A vertical direct-drive motorized spindle cooling system and method

Abstract

The application discloses a vertical direct-drive electric spindle cooling system and method, and belongs to the technical field of electric spindle cooling. The method comprises the following steps: introducing cooling liquid into a cooling flow channel, obtaining first cooling information of a target device in a first time period; determining initial parameters of a calculation model; determining a preset parameter set of the calculation model based on the initial parameters of the calculation model; determining a heat transfer coefficient optimization value and a heat transfer coefficient dispersion degree based on the preset parameter set of the calculation model; determining a convergence state based on the heat transfer coefficient dispersion degree and a dispersion threshold; determining final parameters of the calculation model based on the convergence state; determining first cooling adjustment information of the target device in a second time period; and determining second cooling adjustment information of the target device in a third time period. The application solves the technical problem that the traditional circulating cooling is prone to overcooling or insufficient cooling, and achieves the technical effects of controlling the temperature of the electric spindle in a safe range, prolonging the service life and improving the machining precision.

Description

Technical Field

[0001] This invention relates to the field of electric spindle cooling technology, specifically to a vertical direct-drive electric spindle cooling system and method. Background Technology

[0002] In the field of high-precision CNC machining, thermal errors account for 60%–80% of the total machining errors, and the electric spindle, as a core functional component, directly determines the machining accuracy of the machine tool through its thermo-mechanical state.

[0003] The built-in motor and sealed housing structure cause copper loss, iron loss and bearing friction heat to accumulate mainly in the shaft-rotor system, resulting in local temperature rise and axial and radial thermal expansion. This changes the bearing preload and fit clearance, and then transmits thermal deformation error to the tool center point (TCP), ultimately reducing machining accuracy.

[0004] In existing technologies, traditional circulating cooling adopts a constant flow strategy, which lacks a matching mechanism with real-time thermal load. This can easily lead to overcooling or insufficient cooling, and it is impossible to effectively intervene in the internal heat source of the shaft. On the one hand, it is difficult to suppress thermal deformation, and on the other hand, it is not conducive to energy consumption optimization and reliability improvement. Summary of the Invention

[0005] To address the above problems, the first aspect of this invention provides a cooling method for a vertical direct-drive electric spindle, comprising the following steps:

[0006] Coolant is introduced into the cooling channel to obtain the first cooling information of the target equipment in the first time period.

[0007] The initial parameters of the calculation model are determined based on the first cooling information of the target device during the first time period.

[0008] Determine the preset parameter set of the computation model based on the initial parameters of the computation model;

[0009] Based on the preset parameter set of the calculation model, the optimized value of the heat transfer coefficient and the dispersion of the heat transfer coefficient are determined.

[0010] The convergence state is determined based on the heat transfer coefficient dispersion and dispersion threshold.

[0011] The final parameters of the computational model are determined based on the convergence state.

[0012] Based on the optimal temperature of the equipment, the upper limit of the effective cooling of the coolant, and the converged calculation model, the first cooling adjustment information of the target equipment in the second time period is determined.

[0013] Based on the first cooling adjustment information during the second time period, the second cooling adjustment information of the target device during the third time period is determined.

[0014] Preferably, determining the initial parameters of the calculation model based on the first cooling information of the target device within a first time period includes:

[0015] The coolant heat load at at least one sampling point is determined based on the first cooling information of the target device within the first time period.

[0016] Determine the environmental heat load at at least one sampling point based on the initial heat transfer coefficient;

[0017] The total heat dissipation is determined based on the coolant heat load and the ambient heat load.

[0018] The initial parameters of the calculation model are determined based on the total heat dissipation.

[0019] Preferably, determining the preset parameter set of the computational model based on the initial parameters of the computational model includes:

[0020] The environmental heat load at each sampling point is calculated based on the initial parameters of the computational model.

[0021] The heat transfer coefficient of each sampling point is determined based on the environmental heat load at each sampling point.

[0022] Based on the heat transfer coefficient of each sampling point, a set of heat transfer coefficients is determined.

[0023] Preferably, determining the optimized value of the heat transfer coefficient and the dispersion of the heat transfer coefficient based on the preset parameter set of the calculation model includes:

[0024] Based on the heat transfer coefficient at each sampling point, determine the optimal value of the heat transfer coefficient;

[0025] For each sampling point, determine the heat transfer coefficient dispersion.

[0026] Preferably, the determination of the first cooling adjustment information of the target device within the second time period includes:

[0027] Based on the optimal temperature of the equipment, the calculation model determines the required cooling capacity of the target equipment.

