A backlash elimination mechanism for a fork rotary gear transmission

Abstract

This utility model discloses a backlash elimination mechanism for a fork rotary gear transmission, relating to the field of cargo handling technology. The device includes a bridge frame and a drive motor, a driven motor, and a gear shaft mounted thereon. A drive gear is connected to the output end of the drive motor, and a driven gear is connected to the output end of the driven motor. Both the drive gear and the driven gear mesh with the gear shaft. By controlling the drive motor to output a driving torque that rotates the drive gear, and simultaneously controlling the driven motor to output a reverse damping torque that causes the driven gear to abut against the gear shaft, the bidirectional force completely eliminates the backlash between the drive gear, the driven gear, and the gear shaft. This solves the fork wobbling problem caused by backlash in traditional single-motor gear transmissions, significantly improves the fork rotation positioning accuracy, simplifies the overall structure of the mechanism, and reduces manufacturing and maintenance costs.

Description

Technical Field

[0001] This utility model relates to the field of cargo handling technology, and more specifically, to a backlash elimination mechanism for a fork rotary gear transmission. Background Technology

[0002] With the rapid development of the logistics industry and increasingly fierce market competition, customers have placed higher demands on the efficiency of logistics operations and the precision of cargo handling and placement control. In automated logistics systems, AGVs (Automated Guided Vehicles), as core handling equipment, are widely used in production workshops, warehouses, and other scenarios, undertaking the crucial task of accurately transferring and placing goods between designated workstations and specific shelf locations. Among them, three-way stacker AGVs, with their flexible fork operation capabilities, can adapt to the operational needs of narrow aisles and multi-layered shelves, further improving space utilization and operational efficiency, becoming an important piece of equipment in automated warehousing and production logistics. In actual operation, the AGV forks need to adjust the posture of the goods through rotation to ensure accurate docking of goods with workstations on the production line or shelf locations. The rotational accuracy directly affects the smoothness of subsequent production processes and the standardization of warehouse management.

[0003] In existing three-way stacking forklift AGVs, gear transmission mechanisms are mostly used to achieve power transmission and rotation control. However, due to errors in gear manufacturing, assembly clearances, and wear after long-term use, backlash is unavoidable in gear transmission mechanisms. This backlash causes fork wobbling during fork rotation: when the gear transmission mechanism switches rotation directions, backlash causes a brief delay in power transmission, resulting in momentary fork vibration; when the forks are rotating and positioning goods, the wobbling caused by backlash directly affects the positioning accuracy of the forks, making it impossible to accurately place goods in the designated position, resulting in uneven goods placement. This can not only interfere with subsequent production processing or logistics handling operations, but also increase rework rates, reduce overall operational efficiency, and fail to meet current customer demands for high-precision and high-efficiency AGV operations. Utility Model Content

[0004] This utility model provides a backlash elimination mechanism for a fork rotary gear transmission, which can solve the problem in the prior art where the backlash caused by the fork rotating and positioning the goods directly affects the positioning accuracy of the fork, resulting in the goods not being placed accurately in the designated position and thus causing the goods to be placed untidy.

[0005] A fork rotary gear transmission backlash elimination mechanism includes a bridge frame and an active motor, a passive motor, and a gear shaft mounted thereon; the output end of the active motor is connected to an active gear, the output end of the passive motor is connected to a passive gear, and both the active gear and the passive gear mesh with the gear shaft.

[0006] The fork rotary gear transmission backlash elimination mechanism provided by this utility model has the following beneficial effects compared with the prior art: This fork rotary gear transmission backlash elimination mechanism uses a bridge frame as the basic mounting carrier to integrate the drive motor, driven motor, and gear shaft into one unit. The drive gear connected to the output end of the drive motor and the driven gear connected to the output end of the driven motor both mesh with the gear shaft. The drive motor outputs a driving torque to rotate the drive gear, while the driven motor outputs a reverse damping torque to drive the driven gear to abut against the gear shaft. The bidirectional force completely eliminates the backlash between the drive gear, driven gear, and gear shaft, solving the problem of fork wobbling caused by backlash in traditional single-motor gear transmissions. This significantly improves the fork rotation positioning accuracy, eliminates the need for additional complex backlash compensation mechanical components, simplifies the overall structure of the mechanism, and reduces manufacturing and maintenance costs.

[0007] Furthermore, the gear shaft is rotatably connected to the bridge frame, and a fork carriage for mounting forks is fixedly connected to the gear shaft.

[0008] Furthermore, both the active motor and the passive motor are detachably connected to the bridge frame via a fixing bracket, and both the active motor and the passive motor are detachably connected to the fixing bracket via a pad.

