High-speed precision pneumatic spindle

Abstract

The present application provides a high-speed precision pneumatic spindle, comprising a housing, a spindle, a first air bearing, and a second air bearing. The spindle comprises a first rotating shaft, a second rotating shaft, and a spindle drive rotor disposed on the first and second rotating shafts. The spindle drive rotor has two rows of staggered drive slots on its circumferential surface. Each drive slot comprises a first end for air intake and a second end opposite the first end. The bottom surface of each drive slot is flat and is composed of a rectangular portion at the first end and an arcuate portion at the second end. Each drive slot also comprises an inwardly concave arc surface connected to the arcuate portion for stopping air. The distance between the second end and the axis of the spindle drive rotor is smaller than that of the first end. In this high-speed precision pneumatic spindle, the first and second air bearings suspend the spindle and then drive the spindle to rotate. The coordination between the air drive structure and the drive slots makes the spindle's rotation smoother and more stable, providing higher rotational accuracy and output efficiency, and facilitating control.

Description

Technical Field

[0001] The present application relates to the technical field of spindles, and in particular to a high-speed precision pneumatic spindle. Background Art

[0002] The spindle unit is a core component in mechanical cutting processing equipment. In the field of precision machining, high-speed, high-precision, and high-output power spindle units are important factors affecting machining quality and efficiency. Existing high-speed air-floating spindles mainly use built-in motor drives. Their advantages are high output power and good control performance. However, the design and manufacturing of high-speed spindle motors are difficult, and they need to be equipped with high-frequency drivers when in use. The cost of use is relatively high. In order to avoid the impact of motor heat on spindle accuracy, a forced cooling system is also required. The structural design, manufacturing, and assembly process of the spindle are relatively complex and costly. Pneumatic spindles rely on high-speed airflow to impact the structure on the spindle rotor to generate power. The advantages are high speed, simple structure, and low cost of use, but their control performance is relatively poor. Summary of the Invention

[0003] In view of this, it is necessary to provide a high-speed precision pneumatic spindle, aiming to improve the control performance of the spindle.

[0004] One embodiment of the present application provides a high-speed precision pneumatic spindle, comprising a housing, a first air-floating bearing, a spindle and a second air-floating bearing, wherein the housing comprises a separable first shell, a second shell and a third shell, the second shell being arranged between the first shell and the third shell, and the second shell being connected to the first shell and the third shell respectively, the first air-floating bearing and the second air-floating bearing being coaxial, the inner sides of the first shell and the third shell respectively accommodating the first air-floating bearing and the second air-floating bearing, the spindle having a first rotating shaft passing through the first air-floating bearing, and a first rotating shaft connected to the first rotating shaft. The shaft is coaxial and passes through the second air-floating bearing, and the main shaft drive rotor is integrally connected between the first shaft and the second shaft. The inner side of the second shell accommodates the main shaft drive rotor, and the first shaft and the second shaft form an axial air-floating structure with the first air-floating bearing and the second air-floating bearing respectively. The main shaft drive rotor is cylindrical, and the two opposite end faces of the main shaft drive rotor form a radial air-floating structure with the first air-floating bearing and the second air-floating bearing respectively. Two rows of staggered drive grooves are provided on the circumferential surface of the main shaft drive rotor; each of the The driving groove includes a first end for air intake and a second end opposite to the first end, the bottom surface of each driving groove is a plane, and the bottom surface is composed of a rectangular portion located at the first end and an arc portion located at the second end, each driving groove also includes an inner concave arc surface connected to the arc portion for stopping gas, the distance between the second end and the axis of the main shaft driving rotor is smaller than the first end, the first shell portion includes an air flotation air inlet, an air drive air inlet and a brake air inlet, the first shell portion, the second shell portion and the third shell portion are jointly provided with a connected air flotation air path, the air flotation air path is connected to the air flotation air path The floating air inlet is connected, and the air floating air path is connected to the axial air floating structure and the radial air floating structure. The first shell and the second shell are jointly provided with a connected air drive air path and a brake air path. The air drive air path is connected to the air drive air inlet, and the air drive air path is used to guide the gas to blow directly toward the concave arc surface of each driving groove, and the brake air path is connected to the brake air inlet; the second shell includes a first exhaust hole, and the first shell and the second shell are also jointly provided with an exhaust air path, and the exhaust air path is connected to the first exhaust hole, and the brake air path is used to guide the gas to blow directly toward the rectangular part of each driving groove.

