Constrained space multi-backchain hoisting device and method

Abstract

This invention discloses a multi-chain hoisting device and method for confined spaces, belonging to the field of hoisting technology. It addresses the problem that traditional hoisting tools are insufficient for hoisting requirements in confined spaces. The method includes: S1: Fixing a crossbeam and suspending the upper ends of multiple chain hoists from the crossbeam, with the lower ends connected to a hoisting platform; S2: Installing a thrust self-aligning roller bearing at the center of the hoisting platform, with a lifting rod passing through the inner ring of the thrust self-aligning roller bearing. A nut is threaded onto the upper part of the lifting rod, and a balance beam is connected to the lower end of the lifting rod; S3: Connecting the equipment to be hoisted to the lifting lugs at both ends of the balance beam, simultaneously lifting the multiple chain hoists to raise the hoisting platform, balance beam, and equipment to be hoisted until the equipment reaches a predetermined height; S4: Applying a horizontal torque to the lifting rod or the equipment to be hoisted, causing the balance beam, along with the equipment to be hoisted, to rotate around the rotation axis of the thrust self-aligning roller bearing to a predetermined angle. This invention balances hoisting stability, operational flexibility, and operational safety within confined spaces.

Description

Technical Field

[0001] This invention relates to the technical field of hoisting technology. More specifically, this invention relates to a multi-chain hoisting device and method for confined spaces. Background Technology

[0002] In scenarios where cranes cannot operate, equipment hoisting typically relies on winches or chain hoists. For equipment weighing tens of tons, a single chain hoist cannot meet the load-bearing requirements, necessitating the use of multiple chain hoists working together. Compared to winches, chain hoists offer advantages in ease of operation and practicality; however, when the equipment's orientation needs to be rotated during hoisting, existing multi-chain hoist systems struggle to achieve this function due to the lack of a dedicated rotating mechanism.

[0003] Within the confined space, the distance between the lifting lugs at the top of the equipment and the upper concrete beam is small. If steel wire ropes are used to connect the lifting lugs, the angle of the steel wire ropes will reach 90°, causing a significant increase in stress on the equipment and steel wire ropes, which does not meet safety regulations and poses a significant safety risk. Furthermore, when the equipment needs to be forcibly rotated during the positioning phase, the chain hoist and steel wire ropes are prone to interference with the upper concrete beam, further amplifying the safety hazard.

[0004] While winches can be used for hoisting, they suffer from complex setups and long preparation times, making them less suitable for scenarios with limited space and requiring rapid operation. Multi-chain hoisting, though simple to operate, lacks a rotatable structure, failing to meet the needs of equipment orientation adjustment. The root of these problems lies in the fact that the size limitations of the confined space restrict the layout and freedom of movement of the hoisting equipment, and the structural characteristics of traditional hoisting tools are incompatible with dynamic adjustment requirements. Early attempts to achieve rotation by adding temporary guiding devices or manual prying have proven ineffective due to space constraints and load weight, resulting in low adjustment accuracy and compromised safety. Summary of the Invention

[0005] One objective of this invention is to provide a multi-chain hoisting device and method for confined spaces, which can balance hoisting stability, operational flexibility, and operational safety within confined spaces.

[0006] To achieve these objectives and other advantages of the present invention, according to one aspect of the present invention, a method for lifting multiple chain hoists in confined space is provided, comprising: S1: fixing a crossbeam, suspending the upper ends of multiple sets of chain hoists on the crossbeam, and connecting the lower ends to a lifting platform; S2: installing a thrust self-aligning roller bearing at the center of the lifting platform, with a lifting rod passing through the inner ring of the thrust self-aligning roller bearing, a nut threaded onto the upper part of the lifting rod, and a balance beam connected to the lower end of the lifting rod; S3: connecting the equipment to be lifted to the lifting lugs at both ends of the balance beam, and simultaneously lifting the multiple sets of chain hoists, so that the lifting platform, the balance beam, and the equipment to be lifted rise to a predetermined height; S4: applying a horizontal torque to the lifting rod or the equipment to be lifted, causing the balance beam, together with the equipment to be lifted, to rotate about the rotation axis of the thrust self-aligning roller bearing to a predetermined angle.

[0007] Furthermore, in S2, an angle sensor is installed on the hoisting platform to monitor the tilt angle θ of the platform in real time; a pressure sensor is installed at the connection between the hoisting platform and each set of chain hoists to monitor the load values ​​F1, F2...F of each chain hoist in real time. n n is the number of chain hoist groups, n≥3; an encoder is installed at the drive end of each chain hoist group to detect the chain hoist lifting speed in real time; the data from the tilt sensor, pressure sensor, and encoder are connected to the controller, which performs the following closed-loop control: real-time calculation of the load distribution offset rate η, η=(F max -F min ) / F mean ×100%, where F max =max(F1, F2, ..., F n ), F min =min(F1, F2, ..., F) n ), F mean =(∑F i ) / n; when θ≤θ s When η>δ, adjust the target chain hoisting speed V according to the following formula. x V x =V0×[1+K×(F mean -F x ) / F max ], where the target chain is the chain corresponding to the minimum load in the tilt direction; when θ>θ s Simultaneously adjust the minimum load on the inclined side to accelerate the chain hoist, and the maximum load on the opposite side to decelerate the chain hoist, until θ≤θ s When θ > θ e When an emergency stop command is triggered, θ e This is the emergency tilt angle threshold.

[0008] Furthermore, when θ > θ sWhen the controller performs dynamic torque adjustment, the dynamic torque adjustment includes: acquiring the tilt angle θ measured in real time by the tilt sensor, calculating the tilt angle change Δθ / Δt per unit time, and selecting either a fast correction mode or a steady-state adjustment mode based on Δθ / Δt; when Δθ / Δt > 0.5° / s, the fast correction mode is executed: identifying the target chain hoist with the smallest load in the tilt direction, increasing the output torque of the servo motor of the target chain hoist to 110%-130% of the rated torque, and reducing the output torque of the servo motor of the non-target chain hoist to 70%-90% of the rated torque; when Δθ / Δt ≤ 0.5° / s, the steady-state adjustment mode is executed: identifying the target chain hoist with the smallest load in the tilt direction; increasing the output torque of the servo motor of the target chain hoist in increments of 5%-15% per minute; decreasing the output torque of the servo motor of the non-target chain hoist in increments of 3%-10% per minute, and monitoring the tilt angle data in real time until θ ≤ θ s .

[0009] Furthermore, when θ > θ e When this happens, the controller immediately sends a zero-speed lockout command to all servo drives of the chain hoist, and simultaneously activates the electromagnetic brake of the chain hoist; if θ exceeds θ after stopping... e +1° will increase the output torque of the chain drive motor with the largest load by 10%-20% of the rated torque, and the duration will not exceed 2 seconds.

