WO2020125061A1

WO2020125061A1 - Electric spindle and motor

Info

Publication number: WO2020125061A1
Application number: PCT/CN2019/103504
Authority: WO
Inventors: 何圳涛; 耿继青; 刘永连
Original assignee: 珠海格力电器股份有限公司
Priority date: 2018-12-20
Filing date: 2019-08-30
Publication date: 2020-06-25
Also published as: CN109586498A

Abstract

An electric spindle and a motor; the electric spindle comprises a spindle core (1) and a bearing shaft core (15); the spindle core (1) is hollow, the bearing shaft core (15) is sleeved within the spindle core (1) by means of a bearing, a bearing outer ring of the bearing is fixedly connected to the spindle core (1), and a bearing inner ring of the bearing is fixedly connected to the bearing shaft core (15). The described electric spindle is capable of effectively solving the problem in which a bearing heats up and is severely worn out when an electric spindle is at a high rotational speed, which thereby increases the maximum rotational speed of the electric spindle.

Description

Electric spindle and motor

This application requires the priority of the patent application filed with the State Intellectual Property Office of China on December 20, 2018, with the application number 201811567256.5 and the invention titled "Electric Spindle and Motor".

Technical field

This application belongs to the technical field of motors, and specifically relates to an electric spindle and a motor.

Background technique

There are two key technologies in the electric spindle industry-bearings and motors. At present, high-performance electric spindle motors can provide higher limit speeds and powers. However, the speeds and powers actually used on machine tools are not high, limiting their high speeds. And the key components of high power are bearings, especially the electric spindle of grease lubricated bearings, the speed limit is very obvious. As the speed of the motor increases, the centrifugal force and gyroscopic moment of the bearing ball increase rapidly, and the heat generation phenomenon of the bearing is very obvious, while the centrifugal force and gyroscopic moment of the ball have a positive correlation with the bearing diameter.

The bearing of the electric spindle plays a key role in the performance of the electric spindle. The larger the performance index DmN value (Dm is the middle diameter of the bearing and N is the limiting speed of the spindle), the higher the performance of the electric spindle, under the same DmN value, The smaller the diameter of the bearing, the higher the limit speed can be achieved. However, the current bearing arrangement of the main shaft is that the inner ring of the bearing is fixed on the rotating shaft and rotates with the rotating shaft, and the outer ring is fixed on the cooling jacket of the housing. Due to the large diameter of the rotating shaft, the diameter of the bearing is also large, which greatly limits The increase of the spindle's limit speed.

Summary of the invention

Therefore, the technical problem to be solved by the present application is to provide an electric spindle and a motor, which can effectively solve the problem of serious bearing heating and wear at high rotation speed of the electric spindle, and increase the limit rotation speed of the electric spindle.

In order to solve the above problems, the present application provides an electric spindle, which includes a rotating shaft core and a bearing shaft core, the rotating shaft core is hollow, the bearing shaft core is set in the rotating shaft core through a bearing sleeve, and the bearing outer ring of the bearing is fixed to the rotating shaft core Connection, the bearing inner ring of the bearing is fixedly connected with the bearing shaft core.

Preferably, the bearing includes a front end bearing provided at the front end of the bearing shaft core and a rear end bearing provided at the rear end of the bearing shaft core.

Preferably, there are two front-end bearings and two front-end bearings are arranged side by side; or, there are two rear-end bearings and two rear-end bearings are arranged side by side; or, there are two front-end bearings and two front-end bearings are arranged side by side; and the rear There are two end bearings, and the two rear bearings are arranged side by side.

Preferably, one end of the front-end bearing is provided with a first fastener, the other end of the front-end bearing is provided with a second fastener, the first fastener is fixedly arranged on the bearing shaft core, and forms a bearing inner ring of the front-end bearing For axial stop, the second fastener is fixedly arranged in the inner hole of the shaft core of the rotating shaft, and forms an axial stop for the outer ring of the bearing of the front end bearing.

