Gear-driven centrifugal pump test device and test method

Abstract

This invention discloses a gear-driven centrifugal pump testing device and method, relating to the field of centrifugal pump testing technology. It includes a workbench, a centrifugal pump body, and a gearbox. The centrifugal pump body is connected to the workbench via a mounting structure and to the gearbox via a universal coupling. The gearbox includes a housing, inside which a bearing seat is fixed. A drive shaft is mounted within the bearing seat via bearings, and a gear disc is fixed on the drive shaft. The sidewalls and ends of the bearing seat respectively abut against a first limiting structure and a second limiting structure. This invention, by incorporating a pre-tightening adjusting bolt, an annular damping groove, a PTFE wear-resistant layer, and a universal coupling, solves the problem of multi-directional misalignment between the shaft system and the pump body during operation, achieving precise alignment and stable transmission across the entire drive chain, and avoiding transmission stiffness and accelerated component wear.

Description

Technical Field

[0001] This invention relates to the field of centrifugal pump testing technology, specifically to a gear-driven centrifugal pump testing device and testing method. Background Technology

[0002] Gear-driven centrifugal pumps are fluid transport devices that use a gear transmission mechanism as the core of power transmission. They transmit power to the pump impeller via a motor-driven gear set to achieve fluid pressurization and transport. Due to their high transmission efficiency and stable operation, these centrifugal pumps are widely used in petrochemical, industrial fluid transport, and other fields. The meshing accuracy and stability of the gear transmission system directly determine the pump's operating efficiency and service life.

[0003] To ensure the product quality and operational reliability of gear-driven centrifugal pumps, multiple performance and reliability tests must be conducted before shipment. These tests mainly include transmission efficiency testing, head-flow characteristic testing, long-term start-stop durability testing, and stability testing under variable load conditions. These tests rely on specialized testing equipment to simulate actual operating conditions and collect core operating parameters of the pump body to verify whether the product meets design standards.

[0004] The core problem with existing gear-driven centrifugal pump testing devices lies in the fact that their test gearboxes mostly employ rigid connection structures, lacking effective elastic preload, preload adjustment, and self-centering compensation designs. Furthermore, the limiting structure exhibits high frictional resistance and incomplete impact buffering. Under high-frequency start-stop and variable load test conditions, the gears inside the gearbox are prone to radial and axial micro-movements, which may also be triggered by impact rebound, leading not only to fretting wear on the gear surfaces but also to accelerated wear and accuracy drift of the testing device itself. This drift interferes with the acquisition of performance data from the tested centrifugal pump, making it impossible to accurately distinguish between testing device errors and pump defects, thus affecting the authenticity and reliability of the test results. Therefore, this paper proposes a gear-driven centrifugal pump testing device and method to address these problems. Summary of the Invention

[0005] Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a gear-driven centrifugal pump testing device and method, solving the problems mentioned in the background section.

[0007] Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solution: a gear-driven centrifugal pump testing device, comprising: a workbench, a centrifugal pump body and a gearbox, wherein the centrifugal pump body is connected to the workbench through an installation structure, and the centrifugal pump body is connected to the gearbox through a universal coupling; The gearbox includes a housing, inside which a bearing seat is fixedly installed, and a drive shaft is mounted in the bearing seat via a bearing. A gear disc is fixedly installed on the drive shaft. The sidewall and end of the bearing housing respectively abut against the first limiting structure and the second limiting structure; The first limiting structure includes an arc-shaped plate that abuts against the side wall of the bearing seat and a connecting rod fixed to the side wall of the housing. One end of the arc-shaped plate is fixed with a connecting rod, one end of the connecting rod is slidably connected to the inside of the connecting rod, and a hidden spring is fixed inside the connecting rod. One end of the connecting rod abuts against the hidden spring. The end of the connecting rod away from the connecting rod has an internal threaded hole, and a preload adjustment bolt is internally connected to the internal threaded hole. The inner end of the preload adjustment bolt passes through the interior of the connecting rod and abuts against the end of the hidden spring away from the connecting rod, which is used to adjust the initial preload of the hidden spring. The second limiting structure includes a disc spring that abuts against the end of the bearing housing.

[0009] Preferably, the inner wall of the housing is fixed with a limiting ring to limit the edge of the butterfly spring, and the other end of the butterfly spring is located inside the limiting ring and abuts against the limiting ring.

