Gas turbine wheel disc blade root groove array eddy current probe scanning mechanism and method

Abstract

The invention discloses a gas turbine wheel disc blade root groove array eddy current probe scanning mechanism and method. The mechanism comprises a probe framework, a driving module, a clamping device and a detection module. The probe framework is stably mounted and fixed with a detected turbine wheel disc blade root groove, and provides structural support for the driving module and the detection module, so that direct contact friction between the array eddy current coil and the turbine wheel disc blade root groove is avoided; the driving module and the clamping device provide high-resolution positioning precision and stable scanning speed for the array eddy current coil, and the detection sensitivity and quantitative precision of array eddy current detection are improved; the detection module provides an arrangement surface suitable for the appearance of a turbine wheel disc blade root groove for the array eddy current coil, and meanwhile stable and efficient scanning is achieved through the clamping device and the driving device. Finally, the problems of high labor intensity and low array eddy current detection efficiency and accuracy caused by non-uniform scanning speed, unstable lift-off, inaccurate probe positioning and the like in the traditional array eddy current detection of the in-service turbine wheel disc blade root groove are solved.

Description

Technical Field

[0001] The invention belongs to the field of nondestructive testing of gas turbine components, and in particular relates to a scanning mechanism and method of an eddy current probe for a gas turbine wheel blade root slot array. Background Art

[0002] In rotating machinery such as gas turbines, the blade root groove of the turbine disc is one of the key components, and its quality and integrity are directly related to the safety of the entire machine. Therefore, regular inspection of the blade root groove and timely detection and treatment of potential defects are of great significance to ensure the stable operation of the unit.

[0003] As a high-precision, high-sensitivity non-destructive testing method, array eddy current testing technology has been widely used in the inspection of turbine blade root grooves. However, in traditional array eddy current testing, the inspectors generally manually slide the array eddy current probe to scan, which is not only labor-intensive, but also extremely prone to problems such as uneven scanning speed (stuttering), unstable lift-off, and inaccurate probe positioning caused by floating rust, grease, and pits on the surface of the turbine blade root groove.

[0004] In order to overcome the problems existing in the prior art, a gas turbine turbine impeller blade root slot array eddy current probe scanning mechanism and method are proposed, which ensures uniform speed and stability during the scanning process and accurate positioning of the probe, thereby improving the detection efficiency and accuracy of the turbine impeller blade root slot. Summary of the invention

[0005] The purpose of the present invention is to provide a gas turbine impeller blade root slot array eddy current probe scanning mechanism and method, aiming to solve the problems of high labor intensity and low array eddy current detection efficiency and accuracy caused by uneven scanning speed, unstable lift-off and inaccurate probe positioning in traditional array eddy current detection of in-service turbine impeller blade root slots.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A gas engine turbine wheel blade root slot array eddy current probe scanning mechanism, comprising a probe frame, a driving module, a detection module and a clamping device; The probe skeleton includes a skeleton body, a drive module installation interface, an eddy current coil communication interface and a sliding contact conductive slide rail; the skeleton body is a hollow structure; the drive module installation interface is respectively located at both ends of the skeleton body, and both ends are processed with drive motor installation holes and linear guide rail installation holes; the eddy current coil communication interface is located on the end face of the skeleton body, and is used to connect the array eddy current detector; the sliding contact conductive slide rail is axially installed in the probe skeleton body, one end is covered by an insulating material, and the other end is connected to the eddy current coil communication interface; The driving module includes a driving motor, a transmission belt and a linear guide assembly; there are two driving motors, which are respectively installed at the axial ends of the probe frame body; the transmission belt is sleeved on the two driving motor transmission wheels, and the driving motor drives the transmission belt to move along the axial direction by rotating; there are two sets of linear guide assemblies, in which the guide base is installed in the probe frame body through the linear guide mounting hole, and is respectively located directly above and directly below the transmission belt; The detection module includes a contoured body, an array eddy current coil and a conductive slider; the contoured body detection surface is completely in contact with the inner surface of the probe skeleton body, and the axial width of the contoured body is greater than the width of the array eddy current coil; the array eddy current coil is arranged on the contoured body detection surface; the conductive slider is installed on the upper surface of the contoured body, connected to the array eddy current coil through a cable, and meshed with the sliding contact conductive slide rail to transmit the array eddy current coil signal; The clamping device is used to press the transmission belt to control the movement of the detection module.

