A high-speed precision machine tool electric spindle shell cooling structure, design, manufacture and active temperature control method

Abstract

The application discloses a high-speed precision machine tool electric spindle shell cooling structure and a design, manufacturing and active temperature control method thereof. The cooling structure comprises a plurality of spiral cooling flow channels arranged in the electric spindle shell, and the flow channels are filled with a dot matrix structure to enhance the heat exchange effect between the coolant and the inner wall of the shell, thereby improving the cooling efficiency of the electric spindle and reducing thermal deformation caused by uneven temperature. The dot matrix structure not only improves the heat exchange efficiency, but also enhances the carrying capacity of the shell, reduces the wall thickness of the shell, and reduces the overall weight. In addition, the application realizes temperature uniformity control by monitoring the temperature of the electric spindle at all places through a temperature sensor and dynamically adjusting the coolant flow according to the temperature change of different regions, thereby reducing the machining error and improving the operation precision of the equipment. The application optimizes the cooling effect, improves the mechanical properties and service life of the electric spindle, and is suitable for various high-speed precision machining equipment.

Description

Technical Field

[0001] This invention belongs to the field of machine tool electric spindle cooling technology, and relates to the cooling structure and temperature control of high-speed precision machine tool electric spindles. In particular, it relates to a cooling structure, design, manufacturing and active temperature control method for the housing of a high-speed precision machine tool electric spindle that uses a multi-spiral flow channel and a dot matrix structure to enhance heat exchange and support functions. Background Technology

[0002] With the rapid development of modern manufacturing, the market demand for high-efficiency, high-precision, and high-reliability processing equipment is constantly increasing. High-speed precision machine tools, due to their ability to complete high-precision machining tasks in a short time, have become important equipment in fields such as aerospace, automobile manufacturing, medical devices, and mold manufacturing. The high-speed electric spindle is its core component, directly affecting the machining accuracy, working performance, and service life of high-speed precision equipment.

[0003] The main causes of thermal deformation in high-speed electric spindles during operation are motor losses, electromagnetic effects, and bearing friction. Due to its relatively enclosed structure, the electric spindle accumulates a significant amount of heat during operation due to the presence of internal heat sources. If this heat is not released in a timely manner, it causes uneven temperature distribution within the spindle, leading to thermal deformation. Thermal deformation not only reduces the machining accuracy of the machine tool but can also accelerate the wear of the spindle and its related components, ultimately shortening the service life of the electric spindle and the entire machine tool. Therefore, cooling the electric spindle is essential to reduce the impact of thermal deformation on machining accuracy, thereby improving the spindle's service life and machining precision.

[0004] To address the issue of thermal deformation in electric spindles, cooling technology is of paramount importance. Existing electric spindle cooling methods primarily fall into two categories: passive cooling and active cooling. Passive cooling mainly relies on natural heat dissipation or mechanical conduction. While simple in structure and relatively low in cost, its cooling effect is often less than ideal. Active cooling, on the other hand, offers advantages over passive cooling, such as higher cooling efficiency and precise temperature control. Therefore, active cooling is generally employed for the cooling of spindle bearings in high-speed precision machine tools.

[0005] Active cooling technology removes heat by introducing coolant through cooling channels in the motor housing. This cooling method is typically combined with an external control system, allowing for real-time monitoring and adjustment based on spindle temperature changes, thus effectively controlling the electric spindle temperature. Currently, research on active cooling for electric spindles focuses primarily on channel design, cross-sectional shape, and dimensions, aiming to improve heat dissipation through optimized design. However, despite the significant effectiveness of active cooling technology in electric spindle cooling, several problems remain to be addressed. For example, uneven axial temperature distribution in the electric spindle persists in practical applications, resulting in varying cooling effects at different locations. Furthermore, under high-speed operation, existing cooling systems sometimes fail to adequately remove the heat generated inside the electric spindle, leading to significant temperature fluctuations. These temperature fluctuations not only affect machining accuracy but can also exacerbate mechanical stress within the spindle.

