A check stopper monitoring device based on an L-shaped vibration guide link and a mounting method thereof

Abstract

The application relates to the technical field of check valve application, in particular to a check valve monitoring device based on an L-shaped vibration-guiding connecting rod and a mounting method thereof. The check valve monitoring device comprises a check valve shell, an L-shaped vibration-guiding connecting rod and a vibration acceleration sensor. The L-shaped vibration-guiding connecting rod comprises a first arm and a second arm, one end of the first arm is connected with the check valve shell, the other end of the first arm is connected with one end of the second arm, and the vibration acceleration sensor is arranged on the other end of the second arm. The abnormal vibration generated during the operation of the check valve can be transmitted to the vibration acceleration sensor through the first arm and the second arm by arranging the L-shaped vibration-guiding connecting rod. Compared with directly fixing the sensor on the surface of the shell, the structure can consider the local normal impact vibration of the shell and the structural vibration propagating along the shell, and the sensing sensitivity to the operation abnormalities of the check valve, such as insufficient lubrication, abnormal wear, loose installation and sudden impact, is improved.

Description

Technical Field

[0001] This application relates to the field of backstop application technology, specifically to a backstop monitoring device based on an L-shaped vibration guide rod and its installation method. Background Technology

[0002] A backstop is a safety protection device used to prevent transmission equipment from rotating in the opposite direction or running backwards. It is commonly used in belt conveyors, hoisting equipment, mining transportation equipment, coal washing plant conveying systems, and other mechanical transmission systems that require preventing reverse slippage of the load. When the equipment stops, the load is reversed, or reverse torque occurs, the backstop can limit the reverse movement of the transmission components, thereby preventing material slippage, transmission system impact, and equipment damage.

[0003] During long-term operation, check valves are prone to abnormal vibrations due to factors such as changes in lubrication conditions, component wear, reverse impact loads, and loose installation. For example, insufficient lubrication or dry running with insufficient oil increases friction between internal contact pairs, easily generating continuous frictional vibrations; abnormal impacts between wedges, rollers, cages, or inner rings can easily generate sudden impact vibrations; loose installation or uneven stress on the housing can easily generate knocking vibrations or structural vibrations propagating along the housing. The propagation directions of these abnormal vibrations are not the same. Some abnormal vibrations cause the check valve housing to vibrate approximately perpendicular to the housing surface in the normal direction, while others propagate along the wall, circumferential direction, or installation connection direction of the check valve housing.

[0004] Current vibration monitoring methods for backstops typically involve directly fixing a vibration sensor to a specific detection position on the backstop housing. Changes in vibration at that position are then used to determine if the backstop is malfunctioning. While this method can obtain local vibration signals, the relatively fixed sensor position and direction make it difficult to simultaneously and effectively detect vibrations perpendicular to the housing surface and vibrations propagating along the housing. When abnormal vibrations primarily propagate along the housing surface, directly mounted sensors may not adequately respond to vibrations in that direction; conversely, when abnormal vibrations mainly manifest as impacts to the housing's normal direction, detection structures simply positioned along the housing's propagation path may struggle to fully detect these impacts. Therefore, existing directly fixed vibration monitoring structures cannot establish stable and effective pickup paths for multi-directional abnormal vibrations in backstops.

[0005] Therefore, a monitoring structure is needed that can guide abnormal vibrations in different directions generated by the backstop housing to a vibration acceleration sensor, so that the sensor can not only sense the local normal impact vibration of the housing, but also receive abnormal vibrations propagating along the housing through the vibration guiding structure, thereby improving the monitoring sensitivity and reliability of abnormal vibrations during backstop operation. Summary of the Invention

[0006] To address the above problems, the present invention provides a backstop monitoring device based on an L-shaped vibration guide rod, comprising a backstop housing, an L-shaped vibration guide rod, and a vibration acceleration sensor; the L-shaped vibration guide rod comprises a first arm and a second arm, one end of the first arm is connected to the backstop housing, the other end of the first arm is connected to one end of the second arm, and the vibration acceleration sensor is disposed on the other end of the second arm.

[0007] In this invention, the L-shaped vibration guiding link can form a composite vibration pickup effect for abnormal vibrations propagating in different directions from the backstop housing. For local normal vibrations of the housing caused by impacts, knocks, or dry grinding inside the backstop, this vibration acts approximately perpendicular to the housing surface at the connection between the first arm and the housing, causing the first arm to experience instantaneous pushing, pulling, bending, or root swinging, which is then transmitted to the second arm via the bent connection. Because the second arm is bent relative to the first arm, normal impacts easily generate a significant swinging acceleration or bending acceleration response at the end of the second arm, which is then detected by the vibration acceleration sensor located at the end of the second arm. For abnormal vibrations propagating along the housing wall, circumferentially, or axially, after propagating to the connection between the first arm and the housing, this vibration first causes the first arm to vibrate axially or tangentially with the housing, and then is transmitted to the end of the second arm through the bent connection between the first and second arms. Therefore, the L-shaped vibration guide rod can transmit the normal impact vibration of the shell and the structural vibration propagating along the shell to the vibration acceleration sensor through the response of the second arm and the introduction of the first arm, respectively. This allows the continuous friction vibration caused by insufficient lubrication, the periodic impact caused by abnormal wear, the shell micro-movement caused by loose installation, and the sudden impact vibration generated at the moment of backstop to be monitored, thereby improving the sensitivity and reliability of abnormal vibration monitoring of the backstop.

[0008] Furthermore, the first arm extends away from the backstop housing, while the second arm is bent relative to the first arm, creating a directional-converting vibration-guiding path between the backstop housing and the vibration acceleration sensor using the L-shaped vibration-guiding link. Specifically, the first arm extends outward from the backstop housing, drawing out localized normal impact vibrations from the backstop housing and structural vibrations propagating along the housing to the connection point from the housing surface, reducing the impact of mounting surface shape, oil contamination, and localized interference when the sensor is directly attached to the housing. The bent second arm further converts the vibrations introduced by the first arm into bending, oscillation, or acceleration responses at the end of the second arm, making it easier for the vibration acceleration sensor located at the end of the second arm to detect abnormal signals such as sudden impacts, continuous frictional vibrations, and minor movements due to loose installation. Thus, this structure expands the pickup range for abnormal vibrations in different directions and guides vibration signals to a more suitable location for sensor placement, improving the sensitivity, installation convenience, and signal stability of backstop malfunction monitoring.

