A detection device for turbine rotors

Abstract

This utility model discloses a detection device for turbine rotors, comprising a base component, a rotation adjustment mechanism, telescopic probe arms, an optical acquisition head, and an angle locking assembly. The base component has a ring structure that matches the outer edge contour of the turbine rotor. The rotation adjustment mechanism drives the base to rotate circumferentially. Four sets of telescopic probe arms extend and retract radially, with an optical acquisition head mounted at their front ends. The angle locking assembly, through an arc-shaped guide rail and a slider seat, adjusts the lens's pitch angle. This application enables multi-angle, close-range observation of the turbine rotor blade root and tenon groove area.

Description

Technical Field

[0001] This utility model relates to the field of measurement, testing or detection device technology, and in particular to a detection device for turbine rotors. Background Technology

[0002] As a core rotating component in power plants such as aero engines and gas turbines, the structural integrity and operational status of turbine rotors directly affect the safety and reliability of the entire system. During manufacturing and service, turbine rotors often develop defects such as cracks, deformation, or material degradation due to high temperatures, high stress, and complex load environments. Therefore, it is necessary to periodically or in real-time evaluate their morphology, dimensions, and surface condition using inspection devices. Currently, turbine rotor inspections primarily employ optical measurements, contact probes, or industrial endoscopes, which can acquire partial geometric or surface information under specific operating conditions. However, when inspecting structurally complex and space-constrained areas such as the root of turbine rotor blades and tenon grooves, existing inspection devices are often limited by probe size, field of view angle, or positioning accuracy, making it difficult to achieve comprehensive coverage and stable observation of critical areas. This results in blind spots or insufficient repeatability in the inspection data, affecting the accurate identification and assessment of defects. Utility Model Content

[0003] The purpose of this utility model is to provide a detection device for turbine rotors, which solves the problems mentioned in the background art.

[0004] This utility model is implemented as follows: a detection device for turbine rotors includes a base component, a rotation adjustment mechanism, a telescopic detection arm, an optical acquisition head, and an angle locking assembly, wherein:

[0005] The base component has a ring frame structure, and its inner ring contour matches the outer edge contour of the turbine rotor to be tested. Four support lugs are evenly distributed on the upper surface of the base component along the circumferential direction. Each support lug has a through hole at the top, and the axis of the through hole is perpendicular to the plane where the base component is located.

[0006] The rotation adjustment mechanism includes a central shaft, a bearing housing assembly, and a drive gear ring. The central shaft vertically passes through the geometric center of the base component, with its lower end connected to an external fixed platform and its upper end extending above the base component and equipped with a flange. The bearing housing assembly consists of two sets of rolling bearings, which are respectively embedded in the upper and lower ends of the central hole of the base component to support the free rotation of the central shaft. The drive gear ring is coaxially sleeved in the middle of the central shaft, and its outer tooth surface meshes with the rack segment reserved in the inner wall of the base component. By applying torque through a manual knob, the entire base component can be driven to rotate circumferentially around the central shaft.

[0007] The telescopic detection arm consists of four sets, each set being installed in a through hole of a support lug. The telescopic detection arm body is a hollow tubular structure with an outer diameter slightly smaller than the inner diameter of the through hole. The front end is closed and has a circular light-transmitting opening in the center of the end face, while the rear end is open and rigidly connected to the output shaft of the pneumatic push rod. The bottom of the pneumatic push rod cylinder is fastened to the back side of the support lug by screws, and its piston rod axis coincides with the axis of the through hole, pushing the telescopic detection arm to perform linear reciprocating motion along the axial direction.

[0008] The optical acquisition head is embedded in the front end of the telescopic detection arm, with its lens facing the light-transmitting port. A flexible silicone sealing ring is wrapped around the lens, and the outer edge of the sealing ring is press-fitted with the inner wall of the telescopic detection arm to prevent dust from entering. A signal cable is led out from the back of the optical acquisition head. The cable passes through the internal cavity of the telescopic detection arm and is led out from the tail of the pneumatic push rod, and finally connected to the external image processing host.

