Fork rotating gear transmission backlash eliminating mechanism and eliminating method thereof

Abstract

The invention discloses a fork rotating gear transmission backlash eliminating mechanism and an eliminating method thereof, and relates to the technical field of cargo handling, the device comprises a bridge frame, and a driving motor, a driven motor and a gear shaft which are mounted on the bridge frame; the output end of the driving motor is connected with a driving gear, the output end of the driven motor is connected with a driven gear, and the driving gear and the driven gear are both meshed with the gear shaft. A driving gear connected with the output end of a driving motor and a driven gear connected with the output end of a driven motor are both meshed with a gear shaft, the driving motor is controlled to output driving torque to drive the driving gear to rotate, and meanwhile the driven motor is controlled to output reverse damping torque to drive the driven gear to abut against the gear shaft. The two-way acting force thoroughly eliminates the backlash among the driving gear, the driven gear and the gear shaft, the problem that the pallet fork shakes due to the backlash in traditional single-motor gear transmission is solved, the rotation positioning precision of the pallet fork is greatly improved, the overall structure of the mechanism is simplified, and the manufacturing and maintenance cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cargo handling, in particular to a fork rotation gear transmission backlash elimination mechanism and an elimination method thereof. BACKGROUND

[0002] With the rapid development of the logistics industry, market competition is becoming increasingly fierce, and customers have higher requirements for the efficiency of logistics operations and the control accuracy of cargo handling and placement. In an automated logistics system, AGV (Automatic Guided Vehicle) as a core handling equipment is widely used in production workshops, warehouse rooms and other scenarios, and undertakes the key task of accurately transferring and placing goods between specified workstations and specific locations of shelves. Among them, the three-way stacking forklift AGV, with its flexible fork operation capability, can adapt to the operation needs of narrow passages and multi-layer shelves, further improving space utilization and operation efficiency, and has become an important equipment in automated warehousing and production logistics. In actual operation process, the AGV fork needs to adjust the attitude of the goods through rotation to ensure that the goods are accurately docked with the workstation on the production line or the location on the shelf, and the rotation accuracy is directly related to the smoothness of the subsequent production process and the standardization of warehouse management.

[0003] In the existing fork rotation drive structure of the three-way stacking forklift AGV, a gear transmission mechanism is mostly used to realize power transmission and rotation action control. However, due to the errors in the manufacturing process of the gear, the assembly gap and the wear after long-term use, etc., the gear transmission mechanism inevitably has backlash. This backlash will cause the fork to shake during rotation: when the gear transmission mechanism switches the rotation direction, the backlash will cause a temporary delay in power transmission, causing the fork to shake momentarily; when the fork carrying goods rotates and positions, the shaking caused by the backlash will directly affect the positioning accuracy of the fork, causing the goods to be unable to be accurately placed at the specified location, and thus causing the goods to be placed irregularly, which not only may interfere with subsequent production or logistics handling operations, but also increases the operation rework rate and reduces the overall operation efficiency, making it difficult to meet the current customer demand for high-precision and high-efficiency operation of AGV. SUMMARY

[0004] The present application provides a fork rotation gear transmission backlash elimination mechanism, which can solve the problem that the shaking caused by the backlash directly affects the positioning accuracy of the fork when the fork carrying goods rotates and positions, causing the goods to be unable to be accurately placed at the specified location, and thus causing the goods to be placed irregularly.

[0005] The application discloses a kind of fork rotation gear transmission backlash elimination mechanism, including bridge and being installed on its active motor, passive motor and gear shaft;The output end of the active motor is connected with driving gear, the output end of the passive motor is connected with passive gear, and the driving gear and the passive gear are engaged with the gear shaft.

[0006] The fork rotation gear transmission backlash elimination mechanism provided by the application has the following beneficial effects, but is not limited to: The fork rotation gear transmission backlash elimination mechanism integrates the active motor, the passive motor and the gear shaft by taking the bridge as a basic installation carrier, and the driving gear connected with the output end of the active motor and the passive gear connected with the output end of the passive motor are engaged with the gear shaft. The output driving torque of the active motor drives the driving gear to rotate, and the output reverse damping torque of the passive motor drives the passive gear to abut against the gear shaft. The bidirectional force completely eliminates the backlash between the driving gear, the passive gear and the gear shaft, solves the problem of fork shaking caused by backlash in traditional single-motor gear transmission, greatly improves the rotation positioning accuracy of the fork, does not need to additionally add complex backlash compensation mechanical parts, simplifies the overall structure of the mechanism, and reduces the manufacturing and maintenance costs.

