An electric spindle assembly

Abstract

This invention discloses an electric spindle assembly, relating to the field of CNC lathe technology. It includes a spindle box, through which an electric spindle is rotatably connected. An encoder gear ring and a positioning component for securing the encoder gear ring are fitted onto the electric spindle. Locking nuts and spacers, respectively abutting against both sides of the positioning component, are also fitted onto the electric spindle. The encoder gear ring and positioning component are located on the side of the spindle box furthest from the workpiece. The electric spindle drives the encoder gear ring, positioning component, locking nuts, and spacers to rotate synchronously. The positioning component improves the axial and radial positioning accuracy of the encoder gear ring, ensuring its coaxiality and stability with the electric spindle. Furthermore, this structure facilitates disassembly and maintenance, improving the assembly efficiency and operational stability of the electric spindle assembly. Therefore, this invention solves the problems of difficult encoder gear ring assembly and insufficient positioning accuracy in existing electric spindle assemblies.

Description

Technical Field

[0001] This invention relates to the field of CNC lathes, and more particularly to an electric spindle assembly. Background Technology

[0002] The spindle is a key functional component in a precision longitudinal cutting CNC lathe, and the encoder gear ring mounted on the spindle is a key part of the spindle.

[0003] In existing technology, electric spindle assemblies include structures such as a spindle and an encoder gear ring. The encoder gear ring is installed by heating it, causing its inner diameter to expand thermally, and then quickly installing it onto the spindle after a certain period. Similarly, the encoder gear ring is also disassembled by heating it for a certain time before removal. However, due to the limitations of the encoder gear ring installation method, these disassembly and assembly methods result in two problems: firstly, the assembly of the encoder gear ring is difficult; secondly, the positioning accuracy of the encoder gear ring is insufficient, thus affecting the overall performance of the spindle. Summary of the Invention

[0004] The purpose of this invention is to provide an electric spindle assembly that solves the problems of difficult assembly of the encoder gear ring and insufficient positioning accuracy of the encoder gear ring in the prior art.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] An electric spindle assembly includes a spindle housing, through which an electric spindle is rotatably connected. An encoder gear ring and a positioning component for fastening and fixing the encoder gear ring are fitted on the electric spindle. A locking nut and a spacer are also fitted on the electric spindle, respectively abutting against both sides of the positioning component. The locking nut is threadedly connected to the electric spindle, and the spacer is rotatably connected to the spindle housing.

[0007] The encoder gear ring and the positioning component are both located on the side of the spindle box away from the workpiece. The electric spindle is used to drive the encoder gear ring, the positioning component, the locking nut, and the spacer to rotate synchronously.

[0008] Optionally, the positioning assembly includes a positioning gear sleeve fitted onto the outer wall of the electric spindle, the positioning gear sleeve having the encoder gear ring fitted onto it and a positioning cover pressed against the encoder gear ring, the positioning cover being fastened to the positioning gear sleeve.

[0009] Optionally, the positioning gear sleeve is provided with a first positioning surface and a second positioning surface. The first positioning surface is in contact with the end face of the encoder gear ring away from the positioning cover, and the second positioning surface is in clearance fit with the end face of the positioning cover near the encoder gear ring.

[0010] Optionally, the outer wall of the electric spindle is provided with a first keyway, and a flat key is embedded in the first keyway; the positioning gear is provided with a second keyway corresponding to the first keyway, and the end of the flat key away from the first keyway is inserted into the second keyway, and the second keyway communicates with one end face or both end faces of the positioning gear sleeve along the axial direction of the electric spindle.

[0011] Optionally, the first keyway has a first arc surface, and the flat key has a second arc surface adapted to the first arc surface. The length of the flat key along the axial direction of the electric spindle is less than the length of the second keyway along the axial direction of the electric spindle.

[0012] Optionally, the spindle box includes a housing and a stator installed inside the housing. A first bearing seat and a second bearing seat are respectively installed at both ends of the housing. A cover is fixedly installed on the first bearing seat. The spacer is rotatably connected to the second bearing seat. The electric spindle passes through the second bearing seat, the housing, the first bearing seat, and the cover in sequence.

