An electric spindle and machine tool

Abstract

The application belongs to the technical field of electric spindles, and particularly relates to an electric spindle and a machine tool. The electric spindle comprises a machine body assembly, a shaft core and an oil injection structure. The machine body assembly is provided with an oil inlet channel and an oil return channel; the shaft core is supported on the machine body assembly through a bearing assembly. One end of the oil injection structure is in communication with the oil inlet channel, and the other end of the oil injection structure is in communication with the inner raceway of the first bearing or the second bearing. A spacer sleeve is arranged between the first bearing and the second bearing and is sleeved on the shaft core. The spacer sleeve is provided with a flow guide channel and a return flow channel which is in communication with the oil return channel. The flow guide channel has an oil throwing slope to guide the waste oil in the first bearing and the second bearing to the return flow channel. The electric spindle and the machine tool of the application set the flow guide channel on the spacer sleeve. The oil throwing slope on the flow guide channel can form forced return flow by using centrifugal force, realize automatic oil return, and prevent old oil and excess oil from affecting bearing lubrication and cooling.

Description

Technical Field

[0001] This application belongs to the field of electric spindle technology, specifically relating to an electric spindle and a machine tool. Background Technology

[0002] With the development of high-speed electric spindles, their rotational speeds are constantly increasing, placing higher demands on the lubrication, cooling, and thermal management of their bearings. Especially in ultra-high-speed oil-pneumatic electric spindles, traditional oil-pneumatic systems typically use independent oil injectors or simple internal oil circuits, which have some inherent defects, such as poor oil return. At ultra-high speeds of tens of thousands of revolutions per minute, the centrifugal force is enormous, and traditional oil return methods are unable to effectively overcome this centrifugal force, causing old oil and oil mist to accumulate in the bearing cavity. This not only fails to remove the heat generated during bearing operation in time, but also generates heat due to the accumulation and stirring of old oil and oil mist in the bearing cavity, causing the spindle bearing temperature to rise, seriously affecting the life and accuracy of the spindle bearing. Summary of the Invention

[0003] The purpose of this application is to at least solve one of the technical problems existing in the prior art, and to provide an electric spindle and machine tool, which realizes automatic oil return by setting a guide channel on the spacer, and the oil throwing slope on the guide channel can form forced backflow by centrifugal force, thereby preventing old oil and excess oil from affecting bearing lubrication and cooling.

[0004] The technical solution adopted by this application to solve its technical problem is:

[0005] In a first aspect, an electric spindle includes:

[0006] The engine body components are equipped with an oil inlet channel and an oil return channel;

[0007] The shaft core is supported by the body assembly via a bearing assembly. The bearing assembly includes a first bearing and a second bearing spaced apart in the vertical direction. A spacer sleeve is provided between the first bearing and the second bearing and fitted onto the shaft core. The spacer sleeve includes an inner ring spacer sleeve and an outer ring spacer sleeve. The inner ring spacer sleeve is fitted onto the outer periphery of the shaft core and has an oil-throwing inclined surface on its outer side. The outer ring spacer sleeve is located on the outer periphery of the inner ring spacer sleeve and forms a guide channel with the inner ring spacer sleeve. The top of the guide channel is connected to the internal raceway of the first bearing, and the bottom of the guide channel is connected to the internal raceway of the second bearing. The outer ring spacer sleeve has a return channel connected to the return oil channel and a waste oil receiving groove connected to the return oil channel on its inner side. The guide channel guides the waste oil in the first bearing and the second bearing to the waste oil receiving groove under the action of centrifugal force through the oil-throwing inclined surface.

[0008] The oil injection structure has one end connected to the oil inlet channel and the other end connected to the internal raceway of the first bearing or the second bearing.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the outer side of the inner ring spacer is provided with a flow guiding protrusion, and the flow guiding protrusion is provided with an inclined surface on the upper and / or lower side to form the oil slinging inclined surface.

