High speed motorized spindle

Abstract

The application discloses a high-speed electric spindle, relates to the electric spindle field, and comprises a shell, a stator and a rotor, first rotating parts are arranged at both ends of the rotor, a limiting ring is sleeved on the first rotating part away from the output end of the rotor, a plurality of first bearing cavities are arranged in the inner side of the limiting ring and are matched with the first rotating part, the limiting ring is slidably connected to the shell, a second bearing cavity is arranged between the shell and the limiting ring, a second rotating part is arranged in the second bearing cavity, an installation cavity is formed between the limiting ring and the shell, a plurality of first liquid injection cavities for communicating the first bearing cavities are arranged in the side wall of the limiting ring, a plurality of second liquid injection cavities are arranged on the shell, the second liquid injection cavities are arranged through the installation cavity, a connecting hose is arranged between the first liquid injection cavities and the second liquid injection cavities, and a third discharge port communicating with the installation cavity is arranged on the shell. The application is used for improving the convenience of injecting lubricating oil into the installation cavity, improving the lubricating effect of the lubricating oil on the rotating bearing and ensuring the service life of the electric spindle.

Description

Technical Field

[0001] This application relates to the field of electric spindles, and more particularly to a high-speed electric spindle. Background Technology

[0002] Currently, electric spindles are a new technology that integrates machine tool spindles and spindle motors. They are mechatronic products that convert electrical energy transmitted by frequency converters or drive controllers into mechanical energy output from the spindle end, driving various tools or mechanisms to perform high-speed and high-efficiency cutting and rotary motion. They are characterized by low noise, low vibration, and compact structure.

[0003] In the prior art, an electric spindle includes a housing, a rotor and a stator are disposed inside the housing, and rotating bearings are disposed at both ends of the rotor. The housing is formed with a mounting cavity for mounting the rotating bearings, and the housing is provided with an injection hole that communicates with the mounting cavity. The injection hole is used to inject lubricating oil into the mounting cavity to achieve lubrication of the rotating bearings.

[0004] Regarding the aforementioned existing technology, the electric spindle achieves rotor rotation through the magnetic force between the rotor and stator. During use, the electric spindle has high requirements for the sealing of the internal shaft bearings. When injecting lubricating oil through the injection hole, it is difficult to fully inject it into the mounting cavity, reducing the lubricating effect of the lubricating oil on the rotating bearings, which urgently needs improvement. Summary of the Invention

[0005] To improve the ease of injecting lubricating oil into the mounting cavity, enhance the lubrication effect of the lubricating oil on the rotating bearing, and ensure the service life of the electric spindle, this application provides a high-speed electric spindle.

[0006] The high-speed electric spindle provided in this application adopts the following technical solution: The device includes a housing, a stator, and a rotor. Each end of the rotor has several first rotating parts. A limiting ring is fitted onto the first rotating part furthest from the rotor's output end. Multiple first bearing cavities are formed inside the limiting ring to engage with the first rotating parts. The limiting ring is slidably connected to the housing. A second bearing cavity is formed between the housing and the limiting ring, and a second rotating part is disposed within the second bearing cavity. A mounting cavity is formed between the limiting ring and the housing. Multiple first injection cavities are formed on the sidewall of the limiting ring to connect with the first bearing cavities. Multiple second injection cavities are formed on the housing, penetrating the mounting cavity. A connecting hose is provided between the first and second injection cavities. A first discharge cavity is formed by the limiting ring and the rotor. A locking plate is provided at the rotor's end, and the locking plate has multiple first communicating cavities connecting the first discharge cavity and the mounting cavity. A second discharge cavity is formed inside the limiting ring to connect the first bearing cavity furthest from the mounting cavity and the mounting cavity. A third discharge port is formed on the housing, communicating with the mounting cavity.

[0007] By adopting the above technical solution, during use, lubricant is injected into the first bearing cavity through the first and second injection chambers, and then injected into the mounting cavity through the first and second discharge chambers. Finally, it is discharged through the third discharge port, thereby realizing the circulation of lubricating oil. This allows the lubricating oil to be injected into the first bearing cavity more stably, improving the smoothness and stability of the rotation of the first rotating component; it also improves the convenience of injecting lubricating oil into the mounting cavity, enhances the lubrication effect of the lubricating oil on the rotating bearing, and ensures the service life of the electric spindle.

