CN116146603A - A gas static pressure spindle with multiple air bearing sleeves - Google Patents

Abstract

The invention discloses a gas static pressure main shaft with multiple air floating shaft sleeves, which comprises a base, an auxiliary shaft sleeve, a main shaft rotor and a radial plate, wherein: the main shaft rotor consists of a long shaft and a thrust plate; the shaft sleeve is arranged on the long shaft of the main shaft rotor, and the outer side of the shaft sleeve is fixed on the base; the auxiliary shaft is sleeved at the tail part of the long shaft of the main shaft rotor; the spoke plate is fixed on one side of the flange end face of the shaft sleeve; the inner circle surface of the shaft sleeve and the long shaft of the main shaft rotor form a main radial bearing part, the inner circle surface of the auxiliary shaft sleeve and the long shaft of the main shaft rotor form an auxiliary radial bearing part, and the flange end face of the shaft sleeve, the inner end face of the radial plate and the thrust plate of the main shaft rotor form a thrust bearing part. The invention only adds an auxiliary shaft sleeve support in the original structure of the gas static pressure main shaft, the original structure of each part is basically unchanged, the main shaft structure is not required to be changed greatly, and the existing processing technology and processing equipment are fully utilized.

Description

A gas static pressure spindle with multiple air bearing sleeves

technical field

The invention belongs to the field of ultra-precision machining, and relates to an ultra-precision gas static pressure spindle, in particular to a gas static pressure spindle with multiple air bearing sleeves.

Background technique

With the continuous development and progress of modern technology, the precision requirements for the required parts in various fields are getting higher and higher, so the performance requirements for the parts processing equipment, especially the machine tool spindle, are also getting higher and higher. Due to the high rotation accuracy of the gas static pressure spindle, the temperature change is small in the state of high-speed rotation, so the thermal deformation error caused is very small, so the gas static pressure spindle is widely used in ultra-precision processing machine tools. The traditional aerostatic spindle uses gas as a lubricant, and relies on the pressure source provided by the outside to form a lubricating film around the spindle. The lubricating film can completely float the spindle and provide support stiffness for the spindle. The most notable advantages of the traditional aerostatic spindle are the high rotation accuracy of the spindle, the small air film friction, the lubricating film has an error homogenizing effect, and the influence of the cost machining error on the rotation accuracy is reduced. Compared with the dynamic pressure sliding bearing, the static pressure sliding bearing The lubricating film of the bearing is more stable, and the lubricating film of the spindle can remain intact when it is running at low speed or high speed. Theoretically, it can work without wear at all, and can realize low-speed non-crawling and low heat generation.

Although the ultra-precision spindle using air bearings has so many of the above advantages, after in-depth research by relevant technical personnel, it is found that the traditional gas static pressure spindle will vibrate violently when it reaches a certain speed. Because the vibration frequency brought by the speed reaches the first-order natural frequency of the air bearing spindle, resonance phenomenon occurs, and the traditional gas static pressure spindle has small bearing capacity, low stiffness, and poor anti-interference ability, which have been accompanied by it for a long time. . Therefore, how to solve the above problems of the traditional aerostatic spindle and improve its comprehensive performance has become a more important issue in this field.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, the present invention provides an aerostatic spindle with multiple air bearing sleeves. After supplying air to the overall aerostatic spindle, the entire aerostatic spindle can Considered as three fulcrum supports, the first-order natural frequency is greatly increased, thereby improving the modal performance and running stability of the main shaft, and at the same time improving the stiffness and load-carrying capacity of the main shaft radial bearing, and making the main shaft reachable The speed cap has been greatly increased.

The purpose of the present invention is achieved by the following technical solutions:

An aerostatic main shaft with multiple air bearing sleeves, including a base, an auxiliary sleeve, a shaft sleeve, a main shaft rotor and a spoke plate, wherein:

The main shaft rotor is composed of a long shaft and a thrust plate;

The sleeve is arranged on the long axis of the main shaft rotor, and the outer side is fixed on the base;

The auxiliary shaft sleeve is arranged at the tail of the long axis of the main shaft rotor;

The spoke plate is fixed on one side of the flange end face of the sleeve;

The inner circular surface of the bushing and the long axis of the main rotor form the main radial bearing part, the inner circular surface of the auxiliary bushing and the long axis of the main rotor form the auxiliary radial bearing part, the flange end surface of the bushing and the radial bearing part The inner end face of the plate and the thrust plate of the main shaft rotor form a thrust bearing part.

Compared with the prior art, the present invention has the following advantages:

1. The present invention only adds an auxiliary bushing to the original structure of the gas static pressure main shaft. The original structure of each part is basically unchanged, and there is no need to make too many changes to the structure of the main shaft. Existing processing technology and processing equipment.

