A force transmission support mechanism for a vertical magnetic levitation flywheel rotor

Abstract

A force transmission support mechanism for a vertical magnetic levitation flywheel rotor provides radial support to the flywheel rotor through cylindrical roller bearings with interference fit to the upper squirrel cage elastic support and the upper flywheel rotor shaft; it provides bidirectional radial and axial support to the flywheel rotor through deep groove ball bearings and paired angular contact bearings; and it increases the stability of the squirrel cage elastic support by applying tensile force through the upper and lower squirrel cage elastic supports. When the flywheel rotor vibrates, friction is generated through the relative sliding between the dynamic and static friction plates in the upper master-controlled dry friction damper and the dynamic and static friction plates in the lower master-controlled dry friction damper, thereby absorbing and dissipating the vibration energy generated by the flywheel rotor. This avoids the problem of excessive axial load and short lifespan of a single deep groove ball bearing, and ensures stable rotor operation when the magnetic bearing fails. This invention has a simple structure, low cost, and high reliability.

Description

Technical Field

[0001] This invention relates to the field of electrical energy conversion and storage technology, specifically a force transmission support mechanism for a vertical magnetic levitation flywheel rotor. Background Technology

[0002] Flywheel energy storage is a physical energy storage technology that converts electrical energy into kinetic energy using a bidirectional motor. It boasts advantages such as high energy density, fast response, long lifespan, and low pollution, and has broad application prospects in energy storage, uninterruptible power supplies, and smoothing wind power output. However, its high-speed operation in a vacuum environment, with repeated acceleration and deceleration, continuously causes changes in the magnitude and direction of the load on the rotor-support system, thus exacerbating vibration problems. Therefore, it is necessary to study rotor load-bearing schemes and vibration control under such complex operating conditions to provide support for the high reliability, long lifespan, and stable operation of the flywheel, ensuring the stable operation of the rotor system. Generally, a combination of magnetic bearings and mechanical bearings, along with dampers, is used to achieve these goals.

[0003] An invention patent application (application number 201110038546.2) discloses a flywheel energy storage device with a permanent magnet bearing and a thrust bearing. The device uses a thrust bearing for force transmission, and a ball joint is located at the lower end of the lower flywheel rotor shaft. The ball joint is situated in a groove at the top of the bearing housing, and the bearing is immersed in lubricating oil to reduce friction loss. A titanium carbide film coating, a titanium nitride film coating, a titanium film coating, or a diamond film coating are applied to the surface of the bearing housing groove and the ball joint to further extend the bearing's service life. The invention has a drawback: the upper end of the flywheel lacks a force transmission support and is a free end. When subjected to disturbances such as magnetic bias from the motor, it is prone to large vibrations leading to instability. Furthermore, in a vacuum environment, it is difficult to form a complete oil film, resulting in insufficient lubrication and high friction loss. In his article "Flywheel energy storage system with apermanent magnet bearing and a pair of hybrid ceramic ball bearings[J]. Journal of Mechanical Science and Technology, 2014(28):5043-5053." (DOI:10.1007 / s12206-014-1125z), Shuyun Jiang describes a force transmission support scheme using hybrid ceramic ball bearings for both the upper and lower support bearings. Hybrid ceramic bearings can withstand both radial and axial loads and operate at high speeds. The flywheel rotor is supported and constrained at both ends, ensuring stable rotor operation. However, hybrid ceramic bearings have a small axial clearance and do not allow for large axial movements. When the flywheel rotor expands due to thermal expansion, the bearing may seize, reducing its service life.

[0004] In his article “Nonlinear dynamic characteristics and stability analysis of energy storage flywheel rotor with shape memory allory damper[J]. Journal of Energy Storage, 2022(45)” (DIO:10.016 / j.est.2021.1033392), Xiao-Huan Li used a shape memory alloy damper to suppress flywheel rotor vibration. However, shape memory alloys work slowly and cannot cope with the complex working conditions where flywheel rotors need to respond quickly.

[0005] Invention application number 202021721641 discloses a flywheel rotor system supported by a vertical permanent magnet bearing and a hydrodynamic bearing. In this rotor system, both the upper and lower supports of the flywheel rotor are equipped with extruded film dampers, achieving highly efficient vibration suppression for multiple rotor modes. To reduce wind resistance losses, the flywheel operates in a vacuum environment, resulting in poor heat dissipation. The fluid inside the extruded film damper is significantly affected by temperature; at higher temperatures, its viscosity decreases, reducing the vibration damping effect. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, such as the inability to effectively suppress flywheel rotor vibration under complex working conditions, the inability to guarantee long-term stable operation of flywheel rotor, and the short lifespan of mechanical bearings, this invention proposes a force transmission support mechanism for a vertical magnetic levitation flywheel rotor.

[0007] This invention includes an upper force transmission support assembly, a lower force transmission support assembly, a motor / generator stator coil, and a flywheel rotor. The flywheel rotor includes an upper flywheel rotor shaft, an axial magnetic bearing, a flywheel, and a lower flywheel rotor shaft. Specifically: the lower end face of the upper flywheel rotor shaft is fixed to the upper end face of the flywheel, and the upper end face of the lower flywheel rotor shaft is fixed to the lower end face of the flywheel; the upper flywheel rotor shaft, lower flywheel rotor shaft, and flywheel are coaxial. The axial magnetic bearing is fixed at the outer edge of the upper end face of the flywheel. The flywheel rotor is constituted by the upper flywheel rotor shaft, the flywheel, and the lower flywheel rotor shaft.

[0008] The upper force transmission support assembly is characterized in that it is located at the upper end of the upper flywheel rotor shaft, and the upper flywheel rotor shaft is mounted in the upper squirrel cage elastic support of the upper force transmission support assembly via cylindrical roller bearings. The lower force transmission support assembly is located at the lower end of the lower flywheel rotor shaft, and the lower flywheel rotor shaft is mounted in the lower squirrel cage elastic support of the lower force transmission support assembly via deep groove ball bearings and paired angular contact ball bearings.

