Disassembly-free shaft diameter surveying and mapping device and method for movable guide vane main shaft of water turbine

Abstract

The invention belongs to the field of water turbine maintenance equipment, and particularly provides a water turbine movable guide vane spindle disassembly-free shaft diameter surveying and mapping device and method.The water turbine movable guide vane spindle disassembly-free shaft diameter surveying and mapping device comprises a measuring cylinder, a pushing mechanism is arranged at the upper end of the measuring cylinder and comprises an electric push rod, and a through hole for a telescopic rod of the electric push rod to penetrate out is formed in the top of the measuring cylinder; a telescopic rod of the electric push rod is provided with a pressure head, at least one group of displacement sensors are arranged on the same measuring surface of the lower end of the measuring cylinder, each group of displacement sensors comprises two oppositely arranged displacement sensors, the intersection point of the measuring axes of the two displacement sensors is located on the axis of the shaft to be measured, and the side wall of the measuring cylinder is provided with measuring ports corresponding to the displacement sensors. The device and the method can go deep into a narrow annular space, the diameter of the movable guide vane main shaft of the water turbine at the measurement position is calculated by measuring the gap between the displacement sensor on the shaft section and the outer surface of the movable guide vane main shaft of the water turbine, the main shaft dismounting procedure is not needed, the overhaul workload is reduced, and the movable guide vane main shaft inspection and maintenance efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the field of hydroturbine maintenance equipment, and particularly relates to a device and method for measuring the shaft diameter of a movable guide vane main shaft of a hydroturbine without disassembly. Background Art

[0002] Currently, for the measurement of the wear amount and the evaluation of eccentric wear of the movable guide vane main shaft of a large hydroturbine after operation, it is necessary to remove components such as the bearing bush and bearing bush sleeve that fix the movable guide vane main shaft of the hydroturbine, and then lift the movable guide vane main shaft to measure. The existing measurement and evaluation methods have the following problems: 1. Large workload: In the original method, it is necessary to remove the fixing components such as the bearing bush and bearing bush sleeve one by one, and then lift out the movable guide vane main shaft for measurement. The main shaft is large and heavy, and the disassembly and assembly are inconvenient, resulting in a large workload.

[0003] 2. Long construction period.

[0004] 3. High cost. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a device and method for measuring the shaft diameter of a movable guide vane main shaft of a hydroturbine without disassembly, which can penetrate into a narrow annular space, and by measuring the gap between the displacement sensor and the outer surface of the movable guide vane main shaft of the hydroturbine on the shaft section, calculate the diameter of the movable guide vane main shaft at the measurement position, without the need for the main shaft disassembly process, reducing the maintenance workload and improving the inspection and maintenance efficiency of the movable guide vane main shaft.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: A device for measuring the shaft diameter of a movable guide vane main shaft of a hydroturbine without disassembly includes a measuring cylinder. A pushing mechanism is provided at the upper end of the measuring cylinder. The pushing mechanism includes an electric push rod. A through hole for the telescopic rod of the electric push rod to pass through is provided at the top of the measuring cylinder. A pressing head is provided on the telescopic rod of the electric push rod. At least one group of displacement sensors is arranged on the same measurement plane at the lower end of the measuring cylinder. Each group of displacement sensors includes two oppositely arranged displacement sensors. The intersection point of the measurement axes of the two displacement sensors is located on the axis of the shaft to be measured. A measurement port is provided on the side wall of the measuring cylinder corresponding to the displacement sensor.

[0007] In a preferred solution, at least one group of centering mechanisms is provided on the side wall of the measuring cylinder. The centering mechanism includes a plurality of screw-type steel ball rollers distributed annularly along the measuring cylinder. A threaded cylinder is provided outside the measuring cylinder corresponding to the screw-type steel ball rollers. A through hole for the tail screw of the screw-type steel ball roller to pass through is provided on the side wall of the measuring cylinder corresponding to the threaded cylinder. The tail screw of the screw-type steel ball roller is screwed with the threaded cylinder.

[0008] In a preferred solution, a tightening screw for tightening the screw-type steel ball roller is provided on one side of the threaded cylinder.

