An auxiliary fixture for quick impeller assembly

Abstract

The application relates to the field of impeller assembly, and discloses an auxiliary jig for conveniently and quickly assembling an impeller, which is characterized in that a fixing table and a vertical plate are arranged on the top of a moving lifting mechanism and connected with an extension cylinder, a circular ring and uniformly distributed sliding grooves, and the impeller is accurately centered and clamped by cooperating with clamping screws, connecting plates, telescopic rods and rollers of a centering and clamping mechanism; the overall position and height can be flexibly adjusted by using universal wheels, control screws and connecting shafts; the impeller and a rotating shaft of a volute can be uniformly and tightly installed by using a striker, a swing plate, a U-shaped groove, a clamping groove and a striking adjusting mechanism; and the installation precision and efficiency are further improved by using a centering laser pen.

Description

Technical Field

[0001] This invention relates to the field of impeller assembly technology, specifically to an auxiliary fixture that facilitates rapid impeller assembly. Background Technology

[0002] In the manufacturing and assembly of large centrifugal pumps, turbines, or similar equipment, the installation and alignment of the impeller and volute is a critical step. Impellers typically have large dimensions and mass, and maintaining precise coaxiality and proper axial position during installation into the volute is essential to ensure smooth operation and stable overall performance. However, current technologies often rely on manual operation or simple tooling for the installation and positioning of large impellers.

[0003] In traditional impeller assembly, operators typically use hoisting equipment to lift the impeller to the vicinity of the volute, then make multiple fine adjustments to achieve initial positioning of the impeller relative to the volute. Due to the large size and heavy weight of the impeller, this positioning process often presents the following problems: First, the impeller's interior needs precise alignment with the volute's rotation axis and must engage with pre-reserved keyways or positioning structures. However, due to a lack of effective centering and clamping methods, considerable time is often required for repeated trial and error, slow rotation, and adjustments to barely achieve the initial position. Second, when the impeller is inserted into the volute's inner cavity, without proper support and guiding devices, friction or even jamming can easily occur between the impeller's outer circumference and the volute's inner wall or other mounting components. This not only affects installation speed and quality but may also damage the surface of the parts. Furthermore, adjusting the impeller's height and determining its alignment are also difficult under traditional conditions. If the positioning is inaccurate, the hoisting angle and height must be readjusted, further increasing the complexity and repetitiveness of the installation.

[0004] Furthermore, when the rotating shafts of the impeller and volute need to achieve an interference fit to ensure assembly accuracy and tightness, existing technologies mostly rely on external manual tapping or other unstable tapping devices. These methods cannot ensure uniform and synchronized tapping force, easily leading to uneven stress on the impeller during the interference fit process, affecting the stability and quality of the installation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an auxiliary fixture for the rapid assembly of impellers, thus solving the problem.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An auxiliary fixture for facilitating rapid assembly of an impeller includes a movable lifting mechanism and a connecting ring. The movable lifting mechanism is used to control the position and height of the impeller. A fixed platform is installed on the top of the movable lifting mechanism. The fixed platform includes a lifting plate. A vertical plate is fixed to the front side of the lifting plate. An extension cylinder is fixed to the upper surface of the front side of the vertical plate. A circular ring is provided at the front end of the extension cylinder. Three sliding grooves are evenly opened on the surface of the circular ring.

[0008] The annular surface is equipped with a centering clamping mechanism, which is used to center and clamp the impeller.

[0009] The centering clamping mechanism includes a clamping screw that screws into the center of the extension cylinder and a telescopic rod that slides inside a groove. The front end of the clamping screw has an annular groove, and a connecting plate is rotatably mounted inside the annular groove. A knob is provided at the rear end of the clamping screw. The connecting plate has a triangular structure, and fixing bolts are arranged parallel to each of the three sides of the connecting plate. A first connecting rod is hinged to the surface of the fixing bolt. The end of the first connecting rod opposite to the fixing bolt is hinged to the telescopic rod. A roller is rotatably mounted on the front side of the opposite end of the telescopic rod.

[0010] Furthermore, the connecting ring is placed on the rear side of the upright plate, the clamping screw passes through the connecting ring, the surface of the connecting ring is provided with a slot, and three striking pins are evenly arranged on the front surface of the connecting ring, the striking pins passing through the extension cylinder.