[0009] The force-bearing support assembly includes an upper squirrel cage elastic support, an upper support, and an upper main-controlled elastic dry friction damper. The upper main-controlled elastic dry friction damper includes a piezoelectric ceramic actuator, a static friction plate, and a dynamic friction plate. The upper squirrel cage elastic support is located within the upper support, with its flange outer surface interference-fitted to the inner surface of the large end face of the upper support. The static friction plate of the upper main-controlled elastic dry friction damper is fixed at the outer edge of the small inner diameter end face of the upper support. The dynamic friction plate of the upper main-controlled elastic dry friction damper is fixedly connected to the lower flange of the upper squirrel cage elastic support. Three piezoelectric ceramic actuators of upper main control spring dry friction damper are evenly distributed on the circumference of the inner cavity of the small end of the upper support, and each of the piezoelectric ceramic actuators of upper main control spring dry friction damper is in contact with the inner surface of the small diameter end cavity of the upper support. The ball head of the actuator extends out of the inner cavity and presses against the static friction plate of the upper main control spring dry friction damper.

[0010] The lower force transmission support assembly includes a lower squirrel cage elastic support, a lower support, and a lower master-controlled elastic dry friction damper. The lower master-controlled elastic dry friction damper includes a dynamic friction plate, a static friction plate, and a piezoelectric ceramic actuator. The lower squirrel cage elastic support is located within the lower support, and its connecting flange is fixedly connected to the outer edge of the small end face of the lower support. The static friction plate of the lower master-controlled elastic dry friction damper is fixed to the inner surface of the large inner diameter end face of the lower support. The dynamic friction plate of the lower master-controlled elastic dry friction damper is fixedly connected to the lower flange of the lower squirrel cage elastic support. Three piezoelectric ceramic actuators of the lower main control spring-loaded dry friction damper are evenly distributed in the chamber of the small inner diameter end of the lower support, and the piezoelectric ceramic actuators of each lower main control spring-loaded dry friction damper are in contact with the inner surface of the small diameter end chamber of the lower force transmission support assembly. The ball head of the actuator extends out of the inner cavity and presses against the static friction plate of the lower main control spring-loaded dry friction damper.

[0011] The structure of the lower squirrel cage elastic support, lower support, and lower main-controlled spring dry friction damper is the same as that of the upper squirrel cage elastic support, upper support, and upper main-controlled spring dry friction damper.

[0012] The force-bearing assembly further includes an upper end cover, cylindrical roller bearings, an upper shaft end locking nut, and a cylindrical roller bearing outer ring locking nut. The upper end cover is fixed to the upper end face of each upper main-controlled spring-loaded dry friction damper piezoelectric ceramic actuator. The cylindrical roller bearing outer ring is press-fitted onto the lower end of the upper squirrel cage elastic support and has an interference fit with the inner surface of the squirrel cage elastic support. It is axially fixed by the cylindrical roller bearing outer ring locking nut. Its inner ring is fitted onto the upper end of the upper flywheel rotor shaft and has an interference fit with the outer surface of the upper flywheel rotor shaft. Finally, it is axially fixed by the upper shaft end locking nut.

[0013] The outer circumferential surface of the upper support is stepped, and its large-diameter end has a radially protruding connecting flange on its outer circumference. The inner edge of the large-diameter end face has a groove, which serves as a positioning stop for installing the upper squirrel cage elastic support. The outer edge of the small-diameter end face of the upper support has mounting holes for the static friction plates of the upper master-controlled spring-loaded dry friction damper. The small-diameter end face of the upper support has stepped grooves, where the large-diameter groove serves as a positioning stop for installing the static friction plates of the upper master-controlled spring-loaded dry friction damper, and the small-diameter groove provides space for the ball head of the piezoelectric ceramic actuator of the upper master-controlled spring-loaded dry friction damper. The inner cavity of the small end of the upper support has three evenly distributed mounting holes for the piezoelectric ceramic actuator of the upper master-controlled spring-loaded dry friction damper, with an actuator ball head protrusion hole at the bottom of each mounting hole.

[0014] The lower end of the upper squirrel cage elastic support has a flange for connecting the moving friction plate of the upper main-controlled spring dry friction damper, and a positioning stop for installing the moving friction plate of the upper main-controlled spring dry friction damper is provided on the outer end face of the flange. The inner circumferential surface of the moving friction plate of the upper main-controlled spring dry friction damper is stepped.

[0015] The static friction plate of the upper-controlled spring-supported dry friction damper is divided into a flange edge, a cage bar, and a friction surface. The outer edge of the static friction plate is the flange edge, and the inner edge is the friction surface. Fan-shaped perforated holes are evenly distributed on the circumference between the flange edge and the friction surface, and the cage bar is formed by spacers between adjacent perforated holes. Specifically, the circumferential width of the cage bar is 1.5–2.5 mm, and the radial length is 10–20 mm to meet its axial elastic design requirements. The radial length of the friction surface is greater than the radial contact length between the friction surface and the moving friction plate; the radial contact length between the friction surface and the moving friction plate is 4–6 mm.

[0016] The outer diameter of the upper shaft end locking nut is 1 mm smaller than the outer diameter of the inner ring of the cylindrical roller bearing. The lower inner diameter of the cylindrical roller bearing outer ring locking nut is 2 mm larger than the inner diameter of the outer ring of the cylindrical roller bearing, and the upper inner diameter is 2 mm larger than the outer diameter of the upper shaft end locking nut; there is a grease storage groove with a depth of 4-6 mm on the inner surface of the cylindrical roller bearing outer ring locking nut.

