A kind of electric spindle with shaft core cooling

Abstract

The present invention discloses an electric spindle with shaft core cooling, comprising: a spindle housing, provided with an external cooling channel, the external cooling channel flows through the parts of the spindle housing where the stator, front bearing and rear bearing are installed; a motor, comprising a stator and a rotor, the stator being fixed on the spindle housing, the rotor being sleeved on the spindle; a spindle, being arranged in the spindle housing through the front bearing and the rear bearing, the spindle being provided with a spindle cooling channel connected to a rotary joint, the spindle cooling channel flows through the parts of the spindle where the rotor, front bearing and rear bearing are installed. The purpose is to reduce the thermal elongation of the spindle, while improving the accuracy and service life of the bearing, and ensuring the machining accuracy and stability of the electric spindle.

Description

Technical Field

[0001] The invention relates to the technical field of electric spindles, and in particular to an electric spindle with a shaft core cooled. Background Art

[0002] The heat generated by the electric spindle mainly comes from the motor and bearing parts. In order to ensure the processing accuracy, it is necessary to reduce the thermal impact and reduce the thermal elongation. Therefore, it is very important to cool the electric spindle. At present, the cooling structure of the electric spindle mainly adds external cooling channels on the spindle housing, which can only effectively cool the motor stator and the outer ring of the bearing. In practical applications, since the spindle is difficult to be effectively cooled through the external cooling channel, the heat generated by the electric spindle will cause a large thermal elongation of the spindle, which will have a great impact on the processing accuracy and stability of the electric spindle.

[0003] During the rotation of the spindle, the inner ring and the outer ring of the bearing show different temperature rises relative to their initial temperatures, resulting in different thermal expansions, which in turn causes changes in the internal clearance of the bearing. The cooling effect of the external cooling channel in the spindle housing on the outer ring of the bearing aggravates the temperature difference between the outer ring and the inner ring, which may lead to negative clearance in actual operation, increase frictional heat, increase temperature rise, and further reduce the effective clearance. This vicious cycle may cause the bearing to lock, seriously damage the accuracy and service life of the bearing, and also have a significant impact on the machining accuracy and stability of the electric spindle. Summary of the invention

[0004] The invention provides an electric spindle with shaft core cooling, aiming at reducing the thermal elongation of the spindle, improving the precision and service life of the bearing, and ensuring the machining precision and stability of the electric spindle.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A shaft core cooling electric spindle, comprising:

[0007] The spindle housing is provided with an external cooling channel, and the external cooling channel flows through the part of the spindle housing where the stator, the front bearing and the rear bearing are mounted;

[0008] The motor comprises a stator and a rotor, wherein the stator is fixed on the main shaft housing and the rotor is sleeved on the core shaft;

[0009] The core shaft is arranged in the spindle housing through the front bearing and the rear bearing. The core shaft is provided with a core shaft cooling flow channel connected to the rotary joint. The core shaft cooling flow channel flows through the parts of the core shaft where the rotor, the front bearing and the rear bearing are installed.

[0010] Furthermore, the mandrel comprises a mandrel body and a tool holder seat and a tail end distribution cooling sleeve located at both ends of the mandrel body, and the tool holder seat and the tail end distribution cooling sleeve are detachably connected to the mandrel body;

[0011] The mandrel body is provided with 2n direct current channels arranged in a circular array around the axis of the mandrel body, where n is an integer greater than 1;

[0012] The tool handle seat is provided with n first transition sections arranged in a circular array around the axis of the mandrel body, and each of the first transition sections corresponds to two direct current channels;

[0013] The tail end distribution cooling jacket is provided with n second transition sections arranged in a circular array around the axis of the mandrel body, each second transition section corresponds to two direct current channels, and two second transition sections are provided with interface flow channels connected to the rotary joint;

[0014] The first transition section, the second transition section and the direct flow channel are interconnected to form the core shaft cooling flow channel.

[0015] Furthermore, the tail end distribution cooling sleeve is inserted into the core shaft body, and the core shaft body is provided with a first flow channel opened along the radial direction of the core shaft body, and the direct flow channel is connected to the second transition section through the first flow channel.

[0016] Furthermore, the first transition section is located on the end surface of the tool handle seat close to one end of the mandrel body, and a sealing ring is provided between the first transition section and the mandrel body;

[0017] One end of the tail end distribution cooling sleeve inserted into the core shaft body is the insertion end, the second transition section is located on the outer periphery of the insertion end, two sealing rings are sleeved on the insertion end and the second transition section is located between the two sealing rings.

[0018] Furthermore, it also includes a broaching mechanism arranged in the core shaft, and the broaching mechanism is provided with a central water outlet channel connected to the rotating joint.

