A gear cutting machine tool and tool electric spindle

Abstract

This invention relates to the field of machine tool processing technology, specifically to a gear-removing machine tool cutting tool and its electric spindle. The tool includes an electric spindle body, within which a rotary support module, a drive module, and a tool changing module are disposed. The rotary support module includes a rotary groove formed within the electric spindle body, a rotary sleeve rotatably connected within the rotary groove, and an air bearing disposed between the rotary sleeve and the inner wall of the rotary groove. The rotary sleeve is circumferentially arranged with several pneumatic displacement components, which generate displacement based on the air film pressure fluctuations generated by the air bearing on the rotary sleeve during tool processing. The invention also includes a monitoring mechanism and an alarm mechanism. The monitoring mechanism responds to the displacements generated by the pneumatic displacement components in various directions and performs displacement difference processing to obtain the displacement difference. The alarm mechanism triggers an alarm when the displacement difference exceeds a threshold. This invention enables real-time monitoring of the tool's operating status during gear-removing machining.

Description

Technical Field

[0001] This invention relates to the field of machine tool processing technology, specifically to a gear-grinding machine tool cutting tool and a tool electric spindle. Background Technology

[0002] Gear reaming, as a highly efficient gear finishing process, is particularly suitable for machining internal gears, double gears, and gears with shoulders. This process achieves precise tooth surface shaping through continuous axial relative motion and synchronous meshing between the tool and the workpiece. The reaming tool and its drive unit—the tool electric spindle—are the core components of the machine tool, directly affecting machining quality, efficiency, and cost. The cutting performance and geometric accuracy of the tool, as well as the dynamic characteristics of the spindle (such as speed, stiffness, and rotational accuracy), collectively determine the process outcome.

[0003] Currently, cutting tools are mostly made of high-performance cemented carbide or coated materials, which are complex in structure, require high precision, and are expensive; the electric spindle of the tool needs to have high speed, high rigidity, high precision and good thermal stability to ensure the reliable execution of cutting motion.

[0004] However, existing technologies have significant shortcomings in monitoring and managing tool wear, which has become a key bottleneck restricting process optimization, machining stability, and cost control. The industry generally relies on empirical methods based on the cumulative number of machining operations for wear assessment: that is, setting a fixed "safe machining quantity" threshold for specific machining conditions based on historical experience, and forcibly replacing or regrinding the tool when the threshold is reached.

[0005] This method ignores the actual impact of various dynamic factors on tool wear, such as batch differences in workpiece materials (hardness, microstructure, etc.); real-time fluctuations in cutting parameters; changes in cooling and lubrication conditions; and manufacturing variability of the tool itself. This leads to tools being replaced prematurely while still within their usable lifespan, resulting in waste and increased costs, or tools becoming excessively worn before reaching a predetermined quantity, causing defects such as decreased tooth surface quality, chatter marks, or burns, and triggering the risk of batch scrapping. Furthermore, quantity-based management is a retrospective judgment and cannot achieve real-time status monitoring during processing. Therefore, it cannot adaptively adjust the process based on wear conditions and is difficult to prevent quality problems. Traditional gear-removing machine tool electric spindle designs mainly focus on power transmission and motion accuracy, lacking the ability to acquire wear-related information in real time, making online monitoring technology difficult to implement.

[0006] Given the shortcomings of existing technologies, there is an urgent need for a new type of gear cutting machine tool and tool electric spindle that can achieve more precise tool status management and ensure machining quality. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a gear-removing machine tool cutting tool and a tool electric spindle, which enables real-time monitoring of the tool's operating status during gear-removing machining.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows: an electric spindle for a gear-removing machine tool, comprising an electric spindle body, wherein a rotary support module, a drive module, and a tool changing module are disposed within the electric spindle body; the rotary support module is used to reduce the rotational resistance between the tool and the electric spindle body during tool rotation; the tool changing module is used to mount the tool; and the drive module is used to drive the tool to rotate.

[0009] The rotary support module includes a rotary groove opened inside the electric spindle body, a rotary sleeve rotatably connected inside the rotary groove, and an air bearing disposed between the rotary sleeve and the inner wall of the rotary groove; the rotary sleeve is circumferentially provided with several pneumatic displacement components, which are used to generate displacement based on the air film pressure fluctuation generated by the air bearing on the rotary sleeve during tool machining.

[0010] It also includes a monitoring mechanism and an alarm mechanism. The monitoring mechanism is used to respond to the displacement generated by the air pressure displacement component in each direction and to perform displacement difference elimination processing to obtain the displacement difference. The alarm mechanism is used to trigger an alarm when the displacement difference exceeds a threshold.

[0011] The technical principles of the above solution are as follows:

[0012] In gear cutting, multiple cutting teeth of the tool sequentially cut into the workpiece. When all cutting teeth are in good condition and evenly worn, the cutting force generated by each cutting tooth and the resulting micro-vibration of the tool should theoretically be periodic, consistent, and relatively balanced in all directions. This vibration is transmitted through the tool holder and tool changer to the rotating sleeve that is directly or indirectly connected to it.

[0013] The rotating sleeve is supported and suspended by air bearings. The air bearings form an extremely thin and pressure-stable air film between the rotating sleeve and the spindle body (inner wall of the rotating groove). When the rotating sleeve, carrying the tool vibration signal, experiences a slight vibration, it disturbs the uniformity and pressure distribution of the surrounding air film, generating air film pressure fluctuations at the corresponding radial positions. These minute pressure fluctuations are sensitively captured by the circumferentially distributed pneumatic displacement components and converted into measurable mechanical displacements. The extremely high sensitivity of the air bearings to micro-vibrations allows the weak tool vibration signals to be effectively converted and amplified into a detectable physical quantity (displacement).

