Air spindle, control method and slimmer

Abstract

This application relates to the field of precision machining technology, and in particular to an air spindle, a control method, and a thinning process. An air spindle includes: a housing, which is cylindrical, hollow inside, and open at both ends; a spindle, at least partially disposed inside the housing, coaxially arranged with the housing; an air bearing, disposed between the housing and the spindle, allowing the spindle to rotate relative to the housing; and a motor assembly, comprising multiple motor units disposed between the housing and the spindle. Each motor unit includes: a stator connected to the housing; and a mover connected to the spindle. The multiple motor units are spaced apart to create a heat dissipation space between adjacent sets of motor units. By using multiple independently separate motor units, the technical effect of improving the performance of the air spindle is achieved.

Description

Technical Field

[0001] This application relates to the field of precision machining technology, and in particular to an air spindle, a control method, and a thinning machine. Background Technology

[0002] Air spindles, with their advantages of being frictionless, highly precise, and high-speed, have become core components in the field of ultra-precision.

[0003] In the prior art, an air spindle typically consists of a housing, a spindle suspended in the housing by an air film, and a motor that drives the spindle to rotate. The motor part usually adopts an internal permanent magnet synchronous motor, in which the stator coil is fixed to the housing and the mover is fixed to the spindle. As the speed and power requirements increase, the heat generation of the motor system intensifies, especially the heat generated by the mover and stator due to air film shear and motor losses, which is difficult to be effectively cooled, resulting in a decrease in the performance of the air spindle.

[0004] Therefore, the technical problem with the existing technology is that the performance of the air spindle degrades during operation. Summary of the Invention

[0005] This application provides an air spindle, a control method, and a thinning machine. By setting up multiple sets of independently separate motor units, the technical effect of improving the performance of the air spindle is achieved.

[0006] Firstly, the air spindle provided in this application adopts the following technical solution: An air spindle, comprising: A shell, the shell being cylindrical, hollow inside and open at both ends; A spindle, at least partially disposed inside the housing, and coaxially disposed with the housing; An air bearing, disposed between the housing and the main shaft, allows the main shaft to rotate about an axis relative to the housing; and The motor assembly includes multiple sets of motor units, which are disposed between the housing and the main shaft. Each set of motor units includes: Stator, which is connected to the housing; A mover, the mover being connected to the main shaft; The multiple sets of motor units are spaced apart to create a heat dissipation space between adjacent sets of motor units.

[0007] Preferably, multiple sets of the motor units are arranged at equal intervals.

[0008] Preferably, the motor assembly further includes: The mounting plate is arranged in a ring shape and is slidably connected to the inner wall of the housing along the length direction of the main shaft; wherein, the stator of each group of motor units is fixedly connected to the mounting plate so that the position of the stator of each group of motor units is adjustable.

[0009] Preferably, the motor assembly further includes: A drive unit connected to the housing and acting on the mounting plate, the drive unit having at least one degree of freedom of movement along the length of the main shaft to drive the mounting plate to adjust the axial position of the stator.

[0010] Preferably, the driving component includes an adjusting plate, which is fixedly connected between the housing and the mounting plate, and one end face of the adjusting plate is fixedly connected to the axial end face of the mounting plate; the adjusting plate can generate axial thrust through axial thermal expansion or contraction deformation to drive and control the mounting plate to move axially along the main shaft.

[0011] Preferably, a first flow channel is provided on the housing corresponding to the position of the regulating plate, and the first flow channel is arranged in close contact with the outer peripheral wall of the regulating plate; the first flow channel is used for the flow of temperature control medium, so as to control the temperature of the regulating plate by the temperature change of the temperature control medium, so as to cause the expansion or contraction deformation of the regulating plate, thereby forming a first temperature control zone for regulating the temperature of the regulating plate.

[0012] Preferably, a second flow channel is provided on the housing at a position corresponding to the motor unit. The second flow channel is used for the flow of cooling medium to reduce the temperature of the motor unit, thereby forming a second temperature control zone for cooling the motor unit.

[0013] Preferably, a third flow channel is provided on the housing corresponding to the position of the air bearing. The third flow channel is used for the flow of cooling medium to reduce the temperature of the air bearing, thereby forming a third temperature control zone for cooling the air bearing.

[0014] Secondly, the control method for an air spindle provided in this application adopts the following technical solution: A control method for an air spindle, applicable to the aforementioned air spindle, comprising: Compressed air is introduced into the air bearing to form a stable air film to suspend and support the main shaft. The stator of the motor unit is energized to generate a rotating magnetic field that drives the mover to rotate the main shaft around the axial direction. Obtain the spindle offset; The deformation of the adjusting plate is controlled based on the offset to control the adjusting plate to generate an axial deformation that matches the axial offset; the adjusting plate generates an axial thrust through deformation to drive the mounting plate to slide, thereby adjusting the axial position of the stator so that the stator and the mover are aligned.

[0015] Thirdly, the thinning machine provided in this application adopts the following technical solution: A thinning machine has the aforementioned air spindle, which is used to drive a thinning grinding wheel to rotate for thinning the workpiece.

[0016] In summary, this application includes at least one of the following beneficial technical effects: This application sets up multiple independent motor units, and a heat dissipation space is formed between two adjacent motor units. The heat dissipation space can increase the contact area between the motor assembly and the air, and at the same time facilitate the flow of the cooling medium, accelerate the dissipation of electromagnetic loss heat generated when the motor unit is working, significantly improve the heat dissipation effect of the motor assembly, and achieve the technical effect of improving the performance of the air spindle. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the air spindle described in this application; Figure 2 yes Figure 1 Enlarged view of A in the middle; Figure 3 This is a schematic diagram of the first flow channel of the air main shaft described in this application; Figure 4 yes Figure 3 Enlarged view of B in the middle; Figure 5 This is a schematic diagram of the temperature control zone of the air spindle described in this application; Figure 6 This is a flowchart of the control method for the air spindle described in this application; Figure 7 This is a schematic diagram of the thinning machine described in this application.