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

[0008] Further, the active motor and the passive motor are detachably connected to the bridge via a fixing frame, and the active motor and the passive motor are detachably connected to the fixing frame via a backing plate.

[0009] Further, the driving gear and the passive gear are gears of the same specification with the same modulus and the same number of teeth.

[0010] Further, the driving gear is located directly below the passive gear.

[0011] Further, the gear shaft includes a driving gear and a rotating shaft connected to the bottom of the driving gear, the driving gear is engaged with the driving gear and the passive gear, the rotating shaft is rotatably connected to the bridge via a bearing seat, and the rotating shaft is detachably connected to the fork frame via a fixing bolt.

[0012] Further, a limiting sliding groove is formed in the fork frame, and a limiting sliding block adapted to the limiting sliding groove is mounted on the fork.

[0013] Further, the controller is electrically connected to the active motor and the passive motor.

[0014] The method comprises the following steps: S1, outputting a preset initial damping torque by a passive motor; S2, when the forks need to rotate, controlling the active motor to output a driving torque corresponding to the target motion direction, while maintaining or adjusting the damping torque of the passive motor, so that the active gear and the passive gear continuously abut the gear shaft from both sides; S3, when the forks reach the target position and need to stop, controlling the active motor to enter the braking state, and maintaining the damping torque of the passive motor, so that the gear shaft is bidirectionally clamped and fixed; and S4, when the forks need to rotate reversely, switching the direction of the driving torque of the active motor, and correspondingly adjusting the direction of the damping torque of the passive motor, so as to maintain the gear transmission without backlash.

[0015] Further, the size of the damping torque is adjusted in real time by the controller according to the load state and the motion state of the forks. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Structure diagram of the fork rotating gear transmission backlash elimination mechanism of an embodiment of the present application Figure 1 ; Figure 2 Structure diagram of the fork rotating gear transmission backlash elimination mechanism of an embodiment of the present application Figure 2 ; Figure 3 Front view of the fork rotating gear transmission backlash elimination mechanism of an embodiment of the present application Figure 4 Rear view of the fork rotating gear transmission backlash elimination mechanism of an embodiment of the present application

[0017] Explanation of reference signs: 1, active motor; 2, active gear; 3, passive motor; 4, passive gear; 5, gear shaft; 6, fork frame; 7, fork; 8, bridge frame; 9, controller; 10, fixed frame; 11, pad plate; 12, bearing seat; 13, limiting sliding groove; 14, limiting sliding block; 51, driving gear; 52, rotating shaft; 53, fixed bolt. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings which show the embodiments according to the present application. It should be understood that the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments described in the present application, all other embodiments obtained by those skilled in the art without creative labor shall fall within the scope of protection of the present application.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application; the description herein and the claims and the above drawings are not intended to be all-inclusive in terms of the techniques and compositions they describe, which can include many more than what is presently described and many plausible adaptations suitable for particular applications. The terms "comprises", "comprising", "includes", "including", "has", "having" and the like are open-ended terms that are used to describe various embodiments and are synonymous with the terms "consisting of", "consisting essentially of" and "consisting of". Thus, use of these terms in the description herein is not intended to delimit the application, but rather to open and set the scope of the application defined by the claims. The terms "first", "second", and the like, as used herein do not have any specific one-one correspondence with objects discussed herein, but are used to distinguish between different objects. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or an indicated number of the technical features. Thus, features defined with "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality" is two or more, unless otherwise stated.

[0020] In the description of the application, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and therefore cannot be understood as limiting the application. The indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the application.

[0021] Furthermore, in the drawings, the X-axis represents the lateral direction, that is, the front and back positions, and the positive direction of the X-axis, that is, the direction of the arrow of the X-axis, 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; the Y-axis represents the lateral direction, that is, the left and right positions, and the positive direction of the Y-axis, that is, the direction of the arrow of the Y-axis, 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; the Z-axis represents the vertical direction, that is, the up and down positions, and the positive direction of the Z-axis, that is, the direction of the arrow of the Z-axis, 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.

[0022] It should be noted that the aforementioned X-axis, Y-axis and Z-axis represent the meaning only for the purpose of facilitating the description of the application and simplifying the description, and therefore cannot be understood as limiting the application. The indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the application.

[0023] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "attachment" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0024] It should be emphasized that when the term "comprising / including" is used in the present specification, it is used to explicitly indicate the presence of the features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or groups of features, integers, steps, components.

