Integrated insulation inspection system including insulation inspection bracket with conductive brush

Abstract

An integrated insulation inspection system includes an insulation inspection bracket with conductive brushes. An insulation inspection system includes: a support for an inspected part; comprising a respective set of conductive bristles, wherein the set of conductive bristles brushes a respective insulating portion of the part; at least one motor configured to at least one of i) move the part relative to the brushes and ii) move the one or more brushes relative to the part; and a control module configured to i) control the at least one motor to follow a movement profile, and ii) control the at least one motor during movement of at least one of the part and the one or more brushes, defects in the insulating material of the part due to a short circuit in the defect location between the one or more conductive bristles of the brush and the exposed conductive element of the part are detected.

Description

Technical Field

[0001] The information provided in this section is for the purpose of presenting the context of the present disclosure generally. To the extent that the work of the presently named inventors is described in this section and aspects of this description that may not otherwise be eligible as prior art at the time of filing are neither expressly nor implicitly admitted as prior art against the present disclosure.

[0002] The present disclosure relates to a continuity testing system, and more particularly to an insulation inspection system for inspecting stator windings and other electrical components. Background Art

[0003] Electric vehicles and hybrid vehicles include traction motors for propulsion purposes. Each traction motor includes a stator and a rotor having corresponding windings and conductive bars. The windings and / or conductive bars may be insulated (e.g., having an external insulation coating). During manufacturing, including during the formation and assembly of parts and components, the insulation coating may not be properly formed or may be scratched, scuffed, rubbed, etc. This may result in a lack of and / or removal of part of the insulation coating, thereby exposing the conductive elements. Such exposure may cause short circuits, affect motor performance, and / or shorten motor life. Summary of the Invention

[0004] An insulation inspection system is disclosed and includes: a support for a part to be inspected; a brush having corresponding sets of conductive bristles, wherein the sets of conductive bristles brush over corresponding insulated portions of the part; at least one motor configured to do at least one of the following, i) move the part relative to the brush and ii) move one or more brushes relative to the part; and a control module configured to i) control the at least one motor to follow a movement profile, and ii) during movement of at least one of the part and the one or more brushes, detect a defect in the insulation material of the part due to a short circuit between one or more conductive bristles of the brush and an exposed conductive element of the part at a defect location.

[0005] In other features, the insulation inspection system further includes a frame, wherein: the support for the part is mounted on the frame; and the at least one motor is directly or indirectly mounted on the frame.

[0006] In other features, the support for the part is implemented as a rotating support plate configured to rotate the part relative to the brush.

[0007] In other features, the frame includes guide rails; the brush is mounted on the guide rails via a brush holder; and the brush holder is movable relative to the guide rails.

[0008] Among other features, the at least one electric motor is configured to move at least one brush holder along at least one guide rail.

[0009] Among other features, the guide rail includes a first guide rail and a second guide rail. The first guide rail is mounted to a fixture and supports at least one brush. The fixture is mounted to the second guide rail and is slidable along the second guide rail. A portion of the fixture is rotatable relative to the second guide rail to transition the at least one brush between a retracted state and an extended state.

[0010] Among other features, the at least one electric motor is configured to move the fixture relative to the second guide rail.

[0011] Among other features, the at least one electric motor includes a motor that moves the at least one brush between an extended state and a retracted state. The at least one brush contacts a part when in the extended state and does not contact the part when in the retracted state.

[0012] Among other features, the brush includes at least one straight brush, at least one gamma brush, and at least one "U" - shaped brush.

[0013] Among other features, the part is a stator; and the brush is configured to brush multiple sides of the crown end and the welding end of the stator.

[0014] Among other features, the control module is configured to rotate the part via the at least one electric motor without disturbing the bus bars of the part.

[0015] Among other features, the at least one electric motor is configured to move the part relative to the brush.

[0016] Among other features, the at least one electric motor is configured to move one or more brushes relative to the part.

[0017] Among other features, the conductive bristles of the at least one brush include ends embedded in epoxy resin and held together by a conductive curl layer. The ends of the conductive bristles are connected to a wire via a conductive strip folded over the conductive curl layer. The wire provides a signal to the control module. The control module is configured to determine whether the part has a defect based on the signal.

[0018] Among other features, the epoxy resin includes at least one additive for at least one of increasing viscosity and increasing conductivity.

[0019] Among other features, the insulation inspection system further includes a frame, where the brush is mounted on the frame and is movable relative to the frame to accommodate inspected parts of different sizes.

[0020] Among other features, the brush includes a "U"-shaped brush, which includes: a first brush that brushes a first side of a part of the part; a second brush that brushes a second side of the part of the part; a third brush that brushes a third side of the part of the part; a first brush holder that holds the first brush; a second brush holder that holds the second brush; and a third brush holder that holds the third brush, wherein the first brush holder, the second brush holder, and the third brush holder are connected to each other.

[0021] Among other features, an insulation inspection system is disclosed and includes: a frame; a rotating support table configured to support and rotate a part to be inspected; a brush including respective conductive brush hair groups, wherein the conductive brush hair groups brush respective insulation portions of the part; a motor; and a control module configured to i) control the motor to rotate the part and move at least one brush relative to the part, and ii) during rotation of the part, detect a defect in the insulation material of the part due to a short circuit at a defect location between one or more conductive brush hairs of the brush and an exposed conductive element of the part.

[0022] Among other features, the brush includes a straight brush and a "U"-shaped brush.

[0023] Among other features, the brush is configured to brush a side of a first part of the part and a side of a second part of the part. The second part is different from the first part.

[0024] The present disclosure may further include the following technical solutions:

[0025] 1. An insulation inspection system, comprising:

[0026] a support for the part to be inspected;

[0027] a plurality of brushes including respective conductive brush hair groups, wherein the conductive brush hair groups brush respective insulation portions of the part;

[0028] at least one motor configured to perform at least one of the following: i) move the part relative to the plurality of brushes, and ii) move one or more of the plurality of brushes relative to the part; and

[0029] a control module configured to i) control the at least one motor to follow a movement profile, and ii) during movement of at least one of the part and one or more of the plurality of brushes, detect the defect in the insulation material of the part due to a short circuit at a defect location between one or more conductive brush hairs of the plurality of brushes and an exposed conductive element of the part.

[0030] 2. The insulation inspection system according to technical solution 1, further comprising a frame, wherein:

[0031] The support member for parts is mounted on the frame; and

[0032] The at least one motor is directly or indirectly mounted on the frame.

[0033] 3. The insulation inspection system according to Technical Solution 2, wherein the support member for parts is implemented as a rotating support plate, and the rotating support plate is configured to rotate the parts relative to the plurality of brush electrodes.

[0034] 4. The insulation inspection system according to Technical Solution 2, wherein:

[0035] The frame includes a plurality of guide rails;

[0036] The plurality of brush electrodes are mounted on the plurality of guide rails via a plurality of brush holders; and

[0037] The plurality of brush holders are movable relative to the plurality of guide rails.

[0038] 5. The insulation inspection system according to Technical Solution 4, wherein the at least one motor is configured to move at least one of the brush holders along at least one of the plurality of guide rails.

[0039] 6. The insulation inspection system according to Technical Solution 4, wherein:

[0040] The plurality of guide rails include a first guide rail and a second guide rail;

[0041] The first guide rail is mounted to a fixture and supports at least one of the plurality of brush electrodes;

[0042] The fixture is mounted to the second guide rail and is slidable along the second guide rail; and

[0043] A part of the fixture is rotatable relative to the second guide rail to cause at least one of the plurality of brush electrodes to transition between a retracted state and an extended state.

[0044] 7. The insulation inspection system according to Technical Solution 6, wherein the at least one motor is configured to move the fixture relative to the second guide rail.

[0045] 8. The insulation inspection system according to Technical Solution 1, wherein:

[0046] The at least one motor includes a motor that moves at least one of the plurality of brush electrodes between an extended state and a retracted state; and

[0047] At least one of the plurality of brush electrodes contacts the parts when in the extended state and does not contact the parts when in the retracted state.

[0048] 9. The insulation inspection system according to Technical Solution 1, wherein the plurality of brushes includes at least one straight brush, at least one gamma brush, and at least one "U"-shaped brush.

