Contact surface pressing force loading device and method suitable for shrouded blades

Abstract

The present invention relates to a contact surface compression force loading device and method suitable for blades with crowns, belonging to the field of testing technology for blades with crowns or convex shoulders, and solves the problem of inaccurate and unstable contact surface compression force loading on blades with crowns or convex shoulders in the prior art. The present invention includes a mounting base, a friction block, a force transmission assembly, a first set screw, a friction block lower constraint assembly, a friction block upper constraint assembly, and a friction block lateral constraint assembly; the friction block moves back and forth in the mounting base; the tail of the friction block is fixedly connected to the force transmission assembly, the first set screw is provided on the mounting base, and pushes the force transmission assembly toward the direction of the friction block, so that the head of the friction block protrudes outside the friction block mounting groove of the mounting base; the friction block lower constraint assembly, the friction block upper constraint assembly, and the friction block lateral constraint assembly respectively constrain the movement of the friction block from below, above, and sideways. The loading device of the present invention is accurate in force loading and stable and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of testing blades with shrouds or shoulder blades, and in particular to a contact surface pressing force loading device and method suitable for blades with shrouds. Background Art

[0002] Shrouds or shoulder dry friction damping structures are commonly used in gas turbines to reduce blade vibration. Dynamic response tests on shroud or shoulder blades are necessary to investigate the influence of design parameters on these structures and verify the response or modal solution methods for these blades. The contact pressure of the shroud or shoulder structure is a key parameter in dry friction damping design, and the loading effect of this contact pressure determines the test results.

[0003] In current dynamic tests of blades with crown or shoulder structures, the contact surface is often loaded with a compressive force by squeezing a friction block, or by applying a torque to the blade root so that the blade friction contact surface is pressed against the friction block to achieve the loading of the compressive force. The loading of the compressive force requires ensuring the accuracy of the loading force and the stability of the contact state. Existing loading methods include direct loading and torque loading. The direct loading method squeezes the friction block by weights, springs or force sensors to achieve the loading of the contact surface compressive force. The direct loading method generally does not limit the friction block during the loading process. Due to the lack of constraints during the loading process, the friction block will deflect in the horizontal and vertical directions, resulting in changes in the contact state and contact position of the contact surface. In order to ensure a smooth loading process, small-sized friction blocks and mounting structures are often selected, resulting in weak stiffness of the friction block mounting system. The torque loading method, which applies torque to the blade root to achieve the loading of the contact surface compressive force of the blade crown or shoulder structure, is an indirect loading method and is affected by the uncertainty of the initial gap of the contact surface.

[0004] Because shrouded or shouldered blades typically have specific engagement angles and small dimensions, conventional force-applying devices are subject to interference issues and are often used solely for static loading, without regard for vibration. Consequently, they generally have weak stiffness. During shrouded blade testing, the friction block must provide sufficient stiffness under load to ensure that friction between the shroud contact surface and the friction block remains stiff enough to avoid resonance and prevent contact state changes and inaccuracies in relative motion between the contact surfaces caused by friction block resonance.

[0005] Currently, there is still a lack of a contact surface compression force loading device that can achieve accurate loading of the contact surface of blades with crown or shoulder structures, ensure the stability of the loading state, and have sufficient system stiffness. Summary of the Invention

[0006] In view of the above analysis, an embodiment of the present invention aims to provide a contact surface compression force loading device suitable for shrouded blades, so as to solve the problem of inaccurate and unstable compression force loading on the contact surface of blades with shrouds or shoulder structures.

[0007] On the one hand, the present invention provides a contact surface clamping force loading device suitable for crowned blades, comprising a mounting base, a friction block, a force transmission assembly, a first locking screw and a friction block lower constraint assembly; the mounting base is provided with a friction block mounting groove and a sliding bearing mounting groove extending along a straight line and connected to each other, the friction block is arranged in the friction block mounting groove and can reciprocate along the friction block mounting groove; the tail of the friction block is fixedly connected to the force transmission assembly, the force transmission assembly is arranged in the sliding bearing mounting groove, and can reciprocate along the sliding bearing mounting groove; the first locking screw is arranged on the mounting base, and pushes the force transmission assembly in the direction of the friction block, so that the head of the friction block protrudes out of the friction block mounting groove of the mounting base; the friction block lower constraint assembly is fixedly arranged on the mounting base, located below the friction block, and abuts against the lower surface of the friction block.