[0009] In a preferred embodiment, a transverse connecting plate is provided on the pressure head, a slider is provided at the end of the transverse connecting plate, and a slide rail cooperating with the slider is provided on the inner wall of the measuring cylinder.

[0010] In a preferred embodiment, a plurality of locking mechanisms are provided on the side wall of the lower end of the measuring cylinder. The locking mechanism includes a locking cylinder, a locking block that is abutted against the outer side of the shaft to be measured is provided on the telescopic rod of the locking cylinder, and a through hole for the locking block to pass through is provided on the side wall of the measuring cylinder.

[0011] In a preferred embodiment, a lifting ring and a handle are provided on the measuring cylinder.

[0012] In a preferred embodiment, the measuring cylinder includes a first cylinder section and a second cylinder section. Flanges are provided at the lower end of the first cylinder section and the upper end of the second cylinder section, and the first cylinder section and the second cylinder section are connected through the flanges.

[0013] In a preferred embodiment, a plurality of connecting structures are provided on the flange at the upper end of the second cylinder section. The connecting structure includes a connecting rod and a limiting cap provided at the upper end of the connecting rod. An installation hole for the limiting cap to pass through is provided on the flange at the lower end of the first cylinder section. A strip-shaped hole communicating with the installation hole is provided on one side of the installation hole. The width of the strip-shaped hole is greater than the diameter of the connecting rod and less than the diameter of the limiting cap; a plurality of positioning pins are provided on the two groups of flanges.

[0014] In a preferred embodiment, corresponding openings are provided on one side of the flange at the lower end of the first cylinder section and the flange at the upper end of the second cylinder section. A quick-installation mechanism is provided at the bottom of the flange at the upper end of the second cylinder section corresponding to the opening. The quick-installation mechanism includes a hinge seat provided at the bottom of the flange at the upper end of the second cylinder section. The lower end of the eccentric pressing handle is hinged to the hinge seat. After the eccentric pressing handle is rotated to the opening position and pressed down, the two groups of flanges are connected.

[0015] The present invention also provides a method for measuring the shaft diameter of a shaft diameter surveying and mapping device for a movable guide vane main shaft of a water turbine without disassembly, including the following steps: Step 1: According to the diameter of the shaft to be measured, rotate the screw-type steel ball roller of the centering mechanism, and adjust the length of the screw-type steel ball roller extending into the measuring cylinder so that the roller at the end of the screw-type steel ball roller contacts the outer side of the shaft to be measured; Step 2: Lift the measuring cylinder and hoist it into the annular space outside the shaft to be measured. Confirm that the lower end face of the measuring cylinder reaches the shaft shoulder plane below the shaft to be measured, and the centering mechanism ensures the alignment of the measuring cylinder and the shaft to be measured; Step 3: Turn on the displacement sensor and measure the distance from the surface of the displacement sensor to the outer side of the shaft to be measured that is directly opposite; Step 4: Start the electric push rod to extend, press the pressure head against the top of the shaft to be measured, and continue to extend the electric push rod to move the measuring cylinder upward along the shaft to be measured, change the measuring plane of the displacement sensor, and measure multiple positions in the length direction of the shaft to be measured.

[0016] The shaft diameter surveying device and method for the movable guide vane main shaft of a water turbine provided by the present invention have the following beneficial effects: 1. The device can penetrate into a narrow annular space. By measuring the gap between the displacement sensor and the outer surface of the movable guide vane main shaft of the water turbine on the shaft section, when the measuring axis of the displacement sensor is perpendicular to and intersects with the axis of the movable guide vane main shaft of the water turbine, subtracting the total gap between the emitting light surfaces of the two laser displacement sensors and the movable guide vane main shaft of the water turbine from the distance between the emitting light surfaces of the two laser displacement sensors, the diameter of the main shaft can be obtained, and the diameter of the movable guide vane main shaft at the measuring position can be deduced. There is no need for the main shaft removal process, reducing the maintenance workload and improving the inspection and maintenance efficiency of the movable guide vane main shaft.

[0017] 2. A pushing mechanism is provided at the upper end of the measuring cylinder. Through the provided pushing mechanism, after the pressing head presses tightly against the upper end of the shaft to be measured, as the electric push rod continues to extend, the measuring cylinder is jacked up, causing it to move relative to the shaft to be measured, adjusting the measuring plane, and measuring multiple positions in the length direction of the shaft to be measured.