[0013] Optionally, the electric spindle includes a shaft that passes through the spindle box, and a first balance ring, a rotor, and a second balance ring are sequentially sleeved on the outer wall of the shaft. The outer wall of the shaft is provided with a positioning part that positions and cooperates with the first balance ring, and the rotor is located inside the stator.

[0014] The outer wall of the first balance ring is provided with a first groove arranged in an annular shape, and the outer wall of the second balance ring is provided with a second groove arranged in an annular shape.

[0015] Optionally, the outer wall of the stator is fitted with a cooling sleeve located inside the housing. The cooling sleeve has a spirally arranged cooling groove for accommodating the flow of coolant. The housing has two flow holes, which are respectively connected to the two ends of the cooling groove. One of the flow holes is used for coolant to flow into the cooling groove, and the other flow hole is used for coolant to flow out of the cooling groove.

[0016] Optionally, two spaced-apart sealing grooves are provided at both ends of the cooling jacket, and a sealing ring that abuts against the inner wall of the housing is installed in the sealing groove; a drain groove located between the two sealing grooves is also provided at the end of the cooling jacket, and a drain hole communicating with the drain groove is provided on the housing.

[0017] When the sealing ring near the cooling tank fails to seal, the leaked coolant in the cooling tank enters the drain tank and is discharged into the external space through the drain hole.

[0018] Optionally, the drain hole includes a first hole section and a second hole section that are interconnected. The first hole section is connected to the drain groove, and the second hole section is connected to the outer wall of the housing. The inner diameter of the first hole section is smaller than the inner diameter of the second hole section, and the flow distance of the coolant in the first hole section is smaller than the flow distance in the second hole section.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention provides an electric spindle assembly. By mounting an encoder gear ring and a positioning component on the electric spindle, and providing locking nuts and spacers on both sides of the positioning component, the encoder gear ring and positioning component can form an integrated installation structure with the electric spindle. Since both the encoder gear ring and positioning component are located on the side of the spindle box away from the workpiece, positioning difficulties caused by interference from the machining area are avoided. The positioning component mechanically tightens and positions the encoder gear ring, eliminating the traditional process of heat-based disassembly and assembly, effectively reducing assembly difficulty. Simultaneously, the positioning component improves the axial and radial positioning accuracy of the encoder gear ring, ensuring its coaxiality and stability with the electric spindle, and avoiding problems where insufficient positioning accuracy affects the overall performance of the spindle. Furthermore, this structure facilitates subsequent disassembly and maintenance, improving the assembly efficiency and operational stability of the electric spindle assembly. Therefore, this invention solves the problems of high assembly difficulty and insufficient positioning accuracy of the encoder gear ring in existing electric spindle assemblies. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0023] Figure 1 A three-dimensional structural schematic diagram of an electric spindle assembly provided in an embodiment of the present invention;

[0024] Figure 2 A cross-sectional structural schematic diagram of an electric spindle assembly provided in an embodiment of the present invention;

[0025] Figure 3 for Figure 2 A magnified structural diagram at point A;

[0026] Figure 4 for Figure 2 A magnified structural diagram at point B;

[0027] Figure 5 A partial structural schematic diagram of an electric spindle assembly provided in an embodiment of the present invention;

[0028] Figure 6 This is a partial exploded view of an electric spindle assembly provided in an embodiment of the present invention;

[0029] Figure 7 for Figure 6 A magnified structural diagram at point C;

[0030] Figure 8 This is a schematic diagram of the structure of a flat key in an electric spindle assembly provided by an embodiment of the present invention;

[0031] Figure 9 This is a schematic diagram of the structure of the shaft in an electric spindle assembly provided by an embodiment of the present invention;

[0032] Figure 10 This is a schematic diagram of the structure of the first and second balance rings in an electric spindle assembly provided in an embodiment of the present invention.

