Intelligent monitoring and regulation and control system for motorized spindle

Abstract

The utility model relates to the technical field of motorized spindles, in particular to an intelligent monitoring and regulating system of a motorized spindle, which is characterized in that a first front-end displacement sensor and a second front-end displacement sensor are respectively used for detecting the displacement of a front-end bearing in the X direction and the Y direction, and a first rear-end displacement sensor is used for detecting the displacement of a rear-end bearing in the Z direction; when the displacement of the front-end bearing in the X direction and the Y direction or the displacement of the rear-end bearing in the Z direction exceeds a set threshold value, the signal acquisition control system controls the piezoelectric ceramic sensor to act so as to adjust the pre-tightening force of the motorized spindle, and when the temperature detected by the temperature sensor exceeds the set threshold value, the water cooling system is started for cooling, and when the temperature still exceeds the set threshold value, the motor is started. According to the electric spindle cooling system, accurate control over the cooling effect of the electric spindle is achieved through combination of water cooling and oil cooling.

Description

Technical Field

[0001] This utility model relates to the field of electric spindle technology, and in particular to an intelligent monitoring and control system for electric spindles. Background Technology

[0002] With the rapid development of industrial intelligence, CNC machine tools are being used more and more widely in industrial development. As a core component of CNC machine tools, the electric spindle's operating status determines the machine tool's performance. Currently, the operating status of electric spindles is mostly measured by visual indicators such as the batch pass rate of processed products or changes in machine tool vibration and noise during operation, which cannot accurately predict changes in the electric spindle's performance. In addition, because electric spindles generate heat during operation, changes in this heat can cause thermal deformation of key components such as bearings and shafts. This thermal deformation seriously affects the machining accuracy of the machine tool and the service life of the bearings.

[0003] Therefore, achieving intelligent control and monitoring of electric spindles is an effective method for accurately predicting their working performance. Simultaneously, intelligent regulation of temperature and displacement is an effective way to reduce the impact of temperature variations on spindle accuracy. Thus, realizing intelligent control and condition monitoring of electric spindles is of great significance. Because the spindle housing is the cooling system, and due to the gradient of bearing temperature changes and the integrity and sealing of the bearing housing structure, accurate monitoring of bearing temperature is difficult. Currently, the internal temperature rise of commonly used electric spindles can only be cooled by water cooling or oil misting, which lacks sufficient controllability and thus affects their performance and service life.

[0004] In summary, there are still many shortcomings in the current monitoring of temperature, displacement, and vibration during the operation of electric spindles, as well as in preload compensation and temperature control. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide an intelligent monitoring and control system for electric spindles, which aims to solve the problem that existing electric spindles cannot monitor and control their own performance.

[0006] The technical solution of this utility model is:

[0007] An intelligent monitoring and control system for an electric spindle includes an electric spindle rotor assembly, an electric spindle stator assembly, a temperature control assembly, and a temperature proportional controller.

[0008] The electric spindle stator assembly and the electric spindle housing are arranged sequentially on the outside of the electric spindle rotor assembly. Multiple temperature sensors are evenly distributed on the outside of the front bearing and the rear bearing of the electric spindle rotor assembly.

[0009] The temperature control assembly includes a water-cooled control assembly and an oil-cooled control assembly. The water-cooled control assembly is connected to the cold water channel on the electric spindle housing via a pipeline, and the oil-cooled control assembly is connected to the oil-cooling channel on the electric spindle housing via a pipeline.

[0010] The temperature sensor, water-cooling control component, and oil-cooling control component are connected to the temperature proportional controller. The temperature proportional controller determines whether to start or stop the water-cooling control component and whether the oil-cooling control component needs to be further activated based on the temperature information fed back by the temperature sensor and by comparing it with a preset temperature threshold.

[0011] The water-cooling control component includes a water pump, a cooling fan, and water pipes. The water pump inlet is connected to a water tank, and the water pump outlet is connected to a water storage tank. A cooling fan is installed on one side of the water storage tank. The cooling fan is driven by a fan motor and cools the water in the water storage tank. The water storage tank outlet is connected to the cold water channel inlet through a pipe joint, and the cold water channel outlet is connected to the water tank.

[0012] The temperature proportional controller is connected to the fan motor. Based on the temperature information fed back by the temperature sensor, the controller compares it with a preset temperature threshold to determine whether the fan motor should start or stop, and whether the oil cooling control components need to be activated further.

