High wear-resistant high-speed magnetic suspension motor protection bearing based on variable stiffness damping

Abstract

The application provides a high-wear-resistance high-speed magnetic suspension motor protection bearing based on variable stiffness damping, and belongs to the technical field of magnetic suspension motors. The technical problems that the service life of the bearing is short, the coaxiality of the rotor cannot be guaranteed, and the bearing does not have the functions of buffering and damping are solved. The technical scheme is as follows: a high-wear-resistance high-speed magnetic suspension motor protection bearing based on variable stiffness damping, which comprises an inner ring assembly, an outer ring oil chamber, a valve control assembly and an energy accumulator. The inner ring assembly is sequentially provided with a silicon ceramic gasket, a gasket base and a ball from inside to outside. The outer ring oil chamber is arranged outside the inner ring assembly and comprises an outer concave disc, an inner concave disc, a polyurethane inner sealing ring and a fluorine rubber outer sealing ring. The valve control assembly comprises a throttle valve and a one-way valve which are arranged in parallel. The application has the beneficial effects that the rigid support required by the motor rotor during operation is guaranteed, the impact and vibration caused by the rotor after parking are mitigated and attenuated, and the coaxiality of the rotor is greatly protected.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of magnetic suspension motors, and in particular to a high-wear-resistance high-speed magnetic suspension motor protection bearing based on variable stiffness vibration reduction. BACKGROUND

[0002] A bearing is an important part in contemporary mechanical equipment, and its main functions are to support a mechanical rotating body, reduce the friction coefficient in the movement process, and ensure the rotation accuracy; the protection bearing is a branch of the bearing, and is applied to a high-speed magnetic suspension motor; when the motor is running, the rotor is in non-contact with the protection bearing; and when the motor is stopped, the rotor will fall onto the protection bearing.

[0003] Chinese patent CN101307798A discloses a piston type hydraulic bearing, and the piston body connected with a high-pressure oil channel is used to abut against a rotating shaft and an inner ring of the bearing; the patent can solve the axial deviation of the rotating shaft and the bearing, but cannot relieve the impact and vibration of the rotating shaft, and the working mode of using the high-pressure oil channel has high energy consumption and low cost performance; Chinese patent CN102792051B discloses a self-adaptive engine bearing, which achieves the purpose of inhibiting low and high frequency vibration by arranging an oil chamber, a one-way valve and a throttle hole; however, the bearing can only inhibit the axial vibration, the working mode is single, and the complex process and structure result in high cost; and Chinese patent CN115727090A discloses a hydraulic bearing, which is provided with first and second working chambers between an inner core and an outer sheath, and the direction displacement of the inner core is adjusted by changing the oil volume; although the bearing can realize high damping power in a wide frequency range, the elastic material used in the bearing replaces the traditional ball (column), and the service life is general under harsh working conditions, and the bearing cannot provide large rigid support when the rotating shaft is running.

[0004] Therefore, the current protection bearing still has the following shortcomings in design:

[0005] 1. A single mechanical structure is still used, the number of times that the protection bearing can protect the magnetic suspension bearing from damage is small, and the service life is low;

[0006] 2. Since the protection bearing is a rigid element, the reaction force of the protection bearing on the rotor cannot guarantee the coaxiality of the rotor when the protection bearing is impacted, and the protection bearing also does not have the function of buffering and damping;

[0007] 3. The friction heat caused by the rotor cannot be efficiently dissipated.

[0008] Therefore, a high-wear-resistance high-speed magnetic suspension motor protection bearing based on variable stiffness vibration reduction is needed to solve the above technical problems. SUMMARY

[0009] In view of the above technical deficiencies, the present application aims to provide a high-wear-resistant high-speed magnetic suspension motor protection bearing based on variable stiffness damping, which adopts oil-gas damping, double-working-condition control oil path, silicon nitride ceramic bearing surface and variable stiffness structure, thereby ensuring the rigid support required by the motor rotor during operation, mitigating the impact and vibration caused by the rotor after parking, greatly protecting the coaxiality of the rotor, avoiding damage to the bearing surface of the protection bearing and the magnetic suspension bearing caused by parking impact, and having good heat dissipation effect.