[0008] Furthermore, the force transmission assembly includes a force sensor, a push-pull rod and a push-pull rod tailstock connected in sequence, the force sensor is fixedly connected to the tail of the friction block; the end of the first set screw abuts against the end face of the push-pull rod tailstock.

[0009] Furthermore, a sliding bearing is fixedly arranged in the sliding bearing installation groove, and the push-pull rod passes through the sliding bearing.

[0010] Furthermore, a spring is provided between the sliding bearing and the push-pull rod tailstock, and the spring is sleeved on the push-pull rod; the spring pushes the push-pull rod tailstock in the direction of the first set screw.

[0011] Furthermore, a slide rail groove is provided at the bottom of the friction block mounting groove of the mounting base, and the friction block lower constraint assembly is provided on the slide rail groove.

[0012] Furthermore, the friction block lower constraint assembly includes a friction block sliding base, a slider and a slide rail, the slide rail is arranged on the slide rail groove, the slider is arranged on the slide rail, the friction block sliding base is fixedly arranged on the slider, and the upper surface of the friction block sliding base is provided with a transverse ridge.

[0013] Furthermore, a transverse groove is provided at the bottom of the friction block, and the transverse ridge is engaged with the transverse groove.

[0014] Furthermore, there are two slide rails, which are arranged in parallel and at intervals; there are four sliders, and two sliders are arranged on each slide rail.

[0015] Furthermore, it also includes a friction block upper constraint component, which is arranged on the mounting base and abuts against the upper surface of the friction block.

[0016] On the other hand, the present invention provides a contact surface compression force loading method applicable to shrouded blades, using the contact surface compression force loading device applicable to shrouded blades as described above.

[0017] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0018] (1) In order to meet the requirements of accurate loading, high rigidity and stable loading state of contact surface clamping force loading in the dynamic test of crowned or shouldered blades, the present invention provides a contact surface clamping force loading device suitable for crowned blades for the application scenario of the contact surface clamping force loading of crowned or shouldered blades. For the friction block that conforms to any structural form of the contact surface of the crowned blade, a force transmission component is used to push the friction block, a force sensor is used to measure the size of the clamping force applied to the contact surface, and a mounting base with a bolt-mounted friction block and a high rigidity structural design is used to ensure the rigidity of the system, thereby avoiding the resonance problem of the friction block during the test, thereby improving the stability of the force loading.

[0019] (2) The present invention uses a first set screw to push the force transmission component and then push the friction block. The loading force can be conveniently adjusted by adjusting the position of the first set screw, thereby improving the accuracy of force loading.

[0020] (3) The present invention adopts a lower constraint assembly, an upper constraint assembly and a lateral constraint assembly of the friction block to constrain the movement of the friction block from the bottom, top and side respectively, which can prevent the friction block from being deflected in the horizontal and vertical directions, thereby avoiding changes in the contact state and contact position of the contact surface, and improving the stability and accuracy of force loading.

[0021] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0023] Figure 1 This is a schematic structural diagram of a contact surface pressing force loading device applicable to shrouded blades according to the present invention;

[0024] Figure 2 An exploded view of the internal parts of the contact surface pressing force loading device for shrouded blades of the present invention;

[0025] Figure 3 It is a structural diagram of the installation base;

[0026] Figure 4 A top view of the mounting base;

[0027] Figure 5 A schematic diagram of applying a compressive force to a contact surface of a test object in an application scenario of the present invention;

[0028] Figure 6 This is a schematic diagram of the present invention when used in pairs in an application scenario;

[0029] Figure 7 It is the side view of the friction block;

[0030] Figure 8 Schematic diagram of the structure of the plunger.