[0010] Furthermore, in S4, two rotary drive units are symmetrically installed circumferentially on the hoisting platform. Each rotary drive unit includes a servo motor, a harmonic reducer coaxially connected to the output shaft of the servo motor, and a friction drive wheel connected to the flange of the output shaft of the harmonic reducer. When the equipment to be hoisted needs to be rotated, the controller activates the rotary drive unit on the side of the target rotation direction, controlling the friction drive wheel to move to the side of the lifting rod. The controller acquires the tilt angle θ of the hoisting platform measured by the tilt sensor and calculates the actual rotation angle α using trigonometric functions. The controller then calculates the actual rotation angle α based on the target angle α. t The difference between the actual angle α and e = α t -α, generates the servo motor control signal U(t), U(t) = K p ×e(t)+K i ×∫e(t)dt+K d ×de(t) / dt, where K p K i K d The preset parameters are used; the control signal U(t) drives the servo motor through the servo driver, and the friction drive wheel generates tangential friction force through the harmonic reducer, which drives the boom to rotate.

[0011] Furthermore, when |e|>5°, K is set. p The value range of K is 0.5-0.8. iThe value range of K is 0-0.1. d The value range is 0.1-0.3; when 1°≤|e|≤5°, K is set to... p The value range of K is 1.0-1.5. i The value range of K is 0.1-0.2. d The value range is 0.3-0.6; when |e|<1°, K is set to... p The value range of K is 0.1-0.3. i The value range of K is 0-0.05. d The value range is 0.5-1.0; when |e|≤0.5°, the controller controls the friction drive wheel to retract radially and disengage from the boom.

[0012] Furthermore, before activating the rotary drive unit, the controller determines the target angle α. t The sign of the difference e between the actual angle α and the actual angle α determines the direction of rotation; when e is greater than 0, the first rotation drive unit is activated, and when e is less than 0, the second rotation drive unit is activated; when the friction drive wheel moves to contact the side of the rod, the contact pressure P is detected in real time by a pressure sensor installed on the friction drive wheel; the controller dynamically adjusts the radial displacement of the friction drive wheel to keep the contact pressure P within the preset pressure range.

[0013] The present invention also provides a lifting device, including a crossbeam, multiple sets of chain hoists, a lifting platform, a lifting rod, a thrust self-aligning roller bearing, and a balance beam; wherein, the upper ends of the multiple sets of chain hoists are suspended from the crossbeam and the lower ends are connected to the lifting platform, the self-aligning roller bearing is set at the center of the lifting platform, the lifting rod passes through the inner ring of the thrust self-aligning roller bearing, the upper part of the lifting rod is provided with a nut by thread, the lower end of the lifting rod is connected to the balance beam, and the balance beam is provided with lifting lugs at both ends for connecting the equipment to be lifted.

[0014] Furthermore, it also includes: an inclination sensor mounted on the hoisting platform; a pressure sensor mounted at the connection between the hoisting platform and each set of chain hoists, and on the friction drive wheel; an encoder mounted on the drive end of each set of chain hoists; two rotary drive units symmetrically arranged around the hoisting platform, each rotary drive unit including a servo motor, a harmonic reducer, and a friction drive wheel, the input shaft of the harmonic reducer being connected to the output shaft of the servo motor, and the output shaft of the harmonic reducer being connected to the friction drive wheel; and a controller connected to the inclination sensor, pressure sensor, encoder, and the servo motor of the rotary drive unit.

[0015] The present invention has at least the following beneficial effects:

[0016] This invention utilizes the adaptive characteristics of thrust self-aligning roller bearings to automatically compensate for overturning moments caused by differences in the lifting speeds of multiple chain hoists. This alleviates uneven stress on equipment and lifting devices due to platform tilt, reducing safety risks caused by tilting. It is particularly suitable for scenarios where the distance between the top concrete beam / slab and the lifting lugs of the equipment to be lifted is small. By leveraging the rotational cooperation between the balance beam and the bearings, this invention achieves equipment orientation adjustment during lifting, solving the problems of difficulty in turning the equipment and easy interference with the upper structure when using traditional multi-chain hoists without a rotation device. Compared to winches, it eliminates complex layout procedures, making operation more convenient. Compared to single chain hoists or wire rope hoisting, it balances lifting stability, operational flexibility, and operational safety within confined spaces.

[0017] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of one embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the structure of a hanging platform according to one embodiment of this application;

[0020] Figure 3 This is a schematic diagram of the assembly state of a thrust self-aligning roller bearing, a hanger, and a nut according to an embodiment of this application.

[0021] Figure 4 This is a schematic diagram of the structure of a balance beam according to an embodiment of this application. Detailed Implementation

[0022] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0023] It should be understood that terms such as "having," "comprising," and "including" used in the embodiments of this application do not exclude the presence or addition of one or more other elements or combinations thereof. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. When an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or may have an intervening element present. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element through an intervening element. Descriptions involving "first," "second," etc., in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0024] It should be noted that the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0025] The embodiments of this application provide a method for lifting multiple chain hoists in confined spaces, including: S1: fixing a crossbeam, suspending the upper ends of multiple chain hoists on the crossbeam, and connecting the lower ends to a lifting platform; S2: installing a thrust self-aligning roller bearing at the center of the lifting platform, with a lifting rod passing through the inner ring of the thrust self-aligning roller bearing, a nut threaded onto the upper part of the lifting rod, and a balance beam connected to the lower end of the lifting rod; S3: connecting the equipment to be lifted to the lifting lugs at both ends of the balance beam, and simultaneously lifting multiple chain hoists to raise the lifting platform, balance beam, and equipment to be lifted until the equipment reaches a predetermined height; S4: applying a horizontal torque to the lifting rod or the equipment to be lifted to rotate the equipment around the rotation axis of the thrust self-aligning roller bearing to a predetermined angle.

