Electric spindle and machine tool

Abstract

The application provides an electric spindle and motor, and belongs to the technical field of electric spindles. The electric spindle comprises a shaft core, a bearing seat and a bearing sleeved on the shaft core, and the bearing is arranged in the bearing seat; the electric spindle further comprises a first fixed spacer ring and a second fixed spacer ring arranged in sequence along the axial direction of the shaft core; the first fixed spacer ring is fixedly installed on the opening side of the bearing seat and is configured to preliminarily pre-tighten the bearing in the bearing seat; the second fixed spacer ring is threadedly connected to the surface of the shaft core and rotationally matches with the first fixed spacer ring, and the second fixed spacer ring is configured to secondarily pre-tighten the bearing in the bearing seat and seal the bearing in the bearing seat. Through the arrangement of the first fixed spacer ring and the second fixed spacer ring, the pre-tightening adjustment of the bearing during assembly can be realized, repeated disassembly is reduced, and the pre-tightening assembly efficiency of the bearing is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric spindles, and particularly relates to an electric spindle and a machine tool BACKGROUND

[0002] The electric spindle is a new technology that integrates a machine tool spindle and a spindle motor, the spindle is directly driven by the built-in motor, the gear, belt or coupling transmission of the traditional spindle is cancelled, so that the transmission chain length of the machine tool spindle is shortened to zero, and the electric spindle is widely applied to the manufacturing fields of precision molds, automobiles, ships, aerospace and other high-end products. The electric spindle has a complex structure, the shaft core is a core part of the electric spindle, bearings, motors and other parts are assembled on the shaft core, and the overall assembly precision determines the rotation precision of the electric spindle.

[0003] The bearing is a core part of the electric spindle and transmits the torque of the rotating shaft core. More than 85% of electric spindle failures are caused by bearing damage. The main factors affecting the service life of the bearing are bearing pre-tightening and internal cleaning. If cutting fluid or other impurities enter the bearing, the bearing will rotate unstably, the service life of the bearing will be reduced, and the electric spindle will fail.

[0004] The bearing pre-tightening can prevent the bearing from overheating due to incorrect installation position during operation, that is, the bearing pre-tightening is good, the bearing operation condition is stable, and the service life of the bearing is improved.

[0005] At present, the bearing pre-tightening of the electric spindle is performed after the bearing seat and the bearing are adjusted and assembled in the correct position. The actual situation during the assembly process does not conform to the theory, so the bearing pre-tightening adjustment is performed many times, the workload is increased, and the pre-tightening effect is not good. Therefore, the bearing pre-tightening and sealing on the shaft core are particularly important.

[0006] Therefore, the application is provided. SUMMARY

[0007] The application aims to overcome the shortcomings of the prior art and provide an electric spindle and a machine tool.

[0008] To solve the above technical problems, on the one hand, the application provides an electric spindle, which comprises a shaft core, a bearing seat and a bearing arranged on the shaft core, and the bearing is arranged in the bearing seat.

[0009] The electric spindle further comprises a first fixed spacer ring and a second fixed spacer ring arranged in sequence along the axial direction of the shaft core.

[0010] The first fixed spacer ring is fixedly installed on the opening side of the bearing seat and is configured to preliminarily pre-tighten the bearing in the bearing seat.

[0011] The second fixed spacer ring is threadedly connected to the surface of the shaft core and rotationally matched with the first fixed spacer ring, and is configured to secondarily pre-tighten the bearing in the bearing seat and seal the bearing in the bearing seat.

[0012] In the technical solution, the first fixed spacer ring has a first embedding part, and the second fixed spacer ring has a second embedding part. When the first fixed spacer ring and the second fixed spacer ring are installed, the first embedding part is embedded in the bearing seat to primarily pre-tighten the bearing in the bearing seat, and the second embedding part is embedded in the bearing seat to secondarily pre-tighten the bearing in the bearing seat.

