Electromagnetic bearing structure integrated with mechanical security

Abstract

The invention discloses an electromagnetic bearing structure integrated with mechanical security, which is used on electromagnetic bearing equipment to realize mechanical security and comprises an electromagnetic bearing thrust disc, an overspeed protector, a pilot valve assembly and an electromagnetic bearing body, and the pilot valve assembly, a stop valve and a main valve actuator are mounted on the electromagnetic bearing body. A fly ball type mechanical overspeed protector is installed at the end of the electromagnetic bearing thrust disc, the overspeed protector is impacted by a fly ball which rapidly flies out to trigger a pilot valve assembly, and the pilot valve assembly acts to trigger a main valve actuator to be rapidly closed. According to the electromagnetic bearing structure integrated with the mechanical security, integration of the electromagnetic bearing and the mechanical security is achieved; the security reliability of the unit is upgraded; the internal maintenance requirements of the electromagnetic bearing can be met; multiple locking devices are arranged in the structure, so that the safety is good; the end face large threads are good in overall rigidity and have good torque transmission and positioning functions.

Description

TECHNICAL FIELD

[0001] The present application relates to a rotating electromagnetic bearing device, in particular to an integrated mechanical safety electromagnetic bearing structure for a rotating electromagnetic bearing device. BACKGROUND

[0002] Electromagnetic bearings are gradually widely used due to the advantages of non-contact, low friction, adaptation to high speed, etc. However, the overspeed protection of the existing electromagnetic bearing unit often adopts full-electric safety, or the mechanical safety is separately installed in an area far away from the main electromagnetic bearing. The existing overspeed protection system cannot simultaneously meet the comprehensive needs of safety and compactness of high-speed rotating equipment.

[0003] In the existing related patent technology, such as patent document (CN209942886U), a screw expander overspeed protection device is disclosed. The core principle is that the fly hammer, elastic element and guide assembly are arranged inside the impact sub-shell connected with the rotor. When the normal rotating speed, the pre-pressing force of the elastic element is greater than the centrifugal force of the fly hammer, the fly hammer remains in the initial position. When the overspeed, the centrifugal force is greater than the pre-pressing force, the fly hammer extends to impact the oil door pull hook, and mechanical emergency stop is realized. However, this patent is only designed for the "∞" shaped cylinder structure and rotor characteristics of the screw expander, and cannot be directly migrated to other high-speed rotating equipment such as electromagnetic bearings, gas turbines and centrifugal compressors. Moreover, the mechanical safety is separated from the bearing system, the integration degree is low, the installation and maintenance complexity is high, and the space layout does not match the needs of high-speed equipment.

[0004] Therefore, there is an urgent need for an integrated mechanical safety electromagnetic bearing structure to solve the defects of the existing electromagnetic bearing unit full-electric safety scheme and the low integration degree of the independent mechanical safety scheme.

[0005] Content of the application

[0006] The present application is aimed at the defects of the existing electromagnetic bearing unit full-electric safety scheme and the low integration degree of the independent mechanical safety scheme, and proposes an integrated mechanical safety electromagnetic bearing structure, which breaks the separation design of the mechanical safety device and the electromagnetic bearing body, improves the equipment integration degree, upgrades the safety reliability of the unit, and simultaneously considers the installation and maintenance convenience.

[0007] To achieve the above-mentioned purpose, the technical scheme of the present application is: an integrated mechanical safety electromagnetic bearing structure for realizing mechanical safety on an electromagnetic bearing device, comprising: an electromagnetic bearing thrust disc, an overspeed safety device, an oil door assembly, an electromagnetic bearing body, the electromagnetic bearing body being provided with the oil door assembly, a cut-off valve and a main valve actuator, the electromagnetic bearing thrust disc being provided at the end with the fly hammer type mechanical overspeed safety device, the overspeed safety device being impacted by the fly hammer to touch and drive the oil door assembly, so that the oil door assembly is actuated to trigger the main valve actuator to be closed quickly.

[0008] Further, the fly hammer of the fly hammer type machine is pre-tightened by the spring force and is located on the rotating shaft, rotates with the rotating shaft, and the centrifugal force is proportional to the square of the rotating speed; when the rotating speed exceeds a certain set value, the centrifugal force is greater than the spring pressure, the fly hammer is quickly ejected under the action of the centrifugal force, and the oil gate assembly is triggered to act on the main steam valve actuator to quickly close.