[0028] The coolant flow rate is determined based on the required cooling capacity of the target equipment and the upper limit of the effective cooling capacity of the coolant.

[0029] Preferably, the second cooling adjustment information for determining the target device during the third time period includes:

[0030] Acquire the second cooling information of the target device during the second time period;

[0031] Safety verification is performed based on the second cooling information of the target device during the second time period.

[0032] The temperature rise deviation is determined based on the equipment temperature and the optimal equipment temperature.

[0033] The correction factor is determined based on the temperature rise deviation;

[0034] The cooling correction flow rate for the third time period is determined based on the correction factor.

[0035] Preferably, the optimized value of the heat transfer coefficient is calculated as follows:

[0036] ；

[0037] in, This is the optimized value for the heat transfer coefficient. This represents the median of the heat transfer coefficients from N sampling points;

[0038] The heat transfer coefficient dispersion is calculated as follows:

[0039] ;

[0040] in, For heat transfer coefficient dispersion, It is the first quartile. It is the third quartile. This is the optimized value for the heat transfer coefficient.

[0041] Preferably, the required cooling capacity of the target device is calculated as follows:

[0042] ;

[0043] in, The required cooling capacity for the target equipment; This is the final current loss coefficient. For load current, This is the final mechanical loss coefficient. For rotational speed, This is the final value of the heat transfer coefficient; For the optimal temperature of the equipment, For effective heat dissipation area, The ambient temperature;

[0044] The method for calculating the coolant flow rate is as follows:

[0045] ;

[0046] in, To regulate the flow rate of the coolant, The required cooling capacity for the target equipment. For coolant density, The specific heat capacity of the coolant. This is the upper limit of the effective cooling capacity of the coolant. This refers to the temperature of the coolant at the inlet of the cooling channel.

[0047] Preferably, the temperature rise deviation is calculated as follows:

[0048] ;

[0049] in, For temperature rise deviation, For the target equipment temperature, The optimal temperature for the equipment;

[0050] The correction factor is calculated as follows:

[0051] ;

[0052] in, For correction factor, For proportional gain, For temperature rise deviation, For integral gain, The number of sampling points. The sampling interval;

[0053] The cooling correction flow rate is calculated as follows:

[0054] ;

[0055] in, To adjust the flow rate for cooling, For correction factor, Adjust the flow rate of the coolant.

[0056] A second aspect of the present invention provides a cooling system for a vertical direct-drive electric spindle, used to perform the cooling method for a vertical direct-drive electric spindle as described in any of the above embodiments, the cooling system comprising:

[0057] The stator includes a first end cap and a second end cap connected to the top and bottom of the stator, respectively; wherein the stator, together with the first end cap at the top and the second end cap at the bottom, forms a closed space.

[0058] The direct-drive electric spindle cooling system also includes a rotor disposed in the enclosed space, and cooling channels disposed on the stator;

[0059] The cooling channel includes a cooling sub-channel spirally disposed on the stator, a liquid injection sub-channel and a liquid outlet disposed at both ends of the cooling sub-channel and connected to the interior of the cooling sub-channel, and a liquid injection port connected to the end of the liquid injection sub-channel away from the cooling sub-channel.

[0060] The drain outlet is located above the cooling sub-channel, and the injection sub-channel and injection outlet are located below the cooling sub-channel.

[0061] It also includes: a first temperature sensor for acquiring the coolant temperature at the inlet of the cooling channel, and a second temperature sensor for acquiring the coolant temperature at the outlet of the cooling channel.

[0062] By adopting the above technical solution, the present invention mainly has the following technical effects:

[0063] Based on the converged calculation model and the equipment's safe temperature, the coolant flow rate is calculated to ensure that the target equipment is at its optimal thermal operating point with the best performance and longest lifespan. At the same time, a correction coefficient is set to adjust the coolant flow rate, so that the cooling correction flow rate matches the cooling effect. This solves the technical problem that traditional circulating cooling uses a constant flow strategy, which lacks a matching mechanism with real-time thermal load and is prone to overcooling or undercooling. It achieves the technical effect of controlling the electric spindle temperature within a safe range, extending service life, and improving machining accuracy. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the cooling system of a vertical direct-drive electric spindle according to the present invention;

[0065] Figure 2 for Figure 1 Enlarged view of section A;

[0066] Figure 3 for Figure 1 Enlarged view of section B;

[0067] Figure 4 This is a flowchart of a vertical direct-drive electric spindle cooling method according to the present invention.

