A high-speed grinding wheel spindle structure

Abstract

This invention relates to a novel ultra-high-speed grinding wheel spindle structure, belonging to the field of precision machining technology. It includes a housing, a grinding wheel spindle, a bearing system, and a grinding wheel positioning mechanism. The bearing system integrates hydrostatic and dynamic bearings, and through a fixing sleeve, a preload spring, and a bearing sleeve, provides stable and reliable axial positioning and preload for the grinding wheel spindle. This system is unaffected by the thermal expansion and contraction of the grinding wheel spindle, effectively preventing axial seizure due to abnormal temperature rise. The grinding wheel positioning mechanism includes an elastic positioning sleeve, a clamping nut, and a fastening screw, enabling automatic centering of the ultra-hard grinding wheel during installation and fixing, resulting in a high-rigidity, high-coaxiality clamping effect. This invention improves the installation and positioning accuracy and reliability of the grinding wheel under ultra-high-speed operating conditions, ensuring the long-term stability and machining quality of the grinding wheel spindle.

Description

Technical Field

[0001] This invention relates to the field of precision machining technology, and in particular to a novel ultra-high-speed grinding wheel spindle structure. Background Technology

[0002] In modern manufacturing, with increasingly stringent requirements for the precision, surface quality, and processing efficiency of parts, ultra-high-speed grinding technology has become an important development direction in the field of precision and ultra-precision machining. Ultra-high-speed grinding processes, represented by cubic boron nitride (CBN) grinding wheels, are widely used in industries with stringent requirements for part quality, such as aerospace, high-performance automotive component manufacturing, and precision molds, due to their advantages of high grinding efficiency, stable machining accuracy, excellent workpiece surface quality, and good overall economic efficiency.

[0003] In existing technologies, when the linear velocity of the grinding wheel exceeds a certain value, in order to resist the huge centrifugal force and prevent the matrix from breaking and causing accidents, it is usually necessary to use special materials to manufacture the grinding wheel matrix and bond a layer of superhard abrasive to the matrix.

[0004] Under continuous ultra-high-speed operation, the heat dissipation problem of the spindle system is particularly prominent. At present, the industry generally adopts oil cooling to control the temperature rise of the spindle, that is, to forcibly remove the large amount of heat generated inside the spindle, especially in the bearing area, due to friction and aerodynamic effects by circulating cooling oil.

[0005] In response to the above, if the cooling system fails to cool the spindle in time during continuous ultra-high-speed operation, the spindle temperature will rise significantly, which will cause changes in the clearance between the spindle and the bearing, a decrease in lubrication and cooling performance, and accelerate bearing failure. In extreme cases, it may lead to a "spindle seizure" accident, in which the spindle and the bearing stick, wear, or even weld together due to overheating, causing the equipment to stop and seriously affecting the service life and operational reliability of the spindle. Summary of the Invention

[0006] To improve the operational reliability of ultra-high-speed grinding wheel spindles under high-speed operation, this invention provides an ultra-high-speed grinding wheel box spindle structure.

[0007] This invention provides a high-speed grinding wheel spindle structure, employing the following technical solution:

[0008] A high-speed grinding wheel spindle structure includes a housing, a grinding wheel spindle, and a bearing system. The grinding wheel spindle is rotatably mounted in the housing, and a first protrusion is provided at one end of the grinding wheel spindle near the grinding wheel mounting position. The bearing system includes a fixing sleeve, preload springs, locking screws, and a bearing sleeve. The fixing sleeve is fixedly mounted on the grinding wheel spindle by multiple locking screws, and the fixing sleeve is located at the end of the grinding wheel spindle away from the first protrusion. A second protrusion is provided on the bearing sleeve, and the bearing sleeve is coaxially slidably disposed on the grinding wheel spindle. Multiple preload springs are fixedly disposed between the fixing sleeve and the bearing sleeve. One end of each preload spring abuts against the second protrusion, and the other end abuts against the fixing sleeve.

[0009] Preferably, the bearing system further includes a ball bearing, the inner hole of which is fitted onto the grinding wheel spindle, and the outer circumferential surface of which is fitted into the inner hole of the bearing sleeve.

[0010] Preferably, the outer circumference of the grinding wheel spindle along the axial direction is provided with a positioning conical surface and a positioning end face in sequence; it also includes a grinding wheel positioning mechanism, which includes an elastic positioning sleeve, fastening screws and a clamping nut, wherein the inner hole of the elastic positioning sleeve is conical; the elastic positioning sleeve has multiple elastic openings in the circumferential direction, and the opening directions of two adjacent elastic openings are opposite; the clamping nut is threadedly connected to the grinding wheel spindle, one end of the clamping nut abuts against the elastic positioning sleeve, and the outer diameter of the elastic positioning sleeve abuts against the inner diameter of the grinding wheel; the multiple fastening screws are fixedly connected to the positioning end face of the grinding wheel spindle, and the grinding wheel is fixed on the grinding wheel spindle by the fastening screws.