[0008] Preferably, a sealing spacer is provided between two adjacent first rotating parts, the second discharge cavity includes a second discharge ring groove opened outside the sealing spacer, the bottom side of the second discharge ring groove is provided with a plurality of second discharge holes communicating with the first bearing cavity away from the mounting cavity, and the limiting ring is provided with a plurality of second communicating cavities for connecting the second discharge ring groove and the mounting cavity.

[0009] By adopting the above technical solution, the first connecting cavity and the second connecting cavity cooperate to discharge lubricating oil into the installation cavity, improving the convenience of discharge from the installation cavity. The sealing ring between the two first rotating parts allows the two adjacent first rotating parts to rotate more stably, reducing mutual interference between the two first rotating parts, and allowing for stable discharge of lubricating oil, thus improving the convenience and stability of lubricating oil discharge.

[0010] Preferably, the first injection chamber has a third injection chamber that communicates with the second bearing chamber, and the outer shell has a fourth discharge hole for connecting the second bearing chamber and the third discharge port.

[0011] By adopting the above technical solution, lubricating oil is injected into the second bearing cavity through the first and third injection chambers and discharged through the fourth discharge hole, thereby realizing the circulation of lubricating oil. This allows the lubricating oil to be injected into the second bearing cavity more stably, improving the smoothness and stability of the rotation of the second rotating component; it also improves the lubrication effect of the lubricating oil on the rotating bearing, ensuring the service life of the electric spindle.

[0012] Preferably, the limiting ring has multiple liquid inlet holes and multiple liquid outlet holes on the side near the mounting cavity, and multiple cooling circulation chambers are formed inside the limiting ring. The two ends of the cooling circulation chambers are respectively connected to the liquid inlet holes and the liquid outlet holes. Multiple liquid injection holes and multiple liquid outlets are installed on the outer shell, and flexible connecting pipes are connected between the liquid injection holes and the liquid outlets and the liquid inlet holes and the liquid outlet holes, respectively.

[0013] By adopting the above technical solution, during use, cooling liquid is injected into the cooling circulation chamber through the flexible connecting pipe, which can cool the limiting ring and further cool the first and second rotating parts, thereby better reducing the temperature of the first and second rotating parts, improving the stability of the rotating bearing, improving the cooling effect of the electric spindle, and ensuring the service life of the electric spindle.

[0014] Preferably, the plurality of second communicating cavities correspond one-to-one with the plurality of first communicating cavities and are connected in communication, and a sealing guide wheel is rotatably connected inside the first communicating cavity.

[0015] By adopting the above technical solution, the flow of lubricating oil is restricted by sealing the guide wheel, reducing the flow between the two chambers, and allowing flow when pressurized lubricating oil is injected.

[0016] Preferably, the tilt direction of the first communicating cavity axis is consistent with the rotation direction of the rotor.

[0017] By adopting the above technical solution, lubricating oil can be injected into the first bearing cavity and the second bearing cavity during the rotor rotation process, ensuring the smooth rotation of the first rotating component and the second rotating component.

[0018] Preferably, a sealing ring membrane is provided in the mounting cavity, one end of the sealing ring membrane is fixed to the limiting ring, and the other end of the sealing ring membrane is fixed to the outer shell. A sealing cavity is formed in the sealing ring membrane, and the first injection cavity and the third discharge port are both connected to the sealing cavity.

[0019] By adopting the above technical solution, the sealing ring membrane can reduce the amount of lubricating oil entering the inner wall of the mounting cavity, prevent lubricating oil from contacting the inner wall of the housing, prevent lubricating oil leakage, and ensure the service life of the electric spindle.

[0020] Preferably, the outer shell consists of a ring body and a cover for closing the installation cavity, the sealing ring membrane consists of a sealing soft membrane and a sealing elastic membrane, one end of the sealing soft membrane away from the sealing elastic membrane is fixed to the limiting ring, and the end of the sealing elastic membrane is inserted between the cover and the ring body.