[0068] The meanings of the reference numerals in the attached figures are as follows:

[0069] 1. Stator;

[0070] 2. First end cap;

[0071] 3. Second end cap;

[0072] 4. Rotor;

[0073] 5. Cooling channel; 51. Cooling sub-channel; 52. Liquid injection sub-channel; 53. Liquid discharge port; 54. Liquid injection port. Detailed Implementation

[0074] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0075] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0076] Please see Figures 1-3 The first aspect of the present invention provides a direct-drive electric spindle cooling system, comprising: a stator 1, a first end cover 2 and a second end cover 3 respectively connected to the top and bottom of the stator 1; wherein the stator 1, together with the first end cover 2 at the top and the second end cover 3 at the bottom, forms a closed space; the direct-drive electric spindle cooling system further comprises a rotor 4 disposed in the closed space, and a cooling channel 5 disposed on the stator 1.

[0077] Furthermore, the stator 1, connected to the first end cover 2 and the second end cover 3, forms a sealed space, effectively preventing foreign objects from entering the interior of the direct-drive electric spindle cooling system. It also prevents mechanical collisions from damaging the internal structure of the direct-drive electric spindle cooling system, thus providing excellent protection. The stator 1 is the stationary fixed part of the direct-drive electric spindle cooling system, which generates a rotating magnetic field after current is applied. The rotor 4 is the rotating part of the direct-drive electric spindle cooling system, which rotates based on electromagnetic induction, receiving electromagnetic torque under the influence of the rotating magnetic field generated by the stator 1.

[0078] Furthermore, the rotor 4 is connected to the first end cover 2 and the second end cover 3 respectively through bearings, thereby using the first end cover 2 and the second end cover 3 to fix the rotor 4. In some embodiments, the first end cover 2 and the second end cover 3 are provided with a circular through hole in the center for the rotor 4 to pass through, so that the rotor 4 can extend out of the enclosed space through the circular through hole and connect with other transmission components or parts.

[0079] In some embodiments, the output end of the rotor 4 can be connected to a load such as a milling machine. By directly connecting the rotor 4 to the load, compared to connecting the milling machine to the motor via a gearbox, the power loss caused by the gearbox can be reduced. An exemplary power loss can be the energy lost by the gearbox during transmission due to internal friction, rotation, and vibration. This energy is dissipated in the form of heat, resulting in a decrease in mechanical efficiency.

[0080] In some embodiments, the cooling channel 5 is disposed in the stator 1, and the coolant absorbs heat from the stator 1, thereby cooling the stator 1 and reducing the internal temperature of the direct-drive electric spindle cooling system. This prevents thermal deformation of the stator 1 due to excessive temperature, which could affect the machining accuracy of the direct-drive electric spindle cooling system. For example, the coolant can be cooling oil, which has the characteristics of being locally non-magnetic, non-flammable, non-conductive, and having good thermal conductivity. Using cooling oil as the coolant has no impact on the magnetic circuit of the direct-drive electric spindle cooling system and results in higher heat dissipation efficiency.

[0081] In some embodiments, the cooling channel 5 includes a cooling sub-channel 51 spirally disposed on the stator 1, a liquid injection sub-channel 52 and a liquid outlet 53 disposed at both ends of the cooling sub-channel 51 and communicating with the interior of the cooling sub-channel 51, and a liquid injection port 54 communicating with the end of the liquid injection sub-channel 52 away from the cooling sub-channel 51. In some embodiments, the liquid outlet 53 is located above the cooling sub-channel 51, and the liquid injection sub-channel 52 and the liquid injection port 54 are located below the cooling sub-channel 51. In some embodiments, the liquid injection sub-channel 52 is used to guide the coolant injected through the liquid injection port 54 into the cooling sub-channel 51. The above structure allows the coolant to enter the cooling channel 5 to cool the electric spindle in a low-in, high-out flow pattern. On the one hand, the coolant continuously pushes the air towards the drain port 53, avoiding air blockage and cavitation, ensuring that the channel is always full of liquid, and ensuring that the heat dissipation area is 100% utilized. On the other hand, it can also match the heat load according to the temperature gradient, forming synergistic benefits in terms of thermo-mechanical performance, energy consumption, and reliability.

[0082] In some embodiments, the direct-drive electric spindle cooling system further includes: a first temperature sensor located near the injection port 54 for acquiring the coolant temperature at the inlet of the cooling channel, and a second temperature sensor located near the drain port 53 for acquiring the coolant temperature at the outlet of the cooling channel.