[0010] In combination with the first aspect and the above-described implementations, in some implementations of the first aspect, the oil injection structure includes an oil nozzle disposed at the top or bottom of the outer ring spacer, the oil nozzle extending into the internal raceway of the first bearing and / or the second bearing, and communicating with the oil inlet channel.

[0011] In conjunction with the first aspect and the above-described implementations, in some implementations of the first aspect, the oil injection structure further includes an oil injection sleeve, the oil inlet channel includes a first oil inlet channel and a second oil inlet channel, the oil inlet channel is connected to the oil injector through the first oil inlet channel, the oil injector extends into the inner raceway of either the first bearing or the second bearing, the oil injection sleeve is disposed on the outer periphery of the shaft core and located above the first bearing or below the second bearing, the oil injection sleeve has an oil injection channel connected to the second oil inlet channel, and the oil injection channel is connected to the other inner raceway of either the first bearing or the second bearing.

[0012] In conjunction with the first aspect and the above-described implementations, in some implementations of the first aspect, the spacer includes an upper spacer and a lower spacer, the bearing assembly includes an upper bearing assembly and a lower bearing assembly arranged at an interval along the top and bottom, both the upper bearing assembly and the lower bearing assembly include a first bearing and a second bearing, the upper spacer is installed between the first bearing and the second bearing of the upper bearing assembly, and the lower spacer is installed between the first bearing and the second bearing of the lower bearing assembly, both the upper spacer and the lower spacer include an inner ring spacer and an outer ring spacer.

[0013] In combination with the first aspect and the above implementation methods, in some implementation methods of the first aspect, the first oil inlet channel includes a first upper oil inlet channel, the outer ring of the upper partition sleeve is provided with an oil nozzle at the top that communicates with the first upper oil inlet channel, the oil nozzle extends into the internal raceway of the first bearing of the upper bearing assembly, and the outer ring of the upper partition sleeve is provided with a waste oil receiving groove at the bottom.

[0014] The second oil inlet channel includes a second upper oil inlet channel, and the oil injection sleeve includes an upper oil injection sleeve. The upper oil injection sleeve is installed on the machine body assembly and located below the upper bearing assembly. The upper oil injection sleeve extends upward into the internal raceway of the second bearing of the upper bearing assembly. The upper oil injection sleeve is provided with an oil injection channel that communicates with the second upper oil inlet channel.

[0015] In combination with the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, the upper oil spray sleeve is installed between the shaft core and the machine body assembly, and a first guide slope is provided on the top outer side of the upper oil spray sleeve. The first guide slope and the machine body assembly form a guide groove, and the guide groove is connected to the oil return channel.

[0016] In combination with the first aspect and the above implementation methods, in some implementation methods of the first aspect, the first oil inlet channel further includes a first lower oil inlet channel that is separated from the first upper oil inlet channel. The outer ring of the lower partition sleeve is provided with an oil nozzle at the bottom that communicates with the first lower oil inlet channel. The oil nozzle extends into the internal raceway of the second bearing of the lower bearing assembly. The outer ring of the lower partition sleeve is provided with a waste oil receiving groove at the top.

[0017] The second oil inlet channel includes a second lower oil inlet channel that is separated from the second upper oil inlet channel. The oil injection sleeve also includes a lower oil injection sleeve located below the upper oil injection sleeve. The lower oil injection sleeve is installed on the machine body assembly and located above the lower bearing assembly. The lower oil injection sleeve extends downward into the internal raceway of the first bearing of the lower bearing assembly. The lower oil injection sleeve is provided with an oil injection channel that communicates with the second lower oil inlet channel.

[0018] In combination with the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, the shaft core is provided with a locking member and a bearing seat cover below the lower bearing assembly. The bearing seat cover abuts against the lower part of the body assembly and is provided with an oil collection groove communicating with the return channel. The locking member is provided with a second guide slope, which is used to guide the waste oil in the lower bearing assembly to the oil collection groove.

[0019] In a second aspect, a machine tool includes an electric spindle as described in any implementation of the first aspect.