[0010] To achieve the above-mentioned application purposes, the present application adopts the technical solution, specifically a high-wear-resistant high-speed magnetic suspension motor protection bearing based on variable stiffness damping, comprising an inner ring assembly, an outer ring oil chamber, a valve control assembly and an accumulator, the inner ring assembly is sequentially provided with a silicon nitride ceramic gasket, a gasket base and a ball from inside to outside; the outer ring oil chamber is arranged outside the inner ring assembly and comprises an outer concave disc, an inner concave disc, a polyurethane inner sealing ring and a fluororubber outer sealing ring, the polyurethane inner sealing ring and the fluororubber outer sealing ring are arranged between the outer concave disc and the inner concave disc and are in close contact with the outer concave disc and the inner concave disc to form a closed oil chamber, the outer concave disc and the inner concave disc are arranged in relative sliding mode to change the volume of the closed oil chamber.

[0011] The valve control assembly comprises a throttle valve and a one-way valve arranged in parallel, one end of the throttle valve and the one-way valve is connected with the accumulator, and the other end is connected with a solenoid valve, the solenoid valve is communicated with the closed oil chamber through an oil pipe, and the outer ring oil chamber forms a damping oil path with the accumulator through the opening and closing of the solenoid valve.

[0012] Further, the cross sections of the inner concave disc and the outer concave disc are U-shaped structures.

[0013] Further, the outer concave disc comprises an outer concave male disc and an outer concave female disc, and the outer concave male disc and the outer concave female disc are interference-fitted.

[0014] Further, the gasket base comprises a base female piece and a base male piece, and the base female piece and the base male piece are interference-fitted.

[0015] Further, the gasket base and the ball are in point contact.

[0016] Further, the silicon nitride ceramic gasket and the gasket base are head riveted, and the worn silicon nitride ceramic gasket can be replaced without replacing the main body structure.

[0017] Further, the solenoid valve adopts a two-position two-way solenoid valve, which forms a passage when the motor is powered on and forms an open circuit when the motor is working; the elastic medium in the accumulator adopts nitrogen, which can adaptively change the stiffness in a nonlinear manner according to the impact load, which is more conducive to mitigating the impact, and the throttle valve as a damping element can better attenuate the vibration.

[0018] Further, the motor rotor and the protection bearing are in direct contact through a silicon nitride ceramic gasket, which is made of high wear-resistant silicon nitride ceramic material.

[0019] Further, the silicon nitride ceramic gasket and the gasket base are connected by riveting.

[0020] Further, the oil pipe is a rubber pipe made of rubber material, and the joint type is a buckling joint. The buckling joint has high sealing performance, can effectively prevent liquid leakage, and can be quickly installed and disassembled.

[0021] Compared with the prior art, the beneficial effects of the present application are:

[0022] 1. The structure of oil and gas damping and double working condition control oil way not only ensures the rigid support required when the motor rotor works, but also alleviates the impact and vibration caused by the rotor after parking, greatly protects the coaxiality of the rotor, and avoids the damage of the protection bearing bearing surface and the magnetic suspension bearing caused by parking impact;

[0023] 2. The structure of the silicon nitride ceramic bearing surface and the riveting mode of connecting the silicon nitride ceramic gasket and the gasket base greatly improve the service life of the bearing, avoid the electric erosion of the inner core surface of the bearing, and are more convenient for later maintenance;

[0024] 3. The nitrogen gas chamber in the accumulator is used as an elastic medium, which can adaptively change the stiffness in a nonlinear manner according to the impact load, and is more conducive to alleviating the impact;

[0025] 4. The circulation of oil liquid in the valve control assembly can take away the heat generated by the bearing, greatly improving the heat dissipation effect of the bearing. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation on the present application.

[0027] Figure 1 It is a schematic diagram of the overall structure of the present application.

[0028] Figure 2 It is a three-dimensional half-sectional view of the inner ring assembly and the outer cavity oil chamber of the present application.

[0029] Figure 3 It is a three-dimensional half-sectional view of the gasket base of the present application.