[0083] Please see Figure 4 The second aspect of the present invention provides a method for cooling a direct-drive electric spindle, comprising the following steps:

[0084] S1. Introduce coolant into the cooling channel and obtain the first cooling information of the target equipment in the first time period.

[0085] In some embodiments, the first time period can be a historical time period, for example, the first time period can be a historical 10-second time period.

[0086] In some embodiments, a base flow rate can be preset, and then coolant can be introduced into the cooling channel according to the base flow rate to cool the target device, thereby obtaining the cooling information of the target device under the base flow rate cooling.

[0087] In some embodiments, the first cooling information may be a combination of operating parameters reflecting the thermal load state of the target device; in some embodiments, the first cooling information may include:

[0088] Load current is a parameter that characterizes the magnitude of the current when the motor is under load. The load current can be obtained by detecting a current sensor, such as a Hall effect current sensor.

[0089] Rotational speed is a parameter that characterizes the number of revolutions a shaft makes per unit time. Rotational speed can be obtained through an encoder.

[0090] Equipment temperature is a parameter that characterizes the dynamic balance between the heat generation and heat dissipation systems inside the equipment. For example, the equipment temperature can be obtained by detecting the stator using a temperature sensor.

[0091] Ambient temperature is a parameter that characterizes the degree of external heat or cold felt by the device. An example ambient temperature can be obtained by detecting a temperature sensor.

[0092] Coolant temperature at the inlet of the cooling channel is the instantaneous temperature at which the coolant just enters the cooling channel. It can be obtained by detecting the temperature at the inlet of the cooling channel using a temperature sensor.

[0093] Coolant temperature at the outlet of the cooling channel is the instantaneous temperature at which the coolant just flows out of the cooling channel. It can be obtained by detecting the temperature at the outlet of the cooling channel using a temperature sensor.

[0094] In some embodiments, multiple samplings can be performed within a first time period to obtain cooling information from multiple sampling points.

[0095] S2. Determine the initial parameters of the calculation model based on the first cooling information of the target device in the first time period;

[0096] In some embodiments, the calculation model can be any model capable of determining the heat dissipation of the motor based on the motor's cooling status.

[0097] It should be noted that in the following calculation process, the dimensions in the formula can be kept consistent by setting appropriate units.

[0098] In some embodiments, determining the initial parameters of the calculation model based on the first cooling information of the target device within a first time period includes:

[0099] S201. Determine the coolant heat load at least one sampling point based on the first cooling information of the target device in the first time period.

[0100] In some embodiments, the coolant heat load is used to describe the heat carried away by the coolant as it flows through the cooling channels;

[0101] In some embodiments, the coolant heat load is calculated as follows:

[0102] ;

[0103] in, For the first Heat load at each sampling point The specific heat capacity of the coolant. For coolant density, This is the base flow rate of the coolant. For the first Coolant temperature at the outlet of the cooling channel at each sampling point For the first Coolant temperature at the inlet of the cooling channel at the sampling point;

[0104] S202. Determine the environmental heat load at at least one sampling point based on the initial heat transfer coefficient;

[0105] In some embodiments, the ambient heat load is used to describe the heat carried away by the target device when it exchanges heat with the environment.

[0106] In some embodiments, the environmental heat load is calculated as follows:

[0107] ;

[0108] in, For environmental heat load, The initial heat transfer coefficient is 1. For effective heat dissipation area, For the first The equipment temperature at each sampling point For the first The ambient temperature at each sampling point;

[0109] In some embodiments, the initial heat transfer coefficient The effective heat dissipation area can be preset using historical data and databases. Equipment temperature The target device can be detected, and the ambient temperature can be obtained. This can be obtained after environmental testing.

[0110] S203. Determine the total heat dissipation based on the coolant heat load and the ambient heat load;

[0111] In some embodiments, according to the first law of thermodynamics, the total heat dissipation can be obtained by calculating the sum of the coolant heat load and the ambient heat load.

[0112] In some embodiments, the total load is calculated as follows:

[0113] ;

[0114] in, For the first Total heat dissipation at each sampling point;

[0115] S204. Determine the initial parameters of the calculation model based on the total heat dissipation;

[0116] In some embodiments, the computational model includes:

[0117] ;

[0118] in, The current loss coefficient is... This is the mechanical loss coefficient. For the first Load current at each sampling point For the first Rotational speed at each sampling point;

[0119] It should be noted that the calculation model can maintain consistency of dimensions in the formulas by setting the units for the current loss coefficient and the mechanical loss coefficient. In some embodiments, the unit of the current loss coefficient can be... The unit of mechanical loss coefficient can be... .