[0018] Explanation of reference numerals in the attached drawings: 100, housing; 200, spindle; 300, air bearing; 400, motor assembly; 410, motor unit; 420, heat dissipation space; 411, stator; 412, mover; 413, mounting plate; 414, drive component; 4141, adjusting plate; 415, first flow channel; 4151, first temperature control zone; 416, second flow channel; 4161, second temperature control zone; 417, third flow channel; 4171, third temperature control zone; 1, air spindle; 2, thinning grinding wheel; 3, frame. Detailed Implementation

[0019] The serial numbers assigned to components in this document, such as "first" and "second," are used solely to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used solely for the convenience of describing this application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0020] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0021] To better understand the above technical solutions, a detailed description of the technical solutions will be provided below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit the scope of this application.

[0022] As a precision rotating component that utilizes air film for non-contact support, the air spindle 1 is widely used in semiconductor thinning due to its advantages of frictionless operation, high precision, and high-speed rotation. The motor assembly 400 of the air spindle 1 typically adopts a single-set stator 411 and mover 412 pairing structure, with the stator 411 fixed to the housing 100 and the mover 412 fixed to the spindle 200. This structure of the motor assembly 400 has high electromagnetic coupling efficiency and low leakage magnetic loss, but it has a significant heat dissipation bottleneck. Because the motor assembly 400 generates a large amount of electromagnetic loss heat during operation, the heat of a single set of motor assemblies 400 is concentrated in the middle section of the spindle 200 and is difficult to dissipate quickly, causing thermal deformation of the spindle 200 and the housing 100, destroying the stability of the air film gap, and thus causing the rotational accuracy of the spindle 200 to drift. At the same time, the heat accumulation also limits the current output of the motor assembly 400, resulting in insufficient power output and failing to meet the processing requirements of high-speed and heavy-duty operations.

[0023] To address the heat dissipation issue, the applicant attempted to increase the gap between the motor assembly 400 and the housing 100 or add heat sinks during its continuous exploration. However, this approach had limited heat dissipation effect and negatively impacted the overall performance of the air spindle 1. Subsequently, the applicant further adopted a series arrangement of multiple motor units 410, but did not optimize the arrangement of the multiple motor units 410. There was no effective heat dissipation space 420 between adjacent motor units 410, resulting in minimal improvement in heat dissipation. Moreover, the arrangement of multiple motor units 410 would increase leakage magnetic loss. If the relationship between leakage magnetic loss and heat dissipation gain could not be balanced, the electromagnetic coupling efficiency of the motor assembly 400 would decrease significantly, making it impossible to improve power output.

[0024] Furthermore, when multiple motor units 410 are spaced apart to improve heat dissipation, the spindle 200 will experience axial thermal elongation during operation due to electromagnetic loss heat and air shear heat. This causes the mover 412, fixed to the spindle 200, to synchronously shift axially. Since the stator 411 is fixed to the housing 100 and cannot move, this leads to misalignment of the axial overlap area between the stator 411 and the mover 412, further exacerbating the decrease in electromagnetic coupling efficiency, generating torque pulsation, and affecting the rotational accuracy and power output stability of the spindle 200. Simultaneously, both the air bearing 300 and the motor unit 410 generate heat during operation. If not properly cooled, this can lead to unstable air film clearance and performance degradation of the motor assembly 400, further impacting the overall operational reliability of the air spindle 1.

[0025] To address the above deficiencies, this application proposes an air spindle 1 and its control method, as well as a thinning machine, which improves heat dissipation gain and enhances the performance of the air spindle 1 by optimizing the arrangement of multiple motor units 410.

[0026] This application proposes an air spindle 1, such as Figure 1 As shown, the assembly includes a housing 100, a main shaft 200, an air bearing 300, and a motor assembly 400. The housing 100 is cylindrical, hollow inside, and open at both ends. The main shaft 200 is at least partially disposed inside the housing 100 and is coaxial with the housing 100. The air bearing 300 is disposed between the housing 100 and the main shaft 200, allowing the main shaft 200 to rotate relative to the housing 100 around its axis. The motor assembly 400 includes multiple motor units 410, each set of which is disposed between the housing 100 and the main shaft 200. Each set of motor units 410 includes a stator 411 and a mover 412. The stator 411 is connected to the housing 100, and the mover 412 is connected to the main shaft 200. The multiple sets of motor units 410 are spaced apart to form a heat dissipation space 420 between adjacent sets of motor units 410.

[0027] Specifically, such as Figure 1As shown, the housing 100 is cylindrical and hollow inside. The housing 100 serves as the fixed base for the entire air spindle 1, providing installation support for all other components. Its inner wall needs to be machined with high precision to ensure the coaxiality requirements after the subsequent components are assembled. The housing 100 is made of a material with high damping and low thermal expansion coefficient to effectively reduce the impact of external vibration on the internal components of the air spindle 1, while also reducing the thermal deformation of the housing 100 itself, so as to ensure the stable operation of the air bearing 300 and the reliable operation of the motor assembly 400.

