Ultrasonic vibration rotary machining air floatation static pressure electric spindle

Abstract

The invention discloses an ultrasonic vibration rotary machining air floatation static pressure electric spindle which comprises a barrel shell, a hub, a disc-shaped ultrasonic concentrator and a conductive slip ring, a spindle rotor is coaxially and rotatably arranged in the barrel shell, the tail end of the spindle rotor is coaxially sleeved with a motor rotor, and the motor rotor is coaxially sleeved with a motor stator; the outer wall of the motor stator is connected with the inner wall of the barrel shell; the head end of the main shaft rotor is positioned outside the barrel shell; the hub coaxially sleeves the head end of the main shaft rotor; the disc-shaped ultrasonic energy concentrator is coaxially arranged outside the hub in a sleeving mode, the disc-shaped ultrasonic energy concentrator is sleeved with the thin diamond grinding wheel, piezoelectric ceramics are embedded in the disc face of the disc-shaped ultrasonic energy concentrator, and the piezoelectric ceramics are provided with a control system. The hub is coaxially sleeved with the conductive slip ring, and the conductive slip ring is electrically connected with the piezoelectric ceramic. The motorized spindle can effectively solve the problems that an existing motorized spindle cannot be suitable for a high-speed cutting scribing process of a silicon wafer prepared from a third-generation semiconductor material and cannot be adaptively adjusted according to the thickness of the silicon wafer.

Description

Technical Field

[0001] The invention relates to the technical field of wafer dicing and hard and brittle material processing, and in particular to an ultrasonic vibration rotary processing air-floating static pressure electric spindle. Background Art

[0002] The electric spindle is a new technology that integrates the machine tool spindle and the spindle motor in the field of CNC machine tools. Together with linear motor technology and high-speed tool technology, it has pushed high-speed machining into a new era. The air-floating static pressure support technology is widely used in the field of high-speed and ultra-precision machining. It uses pressurized gas as the spindle support force and has the characteristics of high precision, high rigidity, and high speed.

[0003] In the post-packaging process of integrated circuit semiconductors, the semiconductor dicing process is the first step. As the mainstream product now, silicon wafers are generally cut with a high-speed electric spindle grinding wheel saw of 30,000-60,000 rpm. This method is prone to edge collapse and cracks, which is more serious for wafers with densely distributed chips. And with the development of new energy batteries, third-generation semiconductor materials such as SiC and CaN have been widely used. The hardness of these materials is greater than that of traditional silicon wafers, and the high-speed cutting dicing process will not be applicable. In addition, the thickness of the corresponding wafers during dicing generally varies. The tool needs to be adaptively adjusted according to the different wafer thicknesses during cutting, which further greatly increases the difficulty of dicing. Summary of the invention

[0004] The purpose of the present invention is to provide an ultrasonic vibration rotary processing air-floating static pressure electric spindle to solve the problem that the existing electric spindle is not suitable for the high-speed cutting and dicing process of silicon wafers made of third-generation semiconductor materials, and cannot be adaptively adjusted according to the thickness of the silicon wafer.

[0005] The present invention is achieved through the following technical solutions:

[0006] An ultrasonic vibration rotary machining air-floating piezoelectric spindle comprises: a cylindrical shell, a spindle rotor is coaxially arranged in the cylindrical shell for rotation, a motor rotor is coaxially sleeved on the tail end of the spindle rotor, a motor stator is coaxially sleeved outside the motor rotor, the outer wall of the motor stator is connected to the inner wall of the cylindrical shell, and the head end of the spindle rotor is located outside the cylindrical shell; a wheel hub, the wheel hub is coaxially sleeved on the head end of the spindle rotor; a disc-shaped ultrasonic concentrator, the disc-shaped ultrasonic concentrator is coaxially sleeved outside the wheel hub, a thin diamond grinding wheel is arranged on the outer sleeve of the disc-shaped ultrasonic concentrator, a piezoelectric ceramic is embedded in the disc surface of the disc-shaped ultrasonic concentrator, and the piezoelectric ceramic is provided with a control system to control the voltage borne by the piezoelectric ceramic; a conductive slip ring, the conductive slip ring is coaxially sleeved outside the wheel hub, and the conductive slip ring is electrically connected to the piezoelectric ceramic to supply power to the piezoelectric ceramic.