[0021] By adopting the above technical solution, the sealing soft membrane is thinner than the sealing elastic membrane. The sealing soft membrane can withstand pressure and the sealing elastic membrane has better resilience, which can better prevent lubricating oil leakage.

[0022] Preferably, the sidewall of the mounting cavity is provided with a plurality of supporting compression springs, and a supporting arc plate is provided on the side of the supporting compression springs near the sealing elastic membrane, the supporting arc plate abutting against the sealing elastic membrane.

[0023] By adopting the above technical solution, the support arc plate can increase the contact area with the sealing elastic membrane, which is used to squeeze the lubricating oil and allow it to enter the first bearing cavity from the first connecting cavity, preventing the lubricating oil from entering the mounting cavity and then sliding to the outer shell, thus ensuring the service life of the electric spindle.

[0024] Preferably, a pressure chamber is provided in the third discharge port, a sealing bead is slidably connected in the pressure chamber, and a sealing spring is provided in the pressure chamber for pushing the sealing bead to close the third discharge port. When the sealing bead slides, a liquid leakage space is formed between the sealing bead and the pressure chamber.

[0025] By adopting the above technical solution, when the pressure is too high, the pressurized liquid will push open the sealing bead to ensure the pressure in the mounting cavity and prevent excessive lubricating oil from entering the rotating bearing, causing oil spillage and leakage; when the pressure is low, the sealing spring will push the sealing bead to close the third discharge port, which can ensure the normal operation of the rotating bearing and improve the service life of the electric spindle.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. During use, lubricant is injected into the first bearing cavity through the first and second injection chambers, and then injected into the mounting cavity through the first and second discharge chambers. Finally, it is discharged through the third discharge port, thereby realizing the circulation of lubricating oil. This allows the lubricating oil to be injected into the first bearing cavity more stably, improving the smoothness and stability of the rotation of the first rotating component; it also improves the convenience of injecting lubricating oil into the mounting cavity, enhances the lubrication effect of the lubricating oil on the rotating bearing, and ensures the service life of the electric spindle. 2. The first connecting cavity and the second connecting cavity cooperate to discharge lubricating oil into the mounting cavity, improving the convenience of discharge from the mounting cavity. A sealing ring is set between the two first rotating parts, which allows the two adjacent first rotating parts to rotate more stably, reduces mutual interference between the two first rotating parts, and allows for stable discharge of lubricating oil, improving the convenience and stability of lubricating oil discharge. 3. When the pressure is too high, the pressurized fluid pushes open the sealing bead to ensure the pressure in the mounting cavity and prevent excessive lubricating oil from entering the rotating bearing, causing oil spillage and leakage; when the pressure is low, the sealing spring pushes the sealing bead to close the third discharge port, which can ensure the normal operation of the rotating bearing and improve the service life of the electric spindle. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of a high-speed electric spindle according to Embodiment 1 of this application; Figure 2 for Figure 1 An enlarged schematic diagram of part A in the middle; Figure 3 This is a schematic diagram illustrating the cooling circulation chamber structure, as shown in Embodiment 1 of this application. Figure 4 This is a schematic diagram illustrating the sealing guide wheel structure, which is the main feature of Embodiment 2 of this application. Figure 5 This is a schematic diagram illustrating the main structure of the sealing cavity in Embodiment 2 of this application; Reference numerals: 1. Rotor; 2. Stator; 3. Housing; 4. Second rotating component; 5. Limiting ring; 6. Second injection chamber; 7. Connecting hose; 8. Injection hole; 9. First rotating component; 10. First injection chamber; 11. Fourth discharge hole; 12. Mounting cavity; 13. Third discharge port; 14. Liquid outlet; 15. Second bearing cavity; 16. Second communicating cavity; 17. Second discharge ring groove; 18. First bearing cavity; 19. Second discharge hole; 20. 21. Liquid outlet; 22. Flexible connecting pipe; 23. Third liquid injection chamber; 24. Cooling circulation chamber; 25. Liquid inlet; 26. First discharge chamber; 27. First connecting chamber; 28. Locking plate; 29. ​​Sealing spacer; 30. Sealing guide wheel; 31. Pressure chamber; 32. Sealing spring; 33. Sealing bead; 34. Cover; 35. Sealing elastic membrane; 36. Supporting spring; 37. Supporting arc plate; 38. Sealing soft membrane; 39. Ring body; 30. Sealing chamber. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1 - Figure 5 This application will be described in further detail.

