Method of operating a roller conveyor system with two 90 degree commutations in succession

Abstract

The application discloses a working method of a roller conveyor system capable of realizing twice 90-degree commutation in sequence, which is suitable for the conveying requirement of a lithium battery production line; a commutation transfer unit (3) is arranged on a commutation conveying support (5) arranged along a left-right horizontal direction; a row of front short conveying roller cylinders (6) and a row of rear short conveying roller cylinders (7) are arranged on the top end surface of the commutation conveying support (5) and parallel to each other and along the left-right horizontal direction; a left-side liftable transfer machine (8) is arranged on the commutation conveying support between the left end of the row of front short conveying roller cylinders (6) and the left end of the row of rear short conveying roller cylinders; and a right-side liftable transfer machine (9) is arranged on the commutation conveying support between the right end of the row of front short conveying roller cylinders (6) and the right end of the row of rear short conveying roller cylinders; the effective and uniform conveying of the driving force of the left-right direction short rollers in the commutation unit is realized, and the components of the whole commutation unit are lightened and economical.

Description

Technical Field

[0001] This invention relates to a pallet conveying system, and more particularly to a method for operating a roller conveyor system capable of performing two 90-degree reversals in sequence. Background Technology

[0002] Existing pallet conveying systems that achieve vertical transfer on a plane generally employ chain conveyor systems. A liftable transfer machine is installed between two parallel conveyor chains. Pallets conveyed in the left-right direction are lifted by the liftable transfer machine when they reach the vertical transfer position, causing them to detach from the conveying surface of the chain conveyor in the left-right direction. After turning 90 degrees, they are transferred to another conveyor surface. The goods being conveyed are generally placed on a dedicated pallet. A three-legged pallet support is installed on the bottom surface of the pallet. The three-legged pallet support is about 150 mm wide and its direction is perpendicular to the conveyor chain. The pallet is placed on the conveyor chain by the movement of the support legs and is moved along with the conveyor chain by the friction between the two.

[0003] With the rapid development of the lithium battery industry, pallet conveyor lines have begun to be used to transport batteries and their production parts in lithium battery production workshops and warehouses. This lithium battery conveyor line has extremely high rigid requirements for the cleanliness, low debris, low vibration, anti-static, explosion-proof and low maintenance of the chain conveyor system. The existing chain conveyor system can no longer meet these requirements. If a dense roller conveyor system with added protection is used to replace the chain conveyor system, the cleanliness requirement can be basically solved, but the following problems still exist: (1) Traditional dense long roller conveyors have the disadvantage of high cost of long rollers; (2) When the conveyor line needs to transfer vertically, there is a problem of mutual interference between the transfer machine and the long roller, making it impossible to place the liftable transfer machine directly below the long roller; (3) Since the roller conveyor needs to transmit power through a multi-stage closed sprocket transmission unit, a large-power drive motor is required for the conveyor line with a long transmission distance, resulting in a large motor power in the transmission system, heavy transmission components, and high system cost; in addition, there is also the problem of poor stability of the roller conveyor system. Summary of the Invention

[0004] This invention provides a working method for a roller conveyor system that can sequentially achieve two 90-degree reversals. It achieves a clever combination of the transfer roller conveyor and the liftable transfer machine at the two 90-degree reversals, greatly improves the stability of the entire conveying system, reduces system costs, and well adapts to the conveying requirements of lithium battery production lines.