[0011] Furthermore, through holes are provided at the three corners of the connecting plate surface, the striker passes through the through holes, and the end of the striker is pressed against the center of the impeller.

[0012] Furthermore, symmetrical reinforcing ribs are provided between the back of the upright plate and the lifting plate, and a fixed shaft is provided between the two reinforcing ribs. A swing plate is rotatably mounted on the surface of the fixed shaft.

[0013] Furthermore, a U-shaped groove is provided on the top of the swing plate, which is adapted to the card slot, and a handle groove is provided on the lower surface of the swing plate.

[0014] Furthermore, an impact adjustment mechanism is installed on the back of the upright plate. The impact adjustment mechanism includes two bosses that fix the upright plate on the back. A double screw is rotatably installed between the two bosses. Moving blocks are symmetrically installed on the surface of the double screw, and the two moving blocks are respectively screwed onto different threaded surfaces.

[0015] Furthermore, a second connecting rod is hinged to the surface of the moving block, and the ends of the two second connecting rods are hinged to the horizontal plate. A tension spring is connected to the surface of the horizontal plate, and the end of the tension spring facing away from the horizontal plate is connected to the swing plate.

[0016] Furthermore, the mobile lifting mechanism includes a base plate, with casters installed at the four corners of the bottom of the base plate, a fixed seat installed on the upper surface of the base plate, and a first connecting plate symmetrically hinged to the inner side of the fixed seat, with a connecting shaft installed at the end of the first connecting plate.

[0017] Furthermore, a second connecting plate is hinged to the surface of the connecting shaft, and the two second connecting plates are hinged to the bottom of the connecting platform at the ends opposite to the connecting shaft. The lifting plate is fixed on the connecting platform, and a control screw is laterally screwed between the two connecting shafts. The two connecting shafts are respectively screwed onto different threaded surfaces.

[0018] Furthermore, a centering laser pointer is embedded in the front end face of the clamping screw, which is used to assist in centering.

[0019] This invention provides an auxiliary fixture for convenient and rapid impeller assembly. It offers the following advantages:

[0020] By setting an extension cylinder and a ring at the front end of the fixed platform, and evenly opening grooves on the surface of the ring, the centering and clamping mechanism can effectively achieve preliminary centering and precise clamping before the impeller enters the volute. Through the transmission linkage structure between the clamping screw, connecting plate, first connecting rod, and telescopic rod, the three rollers can simultaneously and evenly extend outward and press tightly against the inner ring surface of the impeller, thereby reducing repeated trial and error and frequent shaking during the impeller insertion into the volute. Compared to traditional tooling that relies on repeated manual adjustments and trial installations, this technical solution allows the impeller shaft to be aligned with the center of the volute in the early stages of impeller installation, significantly improving centering efficiency and accuracy, and reducing the risk of wear and jamming at the impeller-volute mating parts.

[0021] During assembly, the overall device can be moved and its height adjusted flexibly by using casters at the bottom of the fixture and control screws between the two connecting shafts, allowing for precise control of the impeller in both horizontal and vertical directions. This flexible adjustment method allows for quick matching of the mounting port position of the volute after centering and clamping, eliminating the need for repeated lifting and offset of the impeller with external assistance, significantly reducing the intensity and complexity of the installation operation. Simultaneously, when the impeller enters the inner cavity of the volute, the rollers clamp the impeller from the inside out, and the outer ring surface has no additional protrusions, ensuring smooth insertion of the impeller without the need for repeated probing and slow fine-tuning at assembly gaps, improving installation smoothness and reducing surface wear of components.

[0022] By integrating an impact adjustment mechanism and a swing plate with a U-shaped groove and a retaining groove on the back of the fixture, a uniform and controllable impact can be provided when the impeller and volute shaft are in an interference fit. Three impact pins pass through the through-holes in the connecting plate and correspond to the center position of the impeller, thus applying multiple uniform impacts during interference fit installation. This ensures the impeller is under balanced force and avoids tilting, eccentricity, or impeller damage caused by uneven force distribution, as is common with traditional manual hammering methods. The preload and impact intensity of the impact pins can be adjusted using a twin-screw, moving block, second connecting rod, and tension spring adjustment structure, allowing for precise optimization for different impeller sizes or materials. This adjustment method not only improves the assembly quality and efficiency of the interference fit but also reduces repeated replacements or secondary processing during installation, lowering production costs and time consumption.

