Running circle testing device

Abstract

The utility model provides a running circle testing device, and belongs to the technical field of water meter detection. A plurality of rotating shafts with driven gears are rotatably mounted on the mounting bedplate of the base, two adjacent driven gears are meshed with each other, one or more driven gears are in power connection with a driving motor, in addition, each rotating shaft is provided with a shaft sleeve of a replaceable wheel disc, and a wheel disc body is detachably mounted on each shaft sleeve, so that the wheel disc can be replaced conveniently. The running state of the impeller in the water meter is simulated, the test bedplate with the plurality of test stations is installed on the base through the height adjusting assembly, the to-be-tested modules are placed through the test stations, and the to-be-tested modules are matched with the corresponding replaceable wheel discs to complete the running circle test, so that the running circle test of the plurality of to-be-tested modules at the same time is realized, and the efficiency is higher; moreover, the number of used testing devices is reduced, so that the structure compactness is better, the utilization rate is higher, the testing cost is reduced, space occupation is avoided, and resource waste is prevented.

Description

Technical Field

[0001] This utility model relates to the field of water meter testing technology, specifically to a running lap test device. Background Technology

[0002] To facilitate water consumption statistics and management, and considering cost factors, existing smart meters employing mechanical metering and remote modules are gaining popularity. These meters typically have a mechanical structure, including an impeller, inside the casing that rotates under the impact of water flow. A remote module is mounted on the casing and contains a counting structure that works in conjunction with the impeller's structure to count the number of impeller rotations, thus monitoring water consumption. For example, patent CN221992782U discloses an inductive remote water meter module. A main board is located in a first space inside the module casing, with wires connecting inductive elements to it. These inductive elements are installed in a second space. During assembly, the module casing is mounted on the meter housing, and the inductive elements on the main board are aligned with the impeller's structure. This allows the inductive elements to count the rotation of the impeller's components as it rotates, providing the basis for subsequent calculations of water consumption. In addition, there is a type of mechanical meter on the market where the gear mechanism is located within the counting module, which is mounted on the meter casing. In this case, the gear mechanism includes a sensing element that engages with a related structure on the impeller. This allows the impeller to synchronously drive the gear mechanism when water flow impacts the impeller's rotation, thus meeting the flow rate statistics requirements. It can be seen that in existing water meters, the module uses a related structure on the impeller to perform counting, and its performance directly affects the meter's accuracy.

[0003] Currently, the performance testing of modules typically involves simulating impeller rotation to observe whether the module accurately counts. Existing testing methods involve designing a motor with an impeller-related structure (such as a wheel with magnets) mounted on it. During testing, the sensing part of the module under test is aligned with the wheel, and the motor simulates impeller rotation to detect the module's operation, achieving a lap test. While this structure meets the requirements for lap testing, existing testing devices can only test one module at a time, resulting in low efficiency. Furthermore, multiple testing devices often need to be used simultaneously, leading to a large number of devices, increased testing costs, significant space occupation, and substantial resource waste. Summary of the Invention

[0004] To address the aforementioned problems in existing technologies, this invention aims to provide a lap testing device. A drive motor is mounted on a base, and several meshing, identical driven gears are also mounted on the base. One or more driven gears are powered by the drive motor, enabling the drive motor to simultaneously drive all driven gears to rotate synchronously and maintain a consistent speed. A test platform is provided, with several test stations corresponding one-to-one with the driven gears. Each driven gear is equipped with a replaceable wheel, allowing multiple modules to be placed on the test stations, each corresponding to a replaceable wheel. Multiple modules can be tested simultaneously using the same drive motor, improving testing efficiency, reducing the number of testing devices, lowering testing costs, and achieving a compact design that minimizes space occupation and avoids resource waste.

[0005] The specific technical solution is as follows:

[0006] A lap testing device, characterized by the following features:

[0007] The base includes a mounting plate with several rotating holes. A rotating shaft is rotatably installed in each rotating hole. A driven gear is fitted on each rotating shaft. Adjacent driven gears mesh. A drive motor is also installed on the mounting plate. A drive gear is installed on the main shaft of the drive motor, and one or more driven gears mesh with the drive gear.