[0005] The present invention solves the above technical problems through the following technical solutions: A roller conveyor system capable of sequentially performing two 90-degree reversals includes a left rear roller conveyor line and a right front roller conveyor line. A reversing and transfer unit is installed between the left rear roller conveyor line and the right front roller conveyor line. A pallet with a three-legged support is sequentially conveyed through the left rear roller conveyor line, the reversing and transfer unit, and the right front roller conveyor line. The reversing and transfer unit is mounted on a reversing conveyor support arranged horizontally in the left-right direction. On the top surface of the reversing conveyor support, a [missing information - likely a number of units] are arranged parallel to each other in the left-right horizontal direction. A row of front short conveyor rollers and a row of rear short conveyor rollers are arranged. A left-side liftable transfer machine is located between the left end of the row of front short conveyor rollers and the left end of the row of rear short conveyor rollers. A right-side liftable transfer machine is located between the right end of the row of front short conveyor rollers and the right end of the row of rear short conveyor rollers. The pallet from the left rear roller conveyor line is transferred and turned 90 degrees by the left-side liftable transfer machine and then conveyed to the right end of the reversing transfer unit. After being transferred and turned 90 degrees by the right-side liftable transfer machine, it is conveyed to the right front roller conveyor line.

[0006] In the middle of a row of front short conveyor rollers, a front center short conveyor roller 1 and a front center short conveyor roller 2 are arranged side by side; to the left of the front center short conveyor roller 1, front left short conveyor rollers are arranged at equal intervals; to the right of the front center short conveyor roller 2, front right short conveyor rollers are arranged at equal intervals, and the number of front left short conveyor rollers is equal to the number of front right short conveyor rollers; the arrangement of a row of rear short conveyor rollers is exactly the same as the arrangement of a row of front short conveyor rollers.

[0007] In the middle of the reversing conveyor support, a central mounting bracket is provided for the drive motors of two rows of short conveyor rollers. A dual-output shaft motor and a long drive shaft bracket are respectively mounted on the central mounting bracket. A long drive shaft is movably mounted on the long drive shaft bracket. A first front drive sprocket and a second front drive sprocket are respectively provided at the front end of the long drive shaft. At the front end of the first short conveyor roller on the front side center, a first drive sprocket and a second drive sprocket are respectively provided. At the front end of the second short conveyor roller on the front side center, a third drive sprocket and a fourth drive sprocket are respectively provided. The system comprises a wheel; a first annular drive chain is provided between the front sprocket on the front end of the dual-output shaft motor and the first front drive sprocket; a second annular drive chain is provided between the second front drive sprocket, the first drive sprocket, and the third drive sprocket; a left-transfer annular chain that transmits driving force to the left is provided between the second drive sprocket and the adjacent left-side short conveyor roller; a right-transfer annular chain that transmits driving force to the right is provided between the fourth drive sprocket and the adjacent right-side short conveyor roller; and a short conveyor roller drive mechanism with the same structure as the front end of the long drive shaft is provided at the rear end of the long drive shaft.

[0008] The reversing conveyor support is equipped with a closed cover that encloses the left conveyor ring chain and a closed cover that encloses the right conveyor ring chain.

[0009] A method for operating a roller conveyor system capable of sequentially performing two 90-degree reversals, characterized by the following steps: Step 1: The left-side liftable transfer machine rises, and the pallets from the left rear roller conveyor line are transferred to the left-side liftable transfer machine. The second step is that the left-side liftable transfer machine drops down, and the pallet is transferred between a row of front short conveyor rollers and a row of rear short conveyor rollers. After being turned 90 degrees by the row of front short conveyor rollers and the row of rear short conveyor rollers, it is conveyed from left to right. Third step: After the pallet is conveyed to the position between the right end of a row of front short conveyor rollers and the right end of a row of rear short conveyor rollers, the right-side liftable transfer machine rises and transfers the pallet onto the right-side liftable transfer machine; then, the right-side liftable transfer machine turns the pallet 90 degrees and conveys it to the right front roller conveyor line, so that the pallet is conveyed in the right front roller conveyor line in the direction from back to front.