[0007] Optionally, the disk surface of the disk-shaped ultrasonic concentrator is coaxially annularly provided with an embedding groove, and the embedding groove is used to embed the piezoelectric ceramic; the disk-shaped ultrasonic concentrator is provided with a plurality of resonance holes, and the resonance holes penetrate the disk-shaped ultrasonic concentrator along the thickness direction, and all the resonance holes are coaxially annularly arranged on the disk surface of the disk-shaped ultrasonic concentrator.

[0008] Optionally, the resonance hole is in an arc shape matching the embedding groove, and the resonance hole is attached to the outer side or the inner side of the embedding groove.

[0009] Optionally, the wheel hub is in the shape of a cylinder with one end closed, the wheel hub and the head end of the spindle rotor are coaxially screwed together by a thread, a tightening bolt is coaxially passed through the closed end of the wheel hub, and the tightening bolt is coaxially screwed together with the spindle rotor; a limit plate is protruding radially outwardly from the middle part of the wheel hub, the disk surface of the disk-shaped ultrasonic concentrator and the end surface of the conductive slip ring are respectively abutted against two sides of the limit plate, and the piezoelectric ceramic is completely blocked in the limit plate; a cover plate is provided on the side of the disk-shaped ultrasonic concentrator away from the limit plate, and the cover plate is connected to the end surface of the wheel hub by a plurality of fastening screws, so that the disk-shaped ultrasonic concentrator is clamped between the cover plate and the limit plate.

[0010] Optionally, a throttling assembly is provided between the cylinder shell and the spindle rotor to form a micron-level air flotation gap between the spindle rotor and the throttling assembly; the tail end coaxial cover of the cylinder shell is provided with a rear end cover, and an air cavity is provided in the rear end cover, and the air cavity is connected to the air flotation gap. The rear end cover is provided with a plurality of air inlet interfaces for introducing pressurized gas to form an air film in the air flotation gap to support the rotation of the spindle rotor.

[0011] Optionally, the throttling assembly includes a radial throttle, a throttle sleeve and an upper thrust throttle; the radial throttle is coaxially sleeved outside the spindle rotor, both ends of the spindle rotor pass through the two ends of the radial throttle, and the inner diameter of the radial throttle is slightly larger than the diameter of the spindle rotor; the throttle sleeve is coaxially sleeved outside the radial throttle, and the outer wall is tightly abutted against the inner wall of the cylinder shell; the upper thrust throttle is coaxially sleeved outside the head end of the spindle rotor and is connected to the The end face of the throttle sleeve is fixedly connected, and a gasket is coaxially clamped between the upper thrust throttle and the throttle sleeve; the head end of the spindle rotor extends radially outward to form an air flotation disk, and the air flotation disk is located between the throttle sleeve and the upper thrust throttle, the thickness of the air flotation disk is slightly smaller than the thickness of the gasket, and the diameter of the air flotation disk is smaller than the inner diameter of the gasket; the outer wall of the motor stator is tightly connected to the inner wall of the throttle sleeve, and the inner diameter of the motor stator is slightly larger than the outer diameter of the motor rotor.

[0012] Optionally, the head end of the radial throttle extends radially outward to form a lower thrust throttle, and the end face of the lower thrust throttle away from the upper thrust throttle abuts against the end face of the throttle sleeve; the gasket is coaxially clamped between the upper thrust throttle and the lower thrust throttle; the air flotation plate is located between the upper thrust throttle and the lower thrust throttle; the mounting screw passes through the upper thrust throttle, the lower thrust throttle and the end face of the throttle sleeve in sequence and is screwed on.

[0013] Optionally, the inner wall of the radial throttle is provided with a plurality of annular air grooves along the circumferential direction; the side wall of the radial throttle is provided with a plurality of air holes, the air holes penetrate the side wall of the radial throttle, and the inner end of each air hole is connected with any one of the air grooves; an exhaust groove is provided in the throttle sleeve, and the exhaust groove is connected with the outer end of at least one of the air holes; the rear end cover is provided with an exhaust hole, the inner end of the exhaust hole is connected with the exhaust groove, and the outer end is connected with the external environment; a sealing ring is coaxially and tightly laid on the tail end of the radial throttle, and the outer wall of the sealing ring is tightly connected with the inner wall of the throttle sleeve.