[0014] The monitoring agency collects displacement signals generated by all pneumatic displacement components in real time. If the tool wear is uniform or in good condition, its vibration is symmetrical in all directions. By comparing and canceling the displacement differences in each direction (elimination), the final displacement difference is close to zero or fluctuates within a very small baseline range.

[0015] When individual or partial cutting teeth experience abnormal wear, chipping, or manufacturing defects, the cutting force undergoes abrupt changes or imbalances, leading to a change in the tool vibration mode and generating significant radial unbalanced forces or abnormal vibrations in a specific direction. This asymmetrical vibration is transmitted to the rotating sleeve, disrupting the uniformity of the gas film pressure fluctuations. This causes the gas pressure displacement component corresponding to the abnormal vibration direction to generate a displacement signal significantly different from other directions. At this point, error correction processing cannot completely cancel out this difference in signal, resulting in a significant displacement difference.

[0016] A preset displacement difference threshold is established to reflect the tool's health status. When the real-time displacement difference continuously or momentarily exceeds this threshold, an alarm mechanism is triggered, issuing a warning or alarm signal. This alerts the operator or CNC system that the tool may have experienced uneven wear, damage, or other abnormalities, requiring timely inspection, process adjustment, or tool replacement.

[0017] The above approach has the following beneficial effects:

[0018] 1. This solution completely changes the traditional management model that relies on fixed machining quantities and post-processing judgment. It can dynamically sense changes in tool condition during machining, enabling early detection and warning of abnormal wear, and providing the possibility for preventive maintenance and adaptive process adjustment.

[0019] 2. This solution uses physical signals reflecting the actual working state of the cutting tool to determine its performance, avoiding the drawbacks of setting a fixed lifespan based solely on experience. It maximizes the effective lifespan of the cutting tool, prevents waste caused by premature replacement, and eliminates batch quality incidents resulting from overuse, significantly reducing cutting tool usage costs and product scrap rates.

[0020] 3. This solution enables real-time monitoring to promptly detect and warn of unstable factors in the cutting process caused by the deterioration of the tool condition, thereby intervening before defects such as vibration marks and burns appear on the tooth surface, ensuring the quality stability and consistency of the entire machining batch.

[0021] 4. This solution cleverly utilizes the air bearing inherent in the electric spindle and its high sensitivity to micro-vibrations as part of the sensor, eliminating the need to install complex direct measurement devices (such as strain gauges or acoustic emission sensors) in the narrow cutting area or on the high-speed rotating tool holder, thus solving the installation difficulties and signal transmission problems.

[0022] Furthermore, the pneumatic displacement assembly includes a transmission groove formed within the rotating sleeve. One end of the transmission groove is connected to the outside of the rotating sleeve, and the other end is connected to a displacement groove. A pneumatic plate is slidably fitted within the displacement groove. A first spring is provided between the pneumatic plate and the inner wall of the displacement groove, and the first spring is used to support the pneumatic plate in resetting. A first Tesla valve and a second Tesla valve are also connected to the side wall of the displacement groove. The other end of the first Tesla valve is connected to the outside of the rotating sleeve, and the other end of the second Tesla valve is connected to the inside of the rotating sleeve. The first Tesla valve is used to allow only the gas in the air film to enter the displacement groove, and the second Tesla valve is used to allow only the gas to leave the displacement groove. When the air film in the air bearing generates pressure fluctuations, these pressure fluctuations are transmitted to the corresponding transmission groove and act on the pneumatic plate, causing the pneumatic plate to squeeze the gas in the displacement groove and discharge the gas into the second Tesla valve. When the pressure fluctuation ends, the pneumatic plate resets under the action of the first spring. During the resetting process, the pneumatic plate replenishes the gas in the air film into the displacement groove through the first Tesla valve. This process is repeated, continuously transmitting gas through the second Tesla valve to the monitoring mechanism for accumulation.

[0023] Beneficial effects: When the tool vibration causes a local increase in air film pressure (positive fluctuation), high-pressure gas is introduced through the transmission groove and acts on the pressure plate. Under pressure, the pressure plate overcomes the elastic force of the first spring and slides inward in the displacement groove, compressing the closed gas in the displacement groove.

[0024] The compressed gas seeks a release path. At this time, the second Tesla valve, due to its unidirectional conduction setting, allows gas to flow out from the displacement groove, becoming a low-resistance channel. The compressed gas is then discharged through the second Tesla valve to the inside of the rotating sleeve, flowing towards the monitoring mechanism. The first Tesla valve, due to its opposite conduction direction, is in the closed state at this stage, preventing gas from flowing back to the gas film.

[0025] Once the pressure fluctuation has subsided (the pressure returns to normal or decreases), the pressure acting on the pressure plate decreases or disappears. At this time, the restoring force of the first spring pushes the pressure plate to reset outward. During the reset process, the volume of the displacement groove increases, generating negative pressure. This negative pressure will open the first Tesla valve (whose conduction direction allows external gas to enter the displacement groove), thereby drawing gas from the air film outside the rotating sleeve and replenishing it into the displacement groove, preparing for the next fluctuation.

[0026] Each vibration generated by the continuous operation of the cutting tool causes a pressure fluctuation, driving the pneumatic plate to complete a cycle of compression-exhaust-reset-replenishment. Each cycle discharges a small flow of gas towards the monitoring mechanism. Therefore, the cumulative gas flow (or resulting pressure change) delivered to the monitoring mechanism by the pneumatic displacement component in a specific direction directly reflects the intensity and frequency of the film pressure fluctuation (i.e., tool vibration) experienced in that direction. The monitoring mechanism can perform comparison and error correction by measuring the cumulative gas flow from the pneumatic displacement component in different directions.

[0027] Furthermore, the drive module includes a rotating shaft, on which a rotor is sleeved, and several stators for driving the rotor to rotate are arranged circumferentially on the outer side of the rotor.