[0017] The lower force transmission support assembly also includes a deep groove ball bearing outer ring lock nut, a deep groove ball bearing, paired angular contact bearings, a preload adjusting nut, a lower shaft end lock nut, and a lower end cap. The deep groove ball bearing and the paired angular contact ball bearing are press-fitted to the lower end of the lower squirrel cage elastic support. The outer ring of the deep groove ball bearing has an interference fit with the inner surface of the squirrel cage elastic support, while the outer ring of the paired angular contact bearing has a clearance fit. It is also fitted onto the lower flywheel rotor shaft located within the lower squirrel cage elastic support, with an interference fit to the outer surface of the lower flywheel rotor shaft. The deep groove ball bearing is positioned above the paired angular contact ball bearings. A washer is fitted onto the lower flywheel rotor shaft and located between the inner rings of the deep groove ball bearing and the paired angular contact bearing, with a clearance fit to the outer surface of the lower flywheel rotor shaft. A deep groove ball bearing outer ring lock nut is located at the upper end of the deep groove ball bearing for axial fixation. A preload adjusting nut and a lower shaft end locking nut are installed at the lower end of the paired angular contact bearing. The lower shaft end locking nut presses the inner ring of the paired angular contact bearing to ensure axial fixation. The preload adjusting nut presses the outer ring of the paired angular contact bearing. Since there are washers between the inner rings of the deep groove ball bearing and the paired angular contact bearing, the outer rings of the deep groove ball bearing and the paired angular contact bearing are in a non-contact state.

[0018] Each lower master-controlled spring-supported dry friction damper piezoelectric ceramic actuator has a lower end cover on its upper end face to fix the piezoelectric ceramic actuator. The static friction plate of the lower master-controlled spring-supported dry friction damper is fixed to the lower end face of the lower support; the dynamic friction plate of the lower master-controlled spring-supported dry friction damper is fixed to the lower flange of the lower squirrel cage elastic support.

[0019] The lower inner diameter of the locking nut for the outer ring of the deep groove ball bearing is 1 mm larger than the inner diameter of the outer ring of the deep groove ball bearing; the inner surface of the locking nut has a grease reservoir with a depth of 4-6 mm; the upper inner diameter of the locking nut is 2 mm larger than the outer diameter of the lower flywheel rotor shaft. The structure of the preload adjusting nut is the same as that of the locking nut for the outer ring of the deep groove ball bearing. The structure of the lower shaft end locking nut is the same as that of the upper shaft end locking nut.

[0020] The outer ring of the paired angular contact bearing is clearance-fitted with the inner surface of the lower squirrel cage elastic support. By adjusting the tightening force of the preload adjusting nut, the outer ring of the paired angular contact ball bearing is axially displaced, thereby changing the contact angle between the rollers and the outer ring of the paired angular contact ball bearing, and thus adjusting its axial load capacity.

[0021] In this invention, the flywheel rotor is provided with radial support by cylindrical roller bearings that are interference-fitted with the upper squirrel cage elastic support and the upper flywheel rotor shaft. The flywheel rotor is provided with bidirectional radial and axial support by the deep groove ball bearings and paired angular contact bearings. The upper and lower squirrel cage elastic supports are subjected to tensile force, increasing the stability of the squirrel cage elastic support. When the flywheel rotor vibrates, friction is generated through the relative sliding between the dynamic and static friction plates in the upper master-controlled dry friction damper, and between the dynamic and static friction plates in the lower master-controlled dry friction damper, thus absorbing and dissipating the vibration energy generated by the flywheel rotor.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0023] 1. The support bearing of this invention is designed as an upper pivot cylindrical roller bearing and a lower pivot deep groove ball bearing – a pair of angular contact bearings. Cylindrical roller bearings have a large radial load capacity and are suitable for high-speed, impact load, and heavy-load environments. The upper support bearing uses cylindrical roller bearings to provide sufficient radial support for the flywheel rotor to cope with complex operating conditions. Furthermore, because its inner ring can move axially, it can unload the axial additional load generated by thermal expansion of the flywheel rotor, thus ensuring stable rotor operation. The lower support bearing uses a hybrid bearing of deep groove ball bearings and paired angular contact bearings. Both deep groove ball bearings and angular contact bearings can simultaneously withstand radial and axial loads and can operate at high speeds. Angular contact bearings are generally installed in pairs. By adjusting the axial preload, the contact angle is changed. The larger the contact angle, the better the axial load capacity. Therefore, considering the ease of adjustment and installation of the axial preload, angular contact bearings are usually installed with an interference fit between the inner ring and the shaft, and a clearance fit between the outer ring and the bearing housing. The axial preload is changed by adjusting the preload of the outer ring lock nut. Deep groove ball bearings employ interference fits on both the inner and outer rings to ensure radial support stability. When used in combination with paired angular contact bearings, they resolve the issue of discontinuous support stiffness introduced by clearance fits in the outer rings of paired angular contact bearings. Simultaneously, they enhance the axial load capacity of the lower support bearing, preventing excessive axial loads and short lifespans experienced by a single deep groove ball bearing. Furthermore, they ensure stable rotor operation even in the event of magnetic bearing failure. This design is simple in structure, low in cost, and highly reliable.

[0024] 2. Both the upper and lower force transmission support components of this invention employ squirrel-cage elastic supports to reduce support stiffness. The flexible support design allows the flywheel rotor's critical speed to be below its operating speed range. The rotor automatically centers itself at the critical speed, ensuring stable operation at high speeds; it also reduces the radial load on the bearings. According to mechanical principles, the larger the inner diameter of a rolling bearing, the greater its radial load capacity. However, according to rolling bearing theory, small-diameter rolling bearings can significantly reduce bearing friction torque, thus reducing heat generation. Therefore, due to the reduction in radial load, smaller diameter bearings can be selected, reducing friction loss and improving energy storage efficiency; the strain energy distribution of the rotor system can be adjusted, increasing the proportion of strain energy at the damper location and improving the damper's vibration reduction effect. The squirrel-cage elastic support has several elastic strips distributed circumferentially. These strips are slender structures with better tensile strength than compressive strength; therefore, using a tension-based installation method enhances the stability of the squirrel-cage elastic support during operation.