[0018] 3. In order to keep the intersection point of the measuring axes of the two pairs of laser displacement sensors as close as possible to the axis of the shaft to be measured, by setting an alignment mechanism, on the premise of ensuring that there is no rubbing between the measuring cylinder and the outer circle of the measured shaft, it can ensure that the axis deviation between the measuring cylinder and the axis of the measured shaft is very small, minimizing the measurement error as much as possible.

[0019] 4. A number of locking mechanisms are provided on the side wall at the lower end of the measuring cylinder, which can effectively fix the measuring cylinder on the shaft to be measured during the measurement process, preventing the measuring cylinder from shifting or shaking and affecting the accuracy of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the drawings and embodiments: Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic diagram of the overall structure after the installation of the present invention; Figure 3 is a front view of the present invention after installation; Figure 4 is a top view of the present invention; Figure 5 is Figure 1 an enlarged view of part A in Figure 6 is Figure 2 an enlarged view of part B in Figure 7 is Figure 3 a sectional view along the C-C plane in Figure 8 is Figure 3 a sectional view along the D-D plane in Figure 9 is Figure 4 A sectional view along the E-E plane; Figure 10 is a schematic structural diagram of the second cylinder section; Figure 11 is a schematic structural diagram of a screw-type steel ball roller; In the figure: measuring cylinder 100, measuring port 110, positioning pin 120, lifting ring 130, handle 140, first cylinder section 150, second cylinder section 160, flange 170, mounting hole 171, strip hole 172, opening 173, connecting structure 180, connecting rod 181, limit cap 182, quick-installation mechanism 190, hinge seat 191, eccentric pressing handle 192; Pushing mechanism 200, electric push rod 210, pressing head 220, transverse connecting plate 230, slider 240; Displacement sensor 300; Shaft to be measured 400; Centering mechanism 500, screw-type steel ball roller 510, threaded cylinder 520, tightening screw 530; Locking mechanism 600, locking cylinder 610, locking block 620; Slide rail 700. Specific implementation method

[0021] Example 1: In this example, taking a specific water turbine in a hydropower station as an example, the diameter of the movable guide vane main shaft (shaft to be measured 400) is about 450 mm.

[0022] As Figures 1 - 4 shown, a device for measuring the shaft diameter of a movable guide vane main shaft of a water turbine without disassembly includes a measuring cylinder 100. The measuring cylinder 100 is made of high-strength aluminum alloy, and the cylinder wall can be set as a hollow structure to ensure sufficient strength while reducing the overall weight and facilitating operation.

[0023] In this embodiment, as Figure 2 shown, the measuring cylinder 100 includes a first cylinder section 150 and a second cylinder section 160. Flanges 170 are provided at the lower end of the first cylinder section 150 and the upper end of the second cylinder section 160. The first cylinder section 150 and the second cylinder section 160 are connected by the flanges 170. By setting the measuring cylinder 100 as a multi-section structure, it is convenient for transportation and hoisting, and meets the requirements of narrow spaces.

[0024] During specific use, lifting rings 130 and handles 140 are provided on both the first cylinder section 150 and the second cylinder section 160, which are convenient for handling and on-site hoisting.

[0025] In a further embodiment, as Figure 10As shown in the figure, a plurality of connecting structures 180 are provided on the flange 170 at the upper end of the second cylinder section 160. The connecting structure 180 includes a connecting rod 181 and a limiting cap 182 provided at the upper end of the connecting rod 181. An installation hole 171 for the limiting cap 182 to pass through is provided on the flange 170 at the lower end of the first cylinder section 150. A strip-shaped hole 172 communicating with the installation hole 171 is provided on one side of the installation hole 171. The width of the strip-shaped hole 172 is greater than the diameter of the connecting rod 181 and less than the diameter of the limiting cap 182; a plurality of positioning pins 120 are provided on the two groups of flanges 170.

