Gearbox for turning plate assembly

Abstract

A flap assembly for engaging a marine container, the flap assembly comprising a flap arm (1) pivotally mounted on a spreader, the flap arm (1) being movable about a pivot mounting point between an open position and a closed position; the gearbox is connected with the flap arm (1) and the input driver (2), and the gearbox is suitable for transmitting input torque from the input driver so as to drive the flap arm (1) to move between the opening position and the closing position of the flap arm (1); the gearbox comprises a locking mechanism, and the locking mechanism is used for preventing linear vertical movement of one or more components in the gearbox under the condition that the gearbox is impacted by external force during operation.

Description

Technical Field

[0001] This invention relates to a gearbox for a flap assembly, and more particularly to a gearbox suitable for hydraulic or electric input drive for driving the operation of the flap arm. Background Technology

[0002] Currently, the mainstream technology for tilting operations on spreader rigs is hydraulic drive. Hydraulic actuators drive the tilting plate to rotate, providing collection and holding torque to assist in placing the spreader onto shipping containers. However, traditional hydraulic systems are sensitive to temperature changes and prone to oil leaks, affecting their performance and reliability. Hydraulic systems require a continuous power supply to provide pressurized hydraulic energy to drive various spreader operations. This can lead to energy waste due to low system efficiency. With increasing global focus on climate action, port operators are looking to achieve sustainable and resilient operations by adopting electric equipment instead of traditional electro-hydraulic systems. However, current electric tilting drive units on the market are large, heavy, complex in design, have poor performance, and suffer from low reliability and maintainability.

[0003] Therefore, many technologies have been researched and implemented to improve the gearbox of the flap assembly. For example, a Singapore patent with publication number SG186520A1 discloses a spreader assembly that includes a spreader for engaging and disengaging with a container engagement device of a container, and a cover engagement device mounted on the spreader. The cover engagement device has an actuator for positioning a cover engagement frame close to the container cover, the frame engaging with the cover so that the actuator can move the cover relative to the container.

[0004] US Patent Publication No. US11708247B2 discloses a container spreader for connecting containers to a lifting device. The spreader has multiple guide plates and a displacement device connected thereto, allowing the guide plates to shift between a working position A and a non-working position B. The displacement device has a hydraulic rotary motor equipped with an output shaft connected to the guide plate via a connecting element. A hydraulic unit is connected to the rotary motor via a coupling device for supplying and discharging hydraulic oil from the rotary motor. By employing a hydraulic rotary motor, a final drive is eliminated, and valves are not required to keep the hydraulic motor pressurized.

[0005] Another US patent, US8025324B2, discloses a device for a spreader used in container lifting. This device includes a flap arm supported at a corner of the spreader, allowing the flap arm to pivot between a raised rest position and a lowered operating position. When the spreader is attached to a container, the flap arm effectively positions the spreader angle relative to the corresponding angle of the container. The device is characterized by the flap arm being mounted on a rotatable shaft and driven by a motor, with a power transmission device between the motor and the flap arm. This power transmission device effectively transmits torque from the motor to the flap arm when the motor is energized, and locks the flap arm in its pivoted position when the motor is de-energized. Summary of the Invention

[0006] One object of this invention is to accommodate different types of input drives, whether electric, hydraulic, or a combination of both. Another object is to provide a modular design that allows the gearbox to be configured in different ways by mounting the input drives at different angular orientations. A further object is to provide a gearbox that is easy to maintain, repair, and troubleshoot.

[0007] In one aspect of the invention, a flapper assembly for engagement with a shipping container is provided, the flapper assembly including a flapper arm pivotally mounted on a spreader, the flapper arm being movable between an open position and a closed position about a pivot mount; a gearbox operatively connected to the flapper arm and an input drive, the gearbox being used to transmit input torque from the input drive to move the flapper arm between its open and closed positions; wherein the gearbox includes a locking mechanism that prevents one or more components within the gearbox from linear vertical movement in the event of an external impact during operation.