[0009] The angle locking assembly is located at the near-front third of each telescopic probe arm and includes an arc-shaped guide rail, a slider seat, and a locking bolt. The arc-shaped guide rail is welded and fixed to the outer wall of the telescopic probe arm, with its center located on the axis of the telescopic probe arm and its arc length covering a range of 90 degrees. The bottom of the slider seat has a groove that matches the arc-shaped guide rail, allowing it to slide on the guide rail and swing around the axis of the telescopic probe arm. The locking bolt is screwed vertically into the top of the slider seat, with its end pressing against the top surface of the arc-shaped guide rail to fix its position. The mounting base of the optical acquisition head is hinged to the front end of the slider seat via a pivot, allowing the lens tilt angle to be continuously adjusted within the range of -30 degrees to +60 degrees.

[0010] Furthermore, the outer edge of the base component is provided with a scale marking strip, which is divided into 360 angular units along the circumference and is linked with the drive gear ring to indicate the current circumferential orientation of the base component relative to the turbine rotor;

[0011] Furthermore, a displacement scale is provided on the outer wall of the telescopic probe near the front end. The scale uses millimeters as the smallest unit and the zero point is located on the inner side of the support ear plate. It is used to read the extension length of the telescopic probe.

[0012] Furthermore, the pneumatic push rod is equipped with a pressure feedback valve, which is connected in series in the air supply line. When the front end of the telescopic probe contacts the surface of the turbine rotor, the system automatically reduces the intake pressure to maintain the contact force within 0.5 Newtons, thus avoiding damage to the workpiece being tested.

[0013] Furthermore, the optical acquisition head has a built-in dual-light source illumination system. One set is a ring-shaped LED array arranged around the lens to provide uniform frontal fill light, and the other set is a side-directed fiber optic beam that projects light from a 45-degree angle above the lens to enhance the contrast between the groove and the edge shadows.

[0014] Furthermore, a fine-tuning knob is added to the side of the slider seat. This knob is connected to the rotating shaft through a worm gear transmission mechanism. Each rotation corresponds to a one-degree change in the lens pitch angle, which facilitates precise calibration of the observation angle.

[0015] Furthermore, the upper surface of the central shaft flange is provided with magnetic positioning pins, which are distributed at four equal points on the edge of the flange and are attracted and engaged with the preset holes on the turbine rotor disk to ensure that the relative positions of the base component and the rotor are consistent each time they are clamped.

[0016] Furthermore, the base component has three sets of adjustable legs welded to its bottom. Each set of legs includes a threaded sleeve and a lifting screw. The spherical surface at the top of the screw contacts the recess on the bottom surface of the base component. The height of each leg can be adjusted independently by rotating the screw to compensate for unevenness errors of the installation platform.

[0017] Furthermore, a protective glass plate is installed on the outside of the light-transmitting port at the front end of the telescopic detection arm. The glass plate is made of sapphire material, is one millimeter thick, and has an anti-reflective coating on its surface, which protects the internal lens and reduces stray light interference.

[0018] Furthermore, the signal cable is covered with a metal braided shielding layer, which is grounded at both ends to suppress the impact of electromagnetic interference on image transmission quality;

[0019] Furthermore, mechanical limit blocks are provided at both ends of the arc-shaped guide rail to limit the stroke boundary of the slider seat and prevent structural interference caused by excessive movement.

[0020] The detection device for turbine rotors provided by this utility model has the following beneficial effects:

[0021] The device is mounted on a base that fits snugly against the turbine rotor profile. A rotation adjustment mechanism enables circumferential full-coverage scanning. Four independently controlled telescopic probes dynamically adjust their radial position based on different blade spacings, ensuring the optical acquisition head is close to the target area. An angle locking component provides the lens with multi-degree-of-freedom attitude adjustment capabilities. When facing deep and narrow tenon-groove structures, the observation tilt angle can be changed by sliding the slider along the arc-shaped guide rail, and the pitch angle can be finely adjusted with a fine-tuning knob to obtain the optimal imaging perspective. A pressure feedback mechanism from the pneumatic push rod ensures non-rigid contact safety, preventing scratches on high-temperature alloy surfaces. A dual-light source illumination design enhances the representation of three-dimensional morphology, particularly beneficial for identifying crack paths and material spalling boundaries. A displacement scale and angle graduations together form a spatial coordinate reference system, supporting quantitative recording of defect locations. The overall structure has no electronic control components; pure mechanical transmission ensures operational stability in extreme environments, making it suitable for rapid deployment and repeated use in aero-engine maintenance workshops. Attached Figure Description