[0025] 3. Both the upper and lower force transmission support components of this invention employ master-controlled spring-loaded dry friction dampers. The moving friction plates of each master-controlled spring-loaded dry friction damper are fixedly connected to the free end of the squirrel cage elastic support. The stationary friction plate is pushed to press the moving friction plate by a piezoelectric ceramic actuator. When the moving friction plate vibrates together with the squirrel cage elastic support, the moving friction plate and the stationary friction plate rub against each other, providing damping for the rotor, thereby absorbing and consuming the vibration energy generated by the flywheel rotor to ensure the stable operation of the flywheel rotor. Figure 17 This is a comparison chart of the vibration reduction effect of the master-controlled spring-loaded dry friction damper. By comparing the vibration reduction curve 31 without a damper and the vibration reduction curve 32 with a damper, it can be seen that the use of the master-controlled spring-loaded dry friction damper in the upper and lower force transmission support components of this invention achieves excellent vibration reduction effect. It also reduces the external force transmitted to the support, extending the service life of the mechanical bearings. Dampers are installed in both the upper and lower supports. Through the control of piezoelectric ceramic actuators, a single-damper control mode or a double-damper control mode can be selected, and the magnitude of the control force can be actively adjusted to cope with the complex working conditions of the flywheel rotor. The master-controlled spring-loaded dry friction damper has the characteristics of simple structure, significant vibration reduction effect, fast response, and easy implementation of active control (mainly achieved by changing the normal pressure of the moving and stationary friction plates), and is not constrained by a vacuum environment. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the present invention.

[0027] Figure 2 This is a schematic diagram of the load-bearing support component structure.

[0028] Figure 3 This is an exploded view of the load-bearing support assembly.

[0029] Figure 4This is a cross-sectional view of the upper support.

[0030] Figure 5 This is a top view of the upper support.

[0031] Figure 6 This is a schematic diagram of the elastic support structure of the upper mouse cage.

[0032] Figure 7 This is a schematic diagram of the dynamic friction plate structure of the main control type spring-loaded dry friction damper.

[0033] Figure 8 This is a schematic diagram of the static friction plate structure of the upper main control type spring-loaded dry friction damper.

[0034] Figure 9 This is a schematic diagram of the upper shaft end locking nut structure.

[0035] Figure 10 This is a top view of the locking nut on the outer ring of a cylindrical roller bearing.

[0036] Figure 11 This is a cross-sectional view of the lock nut on the outer ring of a cylindrical roller bearing.

[0037] Figure 12 This is a schematic diagram of the assembly of the upper shaft end lock nut and the cylindrical roller bearing outer ring lock nut; where, Figure 12 'a' is the main view. Figure 12 b is Figure 12 A magnified view of part A in diagram a.

[0038] Figure 13 This is a schematic diagram of the lower force transmission support assembly.

[0039] Figure 14 This is an exploded view of the assembly of the lower force transmission support component.

[0040] Figure 15 This is a top view of the lock nut on the outer ring of a deep groove ball bearing.

[0041] Figure 16 This is a cross-sectional view of the lock nut on the outer ring of a deep groove ball bearing.

[0042] Figure 17 This is a comparison chart of the vibration reduction effects of the main-controlled spring-loaded dry friction damper.

[0043] In the diagram: 1. Upper force transmission support assembly; 2. Motor / generator stator coil; 3. Upper flywheel rotor shaft; 4. Axial magnetic bearing; 5. Flywheel; 6. Lower flywheel rotor shaft; 7. Lower force transmission support assembly; 8. Upper squirrel cage elastic support; 9. Upper support; 10. Upper end cover; 11. Upper main-controlled spring-support dry friction damper piezoelectric ceramic actuator; 12. Upper main-controlled spring-support dry friction damper static friction plate; 13. Upper main-controlled spring-support dry friction damper dynamic friction plate; 14. Cylindrical roller bearing; 15. Upper shaft end lock nut; 16. Cylindrical roller bearing outer ring lock nut; 17. Lower squirrel cage elastic support. 18. Lower support; 19. Deep groove ball bearing outer ring lock nut; 20. Deep groove ball bearing; 21. Washer; 22. Opposite angular contact ball bearing; 23. Preload adjusting nut; 24. Lower shaft end lock nut; 25. Lower main-controlled spring-supported dry friction damper moving friction plate; 26. Lower main-controlled spring-supported dry friction damper static friction plate; 27. Lower main-controlled spring-supported dry friction damper piezoelectric ceramic actuator; 28. Lower end cover; 29. ​​Upper main-controlled spring-supported dry friction damper; 30. Lower main-controlled spring-supported dry friction damper; 31. Vibration reduction curve without damper; 32. Vibration reduction curve with damper. Detailed Implementation

[0044] This embodiment is a force transmission support mechanism for a vertical magnetic levitation flywheel rotor, including an upper force transmission support assembly 1, a lower force transmission support assembly 7, a motor / generator stator coil 2, and a flywheel rotor.

[0045] The flywheel rotor includes an upper flywheel rotor shaft 3, an axial magnetic bearing 4, a flywheel 5, and a lower flywheel rotor shaft 6. Specifically: the lower end face of the upper flywheel rotor shaft is fixed to the upper end face of the flywheel 5, and the upper end face of the lower flywheel rotor shaft is fixed to the lower end face of the flywheel 5; the upper flywheel rotor shaft, lower flywheel rotor shaft, and flywheel are coaxial. The axial magnetic bearing 4 is fixed at the outer edge of the upper end face of the flywheel. The flywheel rotor is composed of the upper flywheel rotor shaft 3, the flywheel 5, and the lower flywheel rotor shaft 6. The motor / generator stator coil 2 is a stationary component and is conventionally installed within the flywheel vacuum protective housing. All the above components utilize existing technical solutions.

[0046] The upper force transmission support assembly 1 is located at the upper end of the upper flywheel rotor shaft 3, and the upper flywheel rotor shaft is mounted in the upper squirrel cage elastic support 8 of the upper force transmission support assembly via cylindrical roller bearings 14. The lower force transmission support assembly 7 is located at the lower end of the lower flywheel rotor shaft 6, and the lower flywheel rotor shaft is mounted in the lower squirrel cage elastic support 17 of the lower support via deep groove ball bearings 20 and paired angular contact ball bearings 22.

[0047] The load-bearing support assembly 1 includes an upper squirrel cage elastic support 8, an upper support 9, a cylindrical roller bearing 14, an upper shaft end locking nut 15, a cylindrical roller bearing outer ring locking nut 16, and an upper main control type elastic support dry friction damper 29.

