Zero-backlash shaft angle transmission

Abstract

The application discloses a zero-backlash shaft angle transmission device and belongs to the technical field of transmission. The device comprises a box body, a limiting double-gear, a double-gear of a code disc, a code disc shaft, a limiting shaft and a code disc. The double-gear of the code disc is connected with the code disc through the code disc shaft, and the gear on the code disc shaft is engaged with the limiting double-gear. The double-gear of the code disc is composed of a basic gear, a backlash-eliminating gear and a torsion spring connecting the two gears. The torsion spring keeps the two gears with constant torque, and the gear side gap is eliminated during the engagement process, realizing zero-backlash transmission. The limiting shaft is provided with a limiting block at the top, and cooperates with a proximity switch to realize angle limiting. The limiting block adopts a clamping structure, and the limiting angle is continuously adjustable. The code disc is introduced and installed through gear transmission, the central space is released, the cable, slip ring and waveguide joint are conveniently arranged, the transmission backlash is eliminated, high-precision angle feedback is ensured, and the device is suitable for occasions, such as large-diameter high-frequency antenna seats, which require high-precision shaft angle transmission.

Description

Technical Field

[0001] This invention relates to the field of transmission technology, and in particular to a shaft-angle synchronous transmission device for antenna mounts or similar devices requiring high-precision angle feedback. Background Technology

[0002] As antenna technology advances towards larger apertures and higher frequencies, the pointing accuracy requirements for antenna mounts are increasing. For example, a 1.8-meter aperture Ku-band antenna has a beamwidth of approximately 1.06°, while a 4.5-meter aperture Ka-band antenna has a beamwidth of only 0.16°. This significant reduction in beamwidth directly necessitates higher pointing accuracy from the mount.

[0003] Traditional shaft-angle transmission devices typically employ a coaxial mounting method, directly connecting the encoder disk to the final stage of the transmission via a coupling. While this method avoids transmission backlash, it has significant drawbacks: the encoder disk occupies space on the central shaft, affecting the installation of cables, slip rings, and waveguide rotary joints, thus limiting the overall system layout design.

[0004] To address the issue of occupied central space, code disks are often extended and installed via several sets of gears in engineering practice. While this approach frees up central space and facilitates the installation of cables, slip rings, and waveguide joints, it introduces a new problem—the hysteresis of the gear transmission causes the code disk readings to fail to accurately reflect the actual angle of the antenna, thus affecting pointing accuracy and making it difficult to meet the requirements of large-aperture, high-frequency antennas.

[0005] Therefore, how to eliminate backlash caused by gear transmission while freeing up the center space has become a technical problem that urgently needs to be solved in the design of current shaft angle transmission devices. Summary of the Invention

[0006] The purpose of this invention is to provide a zero-backlash shaft angle transmission device, which aims to achieve the output and installation of shaft angle signals through gear transmission, while eliminating transmission backlash and ensuring high-precision angle feedback.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A zero-backlash shaft angle transmission device includes a limiting double-plate gear, an encoder double-plate gear, and an encoder. The code disk double-plate gear is connected to the code disk via the code disk shaft; a gear is machined at the middle position of the code disk shaft, which meshes with the limiting double-plate gear; the code disk double-plate gear drives the limiting double-plate gear to rotate; The code disk double-plate gear includes a base gear, a backlash-eliminating gear, and a torsion spring; the base gear and the backlash-eliminating gear are arranged in parallel and have relative rotational freedom between them; the torsion spring is located between the base gear and the backlash-eliminating gear and connects the two. In operation, the drive gear of the drive mechanism meshes with both the base gear and the backlash-free gear of the code disk double-plate gear, and the torsion spring is in an extended state, so that a certain torque is maintained between the base gear and the backlash-free gear, thereby achieving backlash-free transmission.

[0008] Furthermore, it also includes a housing; the bottom of the housing is provided with a mounting flange; the code disk is located above the housing and is connected to it through a code disk end cover; the code disk shaft passes through the mounting flange and the housing, and its top end is connected to the code disk through a coupling; the code disk double-plate gear is connected to the code disk shaft through a code disk key, and a retaining ring is provided at the end of the code disk shaft, the retaining ring abutting against the lower surface of the code disk double-plate gear.

