A machine tool swing head electric spindle structure

Abstract

This invention relates to the field of CNC machine tool functional component design technology, and particularly to a machine tool swivel head electric spindle structure, including a housing and a spindle module disposed inside the housing. A through-hole is provided at the center left side of the housing. A motor with its axis pointing left and right is fixedly installed inside the housing. The motor includes a stator sleeve, a rotor sleeve, and a mounting sleeve arranged sequentially from the outside to the inside. Multiple sets of media channels are provided inside both the stator sleeve and the housing. The spindle module is disposed inside the mounting sleeve and coaxial with it. The multiple sets of media channels provide cooling and lubrication for the motor, bearings, and cutting tools, reducing the thermal deformation of the electric spindle during operation and improving its service life and machining accuracy.

Description

Technical Field

[0001] This invention relates to the field of CNC machine tool functional component design technology, and in particular to a machine tool tilting head electric spindle structure. Background Technology

[0002] Currently, existing oscillating electric spindles typically consist of a housing, a motor fixedly installed inside the housing, a shaft driven by the motor, and a bearing assembly supporting the shaft. Their cooling and lubrication often adopt a centralized flow channel arrangement. The cooling of the bearings, the lubrication of the bearings, and the cooling of the motor often share the same flow channel or adopt a mutually interfering arrangement. Moreover, the front and rear bearings often use the same type of bearing combination.

[0003] When the overall size of the oscillating head electric spindle is limited by the installation space of the machine tool oscillating head, the space available for arranging bearings, motors, and cooling and lubrication channels is very small. It is difficult to balance the ratio between the bearing span and the outer diameter of the spindle, making overall rigidity design difficult. Under high torque cutting conditions, the spindle is prone to elastic deformation, making it difficult to stably output high torque. When the oscillating head electric spindle operates at high speed, the motor and bearings generate a lot of heat, and the centralized arrangement of channels cannot simultaneously meet the different requirements of motor cooling, bearing cooling, and bearing lubrication for medium flow rate and medium pressure. The cooling and lubrication effects are mutually restrictive, the thermal elongation of the spindle is difficult to control, and the thermal balance at high speed is difficult to maintain. Summary of the Invention

[0004] The purpose of this invention is to provide a machine tool swivel head electric spindle structure to solve the problems existing in the prior art.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A machine tool swivel head electric spindle structure, comprising: The housing has a through mounting hole at the center of its left side. A motor with its axis pointing left and right is fixedly installed inside the housing. The motor includes a stator sleeve, a rotor sleeve, and a mounting sleeve arranged sequentially from the outside to the inside. The left side of the stator sleeve extends to the outside of the housing, and an integrally formed flange is provided on the centrifugal side of the end of the stator sleeve located on the outside of the housing. Multiple sets of medium channels are provided inside both the stator sleeve and the housing. A shaft module is disposed inside the mounting sleeve, and the shaft module is coaxial with the mounting sleeve.

[0006] By adopting the above technical solution, the purpose of cooling and lubricating the entire spindle is achieved by setting multiple sets of medium channels inside the stator sleeve and the housing. Cooling can reduce the thermal deformation of the electric spindle under working conditions, and lubrication can effectively improve the service life and accuracy of the spindle.

[0007] In a further embodiment, the multiple media channels include at least a bearing cooling oil channel, a bearing lubricating oil channel, a motor water cooling channel, and a tool internal cooling channel; a disc-shaped protrusion integrally formed with the housing is provided at the front center and rear center of the housing; the disc-shaped protrusion at the front center of the housing has the inlet and outlet of the motor water cooling channel, the inlet and outlet of the tool internal cooling channel, and the inlet and outlet of the bearing cooling oil channel spaced apart on its front axial side; the disc-shaped protrusion at the rear center of the housing has the inlet and outlet of the bearing lubricating oil channel spaced apart on its rear axial side; the inlet and outlet of the motor water cooling channel are centrally symmetrically arranged, and there is a closed first cavity between the outer wall of the stator sleeve and the inner wall of the housing; the inlet and outlet of the motor water cooling channel both extend rearward to communicate with the first cavity.

