Dynamic balance platform of ultra-precise gas static pressure main shaft

Abstract

The invention relates to a dynamic balance platform for an ultra-precise gas static pressure main shaft, which is used for measuring vibration data of the ultra-precise gas static pressure main shaft and comprises a preload air floating platform, an objective table and a sensor for measuring the vibration data, the preload air floating platform comprises an air floating base, an air floating block and a negative pressure block, and the air floating block is used for generating an air film between the air floating block and the objective table; the negative pressure block is used for generating suction force opposite to the air floating force of the air floating block in direction. The objective table is provided with a first supporting body and a second supporting body which are located on the two sides in the X direction, a first spring and a second spring are arranged between the objective table and the first supporting body and between the objective table and the second supporting body respectively, and the two ends of the first spring and the two ends of the second spring are provided with a first universal joint and a second universal joint respectively. The arrangement direction of the sensor is perpendicular to the extension direction of the first spring and the second spring. The platform can effectively reduce the attenuation of vibration signals and improve the dynamic balance measurement precision.

Description

Technical Field

[0001] The invention relates to the field of vibration testing devices, and in particular to a platform device for measuring the minute dynamic balance amount of an ultra-precision gas static pressure spindle. Background Art

[0002] Ultra-precision aerostatic spindles require extremely high rotational accuracy, and their dynamic balancing accuracy has a significant impact on the final spindle performance parameters. Conventional support methods limit the propagation of small vibrations, which is not conducive to the collection of vibration data caused by imbalance.

[0003] However, the traditional dynamic balancing support method still has great radial rigidity, and the harmonic data of the bracket itself will be mixed into the measurement, which will have unpredictable effects on the dynamic balancing signal of the spindle itself.

[0004] In this regard, CN 114646377 B discloses a vibration force measuring device, which includes a measuring platform, a lifting device, a sensor, a vibration transmission member, and an elastic support member. The measuring platform has a bearing surface for carrying the object to be measured. The lifting device is configured to lift the measuring platform off the upper surface of the lifting device. The sensor is configured to sense the amount of vibration generated when the object to be measured is in operation. The vibration transmission member has a first end and a second end relative to each other. The first end is engaged with the sensor, and the second end is configured to receive the vibration amount. The elastic support member connects the measuring platform and the supporting structure, wherein the vibration transmission member and the elastic support member are respectively located on two opposite sides of the measuring platform. By arranging the sensor, the vibration transmission member, and the elastic support member on two opposite sides of the object to be measured, the vibration force of the object to be measured during operation can be sensed instantly, and the vibration force data can be quantified and graded, thereby having the ability of rapid full inspection.

[0005] This device is equipped with an air flotation unit that can float the measuring platform and measure the X / Y vibration of the object under test using air flotation and spring restraint. However, the following shortcomings still exist:

[0006] First, after the measurement platform floats, its vertical rigidity is insufficient, making it difficult to control the air film gap within a reasonable range, which will cause slight vibrations on the measurement platform and affect the measurement accuracy.

[0007] Secondly, its elastic support adopts a unilateral layout, which has poor balance and stability, and the vibration force detection device is arranged parallel to the spring support, which is not suitable for measuring the tiny dynamic balance of the ultra-precision gas static pressure spindle.

[0008] Furthermore, it is necessary to separately design a concave support structure, which results in a complex structure, a large floor space, and difficulty in operation. Summary of the Invention

[0009] The purpose of the present invention is to provide an ultra-precision gas static pressure spindle dynamic balancing platform to solve the above technical problems.