[0020] One of the above technical solutions has at least one of the following advantages or beneficial effects: The electric spindle of this solution, by setting a guide channel on the spacer, utilizes the centrifugal force generated by the high-speed rotation of the inner ring spacer along with the spindle core to create a forced backflow on the oil-throwing slope of the guide channel. This guides the waste oil in the first and second bearings to the waste oil receiving tank, achieving automated oil return and more efficient recovery of old and excess oil. The electric spindle's oil return system has been upgraded from passive flow to forced centrifugation, cleverly transforming the disadvantage of high-speed rotational centrifugal force into the core power for efficient oil return. This prevents old and excess oil from affecting bearing lubrication and cooling, ensuring the accuracy and service life of the spindle bearings. Simultaneously, by adjusting the structure of the oil-throwing slope, the oil volume can be controlled, solving the problem of "oil bath heating" caused by poor oil return at ultra-high speeds. Attached Figure Description

[0021] The following description, in conjunction with the accompanying drawings, further illustrates this application:

[0022] Figure 1 This is a schematic diagram showing the connection between the bearing assembly and the first upper oil inlet channel and the second upper oil inlet channel in one embodiment of this application;

[0023] Figure 2 This is a schematic diagram showing the connection between the bearing assembly and the first lower oil inlet channel and the second lower oil inlet channel in one embodiment of this application;

[0024] Figure 3 This is a partial cross-sectional schematic diagram of an electric spindle according to an embodiment of this application;

[0025] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0026] Figure 5 yes Figure 3 Enlarged diagram of point B in the middle.

[0027] Explanation of icon numbers:

[0028] Machine body assembly 1; shaft core 2; oil return channel 3; first bearing 41; second bearing 42; upper bearing assembly 43; lower bearing assembly 44; guide channel 51; return channel 52; inner ring spacer 531; guide protrusion 5311; outer ring spacer 532; oil injector 5321; upper spacer 54; lower spacer 55; waste oil receiving groove 56; first upper oil inlet channel 61; second upper oil inlet channel 62; first lower oil inlet channel 63; second lower oil inlet channel 64; upper spray sleeve 71; first guide slope 711; guide groove 712; lower spray sleeve 72; locking element 81; second guide slope 811; bearing seat cover 82; oil collection groove 83. Detailed Implementation

[0029] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.

[0030] In this application, when directions (up, down, left, right, front, and back) are described, it is only for the purpose of describing the technical solution of this application, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on this application.

[0031] In this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc. are understood to exclude the stated number; "above," "below," "within," etc. are understood to include the stated number. In the description of this application, the terms "first" and "second" are used only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the order of the indicated technical features.

[0032] In this application, unless otherwise explicitly defined, the terms "setup," "installation," and "connection" should be interpreted broadly. For example, they can refer to direct connection or indirect connection through an intermediate medium; they can refer to fixed connection, detachable connection, or integral molding; they can refer to mechanical connection, electrical connection, or connection capable of mutual communication; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this application based on the specific content of the technical solution.

[0033] See Figures 1 to 5 This application provides an electric spindle, including a body assembly 1, a spindle core 2, and an oil injection structure. The body assembly 1 has an oil inlet channel and an oil return channel 3. The spindle core 2 is supported on the body assembly 1 by a bearing assembly, which includes a first bearing 41 and a second bearing 42 spaced apart in a vertical direction. A spacer sleeve is provided between the first bearing 41 and the second bearing 42 and fitted onto the spindle core 2, allowing the spacer sleeve to rotate with the spindle core 2.

[0034] The sleeve is provided with a guide channel 51 and a return channel 52 connected to the return oil channel 3. The top of the guide channel 51 is connected to the internal raceway of the first bearing 41, and the bottom of the guide channel 51 is connected to the internal raceway of the second bearing 42. The guide channel 51 has an oil-throwing slope to guide the waste oil in the first bearing 41 and the second bearing 42 to the return channel 52, thereby allowing the waste oil in the guide channel 51 to flow through the return channel 52 to the return oil channel 3, and then be discharged from the electric spindle.