[0009] Furthermore, a sensor mounting block is provided at the end of the second arm furthest from the first arm. The vibration acceleration sensor is fixedly mounted on the sensor mounting block, providing a flatter and more stable mounting reference for the vibration acceleration sensor. This avoids problems such as insecure fixation, insufficient contact area, or installation angle deviation that can occur when the sensor is directly mounted on the thinner second arm. At the same time, the sensor mounting block can also serve as a local mass and vibration guide at the end of the second arm, enabling the vibration transmitted through the first and second arms to form a more stable acceleration response at the sensor mounting position. This improves the stability and repeatability of the sensor in collecting sudden impact vibrations, friction vibrations, and vibrations caused by loose mounting.

[0010] Furthermore, the vibration accelerometer employs a triaxial vibration accelerometer, which can simultaneously acquire vibration acceleration components in three mutually perpendicular directions, making it more suitable for the complex abnormal vibration directions of the backstop. For normal impact vibrations approximately perpendicular to the shell surface, the triaxial sensor can acquire their corresponding normal acceleration components; for abnormal vibrations propagating along the shell wall, circumferentially, or axially, the triaxial sensor can acquire their corresponding tangential, axial, or transverse vibration components. Simultaneously, since the L-shaped vibration guide rod couples and converts vibrations in different directions between the first arm, the bend, and the second arm, the vibration transmitted to the end of the second arm often exhibits a composite acceleration response. Using a triaxial vibration accelerometer avoids the possibility of single-axis sensors missing some abnormal vibrations due to their unidirectional installation, thereby improving the comprehensive sensing capability for normal impact vibrations and vibrations propagating along the shell.

[0011] Furthermore, the normal direction of the plane containing the L-shaped vibration guide rod is parallel to the axial direction of the backstop housing, which is equivalent to arranging the first and second arms mainly within a radial-circumferential section perpendicular to the backstop axis. Since the abnormal vibrations of the backstop often include radial impact components and vibration components propagating circumferentially along the housing when it experiences backstop action, wedge or roller impact, cage knocking, dry grinding due to lack of lubrication, or loose installation, arranging the L-shaped vibration guide rod within this section facilitates the first arm in picking up radial or normal vibrations of the housing, while the second arm senses vibration responses transmitted circumferentially or converted by bending structures. This allows the L-shaped vibration guide rod to better align with the propagation direction and force path of typical abnormal vibrations of the backstop, improving the sensitivity and reliability of picking up instantaneous backstop impacts, circumferential knocking, bottom micro-motion, and dry grinding vibrations.

[0012] Furthermore, setting the cross-sectional area of ​​the first arm to be larger than that of the second arm allows the first arm to have higher stiffness and connection strength, thus forming a stable vibration induction end at its connection with the backstop housing. This reduces energy loss and connection deformation when housing vibration is transmitted to the L-shaped vibration guide link. Simultaneously, the smaller cross-sectional area of ​​the second arm results in relatively higher vibration response sensitivity. Upon receiving normal impact vibration transmitted from the first arm or abnormal vibration propagating along the housing, it is more likely to generate detectable bending, swaying, or acceleration responses at the sensor mounting end. This creates a vibration guide structure with a rigid first arm for induction and a sensitive second arm for response, ensuring a stable vibration transmission path and improving the vibration acceleration sensor's sensitivity to sudden impacts, frictional vibrations, and vibrations caused by loose installation.

[0013] Furthermore, the first arm, made of alloy steel, stainless steel, or high-strength aluminum alloy, enhances the structural strength and vibration-guiding stiffness at the connection between the first arm and the backstop housing, ensuring that normal impact vibrations generated by the housing and abnormal vibrations propagating along the housing can be stably guided to the L-shaped vibration-guiding link. The second arm, made of spring steel, beryllium copper, titanium alloy, or elastic aluminum alloy, generates a more pronounced and recoverable elastic vibration response after receiving vibrations transmitted by the first arm, enhancing the acceleration changes at the sensor mounting end. This creates a material matching relationship between a high-stiffness first arm for stable vibration guidance and an elastic second arm for sensitive vibration pickup, improving the sensitivity to sudden impacts, frictional vibrations, and loosening vibrations while ensuring structural reliability.

[0014] Furthermore, the backstop housing is fixedly mounted on the base, and an open cavity is provided within the base. The first arm passes through the opening, and the second arm and vibration acceleration sensor are housed within the cavity. This allows the housing vibration to be introduced into the base for detection via the first arm without affecting the normal installation and operation of the backstop housing. On one hand, the base is a crucial transmission point for the backstop's operating load and abnormal vibrations. The first arm, passing through the opening, can guide the normal impact vibration generated by the backstop housing, as well as abnormal vibrations propagating along the housing, into the cavity. On the other hand, the second arm and vibration acceleration sensor being located within the cavity prevent the sensor from being directly exposed to external oil, dust, moisture, collisions, and maintenance interference, improving the sensor's installation stability and protection reliability. Simultaneously, the cavity provides space to accommodate the vibration response of the second arm, enabling it to generate detectable bending, swaying, or acceleration responses when subjected to abnormal vibration excitation, thereby improving the sensitivity and long-term stability of monitoring abnormal vibrations during backstop operation.

[0015] Furthermore, an annular elastic section is provided at the opening, surrounding the first arm. This creates an elastic seal and flexible support at the point where the first arm penetrates the base cavity opening. On one hand, this prevents oil, dust, and moisture from entering the cavity, protecting the second arm and vibration acceleration sensor located within it. On the other hand, the elastic contact between the annular elastic section and the first arm provides limitation and support for the first arm, preventing excessive free swinging at the opening. More importantly, different types of abnormal vibrations have different frequency characteristics, and the conduction and attenuation effects of the annular elastic section vary depending on the frequency: for low-frequency vibrations such as loose installation or slight movement of the housing, the annular elastic section allows the first arm to undergo follow-up displacement, enabling the low-frequency vibration to be transmitted to the second arm more stably; for medium- and high-frequency vibrations such as sudden impacts or dry friction, the annular elastic section can filter out external stray vibrations and invalid noise to a certain extent, while retaining the main abnormal vibration components transmitted through the rigid path of the first arm. Therefore, the annular elastic part not only serves as a sealing and protective element, but also forms an elastic vibration guiding / limiting structure with a certain frequency selectivity at the opening of the first arm, thereby improving the stability and anti-interference capability of the monitoring signal.