[0028] Beneficial effects: The rotor is fixedly mounted on the rotating shaft and rotates together with the shaft. The stator is fixedly installed inside the electric spindle housing and surrounds the rotor. When a variable frequency current is applied to the stator winding, a rotating magnetic field is generated, driving the rotor, which has a permanent magnet structure, to rotate synchronously. This directly converts electrical energy into the mechanical energy of the rotating shaft, providing the necessary main cutting motion for gear cutting.

[0029] Furthermore, the tool changing module includes a pull sleeve, which is coaxially and fixedly connected to the rotating shaft. The pull sleeve is provided with several claw sleeves in the circumferential direction, which are used to hold the pull studs on the tool. The rotating shaft is also provided with a pneumatic piston mechanism for driving the extension and retraction of the pull sleeve. A locking groove is opened inside the rotating sleeve. When the pneumatic piston mechanism pulls the pull sleeve, the inner wall of the locking groove gradually squeezes the claw sleeves to lock the pull studs.

[0030] Beneficial effects: When a tool change is required, the pneumatic piston mechanism pushes the pull sleeve, along with the claw sleeve attached to it, to move inward (or outward, depending on the design direction) along the rotation axis, causing the claw sleeve to disengage from the constraint area of ​​the engagement groove. At this time, the claw sleeve opens radially under its own elasticity, thereby releasing the clamping force on the tool pull stud, and the tool can be removed by the robot arm.

[0031] After a new tool is installed, the pneumatic piston mechanism reverses its action, pulling the pull sleeve towards the working position. As the pull sleeve moves, the inner wall of the engagement groove (usually designed as a conical or inclined surface) begins to contact the outer circumferential surface of the claw sleeve and generates radial compression. This compression force the multiple circumferentially distributed claw sleeves to synchronously and evenly converge towards the center, thus firmly gripping the tool's pull stud like a robotic arm, forming a highly rigid mechanical connection.

[0032] After locking, the pull sleeve is fixedly connected to the rotating shaft. Therefore, the torque of the drive module is transmitted to the tool pull stud and tool body without slippage through the rotating shaft, pull sleeve, and claw sleeve, driving them to rotate at high speed for cutting.

[0033] Furthermore, a second sensing groove is provided inside the electric spindle body, and a first sensing groove is provided inside the rotating sleeve. Both the first and second sensing grooves are fitted with magnetically repulsive magnetic sheets. A parallel plate capacitor for detecting the displacement distance of the magnetic sheets is also provided in the second sensing groove. The first sensing groove is connected to the monitoring mechanism.

[0034] Beneficial effects: The accumulated gas from the pneumatic displacement components in all directions eventually converges and acts on the monitoring mechanism. The pressure change (corresponding to the displacement difference) inside the monitoring mechanism is transmitted to the first sensing slot. The magnetic plate inside the slot undergoes sliding displacement driven by the gas pressure.

[0035] The first sensing slot is located inside the rotating sleeve, while the second sensing slot is located inside the stationary electric spindle body. The magnetic plates in the two slots repel each other. When the magnetic plate inside the rotating sleeve moves due to changes in air pressure, the magnetic repulsion forces couple and push the stationary magnetic plate, resulting in a synchronous and equidistant following displacement. This design ingeniously establishes a signal transmission path between the high-speed rotating component and the stationary component that is free from physical contact and friction.

[0036] A parallel-plate capacitor is installed in the second sensing slot, with one plate connected to a movable magnetic sheet (or the displacement of the magnetic sheet directly changes the distance between the capacitor plates). When the magnetic sheet moves, the capacitance of the parallel-plate capacitor changes in precise proportion to the displacement. By measuring this change in capacitance, the monitoring circuit can calculate the displacement distance of the magnetic sheet in real time and with high resolution.

[0037] The displacement distance of the stationary magnetic sheet precisely corresponds to the displacement of the rotating magnetic sheet, which in turn reflects the gas pressure acting on the first sensing groove, and ultimately corresponds to the intensity of the gas film pressure fluctuation caused by the tool vibration accumulated by the gas pressure displacement component in a specific direction.

[0038] Furthermore, a gear-removing machine tool cutting tool includes a cutting tool, a monitoring mechanism disposed inside the cutting tool, the monitoring mechanism including a plurality of pneumatic grooves circumferentially opened on the outside of the cutting tool, the pneumatic grooves corresponding one-to-one with a second Tesla valve, and when the claw sleeve fixes the pull stud of the cutting tool, the pneumatic grooves are connected to the second Tesla valve.

[0039] The cutting tool is also provided with an annular groove, and several pushing mechanisms are circumferentially connected in the annular groove. The pushing mechanisms are used to push the gas in the annular groove to move along the annular groove. A second balance channel is also connected between adjacent pushing mechanisms. A first balance channel is also provided in the rotating sleeve. When the claw sleeve fixes the pull stud of the cutting tool, the first balance channel is connected to the second balance channel. The first balance channel is connected to the first sensing groove.

[0040] Each pneumatic tank is equipped with a transmission mechanism, which is used to convert the changes in air pressure within the pneumatic tank into the power for the propulsion mechanism.

[0041] Beneficial effects: After the tool is installed and locked, each pneumatic slot precisely aligns with the outlet of the second Tesla valve in the corresponding direction on the spindle side. Accumulated gas pulses representing the tool vibration intensity in that direction, from each pneumatic displacement component, are injected into the corresponding pneumatic slot.

[0042] The transmission mechanism within each pneumatic groove converts the received gas pressure signal into linear mechanical displacement. This displacement drives the connected propulsion mechanism to slide within the annular groove. The key point is that the displacement of each propulsion mechanism is strictly proportional to the cumulative gas flow rate input in the corresponding direction (i.e., the vibration intensity in that direction).