[0014] Optionally, the upper thrust throttle and the lower thrust throttle are provided with a plurality of air flotation holes through-through in the thickness direction, and the air flotation holes are connected with at least one of the air holes; and a throttle plug is provided at one end of the air flotation hole close to the air flotation disk.

[0015] Optionally, an air cooling pipe is passed through the rear end cover, the inner end of the air cooling pipe points to the gap between the motor rotor and the motor stator, and the outer end of the air cooling pipe is used to communicate with a cooling air source.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] The present invention provides an ultrasonic vibration rotary machining air-floating static pressure electric spindle. The present invention provides a cylindrical shell, a motor stator is provided therein, a spindle rotor is coaxially sleeved, and a motor rotor is provided on the spindle rotor. The motor rotor and the motor stator cooperate to drive the spindle rotor to rotate. On this basis, the head end of the spindle rotor is arranged outside the cylindrical shell and is sleeved with a hub. A disc-shaped ultrasonic energy concentrator is sleeved outside the hub. A thin diamond grinding wheel is arranged outside the disc-shaped ultrasonic energy concentrator. The rotation of the spindle rotor drives the disc-shaped ultrasonic energy concentrator to rotate, and then drives the thin diamond grinding wheel to rotate, so that cutting is performed by the thin diamond grinding wheel. On this basis, piezoelectric ceramics are embedded in the disc-shaped ultrasonic energy concentrator, and a conductive slip ring is sleeved on the hub, so that the conductive slip ring is electrically connected to the piezoelectric ceramic, so that the electrical signal is converted into an ultrasonic vibration signal and transmitted. The ultrasonic signal is transmitted to a disc-shaped ultrasonic concentrator, which amplifies the vibration signal and transmits it to a thin diamond grinding wheel, causing the thin diamond grinding wheel to generate radial ultrasonic vibration, thereby causing it to vibrate radially while rotating, thereby realizing ultrasonic vibration processing, which is effectively applicable to the high-speed cutting and slicing process of silicon wafers made of third-generation semiconductor materials. By setting a control system on the piezoelectric ceramic, the voltage borne by the piezoelectric ceramic is controlled to adjust the amplitude of the thin diamond grinding wheel, thereby enabling it to be adaptively adjusted according to the thickness of the silicon wafer. Through the mutual coordination of the above-mentioned features, the ultrasonic vibration rotary processing air-floating hydrostatic electric spindle can effectively solve the problem that the existing electric spindle cannot be applied to the high-speed cutting and slicing process of silicon wafers made of third-generation semiconductor materials, and cannot be adaptively adjusted according to the thickness of the silicon wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0019] Figure 1 A side cross-sectional schematic diagram of an air-floating static pressure electric spindle for ultrasonic vibration rotary machining provided by an embodiment of the present invention;

[0020] Figure 2 A schematic top-sectional view of an air-floating static pressure electric spindle for ultrasonic vibration rotary machining provided by an embodiment of the present invention;

[0021] Figure 3 A schematic top view of an air-floating static pressure electric spindle for ultrasonic vibration rotary machining provided by an embodiment of the present invention;

[0022] Figure 4 A side cross-sectional schematic diagram of a radial throttle of an air-floating static pressure electric spindle for ultrasonic vibration rotary machining provided by an embodiment of the present invention;

[0023] Figure 5 A schematic front view of a disc-shaped ultrasonic concentrator for ultrasonic vibration rotary machining of an air-floating static pressure electric spindle provided in an embodiment of the present invention;

[0024] Figure 6 A side sectional schematic diagram of a disc-shaped ultrasonic energy concentrator for an ultrasonic vibration rotary machining air-floating static pressure electric spindle provided in an embodiment of the present invention.

[0025] Marks and corresponding parts names in the attached drawings:

