A high-speed precision spindle supported by a spherical pneumatic bearing

Abstract

This invention discloses a high-speed precision spindle supported by a spherical gas magnetic bearing, comprising a spindle and a spherical gas magnetic bearing fixedly sleeved on the spherical part of the spindle. The spherical gas magnetic bearing includes a spherical gas magnetic bearing stator and a spherical gas magnetic bearing housing. The spherical gas magnetic bearing stator is provided with several air supply pipes and several spherical gas magnetic bearing poles. The spherical gas magnetic bearing poles are fixedly connected to the spherical gas magnetic bearing housing, and the spherical gas magnetic bearing poles repel the magnetic poles of the spherical part of the spindle. A small-hole throttling device communicating with the air supply pipes is provided inside the spherical gas magnetic bearing stator. The spherical gas magnetic bearing achieves radial and axial suspension support, solving the problems of low load-bearing capacity and low dynamic stiffness caused by separate hydrostatic gas bearing support. It increases the stiffness and load-bearing capacity while ensuring spindle precision, and simultaneously addresses the issue of spindle system volume expansion, significantly improving the volume-to-power ratio and ensuring that the ultra-precision high-speed spindle can stably complete its work under various operating conditions.

Description

Technical Field

[0001] This invention relates to machine tool components for ultra-precision machining, specifically to a high-speed precision spindle supported by a spherical pneumatic bearing. Background Technology

[0002] Precision spindle components are the core of ultra-precision machine tools, ensuring machining accuracy. Spindles require extremely high rotational accuracy, smooth rotation, and vibration-free operation, the key of which lies in the precision bearings used. Early precision spindles employed ultra-precision rolling bearings, such as those used in Hardinge and Schaublin precision machine tools, achieving machining accuracy of 1μm. While these bearings possessed high load-bearing capacity and rigidity, manufacturing such high-precision rolling bearings was extremely difficult, and further improving spindle accuracy was even more challenging. With the advent of hydrostatic and air hydrostatic bearings, the use of rolling bearings in ultra-precision machine tool spindles decreased further. To further improve machining accuracy, some ultra-precision lathes currently use hydrostatic bearings to support the spindle, achieving a rotational accuracy of 0.1μm and high rigidity. However, hydrostatic bearings experience significant oil temperature variations, making temperature control difficult and affecting spindle accuracy. Furthermore, introducing air into the oil source during oil return reduces the dynamic rigidity of the hydrostatic bearing.

[0003] Currently, some ultra-precision lathes use a structure where the spindle is supported by a front spherical and rear cylindrical radial air bearing. This structure can simultaneously function as a radial and axial thrust bearing and has an automatic self-aligning function, effectively reducing the size of the rotor system. Currently, this mainly uses a small-orifice throttling hydrostatic gas bearing. The spindle's rotational accuracy can reach 0.05μm in both the radial and axial directions, achieving higher rotational accuracy. However, its stiffness is low and its load-bearing capacity is not high. In the ABS-12 model spindle, its stiffness is 80N·μm-1, and the maximum load it can withstand is 539N. These figures clearly show that the stiffness and load-bearing capacity of this spherical bearing spindle are not high, even though the ball diameter has reached 120mm. When the ball bearing diameter decreases, its stiffness and load-bearing capacity will also decrease. Therefore, strengthening the spindle's stiffness and load-bearing capacity while ensuring the rotor system's size and rotational accuracy is of great significance. Summary of the Invention

[0004] Purpose of the invention: To address the above-mentioned shortcomings, this invention provides a high-speed precision spindle supported by a spherical pneumatic bearing, which increases the dynamic stiffness and load-bearing capacity of the bearing while ensuring that the rotor's rotational accuracy remains unchanged.