[0005] In this embodiment, by providing two rows of drive grooves on the drive member, the overall mass of the high-speed precision pneumatic spindle is reduced, thereby improving the output torque and acceleration performance of the spindle. In addition, the drive grooves have a certain depth and are staggered, which can reduce the impact of the airflow on the spindle, making the spindle operation more stable. In addition, by providing a rectangular portion and an arc-shaped portion connected to the rectangular portion, the arc-shaped structure can increase the contact area between the drive groove and the airflow, thereby improving the acceleration performance of the drive member. The shell is configured as a segmented type, which facilitates the replacement of one of the shell parts, while the other parts can continue to be used, thereby improving the recycling performance of the shell.

[0006] In at least one embodiment, the first shell further includes a second exhaust hole, which is connected to the exhaust gas path, and the high-speed precision pneumatic spindle further includes a muffler, which is disposed in the second exhaust hole.

[0007] In at least one embodiment, the arc-shaped portion is a semicircle.

[0008] In at least one embodiment, the concave arc surfaces of the two rows of driving grooves are distributed at equal angles along the circumferential direction of the main shaft driving rotor.

[0009] In at least one embodiment, the diameter of the main shaft driving rotor is more than 1.5 times that of the first rotating shaft and the second rotating shaft, and the width of the driving slot is more than 3 times that of the depth of the driving slot.

[0010] In at least one embodiment, the first shell portion is provided with two air flotation air inlets, three radially evenly distributed air drive air inlets and one brake air inlet.

[0011] In at least one embodiment, the diameter D of the brake air inlet is in the range of 1.1 mm ≤ D ≤ 1.3 mm.

[0012] In at least one embodiment, the first shell portion is provided with a groove, and the high-speed precision pneumatic spindle further includes a seal, and the seal is provided in the groove.

[0013] In at least one embodiment, the seal is installed in an interference fit with the groove.

[0014] In at least one embodiment, the length of the first rotating shaft is smaller than the length of the second rotating shaft.

[0015] In this embodiment, the length of the second rotating shaft is greater than that of the first rotating shaft, the second rotating portion can withstand a greater external force, and the first rotating portion can provide a more stable supporting force.

[0016] The high-speed precision pneumatic spindle provided by this application achieves high-speed spindle rotation by reducing the overall mass of the high-speed precision pneumatic spindle rotor and providing a number of evenly spaced drive slots on the spindle drive rotor to facilitate airflow drive. Furthermore, the multiple evenly spaced drive slots and drive airflow mitigate the impact of the airflow on the spindle rotor when the spindle is driven at high speed, thus achieving precise spindle rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a three-dimensional schematic diagram of a high-speed precision pneumatic spindle in one embodiment of the present application.

[0018] Figure 2 for Figure 1 The three-dimensional schematic diagram of the high-speed precision pneumatic spindle from another perspective is shown.

[0019] Figure 3 for Figure 1 The exploded diagram of the high-speed precision pneumatic spindle is shown.

[0020] Figure 4 for Figure 3 The exploded diagram of the high-speed precision pneumatic spindle from another perspective is shown.

[0021] Figure 5 for Figure 1 The cross-sectional schematic diagram of the high-speed precision pneumatic spindle along the VV direction is shown.

[0022] Figure 6 for Figure 1 Exploded diagram of the housing in a high-speed precision pneumatic spindle.

[0023] Figure 7 for Figure 1 The schematic cross-sectional view of the housing along the VII-VII direction is shown.

[0024] Figure 8 for Figure 6 The housing is shown as a schematic cross-sectional view when the spindle is braked.

[0025] Figure 9 for Figure 1 The figure shows a schematic cross-sectional view of the housing of a high-speed precision pneumatic spindle along the axial direction.

[0026] Figure 10 for Figure 1 Schematic diagram of the main spindle in a high-speed precision pneumatic spindle.

[0027] Figure 11 for Figure 10 The main axis is shown in a schematic cross-sectional view along the XI-XI direction.

