CN112303116A - Active-passive integrated protection device for self-eliminating and restoring radial and axial clearances of bearing outer ring - Google Patents

Abstract

The invention relates to the technical field of magnetic suspension bearing systems, in particular to a protection device for automatically eliminating and recovering the radial and axial gaps of an outer ring of a bearing in an active-passive integrated manner. The rotor comprises a rotor, a protective bearing and an end cover, wherein the end cover is fixedly connected with an external machine base; the protective bearing comprises a rolling bearing, a sleeve, a screwing inner assembly, a screwing outer assembly and balls. The invention can simultaneously provide radial and axial protection for the rotor after the magnetic suspension bearing system fails, and can simultaneously eliminate radial and axial clearances between the rolling bearing and the precession inner assembly, eliminate radial and axial clearances between the rolling bearing and the base, and eliminate vibration and impact on the rolling bearing after the high-speed rotor falls down; when the magnetic suspension bearing normally works again, the gap between the rolling bearing and the base can be recovered in time, so that the bearing is protected from interfering the normal work of the magnetic suspension bearing again, the reliability and the safety of the centripetal thrust force protection bearing are improved, and the requirement of the development of a high-speed magnetic suspension bearing system is met.

Description

Active-passive integrated protection device for self-eliminating and restoring radial and axial clearances of bearing outer ring

Technical Field

The invention relates to the technical field of magnetic suspension bearing systems, in particular to a protection device for automatically eliminating and recovering the radial and axial gaps of an outer ring of a bearing in an active-passive integrated manner.

Background

In a magnetic suspension bearing system, a set of protective bearings (also called auxiliary bearings, backup bearings, holding bearings or emergency bearings) are generally required to serve as temporary supports in emergency situations such as system power failure, overload, control system failure or malfunction. The conical roller type centripetal thrust protection bearing capable of automatically eliminating the rotor clearance can bear loads in the radial direction and the axial direction at the same time, and the rotor rotating at a high speed is prevented from colliding and rubbing with a stator part of a system, so that the safety and the reliability of the whole system are guaranteed. The conventional protective bearing design is to assemble a rolling bearing in a bearing seat, and the radial/axial clearance required by the normal operation of a magnetic suspension bearing arranged between an inner ring of the rolling bearing and a rotor is generally half of the radial clearance between the rotor and the radial/axial magnetic suspension bearing. Therefore, the protective bearing is greatly impacted and vibrated when working, and simultaneously, because the rotor can not eliminate the clearance between the protective bearing and the rotor after falling, the protective bearing has poor impact and vibration resistance, and is easy to be damaged, thereby causing serious accidents of the damage of the magnetic suspension bearing system. Therefore, protecting the bearing has been a major factor that restricts the application and development of magnetic bearing systems.

Because the rotating speed of the magnetic suspension bearing system is generally high, and a large radial and axial clearance exists between the rotor and the protective bearing, the rotor can generate large impact and vibration when falling onto the protective bearing. In the prior art, an inner nest with an inclined plane is arranged on an inner ring of a rolling bearing and is in contact with a rotor with the inclined plane, when an electromagnet works, the electromagnet is electrified to enable a structure containing the rolling bearing to compress a spring, and a gap is formed between the inner nest and the rotor, so that the bearing is protected from working; when the magnetic suspension bearing is powered off accidentally, the electromagnet is powered off, the spring pushes the structure of the protection bearing to move integrally, so that the inner nest is in contact with the rotor to eliminate the gap, but the thrust of the spring is utilized to maintain the structure of the protection bearing to be in contact with the rotor, if the rigidity of the spring is too small, the axial supporting rigidity of the protection bearing is very small, and if the rigidity of the spring is too large, the electromagnet cannot compress the spring; in addition, in the scheme, because the taper of the inclined plane of the rotor and the inner nesting is single, under the condition that the taper of the inclined plane is small, the size of the axial gap between the inner nesting and the rotor is multiple times of that of the radial gap, namely under the condition that the radial protection of the magnetic suspension bearing is met, the axial protection of the magnetic suspension bearing cannot be met, and therefore the protection bearing cannot provide radial and axial protection for the magnetic suspension bearing rotor at the same time.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a protection device for automatically eliminating-recovering the radial and axial clearances of an outer ring of a bearing in an active-passive integrated mode.