[0023] During the overall installation process, the laser pointer makes impeller alignment more intuitive. The laser point clearly indicates the deviation between the impeller center and the volute shaft center, eliminating the need for operators to rely on experience for estimation and trial adjustments. Compared to background technologies that lack accurate alignment references and require multiple trial installations, this solution significantly shortens initial positioning time, reduces operational difficulty, and ensures a substantial improvement in final impeller installation accuracy. With the close cooperation of all components, the entire process of moving, clamping, aligning, adjusting, impacting, and finally interference fit can be precisely controlled, making the installation of large impellers simple, efficient, accurate, and stable. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the installation three-dimensional structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the three-dimensional structure of the back of the present invention;

[0026] Figure 3 This is a schematic diagram of the movable lifting mechanism of the present invention;

[0027] Figure 4 This is a three-dimensional schematic diagram of the mounting of the fixing platform and connecting ring of the present invention;

[0028] Figure 5 This is a schematic diagram of the installation structure of the clamping screw and telescopic rod of the present invention;

[0029] Figure 6 This is a three-dimensional structural diagram of the fixed platform and the swing plate of the present invention;

[0030] Figure 7 This is a three-dimensional structural diagram of the connecting plate of the present invention;

[0031] Figure 8 This is a top view schematic diagram of the impact adjustment mechanism of the present invention;

[0032] Figure 9This is a three-dimensional structural diagram of the connecting ring and the firing pin of the present invention.

[0033] Among them, 1. Movable lifting mechanism; 11. Base plate; 12. Casters; 13. Fixed base; 14. First connecting plate; 15. Connecting shaft; 16. Second connecting plate; 17. Control screw; 18. Connecting platform; 2. Fixed platform; 21. Lifting plate; 221. Extension cylinder; 22. Vertical plate; 23. Reinforcing rib plate; 24. Ring; 25. Slide groove; 26. Fixed shaft; 3. Centering clamping mechanism; 31. Clamping screw; 32. Rotary... 33. Button; 34. Ring groove; 35. Centering laser pointer; 36. Connecting plate; 37. Fixing bolt; 38. Through hole; 4. First connecting rod; 59. Telescopic rod; 40. Roller; 51. Swing plate; 52. U-shaped groove; 53. Handle groove; 64. Connecting ring; 55. Slot; 66. Impact adjustment mechanism; 67. Boss; 68. Twin screw; 69. Moving block; 60. Second connecting rod; 61. Horizontal plate; 62. Tension spring. Detailed Implementation

[0034] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1:

[0036] See Figure 1-9 An auxiliary fixture for facilitating rapid impeller assembly includes a movable lifting mechanism 1 and a connecting ring 5. The movable lifting mechanism 1 controls the position and height of the impeller. A fixed platform 2 is mounted on the top of the movable lifting mechanism 1. The fixed platform 2 includes a lifting plate 21. A vertical plate 22 is fixed to the front side of the lifting plate 21. An extension cylinder 221 is fixed to the upper surface of the front side of the vertical plate 22. A ring 24 is provided at the front end of the extension cylinder 221. Three grooves 25 are evenly distributed on the surface of the ring 24. The movable lifting mechanism 1 allows for vertical assembly of large impellers. The impeller can be precisely adjusted to adapt to different volute installation requirements; the stable structure of the fixed platform 2 and the lifting plate 21 can reliably support the impeller and reduce swaying during the centering process; the forward extension structure of the vertical plate 22 and the extension cylinder 221 can make the inner ring of the impeller aligned with the center position of the circular ring 24 to achieve better coaxiality control; the three evenly distributed sliding grooves 25 on the circular ring 24 can provide stable guidance for the telescopic rod 37 of the subsequent centering clamping mechanism 3, thereby ensuring that the impeller maintains precise positioning when inserted into the volute and reducing the process of repeated adjustments.