[0026] For example, the confined space multi-chain hoisting method refers to a closed or semi-closed area with a height of less than 5m, a width of less than 3m, or a limited operating radius, such as an underground pipe gallery, the inside of a boiler furnace, or a maintenance passage for a chemical reactor. Multi-chain hoisting refers to the simultaneous use of multiple sets of chain hoists, which can be 3, 4, or 5 sets. The optional models are DHP-5 electric chain hoist (rated lifting capacity 5t), HSZ-10 manual chain hoist (rated lifting capacity 10t), or CD1 electric chain hoist (rated lifting capacity 8t), and the material is 40CrNiMoA high-strength alloy steel. The feature is that it includes: S1: a fixed crossbeam, which can be a rectangular beam made of Q235B steel (yield strength 235MPa), Q355 steel (yield strength 355MPa), or No. 45 steel (hardness 220-250HB after heat treatment), with a cross-sectional dimension of 200mm×100mm×10mm (length×width×thickness), 250mm×120mm×12mm, or 300mm×150mm×15mm. It is fixed to the underside of the top concrete beam slab using M20 expansion bolts (effective length 150mm), M24 chemical anchors (embedding depth 200mm), or M27 anchor bolts (thread length 80mm). The expansion bolts are installed at both ends of the crossbeam, 300mm from the ends, with two bolts at each end, symmetrically distributed; multiple sets of chain hoists are also included. The upper end of the chain hoist is suspended from the crossbeam. The upper hook of the chain hoist is attached to the lifting ring welded to the bottom of the crossbeam. The lifting ring is made of No. 20 round steel with a diameter of 20mm (load capacity 10t), 22mm (load capacity 12t), or 25mm (load capacity 15t), with a spacing of 1m (for 3 sets of chain hoists), 1.2m (for 4 sets of chain hoists), or 1.5m (for 5 sets of chain hoists). The lower end is connected to the hanging plate, which is a Q235 round steel plate with a diameter of 1.5m (for 3 sets of chain hoists), 1.8m (for 4 sets of chain hoists), or 2m (for 5 sets of chain hoists), and a thickness of 10mm, 12mm, or 15mm. The lower hook of the chain hoist is connected to the ear plate on the edge of the hanging plate. The ear plate is a Q345 steel plate with a thickness of 15mm, welded to the edge of the hanging plate, 50mm away from the outer edge of the hanging plate, and the number of ear plates is the same as the number of chain hoist sets, evenly distributed along the circumference.S2: A thrust self-aligning roller bearing is installed at the center of the lifting platform. The bearing model can be 29416 (inner diameter 80mm, outer diameter 170mm), 29418 (inner diameter 90mm, outer diameter 190mm), or 29420 (inner diameter 100mm, outer diameter 210mm). A lifting rod is threaded through the inner ring of the thrust self-aligning roller bearing. A nut is threaded onto the upper part of the lifting rod, and a balance beam is connected to the lower end of the lifting rod. The nut is used to bear the tension of the lifting rod (derived from the weight of the equipment to be lifted), applying the force to the thrust self-aligning roller bearing. Two or more nuts can be used to improve safety. The lifting rod is perpendicular to the surface of the balance beam. The balance beam is an I-beam (model I20a, section height 200mm), an H-beam (model HW250×250, section height 250mm), or a rectangular beam (200mm×100mm). The balance beam (m×8mm) is connected to the bearing rotating ring flange at its center using 10.9 grade bolts. The bolts are M16 (for bearing 29416), M18 (for bearing 29418), or M20 (for bearing 29420), with 6, 8, or 10 bolts evenly distributed around the flange circumference. When multiple chain hoists experience different lifting speeds due to fluctuations in motor input voltage (±5%), differences in reducer gear wear, or uneven load distribution (deviation within 10%), the hoisting platform will tilt towards the slower lifting side (tilt angle ≤3°). At this time, the spherical rollers of the thrust self-aligning roller bearing can adjust their position along the tilt direction of the inner raceway, automatically adapting to a tilt angle of 0.5°-3° and generating a resistance torque opposite to the overturning moment, compensating for the overturning moment caused by the tilt (compensation efficiency 60%-80%). S3: Connect the equipment to be hoisted to the lifting lugs at both ends of the balance beam. The lifting lugs are made of Q355 steel plates with a thickness of 20mm, 25mm, or 30mm, in a "U" shape, with an opening width of 100mm. They are welded to the lower ends of the balance beam, 500mm from the beam ends, perpendicular to the web of the balance beam. Use 6×37 galvanized steel wire rope (16mm diameter, breaking strength 196kN) or G80 grade lifting chain (14mm diameter, breaking strength 220kN) or polypropylene slings (100mm width, breaking strength 200kN) to connect the equipment lifting lugs to the balance beam lifting lugs. Install shackles (model G209, rated load 10t, 16t, or 20t); synchronously lift multiple sets of chain hoists, and control the chain hoist motor speed through a PLC controller (model S7-1200) to keep the lifting speed deviation of each set of chain hoists within 5% (e.g., when the reference speed is 10m / min, the allowable deviation is ±0.5m / min), so that the lifting platform, balance beam, and equipment to be lifted are raised. The predetermined height can be 2m (small equipment), 3m (medium equipment), or 4m (large equipment), until the bottom of the equipment to be lifted is 100mm-200mm higher than the installation foundation (to facilitate leveling adjustment).S4: Apply horizontal torque to the balance beam or the equipment to be lifted. The application method can be manual pushing (for equipment ≤5t) or mechanical drive (for equipment >5t). The mechanical drive can be a polyurethane friction wheel (200mm diameter) driven by a 1.5kW servo motor (model 130ST-M15015) or a No. 45 steel gear (module 5) driven by a 0.75kW hydraulic motor (model BM1-200). This causes the boom and the equipment to be lifted to rotate around the rotation axis of the thrust self-aligning roller bearing (coinciding with the center line of the inner ring of the bearing). The rotation angle can be 30° (fine adjustment), 90° (right-angle turn), or 180° (turnaround). The rotation angle is monitored in real time by an angle encoder (model E6B2-CWZ6C) installed on the outer ring of the bearing. The force is stopped when the predetermined angle is reached.

[0027] In existing technologies, for multi-chain hoisting in confined spaces, the chain hoists are typically connected directly to the lifting lugs on the top of the equipment via wire ropes, or multiple sets of chain hoists are rigidly connected to the equipment via welded steel frames. The steel frames and the hoisting platform are fully welded and fixed (without relative movement clearance). When the lifting speeds of multiple sets of chain hoists differ due to differences in motor parameters (e.g., a 10% speed deviation) or different wire rope elongations, the steel frame will tilt towards the lower speed side along with the hoisting platform. Since the rigid connection cannot provide adaptive adjustment, the tilt angle will accumulate with the increase in lifting height (e.g., the tilt angle reaches 8°-10° when lifting 3m), failing to compensate for the overturning moment. This causes the equipment's center of gravity to shift, increasing the load on one side of the chain hoists (potentially exceeding the rated load by 20%-30%), posing a risk of falling. If the equipment needs to be rotated, it must first be hoisted at least 300mm above surrounding obstacles. Three to four operators must stand on either side of the equipment, using pry bars inserted into the gap between the bottom of the equipment and the foundation to pry it, or using a hand-operated hoist for lateral traction. Due to the asymmetrical force points, the equipment is prone to swaying (sway amplitude can reach ±200mm), and the wire rope is easily rubbed against the lower edge of the top concrete beam (wear rate 0.5mm / time), posing a significant safety risk. This embodiment utilizes the spherical contact characteristics of thrust self-aligning roller bearings to achieve adaptive tilt compensation (tilt angle can be controlled within ≤3°), reducing unilateral load deviation (controlled within 10%). Simultaneously, it utilizes the bearing's rotational freedom to achieve smooth equipment steering (sway amplitude ≤50mm), solving the problems of uncontrolled tilting and difficult rotation in existing technologies. The operation steps are reduced by 2-3 steps, significantly improving safety.