The technical scheme adopted by the invention for solving the technical problems is as follows: a protection device for automatically eliminating and recovering radial and axial gaps of an outer ring of a bearing in an active-passive integrated mode comprises a rotor, a protection bearing and an end cover, wherein the end cover is fixedly connected with an external machine base;

the protective bearing comprises a rolling bearing, a sleeve, a screwing inner assembly, a screwing outer assembly and a ball;

the inner ring of the rolling bearing is directly arranged at the end part of the rotor in an interference fit manner;

the inner circle of the sleeve is arranged on the outer ring of the rolling bearing, the surface of the outer circle of the sleeve is processed into an inclined plane H1 with small taper and an inclined plane H2 with large taper, and the two inclined planes with different tapers are alternately arranged along the axial direction;

the interior subassembly of precession, subassembly excircle surface axial intermediate position department is provided with 1 ~ 2 circles of external screw thread G3 in the precession, external screw thread G3 revolves to unanimous with the rotor direction of rotation, the one end that is close to the ball is provided with a plurality of circular arc type channels G2 unanimous with external screw thread G3 helical pitch along the axial, one end is provided with gear teeth G4 along circumference in addition, be connected with outside servo motor, the interior subassembly of precession is interior to be close to ball one end and is processed into the inclined plane unanimous with the sleeve excircle, and place the sleeve periphery in, there is radial clearance L68 of even size in this section precession interior subassembly internal surface and the sleeve surface, the axial clearance is L2, the interior subassembly middle part processing becomes the disc shape in the precession, its and the radial clearance between the rotor are L3, L3 sets up to the required radial protection clearance size of magnetic suspension bearing system, and.

The outer circle surface of the precession outer assembly is arranged on the end cover, a circle of arc-shaped channel is arranged on the inner circle surface close to the ball end, and an internal thread matched with an external thread G3 on the outer circle surface of the precession inner assembly is arranged on the other end of the inner circle surface;

the ball is arranged between the circular arc-shaped channels of the screw-in inner assembly and the screw-in outer assembly.

According to another embodiment of the present invention, further comprising: the number of the balls is 2-200.

According to another embodiment of the present invention, further comprising: the rolling bearing is a deep groove ball bearing, a pair of angular contact bearings or a ceramic ball bearing.

According to another embodiment of the present invention, further comprising: the external thread G3 screwed into the inner component and the thread form screwed into the external thread of the outer component can be rectangular, trapezoidal, saw-toothed or common thread.

According to another embodiment of the present invention, further comprising: the protective bearing is made of metal or composite materials made of carbon fiber/glass fiber and the like.

The invention has the advantages that the invention can simultaneously provide radial and axial protection for the rotor after the magnetic suspension bearing system fails, and can simultaneously eliminate the radial and axial clearances between the rolling bearing and the screw-in inner assembly, namely eliminate the radial and axial clearances between the rolling bearing and the base, thereby eliminating the vibration and impact on the rolling bearing after the high-speed rotor falls down; in addition, when the magnetic suspension bearing normally works again, the gap between the rolling bearing and the base can be recovered in time, so that the bearing is protected from interfering the normal work of the magnetic suspension bearing again, the reliability and the safety of the centripetal thrust protection bearing are improved, and the requirement of the development of a high-speed magnetic suspension bearing system is met.