[0016] On the other hand, the present invention provides an installation method for a backstop monitoring device based on an L-shaped vibration guiding link, comprising the following steps: Step 1: Prefabricate L-shaped vibration guiding rod: Connect one end of the first arm to one end of the second arm in advance to form an L-shaped vibration guiding rod between the first arm and the second arm; Step 2: Install the vibration acceleration sensor: Fix the vibration acceleration sensor on the end of the second arm furthest from the first arm; Step 3: Fix the L-shaped vibration guide rod: Fix the L-shaped vibration guide rod with the vibration acceleration sensor installed as a whole to the backstop housing, so that the end of the first arm away from the second arm is connected to the backstop housing.

[0017] The beneficial effects of this invention are: (1) The present invention provides an L-shaped vibration guide rod between the backstop housing and the vibration acceleration sensor, so that abnormal vibrations generated during the operation of the backstop can be transmitted to the vibration acceleration sensor via the first and second arms. Compared with directly fixing the sensor to the housing surface, this structure can take into account both the local normal impact vibration of the housing and the structural vibration propagating along the housing, thereby improving the sensitivity to detecting abnormalities in the backstop such as insufficient lubrication, abnormal wear, loose installation, and sudden impacts.

[0018] (2) In this invention, the L-shaped vibration guide rod forms a clear vibration transmission path. Through this transmission path, the sensor no longer relies solely on the local vibration response of a certain point on the housing, but can receive the vibration signal transmitted and coupled by the vibration guide rod. This helps to reduce the influence of differences in detection position, local morphology of the housing, or mounting status on the monitoring results, and improves the stability and repeatability of vibration signal acquisition.

[0019] (3) The present invention only requires connecting the first arm to the backstop housing and setting the vibration acceleration sensor at the end of the second arm to form a monitoring structure. It does not require modification of the internal transmission components, wedges, rollers, cages or lubrication structures of the backstop. Therefore, the installation method of this solution is simple and easy to add or modify to the existing backstop housing, and has good engineering adaptability.

[0020] (4) This invention mainly utilizes an L-shaped vibration guide rod and a vibration acceleration sensor to monitor the operating status. The structure is simple, with few parts, and does not require complex multi-point sensor arrays or large online diagnostic equipment. The vibration pickup effect can be enhanced through a single vibration guide structure, which helps to reduce manufacturing costs, installation costs, and subsequent maintenance costs.

[0021] (5) Since the vibration acceleration sensor is located at the end of the second arm, it does not have to directly bear the effects of oil stains, thermal shock, friction contact or maintenance collisions on the surface of the backstop housing. At the same time, the L-shaped vibration guide rod can guide the housing vibration to the sensor position, reducing the loosening, failure to fit or poor contact problems that may occur when the sensor is directly installed on the housing, thereby improving the reliability of the sensor connection and the service life of the monitoring device.

[0022] (6) The monitoring component of the present invention is located outside the backstop housing, which facilitates inspection, disassembly and replacement. When the vibration acceleration sensor or L-shaped vibration guide rod needs maintenance, there is no need to disassemble the internal structure of the backstop, which can reduce the difficulty of downtime maintenance and repair time, and is suitable for equipment scenarios that require continuous operation, such as mine conveying and coal washing plant conveying.

[0023] Based on the above beneficial effects, this invention has good application prospects in the field of backstop application technology. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a backstop monitoring device based on an L-shaped vibration guide rod.

[0025] Figure 2 This is a schematic diagram of another backstop monitoring device based on an L-shaped vibration guide rod.

[0026] Figure 3 This is a flowchart of the installation method for a backstop monitoring device based on an L-shaped vibration guide rod.

[0027] In the diagram: 1. Backstop housing; 2. L-shaped vibration guide rod; 21. First arm; 22. Second arm; 3. Vibration acceleration sensor; 4. Base; 5. Cavity. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided with reference to the accompanying drawings and embodiments. Example 1

[0029] This embodiment provides a backstop monitoring device based on an L-shaped vibration guiding link, such as... Figure 1 As shown, the monitoring device includes a backstop housing 1, an L-shaped vibration guide rod 2, and a vibration acceleration sensor 3. The L-shaped vibration guide rod 2 is located on the outside of the backstop housing 1, preferably on the lower side of the backstop housing 1 or near the fixed part of the backstop, so that it can better receive abnormal vibrations transmitted from the housing during the operation of the backstop.

[0030] The L-shaped vibration guide rod 2 includes a first arm 21 and a second arm 22. One end of the first arm 21 is fixedly connected to the backstop housing 1, and the other end of the first arm 21 is connected to one end of the second arm 22. The vibration acceleration sensor 3 is disposed on the end of the second arm 22 away from the first arm 21. The first arm 21 and the second arm 22 can be integrally bent and formed, or they can be separately processed and then fixedly connected by welding, threaded connection, riveting, interference fit, or screw tightening. In this embodiment, the first arm 21 and the second arm 22 are preferably integrally formed L-shaped metal vibration guides to reduce the attenuation of vibration transmission due to the connection gap.

[0031] The first arm 21 extends away from the backstop housing 1, and the second arm 22 is bent relative to the first arm 21. The included angle between the first arm 21 and the second arm 22 is preferably 80°-100°, more preferably 90°. Through this bent structure, the first arm 21 can receive the normal impact vibration at the backstop housing 1 and the structural vibration propagating along the housing to the connection position. The second arm 22 can further transmit the vibration introduced by the first arm 21 to the location of the vibration acceleration sensor 3, so that the sensor end forms a more obvious acceleration response.