[0011] Preferably, the bearing system further includes two hydrostatic bearings, which are arranged opposite to each other. The inner hole of one of the hydrostatic bearings is fitted onto the grinding wheel spindle, and its outer circumferential surface is fixedly connected to the inner wall of the housing. The inner hole of the other hydrostatic bearing is fitted onto the bearing sleeve, and its outer circumferential surface is fixedly connected to the inner wall of the housing. The oil passage in the hydrostatic bearing is connected to the oil supply system.

[0012] Preferably, a radial oil cavity is formed on the inner hole of the hydrostatic bearing, and an end face oil cavity is formed on one side end face of the hydrostatic bearing; one of the end face oil cavities of the hydrostatic bearing acts on the first protrusion, and the other end face oil cavity of the hydrostatic bearing acts on the second protrusion.

[0013] Preferably, the housing is also equipped with a plurality of first oil inlet pipes and a plurality of second oil inlet pipes, the first oil inlet pipes being connected to the radial oil cavity and the second oil inlet pipes being connected to the end face oil cavity; the inner hole of the hydrostatic bearing is also provided with an oil return cavity, and the first oil inlet pipes, the second oil inlet pipes and the oil return cavity are all connected to the oil supply system.

[0014] Preferably, a temperature control device is also connected to the oil line between the hydrostatic bearing and the oil supply system, and the temperature of the hydraulic oil in the oil supply system is controlled by the temperature control device.

[0015] Preferably, the housing is further provided with a drive mechanism, which includes a first pulley, a second pulley, a drive motor and a transmission belt. The first pulley is coaxially and fixedly connected to the grinding wheel spindle. The drive motor is fixedly mounted on the housing. The second pulley is fixedly mounted on the output shaft of the drive motor. The transmission belt is sleeved on the first pulley and the second pulley.

[0016] Preferably, the end of the grinding wheel spindle away from the first protrusion has a mounting conical surface, the inner hole of the first pulley is a conical hole, the first pulley is fixed to the grinding wheel spindle through the mounting conical surface, the inner hole of the first pulley has a disassembly cavity, and the end face of the first pulley has a plurality of oil passage holes, the oil passage holes communicating with the disassembly cavity.

[0017] Preferably, each of the housings is provided with an air inlet and a ventilation circuit, a sealing cover is fixedly installed on the housing, a ventilation groove is provided on the sealing cover, the air inlet and the ventilation circuit are connected to the ventilation groove, and a dustproof ring is installed on the sealing cover.

[0018] In summary, the present invention has at least one of the following beneficial technical effects:

[0019] 1. The bearing system can automatically compensate for the thermal expansion of the grinding wheel spindle and bearing system caused by high-speed operation, allowing the grinding wheel spindle to have a certain amount of axial expansion and contraction. This avoids the bearing axial clearance being too small or too large due to thermal expansion and contraction, preventing shaft seizure or loss of precision, and significantly improving thermal stability.

[0020] 2. Preload springs can provide continuous and stable axial preload to the bearing system, which can eliminate axial clearance error, suppress axial movement of the spindle, ensure the axial positioning accuracy of the spindle, and enhance the retention of axial stiffness and accuracy, making it almost unaffected by temperature changes.

[0021] 3. The inner conical hole of the elastic positioning sleeve and the conical surface at the left end of the grinding wheel spindle form a sliding fit. During the tightening of the clamping nut, the outer circle of the elastic positioning sleeve gradually expands as the inner hole wall slides to the right, and forms a tight fit with the inner hole of the grinding wheel. This makes the right end face of the grinding wheel and the positioning end face of the grinding wheel on the grinding wheel spindle fit tightly together. At this time, the end face and the inner hole provide common support, which greatly enhances the connection rigidity of the grinding wheel. Moreover, this structure can be repeatedly disassembled and reinstalled with high accuracy.

[0022] 4. The elastic positioning sleeve improves the centering accuracy of the grinding wheel installation, which greatly reduces the eccentricity and error of the grinding wheel installation. This not only reduces the vibration caused by the eccentricity of the installation, but also greatly reduces the amount of dressing required for the grinding wheel abrasive layer before it is put into use. To a certain extent, this reduces the wear of the abrasive layer, saves costs, and reduces the time for correction and adjustment.