[0013] The oil cooling control component includes an oil mist system, an oil mist generator, an oil mist flow control valve, and an oil pipe. The oil mist system is connected to the oil inlet of the oil cooling channel through a pipe. The oil mist flow control valve and the oil mist generator are installed on the pipe. The oil outlet of the oil cooling channel is connected to the oil mist system.

[0014] The temperature proportional controller is connected to the oil mist flow control valve. The temperature proportional controller determines the start and stop of the oil mist flow control valve by comparing the temperature information fed back by the temperature sensor with the preset temperature threshold.

[0015] An intelligent monitoring and control system for an electric spindle further includes a signal acquisition and control system. Vibration sensors are respectively provided on the outer side of the front and rear bearings of the electric spindle rotor assembly. The vibration sensors collect vibration information of the front and rear bearings and transmit the vibration information to the signal acquisition and control system. The signal acquisition and control system judges the performance of the front and rear bearings based on the vibration information.

[0016] The front end of the electric spindle rotor assembly is connected to a first front-end displacement sensor for detecting the displacement in the Y direction of the front-end bearing and a second front-end displacement sensor for detecting the displacement in the X direction of the front-end bearing via a displacement sensor mounting bracket. The first front-end displacement sensor is used to detect the displacement in the Y direction of the front-end bearing of the electric spindle rotor assembly, and the second front-end displacement sensor is used to detect the displacement in the X direction of the front-end bearing of the electric spindle rotor assembly.

[0017] The rear end of the electric spindle rotor assembly is connected to a first rear end displacement sensor via a rear end cover for detecting the displacement of the rear end bearing of the electric spindle rotor assembly in the Z direction.

[0018] The rear end of the electric spindle rotor assembly is provided with an adjustable preload assembly. The adjustable preload assembly is fixed to the electric spindle rotor assembly through the rear bearing seat. The adjustable preload assembly includes a piezoelectric ceramic front holding structure, a piezoelectric ceramic rear support structure, and a piezoelectric ceramic sensor. The piezoelectric ceramic front holding structure and the piezoelectric ceramic rear support structure are respectively fixed to the rear bearing seat. The piezoelectric ceramic sensor is placed in the middle of the piezoelectric ceramic front holding structure and the piezoelectric ceramic rear support structure.

[0019] The displacement values ​​of the first front displacement sensor, the second front displacement sensor, and the first rear displacement sensor are transmitted to the signal acquisition and control system, which then controls the piezoelectric ceramic sensor to adjust the preload.

[0020] The beneficial effects of adopting the above technical solution are as follows:

[0021] 1. Precise Prediction and Real-time Monitoring: This invention can monitor key parameters of the electric spindle in real time, such as vibration, preload, displacement, and temperature, enabling precise prediction of changes in the spindle's working performance. This not only allows for the timely detection of potential faults but also enables proactive measures to prevent production interruptions caused by sudden malfunctions, significantly improving production efficiency and equipment reliability.

[0022] 2. Optimized thermal management strategy: In response to the heat generated during the operation of the electric spindle and its impact on the thermal deformation of key components, this utility model overcomes the problem of accurately monitoring bearing temperature in traditional methods through innovative temperature monitoring technology. By monitoring the temperature changes of the bearing and the surrounding environment in real time, the operation strategy of the cooling system is optimized to ensure that the electric spindle operates within the optimal temperature range, effectively reducing thermal deformation and improving the machining accuracy of the machine tool and the service life of the bearing.

[0023] 3. Improved Controllability of Cooling Effect: Addressing the issue of uncontrollable cooling effects in existing methods, this invention combines water and oil cooling for temperature reduction, while dynamically adjusting the parameters of the water cooling control components to achieve precise control of the cooling effect. This not only improves cooling efficiency but also reduces energy waste and lowers operating costs.

[0024] 4. Improve overall machining quality and economic benefits: By accurately monitoring and predicting the working status of the electric spindle, and promptly identifying and resolving potential problems, this utility model can significantly improve the machining accuracy and stability of the machine tool, reduce the defect rate caused by malfunctions, and thus improve the overall machining quality. Attached Figure Description

[0025] Figure 1This is a structural cross-sectional view of an intelligent monitoring and control system for an electric spindle according to this utility model;

[0026] Figure 2 This is a schematic diagram of the water-cooled control component of an intelligent monitoring and control system for an electric spindle according to this utility model;

[0027] Figure 3 This is a schematic diagram of the oil cooling control component of an intelligent monitoring and control system for an electric spindle according to this utility model;

[0028] Figure 4 This is a schematic diagram showing the position of the displacement sensor in an intelligent monitoring and control system for an electric spindle according to this utility model.

