High-precision spherical joint suitable for extreme environment

Abstract

The utility model relates to a high-precision spherical joint suitable for an extreme environment. According to one embodiment, a spherical joint includes: a joint seat on which a joint cavity is formed; the joint rotor comprises a ball head and a connecting rod connected to the ball head, and the ball head is contained in the joint cavity; and the vibration block is fixed on at least one of the joint seat and the joint mover and is used for enabling the joint seat and the joint mover to vibrate relative to each other, so that the ball head rotates in the joint cavity.

Description

Technical Field

[0001] The utility model relates to a high-precision spherical joint suitable for extreme environments. Background Art

[0002] With the rapid development of science and technology, more and more fields need to apply engineering equipment or scientific research instruments to extreme environments, such as deep space exploration, cryogenic physics experiments, strong magnetic field research, and ultra-high vacuum technology. However, under these extreme conditions, existing spherical joints generally face serious performance challenges.

[0003] Ultra-low temperature environment: Traditional spherical joints may have excessive or too small joint clearances at extremely low temperatures (e.g., milliKelvin level) due to the thermal contraction characteristics of the material, changes in the elastic modulus, and freezing of the lubricating medium, resulting in a serious decrease in motion accuracy or even failure to work properly.

[0004] Strong magnetic field environment: In a high-intensity magnetic field, some non-magnetic or weakly magnetic materials may be affected by the magnetostrictive effect, or the performance of lubricants and seals may be degraded due to the magnetic field, further affecting the accuracy and life of the spherical joint.

[0005] Ultra-high vacuum environment: In an ultra-high vacuum environment, some materials of conventional spherical joints will affect the vacuum environment due to their high outgassing rate. At the same time, the lack of effective lubrication will also increase the friction between the joints. For example, the joint cavity wall and the ball head may be cold-welded together, making it difficult to move, reducing its flexibility and service life.

[0006] In view of the above problems, there is an urgent need in the market to develop a spherical joint that can maintain high-precision positioning and good motion performance under extreme conditions. Utility Model Content

[0007] In view of the above problems, the present utility model is proposed. The utility model creatively designs a spherical joint that combines ball-cone contact to achieve high-precision positioning, and uses a piezoelectric vibration block to reduce friction and improve movement smoothness, so as to cope with and solve practical application problems in extreme environments.

[0008] One embodiment of the utility model provides a spherical joint, comprising: a joint seat, on which a joint cavity is formed; a joint mover, comprising a ball head and a connecting rod connected to the ball head, the ball head being accommodated in the joint cavity; and a vibration block, fixed to at least one of the joint seat and the joint mover, for making the joint seat and the joint mover vibrate relative to each other to facilitate the rotation of the ball head in the joint cavity.

[0009] In one embodiment, the vibration mass includes one or more piezoelectric material layers, and the piezoelectric material layers are deformed to generate vibrations when receiving an alternating voltage.

[0010] In one embodiment, the piezoelectric material layer includes barium titanate or lead zirconate titanate.

[0011] In one embodiment, the vibration block forms a part of at least one of the connection rod of the joint mover and the joint seat.

[0012] In one embodiment, the ball head has a circular shape, and the joint cavity has a polygonal pyramid shape or a conical shape.

[0013] In one embodiment, the joint seat and the joint mover include ceramic material.

[0014] In one embodiment, the ceramic material is selected from alumina, zirconium oxide, and silicon nitride.

[0015] In one embodiment, the vibration frequency of the vibration block is equal to the resonance frequency of the joint seat or the joint mover to which it is fixed.

[0016] In one embodiment, the joint seat includes a main body portion on which the joint cavity is formed and a covering plate fixed to the main body portion and covering the joint cavity, the covering plate confining the ball head in the joint cavity, and the connecting rod is connected to the ball head through an opening in the covering plate.

[0017] In one embodiment, the spherical joint further comprises: a driving unit for driving the vibration block using an alternating voltage to generate vibration.

[0018] The above and other features and advantages of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A cross-sectional view of a spherical joint according to an embodiment of the present invention is shown.

[0020] Figure 2 A cross-sectional view showing a spherical joint according to another embodiment of the present invention.

[0021] Figure 3 A cross-sectional view showing a spherical joint according to another embodiment of the present invention.

[0022] Figure 4 A cross-sectional view showing a spherical joint according to another embodiment of the present invention.