[0029] This application discloses a high-speed electric spindle.

[0030] Example 1; Reference Figure 1 A high-speed electric spindle includes a housing 3, a stator 2, and a rotor 1. The rotor 1 has a cylindrical laminated structure. The stator 2 and rotor 1 are made of cold-rolled non-oriented silicon steel sheets. Several first rotating parts 9 are installed at both ends of the rotor 1. Each first rotating part 9 is a first rotating bearing. A limiting ring 5 is fitted on the first rotating part 9 away from the output end of the rotor 1. The limiting ring 5 is circular. A positioning pin is installed between the limiting ring 5 and the housing 3 to ensure that the limiting ring 5 slides along the axis of the rotor 1. Multiple first bearing cavities 18 are opened on the inner side of the limiting ring 5 to engage with the first rotating parts 9. The limiting ring 5 is slidably connected to the housing 3. A second bearing cavity 15 is opened between the housing 3 and the limiting ring 5. A second rotating part 4 is installed in the second bearing cavity 15. The limiting ring 5 and the outer shell 3 form an installation cavity 12. The side wall of the limiting ring 5 has multiple first injection cavities 10 for connecting the first bearing cavity 18. The outer shell 3 has multiple second injection cavities 6, which are opened through the installation cavity 12. A connecting hose 7 is installed between the first injection cavity 10 and the second injection cavity 6. A first discharge cavity 25 is formed between the limiting ring 5 and the rotor 1. A locking plate 27 is installed at the end of the rotor 1. The locking plate 27 has multiple first connecting cavities 26 for connecting the first discharge cavity 25 and the installation cavity 12. The inside of the limiting ring 5 has a second discharge cavity for connecting the first bearing cavity 18, which is away from the installation cavity 12, and the installation cavity 12. The outer shell 3 has a third discharge port 13 that is connected to the installation cavity 12. During operation, lubricant is injected into the first bearing cavity 18 through the first injection cavity 10 and the second injection cavity 6. Then, in conjunction with the first discharge cavity 25 and the second discharge cavity, the lubricant is injected into the mounting cavity 12. Finally, it is discharged through the third discharge port 13, thus achieving lubricant circulation. This allows for more stable injection of lubricant into the first bearing cavity 18, improving the smoothness and stability of the rotation of the first rotating component 9; it also improves the convenience of injecting lubricant into the mounting cavity 12, enhances the lubrication effect of the lubricant on the rotating bearing, and ensures the service life of the electric spindle.

[0031] A sealing spacer 28 is installed between two adjacent first rotating parts 9. The sealing spacer 28 enables the two adjacent first rotating parts 9 to rotate more stably and reduces mutual interference between the two first rotating parts 9. The second discharge chamber includes a second discharge ring groove 17 opened outside the sealing spacer 28. The bottom side of the second discharge ring groove 17 has multiple second discharge holes 19 that communicate with the first bearing cavity 18 away from the mounting cavity 12. The limiting ring 5 has multiple second connecting cavities 16 for connecting the second discharge ring groove 17 and the mounting cavity 12. The first connecting cavity 26 and the second connecting cavity 16 cooperate to inject lubricating oil into the mounting cavity 12, improving the convenience of discharge from the mounting cavity 12. Installing the sealing spacer 28 between the two first rotating parts 9 allows the two adjacent first rotating parts 9 to rotate more stably, reduces mutual interference between the two first rotating parts 9, and allows for stable discharge of lubricating oil, improving the convenience and stability of lubricating oil discharge.