[0031] In the figure: 1-first connecting block; 2-second connecting block; 3-force sensor; 4-slider; 5-slide rail; 6-first fastening screw; 7-first fastening screw; 8-second fastening screw; 9-second fastening screw; 10-mounting slot top cover; 11-push-pull rod; 12-push-pull rod tailstock; 13-friction block; 14-mounting base; 15-friction block sliding base; 16-plunger; 17-bolt; 18-nut; 19-sliding bearing; 20-pressure plate; 21-needle roller row; 22-back cover; 23-spring; 24-friction block mounting slot; 25-slide rail slot; 26-mounting wall; 27-sliding bearing mounting slot; 28-crowned blade; 29-contact surface; 30-ball head. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0033] Example 1

[0034] This embodiment 1 relates to a contact surface pressing force loading device suitable for a shrouded blade 28, such as Figure 1As shown, the friction block 13 comprises a mounting base 14, a friction block 13, a force transmission assembly, a first set screw 7, a lower friction block restraint assembly, an upper friction block restraint assembly, and a lateral friction block restraint assembly. The friction block 13 is slidably mounted on the mounting base 14. The first set screw 7, through the force transmission assembly, pushes the head of the friction block 13 beyond the mounting base 14, facilitating contact with the contact surface of the shrouded blade 28 to apply force. The lower, upper, and lateral friction block restraint assemblies respectively restrain the movement of the friction block 13 from below, above, and laterally to prevent deflection of the friction block 13, thereby affecting the stability and accuracy of force loading.

[0035] The structure of the mounting base 14 is as follows: Figure 1 As shown, it comprises a block-shaped main body and an H-shaped mounting portion protruding upward from the main body's upper surface. A mounting slot is provided at the bottom of the main body, and triangular reinforcing ribs are provided between the mounting portion and the main body's upper surface on both sides. Multiple through-holes are also provided in the main body on both sides of the mounting portion. The mounting base 14 is secured to the test bench via the through-holes and mounting slots.

[0036] See also Figure 3 、 Figure 4 The cross-section of the mounting portion of the mounting base 14 is H-shaped. A friction block mounting groove 24 is provided at one end of the mounting portion, and a sliding bearing mounting groove 27 is provided at the other end. The friction block mounting groove 24 and the sliding bearing mounting groove 27 are in a straight line and are connected in the middle. That is, a through hole is provided on the lateral side wall between the friction block mounting groove 24 and the sliding bearing mounting groove 27, and the size of the through hole is larger than the outer diameter of the push-pull rod 11 in the force transmission assembly. The friction block 13 is arranged in the friction block mounting groove 24 and can move back and forth along the friction block mounting groove 24. The tail of the friction block 13 is fixedly connected to the force transmission assembly, and the force transmission assembly is arranged in the sliding bearing mounting groove 27 and can move back and forth along the sliding bearing mounting groove 27.

[0037] One of the two side walls of the friction block mounting slot 24 has a mounting wall 26, which is provided with a threaded plunger hole and a through hole. The through hole is the same size as the bolt and screw. The other side of the friction block mounting slot 24, opposite the mounting wall 26, also has a through hole, the same size as the sleeve corresponding to the nut 18. Each side wall of the friction block mounting slot 24 has two threaded plunger holes, the same size as the external threads of the plunger 16. The top of the two side walls of the friction block mounting slot 24 has multiple threaded holes. The bottom of the friction block mounting slot 24 has a slide rail slot 25 and threaded holes for the slide rail 5, the size of which matches the slide rail 5.

[0038] The friction block 13 is slidably disposed in the friction block mounting groove 24. Figure 2 、 Figure 7As shown, the friction block 13 is a columnar body, including a head, a tail, and an upper surface, a lower surface and two side surfaces extending from the head to the tail.

[0039] The head of the friction block 13 has an inclined contact surface 29, which is used to abut against the contact surface of the crowned blade 28 to apply force to the crowned blade 28. Therefore, the structural form of the contact surface 29 of the friction block 13 is designed according to the structural form of the contact surface of the crowned blade 28, so that the two can match. The tail of the friction block 13 is provided with a threaded hole for fixed connection with the force transmission component. A horizontal groove is provided in the middle of the bottom of the friction block 13, which is used to achieve lengthwise limitation between the friction block and the lower constraint component. The column of the friction block 13 is also provided with waist-shaped holes running through the two sides. There are two waist-shaped holes, which are used to slidably set the friction block 13 and limit the sliding range of the friction block 13.