[0026] During specific use, after the connecting structure 180 at the upper end of the second cylinder section 160 is inserted into the installation hole 171, the second cylinder section 160 is rotated, and the connecting structure 180 rotates synchronously along the strip-shaped hole 172. Since the width of the strip-shaped hole 172 is less than the diameter of the limiting cap 182, due to the limiting effect of the limiting cap 182, the connection of the two groups of cylinder sections is realized. Then the positioning pins 120 are inserted to limit the relative rotation between the first cylinder section 150 and the second cylinder section 160, ensuring that the two groups of cylinder sections do not rotate after connection.

[0027] Preferably, as Figure 6 shown in the figure, corresponding openings 173 are provided on one side of the flange 170 at the lower end of the first cylinder section 150 and the flange 170 at the upper end of the second cylinder section 160. A quick-installation mechanism 190 is provided at the bottom of the flange 170 at the upper end of the second cylinder section 160 corresponding to the opening 173. The quick-installation mechanism 190 includes a hinge seat 191 provided at the bottom of the flange 170 at the upper end of the second cylinder section 160. The lower end of the eccentric pressing handle 192 is hinged to the hinge seat 191 through a rotating shaft. After the eccentric pressing handle 192 rotates to the position of the opening 173 and is pressed down, the two groups of flanges 170 are connected. The eccentric pressing handle 192 is an existing part. During use, the eccentric pressing handle 192 is rotated to the position of the opening 173, and then the handle is pressed down to press the two groups of flanges 170 to realize connection and achieve quick connection.

[0028] A pushing mechanism 200 is provided at the upper end of the measuring cylinder 100. The pushing mechanism 200 includes an electric push rod 210. A through hole for the telescopic rod of the electric push rod 210 to pass through is provided at the top of the measuring cylinder 100. A pressing head 220 is provided on the telescopic rod of the electric push rod 210. Through the provided pushing mechanism 200, when the pressing head 220 abuts against the upper end of the to-be-measured shaft 400, as the electric push rod 210 continues to extend, the measuring cylinder 100 is jacked up, so that it moves relative to the to-be-measured shaft 400, adjusts the measuring plane, and measures multiple positions in the length direction of the to-be-measured shaft 400.

[0029] At least one set of displacement sensors 300 is arranged on the same measurement surface at the lower end of the measuring cylinder 100. Each set of displacement sensors 300 includes two relatively arranged displacement sensors 300. The intersection point of the measurement axes of the two displacement sensors 300 is located on the axis of the shaft to be measured 400. A measurement port 110 is arranged on the side wall of the measuring cylinder 100 corresponding to the displacement sensor 300.

[0030] The displacement sensor 300 is selected as a laser displacement sensor, and the displacement sensor 300 is arranged on the bracket at the position of the measurement port 110.

[0031] The displacement sensor 300 measures the distance from the surface of the displacement sensor 300 to the outer wall facing the shaft to be measured 400. Since the distance between the light-emitting surfaces of the two displacement sensors 300 is a constant after the displacement sensors 300 are fixed, when the measurement axes of the two displacement sensors 300 are perpendicular to and intersect with the axis of the main shaft of the turbine guide vane, subtracting the total clearance between the light-emitting surfaces of the two laser displacement sensors and the main shaft of the turbine guide vane from the distance between the light-emitting surfaces of the two laser displacement sensors, the diameter of the main shaft can be obtained, as Figure 7 shown.

[0032] In order to measure the shaft diameters in two mutually perpendicular directions, on a cross-section of the main shaft of the turbine guide vane, two sets of laser displacement sensors are arranged in two mutually perpendicular directions and the measurement axes intersect at the center of the main shaft of the turbine guide vane. In order to be able to measure the shaft diameter on different planes in the axial direction, the measuring cylinder 100 as the carrier of the measuring device can be pushed up and down by an electric push rod 210.

[0033] Embodiment 2: Different from Embodiment 1, as Figures 8 - 9 and Figure 11 shown, at least one set of centering mechanisms 500 is arranged on the side wall of the measuring cylinder 100. The centering mechanism 500 includes a number of screw-type steel ball rollers 510 distributed annularly along the measuring cylinder 100. A threaded cylinder 520 is arranged outside the measuring cylinder 100 corresponding to the screw-type steel ball roller 510. A through hole for the tail screw of the screw-type steel ball roller 510 to pass through is arranged on the side wall of the measuring cylinder 100 corresponding to the threaded cylinder 520. The tail screw of the screw-type steel ball roller 510 is screwed with the threaded cylinder 520. A hexagon socket head cap screw hole is machined at the end of the tail screw of the screw-type steel ball roller 510. The distance between the outer steel ball and the axis of the main shaft of the turbine guide vane can be adjusted by rotating the screw of the screw-type steel ball roller 510 to achieve the purpose of centering.

