High-precision two-degree-of-freedom rotating mechanism

Abstract

The invention relates to the field of aircraft operation simulation test equipment, in particular to a high-precision two-degree-of-freedom rotating mechanism which comprises a front hydraulic cylinder, a rear hydraulic cylinder, a roll hydraulic cylinder, a hooke joint assembly, a supporting part, a base table and a rack. The lower end of the front hydraulic cylinder and the lower end of the rear hydraulic cylinder are rotationally installed on the portions, on the front side and the rear side of the supporting part, of the base table correspondingly, and the lower end of the side-tipping hydraulic cylinder is rotationally installed on the portion, on the left side or the right side of the supporting part, of the base table. The hooke joint assembly comprises a spindle, a first rotary supporting seat, a second rotary supporting seat and a middle rotary supporting seat, the middle of the spindle is rotatably mounted at the upper end of the supporting part through the middle rotary supporting seat, the front end of the spindle is rotatably connected with the upper end of a front hydraulic cylinder, and the rear end of the spindle is rotatably connected with the upper end of a rear hydraulic cylinder. A first rotary supporting seat and a second rotary supporting seat are rotationally mounted between the middle position and the two ends of the main shaft respectively; a third rotary supporting seat is rotationally mounted at the upper end of the side-tipping hydraulic cylinder; the upper ends of the first rotary supporting seat, the second rotary supporting seat and the third rotary supporting seat are fixedly connected to the lower end of the rack respectively; according to the invention, the test requirements of the aircraft fuel system are met, and the sealing performance and reliability of the gas-liquid pipeline are ensured.

Description

Technical Field

[0001] This invention relates to the field of aircraft operation simulation test equipment, and specifically to a high-precision two-degree-of-freedom rotation mechanism. Background Technology

[0002] An aircraft fuel system test apparatus is a device used to test and verify the functional performance of aircraft fuel systems. To achieve the test conditions for aircraft fuel systems, it is necessary to transfer gas and liquid to the aircraft without leakage. Common two-degree-of-freedom rotating mechanisms can subject pipelines to complex torsional loads and bending stresses, while traditional fixed supports are prone to stress concentration, posing a risk of pipeline breakage. Therefore, a new two-degree-of-freedom rotating mechanism is needed to meet the testing requirements of aircraft fuel systems and ensure the sealing and reliability of the gas-liquid pipelines. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned technical problems. This invention proposes a high-precision two-degree-of-freedom rotation mechanism to meet the testing requirements of aircraft fuel systems and ensure the sealing and reliability of gas-liquid pipelines. This two-degree-of-freedom rotation mechanism is ingeniously designed, has a reasonable and compact structure, and meets the requirements of aircraft fuel system simulation tests.

[0004] The technical solution of this invention: A high-precision two-degree-of-freedom rotary mechanism includes a front hydraulic cylinder, a rear hydraulic cylinder, a tilting hydraulic cylinder, a Hooke's hinge assembly, a support part, a base, and a frame. The support part is mounted on the middle of the base. The lower ends of the front and rear hydraulic cylinders are rotatably mounted on the base on the front and rear sides of the support part, respectively. The lower end of the tilting hydraulic cylinder is rotatably mounted on the base on either the left or right side of the support part. The Hooke's hinge assembly is mounted on the upper end of the support part. The Hooke's hinge assembly includes a main shaft, a first rotary support seat, a second rotary support seat, and an intermediate rotary support seat. The main shaft is rotatably mounted on the upper end of the support part via the intermediate rotary support seat. The front end of the main shaft is rotatably connected to the upper end of the front hydraulic cylinder, and the rear end of the main shaft is rotatably connected to the upper end of the rear hydraulic cylinder. A rotary support seat, namely the first rotary support seat and the second rotary support seat, is rotatably mounted between the middle and both ends of the main shaft. A third rotary support seat is rotatably mounted on the upper end of the tilting hydraulic cylinder. The upper ends of the first, second, and third rotary support seats are fixedly connected to the lower end of the frame.

[0005] Furthermore, the support part is a four-sided pyramidal reinforced concrete platform that is narrow at the top and wide at the bottom; the lower end of the intermediate rotating support is fixedly installed in the middle of the upper end of the reinforced concrete platform.