[0009] Furthermore, the driving gear and the driven gear are gears of the same specification with the same module and number of teeth.

[0010] Furthermore, the driving gear is located directly below the driven gear.

[0011] Furthermore, the gear shaft includes a drive gear and a rotating shaft connected to its bottom. The drive gear meshes with the active gear and the passive gear. The rotating shaft is rotatably connected to the bridge frame via a bearing housing. The rotating shaft is detachably connected to the fork carriage via fixing bolts. The drive gear is detachably connected to the rotating shaft.

[0012] Furthermore, the fork carriage is provided with a limiting groove, and the forks are equipped with limiting sliders that are adapted to the limiting groove.

[0013] Furthermore, a controller is installed on the bridge, and the controller is electrically connected to the active motor and the passive motor. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the backlash elimination mechanism for a fork rotary gear transmission according to an embodiment of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the backlash elimination mechanism for a fork rotary gear transmission according to an embodiment of the present invention. Figure 2 ; Figure 3 This is a front view of a fork rotary gear transmission backlash elimination mechanism according to an embodiment of the present invention; Figure 4 This is a rear view of a fork rotary gear transmission backlash elimination mechanism according to an embodiment of the present invention.

[0015] Explanation of reference numerals in the attached figures: 1. Drive motor; 2. Drive gear; 3. Passive motor; 4. Passive gear; 5. Gear shaft; 6. Fork carriage; 7. Forks; 8. Bridge; 9. Controller; 10. Fixing frame; 11. Pad; 12. Bearing housing; 13. Limiting groove; 14. Limiting slider; 51. Drive gear; 52. Rotating shaft; 53. Fixing bolt. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0017] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0018] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying 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, they should not be construed as limitations on this utility model.

[0019] Furthermore, in the attached diagram, the X-axis represents the horizontal direction, that is, the front-to-back position, and the positive direction of the X-axis (that is, the direction the arrow points to) represents the front, and the negative direction of the X-axis (that is, the direction opposite to the positive direction of the X-axis) represents the back; in the attached diagram, the Y-axis represents the horizontal direction, that is, the left-to-right position, and the positive direction of the Y-axis (that is, the direction the arrow points to) represents the left, and the negative direction of the Y-axis (that is, the direction opposite to the positive direction of the Y-axis) represents the right; in the attached diagram, the Z-axis represents the vertical direction, that is, the up-to-down position, and the positive direction of the Z-axis (that is, the direction the arrow points to) represents the up, and the negative direction of the Z-axis (that is, the direction opposite to the positive direction of the Z-axis) represents the down.

[0020] It should also be noted that the aforementioned X-axis, Y-axis and Z-axis are only for the purpose of facilitating the description of this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0023] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0024] See Figures 1-3 As shown in the figure, the present invention provides a fork rotary gear transmission backlash elimination mechanism, including a bridge frame 8 and an active motor 1, a passive motor 3 and a gear shaft 5 mounted thereon; the output end of the active motor 1 is connected to an active gear 2, and the output end of the passive motor 3 is connected to a passive gear 4, and both the active gear 2 and the passive gear 4 mesh with the gear shaft 5.

[0025] In this embodiment, the cable tray 8 serves as the basic mounting carrier, integrating the active motor 1, the passive motor 3, and the gear shaft 5 into one unit. The active gear 2 connected to the output end of the active motor 1 and the passive gear 4 connected to the output end of the passive motor 3 both mesh with the gear shaft 5. By controlling the output driving torque of the active motor 1 to drive the active gear 2 to rotate (which can be manually controlled by a switch), and simultaneously controlling the output reverse damping torque of the passive motor 3 to drive the passive gear 4 to abut against the gear shaft 5 (which can be manually controlled by a switch), the bidirectional force completely eliminates the backlash between the active gear 2, the passive gear 4, and the gear shaft 5. This solves the problem of fork wobbling caused by backlash in traditional single-motor gear transmissions, significantly improving the rotational positioning accuracy of the forks. There is no need to add complex backlash compensation mechanical components; backlash elimination can be achieved simply through the cooperation of the existing motor and gears, simplifying the overall structure of the mechanism and reducing manufacturing and maintenance costs.