[0008] By adopting the above technical solution, the purpose of the stator sleeve is to fix the permanent magnet axially and uniformly on the inner wall. The rotor sleeve is completely located inside the stator sleeve. Bearings are fitted at both ends of the rotor sleeve. The bearings are used to make the rotor rotate around the axis. The mounting sleeve is used to fit the middle section of the axis module by interference fit. The mounting sleeve and the rotor sleeve are interference fit.

[0009] In a further embodiment, the left end of the spindle module is used to clamp the tool, and a rear cover module is fixedly installed on the right side of the housing. The rear cover module is used to completely close the right side of the mounting hole. A sealing ring is fixedly installed on the left side of the stator sleeve. The left end of the sealing ring extends to the outside of the stator sleeve. The sealing ring is sleeved on the left end of the spindle module. A sealing module sleeved on the spindle module is provided between the sealing ring and the mounting sleeve. The sealing module includes an angular contact bearing and an isolation ring arranged alternately along the axis of the spindle module. The right end face of the sealing ring, the inner wall of the outer ring of the angular contact bearing, the left end face of the mounting sleeve, and the outer wall of the inner ring of the angular contact bearing form a second cavity. The bearing lubricating oil channel communicates with the second cavity after passing through the inside of the housing, the inside of the stator sleeve, and the inside of the sealing ring.

[0010] By adopting the above technical solution, four angular contact bearings and four isolating rings are provided. The angular contact bearings are divided into two groups, with the two angular contact bearings in each group set back to back to ensure the rotational accuracy of the spindle. The left end of the central module is used to clamp the tool and drive the tool to rotate at high speed, so the axial runout must be suppressed to a very small range.

[0011] In a further embodiment, a central shaft hole is provided at the center of the shaft module, the internal cooling channel of the tool is connected to the central shaft hole, and a mounting hole for mounting the tool is provided at the left end of the central shaft hole.

[0012] By adopting the above technical solution, coolant can be injected into the tool with liquid cooling channel through the tool internal cooling channel and the central spindle hole to complete the internal cooling of the tool.

[0013] In a further embodiment, a cylindrical roller bearing is fitted onto the right end of the shaft module.

[0014] By adopting the above technical solution, the right end of the spindle module is supported by a cylindrical roller bearing. The cylindrical roller bearing can withstand a large radial load and cooperates with the angular contact bearing at the front end, so that the radial deformation of the rear end of the spindle is reduced when subjected to high torque cutting, thereby improving the overall rigidity of the spindle.

[0015] In a further embodiment, four angular contact bearings and four isolation rings are provided. The four angular contact bearings are divided into two groups, with the two angular contact bearings in each group arranged back to back.

[0016] By adopting the above technical solution, the four corner contact bearings are divided into two groups and arranged back to back. This allows them to withstand axial loads in two directions simultaneously and suppress the axial runout of the left end of the spindle module to a very small range, so that the spindle module can maintain high rotational accuracy when holding the tool at high speed.

[0017] In a further embodiment, a rear bearing pressure ring is fitted on the side of the sealing module opposite to the left end of the shaft module. The rear bearing pressure ring has an annular cooling channel arranged around the axis of the shaft module. The bearing cooling oil channel includes a first cooling oil passage arranged inside the housing. One end of the first cooling oil passage is connected to the inlet of the bearing cooling oil channel, and the other end passes through the inside of the housing and the inside of the stator sleeve in sequence before connecting to the annular cooling channel.

[0018] By adopting the above technical solution, the cooling oil enters the annular cooling channel through the first cooling oil path and acts directly on the rear bearing pressure ring, which reduces the temperature of the rear bearing pressure ring, reduces the heat transfer from the rear end of the spindle to the spindle module, and thus reduces the deformation of the rear end of the spindle in the working state.

[0019] In a further embodiment, the interior of the outer shell and the interior of the stator sleeve are provided with interconnected air-tight channels. The left side of the stator sleeve is provided with three air-blowing ports that communicate with the air-tight channels at circumferential intervals. A labyrinth sealing structure is provided between the left end of the sealing ring and the shaft module. The labyrinth sealing structure includes sealing teeth and sealing grooves that are staggered along the axial direction of the shaft module. All three air-blowing ports are oriented towards the labyrinth sealing structure.