[0010] A central mounting bracket for the drive motors driving two rows of short conveyor rollers is located in the middle of the reversing conveyor support. The central mounting bracket houses the drive motors and a long drive shaft bracket, on which the long drive shaft is movably mounted. A first and second front drive sprockets are located at the front end of the long drive shaft. At the front end of the first central short conveyor roller on the front side, a first and a second front drive sprocket are located. At the front end of the second central short conveyor roller on the front side, a third and a fourth front drive sprocket are located. One row of front short conveyor rollers is driven in the following manner: First, the first front-end drive sprocket set at the front end of the long drive shaft is driven to rotate by the front-end sprocket and the first annular drive chain set on the rear end extension shaft of the drive motor, thereby driving the long drive shaft to rotate. Secondly, the second front drive sprocket, which rotates with the long drive shaft, drives the first drive sprocket at the front end of the first short conveyor roller at the front center and the third drive sprocket at the front end of the second short conveyor roller at the front center to rotate simultaneously via the second annular drive chain. Finally, the rotation of the front center short conveyor roller drives the front two drive sprockets set at the front end of the front center short conveyor roller to rotate. The front two drive sprockets drive the other front left short conveyor rollers to rotate in sequence through the left transmission ring chain set between the front left short conveyor rollers adjacent to the front two drive sprockets, which transmits driving force to the left. The rotation of the two short conveyor rollers at the front center drives the four drive sprockets at the front end of the two short conveyor rollers at the front center to rotate simultaneously. The four drive sprockets drive the other short conveyor rollers at the front right side in sequence through the right conveyor ring chain that transmits driving force to the right between the four drive sprockets at the front right side. This enables a row of short front conveyor rollers to rotate clockwise synchronously.

[0011] A first rear drive sprocket and a second rear drive sprocket are respectively arranged at the rear end of the long drive shaft. In the middle of a row of rear short conveyor rollers, a rear center short conveyor roller 1 and a rear center short conveyor roller 2 are respectively arranged. At the rear end of the rear center short conveyor roller 1, a rear drive sprocket 1 and a rear drive sprocket 2 are respectively arranged. At the rear end of the rear center short conveyor roller 2, a rear drive sprocket 3 and a rear drive sprocket 4 are respectively arranged. The drive structure of the row of rear short conveyor rollers is the same as that of the row of front short conveyor rollers. The rotation direction of the row of rear short conveyor rollers is the same as that of the row of front short conveyor rollers, and they rotate synchronously.

[0012] The spacing between two adjacent front short conveyor rollers and the spacing between two adjacent rear short conveyor rollers are both less than the width of each leg of the cross-shaped support on the bottom surface of the tray.