[0022] Figure 1This is a schematic diagram of the overall structure of a detection device for turbine rotors according to the present invention;

[0023] Figure 2 This is a partially enlarged structural diagram of the telescopic probe arm and angle locking assembly according to an embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the assembly structure of the base component and the rotation adjustment mechanism of this utility model;

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Base component; 2. Support ear plate; 3. Through hole; 4. Central shaft; 5. Bearing seat assembly; 6. Drive gear ring; 7. Flange; 8. Telescopic detection arm; 9. Light transmission port; 10. Pneumatic push rod; 11. Signal cable; 12. Optical acquisition head; 13. Flexible silicone sealing ring; 14. Arc-shaped guide rail; 15. Slider seat; 16. Locking bolt; 17. Rotating shaft; 18. Scale marking strip; 19. Displacement scale; 20. Pressure feedback valve; 21. Annular LED array; 22. Lateral fiber optic beam guide; 23. Fine adjustment knob; 24. Magnetic positioning pin; 25. Adjustable support foot; 26. Threaded sleeve; 27. Lifting screw; 28. Protective glass plate; 29. ​​Metal braided shielding layer; 30. Mechanical limit stop; 31. External image processing host; 32. Turbine rotor. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] Please see Figures 1 to 3 This invention provides a detection device for turbine rotors. Addressing the technical challenge of complete observation of the turbine rotor blade root and tenon groove areas due to their narrow space and complex curved surfaces, this device achieves multi-degree-of-freedom adjustment and stable, close-fitting observation through mechanical structure design. The device consists of a base component 1, a rotation adjustment mechanism, four sets of telescopic detection arms 8, an optical acquisition head 12, and an angle locking assembly. All parts work together to complete a comprehensive imaging and recording of the surface features of the turbine rotor 32 without blind spots.

[0029] The base component 1 is a ring-shaped frame structure. Its inner ring contour is machined according to the outer edge contour of the turbine rotor 32 to be tested, ensuring that the two contours fit tightly during installation. Four support lugs 2 are evenly distributed along the circumference on the upper surface of the base component 1. Each support lug 2 has a through hole 3 at its top, and the axis of the through hole 3 is perpendicular to the plane of the base component 1. The support lugs 2 are 12 mm thick and are made of high-strength aluminum alloy and then precision machined by CNC milling to ensure that the roughness of the inner wall of the through hole 3 is no greater than 0.8 micrometers, so as to reduce the frictional resistance during the sliding process of the telescopic probe arm 8.

[0030] The rotation adjustment mechanism includes a central shaft 4, a bearing housing assembly 5, and a drive gear ring 6. The central shaft 4 vertically penetrates the geometric center of the base component 1, with its lower end rigidly connected to an external fixed platform via a flange structure, and its upper end extending above the base component 1 and equipped with a flange 7. The flange 7 has a diameter of 100 mm and a thickness of 15 mm, with magnetic positioning pins 24 at four equal positions along its edge. The magnetic positioning pins 24 are made of neodymium iron boron permanent magnets, with a diameter of 6 mm and a length of 20 mm. After their adsorption surfaces contact the preset holes on the turbine rotor 32 disc, they can form positioning constraints at more than three points, ensuring that the relative orientation of the base component 1 and the turbine rotor 32 is consistent each time they are clamped. The bearing housing assembly 5 consists of two sets of deep groove ball bearings, which are respectively embedded at the upper and lower ends of the central hole of the base component 1. The inner ring of the bearing is interference-fitted with the central shaft 4, and the outer ring is transition-fitted with the central hole of the base component 1, allowing the base component 1 to rotate freely around the central shaft 4. The drive gear ring 6 is coaxially sleeved in the middle of the central shaft 4. Its external gear module is one and the number of teeth is sixty. It meshes with the arc-shaped rack segment reserved in the inner wall of the base component 1. The rack segment covers a 90-degree arc range. The manual knob is welded to the outside of the drive gear ring 6. The operator can rotate the knob to drive the base component 1 to rotate 360 ​​degrees continuously around the central shaft 4. The outer edge of the base component 1 is provided with a scale marking strip 18. The marking strip 18 is marked with 360 angular units by laser engraving. The minimum division value is one degree. It is linked with the drive gear ring 6 to indicate the current circumferential position of the base component 1 relative to the turbine rotor 32.

