Intelligent cooling and lubricating system and method for high-speed motorized spindle

Abstract

The invention discloses an intelligent cooling and lubricating system and method for a high-speed motorized spindle, and belongs to the technical field of high-speed motorized spindles. The system comprises a mechanical transmission core composed of a main shaft, a main shaft bearing, a main shaft motor stator and a main shaft motor rotor, a circulation heat dissipation unit composed of cooling liquid and a cooling liquid refrigerating machine, a lubrication adjusting module composed of a lubricating oil tank, an air refrigerating machine, a flow adjusting valve and an oil-gas mixer, a temperature sensor and a cooling lubrication control system. According to the system, the temperature of a spindle bearing and the temperature of a spindle motor stator are monitored in real time through a temperature sensor, and the cooling lubrication control system dynamically adjusts oil-gas lubrication parameters and cooling liquid parameters based on a preset heat production and dissipation model and a parameter classification method in combination with working condition parameters such as workpiece materials, tools and machining technologies; therefore, intelligent cooling and lubricating are achieved, bearing damage and thermal errors are effectively reduced, and complex working condition requirements are met.

Description

Technical Field

[0001] The present application belongs to the technical field of high-speed electric spindles, and specifically relates to an intelligent cooling and lubrication system and method for high-speed electric spindles. Background Art

[0002] In the field of mechanical equipment manufacturing, high-speed machining of large structural components and parts is a key element in achieving high-quality, efficient, and low-cost manufacturing. As a key foundational component supporting high-speed machining, the performance of high-speed electric spindles directly impacts machining quality and efficiency. Temperature rise, caused by a mismatch between the cooling and lubrication systems of high-speed electric spindles and actual machining conditions, has become a key factor restricting machining accuracy and causing automatic shutdowns in CNC machine tools. With the continuous advancement of integrated manufacturing technologies and the deepening development of the concept of integrated structural and functional manufacturing, CNC machine tools must be able to process a wide range of materials, adapt to a wide range of process parameters, and maintain long-term precision. This requires that machine tool spindles meet the machining requirements of both low-speed, heavy-load and high-speed, light-load conditions. Specifically, under low-speed, heavy-load conditions, spindle bearings require high-viscosity lubricants to provide sufficient load-bearing capacity and prevent lubricant film failure. Under high-speed, light-load conditions, low-viscosity lubricants are required to reduce heat generation and maintain bearing thermal stability.

[0003] Currently, to adapt machine tools to the two aforementioned operating conditions, the industry generally uses medium- to high-viscosity lubricants. While ensuring proper operation and long life of the spindle bearings, cooling systems are also implemented to enhance the cooling and heat dissipation performance of the spindle. Specifically, high-speed electric spindles rely primarily on an oil-air mixture for lubrication, while cooling relies on a coolant and oil-air mixture to remove heat. However, in the practical machining of large structural components and parts, this widely used combination of oil-air lubrication and water cooling still presents numerous issues. For example, existing technologies largely rely solely on empirical, crude, manual methods to adjust lubricant flow, fluid supply frequency, and coolant flow and temperature. This adjustment method is ineffective in effectively eliminating the negative impact of spindle temperature rise, and thermal error compensation alone cannot fundamentally address the related issues. Especially in the context of intelligent manufacturing, automated production lines and smart workshops place extremely stringent requirements on the uptime and stability of machine tools and supporting equipment. Failures such as spindle damage and thermal errors caused by cooling and lubrication issues not only significantly increase repair costs but also pose serious quality risks. In summary, the existing high-speed electric spindle cooling and lubrication technology can no longer meet the complex and changeable processing parameters and working conditions required in the manufacturing of large-scale mechanical equipment. There is an urgent need to develop a complete and highly reliable electric spindle cooling and lubrication technology. Summary of the Invention The purpose of this application is to provide an intelligent cooling and lubrication system and method for a high-speed electric spindle, which can dynamically adjust the oil and gas lubrication parameters and coolant parameters according to the real-time temperature state and processing conditions of the high-speed electric spindle, thereby realizing intelligent cooling and lubrication of the high-speed electric spindle.

[0004] To achieve the above objectives, the present application provides a high-speed electric spindle intelligent cooling and lubrication system, comprising: The spindle, spindle bearings, spindle motor stator and spindle motor rotor, the spindle motor stator is used to cooperate with the spindle motor rotor to achieve rotation, the spindle motor rotor is used to drive the spindle to rotate, and the spindle bearings are used to support the spindle; Coolant and coolant refrigerator, the coolant is used to absorb the heat of the spindle motor stator and the spindle motor rotor, and is circulated through the coolant refrigerator to cool down and then flows back to the cooling channel; Lubricating oil tank, air chiller, flow control valve and oil-air mixer. The lubricating oil tank stores low-viscosity lubricating oil. The air chiller controls the air temperature. The flow control valve adjusts the supply parameters of lubricating oil, air and coolant. The oil-air mixer mixes lubricating oil and air to form an oil-air lubricating medium to cool and lubricate the spindle bearings. Temperature sensor, used to monitor the temperature of the spindle bearing and spindle motor stator in real time and transmit the temperature to the cooling and lubrication control system; The cooling and lubrication control system, based on a preset parameter classification method, dynamically generates control instructions for oil and gas lubrication parameters and coolant parameters according to real-time temperature data and processing conditions, and controls the flow control valve, coolant refrigerator and air refrigerator.

[0005] Furthermore, it also includes an oil-gas separator for separating the lubricating oil and air in the oil-gas lubrication medium and recycling them; the input end of the oil-gas mixer is respectively connected to the oil outlet of the lubricating oil tank and the air outlet of the air refrigerator, and the output end of the oil-gas mixer is connected to the lubrication channel of the main shaft bearing through a pipeline.

[0006] Furthermore, the parameter classification method of the cooling and lubrication control system includes: Classifying workpiece material information into at least three categories including easy-to-machine materials, conventional materials, and difficult-to-machine materials; Categorize tool parameter information into at least four categories according to model and purpose, including milling cutters, boring cutters, drills, and reamers; The processing parameter information is divided into six categories according to the spindle torque and speed, including low speed and light load, low speed and heavy load, medium speed and light load, medium speed and heavy load, high speed and light load, and high speed and heavy load.

[0007] Furthermore, the parameter classification method of the cooling and lubrication control system includes: dividing the spindle bearing temperature or the spindle motor stator temperature into at least six temperature levels including low temperature, medium-low temperature, medium temperature, medium-high temperature, high temperature and ultra-high temperature.