[0034] In order to make the intersection point of the measurement axes of the two pairs of laser displacement sensors approach the axis of the shaft to be measured 400 as much as possible, by setting the centering mechanism 500, on the premise of ensuring that there is no rubbing between the measuring cylinder 100 and the outer circle of the measured shaft 400, it can also ensure that the axis deviation between the axis of the measuring cylinder 100 and the axis of the measured shaft 400 is very small, and the measurement error is minimized as much as possible.

[0035] On one side of the threaded cylinder 520, there is a tightening screw 530 for tightening the screw - type steel ball roller 510. By setting the tightening screw 530, the screw - type steel ball roller 510 is further locked to prevent it from rotating again after being adjusted in place, which may affect the accuracy.

[0036] Embodiment 3: Different from Embodiment 1, as Figure 5 shown, a transverse connecting plate 230 is provided on the indenter 220. A slider 240 is provided at the end of the transverse connecting plate 230, and a slide rail 700 cooperating with the slider 240 is provided on the inner wall of the measuring cylinder 100.

[0037] In order to ensure that the measuring cylinder 100 does not rotate during the measurement process, through the cooperation of the slider 240 and the slide rail 700, the rotation of the measuring cylinder 100 is restricted while not affecting the up - and - down movement of the measuring cylinder 100.

[0038] Embodiment 4: Different from Embodiment 1, as Figure 7 shown, a plurality of locking mechanisms 600 are provided on the side wall of the lower end of the measuring cylinder 100. In this embodiment, four groups are set. The locking mechanism 600 includes a locking cylinder 610. A locking block 620 that abuts against the outside of the shaft to be measured 400 is provided at the telescopic rod of the locking cylinder 610, and a through - hole for the locking block 620 to pass through is provided on the side wall of the measuring cylinder 100.

[0039] The locking block 620 installed at the end of the telescopic rod of the locking cylinder 610 is a rectangular block, made of wear - resistant rubber material, having good elasticity and friction. During the measurement process, it can effectively fix the measuring cylinder 100 on the shaft to be measured 400, preventing the measuring cylinder 100 from displacing or shaking, which may affect the accuracy of the measurement result.

[0040] Embodiment 5: A method for measuring the shaft diameter of a shaft - diameter mapping device for a movable guide vane main shaft of a water turbine without disassembly includes the following steps: Step 1: According to the diameter of the shaft to be measured 400, rotate the screw - type steel ball roller 510 of the centering mechanism 500, and adjust the length of the screw - type steel ball roller 510 extending into the measuring cylinder 100 so that the roller at the end of the screw - type steel ball roller 510 contacts the outside of the shaft to be measured 400.

[0041] Step 2: Steadily lift the measuring cylinder 100 through the lifting ring 130 on the measuring cylinder 100. During the lifting process, the operator closely monitors the attitude and position of the measuring cylinder 100 to ensure its stability. Slowly place the measuring cylinder 100 into the annular space outside the shaft to be measured 400. During the placement process, the operator uses the handle 140 to assist in adjusting the position of the measuring cylinder 100 to ensure that the lower end face of the measuring cylinder 100 accurately reaches the shoulder plane below the shaft to be measured 400. At this time, since the centering mechanism 500 has been preliminarily centered and adjusted before, and further fine-tuned during the placement process, the centering mechanism 500 ensures that the measuring cylinder 100 and the shaft to be measured 400 are in a coaxial state, providing an important guarantee for subsequent precise measurement.

[0042] Step 3: Turn on the displacement sensor 300 and measure the distance from the surface of the displacement sensor 300 to the outside of the shaft to be measured 400 facing it.