[0006] In summary, while existing electric spindle cooling technologies have alleviated the problem of spindle thermal deformation to some extent, issues such as low cooling efficiency and uneven axial temperature remain. Therefore, how to further optimize the electric spindle cooling structure, improve cooling efficiency, and enhance axial temperature uniformity, especially by combining active temperature control technology to achieve precise control of the spindle temperature and thus reduce the impact of thermal deformation on machining accuracy, is a pressing technical problem that needs to be solved. Summary of the Invention

[0007] (I) Purpose of the Invention

[0008] To address the shortcomings and deficiencies of current electric spindle cooling methods, such as uneven axial temperature and insufficient cooling efficiency, this invention aims to provide a cooling structure, design, manufacturing, and active temperature control method for the housing of a high-speed precision machine tool electric spindle. This is achieved by designing multiple spiral flow channels within the electric spindle housing, with internally segmented dot matrix structures to enhance heat exchange between the coolant and the wall surface. The application of the dot matrix structure not only effectively enhances the load-bearing capacity of the flow channels but also allows for a reduction in the wall thickness of the electric spindle housing, thus lowering the overall weight. Furthermore, by adjusting the flow rate of different channels, the temperature of different parts of the spindle can be more accurately controlled, achieving better temperature uniformity and avoiding machining errors and equipment performance degradation caused by uneven temperature, thereby improving the overall performance, machining accuracy, and service life of the equipment.

[0009] (II) Technical Solution

[0010] This invention proposes a cooling structure, design, manufacturing, and active temperature control method for the housing of a high-speed precision machine tool electric spindle. To solve the above-mentioned technical problems, the technical solution adopted by this invention is:

[0011] The first objective of this invention is to provide a cooling structure for the housing of a high-speed precision machine tool electric spindle, which improves the cooling efficiency of the electric spindle during high-speed operation, enhances the uniformity of temperature distribution, strengthens the load-bearing capacity of the housing, and reduces the overall weight. It includes at least an electric spindle housing, specifically:

[0012] The electric spindle housing is an integral cylindrical structure extending along the axial direction. Several independent spiral cooling channels are machined inside the cylindrical sidewall, each spirally extending from the first axial end to the second axial end of the electric spindle housing. These channels are used to exchange heat through the independent spiral cooling channels when the coolant flows, thereby reducing the temperature of the electric spindle.

[0013] Each of the spiral cooling channels is provided with a coolant inlet and a coolant outlet at both ends. The coolant inlet is located at the first axial end of the electric spindle housing, and each coolant inlet is evenly distributed circumferentially at the first axial end of the electric spindle housing. The coolant outlet is located at the second axial end of the electric spindle housing, and each coolant outlet is evenly distributed circumferentially at the second axial end of the electric spindle housing.

[0014] Each of the spiral cooling channels is filled with a lattice structure segment. The lattice structure segment is used to enhance the heat exchange between the coolant in the channel and the inner wall of the electric spindle housing and to support the channel. The axial length of each lattice structure segment is less than the axial length of the spiral cooling channel in which it is located. Furthermore, each lattice structure segment is distributed in different axial positions of the electric spindle housing, so that the whole is arranged in segments along the axial direction of the electric spindle housing.

[0015] The coolant inlet of each spiral cooling channel is connected to the coolant outlet of the external cold source through a pipeline, and the coolant outlet is connected to the coolant return port of the external cold source through a pipeline, so that each spiral cooling channel and the external cold source form an independent coolant circulation loop. Thus, during the coolant circulation process, the uniformity of the electric spindle temperature distribution is achieved by independently controlling each coolant circulation loop.

[0016] The second objective of this invention is to provide a design method for the above-mentioned cooling structure for the electric spindle housing of a high-speed precision machine tool, the design method comprising at least the following steps:

[0017] SS1. Based on the size requirements of the electric spindle, determine the overall external dimensions of the electric spindle housing, including at least its length and diameter, to ensure that it matches other components of the electric spindle and meets the installation requirements;

[0018] SS2. Based on the load-bearing conditions of the electric spindle housing during operation, determine the wall thickness of the electric spindle housing to ensure its strength and rigidity during operation and prevent structural failure due to overload;

[0019] SS3. Based on the axial length and radial wall thickness of the electric spindle housing, design the geometric parameters of the spiral cooling channel, including the channel cross-sectional shape, height, width and pitch. At the same time, consider the fluid dynamics characteristics and optimize the channel design to reduce flow resistance and improve heat exchange efficiency.

[0020] SS4. Based on the axial length of the electric spindle housing, the cooling zone is divided into multiple sections along the axial direction. The number of cooling sections is matched with the number of spiral cooling channels. A lattice structure section is designed in each spiral cooling channel, and the type, size and distribution density of the lattice structure are determined. The total number of lattice structure sections is consistent with the number of cooling sections and corresponds one-to-one with each cooling section in the axial direction.

[0021] SS5. Combining additive manufacturing technology, and based on the extreme forming capacity of the manufacturing process, design the self-supporting cross section of the spiral cooling channel to ensure that the spiral cooling channel and lattice structure can be successfully processed without the need for additional support structures during the manufacturing process.