[0008] A high-speed electric spindle intelligent cooling and lubrication method, applied to a high-speed electric spindle intelligent cooling and lubrication system, comprises the following steps: S1. Data Acquisition The temperature data of the spindle bearing and the spindle motor stator are collected in real time through temperature sensors, and the workpiece material information, tool parameter information and machining process parameter information are extracted from the NC program; S2. Working condition identification Determine the current machining condition type based on the preset weight coefficient and the parameter time ratio within the sampling period ΔT of the cooling and lubrication control system; S3. Parameter matching According to the processing conditions and real-time temperature data, the corresponding oil and gas lubrication parameters and coolant parameters are queried and generated from the preset heat generation and heat dissipation model; S4, dynamic adjustment Control flow control valves, coolant chillers and air chillers to execute oil and gas lubrication parameters and coolant parameters, and continuously monitor temperature changes; S5. Security Response When the spindle bearing temperature or the spindle motor stator temperature remains at a high temperature and there is no downward trend after adjusting the parameters, reduce the high-speed electric spindle speed or stop the machining operation.

[0009] Furthermore, the oil-air lubrication parameters include lubricating oil flow rate, lubricating oil supply frequency, air flow rate and air temperature; the coolant parameters include coolant flow rate and coolant temperature.

[0010] Furthermore, the workpiece material information is extracted based on the following method: A workpiece material identification statement is added to the NC machine tool NC program. The current workpiece material type is determined by converting the weight coefficient based on the processing time proportion of different materials within the sampling period ΔT of the cooling and lubrication control system.

[0011] Furthermore, the tool parameter information is extracted based on the following method: a tool parameter identification statement is added to the NC machine tool NC program, and the current tool parameters are determined by converting the weight coefficient according to the usage time proportion of different tools within the sampling period ΔT of the cooling and lubrication control system.

[0012] Furthermore, the processing parameter information is extracted based on the following method: a processing parameter identification statement is added to the NC machine tool NC program, the spindle torque and speed are used as the judgment basis, and the current processing parameters are determined by weight coefficient conversion according to the time proportion of different processing processes within the sampling period ΔT of the cooling and lubrication control system.

[0013] Furthermore, the oil-air lubrication parameters and coolant parameters are implemented by the following method: When the high-speed and light-load operating condition is identified, the lubricating oil viscosity is controlled to be less than 20 mPa·s (low-viscosity lubricating oil), the air temperature is normal temperature, and the coolant temperature is set within the operating temperature range; When a low-speed, heavy-load operating condition is identified, the air cooler is controlled to lower the air temperature, increase the lubricating oil viscosity to >100 mPa·s (for medium-to-high viscosity lubricating oil), and increase the coolant flow rate. When the spindle bearing temperature is at a high temperature, the air flow rate and coolant flow rate are increased synchronously to reduce the air temperature and coolant temperature; When the spindle motor stator temperature is at a high temperature, increase the coolant flow rate and reduce the coolant temperature.

[0014] In summary, this application has the following advantages: In the system of the present application, the coolant absorbs heat from the spindle motor stator and rotor, then flows back after being cooled by the coolant chiller. The lubricating oil tank provides low-viscosity lubricating oil, which forms a lubricating medium in the oil-air mixer with air cooled by the air chiller, thereby cooling the spindle bearings. The temperature sensor monitors the temperature of the bearings and the spindle motor stator in real time. Based on a preset heat generation and heat dissipation model and parameter classification method, the cooling and lubrication control system classifies workpiece materials, tool parameters, and machining process parameters, and divides them into temperature levels. Combining real-time temperature data with machining operating parameters, it dynamically generates control instructions for oil-air lubrication parameters (lubricating oil flow rate, air flow rate, air temperature) and coolant parameters (coolant flow rate, coolant temperature). This allows for precise adjustment of the operating states of the flow control valve, coolant chiller, and air chiller, thereby achieving intelligent cooling and lubrication for high-speed electric spindles. This allows the spindles to effectively cope with complex operating conditions, further reducing bearing damage and thermal errors, and improving the machining capability and precision stability of CNC machine tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of the high-speed electric spindle intelligent cooling and lubrication system of this application; Among them, 1-spindle, 2-spindle bearing, 3-spindle motor stator, 4-coolant, 5-spindle motor rotor, 6-temperature sensor, 7-oil-gas separator, 8-coolant refrigerator, 9-lubricating oil tank, 10-air refrigerator, 11-flow regulating valve, 12-oil-gas mixer, 13-oil-gas lubrication medium, 14-cooling and lubrication control system.

[0016] Figure 2 This is a schematic diagram of the working principle of the high-speed electric spindle intelligent cooling and lubrication system of this application.

[0017] Figure 3This is a schematic diagram of the working process of the high-speed electric spindle intelligent cooling and lubrication system of this application.

[0018] Figure 4 Schematic diagram of the main shaft bearing lubrication principle.

[0019] Figure 5 Schematic diagram of the lubricating oil viscosity adjustment principle.

[0020] Figure 6 Schematic diagram of lubricating oil temperature regulation principle. DETAILED DESCRIPTION

[0021] The principles and features of the present invention are described below in conjunction with the examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Where specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0022] Currently, the lubrication and cooling of high-speed electric spindles face numerous challenges. Conventional high-speed electric spindles use medium-to-high viscosity lubricants (viscosity >100 mPa·s) to lubricate bearings. While this can prevent oil film rupture and failure at low speeds and heavy loads, it generates significant frictional heat at high speeds. Existing oil-gas lubricated high-speed electric spindles, when machining large structural parts and components, rely on extensive, manual adjustments of lubricant flow, supply frequency, coolant flow, and temperature, relying on empirical experience. This makes it difficult to effectively mitigate the negative impact of spindle temperature rise. Even with thermal error compensation, these adjustments cannot meet the complex and changing machining parameters and operating conditions. To address the aforementioned issues, this application proposes an intelligent cooling and lubrication solution based on a heat generation and heat dissipation model for high-speed electric spindles. The heat generation and heat dissipation model is based on the principle that the primary heat generation in oil-air lubricated high-speed electric spindles comes from the spindle bearings 2 and the spindle motor stator 3, which are the heat generation sources. To address this characteristic, differentiated lubrication and cooling strategies are adopted under different operating conditions, representing the heat dissipation approach. These two strategies together constitute the heat generation and heat dissipation model. The heat dissipation approach includes: under high-speed, light-load conditions, the spindle bearings 2 are lubricated with low-viscosity lubricant (viscosity <20 mPa·s) to reduce frictional heat generation; under low-speed, heavy-load conditions, the spindle bearings 2 are lubricated with lubricant that has been powerfully cooled by cold air, while air / cold air convection is used to cool the spindle bearings 2 and quickly remove heat. For the spindle motor stator 3, efficient cooling is achieved through convection of coolant 4. In addition, this application can also dynamically adjust the oil and gas lubrication parameters (lubricating oil flow, lubricating oil supply frequency, air flow, air temperature) and coolant parameters (coolant flow, coolant temperature) according to the real-time temperature status and processing conditions of the high-speed electric spindle, thereby realizing intelligent cooling and lubrication of the high-speed electric spindle, thereby effectively responding to complex processing requirements.