[0029] Figure 5 This is a schematic diagram showing the positions of the temperature sensor and vibration sensor in an intelligent monitoring and control system for an electric spindle according to this utility model.

[0030] Figure 6 This is a schematic diagram of the front bearing housing of an intelligent monitoring and control system for an electric spindle according to this utility model.

[0031] Figure 7 This is a schematic diagram of the assembly of the front bearing housing of the intelligent monitoring and control system for an electric spindle according to this utility model.

[0032] Figure 8 This is a schematic diagram showing the position of the piezoelectric ceramic sensor in an intelligent monitoring and control system for an electric spindle according to this utility model.

[0033] Figure 9 This is a control flowchart of an intelligent monitoring and control system for an electric spindle according to this utility model;

[0034] In the attached diagram: 1. Electric spindle rotor assembly; 1-1. Electric spindle shaft; 1-2. Electric spindle stator core; 1-3. First electric spindle core retaining ring; 1-4. Second electric spindle core retaining ring; 1-5. Front bearing; 1-6. Rear bearing; 1-7. Bearing retaining ring; 2. Electric spindle stator assembly; 2-1. Water cooling jacket; 2-2. Electric spindle stator system; 2-3. Electric spindle stator retaining ring; 3. Electric spindle housing; 4. Front bearing housing; 4-1. Front bearing housing base; 4-2. Front bearing housing bearing support; 4-3. Front bearing housing bearing adjusting ring; 4-4. Tapered slider; 4-5. Bolt; 5. Front bearing housing sealing end cover; 6. Front bearing threaded retaining ring; 7. Adjustable preload assembly; 7-1 7-1. Piezoelectric ceramic front holding structure; 7-2. Piezoelectric ceramic rear support structure; 7-3. Piezoelectric ceramic sensor; 8. Rear bearing seat; 9. Rear end cover; 10. Displacement sensor mounting bracket; 11. Temperature sensor; 12. Water cooling control assembly; 12-1. Water pump; 12-2. Water storage tank; 12-3. Water pipe; 12-4. Cooling fan; 13. Oil cooling control assembly; 13-1. Oil mist system; 13-2. Oil mist generator; 13-3. Oil mist flow control valve; 13-4. Oil pipe; 14. Temperature proportional controller; 15. Signal acquisition and control system; 16. Vibration sensor; 17. First front displacement sensor; 18. Second front displacement sensor; 19. First rear displacement sensor. Detailed Implementation

[0035] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0036] As a core component of machine tools, the performance monitoring and intelligent control of electric spindles are of paramount importance. This invention provides an intelligent monitoring and control system and method for electric spindles. The basic idea of ​​this invention is as follows: by integrating multiple high-precision sensors, a signal acquisition and control system, and a temperature proportional controller, the system monitors important performance indicators of the electric spindle in real time, such as temperature, vibration, preload, and displacement. The temperature control component performs cooling control based on temperature changes during operation, ensuring that the electric spindle operates within the optimal temperature range, effectively reducing thermal deformation, and improving the machining accuracy and bearing life of the machine tool.

[0037] like Figure 1-9 As shown, an intelligent monitoring and control system for an electric spindle includes an electric spindle rotor assembly 1, an electric spindle stator assembly 2, a temperature control assembly, and a temperature proportional controller 14.

[0038] The electric spindle rotor assembly 1 is sequentially provided with an electric spindle stator assembly 2 and an electric spindle housing 3 on its outer side. Multiple temperature sensors 11 are evenly distributed on the outer side of the front bearing 1-5 and the rear bearing 1-6 of the electric spindle rotor assembly 1. In this embodiment, there are 3 sets of temperature sensors 11, which are respectively set on the upper, lower and side of the bearing.

[0039] The temperature control assembly includes a water-cooling control assembly 12 and an oil-cooling control assembly 13. The water-cooling control assembly 12 is connected to the cold water channel on the electric spindle housing 3 through a pipeline. The water-cooling control assembly is used to cool the electric spindle rotor assembly 1 and the electric spindle stator assembly 2. The oil-cooling control assembly 13 is connected to the oil-cooling channel on the electric spindle housing 3 through a pipeline. The oil-cooling control assembly is used to cool the electric spindle rotor assembly 1 and the electric spindle stator assembly 2.