[0013] In the technical solution, the bearing includes an outer ring, a ball, and an inner ring. The first fixed spacer ring acts on the surface of the outer ring, and the second fixed spacer ring acts on the surface of the inner ring.

[0014] In the technical solution, a sealing position is formed at the rotationally matched position of the first fixed spacer ring and the second fixed spacer ring. The sealing position includes a first sealing section, a second sealing section, and a third sealing section. The first sealing section is a gap seal, and the second sealing section and the third sealing section are labyrinth seals.

[0015] In the technical solution, the first fixed spacer ring has a first matching section, a second matching section, and a third matching section along the sealing path of the sealing position. The second fixed spacer ring has a fourth matching section, a fifth matching section, and a sixth matching section along the sealing path of the sealing position. The first matching section and the fourth matching section form the first sealing section, the second matching section and the fifth matching section form the second sealing section, and the third matching section and the sixth matching section form the third sealing section.

[0016] In the technical solution, a plurality of first annular grooves are arranged at the second matching section, and a plurality of annular convex teeth matched with the first annular grooves are arranged at the fifth matching section. The plurality of annular convex teeth are embedded in the first annular grooves to form the second sealing section.

[0017] A plurality of second annular grooves are arranged at the third matching section, and the third sealing section is formed between the second annular grooves and the outer ring surface of the sixth matching section.

[0018] In the technical solution, a thread is arranged on the inner wall of the second fixed spacer ring, and a thread groove matched with the thread is arranged on the shaft core.

[0019] In the technical solution, the thread is composed of a plurality of thread parts. Each thread part includes an inclined section and a bent section. One end of the inclined section and the bent section is formed on the inner wall of the second fixed spacer ring as the bottom of the thread part, and the other end of the inclined section and the bent section is connected as the top of the thread part.

[0020] In the technical scheme, the bending section has a first positioning surface and a second positioning surface, an included angle a is formed between the first positioning surface and the oblique section, and an included angle b is formed between the first positioning surface and the second positioning surface, wherein 60°<a<90°<b.

[0021] In the technical scheme, the motorized spindle further comprises a third fixed spacer ring embedded in the second fixed spacer ring, the third fixed spacer ring has a first annular clamping section and a second annular clamping section, the second fixed spacer ring is provided with a first clamping position matched with the first annular clamping section, and the second fixed spacer ring is further provided with a second clamping position matched with the second annular clamping section.

[0022] In the technical scheme, the bearing seat is provided with two bearings, and a spacer ring is arranged between the two bearings to adjust the distance between the two bearings.

[0023] In the technical scheme, the spacer ring comprises an outer spacer ring and an inner spacer ring which are arranged in each other, the outer spacer ring is attached to the outer ring of the bearing, and the inner spacer ring is attached to the inner ring of the bearing.

[0024] On the other hand, the embodiment of the present application also provides a machine tool comprising the motorized spindle of any one of claims 1-12.

[0025] Compared with the prior art, the technical scheme has the following beneficial effects:

[0026] I. By arranging the first fixed spacer ring and the second fixed spacer ring, the bearing pre-tightening adjustment can be realized during assembly, the repeated disassembly is reduced, and the bearing pre-tightening assembly efficiency is improved.

[0027] II. Through the structural cooperation of the first fixed spacer ring and the second fixed spacer ring, three layers of seals can be formed, the sealing effect of the bearing is further improved, the impurities or other cutting fluids in the bearing are prevented, and the service life of the bearing is improved.

[0028] III. By arranging the third fixed spacer ring on the second fixed spacer ring, the relative axial position of the motorized spindle parts can be ensured, the repeated matching and grinding of the second fixed spacer ring are reduced, and the assembly efficiency is improved.