[0019] Furthermore, the rotary joint comprises:

[0020] The fixing part fixed on the spindle housing comprises a main body, a first static sealing component and a second static sealing component, wherein the first static sealing component and the second static sealing component are assembled on the main body in a floating manner but not in a rotational manner, and the main body is provided with a central water outlet fixed flow channel, a cooling inlet fixed flow channel and a cooling outlet fixed flow channel;

[0021] A rotating shaft fixed on the core shaft is rotatably assembled on the main body, and a central water outlet rotating flow channel, a cooling inlet rotating flow channel and a cooling outlet rotating flow channel are provided on the rotating shaft;

[0022] The central water outlet rotating flow channel is connected to the central water outlet flow channel, the cooling inlet rotating flow channel is connected to the inlet end of the mandrel cooling flow channel, and the cooling outlet rotating flow channel is connected to the outlet end of the mandrel cooling flow channel;

[0023] The first elastic component is capable of providing an axial force to drive the first static sealing component to press against the first dynamic sealing end of the rotating shaft, so that the end of the first static sealing component and the end of the first dynamic sealing end fit together to form a contact seal, so that the central water outlet fixed flow channel is connected to the central water outlet rotating flow channel, and at the same time, the cooling inlet fixed flow channel is connected to the cooling inlet rotating flow channel;

[0024] The second elastic component can provide axial force to drive the second static sealing component to press on the second dynamic sealing end of the rotating shaft, so that the end of the second static sealing component and the end of the second dynamic sealing end fit together to form a contact seal, so that the cooling outlet fixed flow channel and the cooling outlet rotating flow channel are connected.

[0025] Furthermore, a receiving cavity is provided in the main body, and the first dynamic sealing end is located in the receiving cavity;

[0026] The first dynamic sealing end divides the accommodating cavity into a first distribution cavity and a second distribution cavity. The cooling inlet fixed flow channel is connected to the cooling inlet rotating flow channel through the first distribution cavity. The cooling outlet fixed flow channel is connected to the cooling outlet rotating flow channel through the second distribution cavity.

[0027] Furthermore, a rotation gap is left between the first dynamic seal end and the inner wall of the main body, the rotation gap is located between the first distribution chamber and the second distribution chamber, the two ends of the rotation gap are connected to the first distribution chamber and the second distribution chamber respectively, and a sealing structure is provided in the rotation gap.

[0028] Furthermore, it also includes a knife-beating cylinder assembly, which includes a knife-beating cylinder, a knife-beating disc and a connecting column;

[0029] The knife-beating cylinder is fixed on the spindle housing, the knife-beating disc is provided with a through hole allowing the rotary joint to pass through, the piston of the knife-beating cylinder is fixedly connected to the knife-beating disc, and the knife-beating disc is connected to the pull rod of the knife-pulling mechanism through a connecting column.

[0030] Furthermore, it also includes a rotating joint extension rod, which is fixed to the end of the rotating joint close to one end of the core shaft, and the end of the rotating joint extension rod away from the rotating joint is inserted into the pull rod to connect to the central water outlet channel, and a gray ring is provided between the rotating joint extension rod and the pull rod.

[0031] Beneficial effects:

[0032] The present invention provides an electric spindle with shaft core cooling, which cools the stator, the outer ring of the front bearing and the outer ring of the rear bearing through an external cooling channel provided on the spindle housing, and cools the rotor, the inner ring of the front bearing and the inner ring of the rear bearing through a core shaft cooling channel provided in the core shaft. Simultaneous cooling of the inside and outside not only reduces the thermal elongation of the core shaft, but also reduces the temperature difference between the outer ring and the inner ring of the bearing, thereby improving the operating condition of the bearing, increasing the accuracy and service life of the bearing, and thereby ensuring the processing accuracy and stability of the electric spindle. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 It is a partial cross-sectional schematic diagram of a shaft core cooling electric spindle disclosed in the present invention;

[0035] Figure 2 It is a front view schematic diagram of a shaft core cooling electric spindle disclosed in the present invention;

[0036] Figure 3 It is a schematic diagram of the cooperation between a cutting cylinder assembly and a cutting mechanism of a shaft core cooling electric spindle disclosed in the present invention;

[0037] Figure 4 It is a structural schematic diagram of a tool holder seat of a shaft core cooling electric spindle disclosed in the present invention;

[0038] Figure 5 It is a schematic structural diagram of a cooling jacket distributed at the tail end of a shaft core cooling electric spindle disclosed in the present invention;

[0039] Figure 6 A schematic diagram of the fluid in the spindle of a spindle-core-cooled electric spindle disclosed in the present invention;

[0040] Figure 7 It is a structural schematic diagram of a rotary joint of a shaft core cooling electric spindle disclosed in the present invention;

[0041] Figure 8 It is a left side view of a rotary joint of a shaft core cooling electric spindle disclosed in the present invention;

[0042] Fig. 9 It is a right side view of a rotary joint of a shaft core cooling electric spindle disclosed in the present invention;

[0043] Fig.10It is a structural schematic diagram of a fixing part of a rotary joint of a shaft core cooling electric spindle disclosed in the present invention;

[0044] Fig.11 It is a schematic structural diagram of a rotating shaft of a rotating joint of a shaft core-cooled electric spindle disclosed in the present invention;

[0045] Fig.12 for Fig. 9 AA section view;

[0046] Fig.13 A schematic diagram of the fluid of a rotary joint of a shaft core cooling electric spindle disclosed in the present invention;

[0047] Fig.14 for Fig.13 Enlarged view of point B.

