Winch with lifting point displacement compensation mechanism for stereoscopic warehouse inventory

Abstract

This invention discloses a hoist for inventory management in a three-dimensional warehouse with a lifting point displacement compensation mechanism. It includes a front frame, a rear frame, and a drum. A drive mechanism is installed inside the drum. The outer cylindrical surface of the drum has guide rope helical grooves and a rope guide assembly that cooperates with the guide rope helical grooves. A helical transmission traction mechanism is provided between the drum, the rope guide assembly, and the front and rear frames to provide traction in the horizontal direction, thereby compensating for the horizontal displacement of the lifting point caused by the reciprocating movement of the rope guide assembly along the drum's axial direction. The advantages are: it minimizes the lateral dimensions, allowing drones equipped with this device to safely navigate above dense shelving without worrying about collision risks caused by the hoist's own protrusion. It effectively avoids the collision risks and passageway problems of traditional external structures operating in narrow passages, fundamentally expanding the adaptability of the operating environment.

Description

Technical Field

[0001] This invention relates to a winch mounted on a drone, specifically a winch for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism, belonging to the technical fields of intelligent warehouse automation equipment and drone application. Background Technology

[0002] In intelligent warehousing systems, manual inventory checks typically rely on aerial work platforms to lift personnel to the appropriate height within the automated warehouse. This method is inefficient, prone to human error, and poses safety hazards due to the height of the work area. Using drones equipped with visual inspection systems to visually identify and inventory warehouse shelves can significantly improve efficiency, prevent information errors, and eliminate safety risks.

[0003] However, the constraints of smart warehousing environments limit drones from conducting close-range operations. First, the extremely dense rack layout within automated warehouses, with its complex surface textures on beams, pallets, and goods, results in narrow usable flight gaps, making it difficult for drones to hover slowly at low altitudes or fly close to the racks. Second, the high-speed downdraft generated by drone rotors can easily blow away cartons, labels, documents, or lightweight materials during close-range operations, potentially causing material damage or detached inventory labels. The resulting dust and airflow disturbances can also severely interfere with the accuracy of visual recognition. Furthermore, drones rely on visual obstacle avoidance in indoor environments where GPS / BeiDou positioning signals are denied. Their tolerance for error is extremely low within complex rack structures, and the risk of collisions when flying close to the racks is extremely high. Industrial applications cannot tolerate such high-frequency collision failures.

[0004] For the reasons mentioned above, there are currently very few cases of drones being used for intelligent inventory counting in smart warehousing systems. Although there are a few winches used on drone platforms, most conventional winches are general-purpose, designed primarily for load-bearing, with simple mechanisms and lacking servo control for lifting. Furthermore, their structural design flaws can easily lead to lifting point misalignment, causing the pod to shift horizontally during lifting. Specifically, when the drone is hovering, the existing winch's rope guide moves along the drum axis when retracting or extending the lifting rope, causing horizontal displacement of the lifting point. This displacement is directly transmitted to the pod, causing unexpected swaying or shifting in the horizontal direction. This severely affects the focusing and recognition accuracy of visual sensors (cameras, scanning heads), reducing the reliability of inventory data. Therefore, they cannot be used for high-precision, high-stability inventory counting operations in smart warehousing. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a hoist for three-dimensional warehouse inventory with a lifting point displacement compensation mechanism.

[0006] To solve the above-mentioned technical problems, the present invention provides a hoist for three-dimensional warehouse inventory with a lifting point displacement compensation mechanism, comprising a front frame, a rear frame, and a drum supported and installed between the front frame and the rear frame by a first support bearing. The drum is provided with a drive mechanism capable of driving the drum to rotate. The outer cylindrical surface of the drum is provided with a rope guide helical groove and a rope guide assembly that cooperates with the rope guide helical groove and can reciprocate along the outer cylindrical surface of the drum axially. A helical transmission traction mechanism is provided between the drum, the rope guide assembly, and the front and rear frames to provide traction to the drum, the front frame, and the rear frame in the horizontal direction, thereby compensating for the horizontal displacement of the lifting point caused by the reciprocating movement of the rope guide assembly along the drum axially.