[0010] To achieve the above objectives, the present invention provides an ultra-precision aerostatic spindle dynamic balancing platform for measuring vibration data of an ultra-precision aerostatic spindle. The platform comprises a preloaded air flotation platform, a stage, and a sensor for measuring vibration data. The preloaded air flotation platform comprises an air flotation base, an air flotation block, and a negative pressure block. The air flotation block is connected to an air supply line and is used to generate an air film between the air flotation block and the stage to keep the stage in a floating state. The negative pressure block is connected to a negative pressure line and is used to generate a suction force in the opposite direction of the air flotation force of the air flotation block to apply a preload to the stage. The air flotation base is provided with a first support and a second support located on either side along the X direction. A first spring is provided between the stage and the first support, and a second spring is provided between the stage and the second support. The first spring has first universal joints at both ends, and the second spring has second universal joints at both ends. The sensors are arranged on both sides of the same side of the stage along the Y direction, with their arrangement direction perpendicular to the extension direction of the first and second springs.

[0011] Optionally, the loading platform is located on the preload air flotation platform, is arranged parallel to the air flotation base and has an area smaller than the air flotation base, and the air flotation base is provided with a limiting mechanism for preventing the loading platform from detaching.

[0012] Optionally, the limiting mechanism includes four groups of limiting columns arranged corresponding to the four right-angled parts of the loading platform, and each group of the limiting columns includes a first limiting column and a second limiting column corresponding to two sides of a right-angled part of the loading platform.

[0013] Optionally, the heights of the first and second limiting pillars are greater than the thickness of the air film between the air floating block and the loading platform, and in a floating state, the loading platform does not contact the first and second limiting pillars.

[0014] Optionally, the negative pressure block is arranged at the center of the air floating base, and the air floating blocks are arranged on the air floating base at four right angles corresponding to the loading platform.

[0015] Optionally, the preload air flotation platform is provided with a level adjustment mechanism for adjusting its level.

[0016] Optionally, the horizontal adjustment mechanism includes leveling bolts provided at four right-angle areas of the preload air flotation platform.

[0017] Optionally, the sensors are located on one side of the stage, and there are at least two of them arranged in parallel.

[0018] Optionally, the sensor includes an acceleration sensor that can be connected to a dynamic balance detection device.

[0019] Optionally, the stiffness of the first spring and the second spring is less than 2 N / mm.

[0020] The ultra-precision aerostatic spindle dynamic balancing platform provided by the present invention is equipped with both air flotation blocks and negative pressure blocks. While the air flotation blocks are used to levitate the platform, the negative pressure blocks also preload the platform. This allows the air film thickness to be controlled within a reasonable range, improving the air film stiffness and platform stability. This addresses the problem of insufficient vertical platform rigidity, which can lead to minute vibrations and affect measurement accuracy. Furthermore, a weak rigidity limiter, combining a universal joint and a spring, is designed. The universal joint reduces the effect of additional force at the spring connection point on measurement accuracy. Furthermore, the sensor is positioned perpendicular to the spring direction, reducing the impact of spring constraints on measurement data and making dynamic balancing signal acquisition more efficient. With these improvements, the present invention, compared to the prior art, has significantly lower vibration propagation resistance, effectively reducing vibration signal attenuation, improving dynamic balancing measurement accuracy, and enabling measurement and adjustment of minute dynamic balancing values for ultra-precision aerostatic spindles. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 An isometric view of an ultra-precision gas static pressure spindle dynamic balancing platform provided by an embodiment of the present invention;

[0022] Figure 2 for Figure 1 A top view of the ultra-precision gas hydrostatic spindle dynamic balancing platform shown;

[0023] Figure 3 for Figure 2 The isometric view of the ultra-precision gas static pressure spindle dynamic balancing platform after it moves a certain distance on the stage;

[0024] Figure 4 for Figure 1 The reference diagram of the use status of the ultra-precision gas static pressure spindle dynamic balancing platform shown in the figure;

[0025] Figure 5 This is a schematic diagram of the air path connection between the air flotation block and the negative pressure block;

[0026] Figure 6 Schematic diagram of the first structure for forming an air film between the air floating block and the stage;

[0027] Figure 7 A schematic diagram of a second structure for forming an air film between the air floating block and the stage;

[0028] Figure 8 Schematic diagram of the third structure for forming an air film between the air floating block and the stage.