[0040] Temperature sensor 11, water-cooling control component 12, and oil-cooling control component 13 are connected to temperature proportional controller 14. The temperature proportional controller determines whether to start or stop the water-cooling control component and whether to further activate the oil-cooling control component based on the temperature information fed back by the temperature sensor and by comparing it with a preset temperature threshold. The temperature value collected by temperature sensor 11 is transmitted to temperature proportional controller 14. Temperature proportional controller 14 determines that the collected temperature information exceeds the set temperature threshold and controls water-cooling control component 12 to work for a preset period of time. When the temperature value collected by temperature sensor 11 is less than the set temperature threshold, water-cooling control component 12 stops working. If the temperature value collected by temperature sensor 11 is still greater than the set temperature threshold after water-cooling control component 12 has been working for the preset period of time, and the duration has reached the preset period of time, then temperature proportional controller 14 controls oil-cooling control component 13 to work until the temperature value collected by temperature sensor 11 is less than the set temperature threshold.

[0041] The electric spindle rotor assembly includes an electric spindle shaft 1-1, an electric spindle stator core 1-2, a first electric spindle core retaining ring 1-3, a second electric spindle core retaining ring 1-4, bearings, and bearing retaining rings 1-7. The electric spindle stator core 1-2 is installed on the outside of the electric spindle shaft 1-1. The first electric spindle core retaining ring 1-3 and the second electric spindle core retaining ring 1-4 fix the two sides of the electric spindle stator core 1-2. The bearing 4 includes a front bearing 1-5 and a rear bearing 1-6, which are respectively installed at the front and rear ends of the electric spindle shaft 1-1. The bearing retaining rings 1-7 are respectively located on the outside of the front bearing 1-5 and the rear bearing 1-6 and fixed on the electric spindle shaft 1-1 for transmission control of the electric spindle.

[0042] Among them, the front bearing 1-5 and the rear bearing 1-6 used in the electric spindle are made of all-ceramic materials;

[0043] The electric spindle stator assembly 2 includes a water-cooling jacket 2-1, an electric spindle stator system 2-2, and an electric spindle stator retaining ring 2-3. The electric spindle stator system 2-2 is located outside the electric spindle stator core 1-2. The electric spindle stator retaining ring 2-3 is installed at both ends of the electric spindle stator system 2-2 and located outside the electric spindle stator core 1-2. The water-cooling jacket 2-1 is provided outside the electric spindle stator system 2-2 and the electric spindle stator retaining ring 2-3. The electric spindle housing 3 is provided outside the water-cooling jacket 2-1. The electric spindle housing 3 and the water-cooling jacket 2-1 are assembled by an interference fit. The electric spindle stator system 2-2 is installed inside the assembled electric spindle housing 3 and water-cooling jacket 2-1. This protects the internal structure of the electric spindle and generates a magnetic field and energy conversion.

[0044] A front bearing seat 4 is provided on the outside of the front bearing 1-5 of the electric spindle rotor assembly 1. One end of the front bearing seat 4 is fixed to the electric spindle housing 3, and the other end is connected to the front bearing seat sealing end cover 5. The front bearing threaded retaining ring 6 is locked to the electric spindle shaft 1-1 and the front bearing seat sealing end cover 5 through its own external thread. The displacement sensor fixing bracket 10 is fixedly connected to the outside of the front bearing seat sealing end cover 5. An adjustable preload assembly 7 is provided behind the rear bearing 1-6. A rear bearing seat 8 is provided above the rear bearing 1-6. The rear bearing seat 8 is connected to the electric spindle housing 3. The adjustable preload assembly 7 is connected to the rear bearing seat 8. The rear bearing seat 8 is connected to the rear end cover 9.

[0045] Specifically: the front bearing housing 4 is connected to the electric spindle housing 3 by a thread, the front bearing housing sealing end cover 5 is connected to the front bearing housing 4 by a thread, and the front bearing threaded retaining ring 6 is locked to the electric spindle shaft 1-1 by its own external thread;

[0046] The front bearing housing 4 includes a front bearing housing base 4-1, a front bearing housing bearing support 4-2, a front bearing housing bearing adjusting ring 4-3, a tapered slider 4-4, and bolts 4-5. The front bearing housing bearing support 4-2 is located above the front bearing housing base 4-1, and the front bearing housing bearing adjusting ring 4-3 is located in the cavity of the front bearing housing bearing support 4-2 and fits against it. The front bearing housing bearing support 4-2 is provided with a groove, and multiple tapered sliders 4-4 are provided in the groove. The tapered sliders 4-4 are slidably connected in the groove. The front bearing housing bearing support 4-2 and the multiple tapered sliders 4-4 are connected by bolts 4-5. The tapered sliders 4-4 drive the rotation of the front bearing housing bearing support 4-2, thereby adjusting the position of the first sensor hole and collecting the temperature at each position on the side of the bearing.