[0005] Technical Solution: To solve the above problems, the present invention employs a high-speed precision spindle supported by a spherical pneumatic magnetic bearing, comprising a spindle and a spherical pneumatic magnetic bearing fixedly sleeved on the spindle. The spindle includes a spherical body portion, and the spherical pneumatic magnetic bearing is sleeved outside the spherical body portion. The spherical pneumatic magnetic bearing includes a spherical pneumatic magnetic bearing stator sleeved outside the spherical body portion of the spindle and a spherical pneumatic magnetic bearing seat sleeved outside the spherical pneumatic magnetic bearing stator. An air gap is left between the spherical pneumatic magnetic bearing stator and the spherical body portion of the spindle. The spherical pneumatic magnetic bearing stator is provided with several air supply pipes and several spherical pneumatic magnetic bearing poles. The air supply pipes and the spherical pneumatic magnetic bearing poles are evenly distributed on the outer surface of the spherical pneumatic magnetic bearing stator. The spherical pneumatic magnetic bearing poles are fixedly connected to the spherical pneumatic magnetic bearing seat. The spherical pneumatic magnetic bearing poles repel the magnetic poles of the spherical body portion of the spindle. A small-hole throttling device communicating with the air supply pipes is provided inside the spherical pneumatic magnetic bearing stator.

[0006] Furthermore, a spherical gas magnetic bearing coil is wound around the magnetic pole of the spherical gas magnetic bearing, and changing the current in the spherical gas magnetic bearing coil changes the magnetic force of the spherical gas magnetic bearing pole.

[0007] Furthermore, the magnetic poles of the spherical gas magnetic bearing are U-shaped, including a first base and a first extension extending outward from both ends of the first base. A spherical gas magnetic bearing coil is wound on the first extension. The first base is arc-shaped to match the inner surface of the spherical gas magnetic bearing seat and is fixedly connected to the spherical gas magnetic bearing seat. The end of the first extension is fixedly connected to the stator of the spherical gas magnetic bearing, and the extension direction of the first extension points to the center of the spherical gas magnetic bearing stator.

[0008] Furthermore, the air supply pipe is located between the first base of the spherical gas magnetic bearing pole and the outer surface of the spherical gas magnetic bearing stator, that is, the air supply pipe is located between the two first extensions of the spherical gas magnetic bearing pole. The air supply pipe is L-shaped, and the air supply pipe inlet faces the side of the spherical gas magnetic bearing pole.

[0009] Furthermore, two radial sensors are installed inside the spherical pneumatic bearing housing to detect the distance between the main shaft and the spherical pneumatic bearing housing. The two radial sensors are perpendicular to each other. When the radial sensors detect a shift in the position of the main shaft, the current magnitude of the spherical pneumatic bearing coil is changed to change the magnetic force of the spherical pneumatic bearing poles, thereby adjusting the position of the main shaft relative to the spherical pneumatic bearing housing.

[0010] Furthermore, the spherical gas magnetic bearing stator includes two hemispherical stator units, each of which is provided with an arc-shaped air cavity. The arc-shaped air cavity is located between the air supply pipe and the orifice throttle, and connects all the air supply pipes and the orifice throttle of the hemispherical stator unit.

[0011] Furthermore, it also includes a radial pneumatic bearing, which includes an annular radial pneumatic bearing seat sleeved outside the main shaft. An air gap is left between the radial pneumatic bearing seat and the main shaft. A plurality of radial pneumatic bearing poles are uniformly arranged on the inner surface of the radial pneumatic bearing seat. The radial pneumatic bearing poles are U-shaped and include a second base and second extensions extending outward from both ends of the second base. The second base is fixedly connected to the inner surface of the radial pneumatic bearing seat. The second extensions extend toward the center of the radial pneumatic bearing seat. A radial pneumatic bearing coil is wound around the second extensions. An air supply block is provided between the two second extensions. The air supply block is fixedly connected to the second base. The air supply block is provided with an air supply pipe. The outlet end of the air supply pipe is close to the main shaft, and a small orifice throttle is provided at the outlet end of the air supply pipe.