[0026] 10-cylinder shell; 11-spindle rotor; 111-air flotation disk; 12-motor rotor; 13-motor stator; 14-rear end cover; 141-inlet interface; 142-exhaust hole; 143-air cooling pipe; 20-wheel hub; 21-locking bolt; 22-limiting plate; 23-cover plate; 231-fastening screw; 30-disc-shaped ultrasonic concentrator; 301-embedded groove; 302-resonance hole; 31-thin diamond grinding wheel; 32-piezoelectric ceramic; 40-conductive slip ring; 50-radial throttle; 501-lower thrust throttle; 502-air groove; 503-air hole; 504-sealing ring; 505-air flotation hole; 506-throttle plug; 51-throttle sleeve; 52-upper thrust throttle; 521-mounting screw; 53-gasket. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0028] Please refer to Figures 1 to 6 The embodiment of the present invention provides an ultrasonic vibration rotary machining air-floating hydrostatic electric spindle, comprising: a cylindrical shell 10, wherein a spindle rotor 11 is coaxially arranged in the cylindrical shell 10, a motor rotor 12 is coaxially sleeved on the tail end of the spindle rotor 11, a motor stator 13 is coaxially sleeved on the outside of the motor rotor 12, the outer wall of the motor stator 13 is connected to the inner wall of the cylindrical shell 10, and the head end of the spindle rotor 11 is located outside the cylindrical shell 10; the second includes a hub 20, and the hub 20 is coaxially sleeved on the head end of the spindle rotor 11; the third includes a hub 20, and the hub 20 is coaxially sleeved on the head end of the spindle rotor 11; The first embodiment comprises a disc-shaped ultrasonic concentrator 30, which is coaxially sleeved on the outside of the wheel hub 20, and a thin diamond grinding wheel 31 is arranged on the outer cover of the disc-shaped ultrasonic concentrator 30. A piezoelectric ceramic 32 is embedded in the disc surface of the disc-shaped ultrasonic concentrator 30, and the piezoelectric ceramic 32 is provided with a control system to control the voltage borne by the piezoelectric ceramic 32; the fourth embodiment comprises a conductive slip ring 40, which is coaxially sleeved on the outside of the wheel hub 20, and the conductive slip ring 40 is electrically connected to the piezoelectric ceramic 32 to supply power to the piezoelectric ceramic 32.

[0029] The ultrasonic vibration rotary machining air-floating hydrostatic electric spindle provided in the present embodiment is provided with a cylindrical shell 10, a motor stator 13 is provided therein, a spindle rotor 11 is coaxially sleeved, a motor rotor 12 is provided on the spindle rotor 11, and the spindle rotor 11 is driven to rotate by the cooperation of the motor rotor 12 and the motor stator 13. On this basis, the head end of the spindle rotor 11 is arranged outside the cylindrical shell 10, and a hub 20 is sleeved thereon, a disc-shaped ultrasonic energy concentrator 30 is sleeved outside the hub 20, and a thin diamond grinding wheel 31 is sleeved outside the disc-shaped ultrasonic energy concentrator 30. The rotation of the spindle rotor 11 drives the disc-shaped ultrasonic energy concentrator 30 to rotate, and then drives the thin diamond grinding wheel 31 to rotate, so as to implement cutting by the thin diamond grinding wheel 31. On this basis, a piezoelectric ceramic 32 is embedded in the disc-shaped ultrasonic energy concentrator 30, and a conductive slip ring 40 is sleeved on the hub 20, so that the conductive slip ring 40 is electrically connected to the piezoelectric ceramic 32, so as to convert the electrical signal into The ultrasonic vibration signal is transmitted to the disc-shaped ultrasonic concentrator 30, so that it resonates under the vibration excitation of the piezoelectric ceramic. The disc-shaped ultrasonic concentrator 30 amplifies the vibration signal and transmits it to the thin diamond grinding wheel 31, so that the thin diamond grinding wheel 31 generates radial ultrasonic vibration, so that it vibrates radially while rotating, and realizes ultrasonic vibration processing, which is effectively applicable to the high-speed cutting and slicing process of silicon wafers prepared from third-generation semiconductor materials; by setting a control system on the piezoelectric ceramic 32, the voltage borne by the piezoelectric ceramic 32 is controlled to adjust the amplitude of the thin diamond grinding wheel 31, so that it can be adaptively adjusted according to the thickness of the silicon wafer; through the mutual cooperation of the above-mentioned characteristics, the ultrasonic vibration rotary processing air-floating static pressure electric spindle can effectively solve the problem that the existing electric spindle cannot be applied to the high-speed cutting and slicing process of silicon wafers prepared from third-generation semiconductor materials, and cannot be adaptively adjusted according to the thickness of the silicon wafer.

[0030] It should be noted that, in this embodiment, the electrical connection between the piezoelectric ceramic 32 and the conductive slip ring 40 is implemented by a wire.