[0035] The spacer sleeve can be manufactured as a single piece or assembled from two parts. The spacer sleeve includes an inner ring spacer sleeve 531 and an outer ring spacer sleeve 532. The inner ring spacer sleeve 531 is fitted around the outer circumference of the shaft core 2, and the outer ring spacer sleeve 532 is located around the outer circumference of the inner ring spacer sleeve 531, forming a guide channel 51 between them. The outer ring spacer sleeve 532 has a return channel 52 and an inner waste oil receiving groove 56 communicating with the return channel 52. The outer side of the inner ring spacer sleeve 531 has an oil-throwing slope to guide waste oil from the first bearing 41 and the second bearing 42 to the waste oil receiving groove 56.

[0036] The guide channel 51 guides the waste oil in the first bearing 41 and the second bearing 42 to the waste oil receiving tank 56 under the action of centrifugal force through the oil-throwing inclined surface. With the cooperation of the oil-throwing inclined surface and the waste oil receiving tank 56, the waste oil receiving tank 56 receives the waste oil thrown off by the centrifugal force of the oil-throwing inclined surface, which facilitates the collection of waste oil and makes more efficient use of the centrifugal force generated by the high-speed rotation of the electric spindle to realize the recycling of old oil and excess oil, while improving the reliability of waste oil return.

[0037] One end of the oil injection structure is connected to the oil inlet channel, and the other end of the oil injection structure is connected to the internal raceway of the first bearing 41 or the second bearing 42 to lubricate the internal raceway of the first bearing 41 and the second bearing 42.

[0038] This technical solution utilizes a guide channel 51 on the electric spindle. When the inner ring spacer 531 rotates with the spindle core 2, the centrifugal force generated by the high-speed rotation of the electric spindle forces the oil-throwing slope on the guide channel 51 to create forced backflow. This guides the waste oil in the first bearing 41 and the second bearing 42 to the backflow channel 52, achieving automated oil return and more efficient recovery of old and excess oil. The electric spindle's oil return system has been upgraded from passive flow to forced centrifugation, cleverly transforming the disadvantage of high-speed rotational centrifugal force into the core power for efficient oil return. This prevents old and excess oil from affecting bearing lubrication and cooling, ensuring the accuracy and service life of the spindle bearings. Simultaneously, by adjusting the structure of the oil-throwing slope, the oil volume can be controlled, solving the problem of "oil bath heating" caused by poor oil return at ultra-high speeds.

[0039] See Figure 1 and Figure 2 In some embodiments, the outer side of the inner ring spacer 531 is provided with a guide protrusion 5311. The guide protrusion 5311 has an inclined surface on the upper and / or lower side to form an oil-throwing slope, which facilitates the guidance and throwing of old oil and excess oil in the first bearing 41 and the second bearing 42 into the waste oil receiving tank 56 by centrifugal force. It is understood that the bottom surface of the waste oil receiving tank 56 is an inclined surface or a plane, etc., and can be set according to the actual situation, without limitation here.

[0040] Furthermore, see Figure 1 and Figure 2The oil injection structure includes an oil nozzle 5321 located at the top or bottom of the outer ring spacer 532. The oil nozzle 5321 extends into the internal raceway of the first bearing 41 and / or the second bearing 42 and communicates with the oil inlet channel. The outer ring spacer 532 can directly spray oil and gas into the contact area of ​​the raceway in the first bearing 41 and / or the second bearing 42 that requires lubrication and cooling through the oil nozzle 5321, thereby achieving lubrication and cooling. By using a single spacer component, the three major functions of bearing isolation, oil injection, and waste oil return and guidance can be integrated, which is conducive to the compactness and miniaturization of the overall structure, effectively saving internal space of the spindle and ensuring that the high-speed rotation performance of the electric spindle is not affected.