[0032] The first injection chamber 10 has a third injection chamber 22 that communicates with the second bearing chamber 15, and the outer casing 3 has a fourth discharge hole 11 that connects the second bearing chamber 15 with the third discharge port 13. Lubricating oil is injected into the second bearing chamber 15 through the first injection chamber 10 and the third injection chamber 22, and discharged through the fourth discharge hole 11. This allows for the circulation of lubricating oil, ensuring a more stable injection of lubricating oil into the second bearing chamber 15, improving the smoothness and stability of the second rotating component 4, enhancing the lubrication effect of the lubricating oil on the rotating bearing, and ensuring the service life of the electric spindle.

[0033] The limiting ring 5 has multiple liquid inlet holes 24 and multiple liquid outlet holes 20 on the side near the mounting cavity 12. Multiple cooling circulation chambers 23 are formed inside the limiting ring 5, with both ends of each chamber connected to the liquid inlet holes 24 and the liquid outlet holes 20, respectively. The outer shell 3 has multiple injection holes 8 and liquid outlets 14. Flexible connecting pipes 21 connect the injection holes 8 and the liquid outlets to the injection holes 24 and the liquid outlet holes 20, respectively. The flexible connecting pipes 21 are made of stainless steel braided corrugated tubing with a circular through-hole cross-section and smooth inner walls to reduce flow resistance. During use, coolant is injected into the cooling circulation chambers 23 through the flexible connecting pipes 21, thereby cooling the limiting ring 5 and further cooling the first rotating component 9 and the second rotating component 4. This better reduces the temperature of the first rotating component 9 and the second rotating component 4, improves the stability of the rotating bearings, enhances the cooling effect of the electric spindle, and ensures the service life of the electric spindle.

[0034] The implementation principle of a high-speed electric spindle according to an embodiment of this application is as follows: During use, lubricating oil is injected into the first bearing cavity 18 through the first injection cavity 10 and the second injection cavity 6, and then the lubricating oil is injected into the mounting cavity 12 through the first discharge cavity 25 and the second discharge cavity. Finally, it is discharged through the third discharge port 13, thereby realizing the circulation of lubricating oil and enabling the lubricating oil to be injected into the first bearing cavity 18 more stably, thereby improving the smoothness and stability of the rotation of the first rotating component 9. The first connecting cavity 26 and the second connecting cavity 16 cooperate to inject lubricating oil into the mounting cavity 12, improving the convenience of discharge from the mounting cavity 12. The sealing spacer 28 installed between the two first rotating parts 9 allows the two adjacent first rotating parts 9 to rotate more stably, reducing mutual interference between the two first rotating parts 9, and allowing for stable discharge of lubricating oil, improving the convenience and stability of lubricating oil discharge. Lubricating oil is injected into the second bearing cavity 15 through the first injection cavity 10 and the third injection cavity 22, and discharged through the fourth discharge hole 11, thereby realizing the circulation of lubricating oil and allowing the lubricating oil to be injected into the second bearing cavity 15 more stably, improving the smoothness and stability of the second rotating part 4.

[0035] Example 2; Reference Figure 4 The difference between this embodiment and Embodiment 1 is that the second connecting cavity 16 corresponds one-to-one with and is connected to multiple first connecting cavities 26, and a blocking guide wheel 29 is rotatably connected inside the first connecting cavity 26. The blocking guide wheel 29 restricts the flow of lubricating oil, reducing the flow between the two cavities, while allowing flow when pressurized lubricating oil is injected. The axis of the first connecting cavity 26 is inclined in the same direction as the rotation direction of the rotor 1. During the rotation of the rotor 1, lubricating oil can be injected into the first bearing cavity 18 and the second bearing cavity 15 to ensure the smooth operation of the first rotating component 9 and the second rotating component 4.

[0036] Reference Figure 5 A sealing ring diaphragm made of polyurethane is installed inside the mounting cavity 12. One end of the sealing ring diaphragm is fixed to the limiting ring 5, and the other end is fixed to the outer shell 3. A sealing cavity 39 is formed inside the sealing ring diaphragm, and the first injection cavity 10 and the third discharge port 13 are both connected to the sealing cavity 39. The sealing ring diaphragm can reduce the ingress of lubricating oil into the inner wall of the mounting cavity 12, prevent lubricating oil from contacting the inner wall of the outer shell 3 and causing lubricating oil leakage, and improve the service life of the electric spindle.