[0008] A replaceable wheel, comprising a bushing and a wheel body, wherein a bushing is fitted on each axle and a wheel body is detachably mounted on each bushing;

[0009] The test platform is located above the base. The test platform has several test stations corresponding to the rotating shaft, and a height adjustment component is provided between the test platform and the base.

[0010] In the aforementioned lap test device, the mounting platform includes an upper platform and a lower platform, which are arranged in alternating layers. The driven gear and the driving gear are both located in the interval between the upper and lower platforms. One end of each rotating shaft passes through the upper platform, and a bushing is fitted on the end of the rotating shaft that passes through the upper platform. The drive motor is mounted on the lower platform.

[0011] In the aforementioned lap test device, a plurality of supporting connectors are provided between the upper platform and the lower platform. Each supporting connector includes a supporting sleeve and a first connecting bolt. The supporting sleeve is located between the upper platform and the lower platform and its two ends abut against the upper platform and the lower platform, respectively. The first connecting bolt passes through the upper platform, the supporting sleeve, and the lower platform simultaneously and is then locked.

[0012] In the aforementioned running lap test device, the height adjustment component includes an adjustment sleeve and a second connecting bolt. The test platform and the base are provided with corresponding adjustment holes. The adjustment sleeve is disposed between the test platform and the base, and its two ends abut against the test platform and the base respectively. The second connecting bolt passes through the test platform, the adjustment sleeve and the base and is then locked. Furthermore, there are several sets of adjustment sleeves, and the length of each set of adjustment sleeves is different.

[0013] The aforementioned lap test device further includes a limiting component, which is a locking pin. A locking hole is formed radially on the side wall of the bushing, and a limiting plane or limiting hole is provided on the side wall of the rotating shaft. The limiting component passes through the locking hole and one end abuts against the limiting plane or is inserted into the limiting hole.

[0014] In the aforementioned lap testing device, an insertion hole is provided on the upper end face of the bushing, and a protrusion that mates with the insertion hole is provided on the bottom surface of the wheel body. When the wheel body is installed on the bushing, the protrusion is inserted into the insertion hole.

[0015] The aforementioned lap test device further includes a magnetic suction assembly, which includes a magnet and a magnetic suction element. A recessed groove is provided on the upper end surface of the bushing, and a magnet is embedded in the groove. A magnetic suction element that cooperates with the magnet is embedded on the bottom surface of the wheel body.

[0016] In the aforementioned lap test device, the groove is located at the center of the upper end face of the bushing, and two sets of insertion holes are symmetrically arranged on both sides of the groove.

[0017] In the aforementioned lap testing device, both the bushing and the wheel disc are made of plastic.

[0018] In the aforementioned lap test device, a number of driven gears are evenly divided into two groups, each group of driven gears is arranged along a straight line, and the straight lines of the two groups of driven gears are parallel to each other. Adjacent driven gears in the same group mesh with each other, and the driving gear is set between the two groups of driven gears, and the driving gear meshes with the middle driven gear in each group of driven gears.

[0019] The positive effects of the above technical solution are:

[0020] The aforementioned lap test device features several rotating shafts with driven gears mounted on a base, with adjacent driven gears meshing with each other. A drive motor mounted on the base has a driving gear that meshes with one or more driven gears. Each rotating shaft is equipped with a replaceable wheel, and a test platform with several test stations is mounted on the base. Each test station corresponds to a replaceable wheel. Multiple modules under test are installed on the test platform, and a single drive motor simultaneously rotates multiple replaceable wheels to achieve synchronous testing of multiple modules under test. This results in higher testing efficiency, a reduced number of testing devices, lower testing costs, improved structural utilization, a more compact structure, reduced space occupation, and reduced resource waste. Attached Figure Description

[0021] Figure 1 This is a structural diagram of an embodiment of the running lap testing device of this utility model;

[0022] Figure 2 This is a schematic diagram of the installation of the replacement wheel in a preferred embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the installation of the rotating shaft on the base in a preferred embodiment of the present invention.

[0024] In the attached diagram: 1. Base; 11. Mounting platform; 12. Support connector; 111. Upper platform; 112. Lower platform; 121. Support sleeve; 122. First connecting bolt; 2. Rotating shaft; 3. Driven gear; 4. Drive motor; 5. Replaceable wheel; 51. Bushing; 52. Wheel body; 53. Limiting component; 511. Insertion hole; 512. Magnet; 6. Test platform; 61. Test station; 7. Height adjustment assembly; 71. Adjustment sleeve; 72. Second connecting bolt. Detailed Implementation

[0025] To make the technical means, creative features, objectives, and effects of this utility model easier to understand, the following embodiments are provided in conjunction with the appendix. Figure 1 To be continued Figure 3 The technical solution provided by this utility model is described in detail, but the following content is not intended to limit this utility model.