[0120] In some embodiments, the initial parameters of the calculation model include the current loss coefficient. and mechanical loss coefficient In some embodiments, the initial parameters of the computation model are... , It can be obtained using the least squares method.

[0121] In some embodiments, the initial parameters of the computational model can be determined in the following ways:

[0122] ;

[0123] in, The current loss coefficient is... This is the mechanical loss coefficient; The value of the independent variable to minimize the function;

[0124] In some embodiments, the current loss coefficient that best matches historical data is obtained by optimizing the function. and mechanical loss coefficient .

[0125] S3. Determine the preset parameter set of the calculation model based on the initial parameters of the calculation model;

[0126] In some embodiments, the preset parameters of the calculation model may include the heat transfer coefficient, which may be a set of heat transfer coefficients of multiple sampling points arranged in order of magnitude.

[0127] In some embodiments, determining the preset parameter set of the computational model based on the initial parameters of the computational model includes:

[0128] S301. Calculate the environmental heat load of each sampling point based on the initial parameters of the calculation model;

[0129] In some embodiments, the current loss coefficient that best matches historical data can be used. and mechanical loss coefficient Substitute into the calculation model: The total load at each sampling point is calculated, and then... To calculate the environmental heat load at each sampling point.

[0130] S302. Determine the heat transfer coefficient of each sampling point based on the environmental heat load of each sampling point;

[0131] In some embodiments, after determining the environmental heat load at the sampling point, the calculation method for the environmental heat load can be used as follows: Reverse calculation of the heat transfer coefficient at each sampling point .

[0132] S303. Determine the set of heat transfer coefficients based on the heat transfer coefficient of each sampling point;

[0133] In some embodiments, the heat transfer coefficient at each sampling point is obtained. Subsequently, by measuring the heat transfer coefficient at each sampling point Sort the data according to size to obtain the heat transfer coefficient set.

[0134] S4. Based on the preset parameter set of the calculation model, determine the optimized value of the heat transfer coefficient and the dispersion of the heat transfer coefficient;

[0135] In some embodiments, the optimized heat transfer coefficient value is a heat transfer coefficient value output after optimization based on a heat transfer coefficient set.

[0136] In some embodiments, the optimized heat transfer coefficient value can be obtained by using a preset parameter set of the calculation model.

[0137] In some embodiments, the dispersion is used to describe the degree of dispersion of the heat transfer coefficients in the preset parameter set of the calculation model.

[0138] In some embodiments, determining the optimized value of the heat transfer coefficient and the dispersion of the heat transfer coefficient includes:

[0139] S401. Determine the optimized value of the heat transfer coefficient based on the heat transfer coefficient of each sampling point;

[0140] In some embodiments, the optimized value of the heat transfer coefficient is calculated as follows:

[0141] ；

[0142] in, This is the optimized value for the heat transfer coefficient. This represents the median of the heat transfer coefficients from N sampling points;

[0143] In some embodiments, by using the median of the heat transfer coefficients among N sampling points as the optimized value of the heat transfer coefficient, abnormal temperature measurement values ​​can be effectively resisted and cooling accuracy can be improved.

[0144] In some embodiments, if the number of data is odd, the middle number after sorting can be taken as the optimized value of the heat transfer coefficient; if the number of data is even, the average of the two middle numbers after sorting can be taken.

[0145] S402. For the heat transfer coefficient at each sampling point, determine the dispersion of the heat transfer coefficient;

[0146] In some embodiments, the heat transfer coefficients of each sampling point can be sorted to determine the heat transfer coefficient dispersion.

[0147] In some embodiments, the heat transfer coefficient dispersion is calculated as follows:

[0148] ;

[0149] in, For heat transfer coefficient dispersion, It is the first quartile. It is the third quartile. This is the optimized value for the heat transfer coefficient;

[0150] In some embodiments, This refers to the value at the 25th percentile after sorting the data; that is, 25% of the data are ≤ , This refers to the value at the 75th percentile after sorting the data, meaning 75% of the data is ≤ .

[0151] As an example, suppose the dataset is [10,12,15,17,100], then , , , ;

[0152] Let the sampled values ​​of the heat transfer coefficient be [220, 225, 228, 230, 233, 235, 238, 240, 245, 1000], then , , , ;

[0153] S5. Determine the convergence state based on the heat transfer coefficient dispersion and dispersion threshold;

[0154] In some embodiments, the convergence state describes the degree to which the heat transfer coefficient values ​​of each sampling point are statistically aggregated, promoting the consistency of the overall heat transfer performance evaluation results. When the heat transfer coefficient dispersion is less than or equal to the dispersion threshold, it indicates that the heat transfer coefficient evaluation values ​​of each sampling point are close and meet the convergence state; otherwise, it is a non-converged state, and iterative calculation needs to continue.