Preferably, the second fastener is disposed at the end of the front bearing away from the rear bearing, and a stop flange is also provided on the bearing shaft core, and the stop flange stops at the end of the front bearing away from the rear bearing.

Preferably, an annular protrusion is provided on the inner peripheral wall of the shaft core of the rotating shaft, and the bearing outer rings of the front-end bearing and the rear-end bearing are stopped on the annular protrusion.

Preferably, the bearing shaft core is a stepped shaft, including a first shaft segment and a second shaft segment, the front bearing is sleeved on the first shaft segment, and the rear bearing sleeve is sleeved on the second shaft segment, the first shaft segment and the second shaft segment The diameters of the two shaft sections vary.

Preferably, at least one of the first fastener and the second fastener is a fastening nut.

Preferably, one end of the rear-end bearing is provided with a third fastener, and the other end of the rear-end bearing is provided with a fourth fastener, both the third fastener and the fourth fastener are provided on the bearing shaft core, and An axial limit is formed on the bearing inner ring of the rear-end bearing.

Preferably, at least one of the third fastener and the fourth fastener is a fastening nut.

Preferably, the rear end of the bearing shaft core is fixedly connected with an end cover of the shaft core.

Preferably, the rear end of the bearing shaft core is fixedly connected to the end cover of the shaft core through a plurality of bolts uniformly arranged circumferentially around the central axis of the bearing shaft core.

Preferably, the shaft core end cover is provided with a weight reduction hole.

Preferably, the shaft core end cover includes an end plate, and a plurality of weight-reducing holes are evenly distributed on the end plate along the circumferential direction.

Preferably, the total area of the weight reduction holes accounts for 30% to 50% of the total area of the end plate.

Preferably, the outer cover of the rotating shaft core is provided with a rear end flange end cover, and the shaft core end cover is fixedly connected to the rear end flange end cover.

Preferably, the end cover of the shaft core is sleeved outside the end cover of the rear end flange, the peripheral wall of the end cover of the shaft core is provided with a radial connection hole, and the end cover of the shaft core is connected to the rear end method by a bolt provided in the radial connection hole The blue end cover is fixedly connected.

Preferably, the radial connection hole is a waist-shaped hole, and the waist-shaped hole extends in the axial direction of the shaft core end cover.

According to another aspect of the present application, there is provided a motor including an electric spindle, which is the aforementioned electric spindle.

The electric main shaft provided by the present application includes a rotating shaft core and a bearing shaft core, the rotating shaft core is hollow, the bearing shaft core is set in the rotating shaft core through a bearing sleeve, the bearing outer ring of the bearing is fixedly connected to the rotating shaft core, and the bearing inside the bearing The ring is fixedly connected with the bearing shaft core. The electric main shaft sets the bearing shaft core in the rotating shaft core, so that the bearing is located inside the rotating shaft core, the bearing outer ring is fixed on the rotating shaft core to withstand the high-speed rotation of the main shaft, and the bearing inner ring is fixed to the electric main shaft through the bearing shaft core Part of the connection is fixed, so that the diameter value of the entire bearing can be greatly reduced, effectively solving the problem of serious bearing heating and wear at high speeds of the electric spindle, and increasing the limit speed of the electric spindle.

BRIEF DESCRIPTION

1 is a schematic structural diagram of an electric spindle according to an embodiment of this application;

FIG. 2 is a schematic sectional view taken along line A-A of FIG. 1;

FIG. 3 is a schematic structural side view of an electric spindle according to an embodiment of the present application;

4 is a schematic diagram of a three-dimensional structure of an electric spindle according to an embodiment of the present application.