[0010] Preferably, the second limiting structure further includes a connecting ring sleeved at the end edge of the bearing housing; The inner wall of the connecting ring is fitted with a rubber ring, and each end face of the rubber ring is provided with an annular damping groove. The disc spring abuts against the end of the bearing seat through the rubber ring. The connecting ring is snapped onto the end stepped structure of the bearing housing and is used to axially limit one end of the disc spring.

[0011] Preferably, a soft pad is adhered to the inner wall of the arc-shaped plate, and grooves are equally spaced on the soft pad. The grooves are filled with wear-resistant grease, and the soft pad is in contact with the bearing seat.

[0012] Preferably, the mounting structure includes a base fixed to the top of the workbench, a guide structure fixed to the top of the base, and a slide block slidably connected to the guide structure, and the centrifugal pump body is fixed on the slide block.

[0013] Preferably, the guide structure includes guide columns symmetrically installed on both sides of the base, and each end of the guide column is fixedly provided with a limiting seat, the limiting seat being fixedly connected to the base; Both guide posts are fitted with compression springs, and the two ends of the compression springs abut against the side walls of the limiting seat and the slide, respectively. The slide block has a through hole adapted to the guide post, and the inner wall of the through hole is bonded with a polytetrafluoroethylene wear-resistant layer.

[0014] Preferably, an observation window is provided on the side wall of the enclosure, and an anti-fog transparent plate is embedded in the observation window.

[0015] A test method for a gear-driven centrifugal pump includes the following steps: S1. Test preparation: Check the assembly accuracy of the workbench, centrifugal pump body, gearbox and universal coupling. Adjust the initial preload of the hidden spring by adjusting the preload adjusting bolt. Ensure that the soft pad on the inner wall of the arc plate is undamaged, the wear-resistant grease in the groove is sufficient, the elastic performance of the hidden spring, compression spring and butterfly spring is intact, the annular damping groove of the rubber ring is not blocked, and the limiting state of the connecting ring on the butterfly spring is stable. S2. Assembly: Fix the centrifugal pump body on the slide, and slide the slide onto the guide columns on both sides of the base, ensuring that the two ends of the compression spring abut against the limit seat and the side wall of the slide respectively; connect the centrifugal pump body to the power input end of the gearbox through a universal coupling, so that the transmission structure of the gear plate and the centrifugal pump body is compatible. S3. Start-stop test: Start the centrifugal pump body and control its high-frequency start-stop. Adjust the preload of the first limit structure by adjusting the preload adjustment bolt to suppress the radial movement of the bearing seat. The second limit structure absorbs the axial impact force through the annular damping groove of the rubber ring. Record the transmission stability data under different start-stop frequencies. S4. Variable load test: Adjust the load parameters of the centrifugal pump body to simulate the fluctuation of actual working conditions. Use the PTFE wear-resistant layer on the inner wall of the slide block through hole to reduce sliding friction. Cooperate with the guide column to achieve pump body self-centering. Adapt shaft system offset through universal coupling and collect head, flow rate and transmission efficiency data. S5. Durability test: Maintain continuous operation under rated conditions, reduce friction by relying on the groove of the soft pad and the cooperation of the wear-resistant grease, avoid fretting wear of the gear disk by radial preload of the first limiting structure and axial preload of the second limiting structure, record vibration values ​​and parameter drift data regularly, and monitor the meshing status of the gear disk through the anti-fog transparent plate of the observation window. S6. Data Acquisition and Analysis: Summarize the test data under various working conditions, compare the parameter changes under different pre-tightening conditions, eliminate the interference of wear on the test device itself, and obtain the true performance indicators of the centrifugal pump body. Beneficial effects

[0016] The present invention has the following beneficial effects: (1) The gear-driven centrifugal pump test device and test method solves the problem of multi-directional misalignment between the shaft system and the pump body during the operation of the test device by setting pre-tightening adjusting bolts, annular damping grooves, polytetrafluoroethylene wear-resistant layers and universal couplings, realizing precise alignment and stable transmission of the entire transmission chain, and avoiding transmission stiffness and aggravated wear of components.

[0017] (2) The gear-driven centrifugal pump test device and test method solves the problems of large friction and poor vibration buffering of traditional rigid limit by setting up a soft pad with honeycomb groove and wear-resistant grease, and achieves the effects of flexible limit, friction reduction and noise reduction and wear resistance and life extension, avoiding excessive wear of the bearing seat sidewall and excessive test noise.