[0033] Illustration:

[0034] 10. Spindle box; 11. Housing; 111. Flow hole; 112. Drain hole; 1121. First hole section; 1122. Second hole section; 12. Stator; 13. First bearing housing; 14. Second bearing housing; 15. Cover; 16. Cooling jacket; 161. Cooling groove; 162. Sealing groove; 163. Drain groove; 17. Sealing ring;

[0035] 20. Electric spindle; 21. Shaft body; 211. First keyway; 2111. First arc surface; 212. Positioning part; 22. First balance ring; 221. First groove; 23. Rotor; 24. Second balance ring; 241. Second groove;

[0036] 30. Encoder tooth ring; 31. First tooth; 32. Second tooth;

[0037] 40. Positioning component; 41. Positioning gear sleeve; 411. First positioning surface; 412. Second positioning surface; 413. Second keyway; 42. Positioning cover; 43. Flat key; 431. Second arc surface;

[0038] 50. Locking nut; 60. Spacer; 70. Encoder reading head. Detailed Implementation

[0039] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] In the description of this invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the connection.

[0041] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0042] This invention provides an electric spindle assembly, such as... Figures 1 to 10 As shown, the device includes a spindle housing 10, through which an electric spindle 20 is rotatably connected. An encoder gear ring 30 and a positioning assembly 40 for fastening and fixing the encoder gear ring 30 are fitted on the electric spindle 20. Locking nuts 50 and spacers 60 are also fitted on the electric spindle 20, which respectively abut against both sides of the positioning assembly 40. The locking nuts 50 are threadedly connected to the electric spindle 20, and the spacers 60 are rotatably connected to the spindle housing 10.

[0043] In this embodiment, the encoder gear ring 30 and the positioning component 40 are both located on the side of the spindle housing 10 away from the workpiece. The electric spindle 20 drives the encoder gear ring 30, the positioning component 40, the locking nut 50, and the spacer 60 to rotate synchronously. In this embodiment, the locking nut 50 is fastened to the electric spindle 20 with screws. An encoder reading head 70, which cooperates with the encoder gear ring 30 for detection, is fixedly mounted on the spindle housing 10. The encoder reading head 70 is a structure known in the art. The outer wall of the encoder gear ring 30 is provided with first teeth 31 and second teeth 32 at intervals. Multiple first teeth 31 are evenly distributed along the circumference of the encoder gear ring 30, and the number of first teeth 31 can be 128, 256, 384, etc. The first teeth 31 are used to generate pulse signals, and the second teeth 32 are used to generate a one-revolution signal. Furthermore, the number of pulses generated per unit time directly corresponds to the spindle's rotational speed. By counting the number of pulses, the rotation angle of the electric spindle 20 relative to any starting point can be accurately calculated.

[0044] It should be noted that the electric spindle assembly provided by this invention, by setting an encoder gear ring 30 and a positioning component 40 on the electric spindle 20, and setting a locking nut 50 and a spacer 60 on both sides of the positioning component 40, allows the encoder gear ring 30 and the positioning component 40 to form an integrated installation structure with the electric spindle 20. Since the encoder gear ring 30 and the positioning component 40 are both arranged on the side of the spindle box 10 away from the workpiece, positioning inconvenience caused by interference from the processing area is avoided. The positioning component 40 mechanically tightens and positions the encoder gear ring 30, eliminating the traditional process steps that rely on heating for disassembly and assembly, effectively reducing the assembly difficulty. At the same time, the positioning component 40 improves the positioning accuracy of the encoder gear ring 30 in the axial and radial directions, ensuring its coaxiality and stability with the electric spindle 20, and avoiding the problem of insufficient positioning accuracy affecting the overall performance of the spindle. In addition, this structure facilitates subsequent disassembly and maintenance, improving the assembly efficiency and operational stability of the electric spindle assembly. Therefore, the present invention solves the problems of high assembly difficulty and insufficient positioning accuracy of encoder gear ring 30 in the prior art electric spindle assembly.

[0045] like Figures 1 to 6 As shown, the positioning assembly 40 includes a positioning gear sleeve 41 fitted onto the outer wall of the electric spindle 20. The positioning gear sleeve 41 is fitted with an encoder gear ring 30 and a positioning cover 42 pressed onto the encoder gear ring 30. The positioning cover 42 is fastened to the positioning gear sleeve 41. In this embodiment, the positioning cover 42 and the positioning gear sleeve 41 are fastened together by screws. The number of screws is not limited; it can be 4, 6, 8, etc., and the screws are evenly spaced along the circumference of the positioning gear sleeve 41.