[0008] Preferably, the flap arm is connected to the gearbox via an output shaft that passes through the gearbox.

[0009] Preferably, the gearbox is encapsulated in an upright housing.

[0010] Preferably, the input driver is connected to the gearbox via a plurality of spur gears connected in series and encapsulated in a base housing.

[0011] Preferably, the base housing pivots at the bottom of the upright housing, such that the base housing is positioned relative to the upright housing by an angle of rotation about the pivot.

[0012] Preferably, the input driver is an electric driver or a hydraulic driver.

[0013] Preferably, the locking mechanism includes a rack and pinion integrated with the screw jack.

[0014] Preferably, the screw jack includes a screw jack shaft, a screw jack top nut, and a screw jack bottom boss.

[0015] Preferably, when subjected to external impact during operation, the top nut and bottom boss of the screw jack restrict the vertical linear movement of the screw jack.

[0016] Those skilled in the art will readily understand that the present invention is well capable of achieving these objectives, obtaining the mentioned results and beneficial effects, and realizing its inherent beneficial effects. The embodiments described herein are not intended to limit the scope of the invention. Attached Figure Description

[0017] To facilitate understanding of the invention, preferred embodiments are shown in the accompanying drawings. The invention, its construction, operation, and many advantages will be readily understood and appreciated when examined in conjunction with the following description of the preferred embodiments.

[0018] Figure 1 This is an isometric view of a preferred embodiment of the flap assembly.

[0019] Figure 2 This is a front sectional view of the gearbox of the flap assembly.

[0020] Figure 3 This is a side sectional view of the gearbox of the flap assembly.

[0021] Figure 4 This is a top cross-sectional view of the gearbox of the flap assembly. Detailed Implementation

[0022] The present invention will now be described with reference to preferred embodiments and the accompanying drawings. However, it should be understood that the description is limited to the preferred embodiments of the invention merely for ease of discussion, and it is foreseeable that those skilled in the art can conceive of various modifications without departing from the scope of the appended claims.

[0023] The invention will now be described in more detail by way of example with reference to the accompanying drawings.

[0024] exist Figure 1The diagram illustrates a flap assembly for engaging shipping containers, specifically one of several flap assemblies used in a shipping container lifting spreader. Preferably, the flap assembly is mounted to each corner of the spreader and points outward at a certain angle (e.g., 45 degrees) relative to the corner of the shipping container. To guide the spreader during engagement with the shipping container, the flap assembly includes a flap arm 1 pivotally mounted to the spreader, which is movable between an open position and a closed position. The open position can be described as an elevated rest position or initial position, while the closed position can be described as a lowered operating position; these terms are interchangeable throughout the description of the invention. In operation, when the spreader is lowered to the top side of the shipping container for engagement, the flap arm 1 can extend below the spreader and adjacent to the side or corner of the container, thereby positioning and guiding the spreader.

[0025] It should be understood that the flapper arm 1 may experience high impact loads when the spreader approaches the shipping container. Therefore, the flapper arm 1 is designed to withstand the high impact loads generated by contact with the container when guiding the spreader towards it. It should also be understood that significant swaying or bouncing may occur when the spreader contacts the shipping container and the flapper arm 1 descends to the corner of the container. This swaying can lead to impact loads, which the flapper arm must resist, as high impact loads can potentially damage the flapper arm 1 and the corresponding components driving it. According to the invention, the flapper arm 1 can be connected to the gearbox via an output shaft 14 passing through the gearbox. The gearbox includes a locking mechanism that prevents one or more components within the gearbox from linear vertical movement when subjected to external impact during operation. The external force referred to here is the swaying or bouncing generated when the flapper arm 1 descends to the corner of the shipping container.