[0013] This invention solves the problem of interference between roller conveyors and conveyor rollers by using densely arranged short rollers on both the front and rear sides of the top of the reversing unit support of the conveyor system. This involves removing the middle section of a long roller and designing it as a broken two-section design, freeing up lifting space for the transfer machine. A dual-output shaft motor synchronously drives both ends of a long drive shaft on the reversing unit, and then synchronously drives the two middle short rollers of the two rows of densely arranged short rollers on the front and rear sides. This achieves effective and uniform transmission of driving force in the left and right directions of the short rollers in the reversing unit, resulting in lightweight and economical components and smooth 90-degree turns of the pallet. Furthermore, by replacing the traditional chain conveyor with a densely arranged, broken two-row arrangement of short rollers and enclosing the short roller conveyor chain, this invention meets the stringent requirements of lithium battery manufacturers for stable, reliable, and clean conveyor lines. This invention produces less oil, no debris, low vibration, and requires no maintenance, completely replacing ordinary chain conveyors and is suitable for conveying lithium batteries, photovoltaics, and other new energy sources across all scenarios. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention from a top view. Figure 2This is a schematic diagram of the reversing and transfer unit 3 of the present invention in a top view. Figure 3 This is a schematic diagram of the reversing and transfer unit 3 of the present invention in the main view direction; Figure 4 This is a schematic diagram of the reversing and transfer unit 3 of the present invention in a side view direction; Figure 5 This is a schematic diagram of the short roller drive power transmission mechanism in the reversing and transfer unit 3 of the present invention in the top view direction; Figure 6 This is a schematic diagram of the short roller drive power transmission mechanism in the reversing and transfer unit 3 in the main viewing direction of the present invention. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings: A roller conveyor system capable of sequentially achieving two 90-degree reversals includes a left rear roller conveyor line 1 and a right front roller conveyor line 2. A reversing and transfer unit 3 is arranged between the left rear roller conveyor line 1 and the right front roller conveyor line 2. A tray 4 with a three-legged support is sequentially conveyed through the left rear roller conveyor line 1, the reversing and transfer unit 3, and the right front roller conveyor line 2. The reversing and transfer unit 3 is mounted on a reversing conveyor support 5 arranged horizontally. On the top surface of the reversing conveyor support 5, a row of front short conveyor rollers 6 and a row of rear short conveyor rollers 7 are arranged parallel to each other and horizontally. The row of front short conveyor rollers 6 and the row of rear short conveyor rollers 7 are arranged correspondingly. The corresponding two front short conveyor rollers and rear short conveyor rollers can be understood as the middle part of a long roller being removed, leaving only the front and rear sections. A left-side liftable transfer machine 8 is installed between the left end of the front short conveyor roller 6 and the left end of the rear short conveyor roller 7. When the left-side liftable transfer machine 8 is raised, its top surface will be higher than the conveying working surface of the two rows of short conveyor rollers. When the left-side liftable transfer machine 8 is lowered, its top surface will be lower than the conveying working surface of the two rows of short conveyor rollers. A right-side liftable transfer machine 9 is installed between the right end of the front short conveyor roller 6 and the right end of the rear short conveyor roller 7. The tray 4 from the left rear roller conveyor line 1 is transferred and turned 90 degrees by the left-side liftable transfer machine 8 and then conveyed to the right end of the reversing transfer unit 3. After being transferred and turned 90 degrees by the right-side liftable transfer machine 9, it is conveyed to the right front roller conveyor line 2. The conveying working surfaces of the left rear roller conveyor line 1 and the right front roller conveyor line 2 are both higher than the conveying working surfaces of the two rows of short conveyor rollers on the reversing transfer unit 3.

[0016] In the middle of a row of front short conveyor rollers 6, a front center short conveyor roller 16 and a front center second short conveyor roller 17 are arranged side by side; to the left of the front center short conveyor roller 16, front left short conveyor rollers 21 are arranged continuously to the left at equal intervals; to the right of the front center second short conveyor roller 17, front right short conveyor rollers 22 are arranged continuously to the right at equal intervals. The number of front left short conveyor rollers 21 is equal to the number of front right short conveyor rollers 22; the arrangement of a row of rear short conveyor rollers 7 is exactly the same as the arrangement of a row of front short conveyor rollers 6.

[0017] In the frame of the reversing conveyor bracket 5, a central mounting bracket 10 is provided for two rows of drive motors driving short conveyor rollers. A drive motor 11 and a long drive shaft bracket 12 are respectively mounted on the central mounting bracket 10. A long drive shaft 13 is movably mounted on the long drive shaft bracket 12. A first front drive sprocket 18 and a second front drive sprocket 19 are arranged side-by-side at the front end of the long drive shaft 13. At the front end of the first short conveyor roller 16 at the front side center, a first drive sprocket 23 and a second drive sprocket 24 for the first short conveyor roller 21 at the front side center are respectively provided. At the front end of the second short conveyor roller 17 at the front side center, a third drive sprocket 26 and a fourth drive sprocket 29 for the second short conveyor roller at the front side center are respectively provided. The drive motor 11... A first annular drive chain 14 is provided between the front sprocket 20 on the front end of the extended shaft and the first front drive sprocket 18; a second annular drive chain 15 is provided between the second front drive sprocket 19, the first drive sprocket 23 and the third drive sprocket 26; a left transmission annular chain 27 that transmits driving force to the left is provided between the second drive sprocket 24 and the adjacent front left short transmission roller 21; a right transmission annular chain 28 that transmits driving force to the right is provided between the fourth drive sprocket 29 and the adjacent front right short transmission roller 22; a short transmission roller drive mechanism with the same structure as the front end of the long drive shaft 13 is provided at the rear end of the long drive shaft 13, and the two identical drive mechanisms work together to drive the long drive shaft 13.