Drawings

FIG. 1 is a schematic view of the overall structure of a protection device for the radial and axial clearances of an active-passive integrated self-eliminating-restoring bearing outer ring according to the present invention;

FIG. 2 is a schematic view of the portion I of FIG. 1 with the enlarged gap not removed;

FIG. 3 is a schematic view of the portion I of FIG. 1 with the gap removed;

FIG. 4 is a view of the precessing inner assembly;

FIG. 5 is a partial view taken from the direction A in FIG. 4;

in the figure, 1, a rotor, 2, a rolling bearing, 3, a sleeve, 4, a screw-in inner assembly, 5, a screw-in outer assembly, 6, a ball, 7 and an end cover.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in fig. 1-5, the active-passive integrated protection device for self-eliminating and restoring radial and axial clearances of an outer ring of a bearing comprises a rotor 1, a protection bearing and an end cover 7, wherein the end cover 7 is fixedly connected with an external machine base.

The protective bearing comprises a rolling bearing 2, a sleeve 3, a screw-in inner component 4, a screw-in outer component 5 and balls 6.

The rolling bearing 2 is characterized in that the inner ring of the rolling bearing 2 is directly arranged at the end part of the rotor 1 in an interference fit mode.

The inner circle of the sleeve 3 is arranged on the outer ring of the rolling bearing 2, the outer circle surface of the sleeve 3 is processed into a slope H1 with small taper and a slope H2 with large taper, and the slopes with two different tapers are alternately arranged along the axial direction.

Screwing the inner component 4, wherein 1-2 circles of external threads G3 are arranged at the axial middle position of the outer circle surface of the screwing inner component 4, the rotation direction of the external threads G3 is consistent with the rotation direction of the rotor 1, one end close to the ball 6 is provided with a plurality of arc-shaped channels G2 with the same lead as the external threads G3 along the axial direction, the other end is provided with gear teeth G4 along the circumferential direction and is connected with an external servo motor, one end of the inner circle of the precession inner component 4 close to the ball 6 is processed into an inclined plane which is consistent with the excircle of the sleeve 3, and is arranged at the periphery of the sleeve 3, a radial clearance L1 with uniform size exists between the inner surface of the screwing-in inner component 4 and the outer surface of the sleeve 3, the axial clearance is L2, the middle part of the inner circle of the screwing-in inner component 4 is processed into a disc shape, the radial clearance between the rotor and the rotor 1 is L3, L3 is set as the required radial protection clearance size of the magnetic suspension bearing system, and L1 is set to be larger than L3.

The outer subassembly 5 of precession, the outer surface mounting of subassembly 5 excircle surface mounting of precession is on end cover 7, and interior round surface sets up round circular arc type channel near ball 6 end, and the other end is provided with the external screw thread G3 complex internal thread with subassembly 4 excircle surface in the precession.

And the ball 6 is arranged between the circular arc type channels of the screw-in inner component 4 and the screw-in outer component 5.

The number of the balls 6 is 2-200.

The rolling bearing 2 is a deep groove ball bearing, a pair of angular contact bearings, or a ceramic ball bearing.

The thread profile of the external thread G3 screwed into the inner component 4 and the internal thread screwed into the outer component 5 can be rectangular, trapezoidal, saw-tooth or plain threads.

The protective bearing is made of metal or composite material made of carbon fiber/glass fiber and the like.