[0040] like Figure 2 As shown, the force transmission assembly includes a force sensor 3, a push-pull rod 11, and a push-pull rod tailstock 12, which are connected in sequence. The force sensor 3 is fixedly connected to the tail end of the friction block 13. Preferably, the force sensor 3 is fixedly mounted on the second connecting block 2, which is also provided with a through hole corresponding to the threaded hole in the tail end of the friction block 13. A first fastening screw 6 secures the second connecting block 2 to the tail end of the friction block 13. The other end of the force sensor 3 is fixedly connected to one end of the push-pull rod 11 via the first connecting block 1.

[0041] The push-pull rod 11 is a cylindrical rod slidably mounted in a sliding bearing mounting slot 27 of the mounting base 14. A sliding bearing 19 is fixedly mounted in the sliding bearing mounting slot 27. The sliding bearing 19 has a through hole in its center through which the push-pull rod 11 passes. The other end of the push-pull rod 11 is fixedly connected to the push-pull rod tailstock 12.

[0042] The mounting base 14 also includes a rear cover 22, see Figure 1 The rear cover 22 is fixedly mounted at the opening of the sliding bearing mounting slot 27, sealing the opening. A threaded hole is provided in the rear cover 22, through which the first set screw 7 passes, abutting against the end face of the push-pull rod tailstock 12. This pushes the force transmission assembly toward the friction block 13, causing the head of the friction block 13 to protrude beyond the friction block mounting slot 24 of the mounting base 14. By turning the first set screw 7, the distance that the head of the friction block 13 protrudes from the mounting base 14 can be adjusted, thereby adjusting the contact force between the contact surface 29 of the friction block 13 and the contact surface of the shrouded blade 28.

[0043] A spring 23 is provided between the sliding bearing 19 and the push-pull rod tailstock 12. The spring 23 is sleeved on the push-pull rod 11. The spring 23 pushes the push-pull rod tailstock 12 toward the direction of the first tightening screw 7, so that the push-pull rod tailstock 12 remains in contact with the first tightening screw 7.

[0044] The friction block lower restraint assembly is fixedly disposed on the mounting base 14 , is located below the friction block 13 , and abuts against the lower surface of the friction block 13 .

[0045] See also Figure 2 The lower constraint assembly of the friction block includes a friction block sliding base 15, a slider 4 and a slide rail 5. The slide rail 5 is set on the slide rail groove 25, the slider 4 is set on the slide rail 5, the friction block sliding base 15 is fixedly set on the slider 4, and a transverse convex strip is set on the upper surface of the friction block sliding base 15.

[0046] A transverse groove is provided at the bottom of the friction block 13 . During assembly, the transverse ridges engage with the transverse groove to achieve positioning between the friction block 13 and the friction block sliding base 15 .

[0047] Furthermore, two slide rails 5 are provided, which are arranged in parallel and spaced apart. There are four sliders 4, with two sliders 4 being provided on each slide rail 5.

[0048] The friction block lower constraint assembly can limit the downward movement of the friction block 13 .

[0049] The upper surface of the friction block 13 is a plane, and the restraining assembly on the friction block abuts against the plane. Figure 2 The friction block upper restraint assembly includes a pressure plate 20 and a needle roller row 21. The needle roller row 21 is placed on the upper surface of the friction block 13, with the pressure plate 20 positioned above it. The mounting base 14 also includes a mounting slot cover 10, which is screwed to the top of the mounting base 14, pressing against the pressure plate 20.

[0050] The restraint assembly on the friction block can limit the upward movement of the friction block 13 .

[0051] See also Figure 1The friction block lateral constraint assembly includes a plunger 16, a bolt 17 and a nut 18. The friction block mounting groove 24 of the mounting base 14 has two side walls, one of which is a mounting wall 26. The mounting wall 26 is provided with a through hole and a threaded plunger hole. A plurality of plungers 16 respectively penetrate from the threaded plunger holes on the mounting wall 26 and the side wall opposite thereto, and abut against the side of the friction block 13. In this embodiment, the friction block lateral constraint assembly includes four plungers 16, which respectively limit the lateral movement of the friction block 13 from the two sides of the friction block 13, thereby realizing lateral constraint of the friction block 13 during the debugging process. After the bolt 17 passes through a through hole on the mounting wall 26, it passes through the waist-shaped hole on the friction block 13, passes through the through hole on the side wall opposite to the mounting wall 26, and is fixed by the nut 18. The bolt 17 can limit the stroke of the friction block 13. After loading the contact surface of the shrouded blade 28, the bolt 17 and nut 18 are tightened together, pressing the nut 18 against the side of the friction block 13, thereby pressing the friction block 13 against the mounting wall 26 to achieve compression and tightening. Thus, tightening the bolt 17 and nut 18 can achieve lateral restraint and fixation of the friction block 13.