[0031] Each telescopic probe arm 8 is installed in a through hole 3 of a support lug 2. The main body of the telescopic probe arm 8 is a hollow cylindrical tubular structure, with an outer diameter 0.2 mm smaller than the inner diameter of the through hole 3. It is made of aerospace-grade titanium alloy TC4, and its hardness reaches HRC 35 after heat treatment. The front end is closed, and a circular light-transmitting opening 9 is opened in the center of the end face. The light-transmitting opening 9 has a diameter of 8 mm and an edge chamfer of 0.5 x 45 degrees. The rear end of the telescopic probe arm 8 is open and connected to the output shaft of the pneumatic push rod 10 by a thread. The bottom of the cylinder of the pneumatic push rod 10 is fastened to the back side of the support lug 2 by four M6 screws, and the piston rod axis coincides with the axis of the through hole 3. The pneumatic push rod 10 has a stroke of 50 mm and a maximum thrust of 10 Newtons. It is equipped with a pressure feedback valve 20, which is connected in series in the air supply line. When the front end of the telescopic probe arm 8 contacts the surface of the turbine rotor 32, the system intake pressure automatically drops to 0.3 MPa, maintaining the contact force constant within 0.5 Newtons. A displacement scale 19 is located near the front end of the outer wall of the telescopic probe arm 8. This scale 19 is marked by laser etching, with a minimum scale of one millimeter. The zero point is located on the inner side of the support ear plate 2, and it is used to read the extension length of the telescopic probe arm 8. A protective glass plate 28 is installed on the outside of the light-transmitting port 9. This glass plate 28 is made of sapphire, is one millimeter thick, and is coated with a magnesium fluoride anti-reflective film on both sides. It has a light transmittance of more than 98%, effectively reducing stray light interference and protecting the internal optical components.

[0032] The optical acquisition head 12 is embedded inside the front end of the telescopic detection arm 8, with the lens facing the light-transmitting port 9. The lens has a focal length of 5 mm, a field of view of 70 degrees, and a resolution of 2.3 million pixels. A flexible silicone sealing ring 13 with a Shore A hardness of 50A is wrapped around the lens. The outer edge of the sealing ring has an interference fit of 0.3 mm with the inner wall of the telescopic detection arm 8, forming an airtight barrier to prevent dust intrusion. A signal cable 11 is led out from the back of the optical acquisition head 12. This cable 11 has eight cores and an outer diameter of 4 mm. It passes through the internal cavity of the telescopic detection arm 8 and is led out from the tail of the pneumatic push rod 10, ultimately connecting to the external image processing host 31. The signal cable 11 is covered with a metal braided shielding layer 29, which is a tin-plated copper wire braided mesh with a 95% coverage. Both ends are connected to the equipment casing through grounding terminals to suppress the impact of electromagnetic interference on image transmission quality. The optical acquisition head 12 has a built-in dual-light source illumination system. One set is a ring LED array 21, which consists of sixteen white LED chips evenly distributed around the lens, with a light emission angle of 120 degrees and a color temperature of 5,500 Kelvin. The other set is a side fiber optic beam guide 22, which is led out from 45 degrees above the lens and connected to an external halogen light source at the end. The beam has a spot diameter of 3 millimeters and an illuminance of up to 10,000 lux, enhancing the contrast of the groove and edge shadows.