[0048] In the figure:

[0049] 1. Fixed seat; 101. Center water outlet fixed flow channel;

[0050] 2. Cooling jacket; 201. Cooling inlet fixed flow channel; 202. Cooling outlet fixed flow channel;

[0051] 3. First static sealing component; 301. First through hole;

[0052] 4. Second static sealing component; 401. Second through hole;

[0053] 5. The first ceramic ring;

[0054] 6. Second ceramic ring;

[0055] 7. Connecting rod; 701. Central water outlet rotating flow channel; 702. Cooling inlet rotating flow channel; 7021. Transition section;

[0056] 8. Rotating ring;

[0057] 9. The third ceramic ring;

[0058] 10. Cooling outlet rotating flow channel;

[0059] 11. Fourth ceramic ring;

[0060] 12. First spring;

[0061] 13. Second spring;

[0062] 14. A first guide column;

[0063] 15. Second guide column;

[0064] 16. Rotational clearance;

[0065] 17. Guide slope;

[0066] 18. Sealing structure;

[0067] 19. The ball rises and blocks the head;

[0068] 20. O-ring;

[0069] 21. Step part;

[0070] 22. Sealing ring;

[0071] 23. Gray Circle;

[0072] 24. Inspection cover;

[0073] 25. Encoder gear;

[0074] 26. Rotary joint to extend the rod;

[0075] 27. Knife-beating cylinder;

[0076] 28. Beat the knife plate;

[0077] 29. Connecting column;

[0078] 30. Center water outlet channel;

[0079] 31. broach mechanism; 3101. broach claw; 3102. broach rod;

[0080] 32. mandrel body; 3201. direct flow channel; 3202. first flow channel;

[0081] 33. Tool handle seat; 3301. First transition section;

[0082] 34. Tail end distribution cooling jacket; 3401. Second transition section; 3402. Interface flow channel;

[0083] 35. Front bearing;

[0084] 36. Rear bearing;

[0085] 37. Front bearing outer cover;

[0086] 38. Front sealing sleeve;

[0087] 39. Sleeve;

[0088] 40. Rear flange;

[0089] 41. Back seat;

[0090] 42. Front bearing locking nut;

[0091] 43. Front bearing spacer;

[0092] 44. Front bearing seat;

[0093] 45. Rear bearing locking nut;

[0094] 46. ​​Rear bearing spacer;

[0095] 47. Rear bearing seat;

[0096] 48. Mandrel cooling inlet pipe;

[0097] 49. Mandrel cooling outlet pipe;

[0098] 50. Central cooling inlet pipe;

[0099] 51. Adjustment pad;

[0100] 52. Motor;

[0101] C, first distribution chamber; D, second distribution chamber. DETAILED DESCRIPTION

[0102] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0103] This embodiment provides an electric spindle with shaft core cooling, such as Figure 1 As shown, including:

[0104] The spindle housing is provided with an external cooling channel, and the external cooling channel flows through the part of the spindle housing where the stator, the front bearing 35 and the rear bearing 36 are mounted;

[0105] The motor 52 includes a stator and a rotor, wherein the stator is fixed on the spindle housing and the rotor is sleeved on the core shaft;

[0106] The core shaft is arranged in the spindle housing through the front bearing 35 and the rear bearing 36. The core shaft is provided with a core shaft cooling flow channel connected to the rotary joint. The core shaft cooling flow channel flows through the parts of the core shaft where the rotor, the front bearing 35 and the rear bearing 36 are installed.

[0107] The present embodiment provides a shaft core cooling electric spindle, which cools the stator, the outer ring of the front bearing 35 and the outer ring of the rear bearing 36 through the external cooling channel provided on the spindle housing, and cools the rotor, the inner ring of the front bearing 35 and the inner ring of the rear bearing 36 through the core shaft cooling channel provided in the core shaft. The simultaneous cooling of the inside and the outside not only reduces the thermal elongation of the core shaft, but also reduces the temperature difference between the outer ring and the inner ring of the bearing, thereby improving the operating condition of the bearing, increasing the accuracy and service life of the bearing, and thereby ensuring the processing accuracy and stability of the electric spindle.

[0108] In this embodiment, if Figure 1 As shown, the spindle housing includes a front bearing outer cover 37, a front sealing sleeve 38, a sleeve 39, a rear flange 40 and a rear seat 41 which are fixedly connected in sequence by bolts, and the front bearing 35 and the rear bearing 36 are respectively arranged on the front bearing assembly and the rear bearing assembly;

[0109] The front bearing assembly includes a front bearing locking nut 42, a front bearing spacer 43 and a front bearing seat 44. The front bearing seat 44 is fixed on the spindle housing, the front bearing 35 is mounted on the front bearing seat 44, the front bearing spacer 43 is sleeved on the spindle and located between the two front bearings 35, and the front bearing locking nut 42 is threadedly connected to the spindle to prevent the front bearing 35 from escaping from the front bearing seat 44;

[0110] The rear bearing assembly includes a rear bearing locking nut 45, a rear bearing spacer 46 and a rear bearing seat 47. The rear bearing seat 47 is fixed on the main shaft housing, and the rear bearing 36 is installed on the rear bearing seat 47. The rear bearing spacer 46 is sleeved on the core shaft and located between the two rear bearings 36. The rear bearing locking nut 45 is threadedly connected to the core shaft to prevent the rear bearing 36 from slipping out of the rear bearing seat 47.