[0023] Based on this, in the first aspect, the present application provides a high-speed electric spindle intelligent cooling and lubrication system, such as Figure 1 As shown, it includes: a spindle 1, a spindle bearing 2, a spindle motor stator 3 and a spindle motor rotor 5. The spindle motor stator 3 is used to cooperate with the spindle motor rotor 5 to rotate. The spindle motor rotor 5 is used to drive the spindle 1 to rotate. The spindle bearing 2 is used to support the spindle 1. Coolant 4 and coolant refrigerator 8, the coolant 4 is used to absorb the heat of the spindle motor stator 3 and the spindle motor rotor 5, and is circulated through the coolant refrigerator 8 to reduce the temperature before flowing back to the cooling channel; Lubricating oil tank 9, air chiller 10, flow regulating valve 11 and oil-air mixer 12. Lubricating oil tank 9 stores low-viscosity lubricating oil. Air chiller 10 controls air temperature. Flow regulating valve 11 adjusts the supply parameters of lubricating oil, air and coolant 4. Oil-air mixer 12 mixes lubricating oil with air to form oil-air lubricating medium 13 to cool and lubricate main shaft bearing 2. The temperature sensor 6 is used to monitor the temperature of the spindle bearing 2 and the spindle motor stator 3 in real time and transmit the temperature to the cooling and lubrication control system 14; The cooling and lubrication control system 14 is based on a preset heat generation and heat dissipation model and parameter classification method, and dynamically generates control instructions for oil and gas lubrication parameters and coolant parameters according to real-time temperature data and processing working condition parameters, and controls the flow regulating valve 11, the coolant refrigerator 8 and the air refrigerator 10.

[0024] The preheating heat generation and heat dissipation model in this application includes a heat generation layer and a heat dissipation layer. The heat generation layer mainly includes the heat generated by the operation of the spindle motor stator 3 and the spindle motor rotor 5, as well as the heat generated by the spindle bearing 2 due to friction and other reasons when supporting the rotation of the spindle 1. The heat dissipation layer includes absorbing the heat of the spindle motor stator 3 and the spindle motor rotor 5 through the coolant 4, and then the coolant 4 circulates in the cooling channel, and is cooled by the coolant refrigerator 8 before returning. Its heat dissipation capacity is related to the flow rate, temperature, specific heat capacity of the coolant 4, the contact area between the coolant 4 and the heat-generating component, the convection heat transfer coefficient, etc. At the same time, for the spindle bearing 2, the oil and gas lubricating medium 13 output by the oil-gas mixer 12 is cooled, and the cold air or air convection carries away the heat. The heat dissipation effect is affected by factors such as air flow rate, temperature, flow rate, bearing structure, and surface condition.

[0025] Specifically, the intelligent cooling and lubrication solution proposed in this application based on the heat generation and heat dissipation model of the high-speed electric spindle is based on the following principles: First, the present application uses low-viscosity lubricating oil to lubricate the main shaft bearing 2, which can reduce the friction resistance and friction heat generated by the shearing movement of the lubricating oil during the high-speed operation of the main shaft bearing 2.

[0026] The heat generation calculation formula of the main shaft bearing 2 is Q'B =Q' B1 +Q' B2 +Q' B3 +Q' B4 ; Among them, Q' B1 It is the heat generated by the shear motion of the lubricating oil, which is positively correlated with the viscosity of the lubricating oil η and the bearing speed n, usually Q' B1 ∝η 2 / 3 ˙n 2 / 3 According to this empirical formula, the viscosity of the lubricating oil can be reduced by 5 times, and the speed of the spindle bearing 2 can be increased by 5 times, which significantly improves the machining efficiency of the machine tool.

[0027] Q' B2 The friction heat between the bearing rolling elements and the inner and outer raceways under load is related to the bearing load F, the bearing speed n and the first lubrication state parameter k1, usually Q' B2 ∝k1Fn; Q' B3 It is the friction heat between the bearing rolling elements and the inner and outer raceways of the bearing under the action of the bearing preload, which is related to the bearing preload F0, the bearing speed n and the second lubrication state parameter k2, usually Q' B3 ∝k2F0n; Q' B4 is the friction heat between the bearing rolling elements and the bearing cage, which is related to the bearing load F, the bearing speed n and the third lubrication state parameter k3, usually Q' B4 ∝k3F0n.

[0028] The calculation formula for the heat dissipation of the main shaft bearing 2 is Q'' B =Q'' B1 +Q'' B2 ; Among them, Q'' B1 It is the heat carried away by air convection, which is related to the air flow rate q1 and the air temperature T1, Q'' B1 ∝q1,Q'' B1 ∝1 / T1; Q'' B2 It is the heat carried away by the lubricating oil convection, which is related to the flow rate q2 of the lubricating oil and the temperature T2 of the lubricating oil. B2 ∝q2, Q'' B2 ∝1 / T2.

[0029] Typically, Q'' B2 <Q'' B1That is, during the oil-air lubrication process of a high-speed electric spindle, heat is dissipated primarily through air convection. Lubricant viscosity directly and indirectly affects the heat generation and heat dissipation rates of the spindle bearing 2. The use of low-viscosity lubricant in this application can reduce internal frictional heat and increase lubricant flow, thereby reducing the heat generation and increasing the heat dissipation rate of the spindle bearing 2.