[0018] (3) The gear-driven centrifugal pump test device and test method solves the problems of spring installation offset, preload fluctuation, secondary movement, test interruption and increased fit clearance by setting the connecting ring and bearing seat stepped structure, annular damping groove, anti-fog transparent plate and polytetrafluoroethylene wear-resistant layer. It achieves the effects of stable spring positioning, real-time monitoring of gear plate status and extended device life, and ensures accurate and reliable test data.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of a gear-driven centrifugal pump testing device according to the present invention; Figure 2 This is a schematic diagram of the structure of the centrifugal pump body and the mounting structure in this invention; Figure 3 This is a schematic diagram of the internal structure of the gearbox in this invention; Figure 4 This is a partial cross-sectional view of the first limiting structure in this invention; Figure 5 This is a schematic diagram of the structure of the soft pad in this invention; Figure 6 This is a partial structural diagram of the second limiting structure in this invention; Figure 7 This is a flowchart of a test method for a gear-driven centrifugal pump according to the present invention.

[0021] In the diagram: 1. Workbench; 2. Centrifugal pump body; 3. Mounting structure; 301. Base; 302. Limiting seat; 303. Guide column; 304. Compression spring; 305. Slide; 4. Connecting shaft; 5. Universal coupling; 6. Gearbox; 601. Housing; 602. Gear disc; 603. Bearing seat; 7. First limiting structure; 701. Arc plate; 702. Soft pad; 703. Connecting rod; 704. Connecting rod; 705. Hidden spring; 706. Preload adjusting bolt; 707. Groove; 8. Second limiting structure; 801. Butterfly spring; 802. Connecting ring; 803. Rubber ring. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below 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.

[0023] This invention provides a technical solution: a gear-driven centrifugal pump testing device, such as... Figures 1-6 As shown, the apparatus includes a workbench 1, a centrifugal pump body 2, and a gearbox 6. The centrifugal pump body 2 is connected to the workbench 1 via a mounting structure 3, and to the gearbox 6 via a universal coupling 5. The workbench 1 is the basic load-bearing component of the entire test setup. Its top is fixedly connected to the base 301 of the mounting structure 3 via M10 bolts, with the connection torque controlled between 35 and 40 N·m to ensure load-bearing stability. The centrifugal pump body 2, as the test piece, is fixed to the slide 305 of the mounting structure 3 at its bottom via M8 fasteners. Its power input end is coaxially connected to the output end of the drive shaft of the gearbox 6 via the universal coupling 5. The two ends of the universal coupling 5 are fixed to the input shaft of the centrifugal pump body 2 and the drive shaft of the gearbox 6 respectively via flat keys. The key clearance is controlled between 0.02 and 0.05 mm, which can compensate for the slight radial deviation within ±0.5 mm or the angular deviation within ±1° generated by the shaft system during the test, avoiding transmission stiffness or stress concentration of components caused by rigid connections.

[0024] The gearbox 6 includes a housing 601, which is a closed metal shell formed by bolting together Q235 steel plates. Sealant is applied to the joints to ensure internal dust prevention. Inside, a bearing housing 603 is vertically fixed by M6 bolts. The bearing housing 603 is made of cast aluminum, combining strength and lightweight. The connection gap between the bearing housing 603 and the inner wall of the housing 601 is less than 0.2 mm. A locating pin is used to assist in installation, ensuring that the radial installation deviation does not exceed 0.1 mm. A drive shaft is mounted in the center hole of the bearing housing 603 using a deep groove ball bearing. The drive shaft is interference-fitted with the inner ring of the bearing, with an interference of 0.01 to 0.03 mm, and can rotate freely relative to the bearing housing 603 at a speed not exceeding 3000 r / min. The outer wall of the drive shaft is fixed with a gear disc 602 by a flat key. The gear disc 602 is a tempered 45 steel part, and the tooth surface is carburized and quenched to a hardness of HRC58 to 62. It rotates synchronously with the drive shaft and is used to transmit the power of the gearbox 6 to the centrifugal pump body 2. The meshing clearance between its tooth profile and the input gear of the centrifugal pump body 2 is controlled at 0.15 to 0.2 mm.