[0111] In a specific embodiment, Figure 1 , Figure 2 and Figure 6 As shown, the mandrel includes a mandrel body 32 and a tool holder seat 33 and a tail end distribution cooling sleeve 34 located at both ends of the mandrel body 32. The tool holder seat 33 and the tail end distribution cooling sleeve 34 are detachably connected to the mandrel body 32 by bolts, and different tool holder seats 33 can be replaced according to different tools;

[0112] like Figure 6 As shown, the core shaft body 32 is provided with 2n direct current channels 3201 arranged in a circular array around the axis of the core shaft body 32, where n is an integer greater than 1;

[0113] like Figure 4As shown, the tool handle seat 33 is provided with n first transition sections 3301 arranged in a circular array around the axis of the mandrel body 32, and each of the first transition sections 3301 corresponds to two direct current channels 3201;

[0114] like Figure 5 As shown, the tail end distribution cooling jacket 34 is provided with n second transition sections 3401 arranged in a circular array around the axis of the mandrel body 32, each of the second transition sections 3401 corresponds to two direct current channels 3201, and the two second transition sections 3401 are provided with interface channels 3402 connected to the rotary joint;

[0115] The first transition section 3301, the second transition section 3401 and the direct flow channel 3201 are interconnected to form the serpentine core shaft cooling channel;

[0116] The processing difficulty is reduced by dividing the core shaft cooling channel into the first transition section 3301, the second transition section 3401 and the straight channel 3201 which are interconnected, and the serpentine core shaft cooling channel can effectively ensure the cooling effect.

[0117] In a specific embodiment, Figure 3 and Figure 6 As shown, the tail end distribution cooling jacket 34 is inserted into the mandrel body 32, and the mandrel body 32 is provided with a first flow channel 3202 opened along the radial direction of the mandrel body 32, and the direct flow channel 3201 is connected to the second transition section 3401 through the first flow channel 3202;

[0118] By inserting the tail end distribution cooling jacket 34 into the mandrel body 32 , the overall length of the mandrel can be reduced, thereby increasing the rigidity of the mandrel.

[0119] In a specific embodiment, Figure 4 As shown, the first transition section 3301 is located on the end surface of the tool holder 33 close to the spindle body 32. Figure 1 As shown, a sealing ring 22 is provided between the first transition section 3301 and the core shaft body 32;

[0120] The tail end distribution cooling sleeve 34 is inserted into the core shaft body 32 at one end as an insertion end. Figure 5 As shown, the second transition section 3401 is located on the outer periphery of the insertion end. Figure 3 As shown, two sealing rings 22 are sleeved on the insertion end and the second transition section 3401 is located between the two sealing rings 22;

[0121] The sealing ring 22 provided between the first transition section 3301 and the mandrel body 32 can ensure that the coolant does not leak from the joint;

[0122] In order to reduce the complexity of the sealing structure, in this embodiment, the second transition section 3401 is located between the two sealing rings 22 mounted on the insertion end, so that the coolant will not leak outward from the space enclosed by the two sealing rings 22 mounted on the insertion end, the insertion end and the core shaft body 32. There is a small amount of leakage between adjacent second transition sections 3401, but since the leakage object is the coolant, it does not affect normal use.

[0123] In a specific embodiment, Figure 1 As shown, it also includes a broaching mechanism 31 arranged in the mandrel, and the broaching mechanism 31 is provided with a central water outlet channel 30 connected to the rotary joint to provide coolant to the tool through the central water outlet channel 30.

[0124] In a specific embodiment, Fig.12 and Fig.13 As shown, the rotary joint comprises:

[0125] The fixed part fixed on the spindle housing includes a main body, a first static sealing component 3 and a second static sealing component 4. The first static sealing component 3 and the second static sealing component 4 are assembled on the main body in a floating manner but not in a rotational manner. The main body is provided with a central water outlet fixed flow channel 101, a cooling inlet fixed flow channel 201 and a cooling outlet fixed flow channel 202. The interface flow channels 3402 provided on the two second transition sections 3401 are respectively connected with the cooling inlet fixed flow channel 201 and the cooling outlet fixed flow channel 202;

[0126] A rotating shaft fixed on the core shaft is rotatably mounted on the main body, and a central water outlet rotating flow channel 701, a cooling inlet rotating flow channel 702 and a cooling outlet rotating flow channel 10 are provided on the rotating shaft;

[0127] The central water outlet rotating channel 701 is connected to the central water outlet channel 30, the cooling inlet rotating channel 702 is connected to the inlet end of the mandrel cooling channel, and the cooling outlet rotating channel 10 is connected to the outlet end of the mandrel cooling channel;

[0128] The first elastic component can provide an axial force to drive the first static sealing component 3 to press against the first dynamic sealing end of the rotating shaft, so that the end of the first static sealing component 3 and the end of the first dynamic sealing end fit together to form a contact seal, so that the central water outlet fixed flow channel 101 and the central water outlet rotating flow channel 701 are connected, and at the same time, the cooling inlet fixed flow channel 201 and the cooling inlet rotating flow channel 702 are connected;

[0129] The second elastic component can provide axial force to drive the second static sealing component 4 to press on the second dynamic sealing end of the rotating shaft, so that the end of the second static sealing component 4 and the end of the second dynamic sealing end fit together to form a contact seal, so that the cooling outlet fixed flow channel 202 and the cooling outlet rotating flow channel 10 are connected.