[0048] The upper master-controlled spring-loaded dry friction damper 29 includes an upper master-controlled spring-loaded dry friction damper piezoelectric ceramic actuator 11, an upper master-controlled spring-loaded dry friction damper static friction plate 12, an upper master-controlled spring-loaded dry friction damper dynamic friction plate 13, and an upper end cover 10. The upper squirrel cage elastic support 8 is located inside the upper support 9, and its flange is fixedly connected to the large end face of the upper support. The outer surface of the upper squirrel cage elastic support flange is interference-fitted with the inner surface of the large end face of the upper support. The upper master-controlled spring-loaded dry friction damper static friction plate 12 is fixed at the outer edge of the small inner diameter end face of the upper support. The upper master-controlled spring-loaded dry friction damper dynamic friction plate 13 is fixedly connected to the lower end flange of the upper squirrel cage elastic support. Three upper master-controlled spring-supported dry friction damper piezoelectric ceramic actuators 11 are evenly distributed on the circumference of the inner cavity of the small end of the upper support. The piezoelectric ceramic actuators of each lower master-controlled spring-supported dry friction damper are fitted to the inner surface of the small diameter end cavity of the upper support. The ball head of the actuator extends out of the inner cavity and presses against the static friction plate of the upper master-controlled spring-supported dry friction damper. An upper end cover 10 is installed on the upper end of each upper master-controlled spring-supported dry friction damper piezoelectric ceramic actuator to fix it. The outer ring of the cylindrical roller bearing 14 is press-fitted onto the lower end of the upper squirrel cage elastic support and is interference-fitted with the inner surface of the upper squirrel cage elastic support. It is axially fixed by the cylindrical roller bearing outer ring locking nut 16. Its inner ring is sleeved on the upper end of the upper flywheel rotor shaft 3 and is interference-fitted with the outer surface of the upper flywheel rotor shaft. Finally, it is axially fixed by the upper shaft end locking nut 15.

[0049] The upper support 9 is a hollow rotating body. The outer circumferential surface of the upper support is stepped, with a radially protruding connecting flange at its large-diameter end. The inner edge of the large-diameter end face has a groove, which serves as a positioning stop for mounting the upper squirrel cage elastic support 8. The outer edge of the small-diameter end face of the upper support has mounting holes for the static friction plate 12 of the upper master-controlled spring-loaded dry friction damper. The small-diameter end face of the upper support has stepped grooves, where the large-diameter groove serves as a positioning stop for mounting the static friction plate of the upper master-controlled spring-loaded dry friction damper, and the small-diameter groove provides space for the ball head of the piezoelectric ceramic actuator of the upper master-controlled spring-loaded dry friction damper. The inner cavity of the small end of the upper support has three evenly distributed mounting holes for the piezoelectric ceramic actuator of the upper master-controlled spring-loaded dry friction damper, with an actuator ball head protrusion hole at the bottom of each mounting hole.

[0050] The lower end of the upper squirrel cage elastic support 8 has a flange for connecting the moving friction plate 13 of the upper main-controlled spring dry friction damper. The inner edge of the flange has a positioning stop for installing the moving friction plate of the upper main-controlled spring dry friction damper. The inner circumferential surface of the moving friction plate of the upper main-controlled spring dry friction damper is stepped.

[0051] The static friction plate 12 of the upper-controlled spring-supported dry friction damper is divided into a flange edge, a cage bar, and a friction surface. The outer edge of the static friction plate is the flange edge, and the inner edge is the friction surface. Fan-shaped perforated holes are evenly distributed on the circumference between the flange edge and the friction surface, and the cage bar is formed by the spacers between adjacent perforated holes. Specifically, the circumferential width of the cage bar is 1.5–2.5 mm, and the radial length is 10–20 mm to meet its axial elastic design requirements. The radial length of the friction surface is greater than the radial contact length between the friction surface and the moving friction plate; the radial contact length between the friction surface and the moving friction plate is 4–6 mm. Under the pressure of the piezoelectric ceramic actuator ball head of the upper-controlled spring-supported dry friction damper, the friction surface is tightly pressed against the moving friction plate of the upper-controlled spring-supported dry friction damper.

[0052] The outer diameter of the upper shaft end locking nut 15 is 1 mm smaller than the outer diameter of the inner ring of the cylindrical roller bearing 14. Its internal thread is matched with the upper flywheel rotor shaft 3, and its upper surface has grooves evenly distributed around its circumference for disassembly. The lower inner diameter of the cylindrical roller bearing outer ring locking nut 16 is 2 mm larger than the inner diameter of the outer ring of the cylindrical roller bearing, and its upper inner diameter is 2 mm larger than the outer diameter of the upper shaft end locking nut. Its external thread is matched with the upper squirrel cage elastic support, and its interior has a grease storage groove with a depth of 4-6 mm. Its surface has grooves evenly distributed around its circumference for disassembly.

[0053] The piezoelectric ceramic actuator 11 of the upper main control type spring-loaded dry friction damper is selected from the prior art according to the actuator normal pressure required for vibration reduction. The cylindrical roller bearing 14 is a standard part.

[0054] The lower force transmission support assembly 7 includes a lower squirrel cage elastic support 17, a lower support 18, a deep groove ball bearing outer ring locking nut 19, a deep groove ball bearing 20, a paired diagonal contact bearing 22, a preload adjusting nut 23, a lower shaft end locking nut 24, and a lower main control type spring support dry friction damper 30.