[0043] Specifically, the displacement sensor 300 measures the distance from the surface of the displacement sensor 300 to the outer wall of the shaft to be measured 400. Since the distance between the light-emitting surfaces of the two displacement sensors 300 is a constant after the displacement sensors 300 are fixed, when the measuring axis of the displacement sensor 300 is perpendicular to and intersects with the axis of the main shaft of the movable guide vane of the water turbine, subtracting the total clearance between the light-emitting surfaces of the two laser displacement sensors and the main shaft of the movable guide vane of the water turbine from the distance between the light-emitting surfaces of the two laser displacement sensors gives the diameter of the main shaft.

[0044] Step 4: Start the electric push rod 210 to extend. The telescopic rod of the electric push rod 210 pushes the pressure head 220 to make the pressure head 220 press against the top of the shaft to be measured 400. The electric push rod 210 continues to extend. Due to the good cooperation between the slider 240 and the slide rail 700, the measuring cylinder 100 moves smoothly upward along the shaft to be measured 400. During the movement, the displacement sensor 300 continuously changes the measuring plane. In this way, a comprehensive measurement of the shaft diameter of the main shaft of the movable guide vane of the water turbine at multiple positions is completed, so as to accurately evaluate the wear condition and dimensional accuracy of the main shaft.

[0045] During the whole measurement process, the operator should operate strictly in accordance with the operation procedures, closely monitor the running state of the equipment and the changes in the measurement data to ensure the accuracy and reliability of the measurement results. At the same time, after the measurement is completed, the equipment should be properly maintained and serviced, and check whether each component is damaged or worn to prepare for the next measurement.

[0046] As can be seen from this embodiment, the device and method for measuring the shaft diameter of the movable guide vane main shaft of the water turbine of the present invention can effectively achieve accurate measurement of the main shaft diameter, avoid the cumbersome disassembly work in the traditional measurement method, greatly shorten the maintenance time, reduce the cost, improve the efficiency of inspection and maintenance of the movable guide vane main shaft of the water turbine, and have important practical application value. In practical applications, the components of the measuring device can be appropriately adjusted and optimized according to the specific parameters of different types of water turbines and the shafts to be measured to better meet the measurement requirements.

[0047] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The embodiments and the features in the embodiments in this application can be arbitrarily combined with each other without conflict. The protection scope of the present invention should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, the equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A device for measuring the diameter of a main shaft of a hydraulic turbine movable guide vane without requiring disassembly, characterized in that: The measuring cylinder (100) comprises a measuring cylinder (100), wherein a pushing mechanism (200) is provided at the upper end of the measuring cylinder (100), wherein the pushing mechanism (200) comprises an electric push rod (210), wherein a through hole through which a telescopic rod of the electric push rod (210) passes is provided at the top of the measuring cylinder (100), wherein the telescopic rod of the electric push rod (210) is provided with a pressure head (220), and wherein at least one group of displacement sensors (300) is provided on the same measuring surface at the lower end of the measuring cylinder (100), wherein each group of displacement sensors (300) comprises two displacement sensors (300) arranged opposite to each other, wherein the intersection of the measuring axes of the two displacement sensors (300) is located on the axis of a shaft (400) to be measured, and a measuring port (110) is provided on the side wall of the measuring cylinder (100) corresponding to the displacement sensor (300).

2. The device for measuring the diameter of the main shaft of the movable guide vane of a water turbine without disassembly according to claim 1, characterized in that: At least one set of centering mechanisms (500) is arranged on the side wall of the measuring cylinder (100), the centering mechanisms (500) comprising a plurality of screw-type steel ball rollers (510) distributed in an annular manner along the measuring cylinder (100), a threaded cylinder (520) is arranged on the outer side of the measuring cylinder (100) corresponding to the screw-type steel ball rollers (510), a through hole for the tail screw of the screw-type steel ball roller (510) to pass through is arranged on the side wall of the measuring cylinder (100) corresponding to the threaded cylinder (520), and the tail screw of the screw-type steel ball roller (510) is threadedly connected to the threaded cylinder (520).

3. The device for measuring the diameter of the main shaft of the movable guide vane of a water turbine without disassembly according to claim 2, characterized in that: A tightening screw (530) for tightening the screw-type steel ball roller (510) is provided on one side of the threaded barrel (520).