[0007] A further improvement of the present invention is that the clamping device comprises a pressure plate, a plurality of guide pillars, a plurality of springs, an electromagnet and a pressure head; the pressure plate has two pieces, the lower pressure plate is connected to the contoured body and is processed with a plurality of guide through holes, and the upper pressure plate is processed with guide through holes of the same number and size at the corresponding positions; the plurality of guide pillars respectively pass through the guide through holes corresponding to the upper and lower pressure plates, and a plurality of springs are sleeved between the upper and lower pressure plates of the plurality of guide pillars; the upper and lower surfaces of the plurality of springs are in contact with the lower surface of the upper pressure plate and the upper surface of the lower pressure plate, respectively; the electromagnet is integrated on the upper pressure plate and is located at the geometric center of the plurality of guide through holes of the upper pressure plate; the pressure heads are respectively located on the lower surface of the upper pressure plate and the upper surface of the lower pressure plate, and the pressing condition with the transmission belt is controlled by turning the electromagnet on and off, thereby controlling the movement of the detection module.

[0008] A further improvement of the present invention is that the thickness of the contact portion between the probe skeleton body and the contoured body detection surface is no more than 2 mm and is made of high-strength engineering plastic.

[0009] A further improvement of the present invention is that the axial distance between the center of the drive motor mounting hole and the end surface of the turbine wheel blade root groove is greater than the sum of the axial width of the contoured body and the radius of the drive motor transmission wheel; The axial distance between the center of the linear guide rail mounting hole and the end face of the turbine wheel blade root groove is greater than the axial distance between the center of the drive motor mounting hole and the end face.

[0010] A further improvement of the present invention is that a layer of wear-resistant, low-resistance, low-resistance material is provided on the contact surface between the sliding contact type conductive slide rail and the conductive slider; and a shield is provided at the interface between the sliding contact type conductive slide rail and the conductive slider.

[0011] A further improvement of the present invention is that the driving motor is a micro-stepping motor with forward and reverse rotation functions, and the motor shaft is perpendicular to the axial center plane of the turbine wheel blade root slot; The diameter of the driving motor transmission wheel shall not be less than twice the sum of the thickness of the lower sheet pressing plate and the pressing head.

[0012] A further improvement of the present invention is that the transmission belt type is a flat belt, and the upper and lower surfaces are provided with wear-resistant and anti-skid material layers. The thickness of the transmission belt is at least smaller than the gap between the upper platen pressure head and the lower platen pressure head in the unpressed state.

[0013] A further improvement of the present invention is that the arc length of the detection surface of the contoured body is not less than the arc length of the cross-section of the turbine wheel blade root slot, and the array of eddy current coils arranged thereon is equal in length to the arc length of the detection surface.

[0014] A further improvement of the present invention is that the array eddy current coils are arranged in two rows in a staggered manner, and a time-sharing multi-excitation transmission and reception method is used for excitation and reception; The array eddy current coil is arranged near the surface of the profiling body detection surface to prevent damage caused by friction on the inner surface of the skeleton body during the detection process.

[0015] A method for scanning a gas turbine wheel disc blade root slot array eddy current probe, the method is based on a gas turbine wheel disc blade root slot array eddy current probe scanning mechanism, comprising: Place the probe skeleton body stably in the blade root slot of the turbine disk to be tested, so that the distances between the two end faces of the skeleton body and the end faces of the blade root slot of the turbine disk to be tested are equal, ensuring that the array eddy current coil can completely scan the axial direction of the blade root slot of the turbine disk to be tested; The electromagnet is energized to press the pressing plate onto the transmission belt. When the driving motor drives the transmission belt to move axially, the contour body moves axially along the guide rail base through the slider with the help of the driving force transmitted by the pressing plate. The conductive slider and the sliding contact conductive slide rail are combined to transmit the excitation and receiving signals of the array eddy current coil, and the excitation and receiving instructions of the array eddy current detector are transmitted to the array eddy current coil on the contour body. The driving motor records and transmits the scanning position and distance of the contoured body in real time, and makes a C-scan image through the array eddy current detector to achieve uniform and smooth scanning of the turbine wheel blade root groove.