[0047] A first sensor hole is opened at the front bearing housing 4. The front bearing housing 4 is connected to the temperature sensor 11 on the front bearing through the first sensor hole using a sensor transmission line to collect the real-time temperature of the bearing. The front bearing housing 4 is pre-tightened by a central through-hole bolt structure to prevent the temperature sensor from loosening. A second sensor hole is opened at the connection between the rear bearing housing 8 and the electric spindle housing 3. The rear bearing housing 8 is connected to the temperature sensor 11 on the rear bearing 1-6 through the second sensor hole using a sensor line and is pre-tightened by a central through-hole bolt structure to collect the temperature at each position on the side of the bearing. When the bearing temperature exceeds the set temperature value, the temperature proportional controller 14 controls the water cooling control component 12 and the oil cooling control component 13 to perform self-regulation. The speed of the spindle cooling fan is increased to cool the electric spindle. When the temperature drops to the set value, the speed of the spindle cooling fan begins to decrease. When the temperature is still higher than the set temperature, the oil cooling control component 13 is used for regulation to achieve intelligent regulation of the internal temperature of the electric spindle.

[0048] In this embodiment, the front bearing housing 4 allows for adjustment of the bearing housing adjustment ring 4-3, which changes the contact position of the temperature sensor without requiring replacement of the front bearing housing 4 or drilling at the measurement point. The positional variation of the tapered slider 4-4 enables measurement of any point on the outer ring of the bearing within a 360° radius.

[0049] The front bearing housing 4 features a through-hole design, eliminating the inner shoulder of the front bearing housing. Axial positioning is achieved using the front bearing housing sealing end cap 5. This allows for the assembly of the all-ceramic bearing onto the spindle first, followed by direct installation at the rear end of the spindle, avoiding the need to install the spindle first and then the bearing. This facilitates front bearing installation and ensures uniform cooling of the spindle during liquid nitrogen immersion cooling. This design is suitable for assembling all-ceramic bearings in electric spindles.

[0050] The water-cooling control component 12 includes a water pump 12-1, a cooling fan 12-4, and a water pipe 12-3. The inlet of the water pump 12-1 is connected to a water tank, and the outlet of the water pump 12-1 is connected to a water storage tank 12-2. A cooling fan 12-4 is provided on one side of the water storage tank 12-2. The cooling fan 12-4 is driven by a fan motor and cools the water in the water storage tank 12-2. The outlet of the water storage tank 12-2 is connected to the inlet of the cold water channel through a pipe joint, and the outlet of the cold water channel is connected to the water tank.

[0051] The temperature proportional controller is connected to the cooling fan 12-4. Based on the temperature information fed back by the temperature sensor, the temperature proportional controller determines whether the fan motor should start or stop and whether the oil cooling control component needs to be further activated by comparing it with the preset temperature threshold. If the temperature information collected by the temperature sensor 11 exceeds the set temperature threshold, the temperature proportional controller 14 controls the speed of the cooling fan 12-4. If the temperature value collected by the temperature sensor 11 is less than the set temperature threshold after the speed of the cooling fan 12-4 is modulated to the maximum and continues for a preset period of time, the oil cooling control component 13 is activated.

[0052] The oil cooling control component 13 includes an oil mist system 13-1, an oil mist generator 13-2, an oil mist flow control valve 13-3, and an oil pipe 13-4. The oil mist system 13-1 is connected to the oil inlet of the oil cooling channel via a pipe. The oil mist flow control valve 13-3 and the oil mist generator 13-2 are installed on the pipe. The oil outlet of the oil cooling channel is connected to the oil mist system 13-1. A temperature proportional controller is connected to the oil mist flow control valve 13-3. The temperature proportional controller determines the start and stop of the oil mist flow control valve by comparing the temperature information fed back by the temperature sensor with a preset temperature threshold. After the water cooling component has been working for a preset period of time, the temperature proportional controller determines that the temperature information collected by the temperature sensor exceeds the set temperature threshold. The temperature proportional controller controls the opening and closing of the oil mist flow control valve 13-3 and the flow rate to cool down the electric spindle rotor assembly 1 and the electric spindle stator assembly 2.