[0029] In the picture:

[0030] 10. Preloaded air flotation platform; 11. Air flotation base; 111. First support; 112. Second support; 12. Air flotation block; 121. Micropore; 122. Small hole; 123. Microgroove; 13. Negative pressure block; 14. Air source processing module; 15. Air supply line; 16. Vacuum generator; 17. Negative pressure line; 20. Stage; 30. Sensor; 41. First spring; 42. Second spring; 51. First universal joint; 52. Second universal joint; 61. First limit column; 62. Second limit column; 70. Leveling bolt; 80. Lifting ring; 90. Ultra-precision gas static pressure spindle. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0032] In this article, terms such as "upper, lower, inside, outside" are established based on the positional relationships shown in the drawings. Depending on the different drawings, the corresponding positional relationships may also change accordingly. Therefore, they cannot be understood as absolute limitations on the scope of protection; moreover, relational terms such as "first" and "second" are only used to distinguish one component from another with the same name, and do not necessarily require or imply any actual relationship or order between these components.

[0033] Please refer to Figures 1 to 4 , Figure 1 An isometric view of an ultra-precision gas static pressure spindle dynamic balancing platform provided by an embodiment of the present invention; Figure 2 for Figure 1 A top view of the ultra-precision gas hydrostatic spindle dynamic balancing platform shown; Figure 3 for Figure 2 The isometric view of the ultra-precision gas static pressure spindle dynamic balancing platform after it moves a certain distance on the stage; Figure 4 for Figure 1 The reference diagram of the ultra-precision gas static pressure spindle dynamic balancing platform in use is shown.

[0034] As shown in the figure, in a specific embodiment, the ultra-precision gas static pressure spindle dynamic balancing platform provided by the present invention is used to measure the micro-vibration data generated by the ultra-precision gas static pressure spindle 90 during high-speed rotation due to the imbalance. It is mainly composed of a preload air flotation platform 10, a stage 20, and a sensor 30. The sensor 30 can be an acceleration sensor, which can be connected to a dynamic balance detection device, such as an online dynamic balancing instrument.

[0035] The preload air flotation platform 10 is mainly composed of an air flotation base 11, an air flotation block 12 and a negative pressure block 13. Among them, the air flotation base 11 is generally a horizontally arranged rectangular plate structure, the negative pressure block 13 is generally circular and is located at the center of the air flotation base 11, and the air flotation block 12 is generally square or rectangular and is arranged on the air flotation base 11 corresponding to the four right-angled parts of the worktable 20, and is located directly below the four right-angled parts of the worktable 20. A circular recess and four square or rectangular recesses are provided on the air flotation base 11, and the negative pressure block 13 and the four air flotation blocks 12 are respectively embedded in the corresponding recesses for installation, and their tops can be flush with the upper surface of the air flotation base 11, or slightly higher than the upper surface of the air flotation base 11.

[0036] The stage 20 is also a generally horizontal rectangular plate-shaped structure, which is located on the air-floating base 11. It is parallel to the air-floating base 11 and has a smaller area than the air-floating base 11. The air-floating base 11 is provided with a first support body 111 and a second support body 112 located on both sides along the X direction. In this embodiment, the first support body 111 and the second support body 112 are rectangular support plates located on both sides of the air-floating base 11, and both are fixed to the side surfaces of the air-floating base 11 by screws and are a certain distance higher than the upper surface of the air-floating base 11.

[0037] A first spring 41 is provided between the worktable 20 and the first support body 111, and first universal joints 51 are respectively provided at both ends of the first spring 41, that is, one end of the first spring 41 is connected to the first support body 111 through the first universal joint 51, and the other end is connected to the worktable 20 through another first universal joint 51; a second spring 42 is provided between the worktable 20 and the second support body 112, and second universal joints 52 are respectively provided at both ends of the second spring 42, that is, one end of the second spring 42 is connected to the second support body 112 through the second universal joint 52, and the other end is connected to the worktable 20 through another second universal joint 52.

