surface of the retainer.

[0016] Additionally, the sensing plate may include a first fixing hole formed through a region other than the region where the circuit pattern is formed, wherein the sensing housing includes a cover disposed on an entire surface of the sensing housing and covering the sensing plate, and the cover includes a second fixing hole disposed through the sensing plate at a position corresponding to the first fixing hole.

[0017] In addition, the eccentricity measurement system may also include fasteners that are inserted into the first fixing hole and the second fixing hole, thereby fixing the positions of the first fixing hole and the second fixing hole.

[0018] In addition, the one or more eccentricity measuring sensors may be configured as two or more eccentricity measuring sensors disposed on the sensing plate, and the one or more eccentricity measuring sensors may be configured to be spaced apart from each other at equal intervals.

[0019] In addition, the one or more eccentricity measuring sensors may be configured as two or more eccentricity measuring sensors disposed on the sensing plate, and the one or more eccentricity measuring sensors may be configured to be spaced apart from each other by a phase difference of 90 degrees. Attached Figure Description

[0020] Figure 1 This is an axial sectional view showing the motor system involved in the eccentricity measurement system of this disclosure.

[0021] Figure 2 This is a partial perspective view showing the eccentricity measurement sensor of this disclosure.

[0022] Figure 3 This is a top plan view showing the eccentricity measurement system of this disclosure.

[0023] Figure 4 This is a schematic diagram showing the circuit pattern of this disclosure.

[0024] Figure 5 This is a top plan view showing the sensing housing of this disclosure.

[0025] Figure 6 This is a perspective view showing the sensing housing of this disclosure.

[0026] Figure 7 This is a perspective view showing the sensing housing to which the potting portion of this disclosure is attached.

[0027] Figure 8 This is a perspective view showing the retainer of this disclosure.

[0028] Figure 9 This is a perspective view showing the retainer of this disclosure connected to the sensing housing.

[0029] Figure 10 This is a partial perspective view showing the capture unit of this disclosure.

[0030] Figure 11 This is an axial cross-sectional view showing the sensing housing of this disclosure.

[0031] Figure 12 This is a top plan view showing the sensing plate with a first fixing hole of the present disclosure.

[0032] Figure 13 This is a perspective view showing the sensing housing to which the cover of this disclosure is attached.

[0033] Figures 14 to 16 This is a schematic diagram illustrating an embodiment of the arrangement of the eccentricity measuring sensor of this disclosure.

[0034] Figure 17 and Figure 18 This is a schematic diagram showing the positional relationship between the rotor and the eccentricity measurement sensor when the rotor is tilted and eccentric.

[0035] Figure 19 This is a schematic diagram showing the positional relationship between the rotor and the eccentricity measurement sensor when statically eccentric.

[0036] Figure 20 This is a schematic diagram showing the positional relationship between the rotor and the eccentricity measurement sensor during dynamic eccentricity.

[0037] Figure 21 and Figure 22 This is a schematic diagram showing the magnetic flux measured by two eccentricity measuring sensors when the magnetic field is tilted and eccentric.

[0038] Figure 23This is a schematic diagram showing the magnetic flux measured by two eccentricity measuring sensors when statically eccentric.

[0039] Figure 24 This is a schematic diagram showing the magnetic flux measured by two eccentricity measuring sensors during dynamic eccentricity.