[0031] It should be noted that the disc-shaped ultrasonic concentrator 30 is made of aluminum alloy.

[0032] It should be noted that the thickness of the thin diamond grinding wheel 31 is in the micrometer level, and the exposed amount thereof is 300 μm-1000 μm. The thin diamond grinding wheel 31 is embedded in the disc-shaped ultrasonic concentrator 30 by means of high temperature and high pressure.

[0033] It should be noted that ultrafine diamond abrasive grains are distributed on the surface of the thin diamond grinding wheel 31, and the grain size of the diamond abrasive grains is less than w10.

[0034] It should be noted that the vibration frequency of the piezoelectric ceramic is about 20 Khz, and the amplitude of the thin diamond grinding wheel 31 is adjustable from 0 to 10 μm.

[0035] In order to further explain the specific structure of the disk-shaped ultrasonic concentrator 30, the disk surface of the disk-shaped ultrasonic concentrator 30 is coaxially annularly provided with an embedding groove 301, and the embedding groove 301 is used to embed the piezoelectric ceramic 32; the disk-shaped ultrasonic concentrator 30 is provided with a plurality of resonance holes 302, and the resonance holes 302 penetrate the disk-shaped ultrasonic concentrator 30 along the thickness direction, and all the resonance holes 302 are coaxially annularly arranged on the disk surface of the disk-shaped ultrasonic concentrator 30.

[0036] Through the above-mentioned arrangement, by setting the embedding groove 301, the piezoelectric ceramic 32 is embedded in the disk-shaped ultrasonic energy concentrator 30, so that the vibration signal is transmitted into the disk-shaped ultrasonic energy concentrator 30 for amplification instead of being propagated along the surface; by opening a plurality of resonance holes 302 on the disk surface of the disk-shaped ultrasonic energy concentrator 30, the resonance transmission effect and signal amplification effect of the disk-shaped ultrasonic energy concentrator 30 are improved.

[0037] In order to further enhance the resonance transmission effect, the resonance hole 302 is in an arc shape matching the embedding groove 301 , and the resonance hole 302 is attached to the outer side or the inner side of the embedding groove 301 .

[0038] In order to further explain the specific structure of the hub 20, the hub 20 is in the shape of a tube with one end closed, the hub 20 and the head end of the spindle rotor 11 are coaxially screwed together through a thread, a tightening bolt 21 is coaxially penetrated through the closed end of the hub 20, and the tightening bolt 21 is coaxially screwed together with the spindle rotor 11; a limit plate 22 is radially protruded outwardly from the middle part of the hub 20, the disk surface of the disk-shaped ultrasonic concentrator 30 and the end surface of the conductive slip ring 40 are respectively abutted against the two sides of the limit plate 22, and the piezoelectric ceramic 32 is completely blocked in the limit plate 22; a cover plate 23 is provided on the side of the disk-shaped ultrasonic concentrator 30 away from the limit plate 22, and the cover plate 23 is connected to the end surface of the hub 20 by a plurality of fastening screws 231, so that the disk-shaped ultrasonic concentrator 30 is clamped between the cover plate 23 and the limit plate 22.

[0039] Through the above arrangement, the disc-shaped ultrasonic concentrator 30 is clamped between the limiting plate 22 and the cover plate 23 to stably fix the disc-shaped ultrasonic concentrator 30, and the piezoelectric ceramic 32 is shielded by the limiting plate 22 to protect the piezoelectric ceramic 32 while optimizing the transmission of electrical signals.

[0040] In order to reduce the friction force when the spindle rotor 11 rotates, a throttling assembly is installed between the barrel shell 10 and the spindle rotor 11 to form a micron-level air floating gap between the spindle rotor 11 and the throttling assembly; the tail end coaxial cover of the barrel shell 10 is provided with a rear end cover 14, and the rear end cover 14 is provided with an air cavity, which is connected to the air floating gap, and the rear end cover 14 is provided with a plurality of air inlet interfaces 141 for introducing pressurized gas to form an air film in the air floating gap to support the rotation of the spindle rotor 11.

[0041] Through the above arrangement, a micrometer-level air floating gap is formed outside the spindle rotor 11 by utilizing the throttling component, and then pressurized gas is introduced into the air floating gap by arranging the air inlet interface 141 to form an air film in the air floating gap to support the rotation of the spindle rotor 11 and effectively reduce the friction it bears during rotation.