[0049] 10. The insulation inspection system according to Technical Solution 1, wherein:

[0050] the part is a stator; and

[0051] the plurality of brushes are configured to brush multiple sides of the crown end and the welding end of the stator.

[0052] 11. The insulation inspection system according to Technical Solution 1, wherein the control module is configured to rotate the part via the at least one motor while not disturbing the bus bar of the part.

[0053] 12. The insulation inspection system according to Technical Solution 1, wherein the at least one motor is configured to move the part relative to the plurality of brushes.

[0054] 13. The insulation inspection system according to Technical Solution 1, wherein the at least one motor is configured to move one or more of the plurality of brushes relative to the part.

[0055] 14. The insulation inspection system according to Technical Solution 1, wherein:

[0056] the conductive bristles of at least one of the plurality of brushes include ends embedded in epoxy resin and held together by a conductive crimp layer;

[0057] the ends of the conductive bristles are connected to a wire via a conductive strip folded over the conductive crimp layer;

[0058] the wire provides a signal to the control module; and

[0059] the control module is configured to determine whether there is a defect in the part based on the signal.

[0060] 15. The insulation inspection system according to Technical Solution 14, wherein the epoxy resin includes at least one additive for increasing at least one of viscosity and conductivity.

[0061] 16. The insulation inspection system according to Technical Solution 1, further comprising a frame, wherein the plurality of brushes are mounted on the frame and movable relative to the frame to accommodate parts of different sizes to be inspected.

[0062] 17. The insulation inspection system according to Technical Solution 1, wherein the plurality of brushes includes a "U"-shaped brush, and the "U"-shaped brush includes:

[0063] a first brush for brushing a first side of a part of the part;

[0064] A second electric brush for brushing a second side of the said part of the part to be brushed;

[0065] A third electric brush for brushing a third side of the said part of the part to be brushed;

[0066] A first electric brush holder for holding the first electric brush;

[0067] A second electric brush holder for holding the second electric brush; and

[0068] A third electric brush holder for holding the third electric brush,

[0069] The said first electric brush holder, the said second electric brush holder and the said third electric brush holder are connected to each other.

[0070] 18. An insulation inspection system, comprising:

[0071] A frame;

[0072] A rotating support table configured to support and rotate a part to be inspected;

[0073] A plurality of electric brushes, including corresponding conductive brush hair groups, wherein the said conductive brush hair groups brush corresponding insulation parts of the part;

[0074] A plurality of motors; and

[0075] A control module configured to i) control the said plurality of motors to rotate the part and move at least one of the said plurality of electric brushes relative to the part, and ii) during the rotation of the part, detect the said defect in the insulation material of the part due to a short circuit between one or more conductive brush hairs of the said plurality of electric brushes and an exposed conductive element of the part at a defect location.

[0076] 19. The insulation inspection system according to technical solution 18, wherein the said plurality of electric brushes include straight electric brushes and "U"-shaped electric brushes.

[0077] 20. The insulation inspection system according to technical solution 18, wherein:

[0078] The said plurality of electric brushes are configured to brush a plurality of sides of a first part of the part and a plurality of sides of a second part of the part; and

[0079] The second part is different from the first part.

[0080] Based on the detailed description, claims and drawings, additional fields of applicability of the present disclosure will become apparent. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Description of the Drawings

[0081] In light of the detailed description and the accompanying drawings, the present disclosure will be more fully understood, wherein:

[0082] Figure 1 is a bottom view of a part of the stator, which illustrates an example defect in the insulating coating;

[0083] Figure 2 is a schematic view of an example insulation inspection system for inspecting a stator according to the present disclosure and including a voltage and current balance circuit;

[0084] Figure 3 is a perspective view of an example part insulation inspection bracket according to the present disclosure, including a part rotating table and movable and fixed brushes;

[0085] Figure 4 is Figure 3 a side cross-sectional view of the part insulation inspection bracket of

[0086] Figure 5 is a cross-sectional view of an example "U" - shaped brush assembly according to the present disclosure, the example "U" - shaped brush assembly having three brushes with corresponding brush hair groups;

[0087] Figure 6 is a perspective partial exploded view of an example straight brush according to the present disclosure;

[0088] Figure 7 is a schematic diagram of an example insulation inspection system for testing a stator according to the present disclosure;

[0089] Figure 8 illustrates an example insulation inspection method for detecting, marking, identifying, and reporting defects according to the present disclosure;

[0090] Figure 9 illustrates an example defect indication procedure according to the present disclosure; and

[0091] Figure 10 is a functional block diagram of another part insulation inspection bracket according to the present disclosure, including a movable brush and a fixed part support.

[0092] In the drawings, reference numerals may be reused to identify similar and / or identical elements. Detailed Description

[0093] During manufacturing, the electric machine can be inspected to detect defects, such as defects in the insulation coating of the electrical components of the stator. The insulation coating can be visually inspected. This may include a quality control technician visually inspecting for defects in the insulation coating of the stator using a magnifying glass. Such inspections are labor-intensive and are limited by the technician. A continuity tester can be used to apply a voltage to the stator and detect when a short circuit exists. When there is a lack of insulating material at the point where the tester contacts the stator, current flows between the stator and the continuity tester.

[0094] The continuity tester can include a brush having conductive bristles. The bristles can move across and brush various parts of the stator to detect short circuit locations (i.e., defect locations) where there is a lack of insulating material. The opposite can also occur where the component (or stator) moves past the bristles and the brush is stationary. A circuit is used to monitor changes in voltage at the brush. When a short circuit occurs, the voltage drops significantly. There are large voltage and current fluctuations between when there is no short circuit and when there is indeed a short circuit.

[0095] If not managed properly, over time, the large voltage and current fluctuations in the circuit can be harmful to the component. As a result, the component can degrade over time, and this degradation can negatively impact the operation of the circuit. For example, an A / D converter may have specific voltage and current limits for operation based on the components used. If there is any resulting drift in the circuit components (such as resistors or other circuit components), this can lead to voltage response behavior that may cause problems with voltage threshold settings and improper detection of short circuits. Degradation of the circuit components can cause voltage drift, which may result in subsequent defects going undetected. Therefore, the drift requires circuit adjustment and periodic recalibration (including adjustment of the threshold). A defect can be detected when the voltage drops below the threshold. As an example, the threshold can be set to 5 volts (V), which is significantly lower than the nominal voltage and / or the normally expected voltage (e.g., 24V). The threshold can be set to be less than or equal to 20% of the nominal voltage.

[0096] Drift can also lead to unsafe current levels. If the circuit components degrade over time and there is a resulting change in the expected current of the circuit, this can cause the current level in the circuit to potentially exceed the threshold for perceived and / or actual bodily harm. Additionally, a current level higher than expected can also be harmful to the parts and the brush, even when human exposure is mitigated.

[0097] Examples set forth herein include an insulation inspection system that includes i) a component insulation inspection bracket having one or more continuity test brushes (referred to herein as brushes), and ii) one or more corresponding voltage and current balancing circuits, as Figure 2 and Figure 7As shown. The brush is installed on the part insulation inspection bracket together with the part to be inspected. The part moves relative to one or more brushes, or the brushes move relative to the part, such that the bristles of one or more brushes contact the exposed conductive elements of the part at positions where insulation material is missing. The voltage and current balance circuit provides a balanced voltage response at a nominal low current level, which is detected via the bristles of the continuity test brush for detecting defects (or short circuits). The voltage and current balance provides stability, improves the lifespan of circuit components, and provides improved functionality, thus allowing the insulation inspection system to be used in various applications while being safe for human touch. In addition to the said hardware, the insulation inspection system further includes an algorithm for marking defective parts. The algorithm improves the sensitivity to better detect defects.