[0052] Preferably, see Figure 8 The plunger 16 comprises a cylinder and a rollable ball head 30 arranged on the end face of the cylinder. During assembly, the rollable ball head 30 is abutted against the side of the friction block 13.

[0053] This embodiment of the present invention is suitable for applying a compressive force to the contact surface of a shrouded blade 28. The friction block 13 applies the compressive force to the shrouded blade 28 by pushing the friction block 13 via a force transmission assembly. Under the action of the spring 23, the force transmission assembly tends to move backward, thereby maintaining a constant compressive state between the first set screw 7 and the push-pull rod tailstock 12. When applying compressive force to the blade shroud contact surface, the first set screw 7 is rotated to push the force transmission assembly and the friction block 13. The applied compressive force is then controlled by reading the loading force measured by the force sensor 3. If the applied compressive force is too great, the first set screw 7 is rotated in the opposite direction. Because the spring 23 maintains the compressive state between the push-pull rod tailstock 12 and the first set screw 7, the force transmission assembly and the friction block 13 move backward, reducing the compressive force. During this process, the presence of the spring 23 ensures a constant compressive state between the first set screw 7 and the push-pull rod tailstock 12, preventing backlash during adjustment and facilitating control and adjustment of the compressive force. The sliding bearing 19 provides a direction for the movement of the push-pull rod 11 , thereby preventing the push-pull rod 11 from being deflected during the movement and affecting the measurement accuracy of the force sensor 3 .

[0054] This embodiment is suitable for the contact surface pressing force loading device of the shrouded blade 28. The loading direction control of the friction block 13 is achieved through the combined action of the friction block upper constraint assembly, the friction block lower constraint assembly and the friction block lateral constraint assembly.

[0055] In the vertical direction, the second set screw 9 is pressed against the pressure plate 20 through the threaded hole of the mounting slot top cover 10, and then against the needle roller row 21 and the friction block 13, and then against the friction block sliding base 15 and the slider 4 below the friction block 13. The slider 4 is mounted on the slide rail 5, which can ensure smooth sliding under pressure. In the vertical direction, the needle roller row 21, the pressure plate 20, the slider 4, the slide rail 5 and the friction block sliding base 15 jointly limit the displacement of the friction block 13 under pressure, avoiding vertical deflection during movement. Among them, the influence of the precision and processing errors of each component on the direction of the friction block 13 can be ignored, and under pressure, the needle roller row 21 and the slide rail 5 have extremely small rolling friction, which can ensure the smooth movement of the friction block 13.

[0056] Horizontally, mounting base 14 has two threaded plunger holes on either side of friction block mounting slot 24. Plunger 16 presses against friction block 13 through these holes. During installation, a dial gauge is used to measure the side surface of friction block 13 to determine the degree of horizontal deflection during movement. The loading depth of plunger 16 is then continuously adjusted to control the loading direction of friction block 13. The head of plunger 16 is a rolling ball head 30, which creates minimal rolling friction against the side surface of friction block 13 under load, ensuring smooth movement of friction block 13.

[0057] This embodiment of the contact surface compressive force loading device for shrouded blades 28 achieves the installation rigidity of friction block 13 through its installation method and the structure of mounting base 14. The mounting wall 26 of friction block mounting slot 24 of mounting base 14 is of sufficient thickness, and triangular reinforcing ribs provide sufficient system rigidity for friction block 13, ensuring that the natural frequency of the entire system after installation of friction block 13 is above the frequency range required for testing. The thickness and rib dimensions can be determined based on actual testing requirements.