[0046] In practical implementation, the positioning cap 42 and the positioning gear sleeve 41 are fastened together with screws. Through mechanical clamping, the encoder gear ring 30 can be reliably positioned with the electric spindle 20, avoiding the reliance on heating assembly processes under a single interference fit method and reducing assembly difficulty. Simultaneously, the evenly spaced multi-screw connection ensures uniform clamping force, improving the positioning stability and coaxiality of the encoder gear ring 30 and preventing skewing or loosening. The structure provided in this embodiment not only improves the positioning accuracy and reliability of the encoder gear ring 30 but also significantly improves the convenience of subsequent disassembly and maintenance, effectively solving the problems of insufficient positioning accuracy and inconvenient assembly and disassembly of the encoder gear ring 30 in the prior art.

[0047] like Figures 3 to 6 As shown, the positioning gear sleeve 41 is provided with a first positioning surface 411 and a second positioning surface 412. The first positioning surface 411 contacts the end face of the encoder gear ring 30 away from the positioning cover 42, and the second positioning surface 412 is in clearance fit with the end face of the positioning cover 42 near the encoder gear ring 30. In this embodiment, the clearance between the second positioning surface 412 and the end face of the positioning cover 42 near the encoder gear ring 30 is 0.6 mm.

[0048] In practical implementation, the first positioning surface 411 plays a positioning role, ensuring the encoder gear ring 30 is fixedly positioned in the axial direction and preventing axial movement of the encoder gear ring 30 due to uneven force. The clearance fit between the second positioning surface 412 and the positioning cover 42 ensures reliable transmission of the clamping force, guaranteeing that the positioning cover 42 fully presses the encoder gear ring 30, while avoiding stress concentration caused by excessive tightness. This effectively improves the stability of the structural assembly and the service life of each component. Therefore, this structural design ensures the positioning accuracy of the encoder gear ring 30 while also considering the manufacturability during installation and the reliability during operation, effectively solving the problems of assembly stress and unstable positioning of the encoder gear ring 30 in the prior art. The tight fit between the positioning cover 42 and the positioning gear sleeve 41 effectively positions the encoder gear ring, allowing for quick mechanical disassembly and assembly without the need for heating, thus solving the problems of high assembly difficulty and insufficient positioning accuracy of the encoder gear ring 30 in the prior art.

[0049] like Figures 3 to 9 As shown, the outer wall of the electric spindle 20 is provided with a first keyway 211, and a flat key 43 is embedded in the first keyway 211; the positioning gear sleeve 41 is provided with a second keyway 413 corresponding to the first keyway 211, and the end of the flat key 43 away from the first keyway 211 is inserted into the second keyway 413. The second keyway 413 is connected to one end face or both end faces of the positioning gear sleeve 41 along the axial direction of the electric spindle 20.

[0050] In practical implementation, the flat key 43 ensures a reliable keyed connection between the positioning gear sleeve 41 and the electric spindle 20, thereby guaranteeing the circumferential positioning accuracy while achieving radial fastening of the positioning gear sleeve 41. This prevents slippage and misalignment caused by the positioning gear sleeve 41 relying solely on friction for positioning. Simultaneously, the second keyway 413 extends to the end face of the positioning gear sleeve 41, facilitating operation of the flat key 43 during assembly or disassembly, thus improving the ease of assembly and maintenance efficiency of the parts.

[0051] like Figure 8 and Figure 9 As shown, the first keyway 211 has a first arc surface 2111, and the flat key 43 has a second arc surface 431 that matches the first arc surface 2111. The length of the flat key 43 along the axial direction of the electric spindle 20 is less than the length of the second keyway 413 along the axial direction of the electric spindle 20. In this embodiment, the two first arc surfaces 2111 are spaced apart along the axial direction of the electric spindle 20, and the two second arc surfaces 431 are spaced apart along the axial direction of the electric spindle 20.