[0030] Figure 4 It is a three-dimensional half-sectional view of the outer concave disc of the present application.

[0031] The attached figures are labeled as follows: 1. Silicon nitride ceramic gasket; 2. Gasket base; 2-1. Base female plate; 2-2. Base male plate; 3. Ball bearing; 4. Outer concave disc; 4-1. Outer concave male disc; 4-2. Outer concave female disc; 5. Polyurethane inner sealing ring; 6. Fluororubber outer sealing ring; 7. Inner concave disc; 8. Accumulator; 9. Throttling valve; 10. Check valve; 11. Solenoid valve; 12. Oil pipe; 13. Sealed oil chamber. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] like Figures 1 to 4 As shown, a high wear-resistant high-speed magnetic levitation motor protection bearing based on variable stiffness vibration reduction includes: an inner ring assembly, an outer ring oil chamber, a valve control assembly, an accumulator 8, and an oil pipe 12.

[0034] The inner ring assembly includes a silicon nitride ceramic gasket 1, a gasket base 2, and a ball bearing 3. The gasket base 2 is composed of a base female piece 2-1 and a base male piece 2-2 with an interference fit. The silicon nitride ceramic gasket 1 and the gasket base 2 are countersunk riveted, and the gasket base 2 and the ball bearing 3 are in point contact.

[0035] The outer oil chamber includes an outer concave disc 4, an inner concave disc 7, a polyurethane inner sealing ring 5, and a fluororubber outer sealing ring 6. The outer concave disc 4 is composed of an outer concave male disc 4-1 and an outer concave female disc 4-2 connected by an interference fit. The polyurethane inner sealing ring 5 and the fluororubber outer sealing ring 6 fill the two sides of the inner concave disc 7. The polyurethane inner sealing ring 5 and the fluororubber outer sealing ring 6 are placed between the outer concave disc 4 and the inner concave disc 7. The outer concave disc 4 and the inner concave disc 7 are in close contact to form a closed oil chamber 13.

[0036] The valve control assembly includes a throttle valve 9, a check valve 10, and a two-position two-way solenoid valve 11. The throttle valve 9 and the check valve 10 form a parallel oil circuit and are connected in series with the two-position two-way solenoid valve 11. The oil pipe 12 is a rubber pipe made of rubber material, and the joint type is a crimped joint. When the motor stops, the two-position two-way solenoid valve 11 is energized, and the outer oil chamber is connected to the accumulator. The nitrogen chamber in the accumulator begins to act as an elastic element, and the throttle valve 9 acts as a damping element. When the motor is running, the two-position two-way solenoid valve 11 is de-energized, and the outer oil chamber is disconnected from the accumulator 8.

[0037] The working process of a high-wear-resistant, high-speed magnetic levitation motor protective bearing based on variable stiffness vibration reduction is as follows:

[0038] Reference Figure 1When the motor works, the rotor does not contact with the protection bearing, the protection bearing is in the idle state, the two-position two-way electromagnetic valve 11 is de-energized and closed, the accumulator 8 is in the disconnected state with the outer ring oil chamber, and the protection bearing plays a rigid support role at this time;