[0025] The sidewall of the bearing housing 603 abuts against a first limiting structure 7, which is used to achieve radial flexible constraint and adjustable preload of the bearing housing 603. The first limiting structure 7 includes an arc-shaped plate 701 and a connecting rod 704. The arc-shaped plate 701 is a 65Mn spring steel plate with a thickness of 3 mm, which is adapted to the curvature of the side wall of the bearing housing 603. A soft pad 702 is bonded to its inner wall with polyurethane adhesive. The soft pad 702 is made of nitrile wear-resistant rubber with a thickness of 2 mm. The surface has hexagonal honeycomb grooves 707 with equal spacing. The side length of the groove is 2 mm and the depth is 1 mm. The groove is filled with lithium-based wear-resistant grease. The dropping point of the grease is not lower than 180°C. The honeycomb grooves can reduce the contact area between the soft pad 702 and the bearing housing 603 by about 30%. This reduces the frictional resistance during relative micro-movements and can store grease and buffer high-frequency vibrations. A connecting rod 703 is integrally fixed to the outer wall of the arc plate 701. The connecting rod 703 is a No. 45 steel round rod with a diameter of 8 mm. Its other end slides into the interior of the connecting rod 704 fixed to the side wall of the box shell 601. The connecting rod 704 is a hollow tubular structure with an inner diameter of 10 mm. It is welded and fixed to the inner wall of the box shell 601. A hidden spring 705 is also fixed in its cavity. The hidden spring 705 is a cylindrical helical spring with a wire diameter of 1.2 mm and a free length of 40 mm. The end of the connecting rod 704 away from the connecting rod 703 has an M8 internal thread hole, and a preload adjustment bolt 706 is threaded into the hole. The head of the bolt has a slotted structure, and the inner end of the bolt penetrates into the cavity of the connecting rod 704, abutting against the end of the hidden spring 705 away from the connecting rod 703.

[0026] During assembly, rotating the preload adjusting bolt 706 can change the initial compression of the hidden spring 705, with an adjustment range of 5 to 15 mm, thereby adjusting its preload force, corresponding to a preload force of 50 to 80 N. When the bearing housing 603 experiences radial slight movement due to vibration, it will push the arc plate 701 to drive the connecting rod 703 to compress or stretch the hidden spring 705. The elastic restoring force of the hidden spring 705 will push the arc plate 701 in the opposite direction, so that the soft pad 702 always fits against the side wall of the bearing housing 603, realizing radial flexible preload of the bearing housing 603. At the same time, the preload adjusting bolt can be adapted to centrifugal pump bodies 2 of different weights, with a weight range of 20 to 50 kg, ensuring the consistency of radial constraint effect.

[0027] The bearing housing 603 has a second limiting structure 8 at its end, which is used to achieve axial preload and impact buffering of the bearing housing 603. The second limiting structure 8 includes a butterfly spring 801 (model 65Mn-20×10×1.2) that abuts against the end of the bearing housing 603. A limiting ring is welded to the inner wall of the housing 601 to limit the edge of the butterfly spring 801. The inner diameter of the limiting ring is 20 mm, which matches the outer diameter of the butterfly spring 801. One end of the butterfly spring 801 is embedded in the limiting ring and abuts against the end face of the limiting ring, while the other end contacts the rubber ring 803. The second limiting structure 8 also includes a connecting ring 802 sleeved at the edge of the bearing housing 603. The connecting ring 802 is made of 304 stainless steel and has an inner diameter of 30 mm. The inner wall of 02 is fitted with a rubber ring 803 by butyl rubber adhesive. The rubber ring 803 is made of neoprene rubber and is 3 mm thick. Each end face of the rubber ring 803 has a V-shaped annular damping groove with a groove width of 1.2 mm and a depth of 1 mm. The bottom of the connecting ring 802 is engaged with the step structure preset at the end of the bearing seat 603. The radial width of the step is 2 mm, which is consistent with the wall thickness of the connecting ring 802, and can axially limit one end of the disc spring 801.

[0028] During assembly, after the connecting ring 802 is engaged with the step of the bearing housing 603, the disc spring 801 is compressed to a preset deformation of 2 mm, with an elastic force of approximately 60 N. This force is transmitted to the end of the bearing housing 603 through the rubber ring 803, achieving axial preload. When the bearing housing 603 experiences slight axial movement, the deformation of the disc spring 801 changes synchronously, and the elastic restoring force suppresses its axial displacement. At the same time, the annular damping groove of the rubber ring 803 deforms under force, absorbing axial impact energy through fluid damping effect. The impact absorption efficiency is increased by approximately 35%, preventing secondary movement caused by the rebound of the disc spring, and buffering the rigid impact between the spring and the bearing housing.