[0052] In practical implementation, the use of the first arc surface 2111 and the second arc surface 431 effectively reduces stress concentration between the flat key 43 and the keyway, avoiding the stress sharp angle problem caused by right-angle fits, thereby improving the assembly reliability of the flat key 43 and the service life of the parts. The design of the flat key 43 being shorter than the second keyway 413 facilitates structural assembly and disassembly, reducing the requirements for assembly precision. The use of two first arc surfaces 2111 and two second arc surfaces 431 further enhances the uniformity of force distribution on the flat key 43, ensuring the stability of the encoder gear ring 30 when transmitting torque. Therefore, this design not only improves the reliability and durability of the flat key 43 connection but also solves the problems of stress concentration, inconvenient assembly, and unstable torque transmission in the prior art.

[0053] like Figure 1 and Figure 2 As shown, the spindle housing 10 includes a housing 11 and a stator 12 installed inside the housing 11. A first bearing seat 13 and a second bearing seat 14 are respectively installed at both ends of the housing 11. A cover 15 is fixedly installed on the first bearing seat 13. A spacer 60 is rotatably connected to the second bearing seat 14. The electric spindle 20 passes sequentially through the second bearing seat 14, the housing 11, the first bearing seat 13, and the cover 15. In this embodiment, bearings are installed inside both the first bearing seat 13 and the second bearing seat 14, and the electric spindle 20 passes through and is rotatably connected to the bearings.

[0054] In practical implementation, the electric spindle 20 forms a stable rotational connection under the support of the first bearing housing 13 and the second bearing housing 14, ensuring the smooth operation and positioning accuracy of the electric spindle 20 during high-speed rotation. The housing 15 provides effective protection, preventing chips or coolant from the machining environment from entering the bearing area, thus improving overall protection performance and the service life of the electric spindle 20. The rotational connection between the spacer 60 and the second bearing housing 14 ensures smooth rotation of the electric spindle 20 and avoids radial interference, further improving assembly reliability and operational stability. Therefore, this structure not only optimizes the support and protection of the electric spindle 20 but also solves the problems of insufficient spindle operation stability and poor protection performance in existing technologies, thereby significantly improving the overall performance of the electric spindle assembly.

[0055] like Figures 1 to 10 As shown, the electric spindle 20 includes a shaft 21 that passes through the spindle housing 10. A first balance ring 22, a rotor 23, and a second balance ring 24 are sequentially sleeved on the outer wall of the shaft 21. The outer wall of the shaft 21 is provided with a positioning part 212 that positions and cooperates with the first balance ring 22. The rotor 23 is located inside the stator 12. In this embodiment, a first keyway 211 is formed on the outer wall of the shaft 21, and the shaft 21 and the positioning part 212 are integrally formed.

[0056] The outer wall of the first balancing ring 22 is provided with a first groove 221 arranged in an annular shape, and the outer wall of the second balancing ring 24 is provided with a second groove 241 arranged in an annular shape. In this embodiment, both the first groove 221 and the second groove 241 are V-shaped annular grooves.

[0057] In specific implementation, a positioning part 212 is provided on the outer wall of the shaft 21 to cooperate with the first balance ring 22, ensuring the stable positioning of the first balance ring 22 in the axial direction of the shaft 21; and the rotor 23 is arranged inside the stator 12 to realize the driving function of the electric spindle 20. Since the first keyway 211 is directly opened on the outer wall of the shaft 21, the shaft 21 and the positioning part 212 adopt an integral molding structure, which improves the overall machining accuracy and structural stability. Furthermore, the outer wall of the first balance ring 22 is provided with an annular first groove 221, and the outer wall of the second balance ring 24 is provided with an annular second groove 241, both of which are V-shaped annular grooves. Through this structural design, the mass distribution can be effectively improved when the spindle rotates at high speed, reducing the eccentricity and imbalance of the shaft 21, improving the overall dynamic balance performance of the electric spindle 20, and ensuring that it can still maintain stable operation at high speed. Therefore, this design not only achieves reliable positioning and high-precision assembly of the rotor 23 and the balance ring, but also significantly improves the dynamic balance performance and rotational accuracy of the electric spindle 20, thereby solving the problems of vibration and insufficient positioning accuracy of the electric spindle 20 during high-speed operation in the prior art.