[0026] Figure 1 This is a structural diagram of an embodiment of the running lap testing device of this utility model; Figure 2 This is a schematic diagram illustrating the installation of the replaceable wheel in a preferred embodiment of the present invention. Figure 1 and Figure 2As shown, the lap test device provided in this embodiment includes: a base 1, a replaceable wheel 5, and a test platform 6. The replaceable wheel 5 is installed on the base 1 and driven by the drive motor 4 to rotate the replaceable wheel 5 to simulate the working state of the impeller. In addition, the test platform 6 is set on the base 1 and serves as a carrier for placing the module under test, thus meeting the usage requirements of simultaneously performing lap tests on multiple modules under test.

[0027] Specifically, the base 1 includes a mounting plate 11. The bottom of the mounting plate 11 is provided with feet, creating space at the bottom to facilitate the concealed installation of the drive motor 4. Additionally, the mounting plate 11 has several rotating holes, and a rotating shaft 2 is rotatably mounted in each hole. The rotating shaft 2 simulates the impeller shaft, effectively mimicking impeller rotation. Furthermore, a driven gear 3 is fitted onto each rotating shaft 2. Preferably, the driven gear 3 and the corresponding rotating shaft 2 are an integral structure, resulting in better overall integrity and eliminating relative motion errors, thus ensuring testing accuracy. Moreover, meshing adjacent driven gears 3 allows them to rotate synchronously and maintain the same speed. It also enables mutual transmission between adjacent driven gears 3, eliminating the need for a separate transmission structure, simplifying the structure, reducing manufacturing costs, and saving space. In addition, a drive motor 4 is installed on the mounting plate 11, and a drive gear is installed on the main shaft of the drive motor 4. One or more driven gears 3 mesh with the drive gear, so that the drive motor 4 can drive one or more driven gears 3 to rotate through its own installed drive gear, thereby driving all driven gears 3 to rotate synchronously, maintaining the same speed of all rotating shafts 2, improving the utilization rate of the drive motor 4, meeting the usage requirements of testing multiple modules under test at the same time, improving testing efficiency, reducing the number of testing devices, reducing testing costs, and also making the overall structure of the testing device more compact, reducing space occupation, and avoiding resource waste.

[0028] More specifically, each rotating shaft 2 is equipped with a replaceable wheel 5, which works in conjunction with the module under test to perform a lap test. The replaceable wheel 5 includes a bushing 51 and a wheel body 52. ​​Each rotating shaft 2 is fitted with a bushing 51, allowing the rotating shaft 2 to synchronously drive the corresponding bushing 51 to rotate. Each bushing 51 has a wheel body 52 detachably mounted on it, allowing the bushing 51 to drive the mating wheel body 52 to rotate. The wheel body 52 works in conjunction with the module under test to complete the lap test. Furthermore, because the wheel body 52 is detachably mounted on the bushing 51, different models or specifications of wheel bodies 52 can be replaced on the bushing 51, adapting to different specifications and models of modules under test. This improves structural flexibility and adaptability, increasing the utilization rate of the testing device.

[0029] More specifically, the test platform 6 is positioned above the base 1, leaving space underneath for the installation and movement of the rotating shaft 2 and the replaceable wheel 5. Several test stations 61 corresponding to the rotating shaft 2 are provided on the test platform 6. Each test station 61 can have a perforation of a corresponding shape. After the module under test is placed on the test platform 6, the mating part of the module can extend from the perforation to the replaceable wheel 5, thus achieving mating with the corresponding replaceable wheel 5 and meeting the requirements for lap testing. Furthermore, this allows for the simultaneous placement of multiple modules under test on the test platform 6, satisfying the requirement for simultaneous lap testing of multiple modules, improving testing efficiency, reducing the number of testing devices, lowering testing costs, and achieving a compact design of the device structure, reducing space occupation, and making the structural design more reasonable. Furthermore, a height adjustment component 7 is provided between the test platform 6 and the base 1. The height adjustment component 7 realizes the distance between the test station 61 and the corresponding replacement wheel 5, thereby adapting to the testing requirements of different specifications and models of the module to be tested, which also improves the flexibility of the equipment structure and makes it more adaptable.