[0016] Compared with the prior art, the present invention has at least the following beneficial technical effects: The present invention provides a scanning mechanism and method for an array eddy current probe of a gas turbine wheel blade root slot. The probe frame is stably installed and fixed to the detected turbine wheel blade root slot, and provides structural support for the drive module, the detection module, etc., avoiding direct contact and friction between the array eddy current coil and the turbine wheel blade root slot, ensuring the lifting stability and service life of the array eddy current coil; the drive module and the clamping device provide the array eddy current coil with high-resolution positioning accuracy and stable scanning speed, improving the detection sensitivity and quantitative accuracy of the array eddy current detection; the detection module provides the array eddy current coil with a layout surface suitable for the shape of the turbine wheel blade root slot, and at the same time, stable and efficient scanning is achieved through the clamping device and the drive device. Finally, the uniform, stable and efficient array eddy current scanning of the turbine wheel blade root slot is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an axonometric schematic diagram of a gas engine turbine wheel blade root slot array eddy current probe scanning mechanism of the present invention; Figure 2 It is a side view schematic diagram of a gas engine turbine wheel blade root slot array eddy current probe scanning mechanism of the present invention; Figure 3 It is a schematic side view of a clamping device of a gas engine turbine wheel blade root groove array eddy current probe scanning mechanism of the present invention; Figure 4 The present invention is a schematic flow chart of a method for scanning a gas engine turbine wheel blade root slot array using an eddy current probe.

[0018] Description of reference numerals: 1-probe skeleton, 11-skeleton body, 12-drive module installation interface, 121-drive motor installation hole, 122-linear guide rail installation hole, 13-eddy current coil communication interface, 14-sliding contact conductive slide rail, 2-drive module, 21-drive motor, 22-transmission belt, 23-linear guide rail assembly, 231-guide rail base, 232-slider, 3-detection module, 31-contact body, 32-array eddy current coil, 33-conductive slide, 4-clamping device, 41-pressure plate, 411-lower sheet pressure plate, 412-upper sheet pressure plate, 42-guide column, 43-spring, 44-electromagnet, 45-pressure head, 5-array eddy current detector. DETAILED DESCRIPTION

[0019] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0020] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0024] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0025] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0026] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] Example 1 like Figure 1 to Figure 3 As shown, the present invention provides a gas engine turbine wheel blade root groove array eddy current probe scanning mechanism, including a probe frame 1, a driving module 2, a detection module 3 and a clamping device 4.

[0029] The probe skeleton 1 includes a skeleton body 11, a drive module installation interface 12, an eddy current coil communication interface 13 and a sliding contact conductive rail 14. The skeleton body 11 is a hollow structure, and the outer dimensions of its cross section completely match the cross section of the detected turbine wheel blade root slot, and the axial length is greater than the axial length of the turbine wheel blade root slot; the drive module installation interface 12 is respectively located at both axial ends of the skeleton body 11, and both ends are processed with a drive motor installation hole 121 and a linear guide rail installation hole 122; the eddy current coil communication interface 13 is located on the end face of the skeleton body 11, and is used to connect the array eddy current detector 5, transmit the detection signal of the array eddy current coil 32 to the array eddy current detector 5, and transmit the excitation and reception instructions of the array eddy current detector 5 to the array eddy current coil 32; the sliding contact conductive rail 14 is axially installed in the probe skeleton body 11, one end is coated with an insulating material, and the other end is connected to the eddy current coil communication interface 13.

[0030] The driving module 2 includes a driving motor 21, a transmission belt 22, and a linear guide assembly 23. There are generally two driving motors 21, which are respectively installed at the axial ends of the probe skeleton body 11; the transmission belt 22 is sleeved on the two driving motor 21 transmission wheels, and the driving motor 21 drives the transmission belt 22 to move along the axial direction by rotating; the linear guide assembly 23 generally includes two groups, wherein the guide base 231 is installed in the probe skeleton body 11 through the linear guide mounting hole 122, and is respectively located directly above and directly below the transmission belt 22.

[0031] The detection module 3 includes a contoured body 31, an array eddy current coil 32, and a conductive slider 33. The detection surface of the contoured body 31 is completely in contact with the inner surface of the probe skeleton body 11, and the axial width of the contoured body 31 is greater than the width of the array eddy current coil 32; the array eddy current coil 32 is arranged on the detection surface of the contoured body 31; the conductive slider 33 is installed on the upper surface of the contoured body 31, connected to the array eddy current coil 32 through a cable, and meshed with the sliding contact conductive slide rail 14, for transmitting the array eddy current coil 32 signal.