[0032] In this embodiment, one end of the first arm 21 is connected to the backstop housing 1 via a mounting base. Specifically, a connecting plane or connecting boss is provided on the outer surface of the backstop housing 1, and a mounting hole is provided at the end of the first arm 21 near the backstop housing 1. The first arm 21 is pressed and fixed to the backstop housing 1 by bolts. M6-M10 high-strength bolts can be used. A metal washer or vibration-guiding washer with a thickness of 0.1mm-0.5mm can be provided between the first arm 21 and the backstop housing 1 to improve contact flatness and vibration guidance stability. To reduce loosening of the connection, spring washers, anti-reverse washers, or thread-locking adhesive can be provided at the bolts.

[0033] Furthermore, a toothed, interlocking vibration-guided contact surface is provided between the connecting end of the first arm 21 and the backstop housing 1 or the housing connecting seat. Fine teeth, micro-protrusions, shallow grooves, or coarsened interlocking structures are formed on the mating surface of the first arm 21 connecting end and / or the corresponding mating surface of the housing connecting seat. When the first arm 21 is pressed and fixed to the housing connecting seat by bolts, pressure plates, or other fasteners, the teeth or micro-protrusions can interlock or form local interlocking contact, thereby increasing the actual contact stability and anti-slip capability between the two. Compared with planar mating, the toothed, interlocking vibration-guided contact surface can reduce the micro-movements, loosening, or contact gap changes between the connecting end of the first arm 21 and the housing connecting seat under long-term operating vibration of the backstop. This allows abnormal vibrations propagating along the circumferential, axial, or tangential direction on the housing surface to be transmitted more stably to the first arm 21 and then to the vibration acceleration sensor 3 via the L-shaped vibration-guided connecting rod 2, thereby improving the pickup stability and monitoring reliability of signals from loose installation, abnormal wear, and impact vibrations.

[0034] The length of the first arm 21 is 20mm-80mm; the length of the second arm 22 is 25mm-100mm. The lengths of the first arm 21 and the second arm 22 should not be too long to avoid excessive self-oscillation or low-frequency resonance of the L-shaped vibration guide rod 2; at the same time, they should not be too short to ensure that the vibration acceleration sensor has sufficient installation space and vibration pickup distance.

[0035] To form a rigid, sensitive vibration-guiding structure, the cross-sectional area of ​​the first arm 21 is larger than that of the second arm 22. Specifically, the first arm 21 has a rectangular cross-section with a width of 8mm-20mm and a thickness of 4mm-10mm; the second arm 22 also has a rectangular cross-section with a width of 5mm-15mm and a thickness of 2mm-6mm. Preferably, the cross-sectional area of ​​the first arm 21 is 1.2 to 3 times that of the second arm 22. This gives the first arm 21 higher rigidity, enabling it to stably receive and guide the vibration of the backstop housing 1; and the second arm 22 has relatively higher vibration response sensitivity, allowing it to generate a more pronounced acceleration response at the sensor end.

[0036] In terms of materials, the first arm 21 is made of alloy steel, stainless steel, or high-strength aluminum alloy, and the second arm 22 is made of spring steel, beryllium copper, titanium alloy, or elastic aluminum alloy. Preferably, the first arm 21 is made of 40Cr alloy steel or 304 stainless steel, and the second arm 22 is made of 65Mn spring steel, beryllium copper, or TC4 titanium alloy. Using a high-rigidity material for the first arm 21 is beneficial for improving the vibration-guiding stiffness and fatigue resistance at the connection with the backstop housing; using a material with good elastic response for the second arm 22 is beneficial for enhancing the response to sudden impact vibration, friction vibration, and installation loosening vibration. If the first arm 21 and the second arm 22 are separate structures, they can be connected by welding or threaded locking; if they are an integral structure, the second arm 22 can have a higher elastic response than the first arm 21 through local heat treatment, cross-sectional thinning, or material composite methods.

[0037] Furthermore, the bend connection between the first arm 21 and the second arm 22 is preferably designed as a rounded transition structure with a radius of 3mm-15mm to reduce stress concentration at the bend and improve the fatigue life of the L-shaped vibration guiding link 2. Reinforcing ribs or thickened sections can also be provided on the outer side of the bend connection, with a thickness of 2mm-6mm, to improve structural stability under sudden impact vibration.

[0038] Furthermore, a window-type elastic zone is provided in the middle of the second arm 22. Specifically, an oblong, elliptical, or rounded rectangular window is provided on the second arm 22, forming a parallel elastic beam structure on both sides of the window area. Through this structure, after receiving normal impact vibrations transmitted from the first arm 21, structural vibrations propagating along the shell, or fretting vibrations caused by loose installation, the second arm 22 can generate a more significant elastic bending response in the window area, thereby making it easier to detect acceleration changes at the end of the second arm 22 away from the first arm 21 and on the vibration acceleration sensor 3 thereon. At the same time, the parallel elastic beams on both sides can still provide necessary lateral support and torsional stability for the sensor mounting end, preventing unstable swaying caused by excessive thinning of the second arm 22. Thus, this window-type elastic zone can improve the response sensitivity to small abnormal vibrations and early fault vibrations while ensuring the structural reliability of the second arm 22, enhancing the stability and reliability of the backstop's operating status monitoring.

[0039] A sensor mounting block is provided at the end of the second arm 22 furthest from the first arm 21, and the vibration acceleration sensor 3 is fixedly mounted on the sensor mounting block. The sensor mounting block can be integrally formed with the second arm 22, or it can be fixed to the end of the second arm 22 by welding, screws, press-fitting, or gluing. The sensor mounting block is preferably a rectangular block, a cylindrical block, or a stepped block, with a length of 10mm-30mm, a width of 10mm-25mm, and a thickness of 5mm-15mm. The upper surface of the sensor mounting block is machined into a flat mounting surface, and the flatness of the mounting surface is preferably no greater than 0.05mm to ensure a stable fit between the vibration acceleration sensor and the mounting surface.

[0040] The vibration acceleration sensor 3 is preferably a triaxial vibration acceleration sensor with a range of ±16g, ±32g, or ±50g, and a sampling frequency preferably not less than 1kHz; for scenarios requiring monitoring of sudden impacts, the sampling frequency can be further increased to 20kHz. The sensor can be fixed to the sensor mounting block by screw tightening, cap tightening, adhesive bonding, or potting. Preferably, M3-M5 threaded holes are provided on the sensor mounting block, and the vibration acceleration sensor 3 is fixed to the sensor mounting block using M4 screws. A thin layer of vibration-guiding adhesive with a thickness of 0.05mm-0.2mm is applied between the sensor and the mounting surface to improve the vibration coupling effect between the sensor and the sensor mounting block.