[0029] The specific embodiments of the present application will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0030] The drawings are part of the present application and serve to provide a further understanding of the present application, the illustrative embodiments of the present application and the description thereof serve to explain the present application, but do not constitute an improper limitation on the present application. Obviously, the drawings described below are only some embodiments, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0031] Figure 1 The exploded structural schematic diagram of the electric spindle applied to the machine tool according to the present application;

[0032] Figure 2 The exploded structural schematic diagram of the electric spindle according to the present application Figure 1 The assembly structural schematic diagram of the electric spindle according to the present application;

[0033] Figure 3 The enlarged structural schematic diagram of A in the present application Figure 2 The enlarged structural schematic diagram of B in the present application

[0034] Figure 4 The sectional structural schematic diagram of the first fixed spacer ring in the electric spindle according to the present application Figure 1 The sectional structural schematic diagram of the second fixed spacer ring in the electric spindle according to the present application The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application

[0035] The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figure 5 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figure 1 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application

[0036] The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figure 6 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figure 5 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application

[0037] The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figure 7 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figure 1 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application

[0038] The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figure 8 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figure 1 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application

[0039] The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application Figures 1-8 The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application The sectional structural schematic diagram of the third fixed spacer ring in the electric spindle according to the present application

[0040] It should be noted that these drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0041] In the description of the present application, it should be noted that the terms "inner", "outer" and the like indicate the position or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0042] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "contacting", "communicating" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] At present, the existing electric spindle is easy to enter cutting fluid or other impurities in the bearing during use, which reduces the service life of the bearing, thereby causing the electric spindle to fail; and when assembling the bearing, the bearing needs to be pre-tightened and adjusted for multiple times, which increases the assembly workload. The first fixed spacer ring and the second fixed spacer ring are arranged to improve the sealing performance of the bearing, reduce the shortening of the service life of the bearing due to impurities and cutting fluid, and the second fixed spacer ring is threadedly connected to the shaft core of the electric spindle, which can also be used for online bearing pre-tightening adjustment on the shaft core, ensuring the pre-tightening amount of the bearing and improving the bearing pre-tightening adjustment efficiency.

[0044] In order to further illustrate the technical solutions in the present application, the following specific embodiments are provided in combination with Figures 1-8 The drawings show the following specific embodiments.

[0045] Embodiment 1

[0046] In one aspect, the present application provides an electric spindle as shown in Figure 1 The electric spindle includes a shaft core 1, a bearing seat 2 and a bearing 3 sleeved on the shaft core 1, and the bearing 3 is arranged in the bearing seat 2; the electric spindle further includes a first fixed spacer ring 4 and a second fixed spacer ring 5 arranged in the axial direction of the shaft core 1 in sequence; the first fixed spacer ring 4 is fixedly installed on the opening side of the bearing seat 2 and is configured to preliminarily pre-tighten the bearing 3 in the bearing seat 2; the second fixed spacer ring 5 is threadedly connected to the surface of the shaft core 1 and rotationally cooperates with the first fixed spacer ring 4, wherein the second fixed spacer ring 5 is configured to secondarily pre-tighten the bearing 3 in the bearing seat 2 and simultaneously seal the bearing 3 in the bearing seat 2.

[0047] As shown in Figures 1-3As shown, when the bearing 3 is installed, the bearing 3 is inserted into the bearing seat 2, and then the first fixed spacer ring 4 is fixedly assembled at the open side end face of the bearing seat 2. When the first fixed spacer ring 4 is assembled at the open side of the bearing seat 2, the first fixed spacer ring 4 will be partially inserted into the bearing seat 2 and abut against the bearing 3, and drive the bearing 3 to move towards the bottom of the bearing seat 2, thereby achieving the preliminary pre-tightening of the bearing 3 in the bearing seat 2. After the position of the first fixed spacer ring 4 is fixed, there is still a gap between the first fixed spacer ring 4 and the shaft core 1, which is used to insert the second fixed spacer ring 5. Therefore, the next step is to install the second fixed spacer ring. When installing the second fixed spacer ring 5, the second fixed spacer ring 5 is screwed on the shaft core 1 and at least partially screwed into the gap between the spacer ring 4 and the shaft core 1 (i.e. the second fixed spacer ring 5 is screwed on the shaft core 1 and located in the inner ring of the first fixed spacer ring 4). During installation, the end of the second fixed spacer ring 5 close to the bearing 3 will pass through the gap and abut against the end face of the bearing 3, and drive the bearing 3 to continue to move towards the bottom of the bearing seat 2, thereby achieving the secondary pre-tightening of the bearing 3. The pre-tightening method is a threaded pre-tightening method, which can pre-tighten the bearing 3 online, and after the second fixed spacer ring 5 is connected to the shaft core 1, it will seal the gap between the spacer ring 4 and the shaft core 1, thereby preventing external impurities and cutting fluid from entering the bearing 3, ensuring the cleanliness of the bearing 3 and improving the service life of the bearing.