[0030] Secondly, the present application controls the lubrication state and spindle bearing temperature by adjusting the air temperature. The adjustment of air flow, lubricating oil flow, and lubricating oil supply frequency is mainly to adapt to the adjustment of air temperature, so as to reduce the impact of air temperature changes on the cooling and lubrication system of the high-speed electric spindle. According to the principles of tribology, only when a stable oil film with a thickness of more than 3 times the roughness is formed on the contact area between the rolling elements and the inner and outer raceways of the spindle bearing can the two contact surfaces be effectively separated and a good lubrication effect be achieved. The oil film thickness h of the lubricating oil is positively correlated with the relative motion speed v between the two contact surfaces (rolling element-inner raceway, rolling element-outer raceway), and the lubricating oil viscosity η is positively correlated. The empirical formula is approximately h is positively correlated with v 0.7 η 0.7 . During the high-speed rotation of the main shaft bearing 2, a sufficient film thickness h can be formed by relying on the rotation speed v, and the lubricating oil does not need to have a very high lubricating oil viscosity η; when the main shaft bearing 2 rotates at a low speed or under heavy load conditions, the lubricating oil needs to have a certain lubricating oil viscosity η to form a sufficient film thickness h. The actual application effect of improving the cooling capacity by directly lowering the temperature of the lubricating oil is not ideal. For example, directly cooling the lubricating oil by a refrigerator can improve the heat absorption capacity of the lubricating oil, but the lubricating oil has a higher viscosity and poorer fluidity at low temperatures, which will reduce the fluidity of the lubricating oil in the liquid supply pipeline and inside the bearing. Therefore, its effect on improving the lubrication and cooling performance of the main shaft bearing 2 is limited. In order to circumvent these defects, the present application does not use a refrigerator to directly reduce the temperature of the lubricating oil, but directly reduces the temperature of the air by an air refrigerator 10 (forming cold air), and indirectly reduces the temperature of a small amount of lubricant near the main shaft bearing 2 and inside the main shaft bearing 2, such as Figure 6 When the main shaft bearing 2 is in a low-speed, heavy-loaded condition, an appropriate amount of cold air can properly increase the viscosity of the low-viscosity lubricating oil, improve the film-forming ability of the lubricating oil, reduce the friction and wear of the main shaft bearing 2, and play a protective role for the high-viscosity lubricating oil. Figure 4 and Figure 5As shown. When the main shaft bearing 2 is in a high-speed working condition, an appropriate amount of cold air can greatly improve the heat dissipation capacity of the main shaft bearing 2 and reduce the temperature of the main shaft bearing 2; and maintain the temperature of the lubricating oil to avoid the decrease in the viscosity and adsorption capacity of the lubricating oil at high temperatures, which leads to a decrease in film-forming ability and lubrication ability. In general, the air refrigerator 10 of the present application indirectly cools the lubricating oil near the bearing by lowering the air temperature, thereby reducing the problem of the viscosity of the lubricating oil decreasing due to high temperature; the flow regulating valve 11 of the present application adjusts the flow of the lubricating oil in real time, and further controls the lubricating effect of the lubricating oil in conjunction with the viscosity change; and then identifies the workpiece material, tool parameters and processing time ratio through the NC program, and combines the friction heat formula to dynamically adjust the viscosity and flow of the lubricating oil, thereby achieving a balance between the working efficiency and lubrication effect of the main shaft bearing 2.

[0031] Third, the coolant 4 absorbs heat from the spindle motor stator 3 and surrounding areas through thermal radiation and conduction. The lower the temperature of the coolant 4, the greater its heat absorption capacity. The coolant 4 removes heat from the spindle 1 through thermal convection. The greater the flow rate of the coolant 4, the greater its heat dissipation capacity. Therefore, the present application controls the temperature of the spindle motor stator 3 and surrounding areas by adjusting the coolant temperature and flow rate. The coolant chiller 8 lowers the temperature of the air, thereby indirectly lowering the temperature of the small amount of lubricating oil near and inside the spindle bearing 2, thereby minimizing the impact of increased lubricating oil viscosity on the fluidity and permeability of the lubricating oil in the supply pipeline and bearing.

[0032] Fourthly, the present application uses sensors to monitor the spindle bearing temperature, spindle motor stator temperature, cold air real-time temperature, coolant real-time temperature, spindle power, spindle speed and other related parameters in real time, and stores and processes workpiece material information, tool parameter information, machining parameter information, spindle bearing temperature information, spindle motor stator temperature information through the cooling and lubrication control system 14, and controls the oil and gas lubrication parameters and coolant parameters according to specific logical relationships, thereby ensuring that the high-speed electric spindle still has good cooling and lubrication status under complex machining parameters and machining conditions.

[0033] In some specific embodiments of the present application, the main shaft bearing 2 includes a front bearing and a rear bearing.

[0034] In some specific embodiments of the present application, an oil-gas separator 7 is further included to separate the lubricating oil and air from the oil-gas lubrication medium for recycling. The input end of the oil-gas mixer 12 is connected to the oil outlet of the lubricating oil tank 9 and the air outlet of the air chiller 10, respectively. The output end of the oil-gas mixer 12 is connected to the lubrication channel of the main shaft bearing 2 via a pipeline.

[0035] In some specific embodiments of the present application, the parameter classification method of the cooling and lubrication control system 14 includes: Classifying workpiece material information into at least three categories including easy-to-machine materials, conventional materials, and difficult-to-machine materials; Categorize tool parameter information into at least four categories according to model and purpose, including milling cutters, boring cutters, drills, and reamers; The processing parameter information is divided into six categories according to the spindle torque and speed, including low speed and light load, low speed and heavy load, medium speed and light load, medium speed and heavy load, high speed and light load, and high speed and heavy load.

[0036] In the above scheme, by pre-dividing the grades of workpiece materials, tool parameters, processing parameters, spindle bearing temperature, and spindle electrode stator temperature and setting up a parameter library for oil and gas lubrication and coolant, appropriate oil and gas lubrication parameters and coolant parameters can be quickly matched according to the real-time temperature status and processing conditions of the high-speed electric spindle, avoiding complex logical operations and data processing that increase the computing power and data volume of the machine tool CNC system and PLC system.

[0037] In some specific embodiments of the present application, the parameter classification method of the cooling and lubrication control system 14 includes: dividing the spindle bearing temperature or the spindle motor stator temperature into at least six temperature levels including low temperature, medium-low temperature, medium temperature, medium-high temperature, high temperature and ultra-high temperature.

[0038] Preferably, various classifications or grades in this application need to be set according to actual working conditions, and changes in relevant parameters can be achieved through programming.

[0039] In a second aspect, based on a general inventive concept, the present application discloses a high-speed electric spindle intelligent cooling and lubrication method, which is applied to a high-speed electric spindle intelligent cooling and lubrication system, comprising the following steps: S1. Data Acquisition The temperature data of the spindle bearing 2 and the spindle motor stator 3 are collected in real time through the temperature sensor, and the workpiece material information, tool parameter information and machining process parameter information are extracted from the NC program; S2. Working condition identification Determine the current machining condition type based on a preset weight coefficient and the parameter time ratio within the sampling period ΔT of the cooling and lubrication control system 14; S3. Parameter matching According to the processing conditions and real-time temperature data, the corresponding oil and gas lubrication parameters and coolant parameters are queried and generated from the preset heat generation and heat dissipation model; S4, dynamic adjustment Control the flow regulating valve 11, the coolant chiller 8 and the air chiller 10 to execute the oil-gas lubrication parameters and the coolant parameters, and continuously monitor the temperature changes; S5. Security Response When the spindle bearing temperature or the spindle motor stator temperature remains at a high temperature and there is no downward trend after adjusting the parameters, reduce the high-speed electric spindle speed or stop the machining operation.