[0043] If the tool wear is uniform and the vibration intensity is consistent in all directions, the gas flow rate input to each pneumatic slot will be equal. All the propulsion mechanisms will produce the same displacement, moving in unison like a set of synchronously moving pistons within the annular slot. At this time, the volume changes of the individual air chambers separated by the propulsion mechanisms are synchronized, and the air chambers are connected through the second balancing channel, maintaining pressure balance and preventing net gas flow. The entire system is in equilibrium, with no signal output to the first sensing slot.

[0044] When vibration in a certain direction (e.g., the direction corresponding to several abnormally worn cutting teeth) is enhanced, the gas flow rate input to the pneumatic groove in that direction increases, driving the corresponding propulsion mechanism to produce a larger displacement than other propulsion mechanisms.

[0045] This excessive displacement disrupts the local equilibrium. The extra-moving part of the propulsion mechanism over-compresses the air chamber in front of it or over-expands the air chamber behind it, thus creating a pressure difference between adjacent air chambers instantaneously. This pressure difference cannot be absorbed locally in the annular groove and must be released through the second balancing channel connecting these air chambers.

[0046] The pressure difference is transmitted to the first sensing slot on the stationary side through the connected second and first balancing channels. This pressure difference gas is the physical representation of the displacement difference. It drives the magnetic plate in the first sensing slot to move, which is then detected by the parallel plate capacitor, ultimately triggering evaluation and alarm.

[0047] Furthermore, the propulsion mechanism includes a pair of sliding vanes that slide in a ring groove, with an incomplete toothed ring between the vanes.

[0048] Beneficial effects: Each propulsion mechanism consists of a pair of vanes that slide precisely against the inner and outer walls of the annular groove. This double-vane design forms a movable, highly sealed isolation piston within the annular groove. When the transmission mechanism drives the propulsion mechanism, the paired vanes effectively prevent gas leakage from the gas chambers on both sides through the sliding gap, ensuring that gas pressure can be transmitted and converted efficiently and without loss.

[0049] Furthermore, the transmission mechanism includes a cylinder slidably connected in the pneumatic groove, a spiral groove is provided on the outer circumference of the cylinder, a protrusion is fixedly connected to the side wall of the pneumatic groove, and the protrusion slides in cooperation with the spiral groove; a transmission shaft is coaxially arranged at one end of the cylinder near the annular groove, and a gear is coaxially fixedly connected to the transmission shaft, and the gear meshes with an incomplete gear ring.

[0050] Beneficial effect: The accumulated gas pressure from the second Tesla valve is injected into the pneumatic groove, acting on the end face of the cylinder, pushing the cylinder to slide linearly along the axis of the pneumatic groove.

[0051] The spiral groove on the outer side of the cylinder and the protrusion fixed to the side wall of the pneumatic groove form a sliding fit. When air pressure pushes the cylinder to move in a straight line, the protrusion gets stuck in the spiral groove, forcing the cylinder to rotate precisely along the trajectory of the spiral groove while moving in a straight line. The linear displacement and the rotation angle have a fixed proportional relationship.

[0052] A drive shaft, coaxially fixed to the cylinder, transmits this rotational motion. A gear fixed at the end of the drive shaft meshes with a partially geared ring, thereby transmitting the rotational motion to the entire propulsion mechanism linkage system, driving the vane to move within the annular groove.

[0053] Furthermore, a guide groove is provided on the outer side of the tool, and a guide is provided on the inner side of the rotating sleeve. When the tool is inserted into the rotating sleeve, the guide and the guide groove slide together.

[0054] Beneficial effects: Multiple connections need to be established between the tool and the spindle: each pneumatic groove must be precisely aligned with the corresponding outlet of the second Tesla valve; the port of the second balancing channel must perfectly match the port of the first balancing channel. The cooperation between the guide groove and the guide component is the physical guarantee that these precision pneumatic interfaces can achieve a blind-fit, one-time accurate connection after each tool change.

[0055] Furthermore, the air bearing adopts an air static pressure bearing.

[0056] Beneficial Effects: Air static pressure bearings utilize a constant-pressure external compressed air supply to the bearing clearance (between the rotating sleeve and the inner wall of the rotating groove), forming a stable and uniform static pressure film with load-bearing capacity. This film lifts the rotating sleeve, achieving contactless support. The air film of the air static pressure bearing is actively maintained by a stable external air source, resulting in a highly uniform and constant base pressure field. This means that pressure fluctuations in the air film caused by background vibrations resulting from normal, uniform tool wear will be controlled within a very small and consistent baseline range. When abnormal, asymmetrical tool wear occurs, the resulting additional unbalanced force disturbs this extremely stable reference field, generating a highly characteristic local pressure fluctuation signal with a very high signal-to-noise ratio. This significantly improves the sensitivity and accuracy of subsequent pneumatic displacement components in capturing abnormal signals. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the tool structure of an embodiment of the gear-removing machine tool and tool electric spindle of the present invention;

[0058] Figure 2 for Figure 1 Front view of the cutting tool;

[0059] Figure 3 for Figure 2 Sectional view along the AA direction;

[0060] Figure 4 for Figure 3 Sectional view of the rotating sleeve in the BB direction;

[0061] Figure 5 for Figure 4 A magnified view of a portion of point N in the middle;

[0062] Figure 6 for Figure 3 A magnified view of a portion of point M in the middle.