[0028] Description of main component symbols

[0029] High-speed precision pneumatic spindle 100

[0030] Housing 10

[0031] First shell 11

[0032] Air flotation inlet 111

[0033] Air drive inlet 112

[0034] Brake air intake 113

[0035] Second exhaust hole 114

[0036] Groove 115

[0037] Second shell 12

[0038] First exhaust hole 121

[0039] The third shell portion 13

[0040] Air flotation line 14

[0041] Air drive gas line 15

[0042] Brake air circuit 16

[0043] Exhaust gas line 17

[0044] Spindle 20

[0045] First rotating shaft 21

[0046] Second rotating shaft 22

[0047] Spindle drive rotor 23

[0048] Ontology 231

[0049] Drive slot 232

[0050] First end A

[0051] Second end B

[0052] Rectangular section 2321

[0053] Arc portion 2322

[0054] Concave arc surface 2323

[0055] Bottom 2324

[0056] Dashed lines L, M, N

[0057] First air bearing 30

[0058] Second air bearing 40

[0059] Seal 50 DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0061] It should be noted that when a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be an intermediate component. The terms "top", "bottom", "upper", "lower", "left", "right", "front", "back", and similar expressions used herein are for illustrative purposes only.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0063] One embodiment of the present application provides a high-speed precision pneumatic spindle, comprising a housing, a first air-floating bearing, a spindle and a second air-floating bearing, wherein the housing comprises a separable first shell, a second shell and a third shell, the second shell being arranged between the first shell and the third shell, and the second shell being connected to the first shell and the third shell respectively, the first air-floating bearing and the second air-floating bearing being coaxial, the inner sides of the first shell and the third shell respectively accommodating the first air-floating bearing and the second air-floating bearing, the spindle having a first rotating shaft passing through the first air-floating bearing, and a first rotating shaft connected to the first rotating shaft. The shaft is coaxial, and the second rotating shaft is arranged in the second air floating bearing, and the main shaft driving rotor is integrally connected between the first rotating shaft and the second rotating shaft. The inner side of the second shell accommodates the main shaft driving rotor, and the first rotating shaft and the second rotating shaft form an axial air floating structure with the first air floating bearing and the second air floating bearing respectively. The main shaft driving rotor is cylindrical, and the two opposite end faces of the main shaft driving rotor form a radial air floating structure with the first air floating bearing and the second air floating bearing respectively. Two rows of staggered driving grooves are provided on the circumferential surface of the main shaft driving rotor; each The driving groove includes a first end for air intake and a second end opposite to the first end, the bottom surface of each driving groove is a plane, and the bottom surface is composed of a rectangular portion located at the first end and an arc portion located at the second end, each driving groove also includes an inner concave arc surface connected to the arc portion for stopping gas, the distance between the second end and the axis of the main shaft driving rotor is smaller than the first end; the first shell includes an air flotation air inlet, an air drive air inlet and a brake air inlet, the first shell, the second shell and the third shell are jointly provided with a communicating air flotation air path, the air flotation air path is connected to the The air flotation air inlet is connected, and the air flotation air path is connected to the axial air flotation structure and the radial air flotation structure. The first shell and the second shell are jointly provided with a connected air drive air path and a brake air path. The air drive air path is connected to the air drive air inlet, and the air drive air path is used to guide the gas to blow directly toward the concave arc surface of each driving groove. The brake air path is connected to the brake air inlet, and the brake air path is used to guide the gas to blow directly toward the rectangular part of each driving groove; the second shell includes a first exhaust hole, and the first shell and the second shell are jointly provided with an exhaust air path, and the exhaust air path is connected to the first exhaust hole.

[0064] The above embodiment can improve the output torque and acceleration performance of the main shaft by arranging two rows of drive grooves on the driving member. In addition, the drive grooves have a certain depth and are staggered, which can reduce the impact of the airflow on the main shaft, making the main shaft operation more stable. In addition, by arranging a rectangular portion and an arc-shaped portion connected to the rectangular portion, the arc-shaped structure can increase the contact area between the drive groove and the airflow to improve the acceleration performance of the driving member. The shell is arranged in a segmented type, which facilitates the replacement of a certain shell part, and the other parts can continue to be used, thereby improving the recycling performance of the shell. The above-mentioned high-speed precision pneumatic spindle is adopted, and the main shaft is rotated by gas, which is suitable for high-speed or ultra-high-speed processing of parts. At the same time, by driving the main shaft to suspend, the external structure to stop the main shaft is avoided, and the requirement of precise rotation of the main shaft can be achieved.