[0040] Explanation of reference numerals in the attached figures

[0041] 1000: Eccentricity Measurement System

[0042] 100: Eccentricity Measurement Section

[0043] 110: Sensing board

[0044] 111: First fixing hole

[0045] 120: Eccentricity Measurement Sensor

[0046] 121: Sensing terminal

[0047] 130: External terminal

[0048] 140: Circuit Pattern

[0049] 141: Power cord

[0050] 141a: Power terminal

[0051] 142: Signal line

[0052] 142a: Signal output terminal

[0053] 200: Sensor housing

[0054] 210: Center Hole

[0055] 220: Central fixing part

[0056] 230: Sensor mounting part

[0057] 231: Plate insertion slot

[0058] 232: Interference Avoidance Slot

[0059] 233: Encapsulation Section

[0060] 234: Housing connection part

[0061] 234a: Threaded hole

[0062] 234b: Fixed stepped section

[0063] 240: Cover

[0064] 241: Second fixing hole

[0065] 250: Protective staircase

[0066] 260: Holder

[0067] 261: Sensor housing slot

[0068] 270: Capture Department

[0069] 271: Column

[0070] 272: Capture the Staircase

[0071] 120A: First eccentricity measurement sensor

[0072] 120B: Second eccentricity measurement sensor

[0073] S: Stator

[0074] R: Rotor

[0075] R1: Upper end of rotor

[0076] R2: Lower end of rotor

[0077] H: Motor housing

[0078] B: Bearing Detailed Implementation

[0079] The technical spirit of this disclosure will be described in more detail below with the aid of accompanying drawings. Furthermore, the terms or words used in the specification and claims should not be construed as limited to their general or dictionary meanings, but rather as meanings and concepts consistent with the technical spirit of this disclosure, based on the principle that the concepts of the terms can be appropriately defined to best describe this disclosure.

[0080] The following is for reference Figure 1 The basic structure of the eccentricity measurement system 1000 disclosed herein will be described.

[0081] like Figure 1 As shown, the eccentricity measurement system 1000 of this disclosure can be applied to a motor system including a stator S and a rotor R, and measures the eccentricity of the rotor R. The eccentricity measurement system 1000 may include an eccentricity measurement section 100 and a sensing housing 200. The eccentricity measurement section 100 may be configured to face the axial distal surface of the rotor R, and measures the presence or absence of eccentricity of the rotor R by utilizing the change in the magnetic field generated between the rotor R and the stator S. The eccentricity measurement section 100 may include a Hall sensor as a magnetic flux density sensor. Additionally, a central hole 210 for mounting the rotating shaft of the rotor R is formed through the center of the sensing housing 200. One surface of the sensing housing 200 may be configured to face the distal end of the rotor R, and the eccentricity measurement section 100 may be embedded in the surface of the sensing housing 200 facing the distal end of the rotor R.

[0082] As described above, an eccentricity measuring part 100 for measuring eccentricity and a sensing housing 200 supporting the eccentricity measuring part 100 can be provided at the axial distal end of the rotor R, thereby measuring all tilt eccentricity, axial eccentricity and dynamic eccentricity of the rotor R, reducing costs compared with reflective laser sensors in the prior art, detecting eccentricity factors that have the greatest impact on noise and vibration of the rotating device, and detecting defects in the initial stage of mass production.

[0083] The following is for reference Figures 2 to 4 The eccentricity measurement section of this disclosure will be described in more detail.

[0084] like Figure 2 As shown, the eccentricity measurement section 100 may include a sensing plate 110, which is connected to a front surface of the sensing housing 200 and has a surface for embedding one or more eccentricity measurement sensors 120. In this case, the eccentricity measurement sensor 120 may be a Hall sensor. Therefore, in order to analyze the signal waveform of the eccentricity of the rotor R, an analog signal with a waveform can be output to the outside, and the eccentricity of the rotor R can be identified by analyzing the sensing information based on the analog signal by an external controller. In addition, under the operating conditions of the motor to which the eccentricity measurement system 1000 of this disclosure is applied, since the magnetic flux of the rotor R is large, the number of eccentricity measurement sensors 120 used can be within the range that prevents Hall sensor saturation. Furthermore, this can be controlled by adjusting the connection position of the sensing housing 200, i.e., the axial distance between the eccentricity measurement section 100, the sensing housing 200, and the rotor R.

[0085] Alternatively, the eccentricity measurement sensor 120 can be a leaded sensor. More specifically, the eccentricity measurement sensor 120 may include sensing terminals extending in the axial direction and electrically connected to the sensing plate. Therefore, the eccentricity measurement sensor 120 can be manufactured and integrated with a sensing plate 110, and used together for various types of motors. Furthermore, the type and specifications of the eccentricity measurement sensor 120 can be easily changed according to the operating environment of the motor (temperature, etc.), resulting in advantages in repair and manufacturing costs.

[0086] As described above, since multiple eccentricity measurement sensors 120 are connected to a sensing plate 110, the multiple eccentricity measurement sensors 120 can be detached from the sensing housing 200 as a whole. Therefore, the sensing housing 200, which can be inserted into a sensing plate 110, can be used for various types of motors, thereby improving convenience. That is, the shape of the sensing housing 200 is not limited as long as the shape of the retainer 260 for assembling the eccentricity measurement section 100 exists.