[0025] The term "and / or" in the present application is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the existence of A alone, the existence of A and B together, and the existence of B alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects have an "or" relationship.

[0026] Referring to Figures 1-3 As shown in the figure, the fork rotating gear transmission backlash elimination mechanism provided by the embodiment of the present application comprises a bridge 8 and a driving motor 1, a driven motor 3 and a gear shaft 5 mounted thereon; the driving motor 1 is connected with a driving gear 2 at the output end, the driven motor 3 is connected with a driven gear 4 at the output end, and the driving gear 2 and the driven gear 4 are both engaged with the gear shaft 5.

[0027] In the embodiment, the driving motor 1, the driven motor 3 and the gear shaft 5 are integrated by taking the bridge 8 as a basic mounting carrier, the driving gear 2 connected with the output end of the driving motor 1 and the driven gear 4 connected with the output end of the driven motor 3 are both engaged with the gear shaft 5, the driving motor 1 is controlled to drive the driving gear 2 to rotate (which can be manually controlled by a switch), and the driven motor 3 is controlled to drive the driven gear 4 to abut against the gear shaft 5 (which can be manually controlled by a switch) at the same time, the bidirectional force completely eliminates the backlash between the driving gear 2, the driven gear 4 and the gear shaft 5, solves the problem of fork shaking caused by backlash in the traditional single-motor gear transmission, greatly improves the positioning accuracy of the fork rotation, and does not need to additionally add complex backlash compensation mechanical components, but only needs to realize backlash elimination through the cooperation of the existing motor and gear, simplifies the overall structure of the mechanism, and reduces the manufacturing and maintenance costs.

[0028] Optionally, a controller 9 can be installed on the bridge 8, and the controller 9 is electrically connected with the driving motor 1 and the driven motor 3; and then the controller 9 can be electrically connected with the driving motor 1 and the driven motor 3, so that the driving motor 1 can be precisely controlled to output a driving torque to drive the driving gear 2 to rotate, and the driven motor 3 can be controlled to output a reverse damping torque to drive the driven gear 4 to abut against the gear shaft 5, so that the double-acting force can completely eliminate the backlash between the driving gear 2, the driven gear 4 and the gear shaft 5, solve the problem of fork shaking caused by backlash in the traditional single-motor gear transmission, greatly improve the rotation positioning accuracy of the fork, and at the same time, the controller 9 can be used to centrally control the torque output of the driving motor 1 and the driven motor 3, so that the stable transmission can be maintained when the fork rotates, and the cooperation of the driving motor 1 and the driven motor 3 can prevent the gear shaft 5 from being displaced due to backlash when the fork stops, thereby improving the operation safety.

[0029] The controller 9 can drive the driving gear 2 and the driven gear 4 to always strongly abut against the gear shaft 5 from opposite sides by coordinating the driving torque output by the driving motor 1 and the reverse damping torque output by the driven motor 3, so that a continuous “electronic pretightening force” is formed in the transmission chain, the physical gap between all gear meshes is dynamically filled and completely eliminated, and backlash-free transmission is achieved.

[0030] Referring to Figure 1 , the gear shaft 5 is rotatably connected to the bridge 8, and the fork frame 6 for mounting the fork 7 is fixedly connected to the gear shaft 5.

[0031] In this embodiment, the fork frame 6 for mounting the fork 7 is fixedly connected to the gear shaft 5, so that the rotational power of the gear shaft 5 can be directly and losslessly transmitted to the fork frame 6, thereby driving the fork 7 to synchronously rotate, avoiding the power attenuation or transmission delay problem that may occur in the indirect transmission of the traditional multiple components, and ensuring that the rotation of the fork 7 is completely synchronized with the rotation of the gear shaft 5, thereby improving the accuracy of the fork 7 in adjusting the posture of the goods, docking the work station or the goods location.

[0032] Referring to Figure 2 , the driving motor 1 and the driven motor 3 are detachably connected to the bridge 8 through the fixing frame 10, and the driving motor 1 and the driven motor 3 are detachably connected to the fixing frame 10 through the pad 11.