[0026] refer to Figures 2 to 4 A preferred embodiment of the invention is shown in cross-sectional view of a gearbox, which is preferably encapsulated in an upright housing 7 having upright housing walls 15a, 15b, and 15c for protecting the components within the gearbox from external impurities or impact loads. Additionally, the gearbox includes a base housing 4 for encapsulating a plurality of tandemly configured spur gears 5 and 6, through which the gearbox is connected to an input drive 2, enabling the gearbox to transmit input torque from the input drive 2, thereby driving the flap arm 1 to move between its open and closed positions.

[0027] The base housing 4 is pivotable at the bottom of the upright housing 7, allowing it to be positioned relative to the upright housing 7 at an angle about a pivot axis, for example, an angle ranging from 0° to 180°. Advantageously, this configuration enables the invention to be modular, scalable, and extensible. Furthermore, both the base housing 4 and the upright housing 7 are filled with lubricating oil, which reduces friction generated during operation, minimizes wear on internal components, improves component operating efficiency, and dissipates heat generated by friction to prevent overheating, thereby extending the service life of the internal components.

[0028] refer to Figures 2 to 4 The input drive 2 can be hydraulically or electrically driven. It can be mounted vertically to eliminate the adverse effects of cantilever mounting, or mounted on the same plane adjacent to the gearbox to reduce the overall height of the flap assembly. Hydraulic drives often offer higher force output and smoother operation, but require additional components such as hydraulic pumps, valves, and hydraulic oil, making them more complex. On the other hand, electric drives offer more precise control over the speed and position of the flap arm 1 and are generally more energy-efficient than hydraulic drives. Furthermore, electric drives are cleaner and require less maintenance because they do not require hydraulic oil, reducing the risk of hydraulic oil leaks or gearbox contamination. Although hydraulic drives generally offer higher force output compared to electric drives, advancements in electric drives have enabled them to generate greater force while maintaining high-precision control. However, the optimal choice between hydraulic and electric drives depends on the specific requirements of the application. The gearbox, however, can be adapted for either hydraulic or electric drive, allowing for flexible arrangement according to user requirements.

[0029] In a preferred embodiment, the input driver 2 includes an input drive shaft 3 connected to a first spur gear 5 in the base housing 4. The first spur gear 5 is connected in series with a second spur gear 6, which is connected to a screw jack 8 in the gearbox. Preferably, the gear ratio of the first spur gear 5 and the second spur gear 6 is variable, for example, 1:2, 1:3, etc., so that the speeds of the first spur gear 5 and the second spur gear 6 can be optimally adjusted throughout the flipping operation, thereby achieving effective torque distribution from the input driver 2 to the screw jack 8. In another embodiment, more spur gears can be used and connected in series to accommodate any increased spacing between the input driver 2, the upright housing 7, and the flipping arm 1.

[0030] Preferably, the screw jack 8 is a mechanical device that converts rotary motion into linear motion. For this purpose, the screw jack 8 includes a screw jack shaft 9, a bottom boss 10, and a top nut 11. Preferably, the screw jack 8 is encapsulated in an upright housing 7, so that the screw jack 8 can be integrated with the rack 12 and pinion 13, all of which together constitute the locking mechanism as described above. In a preferred embodiment, the rack 12 and pinion 13 cooperate with the screw jack shaft 9 to convert rotary motion into linear motion, or vice versa. Preferably, the rack 12 can be a linear gear, particularly a toothed gear that travels perpendicularly to the thread of the screw jack shaft 9, while the pinion 13 is a circular gear that meshes with the rack 12, converting the linear motion of the rack 12 into rotary motion. In this embodiment, the upright housing walls 15a, 15b, and 15c further facilitate the linear motion of the rack 12 along the screw jack shaft 9. Furthermore, the pinion 13 is coupled with the output shaft 14 extending outward from the upright housing 7. The output shaft 14 supports the flap arm 1, so that the rotational motion of the pinion 13 drives the flap arm 1 to rotate between its open and closed positions.

[0031] During operation, the input driver 2, spur gears 5 and 6, screw jack 8 and output shaft 14 together form a power transmission system. This system transmits the rotational motion and torque of the input driver 2 to the flap arm 1, thereby changing and adjusting the speed of the input driver 2 accordingly to provide a suitable output speed for the flap arm 1.