[0040] In the above scheme, the main heat dissipation targets are the spindle bearing 2 and the spindle motor stator 3. Under high-speed and light-load conditions, low-viscosity lubricating oil is used to reduce frictional heat generation; under low-speed and heavy-load conditions, lubricating oil lubrication with strong cold air cooling is used in combination with air convection cooling, and the spindle motor stator 3 is cooled by coolant convection. In addition, the method of the present application can dynamically adjust the various parameters of oil-gas lubrication and coolant according to the real-time temperature state and processing conditions of the high-speed electric spindle. Through this intelligent and precise cooling and lubrication control, not only the problems of spindle bearing 2 breakage and thermal error increase are reduced, but also a rapid response to complex working conditions is achieved, thereby giving the CNC machine tool the ability to process multiple materials, the ability to match a wide range of process parameters, and the ability to maintain long-term precision stability, greatly improving the comprehensive performance and processing adaptability of the CNC machine tool.

[0041] In some specific embodiments of the present application, the oil-gas lubrication parameters include lubricating oil flow rate, lubricating oil supply frequency, air flow rate and air temperature; the coolant parameters include coolant flow rate and coolant temperature.

[0042] In some specific embodiments of the present application, workpiece material information is extracted based on the following method: A workpiece material identification statement is added to the NC machine tool NC program, and the current workpiece material type is determined by converting the weight coefficient according to the processing time proportion of different materials within the sampling period ΔT of the cooling and lubrication control system 14.

[0043] In some specific embodiments of the present application, tool parameter information is extracted based on the following method: a tool parameter identification statement is added to the NC machine tool NC program, and the current tool parameters are determined by converting the weight coefficient according to the usage time proportion of different tools within the sampling period ΔT of the cooling and lubrication control system 14.

[0044] In some specific embodiments of the present application, the processing parameter information is extracted based on the following method: adding a processing parameter identification statement to the CNC machine tool NC program, using the spindle torque and speed as the basis for judgment, and determining the current processing parameters by converting the weight coefficient according to the time proportion of different processing processes within the sampling period ΔT of the cooling and lubrication control system 14.

[0045] In some specific embodiments of the present application, the oil-air lubrication parameters and the coolant parameters are implemented by the following method: When the high-speed and light-load operating condition is identified, the lubricating oil viscosity is controlled to be less than 20 mPa·s, the air temperature is normal temperature, and the coolant temperature is set within the operating temperature range; When a low-speed, heavy-load operating condition is identified, the air cooler is controlled to lower the air temperature, increase the lubricating oil viscosity to >100 mPa·s, and increase the coolant flow rate; When the temperature of the main shaft bearing 2 is at a high temperature gear, the air flow rate and the coolant flow rate are increased synchronously to reduce the air temperature and the coolant temperature; When the temperature of the spindle motor stator 3 is at a high temperature gear, the coolant flow rate is increased and the coolant temperature is reduced.

[0046] In summary, this application combines the heat generation and heat dissipation of the bearing and the empirical formula of lubricating oil through a specific hardware architecture (such as an air chiller 10 and a flow control valve 11), a control method (parameter classification and matching algorithm) and a monitoring system (temperature sensor 6 + cooling and lubrication control system 14). The two complement each other through the three-layer architecture of "model-hardware-control", and jointly realize the intelligent cooling and lubrication of the high-speed electric spindle, solving the problems of traditional solutions.

[0047] The above technical solutions of the present application are described in detail below with reference to specific embodiments.

[0048] Example 1 This embodiment discloses a high-speed electric spindle intelligent cooling and lubrication system. Figure 1 As shown, it includes: a spindle 1, a spindle bearing 2, a spindle motor stator 3, a coolant 4, a spindle motor rotor 5, a temperature sensor 6, an oil-gas separator 7, a coolant refrigerator 8, a lubricating oil tank 9, an air refrigerator 10, a flow regulating valve 11, an oil-gas mixer 12, an oil-gas lubricating medium 13 and a cooling and lubrication control system 14.

[0049] Among them, spindle 1 is the rotating axis of the high-speed electric spindle, which carries the tool to process the workpiece under the control of the NC program of the numerical control system. The rotation speed of spindle 1 affects the processing efficiency and quality of the workpiece.

[0050] The spindle bearing 2 is a transmission component used to support the spindle 1 in the high-speed electric spindle, realizing the dynamic and static separation between the spindle 1 and the high-speed electric spindle housing. The spindle bearing 2 includes a front bearing and a rear bearing. Figure 1 Only the cooling and lubrication lines of the front bearing are shown, and the cooling and lubrication lines of the rear bearing are omitted. The cooling and lubrication lines of the rear bearing are the same as those of the front bearing.

[0051] The spindle motor stator 3 is the coil and related accessories of the high-speed electric spindle motor, fixed to the high-speed electric spindle housing. When a certain frequency of alternating current passes through the coil inside the spindle stator 3, a magnetic field with a specific distribution form and changing pattern is generated.

[0052] The coolant 4 is an aqueous solution with good cooling capacity, and is used to absorb the heat generated by the spindle motor stator 3 and the spindle motor rotor 5 during operation.

[0053] The spindle motor rotor 5 is the magnet and related accessories of the high-speed electric spindle, which rotates in the magnetic field generated by the spindle motor stator 3 and drives the spindle 1 to rotate.

[0054] The temperature sensor 6 is used to monitor the temperature of the spindle bearing 2 and the spindle motor stator 3 in real time, and transmit the temperature data to the cooling and lubrication control system 14 in real time.

[0055] The oil-gas separator 7 is used to separate the lubricating oil and air in the oil-gas lubricating medium 13, purify the air and recover the lubricating oil.

[0056] The coolant refrigerator 8 is used to control the temperature of the coolant, thereby changing the heat absorption capacity of the coolant, and can transmit the coolant temperature to the cooling and lubrication control system 14 in real time.

[0057] The lubricating oil tank 9 is used to store the low-viscosity lubricating oil to be used and to prevent the lubricating oil from being contaminated by external impurities.