[0028] like Figure 1 As shown, the air bearing 300 is disposed between the housing 100 and the spindle 200. The air bearing 300 allows the spindle 200 to rotate relative to the housing 100 around its axis. The air bearing 300 is the core component for achieving non-contact rotation of the spindle 200. It forms a uniform and stable air film between the spindle 200 and the housing 100, suspending and supporting the spindle 200, avoiding mechanical contact between the spindle 200 and the housing 100, thereby eliminating frictional loss and improving the rotational accuracy and service life of the spindle 200. The air bearing 300 includes a radial air bearing 300 and a thrust air bearing 300. The radial air bearing 300 is sleeved on the outer peripheral wall of the spindle 200. Between the spindle 200 and the inner wall of the housing 100, a thrust air bearing 300 is used to limit the radial displacement of the spindle 200 and prevent radial wobble during high-speed rotation. The thrust air bearing 300 is disposed between the axial end face of the spindle 200 and the inner wall of the housing 100 to limit the axial displacement of the spindle 200 and prevent axial movement during high-speed rotation. The inner wall of the air bearing 300 is machined with an array of throttling orifices. Compressed air enters the gap between the spindle 200 and the air bearing 300 through these orifices, forming a stable air film. This air film not only provides support but also lubricates and cools, further improving the rotational stability of the spindle 200. The air bearing 300 is a conventional structure in the art and will not be described in detail here.

[0029] like Figure 1 , 2 As shown, the motor assembly 400 includes multiple motor units 410. The motor units 410 are disposed between the housing 100 and the spindle 200. Each motor unit 410 includes a stator 411 and a mover 412. The stator 411 is fixedly connected to the housing 100, and the mover 412 is fixedly connected to the spindle 200. The multiple sets of motor units 410 are spaced apart to form a heat dissipation space 420 between adjacent sets of motor units 410. The motor assembly 400 provides power for the high-speed rotation of the shaft. The arrangement of multiple sets of motor units 410 can achieve power superposition, improve the total output power and torque of the motor assembly 400, and meet the processing requirements of high-speed and heavy-duty operation.

[0030] It should be noted that although the spaced arrangement of multiple motor units 410 leads to an increase in leakage magnetic loss, this arrangement creates a heat dissipation space 420 between adjacent motor units 410. This space increases the contact area between the motor assembly 400 and the air, facilitating airflow and accelerating the dissipation of electromagnetic heat generated during motor unit 410 operation, significantly improving the heat dissipation effect of the motor assembly 400. Repeated experiments have verified that the heat dissipation gain from the spaced arrangement of multiple motor units 410 far outweighs the leakage magnetic loss. On one hand, the improved heat dissipation effectively reduces the temperature rise of the motor unit 410, preventing aging of the motor windings and increased resistance due to excessive temperature rise, thus reducing copper losses. It also increases the maximum allowable current of the motor unit 410, increasing output torque and power. On the other hand, the increase in leakage magnetic loss is relatively small. By rationally designing the spacing and structural parameters of the motor units 410, leakage magnetic loss can be controlled within a reasonable range, without significantly affecting the electromagnetic coupling efficiency of the motor assembly 400, ultimately improving the power output and operational stability of the motor assembly 400.

[0031] The stator 411 and mover 412 of each motor unit 410 are arranged coaxially. The stator 411 is fixedly connected to the inner wall of the housing 100, and the mover 412 is fixedly connected to the outer wall of the main shaft 200. A certain radial gap is maintained between the stator 411 and the mover 412. This gap is used to avoid mechanical contact between the stator 411 and the mover 412, while ensuring that the rotating magnetic field can effectively drive the mover 412 to rotate. For example, the radial gap between the stator 411 and the mover 412 is 0.8 to 1 mm. Multiple motor units 410 are arranged at intervals along the axial direction of the main shaft 200. The width of the heat dissipation space 420 between two adjacent motor units 410 needs to be reasonably designed to ensure sufficient heat dissipation area, while avoiding excessively large intervals that would cause the overall length of the motor assembly 400 to be too long, affecting the compactness of the air main shaft 1, and avoiding excessively small intervals that would result in poor heat dissipation. For example, the axial width of the heat dissipation space 420 is preferably 1 / 3 to 2 / 3 of the axial length of a single motor unit 410, with 1 / 2 being the baseline value in conventional designs. If the extreme heat dissipation requirements for heavy-duty and high-speed applications are emphasized, it can be adjusted to 2 / 3. If the miniaturization and compactness of the air spindle 1 are pursued, it can be adjusted to 1 / 3. Within this range, the heat dissipation gain can be guaranteed to be much greater than the leakage magnetic loss. In one embodiment, the axial length of a single motor unit 410 is mostly 10 to 30 mm, corresponding to an actual width of the heat dissipation space 420 of approximately 3 to 20 mm.

[0032] Preferred, such as Figure 1 , 2As shown, multiple motor units 410 are arranged at equal intervals. This equal spacing ensures a uniform distribution of the heat dissipation space 420 among the multiple motor units 410, guaranteeing consistent heat dissipation conditions for each unit and preventing heat accumulation due to insufficient heat dissipation space 420 in some units, thus avoiding uneven temperature rise. Simultaneously, the equal spacing ensures a uniform distribution of electromagnetic force among the multiple motor units 410, preventing vibration of the spindle 200 due to uneven electromagnetic force and ensuring the rotational accuracy of the spindle 200. Furthermore, it optimizes the magnetic circuit distribution, reduces leakage flux loss, and improves electromagnetic coupling efficiency.

[0033] Multiple motor units 410 are arranged at intervals, forming a heat dissipation space 420 between adjacent motor units 410. Although some leakage magnetic loss will occur, the heat dissipation gain is far greater than the leakage magnetic loss, which can effectively improve the heat dissipation effect of the motor assembly 400, reduce the temperature rise of the motor unit 410, and avoid the performance degradation of the motor due to excessive temperature rise. At the same time, it can increase the maximum allowable current of the motor unit 410, increase the output torque and power, and meet the processing requirements of high speed and heavy load. The equal spacing of multiple motor units 410 can ensure uniform heat dissipation and balanced electromagnetic force, further improving the working stability of the motor assembly 400 and the rotational accuracy of the spindle 200.

[0034] Furthermore, such as Figure 1 As shown, the motor assembly 400 also includes a mounting plate 413, which is arranged in a ring shape and is slidably connected to the inner wall of the housing 100 along the length direction of the main shaft 200; wherein, the stator 411 of each group of motor units 410 is fixedly connected to the mounting plate 413 so that the position of the stator 411 of each group of motor units 410 is adjustable.