[0041] Furthermore, see Figure 1 and Figure 2 The oil injection structure also includes an oil injection sleeve. The oil inlet channel includes a first oil inlet channel and a second oil inlet channel. The first oil inlet channel communicates with the oil injector 5321. The oil injector 5321 extends into the internal raceway of either the first bearing 41 or the second bearing 42. The oil injection sleeve is located on the outer periphery of the shaft core 2, above the first bearing 41 or below the second bearing 42. The oil injection sleeve has an oil injection channel communicating with the second oil inlet channel, which in turn communicates with the other internal raceway of either the first bearing 41 or the second bearing 42. By combining the oil injection sleeve and the spacer, the first bearing 41 and the second bearing 42 in the same bearing assembly can be simultaneously lubricated and cooled.

[0042] See Figures 1 to 5 In some embodiments, the spacer includes an upper spacer 54 and a lower spacer 55, and the bearing assembly includes an upper bearing assembly 43 and a lower bearing assembly 44 spaced vertically. Both the upper bearing assembly 43 and the lower bearing assembly 44 include a first bearing 41 and a second bearing 42. An upper spacer 54 is installed between the first bearing 41 and the second bearing 42 of the upper bearing assembly 43, and a lower spacer 55 is installed between the first bearing 41 and the second bearing 42 of the lower bearing assembly 44. Both the upper spacer 54 and the lower spacer 55 include an inner ring spacer 531 and an outer ring spacer 532. By providing multiple bearing assemblies and spacers within the electric spindle, the stability of the electric spindle, as well as the efficient and controllable lubrication, cooling, and oil return of each bearing assembly, are effectively ensured.

[0043] Further, see Figure 1 The first oil inlet channel includes a first upper oil inlet channel 61. The outer ring spacer 532 of the upper spacer 54 is provided with an oil nozzle 5321 at the top that communicates with the first upper oil inlet channel 61. The oil nozzle 5321 extends into the inner raceway of the first bearing 41 of the upper bearing assembly 43. The outer ring spacer 532 of the upper spacer 54 is provided with a waste oil receiving groove 56 at the bottom.

[0044] The second oil inlet channel includes a second upper oil inlet channel 62, and the oil spray sleeve includes an upper oil spray sleeve 71. The upper oil spray sleeve 71 is installed on the machine body assembly 1 and located below the upper bearing assembly 43. The upper oil spray sleeve 71 extends upward into the internal raceway of the second bearing 42 of the upper bearing assembly 43, and the upper oil spray sleeve 71 is provided with an oil spray channel communicating with the second upper oil inlet channel 62. Through the combined arrangement of the outer ring spacer 532 of the upper spacer 54 and the upper oil spray sleeve 71, lubrication and cooling of the ball contact area inside the first bearing 41 and the second bearing 42 of the upper bearing assembly 43 can be achieved.

[0045] Further, see Figure 2 The first oil inlet channel also includes a first lower oil inlet channel 63 that is separated from the first upper oil inlet channel 61. The outer ring spacer 532 of the lower spacer 55 is provided with an oil nozzle 5321 at the bottom that communicates with the first lower oil inlet channel 63. The oil nozzle 5321 extends into the inner raceway of the second bearing 42 of the lower bearing assembly 44. The outer ring spacer 532 of the lower spacer 55 is provided with a waste oil receiving groove 56 at the top.

[0046] The second oil inlet channel also includes a second lower oil inlet channel 64, which is separated from the second upper oil inlet channel 62. The oil spray sleeve also includes a lower oil spray sleeve 72 located below the upper oil spray sleeve 71. The lower oil spray sleeve 72 is installed on the machine body assembly 1 and is located above the lower bearing assembly 44. The lower oil spray sleeve 72 extends downward into the internal raceway of the first bearing 41 of the lower bearing assembly 44. The lower oil spray sleeve 72 is provided with an oil spray channel communicating with the second lower oil inlet channel 64. Through the combined arrangement of the outer ring spacer 532 of the lower spacer 55 and the lower oil spray sleeve 72, lubrication and cooling of the ball contact area inside the first bearing 41 and the second bearing 42 of the lower bearing assembly 44 can be achieved.