2. In the present invention, by adding an auxiliary air bearing sleeve at the tail of the main shaft rotor, the overall aerostatic main shaft has three supports in the axial direction: the auxiliary radial bearing, the main radial bearing and the thrust bearing, which greatly improves the aerostatic pressure. Compressing the first-order natural frequency of the spindle further improves the modal performance of the spindle and greatly increases the upper limit of the spindle's attainable speed. Due to the addition of a radial bearing, the bearing capacity and rigidity of the main shaft are also greatly improved. At the same time, the anti-interference and anti-overturning capabilities of the main shaft are also improved, so that the stability and angular stiffness of the main shaft during operation are also greatly improved.

Description of drawings

Fig. 1 is a schematic diagram of the axial sectional structure of the gas static pressure spindle of the present invention;

Fig. 2 is a schematic diagram of the three-dimensional structure of the gas static pressure spindle of the present invention;

Among the figure, 1, base, 2, auxiliary shaft sleeve, 3, small hole restrictor, 4, air sealing screw plug, 5, radial air sealing ring I, 6, axle sleeve, 7, main shaft rotor, 8, spoke Plate, 9. Thrust sealing gas ring, 10. Fixture adapter plate, 11. Four-jaw chuck, 12. Connecting ring, 13. Motor stator mounting seat, 14. Motor stator, 15. Motor mover, 16. Moving Submount installation shaft, 17. Resolver stator mounting seat, 18. Resolver stator, 19. Resolver rotor, 20. Back cover, 21. Circular grating, 22. Reading head, 23. Grating installation shaft, 24. Reading head installation Seat, 25, resolver compression nut, 26, radial sealing ring II.

Detailed ways

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered by the present invention. within the scope of protection. In order to express clearly and conveniently, in the following content, the side where the web 8 of the gas static pressure main shaft is located is the front end, the side away from the web 8 is the tail, and the vertical direction is the direction perpendicular to the bottom surface of the base 1, as described in the present invention Words indicating directions such as "front" and "rear" should not be construed as specifically limiting the present invention.

The present invention provides an aerostatic spindle with multiple air flotation bushings. As shown in Figures 1 and 2, the aerostatic spindle includes a base 1, an auxiliary bushing 2, a bushing 6, a spindle rotor 7 and spokes. Plate 8, of which:

The main shaft rotor 7 is mainly composed of a long shaft and a thrust plate;

The bushing 6 is arranged on the long axis of the main shaft rotor 7, and the outer side is fixed on the base 1 through bolt connection;

The auxiliary bushing 2 is arranged at the tail of the long axis of the main shaft rotor 7;

The spoke plate 8 is fixed on one side of the flange end face of the bushing 6 through bolt connection;

The inner circular surface of the shaft sleeve 6 and the long axis of the main shaft rotor 7 form a main radial bearing part, the inner circular surface of the auxiliary shaft sleeve 2 and the long axis of the main shaft rotor 7 form an auxiliary radial bearing part, and the shaft sleeve 6 The end face of the flange and the inner end face of the web 8 and the thrust plate of the main shaft rotor 7 form a thrust bearing part.

In the present invention, the spoke plate 8 is provided with an axial air channel I, a radial air channel I and an axial air channel II uniformly distributed along the circumference, and the axial air channel I and the radial air channel I are one by one Corresponding to and communicating with each other, the flange end surface of the shaft sleeve 6 is provided with axial air passage III, radial air passage II and axial air passage IV uniformly distributed along the circumferential direction, and the axial air passage III is connected to the axial air passage. The air passages II correspond one-to-one and communicate with each other, the axial air passage III and the radial air passage II correspond one-to-one and communicate with each other, and the radial air passage II and the axial air passage IV correspond one-to-one and communicate with each other; An annular circular groove A is arranged on the outer circular surface of the spoke plate 8, and a thrust sealing air ring 9 is arranged in the annular circular groove A to form an annular air passage I, and the inner circular surface of the thrust sealing air ring 9 is a Annular circular groove, the annular air passage I corresponds to several radial air passages I and communicates with each other, thus forming the air path of the entire thrust bearing and can supply air to the entire thrust bearing through only one air supply hole ; The shaft sleeve 6 is provided with radial air passages III and axial air passages uniformly distributed along the circumferential direction, the radial air passages III are arranged in 4 rows in the axial direction, and the axial air passages V Connected to 4 rows of radial air passages III, an annular circular groove B is provided on the rear end surface of the shaft sleeve 6, and a radial air sealing ring I5 is arranged in the annular circular groove B to form an annular air passage II. The inner circular surface of the air ring I5 is an annular circular groove, and the annular air passage II corresponds to several axial air passages V and communicates with each other, thereby forming the air passage of the radial bearing of the main body and can only pass through one air supply hole. Air is supplied to the radial bearing of the entire main body; radial air passages IV and axial air passages VI are evenly distributed on the auxiliary bushing 2 along the circumferential direction, and the radial air passage IV is provided with two row, the axial air passage VI communicates with the two rows of radial air passages VI, an annular circular groove C is provided on the rear end surface of the auxiliary bushing 2, and a radial air sealing ring is arranged in the annular circular groove C II26 forms an annular air passage III, and the inner surface of the radial sealing ring II26 is an annular circular groove. The annular air passage III corresponds to and communicates with several axial air passages VI, thereby forming an auxiliary radial The air path of the bearing can supply air to the entire auxiliary radial bearing through only one air supply hole.