[0023] 5. Utilize the gap between the bearing sleeve and the fixed sleeve to maintain elastic support under the action of the preload spring; when the grinding wheel is subjected to a large axial force, see the instruction manual appendix. Figure 1 As shown, if the axial force is to the left, causing the grinding wheel spindle to shift axially to the left by a certain amount, the gap can continue to be compressed. During this process, a greater reverse resistance will be generated, which also provides the spindle system with more time to make necessary adjustments, achieve the effect of active protection, and further enhance the reliability of the bearing system. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A schematic diagram of the structure of part A;

[0026] Figure 3 yes Figure 2 A schematic diagram of the upper and middle sections;

[0027] Figure 4 yes Figure 2 A schematic diagram of the lower half of the structure;

[0028] Figure 5 yes Figure 1 A structural diagram of section B;

[0029] Figure 6 This is a schematic diagram of the structure of the grinding wheel spindle and the grinding wheel according to an embodiment of the present invention;

[0030] Figure 7 It is a cross-sectional and three-dimensional structural diagram of the elastic positioning sleeve;

[0031] Figure 8 This is a schematic diagram of the structure of the ball bearing and the retaining sleeve in an embodiment of the present invention;

[0032] Figure 9 This is a schematic diagram of the bearing sleeve according to an embodiment of the present invention;

[0033] Figure 10 This is a schematic diagram of the connection status of the oil supply system according to an embodiment of the present invention;

[0034] Figure 11 This is a schematic diagram of an embodiment of the present invention with the addition of a fully automatic balancer and a belt protection cover.

[0035] Explanation of reference numerals in the attached drawings: 100, housing; 110, housing cover; 200, grinding wheel spindle; 210, first protrusion; 220, positioning cone surface; 230, positioning end face; 300, grinding wheel positioning mechanism; 310, elastic positioning sleeve; 320, fastening screw; 330, clamping nut; 340, elastic opening; 350, disassembly screw; 400, bearing system; 410, hydrostatic bearing; 421, radial oil chamber; 422, end face oil chamber; 423, first oil inlet pipe; 424, second oil inlet pipe; 425, oil return chamber; 430, oil supply system; 431, thermostatic device; 43 2. Oil supply pipe; 440. Dense ball bearing; 450. Fixing sleeve; 460. Preload spring; 470. Bearing sleeve; 471. Second protrusion; 480. Locking screw; 500. Drive mechanism; 510. First pulley; 520. Second pulley; 530. Drive motor; 540. Transmission belt; 560. Mounting cone; 570. Discharge chamber; 580. Oil passage hole; 600. Grinding wheel; 710. Air inlet; 720. Ventilation circuit; 730. Ventilation groove; 740. Dustproof ring; 750. Sealing cover; 800. Fully automatic balancer; 900. Belt protection cover. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1 To be continued Figure 11 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0038] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electromagnetic connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0041] This invention discloses a high-speed grinding wheel spindle structure. (Refer to...) Figures 1 to 11 A high-speed grinding wheel spindle structure mainly includes a housing 100, a grinding wheel spindle 200, and a bearing system 400. The grinding wheel spindle 200 is rotatably installed inside the housing 100, and a first protrusion 210 is provided at one end of the grinding wheel spindle 200 near the installation position of the grinding wheel 600. The bearing system 400 includes a fixing sleeve 450, a preload spring 460, a locking screw 480, and a bearing sleeve 470. The fixing sleeve 450 is fixedly installed on the grinding wheel spindle 200 by multiple locking screws 480. The fixing sleeve 450 is located on the grinding wheel spindle. 200 is located away from the end of the first protrusion 210; a second protrusion 471 is provided on the bearing sleeve 470, and the bearing sleeve 470 is slidably disposed on the grinding wheel spindle 200 on the same axis. The bearing sleeve 470 can slide slightly along the axial direction of the grinding wheel spindle 200; a plurality of preload springs 460 are fixedly disposed between the fixed sleeve 450 and the bearing sleeve 470, one end of the preload spring 460 abuts against the second protrusion 471, and the other end of the preload spring 460 abuts against the fixed sleeve 450. A cover 110 is fixedly installed on the upper end of the housing 100.

[0042] The preload spring 460 automatically compensates for the thermal expansion difference between the grinding wheel spindle 200 and the bearing system 400 caused by high-speed operation, allowing the grinding wheel spindle 200 to allow a certain amount of axial displacement. This prevents excessive axial clearance in the bearings due to thermal expansion, avoids bearing seizure accidents, maintains a certain level of rotational accuracy, and improves thermal stability. The preload spring 460 provides a stable and automatically compensated axial preload force, effectively suppressing excessive axial movement of the spindle and improving axial stiffness and rotational accuracy. The elastic preload method reduces hard impacts and stress concentration, protects precision bearing components, extends the service life of the entire bearing system 400, and improves the operational reliability of the ultra-high-speed grinding wheel spindle 200 under high-speed operation.