[0007] The drive mechanism includes a servo drive motor fixedly mounted on the rear frame via a motor mount and a harmonic gear reducer that works with the servo drive motor for power output. The output end of the harmonic gear reducer is connected to the drum and can output power to the harmonic gear reducer through the servo drive motor, thereby driving the drum to rotate.

[0008] The screw drive traction mechanism includes a guide rod and a lead screw that are respectively installed in conjunction with the front frame and the rear frame, a power shaft that can rotate synchronously with the drum, and a transmission mechanism disposed between the power shaft and the lead screw.

[0009] The transmission mechanism includes a main pulley fixedly mounted on the power shaft, a transmission nut mounted on the front frame via a second support bearing and installed in conjunction with a lead screw, a driven pulley fixedly mounted with the transmission nut, and a belt installed between the main pulley and the driven pulley. The power output from the power shaft can be transmitted to the transmission nut via the belt, thereby driving the front frame, rear frame, and drum to move as a whole.

[0010] A front crossbar is fixedly connected between the front ends of the guide rod and the lead screw, and a rear crossbar is fixedly connected between the right ends of the guide rod and the lead screw.

[0011] The front frame is provided with mounting holes. The transmission nut is installed in the inner ring of the support bearing and the second support bearing is fixedly installed in the mounting holes. A spacer is also fitted on the transmission nut. The spacer is pressed and positioned on the end face of the inner ring of the second support bearing by a flat nut screwed onto the transmission nut.

[0012] The transmission nut includes a nut body with a locking section, a shoulder, and a connecting section. The locking section of the nut body extends into the mounting hole through a second support bearing. The shoulder of the nut body presses against the inner ring end face of the second support bearing. The connecting section of the nut body is clearance-fitted with the driven pulley and is locked and fixed by a set screw.

[0013] The driving and driven pulleys of the belt pulleys have the same diameter, and the lead of the lead screw and the lead of the drum are numerically equal and rotate in the same direction, so that the transmission nut can drive the frame and the drum to move in the opposite direction and at the same speed as the rope guide assembly.

[0014] The lead screw includes a smooth section and a threaded section. Linear bearings are provided between the smooth section of the lead screw and the rear frame, as well as between the guide rod and the front and rear frames.

[0015] The drum is fixedly connected to the drive shaft via a flange.

[0016] The advantages of this invention are: (1) The drive mechanism is placed inside the drum and the power is output to the harmonic gear reducer through the servo drive motor, thereby driving the drum to rotate. This minimizes the lateral dimension, allowing the drone equipped with this device to safely pass through the airspace between dense shelves without worrying about the collision risk caused by the protrusion of the winch itself. This effectively avoids the collision risk and passability problem of traditional external structures operating in narrow passages, fundamentally expanding the adaptability of the operation scenario.

[0017] (2) The set lifting point displacement compensation mechanism can maintain the horizontal displacement of the pod during the lifting and lowering process. Especially when the UAV is hovering, the winch is winding and releasing the rope, and the lifting point will change continuously with the change of the position of the rope guide. The horizontal displacement of the lifting point of the system is actively compensated mechanically, so as to ensure that the horizontal position of the pod vision inspection system remains unchanged during the up and down process, without shaking, and ensuring the accurate position control of the vision inspection system.

[0018] (3) The screw drive traction mechanism is mainly composed of a guide rod and a lead screw, a power shaft that can rotate synchronously with the drum, and a transmission mechanism set between the power shaft and the lead screw. It cleverly uses the rotation of the drum as the main force and transmits the power output of the power shaft to the transmission nut through the transmission mechanism. The lead screw is fixed, and then the transmission nut pulls the front frame, the rear frame and the drum to move as a whole. Its structure is ingeniously designed and has good stability, which further ensures the accurate position control of the vision inspection system. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the hoist for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to the present invention. Figure 2 This is a partial structural schematic diagram of the winch used for inventory counting in the three-dimensional warehouse in this invention; Figure 3 This is a schematic diagram of the installation state of the screw drive traction mechanism in this invention. Figure 4This is a side view of the screw drive traction mechanism in the installation state of the present invention. Figure 5 for Figure 3 A magnified structural diagram at point A; Figure 6 for Figure 3 Enlarged cross-sectional view of point A; Figure 7 This is a schematic diagram of the winch for inventory management in a three-dimensional warehouse with a lifting point displacement compensation mechanism, as described in this invention. Detailed Implementation