[0020] By adopting the above technical solution, compressed air is blown into the labyrinth seal structure through three air outlets via the air-tight channel, forming an air curtain at the left end of the sealing ring. This prevents external cutting fluid and dust from entering the sealing module, thereby improving the sealing reliability of the spindle front end and extending the service life of the angular contact bearing.

[0021] In a further embodiment, the sealing ring is provided with a vibration sensor, a thermal expansion sensor and multiple bearing temperature sensors. The vibration sensor is located near the inside of the sealing ring on the side away from the left end of the shaft module. The thermal expansion sensor is located inside the sealing ring on the side near the left end of the shaft module. The multiple bearing temperature sensors are respectively provided with each angular contact bearing. The rear bearing pressure ring is provided with a bearing temperature sensor.

[0022] By adopting the above technical solutions, vibration sensors, thermal expansion sensors, and bearing temperature sensors respectively collect the vibration amount, thermal expansion amount, and bearing temperature of the spindle, providing a data foundation for tool wear prediction, collision protection, and health diagnosis, thereby improving the safety of the spindle during use.

[0023] In a further embodiment, a tool internal cooling tail cover is fixedly installed at the right end of the central shaft hole. The tool internal cooling tail cover is provided with a rotary joint that communicates with an external cooling medium supply device. A waste liquid recovery chamber is provided on the outside of the tool internal cooling tail cover. The waste liquid recovery chamber communicates with a waste liquid recovery channel provided inside the outer shell.

[0024] By adopting the above technical solution, the internal cooling tail cover and rotary joint of the tool introduce the external cooling medium into the central shaft hole. After the cooling medium flows out of the tool, it enters the waste liquid recovery chamber and is discharged along the waste liquid recovery channel, which avoids the cooling medium from entering the interior of the rear cover module, thereby ensuring the sealing performance of the rear end of the spindle.

[0025] In summary, the present invention has the following beneficial effects: 1. By setting up multiple media channels in the housing and inside the motor, the entire spindle can be cooled and lubricated. Cooling can reduce the thermal deformation of the electric spindle during operation, and lubrication can effectively improve the service life and accuracy of the spindle. 2. By using four back-to-back angular contact bearings at the front end and one cylindrical roller bearing at the rear end, the axial runout of the shaft can be suppressed and large radial loads can be borne, thereby ensuring high speed while achieving stable output of large torque; 3. The airtight channel and labyrinth seal structure can prevent cutting fluid and dust from entering the sealing module, thereby ensuring the sealing reliability and service life of the spindle at high speeds. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the positions of the housing and the motor of the present invention; Figure 3 This is the invention Figure 1 The front view; Figure 4 This is a schematic diagram of the internal structure of the motor of the present invention; Figure 5 This is a structural diagram illustrating the cooling channels for the bearings inside the outer casing and stator sleeve. Figure 6 yes Figure 3 Schematic diagram of the 1-1 cross-sectional structure; Figure 7 This is a cross-sectional schematic diagram showing the water-cooling channel inside the motor housing and motor. Figure 8 yes Figure 3 Schematic diagram of the 2-2 cross-sectional structure; Figure 9 yes Figure 3 Schematic diagram of the 3-3 cross-section structure; Figure 10 yes Figure 3 Schematic diagram of the 4-4 cross-section structure; Figure 11 This is a structural schematic diagram illustrating the shaft module of the present invention; Figure 12 yes Figure 11 A schematic diagram of a half-section structure; Figure 13 It is a perspective view of the outer shell, used to show the distribution and location of its internal channels; Figure 14 yes Figure 13 A detailed perspective view of one corner; Figure 15 This is a detailed perspective view of the stator sleeve; Figure 16 This is a detailed perspective view of the stator sleeve flange; Figure 17 This is a schematic diagram of the sealing ring.