[0012] Furthermore, two radial sensors are provided on one side of the radial pneumatic bearing to detect the positional offset of the spindle. The two radial sensors are perpendicular to each other. When the radial sensors detect a positional offset of the spindle, the current magnitude of the radial pneumatic bearing coil is changed to change the magnetic force of the radial pneumatic bearing poles, thereby adjusting the position of the spindle. The two radial sensors provided on one side of the radial pneumatic bearing and the two radial sensors provided in the spherical pneumatic bearing housing are located at both ends of the spindle, respectively. The positional offset of the two ends of the spindle is adjusted by the spherical pneumatic bearing and the radial pneumatic bearing.

[0013] Furthermore, it also includes a drive shaft section. The drive shaft section is connected to one end of the main shaft via an electromagnetic coupling. A drive motor is fitted over the drive shaft section. The electromagnetic coupling includes an electromagnetic coupling housing fixedly connected to the drive shaft section, an outer magnet with an interference fit installed on the inner wall of the electromagnetic coupling housing, an inner shaft of the electromagnetic coupling fixedly connected to the main shaft, and an inner magnet with an interference fit installed on the outer ring of the inner shaft. The outer magnet is fitted over the inner magnet, and there is a gap between the outer magnet and the inner magnet. The drive motor is used to drive the drive shaft section to rotate. The rotation of the drive shaft section drives the electromagnetic coupling housing and the outer magnet to rotate. The magnetic coupling between the outer magnet and the inner magnet drives the main shaft to rotate.

[0014] Furthermore, an axial detection disk is fixedly sleeved on the spindle, and an axial sensor is provided on one side of the axial detection disk. The axial sensor is used to detect the displacement of the axial detection disk, thereby detecting the axial displacement of the spindle.

[0015] Beneficial Effects: Compared with existing technologies, the significant advantage of this invention is that the spherical gas magnetic bearing, acting alone, can achieve radial and axial suspension support, solving the problems of low load-bearing capacity and low dynamic stiffness caused by separate hydrostatic gas bearings. This structure increases the stiffness and load-bearing capacity of the spindle while ensuring its accuracy, and simultaneously addresses the issue of spindle system volume expansion, significantly improving the volume-to-power ratio and ensuring stable operation of the ultra-precision high-speed spindle under various working conditions. The spindle is divided into two parts: a drive shaft section and a working shaft section. The drive shaft section and the working shaft section are connected non-contactly via an electromagnetic coupling. A drive motor is installed on the drive shaft section, and the vibration generated by the drive motor during operation is absorbed by the electromagnetic coupling, meaning that the vibration generated by the drive shaft section will not be transmitted to the spindle working shaft section. Intelligent adjustment and control of the high-speed spindle is achieved through spindle offset adjustment via coils. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the high-speed precision spindle of the present invention.

[0017] Figure 2 This is a cross-sectional view of the high-speed precision spindle of the present invention.

[0018] Figure 3 This is a schematic diagram of the structure of the spherical gas magnetic bearing stator in this invention.

[0019] Figure 4 This is a cross-sectional view of the spherical gas magnetic bearing stator in this invention.

[0020] Figure 5 This is a schematic diagram of the radial gas magnetic bearing in this invention.

[0021] Figure 6 This is a front view of the radial pneumatic bearing in this invention.

[0022] Figure 7 yes Figure 6 A cross-sectional view along the AA direction.

[0023] Figure 8 yes Figure 7 A schematic diagram of the structure of part B in the middle.

[0024] Figure 9 This is a schematic diagram of the air supply block in the radial pneumatic bearing of the present invention. Detailed Implementation

[0025] Combination Figures 1-8This embodiment of a high-speed precision spindle supported by a spherical pneumatic magnetic bearing includes a drive shaft section 1, a drive motor 2, an electromagnetic coupling 3, an axial detection disk 4, a radial sensor 5, a radial pneumatic magnetic bearing 6, a spherical pneumatic magnetic bearing 7, a spindle 8, and an axial sensor 9. The radial pneumatic magnetic bearing 6 and the spherical pneumatic magnetic bearing 7 are respectively sleeved on the left and right ends of the spindle 8. The drive shaft section 1 is connected to the left end of the spindle 8 through the electromagnetic coupling 3. The drive motor 2 is sleeved on the drive shaft section 1, and the axial detection disk 4 is fixedly sleeved on the spindle 8.