[0018] The reversing conveyor support 5 is equipped with a closed cover 25 for enclosing the left conveyor ring chain and a closed cover for enclosing the right conveyor ring chain, respectively, to control the contamination of the conveyor chains within the closed box to meet production requirements.

[0019] A method for operating a roller conveyor system capable of sequentially performing two 90-degree reversals, the roller conveyor system comprising a left rear roller conveyor line 1 and a right front roller conveyor line 2, wherein a reversing transfer unit 3 is provided between the left rear roller conveyor line 1 and the right front roller conveyor line 2, the reversing transfer unit 3 being mounted on a reversing conveyor support 5 arranged horizontally in the left-right direction, wherein on the top surface of the reversing conveyor support 5, a row of front short conveyor rollers 6 and a row of rear short conveyor rollers 7 are arranged parallel to each other in the left-right horizontal direction, a left-side liftable transfer machine 8 is provided between the left end of the row of front short conveyor rollers 6 and the left end of the row of rear short conveyor rollers 7, and a right-side liftable transfer machine 9 is provided between the right end of the row of front short conveyor rollers 6 and the right end of the row of rear short conveyor rollers 7; a tray 4 with a cross-shaped support leg is provided on the left rear roller conveyor line 1, conveying in a rear-to-front direction; characterized by the following steps: Step 1: The left-side liftable transfer machine 8 is raised, and the pallet 4 is transferred from the left rear roller conveyor line 1 to the top surface of the left-side liftable transfer machine 8. The second step is that the left-side liftable transfer machine 8 is lowered, and the pallet 4 is transferred to the short conveyor rollers between a row of front short conveyor rollers 6 and a row of rear short conveyor rollers 7. It is then conveyed by the row of front short conveyor rollers 6 and the row of rear short conveyor rollers 7, thus achieving a 90-degree turn and being conveyed from left to right. Third step: After the pallet 4 is conveyed to the position between the right end of the front short conveyor roller 6 and the right end of the rear short conveyor roller 7, the right-side liftable transfer machine 9 rises to lift the pallet 4, so that it is separated from the front short conveyor roller 6 and the rear short conveyor roller 7, and is transferred to the right-side liftable transfer machine 9; then, the right-side liftable transfer machine 9 conveys the pallet 4 to the right front roller conveyor line 2, so that the pallet 4 achieves a second 90-degree reversal, and is conveyed on the right front roller conveyor line 2 in a back-to-foreign direction.

[0020] A central mounting bracket 10 for driving motors that drive two rows of short conveyor rollers is provided in the middle of the reversing conveyor support 5. A drive motor 11 and a long drive shaft support 12 are respectively mounted on the central mounting bracket 10. A long drive shaft 13 is movably mounted on the long drive shaft support 12. A first front drive sprocket 18 and a second front drive sprocket 19 are respectively provided at the front end of the long drive shaft 13. A first drive sprocket 23 and a second drive sprocket 24 are respectively provided at the front end of the first short conveyor roller 16 at the front side center. A third drive sprocket 26 and a fourth drive sprocket 29 are respectively provided at the front end of the second short conveyor roller 17 at the front side center. A row of front short conveyor rollers 6 is driven in the following manner: First, the first front drive sprocket 20 and the first annular drive chain 14 on the front end of the drive motor 11 drive the first front drive sprocket 18 on the front end of the long drive shaft 13 to rotate, thereby driving the long drive shaft 13 to rotate. Secondly, the second front drive sprocket 19, which rotates with the long drive shaft 13, is set at the front end of the long drive shaft 13 and drives the first drive sprocket 23 set at the front end of the first short conveyor roller 16 and the first third drive sprocket 26 set at the front end of the second short conveyor roller 17 to rotate simultaneously via the second annular drive chain 15. Finally, the front center short conveyor roller 16 drives the front two drive sprockets 24, which are located at the front end of the front center short conveyor roller 16, to rotate. The front two drive sprockets 24, through the left transmission ring chain 27 between the front left short conveyor rollers 21 adjacent to the front two drive sprockets 24, transmit driving force to the left, thereby driving the other front left short conveyor rollers 21 to rotate in sequence. A closed left transmission ring chain 27 is provided between each pair of adjacent front left short conveyor rollers 21. The front center two short conveyor rollers 17 drive the front four drive sprockets 29 set at the front end of the front center two short conveyor rollers 17 to rotate simultaneously. The front four drive sprockets 29 drive the other front right short conveyor rollers 22 to rotate in sequence through the right transmission ring chain 28 set between the front right short conveyor rollers 22 adjacent to the front four drive sprockets. This enables a row of front short conveyor rollers 6 to rotate synchronously in a clockwise direction.