[0155] In some embodiments, the dispersion threshold refers to a threshold used to determine the convergence state. In some embodiments, the heat transfer coefficient dispersion can be compared with the dispersion threshold to confirm the convergence state. When the heat transfer coefficient dispersion is greater than the dispersion threshold, it is a non-converged state. In step S2, the optimized heat transfer coefficient value is used as the initial heat transfer coefficient, and the initial parameters of the calculation model are determined. Then, based on the initial parameters of the calculation model, the preset parameter set of the calculation model is determined. Based on the preset parameter set of the calculation model, the optimized heat transfer coefficient value and the heat transfer coefficient dispersion are determined until the heat transfer coefficient dispersion is less than the dispersion threshold.

[0156] S6. Determine the final parameters of the computational model based on the convergence state;

[0157] In some embodiments, after determining that convergence has been achieved, the initial parameters at this point can be... , The optimized heat transfer coefficient is used as the final parameter of the calculation model.

[0158] In some embodiments, after determining that convergence has been achieved, the final parameters of the calculation model, namely the final current loss coefficient, can be obtained. Final mechanical loss coefficient Final value of heat transfer coefficient .

[0159] In some embodiments, by quantifying the parameter dispersion and determining the iteration requirements, computational redundancy is minimized while ensuring parameter accuracy, thereby achieving efficient and reliable thermal parameter identification, which reduces subsequent calculation errors and improves the cooling effect of the electric spindle.

[0160] S7. Based on the optimal temperature of the equipment, the upper limit of effective cooling of the coolant, and the converged calculation model, determine the first cooling adjustment information of the target equipment in the second time period.

[0161] In some embodiments, the safe operating temperature of the equipment refers to the optimal thermal operating point that ensures the best performance and the longest lifespan. In some embodiments, through thermal simulation and aging experiments, it is determined that when the equipment casing temperature is maintained in the range of 55-65°C, the motor efficiency reaches more than 92% and the insulation life loss rate is less than 2% / thousand hours. Therefore, this temperature range can be defined as the optimal operating temperature range, and a suitable temperature can be selected within this range as the optimal temperature of the equipment.

[0162] In some embodiments, the effective cooling limit of the coolant refers to the highest operating temperature that the coolant is allowed to reach while ensuring continuous and effective heat dissipation. In some embodiments, the effective cooling limit of the coolant can be set based on the type of coolant.

[0163] In some embodiments, the second time period can be a time period after the first time period, for example, the second time period can be a time period of 10 seconds after the first time period.

[0164] In some embodiments, determining the first cooling adjustment information of the target device during the second time period includes:

[0165] S701. Based on the optimal temperature of the equipment, the calculation model determines the required cooling capacity of the target equipment.

[0166] In some embodiments, the required cooling capacity of the target device refers to the amount of cooling required to cool the target device to its optimal temperature.

[0167] In some embodiments, the required cooling capacity of the target device is calculated as follows:

[0168] ;

[0169] in, The required cooling capacity for the target equipment; This is the final current loss coefficient. For load current, This is the final mechanical loss coefficient. For rotational speed, This is the final value of the heat transfer coefficient; For the optimal temperature of the equipment, For effective heat dissipation area, The ambient temperature;

[0170] S702. Determine the coolant flow rate based on the required cooling capacity of the target equipment and the upper limit of the effective cooling capacity of the coolant.

[0171] In some embodiments, the coolant flow rate is calculated as follows:

[0172] ;

[0173] in, To regulate the flow rate of the coolant, The required cooling capacity for the target equipment. For coolant density, The specific heat capacity of the coolant. This is the upper limit of the effective cooling capacity of the coolant. This refers to the temperature of the coolant at the inlet of the cooling channel.

[0174] In some embodiments, the base flow rate and the regulating flow rate of the coolant must be within the flow limit, i.e.:

[0175] ;

[0176] in, , These represent the lower and upper limits of the coolant flow rate, respectively.

[0177] S8. Based on the first cooling adjustment information in the second time period, determine the second cooling adjustment information of the target device in the third time period;

[0178] In some embodiments, the third time period can be a time period after the second time period, for example, the third time period can be a time period of 10 seconds after the second time period.