[0063] The reference numerals in the accompanying drawings include: 1. Electric spindle body; 2. Cutting tool; 3. Pneumatic piston mechanism; 4. Rotor; 5. Stator; 6. Rotating shaft; 7. Pull sleeve; 8. Claw sleeve; 9. Pull stud; 10. Air bearing; 11. Rotating sleeve; 12. Rotating groove; 13. Engaging groove; 14. First sensing groove; 101. Second sensing groove; 102. Parallel plate capacitor; 103. Magnetic sheet; 201. Pneumatic groove; 202. Cylinder ; 203, Annular groove; 204, First balancing channel; 205, Slider; 206, Incomplete gear ring; 207, Gear; 208, Drive shaft; 209, Second spring; 210, Protrusion; 211, Helical groove; 212, Guide groove; 1101, Transmission groove; 1102, Pneumatic plate; 1103, First spring; 1104, First Tesla valve; 1105, Second Tesla valve; 1106, Second balancing channel. Detailed Implementation

[0064] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0065] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0066] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0067] The following detailed description illustrates the specific implementation method:

[0068] Example:

[0069] As attached Figures 1-6 The diagram shows an electric spindle for a gear-removing machine tool, comprising an electric spindle body 1. The electric spindle body 1 mainly houses a rotary support module, a drive module, and a tool changing module. The drive module drives the tool 2 to rotate. In this embodiment, the drive module includes a rotary shaft 6 rotatably connected inside the electric spindle body 1. A rotor 4 is sleeved on the rotary shaft 6, and several stators 5 are circumferentially arranged on the outer side of the rotor 4 to drive its rotation. The tool changing module is used to mount the tool 2; specifically, the tool changing module includes a pull sleeve 7, which is coaxially and fixedly connected to the rotary shaft 6. Several claw sleeves 8 are circumferentially arranged on the pull sleeve 7, which are used to grip the pull studs 9 on the tool 2. The rotary shaft 6 also has a pneumatic piston mechanism 3 for driving the extension and retraction of the pull sleeve 7. The pneumatic piston mechanism 3 is a prior art technology that controls extension and retraction via air. A locking groove 13 is provided inside the rotary sleeve 11. When the pneumatic piston mechanism 3 pulls the pull sleeve 7, the inner wall of the locking groove 13 gradually squeezes the claw sleeves 8, locking the pull studs 9. All of the above are prior art and will not be described in detail here.

[0070] The rotary support module is used to reduce the rotational resistance between the tool 2 and the electric spindle body 1 during rotation. Preferably, the rotary support module includes a rotary groove 12 formed inside the electric spindle body 1, a rotary sleeve 11 rotatably connected inside the rotary groove 12, and an air bearing 10 installed between the rotary sleeve 11 and the inner wall of the rotary groove 12. In this embodiment, the air bearing 10 adopts the structure of an air static pressure bearing. The air bearing 10 includes an air supply system, a throttle, a bearing clearance, a bearing body, etc. It is supplied with compressed air by an external air source, and the gas enters the tiny gap between the shaft and the bearing through the throttle (such as a small hole or shallow cavity) on the bearing. Here, the gas forms a static pressure air film with load-bearing capacity and rigidity, which floats the shaft, thereby achieving frictionless or extremely low friction rotational motion.

[0071] The rotating sleeve 11 is circumferentially provided with several pneumatic displacement components, which are used to generate displacement based on the air film pressure fluctuations generated by the air bearing 10 on the rotating sleeve 11 during the machining process of the tool 2; preferably, combined with the attached Figure 4As shown, the pneumatic displacement assembly includes a transmission groove 1101 formed within the rotating sleeve 11. One end of the transmission groove 1101 communicates with the outer side of the rotating sleeve 11 (i.e., communicates with the bearing clearance, the same below), and the other end of the transmission groove 1101 communicates with a displacement groove. A pneumatic plate 1102 is slidably fitted within the displacement groove. A first spring 1103 is provided between the pneumatic plate 1102 and the inner wall of the displacement groove. The first spring 1103 is used to support the pneumatic plate 1102 to return to its original position. A first Tesla valve 1104 and a second Tesla valve 1105 are also connected to the side wall of the displacement groove. The other end of the first Tesla valve 1104 communicates with the outer side of the rotating sleeve 11 (mainly used to replenish gas from other positions to the pneumatic plate 1102 and the displacement groove), and the other end of the second Tesla valve 1105 communicates with the inner side of the rotating sleeve 11 (the inner side of the rotating sleeve 11...). The area accommodating the cutting tool 2 is connected. The first Tesla valve 1104 is used to allow only the gas in the air film to enter the displacement groove, and the second Tesla valve 1105 is used to allow only the gas to leave the displacement groove (that is, the gas in the displacement groove can enter the inner side of the rotating sleeve 11 through the second Tesla valve 1105). When the air film in the air bearing 10 generates pressure fluctuations, the pressure fluctuations are transmitted to the corresponding transmission groove 1101 and act on the air pressure plate 1102, causing the air pressure plate 1102 to squeeze the gas in the displacement groove and discharge the gas into the second Tesla valve 1105. When the pressure fluctuation ends, the air pressure plate 1102 is reset under the action of the first spring 1103. During the reset process, the air pressure plate 1102 replenishes the gas in the air film to the displacement groove through the first Tesla valve 1104, and this process is repeated.

[0072] Preferably, the electric spindle body 1 is further provided with a second sensing groove 101, and the rotating sleeve 11 is further provided with a first sensing groove 14. Both the first sensing groove 14 and the second sensing groove 101 have magnetically repelling magnetic sheets 103 slidably fitted within them. The second sensing groove 101 also contains a parallel plate capacitor 102 for detecting the displacement distance of the magnetic sheet 103. One plate of the parallel plate capacitor 102 is connected to the movable magnetic sheet 103 (the displacement of the magnetic sheet 103 directly changes the distance between the capacitor plates). When the magnetic sheet 103 moves, the capacitance value of the parallel plate capacitor 102 changes precisely proportionally to the displacement. Preferably, the parallel plate capacitor 102 is electrically connected to the machine tool CNC system. The operator can view the operating status of the tool 2 in real time through the machine tool CNC system for real-time intervention.