[0027] In the diagram, 1. Outer shell; 2. Disc-shaped protrusion; 3. Stator sleeve; 4. Rotor sleeve; 5. Mounting sleeve; 6. Shaft module; 7. Rear cover module; 8. Sealing ring; 9. Sealing module; 10. Angular contact bearing; 11. Isolation ring; 12. Cylindrical roller bearing; 13. Rear bearing pressure ring; 14. Annular cooling channel; 15. Central shaft hole; 16. Mounting hole; 17. Flange; 18. Labyrinth seal structure. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings.

[0029] It should be noted that in the description of this invention, any descriptions of orientation, such as up, down, front, back, left, right, etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and should not be construed as a limitation of this invention.

[0030] Example 1: like Figure 1 and Figure 3 As shown, a machine tool swivel head electric spindle structure includes a housing 1, a motor fixedly installed inside the housing 1, and a spindle module 6 disposed inside the motor. The housing 1 has a through-hole on the left side center position. The motor with the axial direction in the left-right direction is fixedly installed inside the housing 1. The motor includes a stator sleeve 3, a rotor sleeve 4, and a mounting sleeve 5 arranged sequentially from the outside to the inside. The left side of the stator sleeve 3 extends to the outside of the housing 1, and an integrally formed flange 17 is provided radially outward at one end of the stator sleeve 3 located on the outside of the housing 1. Multiple sets of medium channels are provided inside both the stator sleeve 3 and the housing 1. The spindle module 6 is disposed inside the mounting sleeve 5, and the spindle module 6 is coaxial with the mounting sleeve 5.

[0031] like Figure 2 and Figure 4 As shown, permanent magnets are uniformly fixed on the inner wall of the stator sleeve 3 along the axial direction. The rotor sleeve 4 is completely located inside the stator sleeve 3. Bearings are fitted at both ends of the rotor sleeve 4. The mounting sleeve 5 is fitted onto the middle section of the shaft module 6 by an interference fit. The mounting sleeve 5 and the rotor sleeve 4 are interference fitted. After the motor is powered on, it drives the rotor sleeve 4 to rotate. The rotor sleeve 4 drives the shaft module 6 to rotate around the axis through the mounting sleeve 5.

[0032] like Figure 6 and Figure 17 As shown, a sealing ring 8 is fixedly installed on the left side of the stator sleeve 3. The left end of the sealing ring 8 extends to the outside of the stator sleeve 3. The sealing ring 8 is sleeved on the left end of the shaft module 6. A sealing module 9 is provided between the sealing ring 8 and the mounting sleeve 5, and is sleeved on the shaft module 6. The sealing module 9 includes angular contact bearings 10 and isolation rings 11 arranged alternately along the axis of the shaft module 6. There are four angular contact bearings 10 and four isolation rings 11. The four angular contact bearings 10 are divided into two groups, and the two angular contact bearings 10 in each group are arranged back to back. The right end face of the sealing ring 8, the inner wall of the outer ring of the angular contact bearing 10, the left end face of the mounting sleeve 5, and the outer wall of the inner ring of the angular contact bearing 10 form a second cavity. The bearing lubricating oil channel passes through the interior of the housing 1, the interior of the stator sleeve 3, and the interior of the sealing ring 8 in sequence and then communicates with the second cavity. Figure 8 , Figure 9 and Figure 10 As shown, Figure 3 Sections 2-2, 3-3, and 4-4 cut through the outer shell 1 at different positions along the axial direction of the core module 6, showing the distribution of the internal flow channels of the outer shell 1, the internal flow channels of the sealing ring 8, and the relative positional relationship between the angular contact bearing 10 and the isolation ring 11 in the sealing module 9.

[0033] like Figure 6 As shown, a rear cover module 7 is fixedly installed on the right side of the outer casing 1. The rear cover module 7 is used to completely seal the right side of the mounting hole. A cylindrical roller bearing 12 is sleeved on the right end of the shaft module 6. A rear bearing pressure ring 13 is sleeved on the side of the shaft module 6 located away from the left end of the sealing module 9. The rear bearing pressure ring 13 abuts against the inner ring of the cylindrical roller bearing 12. An annular cooling channel 14 is provided inside the rear bearing pressure ring 13, which surrounds the axis of the shaft module 6. The annular cooling channel 14 surrounds the outer ring of the cylindrical roller bearing 12.