[0029] Mounting structure 3 is used to achieve self-centering and stable support of centrifugal pump body 2. It includes a base 301 fixed to the top of workbench 1 by M12 bolts. The base 301 is a Q235 rectangular metal base with a length of 400 mm and a width of 200 mm. A guide structure is fixed to the top of the base 301. The guide structure includes guide posts 303 symmetrically welded on both sides of the base 301. The guide posts 303 are smooth cylindrical rods made of No. 45 steel, with a diameter of 20 mm and a length of 350 mm. The surface of the guide posts is chrome-plated and the roughness is no greater than 0.8 μm. Both ends of the guide post 303 are fixed with limit seats 302 by M6 bolts. The limit seat 302 is a circular baffle with a diameter of 40 mm, which is used to limit the sliding stroke of the slide block 305. The maximum stroke is ±20 mm. The limit seat 302 is attached and fixed to the top surface of the base 301. Compression springs 304 are fitted onto both guide posts 303 with a clearance. The compression springs 304 are cylindrical helical springs with a wire diameter of 2 mm and a free length of 80 mm. A slide block 305 is also slidably connected to the outer wall of the guide post 303. The slide block 305 is made of aluminum alloy and has a length of 250 mm and a width of 150 mm. The bottom of the slide block 305 has a through hole that matches the guide post 303. The inner wall of the through hole is bonded with a polytetrafluoroethylene wear-resistant layer with a thickness of 0.8 mm and a friction coefficient of no more than 0.05, which can reduce the sliding friction between the slide block and the guide post and prevent wear of the through hole. The centrifugal pump body 2 is fixed to the top of the slide 305 by M8 bolts. The two ends of the compression spring 304 abut against the end face of the limit seat 302 and the side wall of the slide 305, respectively. In the initial state, the pre-compression of the compression spring 304 is 5 to 8 mm, corresponding to a pre-tightening force of 40 to 60 N.

[0030] When the shaft of the centrifugal pump body 2 is displaced due to transmission deviation, it will drive the slide 305 to slide along the guide post 303. The compression spring 304 in the corresponding direction will be further compressed, generating a reverse elastic restoring force. This restoring force pushes the slide 305 to reset the centrifugal pump body 2, realizing the pump body self-centering. At the same time, the polytetrafluoroethylene wear-resistant layer can ensure that the slide slides smoothly, the frictional resistance does not exceed 5N, and avoid the wear of the through hole after long-term use, which will cause the fit clearance to increase, maintaining a stable fit clearance of 0.1 to 0.2 mm.

[0031] An observation window is also provided on the side wall of the housing 601. The window is 100×80 mm in size and is fitted with a polycarbonate anti-fog transparent plate. The transparent plate is 3 mm thick and is coated with a nano anti-fog coating. This can prevent fogging caused by temperature changes inside the housing during the test and facilitate real-time observation of the meshing status and wear of the gear disc 602.

[0032] Test methods for gear-driven centrifugal pumps A test method for a gear-driven centrifugal pump, such as Figure 7 As shown, it includes the following steps: S1. Experiment Preparation Check the assembly accuracy of the workbench 1, centrifugal pump body 2, gearbox 6 and universal coupling 5: the connecting bolts between the workbench 1 and the base 301 are not loose, and the coaxiality deviation of the universal coupling 5 is less than 0.3 mm. Adjust the first limit structure 7: Rotate the preload adjusting bolt 706 to adjust the initial preload of the hidden spring 705 to a value that matches the weight of the centrifugal pump body 2. For example, if the pump body weighs 30kg, the preload should be adjusted to 65N. Check the condition of core components: the soft pad 702 is undamaged, the honeycomb groove 707 has sufficient grease, the elastic restoring force of the hidden spring 705, compression spring 304 and butterfly spring 801 meets the design requirements, there is no permanent deformation after compression, the annular damping groove of the rubber ring 803 is not blocked, the connecting ring 802 provides stable limiting for the butterfly spring 801, and the slide 305 slides smoothly.