[0037] A centering clamping mechanism 3 is installed on the surface of the ring 24. The centering clamping mechanism 3 is used to center and clamp the impeller. By directly arranging the centering clamping mechanism 3 on the surface of the ring 24, the clamping screw 31 and the telescopic rod 37 can be guided in the slide groove 25 to accurately abut against the inner ring surface of the impeller. Through this close fit, the impeller can be initially centered before entering the volute, so as to reduce the shaking and repeated trial and error of the impeller during installation, thereby improving the assembly accuracy and efficiency.

[0038] 3 includes a clamping screw 31 that screws into the center of the extension cylinder 221 and a telescopic rod 37 that slides inside the slide groove 25. The front end of the surface of the clamping screw 31 is provided with an annular groove 33. A connecting plate 35 is rotatably installed inside the annular groove 33. A knob 32 is provided at the rear end of the clamping screw 31. The connecting plate 35 has a triangular structure. Fixing bolts 351 are arranged parallel to each other on the three sides of the connecting plate 35. A first connecting rod 36 is hinged to the surface of the fixing bolt 351. The end of the first connecting rod 36 away from the fixing bolt 351 is hinged to the telescopic rod 37. A roller 38 is rotatably installed on the front side of the opposite end of the telescopic rod 37. Rotating the knob 32 can drive the clamping screw 31 to move precisely in the axial direction; the annular groove 33 cooperates with the connecting plate 35 to make the connecting plate 35 move synchronously in the axial direction with the clamping screw 31; the rod transmission structure formed by the connecting plate 35, the fixing bolt 351 and the first connecting rod 36 can make the three telescopic rods 37 extend outward synchronously and press tightly against the inner ring surface of the impeller; the line contact between the roller 38 and the inner ring surface of the impeller can achieve stable centering and clamping without damaging the impeller; through the above linkage and clamping process, the impeller can be kept in a precise coaxial position before the impeller is inserted into the volute, thereby significantly reducing the alignment time in subsequent installation and improving the overall assembly efficiency.

[0039] See Figure 1-5 The connecting ring 5 is positioned behind the vertical plate 22, and the clamping screw 31 passes through the connecting ring 5. A slot 51 is provided on the surface of the connecting ring 5, and three impact pins 52 are evenly distributed on the front surface of the connecting ring 5, penetrating the extension cylinder 221. The distribution of three impact pins 52 on the surface of the connecting ring 5 ensures uniform impact when the impeller aligns with the rotating shaft of the volute. The cooperation between the slot 51 and the subsequent U-shaped groove 41 allows the impact pins 52 to extend outwards after the impeller is initially aligned, generating impact energy with the elastic force of the tension spring 66. The synchronized action of the three impact pins 52 ensures uniform impact on the impeller, reducing errors caused by unbalanced forces. The overall positioning of the connecting ring 5, the vertical plate 22, and the extension cylinder 221 provides precise guidance for the impact pins 52 before the impeller inserts into the volute, thereby improving the control accuracy and stability of the interference fit.

[0040] See Figure 4 and Figure 7The connecting plate 35 has through holes 352 at each of its three corners. The striker 52 passes through the through holes 352, and its end is pressed against the center of the impeller. The distribution of the through holes 352 allows the striker 52 to obtain precise motion guidance on the connecting plate 35; the direct pressing of the end of the striker 52 against the center of the impeller allows the impeller to advance steadily during the interference fit; the uniform action of the three strikers 52 avoids the deflection caused by uneven force on the impeller; this precise layout reduces the frequency of repeated centering and multiple tapping during installation, thereby improving installation efficiency and accuracy.

[0041] See Figure 3-6 A reinforcing rib plate 23 is symmetrically arranged between the back of the upright plate 22 and the lifting plate 21. A fixed shaft 26 is arranged between the two reinforcing rib plates 23, and a swing plate 4 is rotatably mounted on the surface of the fixed shaft 26. By adding a reinforcing rib plate 23 between the upright plate 22 and the lifting plate 21, the overall structural rigidity can be improved; by providing a rotation fulcrum for the swing plate 4 through the fixed shaft 26, the swing plate 4 can be flexibly adjusted according to installation needs; by improving structural rigidity and mobility, the risk of deformation can be reduced during impeller installation and a stable environment can be created for the accurate application of force by the striking pin 52.