[0058] Furthermore, the arrangement of the first groove 221 and the second groove 241 reduces the weight of the first balance ring 22 and the second balance ring 24. The annular grooves increase the surface area of ​​the balance rings, effectively improving heat dissipation efficiency. During high-speed rotation, the groove structure better agitates the surrounding air or cooling medium, creating more efficient air convection and carrying away heat more quickly. This helps control the overall operating temperature of the electric spindle 20, preventing thermal deformation or magnet demagnetization due to localized overheating, thus protecting the performance and lifespan of the main circuit board. The arrangement of the first groove 221 and the second groove 241 effectively reduces the weight of the balance rings and even the entire electric spindle 20 without sacrificing the main structural strength and function, and directly reduces the system's rotational inertia. This allows the electric spindle 20 to achieve faster acceleration and deceleration, better dynamic response performance, and is particularly suitable for applications requiring frequent reversals and high-speed machining.

[0059] Traditional balancing rings are solid rings, and under the centrifugal force of high-speed rotation, stress is generated inside. By designing a reasonable groove shape (e.g., using large rounded corners), stress distribution can be optimized. A well-designed rounded corner avoids stress concentration caused by sharp corners, resulting in a more uniform distribution of internal stress generated by centrifugal force. Due to this uniform stress distribution, the first balancing ring 22 and the second balancing ring 24 are less prone to fatigue cracking under long-term high-speed alternating loads, thus improving their reliability and service life.

[0060] like Figures 1 to 4 As shown, a cooling sleeve 16 located inside a housing 11 is fitted onto the outer wall of the stator 12. The cooling sleeve 16 has a spirally arranged cooling groove 161 for accommodating the flow of coolant. Two flow holes 111 are provided on the housing 11, each connected to one end of the cooling groove 161. One flow hole 111 allows coolant to flow into the cooling groove 161, and the other flow hole 111 allows coolant to flow out of the cooling groove 161. In this embodiment, a circulation pump is connected to the two flow holes 111 to circulate the coolant within the cooling groove 161.

[0061] In specific implementation, two flow holes 111 connected to both ends of the cooling tank 161 are provided on the housing 11. One flow hole 111 is for coolant inflow, and the other flow hole 111 is for coolant outflow. An external circulation pump ensures continuous circulation of the coolant within the cooling tank 161. Through this structural design, the coolant can flow evenly around the spiral cooling tank 161, increasing the contact area and contact time between the coolant and the outer wall of the stator 12, thereby improving heat exchange efficiency and ensuring effective control of the temperature rise of the stator 12 during operation. Simultaneously, the use of the external circulation pump ensures the stability and continuity of coolant circulation, avoiding the problem of stator 12 performance degradation or electric spindle 20 instability due to excessively high local temperatures. Therefore, this design not only improves cooling efficiency and temperature control accuracy but also effectively solves the problems of insufficient heat dissipation and poor operational reliability of the stator 12 in existing technologies, thus ensuring the stability and service life of the electric spindle 20 under long-term high-speed operation.

[0062] like Figure 2 and Figure 4 As shown, two spaced sealing grooves 162 are provided at both ends of the cooling jacket 16, and a sealing ring 17 that abuts against the inner wall of the housing 11 is installed in the sealing groove 162; a drain groove 163 located between the two sealing grooves 162 is also provided at the end of the cooling jacket 16, and a drain hole 112 communicating with the drain groove 163 is provided on the housing 11.

[0063] When the sealing ring 17 near the cooling tank 161 fails to seal, the leaked coolant in the cooling tank 161 enters the drain tank 163 and is discharged to the external space through the drain hole 112. In this embodiment, both the sealing tank 162 and the sealing ring 17 are arranged in annular shape, and the sealing ring 17 can be made of silicone or rubber.