[0055] The lower master-controlled spring-loaded dry friction damper includes a moving friction plate 25, a stationary friction plate 26, a piezoelectric ceramic actuator 27, and a lower end cover 28. The lower squirrel cage elastic support 17 is located within the lower support 18, and its connecting flange is fixedly connected to the small end face of the lower support. The deep groove ball bearing 20 and the paired angular contact ball bearing 22 are both press-fitted to the lower end of the lower squirrel cage elastic support 17, wherein the outer ring of the deep groove ball bearing has an interference fit with the inner surface of the squirrel cage elastic support, and the outer ring of the paired angular contact bearing has a clearance fit with the inner surface of the squirrel cage elastic support. Simultaneously, the deep groove ball bearing 20 is fitted onto the lower flywheel rotor shaft 6 located within the lower squirrel cage elastic support 17, and is interference-fitted with the outer surface of the lower flywheel rotor shaft. The deep groove ball bearing 20 is positioned above the paired angular contact ball bearing 22. A washer 21 is fitted onto the lower flywheel rotor shaft and located between the inner rings of the deep groove ball bearing and the paired angular contact bearing, with a clearance fit to the outer surface of the lower flywheel rotor shaft 6. A deep groove ball bearing outer ring locking nut 19 is located at the upper end of the deep groove ball bearing for axial fixation. A preload adjusting nut 23 and a lower shaft end locking nut 24 are installed at the lower end of the paired angular contact bearing. The lower shaft end locking nut presses the inner ring of the paired angular contact bearing to ensure axial fixation. The preload adjusting nut presses the outer ring of the paired angular contact bearing. Since there is a washer 21 between the inner rings of the deep groove ball bearing 20 and the paired angular contact bearing 22, the outer rings of the deep groove ball bearing and the paired angular contact bearing are in a non-contact state. The outer ring of the paired angular contact bearing is clearance-fitted with the inner surface of the lower squirrel cage elastic support 17. Therefore, by adjusting the locking force of the preload adjusting nut 23, the outer ring of the paired angular contact ball bearing is axially displaced, thereby changing the contact angle between the rollers and the outer ring of the paired angular contact ball bearing 22, and thus adjusting its axial load capacity. Three piezoelectric ceramic actuators 27 of the lower main-controlled spring-loaded dry friction damper are evenly distributed in the cavity at the small inner diameter end of the lower support 18. Each of these actuators is fitted against the inner surface of the small diameter end cavity of the lower force transmission support assembly. The ball head of the actuator extends out of the inner cavity and presses against the static friction plate of the lower main-controlled spring-loaded dry friction damper. Each lower main-controlled spring-loaded dry friction damper has a lower end cap 28 on its upper end face to fix it in place. The static friction plate 26 of the lower main-controlled spring-loaded dry friction damper is fixed to the lower end face of the lower support 18; the dynamic friction plate 25 of the lower main-controlled spring-loaded dry friction damper is fixed to the lower flange of the lower squirrel cage elastic support 17.

[0056] The inner diameter of the lower end of the locking nut 19 of the outer ring of the deep groove ball bearing is 1 mm larger than the inner diameter of the outer ring of the deep groove ball bearing 20; its inner surface has a grease storage groove with a depth of 4 to 6 mm; the external thread is matched with the elastic support of the lower squirrel cage, and the upper outer surface is evenly distributed with grooves for disassembly process grooves; the inner diameter of the upper end of the locking nut of the outer ring of the deep groove ball bearing is 2 mm larger than the outer diameter of the lower flywheel rotor shaft 6.

[0057] The structure of the preload adjusting nut 23 is the same as that of the outer ring locking nut of the deep groove ball bearing. The structure of the lower shaft end locking nut 24 is the same as that of the upper shaft end locking nut 15.

[0058] The lower support 18, lower squirrel cage elastic support 17, and lower main control elastic dry friction damper in the lower force transmission support assembly 7 have the same structural features and matching method as the upper force transmission support assembly 1.

[0059] Both the deep groove ball bearing 20 and the paired angular contact bearing 22 are standard parts.

[0060] In this embodiment, the axial magnetic bearing 4 is located on the upper end face of the flywheel hub 5, bearing approximately 90% of the flywheel rotor's weight, thereby reducing the axial load on the mechanical bearing, extending its service life, and reducing frictional losses. The upper force transmission support assembly 1 is connected to the upper flywheel rotor shaft 3 and fixed with the upper shaft end locking nut 15, providing radial support for the flywheel rotor. The lower force transmission support assembly 7 is connected to the lower flywheel rotor shaft 6 and locked with the lower shaft end locking nut 24, providing both radial and axial bidirectional support for the flywheel rotor. In use, the upper force transmission support assembly 1, the lower force transmission support assembly 7, and the motor / generator stator coil 2 are all installed inside the flywheel vacuum protective housing using conventional methods.

[0061] During the assembly of the load transfer support assembly, the piezoelectric ceramic actuator 11 of the upper main-controlled spring-loaded dry friction damper is installed in the reserved cavity of the upper support and locked with the upper end cover; the static friction plate 12 of the upper main-controlled spring-loaded dry friction damper is connected to the lower part of the upper support by screws and is held in place by the piezoelectric ceramic actuator of the lower main-controlled spring-loaded dry friction damper. The cylindrical roller bearing 14 is press-fitted onto the upper squirrel cage elastic support, with an interference fit, and locked by the cylindrical roller bearing outer ring locking nut 16. The upper end of the upper flywheel rotor shaft 3 is installed, and the cylindrical roller bearing 14 is made to have an interference fit with the upper flywheel rotor shaft 3, and locked by the upper shaft end nut 15. To ensure that the squirrel cage elastic support can withstand tensile force, the connecting flange of the upper squirrel cage elastic support is fixedly connected to the upper mounting base. The dynamic friction plate of the upper main-controlled spring-loaded dry friction damper is connected to the flange of the upper squirrel cage elastic support. The load transfer support assembly is now complete.

[0062] When assembling the lower force transmission support assembly, the piezoelectric ceramic actuator of the lower main-controlled spring-loaded dry friction damper is installed into the reserved slot of the lower support and locked with the lower end cover. The static friction plate of the lower main-controlled spring-loaded dry friction damper is connected to the lower part of the lower support with screws and held in place by the piezoelectric ceramic actuator of the lower main-controlled spring-loaded dry friction damper. The deep groove ball bearing and the paired angular contact bearing are both installed between the lower squirrel cage elastic support and the lower flywheel rotor shaft 6, and the preload is adjusted by the preload adjusting nut. The inner and outer rings of the deep groove ball bearing are both interference fit; the inner ring of the paired angular contact bearing 22 is interference fit with the lower flywheel rotor shaft 6, and the outer ring of the paired angular contact bearing is clearance fit with the lower squirrel cage elastic support. At the same time, the deep groove ball bearing is located at the upper end of the paired angular contact bearing, and there is a washer between the deep groove ball bearing and the paired angular contact bearing. The upper flange of the lower squirrel cage elastic support is fixedly connected to the upper end of the lower support, allowing the lower squirrel cage elastic support to bear tensile force. The dynamic friction plate of the lower main-controlled dry friction damper is fixedly connected to the lower flange of the lower squirrel cage elastic support by screws. The lower force transmission support assembly and the lower flywheel rotor shaft are locked together by the lower shaft end lock nut, thus completing the installation of the lower force transmission support assembly.