[0073] Preferably, a non-metallic reset spring is installed in both the first sensing groove 14 and the second sensing groove 101 to support the magnetic sheet 103 to reset.

[0074] It also includes a monitoring mechanism and an alarm mechanism. The monitoring mechanism is used to respond to the displacement generated by the air pressure displacement components in various directions and to perform displacement difference elimination processing to obtain the displacement difference. The alarm mechanism is used to trigger an alarm when the displacement difference exceeds a threshold. The alarm mechanism integrates a buzzer and an LED flashing light.

[0075] Preferably, this embodiment also provides a gear-removing machine tool cutter, including a cutter 2. Preferably, a guide groove 212 is provided on the outer side of the cutter 2, and a guide member, which is a guide pin, is fixedly connected to the inner side of the rotating sleeve 11. When the cutter 2 is inserted into the rotating sleeve 11, the guide member slides in cooperation with the guide groove 212. A monitoring mechanism is arranged inside the cutter 2. The monitoring mechanism includes several pneumatic grooves 201 circumferentially opened on the outer side of the cutter 2. The pneumatic grooves 201 correspond one-to-one with the second Tesla valve 1105. When the claw sleeve 8 fixes the pull stud 9 of the cutter 2, the pneumatic grooves 201 are connected to the second Tesla valve 1105.

[0076] Combined with appendix Figure 4 and attached Figure 5 As shown, the cutter 2 also has an annular groove 203, and several propulsion mechanisms are circumferentially connected within the annular groove 203. These propulsion mechanisms drive the gas within the annular groove 203 to move along it. A second balance channel 1106 connects adjacent propulsion mechanisms. A first balance channel 204 is also provided within the rotating sleeve 11. When the claw sleeve 8 fixes the pull stud 9 of the cutter 2, the first balance channel 204 connects with the second balance channel 1106; the first balance channel 204 also connects with the first sensing groove 14. Specifically, the propulsion mechanism includes a pair of sliding plates 205, which slide in conjunction with the annular groove 203. An incomplete toothed ring 206 is fixedly connected between the sliding plates 205.

[0077] Each pneumatic tank 201 is equipped with a transmission mechanism, which converts the air pressure changes within the pneumatic tank 201 into power for the propulsion mechanism. Specifically, refer to the attached... Figure 5 As shown, the transmission mechanism includes a cylinder 202 slidably connected within a pneumatic groove 201. A spiral groove 211 is circumferentially formed on the outer side of the cylinder 202. A protrusion 210 is fixedly connected to the side wall of the pneumatic groove 201, and the protrusion 210 slides in engagement with the spiral groove 211. A transmission shaft 208 is coaxially mounted on one end of the cylinder 202 near the annular groove 203. A gear 207 is coaxially fixedly connected to the transmission shaft 208, and the gear 207 meshes with an incomplete gear ring 206. Preferably, a second spring 209 is fixedly connected between the end of the cylinder 202 near the annular groove 203 and the inner wall of the pneumatic groove 201. The second spring 209 is used to support the cylinder 202 to return to its original position.

[0078] The specific implementation process is as follows:

[0079] The operator or automatic tool changer aligns the tool 2 with the electric spindle. The guide groove 212 on the outer side of the tool 2 is aligned with the guide (guide pin) fixed inside the rotating sleeve 11.

[0080] The tool 2 is inserted axially into the rotating sleeve 11, and the guide pin slides into the guide groove 212. This process forcibly determines the unique circumferential angular position of the tool 2 relative to the rotating sleeve 11.

[0081] When the cutter 2 is pushed into position, the pull stud 9 on its handle enters the gripping area formed by several claw sleeves 8. At this time, under the precise guidance of the guide groove 212, the inlets of each pneumatic groove 201 distributed circumferentially on the outer side of the cutter 2 are precisely aligned with the outlet of the corresponding second Tesla valve 1105 on the rotating sleeve 11; at the same time, the port of the second balance channel 1106 inside the cutter 2 is also aligned with the port of the first balance channel 204 inside the rotating sleeve 11.

[0082] The pneumatic piston mechanism 3 is activated, causing it to pull the pull sleeve 7 axially. As the pull sleeve 7 moves, the inner wall (conical surface) of the engaging groove 13 inside the rotating sleeve 11 begins to radially compress the circumferentially distributed claw sleeves 8, forcing all claws to synchronously retract towards the center, thereby firmly locking the pull stud 9 of the tool 2, completing the installation and clamping of the tool 2. In this final locked state, all the aforementioned air passage interfaces (between the pneumatic groove 201 and the second Tesla valve 1105, and between the second balance channel 1106 and the first balance channel 204) achieve reliable sealed connection.

[0083] The external air source is activated to supply air to the air static pressure bearing. Compressed air enters the gap between the inner wall of the rotating sleeve 11 and the rotating groove 12 through the throttle, forming a uniform and stable static pressure air film, which suspends and supports the rotating sleeve 11 and the cutter 2 inside it, and the system enters the standby state.

[0084] Start the drive module: When the accelerator 5 is energized, a rotating magnetic field is generated, which drives the rotor 4 and the rotating shaft 6 fixed thereto to rotate at high speed, and then drives the tool 2 to perform tooth cutting through the pull sleeve 7 and the claw sleeve 8.

[0085] During the cutting process, the vibration of the tool 2 is transmitted to the rotating sleeve 11 through a rigid connection, which disturbs the local air film pressure of the surrounding air static pressure bearing and generates pressure fluctuations.

[0086] When the air film pressure increases (positive fluctuation) at a certain point, high-pressure gas enters through the transmission groove 1101, pushing the air pressure plate 1102 to compress the gas in the displacement groove. The compressed gas is discharged through the activated second Tesla valve 1105, forming a gas pulse that flows into the corresponding pneumatic groove 201 on the tool 2.