[0058] The mounting wall 26 of the friction block mounting slot 24 of the mounting base 14 also has a through-hole sized to accommodate the bolt 17. Oppositely, the other side of the friction block mounting slot 24 also has a through-hole sized to accommodate the sleeve of the nut 18, facilitating installation. During installation, the bolt 17 passes through the through-hole in the mounting wall 26, through the waist-shaped hole in the center of the friction block 13, and then connects with the nut 18. When the contact surface of the shrouded blade 28 is unloaded, the bolt 17 and nut 18 remain loosely fastened. When the friction block 13 moves to load the contact surface of the shrouded blade 28, the waist-shaped hole in the center of the friction block 13 is larger than the bolt 17, so the bolt 17 does not interfere with the normal movement of the friction block 13. After the contact surface of the shrouded blade 28 is loaded, the bolt 17 and nut 18 are tightened together, pressing the nut 18 against the side of the friction block 13, thereby pressing the friction block 13 against the mounting wall 26, achieving a compact and secure fit. Thus, the fastening bolts 17 and the nuts 18 can achieve lateral restraint and fixation of the friction block 13 .

[0059] The present invention uses a force transmission component and a first set screw 7 to push the friction block 13 to load the contact surface of the crowned blade 28, uses a force sensor 3 to measure the loading force, and uses a spring 23 installed between the push-pull rod tailstock 12 and the sliding bearing 19 to avoid idle travel during the loading movement, so as to facilitate accurate and stepless loading and adjustment of the clamping force on the contact surface of the crowned blade 28. The friction block 13 used in the present invention can be designed with a structure of the contact surface portion according to the structural form of the crowned blade 28, and is applicable to contact surfaces of any structural form. The present invention uses a needle roller row 21, a plunger 16, a slide rail 5, and a slider 4 to control the loading direction of the friction block 13, thereby preventing the friction block 13 from deflecting or tilting when loaded, and at the same time preventing the friction force caused by the wall from affecting the loading accuracy. The present invention adopts a thickened mounting base 14, a mounting wall 26 and reinforcing ribs, and uses bolts 17 and nuts 18 to pass through the waist-shaped hole in the middle of the friction block 13 to fasten the friction block 13 and the mounting wall 26 of the mounting base 14 together. Since the waist-shaped hole size of the friction block 13 is larger than the bolt diameter, the tightening process after the friction block 13 is loaded can avoid the influence of the loading state of the friction block 13 on the loading state of the friction block 13, and the reinforcing ribs and the mounting wall 26 can provide the friction block 13 with sufficient rigidity and high natural frequency to avoid resonance.

[0060] The present invention realizes accurate and stepless loading of the pressing force on the contact surface of the shrouded blade 28 from the aspects of the method for loading the pressing force on the contact surface of the shrouded blade 28, the direction control of the friction block and the method for installing and fastening the friction block, avoids the influence of the friction force during loading and controls the loading direction, ensures the stability and reliability of the pressing force loading, and ensures that the friction block has sufficient stiffness and natural frequency during the test.

[0061] Example 2

[0062] Embodiment 2 of the present invention relates to a force loading method for a shrouded blade 28, which uses the contact surface pressing force loading device for the shrouded blade 28 in embodiment 1. The force loading method of this embodiment includes the following steps:

[0063] S1: Fix the shrouded blade 28 to the test bench;

[0064] S2: Fix the two mounting bases 14 to corresponding positions on the test bench so that the openings of the friction block mounting slots 24 face the contact surface of the shrouded blades 28;

[0065] S3: Sequentially assemble the other components of the contact surface pressing force loading device for the shrouded blade 28 in Example 1 onto the mounting base 14;

[0066] S4: Adjust the first set screw 7 to apply a load to the contact surface of the shrouded blade 28;

[0067] S5: Tighten the friction block 13.

[0068] Wherein, step S1 adopts a conventional fixing method.

[0069] In step S2 , the mounting base 14 is fixed to the test bench through the mounting grooves at the bottom of the mounting base 14 and the through holes on the main body.