[0009] Furthermore, it also includes a limit shaft, a limit block, and a proximity switch; the limit shaft passes through the housing and is parallel to the encoder shaft; the limit double-plate gear is coaxially connected to the limit shaft via a limit key; the limit block is fixed to the top of the limit shaft, and the proximity switch is installed on the top of the housing, with the limit block and proximity switch working together to achieve the limit function.

[0010] Furthermore, the limiting block has a groove forming a U-shaped structure; the limiting shaft is assembled in the groove of the limiting block; a through screw hole is provided on the other side of the groove, and a bolt passes through the screw hole to hold the limiting shaft, thereby realizing continuous adjustment of the limiting angle.

[0011] Compared with the prior art, the present invention has the following beneficial effects: Achieving zero backlash transmission: By adopting a structure design with double-plate gears and torsion springs, a constant torque is maintained between the base gear and the backlash-free gear, eliminating tooth backlash during meshing, thereby achieving true "zero backlash" shaft angle transmission and significantly improving angle feedback accuracy.

[0012] Freeing up central space: The code disk is brought out for installation using a gear transmission method, avoiding the code disk occupying the central axis position, and providing ample installation space for key components such as cables, slip rings and waveguide rotary joints, which is conducive to the optimization of the overall system layout.

[0013] The limiting angle is continuously adjustable: the limiting block adopts a U-shaped groove structure and is fixed to the limiting shaft by bolt clamping. The limiting angle can be continuously adjusted according to actual needs (such as ±60°, ±90°, ±135°, etc.), which improves the adaptability and flexibility of the device.

[0014] Modular design with strong adaptability: The invention has a compact structure and a high degree of standardization, making it easy to promote and apply in antenna mounts of different apertures and frequency bands. It has good versatility and engineering practicality. Attached Figure Description

[0015] Figure 1 This is the front view of the present invention; Figure 2 This is a side view of the present invention;

[0016] Figure 3 This is a three-dimensional perspective view of the present invention; Figure 4 This is a structural diagram of a double-plate gear encoder. Figure 5 This is a structural diagram of the limit block.

[0017] In the diagram: 1. Housing; 2. Limiting double-plate gear; 3. Encoder double-plate gear; 4. Encoder key; 5. Retaining ring; 6. Encoder shaft; 7. Limiting key; 8. Encoder end cover; 9. Limiting end cover; 10. Proximity switch flange; 11. End cover; 12. Bushing; 13. Proximity switch flange; 14. Limiting block; 15. Limiting shaft; 16. Outer cover; 17. Mounting flange; 18. Bearing; 19. Sealing ring; 20. Coupling; 21. Proximity switch; 22. Encoder; 23. Base gear; 24. Backlash-eliminating gear; 25. Torsion spring; 26. Retaining ring. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0019] like Figures 1 to 3 As shown, the zero backlash shaft angle transmission device provided in this embodiment mainly includes: a housing 1, a limiting double-plate gear 2, an encoder double-plate gear 3, an encoder shaft 6, a limiting shaft 15, an encoder 22, a coupling 20, a proximity switch 21, and a limiting block 14.

[0020] Among them, the double-plate gear 3 of the encoder disk is the core backlash-free transmission component, and its structure is as follows: Figure 4 As shown, it consists of a base gear 23, a backlash-free gear 24, a torsion spring 25, and a retaining ring 26. The base gear 23 and the backlash-free gear 24 are arranged in parallel and have relative rotational freedom. The torsion spring 25 is installed between the two and connects them. The retaining ring 26 is used for axial restraint.

[0021] The structure of the limiting double-plate gear 2 is the same as that of the code disk double-plate gear 3, and it also adopts a backlash elimination structure with double-plate gears and torsion springs.

[0022] The mounting flange 17 is bolted to the bottom of the housing 1 to support the entire transmission device. The code disk 22 is located above the housing 1 and is fixed to the housing 1 by the code disk end cover 8. The code disk shaft 6 passes through the mounting flange 17 and the housing 1, and its top end is connected to the input shaft of the code disk 22 via a coupling 20.