[0058] The air chiller 10 is used to control the temperature of the air, thereby changing the heat absorption capacity of the air, and can transmit the air temperature to the cooling and lubrication control system 14 in real time.

[0059] The flow control valve 11 is used to control the supply frequency and speed of air, lubricating oil and coolant, and transmit relevant parameters to the cooling and lubrication control system 14 in real time.

[0060] The oil-air mixer 12 mixes lubricating oil and air in a certain proportion and form to form a uniform and stable cooling lubricating medium 13.

[0061] The cooling lubricating medium 13 is a mixture of micron lubricating oil droplets and air, and is used to cool and lubricate the main shaft bearing 2.

[0062] The cooling and lubrication control system 14 is the core of the high-speed electric spindle intelligent cooling and lubrication system. Its control process is as follows: Figure 2 As shown, the cooling and lubrication control system 14 is used to store and process workpiece material information, tool parameter information, machining process parameter information, spindle bearing temperature information and spindle stator temperature information, and control the oil and gas lubrication parameters and coolant parameters according to a specific logical relationship to ensure that the high-speed electric spindle still has good cooling and lubrication status under complex machining parameters and machining conditions.

[0063] Example 2 This embodiment discloses a high-speed electric spindle intelligent cooling and lubrication method, which is applied to the high-speed electric spindle intelligent cooling and lubrication system of Example 1, and includes the following steps: (1) When the high-speed electric spindle intelligent cooling and lubrication system is running, Figure 3As shown, the cooling and lubrication control system 14 first obtains the workpiece material information, tool parameter information, processing parameter information, spindle bearing 2 temperature information and spindle motor stator 3 temperature information, and based on this, screens out the control parameters of the high-speed electric spindle cooling and lubrication system, namely, oil-gas lubrication parameters and coolant parameters.

[0064] (2) Classify the workpiece material, tool parameters, machining process parameters, spindle bearing temperature, spindle stator temperature, oil and gas lubrication parameters, and coolant parameters to obtain a parameter database.

[0065] Specifically, the following steps are included: (201) According to the processing performance, the workpiece materials are divided into the following three categories, such as easy-to-process materials U1, conventional materials U2, and difficult-to-process materials U3; (202) According to the tool model and purpose, the tool parameters are divided into the following four categories, such as milling cutter V1, boring cutter V2, drill bit V3 and reamer V4; (203) The machining parameters are divided into the following six categories, such as low speed and light load W1, low speed and heavy load W2, medium speed and light load W3, medium speed and heavy load W4, high speed and light load W5, and high speed and heavy load W6; (204) The spindle bearing temperatures are divided into the following six categories, such as low temperature X1, medium-low temperature X2, medium temperature X3, medium-high temperature X4, high temperature X5 and ultra-high temperature X6; (205) The spindle stator temperature is divided into the following six categories, such as low temperature Y1, medium-low temperature Y2, medium temperature Y3, medium-high temperature Y4, high temperature Y5 and ultra-high temperature Y6; (206) The oil-air lubrication parameters are divided into the following five categories, such as M1, M2, M3, M4, and M5, representing different lubricating oil flow rates, air flow rates, and air temperatures; (207) The coolant parameters are divided into the following five temperature levels, such as N1, N2, N3, N4, and N5, representing different coolant flow rates and coolant temperatures.

[0066] (208) According to the workpiece material type U, tool parameters V, processing parameters W, spindle bearing 2 temperature X and spindle motor stator 3 temperature Y, select the appropriate level of oil and gas lubrication parameters M and coolant parameters N. For example, when the workpiece material type is U1, the tool parameters are V1, the processing parameters are W1, the spindle bearing temperature is X1 and the spindle stator temperature is Y1, the oil and gas lubrication parameters are M1 and the coolant parameters are N1.

[0067] Among them, the classification or partitioning of workpiece material type, tool parameters, machining process parameters, spindle bearing 2 temperature, spindle motor stator 3 temperature, oil and gas lubrication parameters, and coolant parameters need to be set according to actual working conditions and can be changed through programming.

[0068] (3) The steps for determining the type of workpiece material include: adding a workpiece material type identification statement to the NC program of the CNC machine tool; when the CNC system of the machine tool starts to execute a certain material processing program, it sends a signal that can be interpreted as the type of workpiece material to the cooling and lubrication control system 14; after the cooling and lubrication control system 14 obtains the workpiece material signal, it immediately records the processing time t of the material; within the sampling period ΔT of the cooling and lubrication control system 14, if the workpiece material being processed changes, the material type needs to be approximately converted.

[0069] For example: within the sampling period ΔT of the high-speed electric spindle cooling and lubrication control system 14, the processing time of the easy-to-process material U1 is t1, the processing time of the conventional material U2 is t2, and the processing time of the difficult-to-process material U3 is t3. The maximum values ​​of 0.2t1, 0.3t2, and 0.5t3 are determined; If 0.2t1 is the largest, then within the sampling period ΔT of the cooling and lubrication control system 14 , the material being processed is the easy-to-process material U1; If 0.3t2 is the largest, then the material processed during the sampling period ΔT of the cooling and lubrication control system 14 is the conventional material U2; If 0.5t1 is the largest, then the material being processed within the sampling period ΔT of the cooling and lubrication control system 14 is the difficult-to-process material U3.

[0070] The sampling period ΔT, coefficient 0.2, coefficient 0.3 and coefficient 0.5 of the cooling and lubrication control system 14 can be adjusted according to actual conditions.

[0071] (4) The steps for determining the type of tool parameters include: adding a tool parameter identification statement to the NC program of the CNC machine tool; when the CNC system of the machine tool starts to use a certain tool, it sends a signal that can be parsed as the tool model to the cooling and lubrication control system 14; after the cooling and lubrication control system 14 obtains the tool parameter signal, it immediately records the use time T of the tool; within the sampling period ΔT of the cooling and lubrication control system 14, if the tool parameters used change, the tool parameters need to be approximately converted.

[0072] For example, within the sampling period ΔT of the cooling and lubrication control system 14, the processing time of the milling cutter V1 is T1, the processing time of the boring cutter V2 is T1, the processing time of the drill bit V3 is T3, and the processing time of the reamer V4 is T4. The maximum values ​​of 0.25T1, 0.25T2, 0.25T3, and 0.25T4 are determined; If 0.25T1 is the largest, then within the sampling period ΔT of the cooling and lubrication control system 14 , the tool type parameter used is the milling cutter U1; If 0.25T2 is the largest, then within the sampling period ΔT of the cooling and lubrication control system 14 , the tool parameter used is the boring tool V2; If 0.25T3 is the largest, then within the sampling period ΔT of the cooling and lubrication control system 14 , the tool parameter used is drill V3; If 0.25T4 is the largest, then within the sampling period ΔT of the cooling and lubrication control system 14 , the tool parameter used is reamer V4 .