The reference signs are expressed as:

1. Shaft core; 2. Front sealing flange; 3. Front flange end cover; 4. Cooling sleeve; 5. Front fastening nut; 6. Motor stator; 7. Motor rotor; 8. Motor rotor spacer ring; 9. Motor rotor fastening nut; 10. Rear end flange end cover; 11. Motor encoder; 12. Rear end sealing flange; 13. Rear end fastening nut; 14. Shaft core end cover; 15. Bearing shaft Core; 16, third fastener; 17, rear-end bearing; 18, fourth fastener; 19, first fastener; 20, front-end bearing; 21, second fastener; 22, stop protrusion Edge; 23, first shaft section; 24, second shaft section; 25, radial connection hole; 26, weight reduction hole.

detailed description

Referring to FIGS. 1 to 4, according to an embodiment of the present application, the electric spindle includes a rotating shaft core 1 and a bearing shaft core 15, the rotating shaft core 1 is hollow, and the bearing shaft core 15 is disposed in the rotating shaft core 1 through a bearing sleeve. The bearing outer ring of the bearing is fixedly connected to the rotating shaft core 1, and the bearing inner ring of the bearing is fixedly connected to the bearing shaft core 15.

The electric main shaft sets the bearing shaft core 15 in the rotating shaft core 1, so that the bearing is located inside the rotating shaft core 1, the bearing outer ring is fixed on the rotating shaft core 1 to withstand the high-speed operation of the main shaft, and the bearing inner ring passes through the bearing shaft core 15 and The fixed part of the electro-spindle is fixedly connected, so that the median diameter of the entire bearing can be greatly reduced, which effectively solves the problem of serious bearing heating and wear at high speeds of the electro-spindle, and increases the limit speed of the electro-spindle. The middle diameter of the bearing = (outer diameter of bearing + inner diameter of bearing)/2.

Rolling element linear velocity v = rω = π·d·n/60, where d is the bearing diameter and n is the spindle speed. When the spindle speed is the same, the smaller the value of the bearing diameter d, the calculated rolling element linear velocity The smaller the v, the lower the contact stress between the rolling element and the inner and outer ring raceways of the bearing. Therefore, under the same standard value of the maximum contact stress (about 1700MPa for the rolling bearing), the higher the upper limit of the speed that the spindle can reach, that is, the more the limit speed of the spindle high.

Through the above method, the limit speed of the electric spindle bearing can be greatly broken, the entire electric spindle can achieve higher power and speed, and the high power and high speed performance of the motor can be exerted to a greater extent, which can improve the processing efficiency and the surface quality of the processed parts. . The increase of the limit speed can be widely used in high-speed occasions to avoid oil and gas contamination of the workpiece, such as graphite machine tools.

The bearing includes a front-end bearing 20 provided at the front end of the bearing shaft core 15 and a rear-end bearing 17 provided at the rear end of the bearing shaft core 15. By providing bearings at the front and rear ends of the bearing shaft core 15 and rotating shaft core 1 to achieve rotational connection, the stability of the support structure between the rotating shaft core 1 and the bearing shaft core 15 can be improved.

Preferably, there are two front-end bearings 20, which are arranged side by side; and two rear-end bearings 17, which are arranged side by side. Two front-end bearings 20 are arranged side by side, and two rear-end bearings 17 are arranged side by side, which can further improve the stability of the bearing installation structure and improve the stability and reliability of the bearing to the rotation support structure between the bearing shaft 15 and the rotating shaft core 1 Sex. In other optional embodiments, it may also be arranged such that there are two front-end bearings 20 and two front-end bearings are arranged side by side; or two rear-end bearings 17 and two rear-end bearings 17 are arranged side by side.

As shown in FIG. 2, one end of the front end bearing 20 is provided with a first fastener 19, the other end of the front end bearing 20 is provided with a second fastener 21, and the first fastener 19 is fixedly provided on the bearing shaft 15, An axial stop is formed on the bearing inner ring of the front end bearing 20, the second fastener 21 is fixedly disposed in the inner hole of the rotating shaft core 1, and an axial stop is formed on the bearing outer ring of the front end bearing 20.