[0179] In some embodiments, determining the second cooling adjustment information of the target device during the third time period includes:

[0180] S801, Obtain the second cooling information of the target device during the second time period;

[0181] In some embodiments, the second cooling information of the target device during a second time period includes:

[0182] Load current is a parameter that characterizes the magnitude of the current when the motor is under load. The load current can be obtained by detecting a current sensor, such as a Hall effect current sensor.

[0183] Rotational speed is a parameter that characterizes the number of revolutions a motor shaft makes per unit time. Rotational speed can be obtained through an encoder.

[0184] Equipment temperature is a parameter that characterizes the dynamic balance between the heat generation and heat dissipation systems inside the equipment. For example, the equipment temperature can be obtained by detecting the stator using a temperature sensor.

[0185] S802, Perform security verification based on the second cooling information of the target device during the second time period;

[0186] In some embodiments, safety verification can be performed by comparing the target device temperature with the device's optimal temperature.

[0187] In some embodiments, the security verification based on the second cooling information of the target device during a second time period includes:

[0188] If the equipment temperature This indicates successful control; maintain the current traffic flow. ;

[0189] If the equipment temperature This indicates a control failure; proceed to the next step.

[0190] S803. Determine the temperature rise deviation based on the equipment temperature and the optimal equipment temperature;

[0191] In some embodiments, temperature rise deviation can be confirmed by comparing the target device temperature with the device's optimal temperature.

[0192] In some embodiments, the temperature rise deviation is calculated as follows:

[0193] ;

[0194] in, For temperature rise deviation, For the target equipment temperature, The optimal temperature for the equipment;

[0195] S804. Determine the correction coefficient based on the temperature rise deviation;

[0196] In some embodiments, the correction factor is a dimensionless scaling factor used to adjust the base flow rate of the coolant so that the corrected flow rate matches the target temperature rise effect.

[0197] In some embodiments, the correction coefficient is calculated as follows:

[0198] ;

[0199] in, For correction factor, For proportional gain, For temperature rise deviation, For integral gain, The number of sampling points. The sampling interval;

[0200] In some embodiments, a correction factor is set when the temperature rise deviation... A value greater than 0 indicates insufficient actual cooling effect; in this case, the correction factor is applied. This indicates that the coolant flow rate should be increased.

[0201] S805. Determine the cooling correction flow rate in the third time period based on the correction coefficient;

[0202] In some embodiments, the base flow rate of the coolant can be adjusted according to the coolant flow rate correction coefficient so that the cooling correction flow rate matches the cooling effect, neither increasing the coolant flow rate nor reducing the cooling effect, so that the electric spindle is at the critical point of temperature safety, lowest energy consumption and longest life.

[0203] In some embodiments, the cooling correction flow rate is calculated as follows:

[0204] ;

[0205] in, To adjust the flow rate for cooling, For correction factor, Adjust the flow rate of the coolant;

[0206] In some embodiments, after determining the cooling correction flow rate, the cooling correction flow rate can be used as the flow rate of coolant entering the cooling channel, thereby utilizing the coolant to adequately cool the target device.

[0207] In some embodiments, the base flow rate is dynamically adjusted by a correction factor to achieve precise temperature control, quickly eliminate temperature deviations, and ensure that the equipment always operates at a safe temperature.

[0208] Finally, it should be noted that the embodiments disclosed in this invention are merely preferred embodiments of this invention and are only used to illustrate the technical solutions of this invention, not to limit it. Although this invention 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this invention.