[0032] The clamping device is used to press the transmission belt to control the movement of the detection module.

[0033] In some embodiments, the clamping device 4 includes a pressing plate 41 , a plurality of guide posts 42 , a plurality of springs 43 , an electromagnet 44 , and a pressing head 45 . Among them, the pressing plate 41 has two pieces, the lower pressing plate 411 is connected to the contoured body 31, and is processed with multiple guide through holes, and the upper pressing plate 412 is processed with the same number and size of guide through holes at the corresponding position; multiple guide columns 42 pass through the corresponding guide through holes of the upper pressing plate 412 and the lower pressing plate 411, and multiple springs 43 are sleeved between the upper and lower pressing plates of the multiple guide columns 42; the upper and lower surfaces of the multiple springs 43 are in contact with the lower surface of the upper pressing plate 412 and the upper surface of the lower pressing plate 411 respectively; the electromagnet 44 is integrated on the upper pressing plate 412 and is located at the geometric center of the multiple guide through holes of the upper pressing plate 412; the pressure head 45 is respectively located on the lower surface of the upper pressing plate 412 and the upper surface of the lower pressing plate 411, and the pressing condition with the transmission belt 22 is controlled by turning the electromagnet 44 on and off, thereby controlling the movement of the detection module 3.

[0034] In some embodiments, the thickness of the contact portion between the probe skeleton body 11 and the detection surface of the contoured body 31 is no more than 2 mm and is made of high-strength engineering plastic, thereby controlling the lifting distance of the array eddy current probe within a range that does not significantly affect the detection effect, while ensuring the rigidity of the probe skeleton body 11 itself.

[0035] Preferably, the engineering plastic of the probe skeleton body 11 is ABS engineering plastic or polypropylene engineering plastic.

[0036] In some embodiments, the axial distance between the center of the drive motor mounting hole 121 and the end face of the turbine wheel blade root slot is greater than the sum of the axial width of the contoured body 31 and the radius of the drive wheel of the drive motor 21, so that the array eddy current coil 32 can scan outside the groove surface of the turbine wheel blade root slot, ensuring that the array eddy current coil 32 covers 100% of the axial direction of the turbine wheel blade root slot.

[0037] In some embodiments, the axial distance between the center of the linear guide rail mounting hole 122 and the end surface of the turbine wheel blade root groove is greater than the axial distance between the center of the drive motor mounting hole 121 and it, ensuring that the scanning range of the contoured body 31 is not limited by the linear guide rail assembly 23.

[0038] In some embodiments, the sliding contact conductive rail 14 is made of a material with good conductivity, wear resistance, and corrosion resistance, and its cross-sectional shape and size match the eddy current coil communication interface 13, thereby improving the transmission stability of the array eddy current detection signal.

[0039] Preferably, the material of the sliding contact conductive rail 14 can be copper, silver or gold-plated alloy material.

[0040] In some embodiments, there is a suitable contact pressure between the sliding contact type conductive rail 14 and the conductive slider 33 to ensure stable contact during the movement.

[0041] In some embodiments, a layer of wear-resistant, low-resistance, low-resistance material is provided on the contact surface between the sliding contact conductive rail 14 and the conductive slider 33, thereby reducing friction and wear and maintaining stable signal transmission.

[0042] Preferably, the contact surface between the sliding contact type conductive rail 14 and the conductive slider 33 is selected such as a gold-plated layer or a carbon brush.

[0043] In some embodiments, a shielding layer is provided at the interface between the sliding contact type conductive rail 14 and the conductive slider 33 to prevent the influence of external electromagnetic interference on the detection signal.

[0044] In some embodiments, the connecting cable between the conductive slider 33 and the array eddy current coil 32 is a wear-resistant and stretch-resistant flexible cable, and the cable should not be over-stretched or twisted during the movement of the conductive slider 33, thereby ensuring a stable connection for signal transmission between the array eddy current coil 32 and the conductive slider 33.