[0130] By setting the first elastic component and the second elastic component to provide axial force, the first static sealing component 3 and the second static sealing component 4 on the driving body are respectively pressed on the first dynamic sealing end and the second dynamic sealing end of the rotating shaft, so that a contact seal is formed between the fixed part and the rotating shaft, so that the central water outlet fixed flow channel 101 and the central water outlet rotating flow channel 701, the cooling inlet fixed flow channel 201 and the cooling inlet rotating flow channel 702 are connected, and the cooling outlet fixed flow channel 202 and the cooling outlet rotating flow channel 10 are connected, thereby forming a central flow channel for connecting the central water outlet flow channel, and an inlet flow channel and an outlet flow channel respectively connecting the inlet end and the outlet end of the core shaft cooling flow channel, so as to simultaneously meet the dual needs of the central water outlet of the electric spindle and the cooling of the core shaft.

[0131] In a specific embodiment, a receiving cavity is provided in the main body, and the first dynamic sealing end is located in the receiving cavity;

[0132] The first dynamic sealing end divides the accommodating cavity into a first distribution cavity C and a second distribution cavity D. The cooling inlet fixed flow channel 201 is connected to the cooling inlet rotating flow channel 702 through the first distribution cavity C, and the cooling outlet fixed flow channel 202 is connected to the cooling outlet rotating flow channel 10 through the second distribution cavity D.

[0133] Through the first distribution chamber C and the second distribution chamber D, the coolant flowing in from several cooling inlet fixed flow channels 201 can be evenly distributed to several cooling inlet rotating flow channels 702, and the coolant flowing in from several cooling outlet rotating flow channels 10 can be evenly distributed to several cooling outlet fixed flow channels 202.

[0134] In a specific embodiment, Fig.14 As shown, a rotation gap 16 is left between the first dynamic seal end and the inner wall of the main body, and the rotation gap 16 is located between the first distribution chamber C and the second distribution chamber D. The two ends of the rotation gap 16 are connected to the first distribution chamber C and the second distribution chamber D respectively, and a sealing structure 18 is provided in the rotation gap 16;

[0135] By providing the rotation gap 16, it is ensured that the first dynamic sealing end of the rotating shaft can rotate relative to the main body, and by providing the sealing structure 18, the relative flow of the coolant in the first distribution chamber C and the coolant in the second distribution chamber D is reduced.

[0136] In a specific embodiment, the sealing structure 18 is a wear-resistant ring. In this embodiment, a groove for installing the wear-resistant ring is provided on the cooling jacket 2 of the main body, and the wear-resistant ring forms a contact seal between the fixing seat 1 of the main body and the cooling jacket 2.

[0137] In a specific embodiment, Fig.14 As shown, the cooling inlet rotating flow channel 702 is provided with a transition section 7021 inclined toward the cooling inlet fixed flow channel 201, and the first static sealing component 3 located in the first distribution chamber C is provided with a step portion 21. The coolant flowing from the cooling inlet fixed flow channel 201 into the first distribution chamber C is reversed by the step portion 21 and then flows into the transition section 7021, ensuring that the coolant flows more smoothly. At the same time, when the coolant flows from the cooling inlet rotating flow channel 702 into the first distribution chamber C, direct impact on the fitting part of the first static sealing component 3 and the first dynamic sealing end is avoided to avoid affecting the sealing effect.

[0138] In a specific embodiment, Fig.14 As shown, the second distribution chamber D is provided with a guide bevel 17, and the guide bevel 17 is located at the end of the rotating gap 16 close to one end of the second distribution chamber D. The guide bevel is used to guide the fluid away from the rotating gap 16 and flow toward the cooling outlet fixed flow channel 202, so that the flow of the coolant is smoother, and at the same time, the coolant flowing into the second distribution chamber D from the cooling outlet rotating flow channel 10 does not flow directly to the rotating gap 16, thereby reducing the flow rate of the coolant flowing from the second distribution chamber D to the first distribution chamber C.

[0139] In a specific embodiment, Fig.12 As shown, a third ceramic ring 9 is provided at the end of the first dynamic sealing end, a first ceramic ring 5 is provided at the end of the first static sealing component 3 and is arranged opposite to the third ceramic ring 9, a fourth ceramic ring 11 is provided at the end of the second dynamic sealing end, and a second ceramic ring 6 is provided at the end of the second static sealing component 4 and is arranged opposite to the fourth ceramic ring 11;

[0140] Under the action of the axial force provided by the elastic component, the ceramic rings that fit tightly together show a good sealing effect, and the excellent wear resistance of the ceramic rings makes them suitable for high-speed electric spindles.