[0020] The application scenario of the hoist for inventory counting in automated warehouses in this invention is to lift and lower pods. The lifting and lowering displacement of the pods is controlled by a stepper motor. The pods are equipped with a vision inspection device for performing inventory counting or inspection work on goods in the automated warehouse. The hoist for inventory counting in automated warehouses with a lifting point displacement compensation mechanism of this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] The design concept of this invention is to decouple the functions of the drone body and the visual inspection equipment at the operation terminal. That is, the drone body is only responsible for stable cruising and hovering over a large area, achieving the "long-distance movement" function; while the visual inspection pod, lowered by a winch, is responsible for penetrating deep into the cargo location and adhering to the working surface, completing precise alignment and identification under conditions free from airflow interference, achieving the "close-range operation" function. This structural design constitutes a collaborative working mode of long-distance cruising plus close-range operation, fundamentally solving the stringent limitations of the warehousing environment on drone flight. As shown in the figure, the winch for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism of this invention includes a front frame 301 and a rear frame 30. 2. A drum 101, supported by a pair of No. 1 support bearings (needle roller bearings) 102, is installed between the front frame 301 and the rear frame 302. The drum 101 contains a drive mechanism capable of rotating. This drive mechanism includes a servo drive motor 401 fixedly mounted on the rear frame 302 via a motor mount, and a harmonic gear reducer 402 that cooperates with the servo drive motor 401 and is used for power output. The output end of the harmonic gear reducer 402 is connected to the drum 101 and can output power to the servo drive motor 401. A harmonic gear reducer 402 drives the drum 101 to rotate. The outer cylindrical surface of the drum 101 has rope guide helical grooves and a rope guide assembly 200 that cooperates with the rope guide helical grooves and can reciprocate axially along the outer cylindrical surface of the drum 101. A helical transmission traction mechanism 60 is provided between the drum 101, the rope guide assembly 200, and the front frame 301 and rear frame 302 to provide traction in the horizontal direction, thereby compensating for the horizontal displacement of the lifting point caused by the reciprocating movement of the rope guide assembly 200 along the drum's axial direction. 0. This invention introduces a helical drive traction mechanism 600 as an active displacement compensation mechanism, which can effectively solve the problem of horizontal deviation of the pod and achieve "lifting without deviation". This invention decouples the hovering stability of the "UAV body" from the positioning accuracy of the "pod operation" in terms of function. That is, the UAV only needs to maintain a macroscopic hovering state, while the microscopic horizontal stability is completed by the winch itself. This reduces the complexity and burden of the UAV flight control system, greatly reduces position adjustment control, and significantly improves the operational safety and reliability of the whole system in dense rack storage environment.

[0022] Furthermore, the aforementioned screw drive traction mechanism 600 includes a guide rod 504 and a lead screw 505, a drive shaft 602, and a transmission mechanism. The lead screw includes a smooth section and a threaded section. Both the guide rod 504 and the lead screw 505 pass through the front frame 301 and the rear frame 302, and are located at the rear ends of the guide rod 504 and the lead screw 505. Figure 1 The front crossbar 506, guide rod 504, and lead screw 505 are fixedly connected between the left side (defined as the rear end) and the front end of the lead screw 505. Figure 1 A rear crossbar 507 is fixedly connected between the guide rod 504 and the lead screw 505 (defined as the front end on the right), thus achieving a fixed connection between the guide rod 504 and the lead screw 505. The guide rod 504 also passes through the rope guide assembly 200. To reduce friction between the guide rod and the lead screw in the drum mechanism, linear bearings are installed at both ends of the connection between the front and rear frames and the guide rod, as well as on the smooth section of the lead screw. Specifically, linear bearings are installed between the smooth section of the lead screw and the rear frame 302, and between the guide rod and the front and rear frames 301. The drive shaft 602 is mounted on the drum via a flange 601, enabling it to rotate synchronously with the drum. The aforementioned transmission mechanism is provided between the drive shaft and the lead screw. This transmission mechanism includes a main pulley 604 fixedly mounted on the drive shaft, a transmission nut 606 mounted on the front frame 301 via a second support bearing 607 and fitted with the lead screw, and a transmission... The driven pulley 605 is fixedly installed on the moving nut 606, and the belt 603 is installed between the main pulley 604 and the driven pulley 605. The power output from the power shaft 602 can be transmitted to the transmission nut 606 through the belt 603, thereby pulling the front frame 301, the rear frame 302 and the drum 101 to move as a whole, realizing active compensation. Through this unique active compensation design, the screw, transmission nut and transmission mechanism in the screw drive traction mechanism 600 are linked with the rotation of the drum, so that during the hoisting rope winding and unwinding process, the drum can generate synchronous displacement in opposite directions with the guide rope assembly. This design dynamically compensates for the horizontal displacement caused by the movement of the hoisting point, ensuring that the pod maintains a constant horizontal projection position throughout the entire lifting process, eliminating mechanical interference with the accuracy of visual inspection, and realizing the functional decoupling of UAV flight and inventory operation.