[0042] See Figure 6 and Figure 9 The top of the swing plate 4 has a U-shaped groove 41, which is adapted to the slot 51. A handle groove 42 is provided on the lower surface of the swing plate 4. The precise matching of the U-shaped groove 41 and the slot 51 enables the outward movement and power storage process of the striking pin 52 after the impeller is aligned. The handle groove 42 makes it easier for the operator to operate the swing plate 4 when fine-tuning the impeller and preparing for impact. This ergonomic design provides better controllability and ease of operation during interference fit installation, reducing unnecessary movements and time consumption.

[0043] See Figure 8 An impact adjustment mechanism 6 is installed on the back of the upright plate 22. The impact adjustment mechanism 6 includes two bosses 61 that fix the upright plate 22 on the back. A double screw 62 is rotatably installed between the two bosses 61. Moving blocks 63 are symmetrically installed on the surface of the double screw 62, and the two moving blocks 63 are screwed onto different threaded surfaces. The pretension of the tension spring 66 can be precisely adjusted by the relative movement of the double screw 62 and the moving blocks 63. By changing the pretension, the impact force of the striker 52 on the impeller can be adjusted to meet the interference fit requirements of impellers of different sizes and materials. Integrating this mechanism into the back of the upright plate 22 simplifies the overall structure and improves the convenience of operation and maintenance.

[0044] See Figure 8The surface of the movable block 63 is hinged with a second connecting rod 64, the ends of which are hinged to a horizontal plate 65. A tension spring 66 is connected to the surface of the horizontal plate 65, and the end of the tension spring 66 facing away from the horizontal plate 65 is connected to the swing plate 4. By moving the second connecting rod 64 through the movable block 63, the position of the horizontal plate 65 can be adjusted synchronously when the twin screw 62 is rotated; by changing the initial tension of the tension spring 66 through the horizontal plate 65, the impact energy of the impact pin 52 can be changed; this allows the impeller to obtain a suitable and controllable impact force during interference fit to avoid excessive stress on the impeller; this precision adjustable design allows for flexible fine-tuning for different working conditions, improving installation accuracy and safety.

[0045] See Figure 1-9 The mobile lifting mechanism 1 includes a base plate 11, with casters 12 installed at each of the four corners of the base plate 11. A fixed seat 13 is installed on the upper surface of the base plate 11, and a first connecting plate 14 is symmetrically hinged to the inner side of the fixed seat 13. A connecting shaft 15 is installed at the end of the first connecting plate 14. By installing casters 12 at the four corners of the base plate 11, the auxiliary fixture can move quickly and flexibly in the factory environment; the hinge structure between the fixed seat 13 and the first connecting plate 14 can achieve stable support for the impeller at different work positions and heights; the connecting shaft 15 can provide support for the control screw 17 to achieve lifting adjustment; the combination of overall movement and height control can make the impeller more smoothly aligned with the volute inlet, reduce friction on the outer ring surface, and improve assembly accuracy and work efficiency.

[0046] See Figure 1-3 A second connecting plate 16 is hinged to the surface of the connecting shaft 15. The ends of the two second connecting plates 16 opposite to the connecting shaft 15 are hinged to the bottom of the connecting platform 18. A lifting plate 21 is fixed to the connecting platform 18. A control screw 17 is laterally screwed between the two connecting shafts 15, with each shaft 15 screwed onto a different threaded surface. The reverse thread engagement between the control screw 17 and the two connecting shafts 15 allows for smooth lifting and lowering of the connecting platform 18 and the lifting plate 21 when the control screw 17 is rotated. The hinged characteristics of the second connecting plates 16 maintain the impeller's alignment and stability during height adjustment. This flexible and precise adjustment method allows for rapid matching of the volute's installation height after impeller alignment and clamping, thereby reducing repeated positioning and trial assembly steps and improving the overall efficiency of the installation process.