[0028] In another embodiment, in S2, an angle sensor is installed on the hoisting platform to monitor the tilt angle θ of the platform in real time; a pressure sensor is installed at the connection between the hoisting platform and each set of chain hoists to monitor the load values ​​F1, F2...F of each chain hoist in real time. nn is the number of chain hoist groups, n≥4; an encoder is installed at the drive end of each chain hoist group to detect the chain hoist lifting speed in real time; the data from the tilt sensor, pressure sensor, and encoder are connected to the controller, which performs the following closed-loop control: real-time calculation of the load distribution offset rate η, η=(F max -F min ) / F mean ×100%, where F max =max(F1, F2, ..., F n ), F min =min(F1, F2, ..., F) n ), F mean =(∑F i ) / n; when θ≤θ s When η>δ, adjust the target chain hoisting speed V according to the following formula. x V x =V0×[1+K×(F mean -F x ) / F max ], where the target chain is the chain corresponding to the minimum load in the tilt direction; when θ>θ s Simultaneously adjust the minimum load on the inclined side to accelerate the chain hoist, and the maximum load on the opposite side to decelerate the chain hoist, until θ≤θ s When θ > θ e When an emergency stop command is triggered, θ e This is the emergency tilt angle threshold.

[0029] For example, in step S2, an inclination sensor is installed on the bottom surface of the hoisting platform. The inclination sensor is a device that can measure the angle between an object and the horizontal plane. Optional models include SCA100T (range ±15°, accuracy 0.01°), BNO055 (range ±45°, accuracy 0.1°), or LIS3DH (range ±90°, accuracy 0.5°). The housing is made of ABS engineering plastic and is fixed to the bottom surface of the hoisting platform with M3 countersunk bolts. The bottom surface of the sensor is in contact with the bottom surface of the hoisting platform, and the cable is laid along the side groove of the balance beam to the controller. This sensor monitors the tilt angle θ (in degrees) of the hoisting platform in real time. Pressure sensors are installed at the connecting lugs between the lifting platform and each set of chain hoists. These pressure sensors convert force signals into electrical signals. Available models include PT124G-111 (range 0-50t, accuracy 0.5%FS), CZL601 (range 0-30t, accuracy 0.3%FS), or HBMU9B (range 0-100t, accuracy 0.1%FS). They are made of 304 stainless steel and are mounted on both sides of the lug pins via flange bases (coaxiality tolerance ≤0.1mm). Located between the lugs and the chain hoist hooks, they monitor the load values ​​F1, F2, ..., F of each chain hoist in real time. n(e.g., n=4 when there are 4 sets of chain hoists). An encoder is installed at the drive end of each set of chain hoists. The encoder is a device that converts mechanical rotation into electrical signals. The optional models are E6B2-CWZ5G (1000P / R resolution), HEDL5540 (2000P / R resolution), or TRD-2E1000B (1000P / R resolution). The material is aluminum alloy housing. It is connected to the output shaft of the chain hoist drive motor through a coupling and fixed on the motor end cover to detect the chain hoist lifting speed in real time (unit: meters per minute, m / min). Data from the tilt sensor, pressure sensor, and encoder are connected to the controller via shielded cables. The controller can be a Siemens S7-1200 PLC (model 1214CDC / DC / DC), a Mitsubishi FX5U-32MT (transistor output), or a Rockwell Micro850 (1763-L16BWA). It is installed in a waterproof control box (304 stainless steel, dimensions 300×200×150mm) on the edge of the hanging platform. The controller performs the following closed-loop control: real-time calculation of the load distribution offset rate η. The calculation process is as follows: first, obtain all chain hoist load values ​​F1 to F... n (e.g., F1=12t, F2=10t, F3=8t), determine the maximum value F. max =12t, minimum value F min =8t, average value F mean =(12+10+8) / 3=10t, substituting into the formula: η=(F max -F min ) / F mean ×100%=(12-8) / 10×100%=40%; θ s The safety tilt angle threshold can be selected as 3°, 4°, or 5°; when θ ≤ θ s When θ = 2° ≤ 3° and η > δ (δ is the offset rate threshold, which can be 5%, 10%, or 15%, such as η = 40% > 10%), identify the tilt direction (e.g., tilting to the left) and determine the target chain hoist with the minimum load in that direction (e.g., left side F3 = 8t), and adjust the target chain hoist speed V according to the formula. x V x =V0×[1+K×(F mean -F x ) / F max ]; where V0 is the base lifting speed (selectable as 5m / min, 8m / min, or 10m / min), K is the gain coefficient (selectable as 0.1, 0.2, or 0.3), and Fx is the real-time load value of the target chain hoist (e.g., F3 = 8t), then: V x =8×[1+0.2×(10-8) / 20]=8×(1+0.02)=8.16m / min (actual acceleration due to F) x <F mean ); when θ>θs When θ = 6° > 5°, simultaneously adjust the chain hoist with the least load in the tilt direction to accelerate (e.g., increase the speed of F3 on the left to 9 m / min), and decelerate the chain hoist with the greatest load on the opposite side (e.g., decrease the speed of F1 on the right to 7 m / min), so that the lifting speed dynamically increases or decreases until θ ≤ θ s ;θ e The emergency tilt angle threshold can be selected as 7°, 8°, or 9°, when θ > θ e When θ = 10° > 9°, an emergency stop command is triggered.

[0030] In existing technologies, multi-chain hoisting relies solely on manual observation of the hoisting platform's tilt, lacking real-time monitoring devices, and load distribution is judged entirely by experience. For example, during the hoisting of a chemical plant reactor, when four chains were lifting, the right-side chain hoist motor's speed was slightly lower, and after 10 minutes, the hoisting platform tilted by 6° without being noticed, resulting in the right-side chain hoist's load exceeding its rated value by 30%, causing wire rope breakage. Adjustment required manual operation of the chain hoist handle, with a response delay exceeding 10 seconds, and the tilt angle continued to increase. This embodiment, however, uses sensors to collect data in real time, with a controller providing millisecond-level response. It automatically adjusts the speed when the load offset rate exceeds a threshold and dynamically adjusts the torque when the tilt exceeds a safe value, solving the problems of lag in manual monitoring and low adjustment accuracy, significantly improving hoisting stability.

[0031] In another embodiment, when θ>θ s When the controller performs dynamic torque adjustment, the dynamic torque adjustment includes: acquiring the tilt angle θ of the hanging platform measured in real time by the tilt sensor, calculating the tilt angle change Δθ / Δt per unit time, and selecting either a fast correction mode or a steady-state adjustment mode based on Δθ / Δt; when Δθ / Δt > 0.5° / s, the fast correction mode is executed: identifying the target chain hoist corresponding to the tilt direction, increasing the output torque of the servo motor of the target chain hoist to 110%-130% of the rated torque, and reducing the output torque of the servo motor of the non-target chain hoist to 70%-90% of the rated torque; when Δθ / Δt ≤ 0.5° / s, the steady-state adjustment mode is executed: identifying the target chain hoist corresponding to the tilt direction; increasing the output torque of the servo motor of the target chain hoist in increments of 5%-15% per minute; decreasing the output torque of the servo motor of the non-target chain hoist in increments of 3%-10% per minute, and monitoring the tilt angle data in real time until θ ≤ θ s .