[0023] Figure 5 A cross-sectional view showing a spherical joint according to another embodiment of the present invention.

[0024] Figure 6 A schematic diagram of a joint cavity according to an embodiment of the utility model is shown.

[0025] Figure 7 A schematic diagram of a joint cavity according to another embodiment of the utility model is shown.

[0026] Figure 8 A schematic diagram of a joint cavity according to another embodiment of the utility model is shown. DETAILED DESCRIPTION

[0027] The utility model discloses a high-precision spherical joint suitable for extreme environments, especially for temperatures as low as milliKelvin (mK), magnetic field strengths as high as 18 Tesla (Tesla) and vacuum degrees as high as 10 -11 The utility model improves the spherical joint in the following aspects.

[0028] Structural design: The spherical joint of the utility model adopts an innovative ball head-cone contact positioning design. Through precision machining and assembly, the ball head and the cone joint cavity form a close fit to achieve extremely high rotation positioning accuracy. Compared with the traditional spherical joint cavity, this contact method not only provides high precision, but also reduces the contact area of ​​the ball head, which can reduce cold welding, thereby reducing friction, and is suitable for use in high vacuum and extremely low temperature environments.

[0029] Friction reduction mechanism: In addition to reducing friction through the above-mentioned contact method, the utility model also arranges a piezoelectric ceramic drive module in the spherical joint structure, which can generate tiny and controllable vibrations when joint rotation is required, and reduces the static friction of the contact point between the ball head and the pyramidal joint cavity through dynamic vibration assistance, thereby ensuring that the joint can achieve smooth and low-damping rotation while maintaining high precision.

[0030] Material selection and processing: Considering the requirements of extreme environments, the joint components of the utility model are made of materials with excellent low-temperature resistance, anti-magnetism and low outgassing rate characteristics, and special surface treatment and processing can be performed on them to ensure stability and long life in ultra-low temperature, strong magnetic field and ultra-high vacuum environment. Ceramic materials have the advantages of high temperature resistance, low temperature resistance, corrosion resistance, wear resistance, self-lubrication, etc., so they are very suitable for use as materials for spherical joints. Piezoelectric ceramics are a material that can convert electrical energy into mechanical energy, and it can generate vibrations. The vibrations generated by piezoelectric ceramics can make the spherical joints easily rotated without lubrication.

[0031] Working principle and application: When the spherical joint of the utility model works in extreme environments, the vibration generated by the piezoelectric ceramic module helps to reduce friction and improve movement efficiency, thereby meeting the strict requirements of precision mechanical equipment for high-precision, low-loss, and long-lasting and stable rotating joints under extreme conditions. It can be widely used in aerospace, quantum science, particle physics experimental equipment and other high-tech fields.

[0032] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0033] Figure 1 FIG. 2 shows a cross-sectional view of a spherical joint according to an embodiment of the present invention. Figure 1 As shown, the spherical joint includes a joint seat 10 and a joint mover 20. A joint cavity 11 may be formed on the joint seat 10, which may have a polygonal pyramid or conical structure to form a point contact or line contact with the ball head 22, thereby reducing friction, which will be described in detail below. The joint mover 20 may include a ball head 22 and a connecting rod 24 connected to the ball head 22, and the ball head 22 may be accommodated in the joint cavity 11. Although not shown, the joint mover 20 may be applied with a preload force toward the joint seat 10 so that the ball head 22 is installed in the joint cavity 11.

[0034] Figure 1 Also shown are a vibration block 30 fixed to the connecting rod 24 of the joint mover 20 and a driving unit 40 for driving the vibration block 30. The vibration block 30 can be fixed to the joint mover 20 in any manner, such as but not limited to bonding, screw fixing, etc., and the vibration block 30 can generate vibration when driven by an electrical signal to drive the joint mover 20 to vibrate, thereby reducing the static friction between the cavity wall of the joint cavity 11 and the ball head 22. The driving unit 40 can control the magnitude, frequency, etc. of the driving voltage or current applied to the vibration block 30 to control the vibration amplitude and frequency of the vibration block 30. In one embodiment, the driving unit 40 can control the vibration frequency of the vibration block 30 so that it is substantially equal to (e.g., equal or close to, for example, within ±10%, preferably within ±5%) the resonant frequency of the joint mover 20, so that the vibration block 30 can drive the joint mover 20 to vibrate together with the highest efficiency. The resonant frequency of the joint mover 20 can be determined by pre-measurement, or the resonant frequency between the two can be determined by frequency sweep measurement after the vibration block 30 is fixed to the joint mover 20. The vibration direction of the vibration block 30 is not limited and can be set to be along the axial direction of the connecting rod 24 or perpendicular to the axial direction thereof.