[0047] See Figure 5A centering laser pointer 34 is embedded in the front end face of the clamping screw 31, which is used to assist in centering. By embedding the centering laser pointer 34 in the front end face of the clamping screw 31, a precise beam reference can be provided when the impeller moves towards the volute. This laser reference can quickly determine the deviation between the impeller center and the volute mounting center and make fine adjustments. The centering laser pointer 34 can significantly reduce the error of visual estimation during the centering process, thereby improving the accuracy and efficiency of large impeller installation. Through close linkage with the above-mentioned components, a clear and intuitive positioning reference can be provided throughout the impeller insertion and interference fit process, improving the overall assembly quality and reliability.

[0048] Example 2:

[0049] In this embodiment, the impeller is initially precisely aligned using an extension cylinder (material: Q235 carbon structural steel, outer diameter 200mm, wall thickness 5mm) and a ring (material: 40Cr steel, heat treated HRC45-50) at the front end of the fixed platform. Three evenly spaced grooves (each 10mm wide, 5mm deep) are formed on the surface of the ring. The alignment clamping mechanism consists of a clamping screw (2mm pitch) made of 304 stainless steel, a connecting plate (equilateral triangle, side length 80mm, thickness 8mm), a first connecting rod (50mm length, 8mm diameter), a telescopic rod (10mm diameter, 60mm length), and a roller (30mm diameter, GCr15 bearing steel). Rotating the clamping screw with a knob extends the telescopic rod outwards and presses it tightly against the inner ring surface of the impeller, achieving precise alignment of the impeller before insertion into the volute.

[0050] Test conditions:

[0051] Environmental conditions: Temperature 20±2℃, Humidity 45±5%

[0052] Impeller parameters: outer diameter 800mm, inner ring diameter 300mm

[0053] Initial centering deviation: ±2mm

[0054] Measurement accuracy: Precision laser alignment instrument, accuracy ±0.01mm

[0055] Experimental data table (unit: mm):

[0056]

[0057] Experimental conclusion: By comparison, the coaxiality deviation decreased from an average of approximately 0.30 mm without this structure to an average of approximately 0.10 mm in this embodiment, representing an improvement of over 66%. This solution effectively reduces initial alignment errors and improves installation accuracy.

[0058] Relevant formulas:

[0059] Coaxiality deviation Δ = |X_impeller shaft - X_volute shaft|

[0060] By comparing the Δ value, the improvement in centering accuracy can be quantitatively explained.

[0061] Example 3:

[0062] This embodiment utilizes casters (polyurethane material, 100mm diameter, rotational resistance coefficient f≈0.02), a control screw (42CrMo material, 2.5mm pitch, strength grade 10.9), and a connecting shaft (40Cr tempered steel) to achieve flexible movement and precise height adjustment of the entire fixture. After clamping, rotating the control screw can adjust the height of the lifting plate within ±20mm, allowing the impeller to quickly align with the volute inlet position.

[0063] Test conditions:

[0064] Impeller and volute tolerances: Impeller outer diameter 800mm, volute inlet inner diameter 805mm

[0065] Operating procedure: One technician uses an electric wrench with a constant rotation speed (torque 10 N·m).

[0066] Environmental conditions: Temperature 20±2℃, Humidity 50±5%

[0067] Measurement parameters: insertion time (s), insertion force (N), and change in roughness Ra (μm) of the impeller outer ring surface after insertion.

[0068] Experimental data table:

[0069]

[0070] Experimental conclusion: This embodiment shortens the insertion time from 20s to about 11.6s, reduces the insertion force from 75N to about 43.8N, and reduces the wear Ra increment from 0.8μm to about 0.26μm, significantly improving installation smoothness and reducing friction and surface damage.

[0071] Relevant formula: F=μN (Friction force formula)

[0072] In this embodiment, by improving centering accuracy and flexible movement, the effective friction process and insertion force are reduced, resulting in faster insertion and less wear.

[0073] Example 4:

[0074] This embodiment utilizes an impact adjustment mechanism (the twin screw 62 is made of 20CrMo material, carburized and quenched; the moving block is made of 6061 aluminum alloy; the cross plate is made of Q235 steel; and the tension spring is made of spring steel with a spring coefficient of [missing information - likely a specific value]. The swing plate is made of 40Cr (HRC45). The position of the moving block can be changed by adjusting the twin screws, thereby changing the initial elongation x0 of the tension spring. When released, the three striking pins (GCr15 steel, end radius R=2mm) generate instantaneous impact energy E.