[0035] The mounting plate 413 is arranged in a ring shape and is slidably connected to the inner wall of the housing 100 along the length of the main shaft 200. The stator 411 of each motor unit 410 is fixedly connected to the mounting plate 413 so that the position of the stator 411 of each motor unit 410 can be adjusted. The mounting plate 413 is used to realize the synchronous adjustment of the stators 411 of multiple motor units 410, and solve the problem of the movement 412 shifting and the stator 411 and the movement 412 being axially misaligned due to the thermal expansion of the main shaft 200.

[0036] The mounting plate 413 is arranged in a ring shape. The outer diameter of the mounting plate 413 is adapted to the inner wall of the housing 100, and it can fit against the inner wall of the housing 100 and the outer peripheral wall of the main shaft 200 to ensure the coaxiality of the mounting plate 413 and avoid eccentricity during the sliding process of the mounting plate 413, which would affect the coaxiality of the stator 411 and the mover 412. The mounting plate 413 slides along the length of the main shaft 200 and is connected to the inner wall of the housing 100. The inner wall of the housing 100 is machined with an axially extending sliding guide rail. The outer peripheral wall of the mounting plate 413 is provided with a slider that matches the sliding guide rail. The fit clearance between the slider and the guide rail must be strictly controlled to ensure that the mounting plate 413 can slide smoothly along the guide rail, while avoiding excessive clearance that would cause the mounting plate 413 to wobble and affect the positional accuracy of the stator 411. The length of the sliding guide rail needs to be designed according to the maximum thermal expansion of the spindle 200 to ensure that the sliding stroke of the mounting plate 413 can cover the maximum axial offset of the spindle 200, so as to achieve sufficient adjustment of the position of the stator 411.

[0037] like Figure 1 As shown, the stator 411 of each motor unit 410 is fixedly connected to the inner peripheral wall of the mounting plate 413. Multiple sets of stators 411 are evenly distributed along the axial direction of the mounting plate 413, corresponding one-to-one with the positions of multiple sets of movers 412. This ensures that, in the initial state, the stator 411 and mover 412 of each motor unit 410 can be precisely aligned, guaranteeing electromagnetic coupling efficiency. When the spindle 200 undergoes axial thermal expansion, causing the mover 412 to shift synchronously, the mounting plate 413 can be driven to slide along the sliding guide rail, which can drive all stators 411 to move synchronously axially, adjusting the position of the stator 411 and realigning it with the mover 412, thus avoiding a decrease in electromagnetic coupling efficiency due to misalignment.

[0038] Furthermore, such as Figure 1 As shown, the motor assembly 400 also includes a drive member 414, which is connected to the housing 100 and acts on the mounting plate 413. The drive member 414 has at least one degree of freedom of movement along the length of the main shaft 200 to drive the mounting plate 413 and adjust the axial position of the stator 411. The drive member 414 is the power source for driving the mounting plate 413 to slide, providing axial thrust along the length of the main shaft 200 to drive the mounting plate 413 and adjust the axial position of the stator 411. The drive member 414 is the power source for driving the mounting plate 413 to slide, providing axial thrust to the mounting plate 413 along the length of the main shaft 200, driving the mounting plate 413 to move smoothly along the sliding guide rail, thereby adjusting the axial position of the stator 411 and achieving precise alignment between the stator 411 and the mover 412.

[0039] Specifically, the drive component 414 is connected to the inner wall of the housing 100. The installation position of the drive component 414 needs to be reasonably designed to avoid affecting the arrangement of the motor unit 410 and the heat dissipation effect of the heat dissipation space 420, while ensuring that the drive component 414 can provide sufficient thrust to drive the mounting plate 413 and the stator 411 to slide smoothly. In one embodiment, the power output end of the drive component 414 acts on the axial end face of the mounting plate 413. Preferably, the degree of freedom of movement of the drive component 414 can at least drive the mounting plate 413 along the length direction of the spindle 200. The driving method of the drive component 414 needs to have the characteristics of high precision and high stability, be able to realize the micro-displacement adjustment of the mounting plate 413, and adapt to the ultra-precision rotation requirements of the air spindle 1.

[0040] like Figure 1 As shown, the driving component 414 includes an adjusting plate 4141, which is fixedly connected between the housing 100 and the mounting plate 413. One end face of the adjusting plate 4141 is connected to the axial end face of the mounting plate 413, and the other end face is fixed to the inner wall of the housing 100. The adjusting plate 4141 can generate axial thrust through axial thermal expansion or contraction deformation to drive and control the mounting plate 413 to move axially along the main shaft 200. The adjusting plate 4141 is fixedly connected between the housing 100 and the mounting plate 413, and one end face of the adjusting plate 4141 abuts against the axial end face of the mounting plate 413, while the other end face is fixed to the inner wall of the housing 100. The adjusting plate 4141 can generate axial thrust through axial thermal expansion or contraction deformation to drive and control the mounting plate 413 to move axially along the main shaft 200. The adjustment plate 4141 adopts a thermal expansion deformation drive method, which has a simple structure and no electromagnetic interference. It can achieve precise adjustment of the position of the stator 411 and is suitable for the ultra-precision operation requirements of the air spindle 1.

[0041] Specifically, the adjusting plate 4141 is made of a material with a high coefficient of thermal expansion. In one embodiment, the material of the adjusting plate 4141 is aluminum bronze or brass. The material has a high coefficient of thermal expansion, which can generate a large axial deformation with a small temperature change, making it easy to achieve a small adjustment of the position of the stator 411. At the same time, this material has good rigidity and temperature resistance, and can withstand the temperature environment when the motor assembly 400 is working, avoiding deformation and failure of the adjusting plate 4141 due to excessive temperature. The axial length of the adjusting plate 4141 needs to be designed according to the maximum thermal elongation of the spindle 200 and the coefficient of thermal expansion of the adjusting plate 4141 to ensure that the adjusting plate 4141 can generate sufficient deformation to drive the mounting plate 413 to slide to the required position, so as to achieve precise alignment of the stator 411 and the mover 412.