[0053] When the temperature exceeds the set temperature, the cooling fan 12-4 will adjust its fan speed to increase the cooling rate. After the cooling fan 12-4 is adjusted to its maximum, if the temperature value detected by the temperature sensor 11 is still higher than the set temperature and continues for a preset period of time (this time can be adjusted), the oil mist flow control valve 13-3 will start to increase the pressure and increase the oil supply to reduce the spindle temperature through the oil mist lubricator 13-2, thereby achieving intelligent control of the electric spindle bearing temperature.

[0054] An intelligent monitoring and control system for an electric spindle further includes a signal acquisition and control system 15. Vibration sensors 16 are respectively provided on the outer side of the front bearing 1-5 and the rear bearing 1-6 of the electric spindle rotor assembly 1. The vibration sensors collect vibration information of the front bearing 1-5 and the rear bearing 1-6 and transmit the vibration information to the signal acquisition and control system 15. The signal acquisition and control system 15 judges the performance of the front bearing 1-5 and the rear bearing 1-6 based on the vibration information.

[0055] The front-end vibration sensor is connected to the signal acquisition and control system 15 via a transmission line passing through the first sensor hole on the front-end bearing housing 4. The front-end vibration sensor contacts the front-end bearing 1-5 and collects the vibration signal of the front-end bearing 1-5 in real time, transmitting the vibration information of the front-end bearing to the signal acquisition and control system 15 and displaying it on the interface of the signal acquisition and control system 15. The rear-end vibration sensor is connected to the signal acquisition and control system 15 via a transmission line passing through the second sensor hole on the rear bearing housing 1-8. The rear-end bearing vibration sensor contacts the rear-end bearing 1-6 and collects the vibration signal of the rear-end bearing 1-6 in real time, transmitting the vibration information of the rear-end bearing to the signal acquisition and control system 15 and displaying it on the interface of the signal acquisition and control system 15. By analyzing the bearing vibration signals, the performance of the bearings during the operation of the electric spindle can be clearly identified, thereby enabling timely and effective maintenance and avoiding affecting the operating accuracy of the electric spindle.

[0056] The front end of the electric spindle rotor assembly 1 is connected to a first front end displacement sensor 17 and a second front end displacement sensor 18 via a displacement sensor mounting bracket 10. The first front end displacement sensor 17 is used to detect the displacement of the front end bearing 1-5 in the Y direction of the electric spindle rotor assembly 1, and the second front end displacement sensor 18 is used to detect the displacement of the front end bearing 1-5 in the X direction of the electric spindle rotor assembly 1.

[0057] The rear end of the electric spindle rotor assembly 1 is connected to a first rear end displacement sensor 19 via a rear end cover 9. The first rear end displacement sensor 19 is used to detect the Z-direction displacement of the rear end bearings 1-6 of the electric spindle rotor assembly 1. Specifically, the displacement sensor mounting bracket 10 is connected to the front bearing housing sealing end cover 5 via bolts. Tapered bolts are installed on the displacement sensor mounting bracket 10 to fix the first front end displacement sensor 17 and the second front end displacement sensor 18, which are used to detect the output accuracy of the front end shaft of the electric spindle. The first rear end displacement sensor 19 is placed through the center hole of the rear end cover 9 of the electric spindle, which is used to detect the change in axial displacement of the electric spindle during operation. The real-time displacement of the electric spindle shaft collected by the displacement sensor is transmitted to the signal acquisition and control system 15 and displayed in the interface of the signal acquisition and control system 15.

[0058] The rear end of the electric spindle rotor assembly 1 is provided with an adjustable preload assembly 7. The adjustable preload assembly 7 is fixed to the electric spindle rotor assembly 1 via a rear bearing seat 1-8. The adjustable preload assembly 7 includes a piezoelectric ceramic front holding structure 7-1, a piezoelectric ceramic rear support structure 7-2, and a piezoelectric ceramic sensor 7-3. The piezoelectric ceramic front holding structure 7-1 and the piezoelectric ceramic rear support structure 7-2 are respectively fixed to the rear bearing seat 1-8. The piezoelectric ceramic sensor 7-3 is placed between the piezoelectric ceramic front holding structure 7-1 and the piezoelectric ceramic rear support structure 7-2. Specifically, the piezoelectric ceramic front holding structure 7-1 is connected to the rear bearing seat 1-8, the piezoelectric ceramic sensor 7-3 is inserted, and the piezoelectric ceramic rear support structure is... Structure 7-2 is fixed to the rear bearing housing 1-8 by bolts. The piezoelectric ceramic front retaining structure 7-1 has three cylindrical blind holes. A through hole is opened at the center of the blind holes, which is flush with the center of the bearing outer ring. The piezoelectric ceramic rear support structure 7-2 has three cylindrical blind holes in the same position as the piezoelectric ceramic front retaining structure 7-1. A through hole is opened on the side of the blind holes for connecting the sensor wire. The sensor wire is connected to the piezoelectric ceramic sensor 7-3. The position of the piezoelectric ceramic sensor 7-3 is adjusted by the adjusting bolts behind the piezoelectric ceramic rear support structure 7-2, thereby ensuring that the sensor and the bearing outer ring are in the same horizontal position, and ensuring that the three piezoelectric ceramics can act on the bearing outer ring at the same time to achieve uniform adjustment of the preload.