[0039] When the motor stops, the rotor will fall on the protection bearing and directly impact the friction silicon nitride ceramic gasket 1, at this time, the two-position two-way valve 11 is energized and opened, the accumulator 8 is communicated with the closed oil chamber 13 through the one-way valve 10 and the throttle valve 9, the bearing will vibrate when impacted, and the closed oil chamber 13 will alternately appear two states of extrusion and recovery in the vibration process, because the vibration is in the form of a wave, when the closed oil chamber 13 is extruded, the outward concave disc 4 and the inward concave disc 7 produce a displacement of opposite motion, at this time, the volume of the closed oil chamber 13 is reduced, the oil in the closed oil chamber 13 is pressed, and will flow to the accumulator 8 through the oil pipe 12, the two-position two-way electromagnetic valve 11 and the one-way valve in turn, the nitrogen chamber in the accumulator 8 acts as an elastic element to alleviate the impact of the falling rotor; when the closed oil chamber 13 recovers, the inward concave disc 7 and the outward concave disc 4 move away from each other, at this time, the volume of the closed oil chamber 13 is increased, and the pressure is reduced, the oil in the accumulator 8 will flow to the closed oil chamber 13 through the throttle valve 9, the throttle valve 9 acts as a damping element and can attenuate the vibration caused by the rotor, the stiffness of the throttle valve 9 changes non-linearly with the load, and the impact caused by the falling rotor can be better alleviated, the throttle valve 9 acts as a damping element and can attenuate the vibration caused by the rotor more quickly, in addition, because the parameter setting of the accumulator 8 has considered the influence of the load variation range in advance, the protection bearing always limits the maximum radial displacement of the rotor in the vibration reduction process, and the situation that the rotor touches the magnetic suspension bearing is avoided; when the rotor completely stops running, the volume of the nitrogen chamber in the accumulator 8 tends to be stable, the stiffness remains unchanged, and at this time, the two-position two-way electromagnetic valve 11 is de-energized and closed.

[0040] In summary, the oil-gas vibration damping, double-working-condition control oil circuit, silicon nitride ceramic bearing surface and variable stiffness structure are adopted, the rigid support required when the motor rotor works is ensured, the impact and vibration caused by the rotor after stopping are alleviated and attenuated, the coaxiality of the rotor is greatly protected, and the damage to the protection bearing and the magnetic suspension bearing caused by the stopping impact is avoided, and the high-efficiency vibration damping, wear resistance and safety and reliability are achieved.

[0041] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness vibration damping, characterized by: The inner ring assembly, the outer ring oil chamber, the valve control assembly and the accumulator (8); The inner ring assembly comprises, from inside to outside, a silicon nitride ceramic gasket (1), a gasket base (2) and a ball (3); The outer ring oil chamber is arranged outside the inner ring assembly and comprises an outer concave disc (4), an inner concave disc (7), a polyurethane inner sealing ring (5) and a fluororubber outer sealing ring (6), the polyurethane inner sealing ring (5) and the fluororubber outer sealing ring (6) are arranged between the outer concave disc (4) and the inner concave disc (7) and are in contact with the outer concave disc (4) and the inner concave disc (7) to jointly form a closed oil chamber (13), the outer concave disc (4) and the inner concave disc (7) are arranged in relative sliding mode between each other for changing the volume of the closed oil chamber (13); The valve control assembly comprises a solenoid valve (11), a throttle valve (9) and a check valve (10) which are connected in parallel with each other, one end of the throttle valve (9) and the check valve (10) is connected with the accumulator (8) and the other end is connected with one end of the solenoid valve (11), the other end of the solenoid valve (11) is communicated with the closed oil chamber (13) through an oil pipe (12), the outer ring oil chamber is controlled by the solenoid valve (11) to be in communication or closed with the accumulator (8) to form a damping oil path.

2. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 1, characterized in that, The cross section of the inner concave disc (7) and the outer concave disc (4) is semicircular structure.

3. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 2, characterized in that, The outer concave disc (4) comprises an outer concave male disc (4-1) and an outer concave female disc (4-2), the outer concave male disc (4-1) and the outer concave female disc (4-2) are in interference fit.

4. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 1, characterized in that, The gasket base (2) comprises a base female sheet (2-1) and a base male sheet (2-2), the base female sheet (2-1) and the base male sheet (2-2) are in interference fit.

5. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 4, characterized in that, The gasket base (2) and the ball (3) are in point contact.

6. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 1, characterized in that, The silicon nitride ceramic gasket (1) is in flush joint with the gasket base (2).

7. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 6, characterized in that, The silicon nitride ceramic gasket (1) is made of high wear-resistant silicon nitride ceramic material.

8. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 1, characterized in that, The elastic medium in the accumulator (8) is nitrogen.

9. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 1, characterized in that, The solenoid valve (11) is a two-position two-way solenoid valve.

10. A high wear resistant high speed magnetic levitation motor protection bearing based on variable stiffness damping according to claim 1, characterized in that, The oil pipe (12) is a rubber pipe made of rubber material and the end part adopts a buckling joint.

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