[0042] In order to further explain the specific structure of the throttling assembly, the throttling assembly includes a radial throttle 50, a throttle sleeve 51 and an upper thrust throttle 52; the radial throttle 50 is coaxially sleeved outside the spindle rotor 11, and both ends of the spindle rotor 11 pass through both ends of the radial throttle 50, and the inner diameter of the radial throttle 50 is slightly larger than the diameter of the spindle rotor 11; the throttle sleeve 51 is coaxially sleeved outside the radial throttle 50, and the outer wall is in close contact with the inner wall of the shell 10; the upper thrust throttle 52 is coaxially sleeved outside the head end of the spindle rotor 11, and is fixed by a plurality of mounting screws 51. 21 is fixedly connected to the end face of the throttle sleeve 51, and a gasket 53 is coaxially clamped between the upper thrust throttle 52 and the throttle sleeve 51; the head end of the spindle rotor 11 extends radially outward to form an air flotation disk 111, and the air flotation disk 111 is located between the throttle sleeve 51 and the upper thrust throttle 52, the thickness of the air flotation disk 111 is slightly smaller than the thickness of the gasket 53, and the diameter of the air flotation disk 111 is smaller than the inner diameter of the gasket 53; the outer wall of the motor stator 13 is tightly connected to the inner wall of the throttle sleeve 51, and the inner diameter of the motor stator 13 is slightly larger than the outer diameter of the motor rotor 12.

[0043] By setting a radial throttle 50, it is sleeved on the outside of the main shaft rotor 11, and a micron-level gap is formed between the two by utilizing the difference in diameters of the two; by setting a throttle sleeve 51, the gap between the radial throttle 50 and the cylinder shell 10 is filled and supported; by setting an upper thrust throttle 52, a gasket 53 and an air flotation disk 111, an interlayer is formed between the upper thrust throttle 52 and the end face of the throttle sleeve 51, and the interlayer is structurally supported by the gasket 53, and then the air flotation disk 111 is arranged in the interlayer, so that a micron-level gap is formed between the air flotation disk 111 and the interlayer, and is connected with the aforementioned micron-level gap. After the pressurized gas is introduced, an air film can be formed in the two micron-level gaps, and the air film prevents the air flotation disk 111 from contacting the peripheral side, and the air flotation disk 111 can also reversely play a role in axially limiting the main shaft rotor 11.

[0044] In order to further optimize the structure of the peripheral side of the air flotation disk 111, the head end of the radial throttle 50 extends radially outward to form a lower thrust throttle 501, and the end face of the lower thrust throttle 501 away from the upper thrust throttle 52 abuts against the end face of the throttle sleeve 51; the gasket 53 is coaxially clamped between the upper thrust throttle 52 and the lower thrust throttle 501; the air flotation disk 111 is located between the upper thrust throttle 52 and the lower thrust throttle 501; the mounting screw 521 passes through the upper thrust throttle 52, the lower thrust throttle 501 and the end face of the throttle sleeve 51 in sequence and is screwed on.

[0045] Through the above arrangement, the radial throttle 50, the upper thrust throttle 52 and the throttle sleeve 51 are connected as a whole through the mounting screws 521, thereby effectively improving the structural performance.

[0046] In order to further optimize the air film supporting performance of the radial throttle 50, the inner wall of the radial throttle 50 is provided with a plurality of annular air grooves 502 along the circumferential direction; the side wall of the radial throttle 50 is provided with a plurality of air holes 503, the air holes 503 penetrate the side wall of the radial throttle 50, and the inner end of each of the air holes 503 is connected with any one of the air grooves 502; the throttle sleeve 51 is provided with an exhaust groove, and the exhaust groove is connected with the outer end of at least one of the air holes 503; the rear end cover 14 is provided with an exhaust hole 142, the inner end of the exhaust hole 142 is connected with the exhaust groove, and the outer end is connected with the external environment; the tail end of the radial throttle 50 is coaxially and tightly laid with a sealing ring 504, and the outer wall of the sealing ring 504 is tightly connected with the inner wall of the throttle sleeve 51.

