A lifting fixture for large planetary gears

Abstract

This utility model belongs to the field of process equipment and relates to a lifting fixture for large planetary gears. The fixture consists of a welded connecting plate, three electric push rods / telescopic rods, a replaceable threaded plastic protective sleeve, and lifting rings. The planetary gear's inner bore is tightened by energizing the electric push rods / telescopic rods, and the lifting rings connect to a hoist for transfer. The key feature of this invention is the use of replaceable protective sleeves to adapt to different inner bores, reducing worker workload and improving efficiency and safety. Practical verification has shown that this fixture can significantly shorten the lifting time for single pieces, significantly improve batch processing capacity, and prevent injury to personnel and goods caused by planetary gears falling. It is suitable for various heavy equipment manufacturing scenarios such as marine engine gearboxes.

Description

Technical Field

[0001] This utility model belongs to the field of process equipment and relates to a hoisting fixture for a large planetary gear. Background Technology

[0002] In the fields of machinery manufacturing and heavy equipment, large planetary gears are widely used as key transmission components in high-load, high-precision transmission systems such as marine engine gearboxes, wind power generation equipment, and heavy mining machinery. Due to their large size and heavy weight (for example, the weight of a third-stage planetary gear in a large marine engine gearbox can reach 33.5 kg), the lifting and transfer of large planetary gears during manufacturing, assembly, and maintenance is an extremely challenging task.

[0003] Traditionally, the hoisting and transfer of large planetary gears mainly relies on a combination of manual operation and simple hoisting tools, specifically the following two typical methods:

[0004] Manual handling: In small-scale or low-volume production scenarios, workers directly carry planetary gears from storage to the workbench or inspection area using both hands for subsequent quality inspection processes such as dye penetrant testing. However, as the size and weight of planetary gears increase, the difficulty and risk of manual handling rise sharply. On the one hand, the weight of the planetary gears makes workers prone to fatigue during handling, and long-term engagement in this type of work may lead to occupational diseases such as muscle strain. On the other hand, a slip during handling can not only damage the planetary gear itself but also pose a serious threat to the worker's personal safety. Furthermore, in inspection environments requiring liquids, such as dye penetrant testing, slippery floors further increase the risk of workers slipping and getting injured.

[0005] Simplified Lifting Tool Method: To address the limitations of manual handling, some companies have experimented with simplified lifting tools for transferring planetary gears. Specifically, lifting rings are installed in pre-drilled holes on the planetary gears, and then lifting and transferring are carried out using overhead cranes or other lifting equipment. However, this method also has several drawbacks. First, the lifting rings must be manually installed and removed before each lift, which is cumbersome and inefficient, especially during mass production. Second, due to the limited number and location of the screw holes, stability and balance during lifting are difficult to guarantee, potentially causing the planetary gears to wobble or tilt, increasing the risk of falling and damage. Furthermore, this method has poor applicability to planetary gears and cannot flexibly address the internal hole requirements of products with different specifications and conditions.

[0006] In summary, traditional methods for lifting and transferring large planetary gears have significant shortcomings in terms of efficiency, safety, and applicability, making it difficult to meet the demands of modern machinery manufacturing for efficient, safe, and flexible production. Therefore, developing a new type of large planetary gear lifting fixture to reduce worker workload, improve lifting efficiency, enhance operational safety, and adapt to product requirements of different specifications and conditions has become an urgent technical problem to be solved in the current machinery manufacturing field. Utility Model Content

[0007] In view of this, the purpose of this utility model is to provide a lifting fixture for large planetary gears to solve the existing problems.

[0008] To achieve the above objectives, this utility model provides the following technical solution: a lifting fixture for a large planetary gear, used in conjunction with a crane, includes a welded connecting plate, three electric push rods evenly welded to the welded connecting plate, and a PLC control system. The three electric push rods are on the same plane, and the front end of the telescopic rod of each electric push rod is threadedly connected to a replaceable threaded plastic protective sleeve to adapt to planetary gears with different inner hole states. A threaded hole is opened in the center of the welded connecting plate, and a lifting ring is installed in the hole. A waterproof aviation plug is also installed on the welded connecting plate, and the aviation plug is electrically connected to the three electric push rods through cables. A shielded cable is installed in the crane sling, one end of which is connected to the crane control box, and the other end is connected to the waterproof aviation plug on the welded connecting plate through a quick-connect connector. The PLC control system includes a PLC controller, a pressure sensor, and a displacement sensor. The pressure sensor is located at the front end of the telescopic rod of the electric push rod, and the displacement sensor is built into the electric push rod. The PLC controller is installed in the crane control box, and the pressure sensor and displacement sensor are both connected to the PLC controller through signal lines.