[0045] In some embodiments, the drive motor 21 is a micro-stepping motor with forward and reverse rotation functions. The motor shaft is perpendicular to the axial center plane of the turbine wheel blade root slot, ensuring the stability of the array eddy current scanning speed, improving the positioning accuracy and defect quantification accuracy of the array eddy current coil 32, and realizing the reciprocating scanning function.

[0046] In some embodiments, the diameter of the driving wheel of the driving motor 21 is not less than twice the sum of the thickness of the lower sheet pressing plate 411 and its pressing head 45 to prevent friction and wear between the lower sheet pressing plate 411 and the driving belt 22, thereby affecting the operating stability of the scanning mechanism.

[0047] Preferably, the pressing head of the upper pressing plate 412 has the same thickness as the pressing head of the lower pressing plate 411 .

[0048] In some embodiments, the transmission wheel of the driving motor 21 has good strength and rigidity, and has appropriate tension and good friction between the contact surface with the transmission belt 22, thereby avoiding unstable transmission, belt slippage and excessive wear, etc.

[0049] In some embodiments, the transmission belt 22 is a flat belt with wear-resistant and anti-slip material layers on the upper and lower surfaces. The thickness of the transmission belt 22 is at least smaller than the gap between the pressure head 45 of the upper platen 412 and the pressure head 45 of the lower platen 411 in the unpressed state, thereby increasing the friction between the transmission belt 22 and the pressure head 45 during transmission and avoiding wear caused by friction between the pressure head and the belt.

[0050] In some embodiments, the linear guide rail assembly 23 includes a guide rail base 231 and a slider 232. The guide rail base 231 is made of an aluminum alloy with high strength and rigidity and low density. The slider 232 is a ball-type slider that can reduce friction and improve motion accuracy, thereby reducing the weight of the scanning mechanism and improving the accuracy and flexibility of the scanning process.

[0051] In some embodiments, the installation direction of the two guide rail bases 231 is parallel to the axial direction of the skeleton body 11, and the two sliders 232 are connected to the contour body 31, thereby ensuring the parallelism between the contour body 31 and the skeleton body 11 during the scanning process, avoiding friction between them that affects the scanning speed and even damages the array eddy current coil 32.

[0052] In some embodiments, the arc length of the detection surface of the contoured body 31 is not less than the arc length of the cross-sectional area of ​​the turbine wheel blade root slot, and the array eddy current coil 32 arranged thereon is equal to the arc length of the detection surface, so that the array eddy current coil 32 can scan the entire cross-sectional area of ​​the turbine wheel blade root slot, ensuring that the array eddy current coil covers 100% of the cross-sectional area of ​​the turbine wheel blade root slot.

[0053] In some embodiments, the array eddy current coils 32 are arranged in two rows in an interlaced manner, and a time-sharing multi-excitation transmission and reception method is used for excitation and reception, which reduces the possibility of defect leakage and ensures the effective detection of defects in different orientations.

[0054] Preferably, the center distance of the array eddy current coils 32 is not greater than 4 times the minimum length of the defect to be detected.

[0055] In some embodiments, the array eddy current coil 32 is arranged near the detection surface of the contour body 31 to prevent damage caused by friction on the inner surface of the skeleton body 11 during the detection process.

[0056] Preferably, the distance between the array eddy current coil 32 and the detection surface of the contoured body 31 is 0.2 mm to 0.5 mm.

[0057] In some embodiments, the gap between the pressure head 45 of the lower sheet pressure plate 411 and the lower surface of the upper belt of the transmission belt 22 is between 0.1 mm and 0.2 mm, which avoids friction between the pressure head 45 and the transmission belt 22 and reduces the impact of the pressure plate 41 on the transmission belt 22 when it is pressed.

[0058] In some embodiments, a guide pin is processed inside the guide through hole of the pressure plate 41, which cooperates with the guide groove on the guide column 42, thereby improving the guiding accuracy and reducing the sliding resistance.

[0059] Preferably, the number of guide posts 42 and springs 43 are both three.

[0060] In some embodiments, the pressure head 45 is made of an anti-slip material with certain elasticity and toughness, such as rubber, polyurethane, etc., which increases the friction between the pressure head 45 and the transmission belt 22 during the transmission process.