The first fastener 19 and the second fastener 21 cooperate with each other to form axial limits on the bearing inner ring and the bearing outer ring of the front bearing 20 from both ends of the front bearing 20, to ensure the installation position of the front bearing 20 Accuracy and reliability, and at the same time effectively prevent the axial displacement of the front-end bearing 20 during operation, and improve the stability of the axial relative position between the bearing shaft core 15 and the rotating shaft core 1.

Preferably, at least one of the first fastener 19 and the second fastener 21 is a fastening nut, so that the locking performance of the fastening nut can be used to provide a pre-tightening force for the installation of the front end bearing 20, and can be adjusted as needed This preload force effectively fixes the front bearing 20. In this embodiment, the first fastener 19 is a fastening nut, which has an internal thread, and is sleeved on the bearing shaft core 15 to form a bearing inner ring at the end of the front end bearing 20 close to the rear end bearing 17 Fixed axially. The second fastener 21 is a fastening nut, which has an external thread and is sleeved in the inner hole of the rotating shaft core 1 so as to form an axial direction on the outer ring of the bearing at the end of the front bearing 20 away from the rear bearing 17 fixed.

In the actual work process, only one of the first fastener 19 and the second fastener 21 may be a fastening nut and the other is a positioning ring, so that on the basis of reducing the installation difficulty and processing cost, the The installation of the front bearing 20 provides sufficient preload.

Preferably, as shown in FIG. 2, the second fastener 21 is provided at the end of the front bearing 20 away from the rear bearing 17, and a stop flange 22 is also provided on the bearing shaft 15, and the stop flange 22 stops at The front end bearing 20 is away from the end of the rear end bearing 17. The stop flange 22 stops on the inner ring of the front bearing 20 away from the rear bearing 17. After the front bearing 20 is fixed by the first fastener 19 and the second fastener 21, the front bearing 20 The bearing shaft core 15 forms an axial stop, which prevents axial displacement of the bearing shaft core 15 relative to the front-end bearing 20 during operation, and improves the stability and reliability of the bearing shaft 15 installation structure.

Preferably, the inner peripheral wall of the rotating shaft core 1 is provided with an annular protrusion, and the bearing outer rings of the front-end bearing 20 and the rear-end bearing 17 are stopped on the annular protrusion. By providing an annular protrusion on the inner peripheral wall of the rotating shaft core 1, the axial outer limit of the bearing outer ring of the front-end bearing 20 and the rear-end bearing 17 can be formed by the annular protrusion without adding a new bearing outer ring limit The structure simplifies the processing procedure and reduces the processing cost. Preferably, an annular protrusion may also be provided on the outer peripheral wall of the bearing shaft core 15, so that an axial stop limit position is formed on the inner ring of the bearing by the annular protrusion provided on the outer peripheral wall of the bearing shaft core 15.

In this embodiment, as shown in FIG. 2, the bearing shaft core 15 is a stepped shaft, including a first shaft section 23 and a second shaft section 24, a front bearing 20 is sleeved on the first shaft section 23, and a rear bearing 17 The second shaft section 24 is sleeved, and the diameters of the first shaft section 23 and the second shaft section 24 are different.

As shown in FIG. 2, preferably, one end of the rear-end bearing 17 is provided with the third fastener 16, and the other end of the rear-end bearing 17 is provided with the fourth fastener 18, the third fastener 16 and the fourth fastener The fasteners 18 are all provided on the bearing shaft core 15 and form an axial limit to the bearing inner ring of the rear-end bearing 17.

Preferably, at least one of the third fastener 16 and the fourth fastener 18 is a fastening nut, so that the locking performance of the fastening nut can be used to provide a pre-tightening force for the installation of the rear-end bearing 17 and can be as required Adjusting this pre-tensioning force effectively fixes the rear end bearing 17. In this embodiment, the third fastener 16 is a fastening nut, and the fourth fastener 18 is a bearing positioning ring. The bearing positioning ring is fixedly sleeved on the bearing shaft core 15 and forms an axial limit on the rear end bearing 17 Bit.