[0041] The working principle of the triaxial vibration accelerometer is as follows: when the L-shaped vibration guide rod 2 transmits the abnormal vibration of the backstop housing 1 to the sensor installation position, the inertial mass unit inside the sensor will generate an inertial effect or a small displacement relative to the sensor housing. The sensitive element then converts this inertial effect into an electrical signal output, and obtains vibration acceleration components in three mutually perpendicular directions. Based on this working principle, piezoelectric, piezoresistive, and MEMS capacitive triaxial vibration accelerometers can all be applied to this invention; among them, the piezoelectric triaxial vibration accelerometer has better response to sudden impacts, high-frequency friction vibrations, and structural vibrations, and is more suitable for monitoring impact faults and dry grinding vibrations in industrial backstops, thus it is the preferred solution; in applications with high requirements for size, cost, and integration, the MEMS capacitive triaxial vibration accelerometer is preferred.

[0042] In terms of installation direction, the normal direction of the plane containing the L-shaped vibration guide rod 2 is parallel to the axial direction of the backstop housing 1. That is, the first arm 21 and the second arm 22 are mainly arranged within a section perpendicular to the backstop axis. This arrangement allows the L-shaped vibration guide rod 2 to better receive radial or normal impact vibrations from the backstop housing 1, as well as structural vibrations propagating circumferentially around the housing. For a triaxial vibration acceleration sensor, one sensitive axis can be positioned along the extension direction of the second arm 22, another sensitive axis along the extension direction of the first arm 21, and the third sensitive axis along the axial direction of the backstop housing 1. This allows for the simultaneous acquisition of vibration acceleration components in the directions of the second arm 22, the first arm 21, and the axial direction.

[0043] During operation, when the backstop is running normally, the vibration generated by the backstop housing 1 is transmitted to the vibration acceleration sensor 3 via the first arm 21 and the second arm 22, forming a normal operation vibration signal. When the backstop experiences insufficient lubrication, abnormal wear, loose installation, or sudden impact, the abnormal vibration generated by the backstop housing 1 may manifest as a localized normal impact vibration perpendicular to the housing surface, or it may propagate along the housing wall, circumferentially, or in the installation connection direction. After reaching the connection point between the first arm 21 and the backstop housing 1, the vibration is guided through the first arm 21 to the L-shaped vibration guide rod 2, and undergoes directional conversion and coupling through the bending structure between the first arm 21 and the second arm 22, causing a corresponding acceleration response at the end of the second arm 22 and the sensor mounting block. After acquiring this acceleration response, the vibration acceleration sensor 3 can output a vibration signal used to determine the operating status of the backstop.

[0044] This embodiment, through the aforementioned structure, establishes a clear vibration guiding path between the L-shaped vibration guiding link 2 and the vibration acceleration sensor 3. On one hand, the first arm 21 possesses high rigidity, enabling it to stably receive abnormal vibrations transmitted from the backstop housing 1; on the other hand, the second arm 22 exhibits high response sensitivity, amplifying or enhancing the detectable response of abnormal vibrations at the sensor end. Therefore, this embodiment improves the monitoring sensitivity and reliability for abnormal conditions such as dry running due to lack of lubrication, abnormal wear, loose installation, wedge impact, roller impact, and cage knocking of the backstop. Example 2

[0045] Based on Example 1, such as Figure 2 As shown, the backstop monitoring device based on the L-shaped vibration guide rod also includes a base 4. The backstop housing 1 is fixedly installed on the base 4. A cavity 5 is provided inside the base 4. The cavity 5 has an opening. The first arm 21 passes through the opening. The second arm 22 and the vibration acceleration sensor 3 are installed inside the cavity 5.

[0046] Specifically, the base 4 is a cast steel base or a welded steel structure base. The upper surface of the base 4 has a mounting surface for supporting the backstop housing 1. The backstop housing 1 is fixed to the base 4 by bolts, pressure plates, or locating pins. The cavity 5 inside the base 4 is located near the lower mounting area of ​​the backstop housing 1, placing it near the vibration transmission path between the backstop housing 1 and the base 4. The cavity 5 can be a rectangular cavity, a rounded rectangular cavity, or a stepped cavity, with a length of 40mm-120mm, a width of 25mm-80mm, and a height of 20mm-60mm, sufficient to accommodate the second arm 22, the sensor mounting block, and the vibration acceleration sensor 3. The inner wall of the cavity 5 is deburred and rust-proofed to prevent scratching or damage to the second arm 22 or sensor wiring during vibration.

[0047] An opening is provided on the side of the cavity 5 near the backstop housing 1. The first arm 21 extends from the backstop housing 1 toward the base 4, passes through the opening, and enters the cavity 5. The end of the first arm 21 away from the second arm 22 remains fixedly connected to the backstop housing 1. The second arm 22 is located inside the cavity 5 and is bent relative to the first arm 21. The vibration acceleration sensor 3 is located at the end of the second arm 22 away from the first arm 21. Thus, abnormal vibrations generated by the backstop housing 1 are first introduced into the cavity 5 through the first arm 21, and then transmitted to the vibration acceleration sensor 3 through the second arm 22. This arrangement prevents the vibration acceleration sensor 3 from being directly exposed to the outside of the backstop housing, thereby reducing the impact of oil, dust, moisture, collisions, and maintenance operations on the sensor.

[0048] Furthermore, a clearance gap is preferably formed between the second arm 22 and the inner wall of the cavity 5. This clearance gap can be 1mm-10mm, allowing the second arm 22 to produce a slight bending, swaying, or end acceleration response when subjected to abnormal vibration excitation from the backstop, without rigidly colliding with the inner wall of the cavity 5. An installation gap is also maintained between the vibration acceleration sensor 3 and the inner wall of the cavity 5 to facilitate wiring, maintenance, and replacement. The sensor lead can be led out through a wire hole on the base, where a sealed or waterproof connector can be installed.