[0098] Examples include an automated system having a rotary table for holding a stator and a bracket for holding a plurality of brushes for inspecting the sides of the welded ends and the crown ends of the stator while the stator rotates. The stator is located on the rotary table, and the ears and / or surfaces of the stator are held to the rotary table via brackets, as described below. A plurality of different types of brushes are used to contact the sides of various parts of the stator, such as the three sides of the welded end. In one embodiment, this is done to ensure that the insulation material completely covers the weld and / or bare wire of the welded end or other parts being inspected. A plurality of brushes can be used to brush other parts of the stator, such as the wire insulation on the stator crown end. The brushes are designed such that the bristles of the brushes contact the entire crown area and detect the wires exposed in the crown. This inspection can exclude the inspection of the stator busbars. The brushes are designed to avoid short circuits between the bristles and the stator core.

[0099] Each voltage and current balance circuit improves the safety flexibility by incorporating capacitors for voltage distribution and a pair of appropriately sized resistors. The resistance of the resistor pair is selected to generate a low current response. The capacitors and resistors are connected across the common terminal, negative terminal, and positive terminal of the analog-to-digital (A / D) converter. The value of the resistor is selected to generate a low current response throughout the operation of the voltage and current balance circuit and / or at all operating points. The low current response makes the test setup safe for the operator. When there is no short circuit, the capacitor creates an open circuit condition. When a short circuit is detected using a brush (e.g., a brush with carbon bristles), the voltage at the positive end of the corresponding capacitor drops, which causes a voltage drop across the corresponding resistor, such that the voltage of each positive terminal and negative terminal of the corresponding A / D converter remains within a predetermined voltage range (e.g., ±13V) relative to the voltage on the A / D common terminal.

[0100] The resistors are selected such that when a short circuit exists, the current through the voltage and current balancing circuit is maintained below a predetermined current (e.g., less than or equal to 25 mA, which is not perceptible to human touch). From the perspective of the input analog voltage signal, when no short circuit exists, this will keep the positive terminal of the A / D converter at the nominal operating voltage (e.g., 24 V) and the negative terminal of the A / D converter at 0 V. When a break in the insulation occurs, i.e., a short circuit in the connection from the brush to the phase lead, the corresponding voltage and current balancing circuit undergoes the following changes. The corresponding positive A / D terminal is forced towards 0 V. It should be noted that due to the intermittent contact between the brush bristles, the positive A / D terminal may not reach 0 V exactly, but in the case of a complete short circuit, the positive A / D terminal is forced to 0 V. A defect is detected when the positive A / D terminal drops to a predetermined threshold (e.g., 5 V) or below the predetermined threshold (e.g., 5 V), or is lower compared to the reference or no - short - circuit nominal voltage (e.g., 24 V).

[0101] Since the negative A / D terminal is maintained at 0 V, there is a 0 V difference between the positive and negative A / D terminals of the A / D converter, and thus the common A / D terminal is also at 0 V. Consequently, the resistors (hereinafter referred to as resistors R2, R4, R6,...RM) connected across the negative A / D terminal and the common A / D terminal of the A / D converter experience a 0 V drop (no current flow).

[0102] When a defect is detected, the corresponding capacitor will have charge available for discharging as needed, rather than directly connecting the power source supplying the nominal voltage to the short circuit (or defect). This allows maintaining a constant voltage drop across each capacitor while minimizing the current flow in any branch of the voltage and current balancing circuit when the corresponding brush makes intermittent contact with the defect. This is accomplished by maintaining a resistor - capacitor (RC) time constant long enough such that during the duration of intermittent contact between the brush and the defective area, the discharge of the capacitor does not cause a significant fluctuation in the voltage drop across the capacitor. As an example, each time constant can be 24 seconds. This results in resistors (hereinafter referred to as resistors R1, R3, R5,...RN) being connected between i) the capacitor and ii) the positive A / D terminal and the brush, thus mainly experiencing a voltage drop in the event of a short - circuit condition.

[0103] To ensure that the current in the circuit does not exceed a value that the human body would be able to sense, resistors R1, R3, R5,...RN are selected such that the current will not exceed a threshold (e.g., 1 milliampere (mA)) when a short circuit exists. This voltage and current balancing operation at all operating points allows the entire voltage and current balancing circuit to be safe for human touch and not introduce current or voltage levels that would damage the brush bristles or the part being inspected. The current and voltage levels are kept below a predetermined threshold to prevent, for example, arc discharge.

[0104] When a short circuit exists, the corresponding capacitor can discharge at an appropriate rate for rapid and stable measurement. The current flows through the resistor and provides an analog voltage measurement for the corresponding A / D converter. Once the brush has removed from the defect and the short circuit no longer exists, the capacitor is charged until it returns to the open-circuit state.

[0105] The voltage and current balance circuit prevents circuit component degradation by preventing large fluctuations in voltage and current across circuit components during a short-circuit event. The values of the capacitor and resistor are selected to improve circuit performance and prevent circuit component degradation due to parasitic voltage across the resistor. These values are selected to prevent drift of circuit component values. This prevents a larger-than-expected voltage drop and arcing across the brush bristles.

[0106] A circuit design and defect detection analysis algorithm are disclosed to enable an automated system to detect nicks and other defects in stator insulation. Multiple brushes are used to simultaneously inspect the welded ends and crown ends of the stator. The circuit accommodates multiple brushes and tracks the analog electrical responses of multiple voltage and current balance circuits. The voltage and current balance circuits allow the analog electrical responses to be tracked. Multichannel analog-to-digital conversion is performed while meeting electrical safety parameters. Additionally, the defect detection analysis algorithm and human-machine interface display are configured to allow simultaneous defect detection, identification, and notification (including marking defects for the end user).

[0107] Figure 1 A portion 100 of the stator is shown. The stator includes a pair of welded wires coated with an insulating material. Portion 100 includes a defect 102 where a portion of the insulating coating 104 is missing and the conductive material 106 of the wire is exposed. In Figure 1 a bottom (or welded end) of the stator is shown. The stator includes a laminated stack (or body) 110 having a bottom surface 112 and multiple ears ( Figure 1 one ear 114 is shown in

[0108] Figure 2An insulation inspection system 200 for inspecting a stator 202 is shown. The insulation inspection system 200 includes a human-machine interface (HMI) 204 and a voltage and current balancing circuit 206 connected to a power source 208. The HMI 204 may include a control module 210, an A / D converter 212, a memory 214, a transceiver 216, a display 218, and an auditory device 220. The display 218 includes an LED 222 and / or other visual displays and / or indicator elements. The control module 210 receives digital voltage data from the A / D converter 212, which receives an analog input signal from the voltage and current balancing circuit 206. The control module 210 detects a defect when the voltage of the analog output signal (or the corresponding digital signal) across the positive and negative terminals 223, 226 of the A / D converter 212 drops below a threshold (e.g., 5V or 20% of the nominal or normal expected voltage (e.g., 24V)). The normal expected voltage for no detected defect may be 24V. The control module 210 may indicate the detection of the defect via the display 218 and the auditory device 220. The detection of the defect, the change (or drop) in voltage, the timing of the detection, and / or other relevant information may be stored in the memory 214. As an example, the detection of the defect may be stored together with the approximate location of the defect relative to one or more reference points on the stator 202.

[0109] The display 218 provides visual assistance for indicating the detection of the defect. This also provides an indication of when the defect was detected. When a defect is detected, the auditory device 220 may provide a loud sound, such as a loud alarm signal. The auditory device 220 may include, for example, a speaker. The control module 210 may report the detected defect and the corresponding information stored in the memory 214 to one or more network devices located away from the HMI 204 via the transceiver 216.

[0110] The voltage and current balance circuit 206 includes resistors R1, R2, and capacitor C. Resistor R1 has: i) a first end that is connected to the first (or positive) terminal of the A / D converter 212 and to the brush 228; and ii) a second end that is connected to the first end of the capacitor C and to the positive terminal of the power source 208. Resistor R2 includes: i) a first end that is connected to the second (or negative) input terminal 226 of the A / D converter 212, the second end of the capacitor, one or more three-phase contacts 224, and the negative terminal of the power source 208; and ii) a second end that is connected to the third (or common) terminal COM of the A / D converter 212. The common terminal COM is separated from either of the terminals 223, 226 and is not connected to either of the terminals 223, 226. A lead 225 is connected between i) the negative terminal 226, the first end of resistor R2, and the second end of capacitor C and ii) one or more three-phase contacts 224. The first end of capacitor C is connected to the positive terminal of the power source 208. The second end of capacitor C is connected to the negative terminal of the power source 208.