[0048] Specifically, as shown in Figure 4 and Figure 5 The first fixed spacer ring 4 has a first insertion part 41, and the second fixed spacer ring 5 has a second insertion part 51. When installing the first fixed spacer ring 4 and the second fixed spacer ring 5, first, the first insertion part 41 is inserted into the bearing seat 2 to preliminarily pre-tighten the bearing in the bearing seat 2, and then the second insertion part 51 is inserted into the bearing seat 2 to secondarily pre-tighten the bearing in the bearing seat 2.

[0049] More specifically, the bearing 3 includes an outer ring 311, a ball 312, and an inner ring 312. The first fixed spacer ring 4 acts on the surface of the outer ring 311, and the second fixed spacer ring 4 acts on the surface of the inner ring 312. That is, when the first fixed spacer ring 4 is installed, the first insertion part 41 on the first fixed spacer ring 4 contacts the outer ring 311 of the bearing 3, and the second insertion part 41 on the second fixed spacer ring 5 contacts the inner ring 312 of the bearing 3, thereby achieving the double pre-tightening effect of the bearing 3, and sealing the bearing 3 in the bearing seat 2 at the same time.

[0050] Next, how to seal the bearing 3 in the bearing seat 2 is described in detail:

[0051] Figure 2 and Figure 3The overall sectional structure diagram of the electric spindle after installation is shown.

[0052] As described above, the second fixed spacer ring 5 after installation can rotate on the first fixed spacer ring 4. In order to improve the sealing effect at the rotating joint of the two, as shown in the drawings, a sealing position 6 is formed at the rotating joint of the first fixed spacer ring 4 and the second fixed spacer ring 5 after installation. Specifically, the sealing position 6 includes a first sealing section 611, a second sealing section 612 and a third sealing section 613. The first sealing section 611 is a gap seal, and the second sealing section 612 and the third sealing section 613 are labyrinth seals. Through the gap seal and the labyrinth seal, it is ensured that impurities and cutting fluid and other materials cannot enter the bearing 3, the inside of the bearing 2 is kept clean, and the service life of the bearing 2 is improved. Figure 3

[0053] Specifically, as shown in the drawings, the first fixed spacer ring 4 is formed with a first matching section 411, a second matching section 412 and a third matching section 413 along the sealing path of the sealing position 6, and the second fixed spacer ring 5 is formed with a fourth matching section 511, a fifth matching section 512 and a sixth matching section 513 along the sealing path of the sealing position 6. The first matching section 411 and the fourth matching section 511 cooperate to form the first sealing section 611, the second matching section 412 and the fifth matching section 512 cooperate to form the second sealing section 612, and the third matching section 413 and the sixth matching section 513 cooperate to form the third sealing section 613. Figure 4 Figure 5