[0087] In addition, such as Figure 3 As shown, the eccentricity measurement section 100 may further include an external terminal 130 electrically connected to the eccentricity measurement sensor 120 and configured to transmit sensing information from the eccentricity measurement sensor 120 to the outside, and a circuit pattern 140 printed on a surface of the eccentricity measurement section 100 to electrically connect the external terminal 130 and the eccentricity measurement sensor 120. A connector electrically connected to an external controller can be inserted into the external terminal 130, thereby electrically connecting the external controller, the circuit pattern 140, and the eccentricity measurement sensor 120.

[0088] In addition, such as Figure 4 As shown, circuit pattern 140 may include power line 141 and signal line 142. Power line 141 may include power terminal 141a, which is configured to supply power to and connected to eccentricity measurement sensor 120. Power line 141 may be printed as two + and - lines on each eccentricity measurement sensor 120. At least one power terminal 141a may be provided on each power line 141. Furthermore, signal line 142 may include signal output terminal 142a, which is configured to output the sensed value of eccentricity measurement sensor 120 and connected to eccentricity measurement sensor 120. One signal line 142 may be printed on each eccentricity measurement sensor 120.

[0089] Furthermore, the power line 141 and signal line 142 can be formed to extend in the same direction. For example, the power line 141 and signal line 142 can extend radially in the region corresponding to the sensor fixing part 230. Furthermore, the power terminal 141a and signal output terminal 142a can be configured as two or more power terminals and two or more signal output terminals respectively provided on the power line 141 and signal line 142 and spaced apart from each other at a predetermined interval. More specifically, the power terminal 141a and signal output terminal 142a can be configured to be spaced apart from each other at a predetermined interval in the radial direction that is the extending direction of the power line 141 and signal line 142.

[0090] Therefore, multiple pairs of terminals, each including two power supply terminals 141a and one signal output terminal 142a, can be provided in the radial direction, and the eccentricity measuring sensor 120 can be connected to these terminals. Thus, the connection position of the eccentricity measuring sensor 120 can be easily changed. That is, the radial position to which the eccentricity measuring sensor 120 is connected can be easily changed, so that even if the target radial position of the eccentricity measuring sensor 120 changes according to the type of motor, the eccentricity measuring system 1000 can be easily applied.

[0091] In the following text, reference will be made to Figures 5 to 11The sensing housing of this disclosure will be described in more detail.

[0092] like Figure 5 As shown, the sensing housing 200 may include an annular central fixing portion 220 having a central hole 210 and a sensor fixing portion 230. The sensor fixing portion 230 protrudes radially outward from the central hole 210 and is configured such that the eccentricity measurement sensor 120 is embedded in the sensor fixing portion 230. The sensing housing 200 may be a non-conductive plastic injection molded product. Therefore, the motor housing H made of metal material can be electrically insulated from the sensing plate 110 of the eccentricity measurement portion 100.

[0093] Furthermore, the sensing housing 200 may include a plate insertion groove 231 recessed to allow the sensing plate 110 to be inserted into the plate insertion groove 231, and an interference avoidance groove 232 formed in a cylindrical recess based on the apex of the plate insertion groove 231. The plate insertion groove 231 may be formed to have the same thickness as the sensing plate 110, or may be formed to be deeper than the sensing plate 110. In addition, the interference avoidance groove 232 may be formed at each apex of the plate insertion groove 231. Because of the inclusion of the plate insertion groove 231, the sensing plate 110 can be fully inserted into the sensing housing 200 without protruding from the outer surface of the sensing housing 200. Furthermore, due to the inclusion of the interference avoidance groove 232, it is easier to insert the sensing plate 110 into the plate insertion groove 231.

[0094] Additionally, the sensor mounting portion 230 may include a housing connection portion 234 that connects to the motor housing H, which houses the stator S and rotor R. The housing connection portion 234 may include a threaded hole 234a formed through the sensor mounting portion 230 and the motor housing H. Fasteners can be inserted into the threaded hole 234a. The fasteners inserted into the threaded hole 234a can penetrate the sensing housing 200 and be inserted into the motor housing H. At least one threaded hole 234a may be formed in the radially outwardly protruding sensor mounting portion 230. Therefore, the position of the sensor mounting portion 230 used by the eccentricity measuring sensor 120 can be constantly maintained, thereby further improving the accuracy of eccentricity measurement.