Claims

1. A cooling method for a vertical direct-drive electric spindle, characterized in that, Includes the following steps: Coolant is introduced into the cooling channel to obtain the first cooling information of the target equipment in the first time period. The initial parameters of the calculation model are determined based on the first cooling information of the target device during the first time period. Determine the preset parameter set of the computation model based on the initial parameters of the computation model; Based on the preset parameter set of the calculation model, the optimized value of the heat transfer coefficient and the dispersion of the heat transfer coefficient are determined. The convergence state is determined based on the heat transfer coefficient dispersion and dispersion threshold. The final parameters of the computational model are determined based on the convergence state. Based on the optimal temperature of the equipment, the upper limit of the effective cooling of the coolant, and the converged calculation model, the first cooling adjustment information of the target equipment in the second time period is determined. Based on the first cooling adjustment information in the second time period, determine the second cooling adjustment information of the target device in the third time period; The first cooling adjustment information of the target device during the second time period includes: Based on the optimal temperature of the equipment, the calculation model determines the required cooling capacity of the target equipment. The coolant flow rate is determined based on the required cooling capacity of the target equipment and the upper limit of the effective cooling capacity of the coolant. The optimized value of the heat transfer coefficient is calculated as follows: ； in, This is the optimized value for the heat transfer coefficient. This represents the median of the heat transfer coefficients from N sampling points; The heat transfer coefficient dispersion is calculated as follows: ； in, For heat transfer coefficient dispersion, It is the first quartile. It is the third quartile. This is the optimized value for the heat transfer coefficient; The calculation method for the required cooling capacity of the target equipment is as follows: ； in, The required cooling capacity for the target equipment; This is the final current loss coefficient. For load current, This is the final mechanical loss coefficient. For rotational speed, This is the final value of the heat transfer coefficient; For the optimal temperature of the equipment, For effective heat dissipation area, The ambient temperature; The method for calculating the coolant flow rate is as follows: ； in, To regulate the flow rate of the coolant, The required cooling capacity for the target equipment. For coolant density, The specific heat capacity of the coolant. This is the upper limit of the effective cooling capacity of the coolant. This refers to the temperature of the coolant at the inlet of the cooling channel.

2. The cooling method for a vertical direct-drive electric spindle according to claim 1, characterized in that, The determination of initial parameters for the calculation model based on the first cooling information of the target device within a first time period includes: The coolant heat load at at least one sampling point is determined based on the first cooling information of the target device within the first time period. Determine the environmental heat load at at least one sampling point based on the initial heat transfer coefficient; The total heat dissipation is determined based on the coolant heat load and the ambient heat load. The initial parameters of the calculation model are determined based on the total heat dissipation.

3. The cooling method for a vertical direct-drive electric spindle according to claim 2, characterized in that, The process of determining the preset parameter set of the computation model based on the initial parameters of the computation model includes: The environmental heat load at each sampling point is calculated based on the initial parameters of the computational model. The heat transfer coefficient of each sampling point is determined based on the environmental heat load at each sampling point. Based on the heat transfer coefficient of each sampling point, a set of heat transfer coefficients is determined.

4. The cooling method for a vertical direct-drive electric spindle according to claim 3, characterized in that, The determination of the optimized heat transfer coefficient value and the heat transfer coefficient dispersion based on the preset parameter set of the calculation model includes: Based on the heat transfer coefficient at each sampling point, determine the optimal value of the heat transfer coefficient; For each sampling point, determine the heat transfer coefficient dispersion.

5. A cooling method for a vertical direct-drive electric spindle according to claim 1, characterized in that, The second cooling adjustment information for determining the target device during the third time period includes: Acquire the second cooling information of the target device during the second time period; Safety verification is performed based on the second cooling information of the target device during the second time period. The temperature rise deviation is determined based on the equipment temperature and the optimal equipment temperature. The correction factor is determined based on the temperature rise deviation; The cooling correction flow rate for the third time period is determined based on the correction factor.

6. A cooling method for a vertical direct-drive electric spindle according to claim 5, characterized in that, The temperature rise deviation is calculated as follows: ； in, For temperature rise deviation, For the target equipment temperature, The optimal temperature for the equipment; The correction factor is calculated as follows: ； in, For correction factor, For proportional gain, For temperature rise deviation, For integral gain, The number of sampling points. The sampling interval; The cooling correction flow rate is calculated as follows: ； in, To adjust the flow rate for cooling, For correction factor, Adjust the flow rate of the coolant.

7. A vertical direct-drive electric spindle cooling system, characterized in that, For performing the cooling method for a vertical direct-drive electric spindle according to any one of claims 1-6, the vertical direct-drive electric spindle cooling system comprises: The stator includes a first end cap and a second end cap connected to the top and bottom of the stator, respectively; wherein the stator, together with the first end cap at the top and the second end cap at the bottom, forms a closed space. The direct-drive electric spindle cooling system also includes a rotor disposed in the enclosed space, and cooling channels disposed on the stator; The cooling channel includes a cooling sub-channel spirally disposed on the stator, a liquid injection sub-channel and a liquid outlet disposed at both ends of the cooling sub-channel and connected to the interior of the cooling sub-channel, and a liquid injection port connected to the end of the liquid injection sub-channel away from the cooling sub-channel. The drain outlet is located above the cooling sub-channel, and the injection sub-channel and injection outlet are located below the cooling sub-channel. It also includes: a first temperature sensor for acquiring the coolant temperature at the inlet of the cooling channel, and a second temperature sensor for acquiring the coolant temperature at the outlet of the cooling channel.

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