[0054] ​​​It is worth mentioning that in order to ensure that the second fixed spacer ring 5 can be smoothly installed on the shaft core 1, the sealing structure formed by the third sealing section 612 and the second sealing section 613 is slightly different, wherein the second sealing section 612 is formed by the cooperation of the second matching section 412 on the first fixed spacer ring 4 and the fifth matching section 512 on the second fixed spacer ring 5, specifically, a plurality of first annular grooves are provided at the second matching section 412, and a plurality of annular teeth matched with the first annular grooves are provided at the fifth matching section 512, and the plurality of annular teeth are embedded in the first annular grooves to form the above-mentioned second sealing section 612; the third sealing section 613 is formed by the cooperation of the third matching section 413 on the first fixed spacer ring 4 and the sixth matching section 513 on the second fixed spacer ring 5, specifically, a plurality of second annular grooves (i.e. a plurality of second annular grooves are provided on the inner ring surface of the first fixed spacer ring 4) are provided at the third matching section 413, and in order to ensure that the second fixed spacer ring 5 can be smoothly installed on the shaft core 1 and embedded in the bearing seat 2, therefore, no annular teeth matched with the second annular grooves are provided at the sixth matching section 513. It needs to be further explained that although no annular teeth matched with the second annular grooves are provided at the third sealing section 613, this sealing section still has good sealing effect, and by providing only the second annular grooves at the third sealing section 613, the sealing effect and the collection effect of impurities are achieved at the same time, specifically, when the shaft core 1 drives the second fixed spacer ring 5 to rotate, the impurities at the third sealing section 613 will be thrown into the second annular grooves at the third sealing section 613 due to the centrifugal force, thereby realizing the collection of impurities, and avoiding the impurities entering the bearing seat 2 along the third sealing section 613 to affect the normal use of the bearing 3.

[0055] The second fixed spacer ring 5 will be described below:

[0056] As described above, the second fixed spacer ring 5 is connected to the shaft core 1 by a threaded connection and seals the bearing 3 in the bearing seat 2.

[0057] As shown in Figure 1 and Figure 5 , a thread 514 is provided on the inner wall of the second fixed spacer ring 5, and a thread groove matched with the thread 514 is provided on the shaft core 1, and rotating the second fixed spacer ring 5 can threadedly connect the second fixed spacer ring 5 to the shaft core 1.

[0058] Specifically, as shown in Figure 6As shown, the thread 514 is composed of a plurality of thread portions, including an inclined section 5141 and a bent section 5142, that is, the thread on the second fixed spacer ring 5 is designed as a profiled thread while ensuring normal rotation of the second fixed spacer ring 5 on the shaft core 1, wherein one end of the inclined section 5141 and the bent section 5142 is formed on the inner wall of the second fixed spacer ring 5 as the bottom of the thread portion, and the other end of the inclined section 5141 and the bent section 5142 is connected as the top of the thread portion, and the positioning effect of the second fixed spacer ring 5 can be improved by the provision of the bent section 5142

[0059] More specifically, the bent section 5142 has a first positioning surface 51421 and a second positioning surface 51422, and when the second fixed spacer ring 5 is subjected to a radial force during operation of the electric spindle, the second positioning surface 51422 can achieve self-locking with the external thread of the shaft core 1, thereby achieving axial positioning.

[0060] As shown in Figure 6 , an included angle a is formed between the inclined section 5141 and the first positioning surface 51421, and an included angle b is formed between the first positioning surface 51421 and the second positioning surface 51422, wherein 60° < a < 90° < b.

[0061] In addition, in order to further ensure the fixed position of the second spacer ring 5, the above-mentioned electric spindle further comprises a third fixed spacer ring 7 embedded in the second fixed spacer ring 5, as shown in Figure 7 and Figure 8 , the third fixed spacer ring 7 has a first annular clamping section 711 and a second annular clamping section 712, wherein the second fixed spacer ring 5 is provided with a first clamping position 515 and a second clamping position 516 adapted to the first annular clamping section 711 and the second annular clamping section 712, and during installation, the third fixed spacer ring 7 is positioned in front of the first clamping position 515 and the second clamping position 516 on the second fixed spacer ring 5, thereby fixing the position of the second fixed spacer ring 5, and the third fixed spacer ring 7 has a simple assembly structure, which ensures the relative position of the first fixed spacer ring 4, the second fixed spacer ring 5 and the third fixed spacer ring 7 on the shaft core 1, reduces the matching grinding of the second fixed spacer ring 5 during assembly, and improves the assembly efficiency.