[0034] like Figure 11 and Figure 12 As shown, a central shaft hole 15 is provided at the center of the shaft module 6. A mounting hole 16 for mounting a tool is provided at the left end of the central shaft hole 15. The right end of the central shaft hole 15 extends to the right end face of the shaft module 6. The left end of the shaft module 6 extends out of the left side of the outer shell 1 and is used to clamp the tool. The internal cooling channel of the tool is connected to the central shaft hole 15. An internal cooling tail cover of the tool is fixedly installed at the right end of the central shaft hole 15. A rotary joint connected to an external cooling medium supply device is provided on the internal cooling tail cover of the tool. A waste liquid recovery chamber is provided on the outside of the internal cooling tail cover of the tool. The waste liquid recovery chamber is connected to the waste liquid recovery channel provided inside the outer shell 1.

[0035] like Figure 1 , Figure 2 and Figure 3 As shown, a disc-shaped protrusion 2 integrally formed with the outer shell 1 is provided at the center of the front side and the center of the rear side of the outer shell 1. The disc-shaped protrusion 2 located at the center of the front side of the outer shell 1 has an inlet and outlet of a motor water cooling channel, an inlet and outlet of a tool internal cooling channel, and an inlet and outlet of a bearing cooling oil channel spaced apart on the front side. The disc-shaped protrusion 2 located at the center of the rear side of the outer shell 1 has an inlet and outlet of a bearing lubricating oil channel spaced apart on the rear side. The inlet and outlet of the motor water cooling channel are symmetrically arranged at the center. A closed first cavity is provided between the outer wall of the stator sleeve 3 and the inner wall of the outer shell 1. The inlet and outlet of the motor water cooling channel extend rearward to communicate with the first cavity.

[0036] Example 2: like Figures 5 to 8As shown, the difference between this embodiment and Embodiment 1 is that the multiple media channels in this embodiment include at least a bearing cooling oil channel, a bearing lubricating oil channel, a motor water cooling channel, and a tool internal cooling channel. These channels are independently arranged inside the housing 1 and the stator sleeve 3, respectively, to provide cooling and lubricating media to different parts of the spindle. Figure 15 and Figure 16 As shown, both the interior of the stator sleeve 3 and the interior of the flange 17 integrally formed with the stator sleeve 3 are provided with medium channels that communicate with the internal flow channels of the outer shell 1.

[0037] like Figure 5 As shown, the bearing cooling oil channel includes a first cooling oil path disposed inside the housing 1. One end of the first cooling oil path extends to the disc-shaped protrusion 2 at the center of the front side of the housing 1 and communicates with the inlet of the bearing cooling oil channel. The other end of the first cooling oil path passes through the interior of the housing 1 and the interior of the stator sleeve 3 in sequence and communicates with the annular cooling channel 14. After entering the bearing cooling oil channel through the inlet, the cooling oil flows into the annular cooling channel 14 along the first cooling oil path, directly acts on the rear bearing pressure ring 13 and carries away the heat generated by the cylindrical roller bearing 12. The cooling oil then flows back from the outlet of the bearing cooling oil channel in the opposite direction to the oil inlet direction. The inlet and outlet of the bearing cooling oil channel are arranged at a 90-degree angle at the disc-shaped protrusion 2 at the center of the front side of the housing 1.

[0038] To ensure the connection between the tool cooling channel and the central spindle hole, a rotary joint needs to be installed inside the rear cover module.