Claims

1. A force transmission support mechanism for a vertical magnetic levitation flywheel rotor, comprising an upper force transmission support assembly (1), a lower force transmission support assembly (7), a motor / generator stator coil (2), and a flywheel rotor; the flywheel rotor comprising an upper flywheel rotor shaft (3), an axial magnetic bearing (4), a flywheel (5), and a lower flywheel rotor shaft (6); wherein: The lower end face of the upper flywheel rotor shaft is fixed to the upper end face of the flywheel, and the upper end face of the lower flywheel rotor shaft is fixed to the lower end face of the flywheel; the upper flywheel rotor shaft, the lower flywheel rotor shaft, and the flywheel are coaxial; the axial magnetic bearing is fixed at the outer edge of the upper end face of the flywheel; the upper flywheel rotor shaft, the flywheel, and the lower flywheel rotor shaft constitute the flywheel rotor; The upper force transmission support assembly (1) is located at the upper end of the upper flywheel rotor shaft, and the upper flywheel rotor shaft is mounted in the upper squirrel cage elastic support (8) of the upper force transmission support assembly via cylindrical roller bearings (14); the lower force transmission support assembly is located at the lower end of the lower flywheel rotor shaft (6), and the lower flywheel rotor shaft is mounted in the lower squirrel cage elastic support (17) of the lower force transmission support assembly via deep groove ball bearings (20) and paired angular contact ball bearings (22); The force-bearing assembly (1) includes an upper squirrel cage elastic support (8), an upper support (9), and an upper main-controlled spring-loaded dry friction damper (29); wherein, the upper main-controlled spring-loaded dry friction damper includes an upper main-controlled spring-loaded dry friction damper piezoelectric ceramic actuator (11), an upper main-controlled spring-loaded dry friction damper static friction plate (12), and an upper main-controlled spring-loaded dry friction damper dynamic friction plate (13); the upper squirrel cage elastic support is located inside the upper support (9), and the outer surface of the flange of the squirrel cage elastic support is flush with the inner surface of the large end face of the upper support. The upper main control type spring-loaded dry friction damper static friction plate is fixed at the outer edge of the small inner diameter end face of the upper support; the upper main control type spring-loaded dry friction damper dynamic friction plate is fixedly connected to the lower end flange of the upper squirrel cage elastic support; three upper main control type spring-loaded dry friction damper piezoelectric ceramic actuators are evenly distributed on the circumference of the inner cavity of the small end of the upper support, and the piezoelectric ceramic actuators of each lower main control type spring-loaded dry friction damper are in contact with the inner surface of the small diameter end cavity of the upper support, and the ball head of the actuator extends out of the inner cavity and presses against the upper main control type spring-loaded dry friction damper static friction plate; The lower force transmission support assembly includes a lower squirrel cage elastic support (17), a lower support (18), and three lower main control type elastic dry friction dampers (30); wherein, the lower main control type elastic dry friction damper includes a lower main control type elastic dry friction damper dynamic friction plate (25), a lower main control type elastic dry friction damper static friction plate (26), and a lower main control type elastic dry friction damper piezoelectric ceramic actuator (27); the lower squirrel cage elastic support is located inside the lower support, and the connecting flange of the lower squirrel cage elastic support is fixedly connected to the outer edge of the small end face of the lower support; A static friction plate of a lower main-controlled spring-loaded dry friction damper is fixed on the inner surface of the large inner diameter end face of the lower support; the dynamic friction plate of the lower main-controlled spring-loaded dry friction damper is fixedly connected to the lower end flange of the lower squirrel cage elastic support; three piezoelectric ceramic actuators of the lower main-controlled spring-loaded dry friction damper are evenly distributed in the cavity of the small inner diameter end of the lower support, and each piezoelectric ceramic actuator of the lower main-controlled spring-loaded dry friction damper is in contact with the inner surface of the small diameter end cavity of the lower force transmission support assembly, and the ball head of the actuator extends out of the inner cavity and presses against the static friction plate of the lower main-controlled spring-loaded dry friction damper. The structure of the lower squirrel cage elastic support (17), lower support (18) and lower main control type spring dry friction damper (30) is the same as that of the upper squirrel cage elastic support (8), upper support (9) and upper main control type spring dry friction damper (29).

2. The force transmission support mechanism of the vertical magnetic levitation flywheel rotor as described in claim 1, characterized in that, The load-bearing support assembly (1) further includes an upper end cover (10), a cylindrical roller bearing (14), an upper shaft end locking nut (15), and a cylindrical roller bearing outer ring locking nut (16). The upper end cover (10) is fixed on the upper end face of each upper main control type spring support dry friction damper piezoelectric ceramic actuator. The outer ring of the cylindrical roller bearing (14) is press-fitted onto the lower end of the upper squirrel cage elastic support and is interference-fitted with the inner surface of the squirrel cage elastic support. It is axially fixed by the cylindrical roller bearing outer ring locking nut (16). Its inner ring is sleeved on the upper end of the upper flywheel rotor shaft (3) and is interference-fitted with the outer surface of the upper flywheel rotor shaft. Finally, it is axially fixed by the upper shaft end locking nut (15).