[0026] like Figure 1-2 As shown, the drive shaft section 1 and the main shaft 8 are flexibly connected by the electromagnetic coupling 3. The drive shaft section 1 is fixedly connected to the electromagnetic coupling housing 22 of the electromagnetic coupling 3 by the drive shaft section connecting bolt 12. The main shaft 8 is fixedly connected to the electromagnetic coupling inner shaft 20 of the electromagnetic coupling 3 by the main shaft connecting bolt 14. An outer magnet 13 is installed on the inner wall of the electromagnetic coupling housing 22 by interference fit. An inner magnet 21 is installed on the outer ring of the electromagnetic coupling inner shaft 20 by interference fit. The entire outer ring of the inner magnet 21 is wrapped by the isolation sleeve. The outer magnet 13 is sleeved outside the isolation sleeve. The outer magnet 13, the isolation sleeve and the inner magnet 21 are of equal length. A certain gap is left in the radial direction between the isolation sleeve and the outer magnet 13. A certain gap is left in the axial direction between the ends of the isolation sleeve, the inner magnet 21 and the inner shaft 20 of the electromagnetic coupling and the inner wall of the electromagnetic coupling housing 22.

[0027] A drive motor 2 is mounted on the drive shaft section 1. The drive motor 2 includes a stator and a rotor. The stator includes a drive motor housing 23, a drive motor silicon steel sheet stator 24, and a drive motor coil 25. The rotor includes a motor rotor permanent magnet 10 and a motor rotor protective sleeve 11. The motor rotor permanent magnet 10 is fixedly connected to the drive shaft section 1 by an interference fit. The motor rotor protective sleeve 11 wraps around the entire outer ring of the motor rotor permanent magnet 10. The drive motor coil 25 is sleeved outside the motor rotor protective sleeve 11. The drive motor silicon steel sheet stator 24 is fixedly sleeved outside the drive motor coil 25. The drive motor housing 23 is fixedly sleeved outside the drive motor silicon steel sheet stator 24. The drive motor 2 drives the drive shaft section 1 to rotate.

[0028] The spindle 8 includes a cylindrical part and a spherical part. An axial detection disk 4 is interference-fitted onto the cylindrical part at the left end of the spindle 8. A radial pneumatic bearing 6 is installed on the right side of the axial detection disk 4. A spherical pneumatic bearing 7 is installed on the right side of the radial pneumatic bearing 6. An axial sensor 9 is provided on the left side of the axial detection disk 4. The axial sensor 9 is fixed on the outer housing of the spindle. The axial sensor (9) is used to detect the displacement of the axial detection disk 4, thereby detecting the axial displacement of the spindle 8. Two vertically placed radial sensors 5 are provided between the axial detection disk 4 and the radial pneumatic bearing 6.

[0029] like Figure 2-4As shown, a spherical pneumatic bearing 7 is installed on the left spherical part of the main shaft 8. The spherical pneumatic bearing 7 consists of a spherical pneumatic bearing housing 17, a spherical pneumatic bearing stator 18, a spherical pneumatic bearing air supply pipe 27, a spherical pneumatic bearing magnetic pole 16, a spherical pneumatic bearing coil 26, a radial sensor 5, and a small-hole throttle 28. The spherical pneumatic bearing stator 18 is composed of two hemispherical stator units. Each end face of each hemispherical stator unit is provided with a flange 35. Each flange 35 is provided with 5 through holes. The two hemispherical stators are sleeved on the left spherical part of the main shaft 8 and connected by bolts through the flanges 35.