[0049] In this embodiment, an annular elastic portion is provided at the opening, surrounding the first arm 21. The annular elastic portion can be made of oil-resistant rubber, fluororubber, silicone rubber, polyurethane elastomer, or other oil-resistant and wear-resistant elastic materials. The annular elastic portion is an annular sealing ring, an annular elastic sleeve, a sealing ring with a lip, or an elastic sheath structure. Its inner hole is fitted around the outer periphery of the first arm 21, and its outer periphery mates with the edge of the opening of the cavity 5 or the inner wall of the opening. The thickness of the annular elastic portion can be 2mm-12mm; the fit between its inner hole and the first arm 21 can be an interference fit, a slight compression fit, or a partial elastic contact fit.

[0050] The annular elastic part serves two purposes: firstly, it seals the gap between the first arm 21 and the opening, preventing oil, dust, water vapor, coal dust, or metal debris from entering the cavity 5 and protecting the second arm 22 and the vibration acceleration sensor 3 located within the cavity 5; secondly, it provides flexible restraint for the first arm 21 at the point where it penetrates the opening, preventing hard collisions or wear between the first arm 21 and the edge of the opening during long-term vibration. Because the annular elastic part is elastic, it does not rigidly lock the first arm 21, but allows it to undergo slight displacement with the vibration of the backstop housing 1, thus ensuring that the effective vibration transmitted through the first arm 21 can continue to be transmitted to the second arm 22 and the vibration acceleration sensor 3.

[0051] Furthermore, the annular elastic part exhibits different conduction and attenuation effects for vibrations of different frequencies. For low-frequency vibrations such as loose installation or slight base movement, the annular elastic part can undergo slow elastic deformation along with the first arm 21, allowing such low-frequency vibrations to be transmitted relatively stably to the second arm 22. For medium- and high-frequency vibrations caused by sudden impacts, dry grinding due to lack of lubrication, or localized knocking, the main vibration components are still transmitted along the vibration-guiding path formed by the first arm 21 and the second arm 22, while the annular elastic part can provide a certain degree of damping and attenuation for external stray vibrations, collision noise, and non-target directional vibrations at the opening. Thus, the annular elastic part not only provides sealing and protection but also forms an elastic support and frequency-selective vibration-limiting structure at the opening through the first arm, improving the stability and anti-interference capability of the vibration signal.

[0052] Preferably, the inner side of the annular elastic part can be provided with several annular protruding lips or corrugated parts, and the annular protruding lips form multiple elastic contact seals with the outer periphery of the first arm 21; the outer side of the annular elastic part can be provided with an insert flange, and a corresponding annular groove is provided at the opening of the cavity 5, so that the annular elastic part can be stably fixed at the opening and avoid falling off due to long-term vibration. The position where the first arm 21 passes through the annular elastic part can be set as a circular, elliptical or chamfered rectangular cross section, and its surface roughness is preferably not greater than Ra1.6, so as to reduce wear between the first arm and the annular elastic part.

[0053] Furthermore, the annular elastic part is configured as a dual-hardness composite structure. Specifically, the annular elastic part includes an inner elastic part near the first arm 21 and an outer elastic part near the edge of the cavity 5 opening. The hardness of the inner elastic part is lower than that of the outer elastic part. The inner elastic part is in elastic contact with the outer periphery of the first arm 21, and can undergo flexible deformation when the first arm 21 vibrates with the backstop housing 1 and produces a small displacement. This avoids excessive friction or local wear between the first arm 21 and the annular elastic part, and ensures that effective vibration can continue to be transmitted to the second arm 22 through the first arm 21. The outer elastic part is fixed to the cavity 5 opening or the base, and has high support strength and sealing stability. This can prevent the annular elastic part from loosening, shifting, or failing to seal under long-term vibration. Thus, the dual-hardness structure can both meet the micro-vibration follow-up and vibration guidance requirements of the first arm and improve the dustproof, oil-proof, and water vapor-proof capabilities of the cavity opening. This provides a more reliable protective environment for the second arm 22 and the vibration acceleration sensor 3 located in the cavity, thereby improving the long-term operational stability of the backstop monitoring device.

[0054] In this embodiment, the second arm 22 and the vibration acceleration sensor 3 are placed inside the cavity 5, and an annular elastic part is provided around the first arm 21 at the opening of the cavity 5. This allows the L-shaped vibration guide rod 2 to not only introduce abnormal vibrations of the backstop housing 1 into the cavity 5 for monitoring, but also to improve the sealing protection and installation reliability of the sensor. It is particularly suitable for working conditions with a lot of oil, dust and vibration interference, such as mines, coal washing plants and conveyors. Example 3

[0055] This embodiment provides an installation method for a backstop monitoring device based on an L-shaped vibration guide rod, such as... Figure 3 As shown, the installation method mainly includes the following three steps.

[0056] Step 1: Prefabricate L-shaped vibration guide rod 2.

[0057] The first arm 21 and the second arm 22 are pre-machined, and one end of the first arm 21 is connected to one end of the second arm 22 to form an L-shaped vibration guiding link 2. The first arm 21 and the second arm 22 can be manufactured by integral bending, or they can be machined separately and then connected by welding, threaded connection, riveting, press fitting, or screw fastening. The included angle between the first arm 21 and the second arm 22 is 90° to form a more stable L-shaped vibration guiding path. A rounded transition structure is provided at the connection between the first arm 21 and the second arm 22, with a rounded radius of 3mm-10mm, to reduce stress concentration at the bent part under impact vibration.

[0058] In this embodiment, the first arm 21 serves as the vibration-guided input section connected to the backstop housing 1, and the second arm 22 serves as the vibration-guided output section for mounting the vibration acceleration sensor 3. The length of the first arm 21 is 20mm-80mm, and the length of the second arm 22 is 25mm-100mm. Preferably, the cross-sectional area of ​​the first arm 21 is larger than that of the second arm 22. For example, the first arm 21 can be a rectangular cross-section with a width of 8mm-20mm and a thickness of 4mm-10mm, and the second arm 22 can be a rectangular cross-section with a width of 5mm-15mm and a thickness of 2mm-6mm, so that the first arm 21 has higher vibration-guided stiffness and the second arm 22 has higher vibration response sensitivity.