[0064] In practical implementation, through the combined use of two sealing grooves 162 and two sealing rings 17, when the sealing ring 17 near the cooling groove 161 fails, the leaked coolant in the cooling groove 161 enters the drain groove 163 and is discharged to the external space through the drain hole 112. This creates a double-seal and independent drainage protection system for the cooling jacket 16. Even if one sealing ring 17 is damaged, the leaked coolant can be discharged in time through the drain groove 163 and the drain hole 112, preventing coolant from entering the bearing or the working area of ​​the electric spindle 20, thus improving the safety and reliability of the entire cooling system. Therefore, this design not only improves the sealing performance and service life of the cooling jacket 16, but also solves the problem in the prior art where coolant leakage easily leads to the failure of the electric spindle 20, thereby ensuring the stability and durability of the electric spindle assembly during long-term operation.

[0065] like Figure 2 and Figure 4As shown, the drain hole 112 includes a first hole section 1121 and a second hole section 1122 that are interconnected. The first hole section 1121 is connected to the drain groove 163, and the second hole section 1122 is connected to the outer wall of the housing 11. The inner diameter of the first hole section 1121 is smaller than the inner diameter of the second hole section 1122, and the flow distance of the coolant in the first hole section 1121 is smaller than the flow distance in the second hole section 1122.

[0066] In practical implementation, because the inner diameter of the first orifice 1121 is smaller than that of the second orifice 1122, the coolant travels a shorter distance within the first orifice 1121 than within the second orifice 1122, creating a drainage path with a gradually decreasing flow rate. Through this structural design, the smaller inner diameter of the first orifice 1121 helps limit the coolant flow rate, ensuring that the coolant is adequately guided and buffered before entering the second orifice 1122. The larger inner diameter of the second orifice 1122 ensures smooth coolant drainage, preventing blockages or accumulation. Therefore, this structural design not only improves the stability of the drainage effect but also effectively avoids structural damage or seal failure caused by excessively high coolant flow rates, thus ensuring the long-term reliability of the cooling system and the safety of the electric spindle assembly.

[0067] Working Principle: The electric spindle assembly provided by this invention, by setting an encoder gear ring 30 and a positioning component 40 on the electric spindle 20, and setting locking nuts 50 and spacers 60 on both sides of the positioning component 40, allows the encoder gear ring 30 and the positioning component 40 to form an integrated installation structure with the electric spindle 20. Since the encoder gear ring 30 and the positioning component 40 are both arranged on the side of the spindle box 10 away from the workpiece, positioning inconvenience caused by interference from the processing area is avoided. The positioning component 40 mechanically tightens and positions the encoder gear ring 30, eliminating the traditional process steps that rely on heating for disassembly and assembly, effectively reducing the assembly difficulty. At the same time, the positioning component 40 improves the axial and radial positioning accuracy of the encoder gear ring 30, ensuring its coaxiality and stability with the electric spindle 20, and avoiding the problem of insufficient positioning accuracy affecting the overall performance of the spindle. In addition, this structure facilitates subsequent disassembly and maintenance, improving the assembly efficiency and operational stability of the electric spindle assembly. Because the positioning cover 42 and the positioning gear sleeve 41 are fastened together with screws, the encoder gear ring 30 can be reliably positioned with the electric spindle 20 through mechanical clamping. This avoids the reliance on heating assembly processes under a single interference fit method and reduces assembly difficulty. Therefore, this invention solves the problems of high assembly difficulty and insufficient positioning accuracy of the encoder gear ring 30 in the electric spindle assembly in the prior art.