In the present invention, the end of the radial air passage II, the radial air passage III and the radial air passage IV away from the main shaft rotor 7 is provided with an air sealing screw plug 4, so as to ensure the sealing of each air passage; the axial air passage The end of the channel I and the axial air channel IV close to the thrust plate of the main shaft rotor 7 is provided with a small hole restrictor 3; the end of the radial air channel III and the radial air channel IV close to the long axis of the main shaft rotor 7 is provided There are orifice restrictors 3 .

In the present invention, the aerostatic spindle adopts a small-hole throttling form, but in actual processing applications, the throttling form is not limited, and other throttling forms such as surface throttling and porous throttling can also be used.

In the present invention, the aerostatic spindle further includes a fixture adapter plate 10 , and the fixture adapter plate 10 is fixed on one end of the spindle rotor 7 through bolt connection.

In the present invention, the aerostatic spindle further includes a four-jaw chuck 11, and the four-jaw chuck 11 is fixed on the fixture adapter plate 10 through bolt connection for clamping workpieces.

In the present invention, the aerostatic spindle also includes a connection ring 12, a motor stator mounting base 13, a motor stator 14, a motor mover 15 and a mover mounting shaft 16, and the motor stator mounting base 13 is fixed on the base 1 through the connection ring 12. Above, the motor stator 14 is fixed on the motor stator mounting base 13 through bolt connection, the mover installation shaft 16 is connected with the tail of the main shaft rotor 7 through bolt connection, and the motor mover 15 is fixed on the mover through bolt connection Installed on the shaft 16, the motor stator 14 and the motor mover 15 are rotationally connected to provide power for the aerostatic spindle.

In the present invention, the motor stator 14 and the motor mover 15 are frameless torque motors.

In the present invention, the aerostatic spindle also includes a resolver stator mount 17, a resolver stator 18, a resolver 19, and a resolver compression nut 25, and the resolver stator mount 17 is fixed on the motor stator by bolts. On the seat 13, the resolver stator 18 is fixed on the resolver stator mounting base 17 through bolt connection, and the resolver stator 19 is fixed on the mover installation shaft 16 through the resolver compression nut 25, and the resolver stator 18 is rotationally connected with the rotary rotor 19, which is used for the feedback of the position, direction and speed of the main shaft, and then used for precise control of the motor.

In the present invention, the aerostatic spindle also includes a back cover 20, a circular grating 21, a reading head 22, a grating installation shaft 23, and a reading head mounting seat 24, and the reading head mounting seat 24 is fixed on the resolver stator by bolts. On the mounting base 17, the grating installation shaft 23 is fixed on the mover installation shaft 16 through bolt connection, the circular grating 21 is fixed on the grating installation shaft 23 through bolt connection, and the reading head 22 is fixed on the reading head through bolt connection. The head mounting base 24 is used for the feedback of the spindle speed and position; the rear cover 20 is fixed on the reading head mounting base 24 through bolt connection, and is used to close the spindle.

In the present invention, the aerostatic main shaft of the multi-air flotation bushing is axially supported by the auxiliary radial bearing part, the main radial bearing part and the thrust bearing part after the air supply, which can be regarded as three fulcrums For support, compared with the support of two fulcrums of the traditional gas static pressure spindle, the first-order natural frequency of the gas static pressure spindle of the present invention has been greatly improved, and the modal performance of the spindle has been further improved, so that the upper limit of the speed that the spindle can reach is greatly increased improve. Due to the addition of a radial bearing, the bearing capacity and rigidity of the main shaft are also greatly improved. At the same time, the anti-interference and anti-overturning capabilities of the main shaft are also improved, so that the stability and angular stiffness of the main shaft during operation are also greatly improved.