[0009] Optionally, the replaceable threaded plastic protective sleeve has an inner diameter range of 80–120 mm, and the outer wall is provided with anti-slip texture, with a friction coefficient ≥0.4.

[0010] Optionally, the PLC control system is designed with an overload protection module and a power-off self-locking module. The overload protection module automatically retracts the telescopic rod by 0.5mm to relieve pressure when the pressure sensor detects a value > 350N. The power-off self-locking module is a mechanical self-locking mechanism built into the telescopic rod, which maintains the current position when power is off.

[0011] Optionally, the quick-connect connector and aviation plug feature an anti-accidental contact design with a groove depth of 15mm, and only allow the mating plug to be inserted.

[0012] Optionally, the welding connection plate is a round Q235 steel plate with a thickness of 10mm, and the welding distribution angle of the electric push rod telescopic rod is 120°±1°.

[0013] Optionally, the PLC controller executes the following logic: receiving signals from the pressure sensor and displacement sensor; locking the telescopic rod and sending a "lifting permitted" signal to the crane when the tension force is ≥300N or the stroke reaches the preset value; retracting the telescopic rod and disconnecting the power supply after receiving the release command.

[0014] Optionally, the electric push rod has a thrust of 500N, an adjustable stroke of 50–100mm, and an operating voltage of DC 24V.

[0015] The beneficial effects of this utility model are as follows:

[0016] Reducing worker workload: Traditional methods rely on manual handling of planetary gears by holding them with both hands for transfer. Due to the large weight of the planetary gears (e.g., the third-stage planetary gear in a large ship engine gearbox weighs up to 33.5 kg), workers are prone to fatigue during handling, and long-term operation may lead to occupational diseases such as muscle strain. This lifting fixture, however, uses an electric push rod to expand and tighten the inner hole of the planetary gear, and uses a crane to complete the transfer, completely eliminating the physical exertion of manual handling and significantly reducing the labor intensity of workers.

[0017] Improving lifting efficiency and batch processing capacity: Traditional methods of connecting lifting rings to screw holes require the installation and removal of lifting rings one by one, which is cumbersome and time-consuming, especially inefficient during mass production. This fixture uses replaceable threaded plastic protective sleeves to quickly adapt to different inner holes, and works with electric push rods and telescopic rods to achieve rapid tightening and loosening, significantly reducing the lifting time for a single piece and greatly improving batch processing efficiency.

[0018] Enhancing operational safety and stability: Manual handling is prone to accidental slips that could cause planetary gears to fall, resulting in equipment damage or personal injury; traditional lifting methods may cause planetary gear wobbling due to uneven force on the screw holes. This fixture uses evenly welded electric push rods and telescopic rods to uniformly tighten the inner hole, ensuring the stability of the planetary gears during lifting, while avoiding the risk of slipping during manual handling, significantly improving operational safety.

[0019] Expanding the applicability and flexibility of tooling: Traditional methods have poor adaptability to planetary gear specifications and struggle to meet the needs of different internal hole conditions (such as stepped or non-stepped). This tooling, with its replaceable threaded plastic protective sleeve design, can flexibly adapt to various internal hole sizes and shapes without requiring a complete replacement of the tooling, thus expanding its application scenarios and reducing production costs.

[0020] Optimizing the working environment and reducing potential damage: Manual handling requires operation in liquid environments such as dye penetrant testing, where slippery surfaces can easily lead to falls; traditional lifting methods may result in equipment or personnel injury due to planetary gears falling off. This fixture completely eliminates the risk of slippery surfaces during manual handling through mechanized lifting, while also reducing the probability of planetary gears falling off through stable lifting, thus optimizing the working environment and reducing potential losses.

[0021] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic diagram of the overall design of this utility model;

[0024] Figure 2 This is a schematic diagram of the interaction between the present invention and the planetary gear.

[0025] Attached reference numerals: 1. Electric push rod; 2. Welded connecting plate; 3. Replaceable threaded plastic protective sleeve; 4. Planetary gear; 5. Hoist; 6. Lifting ring. Detailed Implementation

[0026] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0028] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0029] Please see Figures 1-3 This is a specific implementation method for a lifting fixture for a large planetary gear; to enable those skilled in the art to more clearly understand the technical solution of this utility model, the following is in conjunction with the appendix. Figure 1-3 The document details a specific implementation method for a large planetary wheel hoisting fixture, including specific implementation scenarios.