[0037] The outer casing 3 consists of a ring body 38 and a cover 33 for sealing the mounting cavity 12. The sealing ring membrane consists of a sealing soft membrane 37 and a sealing elastic membrane 34. The end of the sealing soft membrane 37 away from the sealing elastic membrane 34 is fixed to the limiting ring 5, and the end of the sealing elastic membrane 34 is inserted between the cover 33 and the ring body 38. The thickness of the sealing elastic membrane 34 is greater than the thickness of the sealing soft membrane 37. The pressure borne by the sealing soft membrane 37 and the better resilience of the sealing elastic membrane 34 can better prevent lubricating oil leakage.

[0038] Multiple support springs 35 are installed on the side wall of the mounting cavity 12. A support arc plate 36 is installed on the side of the support springs 35 near the sealing elastic membrane 34. The support arc plate 36 abuts against the sealing elastic membrane 34 and is a C-shaped plate. The support arc plate 36 increases the contact area with the sealing elastic membrane 34, which is used to squeeze the lubricating oil and allow it to enter the first bearing cavity 18 from the first connecting cavity 26. This prevents the lubricating oil from entering the mounting cavity 12 and sliding to the outer casing 3, thus improving the service life of the electric spindle.

[0039] A pressure chamber 30 is provided inside the third discharge port 13. A sealing bead 32 is slidably connected inside the pressure chamber 30. A sealing spring 31 is installed inside the pressure chamber 30 to push the sealing bead 32 to close the third discharge port 13. When the sealing bead 32 slides, a drainage space is formed between the sealing bead 32 and the pressure chamber 30. When the pressure is too high, the pressurized fluid pushes open the sealing bead 32 to ensure the pressure in the mounting cavity 12 and prevent excessive lubricating oil from entering the rotating bearing, causing oil spillage and leakage. When the pressure is too low, the sealing spring 31 pushes the sealing bead 32 to close the third discharge port 13, which can ensure the normal operation of the rotating bearing and improve the service life of the electric spindle.

[0040] The implementation principle of Example 2 is as follows: the sealing guide wheel 29 restricts the flow of lubricating oil, and the supporting arc plate 36 increases the contact area with the sealing elastic membrane 34 to squeeze the lubricating oil, allowing it to enter the first bearing cavity 18 from the first connecting cavity 26, preventing the lubricating oil from entering the mounting cavity 12 and then sliding to the outer shell 3. When the pressure is too high, the pressurized liquid opens the sealing bead 32 to ensure the pressure in the mounting cavity 12 and prevent excessive lubricating oil from entering the rotating bearing, causing oil splashing and leakage. When the pressure is too low, the sealing spring 31 pushes the sealing bead 32 to close the third discharge port 13, improving the convenience of lubricating oil injection into the mounting cavity 12, improving the lubricating effect of the lubricating oil on the rotating bearing, ensuring the normal operation of the rotating bearing, and improving the service life of the electric spindle.

[0041] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-speed electric spindle, characterized in that: The device includes a housing (3), a stator (2), and a rotor (1). Both ends of the rotor (1) are provided with several first rotating parts (9). A limiting ring (5) is fitted onto the first rotating part (9) furthest from the output end of the rotor (1). Multiple first bearing cavities (18) are formed inside the limiting ring (5) to engage with the first rotating parts (9). The limiting ring (5) is slidably connected to the housing (3). A second bearing cavity (15) is formed between the housing (3) and the limiting ring (5). A second rotating part (4) is provided inside the second bearing cavity (15). An installation cavity (12) is formed between the limiting ring (5) and the housing (3). Multiple first injection cavities (10) for connecting the first bearing cavities (18) are formed on the side wall of the limiting ring (5). The housing... (3) has multiple second injection chambers (6) that penetrate the mounting cavity (12). A connecting hose (7) is provided between the first injection chamber (10) and the second injection chamber (6). The limiting ring (5) and the rotor (1) support and form a first discharge chamber (25). A locking plate (27) is provided at the end of the rotor (1). The locking plate (27) has multiple first connecting chambers (26) for connecting the first discharge chamber (25) and the mounting cavity (12). A second discharge chamber for connecting the first bearing cavity (18) away from the mounting cavity (12) and the mounting cavity (12) is formed in the limiting ring (5). The outer shell (3) has a third discharge port (13) that communicates with the mounting cavity (12).