[0065] The following will describe some embodiments with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0066] See also Figure 1 、 Figure 2 、 Figure 3 and Figure 4 The present application provides a high-speed precision pneumatic spindle 100 comprising a housing 10, a spindle 20, a first air bearing 30, and a second air bearing 40. The spindle 20, the first air bearing 30, and the second air bearing 40 are disposed within the housing 10, and the first air bearing 30 and the second air bearing 40 are sleeved on the surface of the spindle 20. The housing 10 can form an axial air bearing structure with the first air bearing 30 and the second air bearing 40. The first air bearing 30 and the second air bearing 40 can drive the spindle 20 to suspend within the housing 10, and the housing 10 can drive the spindle 20 to rotate.

[0067] See also Figure 3 、 Figure 4 、 Figure 5 and Figure 6The housing 10 is a hollow cylindrical structure, so that the housing 10 can accommodate the main shaft 20, the first air bearing 30, and the second air bearing 40. The housing 10 includes a first shell 11, a second shell 12, and a third shell 13. The second shell 12 is arranged between the first shell 11 and the third shell 13, and the second shell 12 is connected to the first shell 11 and the third shell 13 respectively. The first shell 11 and the third shell 13 respectively accommodate the first air bearing 30 and the second air bearing 40 therein. The housing 10 is configured as a segmented structure to facilitate the replacement of one of the shells. For example, if the first shell 11 is damaged, the first shell 11 can be replaced in time, while the second shell 12 and the third shell 13 can continue to be used, thereby improving the recycling performance of the shell and reducing costs.

[0068] See also Figure 6 、 Figure 7 and Figure 8 The first shell portion 11 includes an air flotation air inlet 111, an air drive air inlet 112, and a brake air inlet 113. The air flotation air inlet 111, the air drive air inlet 112, and the brake air inlet 113 can be connected to an external air source to introduce gas into the interior of the shell 10. The air flotation air inlet 111 is a bearing air inlet hole, the air drive air inlet 112 is a turbine air inlet hole, and the brake air inlet 113 is a brake air inlet hole.

[0069] The first shell portion 11, the second shell portion 12 and the third shell portion 13 are jointly provided with an air flotation air path 14, and the air flotation air path 14 is connected to the air flotation air inlet 111. After the gas is introduced from the air flotation air inlet 111, the gas is transferred to the first air flotation bearing 30 and the second air flotation bearing 40 through the air flotation air path 14. The first shell portion 11 and the third shell portion 13 are provided with outflow holes (not shown in the figure) so that the gas in the air flotation air path 14 can be transferred from the outflow holes to the first air flotation bearing 30 and the second air flotation bearing 40.

[0070] The first shell 11 and the second shell 12 are also provided with an air drive air path 15 and a brake air path 16. The air drive air inlet 112 is connected to the air drive air path 15. After gas is introduced from the air drive air inlet 112, it is transferred to the main shaft 20 through the air drive air path 15. The second shell 12 is also provided with an outflow hole (not shown) to allow the gas in the air drive air path 15 to be transferred from the outflow hole to the main shaft 20. The brake air inlet 113 is connected to the brake air path 16. After gas is introduced from the brake air inlet 113, it is transferred to the main shaft 20 through the brake air path 16. The second shell 12 is also provided with another outflow hole (not shown) to allow the gas in the brake air path 16 to be transferred from the outflow hole to the main shaft 20. Furthermore, the gas transmitted to the main shaft 20 through the air drive air path 15 is used to drive the main shaft 20 to rotate, and the gas transmitted to the main shaft 20 through the brake air path 16 is used to prevent the main shaft 20 from continuing to rotate.

[0071] After the air flotation air path 14 transfers gas to the first air flotation bearing 30 and the second air flotation bearing 40, the inner surfaces of the first air flotation bearing 30 and the second air flotation bearing 40 and the outer surfaces of the first air flotation bearing 30 and the second air flotation bearing 40 form an axial air flotation structure. Furthermore, the first air flotation bearing 30 and the second air flotation bearing 40 use the gas to suspend the main shaft 20. The gas transferred to the main shaft 20 by the air drive air path 15 can cause the main shaft 20 to rotate after the main shaft 20 is suspended, thereby driving the main shaft 20. The gas transferred to the main shaft 20 by the brake air path 16 can prevent the main shaft 20 from continuing to rotate, thereby achieving the purpose of rapidly decelerating the main shaft 20.

[0072] In this embodiment, the first shell portion 11 is provided with two air flotation air inlets 111 , three air drive air inlets 112 and one brake air inlet 113 . Furthermore, the three air drive air inlets 112 are radially and evenly distributed on the first shell portion 11 .