[0042] When the adjusting plate 4141 is heated, it undergoes axial thermal expansion, generating an axial thrust along the length of the main shaft 200, which pushes the mounting plate 413 to move along the sliding guide towards the extension end of the main shaft 200. When the adjusting plate 4141 is cooled, it undergoes axial contraction, which drives the mounting plate 413 to move along the sliding guide away from the extension end of the main shaft 200. Through the thermal expansion or contraction deformation of the adjusting plate 4141, the bidirectional sliding of the mounting plate 413 is achieved, thereby adjusting the axial position of the stator 411 to match the offset of the mover 412, ensuring that the stator 411 and the mover 412 are always precisely aligned.

[0043] The mounting plate 413 and drive component 414 enable precise adjustment of the stator 411 position, solving the problems of mover 412 offset and stator 411 and mover 412 axial misalignment caused by thermal expansion of spindle 200. This avoids the decrease in electromagnetic coupling efficiency and torque pulsation caused by misalignment, ensuring stable electromagnetic coupling efficiency of motor assembly 400 and continuous high-precision rotation of spindle 200. The drive component 414 adopts an adjustment plate 4141, which drives the mounting plate 413 to slide through thermal expansion or contraction deformation. It has a simple structure, no electromagnetic interference, and is suitable for the ultra-precision operation requirements of air spindle 1. It also has high adjustment accuracy and can realize minute displacement adjustment of stator 411 position.

[0044] Furthermore, such as Figure 3 , 4 As shown, a first flow channel 415 is provided on the housing 100 at a position corresponding to the adjustment plate 4141. The first flow channel 415 is arranged in close contact with the outer peripheral wall of the adjustment plate 4141. The first flow channel 415 is used to supply the temperature control medium to flow, so as to control the temperature of the adjustment plate 4141 by the temperature change of the temperature control medium, so as to cause the expansion or contraction deformation of the adjustment plate 4141, thereby forming a first temperature control zone 4151 for adjusting the temperature of the adjustment plate 4141.

[0045] A first flow channel 415 is provided on the housing 100 at a position corresponding to the adjustment plate 4141. The first flow channel 415 is arranged in close contact with the outer peripheral wall of the adjustment plate 4141. The first flow channel 415 is used to supply temperature control medium to flow, so as to control the temperature of the adjustment plate 4141 by the temperature change of the temperature control medium, so as to cause the expansion or contraction deformation of the adjustment plate 4141, thereby forming a first temperature control zone 4151 for adjusting the temperature of the adjustment plate 4141. The setting of the first flow channel 415 is used to precisely control the temperature of the adjustment plate 4141, thereby controlling the thermal expansion or contraction deformation of the adjustment plate 4141, realizing precise control of the sliding distance of the mounting plate 413, and ensuring the alignment accuracy of the stator 411 and the mover 412.

[0046] The first flow channel 415 is located on the inner wall of the housing 100 and is arranged close to the outer peripheral wall of the regulating plate 4141. This arrangement allows the temperature control medium to have full contact with the regulating plate 4141, improving heat exchange efficiency and ensuring that the temperature of the regulating plate 4141 can quickly respond to changes in the temperature of the temperature control medium, thus achieving precise control of the deformation of the regulating plate 4141. The first flow channel 415 has an inlet and an outlet at each end. The inlet is used to introduce the temperature control medium, and the outlet is used to discharge the temperature control medium, forming a circulating flow of the temperature control medium. The temperature control medium can be water, heat transfer oil, or other media with good thermal conductivity. Based on the temperature regulation requirements of the regulating plate 4141, precise temperature control of the regulating plate 4141 is achieved by controlling the temperature and flow rate of the temperature control medium. When the regulating plate 4141 needs to expand thermally, a high-temperature temperature control medium is introduced into the first flow channel 415. The high-temperature temperature control medium exchanges heat with the regulating plate 4141, causing the temperature of the regulating plate 4141 to rise and undergo thermal expansion deformation. When the regulating plate 4141 needs to contract, a low-temperature temperature control medium is introduced into the first flow channel 415. The low-temperature temperature control medium carries away the heat of the regulating plate 4141, causing the temperature of the regulating plate 4141 to drop and undergo contraction deformation.

[0047] The first flow channel 415 forms a first temperature control zone 4151 for adjusting the temperature of the regulating plate 4141. The temperature range of the first temperature control zone 4151 can be set according to the material properties and adjustment requirements of the regulating plate 4141 to ensure that the regulating plate 4141 can generate the required deformation, drive the mounting plate 413 to slide to the appropriate position, and achieve precise alignment of the stator 411 and the mover 412. The temperature control of the first temperature control zone 4151 needs to have high precision, and the temperature fluctuation range should be controlled within a small range to avoid the deformation of the regulating plate 4141 becoming unstable due to temperature fluctuations, which would affect the adjustment accuracy of the stator 411 position.

[0048] Furthermore, such as Figure 5 As shown, a second flow channel 416 is provided on the housing 100 at a position corresponding to the motor unit 410. The second flow channel 416 is used to allow cooling medium to flow to reduce the temperature of the motor unit 410, thereby forming a second temperature control zone 4161 for cooling the motor unit 410.

[0049] A second flow channel 416 is provided on the housing 100 at a position corresponding to the motor unit 410. The second flow channel 416 is used for the flow of cooling medium to reduce the temperature of the motor unit 410, thereby forming a second temperature control zone 4161 for cooling the motor unit 410. The second flow channel 416 is designed to specifically cool the motor unit 410, further improving the heat dissipation effect of the motor assembly 400, preventing the performance degradation of the motor unit 410 due to excessive temperature rise, and reducing the thermal expansion of the spindle 200, thus alleviating the misalignment problem between the stator 411 and the mover 412.