[0068] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electric spindle assembly, characterized by, The application relates to a main shaft box (10) provided with a rotatingly connected electric spindle (20), an encoder gear ring (30) and a positioning assembly (40) for tightly positioning the encoder gear ring (30) are sleeved on the electric spindle (20); a locking nut (50) and a spacer sleeve (60) abutting against two sides of the positioning assembly (40) are further sleeved on the electric spindle (20), the locking nut (50) is threadedly connected with the electric spindle (20), and the spacer sleeve (60) is rotatingly connected with the main shaft box (10). The encoder gear ring (30) and the positioning assembly (40) are located on the side of the main shaft box (10) far from a machining workpiece, and the electric spindle (20) is used for driving the encoder gear ring (30), the positioning assembly (40), the locking nut (50) and the spacer sleeve (60) to perform synchronous rotary motion. The positioning assembly (40) comprises a positioning gear sleeve (41) sleeved on the outer wall of the electric spindle (20), the positioning gear sleeve (41) is sleeved with the encoder gear ring (30) and a positioning gland (42) pressed on the encoder gear ring (30), and the positioning gland (42) is tightly connected with the positioning gear sleeve (41). The positioning gear sleeve (41) is provided with a first positioning surface (411) and a second positioning surface (412), the first positioning surface (411) is in contact with the end surface of the encoder gear ring (30) far from the positioning gland (42), and the second positioning surface (412) is in clearance fit with the end surface of the positioning gland (42) close to the encoder gear ring (30). The outer wall of the electric spindle (20) is provided with a first key groove (211), and a flat key (43) is embedded in the first key groove (211); the positioning gear sleeve (41) is provided with a second key groove (413) corresponding to the first key groove (211), one end of the flat key (43) far from the first key groove (211) is inserted into the second key groove (413), and the second key groove (413) penetrates through one end or both ends of the positioning gear sleeve (41) along the axial direction of the electric spindle (20). The first key groove (211) is provided with a first arc surface (2111), the flat key (43) is provided with a second arc surface (431) matched with the first arc surface (2111), and the length of the flat key (43) along the axial direction of the electric spindle (20) is smaller than the length of the second key groove (413) along the axial direction of the electric spindle (20).

2. The electric spindle assembly according to claim 1, characterized in that, The main shaft box (10) comprises a box shell (11) and a stator (12) mounted in the box shell (11), two ends of the box shell (11) are respectively provided with a first bearing seat (13) and a second bearing seat (14), the first bearing seat (13) is fixedly provided with a cover shell (15), the spacer sleeve (60) is rotatably connected to the second bearing seat (14), and the electric spindle (20) sequentially penetrates through the second bearing seat (14), the box shell (11), the first bearing seat (13) and the cover shell (15).

3. The electric spindle assembly according to claim 2, characterized in that, The electric spindle (20) comprises a shaft body (21) penetrating through the main shaft box (10), an outer wall of the shaft body (21) is sequentially sleeved with a first balance ring (22), a rotor (23) and a second balance ring (24), and the outer wall of the shaft body (21) is provided with a positioning portion (212) in positioning cooperation with the first balance ring (22), and the rotor (23) is located in the stator (12). The outer wall of the first balance ring (22) is provided with a first annular groove (221), and the outer wall of the second balance ring (24) is provided with a second annular groove (241).

4. The electric spindle assembly according to claim 3, characterized in that, The outer wall of the stator (12) is sleeved with a cooling jacket (16) located in the box shell (11), the cooling jacket (16) is provided with a cooling groove (161) in a spiral shape and used for accommodating the flow of the cooling liquid, and the box shell (11) is provided with two flow-through holes (111) in communication with two ends of the cooling groove (161), wherein one of the flow-through holes (111) is used for the inflow of the cooling liquid into the cooling groove (161), and the other flow-through hole (111) is used for the outflow of the cooling liquid out of the cooling groove (161).

5. The electric spindle assembly according to claim 4, characterized in that, Both ends of the cooling jacket (16) are provided with two spaced sealing grooves (162), the sealing grooves (162) are provided with sealing rings (17) in abutment with the inner wall of the box shell (11), and the end of the cooling jacket (16) is provided with a drainage groove (163) located between the two sealing grooves (162), and the box shell (11) is provided with a drainage hole (112) in communication with the drainage groove (163). When the sealing ring (17) close to the cooling groove (161) fails, the leaked cooling liquid in the cooling groove (161) enters the drainage groove (163) and is discharged to the outside space through the drainage hole (112).

6. The electric spindle assembly according to claim 5, characterized in that, The drainage hole (112) comprises a first hole section (1121) and a second hole section (1122) in communication with each other, the first hole section (1121) is in communication with the drainage groove (163), the second hole section (1122) is in communication with the outer wall of the box shell (11), the inner diameter of the first hole section (1121) is smaller than that of the second hole section (1122), and the flow distance of the cooling liquid in the first hole section (1121) is smaller than that in the second hole section (1122).

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