[0087] After the pressure fluctuations subside, the first spring 1103 pushes the pneumatic plate 1102 to reset, generating negative pressure in the displacement groove. At this time, the first Tesla valve 1104 is turned on, drawing gas from the gas film to replenish the displacement groove, preparing for the next fluctuation (the tooth surfaces on the tool 2 will not continuously contact the workpiece; when one tooth surface is worn, it needs to rotate the tool 2 one revolution before it can contact the workpiece again).

[0088] In this cycle, each pneumatic displacement component converts the air film pressure fluctuation at its radial position into a series of gas pulses that flow directionally into the corresponding pneumatic groove 201 of the tool 2. During the machining process, each tooth surface on the tool 2 will make multiple contact cuts with the workpiece, and the vibration generated by each cut will accumulate in the pneumatic groove 201 (therefore, even a small vibration on the tool 2 can be amplified in the pneumatic groove 201 after one machining operation).

[0089] The gas pulses flowing from each of the second Tesla valves 1105 into the pneumatic slots 201 act on the cylinder 202. The gas pressure within each pneumatic slot 201 drives the cylinder 202 in a linear motion. Because the spiral groove 211 on the outer side of the cylinder 202 engages with the protrusion 210 on the sidewall of the pneumatic slot 201, the cylinder 202 generates a precise rotational motion while maintaining its linear motion. This rotational motion is output through the gear 207 at the end of the drive shaft 208.

[0090] Each gear 207 meshes with an independent incomplete gear ring 206, and each incomplete gear ring 206 is fixedly connected to a pair of vanes 205, forming an independent propulsion mechanism. Therefore, the gas flow rate input to each pneumatic groove 201 independently drives its corresponding propulsion mechanism to slide within the annular groove 203, and the final displacement of its vane 205 is proportional to the input air pressure in that direction (i.e., the cumulative vibration intensity).

[0091] If the wear of the tool 2 is uniform and the vibration intensity in all directions is consistent, then the gas flow rate input to all pneumatic slots 201 is equal, driving the sliders 205 of all propulsion mechanisms to move the same distance. At this time, the relative position between adjacent sliders 205 remains unchanged, the volume change of each air chamber they separate is synchronized, the air pressure between each air chamber connected by the second balance channel 1106 remains balanced, and there is no net gas flow.

[0092] If abnormal wear (such as chipping) occurs in a certain direction of the cutting tool 2, the vibration in that direction intensifies, and the gas flow rate input to the corresponding pneumatic groove 201 increases. This causes the sliding vane 205 of its propulsion mechanism to generate excessive displacement relative to the adjacent sliding vane 205. This excessive displacement directly leads to the excessive compression or expansion of the air chamber between the sliding vane 205 and the adjacent sliding vane 205, thereby generating a pressure difference between the second balance channels 1106 corresponding to these two adjacent sliding vanes 205.

[0093] The pressure difference gas is transmitted from the rotating cutter 2 side to the stationary first sensing groove 14 through the connected second balance channel 1106 and the first balance channel 204.

[0094] The pressure difference in the gas pushes the magnetic plate 103 within the first sensing slot 14 to move. Since the first sensing slot 14 is located within the rotating sleeve 11, and the second sensing slot 101 is located within the stationary electric spindle body 1, and the magnetic plates 103 within the two slots repel each other, this magnetic coupling enables non-contact displacement transmission during rotation. The movement of the magnetic plate 103 within the first sensing slot 14 directly alters the plate spacing of the associated parallel-plate capacitor 102, resulting in a precise change in capacitance.

[0095] The monitoring circuit detects changes in capacitance in real time and converts them into the displacement of the magnetic plate 103. This displacement is the displacement difference obtained after comparison and amplification by the aforementioned mechanical system, directly representing the degree of imbalance in the wear of the tool 2.

[0096] When the displacement difference continuously or momentarily exceeds the preset threshold, the alarm mechanism is triggered, issuing an audible and visual alarm signal, or sending a signal to the machine tool CNC system, indicating that the tool 2 is in an abnormal state and needs to be inspected, the process adjusted, or the tool 2 replaced.

[0097] When tool 2 is replaced, all connecting air passages (pneumatic groove 201 and second Tesla valve 1105, second balance channel 1106 and first balance channel 204) are disconnected. Under the elastic force of the first spring 1103, the pneumatic plate 1102 in the pneumatic displacement assembly has returned to its initial position, and its displacement groove is balanced with the pressure of the air film region through the first Tesla valve 1104, so there is no gas accumulation in the assembly.

[0098] Without external air pressure, the transmission mechanism inside the cutter 2 returns its cylinder 202 to its initial position under the action of the second spring 209. The linkage propulsion mechanism (slider 205) also returns to its preset initial position in the annular groove 203.

[0099] The magnetic sheet 103 in the first sensing slot 14 and the second sensing slot 101 also returns to the zero position under the action of the reset spring, and the parallel plate capacitor 102 outputs the reference capacitance value.