[0030] Two rows of spherical pneumatic bearing poles 16 are installed on the outer spherical surface of each hemisphere, with two spherical pneumatic bearing poles 16 in each row. The four spherical pneumatic bearing poles 16 are evenly distributed on the entire spherical pneumatic bearing stator 18. A spherical pneumatic bearing air supply pipe 27 is provided between each spherical pneumatic bearing pole 16 and the spherical pneumatic bearing stator 18. The spherical pneumatic bearing pole 16 is U-shaped, including a first base and first extensions extending outward from both ends of the first base. A spherical pneumatic bearing coil 26 is wound on the first extension. The first base is shaped as follows: The shape is an arc that fits the inner surface of the spherical gas magnetic bearing seat 17 and is fixedly connected to the spherical gas magnetic bearing seat 17. The end of the first extension is fixedly connected to the spherical gas magnetic bearing stator 18, and the extension direction of the first extension is pointing towards the center of the spherical gas magnetic bearing stator 18. The spherical gas magnetic bearing air supply pipe 27 is between the two first extensions of the spherical gas magnetic bearing magnetic pole 16. The spherical gas magnetic bearing air supply pipe 27 and the spherical gas magnetic bearing stator 18 are an integral structure. The spherical gas magnetic bearing air supply pipe 27 is "7" type (L type), and the inlet faces the side of the spherical gas magnetic bearing magnetic pole 16.

[0031] The air supply pipe 27 is supplied by an external air source. Each spherical pneumatic bearing air supply pipe 27 has a small orifice throttle 28 installed at its end. The end of the small orifice throttle 28 is tangent to the inner spherical surface of the spherical pneumatic bearing stator 18. The spherical pneumatic bearing stator 18 has an arc-shaped air cavity 29 inside. The angle between the two ends of the arc-shaped air cavity 29 and the center of the sphere is 90°. The angle between the central axis of the spherical pneumatic bearing air supply pipe 27 and the horizontal line is 60°. The arc-shaped air cavity 29 is located between the air supply pipe 27 and the small orifice throttle 28 and connects all the air supply pipes 27 and small orifice throttles 28 of the hemispherical stator unit.

[0032] The spherical pneumatic bearing housing 17 is a two-half combined structure. The two half-bearing housings are sleeved on the stator of the spherical pneumatic bearing and fixedly connected by 4 bolts. The external shape of the spherical pneumatic bearing housing 17 is cylindrical and the internal shape is spherical. It is fixedly connected to the magnetic pole 16 of the spherical pneumatic bearing. Two mutually perpendicular radial sensors 5 are installed inside the right side of the spherical pneumatic bearing housing 17 to detect the radial offset of one end of the spherical structure of the spindle 8. The two magnetic poles symmetrical about the center of the spherical pneumatic bearing work together to adjust the position of the center of the spherical bearing.

[0033] like Figure 5-8 As shown, a radial pneumatic bearing 6 is installed on the columnar part on the left side of the main shaft 8. The radial pneumatic bearing 6 includes a radial pneumatic bearing seat 15, radial pneumatic bearing poles 19, radial pneumatic bearing coils 31, an air supply block 30, and a small orifice throttle 28. There are four radial pneumatic bearing poles 19. The radial pneumatic bearing poles 19 are U-shaped and include a second base and second extensions extending outward from both ends of the second base. The second base is fixedly connected to the inner surface of the radial pneumatic bearing seat 15. The second extensions extend towards the center of the radial pneumatic bearing seat 15. The second extensions at both ends are wound with radial pneumatic bearing coils 31. The radial pneumatic bearing poles 19 are fixedly installed axially inside the radial pneumatic bearing seat 15. The length of the radial pneumatic bearing seat 15 is equal to that of the radial pneumatic bearing poles 19.