[0022] SS6. In the bearing chambers at both ends of the electric spindle housing, design the inlet and outlet positions of each spiral cooling channel to ensure that each channel has an independent coolant inlet and outlet, so as to realize an independent coolant circulation loop;

[0023] SS7. Perform strength and heat transfer performance verification analysis on the designed electric spindle housing to ensure that it meets the requirements of mechanical strength and heat dissipation performance in actual use. If the requirements are not met, repeat optimization steps SS2 to SS6 for iterative optimization. If the requirements are met, the design process is completed and the final electric spindle housing cooling structure design scheme is output.

[0024] The third objective of this invention is to provide a method for manufacturing the above-mentioned cooling structure for the housing of a high-speed precision machine tool electric spindle, the method comprising at least the following steps:

[0025] SS1. Based on the requirements of additive manufacturing process, the three-dimensional model of the cooling structure of the electric spindle housing is adjusted to minimize the addition of process support, so as to ensure the minimization of the support structure during additive manufacturing. Then, the model is sliced ​​into layers, the processing path and process parameters are set, and additive forming is carried out by selective laser melting technology to form the electric spindle housing and its internal spiral cooling channels and lattice structure.

[0026] SS2. After the cooling structure of the electric spindle housing is completed by additive manufacturing, it is heat-treated together with the substrate to remove the thermal stress generated during the manufacturing process. Then, the electric spindle housing is separated from the substrate by wire cutting process and the support structure formed during the additive manufacturing process is removed to ensure that the structure is intact and without defects.

[0027] SS3. Treat the outer surface of the electric spindle housing by sandblasting and / or manual grinding to remove powder residue adhering to the outer surface; at the same time, finely treat the inner wall of the electric spindle housing by abrasive flow machining or electrochemical polishing to remove powder adhering to the inner wall, ensuring smoothness inside the cooling channel, reducing fluid resistance and improving the heat exchange efficiency of the channel.

[0028] SS4. Precision machine the coolant inlet and outlet of the electric spindle housing to ensure that its size and shape meet the design requirements, and conduct a sealing performance test. Through leak testing, ensure that the sealing performance of all coolant inlets and outlets is good to avoid coolant leakage.

[0029] The fourth objective of this invention is to provide an active temperature control method based on the above-mentioned cooling structure for the housing of a high-speed precision machine tool electric spindle, wherein the temperature control method includes at least the following steps:

[0030] SS1. Multiple temperature sensors are arranged on the inner wall of the electric spindle housing and / or on the motor stator to monitor temperature data at different locations of the electric spindle in real time. The temperature sensors are evenly distributed in the key hot and cold areas of the electric spindle to ensure accurate monitoring of temperature distribution.

[0031] SS2. Based on the temperature data fed back by the temperature sensor, identify the high-temperature area inside the electric spindle housing, and adjust the coolant flow rate of the corresponding cooling channel through the automatic temperature control system so that the coolant flows preferentially to the higher temperature area for cooling, thereby reducing the temperature of the high-temperature area;

[0032] SS3. Repeat the temperature monitoring and coolant flow regulation steps to ensure that the temperature of all parts of the electric spindle remains uniform throughout the entire operation, avoiding thermal deformation and machining errors caused by temperature differences, thereby improving the machining accuracy and service life of the electric spindle.

[0033] (III) Technical Effects

[0034] Compared with the prior art, the cooling structure, design, manufacturing, and active temperature control method for the high-speed precision machine tool electric spindle housing of the present invention have the following beneficial and significant technical effects:

[0035] (1) The cooling structure of the high-speed precision machine tool electric spindle housing of the present invention adopts a multi-spiral cooling channel, and the inside of the channel is filled with a dot matrix structure. This structure can enhance the heat exchange between the coolant and the wall surface, and improve the cooling efficiency of the electric spindle. Through this structural design, the coolant can fully exchange heat with the wall surface when flowing in the spiral channel, quickly remove the heat generated during the operation of the spindle, and effectively reduce the problem of thermal deformation caused by temperature rise.

[0036] (2) The dot matrix structure inside each spiral cooling channel of the present invention not only enhances the heat exchange effect but also provides support for the channel, thereby improving the load-bearing capacity of the electric spindle housing. Through the rational design and segmented arrangement of the dot matrix structure, the wall thickness of the housing can be reduced, thereby reducing the weight of the electric spindle. This lightweight design not only reduces the load on the spindle operation but also improves the overall working efficiency and mechanical performance of the equipment while maintaining structural strength.