[0021] A first rear drive sprocket and a second rear drive sprocket are respectively provided at the rear end of the long drive shaft 13. In the middle of a row of rear short conveyor rollers 7, a rear center short conveyor roller 1 and a rear center short conveyor roller 2 are respectively provided. At the rear end of the rear center short conveyor roller 1, a rear drive sprocket 1 and a rear drive sprocket 2 are respectively provided. At the rear end of the rear center short conveyor roller 2, a rear drive sprocket 3 and a rear drive sprocket 4 are respectively provided. The drive structure of the row of rear short conveyor rollers 7 is the same as the drive structure and method of the row of front short conveyor rollers 6. The rotation direction of the row of rear short conveyor rollers 7 is the same as the rotation direction of the row of front short conveyor rollers 6, and they rotate synchronously.

[0022] The distance between two adjacent front short conveyor rollers 6 and the distance between two adjacent rear short conveyor rollers 7 are both less than the width of each leg of the cross-shaped support on the bottom surface of the tray 4, so as to avoid jamming of the cross-shaped support.

Claims

1. A method for operating a roller conveyor system capable of sequentially performing two 90-degree reversals, the roller conveyor system comprising a left rear roller conveyor line (1) and a right front roller conveyor line (2), wherein a reversing transfer unit (3) is provided between the left rear roller conveyor line (1) and the right front roller conveyor line (2), the reversing transfer unit (3) is provided on a reversing conveyor support (5) arranged in a left-right horizontal direction, and on the top surface of the reversing conveyor support (5), the units are parallel to each other and arranged in a left-right horizontal direction. In a horizontal direction, a row of front short conveyor rollers (6) and a row of rear short conveyor rollers (7) are arranged respectively. A left-side liftable transfer machine (8) is provided between the left end of the row of front short conveyor rollers (6) and the left end of the row of rear short conveyor rollers (7). A right-side liftable transfer machine (9) is provided between the right end of the row of front short conveyor rollers (6) and the right end of the row of rear short conveyor rollers (7). A tray (4) with a cross-shaped support leg is provided on the left rear roller conveyor line (1) and conveys in a direction from back to front. Its features are as follows: The following steps: Step 1: The left-side liftable transfer machine (8) is raised, and the pallet (4) from the left rear roller conveyor line (1) is transferred to the left-side liftable transfer machine (8); The second step is that the left-side liftable transfer machine (8) is lowered, and the pallet (4) is transferred between a row of front short conveyor rollers (6) and a row of rear short conveyor rollers (7). After being turned 90 degrees by the row of front short conveyor rollers (6) and the row of rear short conveyor rollers (7), it is conveyed from left to right. Third step: When the pallet (4) is conveyed to the position between the right end of a row of front short conveyor rollers (6) and the right end of a row of rear short conveyor rollers (7), the right-side liftable transfer machine (9) is raised and the pallet (4) is transferred to the right-side liftable transfer machine (9); then, the right-side liftable transfer machine (9) turns the pallet (4) 90 degrees and conveys it to the right front roller conveyor line (2), so that the pallet (4) is conveyed on the right front roller conveyor line (2) in the direction from back to front.