[0034] Each radial air-magnetic bearing pole 19 has an internally installed air supply block 30 located between the two second extensions. The upper arc surface of the air supply block 30 has the same radius as the inner arc surface of the radial air-magnetic bearing pole 19 and is fixedly connected. The lower arc surface of the air supply block 30 has the same radius as the lower arc surface of the winding of the radial air-magnetic bearing pole 19. The width of the air supply block 30 is greater than the width of the radial air-magnetic bearing pole 19, providing a higher load-bearing capacity for the air film. Each air supply block 30... The interior is equipped with a radial pneumatic bearing air supply pipe 32. The inlet end of the radial pneumatic bearing air supply pipe 32 is located on the right side of the air supply block 30, and there are two outlet ends located on the lower arc surface of the air supply block 30. The air supply pipe enters the interior of the air supply block 30, makes a 90° turn, and reaches the center of the air supply block 30. Then the air supply pipe branches to both sides and finally turns to the lower arc surface of the air supply block 30 to form an air supply path. The air source of the radial pneumatic bearing air supply pipe 32 is provided by an external air source.

[0035] A small-hole throttle 28 is installed at the end of each radial pneumatic bearing air supply pipe 32. The end of the small-hole throttle 28 is tangentially installed to the lower arc surface of the air supply block 30. The small-hole throttle 28 has a throttling orifice 34, which can form a high-load-bearing air film. A glue groove 33 is provided on the outside of the small-hole throttle 28, which is filled with high-temperature resistant adhesive. The small-hole throttle 28 is installed at the end of the spherical pneumatic bearing air supply pipe 27 and the radial pneumatic bearing air supply pipe 32 by adhesive bonding. Two radial sensors 5 are arranged perpendicularly between the radial pneumatic bearing 6 and the axial detection disk 4 to detect the radial offset of the left end of the main shaft 8.

[0036] like Figure 1-9 As shown, the working principle of the high-speed precision spindle is as follows: The high-speed spindle is powered by the drive motor 2, the electromagnetic coupling 3 flexibly connects the drive shaft section 1 and the spindle 8, and the radial pneumatic bearing 6 and the spherical pneumatic bearing 7 cooperate to realize the suspension and offset adjustment of the spindle 8 in the radial and axial directions.

[0037] When the spindle is started, the drive motor 2 provides torque to the drive shaft section 1. The drive shaft section 1 rotates, thereby driving the electromagnetic coupling housing 22 and the outer magnet 13 to rotate. Through the magnetic coupling between the outer magnet 13 and the inner magnet 21, the spindle 5 is driven to rotate together. Therefore, the drive shaft section 1 and the spindle 8 are flexible connections. This structure has good vibration reduction and vibration absorption performance.

[0038] Before the spindle 8 rotates, an external air source is introduced into the air passages of the radial pneumatic bearing 6 and the spherical pneumatic bearing 7 to provide stable air pressure for the spindle 8, avoiding mechanical collision and friction during cold starts. When the spindle 8 is working normally, the radial and axial levitation forces are mainly provided by static pressure air. The radial levitation force is mainly provided by the radial pneumatic bearing 6 and the spherical pneumatic bearing 7 working together, while the axial levitation force is mainly provided by the spherical pneumatic bearing 7 alone. The working principle of the radial pneumatic bearing 6 and the spherical pneumatic bearing 7 is that they are supplied with their own independent constant external air source, which flows into the orifice throttle 28 through the air supply passage, and finally sprays out from the throttle orifice 34 to act on the spindle 8 to form a load-bearing air film, thereby achieving the levitation of the spindle 8.