[0037] (3) This invention employs multiple spiral cooling channels and a segmented lattice structure, combined with an active temperature control method. By adjusting the coolant flow rate in different channels according to actual needs, better temperature uniformity of the electric spindle can be achieved. This design avoids machining errors caused by uneven electric spindle temperature, improves the machining accuracy and stability of the machine tool, and thus ensures the consistency of product quality.

[0038] (4) The cooling structure of the high-speed precision machine tool electric spindle housing of the present invention is processed by additive manufacturing, realizing the integral forming of the internal flow channel and the dot matrix structure. This manufacturing method simplifies the structure, reduces the risk of coolant leakage that may occur in the traditional processing process, and at the same time reduces the complexity and cost of the production process, improves production efficiency, and ensures the reliability and long-term stable operation of the cooling system. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the cooling structure for the high-speed precision machine tool electric spindle housing of the present invention;

[0040] Figure 2 This is a schematic diagram of the arrangement of the coolant inlet and outlet in this invention;

[0041] Figure 3 This is a schematic diagram of the spiral cooling channel and lattice structure arrangement in this invention, wherein (A) is a cross-sectional view and (B) is a longitudinal section view;

[0042] Figure 4 The diagram shows the types of lattice structures that can be filled internally in this invention (not limited to these types), where (A) is a body-centered cubic structure, (B) is a face-centered cubic structure, and (C) is an arched lattice structure.

[0043] Figure 5This is a flowchart illustrating the design method of the cooling structure for the high-speed precision machine tool electric spindle housing according to the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0045] This invention aims to provide a cooling structure, design, manufacturing, and active temperature control method for the housing of a high-speed precision machine tool electric spindle. By designing multiple spiral flow channels within the electric spindle housing and filling the interior with a segmented lattice structure, heat exchange between the coolant and the wall surface is enhanced. Furthermore, by adjusting the flow rate of different channels, the temperature of different parts of the spindle can be more accurately controlled, achieving better temperature uniformity.

[0046] Example 1

[0047] As a specific example, the cooling structure for the housing of the high-speed precision machine tool electric spindle of the present invention is as follows: Figure 1 As shown in the figure, 1 is the electric spindle housing, 2 is the motor stator, 3 is the motor rotor, 4 is the main spindle, 5 is the rear bearing support, 6 is the rear support bearing, 7 is the front bearing support, 8 is the front bearing, 9 is the front bearing cooling, 10 is the coolant inlet, 11 is the cooling channel and lattice structure section, 12 is the coolant outlet, 10-1 is the coolant inlet I, 10-2 is the coolant inlet II, 10-3 is the coolant inlet III, 11-1 is the spiral cooling channel I, 11-2 is the spiral cooling channel II, 11-3 is the spiral cooling channel III, 11-4 is the lattice structure, 12-1 is the coolant outlet I, 12-2 is the coolant outlet II, and 12-3 is the coolant outlet III.

[0048] In the high-speed precision machine tool electric spindle housing cooling structure of the present invention, such as Figures 1-4As shown, the electric spindle housing 1 is an axially extending cylindrical structure. Several independent spiral cooling channels (see figures 11, 11-1, 11-2, 11-3, etc.) are machined inside its cylindrical sidewall. Each spiral cooling channel (11-1, 11-2, 11-3, etc.) extends spirally from the first axial end to the second axial end of the electric spindle housing 1. Each spiral cooling channel (11-1, 11-2, 11-3, etc.) has a coolant inlet 10 and a coolant outlet 12 at both ends. The coolant inlet 10 is located at the first axial end of the electric spindle housing 1, and each coolant inlet (see figures 10, 10-1, 10-2, 10-3, etc.) is evenly distributed circumferentially at the first axial end of the electric spindle housing. The coolant outlet 12 is located at the second axial end of the electric spindle housing, and each coolant outlet (see figures 12, 12-1, 12-2, 12-3, etc.) is evenly distributed circumferentially at the second axial end of the electric spindle housing 1.

[0049] In the high-speed precision machine tool electric spindle housing cooling structure of the present invention, such as Figures 1-4 As shown, each spiral cooling channel (11-1, 11-2, 11-3, etc.) is filled with a lattice structure segment (see 11 in the figure). The lattice structure segment is used to enhance the heat exchange between the coolant in the channel and the inner wall of the electric spindle housing 1 and to support the channel. The axial length of each lattice structure segment is less than the axial length of the spiral cooling channel in which it is located. Furthermore, each lattice structure segment is distributed in different axial positions of the electric spindle housing 1, so that the whole is arranged in segments along the axial direction of the electric spindle housing.