[0039] like Figure 6 and Figure 17 As shown, the inlet of the bearing lubricating oil channel is located at the center of the rear side of the housing 1, at the disc-shaped protrusion 2. The bearing lubricating oil channel passes through the interior of the housing 1, the interior of the stator sleeve 3, and the interior of the sealing ring 8 in sequence, and then connects to the second cavity. The lubricating oil enters the sealing module 9 from the second cavity and lubricates the four corner contact bearings 10. The interior of the housing 1 is also provided with a diversion module that connects to the bearing lubricating oil channel. The diversion module divides the lubricating oil into four front bearing oil supply channels and one rear bearing oil supply channel. The four front bearing oil supply channels are respectively connected to the interior of the sealing ring 8 and correspond one-to-one with the four corner contact bearings 10. The one rear bearing oil supply channel is connected to the rear bearing pressure ring 13 and corresponds to the rear bearing pressure ring 13.

[0040] Waste oil from the front bearing flows back into the sealing ring 8, and waste oil from the rear bearing flows back into the rear bearing pressure ring 13. The two waste oils converge into the oil drain channel inside the stator sleeve 3, and then flow out through the oil outlet of the housing 1 via the oil drain channel inside the housing 1. The four corner contact bearings 10 and the rear bearing are each provided with their own independent discharge channels to prevent waste oil from accumulating at the bearings. The gas inside the spindle is discharged along with the waste oil through the oil drain channel, achieving centralized discharge of waste gas and waste oil.

[0041] like Figure 7 As shown, the inlet and outlet of the motor water cooling channel are located at the center of the front side of the outer casing 1, and are arranged symmetrically. Both the inlet and outlet of the motor water cooling channel extend backward to communicate with the first cavity. Cooling water enters the first cavity through the inlet and flows around the outer wall of the stator sleeve 3, and then flows out through the outlet, thereby carrying away the heat generated by the motor during operation.

[0042] like Figure 6 and Figure 12 As shown, the inlet and outlet of the tool internal cooling channel are located at the disc-shaped protrusion 2 at the center of the front side of the housing 1. The tool internal cooling channel is connected to the central shaft hole 15 of the spindle module 6 through the inside of the housing 1. The high-pressure coolant enters through the inlet of the tool internal cooling channel and is transported through the central shaft hole 15 to the inside of the tool installed on the mounting hole 16. It is then sprayed out from the cutting edge of the tool to achieve direct cooling of the tool's interior. The coolant flowing back into the tool is discharged through the waste liquid recovery chamber and the waste liquid recovery channel located inside the housing 1, preventing the coolant from entering the interior of the rear cover module 7.

[0043] like Figure 13 and Figure 14 As shown, the interior of the outer casing 1 and the interior of the stator sleeve 3 are also provided with interconnected air-sealing channels. Three air-blowing ports communicating with the air-sealing channels are arranged circumferentially on the left side of the stator sleeve 3. A labyrinth seal structure 18 is provided between the left end of the sealing ring 8 and the shaft module 6. The labyrinth seal structure 18 includes sealing teeth and sealing grooves arranged alternately along the axial direction of the shaft module 6. The three air-blowing ports are all facing the labyrinth seal structure 18. After entering through the air-sealing channel, compressed air is blown towards the labyrinth seal structure 18 through the three air-blowing ports, forming an air curtain at the left end of the sealing ring 8 to prevent external cutting fluid and dust from entering the sealing module 9.

[0044] The sealing ring 8 is equipped with a vibration sensor, a thermal expansion sensor and multiple bearing temperature sensors. The vibration sensor is located near the angular contact bearing 10 on the side of the sealing ring 8 away from the left end of the shaft module 6. The thermal expansion sensor is located on the front side of the angular contact bearing 10 on the side of the sealing ring 8 near the left end of the shaft module 6. The multiple bearing temperature sensors are respectively set one-to-one with the four angular contact bearings 10. The rear bearing pressure ring 13 is equipped with a bearing temperature sensor corresponding to the cylindrical roller bearing 12.

[0045] The outer diameter of the shaft segment that mates with the cylindrical roller bearing 12 on the shaft module 6 is the outer diameter of the shaft center. The length of the shaft segment between the sealing module 9 and the cylindrical roller bearing 12 constitutes the bearing span. The ratio of the bearing span to the outer diameter of the shaft center is three to one. The above ratio was obtained after analyzing the stiffness of the electric spindle based on a large amount of measured data and the pendulum length principle. This ratio enables the electric spindle to obtain the optimal length-to-diameter ratio within a limited installation space. The rated maximum torque of the pendulum electric spindle in this embodiment is 1000 Nm, and the rated maximum speed is 8000 rpm.