[0111] Resistors R1, R2, and capacitor C are connected in series between the terminal 223 and the common terminal COM. In the example shown, capacitor C is connected between resistors R1 and R2. In one embodiment, resistors R1 and R2 are directly connected to the terminals 223, 226 and directly connected to capacitor C. Resistor R1 can be directly connected to the brush 228. Resistor R2 can be directly connected to the stator 202.

[0112] As an example, resistor R1 can be 20 - 30 kiloohms (kΩ), resistor R2 can be 400 - 500 kΩ, and the capacitor can be 500 - 1500 microfarads (μF). In one embodiment, R1 is 24 kΩ, R2 is 470 kΩ, and C is 1000 μF. The resistance of the resistors and the capacitance of the capacitor are selected to provide the RC time constant referred to herein. In one embodiment, the resistance of resistors R1, R2 is selected to limit the amount of current flowing through the stator 202, the voltage and current balance circuit 206, and the brush 228. The resistance of resistors R1 and R2 and the capacitance of capacitor C are selected, i) to prevent arcing and sparking at the bristles 230 when a defect (short circuit) occurs, and ii) for proper current balance in the circuit during all test conditions to maintain safety for human touch (less than 1 mA). For example, the resistance of resistors R1 and R2 can be selected to prevent the current through the circuit 206, brush 228, and stator 202 from exceeding a predetermined threshold.

[0113] Select a resistance value to limit current during all aspects of operation and balance the voltage load permitted across the channels of the A / D converter 212, such as the voltage loads associated with terminals 223, 226. In one embodiment, and regardless of whether a defect (a short circuit occurs) or no defect (no short circuit) exists, the current is maintained between 25 microamps (uA) and 1 mA due to i) the placement and selected values of resistors R1 and R2 and capacitor C in the voltage and current balancing circuit 206 associated with the power source 208 (e.g., a 24V DC power source), and ii) the A / D voltage channel limits between different channels with respect to the A / D common terminal COM. The resistance of R1 and R2 can be changed based on the A / D behavior limits to maintain the described current behavior. As an example, the channel limits can be such that the A / D channels of the A / D converter are within ±10 - 13V of the A / D common terminal COM. In one embodiment, the channel limits are such that the A / D channels are within ±10.2V of the A / D common terminal COM.

[0114] Select the capacitance rating of capacitor C to provide a long enough RC time constant in combination with the value of R1 chosen for current level reasons. This is done to provide a stable nominal voltage (e.g., a stable 24V) to the voltage and current balancing circuit 208 during the time window required to determine whether a short circuit has occurred. The R1*C value can provide a time constant of approximately 24 seconds. This provides a long enough time constant that does not need to be further increased with larger C values, although the time constant can be further increased. If the time constant is too small, then the charging and discharging behavior of capacitor C will affect the circuit operation because when a defect occurs, the nominal voltage will no longer be maintained at a stable 24V. Since the voltage response will be complicated by the behavior of capacitor C, this can make it challenging to assign a specific defect detection threshold.

[0115] The capacitance of capacitor C affects the rate of change of current flowing through stator 202, voltage and current balance circuit 206, and brush 228. Capacitor C is included as a protection device for brush 228 and bristles 230 and prevents current surges from the power source 208 to the short - circuit location. When there is no short - circuit, capacitor C is charged. When a short - circuit exists, capacitor C discharges. Due to the use of the RC time - constant, capacitor C does not fully discharge. This helps to limit the current in the circuit during a short - circuit event. After discharging, power source 208 re - charges capacitor C. Typically, if the bristles are moving, the short - circuit lasts for a very short period of time. In the absence of capacitor C, resistors R1 and R2 may deteriorate due to the short - circuit and the current surge through resistors R1 and R2. The capacitance and resistance values can also be selected based on the application used to provide low current consumption for safe operator use. For example, the capacitance of capacitor C and the resistance of resistors R1, R2 can be selected to accommodate different electric brush head designs for defect detection. In one embodiment, the brush is designed to have a low impedance compared to the circuit components. The insulation inspection system 200 is capable of accommodating brushes with a variety of different designs.

[0116] HMI 204 and / or A / D converter 212 detect the analog voltage across terminals 223, 226. Filtering of the A / D signal is done through data sampling to remove the noise associated with the electrical behavior of the bristles of the brush. The voltage from power source 208 is provided across capacitor C, which in combination with resistor R1 provides a stable voltage to brush 228, and one of the three - phase contacts 224 of stator 202 is connected to lead 225. When one or more of the conductive bristles 230 contact the exposed conductive elements of stator 202, current flows from one of the three - phase contacts 224 through stator 202 and to one or more bristles 230 in contact with the exposed conductive elements. The three - phase contacts 224 include three contacts: one for each phase of the three - phase stator 202. In one embodiment, the three - phase contacts 224 are connected to each other such that current can flow through any phase of stator 202. In another embodiment, voltage is provided to one of the three - phase contacts 224 of stator 202 and the brush is connected to lead 225.

[0117] The insulation inspection system 200 can be used to inspect the crown end 240, welded end 242, and / or other parts of stator 202 as shown. The insulation inspection system 200 can also be used to inspect individual electrical components and / or elements, examples of which are shown in Figure 3 It is shown. The crown end 240 extends upward from the lamination stack 244. The welded end extends downward from the lamination stack 244. The bristles 230 can move along different parts of stator 202 to detect the locations where the insulating material is missing.

[0118] The insulation inspection system 200 includes software and hardware with an adjustable A / D voltage threshold for marking defects. As an example, the threshold for marking defects can be set to 5V, but it can be different for different applications. The control module 210 implements a detection algorithm that detects when the voltage across terminals 223, 226 drops below one of the A / D voltage thresholds and generates a visual and / or audible signal to mark the detected defect.

[0119] The voltage and current balancing circuit described above minimizes the current level at all operating points, regardless of the presence of a short circuit. The inclusion, selection, and arrangement of the resistors and capacitors as described prevent large voltage and current fluctuations and, thus, prevent component degradation over time. This keeps the current level below the threshold associated with perceived and / or actual harm.

[0120] Figure 3 A parts insulation inspection bracket 300 is shown, which includes a parts turntable assembly (which can be referred to as a parts support) 302, a frame 304 with rails 306, a brush holder member 308, a first "U" shaped brush assembly 310, a first straight brush 312, a second straight brush 314, and a second "U" shaped brush assembly (or "U" brush) 316. The brushes 310 and 312 together are referred to as a gamma brush. Although Figure 3 - Figure 4 A bracket arrangement is shown that rotates the parts and holds the brushes in fixed positions, but the bracket can be modified to hold the parts in fixed positions and move the brushes relative to the parts. Figure 10 This example is shown in

[0121] Figure 3 The parts turntable assembly 302 of includes a base 320 and a support plate 322 that rotates relative to the base 320 (or turntable). The parts turntable assembly 302 can include a parts support bracket 324. The support bracket 324 is fastened to the support plate 322 and the part to be inspected 326 (e.g., the stator of a motor). The support bracket 324 can be "C" shaped and fastened to the ear 328 of the laminated stack 329 of the stator. If only one side is being inspected at a time, the support bracket 324 can be replaced with a pin with a tapered end. If pins are used, the stator will need to be flipped to test the other side of the stator. The part 326 rotates with the support plate 322.

[0122] The part turntable assembly 302 is part of an automated system that includes a turntable 320 with a support (or pallet) plate 322 on top. The palletizing system can use at least one pallet to load the parts to be inspected (or stators) away from the turntable 320, and a saddle can bring the pallet with the stator to the top of the turntable 320. The stator can also be transferred to a fixture located on the turntable 320 (by a robot or a human). The brushes of the system described below can be activated to move to a control position in a specific inspection section of the stator wires ready to contact the stator. The angular rotation of the stator is determined by the arrangement of one or more brushes to inspect the exposed insulated wires of the stator. Using a system such as Figure 2 , a human or a robot can use one or more other brushes to inspect all the exposed stator insulated wires.