[0033] S2. Device Assembly The centrifugal pump body 2 is fixed to the top mounting surface of the slide 305 with M8 bolts, so that the slide 305 is slidably sleeved on the guide post 303, ensuring that the slide slides smoothly without jamming. The two ends of the compression spring 304 are in close contact with the limit seat 302 and the slide 305, and the pre-compression is maintained at 5 to 8 mm. The centrifugal pump body 2 is connected to the power input end of the gearbox 6 via a universal coupling 5. The connection position is adjusted so that the gear plate 602 and the centrifugal pump input gear are precisely meshed, with the meshing gap controlled between 0.15 and 0.2 mm, and there is no jamming.

[0034] S3. Start-stop test Start the centrifugal pump body 2 and control it to start and stop at a high frequency of 30 to 50 times per hour; The preload of the hidden spring 705 is adjusted by the preload adjusting bolt 706 in a gradient manner. The gradient values ​​are 50N, 65N, and 80N. The radial movement of the bearing housing 603 under different preloads is recorded, and the movement is controlled within 0.1 mm. The second limiting structure 8 absorbs axial impact through the annular damping groove of the rubber ring 803, and simultaneously records transmission noise (noise value not exceeding 75dB), as well as stability data such as shaft vibration amplitude (vibration amplitude not exceeding 0.05mm).

[0035] S4. Variable Load Test By adjusting the opening of the outlet valve of the centrifugal pump body 2, a load fluctuation of 10% to 110% is simulated. The wear-resistant polytetrafluoroethylene layer on the inner wall of the through hole of the slide block 305 reduces sliding friction, and the guide column 303 enables the pump body to self-align. The universal coupling 5 compensates for shaft misalignment. Head, flow rate, and transmission efficiency data were collected at 5% load intervals, for a total of 21 sets of data.

[0036] S5. Durability Test Maintain the centrifugal pump body under rated operating conditions for continuous operation for no less than 1000 hours; Friction is reduced by the cooperation of the honeycomb grooves 707 of the soft pad 702 and the grease. The radial pre-tightening of the first limiting structure 7 and the axial pre-tightening of the second limiting structure 8 prevent the fretting wear of the gear disk 602. Record shaft vibration values ​​and gear meshing clearance every 24 hours. Monitor gear wear through the anti-fog transparent plate in the observation window. Wear amount should not exceed 0.02 mm.

[0037] S6. Data Acquisition and Analysis Summarize data from various operating conditions and establish an error calibration model; Excluding the interference of wear on the test device itself, such as the wear of the slide wear layer not exceeding 0.01 mm, the true performance indicators of the centrifugal pump body 2 are obtained through data fitting: rated efficiency not less than 85%, start-stop reliability of 500 consecutive start-stop cycles without failure, and durability life of not less than 8000 hours.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A gear-driven centrifugal pump test device characterized by, include: The centrifugal pump body (2) and the gearbox (6) are connected to the workbench (1) via an installation structure (3) and to the gearbox (6) via a universal coupling (5). The gearbox (6) includes a housing (601), and a bearing seat (603) is fixed inside the housing (601). A drive shaft is installed in the bearing seat (603) through a bearing, and a gear disc (602) is fixed on the drive shaft. The sidewall and end of the bearing housing (603) respectively abut against the first limiting structure (7) and the second limiting structure (8). The first limiting structure (7) includes an arc-shaped plate (701) that abuts against the side wall of the bearing seat (603) and a connecting rod (704) fixed to the side wall of the housing (601). One end of the arc-shaped plate (701) is fixedly provided with a connecting rod (703). One end of the connecting rod (703) is slidably connected to the inside of the connecting rod (704). A hidden spring (705) is fixedly provided inside the connecting rod (704). One end of the connecting rod (703) abuts against the hidden spring (705). The connecting rod (704) has an internal threaded hole at one end away from the connecting rod (703). The internal threaded hole is connected to a preload adjusting bolt (706). The inner end of the preload adjusting bolt (706) extends into the connecting rod (704) and abuts against the end of the hidden spring (705) away from the connecting rod (703), which is used to adjust the initial preload of the hidden spring (705). The second limiting structure (8) includes a butterfly spring (801) that abuts against the end of the bearing housing (603).

2. A gear-driven centrifugal pump test facility according to claim 1, wherein: The inner wall of the housing (601) is fixed with a limiting ring that limits the edge of the butterfly spring (801), and the other end of the butterfly spring (801) is located inside the limiting ring and abuts against the limiting ring.