[0043] When the fixed sleeve 450 is fixed to the grinding wheel spindle 200 by the locking screws 480, the multiple circumferentially distributed locking screws 480 abut against the grinding wheel spindle 200, causing the fixed sleeve 450 to undergo an elastic deformation of approximately a regular polygon. After deformation, a circumferentially encircling fastening effect is achieved, firmly fixing the fixed sleeve 450 and the grinding wheel spindle 200 together. When all the locking screws 480 are loosened, the elastic deformation is restored, and the inner hole of the fixed sleeve 450 forms a gap of 0.01 to 0.02 mm with the grinding wheel spindle 200, allowing for axial movement and facilitating the assembly and adjustment of the fixed sleeve 450.

[0044] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 8 In some embodiments, the bearing system 400 further includes a ball bearing 440, the inner bore of which is fitted onto the grinding wheel spindle 200, and the outer circumference of which is fitted into a bearing sleeve 470. The ball bearing 440 includes, but is not limited to, having hundreds of precision steel balls of uniform diameter. These steel balls are evenly and regularly spaced within a copper sleeve, which has hundreds of small holes. Each hole is slightly smaller at the bottom, just large enough to accommodate a steel ball without it passing through. The steel ball can roll within these holes, and the even pressure on the outer edges of the holes prevents the steel ball from falling out.

[0045] The inner bore of the bearing sleeve 470 is precision ground to create a uniform gap between it and the right side diameter of the grinding wheel spindle 200. This gap is precisely designed to accommodate a set of ball bearings 440. The actual installation process requires a minute elastic deformation, typically 2 to 4 micrometers. The elastic deformation of hundreds of steel balls eliminates the gap between the grinding wheel spindle 200 and the bearing sleeve 470, creating a degree of interference fit for better stable support. During axial displacement, the steel balls in the ball bearing 440 roll, allowing the bearing sleeve 470 to move axially on the grinding wheel spindle 200 with virtually no clearance. This displacement typically does not exceed 1 millimeter. The rotation amplitude of the steel balls in the ball bearing 440 is very small, and with hundreds of steel balls supporting and rolling together, the axial displacement is extremely smooth and precise, resulting in a very long lifespan for the ball bearing 440.

[0046] The preload spring 460 provides a continuous and stable axial preload, improving the axial stiffness and accuracy retention of the grinding wheel spindle 200. It compensates for the thermal expansion of the grinding wheel spindle 200 due to temperature rise, preventing bearing seizure caused by thermal stress, and also further absorbs axial vibration.

[0047] Reference Figure 5 , Figure 6 and Figure 7 In some embodiments, a positioning conical surface 220 and a positioning end face 230 are sequentially formed on the outer periphery of the grinding wheel spindle 200 along the axial direction; it also includes a grinding wheel positioning mechanism 300, which includes an elastic positioning sleeve 310, a fastening screw 320 and a clamping nut 330. The inner hole of the elastic positioning sleeve 310 is a tapered hole, which is taper-fitted with the positioning conical surface 220; along the circumference of the elastic positioning sleeve 310, multiple [features are provided on the elastic positioning sleeve 310]. Each grinding wheel 600 has a flexible opening 340, with adjacent openings facing opposite directions. A clamping nut 330 is threadedly connected to the left end of the grinding wheel spindle 200, with one end of the clamping nut 330 abutting against an elastic positioning sleeve 310. The outer diameter of the elastic positioning sleeve 310 abuts against the inner diameter of the grinding wheel 600. Multiple fastening screws 320 are fixedly connected to threaded holes on the positioning end face 230 of the grinding wheel spindle 200, thus securing the grinding wheel 600 to the grinding wheel spindle 200. The number of flexible openings 340 can be adjusted according to working conditions.

[0048] The abrasive layer of grinding wheels 600 commonly uses cubic boron nitride or diamond. Due to the huge energy consumption, high equipment investment, and extremely high technical threshold in their manufacturing process, the raw material cost is much higher than that of traditional abrasives such as corundum and silicon carbide, resulting in high costs. Usually, after installing a grinding wheel 600, the abrasive layer needs to be corrected and adjusted before it can be put into production.