[0050] The second flow channel 416 is arranged corresponding to the position of the motor unit 410 to ensure that the cooling medium can fully contact the motor unit 410 and remove the electromagnetic loss heat generated by the motor unit 410 during operation. Preferably, the second flow channel 416 includes a main flow channel and branch flow channels. The main flow channel extends along the axial direction of the main shaft 200, and the branch flow channels branch off from the main flow channel and are arranged corresponding to the position of each group of motor units 410, so that the cooling medium can be evenly distributed around each group of motor units 410, ensuring that the cooling effect of each group of motor units 410 is consistent and avoiding uneven temperature rise caused by insufficient cooling of some motor units 410.

[0051] The second flow channel 416 is used for the circulation of cooling medium. The cooling medium can be water, coolant, or other media with good cooling performance. The cooling medium enters the second flow channel 416 through the inlet, exchanges heat with the motor unit 410, removes the heat from the motor unit 410, and then exits through the outlet, forming a circulation of the cooling medium. The flow rate of the cooling medium can be adjusted according to the heating status of the motor unit 410. When the motor unit 410 generates a lot of heat, the flow rate of the cooling medium is increased to improve the cooling effect; when the motor unit 410 generates less heat, the flow rate of the cooling medium is reduced to save energy.

[0052] The second flow channel 416 forms a second temperature control zone 4161 for cooling the motor unit 410. The function of the second temperature control zone 4161 is to control the temperature of the motor unit 410 within a reasonable range, preventing the motor unit 410 from aging and increasing resistance due to excessive temperature rise, thereby reducing copper and iron losses and improving the electromagnetic coupling efficiency and operational stability of the motor assembly 400. At the same time, the cooling effect of the second temperature control zone 4161 can reduce the heat transferred from the motor unit 410 to the spindle 200, reduce the thermal expansion of the spindle 200, alleviate the offset of the mover 412, reduce the adjustment frequency of the stator 411 position, and further improve the overall operational stability of the air spindle 1.

[0053] Furthermore, such as Figure 5 As shown, a third flow channel 417 is provided on the housing 100 at a position corresponding to the air bearing 300. The third flow channel 417 is used to allow cooling medium to circulate in order to reduce the temperature of the air bearing 300, thereby forming a third temperature control zone 4171 for cooling the air bearing 300.

[0054] A third flow channel 417 is provided on the housing 100 at a position corresponding to the air bearing 300. The third flow channel 417 is used to allow cooling medium to circulate and reduce the temperature of the air bearing 300, thereby forming a third temperature control zone 4171 for cooling the air bearing 300. The third flow channel 417 is designed to specifically cool the air bearing 300, maintain the stability of the air film gap, and prevent the air bearing 300 from changing the air film thickness due to excessive temperature rise, which would affect the rotational accuracy of the spindle 200. During operation, when compressed air enters the air film gap through the throttling orifice, it will generate viscous heat dissipation due to air shearing. At the same time, the heat transfer between the air bearing 300 and the spindle 200 and housing 100 will also cause the temperature of the air bearing 300 to rise. The temperature rise of the air bearing 300 will cause changes in the viscosity and pressure of the air film, which will disrupt the stability of the air film gap and cause radial runout and axial movement of the spindle 200, affecting the rotational accuracy of the spindle 200. Therefore, the air bearing 300 needs to be cooled specifically through the third flow channel 417.

[0055] The third flow channel 417 is used for the flow of cooling medium. The cooling medium can be the same type as the cooling medium in the second flow channel 416, which facilitates the integrated design of the cooling system. The cooling medium enters the third flow channel 417 through the liquid inlet, exchanges heat with the air bearing 300, removes the heat from the air bearing 300, and then exits through the liquid outlet, forming a circulation of the cooling medium. The flow rate of the cooling medium can be adjusted according to the heating status of the air bearing 300 to ensure the temperature stability of the air bearing 300 and maintain the uniformity and stability of the air film gap.

[0056] The third flow channel 417 forms a third temperature control zone 4171 for cooling the air bearing 300. The function of the third temperature control zone 4171 is to control the temperature of the air bearing 300 within a reasonable range, to prevent the air bearing 300 from changing the air film gap due to excessive temperature rise, and to ensure that the air film can stably suspend and support the spindle 200, so as to achieve high precision and high stability rotation of the spindle 200. At the same time, the cooling effect of the third temperature control zone 4171 can reduce the heat transferred from the air bearing 300 to the spindle 200, further reduce the thermal elongation of the spindle 200, alleviate the misalignment problem between the stator 411 and the mover 412, and improve the overall working reliability of the air spindle 1.

[0057] Furthermore, this application also provides a control method for the air spindle 1, applicable to the aforementioned air spindle 1. By controlling the deformation of the adjusting plate 4141, the axial position of the stator 411 is adjusted, ensuring that the stator 411 and the mover 412 are always precisely aligned, thus ensuring the electromagnetic coupling efficiency of the motor assembly 400 and the rotational accuracy of the spindle 200. Figure 6 As shown, it includes: S1: Compressed air is introduced into the air bearing 300 to form a stable air film to suspend and support the main shaft 200. S2: The stator 411 of the control motor unit 410 is energized, generating a rotating magnetic field to drive the mover 412 to rotate the main shaft 200 around the axis; S3: Get the spindle offset of 200; S4: Based on the offset, control the deformation of the adjusting plate 4141 to control the adjusting plate 4141 to generate an axial deformation that matches the axial offset; the adjusting plate 4141 generates an axial thrust through deformation to drive the mounting plate 413 to slide, so as to adjust the axial position of the stator 411 so that the stator 411 and the mover 412 are aligned.