[0039] The magnetic levitation force provided by the radial pneumatic bearing 6 and the spherical pneumatic bearing 7 plays an auxiliary supporting and adjusting role. When the spindle 8 is disturbed in a stable state, four radial sensors 5 and one axial sensor 9 detect the radial and axial offsets of the spindle 8 in real time and transmit the detected offset signals to the signal processing system. After processing, the signal processing system feeds back to the radial pneumatic bearing 6 and the spherical pneumatic bearing 7. The radial pneumatic bearing 6 and the spherical pneumatic bearing 7 adjust the radial and axial offsets of the spindle 8 by changing the magnitude of the winding current on the magnetic poles. This achieves a certain gap between the spindle 8 and the radial pneumatic bearing 6 and the spherical pneumatic bearing 7 in the radial direction and maintains the initial position in the axial direction. When the spindle 8 returns to the initial equilibrium state, the radial pneumatic bearing 6 and the spherical pneumatic bearing 7 will no longer provide magnetic levitation force, and only static pressure gas will play a levitation role, realizing non-contact rotation and intelligent adjustment of the high-speed spindle under all working conditions.

[0040] When the spindle 8 is in braking condition, the drive motor 2 will stop providing power. When the spindle 8 is stationary, the external air source will no longer provide constant air pressure, and the bearing capacity of the air film will gradually decrease until the spindle 8 contacts the radial pneumatic bearing 6 and the spherical pneumatic bearing 7.

Claims

1. A high-speed precision spindle supported by a spherical pneumatic bearing, characterized in that, The system includes a main shaft (8) and a spherical pneumatic bearing (7) fixedly sleeved on the main shaft (8). The main shaft (8) includes a spherical body portion, and the spherical pneumatic bearing (7) is sleeved outside the spherical body portion. The spherical pneumatic bearing (7) includes a spherical pneumatic bearing stator (18) sleeved outside the spherical body portion of the main shaft (8) and a spherical pneumatic bearing seat (17) sleeved outside the spherical pneumatic bearing stator (18). An air gap is left between the spherical pneumatic bearing stator (18) and the spherical body portion of the main shaft (8). The stator (18) is provided with several air supply pipes (27) and several spherical gas magnetic bearing poles (16). The air supply pipes (27) and the spherical gas magnetic bearing poles (16) are evenly distributed on the outer surface of the spherical gas magnetic bearing stator (18). The spherical gas magnetic bearing poles (16) are fixedly connected to the spherical gas magnetic bearing seat (17). The spherical gas magnetic bearing poles (16) repel the spherical body poles of the main shaft (8). The spherical gas magnetic bearing stator (18) is provided with a small hole throttle (28) that communicates with the air supply pipes (27). The spherical gas magnetic bearing pole (16) is U-shaped, including a first base and a first extension extending outward from both ends of the first base. A spherical gas magnetic bearing coil (26) is wound on the first extension. The first base is arc-shaped to match the inner surface of the spherical gas magnetic bearing seat (17) and is fixedly connected to the spherical gas magnetic bearing seat (17). The end of the first extension is fixedly connected to the spherical gas magnetic bearing stator (18), and the extension direction of the first extension points to the center of the spherical gas magnetic bearing stator (18).

2. The high-speed precision spindle according to claim 1, characterized in that, The spherical gas magnetic bearing pole (16) is wound with a spherical gas magnetic bearing coil (26). Changing the current of the spherical gas magnetic bearing coil (26) changes the magnetic force of the spherical gas magnetic bearing pole (16).

3. The high-speed precision spindle according to claim 2, characterized in that, The air supply pipe (27) is located between the first base of the spherical gas magnetic bearing pole (16) and the outer surface of the spherical gas magnetic bearing stator (18), that is, the air supply pipe (27) is located between the two first extensions of the spherical gas magnetic bearing pole (16). The air supply pipe (27) is L-shaped, and the inlet of the air supply pipe (27) faces the side of the spherical gas magnetic bearing pole (16).

4. The high-speed precision spindle according to claim 2, characterized in that, Two radial sensors (5) are installed inside the spherical pneumatic bearing housing (17) to detect the distance between the main shaft (8) and the spherical pneumatic bearing housing (17). The two radial sensors (5) are perpendicular to each other. When the radial sensors (5) detect that the position of the main shaft (8) has shifted, the current of the spherical pneumatic bearing coil (26) is changed to change the magnetic force of the spherical pneumatic bearing pole (16), thereby adjusting the position of the main shaft (8) relative to the spherical pneumatic bearing stator (18).