[0006] Furthermore, the intermediate rotating support includes a first support base and a first rotating shaft. The first support base is designed as a U-shaped base. The lower end of the first support base is installed in the middle of the upper end of the support part. The middle of the main shaft is rotatably installed on the U-shaped base through the first rotating shaft. The first rotating shaft is vertically fixed in the middle of the main shaft. The two ends of the first rotating shaft are respectively rotatably installed on the upper ends of both sides of the U-shaped base through bearings.

[0007] Furthermore, the first and second rotary support seats have the same structure, both including an upper mounting positioning plate and a quasi-isosceles trapezoidal support. The quasi-isosceles trapezoidal support is designed to be wider at the top and narrower at the bottom. The upper mounting positioning plate is installed on the upper end of the quasi-isosceles trapezoidal support, and the lower end of the quasi-isosceles trapezoidal support is rotatably mounted on the main shaft via a bearing.

[0008] Furthermore, the upper ends of the front hydraulic cylinder and the rear hydraulic cylinder are respectively connected to the two ends of the main shaft via U-shaped plates and short shafts. A U-shaped plate is installed on the upper end of the front hydraulic cylinder and the rear hydraulic cylinder, and a short shaft is fixedly and vertically installed on both ends of the main shaft. The two ends of the short shaft are respectively rotatably installed on the upper ends of the corresponding U-shaped plates via bearings.

[0009] Furthermore, the third rotary support includes a U-shaped support, a long shaft, a second rotating shaft, and a U-shaped plate. The two ends of the long shaft are rotatably mounted on the upper ends of the two sides of the U-shaped support via bearings. The second rotating shaft passes vertically through the middle of the long shaft and is rotatably mounted in the middle position of the long shaft via a bearing. The two ends of the second rotating shaft are rotatably mounted on the upper end of the U-shaped plate via bearings. The lower end of the U-shaped plate is fixed to the upper end of the tilting hydraulic cylinder. An upper mounting positioning plate is installed on the lower end of the U-shaped support, and the U-shaped support is connected to the lower end of the platform via the upper mounting positioning plate. The lower end of the tilting hydraulic cylinder is connected to the base via a fourth rotary support. The fourth rotary support has the same structure as the third rotary support. A fixing plate is installed at the bottom of the U-shaped support of the fourth rotary support, and the fixing plate is fixedly mounted on the base.

[0010] Furthermore, the lower ends of the front hydraulic cylinder and the rear hydraulic cylinder are respectively mounted on the base via a U-shaped base and a fixed shaft. The U-shaped base is mounted on the base, and the two ends of the fixed shaft are fixedly mounted on the upper sides of the U-shaped base. The middle of the fixed shaft is rotatably mounted on the lower end of the front hydraulic cylinder or the rear hydraulic cylinder via a bearing.

[0011] Furthermore, the upper mounting positioning plate is designed with a tapered positioning hole in the middle; a lower mounting plate is installed at the lower end of the frame corresponding to the upper mounting positioning plate, a tapered pin is installed in the middle of the lower mounting plate, and a stop block is installed around the lower mounting plate. The lower mounting plate and the corresponding upper mounting positioning plate below are positioned by inserting the tapered pin into the tapered positioning hole, and the stop block around the lower mounting plate is locked around the upper mounting positioning plate; the lower mounting plate and the upper mounting positioning plate are then connected by bolts and / or welding.

[0012] Furthermore, an avoidance pit is provided on the front and rear sides of the support on the base, and the lower ends of the front hydraulic cylinder and the rear hydraulic cylinder are respectively installed at the bottom of the avoidance pit on the corresponding side.

[0013] Furthermore, the axial center lines of the first and second rotating shafts are located on the same vertical plane.

[0014] The beneficial effects of this invention are: This invention provides a high-precision two-degree-of-freedom rotation mechanism with an ingenious design and a reasonable and compact structure. Through the design of three hydraulic cylinders, a Hooke's hinge assembly, a support platform, and a test bench, it can realize large-tonnage flight simulation tests. The Hooke's hinge assembly is stably supported by a four-sided pyramidal columnar support, capable of supporting large-tonnage test benches and aircraft simulation test components. The front and rear hydraulic cylinders, in conjunction with the Hooke's hinge assembly, can achieve a pitch angle range of -36.6° to +36.6°; the roll hydraulic cylinder, in conjunction with the Hooke's hinge assembly, can achieve a roll angle range of -23.8° to +30.4°. This invention exhibits high structural stability and can achieve high-precision flight simulation tests. Attached Figure Description

[0015] Figure 1 This is a front view of the present invention.