[0095] In addition, such as Figure 6 As shown, the sensing housing 200 may include a protective step portion 250 formed along the edge of the sensing housing 200, and the axially extending height is equal to or greater than the height of the eccentricity measuring sensor 120. The protective step portion 250 may be formed along the edge region other than the region adjacent to the aforementioned external terminals. Because the protective step portion 250 is formed with a height equal to or greater than the height of the eccentricity measuring sensor 120, the protective step portion 250 can protect the eccentricity measuring sensor 120 even if the eccentricity measuring sensor 120 is elongated in the axial direction.

[0096] In addition, such as Figure 7 As shown, the sensing housing 200 may further include a flat potting portion 233 configured to cover and protect one surface of the sensing plate 110 and disposed inside the protective stepped portion 250. The potting portion 233 is formed with a height equal to or greater than the height of the eccentricity measuring sensor 120 including the sensing terminal 121. The potting portion 233 may be made of epoxy resin or silicone resin. The potting portion 233 can fill the interior of the protective stepped portion 250 while covering the entire eccentricity measuring portion 100. Therefore, even when using a lead-type sensor with a sensing terminal that is elongated in the axial direction, the position and structure of the eccentricity measuring sensor 120 can be supported by the potting portion 233, thereby ensuring stability. Furthermore, even in harsh environments, the eccentricity measuring sensor 120 and the sensing plate 110 can be protected, thereby improving the utilization rate of the eccentricity measuring system 1000.

[0097] Alternatively, for example, the eccentricity measuring portion 100 can be pre-inserted into a mold used for injection molding the sensing housing 200, and the eccentricity measuring portion 100 can be manufactured together with the sensing housing 200 by insert injection molding. In this case, considering the heat resistance of the eccentricity measuring portion 100, a material that can be injected at low temperatures can be applied to the sensing housing 200. For example, body molding compound (BMC) can be used as the material of the sensing housing 200. By applying this embodiment, the eccentricity measuring system 1000 of this disclosure can be used even in harsh environments, thereby improving the utilization rate of the eccentricity measuring system 1000.

[0098] In addition, such as Figure 8 As shown, in another embodiment of the sensing housing 200, the sensing housing 200 may further include a retainer 260, one surface of which covers and protects one surface of the sensing plate 110, and is disposed inside the protective step portion 250. The retainer 260 has a sensor receiving groove 261 that protrudes axially to accommodate the eccentricity measuring sensor 120. That is, the sensor receiving groove 261 opens on one surface of the retainer 260 adjacent to the sensing plate 110. The sensor receiving groove 261 may extend toward the other surface of the retainer 260 and protrude beyond the axial height of the eccentricity measuring sensor 120. Figure 9 As shown, the retainer 260 can be mounted on the sensing housing 200 to protect the eccentricity measuring part 100.

[0099] In one embodiment, the sensor receiving groove 261 may have a multi-level chamfered shape with a polygonal cross-section perpendicular to the axis. More specifically, the sensor receiving groove 261 may be shaped to fit the shape of the eccentricity measuring sensor 120. Therefore, the eccentricity measuring sensor 120 and the sensor receiving groove 261 can be in surface contact with each other, allowing the eccentricity measuring sensor 120 to be supported more stably. Furthermore, a stepped portion with a predetermined height may protrude from the edge of one surface of the retainer 260. In this case, the height of the stepped portion may have the same thickness as or greater than that of the sensing plate 110. Therefore, the retainer 260 can abut against both the sensing plate 110 and the sensing housing 200, and can more stably support the position of the retainer 260.

[0100] Because of the inclusion of the retainer 260 as described above, the position of the eccentricity measuring sensor 120 can be stably supported even if the sensing terminal 121 is deformed or a gap is formed between the sensing terminal 121, the power supply terminal 141a and the signal output terminal 142a, since the eccentricity measuring sensor 120 is elongated in the axial direction.

[0101] In addition, such as Figure 10 As shown, the sensing housing 200 may further include at least one capturing portion 270 configured to fix the position of the retainer 260. More specifically, the capturing portion 270 may include a post 271 projecting axially from the edge of the sensing housing 200 and a capturing step portion 272 projecting radially from the distal end of the post 271 and configured to abut against another surface of the retainer 260.

[0102] The capturing portion 270 may be formed at the edge of the central fixing portion 220 of the sensing housing 200. The post 271 may be formed with thickness and height, allowing it to be easily bent in the radial direction. Before the retainer 260 is installed, the post 271 may extend beyond the edge of the central fixing portion 220 of the sensing housing 200. After the retainer 260 is installed and bonded, the post 271 may return to its original shape, and the capturing step portion 272 may abut against another surface of the retainer 260 to fix the position of the retainer 260.