[0073] Among them, coefficient 0.25, coefficient 0.25, coefficient 0.25 and coefficient 0.25 can be adjusted according to actual conditions.

[0074] (5) The steps for determining the type of processing parameters include: adding a processing parameter identification statement to the NC program of the CNC machine tool. The CNC system of the machine tool uses the spindle torque (i.e., load) and speed as the basis for judgment. When executing different processing programs, it sends a signal that can be interpreted as the processing type to the cooling and lubrication control system 14. After the cooling and lubrication control system 14 obtains the processing parameter signal, it immediately records the execution time t' of the process. During the sampling period ΔT of the cooling and lubrication control system 14, if the processing parameter changes, the processing parameter needs to be approximately converted.

[0075] For example, within the sampling period ΔT of the cooling and lubrication control system 14, the execution time of the low speed and light load W1 is t1', the execution time of the low speed and heavy load W2 is t2', the execution time of the medium speed and light load W3 is t3', the execution time of the medium speed and heavy load W4 is t4', the execution time of the high speed and light load W5 is t5', and the execution time of the high speed and heavy load W6 is t6'. The maximum values ​​of 0.1t1', 0.15t2', 0.1t3', 0.15t4', 0.2t5', and 0.2t6' are determined; If 0.1t1′ is the largest, then within the sampling period ΔT of the cooling and lubrication control system 14, the machining process parameters are low speed and light load W1; If 0.15t2′ is the maximum, then within the sampling period ΔT of the cooling and lubrication control system 14, the machining process parameter is low speed and heavy load W2; The sampling period ΔT and the coefficients 0.1, 0.15 and 0.2 of the cooling and lubrication control system 14 can be adjusted according to actual conditions.

[0076] (6) The steps for determining the temperature level of the main shaft bearing 2 include: measuring the temperature of the main shaft bearing 2 in real time by the temperature sensor 6 of the main shaft bearing 2, and transmitting the collected temperature data to the cooling and lubrication control system 14 in real time. After the cooling and lubrication control system 14 obtains the temperature signal, it immediately records the temperature value; within the sampling period ΔT of the cooling and lubrication control system 14, if the temperature of the main shaft bearing 2 changes, it needs to be approximately converted to the main shaft bearing temperature within the sampling period ΔT of the cooling and lubrication control system 14.

[0077] For example, within the sampling period ΔT of the cooling and lubrication control system 14, the duration of the low temperature X1 is t1'', ​​the duration of the medium-low temperature X2 is t2'', the duration of the medium temperature X3 is t3'', the duration of the medium-high temperature X4 is t4'', the duration of the high temperature X5 is t5'', and the duration of the ultra-high temperature X6 is t6''. The maximum values ​​of 0.2t1'', ​​0.2t2'', 0.2t3'', 0.15t4'', 0.15t5'', and 0.1t6'' are determined; If 0.2t1″ is the maximum, then within the sampling period ΔT of the cooling and lubrication control system 14 , the temperature of the main shaft bearing 2 is the low temperature X1; If 0.2t2″ is the maximum, then within the sampling period ΔT of the cooling and lubrication control system 14, the temperature of the main shaft bearing 2 is a medium-low temperature X2; The same can be deduced in this way. The sampling period ΔT and various coefficients of the cooling and lubrication control system 14 can be adjusted according to actual conditions.

[0078] (7) The steps for determining the temperature level of the spindle motor stator 3 include: measuring the temperature of the spindle motor stator 3 in real time by the temperature sensor 6 of the spindle motor stator 3, and transmitting the collected temperature data to the cooling and lubrication control system 14 in real time. After the cooling and lubrication control system 14 acquires the temperature signal, it immediately records the temperature value; within the sampling period ΔT of the cooling and lubrication control system 14, if the temperature of the spindle motor stator 3 changes, it is necessary to approximately convert it to the temperature of the spindle motor stator 3 within the sampling period ΔT of the cooling and lubrication control system 14.

[0079] For example, within the sampling period ΔT of the cooling and lubrication control system 14, the duration of the low temperature Y1 is t1''', the duration of the medium-low temperature Y2 is t2''', the duration of the medium temperature Y3 is t3''', the duration of the medium-high temperature Y4 is t4''', the duration of the high temperature Y5 is t5''', and the duration of the ultra-high temperature Y6 is t6'''. The maximum values ​​of 0.2t1''', 0.2t2''', 0.2t3''', 0.15t4''', 0.15t5''', and 0.1t6''' are determined; If 0.2t1''' is the largest, then within the sampling period ΔT of the cooling and lubrication control system 14, the temperature of the spindle motor stator 3 is the low temperature Y1; If 0.2t2''' is the largest, then within the sampling period ΔT of the cooling and lubrication control system 14, the temperature of the spindle motor stator 3 is a medium-low temperature Y2; The sampling period ΔT and various coefficients of the cooling and lubrication control system 14 can be adjusted according to actual conditions.

[0080] (8) According to the parameter database set in step (2), the workpiece material type, tool parameters, machining process parameters, spindle bearing temperature, and spindle motor stator temperature are obtained, and the appropriate oil-gas lubrication parameters and coolant parameters are quickly matched according to the real-time temperature status of the high-speed electric spindle and the machining conditions.

[0081] (9) The obtained spindle bearing 2 temperature gear is analyzed. When the spindle bearing 2 temperature (including the front and rear bearings) is continuously in the high temperature X5 range within 3 to 6 sampling cycles ΔT of the cooling and lubrication control system 14, and there is still no downward trend after matching the optimal oil-gas lubrication parameters, the electric spindle speed is reduced or the processing is stopped.

[0082] When the temperature of spindle bearing 2 (including the front and rear bearings) is in the ultra-high temperature X6 range, directly reduce the spindle speed or stop processing.

[0083] (10) The obtained spindle motor stator 3 temperature level is analyzed. When the spindle motor stator 3 temperature is continuously in the high temperature Y5 range within 3 to 6 sampling cycles ΔT of the cooling and lubrication control system 14, and there is still no downward trend after matching the optimal coolant parameters, the electric spindle speed is reduced or the processing is stopped. When the spindle motor stator 3 temperature is in the ultra-high temperature Y6 range, the electric spindle speed is directly reduced or the processing is stopped.