2. A high-speed electric spindle according to claim 1, characterized in that: A sealing spacer (28) is provided between two adjacent first rotating parts (9). The second discharge cavity includes a second discharge ring groove (17) opened outside the sealing spacer (28). The bottom side of the second discharge ring groove (17) is provided with a plurality of second discharge holes (19) that communicate with the first bearing cavity (18) away from the mounting cavity (12). The limiting ring (5) is provided with a plurality of second communicating cavities (16) for connecting the second discharge ring groove (17) and the mounting cavity (12).

3. A high-speed electric spindle according to claim 2, characterized in that: The first injection chamber (10) is provided with a third injection chamber (22) that communicates with the second bearing chamber (15), and the outer shell (3) is provided with a fourth discharge hole (11) for connecting the second bearing chamber (15) and the third discharge port (13).

4. A high-speed electric spindle according to claim 3, characterized in that: The limiting ring (5) has multiple liquid inlet holes (24) and multiple liquid outlet holes (20) on the side near the mounting cavity (12). Multiple cooling circulation cavities (23) are provided inside the limiting ring (5). The two ends of the cooling circulation cavities (23) are respectively connected to the liquid inlet holes (24) and the liquid outlet holes (20). Multiple injection holes (8) and multiple outlets (14) are installed on the outer shell (3). Flexible connecting pipes (21) are connected between the injection holes (8) and the outlets (14) and the liquid inlet holes (24) and the liquid outlet holes (20) respectively.

5. A high-speed electric spindle according to claim 4, characterized in that: Multiple second connecting cavities (16) correspond one-to-one with multiple first connecting cavities (26) and are connected in communication. A sealing guide wheel (29) is rotatably connected inside the first connecting cavity (26).

6. A high-speed electric spindle according to claim 5, characterized in that: The axis of the first communicating cavity (26) is tilted in the same direction as the rotation direction of the rotor (1).

7. A high-speed electric spindle according to claim 6, characterized in that: A sealing ring membrane is provided in the mounting cavity (12). One end of the sealing ring membrane is fixed to the limiting ring (5), and the other end of the sealing ring membrane is fixed to the outer shell (3). A sealing cavity (39) is formed in the sealing ring membrane. The first liquid injection cavity (10) and the third discharge port (13) are both connected to the sealing cavity (39).

8. A high-speed electric spindle according to claim 7, characterized in that: The outer shell (3) is composed of a ring body (38) and a cover (33) for sealing the mounting cavity (12). The sealing ring membrane is composed of a sealing soft membrane (37) and a sealing elastic membrane (34). The end of the sealing soft membrane (37) away from the sealing elastic membrane (34) is fixed to the limiting ring (5). The end of the sealing elastic membrane (34) is inserted between the cover (33) and the ring body (38).

9. A high-speed electric spindle according to claim 8, characterized in that: The mounting cavity (12) has a plurality of support springs (35) on its sidewall. The support springs (35) have a support arc plate (36) on the side of the support springs (35) close to the sealing elastic membrane (34). The support arc plate (36) abuts against the sealing elastic membrane (34).

10. A high-speed electric spindle according to claim 9, characterized in that: A pressure chamber (30) is provided inside the third discharge port (13). A sealing bead (32) is slidably connected inside the pressure chamber (30). A sealing spring (31) is provided inside the pressure chamber (30) to push the sealing bead (32) to close the third discharge port (13). When the sealing bead (32) slides, a liquid leakage space is formed between the sealing bead (32) and the pressure chamber (30).

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