[0103] In addition, such as Figure 11 As shown, the housing connection portion 234 may include a fixed stepped portion 234b placed on the connection structure of the bearing B of the motor housing H. Because of the fixed stepped portion 234b, the axial position of the sensing housing 200 can be fixed. The radial position of the sensing housing 200 can be maintained by the aforementioned central hole 210. Therefore, even when the motor rotates at high speed, the position of the sensing housing 200 can be fixed more stably, thereby further improving the measurement accuracy of the eccentricity.

[0104] The following is for reference Figure 12 and Figure 13 This will explain in more detail the connection between the eccentricity measurement section and the sensing housing of this disclosure.

[0105] In addition, such as Figure 12 As shown, the sensing plate 110 may further include a first fixing hole 111 formed through the area excluding the area where the circuit pattern 140 is formed. Because the first fixing hole 111 can be formed to avoid the circuit pattern 140 without affecting the electrical connection between the eccentricity measurement sensor 120, the external terminal 130, and the external controller. For this purpose, the first fixing hole 111 can be formed at different distances from the center. That is, Figure 12 d1 and d2 in the equation can be different from each other.

[0106] In addition, such as Figure 13 As shown, the sensing housing 200 may include a cover 240 disposed integrally on a surface and configured to cover the sensing plate 110, and the cover 240 may include a second fixing hole 241 formed through the surface at a position corresponding to the first fixing hole 111. In this case, fasteners can be inserted into the first fixing hole 111 and the second fixing hole 241 to fix the positions of the first fixing hole 111 and the second fixing hole 241. Because of the inclusion of the cover 240, the eccentricity measurement system 1000 of this disclosure can be used even in harsh environments, thereby improving the utilization rate of the eccentricity measurement system 1000.

[0107] In the following text, reference will be made to Figures 14 to 16 The embodiment of the arrangement of the eccentricity measurement sensor 120 of this disclosure is described in more detail.

[0108] like Figure 14 and Figure 15 As shown, two or more eccentricity measurement sensors 120 can be provided on the sensing plate 110, one eccentricity measurement sensor 120 can be embedded in each sensor fixing part 230, and the eccentricity measurement sensors 120 can be provided at equal intervals. Because two or more eccentricity measurement sensors 120 are used, when it is difficult to identify reference data when there is no eccentricity, the eccentricity state can be identified by comparing the data between the sensors. More specifically, as... Figure 14 As shown, when using three eccentricity measuring sensors 120, the eccentricity measuring sensors 120 can be positioned at a location with a 120-degree phase difference based on the rotation axes of the stator S and rotor R. Alternatively, as... Figure 15As shown, when four eccentricity measuring sensors 120 are used, the eccentricity measuring sensors 120 can be positioned at a location with a 90-degree phase difference based on the rotation axes of the stator S and the rotor R. Similarly, when two eccentricity measuring sensors 120 are used, the eccentricity measuring sensors 120 can be positioned at a location with a 180-degree phase difference based on the rotation axes of the stator S and the rotor R.

[0109] In addition, such as Figure 16 As shown, two or more eccentricity measurement sensors 120 can be provided on the sensing plate 110, with one eccentricity measurement sensor 120 embedded in each sensor fixing part 230, and the eccentricity measurement sensors 120 are spaced apart from each other with a phase difference of 90 degrees. Therefore, when it is difficult to identify reference data when there is no eccentricity, the eccentricity state can be identified by comparing the data between the sensors.

[0110] The following is for reference Figures 17 to 24 The algorithm for measuring the eccentricity of rotor R using the eccentricity measurement sensor 120 disclosed herein is described.

[0111] like Figure 17 As shown, when an eccentricity measuring sensor 120 is applied and the upper end R1 and lower end R2 of the rotor are tilted to the same degree in opposite (radial) directions (tilted eccentricity case 1), the magnetic flux on the side closer to the eccentricity measuring sensor 120 can increase, while the magnetic flux on the side farther from the eccentricity measuring sensor 120 can decrease. That is, the total magnetic flux may change.