Preferably, the diameter of the first shaft section 23 is larger than the diameter of the second shaft section 24. Since both ends of the front-end bearing 20 and the rear-end bearing 17 are provided with fasteners, it is necessary to install fasteners in the process of installing the front-end bearing 20 and the rear-end bearing 17, if the bearing shaft 15 adopts an equal-diameter structure , During the installation process, some fasteners need to be operated from one end of the bearing shaft core 15 through the tool to the installation position of the other end of the bearing shaft core 15, the operation structure is complicated, the installation process is complicated, it is not easy to operate, and the installation The efficiency is low. In this embodiment, a stepped shaft structure is adopted. When installing the fastener, the front end bearing 20 can be first sleeved on the bearing shaft core 15, and then the first fastener 19 can be removed from the bearing shaft core 15. The second shaft section 24 is installed and mounted on the first shaft section 23. Since the diameter of the second shaft section 24 is smaller than that of the first shaft section 23, the first fastener 19 is removed from the second shaft section 24 When passing by, it does not require tools to operate, and can directly reach the position of the first shaft section 23, so the installation process of the first fastener 19 can be simplified, the installation difficulty of the first fastener 19 can be reduced, and the first tightening can be improved Installation efficiency of firmware 19.

Preferably, as shown in FIG. 2, a shaft core end cover 14 is fixedly connected to the rear end of the bearing shaft core 15. By providing the shaft core end cover 14, the installation foundation for the fixed installation of the bearing shaft core 15 can be provided, which is convenient for the bearing shaft core 15 to be fixedly installed on the non-rotating structure of the electric spindle, so as to realize the rotation shaft core 1 relative to the bearing shaft core 15 Turn the setting.

The rear end of the bearing shaft core 15 is fixedly connected to the shaft core end cover 14 by a plurality of bolts uniformly arranged circumferentially around the central axis of the bearing shaft core 15. The bearing shaft core 15 is fixedly connected to the shaft core end cover 14 through a plurality of bolts, which can enhance the connection strength between the bearing shaft core 15 and the shaft core end cover 14 and improve the coaxiality between the bearing shaft core 15 and the rotating shaft core 1 Degree, improve the bearing capacity and anti-deformation capacity of the bearing shaft core 15, and improve the stability of the matching structure between the bearing shaft core 15 and the rotating shaft core 1.

Preferably, as shown in FIGS. 1 and 4, the shaft end cover 14 is provided with a weight-reducing hole 26, which can reduce the quality of the shaft end cover 14, and at the same time provide a path for drawing out the main shaft circuit, which facilitates the circuit design of the electric main shaft.

Preferably, the shaft core end cover 14 includes an end plate, and a plurality of weight-reducing holes 26 are evenly distributed on the end plate along the circumferential direction, which can ensure that the structural strength of each position of the shaft core end cover 14 is balanced, and improve the shaft core end cover 14 Stability of supporting structure.

Preferably, the total area of the weight reduction holes 26 accounts for 30% to 50% of the total area of the end plate, which can not only ensure sufficient weight reduction quality, but also ensure that the structural strength of the shaft core end cover 14 is not affected.

In this embodiment, the outer periphery of the rotating shaft core 1 is provided with a rear end flange end cover 10, and the shaft end cover 14 is fixedly connected to the rear end flange end cover 10. Specifically, the electro-spindle also includes a cooling jacket 4, the rear end flange end cover 10 is fixedly stopped on the end surface of the cooling jacket 4 through the rear end sealing flange 12, and the rear end sealing flange 12 is provided on the rotating shaft core 1 The rear-end fastening nut 13 of the outer periphery is fixed on the rotating shaft core 1, and a mounting cavity is formed between the rear-end sealing flange 12 and the shaft core end cover 14, and a motor encoder 11 is installed in the mounting cavity.

As shown in FIG. 3, the shaft core end cover 14 is sleeved outside the rear flange end cover 10, and the peripheral wall of the shaft core end cover 14 is provided with a radial connection hole 25. The shaft core end cover 14 is connected in the radial direction The bolt in the hole 25 is fixedly connected with the rear flange end cover 10.