[0050] In the high-speed precision machine tool electric spindle housing cooling structure of the present invention, such as Figures 1-4 As shown, the coolant inlets (10-1, 10-2, 10-3, etc.) of each spiral cooling channel (11-1, 11-2, 11-3, etc.) are connected to the coolant outlets of the external cold source through pipelines, and the coolant outlets (12-1, 12-2, 12-3, etc.) are connected to the coolant return ports of the external cold source through pipelines. This ensures that each spiral cooling channel (11-1, 11-2, 11-3, etc.) forms an independent coolant circulation loop with the external cold source. Thus, during the coolant circulation process, the uniformity of the electric spindle temperature distribution is achieved through independent control of each coolant circulation loop.

[0051] In some preferred examples, such as Figures 1-3As shown, the number of spiral cooling channels can be set to 3-8, and can be adjusted according to the structural dimensions of the electric spindle housing and cooling requirements. The cooling channel shown in the figure consists of three spiral cooling channels 11-1, 11-2, and 11-3, with the same pitch. The coolant inlet and outlet are located at both ends, for a total of 3 inlets and 3 outlets. The coolant outlets 12-1, 12-2, and 12-3 and the coolant inlets 10-1, 10-2, and 10-3 are evenly distributed along the circumference, corresponding to the 3 channels respectively (e.g., ...). Figure 2 (As shown). Preferably, the pitch, height, and width of each spiral cooling channel are the same, and the height, width, and pitch of the spiral cooling channels are optimized according to the axial length and radial thickness of the electric spindle housing to ensure the stability of the flow rate and pressure distribution of the coolant in the channels, while avoiding local overcooling or overheating caused by coolant accumulation or excessive flow in the channels. In addition, the cross-sectional shape of each spiral cooling channel can be one of circular, elliptical, rectangular, or polygonal, and the long side characteristic dimension of the cross-sectional shape is arranged radially to increase the contact area with the electric spindle housing and improve heat exchange efficiency. The selection of the cross-sectional shape is optimized according to the flow characteristics of the channels to reduce the flow resistance of the coolant and improve the flow stability of the coolant.

[0052] In some preferred embodiments, the lattice structure filling the flow channel can be a body-centered cubic, face-centered cubic, arched, or three-period minimal surface lattice, but is not limited to these types (e.g., Figure 4 As shown in the diagram, the arrangement of each lattice structure unit is optimized according to cooling requirements and flow channel geometry to ensure that the lattice structure not only enhances heat exchange within the flow channel but also effectively supports the inner wall of the flow channel, preventing structural deformation. By selecting appropriate lattice structure units, a cooling solution can be customized based on the heat load of different areas of the electric spindle, improving overall heat dissipation efficiency and the load-bearing capacity of the electric spindle housing.

[0053] The three spiral cooling channels 11-1, 11-2, and 11-3 are filled with lattice structures at different locations. For example, channel 11-1 has a lattice structure arranged near the coolant inlet along the main axis; channel 21-2 has a lattice structure arranged in the middle of the coolant inlet and outlet along the main axis; and channel 31-3 has a lattice structure arranged at the coolant outlet along the main axis. Figure 3 (As shown). The complex electric spindle housing cooling structure is manufactured using additive manufacturing. Through this differentiated axial arrangement strategy of the lattice structure segments, the cooling system can be segmented and strengthened according to the temperature distribution and cooling requirements of each flow channel, effectively improving the overall heat dissipation efficiency, optimizing the temperature uniformity of the electric spindle, and avoiding local overcooling or overheating.

[0054] In some preferred embodiments, the high-speed precision machine tool electric spindle housing cooling structure of the present invention further includes a temperature monitoring system and a flow regulation system, wherein: the temperature monitoring system includes multiple temperature sensors, which are arranged axially and circumferentially on the inner wall of the electric spindle housing and / or on the motor stator to monitor the temperature of various parts of the electric spindle in real time; the flow regulation system includes control valves installed on pipelines connected to the coolant inlet and / or coolant outlet of each spiral cooling channel, for independently adjusting the coolant flow of each spiral cooling channel according to the feedback information of the temperature monitoring system, thereby achieving precise temperature control and uniform distribution.

[0055] Example 2

[0056] Based on Embodiment 1 above, Embodiment 2 details the design method of the cooling structure for the housing of the high-speed precision machine tool electric spindle, such as... Figure 5 As shown, the design steps for this cooling structure are as follows:

[0057] SS1. Based on the size requirements of the electric spindle, determine the overall external dimensions of the electric spindle housing, including at least its length and diameter, to ensure that it matches other components of the electric spindle and meets the installation requirements;

[0058] SS2. Determine the wall thickness of the electric spindle housing based on the load it bears during operation to ensure its strength and rigidity during operation and prevent structural failure due to overload.