[0059] Step 2: Install the vibration acceleration sensor 3.

[0060] The vibration acceleration sensor 3 is fixedly mounted on the end of the second arm 22 away from the first arm 21, so that the vibration acceleration sensor 3 and the second arm 22 form a stable vibration coupling. Preferably, a sensor mounting block is provided at the end of the second arm 22 away from the first arm 21. The sensor mounting block has a flat mounting surface, and the vibration acceleration sensor 3 is fixed on the mounting surface. The sensor mounting block can be integrally formed with the second arm 22, or it can be fixed to the end of the second arm 22 by welding, screw connection, press fitting, or adhesive bonding.

[0061] The vibration acceleration sensor 3 is installed using methods such as screw clamping, cap clamping, snap-fit, vibration-guided adhesive bonding, or potting. Preferably, M3-M5 threaded holes are provided on the sensor mounting block, and the vibration acceleration sensor 3 is clamped and fixed to the sensor mounting block by screws. A vibration-guided adhesive layer with a thickness of 0.05mm-0.2mm can be applied between the sensor and the sensor mounting block to improve contact stability and reduce the influence of micro-gap on signal acquisition. If a triaxial vibration acceleration sensor is used, it is preferable that one sensitive axis corresponds to the extension direction of the second arm 22, another sensitive axis corresponds to the extension direction of the first arm 21, and the third sensitive axis corresponds to the direction perpendicular to the plane where the L-shaped vibration-guided connecting rod 2 is located, so as to collect vibration acceleration components in different directions.

[0062] After the sensor installation is completed, the connecting wires of the vibration acceleration sensor 3 can be initially fixed, for example, by using cable ties, wire clips, or flexible sheaths to arrange the cable along the second arm 21 or the first arm 22 to prevent the cable from swinging freely and interfering with the vibration signal. The fixing point between the cable and the vibration guiding rod should not be set in the sensitive area at the end of the second arm 22, so as not to affect the vibration response of the second arm 22.

[0063] Step 3: Fix the L-shaped vibration guide rod 2.

[0064] The L-shaped vibration guide rod 2, equipped with the vibration acceleration sensor 3, is fixed as a single component to the backstop housing 1, so that the end of the first arm 21 away from the second arm 22 is connected to the backstop housing 1. Specifically, an area near the internal rollers, wedges, retainers, or fixed mounting parts of the backstop is selected on the outer surface of the backstop housing 1 as the installation position, and a connecting plane, connecting boss, or threaded hole is provided at this position. The end of the first arm 21 away from the second arm 22 is fixed to the backstop housing 1 by bolts, welding, pressure plates, clamps, threaded connections, or adhesive bonding.

[0065] Preferably, the first arm 21 is bolted to the backstop housing 1. The first arm 21 has a mounting hole at its connecting end, and the backstop housing 1 has a corresponding threaded hole. M6-M10 high-strength bolts are used to press and fix the first arm 21 to the backstop housing 1. To ensure vibration guidance, the connecting end of the first arm 21 and the backstop housing 1 preferably form a metal-to-metal contact. The contact surfaces are cleaned, degreased, and deburred before installation. If necessary, a thin metal vibration-guiding pad with a thickness of 0.1mm-0.5mm can be placed between the contact surfaces to improve the uniformity of the fit. To prevent loosening due to long-term vibration, spring washers, anti-loosening washers, double nuts, or thread-locking adhesive can be used at the bolt locations.

[0066] During installation, it is preferable that the first arm 21 extends away from the backstop housing 1, and the second arm 22 is bent relative to the first arm 21, with the normal direction of the plane containing the L-shaped vibration guiding link 2 parallel to the axial direction of the backstop housing 1. In this way, the first arm 21 can better receive the local normal vibration of the backstop housing 1 and the structural vibration propagating along the housing to the connection position, and the second arm 22 can transmit the vibration introduced by the first arm 21 to the end where the vibration acceleration sensor 3 is located.

[0067] After fixing, check the connection between the L-shaped vibration guide rod 2 and the backstop housing 1, and perform initial signal acquisition. Specifically, acquire an initial vibration signal under no-load or low-load operating conditions of the backstop as a reference for subsequent judgment of the backstop's operating status. When the backstop experiences insufficient lubrication, abnormal wear, loose installation, or sudden impact, the abnormal vibration is transmitted through the backstop housing to the first arm 21, and then through the second arm 22 to the vibration acceleration sensor 3. The vibration acceleration sensor 3 outputs a corresponding vibration acceleration signal for monitoring the operating status.

[0068] This embodiment adopts an installation sequence of first prefabricating the L-shaped vibration guide rod 2, then installing the vibration acceleration sensor 3, and finally fixing the whole assembly to the backstop housing 1. This allows the sensor to be fixed and the cables to be organized before installation on the backstop housing 1, which helps to ensure the installation accuracy and vibration coupling stability between the sensor and the second arm 22. At the same time, installing the L-shaped vibration guide rod 2 with the sensor onto the backstop housing 1 as a whole reduces on-site assembly steps, lowers installation difficulty, and facilitates external modification of existing backstops. Example 4

[0069] Based on embodiment 3, the L-shaped vibration guide rod 2 with the vibration acceleration sensor 3 installed is installed in the cavity 5 of the base 4, so that the second arm 22 and the vibration acceleration sensor 3 are located inside the base 4.

[0070] Specifically, before installation, a cavity is pre-machined within the base 4, and the cavity 5 is located near the lower fixing area of ​​the backstop housing 1. The cavity 5 can be a rectangular cavity, a rounded rectangular cavity, or a stepped cavity, and its dimensions are designed to accommodate the second arm 22, the sensor mounting block, and the vibration acceleration sensor. For example, the cavity 5 has a length of 50mm-120mm, a width of 30mm-80mm, and a height of 25mm-60mm. An opening is provided on the side of the cavity 5 near the backstop housing 1, allowing the first arm 21 to pass through. The opening size is slightly larger than the external dimensions of the first arm 21 so that the first arm 21 can pass through while maintaining a small movement gap.