[0141] In a specific embodiment, Figures 7 to 12 As shown, the main body includes a fixing seat 1 and a cooling jacket 2, the cooling jacket 2 is fixed to the fixing seat 1 by bolts, and the cooling jacket 2 and the fixing seat 1 form a receiving cavity;

[0142] The fixing seat 1 is provided with a central water outlet fixed flow channel 101, the first static sealing component 3 is assembled on the fixing seat 1 in a floating manner but not in a rotational manner, the first static sealing component 3 is provided with a first through hole 301 connected to the central water outlet fixed flow channel 101, the first static sealing component 3 is provided with a first ceramic ring 5 at the end of the first through hole 301, and in this embodiment, the first ceramic ring 5 is embedded in a groove provided on the first static sealing component 3;

[0143] The cooling jacket 2 is provided with a cooling inlet fixed flow channel 201 and a cooling outlet fixed flow channel 202. The second static sealing component 4 is assembled on the cooling jacket 2 in a floating manner but not in a rotational manner. The second static sealing component 4 is provided with a second through hole 401 connected to the cooling outlet fixed flow channel 202. The second static sealing component 4 is provided with a second ceramic ring 6 at the end of the second through hole 401. In this embodiment, the second ceramic ring 6 is embedded in a groove provided on the second static sealing component 4.

[0144] A rotating shaft, comprising a connecting rod 7 and a rotating ring 8, wherein the connecting rod 7 is rotatably mounted on the cooling jacket 2, and the rotating ring 8 is fixed on the connecting rod 7 by bolts;

[0145] The connecting rod 7 is provided with a central water outlet rotating flow channel 701 and a cooling inlet rotating flow channel 702, and the connecting rod 7 is provided with a third ceramic ring 9 arranged opposite to the first ceramic ring 5, and one end of the connecting rod 7 provided with the third ceramic ring 9 is a first dynamic sealing end;

[0146] The rotating ring 8 and the connecting rod 7 form a cooling outlet rotating flow channel 10, and the rotating ring 8 is provided with a fourth ceramic ring 11 arranged opposite to the second ceramic ring 6, and one end of the rotating ring 8 provided with the fourth ceramic ring 11 is a second dynamic sealing end;

[0147] The first elastic component can provide an axial force to drive the first ceramic ring 5 to press on the third ceramic ring 9, so that the first ceramic ring 5 and the third ceramic ring 9 are closely fitted, so that the central water outlet fixed flow channel 101 is connected with the central water outlet rotating flow channel 701 through the first through hole 301, and at the same time, the cooling inlet fixed flow channel 201 is connected with the cooling inlet rotating flow channel 702;

[0148] The second elastic component can provide an axial force to drive the second ceramic ring 6 to press on the fourth ceramic ring 11, so that the second ceramic ring 6 and the fourth ceramic ring 11 are closely fitted, so that the cooling outlet fixed flow channel 202 is connected with the cooling outlet rotating flow channel 10 through the second through hole 401;

[0149] The connecting rod 7 can be inserted into the mandrel body 32, so that the central flow channel and the inlet flow channel and the outlet flow channel on the rotary joint are connected with the inlet end and the outlet end of the central water outlet flow channel and the mandrel cooling flow channel respectively, the rotating ring 8 is fixedly connected with the mandrel body 32 by bolts, the connecting rod 7 and the mandrel body 32 are sealed by an O-ring 20, and the cooling jacket 2 is fixedly connected with the spindle housing by bolts;

[0150] In this embodiment, if Fig.12 As shown, in order to prevent fluid leakage, the contact part between the rotary joint and the mandrel body 32, the contact part between the rotary joint and the tail end distribution cooling jacket 34, and the contact surface of the parts inside the rotary joint that do not rotate relative to each other are all provided with grooves for installing the O-ring 20, so as to facilitate the installation of the O-ring 20;

[0151] In this embodiment, if Fig.12 As shown, for the convenience of processing, a part of the central water outlet fixed flow channel 101 is processed on the fixing seat 1, and the other part is processed on the cooling jacket 2; the holes left during processing can be sealed with a ball expansion plug 19.

[0152] In a specific embodiment, Fig.12 As shown, the first elastic component is a first spring 12, the first spring 12 is placed between the main body and the first static sealing component 3, and the first static sealing component 3 is evenly distributed with a plurality of blind holes for accommodating the first spring 12;

[0153] The second elastic component is a second spring 13 , which is disposed between the main body and the second static sealing component 4 . The second static sealing component 4 is evenly distributed with a plurality of blind holes for accommodating the second spring 13 .

[0154] In a specific embodiment, it also includes a first guide column 14 and a second guide column 15 fixed to the main body by bolts, the first guide column 14 and the second guide column 15 extend along the axial direction of the rotating shaft, the first static sealing component 3 is provided with a first guide hole corresponding to the first guide column 14, and the second static sealing component 4 is provided with a second guide hole corresponding to the second guide column 15, so as to perform a guiding function and ensure that the first spring 12 and the second spring 13 can accurately apply axial force.