[0009] Further, after the overspeed protector acts, the rotating speed of the unit decreases, the centrifugal force of the fly hammer decreases, and when the rotating speed is less than a certain value, the centrifugal force is less than the spring force, and the fly hammer is quickly reset.

[0010] Further, the electromagnetic bearing thrust disc serves as an electromagnetic axial limiting element and a mounting base of the overspeed protector.

[0011] Further, the electromagnetic bearing body is a mounting base of the electromagnetic bearing stator part and the oil gate assembly, and realizes organic coupling of the electromagnetic bearing and the mechanical security.

[0012] Further, the electromagnetic bearing thrust disc is fixed on the rotor through a large screw thread at the shaft end, is positioned through an end face, four axial bolts are arranged in the inner ring to prevent the large screw thread at the shaft end from loosening, and lock washers are used to prevent the axial bolts from loosening.

[0013] Further, the axial bolts are sunk in the electromagnetic bearing thrust disc, and are used to reduce the blowing heat during the operation of the rotor.

[0014] Further, the electromagnetic bearing thrust disc is provided with a spline interface, which is used for accurate control of the installation torque of the entire electromagnetic bearing thrust disc, and facilitates disassembly and assembly of the electromagnetic bearing thrust disc.

[0015] Further, the electromagnetic bearing thrust disc is also provided with a speed measuring tooth, which is used for phase measurement and rotating speed measurement for electromagnetic bearing control, and realizes unit speed regulation and bearing control.

[0016] Further, the electromagnetic bearing thrust disc is also provided with a dynamic balancing screw hole, which is used for overall balance of the electromagnetic bearing thrust disc and on-site dynamic balance requirement of the unit.

[0017] The beneficial effects of the present application are: The integrated mechanical security electromagnetic bearing structure of the present application realizes integration of the electromagnetic bearing and the mechanical security; upgrades the security reliability of the unit; is convenient to disassemble and assemble, can match the internal maintenance requirement of the electromagnetic bearing; has good safety due to the multiple anti-loosening structure; and has good overall rigidity of the end face large screw thread, and has good torque transmission and positioning functions. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the overall view of the integrated mechanical security electromagnetic bearing structure provided by the embodiment of the present application; Figure 2 is a structure view of the electromagnetic bearing thrust disc; In the figure: 1-electromagnetic bearing thrust plate, 2-over-speed protector, 3-misoperation valve assembly, 4-electromagnetic bearing body, 5-axial bolt, 6-loose washer, 7-spline interface, 8-speed measuring tooth, 9-dynamic balance screw hole. DETAILED DESCRIPTION

[0019] The application will be further described in detail below in combination with the drawings and examples.

[0020] As Figure 1 , 2, the integrated mechanical security electromagnetic bearing structure provided by the embodiment of the application can realize mechanical security on the electromagnetic bearing equipment, mainly comprising: an electromagnetic bearing thrust plate 1, an over-speed protector 2, a misoperation valve assembly 3, an electromagnetic bearing body 4, an axial bolt 5, a loose washer 6, a spline interface 7, a speed measuring tooth 8, and a dynamic balance screw hole 9.

[0021] The misoperation valve assembly 3, a cut-off valve, a main valve actuator and the like are installed on the electromagnetic bearing body 4. The over-speed protector 2 of the fly hammer type machinery is installed at the end of the electromagnetic bearing thrust plate 1. The fly hammer of the fly hammer type machinery is in place on the rotating shaft under the pre-tightening force of the spring and rotates together with the rotating shaft. The centrifugal force of the fly hammer is proportional to the square of the rotating speed. When the rotating speed exceeds a certain set value, the centrifugal force is greater than the spring pressure, and the fly hammer will quickly fly out under the action of the centrifugal force, triggering the main valve to close at high speed. After the action of the protector, the rotating speed of the unit decreases, and the centrifugal force of the fly hammer decreases. When the rotating speed decreases to less than a certain value, the centrifugal force is less than the spring force, and the fly hammer quickly returns to the original position.

[0022] The electromagnetic bearing thrust plate 1 is not only the core element of the electromagnetic axial limiting, but also the installation base body of the over-speed protector 2. The electromagnetic bearing body 4 is not only the stator part of the electromagnetic bearing, but also the installation base body of the misoperation valve assembly 3, thereby realizing the organic coupling of the electromagnetic bearing and the mechanical security.