[0032] For example, when θ > θ sWhen θ = 6° > 5°, the controller (e.g., S7-1200 PLC) initiates the torque dynamic adjustment program. The torque dynamic adjustment operation includes: the controller reads the balance beam tilt angle θ from the tilt sensor (e.g., SCA100T) every 100ms (e.g., θ1 = 5.2° at time t1, θ2 = 6.4° at time t2, Δt = 0.5s), calculates the tilt angle change per unit time Δθ / Δt = (6.4 - 5.2) / 0.5 = 2.4° / s, and selects the adjustment mode based on this value. When Δθ / Δt > 0.5° / s (e.g., 2.4° / s > 0.5° / s), the fast correction mode is executed: the tilt direction is determined (the direction of increasing θ is the tilt direction; for example, if tilting to the right, the right side is the target side); the pressure sensor data at the hanging plate ear plate is read to identify the target chain hoist with the smallest load in the tilt direction (e.g., F in the two right-side chain hoists). min =8t chain hoist); the servo motor of the target chain hoist (model 130ST-M15015, rated torque 15N·m) increases the output torque to 130% of the rated torque (19.5N·m); the servo motor of the non-target chain hoist decreases the output torque to 70% of the rated torque (10.5N·m). When Δθ / Δt≤0.5° / s (e.g., θ increases from 5.1° to 5.3°, Δt=1s, Δθ / Δt=0.2° / s), the steady-state adjustment mode is executed: the target chain hoist with the smallest load in the tilt direction is identified (e.g., the chain hoist with the smallest load on the front side when tilting forward); the output torque of the servo motor of the target chain hoist increases in steps of 10% per minute (e.g., initial 10N·m → 11N·m after 1 minute); the output torque of the servo motor of the non-target chain hoist decreases in steps of 7% per minute (e.g., initial 10N·m → 9.3N·m after 1 minute); tilt angle data is collected every 3 seconds until θ≤θ s (e.g., θ decreases to 4°≤5°).

[0033] This embodiment adjusts the tilt angle according to the tilt angle change rate. When quickly correcting the tilt, it accurately increases the minimum chain hoist torque and can suppress the tilting from worsening within 1 second. During steady-state adjustment, it slowly changes the torque in a stepwise manner to avoid impact. This solves the problem that the existing technology adjustment method is rough and easily causes secondary imbalance.

[0034] In another embodiment, when θ>θ e When this happens, the controller immediately sends a zero-speed lockout command to all servo drives of the chain hoist, and simultaneously activates the electromagnetic brake of the chain hoist; if θ exceeds θ after stopping... e +1° will increase the output torque of the chain drive motor on the opposite side of the tilt direction by 10%-20% of the rated torque, with a duration not exceeding 2 seconds.

[0035] For example, when θ > θ eWhen θ = 10° > 8°, the controller (e.g., Mitsubishi FX5U) sends a zero-speed lockout command (control word 0x047F) to all servo drives (model MR-J4-10A) of the chain hoist via the Profibus bus. Upon receiving the command, the servo drive adjusts the current to reduce the output torque of the servo motor (model HF-KP13) to 60% (18N·m), 70% (21N·m), or 80% (24N·m) of the torque required to keep the load stationary (e.g., 30N·m for a 30t load). Simultaneously, the controller outputs a 24V signal to activate the chain hoist's electromagnetic brake (model YWZ4-100 / 23, braking torque 150N·m), energizing the brake core and engaging the brake pads to grip the brake wheel. If the tilt sensor detects θ exceeding θ within 1 second after stopping... e +1° (e.g., θ) e =8°, θ=10°>9°), then: read the pressure sensor data at the hanging plate ear plate in real time to identify the chain hoist with the largest load (such as F). max =15t corresponding to the chain hoist); the drive motor controlling the maximum chain hoist of this load outputs 10%-20% of the rated torque to increase the torque (in the same direction as the increase): when the rated torque is 13 N·m, the output is 1.3 N·m (10%) or 1.95 N·m (15%) or 2.6 N·m (20%) for a duration strictly not exceeding 2 seconds (e.g., 1.5 seconds or 2 seconds); then the static torque is restored.

[0036] In existing technologies, emergency shutdowns involve directly cutting off the motor power and applying the brakes. For example, when a tower crane in an oil refinery tilted beyond its limits during hoisting, the brakes locked instantly. The 30-ton load generated a huge impact force due to inertia, causing two sets of chain hoists to overload and break, resulting in the equipment falling. This embodiment, however, solves the problem of large impacts and easy chain breakage during emergency stops by simultaneously activating the brakes and increasing torque through maximum load chain output.

[0037] In another embodiment, in S4, two rotary drive units are circumferentially symmetrically mounted on the hoisting platform. Each rotary drive unit includes a servo motor, a harmonic reducer coaxially connected to the output shaft of the servo motor, and a friction drive wheel connected to the flange of the output shaft of the harmonic reducer. When the equipment to be hoisted needs to be rotated, the controller activates the rotary drive unit on the side of the target rotation direction, controlling the friction drive wheel to move to the side of the hoisting rod. The controller acquires the hoisting platform tilt angle θ measured by the tilt sensor and calculates the actual rotation angle α using trigonometric functions. The controller then calculates the actual rotation angle α based on the target angle α. t The difference between the actual angle α and e = α t -α, generates the servo motor control signal U(t), U(t) = K p ×e(t)+K i ×∫e(t)dt+K d ×de(t) / dt, where Kp K i K d The preset parameters are used; the control signal U(t) drives the servo motor through the servo driver, and the friction drive wheel generates tangential friction force through the harmonic reducer, which drives the boom to rotate.