[0038] The first spring 41 and the second spring 42 are used to constrain the stage 20 in the X and Y directions after the stage 20 floats. In order to reduce the influence of the elastic force of the first spring 41 and the second spring 42 on the detection data, the first spring 41 and the second spring 42 can be low-rigidity springs with a stiffness of less than 2N / mm.

[0039] Since universal joints are provided at both ends of the springs, if the first spring 41 and the second spring 42 are deformed away from their axes, the universal joints can further reduce the influence of the extra force at the spring connection points on the measurement accuracy.

[0040] Two sensors 30 are arranged on one side of the stage 20 along the Y direction. Their orientation is perpendicular to the extension direction of the first spring 41 and the second spring 42, and the two sensors 30 are arranged parallel to each other. By providing at least two sensors 30, more accurate measurement data can be obtained. Furthermore, the sensors 30 are arranged perpendicular to the spring direction, reducing the impact of spring constraints on measurement data, making dynamic balancing signal acquisition more scientific and reasonable.

[0041] The air flotation base 11 is equipped with a limiting mechanism for preventing the stage 20 from detaching. In this embodiment, the limiting mechanism comprises four sets of limiting posts arranged corresponding to the four right-angled portions of the stage 20. Taking one set of limiting posts as an example, each set of limiting posts comprises a first limiting post 61 and a second limiting post 62, each corresponding to the two sides of a right-angled portion of the stage 20. The height of the first limiting post 61 and the second limiting post 62 is greater than the thickness of the air film between the air flotation block 12 and the stage 20, thereby preventively limiting the stage 20 in both the X and Y directions. When in the floating state, the stage 20 does not contact the first limiting post 61 and the second limiting post 62. The first limiting post 61 and the second limiting post 62 are primarily used to prevent the stage 20 from accidentally detaching from the preload air flotation platform 10 after detachment, which could cause a dangerous situation.

[0042] The preloaded air flotation platform 10 is also equipped with a leveling mechanism for adjusting its level. In this embodiment, the leveling mechanism comprises leveling bolts 70 located at four right angles to the air flotation base 11. By tightening the leveling bolts 70, the distance between the air flotation base 11 and the ground can be locally adjusted, ensuring that the preloaded air flotation platform 10 is level and that the loading platform 20 does not contact the aforementioned limit posts.

[0043] In addition, in order to facilitate the movement of the ultra-precision gas static pressure spindle dynamic balancing platform so that it can be transferred to meet different measurement requirements, four lifting rings 80 are provided at the four right-angle areas of the air flotation base 11 near the leveling bolts 70. The entire set of ultra-precision gas static pressure spindle dynamic balancing platform can be lifted by lifting equipment and transferred to a suitable site.

[0044] Please refer to Figure 5 、 Figure 6 , Figure 5 This is a schematic diagram of the air path connection between the air flotation block and the negative pressure block; Figure 6 This is a schematic diagram of the first structure for forming an air film between the air floating block and the stage.

[0045] As shown in the figure, an air path interface is provided on the side of the air flotation base 11, and an air path flow channel is provided inside. The air flotation block 12 is connected to the air supply pipeline 15 through the air path interface. When the control gas source processing module 14 supplies steam to the air flotation block 12, the air flotation block 12 can generate upward positive pressure, thereby generating an air film between the air flotation block 12 and the worktable 20, so that the worktable 20 can be in a floating state.

[0046] The negative pressure block 13 is connected to the negative pressure pipeline 17 through the air circuit interface. When the vacuum generator 16 is controlled to evacuate the negative pressure block 13, the negative pressure block 13 can generate a suction force in the opposite direction of the buoyancy force of the air float block 12, thereby adding a preload to the stage 20. By introducing the vacuum preload, the thickness of the air film can be controlled within a reasonable range, the stiffness of the air film and the stability of the stage 20 can be improved, and the problem of insufficient vertical rigidity of the stage 20 causing micro-vibration and affecting the measurement accuracy can be solved.