[0059] The displacement values ​​of the first front displacement sensor 17, the second front displacement sensor 18, and the first rear displacement sensor 19 are transmitted to the signal acquisition and control system 15. The signal acquisition and control system 15 controls the piezoelectric ceramic sensor 7-3 to adjust the preload. This is based on the existing spring preload and adjusts the preload of the intelligent electric spindle by expanding and contracting the piezoelectric ceramic under different current and voltage conditions. When the electric spindle rotates axially due to temperature changes during operation, causing a change in the preload, the signal acquisition and control system 15 sends an analog electrical signal to the piezoelectric ceramic sensor 7-3 to compensate for the preload. The piezoelectric ceramic component changes its displacement, pushing the outer ring of the bearing to move, thereby controlling the preload, that is, adjusting the preload of the electric spindle during operation.

[0060] A control method for an intelligent monitoring and control system for an electric spindle, which evaluates the operating accuracy of the electric spindle by detecting changes in its displacement, includes the following steps:

[0061] Step 1: The electric spindle is running. Temperature sensor 11 detects the real-time temperature values ​​of the front bearing 1-5 and the rear bearing 1-6. The first front displacement sensor 17 and the second front displacement sensor 18 detect the displacement of the front bearing 1-5 in the X and Y directions, respectively. The first rear displacement sensor 19 detects the displacement of the rear bearing 1-6 in the Z direction.

[0062] Step 2: When the displacement of the front bearing 1-5 in the X and Y directions or the displacement of the rear bearing 1-6 in the Z direction exceeds the set threshold, the signal acquisition and control system 15 controls the piezoelectric ceramic sensor 7-3 to act, thereby adjusting the preload of the electric spindle.

[0063] Step 3: When the temperature detected by temperature sensor 11 exceeds the set threshold, temperature proportional controller 14 controls cooling fan 12-4 to start. Simultaneously, based on the temperature of the front bearing 1-5 or rear bearing 1-6 detected by temperature sensor 11, the power of cooling fan 12-4 is adjusted. Cooling water circulates in the water-cooling channel to cool the electric spindle rotor assembly 1 and electric spindle stator assembly 2. After a preset time period, when the temperature detected by temperature sensor 11 is lower than the set threshold, cooling fan 12-2 stops working. When the cooling fan stops working, but the temperature detected by temperature sensor 11 is still higher than the set threshold, temperature proportional controller 14 controls oil mist flow control valve 13-3 to operate. After a preset time period, oil mist flow control valve 13-3 begins to increase pressure and increase oil supply to reduce the spindle temperature through oil mist lubricator 13-2, thereby achieving intelligent control of the electric spindle bearing temperature.

[0064] This invention enables constant-temperature control of the internal temperature rise of the electric spindle. When the spindle bearing is under load and the rotational speed increases, the temperature rises, which affects the thermal deformation of the shaft. Temperature sensors collect temperature rise data at three locations on the bearing (high, medium, and low) and compare this data with a set temperature value. When the temperature rise exceeds the set value, the cooling fan in the cooling control assembly increases its cooling speed to lower the temperature. Once the temperature stabilizes at the set temperature, the cooling fan maintains a constant speed. If the cooling fan speed is insufficient to reduce the temperature, the oil pump's oil supply is increased to further reduce the spindle temperature. When the temperature drops to the set value, the oil pump maintains its oil supply rate.

[0065] When the spindle is subjected to load, its temperature rise changes. This temperature change affects the axial deformation of the spindle, i.e., the preload. This, in turn, affects the spindle's vibration value, leading to a decrease in machining accuracy. To effectively achieve high-precision spindle operation, i.e., to reduce the axial displacement changes caused by spindle temperature rise, we can detect the displacement variations in the X, Y, and Z directions of the spindle to estimate the changes in preload. Furthermore, by controlling the current or voltage signal of a piezoelectric sensor, we can change the expansion and contraction of the piezoelectric ceramic, thereby compensating for the preload.