[0023] The double-plate gear 3 of the code disk is coaxially connected to the code disk shaft 6 via the code disk key 4 and can rotate synchronously with the code disk shaft 6. A retaining ring 5 is provided at the lower end (end) of the code disk shaft 6. The retaining ring 5 abuts against the lower surface of the double-plate gear 3 of the code disk to prevent the double-plate gear 3 of the code disk from falling off axially.

[0024] The limiting shaft 15 passes through the housing 1 and is arranged parallel to the encoder shaft 6. The limiting double-plate gear 2 is coaxially connected to the limiting shaft 15 via the limiting key 7 and can rotate synchronously with the limiting shaft 15. The bushing 12 is installed on the housing 1 to support and fix the axial position of the limiting double-plate gear 2.

[0025] A gear segment is machined at the middle position of the code disk shaft 6. This gear segment meshes with the external teeth of the limiting double-plate gear 2 to form a parallel shaft gear transmission pair. When the code disk double-plate gear 3 drives the code disk shaft 6 to rotate, the code disk shaft 6 drives the limiting double-plate gear 2 and the limiting shaft 15 to rotate synchronously through gear meshing.

[0026] The limiting block 14 is fixedly installed on the top of the limiting shaft 15 by screws and can rotate together with the limiting shaft 15. Figure 5 As shown, the limiting block 14 is machined with a U-shaped groove, and the limiting shaft 15 is assembled in the groove. The other side of the groove is provided with a through screw hole. By tightening the bolt, the groove can hug the limiting shaft 15, thereby realizing the continuous adjustment of the angle position of the limiting block 14 on the limiting shaft 15.

[0027] The proximity switch 21 is mounted on the proximity switch flange 13, which is fixed to the top of the housing 1 with screws. When the limit block 14 rotates with the limit shaft 15 and enters the sensing area of ​​the proximity switch 21, the proximity switch 21 outputs a limit signal to realize the angle limit protection function.

[0028] Four sets of bearings 18 are installed on the housing 1 to support the encoder shaft 6 and the limit shaft 15, respectively, to ensure their smooth rotation. The sealing ring 19, end cover 11, encoder end cover 8 and limit end cover 9 are respectively installed in the corresponding positions of the housing 1 to prevent external dust and moisture from entering the device and to ensure the cleanliness and reliability of the transmission system.

[0029] The outer cover 16 is installed above the housing 1 to protect the internal transmission components and the code disk 22.

[0030] In operation, the drive mechanism (such as the final stage gear of the antenna mount) meshes simultaneously with the code disk double-plate gear 3. Both the base gear 23 and the backlash-eliminating gear 24 of the code disk double-plate gear 3 mesh with the drive gear. Because the torsion spring 25 is installed between the base gear 23 and the backlash-eliminating gear 24 and is in a pre-tensioned state, a certain relative torque is maintained between the two gears.

[0031] During actual assembly, the backlash-eliminating gear 24 is pre-staggered by 1 to 2 teeth relative to the base gear 23, so that the tooth surfaces of both are respectively pressed against the two sides of the drive gear tooth groove. When the drive gear rotates forward or backward, one of the base gear 23 and the backlash-eliminating gear 24 is always in a tooth surface pressing state, and the other is in a tooth back pressing state, thereby completely eliminating tooth backlash and realizing "zero backlash" transmission.

[0032] The rotation angle of the encoder shaft 6 is accurately transmitted to the encoder 22 through the coupling 20. The angle signal output by the encoder 22 can truly reflect the actual angular position of the drive mechanism, avoiding the angle error caused by backlash in traditional gear transmission.

[0033] The limiting shaft 15 rotates synchronously with the encoder shaft 6, and the limiting block 14 is fixed on the limiting shaft 15 and rotates accordingly. When the limiting shaft 15 rotates to a preset angle, the limiting block 14 enters the sensing range of the proximity switch 21, and the proximity switch 21 sends an electrical signal, thereby stopping the drive or reversing the operation, thus playing a mechanical limit protection role.