Preferably, the radial connecting hole 25 is a waist-shaped hole, and the waist-shaped hole extends along the axial direction of the shaft end cover 14. By providing an axially extending waist-shaped hole, the gap between the shaft core end cover 14 and the bearing shaft core 15 can be easily adjusted, thereby facilitating the fixed installation of the bearing shaft core 15 on the shaft core end cover 14.

The above-mentioned bearing is, for example, a rolling bearing.

As shown in FIG. 2, the electric spindle further includes a front end sealing flange 2, a front end flange end cover 3, a front end fastening nut 5, a motor stator 6, a motor rotor 7, a motor rotor spacer ring 8, and a motor rotor fastening nut 9.

The front end sealing flange 2 and the front end flange end cover 3 are sleeved on the rotating shaft core 1 and fixed with a front end fastening nut 5. The motor rotor 7 is sleeved on the rotating shaft core 1 and fixed by the motor rotor spacer ring 8 and the motor rotor fastening nut 9 to finally form a rotating shaft core assembly. The motor stator 6 is sleeved on the cooling sleeve 4 to form a cooling sleeve ligand.

The rotating shaft core assembly obtained in the previous step is sleeved on the cooling sleeve ligand, the front end flange end cover 3 and the cooling sleeve 4 are fixed with nuts, and the rear end flange end cover 10 and the cooling sleeve 4 are fixed with nuts.

The motor encoder 11 is sleeved on the rear end sealing flange 12 to form a motor encoder assembly. The whole is sleeved on the rotating shaft core 1 and fixed with a rear end fastening nut 13.

The bearing inner ring of the front end bearing 20 is fixed to the bearing shaft core 15, the pre-tightening force is adjusted and fixed by the first fastener 19, the fourth fastener 18 is fixed to the bearing shaft core 15 using a measuring tool, and the front end bearing is fixed by tooling The bearing outer ring of 20 is fixed to the rotating shaft core 1, and its pretension is adjusted and fixed by the second fastener 21.

The rear-end bearing 17 is integrally pressed into the rotating shaft core 1 and the bearing shaft core 15 by hot pressing, and the pretension of the third fastener 16 is adjusted and fixed.

The inner wall of the shaft end cover 14 is in contact with the end surface of the bearing shaft core 15 and the rear end flange end cover 10 respectively, and is fixed to the bearing shaft core 15 and the rear end flange end cover 10 by screws, and the shaft end cover 14 has a waist hole The structure can eliminate the machining error of the parts and the clearance error caused by the assembly of the bearing shaft core 15, the front end bearing 20, the rear end bearing 17 and the rotating shaft core 1.

According to an embodiment of the present application, the motor includes an electric spindle, which is the aforementioned electric spindle.

It is easily understood by those skilled in the art that the above-mentioned advantageous methods can be freely combined and superimposed on the premise of no conflict.

The above are only the preferred embodiments of this application and are not intended to limit this application. Any modification, equivalent replacement and improvement made within the spirit and principle of this application should be included in the scope of protection of this application Inside. The above are only the preferred embodiments of the present application. It should be noted that those of ordinary skill in the art can make several improvements and modifications without departing from the technical principles of the present application. These improvements and modifications should also It is regarded as the scope of protection of this application.

Claims

An electric spindle is characterized by comprising a rotating shaft core (1) and a bearing shaft core (15), the rotating shaft core (1) is hollow, and the bearing shaft core (15) is arranged on the rotating shaft through a bearing sleeve In the shaft core (1), the bearing outer ring of the bearing is fixedly connected to the rotating shaft core (1), and the bearing inner ring of the bearing is fixedly connected to the bearing shaft core (15).
The electric spindle according to claim 1, wherein the bearing includes a front end bearing (20) disposed at a front end of the bearing shaft core (15) and a rear end disposed at a rear end of the bearing shaft core (15) Rear bearing (17).
The electro-spindle according to claim 2, wherein