[0066] Control program based on cooling system:

[0067]

[0068]

[0069]

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the claims of this utility model.

Claims

1. An intelligent monitoring and control system for an electric spindle, characterized in that, Includes electric spindle rotor assembly, electric spindle stator assembly, temperature control assembly, and temperature proportional controller. The electric spindle stator assembly and the electric spindle housing are arranged sequentially on the outside of the electric spindle rotor assembly. Multiple temperature sensors are evenly distributed on the outside of the front bearing and the rear bearing of the electric spindle rotor assembly. The temperature control component includes a water-cooled control component and an oil-cooled control component. The water-cooled control component is connected to the cold water channel on the electric spindle housing via a pipeline, and the oil-cooled control component is connected to the oil-cooled channel on the electric spindle housing via a pipeline. The temperature sensor, the water-cooled control component, and the oil-cooled control component are connected to a temperature proportional controller. The temperature proportional controller determines whether to start or stop the water-cooled control component and whether the oil-cooled control component needs to be further activated based on the temperature information fed back by the temperature sensor and by comparing it with a preset temperature threshold.

2. The intelligent monitoring and control system for an electric spindle according to claim 1, characterized in that, The water-cooling control component includes a water pump, a cooling fan, and water pipes. The water pump inlet is connected to a water tank, and the water pump outlet is connected to a water storage tank. A cooling fan is installed on one side of the water storage tank. The cooling fan is driven by a fan motor and cools the water in the water storage tank. The water storage tank outlet is connected to the cold water channel inlet through a pipe joint, and the cold water channel outlet is connected to the water tank. The temperature proportional controller is connected to the fan motor. Based on the temperature information fed back by the temperature sensor, the temperature proportional controller compares it with a preset temperature threshold to determine whether the fan motor should start or stop and whether the oil cooling control component needs to be activated.

3. The intelligent monitoring and control system for an electric spindle according to claim 1, characterized in that, The oil cooling control component includes an oil mist system, an oil mist generator, an oil mist flow control valve, and an oil pipe. The oil mist system is connected to the oil inlet of the oil cooling channel through a pipe. The oil mist flow control valve and the oil mist generator are installed on the pipe. The oil outlet of the oil cooling channel is connected to the oil mist system. The temperature proportional controller is connected to the oil mist flow control valve. The temperature proportional controller determines the start and stop of the oil mist flow control valve by comparing the temperature information fed back by the temperature sensor with the preset temperature threshold.

4. The intelligent monitoring and control system for an electric spindle according to claim 1, characterized in that, It also includes a signal acquisition and control system. Vibration sensors are respectively provided on the outer side of the front bearing and the rear bearing of the electric spindle rotor assembly. The vibration sensors collect the vibration information of the front bearing and the rear bearing and transmit the vibration information to the signal acquisition and control system. The signal acquisition and control system judges the performance of the front bearing and the rear bearing based on the vibration information.

5. The intelligent monitoring and control system for an electric spindle according to claim 1, characterized in that, The front end of the electric spindle rotor assembly is connected to a first front-end displacement sensor for detecting the displacement in the Y direction of the front-end bearing and a second front-end displacement sensor for detecting the displacement in the X direction of the front-end bearing via a displacement sensor mounting bracket. The rear end of the electric spindle rotor assembly is connected to a first rear-end displacement sensor for detecting the displacement in the Z direction of the rear-end bearing of the electric spindle rotor assembly via a rear-end cover. The rear end of the electric spindle rotor assembly is provided with an adjustable preload assembly. The adjustable preload assembly is fixed to the electric spindle rotor assembly through the rear bearing seat. The adjustable preload assembly includes a piezoelectric ceramic front holding structure, a piezoelectric ceramic rear support structure, and a piezoelectric ceramic sensor. The piezoelectric ceramic front holding structure and the piezoelectric ceramic rear support structure are respectively fixed to the rear bearing seat. The piezoelectric ceramic sensor is placed in the middle of the piezoelectric ceramic front holding structure and the piezoelectric ceramic rear support structure. The displacement values ​​of the first front displacement sensor, the second front displacement sensor, and the first rear displacement sensor are transmitted to the signal acquisition and control system, which then controls the piezoelectric ceramic sensor to adjust the preload.

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