[0100] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An electric spindle for a gear cutting machine tool, comprising an electric spindle body (1), wherein a rotary support module, a drive module, and a tool changing module are disposed within the electric spindle body (1); the rotary support module is used to reduce the rotational resistance between the tool (2) and the electric spindle body (1) during rotation; the tool changing module is used to install the tool (2); and the drive module is used to drive the tool (2) to rotate; characterized in that, The rotary support module includes a rotary groove (12) opened in the electric spindle body (1), a rotary sleeve (11) is rotatably connected in the rotary groove (12), and an air bearing (10) is provided between the rotary sleeve (11) and the inner wall of the rotary groove (12); a number of pneumatic displacement components are arranged circumferentially on the rotary sleeve (11), and the pneumatic displacement components are used to generate displacement based on the air film pressure fluctuation generated by the air bearing (10) on the rotary sleeve (11) during the machining process of the tool (2); It also includes a monitoring mechanism and an alarm mechanism. The monitoring mechanism is used to respond to the displacement generated by the air pressure displacement component in each direction and perform displacement difference elimination to obtain the displacement difference. The alarm mechanism is used to trigger an alarm when the displacement difference exceeds a threshold. The main body of the electric spindle (1) is also provided with a second sensing groove (101), and the rotating sleeve (11) is also provided with a first sensing groove (14). Both the first sensing groove (14) and the second sensing groove (101) are slidably fitted with magnetically repulsive magnetic sheets (103). The second sensing groove (101) is also provided with a parallel plate capacitor (102) for detecting the displacement distance of the magnetic sheet (103). The first sensing groove (14) is connected to the monitoring mechanism. The pneumatic displacement assembly includes a transmission groove (1101) formed inside a rotating sleeve (11). One end of the transmission groove (1101) is connected to the outside of the rotating sleeve (11), and the other end of the transmission groove (1101) is connected to a displacement groove. A pneumatic plate (1102) is slidably fitted inside the displacement groove. A first spring (1103) is provided between the pneumatic plate (1102) and the inner wall of the displacement groove. The first spring (1103) is used to support the pneumatic plate (1102) to return to its original position. A first Tesla valve (1104) and a second Tesla valve (1105) are also connected to the side wall of the displacement groove. The other end of the first Tesla valve (1104) is connected to the outside of the rotating sleeve (11), and the other end of the second Tesla valve (1105) is connected to the inside of the rotating sleeve (11). The first Tesla valve (1104) is used to... The second Tesla valve (1105) is used to allow only the gas in the air film to enter the displacement groove, and only the gas to leave the displacement groove. When the air film in the air bearing (10) generates pressure fluctuations, the pressure fluctuations are transmitted to the corresponding transmission groove (1101) and act on the air pressure plate (1102), causing the air pressure plate (1102) to squeeze the gas in the displacement groove and discharge the gas into the second Tesla valve (1105). When the pressure fluctuation ends, the air pressure plate (1102) is reset under the action of the first spring (1103). During the reset process, the air pressure plate (1102) replenishes the gas in the air film to the displacement groove through the first Tesla valve (1104). This process is repeated to continuously transmit the gas to the monitoring mechanism through the second Tesla valve (1105) for accumulation.

2. The electric spindle for a gear-cutting machine tool according to claim 1, characterized in that, The drive module includes a rotating shaft (6), on which a rotor (4) is sleeved, and several stators (5) are arranged circumferentially on the outer side of the rotor (4) for driving the rotor (4) to rotate.

3. The electric spindle for a gear-cutting machine tool according to claim 2, characterized in that, The tool changing module includes a pull sleeve (7), which is coaxially and fixedly connected to the rotating shaft (6). Several claw sleeves (8) are arranged circumferentially on the pull sleeve (7), and the claw sleeves (8) are used to hold the pull studs (9) on the tool (2). The rotating shaft (6) is also provided with a pneumatic piston mechanism (3) for driving the pull sleeve (7) to extend and retract. A locking groove (13) is opened in the rotating sleeve (11). When the pneumatic piston mechanism (3) pulls the pull sleeve (7), the inner wall of the locking groove (13) gradually squeezes the claw sleeves (8) to lock the pull studs (9).

4. A gear-removing machine tool cutting tool, based on the gear-removing machine tool cutting tool electric spindle of claim 3, comprising a cutting tool (2), characterized in that, The monitoring mechanism is installed inside the tool (2). The monitoring mechanism includes several pneumatic grooves (201) circumferentially opened on the outside of the tool (2). The pneumatic grooves (201) correspond one-to-one with the second Tesla valve (1105). When the claw sleeve (8) fixes the pull stud (9) of the tool (2), the pneumatic grooves (201) are connected to the second Tesla valve (1105). The cutter (2) is also provided with an annular groove (203), and several pushing mechanisms are circumferentially connected in the annular groove (203). The pushing mechanisms are used to push the gas in the annular groove (203) to move along the annular groove (203). The adjacent pushing mechanisms are also connected by a second balance channel (1106). The rotating sleeve (11) is also provided with a first balance channel (204). When the claw sleeve (8) fixes the pull stud (9) of the cutter (2), the first balance channel (204) is connected to the second balance channel (1106). The first balance channel (204) is connected to the first sensing groove (14). Each pneumatic tank (201) is equipped with a transmission mechanism, which is used to convert the air pressure change in the pneumatic tank (201) into the power of the propulsion mechanism.

5. The gear-removing machine tool according to claim 4, characterized in that, The propulsion mechanism includes a pair of sliding vanes (205), which slide in conjunction with an annular groove (203), and an incomplete toothed ring (206) is provided between the sliding vanes (205).

6. The gear-removing machine tool cutting tool according to claim 5, characterized in that, The transmission mechanism includes a cylinder (202) slidably connected in a pneumatic groove (201), a spiral groove (211) is provided on the outer circumference of the cylinder (202), a protrusion (210) is fixedly connected to the side wall of the pneumatic groove (201), and the protrusion (210) slides in cooperation with the spiral groove (211); a transmission shaft (208) is coaxially provided at one end of the cylinder (202) near the annular groove (203), and a gear (207) is coaxially fixedly connected to the transmission shaft (208), and the gear (207) meshes with an incomplete gear ring (206).

7. The gear-removing machine tool cutting tool according to claim 6, characterized in that, The outer side of the cutting tool (2) is also provided with a guide groove (212), and the inner side of the rotating sleeve (11) is provided with a guide. When the cutting tool (2) is inserted into the rotating sleeve (11), the guide and the guide groove (212) slide together.

8. The gear-removing machine tool cutting tool according to claim 7, characterized in that, The air bearing (10) is an air static pressure bearing.

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