There are two front-end bearings (20), and the two front-end bearings (20) are arranged side by side;

Alternatively, there are two rear-end bearings (17), and the two rear-end bearings (17) are arranged side by side;

Alternatively, there are two front-end bearings (20), and the two front-end bearings (20) are arranged side by side; and there are two rear-end bearings (17), and the two rear-end bearings (17) are arranged side by side .
The electric spindle according to claim 2, characterized in that one end of the front end bearing (20) is provided with a first fastener (19), and the other end of the front end bearing (20) is provided with a second fastening (21), the first fastener (19) is fixedly arranged on the bearing shaft core (15), and forms an axial stop for the bearing inner ring of the front end bearing (20), the first Two fasteners (21) are fixedly arranged in the inner hole of the rotating shaft core (1), and form an axial stop for the bearing outer ring of the front end bearing (20).
The electric spindle according to claim 4, wherein the second fastener (21) is provided at an end of the front-end bearing (20) away from the rear-end bearing (17), and the bearing shaft core (15) A stop flange (22) is also provided, and the stop flange (22) stops at an end of the front-end bearing (20) away from the rear-end bearing (17).
The electric spindle according to claim 2, characterized in that an annular protrusion is provided on the inner peripheral wall of the rotating shaft core (1), bearings of the front end bearing (20) and the rear end bearing (17) The outer ring is stopped on the annular protrusion.
The electric spindle according to claim 2, wherein the bearing shaft core (15) is a stepped shaft, including a first shaft section (23) and a second shaft section (24), and the front-end bearing (20) Sleeved on the first shaft section (23), the rear end bearing (17) is sleeved on the second shaft section (24), the first shaft section (23) and the second The diameter of the shaft section (24) varies.
The electric spindle according to claim 4, wherein at least one of the first fastener (19) and the second fastener (21) is a fastening nut.
The electric spindle according to any one of claims 2 to 8, wherein a third fastener (16) is provided at one end of the rear end bearing (17), and the end of the rear end bearing (17) The other end is provided with a fourth fastener (18), the third fastener (16) and the fourth fastener (18) are both provided on the bearing shaft core (15), and The bearing inner ring of the rear-end bearing (17) forms an axial limit.
The electric spindle according to claim 9, characterized in that at least one of the third fastener (16) and the fourth fastener (18) is a fastening nut.
The electric spindle according to any one of claims 1 to 8, characterized in that an end cover (14) of the shaft core is fixedly connected to the rear end of the bearing shaft core (15).
The electric spindle according to claim 11, characterized in that the rear end of the bearing shaft core (15) passes through a plurality of bolts uniformly arranged circumferentially around the central axis of the bearing shaft core (15) and the The shaft core end cover (14) is fixedly connected.
The electric spindle according to claim 11, wherein the shaft core end cover (14) is provided with a weight reduction hole (26).
The electric spindle according to claim 13, wherein the shaft core end cover (14) includes an end plate, and a plurality of the weight-reducing holes (26) are evenly distributed on the end plate in a circumferential direction.
The electric spindle according to claim 14, characterized in that the total area of the weight-reducing holes (26) accounts for 30% to 50% of the total area of the end plate.
The electro-spindle according to claim 11, characterized in that the outer periphery of the rotating shaft core (1) is provided with a rear flange end cover (10), and the shaft core end cover (14) is fixedly connected to the rear End flange (10).
The electric spindle according to claim 16, characterized in that the shaft core end cover (14) is sleeved outside the rear end flange end cover (10), and the peripheral wall of the shaft core end cover (14) A radial connection hole (25) is provided on the shaft, and the shaft core end cover (14) is fixedly connected to the rear end flange end cover (10) through a bolt provided in the radial connection hole (25).
The electric spindle according to claim 17, wherein the radial connection hole (25) is a waist-shaped hole, and the waist-shaped hole extends in the axial direction of the shaft core end cover (14).
A motor including an electric spindle, characterized in that the electric spindle is the electric spindle according to any one of claims 1 to 18.