[0030] More specifically, the mounting platform 11 of the base 1 also includes an upper platform 111 and a lower platform 112. The upper platform 111 and the lower platform 112 are arranged in alternating layers, creating space between them. The driven gear 3 and the driving gear are both positioned within the space between the upper platform 111 and the lower platform 112. This space provides installation and movement space for the driven gear 3 and the driving gear, allowing them to be concealed within the mounting platform 11 for better external protection and safety. Furthermore, one end of each rotating shaft 2 passes through the upper platform 111, and a bushing 51 is fitted onto the end of the rotating shaft 2 that passes through the upper platform 111. This facilitates the installation and removal of the wheel body 52 of the replaceable wheel 5 from the bushing 51, and also allows the wheel body 52 to be closely aligned with the test station 61, meeting testing requirements. Furthermore, the drive motor 4 is mounted on the lower platform 112, which provides a mounting carrier for the drive motor 4, resulting in a more rational structural design. It is worth noting that the two partitions of the rotating shaft 2 are rotatably mounted on the upper platform 111 and the lower platform 112, respectively, so that both ends of the rotating shaft 2 have corresponding support structures, thereby improving the stability of the rotating shaft 2 after installation.

[0031] More specifically, several supporting connectors 12 are provided between the upper platform 111 and the lower platform 112. These connectors provide a stable connection between the upper platform 111 and the lower platform 112, forming a unified structure. Each supporting connector 12 includes a supporting sleeve 121 and a first connecting bolt 122. During installation, the supporting sleeve 121 is positioned between the upper platform 111 and the lower platform 112, with both ends abutting against the upper platform 111 and the lower platform 112 respectively. Simultaneously, the first connecting bolt 122 passes through the upper platform 111, the supporting sleeve 121, and the lower platform 112 and is then tightened. The supporting sleeve 121 supports the upper platform 111 and the lower platform 112. The upper platform 111 and the lower platform 112 are tightened by the first connecting bolt 122, which realizes the positioning and locking of both sides of the upper platform 111 and the lower platform 112, maintains the stability of the gap between the upper platform 111 and the lower platform 112, and makes the structure of the mounting platform 11 more stable. At the same time, the upper platform 111 can be disassembled on the lower platform 112 by removing the first connecting bolt 122, which facilitates the disassembly and assembly of structures such as the rotating shaft 2, the driven gear 3, and the driving gear.

[0032] More specifically, the height adjustment assembly 7 between the base 1 and the test platform 6 includes an adjustment sleeve 71 and a second connecting bolt 72. During installation, corresponding adjustment holes are provided on the test platform 6 and the base 1. The adjustment sleeve 71 is placed between the test platform 6 and the base 1, with both ends of the adjustment sleeve 71 abutting against the test platform 6 and the base 1 respectively. The adjustment sleeve 71 supports the test platform 6 on the base 1, and the height gap between the test platform 6 and the base 1 is consistent with the length of the adjustment sleeve 71. Furthermore, the second connecting bolt 72 is passed through the adjustment holes in the test platform 6, the adjustment sleeve 71, and the adjustment holes on the upper plate 111 of the base 1, and then locked. The adjustment sleeve 71 provides support between the test platform 6 and the base 1, while the second connecting bolt 72 tightens the test platform 6 and the base 1, achieving stable installation of the test platform 6 on the base 1. In addition, there are several sets of adjustment sleeves 71, and the length of each set of adjustment sleeves 71 is different. By replacing the adjustment sleeves 71 of different lengths, the test platform 6 can be stably installed on the base 1, and the gap between the test platform 6 and the base 1 can be adjusted to meet the testing requirements of different specifications and models of the test module.

