CN216540869U

CN216540869U - Aerostatic ceramic ball composite bearing electric spindle

Info

Publication number: CN216540869U
Application number: CN202122542705.4U
Authority: CN
Inventors: 魏传波; 王强志
Original assignee: LUOYANG CHUANSHUN MACHINERY EQUIPMENT CO Ltd
Current assignee: LUOYANG CHUANSHUN MACHINERY EQUIPMENT CO Ltd
Priority date: 2021-10-22
Filing date: 2021-10-22
Publication date: 2022-05-17
Anticipated expiration: 2031-10-22

Abstract

The utility model provides an aerostatic ceramic ball composite bearing electricity main shaft, relates to bearing technical field, including the casing, rotate the main shaft that sets up in the casing and be used for driving main shaft pivoted power unit, is provided with air bearing between casing and the main shaft, still is provided with angular contact bearing between casing and the main shaft, and angular contact bearing's inner ring and main shaft fixed connection are provided with elasticity pretension mechanism between outer loop and the casing of angular contact bearing. The utility model is used for improving the rigidity of the aerostatic pressure electric main shaft and increasing the bearing capacity and stability of the main shaft.

Description

Aerostatic ceramic ball composite bearing electric spindle

Technical Field

The utility model relates to the technical field of bearings, in particular to an electric spindle of an aerostatic ceramic ball composite bearing.

Background

With the development of the country and the progress of science and technology, the demand of China for a high-performance electric spindle of ultra-precision machining equipment is urgent day by day. The machining of microstructures and micro parts based on a mechanical cutting method has attracted more and more attention due to the characteristics of high machining efficiency, low cost, wide range of machining materials and the like. The ultra-precise processing machine tool facing to the microstructure and the micro part requires that a main shaft part has extremely high rotation precision.

The air static pressure electric main shaft is widely applied to the field of ultra-precision machining tools by virtue of the characteristics of high precision, high speed, low friction and the like. The air static pressure electric main shaft adopts a bearing which is an air static pressure bearing, the air static pressure bearing is also called as an air bearing or an air bearing, and the air static pressure electric main shaft has the defects of low rigidity, small bearing capacity, poor stability and the like because compressible gas is used as a lubricant, thereby limiting the further expansion of the application range of the air static pressure electric main shaft.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an aerostatic ceramic ball composite bearing electric main shaft so as to improve the rigidity of the aerostatic electric main shaft and increase the bearing capacity and stability of the main shaft.

In order to solve the technical problems, the utility model adopts the specific scheme that: an electric spindle of a aerostatic ceramic ball composite bearing comprises a shell, a spindle rotatably arranged in the shell and a power mechanism used for driving the spindle to rotate, wherein an air bearing is arranged between the shell and the spindle, an angular contact bearing is further arranged between the shell and the spindle, an inner ring of the angular contact bearing is fixedly connected with the spindle, and an elastic pre-tightening mechanism is arranged between an outer ring of the angular contact bearing and the shell.

As a further optimization of the above technical solution, the number of the angular contact bearings is two and the two angular contact bearings are respectively arranged at two ends of the main shaft, and the two angular contact bearings are arranged face to face or back to back.

As a further optimization of the above technical solution, an end face of the inner ring of the angular contact bearing is disposed on a shaft shoulder of the main shaft, the elastic pre-tightening mechanism is an elastic washer, a ring groove is disposed at a position of the housing corresponding to the end face of the outer ring of the angular contact bearing, the elastic washer is disposed in the ring groove, and the elastic washer is in a compressed state to apply an elastic pre-tightening force to the angular contact bearing.

As a further optimization of the technical scheme, the rolling bodies of the angular contact bearing are ceramic balls.

As a further optimization of the technical scheme, the power mechanism is a motor.

Compared with the prior art, the utility model has the following beneficial effects: 1. according to the utility model, through the composite bearing technology of the air bearing and the angular contact bearing and the internal structure design, the two bearings can automatically switch the working states, the angular contact bearing has the characteristics of high rigidity and large load, and the air bearing also has the characteristics of high precision and high rotating speed, the two bearings can automatically switch the working states according to the load, the angular contact bearing plays a supporting role when the load is heavy, and the air bearing plays a supporting role when the load is light.