[0123] The stator includes a crown end 330 and a welded end 332. The crown end 330 is inspected using a first "U" - shaped brush assembly 310 and straight brushes 312, 314. The first "U" - shaped brush assembly (or first "U" - shaped brush) 310 includes three brushes arranged in a "U" shape and forms part of a gamma brush. The gamma brush assembly also includes three brushes and the straight brush 312. A single brush member 334 holds the bristles 336 of the three brushes and the bristles 338 of the straight brush 312. The bristles 336 brush over the outer, upper, and inner sides of the crown end 330. The bristles 338 brush over the inner side of the crown end 330. The gamma brush assembly is capable of moving between a deployed state and a retracted state, as indicated by the arrow 339. This can be done, for example, by loosening or tightening the clamp 340 of the swing arm 341 via a handle 343. In one embodiment, the clamp 340 includes or is attached to a motor controlled by a control module (e.g., Figure 7 's control module). The brush holding members 308 can move laterally along the corresponding rails in the rail 306 as indicated by the arrows 342, 345 respectively. In one embodiment, the brush holding member 308 has slots that allow the brush holding member 308 to move closer to or farther from the stator to obtain proper contact with the stator. The brush 314 has bristles 344. The bristles 336, 338, and 3 are held in grooves of the corresponding brush holding member (or brush holder) 308, and the brush holding member 308 can have internal grooves for the ends of at least some of the bristles 336, 338, and 344.

[0124] The second "U" - shaped brush assembly 316 includes three brushes arranged in a "U" shape and is held by a single brush member 347. The three brushes of the second "U" - shaped brush assembly 316 brush over the inner, bottom, and outer sides of the welded end 332. Another "U" - shaped brush assembly is included and is shown in Figure 4 .

[0125] The stator has a bus bar 350 with three-phase contacts 352. The part to be inspected (or stator) 326 can be rotated so that the brushes of a single brush member 334 do not contact the bus bar 350. The part 326 can be rotated to inspect the stator crown section not covered by the bus bar 350. This is a rotation greater than 180° and less than 360°. As shown, the single brush member 334 is in a 90° position relative to the part 326. With the above-mentioned rotational movement of the part 326, the brushes 310, 312 can brush the inner surface of the crown end 330 through 360°. The gamma brush assembly can be switched to a retracted state to allow the brush 314 to brush the outer side of the crown end 330 through 360°. The part 326 is rotated through 360° to perform this operation. The second "U"-shaped brush assembly 316 also brushes the inner surface, bottom surface, and outer surface of the welding end 332 through 360°. While capturing data for the inner surface, bottom side surface, and outer surface of the welding end 332, the data collected for the outer surface of the crown end 330 can be captured.

[0126] Figure 4 The part insulation inspection bracket 300 is shown, which includes a part rotating table assembly 302, a frame 304 with guide rails 306, a brush holding member 308, a first "U"-shaped brush assembly 310, a first straight brush 312, a second "U"-shaped brush assembly 316, and a third "U"-shaped brush assembly (or third "U"-shaped brush) 400. The first "U"-shaped brush assembly 310 includes bristles 336, and the bristles 336 include bristle groups 336A, 336B, 336C corresponding to the respective brushes.

[0127] The part rotating table assembly 302 includes a rotating table base / casing 320 and a support plate 322. The support plate 322 is rotated via a shaft 402 by a motor 401 (shown in Figure 3 ), and the motor 401 can be controlled by a Figure 7 control module. A support rod 404 extends through the shaft 402 and is connected to a support member 406, and the support member 406 is connected to and supports the "U"-shaped brush assemblies 316 and 400. The "U"-shaped brush assemblies 316 and 400 include "U"-shaped members 345, 408 connected to the support member 406 and laterally extending members 410, 412. The "U"-shaped brush assemblies 316 and 400 further include bristle groups 420A, 420B, 420C and 422A, 422B, 422C. The bristles of the bristle groups 420A, 420B, 420C and 422A, 422B, 422C can include bristles of different lengths.

[0128] In the example shown, the part to be inspected 326 is shown as the above-mentioned stator, which has a crown end 330, a welding end 332, and a bus bar 350. The part 326 is held to the support plate 322 via a support bracket 324, and the support bracket 324 is "C"-shaped.

[0129] Figure 5 Shows a "U"-shaped brush assembly 500 having a holder design for three brushes 502, 504, 506 with corresponding brush tufts 508, 510, 512. The brushes 502, 504, 506 have corresponding wires 514, 516, 518 which are connected to corresponding voltage and current balancing circuits, examples of which are shown in Figure 7 . The bristles of the brush tufts 508, 510, 512 are conductive and flexible and are held by crimping and / or bristle retaining members 520, 522, 524. The brushes 502, 504, 506 have interlocking grooves which allow them to be held together and connected to a lateral extension member similar to some brushes shown in Figure 3 .

[0130] The holder design (or holder) can be adapted to different stator models, different stator sizes of the same series, etc. The holder includes a plate 521 attached to the brush body, where the brush body has a first corresponding channel for the wires 514, 516, 518 and a second corresponding channel for mounting the bristle retaining members 520, 522, 524. The holder can be "U"-shaped, flat or have another shape to accommodate the detection area of the exposed wires of the stator. The wires 514, 516, 518 are used to monitor the voltage at the brushes 502, 504, 506 respectively in order to determine the location of a defect (or the location where a short circuit is detected).

[0131] The bristles (or fibers) of the brushes 502, 504, 506 can be carbon fiber, one end of which is embedded in epoxy resin to prevent the carbon fiber from "falling out" and / or breaking from the bristle retaining members 520, 522, 524. The epoxy resin can be conductive and can include additives to increase the viscosity and / or conductivity of the epoxy resin and prevent wicking (or the movement of the epoxy resin along the fiber). Other additives can be zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D) or three-dimensional (3D) nanomaterials and depend on the shape and size of the additive. Nanoparticles and micron-sized particles such as metallic, non-metallic, polymeric and non-polymeric particles can be included. Other additives can include carbon-based nanomaterials and particles such as graphene, graphene nanosheets, graphite, fullerenes, carbon nanotubes, carbon black and carbon dots. The epoxy resin can increase the hardness of the bristles. Figure 6 Shows an example structural arrangement of a brush which can be used for each of the brushes 502, 504, 506.

[0132] Figure 6Shows a straight brush 600 and corresponding bristles 602, a conductive crimp layer 604, an epoxy resin layer 606, and a conductive strip 608. The epoxy resin layer 606 is outlined and shown in a transparent form to show the conductive crimp layer 604. The bristles 602 include a first end 610 and a second end 612. The first end 610 is not coated and / or embedded in the epoxy resin. The second end 612 is coated and embedded in the epoxy resin of the epoxy resin layer 606. The second end 612 is coated with epoxy resin. The epoxy resin can be conductive and connect the second end 612, the conductive crimp layer 604, and the conductive strip 608. The conductive crimp layer 604 winds around at least three sides of the second end 612, and curls onto the bristles 602 and holds the bristles 602 together. In one embodiment, the conductive crimp layer 604 winds around four sides of the second end 612. Although Figure 6 not shown in, the conductive strip 608 folds over the second end 612 and covers at least one side of the conductive crimp layer 604. The conductive strip 608 covers three sides of the second end 612. The conductive strip 608 is connected to a wire 614, which can be an output wire for detecting a short circuit.

[0133] The bristles 602 can include carbon fibers, metal fibers, or other conductive fibers. The density, hardness, and pull-out strength characteristics of the bristles can be selected and optimized. The conductive crimp layer 604 and the conductive strip 608 can be formed of a metallic material. In one embodiment, the second end 612, the conductive crimp layer 604, the epoxy resin layer 606, and the conductive strip 608 are placed, set, and cured within a brush holder. Figure 5 An example brush holder is shown in.

[0134] Figure 7 Shows an insulation inspection system 700 for testing a stator 702. The insulation inspection system 700 is similar to Figure 2 's insulation inspection system, but includes a component insulation inspection assembly 704 (such as Figure 3 - Figure 4 's component insulation inspection bracket 300), and a plurality of voltage and current balancing circuits 706 for a plurality of brushes 708 of the component insulation inspection assembly 704, respectively.