[0030] I. Tooling Structure Composition

[0031] The hoisting fixture of this utility model includes the following core components:

[0032] Welded connecting plate 2: Made of round Q235 steel plate, 10mm thick, serving as the mounting base for the electric actuators. The three electric actuators 1 are evenly distributed along the edge of the connecting plate at a welding angle of 120°±1° to ensure uniform force distribution.

[0033] Electric actuator 1: Thrust 500N, stroke adjustable from 50-100mm, operating voltage DC 24V. The front end of the telescopic rod has a replaceable threaded plastic protective sleeve 3, which is compatible with planetary gears 4 with different inner hole conditions via a threaded connection.

[0034] Replaceable threaded plastic protective sleeve 3: inner diameter range 80-120mm, outer wall with anti-slip texture (friction coefficient ≥0.4), material is wear-resistant nylon or polyethylene, and is tightly connected to the electric push rod telescopic rod through threads.

[0035] Lifting ring 6: Installed in the center threaded hole of the welded connecting plate, it is directly connected to the lifting sling of the crane and bears the total weight of the tooling and planetary gears.

[0036] The PLC control system includes a PLC controller (integrated into the crane control box), pressure sensors (located at the front end of the electric push rod extension), displacement sensors (built into the electric push rod), and waterproof aviation connectors. Sensor signals are transmitted to the PLC controller via shielded cables to achieve real-time monitoring of tension force and stroke.

[0037] II. Operation Procedures and Implementation Steps

[0038] Step 1: Tooling preparation and planetary gear positioning

[0039] Based on the inner diameter of the planetary gear 4 to be hoisted (e.g., 100mm), select a replaceable threaded plastic protective sleeve 3 with a matching inner diameter and install it on the front end of the telescopic rod of the electric push rod 1 via threads.

[0040] Place the welding connection plate 2 horizontally above the planetary gear and adjust its position so that the telescopic rods of the three electric push rods 1 are aligned with the inner hole of the planetary gear.

[0041] Step 2: Tightening Operation

[0042] The crane sling connects to the waterproof aviation plug on the welding connection plate 2 via a quick-connect coupling to establish a power and signal transmission channel.

[0043] Operate the crane control box and start the PLC control system. The PLC controller sends a command to drive the three electric push rods 1 to extend the telescopic rods synchronously, so that the outer wall of the replaceable threaded plastic protective sleeve 3 contacts the inner wall of the planetary gear.

[0044] The pressure sensor monitors the tension force in real time. When the detected value reaches 300N, the PLC controller locks the position of the telescopic rod. At the same time, the displacement sensor confirms whether the travel of the telescopic rod has reached the preset value (such as 80mm). After both conditions are met, a "lifting permitted" signal is sent to the crane.

[0045] Step 3: Safe Lifting and Transfer

[0046] After receiving the "lifting permitted" signal, the crane 5 slowly raises the slings and lifts the tooling and planetary gear 4 as a whole through the lifting ring 6.

[0047] During hoisting, the PLC control system continuously monitors the pressure sensor data. If the tension force exceeds 350N due to vibration, the overload protection module is automatically triggered, retracting the telescopic rod by 0.5mm to release pressure and prevent the planetary gears from slipping.

[0048] In the event of a power outage, the power outage self-locking module maintains its current position through the built-in mechanical self-locking mechanism on the telescopic rod, preventing the planetary gears from falling.

[0049] In this embodiment, the power-off self-locking structure employs a worm gear self-locking mechanism. Through the toothed structure of the worm gear and worm, when the motor stops running, the lead angle of the worm is smaller than the equivalent friction angle of the worm gear contact surface, keeping the push rod in its current position. This design makes it difficult for the push rod to move in the opposite direction without external force, thus achieving self-locking. It is not limited to worm gear self-locking; for example, a lead screw and nut self-locking mechanism can be used. When a trapezoidal lead screw is used, self-locking is achieved by increasing the friction between the nut and the lead screw. When the motor stops working, static friction prevents the nut from rotating, keeping the push rod in a fixed position. If a ball screw is used, a braking device (such as a brake) is required to lock the lead screw when the motor stops, preventing its rotation. The above self-locking structures and methods are all existing mature technologies, sufficient to achieve the functions claimed in our application.

[0050] Step 4: Release and Reset

[0051] After being hoisted to the target position, the crane control box sends a release command. The PLC controller drives the electric push rod 1 to retract the telescopic rod, allowing the replaceable threaded plastic protective sleeve 3 to disengage from the planetary gear inner hole.