[0023] Furthermore, the detailed structure of the connection between the transmission nut 606 and the frame 301 is shown in [reference needed]. Figure 6 The front frame 301 is provided with mounting holes. The outer ring of the second support bearing 607 is interference-fitted with the mounting hole of the front frame, so that the second support bearing 607, the front frame and the hoisting mechanism become a rigid whole. That is, the transmission nut 606 is installed in the inner ring of the second support bearing 607 (the inner ring of the second support bearing 607 and the outer diameter of the transmission nut 606 are clearance-fitted) and the second support bearing is fixedly installed in the mounting hole. The function of the second support bearing 607 is: the inner ring is used to release the rotational freedom of the transmission nut 606, so that the transmission nut can rotate freely on the lead screw. At the same time, the outer ring of the bearing is interference-fitted with the frame hole, so that the frame 301 and the drum can be moved as a whole.

[0024] In addition, a spacer 608 is fitted onto the transmission nut 606. The spacer 608 is pressed and positioned on the inner ring end face of the second support bearing 607 by a flat nut 609 screwed onto the transmission nut. Specifically, by... Figure 6As can be seen, the transmission nut 606 includes a nut body with a locking section, a shoulder, and a connecting section. The locking section of the nut body extends into the mounting hole through the second support bearing. The shoulder of the nut body presses against the inner ring end face of the second support bearing 607. That is to say, the movement of the transmission nut 606 and the second support bearing 607 along the axial direction is locked by the shoulder of the nut body on the right side of the bearing, the spacer 608 on the left side of the second support bearing 607, and the flat nut 609. The flat nut and the thread on the outer diameter of the left side of the nut body (i.e., the locking section) achieve self-locking. The flat nut can be a knurled flat nut, and the knurling on its outer diameter provides friction for manual locking. The connecting section of the nut body is clearance-fitted with the driven pulley 605 and is locked and fixed by the set screw 610 (i.e., the right side of the transmission nut 606). Figure 6 (As shown in the left and right directions) The outer diameter and the inner hole of the driven pulley 605 are clearance-fitted.

[0025] It should also be noted that, in terms of transmission ratio, the driving pulley 604 and the driven pulley 605 have the same diameter, achieving a 1:1 transmission ratio. This 1:1 transmission ratio ensures that the drum 101 and the drive nut 606 have the same angular velocity. The lead of the lead screw 505 is numerically equal to the lead of the drum 101 and rotates in the same direction, enabling the drive nut 606 to drive the frame and drum to move in the opposite direction and at the same speed as the rope guide assembly 200.

[0026] Its working principle is as follows: The built-in servo motor and harmonic gear reducer drive the drum to generate rotational motion, providing winding power for the hoisting rope. At the same time, the drum 101 is fixedly connected to the main pulley 604 through the flange 601 and the power shaft 602. The main pulley, as the active end of the rotational motion, transmits the rotational motion to the driven pulley 605 through the belt 603. The driven pulley is fixedly connected to the transmission nut 606 through the set screw. The rotation of the transmission nut 606 is screwed with the lead screw 505. The lead screw is fixedly connected to the guide rod through the front crossbar 506 and the rear crossbar 507. The rotational and translational motions of the lead screw are locked. As a result, the transmission nut 606 will move linearly along the axis of the lead screw, thereby pulling the front frame 301, the rear frame 302 and the drum as a whole to move.