When in installation, the sleeve 3 is firstly installed on the outer ring of the rolling bearing 4, and then the rolling bearing 4 is installed on the end part of the rotor 1; then the screwed-in inner component 4 is screwed into the screwed-in outer component 5, when the circular arc-shaped ball inlet (G1 in figure 2) at the beginning end of the circular arc-shaped channel on the outer surface of the screwed-in inner component 4 is overlapped with the circular arc-shaped channel on the inner surface of the screwed-in outer component 5 in the process, the ball 6 is respectively correspondingly arranged in each circular arc-shaped ball inlet, the screwed-in inner component 4 is continuously screwed in, the screwed-in inner component 4 and the screwed-in outer component 5 have relative axial displacement in the process of screwing in the screwed-in inner component 4, and the ball rolls in the circular arc-shaped channels of the screwed-in inner component 4 and the screwed-in outer component 5, because the circular arc-shaped channel in the screwed-in outer component 5 is sealed end to end without axial deviation in the circumferential direction, and the circular arc-shaped channel on the outer surface of the screwed-in inner component 4 has the same axial displacement with the external thread lead, the, the axial movement of the screwed-in inner component 4 is allowed, and the balls 6 can be always kept inside the channel and uniformly distributed along the circumferential direction due to the constraint of the circular arc-shaped channels of the screwed-in inner component 4 and the screwed-in outer component 5; finally, the screwing-in inner assembly 4 and the screwing-in outer assembly 5 are integrally connected to the machine base through the end cover 7, the proper gap between the screwing-in inner assembly 4 and the sleeve 3 is adjusted by adjusting the screwing-in depth of the screwing-in inner assembly 4, an external servo motor is fixedly arranged on the machine base, and the external servo motor is meshed with gear teeth in the screwing-in inner assembly 4 through a gear. When the magnetic suspension bearing works normally, the inner screwing component 4 is always kept at a proper position of initial adjustment, namely the position A shown in figure 1, due to the constraint of the servo motor on the inner screwing component, at the moment, a radial gap L1 and an axial gap L2 with uniform sizes are formed between the inner screwing component and the sleeve 3, so that the bearing device is protected from interfering the normal rotation of the rotor 1, wherein the axial gap L2 is the axial protection gap of the magnetic suspension bearing system, and the magnetic suspension bearing system is obtained by designing the taper size of the outer surface of the H2 section of the end part of the rotor.

When the magnetic suspension bearing system works normally, the radial clearance between the rotor 1 and a disc in the precession inner assembly 4 is about 0.15mm, the radial clearance between the rotor 1 and the sleeve 3 is slightly larger than 0.15mm, the axial clearance is about 0.2mm, the rotor 1, the rolling bearing 2 and the sleeve 3 rotate at high speed, and the precession inner assembly 4 is in a static state;

when the magnetic suspension bearing fails, the failure mode is divided into two cases: (1) when the magnetic suspension bearing system causes the instability of the rotor 1 to fall due to overload and the like, in the falling process of the rotor 1, the control system immediately controls the external servo motor to rotate after detecting the instability of the system, the servo motor drives the precession inner assembly 4 to carry out screwing action relative to the precession outer assembly 5, the radial and axial gaps between the sleeve 3 and the precession inner assembly 4 are simultaneously reduced, and when the sleeve 3 and the precession inner assembly 4 move to a relative position B, the gap between the sleeve 3 and the precession inner assembly 4 is reduced to zero, namely the radial and axial gaps between the outer ring of the rolling bearing 2 and the precession inner assembly 4 are eliminated; (2) when the magnetic suspension bearing system is completely powered off, the control system and the external servo motor lose the power supply at the moment, the rotor 1 and the rolling bearing 2 fall off, during the fall, since the radial clearance existing between the rotor 1 and the disc of the precessing inner assembly 4 is smaller than the radial clearance existing between the sleeve 3 and the precessing inner assembly 4, therefore, the outer surface of the rotor 1 first contacts and collides with the inner screwed component 4, at this time, there is a large relative speed between the rotor 1 and the inner screwed component 4 on the one hand, and there is a collision force on the other hand, the inner screwed component 4 rotates relative to the outer screwed component 5 due to the friction force generated by the collision force between the rotor 1 and the inner screwed component 4, during the rotation of the screwed-in inner component 4, the clearance between the screwed-in inner component 4 and the sleeve 3 is gradually reduced and finally reduced to zero, i.e. the radial and axial clearances between the outer ring of the rolling bearing 2 and the screwed-in inner component 4 are eliminated. The active and passive integrated protection bearing device for self-eliminating and restoring the radial and axial clearances of the outer ring of the bearing can realize active/passive simultaneous elimination of the radial and axial clearances between the rotor and the rolling bearing after the magnetic suspension bearing system is unstable under any condition, eliminates the impact and vibration of the rotor on the protection bearing after falling, and can obviously improve the reliability and the service life of the centripetal thrust protection bearing in the magnetic suspension bearing system.