[0016] Figure 2 This is a side view of the present invention.

[0017] Figure 3 This is a schematic diagram of the Hooke's hinge assembly of the present invention.

[0018] Figure 4 yes Figure 3 A horizontal top sectional view.

[0019] Figure 5 This is a schematic diagram showing the connection between the lower ends of the front and rear hydraulic cylinders of the present invention.

[0020] Figure 6 yes Figure 5 A horizontal top sectional view.

[0021] Figure 7 This is a schematic diagram of the tilting hydraulic cylinder and the connecting structure at both ends of the present invention.

[0022] Figure 8 yes Figure 7 Vertical sectional view.

[0023] Figure 9 yes Figure 7 A longitudinal sectional view.

[0024] Figure 10 This is a bottom view of the stand of the present invention.

[0025] Figure 11This is a schematic diagram of the lower mounting plate at the lower end of the stand of the present invention.

[0026] Figure 12 This is a schematic diagram of the pitching motion of the present invention.

[0027] Figure 13 This is a schematic diagram of the tilting action of the present invention.

[0028] Figure 14 This is a schematic diagram of the mixed action of the present invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Reference Figure 1-14 This invention proposes a high-precision two-degree-of-freedom rotation mechanism, comprising a front hydraulic cylinder 1, a rear hydraulic cylinder 2, a tilting hydraulic cylinder 3, a Hooke's hinge assembly 4, a support part 5, a base 6, and a frame 7. The support part 5 is mounted on the middle of the base 6. The lower ends of the front hydraulic cylinder 1 and the rear hydraulic cylinder 2 are respectively rotatably mounted on the front and rear sides of the base 6 of the support part 5. The lower end of the tilting hydraulic cylinder 3 is rotatably mounted on either the left or right side of the base 6 of the support part 5. The Hooke's hinge assembly 4 is mounted on the upper end of the support part 5 and includes a main shaft 41, a first rotary support 42, a second rotary support 43, and an intermediate... A rotating support 44 is provided, and the main shaft 41 is rotatably mounted on the upper end of the support part 5 via the intermediate rotating support 44. The front end of the main shaft 41 is connected to the upper end of the front hydraulic cylinder 1, and the rear end of the main shaft 41 is connected to the upper end of the rear hydraulic cylinder 2. A rotating support seat is rotatably mounted between the middle position and the two ends of the main shaft 41, namely the first rotating support seat 42 and the second rotating support seat 43. A third rotating support seat 31 is rotatably mounted on the upper end of the tilting hydraulic cylinder 3. The upper ends of the first rotating support seat 42, the second rotating support seat 43 and the third rotating support seat 31 are respectively fixedly connected to the lower end of the frame 7.

[0031] In this invention, the support 5 is a reinforced concrete platform 51 in the shape of a four-sided pyramid, narrower at the top and wider at the bottom; the lower end of the intermediate rotating support 44 is fixedly installed at the middle of the upper end of the reinforced concrete platform 51. This four-sided pyramid-shaped reinforced concrete platform structure, narrower at the top and wider at the bottom, provides greater structural stability. The conical foundation provides a larger bottom contact area, thus distributing the weight of the building more evenly across the foundation. This helps reduce local settlement of the foundation and improves overall stability. The conical foundation design allows for more even load transfer to the foundation, avoiding localized damage caused by concentrated stress. This uniform stress distribution helps improve the overall bearing capacity of the foundation.

[0032] In this invention, the intermediate rotating support 44 includes a first support base 441 and a first rotating shaft 442. The first support base 441 is designed as a U-shaped base, with its lower end installed in the middle of the upper end of the support part 5. The main shaft 41 is rotatably mounted on the U-shaped base via the first rotating shaft 442. The first rotating shaft 442 is vertically fixed in the middle of the main shaft 41, and its two ends are rotatably mounted on the upper ends of both sides of the U-shaped base via bearings. This design mainly ensures that the main shaft can swing back and forth around the middle position, allowing the steps installed on it to tilt forward and backward.