[0046] Specific implementation process: During assembly, first, the four angular contact bearings 10 and four isolation rings 11 are staggered and fitted onto the left end of the shaft module 6 along the axis of the shaft module 6, with the two angular contact bearings 10 in each group arranged back to back. The assembled sealing module 9 is then fitted into the inside of the mounting sleeve 5. Subsequently, the mounting sleeve 5 is fitted into the middle section of the shaft module 6 with an interference fit. The cylindrical roller bearing 12 is fitted onto the right end of the shaft module 6, and the rear bearing pressure ring 13 is fitted onto the right end of the shaft module 6, with the rear bearing pressure ring 13 abutting against the inner ring of the cylindrical roller bearing 12. The stator sleeve 3 is fitted onto the outside of the mounting sleeve 5, with the permanent magnet on its inner wall corresponding to the rotor sleeve 4. The sealing ring 8 is fixedly installed on the left side of the stator sleeve 3. The assembled motor is then installed into the inside of the housing 1. Finally, the rear cover module 7 is fixedly installed on the right side of the housing 1, completely sealing the right side of the mounting hole.

[0047] Before use, connect the inlet and outlet of the bearing cooling oil channel, the inlet and outlet of the bearing lubricating oil channel, the inlet and outlet of the motor water cooling channel, and the inlet and outlet of the tool internal cooling channel to the corresponding cooling and lubrication system of the machine tool. Connect the air seal channel to the compressed air source, and connect the signal lines of the vibration sensor, thermal expansion sensor, and bearing temperature sensor to the CNC system of the machine tool.

[0048] During operation, the motor drives the rotor sleeve 4 to rotate after being powered on. The rotor sleeve 4 drives the shaft module 6 to rotate at high speed around the axis through the mounting sleeve 5. The left end of the shaft module 6 holds the cutting tool to perform cutting on the workpiece. Cooling water enters the first cavity through the motor water cooling channel and cools the stator sleeve 3. Cooling oil enters the annular cooling channel 14 through the bearing cooling oil channel and cools the rear bearing pressure ring 13. Lubricating oil enters the second cavity through the bearing lubricating oil channel and lubricates the four corner contact bearings 10. High-pressure coolant enters the central shaft hole 15 through the tool internal cooling channel and is sprayed out from the cutting edge of the tool to cool the tool. Compressed air is blown into the labyrinth seal structure 18 through the air seal channel and three air blowers. Cutting fluid and dust are blocked by the air curtain on the outside of the sealing ring 8. When the spindle temperature, vibration or thermal elongation exceeds the set range, the CNC system adjusts the spindle speed and feed rate according to the data collected by each sensor to achieve prediction of tool wear and protection against collisions.

[0049] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0050] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A machine tool swivel head electric spindle structure, characterized in that, include: The housing has a through mounting hole at the center of its left side. A motor with its axis pointing left and right is fixedly installed inside the housing. The motor includes a stator sleeve, a rotor sleeve, and a mounting sleeve arranged sequentially from the outside to the inside. The left side of the stator sleeve extends to the outside of the housing, and an integrally formed flange is provided on the centrifugal side of the end of the stator sleeve located on the outside of the housing. Multiple sets of medium channels are provided inside both the stator sleeve and the housing. A shaft module is disposed inside the mounting sleeve, and the shaft module is coaxial with the mounting sleeve.