[0058] Specifically, it includes: The first step is to introduce compressed air into the air bearing 300 to form a stable air film to suspend and support the main shaft 200. The compressed air enters the gap between the main shaft 200 and the air bearing 300 through the air bearing 300, forming a uniform and stable air film. The pressure of the compressed air needs to be controlled within a reasonable range to ensure that the air film can provide sufficient support force to stably suspend the main shaft 200 and avoid mechanical contact between the main shaft 200 and the air bearing 300. At the same time, the purification level of the compressed air needs to meet the requirements to avoid impurities clogging the throttling orifice and affecting the uniformity and stability of the air film. After the air film is formed, the main shaft 200 is suspended and supported, and has the condition to rotate around the axial direction.

[0059] The second step involves energizing the stator 411 of the control motor unit 410, generating a rotating magnetic field that drives the mover 412 to rotate the main shaft 200 around the axial direction. High-frequency alternating current is supplied to the stator 411 windings of each motor unit 410, generating a rotating magnetic field. Since the mover 412 is fixed to the main shaft 200 and coaxially arranged with the stator 411, the mover 412 generates electromagnetic torque under the influence of the rotating magnetic field, which drives the main shaft 200 to rotate at high speed around the axial direction. Multiple motor units 410 work together... Simultaneously, the superimposed electromagnetic torque output provides sufficient power for the high-speed rotation of the spindle 200. During the rotation of the spindle 200, the second flow channel 416 and the third flow channel 417 are simultaneously supplied with cooling medium. The cooling medium in the second flow channel 416 carries away the electromagnetic loss heat generated when the motor unit 410 is working, and the cooling medium in the third flow channel 417 carries away the viscous loss heat generated when the air bearing 300 is working, thus maintaining the temperature stability of the motor unit 410 and the air bearing 300 and reducing the thermal elongation of the spindle 200.

[0060] The third step is to obtain the offset of the spindle 200. During high-speed rotation, the spindle 200 will experience axial thermal expansion due to the electromagnetic loss heat of the motor unit 410 and the viscous heat dissipation of the air bearing 300. This will cause the mover 412 fixed on the spindle 200 to move axially synchronously. The offset of the spindle 200 is the axial thermal expansion of the spindle 200, which is also the axial offset of the mover 412. There are two ways to obtain the offset of the spindle 200. One is to calculate it through a preset correlation model of spindle 200 temperature rise and thermal expansion. That is, by detecting the temperature change of the spindle 200, combined with the thermal expansion coefficient of the spindle 200 material and the effective length of the spindle 200, the axial thermal expansion of the spindle 200 is calculated by the thermal expansion formula. The other is to detect it through a displacement sensor set at the end of the spindle 200. The displacement sensor adopts a non-contact sensor, such as a fiber optic displacement sensor or a capacitive displacement sensor, to detect the axial displacement change of the spindle 200 in real time and directly obtain the offset of the spindle 200. Regardless of the method used, the detection accuracy of the spindle 200 offset must be ensured to guarantee the accuracy of the deformation control of the subsequent adjustment plate 4141.

[0061] The fourth step involves controlling the deformation of the adjustment plate 4141 based on the offset, thereby controlling the adjustment plate 4141 to generate an axial deformation that matches the axial offset. The adjustment plate 4141 generates axial thrust through deformation to drive the mounting plate 413 to slide, thereby adjusting the axial position of the stator 411 so that the stator 411 and the mover 412 are aligned. Based on the obtained offset of the main shaft 200, the required axial deformation of the adjustment plate 4141 is determined to ensure that the deformation of the adjustment plate 4141 is equal to the offset of the main shaft 200, so that the distance that the mounting plate 413 drives the stator 411 to move is equal to the offset of the mover 412, thus achieving precise alignment of the stator 411 and the mover 412.

[0062] Specifically, if the offset of the spindle 200 is ΔL, the coefficient of thermal expansion of the adjusting plate 4141 is α, the initial length of the adjusting plate 4141 is L, and the temperature change of the adjusting plate 4141 is ΔT, then the deformation of the adjusting plate 4141 is ΔL' = α × L × ΔT. By controlling the temperature change ΔT of the adjusting plate 4141 to make ΔL' = ΔL, the deformation of the adjusting plate 4141 and the offset of the spindle 200 can be matched. The temperature change of the regulating plate 4141 is controlled by adjusting the temperature of the temperature control medium in the first flow channel 415. When the regulating plate 4141 needs to expand thermally, a high-temperature temperature control medium is introduced into the first flow channel 415. The high-temperature temperature control medium exchanges heat with the regulating plate 4141, causing the temperature of the regulating plate 4141 to rise by ΔT, resulting in thermal expansion deformation and generating axial thrust. When the regulating plate 4141 needs to contract, a low-temperature temperature control medium is introduced into the first flow channel 415. The low-temperature temperature control medium carries away the heat of the regulating plate 4141, causing the temperature of the regulating plate 4141 to drop by ΔT, resulting in contraction deformation and causing the mounting plate 413 to slide in the opposite direction.

[0063] After the adjusting plate 4141 generates axial deformation, it will generate axial thrust on the mounting plate 413, pushing the mounting plate 413 to slide smoothly along the sliding guide rail of the housing 100. Since the stator 411 of each motor unit 410 is fixed on the mounting plate 413, the sliding of the mounting plate 413 will drive all stators 411 to move axially synchronously, adjusting the axial position of the stator 411. During the adjustment of the stator 411 position, the alignment of the stator 411 and the mover 412 is monitored in real time. The alignment of the stator 411 and the mover 412 can be detected by a displacement sensor. The axial overlap length of stator 411 and mover 412 is measured, or the electromagnetic coupling efficiency and torque pulsation of motor assembly 400 are monitored to determine whether stator 411 and mover 412 are aligned. When the deviation of the axial overlap length of stator 411 and mover 412 is within the allowable range, or when the electromagnetic coupling efficiency of motor assembly 400 reaches the set value and the torque pulsation is within the allowable range, the temperature of the temperature control medium in the first flow channel 415 is stopped, the deformation of the adjustment plate 4141 is maintained, and the stator 411 and mover 412 are always kept in a precise alignment state.