[0112] More specifically, in Figure 17 In the case of eccentricity in the left-right direction, the following can be measured: the magnetic flux increases only at either the upper end R1 or the lower end R2 of the rotor R, and decreases at the other end R1 or the lower end R2 of the rotor R. That is, it can be determined that when the magnetic flux increases at the upper end R1 of the rotor and decreases at the lower end R2 of the rotor, the upper end R1 of the rotor is tilted toward the eccentricity measuring sensor 120. Conversely, it can be determined that the lower end R2 of the rotor is tilted toward the eccentricity measuring sensor 120.

[0113] In addition, Figure 17 When eccentricity occurs in the vertical direction, both the upper end R1 and the lower end R2 of the rotor R move away from the eccentricity measuring sensor 120, potentially reducing the magnetic flux at these locations. Therefore, it can be determined that eccentricity occurs in a direction perpendicular to the direction of the rotor R facing the eccentricity measuring sensor 120.

[0114] like Figure 18As shown, when an eccentricity measuring sensor 120 is applied and only one of the upper end R1 and the lower end R2 of the rotor R is tilted (tilted eccentricity case 2), the tilted side of the rotor R becomes closer to or farther away from the eccentricity measuring sensor 120, so that the magnetic flux can be increased or decreased.

[0115] More specifically, in the case of eccentricity, the following can be measured: where the magnetic flux increases or decreases only at either the upper end R1 or the lower end R2 of the rotor R, and the magnetic flux remains constant at the other end R1 or the lower end R2 of the rotor R. That is, it can be determined that if the magnetic flux at the upper end R1 of the rotor increases or decreases while the magnetic flux at the lower end R2 of the rotor remains constant, the upper end R1 of the rotor is tilted. Conversely, it can be determined that the lower end R2 of the rotor is tilted.

[0116] like Figure 19 As shown, when an eccentricity measuring sensor 120 is applied and the upper end R1 and lower end R2 of the rotor R are always eccentric, that is, when the rotor R is eccentric in the radial direction (static eccentricity), the upper end R1 and lower end R2 of the rotor R become closer to or further away from the eccentricity measuring sensor 120 in the same way, so that the magnetic flux can increase or decrease. That is, when the magnetic flux at the upper end R1 and lower end R2 of the rotor increases simultaneously in the same way, it can be determined that the rotor R is statically eccentric towards the eccentricity measuring sensor 120; when the magnetic flux at the upper end R1 and lower end R2 of the rotor decreases simultaneously in the same way, it can be determined that the rotor R is statically eccentric in a direction away from the eccentricity measuring sensor 120.

[0117] In addition, such as Figure 20 As shown, when an eccentricity measuring sensor 120 is applied and the air gap value changes over time (dynamic eccentricity), the magnetic flux measured from the rotor R changes over time, and the period of the magnetic flux may also change. More specifically, when the rotor R gets closer to the eccentricity measuring sensor 120, the magnetic flux may increase simultaneously as the period of the magnetic flux shortens. When the rotor R moves away from the eccentricity measuring sensor 120 in the opposite direction, the magnetic flux may decrease simultaneously as the period of the magnetic flux lengthens.

[0118] In addition, such as Figure 21 As shown, when two eccentricity measuring sensors 120 are applied and the upper and lower sides of the rotor R are tilted to the same degree in opposite (radial) directions (tilted eccentricity case 1), the magnetic flux on the side closer to the eccentricity measuring sensor 120 can increase, while the magnetic flux on the side farther from the eccentricity measuring sensor 120 can decrease. That is, the total magnetic flux may change.

[0119] For example, when the first eccentricity measuring sensor 120A and the second eccentricity measuring sensor 120B are spaced apart from each other by a phase difference of 180 degrees, and when tilting eccentricity of the rotor R occurs at both the first eccentricity measuring sensor 120A and the second eccentricity measuring sensor 120B, the magnetic flux can be partially reduced compared to the reference magnetic flux determined when no eccentricity occurs at either the first eccentricity measuring sensor 120A or the second eccentricity measuring sensor 120B. This represents the aspect of magnetic flux reduction as the upper end R1 or the lower end R2 of the rotor R moves away from the first eccentricity measuring sensor 120A and the second eccentricity measuring sensor 120B.