[0035] Although the vibration block 30 can be implemented as various devices capable of realizing the vibration function, such as a motor, etc., in order to be suitable for use under various extreme conditions, in some embodiments, the vibration block 30 can be preferably implemented as a piezoelectric vibration device, which may include one or more piezoelectric material layers. When voltage is applied to the piezoelectric material layer, deformation occurs, so by applying an AC voltage, the piezoelectric material layer can be reciprocated in the opposite direction. The deformation, thus generating vibration, the amplitude of the vibration depends on the voltage, and the frequency of the vibration depends on the frequency of the AC voltage, so the driving unit 40 can easily control the vibration of the vibration block 30. The piezoelectric material layer may include a ceramic piezoelectric material, such as barium titanate, lead zirconate titanate, etc., which is suitable for use under various extreme conditions.

[0036] In some embodiments, when the joint mover 20 needs to rotate relative to the joint seat 10, the driving unit 40 can drive the vibration block 30 to generate vibration to reduce the static friction between the joint seat 10 and the joint mover 20, so as to facilitate the rotation of the joint mover 20. When the joint mover 20 is stationary relative to the joint seat 10, the driving unit 40 may not drive the vibration block 30, that is, no vibration is generated, and at this time, the ball head 22 of the joint mover 20 can be accurately positioned in the joint cavity 11 of the joint seat 10.

[0037] Although the joint seat 10 and the joint mover 20 can be formed of various materials, in some embodiments, in order to be suitable for use under various extreme conditions, the joint seat 10 and the joint mover 20 are preferably formed of ceramic materials, such as aluminum oxide, zirconium oxide, silicon nitride, etc. These materials can withstand ultra-low temperatures, have very small thermal expansion and contraction and magnetostriction, and have a very small outgassing rate, and are therefore suitable for use under the aforementioned extreme conditions. In some embodiments, the surface of the ball head 22 and the inner wall of the joint cavity 11 (especially the part in contact with the ball head 22) can also be polished to improve the surface smoothness, thereby improving the positioning accuracy of the ball head 22 and reducing the friction between the ball head 22 and the joint cavity 11, so as to facilitate the rotation of the joint mover 20. It can be understood that the joint mover 20 can rotate around the axis of the connecting rod 24, or it can rotate perpendicular to the axis of the connecting rod 24.

[0038] Figure 2 A cross-sectional view of a spherical joint according to another embodiment of the utility model is shown. Figure 2 In, with Figure 1 The same components are indicated by the same reference numerals, and repeated descriptions thereof will be omitted here. Figure 2 The embodiment shown is Figure 1 The difference.

[0039] like Figure 2As shown, the joint seat 10 includes a main body 12 and a cover plate 14, a joint cavity 11 is formed in the main body 12, and a ball head 22 is arranged in the joint cavity 11 and covered by the cover plate 14, so as to be restricted in the joint cavity 11. In this way, the cover plate 14 can prevent the ball head 22 from being separated from the joint cavity 11. The cover plate 14 can be fixed to the main body 12 by means of screws 13 or any other structure, for example, and an opening can be formed on the cover plate 14, through which a part of the ball head 22 can be exposed, so that it can be connected to the connecting rod 24. The opening on the cover plate 14 can be set to have a suitable size to facilitate the rotation of the connecting rod 24 within an appropriate range, but its maximum diameter should be smaller than the diameter of the ball head 22. In one embodiment, the cover plate 14 can include two symmetrical parts, each of which is formed with a semicircular opening, so that a circular opening around the connecting rod 24 is formed when combined, which facilitates the assembly of the spherical joint and avoids the need to make the connecting rod 24 pass through the opening in the cover plate 14 when the cover plate 14 is formed as an integral structure. In one embodiment, one or more through holes may be formed on the cover plate 14 , which are connected to the joint cavity 11 , so that the air in the joint cavity 11 can be discharged to the outside when vacuum is drawn.

[0040] Figure 2 Other aspects of the ball joint shown may be Figure 1 The embodiments shown are the same and will not be described again here.