[0033] In this embodiment, when the active motor 1 or the passive motor 3 needs to be repaired or replaced due to failure, it is not necessary to disassemble the bridge 8 or other core components of the mechanism destructively, and the motor can be disassembled only by disassembling the connecting components between the fixed frame 10 and the bridge 8 and between the motor and the fixed frame 10, which significantly reduces the difficulty of maintenance and downtime, and meets the needs of efficient operation and maintenance of AGV equipment in the logistics scene; the addition of the shim 11 provides flexible space for gear meshing precision adjustment. Due to long-term use or assembly errors, the meshing gap 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 adjusted by replacing shims 11 of different thicknesses, to ensure that the active gear 2 and the passive gear 4 can always be in precise meshing state with the gear shaft 5, avoiding the influence of meshing deviation on the effect of backlash elimination, and further ensuring the stability and positioning accuracy of the fork rotation.

[0034] Referring to Figure 3 , the active gear 2 and the passive gear 4 are gears of the same size with the same modulus and number of teeth.

[0035] In this embodiment, by setting the active gear 2 and the passive gear 4 as gears of the same size with the same modulus and number of teeth, a completely symmetrical transmission interface is constructed. This symmetrical structure ensures that the meshing conditions and transmission ratios of the two gears and the gear shaft 5 are completely consistent, which not only simplifies and standardizes the output torque control strategy of the controller 9 for the active motor 1 and the passive motor 3, but more importantly, it ensures that the forces acting on both sides of the gear shaft 5 are completely balanced in the process of eliminating backlash, thereby fundamentally avoiding additional bending moments, vibrations or eccentric wear caused by asymmetric transmission, achieving balanced and stable force transmission, and significantly improving the control accuracy and mechanical life of the system.

[0036] Specifically, the active gear 2 is located directly below the passive gear 4; by arranging the active gear 2 directly below the passive gear 4, a symmetrical and stable structure that jointly clamps the gear shaft 5 is formed in the vertical direction, so that the stress points of the gear shaft 5 are distributed on both sides of its vertical central axis, forming a balanced couple, thereby significantly improving the anti-overturning moment capacity and overall rigidity of the transmission system. When the fork 7 carries goods, this structure can more effectively resist the additional bending moment generated by the load, ensuring that the abutting force of the active gear 2 and the passive gear 4 on the gear shaft 5 remains uniform, avoiding unilateral wear or jamming caused by asymmetric structure, and greatly enhancing the running stability and reliability of the mechanism under heavy load conditions.

[0037] Referring to Figure 2The gear shaft 5 comprises a driving gear 51 and a rotating shaft 52 connected at the bottom of the driving gear 51, the driving gear 51 is engaged with the driving gear 2 and the driven gear 4, the rotating shaft 52 is rotatably connected with the bridge 8 through the bearing seat 12, and the rotating shaft 52 is detachably connected with the fork frame 6 through the fixing bolt 53.

[0038] In the embodiment, the driving gear 51 at the upper part is engaged with the driving gear 2 and the driven gear 4 to transmit the anti-backlash torque, and the rotating shaft 52 at the bottom is stably rotatably supported by the bearing seat 12 and the bridge 8, and is firmly and detachably connected with the fork frame 6 through the fixing bolt 53. Not only the gear part bearing the engagement force and the shafting part bearing the bending moment and supporting the load are clearly separated in structure, so that each part can be selected in material and manufactured in process according to the optimal performance, but also the assembly, debugging and later maintenance are greatly facilitated. If the driving gear 51 is worn, it can be replaced independently without disturbing the whole rotating support system, so that the maintenance efficiency is effectively improved and the whole life cycle cost is reduced.

[0039] Referring to Figure 4 The fork frame 6 is provided with a limiting sliding groove 13, and the fork 7 is provided with a limiting sliding block 14 matched with the limiting sliding groove 13.

[0040] In the embodiment, the limiting sliding groove 13 and the limiting sliding block 14 together form a high-precision guiding and bearing system, so that the movement track of the fork 7 is strictly limited on the preset path during the installation and disassembly, the deflection or warping is effectively prevented, and the positioning accuracy and stability of the picking and placing operation are greatly improved.

[0041] Specifically, the limiting sliding groove 13 is arranged at the top and the bottom of the fork frame 6.

[0042] A fork rotating gear transmission backlash elimination method, comprising: S1: outputting a preset initial damping torque by the driven motor 3; S2: when the fork 7 needs to rotate, controlling the driving motor 1 to output a driving torque corresponding to the target movement direction, while maintaining or adjusting the damping torque of the driven motor 3, so that the driving gear 2 and the driven gear 4 continuously abut the gear shaft 5 from both sides; S3: when the fork 7 reaches the target position and needs to stop, controlling the driving motor 1 to enter the braking state, and maintaining the damping torque of the driven motor 3, so that the gear shaft 5 is bidirectionally clamped and fixed; S4: when the fork 7 needs to rotate in the opposite direction, switching the direction of the driving torque of the driving motor 1, and correspondingly adjusting the direction of the damping torque of the driven motor 3, so as to maintain the backlash-free transmission.