[0034] Since the limiting block 14 is fixed to the limiting shaft 15 by bolt clamping, the installation angle of the limiting block 14 can be adjusted along the circumference of the limiting shaft 15 after the bolt is loosened, so as to realize the continuous adjustment of the limiting angle. For example, it can be set to a variety of stroke ranges such as ±60°, ±90°, and ±135° to meet the needs of different application scenarios.

[0035] The code disk 22 is led out from the central shaft position to the top of the housing 1 via a parallel shaft gear transmission chain consisting of the code disk double-plate gear 3 and the limiting double-plate gear 2. This frees up space in the central area of ​​the device, facilitating the arrangement of components such as cables, slip rings, and waveguide rotary joints. Furthermore, the entire device adopts a modular design, making each component easy to disassemble, assemble, and maintain, and highly adaptable.

[0036] After the device is started, the drive gear drives the double-plate gear 3 of the encoder disk to rotate. The double-plate gear 3 drives the encoder disk 22 to rotate through the encoder disk shaft 6 and coupling 20, outputting an angle signal. At the same time, the encoder disk shaft 6 drives the limit double-plate gear 2 and the limit shaft 15 to rotate synchronously through gear meshing. When the limit block 14 on the limit shaft 15 rotates to the sensing position of the proximity switch 21, the proximity switch 21 sends a limit signal, and the control system executes the limit protection action.

[0037] Throughout the entire process described above, due to the action of the torsion spring 25 inside the code disk double-plate gear 3, the base gear 23 and the backlash-free gear 24 always maintain a backlash-free meshing state with the drive gear, thereby achieving zero-backlash angle transmission.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A zero-backlash shaft angle transmission device, characterized in that: It includes a limit double-plate gear (2), a code disk double-plate gear (3) and a code disk (22); The code disk double-plate gear (3) is connected to the code disk (22) through the code disk shaft (6); a gear is machined in the middle position of the code disk shaft (6), and the gear meshes with the limiting double-plate gear (2); the code disk double-plate gear (3) drives the limiting double-plate gear (2) to rotate; The code disk double-plate gear (3) includes a base gear (23), a backlash-eliminating gear (24), and a torsion spring (25); the base gear (23) and the backlash-eliminating gear (24) are arranged in parallel and have a degree of freedom of relative rotation; the torsion spring (25) is located between the base gear (23) and the backlash-eliminating gear (24) and connects the two. In the working state, the drive gear of the drive mechanism and the base gear (23) and backlash-free gear (24) of the code disk double-plate gear (3) are all meshed, and the torsion spring (25) between the base gear (23) and backlash-free gear (24) is in an extended state, that is, the base gear (23) and backlash-free gear (24) have a certain torque.

2. The zero-backlash shaft angle transmission device according to claim 1, characterized in that, It also includes the housing (1); The bottom of the housing (1) is provided with a mounting flange (17); the code disk (22) is located above the housing (1) and is connected to it through the code disk end cover (8); the code disk shaft (6) passes through the mounting flange (17) and the housing (1), and its top end is connected to the code disk (22) above the housing (1) through a coupling (20); The code disk double-plate gear (3) is connected to the code disk shaft (6) via the code disk key (4), and has a retaining ring (5) at the end of the code disk shaft (6); the retaining ring (5) abuts against the lower surface of the code disk double-plate gear (3).

3. A zero-backlash shaft angle transmission device according to claim 2, characterized in that, It also includes a limiting shaft (15), a limiting block (14) and a proximity switch (21). The limiting shaft (15) passes through the housing (1) and is parallel to the encoder shaft (6). The limiting double-plate gear (2) is coaxially connected to the limiting shaft (15) through a limiting key (7). The limiting block (14) is fixed to the top of the limiting shaft (15), and the proximity switch (21) is installed on the top of the housing (1). The cooperation between the limiting block (14) and the proximity switch (21) achieves the limiting effect.

4. A zero-backlash shaft angle transmission device according to claim 3, characterized in that, The limiting block (14) has a groove forming a U-shaped structure; the limiting shaft (15) is assembled in the groove of the limiting block (14); a through screw hole is provided on the other side of the groove; a bolt passes through the screw hole to hold the limiting shaft (15).

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