[0075] Let E = (1 / 2)kx². When x = 15 mm, E is approximately 1.5 J ≈ 37.5 J.

[0076] Test conditions:

[0077] Material parameters: Impeller material ZG230-450

[0078] Interference allowance for the volute: 0.05±0.01mm

[0079] Measurement parameters: Average impact force (N), impeller tilt deviation (°), interference fit success rate (%), force sensor accuracy ±0.5N.

[0080] Experimental data table:

[0081]

[0082] Experimental conclusions: By precisely adjusting the preload of the firing pin, uniform and controllable impact can be achieved and tilt deviation can be reduced; the success rate of interference fit is increased by more than 14%.

[0083] Relevant formula: E=(1 / 2)kx²

[0084] By controlling x to change E, the impact energy can be controlled, thus achieving precise interference fit.

[0085] Example 5:

[0086] In this embodiment, a centering laser pointer (wavelength 650nm, spot size ≤1mm, output power ≤5mW) is embedded at the front end of the clamping screw. The laser point is aligned with the center of the volute before the impeller enters the volute, thereby improving the centering speed and accuracy.

[0087] Test conditions:

[0088] Ambient illuminance: 500 lux

[0089] volute coaxiality tolerance: ±0.05mm

[0090] Measurement parameters: final coaxiality error (mm), total installation time (s), first-time alignment success rate (%) (average after 5 repetitions).

[0091] Experimental data table:

[0092]

[0093] Experimental conclusion:

[0094] With the assistance of a laser pointer, the centering error is reduced by about 50%, the total installation time is reduced by about 50%, and the success rate is increased from 80% to 100%, significantly simplifying the centering process and improving accuracy and efficiency.

[0095] Working principle: A large impeller is hoisted next to the fixture, with the inner ring surface of the impeller corresponding to the three rollers 38. Rotating the knob 32 drives the clamping screw 31 to rotate. The rotation of the screw 31's thread controls its axial movement. Due to the cooperation between the connecting plate 35 and the ring groove 33, the connecting plate 35 and the clamping screw 31 move axially synchronously. Controlling the connecting plate 35 to move backward pushes the telescopic rod 37 outward through the three first connecting rods 36. The telescopic rod 37 slides inside the slide groove 25. The T-shaped slide groove 25 ensures that the telescopic rod 37 can only slide. At this time, the outward extension of the telescopic rod 37 allows the rollers 38 to press against the inner ring surface of the impeller to achieve centering and clamping. At this time, the impeller coincides with the center of the ring 24 and remains fixed. The rollers 38 allow the impeller to rotate after clamping, so as to adjust the keyway position when key mating is required.

[0096] The jig can be moved as a whole by the bottom caster 12 to move the impeller closer to the volute. The distance between the two connecting shafts 15 can be controlled by rotating the control screw 17 to adjust the height of the impeller after clamping. The height position can be easily determined by the centering laser pointer 34, so that the laser point of the centering laser pointer 34 corresponds to the center of the volute to be installed. At this time, since the extension tube 221 extends forward, the impeller can be driven into the volute by moving the jig. The clamping method of the roller 38 from the inside to the outside makes the outer ring surface of the impeller free of protrusions, so that the impeller is not obstructed when entering the volute.

[0097] After the impeller and the volute rotating shaft are properly aligned, the bottom of the swing plate 4 is pushed inward by the handle groove 42, which causes the top U-shaped groove 41 to flip outward. The U-shaped groove 41 and the slot 51 work together to pull the striker 52 outward. At this time, the tension spring 66 is stretched and releases its force on the handle groove 42. The tension spring 66 then allows the end of the striker 52 to strike the impeller, thus installing the impeller and the volute rotating shaft in place. The synchronous impact of the three strikers 52 ensures that the impact force on the impeller is uniform. The reciprocating impact on the impeller achieves an interference fit, ensuring the accuracy of the installation. The position of the cross plate 65 can be controlled by rotating the double screw 62, which in turn controls the tension force on the tension spring 66, thereby adjusting the distance between the striker 52 and the impeller when no force is applied, improving the flexibility of the fixture.