2. The utility model has the characteristics of large bearing capacity and high rigidity of the traditional angular contact bearing electric main shaft, and high rotating speed and high precision of the air bearing electric main shaft; the device has the advantages of realizing the effects of heavy-load rough machining and ultra-precision machining on one machine tool, greatly improving the reliability and the application range of precision machining equipment due to the superior performance.

3. The built-in direct drive motor adopts a variable frequency driver to realize stepless speed regulation. The grinding machine is the best selected part of precision machine tools such as precision numerical control grinding machines, lathes, highlight machine tools, high-end bearing grinding machines and the like, and therefore has important social and economic significance.

Drawings

FIG. 1 is a cross-sectional view of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1;

1. the structure comprises a working end, 3 parts of an angular contact bearing, 301 parts of an outer ring, 302 parts of a rolling body, 303 parts of an inner ring, 4 parts of an air bearing, 5 parts of a main shaft, 6 parts of a shell, 7 parts of an air passage, 8 parts of a power mechanism, 801 parts of a motor rotor, 802 parts of a motor stator, 9 parts of an end cover, 10 parts of a cooling channel, 11 parts of an annular groove, 12 parts of an elastic gasket.

Detailed Description

As shown in fig. 1, the present invention is an electric spindle with aerostatic ceramic ball composite bearing, comprising a housing 6, a spindle 5 rotatably disposed in the housing 6, and a power mechanism 8 for driving the spindle 5 to rotate.

Be provided with air bearing 4 between casing 6 and the main shaft 5, the quantity of air bearing 4 sets up according to the length of main shaft 5, and the quantity of air bearing 4 is three in this embodiment, and wherein two air bearing 4 set up side by side in power unit 8's left side, and third air bearing 4 sets up the right side at power unit 8. The external diameter and the casing 6 fixed connection of air supporting bearing 4, be provided with the air flue 7 that lets in gas to air supporting bearing 4 on the casing 6, be formed with the working air gap between the internal diameter of air supporting bearing 4 and main shaft 5, the micropore that the gas of seting up on air supporting bearing 4 in the air flue 7 gets into the working air gap, form the lubricated air film that the one deck has certain bearing and rigidity in the working air gap, rely on the lubricated supporting role of this air film to float main shaft 5 in air supporting bearing 4, air supporting bearing 4's structure is prior art, no longer describe herein.

Angular contact bearings 3 are further arranged between the shell 6 and the main shaft 5, the number of the angular contact bearings 3 is two, the two angular contact bearings are respectively arranged at two ends of the main shaft 5, and the angular contact bearings 3 are respectively positioned at one side, away from the power mechanism 8, of the adjacent air bearing 4. The angular contact bearing 3 comprises an inner ring 303, an outer ring 301 and a rolling body 302, the rolling body 302 is a ceramic ball, the angular contact bearing 3 is a ceramic ball bearing, the thermal expansion coefficient of the ceramic ball is small, the ceramic ball cannot expand due to temperature in a high-temperature environment, the service temperature of the whole ceramic ball bearing is greatly improved, the ceramic ball has oil-free self-lubricating property, the friction coefficient of the ceramic ball is small, and therefore the ceramic ball bearing has high rotating speed. The ceramic ball bearing can be operated without adding any grease, namely even if the grease is dried, the phenomenon of premature bearing damage caused by drying of the grease in a common bearing is avoided, the ceramic ball is an insulator, the ceramic ball bearing can achieve the insulating effect, and the ceramic ball bearing can be used in a conductive environment. Therefore, the high-speed electric spindle assembled by the ceramic ball bearing has the advantages of high speed, high rigidity, high power, long service life and the like. The inner diameter of the inner ring 303 is fixedly connected with the outer diameter of the main shaft 5, and the end surface of the inner ring 303 facing the air bearing 4 is arranged on the shaft shoulder of the main shaft 5.

In the present embodiment, the two angular contact bearings 3 are mounted back to back, that is, the wide end faces of the two angular contact bearings 3 are opposite to each other, and at this time, the contact angle line of the angular contact bearing 3 is spread along the rotation axis direction, so that the radial and axial support angle rigidity can be increased, and the deformation resistance is maximized. The two angular contact bearings 3 may be mounted in a face-to-face manner, and when mounted in a face-to-face manner, the narrow end faces of the two angular contact bearings 3 are opposed to each other, and the contact angle line of the angular contact bearings 3 converges in the direction of the rotation axis, so that the angular rigidity of the bearings is small, and the preload of the angular contact bearings 3 can be increased.