[0033] An angle locking assembly is located at approximately one-third of the front end of each telescopic probe arm 8, including an arc-shaped guide rail 14, a slider seat 15, and a locking bolt 16. The arc-shaped guide rail 14 is welded and fixed to the outer wall of the telescopic probe arm 8, with its center located on the axis of the telescopic probe arm 8, and its arc length covering a range of 90 degrees. The guide rail has a T-shaped cross-section, with a width of 6 mm and a height of 4 mm. The bottom of the slider seat 15 has a groove that matches the arc-shaped guide rail 14, and a polytetrafluoroethylene (PTFE) sliding piece is embedded in the groove. The coefficient of friction is less than 0.05, allowing the slider seat 15 to slide smoothly on the guide rail and swing around the axis of the telescopic probe arm 8. The locking bolt 16 is screwed vertically into the top of the slider seat 15, with a thread specification of M5 and a tapered pressure head at the end. After tightening, it presses against the top surface of the arc-shaped guide rail 14 to fix the position. The mounting base of the optical acquisition head 12 is hinged to the front end of the slider seat 15 via a rotating shaft 17. The rotating shaft 17 has a diameter of 4 mm and is equipped with miniature needle roller bearings at both ends, allowing the lens tilt angle to be continuously adjusted within the range of -30 degrees to +60 degrees. A fine-tuning knob 23 is added to the side of the slider base 15. This knob 23 is connected to the rotating shaft 17 through a worm gear transmission mechanism. The worm has a module of 0.5 and the worm gear has 60 teeth. Each rotation corresponds to a one-degree change in the lens pitch angle. The knob surface is engraved with fine scale lines for easy angle fine-tuning by the operator. Mechanical limit blocks 30 are set at both ends of the arc-shaped guide rail 14. The blocks 30 are made of brass and extend 3 mm above the top surface of the guide rail to limit the stroke boundary of the slider base 15 and prevent structural interference caused by excessive movement.

[0034] The base component 1 has three sets of adjustable support legs 25 welded to its bottom. Each set of support legs 25 includes a threaded sleeve 26 and a lifting screw 27. The threaded sleeve 26 has an outer diameter of 25 mm and an internal thread specification of M20, and is welded to a triangular distribution position on the bottom surface of the base component 1. The top of the lifting screw 27 has a spherical structure with a radius of 10 mm, which contacts a recess on the bottom surface of the base component 1. The recess has a depth of 5 mm, and grease is filled between the spherical surface and the recess, allowing the screw to self-adjust within a range of ±5 degrees. Rotating the lifting screw 27 allows for independent adjustment of the height of each support leg 25, compensating for unevenness errors of the installation platform, with a maximum adjustment stroke of 30 mm.

[0035] After the device is assembled, the turbine rotor 32 is first placed in the testing position. The operator holds the base component 1 and aligns its inner ring contour with the outer edge of the rotor. The magnetic positioning pin 24 is attached to the preset hole position on the wheel to complete the initial positioning. Then, the three sets of adjustable feet 25 are adjusted to keep the upper surface of the base component 1 horizontal. The level instrument shows that the bubble is centered, indicating that the leveling is complete. The external air source is activated, and the pneumatic push rod 10 pushes the telescopic probe arm 8 to extend axially along the through hole 3. The displacement scale 19 displays the extension amount in real time. When the protective glass plate 28 contacts the blade surface, the pressure feedback valve 20 is activated to maintain a constant contact force. According to the spatial orientation of the area to be measured, the operator slides the slider seat 15 along the arc guide rail 14 to a suitable tilt angle position, tightens the locking bolt 16 to fix it, and then rotates the fine adjustment knob 23 to finely adjust the lens tilt angle so that the imaging image clearly covers the target features. The rotating drive gear ring 6 drives the base component 1 to rotate circumferentially, and the scale marking strip 18 synchronously indicates the current azimuth angle. Combined with four independently controlled telescopic detection arms 8, it achieves full coverage scanning of the entire blade root and tenon groove area. Image data is transmitted to the external image processing host 31 via signal cable 11. The software system automatically stitches multi-angle images and marks the defect coordinates. The coordinate values ​​are calculated jointly by the readings of the displacement scale 19 and the angle values ​​of the scale marking strip 18, supporting subsequent quantitative analysis and historical comparison.