[0047] Through the above-mentioned arrangement, the spindle rotor 11 is radially supported circumferentially through the air groove 502 to ensure the support stability, and the continuously introduced high-pressure gas is discharged from between the radial throttle 50 and the spindle rotor 11 to the exhaust groove in the throttle sleeve 51 through the air hole 503, and then discharged to the external environment through the exhaust hole 142 to avoid excessive air pressure in the device; by setting the sealing ring 504, the high-pressure gas is prevented from directly escaping from the gap between the radial throttle 50 and the throttle sleeve 51 without forming an air film.

[0048] In order to further prevent the air flotation disk 111 from contacting the surrounding environment, the upper thrust throttle 52 and the lower thrust throttle 501 are provided with a plurality of air flotation holes 505 along the thickness direction, and the air flotation holes 505 are connected to at least one of the air holes 503; a throttle plug 506 is installed at one end of the air flotation hole 505 close to the air flotation disk 111.

[0049] Through the above arrangement, the high-pressure gas in the air hole 503 is pressed into the micron-level gap around the air flotation disk 111 through the air flotation hole 505, thereby further avoiding contact between the air flotation disk 111 and the surrounding side. The throttle plug 506 can control the flow of the high-pressure gas.

[0050] In order to effectively dissipate heat at the fitting point of the motor rotor 12 and the motor stator 13, the rear end cover 14 is provided with an air cooling pipe 143, the inner end of the air cooling pipe 143 points to the gap between the motor rotor 12 and the motor stator 13, and the outer end of the air cooling pipe 143 is used to connect with a cooling air source.

[0051] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An ultrasonic vibration rotary machining air-floating static pressure electric spindle, characterized in that: include: A cylindrical shell (10), wherein a main shaft rotor (11) is coaxially rotatably arranged inside the cylindrical shell (10), a motor rotor (12) is coaxially sleeved on the tail end of the main shaft rotor (11), a motor stator (13) is coaxially sleeved outside the motor rotor (12), an outer wall of the motor stator (13) is connected to an inner wall of the cylindrical shell (10), and a head end of the main shaft rotor (11) is located outside the cylindrical shell (10); A wheel hub (20), the wheel hub (20) being coaxially sleeved on the head end of the main shaft rotor (11); A disc-shaped ultrasonic energy concentrator (30), the disc-shaped ultrasonic energy concentrator (30) is coaxially sleeved outside the wheel hub (20), a thin diamond grinding wheel (31) is provided on the outer cover of the disc-shaped ultrasonic energy concentrator (30), a piezoelectric ceramic (32) is embedded in the disc surface of the disc-shaped ultrasonic energy concentrator (30), and the piezoelectric ceramic (32) is provided with a control system to control the voltage to which the piezoelectric ceramic (32) is subjected; A conductive slip ring (40) is coaxially sleeved outside the hub (20), and the conductive slip ring (40) is electrically connected to the piezoelectric ceramic (32) to supply power to the piezoelectric ceramic (32).

2. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to claim 1, characterized in that: The disk surface of the disk-shaped ultrasonic concentrator (30) is coaxially provided with an annular embedding groove (301), and the embedding groove (301) is used to embed the piezoelectric ceramic (32); The disk-shaped ultrasonic concentrator (30) is provided with a plurality of resonance holes (302), the resonance holes (302) penetrate the disk-shaped ultrasonic concentrator (30) along the thickness direction, and all the resonance holes (302) are coaxially arranged in an annular shape on the disk surface of the disk-shaped ultrasonic concentrator (30).

3. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to claim 2, characterized in that: The resonance hole (302) is in an arc shape matching the embedding groove (301), and the resonance hole (302) is arranged on the outside or inside of the embedding groove (301).

4. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to claim 3, characterized in that: The wheel hub (20) is in the shape of a cylinder with one end closed, and the wheel hub (20) is coaxially screwed to the head end of the spindle rotor (11) through a thread, and a tightening bolt (21) is coaxially passed through the closed end of the wheel hub (20), and the tightening bolt (21) is coaxially screwed to the spindle rotor (11); A limiting disk (22) is provided at the middle of the hub (20) protruding radially outward, the disk surface of the disk-shaped ultrasonic concentrator (30) and the end surface of the conductive slip ring (40) are respectively in contact with two sides of the limiting disk (22), and the piezoelectric ceramic (32) is completely shielded in the limiting disk (22); A cover plate (23) is provided on the side of the disc-shaped ultrasonic concentrator (30) away from the limiting plate (22), and the cover plate (23) is connected to the end surface of the hub (20) via a plurality of fastening screws (231) so that the disc-shaped ultrasonic concentrator (30) is clamped between the cover plate (23) and the limiting plate (22).

5. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to any one of claims 1 to 4, characterized in that: A throttling assembly is mounted between the cylindrical shell (10) and the main shaft rotor (11) to form a micrometer-level air floating gap between the main shaft rotor (11) and the throttling assembly; The rear end coaxial cover of the cylindrical shell (10) is provided with a rear end cover (14), and an air cavity is provided in the rear end cover (14), and the air cavity is connected with the air floating gap. The rear end cover (14) is provided with a plurality of air inlet interfaces (141) for introducing pressurized gas to form an air film in the air floating gap to support the rotation of the main shaft rotor (11).

6. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to claim 5, characterized in that: The throttling assembly comprises a radial throttle (50), a throttle sleeve (51) and an upper thrust throttle (52); The radial throttle (50) is coaxially sleeved outside the main shaft rotor (11), and both ends of the main shaft rotor (11) pass through both ends of the radial throttle (50), and the inner diameter of the radial throttle (50) is slightly larger than the diameter of the main shaft rotor (11); The throttle sleeve (51) is coaxially sleeved outside the radial throttle (50), and the outer wall thereof is in close contact with the inner wall of the cylindrical shell (10); The upper thrust throttle (52) is coaxially sleeved outside the head end of the main shaft rotor (11) and fixedly connected to the end surface of the throttle sleeve (51) through a plurality of mounting screws (521); a gasket (53) is coaxially clamped between the upper thrust throttle (52) and the throttle sleeve (51); The head end of the main shaft rotor (11) extends radially outward to form an air flotation disk (111), the air flotation disk (111) is located between the throttle sleeve (51) and the upper thrust throttle (52), the thickness of the air flotation disk (111) is slightly smaller than the thickness of the gasket (53), and the diameter of the air flotation disk (111) is smaller than the inner diameter of the gasket (53); The outer wall of the motor stator (13) is tightly connected to the inner wall of the throttle sleeve (51), and the inner diameter of the motor stator (13) is slightly larger than the outer diameter of the motor rotor (12).

7. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to claim 6, characterized in that: The head end of the radial throttle (50) extends radially outward to form a lower thrust throttle (501), and the end surface of the lower thrust throttle (501) away from the upper thrust throttle (52) abuts against the end surface of the throttle sleeve (51); The gasket (53) is coaxially clamped between the upper thrust throttle (52) and the lower thrust throttle (501); The air floating disk (111) is located between the upper thrust throttle (52) and the lower thrust throttle (501); The mounting screw (521) sequentially passes through the upper thrust throttle (52), the lower thrust throttle (501) and the end surface of the throttle sleeve (51) and is screwed on.

8. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to claim 7, characterized in that: The inner wall of the radial throttle (50) is provided with a plurality of annular air grooves (502) along the circumferential direction; The side wall of the radial throttle (50) is provided with a plurality of air holes (503), the air holes (503) penetrate the side wall of the radial throttle (50), and the inner end of each of the air holes (503) is connected to any one of the air grooves (502); An exhaust groove is provided in the throttle sleeve (51), and the exhaust groove is communicated with the outer end of at least one of the air holes (503); The rear end cover (14) is provided with an exhaust hole (142), the inner end of the exhaust hole (142) is communicated with the exhaust groove, and the outer end of the exhaust hole (142) is communicated with the external environment; A sealing ring (504) is coaxially and hermetically laid at the tail end of the radial throttle (50), and the outer wall of the sealing ring (504) is hermetically connected to the inner wall of the throttle sleeve (51).

9. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to claim 8, characterized in that: The upper thrust throttle (52) and the lower thrust throttle (501) are provided with a plurality of air flotation holes (505) penetrating along the thickness direction, and the air flotation holes (505) are connected to at least one of the air holes (503); A throttle plug (506) is installed at one end of the air flotation hole (505) close to the air flotation plate (111).

10. The ultrasonic vibration rotary machining air-floating static pressure electric spindle according to claim 8, characterized in that: The rear end cover (14) is provided with an air cooling pipe (143), the inner end of the air cooling pipe (143) points to the gap between the motor rotor (12) and the motor stator (13), and the outer end of the air cooling pipe (143) is used to communicate with a cooling air source.

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