[0038] For example, in step S4 (i.e., after the equipment is raised to the predetermined height), two rotary drive units are circumferentially symmetrically (180° apart) mounted on the hoisting platform (2m in diameter). Each rotary drive unit includes a servo motor (model 130ST-M06025, rated power 0.6kW), a harmonic reducer (model CSF-17-50-2UH, reduction ratio 50:1) coaxially mounted with the output shaft of the servo motor via a key connection, and a friction drive wheel (material polyurethane, diameter 200mm, width 50mm, surface texture depth 2mm) bolted to the output shaft flange of the harmonic reducer. The drive wheel is mounted on the hoisting platform via a guide rail slider assembly and can move radially (stroke 100mm). When the equipment to be hoisted needs to be rotated (e.g., from 0° to 90°), the controller (S7-1200) determines the target rotation direction (clockwise) and activates the right-side rotation drive unit. The electric push rod (model DT300, thrust 5kN) pushes the friction drive wheel radially (towards the center) to contact the side of the hoisting rod (I25a I-beam), maintaining a contact pressure of 200N-300N. The controller acquires the tilt angle θ of the hoisting platform measured by the tilt sensor (e.g., θ=2°). Due to the angle between the rotation plane and the horizontal plane, the actual rotation angle α is calculated using trigonometric functions: If the encoder measures the drive wheel to have rotated 3 revolutions (circumference 0.628m, travel 1.884m), and the rotation radius of the balance beam is 0.8m, then the theoretical angle α0 = 1.884 / (2π×0.8)×360° ≈ 135°, and the actual angle α = α0×cosθ ≈ 135°×cos2° ≈ 134.9°. Target angle α t =180°, the difference e=180°-134.9°=45.1°, generating the servo motor control signal U(t)=K p ×e(t)+K i ×∫e(t)dt+K d ×de(t) / dt, where K p =0.6, K i =0.05, K d =0.2; The control signal is converted into a voltage signal (0-10V) by the servo driver (model SV-DA200), which drives the servo motor to rotate. After being reduced in speed by the harmonic reducer, the friction drive wheel rotates at a speed of 5r / min, generating friction force (f=μN, μ=0.8, N=250N, f=200N) with the side of the boom, driving the boom to rotate around the bearing.

[0039] In existing technologies, rotating equipment in confined spaces requires manual prying with crowbars or lateral traction using hand-operated hoists. For example, during the hoisting of a ventilation fan in a subway tunnel, four workers had to stand on a narrow platform and use a 1.5m long crowbar to rotate the equipment 5° every 5 minutes, resulting in only 60° rotation in one hour, with a deviation of over 10°. This embodiment utilizes an electric rotary drive unit to achieve smooth rotation through friction transmission, and PID control ensures an angle accuracy of ±0.5°. This solves the problems of low efficiency, poor accuracy, and high operational risks associated with manual rotation, making it particularly suitable for confined space scenarios.

[0040] In another embodiment, K is set when |e|>5°. p The value range of K is 0.5-0.8. i The value range of K is 0-0.1. d The value range is 0.1-0.3; when 1°≤|e|≤5°, K is set to... p The value range of K is 1.0-1.5. i The value range of K is 0.1-0.2. d The value range is 0.3-0.6; when |e|<1°, K is set to... p The value range of K is 0.1-0.3. i The value range of K is 0-0.05. d The value range is 0.5-1.0; when |e|≤0.5°, the controller controls the friction drive wheel to retract radially and disengage from the boom.

[0041] For example, the absolute value of the angle difference e, |e|, reflects the deviation between the target angle and the actual angle: when |e| > 5° (e.g., e = 8° or e = -7°), the scaling factor K is set. p =0.5 or 0.6 or 0.8, integral coefficient K i =0, 0.05, or 0.1, differential coefficient K d =0.1 or 0.2 or 0.3 (at this time, the focus is on rapidly reducing the deviation, and the integration is weakened to avoid overshoot); when 1°≤|e|≤5° (such as e=3° or e=-2°), set K. p =1.0, 1.2, or 1.5; Ki = 0.1, 0.15, or 0.2; Kd = 0.3, 0.4, or 0.6 (enhancing proportional and integral action, improving adjustment accuracy); when |e| < 1° (e.g., e = 0.8° or e = -0.6°), set K... p =0.1 or 0.2 or 0.3, K i =0 or 0.03 or 0.05, K d=0.5, 0.8, or 1.0 (reduce proportional effect, enhance differential effect to suppress oscillation); when |e|≤0.5° (e.g., e=0.4° or e=-0.3°), the controller sends a reverse signal to the electric actuator, driving the friction drive wheel to move radially outward (away from the boom) until it is completely disengaged (gap ≥10mm), stopping the rotation drive. For example, a water pump hoisting requires rotation to 90°, initially |e|=15°>5°, K p =0.6, K i =0、K d =0.2, quickly drive to |e|=3°; switch K p =1.2、K i =0.15, K d =0.4, adjust to |e|=0.4°; finally K p =0.2、K i =0、K d =0.8, after stabilization, the drive wheel retracts.

[0042] In existing technologies, rotation control does not involve segmented parameter adjustment; the same PID parameter is used throughout the entire process. For example, when a sterilizing pot in a food factory rotates, the initial deviation of 10° is controlled by a small K parameter. p This leads to slow adjustment, and when approaching the target, due to K p The failure to reduce the overshoot by ±3° necessitates repeated adjustments. This embodiment dynamically switches PID parameters based on the magnitude of the deviation, quickly catching up with large deviations, precisely adjusting with medium deviations, and stably converging with small deviations, thus solving the problem of balancing adjustment speed and accuracy in existing technologies.

[0043] In another embodiment, before activating the rotation drive unit, the controller determines the target angle α. t The sign of the difference e between the actual angle α and the actual angle α determines the direction of rotation; when e is greater than 0, the first rotation drive unit is activated, and when e is less than 0, the second rotation drive unit is activated; when the friction drive wheel moves radially to contact the side of the rod, the contact pressure P is detected in real time by a pressure sensor installed in the axial direction of the friction drive wheel; the controller dynamically adjusts the radial displacement of the friction drive wheel to keep the contact pressure P within the preset pressure range.

[0044] For example, before starting the rotary drive unit, the controller reads the target angle (e.g., 270°) and the actual angle α (e.g., 180°), calculates the difference e = 270° - 180° = 90° > 0, determines the rotation direction to be clockwise, and starts the first rotary drive unit (right unit); if e = 180° - 270° = -90° < 0, the direction is counterclockwise, and starts the second rotary drive unit (left unit). During the radial movement of the friction drive wheel to contact the side of the boom via the electric push rod, a pressure sensor (model CYT-103, range 0-500N) installed on the axial direction (end of the wheel axle) of the friction drive wheel detects the contact pressure P (unit N) in real time. The preset pressure range can be selected as 150-250N, 200-300N, or 250-350N. The controller compares the measured pressure P with the range: if P=120N<150N, the electric push rod extends 2mm to increase the displacement, and the pressure increases to 180N; if P=380N>350N, the electric push rod retracts 1mm, and the pressure drops to 320N. The dynamic adjustment keeps P within the preset range. For example, when hoisting a reactor, if the balance beam is made of H200 steel, P=160N after the friction wheel contacts. The controller drives the push rod to make fine adjustments 3 times to stabilize P in the 200-250N range.

[0045] In existing technologies, the contact pressure of the friction drive wheel is fixed, but the pressure fluctuates wildly (400N) and (100N). When the pressure is high, the drive wheel slips and smokes; when the pressure is low, it cannot rotate and requires a shutdown for readjustment. This embodiment uses a pressure sensor to monitor in real time and dynamically adjust the radial displacement to ensure stable contact pressure, thus solving the problem of slippage or insufficient driving force caused by pressure fluctuations. The rotation process is continuous and uninterrupted.