[0033] In this invention, the first rotary support 42 and the second rotary support 43 have the same structure, both including an upper mounting positioning plate 421 and a quasi-isosceles trapezoidal support 422. The quasi-isosceles trapezoidal support 422 is designed to be wider at the top and narrower at the bottom. The upper mounting positioning plate 421 is mounted on the upper end of the quasi-isosceles trapezoidal support 422, and the lower end of the quasi-isosceles trapezoidal support 422 is rotatably mounted on the main shaft 41 via a bearing. The two rotary supports are used to rotatably support the lower end of the connecting frame, and the frame can also achieve left and right rotation and tilting movements through the two rotary supports.

[0034] In this invention, the upper ends of the front hydraulic cylinder 1 and the rear hydraulic cylinder 2 are respectively connected to both ends of the main shaft 41 via U-shaped plates and short shafts 12. A U-shaped plate is mounted on the upper end of each of the front and rear hydraulic cylinders 1 and 2. A short shaft 12 is fixedly and vertically mounted on both ends of the main shaft 41. The two ends of the short shafts 12 are rotatably mounted on the upper ends of the corresponding U-shaped plates via bearings. The lower ends of the front hydraulic cylinder 1 and the rear hydraulic cylinder 2 are respectively mounted on the base 6 via U-shaped bases 21 and fixed shafts 22. The U-shaped bases 21 are mounted on the base 6, and the two ends of the fixed shafts 22 are fixedly mounted on the upper ends of both sides of the U-shaped bases 21. The middle of the fixed shaft 22 is mounted on the lower end of either the front hydraulic cylinder 1 or the rear hydraulic cylinder 2 via a bearing. This design ensures that both ends of the front and rear hydraulic cylinders rotate and swing back and forth, achieving pitching motion in conjunction with the Hooke's hinge assembly.

[0035] In this invention, the third rotating support 31 includes a U-shaped support 311, a long shaft 312, a second rotating shaft 313, and a U-shaped plate. The two ends of the long shaft 312 are rotatably mounted on the upper sides of the U-shaped support 311 via bearings. The second rotating shaft 313 passes vertically through the middle of the long shaft 312 and is rotatably mounted at the middle position of the long shaft 312 via a bearing. The two ends of the second rotating shaft 313 are rotatably mounted on the upper end of the U-shaped plate via bearings. The lower part of the U-shaped plate... The upper end of the tilting hydraulic cylinder 3 is fixed in the middle. An upper mounting positioning plate 421 is installed on the upper end of the U-shaped support 311, which is connected to the lower end of the platform 7 via the upper mounting positioning plate 421. The lower end of the tilting hydraulic cylinder 3 is connected to the base 6 via a fourth rotating support 32. The structure of the fourth rotating support 32 is the same as that of the third rotating support 31. A fixing plate 321 is installed at the bottom of the U-shaped support of the fourth rotating support 32, and the fixing plate 321 is fixedly installed on the base 6. The upper and lower ends of the tilting hydraulic cylinder are connected by independent small Hooke hinges, allowing both ends to rotate forward and backward, as well as left and right. This design ensures that the rotation of the upper and lower ends of the tilting hydraulic cylinder can be coordinated when the platform tilts forward and backward. The vertical extension and retraction of the tilting hydraulic cylinder controls the rotation of the step around the main axis. Simultaneously, the tilting hydraulic cylinder, in conjunction with the front and rear hydraulic cylinders, can achieve compound rotational movements, including both tilting and pitching actions.

[0036] In this invention, the upper mounting positioning plate 421 has a tapered positioning hole 4211 in the middle; a lower mounting plate 108 is installed at the lower end of the frame 7 corresponding to the upper mounting positioning plate 421, a tapered pin 1081 is installed in the middle of the lower mounting plate 108, and a stop block 1083 is installed around the lower mounting plate 108. The lower mounting plate 108 and the corresponding upper mounting positioning plate 421 are positioned by inserting the tapered pin 1081 into the tapered positioning hole 4211, and the stop block 1083 around the lower mounting plate 108 is locked around the upper mounting positioning plate 421; the lower mounting plate 108 and the upper mounting positioning plate 421 are then connected by bolts and / or welding. This design ensures that the frame and the lower Hooke hinge assembly are quickly and accurately positioned and installed. The stop block design is to ensure that the upper mounting positioning plate can be temporarily locked during installation to prevent the frame of large tonnage from shifting, facilitate subsequent bolting and welding operations, and provide a protective limiting mechanism during later work.