[0135] The insulation inspection system 700 includes an HMI 710. The HMI 710 includes a control module 711, an A / D converter 712 for the voltage and current balance circuit 706 respectively, a memory 714, a transceiver 716, a display 718, and an auditory device 720. The display 718 includes an LED 722 and / or other visual displays and / or indicator elements. The control module 711 receives digital voltage data from the A / D converter 712, which receives an analog input signal from the voltage and current balance circuit 706. The control module 711 detects a defect when the voltage of the analog output signal (or the corresponding digital signal) drops below a threshold (e.g., 5V or 20% of the nominal or normal expected voltage (e.g., 24V)). The control module 711 can indicate the detection of the defect via the display 718 and the auditory device 720. The detection of the defect, the change (or drop) in voltage, the timing of the detection, and / or other relevant information can be stored in the memory 714, as described above and as further described below.

[0136] The part insulation inspection assembly 704 includes a motor 730 and a brush 732, and may further include a sensor 734. The motor 730 may include a motor for rotating a support plate of a part (such as the stator 702). The motor 730 may further include a motor i) for moving the brush along a guide rail and / or relative to a corresponding part of the part to be inspected, and / or ii) for moving the brush between a deployed position and a retracted position. The brush 732 may include a straight brush, a "U" - shaped brush, and / or other brushes. Some brushes may be implemented in a gamma brush assembly. The sensor 734 may include a motor encoder for determining the position of the shaft of the motor 730, a camera for monitoring the position of the brush 732 relative to the part to be inspected, a speed sensor for monitoring the speed of one or more motors 730, and / or other sensors.

[0137] The stator 702 includes a crown end 740, a laminated stack 742, and a welded end 744. The crown end 740 extends from the top surface 746 of the laminated stack 742. The welded end 744 extends from the bottom surface 748 of the laminated stack 742. The stator 702 has three phases with corresponding 3 - phase contacts 750.

[0138] Each voltage and current balance circuit 706 includes i) a pair of resistors R1 and R2, R3 and R4,... or RM and RN, and ii) a corresponding one of the capacitors C1 - CP, where M, N, and P are integers. The number of resistor pairs is equal to the number of capacitors.

[0139] Each of the resistors R1, R3, ... RM has i) a first end connected to the first (or positive) terminal of a respective one of the A / D converters 712 and to a respective one of the brushes 732, and ii) a second end connected to a respective one of the capacitors C1-CP and to the positive terminal of the power source 760. The first ends of the capacitors C1-CP are connected to the resistors R1, R3, ... RM and to the positive terminal of the power source 760. The second ends of the capacitors C1-CP are connected to the negative terminal of the power source 760, a respective one of the resistors R2, R4, ... RN, the second (or negative) terminal of a respective one of the A / D converters 712, and one or more three-phase contacts 750.

[0140] Each of the resistors R2, R4, ... RN includes i) a first end connected to the third (or common) terminal of a respective one of the A / D converters 712, and ii) a second end connected to the second end of a respective one of the capacitors C1-CP, the negative terminal of the power source 760, and one or more three-phase contacts 750 of the stator 702. The leads 725 are connected between: i) the negative terminals of the A / D converters 712, the second ends of the resistors R II, R4, ... RN, and the second ends of the capacitors C1-CP; and ii) one or more three-phase contacts 750.

[0141] The resistors and capacitors of each voltage and current balancing circuit 706 are connected in series between the positive terminal of the A / D converter 712 and the common terminal of the A / D converter 712. In the example shown, each of the capacitors C1-CP is connected between a respective one of the resistors R1, R3, ... RM and a respective one of the resistors R2, R4, ... RN. In one embodiment, the resistors R1, R3, ... RM and R2, R4, ... RN are directly connected to respective ones of the terminals of the A / D converter 712 and directly connected to corresponding ones of the capacitors C1-CP. The resistors R2, R4, ... RN may be directly connected to the stator 702. The resistors R1, R3, ... RM may be directly connected to the brushes 732.

[0142] By way of example, each of the resistors R1, R3, ... RM may be 20 - 30 kiloohms (kΩ), each of the resistors R2, R4, ... RN may be 400 - 500 kΩ, and each of the capacitors may be 500 - 1500 microfarads (μF). In one embodiment, each of the resistors R1, R3, ... RM is 24 kΩ, each of the resistors R2, R4, ... RN is 470 kΩ, and each of the capacitors C1-CP is 1000 μF.

[0143] The resistances of resistors R1, R3, ... RM, R2, R4, ... RN and the capacitances of capacitors C1 - CP are selected to provide the RC time constants referred to herein. In one embodiment, the resistors are selected to limit the amount of current flowing through the stator 702, the voltage and current balance circuit 706, and the brushes 1 - N. The resistors and capacitors are selected i) to prevent arcing and sparking at the bristles of the brushes 1 - N when a defect (short circuit) occurs, and ii) for proper current balance in the circuit during all test conditions to maintain safety for human touch (less than 1 mA). For example, the resistors can be selected to prevent the current through the circuit 700, the brushes 1 - N, and the stator 702 from exceeding a predetermined threshold.

[0144] The resistor values are selected to limit the current in all aspects of operation and to balance the voltage loads permitted across the channels of the A / D converter 712, such as the voltage loads associated with the positive and negative terminals of the A / D converter 712. In one embodiment, and regardless of whether a defect (short circuit occurs) or not (no short circuit), the current is maintained between 25 microamps (uA) and 1 mA due to i) the placement and selected values of the resistors in the voltage and current balance circuit 706 associated with the power source 760 (e.g., 24V DC power source) along with the capacitors, and ii) the A / D voltage channel limits between different channels with respect to the A / D common terminal COM. The resistors can be changed based on the A / D behavior limits to maintain the described current behavior. As an example, the channel limits can be such that the A / D channels of the A / D converter 712 are within ±10 - 13V of the A / D common terminal COM. In one embodiment, the channel limits are such that the A / D channels are within ±10.2V of the A / D common terminal COM.

[0145] The capacitance ratings of the capacitors are selected to provide an RC time constant long enough, in combination with the resistances of the resistors R1, R3, ... RM selected for current level reasons. This is done to provide a stable nominal voltage (e.g., a stable 24V) to the voltage and current balance circuit 706 during the time window for determining whether a short circuit has occurred. The RC value can provide a time constant of approximately 24 seconds. This provides a long enough time constant that does not need to be further increased with larger C values, although the time constant can be further increased. If the time constant is too small, then the charging and discharging behavior of the capacitors C1 - CP will affect the circuit operation because when a defect occurs, the nominal voltage will no longer remain at a stable 24V. Since the voltage response will become intricate due to the behavior of the capacitors C1 - CP, this can make it challenging to assign a specific defect detection threshold.

[0146] In one embodiment, the resistances of resistors R1, R3, ... RM and R2, R4, ... RN are selected to limit the amount of current flowing through the stator 702, the voltage and current balance circuit 706, and the brushes 732. The resistances of resistors R1, R3, ... RM and R2, R4, ... RN and the capacitances of capacitors C1 - CP are selected to prevent arcing and sparking at the bristles of the brushes 732 when a defect (short circuit) occurs. For example, the resistances of resistors R1, R3, ... RM and R2, R4, ... RN can be selected to prevent the current through each brush 732 from exceeding a predetermined threshold.

[0147] The voltage and current balance circuit 706 operates similarly to Figure 2 the voltage and current balance circuit 206. The brushes 732 can include Figure 3 - Figure 4 the brushes 310, 312, 314, 316, 400. The control module 711 monitors the defects detected via the voltage and current balance circuit 706, the A / D converter 712, and the brushes 732.

[0148] Figure 8 Illustrated is an example insulation inspection method for detecting, marking, identifying, and reporting defects via multiple brushes (e.g., Figure 3 - Figure 4 and Figure 7 the brushes). The insulation inspection method implements a defect detection analysis algorithm including the following operations. These operations can be performed iteratively. The operations shown in solid boxes can be performed by Figure 2 the insulation inspection system 200 and / or Figure 7 the insulation inspection system 700 using Figure 3 - Figure 4 the part insulation inspection bracket 300 or another bracket similar to the part insulation inspection bracket 300. Although these operations are mainly described with respect to Figure 7 the insulation inspection system 700, these operations are applicable to other embodiments of the present disclosure.