[0073] It can be understood that in other embodiments, the connection between each air inlet and the air path can be set or replaced as needed, and the function of each air inlet can also be set according to the specific structure. For example, the air flotation air inlet 111 is a turbine air inlet, and the air drive air inlet 112 is a bearing air inlet.

[0074] See also Figure 6 and Figure 7In order to stop the main shaft 20 from rotating, the gas in the shell 10 needs to be discharged. In order to facilitate the discharge of the gas, the second shell portion 12 includes a first exhaust hole 121, which can extend to the surface of the second shell portion 12 to allow the gas to be discharged, so that the speed of the main shaft 20 is reduced until it stops rotating.

[0075] It is understandable that the first exhaust hole 121 may also extend from the inner surface of the second shell 12 to the end where the second shell 12 is connected to the first shell 11 , so as to exhaust gas from the end position of the second shell 12 .

[0076] See also Figure 6 and Figure 7 The first shell portion 11 and the second shell portion 12 are also provided with an exhaust gas path 17. The first exhaust holes 121 are connected to the exhaust gas path 17, and the exhaust gas path 17 ends at the arc surface of the first shell portion 11. The multiple first exhaust holes 121, evenly distributed longitudinally and circumferentially, effectively improve the efficiency of airflow exhaust, preventing the formation of an unstable pressure field inside the spindle due to gas accumulation, which affects the spindle's driving efficiency and stability.

[0077] See also Figure 6 In one embodiment, the first shell portion 11 is further provided with a second exhaust hole 114, which extends from the arc surface of the first shell portion 11 to the end of the first shell portion 11 away from the second shell portion 12, and is connected to the exhaust gas path 17, so that the gas flowing out of the exhaust gas path 17 can flow out from the second exhaust hole 114.

[0078] To allow gas to flow from the exhaust path 17 to the second exhaust hole 114, a groove 115 is formed on the arcuate surface of the first shell 11. The end of the exhaust path 17 and the starting point of the second exhaust hole 114 are located at the groove 115. The high-speed precision pneumatic spindle 100 also includes a seal 50. The seal 50 is located in the groove 115 and is interference-fitted with the first shell 11. This allows gas flowing from the end of the exhaust path 17 to pass through the stop of the seal 50 and then be discharged from the second exhaust hole 114, thereby improving the gas exhaust speed and protecting the spindle 20.

[0079] See also Figure 9 and Figure 10The main shaft 20 includes a first rotating shaft 21 passing through the first air bearing 30, a second rotating shaft 22 coaxial with the first rotating shaft 21 and passing through the second air bearing 40, and a main shaft drive rotor 23 integrally connected between the first rotating shaft 21 and the second rotating shaft 22. After the air source is introduced into the shell 10, the first air bearing 30 and the second air bearing 40 can drive the first rotating shaft 21 and the second rotating shaft 22 to suspend inside the shell 10. The two opposite end faces of the main shaft drive rotor 23 form a radial air floating structure between the first air bearing 30 and the second air bearing 40 respectively. The first air bearing 30 and the second air bearing 40 drive the main shaft drive rotor 23 to suspend inside the shell 10. Furthermore, after the air source is introduced into the shell 10, the main shaft drive rotor 23 can be driven to rotate.

[0080] Along the axial direction of the first rotating shaft 21 and the second rotating shaft 22, the length of the first rotating shaft 21 is smaller than the length of the second rotating shaft 22, the second rotating shaft 22 can withstand a larger external force, and the first rotating shaft 21 can provide a more stable supporting force to the second rotating shaft 22, so that the main shaft 20 is more stable during the rotation process.

[0081] See also Figure 4 、 Figure 10 and Figure 11 The spindle drive rotor 23 is generally cylindrical in structure. The second housing 12 accommodates the spindle drive rotor 23 therein. The outer diameter of the spindle drive rotor 23 is at least 1.5 times the diameter of the first rotating shaft 21 and the second rotating shaft 22. The spindle drive rotor 23 includes a cylindrical body 231 and a plurality of drive slots 232 disposed on the body 231. The drive slots 232 are arranged in two rows along the rotational direction of the body 231. The two rows of drive slots 232 are circumferentially disposed on the outer surface of the body 231 and are staggered.

[0082] In one embodiment, the outer diameter of the main shaft drive rotor 23 is twice the diameter of the first rotating shaft 21 and the second rotating shaft 22. It is understood that in other embodiments, the outer diameter of the main shaft drive rotor 23 is 1.5 times, 2.5 times, etc., the diameter of the first rotating shaft 21 and the second rotating shaft 22.