[0037] In this invention, a clearance pit 61 is provided on the base 6 on both the front and rear sides of the support part 5, and the lower ends of the front hydraulic cylinder 1 and the rear hydraulic cylinder 2 are respectively installed at the bottom of the clearance pit 61 on the corresponding side. The design of the clearance pit ensures that the extension and retraction stroke of the front and rear hydraulic cylinders is sufficient.

[0038] In this invention, the axial center lines of the first rotating shaft 442 and the second rotating shaft 313 are located on the same vertical plane. This design ensures maximum pitch angle and maximum tilt angle during combined movements, while avoiding rotational interference problems.

[0039] When this invention is used, during the pitching motion, one of the front and rear hydraulic cylinders extends while the other retracts synchronously, controlling the main shaft to rotate around the central first axis. As a result, the frame mounted on the main shaft also pitches back and forth. The tilting hydraulic cylinder does not move, preventing the frame from rotating or tilting left and right. During the tilting action, the front and rear hydraulic cylinders do not move to ensure that the main shaft does not rotate, while the tilting hydraulic cylinder extends and retracts, thereby controlling the frame to rotate and tilt left and right around the main shaft. The compound action is a pitching action that is performed simultaneously with a tilting action. In this case, the small Hooke's hinge connection mechanism at both ends of the tilting hydraulic cylinder can adapt to the changes in the compound action and cooperate with the action of the Hooke's hinge assembly to ensure the completion of the compound action.

[0040] The Hooke hinge assembly features a large Hooke hinge structure design, ensuring the test platform can rotate simultaneously in all directions. It is supported by a four-sided pyramidal reinforced concrete platform structure, ensuring stable load-bearing capacity for the total tonnage of the platform and the testing equipment above. The platform itself must weigh at least 30 tons, and the testing equipment above must weigh no less than 50 tons. This invention requires only three hydraulic cylinders to achieve pitch and roll movements, providing sufficient stability and operational precision. Performance requirements: The platform's pitch angle range is -35° to +35°, and the roll angle range is -20° to +20°. The invention's extreme pitch angle range is -36.6° to +36.6°, and the roll angle range is -23.8° to +30.4°.

[0041] The above description is merely a specific embodiment of the present invention, providing a detailed description of the invention. Parts not covered herein are conventional techniques. However, the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-precision two-degree-of-freedom rotational mechanism, characterized in that, The system includes a front hydraulic cylinder, a rear hydraulic cylinder, a tilting hydraulic cylinder, a Hooke's hinge assembly, a support unit, a base, and a frame. The support unit is mounted on the center of the base. The lower ends of the front and rear hydraulic cylinders are rotatably mounted on the base on the front and rear sides of the support unit, respectively. The lower end of the tilting hydraulic cylinder is rotatably mounted on the base on either the left or right side of the support unit. The Hooke's hinge assembly is mounted on the upper end of the support unit and includes a main shaft, a first rotary support, a second rotary support, and an intermediate rotary support. The main shaft is rotatably mounted on the upper end of the support unit via the intermediate rotary support. The front end of the main shaft is rotatably connected to the upper end of the front hydraulic cylinder, and the rear end of the main shaft is rotatably connected to the upper end of the rear hydraulic cylinder. The first and second rotary support are rotatably mounted between the middle and both ends of the main shaft, respectively. A third rotary support is rotatably mounted on the upper end of the tilting hydraulic cylinder. The upper ends of the first, second, and third rotary support are fixedly connected to the lower end of the frame.

2. The high-precision two-degree-of-freedom rotational mechanism according to claim 1, characterized in that, The support is a four-sided pyramidal reinforced concrete platform that is narrow at the top and wide at the bottom; the lower end of the intermediate rotating support is fixedly installed in the middle of the upper end of the reinforced concrete platform.