[0032] During the lowering operation of the tilting arm 1, the input driver 2 drives the first spur gear 5 via the input drive shaft 3. The first spur gear 5 then drives the second spur gear 6, which in turn drives the screw jack shaft 9 to rotate in the same direction as the second spur gear 6. As the screw jack shaft 9 moves, the rack 12 can move vertically upward or downward along the screw jack shaft 9. The bottom boss 10 of the screw jack restricts the upward movement of the rack 12, while the top nut 11 of the screw jack restricts the downward movement of the rack 12. With this configuration, the input driver 2 can generate a concentrated torque on the tilting arm 1, and particularly on the screw jack 8.

[0033] In this embodiment, the gearbox may also be subjected to external impact loads when the flap arm 1 moves between the open and closed positions. Under such external impact loads, the rearward movement of the flap arm 1 due to the rotational movement of the output shaft 14 may cause the screw jack 8 to produce a linear movement in the vertical direction. However, the vertical movement of the screw jack 8 is restricted by the screw jack bottom boss 10 and the screw jack top nut 11, which respectively constrain its upward and downward movement. In turn, this generates a strong holding torque on the flap arm 1, enabling the flap arm 1 to resist external impact loads and remain in its original position. This strong holding torque prevents the screw jack 8 and the flap arm 1 from moving uncontrollably, which could potentially damage the gearbox inside.

[0034] This invention provides a gearbox suitable for various types of input drives 2, featuring a modular design that allows for conversion into different configurations. The gearbox can be installed in the narrowest spaces on a spreader and is scalable, integrating other functional options as needed, such as a slipper clutch. Compared to existing technologies, this gearbox is also simpler in design and easier to maintain and troubleshoot in case of failure.

[0035] This disclosure includes the appended claims and the content contained in the foregoing description. Although the invention has been described in detail to some extent in its preferred form, it should be understood that the disclosure of the preferred form of the invention is by way of example only, and many changes may be made in terms of structural details, combinations and arrangements of components without departing from the scope of the invention.

Claims

1. A flap assembly for engaging a shipping container, the flap assembly comprising: a pivotally mounted flap arm (1) on a spreader, the flap arm (1) being movable about the pivotal mounting between an open position and a closed position; and a gearbox in operative connection with the flap arm (1) and an input drive (2), wherein the gearbox is adapted to transmit input torque from the input drive (2) to move the flap arm (1) between its open and closed positions; the gearbox comprising a locking mechanism for preventing linear vertical movement of one or more components within the gearbox in the event of an external force impact during operation. the flap arm (1) is connected to the gearbox by an output shaft (14) that passes through the gearbox.

2. The flap assembly of claim 1, wherein the gearbox is enclosed in an upright housing (7).

3. The flap assembly of claim 1 or 2, wherein, the input drive (2) is connected to the gearbox by a plurality of spur gears (5, 6) connected in series and enclosed in a base housing (4).

4. The flap assembly of any of the preceding claims, wherein, the base housing (4) is pivotal at the bottom of the upright housing (7) such that the base housing (4) is at an angle of rotation about the pivot axis relative to the upright housing (7).

5. The flap assembly of claim 4, wherein, the input drive (2) is an electric drive or a hydraulic drive.

6. The flap assembly of any of the preceding claims, wherein, the locking mechanism comprises a rack (12) and pinion (13) integrated with a screw jack (8).

7. The flap assembly of any of the preceding claims, wherein, the screw jack (8) comprises a screw jack shaft (9), a screw jack bottom boss (10) and a screw jack top nut (11).

8. The flap assembly of claim 7, wherein, the screw jack top nut (11) and the screw jack bottom boss (10) are for limiting vertical linear movement of the screw jack (8) in the event of an external force impact during operation.

9. The flap assembly of claim 8, wherein, ​

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