[0047] In this embodiment, the air flotation block 12 adopts a porous throttling method, that is, the air flotation block 12 is provided with a plurality of densely distributed micropores 121, whose pore diameter can be about 5-25 μm. The high-speed airflow passes through the air supply pipe 15 and reaches the air flotation block 12, and acts as a throttling agent through the micropores 121, thereby forming an air film between the air flotation block 12 and the worktable 20, causing the worktable 20 to float. The negative pressure block 13 is connected to the negative pressure, adding a preload to the worktable 20, adjusting the optimal working air film thickness, and increasing the air film stiffness.

[0048] After the stage 20 floats, it will lose the horizontal X and Y direction constraints. The low-rigidity first spring 41 and the second spring 42 can constrain the stage 20 along the horizontal X and Y directions. The first universal joint 51 and the second universal joint 52 are respectively arranged at the two ends of the low-rigidity first spring 4-1 and the second spring 4-2, which can eliminate the additional force at the spring connection point. The two acceleration sensors 30 are arranged perpendicular to the spring direction to reduce the influence of the spring constraint on the measurement data.

[0049] During use, the ultra-precision gas static pressure spindle 90 is placed on the stage 20, a stable airflow is introduced along the air supply pipe 15 to make the stage 20 float, and the negative pressure block 13 is connected to negative pressure to add a preload to the stage 20; then the leveling bolt 70 is adjusted to make the stage 20 horizontal and not in contact with the limit column, and the acceleration sensor 30 is connected to the online dynamic balancing instrument (not shown in the figure), and the dynamic balance data of the ultra-precision gas static pressure spindle 90 can be measured and adjusted.

[0050] Please refer to Figure 7 , Figure 7 Schematic diagram of the second structure for forming an air film between the air floating block and the stage.

[0051] As shown in the figure, compared with the first embodiment, the difference of this embodiment is:

[0052] The air flotation block 12 adopts a small hole throttling method, that is, a small hole 122 is provided at the center of the air flotation block, and its aperture can be between 0.2mm and 0.3mm. The high-speed airflow reaches the air flotation block 12 through the air supply pipe 15, and acts as a throttling agent through the small hole 122, thereby forming an air film between the air flotation block 12 and the stage 20, causing the stage 20 to float. The negative pressure block 13 is connected to negative pressure, adding a preload to the stage 20, adjusting the optimal working air film thickness, and increasing the air film stiffness.

[0053] In this embodiment, the same parts as those in the first embodiment are given the same reference numerals, and the same text descriptions are omitted.

[0054] Please refer to Figure 8 , Figure 8 Schematic diagram of the third structure for forming an air film between the air floating block and the stage.

[0055] As shown in the figure, compared with the first embodiment, the difference of this embodiment is:

[0056] The air flotation block 12 adopts a surface throttling method, that is, a plurality of microgrooves 123 are machined on the upper surface of the air flotation block 12. The microgrooves 123 can be specifically in the form of a parallel structure, a concentric circle structure, or a network staggered structure. The high-speed airflow passes through the air supply pipe 15 and reaches the air flotation block 20. The microgrooves 123 play a throttling role, thereby forming an air film between the air flotation block 12 and the stage 20, causing the stage 20 to float. The negative pressure block 13 is connected to the negative pressure, adding a preload to the stage 20, adjusting the optimal working air film thickness, and increasing the air film stiffness.

[0057] In this embodiment, the same parts as those in the first embodiment are given the same reference numerals, and the same text descriptions are omitted.

[0058] The above embodiments are merely preferred solutions of the present invention and are not intended to be limiting. Based on these solutions, targeted adjustments can be made based on actual needs to achieve different implementations. For example, sensors 30 could be arranged on both sides of stage 20 along the Y direction, or first and second supports 111, 112 could be integrated with air flotation base 11, and so on. Due to the numerous possible implementations, we will not provide a detailed description of each one here.