[0059] SS3. Based on the axial length and radial thickness of the electric spindle housing, determine the geometric parameters such as the cross-sectional height, width, and pitch of the spiral cooling channel. At the same time, consider the fluid dynamics characteristics and optimize the channel design to reduce flow resistance and improve heat exchange efficiency.

[0060] SS4. Based on the axial length of the electric spindle housing, the cooling zone is divided into multiple sections along the axial direction (for example, it can be divided into three sections). The number of cooling sections is matched with the number of spiral cooling channels. A lattice structure is designed in each spiral cooling channel, and the type, size and distribution density of the lattice structure are determined. The total number of lattice structure segments is consistent with the number of cooling sections and corresponds one-to-one with each cooling section in the axial direction.

[0061] SS5. Combining additive manufacturing technology, and based on the limit forming capability of additive manufacturing, design a self-supporting cross section for the flow channel without lattice structure support, so that the spiral cooling flow channel and lattice structure can be processed and manufactured without the need for a support structure during manufacturing.

[0062] SS6. In the bearing chambers at both ends of the electric spindle housing, design the inlet and outlet of each spiral cooling channel to ensure that each spiral channel has a coolant inlet and outlet to achieve an independent coolant circulation loop;

[0063] SS7. Perform strength and heat transfer performance verification analysis on the electric spindle housing to ensure that it meets the requirements of mechanical strength and heat dissipation performance in actual use. If the requirements are not met, repeat steps SS2 to SS6; if the requirements are met, the design process ends and the final electric spindle housing cooling structure design scheme is output.

[0064] Example 3

[0065] Based on Embodiment 1 above, Embodiment 3 details the manufacturing method of the cooling structure for the housing of the high-speed precision machine tool electric spindle, and its main steps are as follows:

[0066] SS1. Based on the requirements of additive manufacturing process, the three-dimensional model of the cooling structure of the electric spindle housing is adjusted to minimize the addition of process support. This ensures that the support structure is minimized during the additive manufacturing process. Then, the support structure is set for the model, layer slicing is performed, process paths and parameters are set, and laser selective melting additive forming is used to form the electric spindle housing and its internal spiral cooling channels and lattice structure.

[0067] SS2. After the electric spindle housing cooling structure is completed by additive manufacturing, the substrate is heat-treated to remove the thermal stress generated during the manufacturing process. Then, the electric spindle housing is separated from the substrate by wire cutting to remove the support formed during the additive manufacturing process, ensuring that the structure is intact and without defects.

[0068] SS3. The outer surface of the electric spindle housing is treated by sandblasting or manual grinding to remove powder residue adhering to the outer surface; at the same time, the inner wall of the electric spindle housing is finely treated by abrasive flow or electrochemical polishing to remove adhering powder, ensuring that the cooling channel is smooth, reducing fluid resistance and improving the heat exchange efficiency of the channel.

[0069] SS4. Machin the coolant inlet and outlet of the electric spindle housing to ensure that their size and shape meet the design requirements, and conduct leak testing to ensure that all coolant inlet and outlet are well sealed to avoid coolant leakage.

[0070] Example 4

[0071] Based on Embodiment 1 above, Embodiment 4 details the active temperature control process of the cooling structure for the housing of the high-speed precision machine tool electric spindle as follows:

[0072] SS1. Temperature sensors arranged on the inner wall of the electric spindle housing and on the motor stator are used to measure the temperature at key hot and cold areas of the electric spindle to ensure accurate monitoring of temperature distribution;

[0073] SS2. Based on the temperature data fed back by the temperature sensor, identify the high-temperature area inside the electric spindle housing, and adjust the flow rate of the corresponding flow channel according to the location of the high temperature, so that the coolant flows preferentially to the high-temperature area for cooling, thereby reducing the temperature of the high-temperature area.

[0074] SS3. Repeat steps 1-2 continuously to achieve uniform temperature throughout the electric spindle, avoiding thermal deformation and machining errors caused by temperature differences, thereby improving the machining accuracy and service life of the electric spindle.

[0075] The objectives of this invention have been fully and effectively achieved through the above embodiments. Those skilled in the art will understand that this invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments described above. Although the invention has been described with reference to what is currently considered the most practical and preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments, and any modifications that do not depart from the functional and structural principles of the invention will be included within the scope of the claims.