[0149] At 800, the lead 725 is connected to the part to be inspected, such as the stator 702 or other electrical components. For example, the lead 725 can be connected to one or more three - phase contacts 750.

[0150] At 802, the control module 711 begins to rotate the part according to the movement profile while moving the brush through the insulated section of the part. The part can be rotated incrementally or in continuous motion. The part can be rotated when the following operations are performed. The brush 732 moves over the insulated section of the part being inspected. This includes brushing the bristles of the brush 732 on the insulated section such that one or more bristles contact any uninsulated (exposed) conductive material of the part. The exposed conductive material is at the voltage applied to the part by the power source 760. When one or more bristles contact the exposed portion of the part, a short circuit occurs and the control module 711 detects a voltage drop. The short circuit results in a sharp voltage drop from the nominal (or normally expected) level to below a threshold level. The bristles maintain contact with the part while moving relative to the part.

[0151] At 804A, 804B,... 804P (collectively operation 804), the control module 210 begins to monitor the voltage at the input terminal of the A / D converter 712 and thus the voltage at the bristles of the brush 732. This can include determining the position of the bristles of the brush 732 relative to one or more reference points on the part being inspected. In one embodiment, the bristles of the brush 732 initially contact a corresponding position on the part whose coordinates are known to the control module and then the brush 732 is moved. As an example, the control module 711 can track the movement including position and velocity information based on the output of the sensor 734.

[0152] At 806A, 806B,... 806P (collectively operation 806), the control module 811 determines whether a defect has been detected. If one or more defects have been detected, operations 808A, 808B,... 808P (collectively operation 808) are performed on the brush(es) where the defect(s) were detected, otherwise operations 812A, 812B,... 812P are performed on the brush(es) where no defect was detected. A defect is detected when there is a short circuit between one or more bristles of one or more brushes 732 and one or more exposed conductive elements of the part. When the part is a stator, there may be a short circuit between one or more bristles and one or more exposed wires of the stator and thus there may be a short circuit between one or more bristles and one or more three-phase contacts 750 of the stator 702.

[0153] At 808A, 808B,... 808P (collectively operation 808), the control module executes a defect indication program, which is illustrated in Figure 9 FIG.

[0154] At 900, the control module visually and / or audibly indicates the detected defect via one or more indicators, such as via display 718, LED 722, and / or auditory device 720. In one embodiment, a message is displayed via display 718. The message may include information about the detected defect, including the location of the defect, the time the defect was detected, the voltage drop at A / D converter 712 experienced as a result of the defect, the rate of the voltage drop, how long the defect was detected, etc. In another embodiment, the message is sent from HMI 710 to another network device via transceiver 716. Depending on the size of the defect and the speed of movement of the corresponding brush relative to the inspected part, the defect may be detected within a short period of time. The location of the defect may be indicated relative to one or more reference points on the inspected part.

[0155] As an example, a ring can be attached to the welding end 744 and have a clock index and / or the laminate stack 742 can have a reference point. The index and / or reference point can be used to determine the location of the detected defect. In one embodiment, the control module 711 marks the defect by lighting a red LED (one for each defect) or displaying a red icon (one for each defect). For brushes for which no defects are detected, a green LED may be turned on and / or a green icon may be displayed. The display may include an LED and / or display an icon for each brush that indicates whether a defect has been detected using that brush. In another embodiment, the control module 711 marks the defect by activating an audible defect alarm signal.

[0156] At 902, the control module 711 records information about the detected defect. At 904, the brush 732 is removed from the part (ie, moved to a stowed position away from the part). At 906, the voltage of the voltage and current balancing circuit 706 returns to a nominal level.

[0157] At 908, the control module 711 stops indicating that a defect has been detected and returns one or more indicators to a normal state. For example, the auditory device 720, which may be providing an auditory message (or alarm), turns off. An illuminated LED turns green or turns off. A displayed icon indicating the presence of a defect turns from red to green or is no longer displayed. Figure 8 Operations 810A, 810B, . . . 810P (collectively referred to as operation 810 ) may be performed after operation 908 .

[0158] At 810 , the control module 711 may determine whether there are more parts to inspect. If so, operation 804 may be performed, otherwise the method may end.

[0159] At 812, the control module 711 can compile defect information for each detected defect, which includes the location of the defect and other relevant information. The compiled information can be stored in the memory 714 as a compiled information file.

[0160] At 814, the control module 711 can report the compiled information in an overall compiled defect presence report and / or portions thereof via the display 718 and / or the auditory device 720. The report and / or the compiled information can be transmitted to a remote network device via the transceiver 716. The information can include the location of the defect, identify one or more defect regions in which the defect is located, and / or other relevant information (e.g., any of the above information). This can include an indication of the defect location on the part, the time the defect was detected, and / or other information indicating the defect location.

[0161] Based on the detected defects and the corresponding information, the defects can then be inspected and repaired. The control module 711 can rotate the part to allow manual inspection and / or allow repair of the defect. If the defect cannot be repaired and / or if there are too many defects, the part may be recycled or discarded. The control module 711 can indicate whether the part is repairable and / or whether the part should be recycled or discarded based on the information collected.

[0162] Figure 10 A part insulation inspection bracket 1000 is shown, which includes a movable brush 1002 and a fixed part support 1004 that is holding the part 1006 in a fixed position. Any number of brushes can be included. The brushes can be of any of the types mentioned above. Figure 10 is provided as an example and shows an example arrangement of the brushes relative to the part. The brushes can be in various other arrangements relative to the part. The part 1006 can be a stator or other type of part. The brush 1002 can be held by a brush holder 1008, which can be mounted to one or more support members. An example support member 1010 is shown. One or more motors can be included to move one or more support members and thus move the brush 1002. The motors can be mounted on the frame 1011. One motor 1012 is shown and moves the support member 1010. The motor moves the brush 1002 relative to the part. This movement can be a rotational movement or a linear movement. Motors can be included to move the brush between a deployed and a retracted state. The brush 1002 can be connected to the voltage and current balancing circuit of the insulation inspection system, as Figure 7 shown. The part support 1004 can also be mounted to the frame 1011.

[0163] The exemplary automated systems disclosed herein detect nicks on the exposed wires at the welded ends and crown ends of assembled stators. The brush holders are adjustable to accommodate different stator sizes of the same series as well as different brush head types and designs. This provides a high degree of flexibility in meeting the requirements of a given application. The automated system can be configured with stationary brushes and rotate the stator relative to the brushes, or can be configured with a stationary stator support member and rotate (or move) the brushes relative to the stator. The brushes are configured to detect the exposed wires at the welded ends and crown ends. The brush holders are optimized for each specific stator size and design. In one embodiment, the ends of carbon fibers are embedded in epoxy and inserted into the grooves of the brush holders. Additives such as carbon black can be utilized to increase the viscosity of the epoxy to prevent the bristles from pulling out, provide a low and consistent interface resistance, and prevent capillary action. The bristle lengths of the "U" shaped conductive brushes are selected for each application in use and are configured to avoid significant overlap of the bristles i) at the curved (or 90-degree angled) section of the "U" shaped holder to allow proper deflection of the bristles, and ii) at the contact section (or contact end) where the bristles contact the part being inspected.

[0164] The above example includes a circuit design for multi-channel analog-to-digital conversion of brush signals while meeting the electrical safety parameters for the operator. The circuit design allows parallel analog signal tracking of each brush integrated in the automated system. The multi-channel circuit design can include multiple brushes to comprehensively inspect each insulated portion of the part (perform electrical tests on each insulated portion of the part).

[0165] An analysis algorithm is provided that separately monitors the digitally converted signals from each brush while tracking the movement profiles of the brushes or the parts being inspected as the brushes or parts move relative to each other (e.g., rotate) for both defect identification and position determination. The HMI display is used for simultaneous defect detection and notification (e.g., marking). In one embodiment, when the inspection is performed with a repeatable movement profile, the location of the detected defect is reported to the end user and / or a remote network device.