3. The high-precision two-degree-of-freedom rotation mechanism according to claim 1, characterized in that, The intermediate rotating support includes a first support base and a first rotating shaft. The first support base is a U-shaped base. The lower end of the first support base is installed in the middle of the upper end of the support part. The middle of the main shaft is rotatably installed on the U-shaped base through the first rotating shaft. The first rotating shaft is vertically fixed in the middle of the main shaft. The two ends of the first rotating shaft are respectively rotatably installed on the upper ends of the two sides of the U-shaped base through bearings.

4. The high-precision two-degree-of-freedom rotational mechanism according to claim 1, characterized in that, The first and second rotary support seats have the same structure, both including an upper mounting positioning plate and a quasi-isosceles trapezoidal support. The quasi-isosceles trapezoidal support is wider at the top and narrower at the bottom. The upper mounting positioning plate is installed on the upper end of the quasi-isosceles trapezoidal support, and the lower end of the quasi-isosceles trapezoidal support is rotatably mounted on the main shaft through a bearing.

5. A high-precision two-degree-of-freedom rotational mechanism according to claim 1, characterized in that, The upper ends of the front hydraulic cylinder and the rear hydraulic cylinder are respectively connected to the two ends of the main shaft via U-shaped plates and short shafts. A U-shaped plate is installed on the upper end of the front hydraulic cylinder and the rear hydraulic cylinder respectively. A short shaft is fixedly and vertically installed on both ends of the main shaft. The two ends of the short shaft are respectively rotatably installed on the upper end of the U-shaped plate on the corresponding side via bearings.

6. A high-precision two-degree-of-freedom rotational mechanism according to claim 3, characterized in that, The third rotary support includes a U-shaped support, a long shaft, a second rotating shaft, and a U-shaped plate. The two ends of the long shaft are rotatably mounted on the upper sides of the U-shaped support via bearings. The second rotating shaft passes vertically through the middle of the long shaft and is rotatably mounted in the middle position of the long shaft via a bearing. The two ends of the second rotating shaft are rotatably mounted on the upper end of the U-shaped plate via bearings. The lower end of the U-shaped plate is fixed to the upper end of the tilting hydraulic cylinder. An upper mounting positioning plate is installed on the lower end of the U-shaped support, and the U-shaped support is connected to the lower end of the platform via the upper mounting positioning plate. The lower end of the tilting hydraulic cylinder is connected to the base via a fourth rotary support. The fourth rotary support has the same structure as the third rotary support, and a fixing plate is installed at the bottom of the U-shaped support of the fourth rotary support, which is fixedly mounted on the base.

7. A high-precision two-degree-of-freedom rotational mechanism according to claim 1, characterized in that, The lower ends of the front hydraulic cylinder and the rear hydraulic cylinder are respectively mounted on the base via a U-shaped base and a fixed shaft. The U-shaped base is mounted on the base, and the two ends of the fixed shaft are fixedly mounted on the upper sides of the U-shaped base. The middle of the fixed shaft is rotatably mounted on the lower end of the front hydraulic cylinder or the rear hydraulic cylinder via a bearing.

8. A high-precision two-degree-of-freedom rotational mechanism according to claim 4 or 6, characterized in that, The upper mounting positioning plate is designed with a tapered positioning hole in the middle; a lower mounting plate is installed at the lower end of the frame corresponding to the upper mounting positioning plate, a tapered pin is installed in the middle of the lower mounting plate, and a stop block is installed around the lower mounting plate. The lower mounting plate and the corresponding upper mounting positioning plate below are positioned by inserting the tapered pin into the tapered positioning hole, and the stop block around the lower mounting plate is locked around the upper mounting positioning plate; the lower mounting plate and the upper mounting positioning plate are then connected by bolts and / or welding.

9. A high-precision two-degree-of-freedom rotational mechanism according to claim 1, characterized in that, The base has a clearance pit on the front and rear sides of the support, and the lower ends of the front hydraulic cylinder and the rear hydraulic cylinder are respectively installed at the bottom of the clearance pit on the corresponding side.

10. A high-precision two-degree-of-freedom rotational mechanism according to claim 1, characterized in that, The axial center lines of the first and second rotating shafts are located on the same vertical plane.

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