[0083] The two rows of driving slots 232 provided on the main shaft driving rotor 23 can significantly increase the output torque of the main shaft 20 and improve the acceleration performance of the main shaft 20 .

[0084] See also Figure 4, a plurality of the drive grooves 232 are arranged along the outer circular surface of the main body 231, and a plurality of the drive grooves 232 are divided into two circles and arranged on the surface of the main body 231. The width of the drive groove 232 is more than three times the depth of the drive groove 232. The depth of the drive groove 232 is along the radial direction of the drive groove 232, and the width of the drive groove 232 is perpendicular to its depth. The spindle drive rotor 23 includes a first end A and a second end B extending from the first end A. The distance between the second end B and the axis of the spindle drive rotor 23 is less than the distance between the first end A and the axis of the spindle drive rotor 23. It can be understood that the second end B is at a certain distance from the outer surface of the main body 231 compared to the first end A.

[0085] See also Figure 10 and Figure 11 The driving groove 232 further includes a rectangular portion 2321 and an arcuate portion 2322 connected to the rectangular portion 2321. The first end portion A is provided at the rectangular portion 2321, and the second end portion B is provided at the arcuate portion 2322. The brake air path 16 is used to guide the gas to blow directly toward the rectangular portion 2321 of each driving groove 232. Specifically, in combination with Figure 10 perspective, with Figure 10 The dotted line L is a dividing line. The driving groove 232 can be divided into the rectangular portion 2321 and the arc portion 2322. The first end A is the end of the rectangular portion 2321 away from the arc portion 2322. The second end B is the end of the arc portion 2322 away from the rectangular portion 2321. The arc portion 2322 is a semicircular structure. Figure 4 The second end portion B is recessed downward from the surface of the main body 231 by a preset distance. Furthermore, an inclined structure is formed from the first end portion A to the second end portion B.

[0086] See also Figure 4 The drive groove 232 also includes an inner concave arc surface 2323 for stopping gas. The inner concave arc surface 2323 is a step surface between the main body 231 and the drive groove 232. The gas drive path 15 is used to guide gas directly toward the inner concave arc surface 2323 of each drive groove 232. In addition, the inner concave arc surfaces 2323 of the two rows of drive grooves 232 are equiangularly distributed along the circumference of the main shaft drive rotor 23. Furthermore, the inner concave arc surface 2323 is connected to the arc-shaped portion 2322 and serves as the sidewall surface of the drive groove 232. The drive groove 232 also includes a bottom surface 2324 formed by the rectangular portion 2321 and the arc-shaped portion 2322. The inclined surface formed between the first end portion A and the second end portion B serves as the bottom surface 2324.

[0087] See also Figure 7 The inner concave arc surface 2323 corresponds to the outlet end of the gas drive gas path 15. Figure 7 The dotted lines M and N in FIG2 , where the dotted line M refers to the concave arc surface 2323 and the dotted line N refers to the bottom surface 2324, need to coordinate the angle and position of the outlet end of the gas drive passage 15 with the drive groove 232. For example, when the main shaft 20 rotates to a certain angle, the bottom surface 2324 is approximately parallel to the direction of the airflow output from the gas drive passage 15. At this time, the airflow is approximately perpendicular to the concave arc surface 2323 and directly impacts the concave arc surface 2323. The bottom surface 2324 and the concave arc surface 2323 are spatially perpendicular to each other. For example, if an arbitrary cross-section is made perpendicular to the axis of the main shaft 20, the angle between the two intersection lines of the cross-section and the bottom surface 2324 and the concave arc surface 2323 is within a range of +1° / -1°. This ensures that when the high-speed airflow impacts the concave arc surface 2323 perpendicularly, its direction is parallel to the bottom surface 2324. The provision of multiple concave arcuate surfaces 2323 increases the total contact area between the drive slots 232 and the airflow, thereby maximizing the drive efficiency of the spindle drive rotor 23. During rotation of the spindle drive rotor 23, the airflow from the uniformly distributed multiple air drive paths 15 drives each drive slot 232, thereby increasing the output torque of the spindle drive rotor 23.