Claims (9)

1. A gas static pressure main shaft with multiple air bearing sleeves, characterized in that the gas static pressure main shaft comprises a base, an auxiliary shaft sleeve, a shaft sleeve, a main shaft rotor and a radial plate, wherein: The main shaft rotor is composed of a long shaft and a thrust plate; The sleeve is arranged on the long axis of the main shaft rotor, and the outer side is fixed on the base; The auxiliary shaft sleeve is arranged at the tail of the long axis of the main shaft rotor; The spoke plate is fixed on one side of the flange end face of the sleeve; The inner circular surface of the bushing and the long axis of the main rotor form the main radial bearing part, the inner circular surface of the auxiliary bushing and the long axis of the main rotor form the auxiliary radial bearing part, the flange end surface of the bushing and the radial bearing part The inner end face of the plate and the thrust plate of the main shaft rotor form a thrust bearing part. 2. The aerostatic main shaft with multiple air bearing sleeves according to claim 1, characterized in that the radial air passages I, radial air passages I and axial air passages uniformly distributed along the circumference are arranged on the web plate. Channel II, the axial air channel I and the radial air channel I correspond one-to-one and communicate with each other, and the end surface of the flange of the sleeve is provided with axial air channel III and radial air channel II uniformly distributed along the circumferential direction And the axial airway IV, the axial airway III corresponds to the axial airway II and communicates with each other, the axial airway III corresponds to the radial airway II and communicates with each other, the diameter The direction air channel II and the axial air channel IV correspond one-to-one and communicate with each other; an annular circular groove A is provided on the outer surface of the spoke plate, and a thrust sealing ring is arranged in the annular circular groove A to form an annular air channel I, the annular air passage I corresponds to several radial air passages I and communicates with each other; the shaft sleeve is provided with radial air passages III and axial air passages V uniformly distributed along the circumferential direction, and the axial air passages The channel V communicates with the radial air channel III, and an annular circular groove B is provided on the rear end surface of the sleeve, and a radial air sealing ring I is arranged in the annular circular groove B to form an annular air channel II, and the annular air channel II Corresponding to several axial air passages V and communicating with each other; radial air passages IV and axial air passages VI are evenly distributed on the auxiliary sleeve along the circumferential direction, and the axial air passage VI and radial air passage VI In communication with each other, an annular circular groove C is provided on the rear end surface of the auxiliary bushing, and a radial air sealing ring II is arranged in the annular circular groove C to form an annular air passage III, and the annular air passage III is connected with several axial air passages. Road VI corresponds to and communicates with each other. 3. The aerostatic main shaft with multiple air bearing sleeves according to claim 2, characterized in that the ends of the radial air passage II, radial air passage III and radial air passage IV far away from the main shaft rotor are all provided with seals The air screw plug, the axial air passage I and the axial air passage IV are provided with a small hole restrictor at the end of the thrust plate close to the main shaft rotor, and the radial air passage III and the radial air passage IV are close to the main shaft rotor One end of the long axis is provided with a small hole restrictor. 4 . The gas static pressure spindle with multiple air bearing sleeves according to claim 1 , wherein the gas static pressure spindle further comprises a fixture adapter plate, and the fixture adapter plate is fixed at one end of the spindle rotor. 5. The gas static pressure spindle with multiple air bearing sleeves according to claim 4, characterized in that the gas static pressure spindle further comprises a four-jaw chuck, and the four-jaw chuck is fixed on the clamp adapter plate. 6. The gas static pressure spindle with multiple air bearing sleeves according to claim 1, 4 or 5, characterized in that the gas static pressure spindle also includes a connecting ring, a motor stator mounting seat, a motor stator, a motor mover and The mover installation shaft, the motor stator mount is fixed on the base through the connecting ring, the motor stator is fixed on the motor stator mount, the mover installation shaft is connected with the tail of the main shaft rotor, and the motor mover is fixed On the mover installation shaft, the motor stator is rotatably connected with the motor mover. 7. The aerostatic spindle with multiple air bearing sleeves according to claim 6, wherein the motor stator and the motor mover are frameless torque motors. 8. The gas static pressure spindle with multiple air bearing sleeves according to claim 6, characterized in that the gas static pressure spindle also includes a resolver stator mounting seat, a resolver stator, a resolver rotor and a resolver compression nut , the resolver stator mount is fixed on the motor stator mount, the resolver stator is fixed on the resolver stator mount, the resolver is fixed on the mover installation shaft, the resolver stator and the resolver The changer rotates and connects. 9. The gas static pressure spindle with multiple air bearing sleeves according to claim 8, characterized in that the gas static pressure spindle also includes a rear cover, a circular grating, a reading head, a grating installation shaft and a reading head mounting seat, the The reading head mounting base is fixed on the resolver stator mounting base, the grating mounting shaft is fixed on the mover mounting shaft, the circular grating is fixed on the grating mounting shaft, the reading head is fixed on the reading head mounting base, The back cover is fixed on the reading head installation seat.

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