[0120] In addition, such as Figure 22 As shown, when two eccentricity measuring sensors 120 are applied and only one of the upper end R1 and the lower end R2 of the rotor R is tilted (tilted eccentricity case 2), the magnetic flux on the side closer to the eccentricity measuring sensor 120 can be increased, the magnetic flux on the side farther from the eccentricity measuring sensor 120 can be decreased, and the magnetic flux on the other side can be maintained. For example, when the first eccentricity measuring sensor 120A and the second eccentricity measuring sensor 120B are spaced apart from each other by a phase difference of 180 degrees, and the eccentricity of the upper end R1 of the rotor occurs in such a way that the upper end R1 of the rotor approaches the second eccentricity measuring sensor 120B, the magnetic flux at the first eccentricity measuring sensor 120A can be partially less than the reference value, and the magnetic flux at the second eccentricity measuring sensor 120B can be partially greater than the reference value.

[0121] In addition, such as Figure 23 As shown, when two eccentricity measuring sensors 120 are applied and the upper end R1 and lower end R2 of the rotor R are always eccentric, that is, when the rotor R is eccentric in the radial direction (static eccentricity), the upper end R1 and lower end R2 of the rotor R become closer to or further away from the eccentricity measuring sensor 120 in the same way, so that the magnetic flux can increase or decrease. That is, the magnetic flux at the upper end R1 and lower end R2 of the rotor can increase simultaneously in the same way. For example, when the first eccentricity measuring sensor 120A and the second eccentricity measuring sensor 120B are spaced apart from each other by a phase difference of 180 degrees and the eccentricity of the rotor causes the rotor to move closer to the second eccentricity measuring sensor 120B, the magnetic flux at the first eccentricity measuring sensor 120A can become significantly less than the reference value, and the magnetic flux at the second eccentricity measuring sensor 120B can become significantly greater than the reference value.

[0122] In addition, such as Figure 24As shown, when two eccentricity measuring sensors 120 are applied and the air gap value changes over time (dynamic eccentricity), the magnetic flux measured from the rotor R can change over time, and both the rotation angle and the magnetic flux change over time. For example, when the first eccentricity measuring sensor 120A and the second eccentricity measuring sensor 120B are spaced apart from each other by 180 degrees to generate dynamic eccentricity in the rotor R, the magnetic flux curves of the first eccentricity measuring sensor 120A and the second eccentricity measuring sensor 120B can be formed in opposite directions, and the magnetic flux and period are different from the reference value.

[0123] Furthermore, at least two or more of the tilt eccentricity, static eccentricity, and dynamic eccentricity can occur simultaneously, overlapping each other. In this case, the type of eccentricity can be analyzed by comparing each eccentricity data point with the measurement data.

[0124] The eccentricity measurement system disclosed herein may include an eccentricity measurement sensor mounted in a motor and configured to measure all tilting eccentricities, static eccentricities, and dynamic eccentricities of the rotor by utilizing changes in the magnetic field generated between the rotor and stator. This overcomes the limitations of reflective laser sensors in the prior art, reduces costs compared to reflective laser sensors in the prior art, detects eccentricity factors that have the greatest impact on noise and vibration of rotating devices, detects defects in the initial stages of mass production to prevent the shipment of potentially defective products, and measures eccentricities caused by wear, etc., after product durability testing or long-term vehicle operation to detect problems in advance and take proactive actions such as repairs.

[0125] Furthermore, by utilizing the aforementioned eccentricity measurement system, in the future application of eccentricity measurement systems to autonomous vehicles, it is possible to monitor the mechanical state of rotating devices. Applying the eccentricity measurement system to intelligent rotating device systems that can evaluate their state using pre-defined defect level indicators allows for the identification of the rotating device's state in areas imperceptible to humans. Moreover, the eccentricity measurement system can be applied to situations where the state of individual rotating devices is difficult to identify due to external vibrations or noise, enabling the system to be used for the pre-detection and resolution of problems in electric motors used in Urban Air Mobility (UAM) aircraft.

[0126] The technical spirit should not be construed as limiting oneself to the embodiments of this disclosure. Of course, the scope of application is diverse, and those skilled in the art can make various modifications and implementations without departing from the subject matter of this disclosure as claimed in the claims. Therefore, any improvements and modifications that are obvious to those skilled in the art will fall within the scope of this disclosure.

Claims

1. An eccentricity measurement system, said eccentricity measurement system being applied to a motor system including a stator and a rotor, and measuring the eccentricity of said rotor, characterized in that, The eccentricity measurement system includes: An eccentricity measurement section measures the presence or absence of rotor eccentricity by measuring the change in the magnetic field generated between the rotor and the stator. The eccentricity measurement section includes one or more eccentricity measurement sensors. Sensing housing, the sensing housing comprising: A surface in which the eccentricity measuring portion is embedded; and A central hole is formed through the center of the sensing housing, into which the rotating shaft of the rotor is fitted. The eccentricity measuring portion is connected to a front surface of the sensing housing and includes a sensing plate disposed on one surface of the eccentricity measuring portion, such that one or more eccentricity measuring sensors are embedded in the sensing plate. The one or more eccentricity measuring sensors include sensing terminals that extend in the axial direction and are electrically connected to the sensing plate.