The working principle of the invention is as follows: during installation, the size of a gap between the sleeve 3 and the screwed-in inner component 4 is adjusted by adjusting the screwing depth of the screwed-in inner component 4, and the external servo motor is utilized to restrict the screwed-in inner component 4, so that when the magnetic suspension bearing system normally operates, the gap between the screwed-in inner component 4 and the sleeve 3 is always kept unchanged (position A), at the moment, the rolling bearing 2 and the sleeve 3 normally rotate along with the rotor, the screwed-in inner component 4 keeps a static state relative to the screwed-in outer component 5, a normal radial protection gap (generally about 0.15mm) exists between the rotor 1 and a disc of the screwed-in inner component 4, and a normal axial protection gap (generally about 0.2mm) exists between the sleeve 1 and the screwed-in inner component 4. When the magnetic suspension bearing system fails due to overload and other situations, and the control system detects the instability of a rotor, the control system immediately controls the external servo motor to drive the precession inner assembly to perform a screwing action relative to the precession outer assembly 5, so that a gap between the sleeve 3 and the precession inner assembly 4 is gradually reduced to zero, namely, radial and axial gaps existing between the sleeve 3 and the precession inner assembly 4 are eliminated simultaneously, and the controller controls the external servo motor to eliminate the protection gap, so the protection device is called as an active self-elimination-recovery bearing outer ring radial and axial gap protection device; when the whole magnetic suspension bearing system causes the rotor 1 to fall due to power loss, the controller and the external servo motor are all ineffective to actively eliminate the gap, but because the rotor 1 firstly contacts and collides with the disc of the screw-in inner assembly 4 after falling, the rotor 1 rotating at high speed generates a collision force with the screw-in inner assembly 4 and also generates a tangential friction force, under the action of the friction force, the screw-in inner assembly 4 generates rotation in the same direction as the rotor 1, i.e. the screwing-in of the inner component 4 relative to the screwing-in of the outer component 5, when the screwing-in of the inner component 4 reaches the position B, the gap between the sleeve 3 and the precessing inner assembly 4 is completely eliminated, since the whole magnetic bearing system is de-energized, in the process of eliminating the clearance by the protection device, the active control system is not involved, and the clearance is completely and automatically eliminated by the protection device, so the protection device is called as a passive self-eliminating-restoring bearing outer ring diameter axial clearance protection device. When the clearance of the protection device is completely eliminated, the inner ring of the rolling bearing 2 still rotates around the rotation center of the magnetic suspension bearing system when the rotor 1 works normally, the sleeve 3, the outer ring of the rolling bearing 2 and the precession inner component 4 are stably supported by the balls 6 uniformly distributed along the circumferential direction in the circular arc-shaped channel, and the screw thread has the characteristic of self-locking, so that in the passive protection bearing device, the precession inner component 4 can not automatically generate rotary motion relative to the precession outer component 5, and in the active protection bearing device, the precession inner component 4 can not generate rotary motion due to the holding action of an external servo motor, the precession inner component 4 can not generate rotary motion, the sleeve 3 and the precession inner component 4 can not generate looseness, therefore, the rolling bearing can stably support the rotor to continue rotating all the time no matter the protection device is an active type or a passive type to eliminate the clearance, the collision between the rotor and the rolling bearing can not occur, repeated impact and vibration can not be generated on the rolling bearing 2, and the inner ring of the rolling bearing 2 is arranged on the rotor 1, and the sleeve 3 is arranged on the outer ring of the rolling bearing 2, so that the inner ring and the outer ring of the rolling bearing 2 can be arranged with pretightening force as required, the requirement of pretightening during high-speed operation of the rolling bearing is met, and the operation precision, reliability and service life of the protective bearing are improved. After the magnetic suspension bearing system recovers power supply or the control system recovers normal work, the control system controls the external servo motor to make the precession inner assembly generate convolution action, at the moment, the gap between the sleeve 3 and the precession inner assembly 4 is gradually increased from zero, after the precession inner assembly 4 convolutes to the initial position, the gap between the sleeve 3 and the precession inner assembly 4 recovers to the original state, namely, the protection device does not interfere with the normal work of the magnetic suspension bearing system again.