[0062] It is worth noting that the above-mentioned bearing 3 installed in the bearing seat 2 can also be provided with two bearings 3 in some alternative embodiments, as shown in Figure 1 and Figure 2 , when the bearing seat 2 is provided with two bearings 3, a spacer 8 is provided between the two bearings 3, and the spacer 8 is configured to adjust the distance between the two bearings 3.

[0063] Specifically, the spacer ring 8 comprises an outer spacer ring 811 and an inner spacer ring 812 which are sleeved with each other, wherein the outer spacer ring 811 is attached to the outer ring 311 of the bearing 3, and the inner spacer ring 812 is attached to the inner ring 313 of the bearing.

[0064] To sum up, the electric spindle in the embodiment of the present application has the following beneficial effects compared with the prior art by adopting the above structure:

[0065] In the embodiment of the present application, the first fixed spacer ring 4 and the second fixed spacer ring 5 can be used to adjust the pre-tightening of the bearing 3 during assembly, reduce repeated disassembly and assembly, and improve the efficiency of pre-tightening assembly of the bearing 3.

[0066] In the embodiment of the present application, the structure of the first fixed spacer ring 4 and the second fixed spacer ring 5 can form a three-layer seal, further improve the sealing effect of the bearing 3, prevent impurities or other cutting fluids from entering the inside of the bearing 3, and improve the service life of the bearing 3.

[0067] In the embodiment of the present application, the special-shaped thread structure is designed on the second fixed spacer ring 5, which can prevent the axial movement of the second fixed spacer ring 5 during the rotation of the electric spindle while ensuring the rotation direction, and further ensure the pre-tightening effect of the bearing 3.

[0068] In the embodiment of the present application, the third fixed spacer ring 7 is arranged on the second fixed spacer ring 5, which can ensure the axial position of the electric spindle parts, reduce the repeated matching and grinding of the second fixed spacer ring 5, and improve the assembly efficiency.

[0069] On the other hand, the embodiment of the present application also provides a machine tool, and the above-mentioned electric spindle structure is applied to the machine tool.

[0070] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above-mentioned technical content without departing from the scope of the technical solution of the present application, and any simple modification, equivalent change and modification of the above-mentioned technical content without departing from the scope of the technical solution of the present application are still within the scope of the present application.

Claims

1. An electric spindle, characterized by, The electric spindle comprises a spindle core (1), a bearing seat (2) and a bearing (3) sleeved on the spindle core (1), and the bearing (3) is arranged in the bearing seat (2); The electric spindle further comprises a first fixed spacer ring (4) and a second fixed spacer ring (5) arranged in sequence along the axial direction of the spindle core (1); The bearing seat (2) is provided with an opening side, the first fixed spacer ring (4) is fixedly installed on the opening side of the bearing seat (2) and is configured to preliminarily pre-tighten the bearing (3) in the bearing seat (2); The second fixed spacer ring (5) is threadedly connected to the surface of the spindle core (1) and rotationally matched with the first fixed spacer ring (4), and the second fixed spacer ring (5) is configured to secondarily pre-tighten the bearing (3) in the bearing seat (2) and seal the bearing (3) in the bearing seat (2); The electric spindle further comprises a third fixed spacer ring (7) embedded in the second fixed spacer ring (5), the third fixed spacer ring (7) has a first annular clamping section (711) and a second annular clamping section (712), the second fixed spacer ring (5) is provided with a first clamping position (515) matched with the first annular clamping section (711), and the second fixed spacer ring (5) is further provided with a second clamping position (516) matched with the second annular clamping section (712).