3. A gear-driven centrifugal pump test facility according to claim 2, wherein: The second limiting structure (8) also includes a connecting ring (802) sleeved at the end edge of the bearing housing (603); The inner wall of the connecting ring (802) is fitted with a rubber ring (803), and each end face of the rubber ring (803) is provided with an annular damping groove. The disc spring (801) abuts against the end of the bearing seat (603) through the rubber ring (803). The connecting ring (802) is snapped onto the end step structure of the bearing seat (603) to axially limit one end of the disc spring (801).

4. A gear-driven centrifugal pump test facility according to claim 3, wherein: The inner wall of the arc plate (701) is bonded with a soft pad (702), and grooves (707) are equally spaced on the soft pad (702). The grooves (707) are filled with wear-resistant grease, and the soft pad (702) is in contact with the bearing seat (603).

5. A gear-driven centrifugal pump test facility according to claim 4, wherein: The mounting structure (3) includes a base (301) fixed on the top of the workbench (1), a guide structure is fixed on the top of the base (301), and a slide (305) is slidably connected on the guide structure. The centrifugal pump body (2) is fixed on the slide (305).

6. A gear-driven centrifugal pump test facility according to claim 5, wherein: The guide structure includes guide columns (303) symmetrically installed on both sides of the base (301), and each end of the guide column (303) is fixedly provided with a limiting seat (302), and the limiting seat (302) is fixedly connected to the base (301). Compression springs (304) are fitted onto both guide posts (303), and the two ends of the compression springs (304) abut against the side walls of the limiting seat (302) and the slide (305), respectively. The slide (305) has a through hole adapted to the guide post (303), and the inner wall of the through hole is bonded with a polytetrafluoroethylene wear-resistant layer.

7. A gear-driven centrifugal pump test facility according to claim 6, wherein: An observation window is also provided on the side wall of the housing (601), and an anti-fog transparent plate is embedded in the observation window.

8. A method of testing a gear driven centrifugal pump, for use in a test apparatus as claimed in claim 7, characterized in that: Includes the following steps: S1. Test preparation: Check the assembly accuracy of the workbench (1), centrifugal pump body (2), gearbox (6) and universal coupling (5), adjust the initial preload of the hidden spring (705) by adjusting the preload adjusting bolt (706), ensure that the soft pad (702) on the inner wall of the arc plate (701) is undamaged, the wear-resistant grease in the groove (707) is sufficient, the elastic properties of the hidden spring (705), compression spring (304) and butterfly spring (801) are intact, the annular damping groove of the rubber ring (803) is not blocked, and the limiting state of the connecting ring (802) on the butterfly spring (801) is stable; S2. Assembly: Fix the centrifugal pump body (2) on the slide (305), so that the slide (305) is slidably sleeved on the guide columns (303) on both sides of the base (301), ensuring that the two ends of the compression spring (304) abut against the limit seat (302) and the side wall of the slide (305) respectively; connect the centrifugal pump body (2) and the power input end of the gearbox (6) through the universal coupling (5), so that the gear plate (602) and the transmission structure of the centrifugal pump body (2) are adapted. S3. Start-stop test: Start the centrifugal pump body (2), control its high-frequency start-stop, adjust the preload of the first limiting structure (7) by the preload adjusting bolt (706) to suppress the radial movement of the bearing seat (603), and the second limiting structure (8) absorbs the axial impact force through the annular damping groove of the rubber ring (803). Record the transmission stability data under different start-stop frequencies. S4. Variable load test: Adjust the load parameters of the centrifugal pump body (2) to simulate the fluctuation of actual working conditions. Use the polytetrafluoroethylene wear-resistant layer on the inner wall of the slide (305) through hole to reduce sliding friction. Cooperate with the guide column (303) to realize the pump body self-centering. Adapt the shaft system offset through the universal coupling (5) and collect head, flow rate and transmission efficiency data. S5. Durability test: Maintain continuous operation under rated conditions, reduce friction by relying on the groove (707) of the soft pad (702) and the wear-resistant grease, avoid fretting wear of the gear disc (602) by radial pre-tightening of the first limiting structure (7) and axial pre-tightening of the second limiting structure (8), record vibration values ​​and parameter drift data periodically, and monitor the meshing state of the gear disc (602) through the anti-fog transparent plate of the observation window; S6. Data acquisition and analysis: Summarize the test data under various working conditions, compare the parameter changes under different pre-tightening conditions, eliminate the interference of wear of the test device itself, and obtain the true performance index of the centrifugal pump body (2).

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