The above additional technical features can be freely combined and used in superposition by those skilled in the art without conflict.

It is to be understood that the present invention has been described with reference to certain embodiments, and that various changes in the features and embodiments, or equivalent substitutions may be made therein by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (5)

1. A protection device for automatically eliminating and recovering radial and axial clearances of an outer ring of a bearing in an active-passive integrated mode comprises a rotor (1), a protection bearing and an end cover (7), wherein the end cover (7) is fixedly connected with an external machine base;

the protective bearing comprises a rolling bearing (2), a sleeve (3), a screwing inner assembly (4), a screwing outer assembly (5) and balls (6);

the outer circle surface of the precession outer assembly (5) is arranged on the end cover (7), a circle of arc-shaped channel is arranged at the end, close to the ball (6), of the inner circle surface, and an internal thread matched with an external thread G3 on the outer circle surface of the precession inner assembly (4) is arranged at the other end of the inner circle surface;

the ball (6) is arranged between the circular arc-shaped channels of the precession inner component (4) and the precession outer component (5);

the method is characterized in that:

the inner ring of the rolling bearing (2) is directly arranged at the end part of the rotor (1) in an interference fit manner;

the inner circle of the sleeve (3) is arranged on the outer ring of the rolling bearing (2), the outer circle surface of the sleeve (3) is processed into a slope H1 with smaller taper and a slope H2 with larger taper, and the slopes with two different tapers are alternately arranged along the axial direction;

the inner screw-in component (4) is characterized in that 1-2 circles of external threads G3 are arranged at the axial middle position of the outer circle surface of the inner screw-in component (4), the screwing direction of the external threads G3 is consistent with the rotating direction of the rotor (1), one end close to a ball (6) is axially provided with a plurality of arc-shaped channels G2 consistent with the lead of the external threads G3, the other end is circumferentially provided with gear teeth G4 and is connected with an external servo motor, one end of the inner circle of the inner screw-in component (4) close to the ball (6) is processed into an inclined plane consistent with the outer circle of the sleeve (3) and is arranged at the periphery of the sleeve (3), the inner surface of the inner screw-in component (4) and the outer surface of the sleeve (3) have a radial gap L1 with uniform size, the axial gap is L2, the middle part of the inner circle of the inner screw-in component (4) is processed into a disc shape, the radial gap between the inner screw-in the inner, and L1 is set to be greater than L3.

2. The active-passive integrated protection device for self-eliminating and restoring radial and axial clearances of the outer ring of the bearing according to claim 1, characterized in that: the number of the balls (6) is 2-200.

3. The active-passive integrated protection device for self-eliminating and restoring radial and axial clearances of the outer ring of the bearing according to claim 1, characterized in that: the rolling bearing (2) is a deep groove ball bearing, a pair of angular contact bearings or a ceramic ball bearing.

4. The active-passive integrated protection device for self-eliminating and restoring radial and axial clearances of the outer ring of the bearing according to claim 1, characterized in that: the thread shape of the external thread G3 screwed into the inner component (4) and the thread shape of the internal thread screwed into the outer component (5) can be rectangular, trapezoidal, saw-toothed or common thread.

5. The active-passive integrated protection device for self-eliminating and restoring radial and axial clearances of the outer ring of the bearing according to claim 1, characterized in that: the protective bearing is made of metal or a composite material made of carbon fiber/glass fiber.

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