2. The electric spindle according to claim 1, characterized in that, The first fixed spacer ring (4) has a first embedding part (41), and the second fixed spacer ring (5) has a second embedding part (51), when the first fixed spacer ring (4) and the second fixed spacer ring (5) are installed, the first embedding part (41) is embedded in the bearing seat (2) to preliminarily pre-tighten the bearing in the bearing seat (2), and the second embedding part (51) is embedded in the bearing seat (2) to secondarily pre-tighten the bearing in the bearing seat (2).

3. The electric spindle according to claim 2, characterized in that, The bearing (3) comprises an outer ring (311), a ball (312) and an inner ring (313), the first fixed spacer ring (4) acts on the surface of the outer ring (311), and the second fixed spacer ring (5) acts on the surface of the inner ring (313).

4. The electric spindle according to any of claims 1-3, characterized in that, The rotationally matched position of the first fixed spacer ring (4) and the second fixed spacer ring (5) is formed with a sealing position (6), the sealing position (6) comprises a first sealing section (611), a second sealing section (612) and a third sealing section (613), the first sealing section (611) is a gap seal, and the second sealing section (612) and the third sealing section (613) are labyrinth seals.

5. The electric spindle according to claim 4, characterized in that, The first fixed spacer ring (4) is formed with a first matching section (411), a second matching section (412) and a third matching section (413) along the sealing path of the sealing position (6), the second fixed spacer ring (5) is formed with a fourth matching section (511), a fifth matching section (512) and a sixth matching section (513) along the sealing path of the sealing position (6), the first matching section (411) and the fourth matching section (511) cooperate to form the first sealing section (611), the second matching section (412) and the fifth matching section (512) cooperate to form the second sealing section (612), and the third matching section (413) and the sixth matching section (513) cooperate to form the third sealing section (613).

6. The electric spindle according to claim 5, characterized in that, A plurality of first annular grooves are arranged at the second matching section (412), a plurality of annular convex teeth adapted to the first annular grooves are arranged at the fifth matching section (512), and the plurality of annular convex teeth are embedded in the first annular grooves to form the second sealing section (612). A plurality of second annular grooves are arranged at the third matching section (413), and the third sealing section is formed between the second annular grooves and the outer ring surface of the sixth matching section (513).

7. The electric spindle according to claim 6, characterized in that, A screw thread (514) is arranged on the inner wall of the second fixed spacer ring (5), and a screw groove adapted to the screw thread (514) is arranged on the shaft core (1).

8. The electric spindle according to claim 7, characterized in that, The screw thread (514) is composed of a plurality of screw portions, each of which includes an inclined section (5141) and a bent section (5142), one end of each of the inclined section (5141) and the bent section (5142) is formed on the inner wall of the second fixed spacer ring (5) as the bottom of the screw portion, and the other end of each of the inclined section (5141) and the bent section (5142) is connected as the top of the screw portion.

9. The electric spindle according to claim 8, characterized in that, The bent section (5142) has a first positioning surface (51421) and a second positioning surface (51422), an included angle a is formed between the inclined section (5141) and the first positioning surface (51421), and an included angle b is formed between the first positioning surface (51421) and the second positioning surface (51422), wherein 60°<a<90°<b.

10. The electric spindle according to any of claims 5-9, characterized in that, Two bearings (3) are arranged in the bearing seat (2), and a spacer ring (8) is arranged between the two bearings (3) to adjust the distance between the two bearings (3).

11. The electric spindle according to claim 10, characterized in that, The spacer ring (8) includes an outer spacer ring (811) and an inner spacer ring (812) which are sleeved with each other, the outer spacer ring (811) is attached to the outer ring (311) of the bearing (3), and the inner spacer ring (812) is attached to the inner ring (313) of the bearing (3).

12. A machine tool, characterized by The electric spindle comprises the electric spindle according to any one of claims 1-11.

Images