[0049] When installing the grinding wheel 600, the clamping nut 330 is gradually tightened onto the grinding wheel spindle 200 using the thread. The clamping nut 330 at one end of the grinding wheel spindle 200 gradually compresses the elastic positioning sleeve 310. The tapered inner hole of the elastic positioning sleeve 310 and the tapered surface at the left end of the grinding wheel spindle 200 form a sliding fit. As it is tightened, the outer diameter of the elastic positioning sleeve 310 gradually expands under the action of the tapered surface until it fits tightly against the inner hole of the grinding wheel 600, forming an interference fit. This completes the automatic centering of the grinding wheel 600. Then, the multiple fastening screws 320 on the end face of the grinding wheel 600 are tightened, so that the right end face of the grinding wheel 600 and the positioning end face 230 of the grinding wheel 600 on the grinding wheel spindle 200 fit tightly. At this time, the end face and the inner hole are supported together, which greatly enhances the connection rigidity of the grinding wheel 600. Moreover, this structure can be repeatedly disassembled and reinstalled with high accuracy.

[0050] The above installation process greatly improves the centering accuracy of the grinding wheel 600, significantly reducing the eccentricity and error of the grinding wheel 600 installation. This not only reduces the vibration caused by the eccentricity of the installation, but also greatly reduces the amount of dressing required for the abrasive layer, thus significantly reducing the wear of the abrasive layer, saving equipment operating costs, improving the rotational accuracy of the grinding wheel 600 and the utilization rate of the abrasive layer, saving the correction and debugging time in the early stage of use, and also helping to improve work efficiency.

[0051] When disassembling the grinding wheel 600, first loosen the clamping nut 330 and simultaneously loosen the symmetrical fastening screws 320. Then, remove two of the fastening screws 320 and screw in the disassembly screws 350 into the corresponding holes, making the head of the disassembly screw 350 abut against the positioning end face 230. Continue screwing in the disassembly screws 350. Under the action of the clamping force, the elastic positioning sleeve 310, which is interference-fitted with the inner diameter of the grinding wheel 600, moves in the disassembly direction using the inner diameter of the grinding wheel 600. This causes the elastic positioning sleeve 310 to finally disengage from the positioning cone surface 220. After the grinding wheel 600 disengages from the positioning end face 230 of the grinding wheel spindle 200, finally remove all the fastening screws 320 to complete the disassembly of the grinding wheel 600. This process ensures the safety and controllability of the disassembly process and maintains the reference accuracy for repeated installation of the grinding wheel spindle 200 and the grinding wheel 600.

[0052] Reference Figures 1 to 5 In some embodiments, the bearing system 400 further includes two hydrostatic bearings 410, which are arranged opposite to each other. The inner hole of one hydrostatic bearing 410 is fitted onto the grinding wheel spindle 200, and its outer circumferential surface is fixedly connected to the inner wall of the housing 100. The inner hole of the other hydrostatic bearing 410 is fitted onto the bearing sleeve 470, and its outer circumferential surface is fixedly connected to the inner wall of the housing 100. The oil passage in the hydrostatic bearing 410 is connected to the oil supply system 430.

[0053] The outer diameter of the bearing sleeve 470 is the same as the outer diameter of the first protrusion 210 of the grinding wheel spindle 200. The bearing sleeve 470 and the hydrostatic bearing 410 at the right end of the housing 100 form a fluid sliding fit. When the hydrostatic bearing 410 rotates at high speed, it supports the grinding wheel spindle 200 by the hydrostatic oil film formed.

[0054] Reference Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 9 In some embodiments, a radial oil cavity 421 is provided on the inner hole of the hydrostatic bearing 410, and an end face oil cavity 422 is provided on one end face of the hydrostatic bearing 410; wherein the end face oil cavity 422 of the hydrostatic bearing 410 on the left side of the grinding wheel spindle 200 acts on the first protrusion 210, and the end face oil cavity 422 of the hydrostatic bearing 410 on the right side of the grinding wheel spindle 200 acts on the second protrusion 471, and a hydrostatic oil film is formed between the end face oil cavity 422 and the first protrusion 210 and the second protrusion 471 respectively.

[0055] The end-face oil chambers 422 on the two hydrostatic bearings 410 located on the left and right sides of the grinding wheel spindle 200 are filled with hydraulic oil, forming a stable supporting oil film to provide stable load-bearing capacity. When the grinding wheel 600 is subjected to a rightward axial grinding force, and the grinding wheel spindle 200 shifts axially to the right, the first protrusion 210 of the grinding wheel spindle 200 interacts with the end-face oil chambers 422 on the hydrostatic bearings 410, causing the oil film pressure at that location to increase, thereby limiting the rightward axial shift of the grinding wheel spindle 200. Similarly, when the grinding wheel spindle 200 shifts axially to the left, in addition to causing an increase in the oil film pressure in the right-side end-face oil chamber 422, limiting the axial shift of the bearing sleeve 470, the gap between the second protrusion 471 of the bearing sleeve 470 and the fixed sleeve 450 will decrease, and the preload spring 460 will be further compressed, thereby providing stronger axial support; ensuring the stability and rigidity of the grinding wheel spindle 200.