[0026] Optionally, a controller 9 can be installed on the cable tray 8. The controller 9 is electrically connected to the drive motor 1 and the passive motor 3. Through the electrical connection between the controller 9 and the drive motor 1 and the passive motor 3, the controller 9 can precisely control the output drive torque of the drive motor 1 to drive the drive gear 2 to rotate. At the same time, it controls the output reverse damping torque of the passive motor 3 to drive the passive gear 4 to abut against the gear shaft 5. The bidirectional force completely eliminates the backlash between the drive gear 2, the passive gear 4 and the gear shaft 5, solving the problem of fork wobbling caused by backlash in traditional single-motor gear transmission. This significantly improves the rotation and positioning accuracy of the forks. At the same time, through centralized control by the controller 9, the torque output of the drive motor 1 and the passive motor 3 can be coordinated in real time. This can maintain stable transmission when the forks are rotating, and when the forks stop, the braking of the drive motor 1 and the damping torque of the passive motor 3 can prevent the gear shaft 5 from displaced due to backlash, thus improving operational safety.

[0027] The controller 9 coordinates the output of the driving torque of the active motor 1 and the synchronous output of the reverse damping torque of the passive motor 3, thereby driving the active gear 2 and the passive gear 4 to always strongly abut against the gear shaft 5 from opposite sides, thus forming a continuous "electronic preload" in the transmission chain, dynamically filling and completely eliminating the physical gap between all gear meshing, and realizing backlash-free transmission.

[0028] See Figure 1 The gear shaft 5 is rotatably connected to the bridge frame 8, and a fork carriage 6 for mounting the forks 7 is fixedly connected to the gear shaft 5.

[0029] In this embodiment, the fork carriage 6 for mounting the forks 7 is fixedly connected to the gear shaft 5, so that the rotational power of the gear shaft 5 can be directly and without loss transmitted to the fork carriage 6, thereby driving the forks 7 to rotate synchronously. This avoids the power attenuation or transmission delay problems that may occur in traditional multi-component indirect transmission, ensuring that the rotation of the forks 7 is completely synchronized with the rotation of the gear shaft 5, and improving the accuracy of the forks 7 in adjusting the posture of goods and docking with workstations or cargo positions.

[0030] See Figure 2 Both the active motor 1 and the passive motor 3 are detachably connected to the bridge frame 8 via the fixing frame 10, and both the active motor 1 and the passive motor 3 are detachably connected to the fixing frame 10 via the pad 11.

[0031] In this embodiment, when the active motor 1 or the passive motor 3 malfunctions and needs to be repaired or replaced, there is no need to destructively disassemble the bridge frame 8 or other core components of the mechanism. Only the connecting parts between the fixed frame 10 and the bridge frame 8, and between the motor and the fixed frame 10, need to be disassembled to complete the motor disassembly and assembly. This significantly reduces maintenance difficulty and downtime, and meets the needs of efficient operation and maintenance of AGV equipment in logistics scenarios. The addition of the pad 11 provides flexible space for adjusting the gear meshing accuracy. Due to long-term use or assembly errors, the meshing clearance between the active gear 2, the passive gear 4 and the gear shaft 5 may change slightly. At this time, the installation height and horizontal position of the active motor 1 and the passive motor 3 can be finely adjusted by replacing the pad 11 with one of different thicknesses. This ensures that the active gear 2 and the passive gear 4 can always maintain a precise meshing state with the gear shaft 5, avoiding the effect of tooth backlash elimination due to meshing deviation, and further ensuring the stability and positioning accuracy of the fork rotation.

[0032] See Figure 3 The driving gear 2 and the driven gear 4 are gears of the same specification with the same module and number of teeth.

[0033] In this embodiment, a completely symmetrical transmission interface is constructed by setting the driving gear 2 and the driven gear 4 to be gears of the same specification with the same module and number of teeth. This symmetrical structure ensures that the meshing conditions and transmission ratios of the two gears with the gear shaft 5 are completely consistent. This not only simplifies and standardizes the output torque control strategy of the controller 9 for the driving motor 1 and the driven motor 3, but more importantly, it ensures that the forces acting on both sides of the gear shaft 5 are completely balanced during the "push-pull" process of eliminating backlash. This fundamentally avoids the additional bending moment, vibration, or uneven wear that may be caused by transmission asymmetry, achieving balanced and stable force transmission and significantly improving the control accuracy and mechanical life of the system.

[0034] Specifically, the driving gear 2 is located directly below the driven gear 4. By arranging the driving gear 2 directly below the driven gear 4, a symmetrical and stable structure is formed in the vertical direction, jointly clamping the gear shaft 5. This distributes the force points of the gear shaft 5 on both sides of its vertical central axis, forming a balanced couple, which significantly improves the transmission system's anti-tipping moment capability and overall rigidity. When the forks 7 are carrying goods, this structure can more effectively resist the additional bending moment generated by the load, ensuring that the contact force between the driving gear 2 and the driven gear 4 and the gear shaft 5 remains uniform and consistent. This avoids unilateral wear or jamming that may be caused by structural asymmetry, greatly enhancing the operational stability and reliability of the mechanism under heavy load conditions.