Claims

1. A cooling structure for the housing of a high-speed precision machine tool electric spindle, used to improve the cooling efficiency of the electric spindle during high-speed operation, improve the uniformity of temperature distribution, enhance the load-bearing capacity of the housing, and reduce the overall weight, comprising at least one electric spindle housing, characterized in that: The electric spindle housing is an integral cylindrical structure extending along the axial direction. Several independent spiral cooling channels are machined inside the cylindrical sidewall, each spirally extending from the first axial end of the electric spindle housing to the second axial end. Each of the spiral cooling channels is provided with a coolant inlet and a coolant outlet at both ends. The coolant inlet is located at the first axial end of the electric spindle housing, and each coolant inlet is evenly distributed circumferentially at the first axial end of the electric spindle housing. The coolant outlet is located at the second axial end of the electric spindle housing, and each coolant outlet is evenly distributed circumferentially at the second axial end of the electric spindle housing. Each of the spiral cooling channels is filled with a lattice structure segment. The lattice structure segment is used to enhance the heat exchange between the coolant in the channel and the inner wall of the electric spindle housing and to support the channel. The axial length of each lattice structure segment is less than the axial length of the spiral cooling channel in which it is located. Furthermore, each lattice structure segment is distributed in different axial positions of the electric spindle housing, so that the whole is arranged in segments along the axial direction of the electric spindle housing. The coolant inlet of each spiral cooling channel is connected to the coolant outlet of the external cold source through a pipeline, and the coolant outlet is connected to the coolant return port of the external cold source through a pipeline, so that each spiral cooling channel forms an independent coolant circulation loop with the external cold source.

2. The cooling structure for the housing of a high-speed precision machine tool electric spindle according to claim 1, characterized in that, The number of spiral cooling channels is 3-8, and is adjusted according to the structural dimensions and cooling requirements of the electric spindle housing. Each spiral cooling channel is evenly distributed circumferentially within the cylindrical sidewall of the electric spindle housing, and the spiral direction of each spiral cooling channel is the same.

3. The cooling structure for the housing of a high-speed precision machine tool electric spindle according to claim 1, characterized in that, The pitch, height, and width of each spiral cooling channel are the same, and the height, width, and pitch of the spiral cooling channel are optimized according to the axial length and radial thickness of the electric spindle housing to ensure the stability of the flow rate and pressure distribution of the coolant in the channel, while avoiding local overcooling or overheating caused by coolant accumulation or excessive flow in the channel.

4. The cooling structure for the housing of a high-speed precision machine tool electric spindle according to claim 1, characterized in that, The cross-sectional shape of each spiral cooling channel is one of circular, elliptical, rectangular or polygonal, and the long side characteristic dimension of the cross-sectional shape is arranged radially to increase the contact area with the electric spindle housing and improve the heat exchange efficiency. The selection of the cross-sectional shape is optimized according to the flow characteristics of the channel to reduce the flow resistance of the coolant and improve the flow stability of the coolant.

5. The cooling structure for the housing of a high-speed precision machine tool electric spindle according to claim 1, characterized in that, Each of the aforementioned lattice structure segments is composed of multiple periodically arranged lattice structure units. The shape of the lattice structure units is one of body-centered cubic, face-centered cubic, arch, three-period minimal surface, or a combination thereof. The arrangement of each type of lattice structure unit is optimized according to cooling requirements and flow channel geometry to ensure that the lattice structure can not only enhance the heat exchange effect in the flow channel, but also effectively support the inner wall of the flow channel and prevent structural deformation.

6. The cooling structure for the housing of a high-speed precision machine tool electric spindle according to claim 1, characterized in that, The lattice structure segments in different spiral cooling channels have different axial arrangement positions. Some lattice structure segments in spiral cooling channels are arranged near their coolant inlet, some are arranged near their coolant outlet, and some are arranged axially in the middle position between the coolant inlet and the coolant outlet.

7. The cooling structure for the housing of a high-speed precision machine tool electric spindle according to claim 1, characterized in that, The cooling structure of the high-speed precision machine tool electric spindle housing also includes a temperature monitoring system and a flow regulation system. The temperature monitoring system includes multiple temperature sensors arranged axially and circumferentially on the inner wall of the electric spindle housing and / or on the motor stator to monitor the temperature of various parts of the electric spindle in real time. The flow regulation system includes control valves installed on pipelines connected to the coolant inlet and / or coolant outlet of each of the spiral cooling channels to independently adjust the coolant flow rate of each spiral cooling channel based on feedback information from the temperature monitoring system.