[0056] Reference Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 10 In some embodiments, the housing 100 is also equipped with a plurality of first oil inlet pipes 423 and a plurality of second oil inlet pipes 424. The first oil inlet pipes 423 are connected to the radial oil cavity 421, and the second oil inlet pipes 424 are connected to the end face oil cavity 422. The inner hole of the hydrostatic bearing 410 is also provided with an oil return cavity 425, which is connected to the oil supply system 430 through an oil return pipe. The first oil inlet pipes 423 and the second oil inlet pipes 424 are connected to the oil supply system 430 through an oil supply pipe 432.

[0057] Using an external oil supply system 430, hydraulic oil is input into the first oil inlet pipe 423 and the second oil inlet pipe 424, ensuring that the end face oil chamber 422 is continuously and stably filled with hydraulic oil. The independent oil inlet path ensures sufficient oil supply and stable pressure in the end face oil chamber 422; the design of the return oil chamber 425 ensures smooth return of hydraulic oil.

[0058] Reference Figure 10 In some embodiments, a temperature control device 431 is also connected to the oil supply line between the hydrostatic bearing 410 and the oil supply system 430 via an oil supply pipe 432. The temperature control device 431 contains an oil temperature regulating mechanism and an oil filtration mechanism. The temperature control device 431 regulates the temperature of the spindle oil pumped into the grinding wheel spindle 200 by the oil supply system 430. The temperature control device 431 actively controls the lubricating oil temperature within the optimal range, solving the heat generation problem at ultra-high speeds, minimizing the impact of thermal deformation on machining accuracy, and filtering impurities in the oil.

[0059] Reference Figures 1 to 4 In some embodiments, the housing 100 is further provided with a drive mechanism 500, which includes a first pulley 510, a second pulley 520, a drive motor 530, and a transmission belt 540. The first pulley 510 is coaxially and fixedly connected to the grinding wheel spindle 200. The drive motor 530 is fixedly mounted on the housing 100, and the second pulley 520 is fixedly mounted on the output shaft of the drive motor 530. The transmission belt 540 is sleeved on the first pulley 510 and the second pulley 520 to form a transmission connection. The diameter of the second pulley 520 may be larger than the diameter of the first pulley 510.

[0060] The drive motor 530 drives the second pulley 520 to rotate, which in turn drives the first pulley 510 to rotate via the transmission belt 540. The first pulley 510 drives the grinding wheel spindle 200 to rotate. This structure can also be equipped with a belt unloading device to avoid the problem of the grinding wheel spindle 200 being deflected or skewed after being subjected to force due to the tension of the transmission belt 540, thereby improving the rotational accuracy of the grinding wheel spindle 200.

[0061] The drive motor 530 can be a permanent magnet synchronous motor, or driven by an electric spindle, or replaced by another external power source to drive the grinding wheel spindle 200 to rotate. The output shaft of the drive motor 530 can have a tapered structure, and a second pulley 520 is mounted on the output shaft. The inner bore of the output shaft pulley and the second pulley 520 are tapered and, after being tightened with screws, form a rotating body with uniform mass. The diameter of the second pulley 520 is different from that of the first pulley 510, thus allowing the motor speed to be adjusted via belt drive. This can increase the output torque of the drive motor 530 by reducing speed, or decrease the speed of the drive motor 530 by increasing speed, which helps extend the life of the bearings inside the drive motor 530. Furthermore, the belt drive prevents vibrations generated during the operation of the drive motor 530 from being transmitted to the grinding wheel spindle 200. Reduced vibration contributes to the smooth rotation of the grinding wheel spindle 200 and extends bearing life, further enhancing the stability of the invention.

[0062] Reference Figure 2 , Figure 3 , Figure 4 and Figure 6 In some embodiments, the end of the grinding wheel spindle 200 away from the first protrusion 210 has a mounting conical surface 560. The inner hole of the first pulley 510 is a tapered hole. The first pulley 510 is fixed to the grinding wheel spindle 200 through the mounting conical surface 560 in its inner hole, forming a tapered fit. A disassembly cavity 570 is formed in the inner hole of the first pulley 510. At least one oil passage hole 580 is formed on the end face of the first pulley 510, and the oil passage hole 580 communicates with the disassembly cavity 570. The first pulley 510 is fixed to the grinding wheel spindle 200 by the tapered fit of the mounting conical surface 560. The tapered fit ensures a very high coaxiality between the first pulley 510 and the grinding wheel spindle 200. A hydraulic device is connected to the oil passage 580 to introduce high-pressure hydraulic oil into the unloading cavity 570, so that the first pulley 510 can be easily disengaged from the mounting cone surface 560, which facilitates disassembly and solves the problem of difficult disassembly of interference fit or cone fit parts, making maintenance and replacement easier.