[0084] Although the specific embodiments of the present application have been described in detail, this should not be construed as limiting the scope of protection of the present application. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of the present application.

Claims

1. A high-speed electric spindle intelligent cooling and lubrication system, characterized in that: include: A spindle (1), a spindle bearing (2), a spindle motor stator (3), and a spindle motor rotor (5), wherein the spindle motor stator (3) is used to cooperate with the spindle motor rotor (5) to achieve rotation, the spindle motor rotor (5) is used to drive the spindle (1) to rotate, and the spindle bearing (2) is used to support the spindle (1); A coolant (4) and a coolant refrigerator (8), wherein the coolant (4) is used to absorb heat from the spindle motor stator (3) and the spindle motor rotor (5), and is circulated through the coolant refrigerator (8) to cool the coolant and then flow back to the cooling channel; A lubricating oil tank (9), an air refrigeration machine (10), a flow regulating valve (11) and an oil-air mixer (12), wherein the lubricating oil tank (9) stores low-viscosity lubricating oil, the air refrigeration machine (10) controls the air temperature, the flow regulating valve (11) adjusts the supply parameters of the lubricating oil, air and coolant (4), and the oil-air mixer (12) mixes the lubricating oil with the air to form an oil-air lubricating medium (13) to cool and lubricate the main shaft bearing (2); A temperature sensor (6) for monitoring the temperature of the spindle bearing (2) and the spindle motor stator (3) in real time and transmitting the temperature to a cooling and lubrication control system (14); The cooling and lubrication control system (14) dynamically generates control instructions for oil and gas lubrication parameters and coolant parameters based on a preset parameter classification method and according to real-time temperature data and processing condition parameters, and controls the flow regulating valve (11), the coolant refrigerator (8) and the air refrigerator (10).

2. The intelligent cooling and lubrication system for a high-speed electric spindle (1) according to claim 1 is characterized in that: It also includes an oil-gas separator (7) for separating low-viscosity lubricating oil and air in the oil-gas lubricating medium (13) and recycling them; The input end of the oil-gas mixer (12) is respectively connected to the oil outlet of the lubricating oil tank (9) and the air outlet of the air chiller (10), and the output end of the oil-gas mixer (12) is connected to the lubrication channel of the main shaft bearing (2) through a pipeline.

3. The high-speed electric spindle intelligent cooling and lubrication system according to claim 1, characterized in that: The parameter classification method of the cooling and lubrication control system (14) includes: Classifying the workpiece material information into at least three categories including easy-to-process materials, conventional materials, and difficult-to-process materials; Classifying the tool parameter information into at least four categories including milling cutters, boring cutters, drill bits, and reamers according to model and purpose; The processing parameter information is divided into six categories according to the spindle torque and speed, including low speed and light load, low speed and heavy load, medium speed and light load, medium speed and heavy load, high speed and light load, and high speed and heavy load.

4. The high-speed electric spindle intelligent cooling and lubrication system according to claim 1, characterized in that: The parameter classification method of the cooling and lubrication control system (14) includes: dividing the temperature of the spindle bearing (2) or the temperature of the spindle motor stator (3) into at least six temperature levels including low temperature, medium-low temperature, medium temperature, medium-high temperature, high temperature and ultra-high temperature.

5. A high-speed electric spindle intelligent cooling and lubrication method, applied to the high-speed electric spindle intelligent cooling and lubrication system according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Data Acquisition The temperature data of the spindle bearing (2) and the spindle motor stator (3) are collected in real time by a temperature sensor, and workpiece material information, tool parameter information and machining process parameter information are extracted from the NC program; S2. Working condition identification Determine the current machining condition type based on a preset weight coefficient and a parameter time ratio within a sampling period ΔT of a cooling and lubrication control system (14); S3. Parameter matching According to the processing condition type and real-time temperature data, query and generate corresponding oil and gas lubrication parameters and coolant parameters from a preset heat generation and heat dissipation model; S4, dynamic adjustment Controlling the flow regulating valve (11), the coolant refrigerator (8) and the air refrigerator (10) to execute the oil-gas lubrication parameters and the coolant parameters, and continuously monitoring temperature changes; S5. Security Response When the temperature of the spindle bearing (2) or the temperature of the spindle motor stator (3) is continuously at a high temperature gear and there is no downward trend after adjusting the parameters, the operation of reducing the high-speed electric spindle speed or stopping the processing is executed.

6. The intelligent cooling and lubrication method for a high-speed electric spindle according to claim 5, characterized in that: The oil-gas lubrication parameters include lubricating oil flow rate, lubricating oil supply frequency, air flow rate and air temperature; the coolant parameters include coolant flow rate and coolant temperature.

7. The intelligent cooling and lubrication method for a high-speed electric spindle according to claim 5, characterized in that: The workpiece material information is extracted based on the following method: A workpiece material identification statement is added to the NC machine tool NC program, and the current workpiece material type is determined by weight coefficient conversion based on the processing time proportion of different materials within the sampling period ΔT of the cooling and lubrication control system (14).

8. The intelligent cooling and lubrication method for a high-speed electric spindle according to claim 5, characterized in that: The tool parameter information is extracted based on the following method: adding a tool parameter identification statement to the NC machine tool NC program, and determining the current tool parameter by converting the weight coefficient according to the usage time proportion of different tools within the sampling period ΔT of the cooling and lubrication control system (14).

9. The intelligent cooling and lubrication method for a high-speed electric spindle according to claim 5, characterized in that: The processing parameter information is extracted based on the following method: adding a processing parameter identification statement to the NC machine tool NC program, using the spindle torque and speed as the judgment basis, and determining the current processing parameter by converting the weight coefficient according to the time proportion of different processing processes within the sampling period ΔT of the cooling and lubrication control system (14).

10. The intelligent cooling and lubrication method for a high-speed electric spindle according to claim 5, characterized in that: The oil-air lubrication parameters and coolant parameters are implemented by the following method: When the high-speed and light-load operating condition is identified, the lubricating oil viscosity is controlled to be less than 20 mPa·s, the air temperature is normal temperature, and the coolant temperature is set within the operating temperature range; When a low-speed heavy-load operating condition is identified, the air refrigeration unit (10) is controlled to reduce the air temperature, increase the viscosity of the lubricating oil to >100 mPa·s, and increase the flow rate of the coolant; When the temperature of the main shaft bearing (2) is at a high temperature gear, the air flow rate and the coolant flow rate are increased synchronously to reduce the air temperature and the coolant temperature; When the temperature of the spindle motor stator (3) is at a high temperature gear, the coolant flow rate is increased and the coolant temperature is reduced.

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