[0033] More specifically, a limiting member 53 is provided between the rotating shaft 2 and the corresponding bushing 51. In this case, the limiting member 53 is a locking pin, and a locking hole is radially formed on the side wall of the bushing 51. This allows the bushing 51 to be fitted onto the corresponding rotating shaft 2, where the locking pin can be inserted into the locking hole and abut against the outside of the rotating shaft 2, achieving circumferential limiting between the bushing 51 and the rotating shaft 2 and preventing accidental rotation. Preferably, a limiting plane or a limiting hole is also provided on the side wall of the rotating shaft 2. When the limiting member 53 is inserted into the locking hole, one end of the limiting member 53 abuts against the limiting plane or is inserted into the limiting hole. The cooperation between the end of the limiting member 53 and the limiting plane or the limiting hole prevents circumferential rotation between the limiting member 53 and the rotating shaft 2, further improving the synchronization of the rotation of the bushing 51 and the rotating shaft 2.

[0034] More specifically, an insertion hole 511 is provided on the upper end face of the bushing 51, and a protrusion that mates with the insertion hole 511 is provided on the bottom surface of the wheel body 52. ​​That is, when the wheel body 52 is installed on the bushing 51, the wheel body 52 and the bushing 51 are arranged coaxially, and the protrusion on the wheel body 52 is engaged into the insertion hole 511 of the bushing 51. The circumferential limit is achieved through the mutual cooperation of the protrusion and the insertion hole 511, ensuring that the wheel body 52 can rotate synchronously with the bushing 51, and the structural design is more reasonable.

[0035] More specifically, a magnetic attraction assembly is provided between the bushing 51 and the corresponding wheel body 52. ​​This magnetic attraction assembly includes a magnet 512 and a magnetic attractor. Additionally, a recessed groove is formed on the upper surface of the bushing 51, and a magnet 512 is embedded within the groove. Furthermore, a magnetic attractor that mates with the magnet 512 is embedded on the bottom surface of the wheel body 52. ​​This allows the wheel body 52 to be connected to the bushing 51 through the mutual attraction of the magnetic attractor and the magnet 512 when it is mounted on the bushing 51, ensuring that the wheel body 52 is stably mounted on the bushing 51 and rotates with it. Preferably, the magnetic attractor can be a patch easily attracted by the magnet 512, or it can be the magnet 512 itself, as long as it can attract the magnet 512 on the bushing 51, thus facilitating the installation of the wheel body 52 on the bushing 51.

[0036] More specifically, the groove is positioned at the center of the upper end face of the bushing 51, allowing the center of the wheel body 52 to magnetically connect with the center of the bushing 51 when the wheel body 52 is installed on the bushing 51. This results in more even force distribution on the wheel body 52 and better connection stability. Furthermore, two sets of insertion holes 511 are symmetrically arranged on both sides of the groove, achieving a uniform distribution of the insertion holes 511 on the bushing 51. While meeting circumferential positioning requirements, this maintains uniform force distribution on both sides of the magnetic assembly and enables multi-point positioning, preventing the wheel body 52 from shifting after installation on the bushing 51.

[0037] More specifically, both the bushing 51 and the wheel body 52 are made of plastic, and the wheel body 52 has a predetermined length, which can reduce the impact on the mating of the wheel body 52 and the module under test, improve the test accuracy, and can be directly injection molded or 3D printed, which facilitates processing and manufacturing and reduces the manufacturing cost of the device.

[0038] Figure 3 This is a schematic diagram showing the installation of the rotating shaft on the base in a preferred embodiment of this utility model. Figures 1 to 3 As shown, several driven gears 3 are evenly divided into two groups. Each group of driven gears 3 is arranged along a straight line, and the two groups are parallel to each other, meaning they are distributed in two columns, achieving a regular arrangement of multiple driven gears 3. Furthermore, adjacent driven gears 3 within the same group mesh with each other, so that when one driven gear 3 rotates, the rest of the driven gears 3 will also rotate. Additionally, a driving gear is positioned between the two groups of driven gears 3, meshing with the middle driven gear 3 in each group. This allows the driving gear to drive all the driven gears 3 through one of the driven gears 3 in each group, and the middle driven gear 3 can simultaneously transmit power to the driven gears on either side, further improving synchronization with other driven gears 3 and enhancing the accuracy of the lap test.