[0098] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An auxiliary fixture for facilitating rapid impeller assembly, characterized in that: The device includes a movable lifting mechanism (1) and a connecting ring (5). The movable lifting mechanism (1) is used to control the position and height of the impeller. A fixed platform (2) is installed on the top of the movable lifting mechanism (1). The fixed platform (2) includes a lifting plate (21). A vertical plate (22) is fixed on the front side of the lifting plate (21). An extension cylinder (221) is fixed on the upper surface of the front side of the vertical plate (22). A ring (24) is provided at the front end of the extension cylinder (221). Three sliding grooves (25) are evenly opened on the surface of the ring (24). The ring (24) is equipped with a centering clamping mechanism (3), which is used to center and clamp the impeller; The centering clamping mechanism (3) includes a clamping screw (31) that screws into the center of the extension cylinder (221) and a telescopic rod (37) that slides inside the slide groove (25). The clamping screw (31) has an annular groove (33) at its front end. A connecting plate (35) is rotatably installed inside the annular groove (33). A knob (32) is provided at the rear end of the clamping screw (31). The connecting plate (35) has a triangular structure. Fixing bolts (351) are arranged parallel to each other on the three sides of the connecting plate (35). A first connecting rod (36) is hinged to the surface of the fixing bolt (351). The end of the first connecting rod (36) away from the fixing bolt (351) is hinged to the telescopic rod (37). A roller (38) is rotatably installed on the front side of the telescopic rod (37) that is away from each other. The connecting ring (5) is placed on the rear side of the upright plate (22), the clamping screw (31) passes through the connecting ring (5), the surface of the connecting ring (5) is provided with a slot (51), and three impact pins (52) are evenly arranged on the front surface of the connecting ring (5), and the impact pins (52) pass through the extension cylinder (221). Through holes (352) are provided at the three corners of the surface of the connecting plate (35), the impact pin (52) passes through the through holes (352), and the end of the impact pin (52) is pressed against the center of the impeller; A reinforcing rib (23) is symmetrically arranged between the back of the upright plate (22) and the lifting plate (21), and a fixed shaft (26) is arranged between the two reinforcing ribs (23). A swing plate (4) is rotatably mounted on the surface of the fixed shaft (26). The top of the swing plate (4) is provided with a U-shaped groove (41), which is adapted to the slot (51). The bottom surface of the swing plate (4) is provided with a handle groove (42). The back of the upright plate (22) is equipped with an impact adjustment mechanism (6). The impact adjustment mechanism (6) includes two bosses (61) that fix the upright plate (22) on the back. A double screw (62) is rotatably installed between the two bosses (61). Moving blocks (63) are symmetrically installed on the surface of the double screw (62). The two moving blocks (63) are respectively screwed onto different threaded surfaces.

2. The auxiliary fixture for facilitating rapid impeller assembly according to claim 1, characterized in that: The surface of the moving block (63) is hinged with a second link (64), the ends of the two second links (64) are hinged to the horizontal plate (65), the surface of the horizontal plate (65) is connected with a tension spring (66), and the end of the tension spring (66) away from the horizontal plate (65) is connected to the swing plate (4).

3. The auxiliary fixture for facilitating rapid impeller assembly according to claim 1, characterized in that: The mobile lifting mechanism (1) includes a base plate (11), with universal wheels (12) installed at the four corners of the bottom of the base plate (11), a fixed seat (13) installed on the upper surface of the base plate (11), a first connecting plate (14) symmetrically hinged to the inner side of the fixed seat (13), and a connecting shaft (15) installed at the end of the first connecting plate (14).

4. The auxiliary fixture for facilitating rapid impeller assembly according to claim 3, characterized in that: The surface of the connecting shaft (15) is hinged with a second connecting plate (16). The two second connecting plates (16) are hinged at the bottom of the connecting platform (18) at one end away from the connecting shaft (15). The lifting plate (21) is fixed on the connecting platform (18). A control screw (17) is laterally screwed between the two connecting shafts (15). The two connecting shafts (15) are screwed onto different threaded surfaces respectively.

5. The auxiliary fixture for facilitating rapid impeller assembly according to claim 1, characterized in that: The clamping screw (31) has a centering laser pointer (34) embedded in its front end face, which is used to assist in centering.

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