2. The machine tool swivel head electric spindle structure according to claim 1, characterized in that: The multiple media channels include at least a bearing cooling oil channel, a bearing lubricating oil channel, a motor water cooling channel, and a tool internal cooling channel; a disc-shaped protrusion integrally formed with the housing is provided at the center of the front side and the center of the rear side of the housing; the disc-shaped protrusion at the center of the front side of the housing has the inlet and outlet of the motor water cooling channel, the inlet and outlet of the tool internal cooling channel, and the inlet and outlet of the bearing cooling oil channel spaced apart on its front side; the disc-shaped protrusion at the center of the rear side of the housing has the inlet and outlet of the bearing lubricating oil channel spaced apart on its rear side; the inlet and outlet of the motor water cooling channel are centrally symmetrically arranged, and there is a closed first cavity between the outer wall of the stator sleeve and the inner wall of the housing; the inlet and outlet of the motor water cooling channel both extend rearward to communicate with the first cavity.

3. The machine tool swivel head electric spindle structure according to claim 2, characterized in that: The left end of the spindle module is used to clamp the cutting tool. A rear cover module is fixedly installed on the right side of the housing, which is used to completely seal the right side of the mounting hole. A sealing ring is fixedly installed on the left side of the stator sleeve. The left end of the sealing ring extends to the outside of the stator sleeve. The sealing ring is sleeved on the left end of the spindle module. A sealing module is provided between the sealing ring and the mounting sleeve and sleeved on the spindle module. The sealing module includes an angular contact bearing and an isolation ring arranged alternately along the axis of the spindle module. The right end face of the sealing ring, the inner wall of the outer ring of the angular contact bearing, the left end face of the mounting sleeve, and the outer wall of the inner ring of the angular contact bearing form a second cavity. The bearing lubricating oil channel communicates with the second cavity after passing through the inside of the housing, the inside of the stator sleeve, and the inside of the sealing ring.

4. The machine tool swivel head electric spindle structure according to claim 3, characterized in that: A central shaft hole is provided at the center of the shaft module, the internal cooling channel of the tool is connected to the central shaft hole, and a mounting hole for mounting the tool is provided at the left end of the central shaft hole.

5. The machine tool swivel head electric spindle structure according to claim 1, characterized in that: A cylindrical roller bearing is fitted onto the right end of the shaft module.

6. The machine tool swivel head electric spindle structure according to claim 3, characterized in that: There are four angular contact bearings and four isolating rings. The four angular contact bearings are divided into two groups, and the two angular contact bearings in each group are arranged back to back.

7. The machine tool swivel head electric spindle structure according to claim 3, characterized in that: A rear bearing pressure ring is fitted on the side of the sealing module away from the left end of the shaft module. The rear bearing pressure ring has an annular cooling channel arranged around the axis of the shaft module. The bearing cooling oil channel includes a first cooling oil passage arranged inside the housing. One end of the first cooling oil passage is connected to the inlet of the bearing cooling oil channel, and the other end passes through the inside of the housing and the inside of the stator sleeve in sequence before connecting to the annular cooling channel.

8. The machine tool swivel head electric spindle structure according to claim 3, characterized in that: The interior of the outer casing and the interior of the stator sleeve are provided with interconnected air-tight channels. Three air-blowing ports communicating with the air-tight channels are arranged circumferentially on the left side of the stator sleeve. A labyrinth seal structure is provided between the left end of the sealing ring and the shaft module. The labyrinth seal structure includes sealing teeth and sealing grooves arranged alternately along the axial direction of the shaft module. All three air-blowing ports are arranged facing the labyrinth seal structure.

9. The machine tool swivel head electric spindle structure according to claim 7, characterized in that: The sealing ring is equipped with a vibration sensor, a thermal expansion sensor, and multiple bearing temperature sensors. The vibration sensor is located near the inside of the sealing ring on the side away from the left end of the shaft module. The thermal expansion sensor is located inside the sealing ring on the side near the left end of the shaft module. The multiple bearing temperature sensors are respectively set with each angular contact bearing. The rear bearing pressure ring is equipped with a bearing temperature sensor.

10. The machine tool swivel head electric spindle structure according to claim 4, characterized in that: A tool internal cooling tail cover is fixedly installed at the right end of the central shaft hole. The tool internal cooling tail cover is provided with a rotary joint that communicates with an external cooling medium supply device. A waste liquid recovery chamber is provided on the outside of the tool internal cooling tail cover. The waste liquid recovery chamber communicates with a waste liquid recovery channel located inside the outer shell.

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