[0046] like Figure 1-4 As shown, embodiments of this application also provide hoisting equipment, including a crossbeam 1, multiple sets of chain hoists 3, a hoisting platform 5, a hoisting rod 14, a thrust self-aligning roller bearing 12, and a balance beam 6; wherein, the upper ends of the multiple sets of chain hoists 3 are suspended from the crossbeam 1, and the lower ends are connected to the hoisting platform 5, the thrust self-aligning roller bearing 12 is set at the center of the hoisting platform, the hoisting rod 14 passes through the inner ring of the thrust self-aligning roller bearing 12, the upper part of the hoisting rod 14 is provided with a nut 10 by thread, the lower end of the hoisting rod 14 is connected to the balance beam 6, and the balance beam 6 is provided with lifting lugs at both ends for connecting the equipment 8 to be hoisted.

[0047] Taking the hoisting of a coal-fired power plant inert gas generator as an example, the inert gas generator needs to be hoisted within a confined space surrounded by a concrete beam 13. The coal-fired power plant inert gas generator weighs 29 tons, and its volume is close to that of the confined space. First, the assembly of the foundation components is completed. The horizontal beam 1 is placed horizontally above the concrete floor slab at a predetermined position, serving as the load-bearing foundation for the hoisting system. Using shackles 2, one end of the sling 4 is connected and fixed to the lifting point at the bottom of the horizontal beam 1. The other end of the sling 4 is connected to the upper hook of the chain hoist 3 via shackles 2, ensuring that each connection point is installed in place. The lower end of the chain hoist 3 is also connected to the ear plates on the edge of the hoisting platform 5 via shackles 2. The hoisting platform 5 is a circular or square steel plate structure, with ear plates evenly distributed along its edge to match the number of chain hoists 3, ensuring balanced force distribution.

[0048] Next, the core rotation and self-aligning structure is installed. A thrust self-aligning roller bearing 12 is installed in the mounting hole at the center of the lifting platform 5. The lifting rod 14 is passed through the inner ring of the thrust self-aligning roller bearing 12. The lower end of the lifting rod 14 is connected to the balance beam 6, and the upper end is fitted with a washer 11 and a nut 10 to prevent the lifting rod 14 from coming off. This structure allows the lifting platform 5 to tilt at a certain angle (≤3°) when there are differences in the lifting speed of multiple sets of chain hoists 3, while allowing the balance beam 6 to rotate flexibly around the central axis of the lifting platform 5 (rotation angle range 0°-360°).

[0049] The operation procedure during the equipment hoisting stage is as follows: Connect the lifting lugs of the equipment 8 to be hoisted to the lifting lugs at both ends of the balance beam 6 using pins 7. Secure the ends of the pins 7 with cotter pins to prevent them from falling off. Start multiple sets of chain hoists 3 for synchronous lifting. During the lifting process, if the hoisting platform 5 tilts due to inconsistent lifting speeds of the chain hoists 3, the spherical rollers of the thrust self-aligning roller bearing 12 will adaptively adjust along the inner raceway to compensate for the overturning moment caused by the tilt, ensuring the stability of the balance beam 6 and the equipment under stress. After the equipment is lifted to the predetermined height, if it is necessary to adjust the equipment's orientation, a horizontal torque can be applied to rotate the balance beam 6 around the rotation axis of the thrust self-aligning roller bearing 12 until the equipment 8 to be hoisted reaches the preset installation angle. Finally, slowly lower the equipment 8 to be hoisted onto the concrete beam 13 to complete the installation. Throughout the process, shackles 2, slings 4, chain hoists 3 and other rigging are all made from existing standard parts. Crossbeams 1, lifting platforms 5, and balance beams 6 are made from conventional structural steel such as Q355 steel. Thrust self-aligning roller bearings 12 are commercially available 294 series models. No special processes are required for the assembly of each component, and on-site deployment can be completed quickly.

[0050] In existing technology, lifting equipment without thrust self-aligning roller bearings 12 suffers from a 3° tilt caused by differences in lifting speed. The balance beam rigidly tilts with the lifting platform, resulting in a 40% load difference between the two ends and triggering an overload alarm on the right-side chain hoist. This embodiment achieves tilt self-adaptation through bearings, controlling the load difference to within 15% when tilted at 3°. This solves the problem of uneven load distribution caused by rigid connections, making the equipment structure more adaptable to conditions with multiple chain hoists exhibiting synchronization deviations.

[0051] In another embodiment, the system further includes: a tilt sensor mounted on the hanging platform 5; a pressure sensor mounted at the connection between the hanging platform 5 and each set of chain hoists 4, and on the friction drive wheel; an encoder mounted on the drive end of each set of chain hoists 4; two rotary drive units symmetrically arranged around the circumference of the hanging platform 5, each rotary drive unit including a servo motor, a harmonic reducer, and a friction drive wheel, the input shaft of the harmonic reducer being connected to the output shaft of the servo motor, and the output shaft of the harmonic reducer being connected to the friction drive wheel; and a controller connected to the tilt sensor, the pressure sensor, the encoder, the servo motor of the rotary drive unit, and the third pressure sensor.

[0052] Taking the hoisting of a coal-fired power plant inert gas generator as an example, the initial assembly is carried out first. The crossbeam 1 is fixed to the bottom of the top concrete beam slab with expansion bolts or chemical anchors. Multiple sets of chain hoists 3 are suspended from the lifting rings at the bottom of the crossbeam, and the lower ends are connected to the lugs on the edge of the hoisting platform 5 through shackles 2. A thrust self-aligning roller bearing 12 is installed at the center of the hoisting platform 5. The lifting rod 14 is passed through the inner ring of the thrust self-aligning roller bearing 12. The lower end of the lifting rod 14 is connected to the balance beam 6, and the upper end is equipped with washers 11 and nuts 10 to prevent the lifting rod 14 from coming off. An angle sensor is installed at the center of the hoisting platform 5. Pressure sensors are installed axially at the lifting lugs and the friction drive wheels of the subsequent rotary drive units. An encoder is installed at the drive end of each set of chain hoists 4. Two rotary drive units containing servo motors, harmonic reducers and friction drive wheels are symmetrically arranged around the hoisting platform. All sensors and drive units are connected to the controller.

[0053] After assembly, the hoisting operation begins. The equipment 8 to be hoisted is connected to the lifting lugs of the balance beam using wire ropes or slings via pins. The controller simultaneously lifts multiple sets of chain hoists 4, monitoring the lifting speed through encoders to ensure the speed deviation of each set is controlled within 5% until the equipment reaches the predetermined height. During the lifting process, the controller receives the tilt angle θ from the tilt sensor and the load value at the lifting lugs in real time, calculating the load distribution offset rate η. When θ ≤ the safe tilt angle threshold θ... s When η > offset rate threshold δ (e.g., 3°, 4°, or 5°) and η > offset rate threshold δ (e.g., 5%, 10%, or 15%), according to formula V x =V0×[1+K×(F mean -F x ) / F max Adjust the target chain rewind speed.