[0047] See Figure 1 , Figure 3 and Figure 4 In some embodiments, the upper oil spray sleeve 71 is installed between the shaft core 2 and the machine body assembly 1. The top outer side of the upper oil spray sleeve 71 is provided with a first guide slope 711, and a guide groove 712 is formed between the first guide slope 711 and the machine body assembly 1. The guide groove 712 is connected to the oil return channel 3. The first guide slope 711 is used to guide the old oil and excess oil in the upper bearing assembly 43 to the guide groove 712, and then the old oil and excess oil are recovered through the oil return channel 3, effectively ensuring that the old oil in the upper bearing assembly 43 can be recovered more thoroughly.

[0048] See Figure 2 , Figure 3 and Figure 5In some embodiments, the shaft core 2 is provided with a locking member 81 and a bearing seat cover 82 below the lower bearing assembly 44. The bearing seat cover 82 abuts against the lower part of the body assembly 1 and is provided with an oil collection groove 83 communicating with the return channel 52. The locking member 81 is provided with a second guide slope 811. The second guide slope 811 is used to guide the old oil and excess oil in the lower bearing assembly 44 to the oil collection groove 83, so that the old oil and excess oil can be recycled through the return channel 3, effectively ensuring that the old oil in the lower bearing assembly 44 can be recycled more thoroughly.

[0049] The present invention also provides a machine tool including the electric spindle of any of the above embodiments.

[0050] In the description of this specification, references to terms such as "example," "embodiment," or "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of this application, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. An electric spindle, characterized by, The application relates to a bearing assembly of a rotating machine. The bearing assembly comprises a machine body assembly provided with an oil inlet channel and an oil return channel; an axle core supported by a bearing assembly on the machine body assembly, the bearing assembly comprising a first bearing and a second bearing arranged in a spaced manner along an up-down direction, a spacer sleeve sleeved on the axle core arranged between the first bearing and the second bearing, the spacer sleeve comprising an inner ring spacer sleeve and an outer ring spacer sleeve, the inner ring spacer sleeve sleeved on the outer periphery of the axle core and provided with an oil throwing inclined surface on the outer side, the outer ring spacer sleeve located on the outer periphery of the inner ring spacer sleeve and formed with a flow guide channel between the inner ring spacer sleeve, the top of the flow guide channel communicated with the inner raceway of the first bearing, the bottom of the flow guide channel communicated with the inner raceway of the second bearing, the outer ring spacer sleeve provided with a return flow channel communicated with the oil return channel and provided with a waste oil receiving groove communicated with the return flow channel on the inner side, the flow guide channel guiding the waste oil in the first bearing and the second bearing to the waste oil receiving groove under the action of centrifugal force through the oil throwing inclined surface. The bearing assembly further comprises an oil injection structure, one end of the oil injection structure communicated with the oil inlet channel, the other end of the oil injection structure communicated with the inner raceway of the first bearing or the second bearing. The outer side of the inner ring spacer sleeve is provided with a flow guide protrusion, the flow guide protrusion provided with an inclined surface on the upper side and / or the lower side, forming the oil throwing inclined surface.

2. The electric spindle according to claim 1, characterized in that, The oil injection structure comprises an oil injection nozzle arranged on the top or the bottom of the outer ring spacer sleeve, the oil injection nozzle extended into the inner raceway of the first bearing and / or the second bearing and communicated with the oil inlet channel.

3. The electrospindle according to claim 1 or 2, characterized in that, The oil injection structure further comprises an oil injection sleeve, the oil inlet channel comprises a first oil inlet channel and a second oil inlet channel, the oil inlet channel communicated with the oil injection nozzle through the first oil inlet channel, the oil injection nozzle extended into any one of the inner raceways of the first bearing and the second bearing, the oil injection sleeve arranged on the outer periphery of the axle core and located above the first bearing or below the second bearing, the oil injection sleeve provided with an oil injection channel communicated with the second oil inlet channel, the oil injection channel communicated with the other one of the inner raceways of the first bearing and the second bearing.