[0071] During installation, firstly, L-shaped vibration guide rod 2 is prefabricated according to the method of Example 3, and vibration acceleration sensor 3 is fixed at the end of the second arm 22 away from the first arm 21; then, the second arm 22 and vibration acceleration sensor 3 are sent into the cavity 5 through the opening or inspection port of the cavity 5, so that the first arm 21 passes through the opening and the second arm 22 is located entirely in the cavity 5; then, the end of the first arm 21 away from the second arm 22 is fixed to the backstop housing 1, so that the vibration generated by the backstop housing 1 can be transmitted through the first arm 21 to the second arm 21 and vibration acceleration sensor 3 located in the cavity 5.

[0072] Preferably, a clearance of 2mm-8mm is maintained between the second arm 22 and the inner wall of the cavity 5 to prevent the second arm 22 from colliding hard with the inner wall of the cavity 5 when subjected to abnormal vibration excitation, while ensuring that the second arm 22 can produce slight bending, swinging, or end acceleration response. A maintenance clearance is also maintained between the vibration acceleration sensor 3 and the inner wall of the cavity 5 to facilitate the arrangement of sensor leads and subsequent maintenance. The sensor leads can be led out through the wire hole on the base, and a sealing joint or protective sleeve is provided at the wire hole.

[0073] Furthermore, an annular elastic portion is provided at the opening of cavity 5, surrounding the first arm 21. The annular elastic portion can be made of oil-resistant rubber, fluororubber, silicone rubber, or polyurethane elastomer. The inner hole of the annular elastic portion is in elastic contact with the outer periphery of the first arm 21, and the outer periphery is fitted and fixed to the edge of the opening or the inner wall of the opening. The annular elastic portion is used to seal the gap between the first arm and the opening, preventing oil, dust, and moisture from entering the cavity, while also providing a flexible limiting function for the first arm to prevent it from hardly colliding with the base at the opening.

[0074] In this embodiment, by placing the second arm 22 and the vibration acceleration sensor 3 inside the cavity 5, the first arm 21 can be used to introduce the normal impact vibration of the backstop housing 1 and the abnormal vibration propagating along the housing into the cavity 5 for detection. On the other hand, the vibration acceleration sensor 3 can be prevented from being directly exposed to external oil, dust, collision and maintenance interference environments, thereby improving the sensor's protection reliability and long-term monitoring stability.

[0075] In summary, this invention provides a backstop monitoring device and its installation method based on an L-shaped vibration guide rod 2. By setting an L-shaped vibration guide rod 2 between the backstop housing 1 and the vibration acceleration sensor 3, a directional vibration guide path is formed between the housing, the first arm 21, the second arm 22, and the sensor. This allows abnormal vibrations generated during backstop operation due to insufficient lubrication, abnormal wear, loose installation, or impact from wedges or rollers to be effectively extracted and transmitted to the sensor. Simultaneously, the L-shaped structure can accommodate both normal impact vibrations of the housing and structural vibrations propagating along the housing, improving the ability to detect abnormal vibrations in multiple directions and of multiple types. The device has a simple structure, low cost, and convenient installation. It can be directly externally installed on the existing backstop housing 1, or the second arm 22 and the sensor can be arranged within the cavity 5 of the base 4 to improve dustproof, oil-proof, collision-proof, and long-term operational reliability. It is suitable for complex engineering scenarios with high backstop safety requirements, such as mining conveying, coal washing plants, belt conveyors, and hoisting equipment. It is beneficial for early warning of backstop failures, reducing unplanned downtime, and improving equipment operation safety.

[0076] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A backstop monitoring device based on an L-shaped vibration guiding link, characterized in that: It includes a backstop housing, an L-shaped vibration guide rod, and a vibration acceleration sensor; the L-shaped vibration guide rod includes a first arm and a second arm, one end of the first arm is connected to the backstop housing, the other end of the first arm is connected to one end of the second arm, and the vibration acceleration sensor is disposed on the other end of the second arm.

2. The backstop monitoring device based on an L-shaped vibration guiding rod as described in claim 1, characterized in that: The first arm extends away from the backstop housing, and the second arm is bent relative to the first arm.

3. The backstop monitoring device based on an L-shaped vibration guiding rod as described in claim 1, characterized in that: A sensor mounting block is provided at the end of the second arm away from the first arm, and the vibration acceleration sensor is fixedly mounted on the sensor mounting block.

4. The backstop monitoring device based on an L-shaped vibration guiding rod as described in claim 1, characterized in that: The vibration acceleration sensor is a triaxial vibration acceleration sensor.

5. The backstop monitoring device based on an L-shaped vibration guiding rod as described in claim 2, characterized in that: The normal direction of the plane containing the L-shaped vibration guide rod is parallel to the axial direction of the backstop housing.

6. The backstop monitoring device based on an L-shaped vibration guiding rod as described in claim 2, characterized in that: The cross-sectional area of ​​the first arm is greater than that of the second arm.

7. The backstop monitoring device based on an L-shaped vibration guiding rod as described in claim 2, characterized in that: The first arm is made of alloy steel, stainless steel or high-strength aluminum alloy, and the second arm is made of spring steel, beryllium copper, titanium alloy or elastic aluminum alloy.

8. The backstop monitoring device based on an L-shaped vibration guiding rod as described in any one of claims 1-7, characterized in that: It also includes a base, the backstop housing is fixedly mounted on the base, the base has a cavity with an opening, the first arm passes through the opening, and the second arm and the vibration acceleration sensor are disposed in the cavity.

9. The backstop monitoring device based on an L-shaped vibration guiding rod as described in claim 8, characterized in that: An annular elastic portion is provided at the opening, and the annular elastic portion surrounds the first arm.

10. The installation method of the backstop monitoring device based on the L-shaped vibration guiding rod as described in claim 1, characterized in that, Includes the following steps: Step 1: Prefabricate the L-shaped vibration guiding link: Connect one end of the first arm to one end of the second arm in advance, so that the first arm and the second arm form the L-shaped vibration guiding link; Step 2: Install the vibration acceleration sensor: Fix the vibration acceleration sensor on the end of the second arm away from the first arm; Step 3: Fix the L-shaped vibration guide rod: Fix the L-shaped vibration guide rod, on which the vibration acceleration sensor is installed, to the backstop housing, so that the end of the first arm away from the second arm is connected to the backstop housing.

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