[0023] The electromagnetic bearing thrust plate 1 is fixed on the rotor through the shaft end large thread, is positioned through the end face, and the inner ring is provided with four axial bolts 5 to prevent the shaft end large thread from loosening. The loose washer 6 can prevent the axial bolt 5 from loosening. In order to reduce the air blowing heat of the rotor as much as possible, the axial bolt 5 is sunk in the electromagnetic bearing thrust plate 1.

[0024] In order to match the electromagnetic bearing and other application requirements of the unit, the spline interface 7 can also be arranged on the electromagnetic bearing thrust plate 1. The spline interface 7 is used for accurate control of the installation torque of the entire electromagnetic bearing thrust plate 1 and convenient disassembly and assembly of the electromagnetic bearing thrust plate 1.

[0025] The speed measuring tooth 8 is used for phase measurement and unit rotating speed measurement for electromagnetic bearing control, realizing unit speed regulation and bearing control.

[0026] Dynamic balance screw hole 9, for the overall balance of the electromagnetic bearing thrust disc 1, and the on-site dynamic balance requirement of the unit.

[0027] The above-described embodiments are only a preferred scheme of the present application, and are not intended to limit the present application. Those skilled in the art can make various changes and modifications without departing from the concept and scope of the present application. Therefore, any technical scheme obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present application.

Claims

1. An electromagnetic bearing structure integrating mechanical safety features, used to achieve mechanical safety features on electromagnetic bearing equipment, characterized in that, include: The electromagnetic bearing thrust plate, overspeed safety device, misalignment valve assembly, and electromagnetic bearing body are equipped with a misalignment valve assembly, shut-off valve, and main steam valve actuator. The end of the electromagnetic bearing thrust plate is equipped with a hammer-type mechanical overspeed safety device. The overspeed safety device is triggered by the impact of a rapidly flying hammer on the misalignment valve assembly, causing the misalignment valve assembly to activate and trigger the main steam valve actuator to close quickly.

2. The electromagnetic bearing structure for integrated mechanical security as described in claim 1, characterized in that, In a flying hammer type machine, the flying hammer is positioned on the rotating shaft by the spring preload and rotates together with the shaft. Its centrifugal force is proportional to the square of the rotation speed. When the rotation speed exceeds a certain set value, the centrifugal force is greater than the spring pressure, and the flying hammer flies out rapidly under the action of centrifugal force. The throttle assembly then triggers the main steam valve actuator to close quickly.

3. The electromagnetic bearing structure for integrated mechanical security according to claim 2, characterized in that, After the overspeed safety device is activated, the unit speed decreases, the centrifugal force of the flyweight decreases, and when the speed drops below a certain value, the centrifugal force is less than the spring force, and the flyweight quickly resets.

4. The electromagnetic bearing structure for integrated mechanical security according to claim 1, characterized in that, The electromagnetic bearing thrust plate serves as the mounting base for electromagnetic axial limiting elements and overspeed protection devices.

5. The electromagnetic bearing structure for integrated mechanical security according to claim 1, characterized in that, The electromagnetic bearing body serves as the mounting base for the electromagnetic bearing stator and the throttle valve assembly, achieving an organic coupling between the electromagnetic bearing and mechanical safety.

6. The electromagnetic bearing structure for integrated mechanical security according to claim 1, characterized in that, The electromagnetic bearing thrust plate is fixed to the rotor by the large thread at the shaft end and positioned by the end face. Four axial bolts are set on the inner ring to prevent the large thread at the shaft end from loosening, and anti-loosening washers are used to prevent the axial bolts from loosening.

7. The electromagnetic bearing structure for integrated mechanical security according to claim 6, characterized in that, The axial bolts are recessed inside the electromagnetic bearing thrust plate to reduce the heat generated by the blower air during rotor operation.

8. The electromagnetic bearing structure for integrated mechanical security according to claim 1, characterized in that, The electromagnetic bearing thrust plate is equipped with a splined interface for precise control of the installation torque of the entire electromagnetic bearing thrust plate, as well as for convenient disassembly and assembly of the electromagnetic bearing thrust plate.

9. The electromagnetic bearing structure for integrated mechanical security according to claim 1, characterized in that, The electromagnetic bearing thrust disc is also equipped with speed measuring teeth for measuring the phase and unit speed for electromagnetic bearing control, thereby enabling unit speed regulation and bearing control.

10. The electromagnetic bearing structure for integrated mechanical security according to claim 1, characterized in that, The electromagnetic bearing thrust plate is also equipped with dynamic balancing screw holes for overall balancing of the electromagnetic bearing thrust plate and for on-site dynamic balancing requirements of the unit.

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