[0054] If θ>θ s The controller calculates the change in tilt angle per unit time, Δθ / Δt. When Δθ / Δt > 0.5° / s, it executes the fast correction mode; when Δθ / Δt ≤ 0.5° / s, it executes the steady-state adjustment mode until θ ≤ θ s .

[0055] When the hoisting equipment 8 needs to be rotated after being lifted to the predetermined height, the controller determines the rotation direction based on the difference e between the target angle and the actual angle. If e > 0, the first rotation drive unit is activated; if e < 0, the second rotation drive unit is activated. This controls the friction drive wheel to move radially to contact the side of the boom, and the contact pressure is maintained within a preset range by a pressure sensor. The controller combines the tilt sensor data and uses trigonometric functions to calculate the actual rotation angle α, dynamically adjusting the PID parameters based on the absolute value of e.

[0056] If during hoisting θ > emergency tilt angle threshold θ e (e.g., 7°, 8°, or 9°), the controller immediately sends a zero-speed lockout command and simultaneously activates the electromagnetic brake.

[0057] The entire process combines mechanical structure and intelligent control to achieve stable lifting and precise rotation of equipment within a confined space. The entire process is monitored in real time by sensors and dynamically adjusted by the controller to ensure lifting safety and accuracy.

[0058] In existing technologies, hoisting equipment lacks sensors and controllers. For example, when hoisting a ball mill in a cement plant, two workers need to observe the hoisting platform's status throughout the process and use walkie-talkies to notify ground personnel to adjust the chain hoist. This results in significant information transmission errors and adjustment delays exceeding 5 seconds. This embodiment integrates various sensors and controllers to form a closed-loop control system. The data acquisition interval is ≤10ms, and the adjustment response is ≤100ms, solving the problem of existing equipment lacking intelligent sensing and automatic control functions, and realizing intelligent monitoring and adjustment of the hoisting process.

[0059] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A method for hoisting objects in confined spaces using multiple chain hoists, characterized in that: This invention relates to a lifting equipment comprising a crossbeam, multiple sets of chain hoists, a lifting platform, a lifting rod, a thrust self-aligning roller bearing, and a balance beam. The upper ends of the multiple sets of chain hoists are suspended from the crossbeam, and the lower ends are connected to the lifting platform. The self-aligning roller bearing is positioned at the center of the lifting platform. The lifting rod passes through the inner ring of the thrust self-aligning roller bearing, and a nut is threaded onto the upper part of the lifting rod. The lower end of the lifting rod is connected to the balance beam, and lifting lugs are provided at both ends of the balance beam for connecting the equipment to be lifted. The lifting equipment also includes: a tilt sensor mounted on the lifting platform; an encoder mounted on the drive end of each set of chain hoists; two rotary drive units symmetrically arranged around the circumference of the lifting platform, each rotary drive unit including a servo motor, a harmonic reducer, and a friction drive wheel. The input shaft of the harmonic reducer is connected to the output shaft of the servo motor, and the output shaft of the harmonic reducer is connected to the friction drive wheel; pressure sensors are mounted at the connection points between the lifting platform and each set of chain hoists, as well as on the friction drive wheel; and a controller connected to the tilt sensor, pressure sensor, encoder, and the servo motor of the rotary drive unit. Lifting methods include: S1: Fixed crossbeam, the upper ends of multiple sets of chain hoists are suspended on the crossbeam, and the lower ends are connected to the hanging plate; S2: A thrust self-aligning roller bearing is installed in the center of the lifting platform. A lifting rod is inserted through the inner ring of the thrust self-aligning roller bearing. A nut is threaded onto the upper part of the lifting rod, and a balance beam is connected to the lower end of the lifting rod. S3: Connect the equipment to be hoisted to the lifting lugs at both ends of the balance beam, and simultaneously lift multiple sets of chain hoists to raise the hoisting platform, balance beam and equipment to be hoisted to the predetermined height; S4: By applying a horizontal torque to the boom or the equipment to be lifted, the balance beam, together with the equipment to be lifted, rotates to a predetermined angle about the rotation axis of the thrust self-aligning roller bearing. In S2, a tilt sensor is installed on the hoisting platform to monitor the tilt angle θ of the hoisting platform in real time; Pressure sensors are installed at the connection points between the lifting platform and each set of chain hoists to monitor the load values ​​F1, F2...F of each chain hoist in real time. n n is the number of reversed chain groups, n≥3; An encoder is installed at the drive end of each chain hoist to detect the chain hoisting speed in real time; The data from the tilt sensor, pressure sensor, and encoder are input to the controller, which then performs the following closed-loop control: Real-time calculation of load distribution offset rate η, η=(F max -F min ) / F mean ×100%, where F max =max(F1, F2, ..., F n ), F min =min(F1, F2, ..., F) n ), F mean =(∑F i ) / n; When θ≤θ s When η>δ, adjust the target chain hoisting speed V according to the following formula. x : V x =V0×[1+K×(F mean -F x ) / F max ], where the target chain is the chain corresponding to the minimum load in the tilt direction; When θ>θ s Simultaneously adjust the minimum load on the inclined side to accelerate the chain hoist, and the maximum load on the opposite side to decelerate the chain hoist, until θ≤θ s ; When θ>θ e When an emergency stop command is triggered, θ e This is the emergency tilt angle threshold; When θ>θ s At this time, the controller performs dynamic torque adjustment. The torque dynamic adjustment operation includes: acquiring the tilt angle θ measured in real time by the tilt sensor, calculating the tilt angle change Δθ / Δt per unit time, and selecting the fast correction mode or the steady-state adjustment mode based on Δθ / Δt; When Δθ / Δt>0.5° / s, execute the fast correction mode: identify the target chain hoist with the smallest load in the tilt direction, increase the output torque of the servo motor of the target chain hoist to 110%-130% of the rated torque, and reduce the output torque of the servo motor of the non-target chain hoist to 70%-90% of the rated torque; When Δθ / Δt ≤ 0.5° / s, execute steady-state adjustment mode: identify the target chain hoist with the minimum load in the tilt direction; increase the servo motor output torque of the target chain hoist in steps of 5%-15% per minute; decrease the servo motor output torque of the non-target chain hoist in steps of 3%-10% per minute, and monitor the tilt angle data in real time until θ ≤ θ s .

2. The confined space multi-chain hoisting method as described in claim 1, characterized in that, When θ>θ e At that time, the controller immediately sends a zero-speed lockout command to all servo drives of the chain hoist and simultaneously activates the electromagnetic brake of the chain hoist. If θ exceeds θ after shutdown e +1° will increase the output torque of the chain drive motor with the largest load by 10%-20% of the rated torque, and the duration will not exceed 2 seconds.

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