[0059] Traditional dynamic balancing supports, due to their significant radial rigidity, can introduce harmonics into the support during measurement, potentially impacting the spindle's dynamic balancing signal. This device utilizes a preloaded air-floating platform, a weak-rigidity limiter consisting of a universal joint and spring, and a vertical arrangement of the sensor and weak-rigid support. This significantly amplifies the spindle's dynamic balancing signal, reduces external signal interference, and addresses the vibration attenuation issue associated with contact supports, ultimately improving the dynamic balancing accuracy of ultra-precision aerostatic spindles.

[0060] The above is a detailed introduction to the ultra-precision gas static pressure spindle dynamic balancing platform provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. Ultra-precision aerostatic spindle dynamic balancing platform, used to measure the vibration data of ultra-precision aerostatic spindle, characterized by: The device comprises a preloaded air flotation platform, a loading platform, and a sensor for measuring vibration data; the preloaded air flotation platform comprises an air flotation base, an air flotation block, and a negative pressure block; the air flotation block is connected to an air supply line and is used to generate an air film between the air flotation block and the loading platform so that the loading platform can be in a floating state; the negative pressure block is connected to a negative pressure line and is used to generate a suction force in the opposite direction to the air flotation force of the air flotation block to add a preload to the loading platform; the air flotation base is provided with a first support body and a second support body located on both sides along the X direction, a first spring is provided between the loading platform and the first support body, and a second spring is provided between the loading platform and the second support body, the first spring is provided with a first universal joint at both ends, and the second spring is provided with a second universal joint at both ends; the sensors are arranged on both sides of the same side of the loading platform along the Y direction, and their arrangement direction is perpendicular to the extension direction of the first and second springs.

2. The ultra-precision gas static pressure spindle dynamic balancing platform according to claim 1, characterized in that: The loading platform is located on the preload air floating platform, is arranged parallel to the air floating base and has an area smaller than the air floating base. The air floating base is provided with a limiting mechanism for preventing the loading platform from detaching.

3. The ultra-precision gas static pressure spindle dynamic balancing platform according to claim 2, characterized in that: The limiting mechanism includes four groups of limiting columns arranged corresponding to the four right-angled parts of the loading platform, and each group of limiting columns includes a first limiting column and a second limiting column corresponding to the two sides of a right-angled part of the loading platform.

4. The ultra-precision gas static pressure spindle dynamic balancing platform according to claim 3, characterized in that: The heights of the first and second limiting pillars are greater than the thickness of the air film between the air floating block and the carrier. In a floating state, the carrier does not contact the first and second limiting pillars.

5. The ultra-precision gas static pressure spindle dynamic balancing platform according to claim 1, characterized in that: The negative pressure block is arranged at the center of the air floating base, and the air floating blocks are arranged on the air floating base at four right angles corresponding to the object carrier.

6. The ultra-precision gas static pressure spindle dynamic balancing platform according to claim 1, characterized in that: The preload air flotation platform is provided with a level adjustment mechanism for adjusting its level.

7. The ultra-precision gas static pressure spindle dynamic balancing platform according to claim 6, characterized in that: The horizontal adjustment mechanism includes leveling bolts provided at four right-angle areas of the preload air floating platform.

8. The ultra-precision gas static pressure spindle dynamic balancing platform according to claim 1, characterized in that: The sensors are located on one side of the loading platform, and there are at least two of them and they are arranged in parallel.

9. The ultra-precision gas static pressure spindle dynamic balancing platform according to claim 8, characterized in that: The sensor includes an acceleration sensor that can be connected to a dynamic balance detection device.

10. The ultra-precision aerostatic spindle dynamic balancing platform according to any one of claims 1 to 9, characterized in that: The stiffness of the first spring and the second spring is less than 2 N / mm.

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