[0043] In the embodiment, the controller 9 controls the passive motor 3 to output a preset initial damping torque in advance, so that the passive gear 4 preliminarily abuts against the gear shaft 5 when the forks 7 are not started, thereby laying a foundation for the backlash-free transmission in the subsequent rotating operation and avoiding the starting jitter caused by the backlash in the initial stage; the controller 9 controls the driving motor 1 to output a driving torque in a corresponding direction to drive the driving gear 2 to rotate, while maintaining or adjusting the damping torque of the passive motor 3, so that the driving gear 2 and the passive gear 4 continuously abut against the gear shaft 5 from both sides, thereby ensuring the power transmission without delay during the rotation of the forks 7 and completely eliminating the backlash to avoid the shaking of the forks 7 when the forks 7 rotate while carrying the goods and to ensure the positioning accuracy; when the forks 7 stop at the target position, the controller 9 controls the driving motor 1 to brake, while the passive motor 3 maintains the damping torque, so that the gear shaft 5 is clamped and fixed in both directions, which can effectively prevent the displacement of the gear shaft 5 due to the backlash compared with the braking of the single motor alone, further improves the stability of the forks 7 after stopping, and avoids the displacement of the goods; when the forks 7 rotate reversely, the controller 9 synchronously switches the driving torque direction of the driving motor 1 and the damping torque direction of the passive motor 3, so as to ensure that the driving gear 2 and the passive gear 4 always abut against the gear shaft 5 in both directions and maintain the backlash-free transmission state, thereby solving the problem of the instantaneous jitter caused by the backlash when the transmission direction is switched in the traditional transmission, making the reverse rotation of the forks 7 more stable, and adapting to the efficient and accurate operation requirements of the three-way stacking forklift AGV in complex operation scenarios.

[0044] Specifically, the size of the damping torque is adjusted by the controller 9 according to the load state and the motion state of the forks 7 in real time; by giving the controller 9 the real-time sensing and decision-making ability, the dynamic and intelligent management of the damping torque is realized, in the starting or braking stage of the forks 7, the controller 9 will increase the damping torque of the passive motor 3 to eliminate the gap between the transmission chains in a strong manner and ensure the action response without delay and the positioning without overshoot; in the uniform speed running stage, the damping torque is appropriately reduced to effectively reduce the system loss and the motor heating and realize the energy-saving operation; when the system senses that the load increases, the controller 9 can adaptively increase the damping torque in proportion to ensure that the backlash is reliably eliminated under any load condition, and the real-time closed-loop control based on the load and the motion state makes the mechanism achieve the optimal balance among the precision, the efficiency and the reliability.

[0045] The above disclosure is only a few specific embodiments of the present application, but the embodiments of the present application are not limited thereto, and any changes that can be thought of by those skilled in the art shall fall within the protection scope of the present application.

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). The rotating shaft (52) is detachably connected to the fork carriage (6) through a fixing bolt (53).

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 1, characterized in that, The controller (9) is electrically connected to the active motor (1) and the passive motor (3).

9. A method for eliminating backlash in a fork rotary gear transmission, using the backlash elimination mechanism for a fork rotary gear transmission as described in any one of claims 1-8, characterized in that, include: S1: Output a preset initial damping torque through the passive motor (3); S2: When the forks (7) need to rotate, control the active motor (1) to output the driving torque corresponding to the target movement direction, and at the same time maintain or adjust the damping torque of the passive motor (3) so that the active gear (2) and the passive gear (4) continuously abut against the gear shaft (5) from both sides. S3. When the forks (7) reach the target position and need to stop, control the active motor (1) to enter the braking state and maintain the damping torque of the passive motor (3) so that the gear shaft (5) is clamped and fixed in both directions. S4. When the forks (7) need to rotate in the opposite direction, switch the direction of the driving torque of the active motor (1) and adjust the direction of the damping torque of the passive motor (3) accordingly to maintain backlash-free transmission.

10. The method for eliminating backlash in a fork rotary gear transmission as described in claim 9, characterized in that, The magnitude of the damping torque is adjusted in real time by the controller (9) according to the load state and motion state of the forks (7).

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