[0052] Disconnect the quick-connect connector from the aviation plug to complete a single hoisting cycle.

[0053] III. Key Technical Details

[0054] Anti-accidental contact design: The quick-connect connector and aviation plug adopt an anti-accidental contact structure with a groove depth of 15mm, which only allows the matching plug to be inserted, avoiding signal interruption or equipment damage caused by accidental operation.

[0055] Dynamic balance control: Three electric push rods 1 are evenly distributed at 120°, and with the synchronous drive algorithm of the PLC controller, the axial and radial stability of the planetary gear 4 is ensured during the hoisting process.

[0056] Environmental adaptability: The waterproof aviation plug and shielded cable design are suitable for humid environments such as dye penetrant testing, preventing signal interference or short circuits.

[0057] IV. Implementation Results Verification

[0058] In a certain marine engine gearbox production line, when using this tooling to lift a third-stage planetary gear (weight 33.5kg, inner diameter 100mm):

[0059] Efficiency improvement: The lifting time for a single piece has been reduced from 5 minutes to 1 minute, and the batch processing capacity has been increased by 400%.

[0060] Enhanced safety: No planetary gear slipped or wobbled during the hoisting process, reducing the labor intensity of workers by 90%, and no cases of muscle strain occurred.

[0061] Expanded applicability: By replacing the replaceable threaded plastic protective sleeve 3 with different inner diameters, it can successfully adapt to various planetary gears with inner diameters of 80-120mm, with or without steps, reducing tooling change frequency by 80%.

[0062] This implementation method achieves high efficiency, safety, and flexibility in the hoisting of large planetary gears through the collaborative design of mechanical structure and PLC control system, providing an innovative solution for the heavy equipment manufacturing field.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A hoisting tool for a large planetary wheel, used in cooperation with a hoisting machine, characterized in that: It includes a welding connection plate, three electric push rods evenly welded to the welding connection plate, and a PLC control system. The three electric push rods are on the same plane. The front end of the telescopic rod of each electric push rod is connected to a replaceable threaded plastic protective sleeve by thread to adapt to planetary gears with different inner hole states. The welded connecting plate has a threaded hole in the center, in which a lifting ring is installed. The welded connecting plate is also equipped with a waterproof aviation plug, which is electrically connected to three electric push rods via cables. The crane slings are equipped with shielded cables, one end of which is connected to the crane control box, and the other end is connected to the waterproof aviation plug on the welding connection plate via a quick-connect connector. The PLC control system includes a PLC controller, a pressure sensor, and a displacement sensor. The pressure sensor is located at the front end of the electric push rod extension rod, and the displacement sensor is built into the electric push rod. The PLC controller is installed in the crane control box, and both the pressure sensor and the displacement sensor are connected to the PLC controller via signal lines.

2. A hoisting tool for a large planetary wheel according to claim 1, characterized in that: The replaceable threaded plastic protective sleeve has an inner diameter range of 80–120 mm, and the outer wall is provided with anti-slip texture, with a friction coefficient ≥0.

4.

3. The hoisting tool for a large planetary wheel according to claim 1, characterized in that: The PLC control system is designed with an overload protection module and a power-off self-locking module. The overload protection module automatically retracts the telescopic rod by 0.5mm to relieve pressure when the pressure sensor detects a value >350N. The power-off self-locking module is a mechanical self-locking mechanism built into the telescopic rod, which maintains the current position when power is off.

4. The hoisting tool for a large planetary wheel according to claim 1, characterized in that: The quick-connect connectors and aviation plugs are designed to prevent accidental contact, with a groove depth of 15mm, and only allow the mating plug to be inserted.

5. The hoisting tool for a large planetary wheel according to claim 1, characterized in that: The welding connection plate is a round Q235 steel plate with a thickness of 10mm, and the welding distribution angle of the electric push rod telescopic rod is 120°±1°.

6. The hoisting tool for a large planetary wheel according to claim 1, characterized in that: The PLC controller executes the following logic: receives signals from the pressure sensor and displacement sensor; when the tension force is ≥300N or the stroke reaches the preset value, it locks the telescopic rod and sends a "lifting permitted" signal to the crane; after receiving the release command, it retracts the telescopic rod and disconnects the power supply.

7. The hoisting tool for a large planetary wheel according to claim 1, characterized in that: The electric push rod has a thrust of 500N, an adjustable stroke of 50–100mm, and a working voltage of DC 24V.

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