4. The device for measuring the diameter of a main shaft of a hydraulic turbine movable guide vane without disassembly according to claim 1, characterized in that: The pressure head (220) is provided with a transverse connecting plate (230), an end of the transverse connecting plate (230) is provided with a sliding block (240), and an inner wall of the measuring cylinder (100) is provided with a sliding rail (700) that cooperates with the sliding block (240).

5. The device for measuring the diameter of a main shaft of a water turbine movable guide vane without disassembly according to claim 1, characterized in that: The side wall at the lower end of the measuring cylinder (100) is provided with a plurality of locking mechanisms (600), the locking mechanisms (600) comprising a locking cylinder (610), a telescopic rod of the locking cylinder (610) being provided with a locking block (620) pressed against the outside of the shaft to be measured (400), and a through hole for the locking block (620) to pass through being provided on the side wall of the measuring cylinder (100).

6. The device for measuring the diameter of a main shaft of a water turbine movable guide vane without disassembly according to claim 1, characterized in that: The measuring tube (100) is provided with a hanging ring (130) and a handle (140).

7. The device for measuring the diameter of a main shaft of a hydraulic turbine guide vane without disassembly according to claim 1, characterized in that: The measuring cylinder (100) comprises a first cylinder section (150) and a second cylinder section (160), the lower end of the first cylinder section (150) and the upper end of the second cylinder section (160) are both provided with flanges (170), and the first cylinder section (150) and the second cylinder section (160) are connected via the flanges (170).

8. The device for measuring the diameter of the main shaft of the movable guide vane of a water turbine without disassembly according to claim 7, characterized in that: A plurality of connection structures (180) are provided on the flange (170) at the upper end of the second cylinder section (160), the connection structures (180) comprising a connection rod (181) and a limiting cap (182) arranged at the upper end of the connection rod (181); a mounting hole (171) for the limiting cap (182) to pass through is provided on the flange (170) at the lower end of the first cylinder section (150); a strip hole (172) communicating with the mounting hole (171) is provided on one side of the mounting hole (171); the width of the strip hole (172) is greater than the diameter of the connection rod (181) and smaller than the diameter of the limiting cap (182); and a plurality of positioning pins (120) are provided on the two sets of flanges (170).

9. The device for measuring the diameter of a main shaft of a water turbine movable guide vane without disassembly according to claim 7, characterized in that: The flange (170) at the lower end of the first barrel section (150) and one side of the flange (170) at the upper end of the second barrel section (160) are provided with corresponding openings (173); the bottom of the flange (170) at the upper end of the second barrel section (160) corresponding to the opening (173) is provided with a quick-installation mechanism (190); the quick-installation mechanism (190) comprises a hinge seat (191) arranged at the bottom of the flange (170) at the upper end of the second barrel section (160); the lower end of the eccentric pressing handle (192) is hinged to the hinge seat (191); the eccentric pressing handle (192) is rotated to the position of the opening (173) and then pressed downward to connect the two sets of flanges (170).

10. A method for measuring the shaft diameter of a hydraulic turbine movable guide vane main shaft without disassembly of the shaft diameter measuring device, characterized in that: The following steps are involved: Step 1: according to the diameter of the shaft (400) to be measured, the screw-type steel ball roller (510) of the centering mechanism (500) is rotated to adjust the length of the screw-type steel ball roller (510) extending into the measuring tube (100) so that the end roller of the screw-type steel ball roller (510) contacts the outer side of the shaft (400) to be measured; Step 2: hoist the measuring tube (100) into the annular space outside the shaft (400) to be measured, confirm that the lower end surface of the measuring tube (100) reaches the shoulder plane below the shaft (400) to be measured, and the centering mechanism (500) ensures that the measuring tube (100) and the shaft (400) to be measured are aligned; Step 3: Turn on the displacement sensor (300) and measure the distance from the surface of the displacement sensor (300) to the outside of the axis to be measured (400); Step 4: Start the electric push rod (210) to extend, the pressure head (220) is pressed against the top of the shaft to be measured (400), and the electric push rod (210) continues to extend, so that the measuring tube (100) moves upward along the shaft to be measured (400), changes the measuring plane of the displacement sensor (300), and measures multiple positions in the length direction of the shaft to be measured (400).

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