[0063] Reference Figure 5In some embodiments, the housing 100 is provided with an air inlet 710 and a ventilation circuit 720. A sealing cover 750 is fixedly installed on the housing 100, and a ventilation groove 730 is provided on the sealing cover 750. The air inlet 710 and the ventilation circuit 720 are connected to the ventilation groove 730. A dustproof ring 740 is installed on the sealing cover 750. The processed compressed gas enters the ventilation groove 730 through the air inlet 710 and the ventilation circuit 720, making the air pressure there greater than the external atmospheric pressure. This effectively prevents oil leakage from inside the grinding wheel spindle 200 or external contaminants from being sucked into the housing 100. The ventilation groove 730 and the dustproof ring 740 together constitute an effective sealing and dustproof system, which can prevent extremely fine abrasive particles and dust generated during grinding from entering the precision bearing area, protecting the bearing system 400 and the grinding wheel spindle 200, and ensuring the long-term accuracy and life of the grinding wheel spindle 200.

[0064] Reference Figure 11 In some embodiments, a fully automatic balancing device 800 is fixedly mounted on the right end of the grinding wheel spindle 200. The fully automatic balancing device 800 can detect and compensate for imbalances in the grinding wheel spindle 200 and the grinding wheel 600 caused by uneven mass, installation errors, or wear in real time. It automatically and continuously corrects imbalances within the speed range, always suppressing vibration to a minimum. This ensures machining accuracy and surface quality at ultra-high speeds and significantly extends the service life of key components such as the bearing system 400 and the grinding wheel spindle 200.

[0065] Reference Figure 11 In some embodiments, a belt guard 900 is also fixedly installed on the housing 100. The belt guard 900 effectively isolates the high-speed rotating transmission belt 540, eliminating the risk of operators coming into contact with transmission components, and complies with safety production regulations. It prevents external debris from being drawn into the transmission system, avoiding equipment downtime or damage accidents caused by it, and ensuring the continuity and stability of production.

[0066] The implementation principle of the ultra-high-speed grinding wheel box spindle structure of this invention is as follows:

[0067] The bearing system 400 integrates hydrostatic and hydrodynamic bearings 410, and through a fixed sleeve 450, a preload spring 460, and a bearing sleeve 470, provides stable axial positioning and preload for the high-speed grinding wheel spindle 200. This automatically compensates for the thermal expansion difference between the grinding wheel spindle 200 and the bearing system 400 caused by high-speed operation, enabling the grinding wheel spindle 200 to have axial self-adjustment capability. This effectively prevents the grinding wheel spindle 200 from axially seizing due to abnormal temperature rise, ensuring smooth operation of the bearing system 400. The grinding wheel positioning mechanism 300 uses an elastic positioning sleeve 310, combined with a clamping nut 330 and a fastening screw 320, to achieve automatic centering of the superhard grinding wheel 600 during installation and fixing, forming a high-rigidity, high-coaxiality clamping effect.