[0061] Example 2 like Figure 4 As shown, the present invention provides a method for scanning an eddy current probe of a gas turbine wheel blade root slot array, comprising the following steps: Step S1: stably place the probe skeleton body 11 in the blade root groove of the turbine disc to be inspected, so that the distances between the two end faces of the skeleton body 11 and the end faces of the blade root groove of the turbine disc to be inspected are equal, ensuring that the array eddy current coil 32 can completely scan the axial direction of the blade root groove of the turbine disc to be inspected.

[0062] Step S2: energize the electromagnet 44 to press the pressure plate 41 onto the transmission belt 22. When the driving motor 21 drives the transmission belt 22 to move axially, the contoured body 31 moves axially along the guide rail base 231 through the slider 232 with the help of the driving force transmitted by the pressure plate 41. The conductive slider 33 and the sliding contact conductive rail 14 are combined to transmit the excitation and receiving signals of the array eddy current coil 32, and transmit the excitation and receiving instructions of the array eddy current detector 5 to the array eddy current coil 32 on the contoured body 31.

[0063] Step S3: the driving motor 21 records and transmits the scanning position and distance of the contour body 31 in real time, and makes a C-scan image through the array eddy current detector 5 to achieve a uniform and stable scanning of the turbine wheel blade root groove.

[0064] Example 3 1. Assemble the probe frame The hollow probe skeleton body 11 is made of high-strength engineering plastics, the thickness of the hollow part is not more than 2mm, and the cross-sectional dimensions are completely consistent with the cross-sectional dimensions of the turbine wheel blade root groove being tested, and the axial length is greater than the axial length of the turbine wheel blade root groove.

[0065] A drive motor mounting hole 121 and a linear guide rail mounting hole 122 are processed at both axial ends of the skeleton body 11. The axial distance between the center of the drive motor mounting hole 121 and the end face of the turbine wheel blade root groove is greater than the sum of the axial width of the contoured body 31 and the radius of the driving wheel of the drive motor 21. The axial distance between the center of the linear guide rail mounting hole 122 and the end face of the turbine wheel blade root groove is greater than the axial distance between the center of the drive motor mounting hole 121 and it.

[0066] An eddy current coil communication interface 13 is provided on the end surface of the skeleton body 11 for connecting to the array eddy current detector 5 .

[0067] A sliding contact conductive rail 14 is installed, one end of which is covered by an insulating material and the other end is connected to the eddy current coil communication interface 13 , and its cross-sectional shape and size match those of the eddy current coil communication interface 13 .

[0068] 2. Install the driver module A micro-stepping drive motor 21 with forward and reverse rotation functions is installed at each axial end of the probe skeleton body 11 , and the diameter of the drive wheel of the drive motor 21 is not less than twice the sum of the thickness of the lower platen 411 and its pressure head 45 .

[0069] Install the flat-belt transmission belt 22 and ensure that it is sleeved on the transmission wheel of the driving motor 21. The driving motor 21 drives the transmission belt 22 to move axially by rotation. The upper and lower surfaces of the transmission belt 22 are provided with wear-resistant and anti-slip material layers, and the thickness is at least smaller than the gap between the pressure head 45 of the upper platen 412 and the pressure head 45 of the lower platen 411 in the unpressed state.

[0070] Install the linear guide rail assembly 23, generally two sets, respectively located above and below the transmission belt 22. The two guide rail bases 231 are fixed in the probe skeleton body 11 through the linear guide rail mounting holes 122, and the mounting direction is parallel to the axial direction of the skeleton body 11. The two sliders 232 are ball sliders connected to the contour body 31.

[0071] 3. Assemble the detection module The contoured body 31 is manufactured to ensure that its detection surface is completely fitted with the inner surface of the probe skeleton body 11, the axial width of the contoured body 31 is greater than the width of the array eddy current coil 32, and the arc length of the detection surface is not less than the arc length of the cross-section of the turbine wheel blade root groove.

[0072] Two rows of staggered array eddy current coils 32 are arranged near the detection surface of the contoured body 31, with a distance of 0.2 mm to 0.5 mm from the surface.

[0073] A conductive slider 33 is installed on the upper surface of the contoured body 31 , and is ensured to be connected to the array eddy current coil 32 via a cable, and is engaged with the sliding contact type conductive rail 14 .

[0074] 4. Install the clamping device The pressing plate 41 is installed, wherein the lower pressing plate 411 is connected to the contoured body 31 and is processed with three guide through holes with guide pins, and the upper pressing plate 412 is processed with three guide through holes with guide pins of the same size at corresponding positions.