3. The force transmission support mechanism of the vertical magnetic levitation flywheel rotor as described in claim 2, characterized in that, The outer circumferential surface of the upper support (9) is stepped, and the outer circumference of its large diameter end has a radially protruding connecting flange; the inner edge groove of the large diameter end face is a positioning stop for installing the upper squirrel cage elastic support (8); the outer edge of the small diameter end face of the upper support has mounting holes for the static friction plate (12) of the upper master control spring dry friction damper; the small diameter end face of the upper support has a stepped groove, in which the large diameter groove is a positioning stop for installing the static friction plate of the upper master control spring dry friction damper, and the small diameter groove is a reserved space for the ball head of the piezoelectric ceramic actuator of the upper master control spring dry friction damper; the inner cavity of the small end of the upper support has three mounting holes for the piezoelectric ceramic actuator (11) of the upper master control spring dry friction damper, and the bottom of the mounting holes has a ball head protrusion hole.

4. The force transmission support mechanism of the vertical magnetic levitation flywheel rotor as described in claim 1, characterized in that, The lower end of the upper squirrel cage elastic support (8) has a flange for connecting the upper main control type spring dry friction damper dynamic friction plate (13), and there is a positioning stop on the outer end face of the flange for installing the upper main control type spring dry friction damper dynamic friction plate; the inner circumferential surface of the upper main control type spring dry friction damper dynamic friction plate is stepped.

5. The force transmission support mechanism of the vertical magnetic levitation flywheel rotor as described in claim 1, characterized in that, The static friction plate (12) of the upper main control type spring-supported dry friction damper is divided into a flange edge, a cage bar, and a friction surface; the outer edge of the static friction plate of the upper main control type spring-supported dry friction damper is the flange edge, and the inner edge of the static friction plate of the upper main control type spring-supported dry friction damper is the friction surface; fan-shaped hollow holes are evenly distributed on the circumference between the flange edge and the friction surface, and the cage bar is formed by the spacers between each adjacent hollow hole; wherein: the circumferential width of the cage bar is 1.5~2.5mm, and the radial length is 10~20mm, to meet its axial elastic design requirements; the radial length of the friction surface is greater than the radial contact length between the friction surface and the moving friction plate; the radial contact length between the friction surface and the moving friction plate is 4~6mm.

6. The force transmission support mechanism of the vertical magnetic levitation flywheel rotor as described in claim 2, characterized in that, The outer diameter of the upper shaft end locking nut (15) is 1 mm smaller than the outer diameter of the inner ring of the cylindrical roller bearing (14); the lower inner diameter of the cylindrical roller bearing outer ring locking nut (16) is 2 mm larger than the inner diameter of the outer ring of the cylindrical roller bearing, and the upper inner diameter is 2 mm larger than the outer diameter of the upper shaft end locking nut; there is a grease storage groove with a depth of 4~6 mm on the inner surface of the cylindrical roller bearing outer ring locking nut.

7. The force transmission support mechanism of the vertical magnetic levitation flywheel rotor as described in claim 1, characterized in that, The lower force transmission support assembly (7) also includes a deep groove ball bearing outer ring locking nut (19), a deep groove ball bearing (20), a paired angular contact ball bearing (22), a preload adjusting nut (23), a lower shaft end locking nut (24), and a lower end cap (28). The deep groove ball bearing (20) and the paired angular contact ball bearing (22) are both press-fitted onto the lower end of the lower squirrel cage elastic support (17). The outer ring of the deep groove ball bearing is interference-fitted with the inner surface of the squirrel cage elastic support, while the outer ring of the paired angular contact ball bearing is clearance-fitted with the inner surface of the squirrel cage elastic support. They are also fitted onto the lower flywheel rotor shaft (6) located within the lower squirrel cage elastic support (17), with interference fits to the outer surface of the lower flywheel rotor shaft. The deep groove ball bearing (20) is positioned above the paired angular contact ball bearing (22). A washer (21) is fitted onto the lower flywheel rotor shaft and located between the inner rings of the deep groove ball bearing and the paired angular contact ball bearing. Between them, there is a clearance fit with the outer surface of the lower flywheel rotor shaft (6); at the upper end of the deep groove ball bearing, there is a deep groove ball bearing outer ring locking nut (19) for axial fixation of the deep groove ball bearing; at the lower end of the paired angular contact ball bearing, there is a preload adjusting nut (23) and a lower shaft end locking nut (24), wherein the lower shaft end locking nut presses the inner ring of the paired angular contact ball bearing to ensure axial fixation; the preload adjusting nut presses the outer ring of the paired angular contact ball bearing, and since there is a washer (21) between the inner rings of the deep groove ball bearing (20) and the paired angular contact ball bearing (22), the deep groove ball bearing and the outer ring of the paired angular contact ball bearing are in a non-contact state; Each of the lower master-controlled spring-supported dry friction dampers has a lower end cover (28) on its upper end face to fix the lower master-controlled spring-supported dry friction damper piezoelectric ceramic actuator; the lower master-controlled spring-supported dry friction damper static friction plate (26) is fixed on the lower end face of the lower support; the lower master-controlled spring-supported dry friction damper dynamic friction plate (25) is fixed on the lower flange of the lower squirrel cage elastic support (17).

8. The force transmission support mechanism of the vertical magnetic levitation flywheel rotor as described in claim 7, characterized in that, The lower inner diameter of the outer ring locking nut (19) of the deep groove ball bearing is 1 mm larger than the inner diameter of the outer ring of the deep groove ball bearing (20); there is a grease storage groove with a depth of 4~6 mm on the inner surface of the outer ring locking nut of the deep groove ball bearing; the upper inner diameter of the outer ring locking nut of the deep groove ball bearing is 2 mm larger than the outer diameter of the lower flywheel rotor shaft (6); the structure of the preload adjusting nut (23) is the same as that of the outer ring locking nut of the deep groove ball bearing; the structure of the lower shaft end locking nut (24) is the same as that of the upper shaft end locking nut (15).

9. The force transmission support mechanism of the vertical magnetic levitation flywheel rotor as described in claim 1, characterized in that, The outer ring of the paired angular contact ball bearing is clearance-fitted with the inner surface of the lower squirrel cage elastic support (17). By adjusting the locking force of the preload adjusting nut (23), the outer ring of the paired angular contact ball bearing is axially displaced, thereby changing the contact angle between the rollers and the outer ring of the paired angular contact ball bearing (22) and thus adjusting its axial load capacity.

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