8. A design method for a cooling structure for the housing of a high-speed precision machine tool electric spindle according to any one of claims 1 to 7, characterized in that, The design method includes at least the following steps: SS1. Based on the size requirements of the electric spindle, determine the overall external dimensions of the electric spindle housing, including at least its length and diameter, to ensure that it matches other components of the electric spindle and meets the installation requirements; SS2. Based on the load-bearing conditions of the electric spindle housing during operation, determine the wall thickness of the electric spindle housing to ensure its strength and rigidity during operation and prevent structural failure due to overload. SS3. Based on the axial length and radial wall thickness of the electric spindle housing, design the geometric parameters of the spiral cooling channel, including the channel cross-sectional shape, height, width and pitch. At the same time, consider the fluid dynamics characteristics and optimize the channel design to reduce flow resistance and improve heat exchange efficiency. SS4. Based on the axial length of the electric spindle housing, the cooling zone is divided into multiple sections along the axial direction. The number of cooling sections is matched with the number of spiral cooling channels. A lattice structure section is designed in each spiral cooling channel, and the type, size and distribution density of the lattice structure are determined. The total number of lattice structure sections is consistent with the number of cooling sections and corresponds one-to-one with each cooling section in the axial direction. SS5. Combining additive manufacturing technology, and based on the extreme forming capacity of the manufacturing process, design the self-supporting cross section of the spiral cooling channel to ensure that the spiral cooling channel and lattice structure can be successfully processed without the need for additional support structures during the manufacturing process. SS6. In the bearing chambers at both ends of the electric spindle housing, design the inlet and outlet positions of each spiral cooling channel to ensure that each channel has an independent coolant inlet and outlet to achieve an independent coolant circulation loop; SS7. Perform strength and heat transfer performance verification analysis on the designed electric spindle housing to ensure that it meets the requirements of mechanical strength and heat dissipation performance in actual use. If the requirements are not met, repeat optimization steps SS2 to SS6 for iterative optimization. If the requirements are met, the design process is completed and the final electric spindle housing cooling structure design scheme is output.

9. A method for manufacturing a cooling structure for the housing of a high-speed precision machine tool electric spindle according to any one of claims 1 to 7, characterized in that, The manufacturing method includes at least the following steps: SS1. Based on the requirements of additive manufacturing process, the three-dimensional model of the cooling structure of the electric spindle housing is adjusted to minimize the addition of process support, so as to ensure the minimization of the support structure during additive manufacturing. Then, the model is sliced ​​into layers, the processing path and process parameters are set, and additive forming is carried out by selective laser melting technology to form the electric spindle housing and its internal spiral cooling channels and lattice structure. SS2. After the electric spindle housing cooling structure is additively manufactured, it is heat-treated together with the substrate to remove the thermal stress generated during the manufacturing process. Then, wire cutting is used to separate the electric spindle housing from the substrate and remove the support structure formed during the additive manufacturing process to ensure that the structure is intact and defect-free. SS3. Treat the outer surface of the electric spindle housing by sandblasting and / or manual grinding to remove powder residue adhering to the outer surface; at the same time, finely treat the inner wall of the electric spindle housing by abrasive flow machining or electrochemical polishing to remove powder adhering to the inner wall, ensuring that the cooling channel is smooth, reducing fluid resistance and improving the heat exchange efficiency of the channel. SS4. Precision machine the coolant inlet and outlet of the electric spindle housing to ensure that its size and shape meet the design requirements, and conduct a sealing performance test. Through leak testing, ensure that the sealing performance of all coolant inlets and outlets is good to avoid coolant leakage.

10. An active temperature control method for the cooling structure of the high-speed precision machine tool electric spindle housing according to any one of claims 1 to 7, characterized in that, The temperature control method includes at least the following steps: SS1. Multiple temperature sensors are arranged on the inner wall of the electric spindle housing and / or on the motor stator to monitor temperature data at different locations of the electric spindle in real time. The temperature sensors are evenly distributed in the key hot and cold areas of the electric spindle to ensure accurate monitoring of temperature distribution. SS2. Based on the temperature data fed back by the temperature sensor, identify the high-temperature area inside the electric spindle housing, and adjust the coolant flow rate of the corresponding cooling channel through the automatic temperature control system so that the coolant flows preferentially to the higher temperature area for cooling, thereby reducing the temperature of the high-temperature area; SS3. Repeat the temperature monitoring and coolant flow regulation steps to ensure that the temperature of all parts of the electric spindle remains uniform throughout the entire operation, avoiding thermal deformation and machining errors caused by temperature differences, thereby improving the machining accuracy and service life of the electric spindle.

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