[0075] Install guide columns 42 and springs 43. Three guide columns 42 with guide grooves pass through the corresponding guide holes of the upper platen 412 and the lower platen 411 respectively, and three springs 43 are sleeved between the upper and lower plates of the three guide columns 42; the upper and lower surfaces of the three springs 43 are in contact with the lower surface of the upper platen 412 and the upper surface of the lower platen 411 respectively.

[0076] The electromagnet 44 is installed on the upper sheet pressing plate 412 and ensured to be located at the geometric center of the three guide through holes of the upper sheet pressing plate 412 .

[0077] A pressing head 45 is installed on the lower surface of the upper platen 412 and the upper surface of the lower platen 411, and the pressing condition with the transmission belt 22 is controlled by turning on and off the electromagnet 44. The gap between the pressing head 45 and the lower surface of the upper belt of the transmission belt 22 is between 0.1mm and 0.2mm.

[0078] 5. Scanning method The probe skeleton body 11 is stably placed in the blade root groove of the turbine disk to be inspected, so that the distances between the two end faces of the skeleton body 11 and the end faces of the blade root groove of the turbine disk to be inspected are equal, ensuring that the array eddy current coil 32 can completely scan the axial direction of the blade root groove of the turbine disk to be inspected.

[0079] When the electromagnet 44 is energized to press the pressure plate 41 onto the transmission belt 22, and the driving motor 21 drives the transmission belt 22 to move axially, the contoured body 31 moves axially along the guide rail base 231 through the slider 232 with the help of the driving force transmitted by the pressure plate 41, and the conductive slider 33 and the sliding contact conductive slide rail 14 are combined to transmit the excitation and receiving signals of the array eddy current coil 32, and transmit the excitation and receiving instructions of the array eddy current detector 5 to the array eddy current coil 32 on the contoured body 31.

[0080] The driving motor 21 records and transmits the scanning position and distance of the contour body 31 in real time, and makes a C-scan image through the array eddy current detector 5, so as to realize a uniform and stable scanning of the turbine wheel blade root groove.

[0081] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0082] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A gas turbine wheel blade root slot array eddy current probe scanning mechanism, characterized in that: It includes a probe frame, a driving module, a detection module and a clamping device; The probe skeleton includes a skeleton body, a drive module installation interface, an eddy current coil communication interface and a sliding contact conductive slide rail; the skeleton body is a hollow structure; the drive module installation interface is respectively located at both ends of the skeleton body, and both ends are processed with drive motor installation holes and linear guide rail installation holes; the eddy current coil communication interface is located on the end face of the skeleton body, and is used to connect the array eddy current detector; the sliding contact conductive slide rail is axially installed in the probe skeleton body, one end is covered by an insulating material, and the other end is connected to the eddy current coil communication interface; The driving module includes a driving motor, a transmission belt and a linear guide assembly; there are two driving motors, which are respectively installed at the axial ends of the probe frame body; the transmission belt is sleeved on the two driving motor transmission wheels, and the driving motor drives the transmission belt to move along the axial direction by rotating; there are two sets of linear guide assemblies, in which the guide base is installed in the probe frame body through the linear guide mounting hole, and is respectively located directly above and directly below the transmission belt; The detection module includes a contoured body, an array eddy current coil and a conductive slider; the contoured body detection surface is completely in contact with the inner surface of the probe skeleton body, and the axial width of the contoured body is greater than the width of the array eddy current coil; the array eddy current coil is arranged on the contoured body detection surface; the conductive slider is installed on the upper surface of the contoured body, connected to the array eddy current coil through a cable, and meshed with the sliding contact conductive slide rail to transmit the array eddy current coil signal; The clamping device is used to press the transmission belt to control the movement of the detection module.