[0068] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A super-speed grinding wheel box spindle structure, characterized in that: The application relates to a grinding wheel positioning device, which comprises a box body (100), a grinding wheel spindle (200) and a bearing system (400), wherein the grinding wheel spindle (200) is rotatably arranged in the box body (100), and the grinding wheel spindle (200) is provided with a first protruding part (210) at one end close to the installation position of a grinding wheel (600); the bearing system (400) comprises a fixing sleeve (450), pre-tightening springs (460), locking screws (480) and a bearing sleeve (470), the fixing sleeve (450) is fixedly arranged on the grinding wheel spindle (200) through the locking screws (480), and the fixing sleeve (450) is located at one end of the grinding wheel spindle (200) away from the first protruding part (210); the bearing sleeve (470) is provided with a second protruding part (471) and is coaxially and slidably arranged on the grinding wheel spindle (200), and the pre-tightening springs (460) are fixedly arranged between the fixing sleeve (450) and the bearing sleeve (470); one end of the pre-tightening spring (460) is in abutment with the second protruding part (471), and the other end is in abutment with the fixing sleeve (450); the bearing system (400) further comprises two dynamic and static pressure bearings (410), the two dynamic and static pressure bearings (410) are oppositely arranged, the inner hole of one of the dynamic and static pressure bearings (410) is sleeved on the grinding wheel spindle (200), the outer circumferential surface of the dynamic and static pressure bearing (410) is fixedly connected with the inner wall of the box body (100), the inner hole of the other dynamic and static pressure bearing (410) is sleeved on the bearing sleeve (470), and the outer circumferential surface of the dynamic and static pressure bearing (410) is fixedly connected with the inner wall of the box body (100); the oil channel in the dynamic and static pressure bearing (410) is communicated with an oil supply system (430); the inner hole of the dynamic and static pressure bearing (410) is provided with a radial oil cavity (421), and the end surface of the dynamic and static pressure bearing (410) is provided with an end surface oil cavity (422); the end surface oil cavity (422) of one of the dynamic and static pressure bearings (410) acts on the first protruding part (210), and the end surface oil cavity (422) of the other dynamic and static pressure bearing (410) acts on the second protruding part (471); the bearing system (400) further comprises a tight-pear bearing (440), the inner hole of the tight-pear bearing (440) is sleeved on the grinding wheel spindle (200), and the outer circumferential surface of the tight-pear bearing (440) is sleeved in the inner hole of the bearing sleeve (470). The outer circumferential surface of the grinding wheel spindle (200) in the axial direction is sequentially provided with a positioning conical surface (220) and a positioning end surface (230); the grinding wheel positioning device (300) comprises an elastic positioning sleeve (310), a fastening screw (320) and a pressing nut (330), and the inner hole of the elastic positioning sleeve (310) is conical; a plurality of elastic openings (340) are formed in the circumferential surface of the elastic positioning sleeve (310), and the opening directions of two adjacent elastic openings (340) are opposite. ​ ​ ​ ​ ​ 2. The ultra-high speed grinding wheel cartridge spindle structure of claim 1, wherein: ​ ​ ​ The compression nut (330) is in threaded connection with the grinding wheel spindle (200), one end of the compression nut (330) is in abutment with the elastic positioning sleeve (310), and the outer diameter of the elastic positioning sleeve (310) is in abutment with the inner diameter of the grinding wheel (600); A plurality of the fastening screws (320) are fixedly connected with the positioning end face (230) of the grinding wheel spindle (200), and the grinding wheel (600) is fixed on the grinding wheel spindle (200) through the fastening screws (320).

3. The ultra-high speed grinding wheel cartridge spindle structure of claim 1, wherein: A plurality of first oil inlet pipes (423) and a plurality of second oil inlet pipes (424) are further installed on the box body (100), the first oil inlet pipes (423) are in communication with the radial oil cavity (421), and the second oil inlet pipes (424) are in communication with the end face oil cavity (422); an oil return cavity (425) is further formed in the inner hole of the dynamic-static pressure bearing (410), and the first oil inlet pipes (423), the second oil inlet pipes (424) and the oil return cavity (425) are all in communication with the oil supply system (430).

4. The ultra-high speed grinding wheel cartridge spindle structure of claim 3, wherein: A constant temperature device (431) is further connected to the oil circuit between the dynamic-static pressure bearing (410) and the oil supply system (430), and the constant temperature device (431) is used for temperature regulation and control of the hydraulic oil of the oil supply system (430).

5. The ultra-high speed grinding wheel cartridge spindle structure according to any one of claims 1-4, characterized in that: A driving mechanism (500) is further arranged on the box body (100), the driving mechanism (500) comprises a first belt pulley (510), a second belt pulley (520), a driving motor (530) and a transmission belt (540), the first belt pulley (510) is coaxially fixedly connected with the grinding wheel spindle (200), the driving motor (530) is fixedly installed on the box body (100), the second belt pulley (520) is fixedly installed on the output shaft of the driving motor (530), and the transmission belt (540) is sleeved on the first belt pulley (510) and the second belt pulley (520).

6. The ultra-high speed grinding wheel cartridge spindle structure of claim 5, wherein: A mounting taper surface (560) is formed at one end of the grinding wheel spindle (200) away from the first protruding portion (210), the inner hole of the first belt pulley (510) is a taper hole, the first belt pulley (510) is fixed with the grinding wheel spindle (200) through the mounting taper surface (560), a dismounting cavity (570) is formed in the inner hole of the first belt pulley (510), a plurality of oil through holes (580) are formed in the end face of the first belt pulley (510), and the oil through holes (580) are in communication with the dismounting cavity (570).

7. The ultra-high speed grinding wheel cartridge spindle structure of claim 2, wherein: An air inlet (710) and an air circulation loop (720) are formed on the box body (100), a sealing cover (750) is fixedly installed on the box body (100), an air vent groove (730) is formed on the sealing cover (750), the air inlet (710) and the air circulation loop (720) are in communication with the air vent groove (730), and a dustproof ring (740) is installed on the sealing cover (750).

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