A gap is formed between the outer diameter of the outer ring 301 of the angular contact bearing 3 and the housing 6, an elastic pre-tightening mechanism is arranged between the end face of the outer ring 301 close to the air bearing 4 side and the housing 6, the elastic pre-tightening mechanism is an elastic gasket 12, and the elastic gasket 12 is an elastic sealing ring made of rubber. An annular groove 11 is formed in the position, corresponding to the end face of the outer ring 301, of the shell 6, an elastic gasket 12 is arranged in the annular groove 11, a certain gap is reserved between the shell 6 and the end face of the outer ring 301, and the diameter of the elastic gasket 12 is larger than the sum of the depth of the annular groove 11 and the width of the gap, so that the elastic gasket 12 is in a compression state and applies elastic pre-tightening force to the angular contact bearing 3. By adopting the composite bearing technology of the air bearing 4 and the angular contact bearing 3 and the design of the internal structure, the two bearings can automatically switch the working state according to the load size, the angular contact bearing 3 plays a role in supporting when the load is heavy, and the air bearing 4 plays a role in supporting when the load is light, so that the electric spindle has the advantages of large bearing capacity and high rigidity of the traditional ball bearing electric spindle, and simultaneously has the advantages of high speed and high precision (the rotation precision is less than or equal to 0.1um) of the air hydrostatic bearing electric spindle.

The power mechanism 8 is a built-in direct drive motor, the motor comprises a motor rotor 801 and a motor stator 802, the motor stator 802 is assembled inside the shell 6, the motor rotor 801 is arranged outside the main shaft 5, and the speed change range of the main shaft 5 is controlled by the motor. The built-in direct drive motor adopts a variable frequency driver to realize stepless speed regulation, vector control can be realized, and the rotating speed control precision can reach +/-0.1%.

The end of the main shaft 5 far away from the power mechanism 8 is a working end 1, a cooling channel 10 is arranged on the shell 6 between the working end 1 and the power mechanism 8, the cooling channel 10 is positioned between the air passage 7 and the outer wall of the shell 6 and arranged around the shell 6 (the arrangement of a liquid inlet and a liquid outlet in the cooling channel 10 is the prior art, not shown in the figure), and the heat generated by the air bearing 4 in the working process is taken away through the inflow and outflow of the cooling liquid circulation in the cooling channel 10, so that the main shaft 5 is kept in a stable working state.

One end of the main shaft 5 close to the power mechanism 8 is provided with an end cover 9 to avoid danger caused by mistaken touch of an operator.

Claims

1. The utility model provides an aerostatic ceramic ball composite bearing electricity main shaft, includes casing (6), main shaft (5) and power unit (8) that are used for driving main shaft (5) pivoted that rotate to set up in casing (6), be provided with air supporting bearing (4) between casing (6) and main shaft (5), its characterized in that, still be provided with angular contact bearing (3) between casing (6) and main shaft (5), inner ring (303) and main shaft (5) fixed connection of angular contact bearing (3), be provided with elasticity pretension mechanism between outer loop (301) of angular contact bearing (3) and casing (6).

2. The aerostatic ceramic ball composite bearing motorized spindle of claim 1, wherein the number of angular contact bearings (3) is two and disposed at each end of the spindle (5), and the two angular contact bearings (3) are disposed face to face or back to back.

3. The aerostatic ceramic ball composite bearing electric spindle of claim 1, wherein an end surface of the inner ring (303) of the angular contact bearing (3) is disposed on a shoulder of the spindle (5), the elastic pre-tightening mechanism is an elastic washer (12), a circular groove (11) is disposed in a position of the housing (6) corresponding to the end surface of the outer ring (301) of the angular contact bearing (3), the elastic washer (12) is disposed in the circular groove (11), and the elastic washer (12) is in a compression state to apply the elastic pre-tightening force to the angular contact bearing (3).

4. Aerostatic ceramic ball composite bearing electric spindle according to claim 1, characterized in that the rolling bodies (302) of the angular contact bearing (3) are ceramic balls.

5. An aerostatic ceramic ball composite bearing electric spindle according to claim 1, characterized in that the power mechanism (8) is an electric motor.