[0088] See also Figure 8 The bottom surface 2324 corresponds to the outlet end of the brake air path 16. Figure 8 The dashed lines M and N in FIG. 23 are shown, where the dashed line M represents the concave arc surface 2323, and the dashed line N represents the bottom surface 2324. The angle and position of the outlet end of the brake air path 16 must align with the drive slot 232. For example, when the main shaft 20 rotates to a certain angle, the bottom surface 2324 is approximately perpendicular to the direction of the airflow output from the brake air path 16, and the airflow directly impacts the bottom surface 2324, achieving maximum braking efficiency for the main shaft drive rotor 23, enabling rapid braking and reducing the speed of the main shaft drive rotor 23. Furthermore, employing airflow braking can reduce the possibility of damage to the main shaft 20, shorten downtime, and improve the operating efficiency of the main shaft 20.

[0089] In one specific embodiment, the outer diameter of the spindle drive rotor 23 is 38.5 mm, the width of the drive slot 232 is 6 mm, the radius of the arcuate portion 2322 is 3 mm, and the depth at the second end portion B is 1.6 mm. The diameter of the outlet end of the air path directly affects the outlet velocity and flow rate of the airflow. To ensure driving and braking efficiency, the diameter of the outlet end of the air drive air path 15, the diameter of the outlet end of the brake air path 16, and the diameter D of the brake air inlet are within the range of 1.1 mm ≤ D ≤ 1.3 mm. Furthermore, the diameter D of the brake air inlet is 1.2 mm.

[0090] It is understood that in other embodiments, the spindle drive rotor 23 can be designed as needed. The arcuate portion 2322 of the drive slot 232 is shallow, and two rows of drive slots 232 are arranged in a staggered pattern along the rotation direction of the body 231. This ensures smooth and stable torque output from the spindle 20 while mitigating the impact of airflow on the spindle drive rotor 23, resulting in more stable operation of the spindle 20.

[0091] Please refer to Figure 3 and Figure 4 The first air bearing 30 and the second air bearing 40 are coaxially arranged, and the first air bearing 30 and the second air bearing 40 are disposed between the housing 10 and the first rotating shaft 21 and the second rotating shaft 22. Furthermore, the first air bearing 30 is disposed on the surface of the first rotating shaft 21, and the second air bearing 40 is disposed on the surface of the second rotating shaft 22.

[0092] The first air bearing 30 includes a third exhaust hole (not shown in the figure), and the second air bearing 40 also includes a third exhaust hole (not shown in the figure). When the main shaft 20 stops working, the gas that suspends the main shaft 20 flows out from the third exhaust hole and then is discharged from the first exhaust hole 121 of the second shell 12.

[0093] In one embodiment, the high-speed precision pneumatic spindle 100 further includes a muffler disposed in the second exhaust hole 114. By disposing the muffler in the second exhaust hole 114, noise can be reduced when the driving airflow accumulated in the air chamber is quickly discharged.

[0094] Please refer to Figure 3 and Figure 4During the rotation process, the high-speed precision pneumatic spindle 100 is first connected to the pressure air source through the air flotation air inlet 111. The air flow flows through the air flotation air path 14 to form an air chamber between the first air flotation bearing 30, the second air flotation bearing 40 and the shell 10. After further air flow is introduced, a layer of pressure air film is formed between the bearing and the spindle 20, so that the spindle 20 is suspended and only in contact with the air.

[0095] Then, after the air drive inlet 112 is connected to a pressurized air source, air flows from the air drive air path 15 into the interior of the housing 10 and impacts the spindle drive rotor 23, causing the spindle 20 to rotate. When shutdown is required, the brake air inlet 113 is connected to a pressurized air source, and air flows from the brake air path 16 into the interior of the housing 10, impacting the spindle drive rotor 23 in the opposite direction of the spindle 20's rotation, thereby preventing the spindle 20 from continuing to rotate.

[0096] Finally, the gas is exhausted through the first exhaust hole 121 , the second exhaust hole 114 and the exhaust gas path 17 . After the airflow that drives the main shaft 20 to rotate is exhausted, the airflow that causes the main shaft 20 to suspend is exhausted again.

[0097] In summary, the embodiments of the present application provide a high-speed, precision pneumatic spindle 100. By providing parallel and staggered drive slots 232 on the spindle drive rotor 23, the output torque of the spindle 20 can be increased, and the acceleration performance of the spindle 20 can be improved. Airflow is used to drive the spindle 20 to rotate, making the operation of the spindle 20 more stable. Airflow is used to brake the spindle 20, reducing the possibility of damage to the spindle 20.

[0098] In addition, those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present application and are not intended to limit the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments are within the scope of the present application.