2. The working method of a roller conveyor system capable of sequentially achieving two 90-degree reversals according to claim 1, characterized in that, A central mounting bracket (10) for driving motors that drive two rows of short conveyor rollers is provided in the middle of the reversing conveyor bracket (5). A drive motor (11) and a long drive shaft bracket (12) are respectively provided on the central mounting bracket (10). A long drive shaft (13) is movably provided on the long drive shaft bracket (12). A first front drive sprocket (18) and a second front drive sprocket (19) are respectively provided at the front end of the long drive shaft (13). A first drive sprocket (23) and a second drive sprocket (24) for the front center short conveyor roller (16) are respectively provided at the front end of the front center short conveyor roller (17). A third drive sprocket (26) and a fourth drive sprocket (29) for the front center short conveyor roller (17) are respectively provided at the front end of the front center short conveyor roller (17). A row of front short conveyor rollers (6) is driven in the following manner: First, the first front drive sprocket (18) set at the front end of the long drive shaft (13) is driven to rotate by the front sprocket (20) and the first annular drive chain (14) on the front end extension shaft of the drive motor (11), thereby driving the long drive shaft (13) to rotate. Secondly, the second front drive sprocket (19) set at the front end of the long drive shaft (13) and rotating with the long drive shaft (13) drives the first drive sprocket (23) set at the front end of the first short conveyor roller (16) and the first third drive sprocket (26) set at the front end of the second short conveyor roller (17) to rotate simultaneously via the second annular drive chain (15). Finally, the rotation of the front center short conveyor roller (16) drives the front two drive sprockets (24) set at the front end of the front center short conveyor roller (16) to rotate. The front two drive sprockets (24) drive the other front left short conveyor rollers (21) to rotate in sequence through the left conveying ring chain (27) set between the front left short conveyor rollers (21) adjacent to the front two drive sprockets (24) to transmit driving force to the left. The front center two short conveyor rollers (17) rotate, which drives the front four drive sprockets (29) set at the front end of the front center two short conveyor rollers (17) to rotate simultaneously. The front four drive sprockets (29) drive the other front right short conveyor rollers (22) to rotate in sequence through the right transmission ring chain (28) set between the front right short conveyor rollers (22) adjacent to the front four drive sprockets, which transmits driving force to the right. This enables the clockwise synchronous rotation of a row of front short conveyor rollers (6).

3. The working method of a roller conveyor system capable of sequentially achieving two 90-degree reversals according to claim 2, characterized in that, A first rear drive sprocket and a second rear drive sprocket are respectively provided at the rear end of the long drive shaft (13). In the middle of a row of rear short conveyor rollers (7), a rear center short conveyor roller and a rear center short conveyor roller are respectively provided. A rear drive sprocket and a rear drive sprocket of the rear center short conveyor roller are respectively provided at the rear end of the rear center short conveyor roller. A rear drive sprocket and a rear drive sprocket of the rear center short conveyor roller are respectively provided at the rear end of the rear center short conveyor roller. The driving structure of the row of rear short conveyor rollers (7) is the same as that of the row of front short conveyor rollers (6). The rotation direction of the row of rear short conveyor rollers (7) is the same as that of the row of front short conveyor rollers (6), and they rotate synchronously.

4. The working method of a roller conveyor system capable of sequentially achieving two 90-degree reversals according to claim 1 or 3, characterized in that, The distance between two adjacent front short conveyor rollers (6) and the distance between two adjacent rear short conveyor rollers (7) are both less than the width of each leg of the cross-shaped support leg on the bottom surface of the tray (4).

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