[0155] In a specific embodiment, it also includes a knife-beating cylinder assembly, such as Figure 3 As shown, the knife-beating cylinder assembly includes a knife-beating cylinder 27, a knife-beating disc 28 and a connecting column 29;

[0156] The knife-beating cylinder 27 is fixed on the rear seat 41 of the spindle housing, and the knife-beating disc 28 is provided with a through hole allowing the rotary joint to pass through. The piston of the knife-beating cylinder 27 is fixedly connected to the knife-beating disc 28, and the knife-beating disc 28 is connected to the pull rod 3102 of the knife-broaching mechanism 31 through a connecting column 29. In this embodiment, one end of the connecting column 29 is connected to the knife-beating disc 28 by a bolt, and the other end of the connecting column 29 is provided with a threaded portion threadedly connected to the spindle body 32;

[0157] In this embodiment, a through hole is provided on the cooling sleeve 34 at the tail end of the rotary joint box to allow the connecting column 29 to pass through. The connecting column 29 can slide along the through hole, and the piston of the cutting cylinder 27 drives the cutting disc 28 to axially move. The cutting disc 28 drives the pull rod 3102 to move through the connecting column 29 that can slide along the through hole, thereby driving the pulling claw 3101 of the pulling mechanism to grab and release the tool at the tool handle seat 33.

[0158] In a specific embodiment, Figure 3 As shown, it also includes a rotating joint extension rod 26, which is fixed to the end of the rotating joint near one end of the core shaft by screws, and the end of the rotating joint extension rod 26 away from the rotating joint is inserted into the pull rod 3102 to connect to the central water outlet channel 30, and a grid ring 23 is provided between the rotating joint extension rod 26 and the pull rod 3102 to ensure that when the pull rod 3102 follows the connecting column 29 for axial reciprocating motion, the rotating joint extension rod 26 and the pull rod 3102 can be reliably sealed.

[0159] In a specific embodiment, Figure 1 As shown, it also includes an encoder gear 25 mounted on the rotating ring. The spindle housing is provided with a reading head corresponding to the encoder gear 25 to facilitate closed-loop control of the electric spindle. In this embodiment, it also includes an adjustment pad 51, which is mounted on the rotating ring to ensure the relative position of the encoder gear 25 in the axial direction of the core shaft.

[0160] In a specific embodiment, Figure 1 As shown, an inspection cover 24 is provided on the rear seat 41 of the spindle housing to facilitate the inspection of the rotary joint.

[0161] In a specific embodiment, Figure 1 As shown, the rear seat 41 is provided with a core shaft cooling inlet pipe 48, a core shaft cooling outlet pipe 49 and a central cooling inlet pipe 50 of an external cooling system, and the core shaft cooling inlet pipe 48, the core shaft cooling outlet pipe 49 and the central cooling inlet pipe 50 are connected to the central water outlet fixed flow channel 101, the cooling inlet fixed flow channel 201 and the cooling outlet fixed flow channel 202 through hoses respectively.

[0162] In actual use, the O-ring 20 and the sealing ring 22 are both O-rings.

[0163] Example 2

[0164] This embodiment provides an electric spindle with shaft core cooling. The main structure of this embodiment is similar to that of Embodiment 1. The difference between this embodiment and Embodiment 1 is as follows:

[0165] In embodiment 1, the sealing structure 18 is a wear-resistant ring.

[0166] In the present embodiment, the sealing structure 18 is a sealing groove, and the flow cross-sectional area of ​​the sealing groove is larger than the flow cross-sectional area of ​​the rotating gap 16, so that the coolant entering the rotating gap 16 from the first distribution chamber C and the coolant entering the rotating gap 16 from the second distribution chamber D can be decompressed after entering the sealing groove, thereby reducing the flow rate of the coolant passing through the rotating gap 16.

[0167] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A core-cooled electric spindle, characterized in that: include: The spindle housing is provided with an external cooling channel, wherein the external cooling channel flows through the portion of the spindle housing where the stator, the front bearing (35) and the rear bearing (36) are mounted; The motor (52) comprises a stator and a rotor, wherein the stator is fixed on the main shaft housing and the rotor is sleeved on the core shaft; The core shaft is arranged in the spindle housing through a front bearing (35) and a rear bearing (36). A core shaft cooling flow channel connected to a rotary joint is provided in the core shaft. The core shaft cooling flow channel flows through the parts of the core shaft where the rotor, the front bearing (35) and the rear bearing (36) are installed.

2. The shaft-core-cooled electric spindle according to claim 1, characterized in that: The mandrel comprises a mandrel body (32) and a tool holder seat (33) and a tail end distribution cooling sleeve (34) located at two ends of the mandrel body (32), wherein the tool holder seat (33) and the tail end distribution cooling sleeve (34) are detachably connected to the mandrel body (32); The core shaft body (32) is provided with 2n direct current channels (3201) arranged in a circular array around the axis of the core shaft body (32), where n is an integer greater than 1; The tool handle seat (33) is provided with n first transition sections (3301) arranged in a circular array around the axis of the mandrel body (32), and each of the first transition sections (3301) corresponds to two direct current channels (3201); The tail end distribution cooling jacket (34) is provided with n second transition sections (3401) arranged in a circular array around the axis of the core shaft body (32), each of the second transition sections (3401) corresponds to two direct current channels (3201), and the two second transition sections (3401) are provided with interface flow channels (3402) connected to the rotary joint; The first transition section (3301), the second transition section (3401) and the direct flow channel (3201) are interconnected to form the core shaft cooling channel.