[0036] All moving parts of the device are purely mechanical structures with no electronic control unit intervention. The clearance between transmission pairs is precisely ground and controlled within 0.02 mm, and the repeatability is better than ±0.05 mm. The materials selected take into account both lightweight and high-temperature resistance, and can work continuously for four hours at an ambient temperature of 80 degrees Celsius without performance degradation. It is suitable for rapid deployment and repeated use in aero-engine maintenance workshops.

[0037] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A detection device for a turbine rotor, characterized in that, It includes a base component (1), a rotation adjustment mechanism, a telescopic detection arm (8), an optical acquisition head (12), and an angle locking assembly, wherein: The base component (1) has an annular frame structure, and its inner ring contour matches the outer edge contour of the turbine rotor (32) to be tested. Four support lugs (2) are evenly distributed on the upper surface of the base component (1) along the circumferential direction. Each support lug (2) has a through hole (3) at the top. The axis of the through hole (3) is perpendicular to the plane where the base component (1) is located. The rotation adjustment mechanism includes a central shaft (4), a bearing seat assembly (5), and a drive gear ring (6). The central shaft (4) passes vertically through the geometric center of the base component (1), with its lower end connected to an external fixed platform and its upper end provided with a flange (7). The bearing seat assembly (5) is embedded in the upper and lower ends of the central hole of the base component (1) to support the rotation of the central shaft (4). The drive gear ring (6) is coaxially sleeved in the middle of the central shaft (4), and its outer tooth surface meshes with the rack segment of the inner wall of the base component (1). The telescopic detection arm (8) is a set of four hollow tubular structures, which are respectively inserted into each through hole (3). The front end is closed and a light-transmitting port (9) is provided in the center. The rear end is connected to the output shaft of the pneumatic push rod (10). The optical acquisition head (12) is embedded in the front end of the telescopic detection arm (8), with the lens facing the light-transmitting port (9). The angle locking assembly is located at the front third of the telescopic probe arm (8) and includes an arc-shaped guide rail (14), a slider seat (15) and a locking bolt (16). The slider seat (15) is hinged to the mounting base of the optical acquisition head (12) via a rotating shaft (17).

2. The detection device for turbine rotors according to claim 1, characterized in that: The base component (1) has a scale marking strip (18) on its outer edge. The scale marking strip (18) marks 360 angular units along the circumference and is linked with the drive gear ring (6) to indicate the circumferential orientation of the base component (1) relative to the turbine rotor (32).

3. The detection device for turbine rotors according to claim 1, characterized in that: The telescopic probe arm (8) has a displacement scale (19) on its outer wall near the front end. The displacement scale (19) uses millimeters as the smallest unit and the zero point is located on the inner side of the support ear plate (2).

4. The detection device for turbine rotors according to claim 1, characterized in that: The pneumatic push rod (10) is equipped with a pressure feedback valve (20), which is connected in series in the air supply line. When the front end of the telescopic probe (8) contacts the surface of the turbine rotor (32), the system intake pressure is automatically adjusted to maintain the contact force within 0.5 Newtons.

5. The detection device for a turbine rotor according to claim 1, characterized in that: The optical acquisition head (12) has a built-in dual-light source illumination system, including a ring-shaped LED array (21) arranged around the lens and a lateral fiber optic beam (22) that projects light from a 45-degree angle above the lens.

6. The detection device for a turbine rotor according to claim 1, characterized in that: The slider seat (15) is provided with a fine adjustment knob (23) on its side. The fine adjustment knob (23) is connected to the rotating shaft (17) through a worm gear transmission mechanism. Each rotation corresponds to a change of one degree in the lens pitch angle.

7. The detection device for turbine rotors according to claim 1, characterized in that: The upper surface of the flange (7) of the central shaft (4) is provided with magnetic positioning pins (24), which are distributed at four equal points on the edge of the flange (7) and are attracted and engaged with the preset holes on the turbine rotor (32) disk.

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