Claims

1. A high-speed precision pneumatic spindle, characterized in that: The high-speed precision pneumatic spindle comprises: a housing, the housing comprising a separable first housing portion, a second housing portion, and a third housing portion, wherein the second housing portion is disposed between the first housing portion and the third housing portion, and the second housing portion is connected to the first housing portion and the third housing portion; a first air bearing; a second air bearing coaxial with the first air bearing, wherein the first shell portion and the third shell portion respectively accommodate the first air bearing and the second air bearing; and A main shaft, the main shaft includes a first rotating shaft passing through the first air floating bearing, a second rotating shaft coaxial with the first rotating shaft and passing through the second air floating bearing, and a main shaft driving rotor integrally connected between the first rotating shaft and the second rotating shaft, the inner side of the second shell portion accommodates the main shaft driving rotor, the first rotating shaft and the second rotating shaft respectively form an axial air floating structure with the first air floating bearing and the second air floating bearing, the main shaft driving rotor is cylindrical, and the two opposite end faces of the main shaft driving rotor respectively form a radial air floating structure with the first air floating bearing and the second air floating bearing, the main shaft driving rotor Two rows of staggered drive grooves are provided on the circumferential surface of the spindle. The drive grooves in the same row are spaced apart. In the axial direction of the main shaft, each drive groove in one row partially overlaps with two adjacent drive grooves in the other row. Each drive groove includes a first end for air intake and a second end opposite the first end. The bottom surface of each drive groove is flat, and the bottom surface is composed of a rectangular portion located at the first end and an arc-shaped portion located at the second end. Each drive groove also includes an inwardly concave arc surface connected to the arc-shaped portion for stopping gas. The distance between the second end and the axis of the main shaft drive rotor is smaller than the first end. The first shell portion includes an air flotation air inlet, an air drive air inlet and a brake air inlet. The first shell portion, the second shell portion and the third shell portion are jointly provided with a connected air flotation air path, the air flotation air path is connected to the air flotation air inlet, the air flotation air path is connected to the axial air flotation structure and the radial air flotation structure, the first shell portion and the second shell portion are jointly provided with a connected air drive air path and a brake air path, the air drive air path is connected to the air drive air inlet, the air drive air path is used to guide the gas to blow directly toward the concave arc surface of each driving groove, the brake air path is connected to the brake air inlet, and the brake air path is used to guide the gas to blow directly toward the rectangular portion of each driving groove; The second shell portion includes a first exhaust hole, and the first shell portion and the second shell portion are jointly provided with an exhaust gas path, and the exhaust gas path is connected to the first exhaust hole; The first shell further includes a second exhaust hole, the second exhaust hole being in communication with the exhaust gas path, and the gas flowing out of the exhaust gas path can flow out from the second exhaust hole; A groove is provided on the arc surface of the first shell portion, and the end of the exhaust gas path and the starting end of the second exhaust hole are provided at the groove; The high-speed precision pneumatic spindle further includes a sealing member, which is disposed at the groove and seals the groove.

2. The high-speed precision pneumatic spindle according to claim 1, characterized in that: The high-speed precision pneumatic spindle further includes a muffler, which is disposed in the second exhaust hole.

3. The high-speed precision pneumatic spindle according to claim 2, characterized in that: The arc-shaped portion is a semicircle.

4. The high-speed precision pneumatic spindle according to claim 1, characterized in that: The inner concave arc surfaces of the two rows of driving grooves are distributed at equal angles along the circumferential direction of the main shaft driving rotor.

5. The high-speed precision pneumatic spindle according to claim 1, characterized in that: The diameter of the main shaft driving rotor is more than 1.5 times that of the first rotating shaft and the second rotating shaft, and the width of the driving groove is more than 3 times that of the depth of the driving groove.

6. The high-speed precision pneumatic spindle according to claim 1, characterized in that: The first shell portion is provided with two air-floating air inlets, three radially evenly distributed air-driven air inlets and one brake air inlet.

7. The high-speed precision pneumatic spindle according to claim 6, characterized in that: The diameter D of the brake air inlet is in the range of 1.1 mm≤D≤1.3 mm.

8. The high-speed precision pneumatic spindle according to claim 1, characterized in that: The sealing member is installed in an interference fit with the groove.

9. The high-speed precision pneumatic spindle according to claim 1, characterized in that: The length of the first rotating shaft is smaller than the length of the second rotating shaft.

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