[0166] The inspection circuit and analysis algorithm disclosed herein enable an automated system to inspect for cuts, nicks, and other defects in the wire insulation at both ends of a stator assembly. The inspection circuit has improved circuit performance to avoid deterioration of circuit components due to parasitic voltages across the resistance of the inspection circuit. The analysis algorithm is used to separately monitor the digital conversion signals from each brush while tracking their movement profiles as the brush and / or the part being inspected move relative to each other, for both defect identification and approximate localization. The HMI display is updated for the end user to allow for simultaneous brush detection and notification for marking defects. The HMI display can be used as a visual aid to understand when and where a defect occurs. If a short circuit exists, the corresponding defect can be shown via the HMI on the screen and / or with an audible alarm.

[0167] Flexibility of safety is improved by incorporating capacitors at each analog-to-digital channel of the voltage distribution within the circuit. Resistors with selected resistances are included to generate a low current response, making the test setup safe for the operator and preventing arcing between the brush bristles and the part being inspected. When a short circuit (short circuit condition) does not exist, the capacitor creates an open circuit condition. When the brush detects a short circuit (or short circuit condition), the voltage at the positive terminal of the corresponding capacitor drops, which results in a drop in the voltage across the corresponding pair of resistors, such that the voltages of each positive and negative terminal of the corresponding A / D converter remain within a predetermined voltage range (e.g., ±13V) relative to the voltage on the A / D common terminal. Once the brush is removed from the short circuit position, the capacitor is charged until it returns to its open circuit state. The voltage drop is limited, and the amount of current flowing through the circuit due to the short circuit is limited. This helps prevent circuit deterioration and makes the circuit safe for human contact. The values of the capacitor and resistor are set to meet the application requirements while providing low current consumption for safe operator use.

[0168] The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Thus, while the disclosure includes specific examples, the true scope of the disclosure should not be so limited since other modifications will become apparent after study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method can be executed in a different order (or concurrently) without altering the principles of the disclosure. Additionally, although each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more of the embodiments with each other are still within the scope of the disclosure.

[0169] The spatial and functional relationships between components (e.g., between modules, circuit components, semiconductor layers, etc.) are described using various terms, including "connected," "engaged," "coupled," "adjacent," "immediately adjacent," "on," "above," "below," and "disposed." Unless explicitly described as "direct," when the relationship between a first and a second component is described in the foregoing disclosure, the relationship can be a direct relationship in which no other intervening components exist between the first and second components, but can also be an indirect relationship in which one or more intervening components exist between the first and second components (spatially or functionally). As used herein, the phrase "at least one of A, B, and C" should be construed to mean a logical (A or B or C) using a non-exclusive logical "or," and should not be construed to mean "at least one of A, at least one of B, and at least one of C."

[0170] In the various figures, the direction of an arrow, as indicated by the arrowhead, generally indicates the information flow (such as data or instructions) of interest for that figure. For example, when components A and B exchange various information, but the information transmitted from component A to component B is relevant to that figure, the arrow can point from component A to component B. This one-way arrow does not imply that no other information is transmitted from component B to component A. Additionally, for information sent from component A to component B, component B can send a request for that information or receive an acknowledgement.

[0171] In this application, including the definitions below, the term "module" or the term "controller" can be replaced with the term "circuit." The term "module" can refer to, be part of, or include the following: an application specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinatorial logic circuit; a field programmable gate array (FPGA); a processor circuit that executes code (shared, dedicated, or grouped); a memory circuit that stores code executed by the processor circuit (shared, dedicated, or grouped); other suitable hardware components that provide the described functionality; or a combination of some or all of the foregoing, such as in a system-on-chip.

[0172] A module can include one or more interface circuits. In some examples, the interface circuit can include a wired or wireless interface connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module of the present disclosure can be distributed among multiple modules connected via the interface circuit. For example, multiple modules can allow for load balancing. In a further example, a server (also referred to as remote or cloud) module can implement some functions on behalf of a client module.

[0173] As used above, the term "code" can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuit" encompasses a single processor circuit that executes some or all of the code from multiple modules. The term "group processor circuit" encompasses a processor circuit that, in combination with additional processor circuits, executes some or all of the code from one or more modules. References to multiple processor circuits encompass multiple processor circuits on separate die, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or any combination of the above. The term "shared memory circuit" encompasses a single memory circuit that stores some or all of the code from multiple modules. The term "group memory circuit" encompasses a memory circuit that, in combination with additional memory, stores some or all of the code from one or more modules.

[0174] The term "memory circuit" is a subset of the term "computer-readable medium". As used herein, the term "computer-readable medium" does not encompass transitory electrical or electromagnetic signals propagated through a medium (such as on a carrier wave); thus, the term "computer-readable medium" can be considered tangible and non-transitory. Non-limiting examples of non-transitory tangible computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask ROM circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0175] The apparatuses and methods described in this application can be implemented in part or in whole by a special purpose computer created by configuring a general purpose computer to execute one or more specific functions embodied in a computer program. The functional blocks, flowchart components, and other elements described above serve as a software specification that can be translated into a computer program by the routine work of a skilled artisan or programmer.

[0176] A computer program includes processor-executable instructions stored on at least one non-transitory tangible computer-readable medium. The computer program can also include or rely on stored data. The computer program can encompass a basic input / output system (BIOS) that interacts with the hardware of the special purpose computer, device drivers that interact with specific devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0177] A computer program may include: (i) descriptive text to be parsed, such as HTML (HyperText Markup Language), XML (eXtensible Markup Language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated by a compiler from source code, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. By way of example only, the source code may be written using the syntax from languages including: C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Fortran, Perl, Pascal, Curl, OCaml, HTML5 (the fifth version of HyperText Markup Language), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Visual Lua, MATLAB, SIMULINK and

Claims

1. An insulation inspection system, comprising: a support for the part to be inspected; a plurality of brushes, including respective groups of conductive bristles, wherein the groups of conductive bristles brush over respective insulating portions of the part; at least one motor configured to do at least one of the following: i) move the part relative to the plurality of brushes, and ii) move one or more of the plurality of brushes relative to the part; and a control module configured to i) control the at least one motor to follow a movement profile, and ii) during movement of at least one of the part and one or more of the plurality of brushes, detect a defect in the insulating material of the part due to a short circuit in a defect location between one or more conductive bristles of the plurality of brushes and an exposed conductive element of the part.

2. The insulation inspection system according to claim 1, further comprising a frame, wherein: the support for the part is mounted on the frame; and the at least one motor is directly or indirectly mounted on the frame.

3. The insulation inspection system according to claim 2, wherein the support for the part is implemented as a rotating support plate configured to rotate the part relative to the plurality of brushes.

4. The insulation inspection system according to claim 2, wherein: the frame includes a plurality of guide rails; the plurality of brushes are mounted on the plurality of guide rails via a plurality of brush holders; and the plurality of brush holders are movable relative to the plurality of guide rails.

5. The insulation inspection system according to claim 4, wherein the at least one motor is configured to move at least one of the brush holders along at least one of the plurality of guide rails.

6. The insulation inspection system according to claim 4, wherein: the plurality of guide rails include a first guide rail and a second guide rail; the first guide rail is mounted to a fixture and supports at least one of the plurality of brushes; the fixture is mounted to the second guide rail and is slidable along the second guide rail; and a part of the fixture is rotatable relative to the second guide rail to transition at least one of the plurality of brushes between a retracted state and a deployed state.

7. The insulation inspection system according to claim 6, wherein the at least one motor is configured to move the fixture relative to the second guide rail.

8. The insulation inspection system according to claim 1, wherein: the at least one motor includes a motor that moves at least one of the plurality of brushes between a deployed state and a retracted state; and at least one of the plurality of brushes contacts the part when in the deployed state and does not contact the part when in the retracted state.

9. The insulation inspection system according to claim 1, wherein the plurality of brushes include at least one straight brush, at least one gamma brush, and at least one "U" - shaped brush.

10. The insulation inspection system according to claim 1, wherein: the part is a stator; and the plurality of brushes are configured to brush a plurality of sides of the crown end and the welded end of the stator.

Images