[0041] Figure 3 A cross-sectional view of a spherical joint according to another embodiment of the utility model is shown. Figure 3 In, with Figure 1 The same components are indicated by the same reference numerals, and repeated descriptions thereof will be omitted here. Figure 3 The embodiment shown is Figure 1 The difference.

[0042] like Figure 3 As shown, the vibration block 30 can be arranged on the joint seat 10, that is, fixed to the joint seat 10, instead of being arranged on the joint mover 20. Figure 3 Although not shown, the spherical joint also includes a driving unit 40 for controlling the magnitude and frequency of the driving voltage or current applied to the vibration block 30 to control the vibration amplitude and frequency of the vibration block 30. Figure 3In the illustrated embodiment, the vibration frequency of the vibration block 30 can be substantially equal to (e.g., equal to or close to, for example, within ±10%, preferably within ±5%) the resonant frequency of the joint seat 10, so that the vibration block 30 can drive the joint seat 10 to vibrate with the highest efficiency. The resonant frequency of the joint seat 10 can be determined by pre-measurement, or after the vibration block 30 is fixed to the joint seat 10, the resonant frequency between the two can be determined by frequency sweep measurement. The vibration direction of the vibration block 30 is not limited, and can be along Figure 3 The vibration block 30 can be fixed to different side walls of the joint seat 10 depending on the desired vibration direction.

[0043] Figure 2 Other aspects of the ball joint shown may be Figure 1 The embodiments shown are the same and will not be described again here.

[0044] It should be understood that in some embodiments, a plurality of vibration blocks 30 may be provided on the joint seat 10 or the joint mover 20, or one or more vibration blocks 30 may be provided on each of the joint seat 10 and the joint mover 20. A separate driving unit 40 may be provided for each vibration block 30, or one driving unit 40 may be used to drive all vibration blocks 30.

[0045] Figure 4 A cross-sectional view of a spherical joint according to another embodiment of the utility model is shown. Figure 4 In, with Figure 1 The same components are indicated by the same reference numerals, and repeated descriptions thereof will be omitted here. Figure 4 The embodiment shown is Figure 1 The difference.

[0046] Reference Figure 4 , the vibration block 30 can be formed as a part of the connecting rod 24 of the joint mover 20, in other words, a part of the connecting rod 24 is formed using a ceramic piezoelectric material. Figure 4 Although not shown, a driving unit 40 may also be provided to drive the vibration block 30 to generate vibration, thereby driving the connecting rod 24 and the ball head 22 to vibrate. Figure 4 Other aspects of the ball joint shown may be Figure 1 The embodiments shown are the same and will not be described again here.

[0047] Figure 5 A cross-sectional view of a spherical joint according to another embodiment of the utility model is shown. Figure 5 In, with Figure 1 The same components are indicated by the same reference numerals, and repeated descriptions thereof will be omitted here. Figure 5The embodiment shown is Figure 1 The difference.

[0048] Reference Figure 5 , the vibration block 30 can be formed as a part of the joint seat 10, in other words, a part of the joint seat 10 is formed using a ceramic piezoelectric material. Figure 5 Although not shown, a driving unit 40 may also be provided to drive the vibration block 30 to generate vibration, thereby driving the joint seat 10 to vibrate. Figure 5 Other aspects of the ball joint shown may be Figure 1 The embodiments shown are the same and will not be described again here.

[0049] It is understood that in some embodiments, the vibration block 30 may be formed as a part of each of the joint seat 10 and the joint mover 20 , and a separate driving unit 40 may be provided for the two vibration blocks 30 , or one driving unit 40 may be used to drive the two vibration blocks 30 .

[0050] Figure 6 , Figure 7 and Figure 8 The schematic diagram of the shape of the joint cavity 11 according to some embodiments of the utility model is shown. Figure 6 The joint cavity is shown in the shape of a regular triangular pyramid. Figure 7 The joint cavity is shown in the shape of a regular tetrahedron. Figure 8 The conical joint cavity is shown. The joint cavity 11 of the present invention can have a polygonal pyramid shape or a conical shape, wherein the polygonal pyramid joint cavity 11 forms a plurality of point contacts with the ball head 22, while the conical joint cavity 11 forms a closed line contact with the ball head 22. It can be understood that from the perspective of reducing friction and facilitating the discharge of air in the joint cavity 11, the polygonal pyramid shape is preferred. It should be understood that the polygonal pyramid or conical shape mentioned in the present invention also covers the following Figure 8 The truncated cone shape shown.