[0039] The lap test device provided in this embodiment includes a base 1, a replaceable wheel 5, and a test platform 6. Several driven gears 3 are rotatably mounted on the mounting platform 11 of the base 1, with adjacent driven gears 3 meshing with each other. One or more driven gears 3 are powered by a drive motor 4. Additionally, a bushing 51 of the replaceable wheel 5 is mounted on each rotating shaft 2, and a wheel body 52 is detachably mounted on the bushing 51, simulating the operation of an impeller in a water meter. The test platform 6 is mounted on the base 1 via a height adjustment assembly 7, and several test stations 61 corresponding to the rotating shaft 2 are provided on the test platform 6. The test modules are placed at the test stations 61, and the test modules cooperate with the corresponding replaceable wheels 5 to complete the lap test. This allows for simultaneous lap testing of multiple test modules, resulting in higher efficiency. Furthermore, it reduces the number of test devices used, making the structure more compact and increasing utilization, thereby reducing testing costs, avoiding space occupation, and preventing resource waste.

[0040] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A lap testing device, characterized in that, include: The base includes a mounting plate with several rotating holes. A rotating shaft is rotatably installed in each rotating hole. A driven gear is sleeved on each rotating shaft. Adjacent driven gears mesh. A drive motor is also installed on the mounting plate. A drive gear is installed on the main shaft of the drive motor, and one or more driven gears mesh with the drive gear. A replaceable wheel, the replaceable wheel comprising a bushing and a wheel body, wherein the bushing is fitted on each of the rotating shafts, and a wheel body is detachably mounted on each bushing; A test platform is disposed above the base. The test platform has several test stations corresponding to the rotating shaft. A height adjustment component is provided between the test platform and the base.

2. The running lap testing device according to claim 1, characterized in that, The mounting platform includes an upper platform and a lower platform, which are arranged in an alternating upper and lower layer. The driven gear and the driving gear are both located in the interval between the upper platform and the lower platform. One end of each rotating shaft passes through the upper platform, and a bushing is fitted on the end of the rotating shaft that passes through the upper platform. The drive motor is mounted on the lower platform.

3. The running lap testing device according to claim 2, characterized in that, A plurality of supporting connectors are provided between the upper platform and the lower platform. Each supporting connector includes a supporting sleeve and a first connecting bolt. The supporting sleeve is disposed between the upper platform and the lower platform and its two ends abut against the upper platform and the lower platform respectively. The first connecting bolt passes through the upper platform, the supporting sleeve and the lower platform simultaneously and is then locked.

4. The running lap testing device according to claim 1, characterized in that, The height adjustment assembly includes an adjustment sleeve and a second connecting bolt. The test platform and the base have corresponding adjustment holes. The adjustment sleeve is disposed between the test platform and the base, and its two ends abut against the test platform and the base respectively. The second connecting bolt passes through the test platform, the adjustment sleeve and the base and is then locked. Furthermore, there are several sets of adjustment sleeves, and the length of the adjustment sleeve in each set is different.

5. The running lap testing device according to claim 1, characterized in that, It also includes a limiting member, which is a locking pin. A locking hole is formed radially on the side wall of the bushing, and a limiting plane or limiting hole is provided on the side wall of the rotating shaft. The limiting member passes through the locking hole and one end abuts against the limiting plane or is inserted into the limiting hole.

6. The running lap testing device according to claim 1, characterized in that, The upper end face of the bushing is provided with an insertion hole, and the bottom surface of the wheel body is provided with a protrusion that mates with the insertion hole. When the wheel body is installed on the bushing, the protrusion is inserted into the insertion hole.

7. The running lap testing device according to claim 6, characterized in that, It also includes a magnetic suction assembly, which includes a magnet and a magnetic suction element. A recessed groove is provided on the upper end surface of the bushing, and the magnet is embedded in the groove. The magnetic suction element that cooperates with the magnet is embedded on the bottom surface of the wheel body.

8. The running lap testing device according to claim 7, characterized in that, The groove is located at the center of the upper end face of the bushing, and two sets of insertion holes are provided and symmetrically arranged on both sides of the groove.

9. The running lap testing device according to claim 1, characterized in that, Both the bushing and the wheel body are made of plastic.

10. The running lap testing device according to claim 1, characterized in that, The driven gears are evenly divided into two groups, each group of driven gears is arranged along a straight line, and the straight lines of the arrangement of the two groups of driven gears are parallel to each other. Adjacent driven gears in the same group mesh with each other. The driving gear is disposed between the two groups of driven gears, and the driving gear meshes with the middle driven gear in each group of driven gears.

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