[0070] The installation sequence of step S3 is as follows:

[0071] S31: Assemble the force transmission component and the friction block 13, as shown in FIG. Figure 2 As shown, the force sensor 3 is connected to the first connecting block 1 and the second connecting block 2 respectively through the first fastening screw 6. Then, the second connecting block 2 is connected to the rear end of the friction block 13 through the first fastening screw 6, and the first connecting block 1 is connected to the push-pull rod 11 through the first fastening screw 6.

[0072] S32: Assemble the friction block lower constraint assembly. Install the slide rail 5 into the slide rail groove 25 at the bottom of the friction block mounting groove 24 in the mounting base 14. Install the slider 4 on the slide rail 5, and place the friction block sliding base 15 on the slider 4. The friction block sliding base 15 has four countersunk through holes, the same size as the first fastening screws 6. During installation, the first fastening screws 6 pass through the countersunk through holes on the friction block sliding base 15 and are screwed into the threaded holes on the slider 4, connecting the slider 4 and the friction block sliding base 15 together. Figure 2 shown.

[0073] S33: Install the force transmission assembly and the friction block 13 on the mounting base 14. The friction block 13 is placed on the friction block sliding base 15, and the horizontal groove at the bottom of the friction block 13 is matched with the protrusion on the friction block sliding base 15, as shown in FIG. Figure 2As shown. The push-pull rod 11 of the force transmission assembly passes through the through hole at the rear end of the friction block mounting groove 24 of the mounting base 14 and passes through the sliding bearing 19, wherein the sliding bearing 19 is mounted on the mounting base 14 by the first fastening screw 6, as shown. Figure 1 As shown. Put the spring 23 on the push-pull rod 11, with one end against the sliding bearing 19 and the other end against the push-pull rod tailstock 12. At the same time, use the thread at the end of the push-pull rod 11 and the threaded hole of the push-pull rod tailstock 12 to connect the push-pull rod 11 together. Install the rear cover 22 on the mounting base 14 through the first fastening screw 6, as shown. Figure 1 As shown, the first set screw 7 is passed through the threaded hole of the rear cover 22 to tighten the push-pull rod tailstock 12.

[0074] S34: Assemble the upper constraint assembly of the friction block. Place the needle roller row 21 and the pressure plate 20 on the friction block 13 in sequence. Figure 2 As shown, the mounting groove cover 10 is mounted on the friction block mounting groove of the mounting base 14 using the second fastening screw 8, and the second fastening screw 9 is passed through the threaded hole of the mounting groove cover 10 and pressed against the pressure plate, thereby pressing the needle roller row 21, the friction block 13, the friction block sliding base 15 and the slider 4.

[0075] S35: Assemble the friction block lateral restraint assembly. Pass the plunger 16 through the threaded plunger holes on both sides of the friction block mounting groove 24 of the mounting base 14 and press it toward the friction block 13, wherein the plunger 16 is as shown in FIG. Figure 8 As shown, the top portion is a rollable ball head 30 .

[0076] S36: Debug and calibrate. After assembly is completed, place the dial gauge on the side of the mounting base 14 and use the dial gauge to measure the side of the friction block 13. Figure 6 As shown. Turn the first set screw 7 to push the force transmission assembly and friction block 13. Observe the changes in the micrometer reading during the movement of the friction block 13. Adjust the tightening depth of the plunger 16 accordingly to adjust the direction of movement of the friction block 13. When the micrometer reading fluctuates less than 0.1mm, the adjustment is complete. It should be noted that the upper and lower restraining assemblies of the friction block can ensure accurate vertical positioning of the friction block 13 with conventional machining accuracy. Therefore, no adjustment is required and they only serve as a restraint.

[0077] In step S4, when applying a pressing force to the contact surface of the shrouded blade 28, as shown in FIG. Figure 5 and Figure 6 As shown, the contact surface of the friction block 13 matches the contact surface of the shrouded blade 28. Tightening the first set screw 7 pushes the friction block 13 to compress the contact surface. The force measured by the force sensor 3 is read to control the magnitude of the contact surface compressive force until the force measured by the force sensor 3 reaches the specified magnitude.

[0078] In any of steps S3 to S5, bolt 17 is passed through the through hole of mounting wall 26 and the waist-shaped hole of friction block 13, and is connected with nut 18, while maintaining a loose connection between bolt 17 and nut 18. In step S5, bolt 17 and nut 18 are tightened, and nut 18 is pressed against friction block 13, thereby pressing friction block 13 against mounting wall 26, thereby achieving tightening.