2. The eccentricity measurement system according to claim 1, characterized in that, The eccentricity measurement section also includes: External terminals, electrically connected to the one or more eccentricity measuring sensors and transmitting the sensing information from the one or more eccentricity measuring sensors to the outside; and A circuit pattern printed on one surface of the eccentricity measuring portion to electrically connect the external terminals and the one or more eccentricity measuring sensors.

3. The eccentricity measurement system according to claim 2, characterized in that, The circuit pattern includes: Two power lines, each including a power terminal, the power terminal being connected to the sensing terminal of the one or more eccentricity measuring sensors and supplying power to the one or more eccentricity measuring sensors; and A signal line, the signal line including a signal output terminal, the signal output terminal being connected to the sensing terminals of the one or more eccentricity measuring sensors and outputting the sensed values ​​of the one or more eccentricity measuring sensors. Wherein, each of the two power lines and the signal line extends in the same direction, and The power supply terminal and the signal output terminal are configured as two or more power supply terminals and two or more signal output terminals respectively disposed in the power supply line and the signal line and spaced apart from each other at a predetermined interval.

4. The eccentricity measurement system according to claim 2, characterized in that, The sensing housing includes: An annular central fixing part having the central hole; A sensor fixing part, which protrudes radially outward from the central hole, wherein one or more eccentricity measuring sensors are embedded in the sensor fixing part; A plate insertion slot, wherein the plate insertion slot is recessed along the axial direction, such that the sensing plate is inserted into the plate insertion slot; and An interference avoidance groove is provided in a cylindrical shape and recessed along the axial direction based on the apex of the plate insertion groove.

5. The eccentricity measurement system according to claim 1, characterized in that, The sensing housing also includes: A protective step portion is provided along the edge of the sensing housing and extends axially to a height equal to or greater than the height of the one or more eccentricity measuring sensors; and A flat potting portion covers and protects one surface of the sensing plate and is disposed inside the protective step portion. The height of the potting portion is equal to or higher than the height of the one or more eccentricity measuring sensors including the sensing terminal.

6. The eccentricity measurement system according to claim 1, characterized in that, The sensing housing also includes: A protective step portion is provided along the edge of the sensing housing and extends axially to a height equal to or greater than the height of the one or more eccentricity measuring sensors; and A retainer having a first surface that covers and protects one surface of the sensing plate, the retainer being disposed inside the protective step portion, and including a sensor receiving groove projecting along the axial direction, such that one or more eccentricity measuring sensors are received in the sensor receiving groove.

7. The eccentricity measurement system according to claim 6, characterized in that, The sensing housing also includes a capturing part for fixing the position of the retainer.

8. The eccentricity measurement system according to claim 7, characterized in that, The capturing unit includes: A post, the post protruding from the edge of the sensing housing along the axial direction; and A capture step portion that protrudes radially from the distal end of the post and abuts the second surface of the retainer.

9. The eccentricity measurement system according to claim 2, characterized in that, The sensing board further includes a first fixing hole, which is formed through an area other than the area where the circuit pattern is formed. The sensing housing includes a cover, which is disposed on an entire surface of the sensing housing and covers the sensing plate. The cover includes a second fixing hole, which is disposed through the cover at a position corresponding to the first fixing hole.

10. The eccentricity measurement system according to claim 9, characterized in that, The eccentricity measurement system also includes fasteners that are inserted into the first fixing hole and the second fixing hole to fix their positions.

11. The eccentricity measurement system according to claim 1, characterized in that, The one or more eccentricity measuring sensors are configured as two or more eccentricity measuring sensors disposed on the sensing plate, and the one or more eccentricity measuring sensors are configured to be spaced apart from each other at equal intervals.

12. The eccentricity measurement system according to claim 1, characterized in that, The one or more eccentricity measuring sensors are configured as two or more eccentricity measuring sensors disposed on the sensing plate, and the one or more eccentricity measuring sensors are configured to be spaced apart from each other by a phase difference of 90 degrees.

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