2. The gas engine turbine wheel blade root slot array eddy current probe scanning mechanism according to claim 1, characterized in that: The clamping device comprises a pressing plate, a plurality of guide pillars, a plurality of springs, an electromagnet and a pressing head; the pressing plates have two pieces, the lower pressing plate is connected to the contoured body and is processed with a plurality of guide through holes, and the upper pressing plate is processed with guide through holes of the same number and size at the corresponding positions; the plurality of guide pillars respectively pass through the corresponding guide through holes of the upper and lower pressing plates, and a plurality of springs are sleeved between the upper and lower pressing plates of the plurality of guide pillars; the upper and lower surfaces of the plurality of springs are in contact with the lower surface of the upper pressing plate and the upper surface of the lower pressing plate respectively; the electromagnet is integrated on the upper pressing plate and is located at the geometric center of the plurality of guide through holes of the upper pressing plate; the pressing heads are respectively located on the lower surface of the upper pressing plate and the upper surface of the lower pressing plate, and the pressing condition with the transmission belt is controlled by turning the electromagnet on and off, thereby controlling the movement of the detection module.

3. The gas engine turbine wheel blade root slot array eddy current probe scanning mechanism according to claim 1, characterized in that: The thickness of the contact part between the probe skeleton body and the contoured body detection surface is no more than 2mm, and it is made of high-strength engineering plastic.

4. The gas engine turbine wheel blade root slot array eddy current probe scanning mechanism according to claim 1, characterized in that: The axial distance between the center of the drive motor mounting hole and the end surface of the turbine wheel blade root groove is greater than the sum of the axial width of the contoured body and the radius of the drive motor transmission wheel; The axial distance between the center of the linear guide rail mounting hole and the end face of the turbine wheel blade root groove is greater than the axial distance between the center of the drive motor mounting hole and the end face.

5. The gas engine turbine wheel blade root slot array eddy current probe scanning mechanism according to claim 1, characterized in that: A layer of wear-resistant, low-resistance and low-resistance material is provided on the contact surface between the sliding contact type conductive slide rail and the conductive slider; a shield is provided on the interface between the sliding contact type conductive slide rail and the conductive slider.

6. The gas engine turbine wheel blade root groove array eddy current probe scanning mechanism according to claim 1, characterized in that: The driving motor is a micro-stepping motor with forward and reverse functions, and the motor shaft is perpendicular to the axial center plane of the turbine wheel blade root slot; The diameter of the driving motor transmission wheel shall not be less than twice the sum of the thickness of the lower sheet pressing plate and the pressing head.

7. The gas engine turbine wheel blade root groove array eddy current probe scanning mechanism according to claim 1, characterized in that: The transmission belt type is a flat belt, and the upper and lower surfaces are provided with wear-resistant and anti-skid material layers. The thickness of the transmission belt is at least smaller than the gap between the upper platen pressure head and the lower platen pressure head in the unpressed state.

8. The gas engine turbine wheel blade root slot array eddy current probe scanning mechanism according to claim 1, characterized in that: The arc length of the detection surface of the contoured body is not less than the arc length of the cross-section of the turbine wheel blade root slot, and the array eddy current coils arranged thereon are equal in length to the arc length of the detection surface.

9. The gas engine turbine wheel blade root slot array eddy current probe scanning mechanism according to claim 1, characterized in that: The array eddy current coils are arranged in two rows in an interlaced manner, and a time-sharing multi-excitation transmission and reception method is used for excitation and reception; The array eddy current coil is arranged near the surface of the profiling body detection surface to prevent damage caused by friction on the inner surface of the skeleton body during the detection process.

10. A method for scanning a gas turbine blade root slot array using an eddy current probe, characterized in that: The method is based on a gas engine turbine wheel blade root slot array eddy current probe scanning mechanism according to any one of claims 1 to 9, comprising: Place the probe skeleton body stably in the blade root slot of the turbine disk to be tested, so that the distances between the two end faces of the skeleton body and the end faces of the blade root slot of the turbine disk to be tested are equal, ensuring that the array eddy current coil can completely scan the axial direction of the blade root slot of the turbine disk to be tested; The electromagnet is energized to press the pressing plate onto the transmission belt. When the driving motor drives the transmission belt to move axially, the contour body moves axially along the guide rail base through the slider with the help of the driving force transmitted by the pressing plate. The conductive slider and the sliding contact conductive slide rail are combined to transmit the excitation and receiving signals of the array eddy current coil, and the excitation and receiving instructions of the array eddy current detector are transmitted to the array eddy current coil on the contour body. The driving motor records and transmits the scanning position and distance of the contoured body in real time, and makes a C-scan image through the array eddy current detector to achieve uniform and smooth scanning of the turbine wheel blade root groove.

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