3. The shaft-core-cooled electric spindle according to claim 1, characterized in that: The tail end distribution cooling sleeve (34) is inserted into the core shaft body (32), and the core shaft body (32) is provided with a first flow channel (3202) opened radially along the core shaft body (32), and the direct flow channel (3201) is connected to the second transition section (3401) through the first flow channel (3202).

4. The shaft-core-cooled electric spindle according to claim 3, characterized in that: The first transition section (3301) is located on an end surface of the tool handle seat (33) close to one end of the spindle body (32), and a sealing ring (22) is provided between the first transition section (3301) and the spindle body (32); One end of the tail end distribution cooling sleeve (34) inserted into the core shaft body (32) is the insertion end, the second transition section (3401) is located on the outer periphery of the insertion end, two sealing rings (22) are provided on the insertion end and the second transition section (3401) is located between the two sealing rings (22).

5. The shaft-core-cooled electric spindle according to claim 1, characterized in that: It also includes a broaching mechanism (31) disposed in the core shaft, wherein the broaching mechanism (31) is provided with a central water outlet channel (30) connected to the rotary joint.

6. The shaft-core-cooled electric spindle according to claim 5, characterized in that: The rotary joint comprises: A fixed part fixed on the main shaft housing comprises a main body, a first static sealing component (3) and a second static sealing component (4), wherein the first static sealing component (3) and the second static sealing component (4) are mounted on the main body in a floating manner but not in a rotational manner, and the main body is provided with a central water outlet fixed flow channel (101), a cooling inlet fixed flow channel (201) and a cooling outlet fixed flow channel (202); A rotating shaft fixed on the core shaft is rotatably mounted on the main body, and a central water outlet rotating flow channel (701), a cooling inlet rotating flow channel (702) and a cooling outlet rotating flow channel (10) are provided on the rotating shaft; The central water outlet rotating channel (701) is connected to the central water outlet channel (30), the cooling inlet rotating channel (702) is connected to the inlet end of the mandrel cooling channel, and the cooling outlet rotating channel (10) is connected to the outlet end of the mandrel cooling channel; The first elastic component is capable of providing an axial force to drive the first static sealing component (3) to press against the first dynamic sealing end of the rotating shaft, so that the end of the first static sealing component (3) and the end of the first dynamic sealing end fit together to form a contact seal, so that the central water outlet fixed flow channel (101) and the central water outlet rotating flow channel (701) are connected, and at the same time, the cooling inlet fixed flow channel (201) and the cooling inlet rotating flow channel (702) are connected; The second elastic component can provide an axial force to drive the second static sealing component (4) to press against the second dynamic sealing end of the rotating shaft, so that the end of the second static sealing component (4) and the end of the second dynamic sealing end fit together to form a contact seal, so that the cooling outlet fixed flow channel (202) and the cooling outlet rotating flow channel (10) are connected.

7. The shaft-core-cooled electric spindle according to claim 5, characterized in that: A receiving cavity is provided in the main body, and the first dynamic sealing end is located in the receiving cavity; The first dynamic sealing end divides the accommodating cavity into a first distribution cavity and a second distribution cavity, the cooling inlet fixed flow channel (201) is connected to the cooling inlet rotating flow channel (702) through the first distribution cavity, and the cooling outlet fixed flow channel (202) is connected to the cooling outlet rotating flow channel (10) through the second distribution cavity.

8. The shaft-core-cooled electric spindle according to claim 7, characterized in that: A rotation gap (16) is left between the first dynamic seal end and the inner wall of the main body, the rotation gap (16) is located between the first distribution chamber and the second distribution chamber, the two ends of the rotation gap (16) are respectively connected to the first distribution chamber and the second distribution chamber, and a sealing structure (18) is provided in the rotation gap (16).

9. The shaft-core-cooled electric spindle according to claim 5, characterized in that: It also includes a knife-beating cylinder assembly, which includes a knife-beating cylinder (27), a knife-beating disc (28) and a connecting column (29); The knife-beating cylinder (27) is fixed on the spindle housing, and the knife-beating disc (28) is provided with a through hole allowing a rotary joint to pass through. The piston of the knife-beating cylinder (27) is fixedly connected to the knife-beating disc (28), and the knife-beating disc (28) is connected to the pull rod (3102) of the knife-pulling mechanism (31) via a connecting column (29).

10. The shaft-core-cooled electric spindle according to claim 9, characterized in that: It also includes a rotating joint extension rod (26), which is fixed to the end of the rotating joint close to one end of the core shaft, and the end of the rotating joint extension rod (26) away from the rotating joint is inserted into the pull rod (3102) to connect to the central water outlet channel (30), and a gray ring (23) is provided between the rotating joint extension rod (26) and the pull rod (3102).

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