[0064] During the continuous operation of the air spindle 1, the offset of the spindle 200 is acquired in real time, the deformation of the adjustment plate 4141 is dynamically adjusted, the axial thermal expansion of the spindle 200 is compensated in time, the stator 411 and the mover 412 are prevented from misaligning, the electromagnetic coupling efficiency of the motor assembly 400 is kept stable, and the spindle 200 can rotate continuously at high speed and high precision.

[0065] Furthermore, this application also provides a thinning machine having the aforementioned air spindle 1, which drives the thinning grinding wheel 2 to rotate for thinning the workpiece. Figure 7As shown, the air spindle 1 is mounted on the frame 3 of the thinning machine. A thinning grinding wheel 2 is fixedly connected to one end of the air spindle 1 that extends outside the housing 100. The thinning grinding wheel 2 is coaxially arranged with the spindle 200 and rotates synchronously with the spindle 200 at high speed. During the thinning process, the air spindle 1 is started, and the spindle 200 drives the thinning grinding wheel 2 to rotate at high speed. At the same time, the workpiece is fixed by the fixture of the thinning machine. The relative position of the workpiece and the thinning grinding wheel 2 is adjusted so that the thinning grinding wheel 2 contacts the surface of the workpiece. Through the high-speed rotation of the thinning grinding wheel 2, the workpiece is subjected to ultra-precision thinning.

[0066] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0067] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An air spindle, characterized in that, include: The housing (100) is cylindrical, and the interior of the housing (100) is hollow and has through ends; A main shaft (200) is at least partially disposed inside the housing (100), and the main shaft (200) is coaxially disposed with the housing (100); An air bearing (300) is disposed between the housing (100) and the main shaft (200), the air bearing (300) enabling the main shaft (200) to rotate about an axis relative to the housing (100); and A motor assembly (400) includes multiple motor units (410), each motor unit (410) being disposed between the housing (100) and the main shaft (200). Each group of motor units (410) includes: Stator (411), which is connected to the housing (100); A mover (412) is connected to the main shaft (200); The multiple sets of motor units (410) are spaced apart so that a heat dissipation space (420) is formed between two adjacent sets of motor units (410).

2. An air spindle according to claim 1, characterized in that, Multiple sets of the motor units (410) are arranged at equal intervals.

3. An air spindle according to claim 1, characterized in that, The motor assembly (400) also includes: Mounting plate (413) is arranged in a ring shape and is slidably connected to the inner wall of housing (100) along the length direction of main shaft (200); wherein, the stator (411) of each group of motor units (410) is fixedly connected to the mounting plate (413) so that the position of the stator (411) of each group of motor units (410) can be adjusted.

4. An air spindle according to claim 3, characterized in that, The motor assembly (400) also includes: A drive member (414) is connected to the housing (100) and acts on the mounting plate (413). The drive member (414) has at least one degree of freedom of movement along the length of the main shaft (200) to drive the mounting plate (413) to adjust the axial position of the stator (411).

5. An air spindle according to claim 4, characterized in that, The driving component (414) includes an adjusting plate (4141), which is fixedly connected between the housing (100) and the mounting plate (413), and one end face of the adjusting plate (4141) is fixedly connected to the axial end face of the mounting plate (413); the adjusting plate (4141) can generate axial thrust through axial thermal expansion or contraction deformation to drive and control the mounting plate (413) to move axially along the main shaft (200).

6. An air spindle according to claim 5, characterized in that, A first flow channel (415) is provided on the housing (100) at a position corresponding to the adjustment plate (4141). The first flow channel (415) is arranged in close contact with the outer peripheral wall of the adjustment plate (4141). The first flow channel (415) is used to allow the temperature control medium to flow through, so as to control the temperature of the adjustment plate (4141) by the temperature change of the temperature control medium, so as to cause the expansion or contraction deformation of the adjustment plate (4141) to form a first temperature control zone (4151) for adjusting the temperature of the adjustment plate (4141).

7. An air spindle according to claim 1, characterized in that, A second flow channel (416) is provided on the housing (100) at a position corresponding to the motor unit (410). The second flow channel (416) is used for the flow of cooling medium to reduce the temperature of the motor unit (410) and form a second temperature control zone (4161) for cooling the motor unit (410).

8. An air spindle according to claim 1, characterized in that, A third flow channel (417) is provided on the housing (100) at a position corresponding to the air bearing (300). The third flow channel (417) is used to allow cooling medium to flow to reduce the temperature of the air bearing (300) and form a third temperature control zone (4171) for cooling the air bearing (300).

9. A control method for an air spindle, applicable to the air spindle (1) as described in claim 5 or 6, comprising: Compressed air is introduced into the air bearing (300) to form a stable air film to suspend and support the main shaft (200). The stator (411) of the motor unit (410) is energized to generate a rotating magnetic field that drives the mover (412) to rotate the main shaft (200) around the axis. Obtain the offset of the spindle (200); Based on the offset, the deformation of the adjusting plate (4141) is controlled to generate an axial deformation that matches the axial offset. The adjusting plate (4141) generates an axial thrust through deformation to drive the mounting plate (413) to slide, thereby adjusting the axial position of the stator (411) so that the stator (411) and the mover (412) are aligned.

10. A thinning machine, characterized in that, The device has an air spindle (1) as described in any one of claims 1-8, the air spindle (1) being used to drive a thinning grinding wheel (2) to rotate for thinning of a workpiece.

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