[0027] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A hoist for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism, comprising a front frame (301), a rear frame (302), and a drum (101) supported and installed between the front frame (301) and the rear frame (302) by a first support bearing (102), wherein a drive mechanism capable of driving the drum to rotate is provided inside the drum (101), and a rope guide spiral groove is arranged on the outer cylindrical surface of the drum (101) and a rope guide assembly (200) that cooperates with the rope guide spiral groove and is capable of reciprocating along the outer cylindrical surface of the drum (101) axially, characterized in that: A helical drive traction mechanism (600) is provided between the drum (101), the rope guide assembly (200), and the front frame (301) and the rear frame (302) to provide traction to the drum (101), the front frame (301) and the rear frame (302) in the horizontal direction, thereby compensating for the horizontal offset of the lifting point caused by the reciprocating movement of the rope guide assembly (200) along the drum axis.

2. The hoist for inventory management in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 1, characterized in that: The drive mechanism includes a servo drive motor (401) fixedly mounted on the rear frame (302) via a motor mount and a harmonic gear reducer (402) that cooperates with the servo drive motor (401) and is used for power output. The output end of the harmonic gear reducer (402) is connected to the drum (101) and can output power to the harmonic gear reducer (402) through the servo drive motor (401), thereby driving the drum (101) to rotate.

3. The hoist for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 1 or 2, characterized in that: The helical drive traction mechanism (600) includes a guide rod (504) and a lead screw (505) that are respectively installed in cooperation with the front frame (301) and the rear frame (302), a power shaft (602) that can rotate synchronously with the drum, and a transmission mechanism disposed between the power shaft and the lead screw.

4. The hoist for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 3, characterized in that: The transmission mechanism includes a main pulley (604) fixedly mounted on the power shaft, a transmission nut (606) mounted on the front frame (301) via a second support bearing (607) and installed in conjunction with a lead screw, a driven pulley (605) fixedly mounted with the transmission nut (606), and a belt (603) installed between the main pulley (604) and the driven pulley (605). The power output from the power shaft (602) can be transmitted to the transmission nut (606) via the belt (603) to drive the front frame (301), the rear frame (302), and the drum (101) to move as a whole.

5. The hoist for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 4, characterized in that: A front crossbar (506) is fixedly connected between the front ends of the guide rod (504) and the lead screw (505), and a rear crossbar (507) is fixedly connected between the right ends of the guide rod (504) and the lead screw (505).

6. The hoist for inventory management in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 5, characterized in that: The front frame (301) is provided with mounting holes. The transmission nut (606) is installed in the inner ring of the support bearing and the second support bearing is fixedly installed in the mounting holes. The transmission nut (606) is also fitted with a spacer (608). The spacer (608) is pressed and positioned on the inner ring end face of the second support bearing by a flat nut (609) screwed onto the transmission nut.

7. The hoist for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 6, characterized in that: The transmission nut (606) includes a nut body having a locking section, a shoulder, and a connecting section. The locking section of the nut body extends into the mounting hole through a second support bearing. The shoulder of the nut body presses against the inner ring end face of the second support bearing (607). The connecting section of the nut body is clearance-fitted with the driven pulley (605) and is locked and fixed by a set screw (610).

8. A hoist for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 4, 5, 6 or 7, characterized in that: The driving pulley (604) and driven pulley (605) have the same diameter, and the lead of the screw (505) is numerically equal to the lead of the drum (101) and rotates in the same direction, so that the transmission nut (606) can drive the frame and the drum to move in the opposite direction and at the same speed as the rope guide assembly (200).

9. The hoist for inventory management in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 8, characterized in that: The lead screw includes a smooth section and a threaded section. Linear bearings are provided between the smooth section of the lead screw and the rear frame (302) and between the guide rod and the front frame (301) and the rear frame (302).

10. The hoist for inventory counting in a three-dimensional warehouse with a lifting point displacement compensation mechanism according to claim 0, characterized in that: The drum is fixedly connected to the drive shaft via a flange.

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