[0051] Unless the context clearly requires otherwise, throughout the specification and claims, contrary to the exclusive or exhaustive meaning, the words "including", "comprising", etc. should be understood in an inclusive sense, that is, in the sense of "including but not limited to". In the embodiments described above, some commonly used known devices, operations, etc. in the relevant field may be omitted. The wording "connected" generally used here means that two or more elements can be directly connected or connected by means of one or more intermediate elements. In addition, when used in this application, the words "here", "above", "below" and words of similar meanings should refer to the application as a whole, rather than any specific part of the application. When the context permits, the words used in the above description in the singular or plural may also include the plural or singular, respectively. The wording "or" when referring to a list of two or more items covers all of the following interpretations thereof: any item in the list, all items in the list, and any combination of items in the list.

[0052] The above detailed description of the embodiment of the utility model is not intended to be exhaustive or to limit the utility model to the precise form disclosed above. Although the specific embodiment of the utility model and the example for the utility model are described above for the purpose of illustration, as will be appreciated by those skilled in the art, various equivalent modifications within the scope of the utility model are feasible. For example, although a process or block is presented in a given order, an alternative embodiment can perform a process with steps in different orders, or adopt a system with blocks in different orders, and some processes or blocks can be deleted, moved, added, subtracted, combined and / or modified. Each of these processes or blocks can be implemented in a variety of different ways. Similarly, although a process or block is sometimes shown as being executed serially, on the contrary, these processes or blocks can also be executed in parallel, or can be executed at different times.

[0053] Although some embodiments of the utility model have been described, these embodiments have been presented only by way of example, and the embodiments are not intended to limit the scope of the present disclosure. In fact, the novel methods and systems described herein can be implemented in a variety of other forms; in addition, various omissions, substitutions, and changes in the form of the methods and systems described herein can be made without departing from the spirit of the present disclosure. The drawings and their equivalents are intended to cover such forms or modifications that will fall within the scope and spirit of the present disclosure.

Claims

1. A spherical joint, characterized in that include: A joint seat (10) having a joint cavity (11) formed thereon; A joint mover (20) comprising a ball head (22) and a connecting rod (24) connected to the ball head (22), wherein the ball head (22) is accommodated in the joint cavity (11); as well as A vibration block (30) is fixed to at least one of the joint seat (10) and the joint mover (20) and is used to make the joint seat (10) and the joint mover (20) vibrate relative to each other so as to facilitate the rotation of the ball head (22) in the joint cavity (11).

2. The spherical joint according to claim 1, characterized in that: The vibration block (30) comprises one or more piezoelectric material layers, which deform to generate vibrations when receiving an alternating voltage.

3. The spherical joint according to claim 2, characterized in that: The piezoelectric material layer includes barium titanate or lead zirconate titanate.

4. The spherical joint according to any one of claims 1 to 3, characterized in that The vibration block (30) forms a part of at least one of the connecting rod (24) of the joint mover (20) and the joint seat (10).

5. The spherical joint according to any one of claims 1 to 3, characterized in that The ball head has a circular shape, and the joint cavity has a polygonal pyramid shape or a conical shape.

6. The spherical joint according to any one of claims 1 to 3, characterized in that The joint seat (10) and the joint mover (20) include ceramic material.

7. The spherical joint according to claim 6, characterized in that: The ceramic material is selected from alumina, zirconium oxide and silicon nitride.

8. The spherical joint according to any one of claims 1 to 3, characterized in that The vibration frequency of the vibration block (30) is equal to the resonance frequency of the joint seat (10) or the joint mover (20) to which it is fixed.

9. The spherical joint according to any one of claims 1 to 3, characterized in that The joint seat (10) comprises a main body portion (12) on which the joint cavity (11) is formed and a covering plate (14) fixed to the main body portion (12) and covering the joint cavity (11), wherein the covering plate (14) confines the ball head (22) in the joint cavity (11), and the connecting rod (24) is connected to the ball head (22) through an opening in the covering plate (14).

10. A spherical joint according to any one of claims 1 to 3, characterized in that Also includes: A driving unit (40) is used to drive the vibration block (30) using an alternating voltage to generate vibration.

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