[0079] Through the method of this embodiment, accurate and measurable stepless loading of the contact surface clamping force can be achieved for the crowned blade 28, which can ensure the stability and accuracy of the contact surface state between the friction block 13 and the crowned blade 28, and provide a tightening constraint for the friction block 13 without affecting the contact surface clamping force loading.

[0080] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A contact surface pressing force loading device suitable for shrouded blades, characterized in that: The invention comprises a mounting base, a friction block, a force transmission assembly, a first set screw, a friction block lower constraint assembly, a friction block upper constraint assembly and a friction block lateral constraint assembly; the mounting base is provided with a friction block mounting groove and a sliding bearing mounting groove extending in a straight line and communicating with each other, the friction block is arranged in the friction block mounting groove and can reciprocate along the friction block mounting groove; the tail end of the friction block is fixedly connected to the force transmission assembly, the force transmission assembly is arranged in the sliding bearing mounting groove and can reciprocate along the sliding bearing mounting groove; the first set screw is arranged on the mounting base and pushes the force transmission assembly in the direction of the friction block so that the head of the friction block protrudes out of the friction block mounting groove of the mounting base; A slide rail groove is provided at the bottom of the friction block mounting groove of the mounting base, and the friction block lower constraint assembly is provided on the slide rail groove, is located below the friction block, and abuts against the lower surface of the friction block; the friction block lower constraint assembly includes a friction block sliding base, a slider and a slide rail, the slide rail is provided on the slide rail groove, the slider is provided on the slide rail, and the friction block sliding base is fixedly provided on the slider; The friction block upper constraint assembly is arranged on the mounting base and abuts against the upper surface of the friction block; the friction block upper constraint assembly includes a pressure plate and a needle roller row; the needle roller row is placed on the upper surface of the friction block, and the pressure plate is located above the needle roller row; the mounting base also includes a mounting groove top cover, which is fixed to the top of the mounting base by screws to press the pressure plate; The friction block lateral constraint assembly includes a plunger, a fastening bolt and a nut; the plunger includes a cylinder and a rollable ball head arranged on the end face of the cylinder; multiple plungers are respectively inserted into the threaded plunger holes on the two side walls of the friction block mounting groove, so that the rollable ball head abuts against the side of the friction block, limiting the lateral movement of the friction block, and realizing lateral constraint of the friction block during debugging; after the loading of the contact surface of the crowned blade is completed, the fastening bolt and the nut can realize lateral constraint and fixation of the friction block.

2. The contact surface pressing force loading device for shrouded blades according to claim 1, characterized in that: The force transmission assembly includes a force sensor, a push-pull rod and a push-pull rod tailstock connected in sequence. The force sensor is fixedly connected to the tail of the friction block; the end of the first set screw abuts against the end surface of the push-pull rod tailstock.

3. The contact surface pressing force loading device for shrouded blades according to claim 2, characterized in that: A sliding bearing is fixedly arranged in the sliding bearing installation groove, and the push-pull rod passes through the sliding bearing.

4. The contact surface pressing force loading device for shrouded blades according to claim 3, characterized in that: A spring is provided between the sliding bearing and the push-pull rod tailstock, and the spring is sleeved on the push-pull rod; the spring pushes the push-pull rod tailstock in the direction of the first set screw.

5. The contact surface pressing force loading device for shrouded blades according to claim 1, characterized in that: The upper surface of the friction block sliding base is provided with a transverse convex strip.

6. The contact surface pressing force loading device for shrouded blades according to claim 5, characterized in that: A transverse groove is provided at the bottom of the friction block, and the transverse ridge is engaged with the transverse groove.

7. The contact surface pressing force loading device for shrouded blades according to claim 5, characterized in that: There are two slide rails, which are arranged in parallel and at intervals; there are four sliders, and two sliders are arranged on each slide rail.

8. A contact surface compression force loading method suitable for shrouded blades, characterized in that: Use the contact surface pressing force loading device suitable for shrouded blades according to any one of claims 1 to 7.

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