5. The high-speed precision spindle according to claim 4, characterized in that, The spherical gas magnetic bearing stator (18) includes two hemispherical stator units. Each hemispherical stator unit is provided with an arc-shaped air cavity (29). The arc-shaped air cavity (29) is located between the air supply pipe (27) and the orifice throttle (28) and connects all the air supply pipes (27) and the orifice throttle (28) of the hemispherical stator unit.

6. The high-speed precision spindle according to claim 4, characterized in that, It also includes a radial pneumatic bearing (6), which includes an annular radial pneumatic bearing seat (15) sleeved outside the main shaft (8). An air gap is left between the radial pneumatic bearing seat (15) and the main shaft (8). A plurality of radial pneumatic bearing poles (19) are uniformly arranged on the inner surface of the radial pneumatic bearing seat (15). The radial pneumatic bearing poles (19) are U-shaped, including a second base and a second extension extending outward at both ends of the second base. The second base is fixedly connected to the inner surface of the radial pneumatic bearing seat (15). The second extension extends toward the center of the radial pneumatic bearing seat (15). A radial pneumatic bearing coil (31) is wound around the second extension. An air supply block (30) is provided between the second extensions at both ends of the second base. The air supply block (30) is fixedly connected to the second base. An air supply pipe (32) is provided on the air supply block (30). The outlet end of the air supply pipe (32) is close to the main shaft (8), and a small orifice throttle (28) is provided at the outlet end of the air supply pipe (32).

7. The high-speed precision spindle according to claim 6, characterized in that, Two radial sensors (5) are provided on one side of the radial pneumatic bearing (6) to detect the position offset of the spindle (8). The two radial sensors (5) are perpendicular to each other. When the radial sensors (5) detect that the position of the spindle (8) has shifted, the current of the radial pneumatic bearing coil (31) is changed to change the magnetic force of the radial pneumatic bearing pole (19), thereby adjusting the position of the spindle (8). The two radial sensors (5) provided on one side of the radial pneumatic bearing (6) and the two radial sensors (5) provided in the spherical pneumatic bearing seat (17) are located at both ends of the spindle (8), respectively. The position offset of both ends of the spindle (8) is adjusted by the spherical pneumatic bearing (7) and the radial pneumatic bearing (6).

8. The high-speed precision spindle according to claim 1, characterized in that, It also includes a drive shaft section (1), which is connected to one end of the main shaft (8) via an electromagnetic coupling (3). The drive shaft section (1) is fitted with a drive motor (2). The electromagnetic coupling (3) includes an electromagnetic coupling housing (22) fixedly connected to the drive shaft section (1), an outer magnet (13) with an interference fit installed on the inner wall of the electromagnetic coupling housing (22), an electromagnetic coupling inner shaft (20) fixedly connected to the main shaft (8), and an electromagnetic coupling inner shaft. (20) An inner magnet (21) is installed with an interference fit on the outer ring. The outer magnet (13) is sleeved on the outer side of the inner magnet (21), and there is a gap between the outer magnet (13) and the inner magnet (21). The drive motor (2) is used to drive the drive shaft section (1) to rotate. The drive shaft section (1) rotates, thereby driving the electromagnetic coupling housing (22) and the outer magnet (13) to rotate. The main shaft (8) is driven to rotate through the magnetic coupling between the outer magnet (13) and the inner magnet (21).

9. The high-speed precision spindle according to claim 1, characterized in that, An axial detection disk (4) is fixedly sleeved on the main shaft (8). An axial sensor (9) is provided on one side of the axial detection disk (4). The axial sensor (9) is used to detect the displacement of the axial detection disk (4), thereby detecting the axial displacement of the main shaft (8).

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