[0035] See Figure 2The gear shaft 5 includes a drive gear 51 and a rotating shaft 52 connected to its bottom. The drive gear 51 meshes with the driving gear 2 and the driven gear 4. The rotating shaft 52 is rotatably connected to the bridge frame 8 through the bearing seat 12. The rotating shaft 52 is detachably connected to the fork carriage 6 through the fixing bolt 53. The drive gear 51 and the rotating shaft 52 are detachably connected.

[0036] In this embodiment, the upper drive gear 51 meshes with the driving gear 2 and the driven gear 4 to transmit backlash-free torque, while the bottom rotating shaft 52 forms a stable rotational support with the bridge frame 8 through the bearing housing 12, and is connected to the fork carriage 6 by fixing bolts 53 in a robust and detachable manner. This not only clearly separates the gear part that bears the meshing force from the shaft part that bears the bending moment and supports the load, allowing each part to be selected for materials and manufactured according to optimal performance, but also greatly facilitates assembly, debugging, and subsequent maintenance. If the drive gear 51 wears, it can be replaced independently without disturbing the entire rotating support system, effectively improving maintenance efficiency and reducing the total life cycle cost.

[0037] See Figure 4 The fork carriage 6 has a limit groove 13, and the fork 7 is equipped with a limit slider 14 that is compatible with the limit groove 13.

[0038] In this embodiment, the limiting slide 13 and the limiting slider 14 together form a high-precision guiding and bearing system, which ensures that the movement trajectory of the fork 7 is strictly limited to the preset path when it is installed or disassembled, effectively preventing swaying or warping, and greatly improving the positioning accuracy and stability of picking up and placing goods.

[0039] Specifically, the limiting groove 13 is provided at the top and bottom of the fork carriage 6.

[0040] The above-disclosed embodiments are only a few specific examples of the present utility model. However, the embodiments of the present utility model are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present utility model.

Claims

1. A backlash elimination mechanism for a fork rotary gear transmission, characterized in that, Includes a bridge (8) and an active motor (1), a passive motor (3) and a gear shaft (5) mounted thereon; The output end of the active motor (1) is connected to an active gear (2), and the output end of the passive motor (3) is connected to a passive gear (4). Both the active gear (2) and the passive gear (4) mesh with the gear shaft (5).

2. The fork rotary gear transmission backlash elimination mechanism as described in claim 1, characterized in that, The gear shaft (5) is rotatably connected to the bridge frame (8), and a fork carriage (6) for mounting forks (7) is fixedly connected to the gear shaft (5).

3. The fork rotary gear transmission backlash elimination mechanism as described in claim 2, characterized in that, The active motor (1) and the passive motor (3) are detachably connected to the bridge frame (8) via a fixing frame (10), and the active motor (1) and the passive motor (3) are detachably connected to the fixing frame (10) via a pad (11).

4. The fork rotary gear transmission backlash elimination mechanism as described in claim 1, characterized in that, The driving gear (2) and the driven gear (4) are gears of the same specification with the same module and number of teeth.

5. The fork rotary gear transmission backlash elimination mechanism as described in claim 1, characterized in that, The driving gear (2) is located directly below the driven gear (4).

6. The fork rotary gear transmission backlash elimination mechanism as described in claim 1, characterized in that, The gear shaft (5) includes a drive gear (51) and a rotating shaft (52) connected to its bottom. The drive gear (51) meshes with the active gear (2) and the passive gear (4). The rotating shaft (52) is rotatably connected to the bridge frame (8) through a bearing seat (12).

7. The fork rotary gear transmission backlash elimination mechanism as described in claim 2, characterized in that, The fork carriage (6) has a limiting groove (13), and the fork (7) is equipped with a limiting slider (14) that is compatible with the limiting groove (13).

8. The fork rotary gear transmission backlash elimination mechanism as described in claim 7, characterized in that, The limiting groove (13) is provided at the top and bottom of the fork carriage (6).

9. The fork rotary gear transmission backlash elimination mechanism as described in claim 6, characterized in that, The rotating shaft (52) is detachably connected to the fork carriage (6) by fixing bolts (53).

10. The fork rotary gear transmission backlash elimination mechanism as described in claim 6, characterized in that, A controller (9) is installed on the bridge (8), and the controller (9) is electrically connected to the active motor (1) and the passive motor (3).

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