4. The electric spindle according to claim 3, characterized in that, The spacer sleeve comprises an upper spacer sleeve and a lower spacer sleeve, the bearing assembly comprises an upper bearing assembly and a lower bearing assembly arranged in a spaced manner along an up-down direction, the upper bearing assembly and the lower bearing assembly both comprising the first bearing and the second bearing, the upper spacer sleeve mounted between the first bearing and the second bearing of the upper bearing assembly, the lower spacer sleeve mounted between the first bearing and the second bearing of the lower bearing assembly, the upper spacer sleeve and the lower spacer sleeve both comprising the inner ring spacer sleeve and the outer ring spacer sleeve.

5. The electric spindle according to claim 4, characterized in that, The first oil inlet channel comprises a first upper oil inlet channel, the outer ring spacer sleeve of the upper spacer sleeve provided with the oil injection nozzle communicated with the first upper oil inlet channel on the top, the oil injection nozzle extended into the inner raceway of the first bearing of the upper bearing assembly, the outer ring spacer sleeve of the upper spacer sleeve provided with the waste oil receiving groove on the bottom.

6. The electric spindle according to claim 5, characterized in that, The outer ring spacer sleeve of the lower spacer sleeve provided with the oil injection nozzle communicated with the second oil inlet channel on the top, the oil injection nozzle extended into the inner raceway of the second bearing of the lower bearing assembly, the outer ring spacer sleeve of the lower spacer sleeve provided with the waste oil receiving groove on the bottom. The second oil inlet channel comprises a second upper oil inlet channel, the oil injection sleeve comprises an upper oil injection sleeve, the upper oil injection sleeve is installed on the machine body assembly and is located below the upper bearing assembly, the upper oil injection sleeve extends into the inner raceway of the second bearing of the upper bearing assembly, and the upper oil injection sleeve is provided with the oil injection channel connected with the second upper oil inlet channel.

7. The electric spindle according to claim 6, characterized in that, The upper oil injection sleeve is installed between the shaft core and the machine body assembly, the top outer side of the upper oil injection sleeve is provided with a first flow guide slope, a flow guide groove is formed between the first flow guide slope and the machine body assembly, and the flow guide groove is connected with the oil return channel.

8. The electric spindle according to claim 6, characterized in that, The first oil inlet channel further comprises a first lower oil inlet channel which is separately arranged from the first upper oil inlet channel, the outer ring spacer of the lower spacer is provided with the oil injection nozzle connected with the first lower oil inlet channel at the bottom, the oil injection nozzle extends into the inner raceway of the second bearing of the lower bearing assembly, and the outer ring spacer of the lower spacer is provided with the waste oil receiving groove at the top. The second oil inlet channel further comprises a second lower oil inlet channel which is separately arranged from the second upper oil inlet channel, the oil injection sleeve further comprises a lower oil injection sleeve located below the upper oil injection sleeve, the lower oil injection sleeve is installed on the machine body assembly and is located above the lower bearing assembly, the lower oil injection sleeve extends into the inner raceway of the first bearing of the lower bearing assembly, and the lower oil injection sleeve is provided with the oil injection channel connected with the second lower oil inlet channel.

9. The electric spindle according to claim 8, characterized in that, The shaft core is provided with a locking member and a bearing seat gland below the lower bearing assembly, the bearing seat gland abuts against the lower side of the machine body assembly and is provided with an oil collecting groove connected with the oil return channel, and the locking member is provided with a second flow guide slope for guiding the waste oil in the lower bearing assembly to the oil collecting groove.

10. A machine tool, characterized by The electric spindle comprises the electric spindle according to any one of claims 1 to 9.

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