A mechanically supported energy storage flywheel device utilizing axial magnetic bearing unloading

Abstract

The present application relates to the technical field of energy storage flywheel devices, and in particular to a mechanically supported energy storage flywheel device that utilizes axial magnetic bearings for unloading. The energy storage flywheel device includes a flywheel support assembly and a flywheel rotor assembly in the center; the flywheel support assembly includes a bottom support assembly, a middle shell assembly, and a top support assembly, and is characterized in that it is provided with an axial magnetic bearing, an axial disc spring, a mechanical bearing, etc.; the middle shell assembly is used to connect the top support assembly and the bottom support assembly; the flywheel rotor assembly includes a flywheel and a motor rotor. The present invention utilizes axial magnetic bearings to suspend the flywheel rotor, so that the support bearings of the flywheel rotor do not bear the weight of the rotor, and high-speed rotation is achieved through mechanical bearing support, thereby reducing the power consumption of the mechanical bearings. The axial disc springs in the flywheel rotor support bearing assembly are utilized to provide elastic damping when the axial magnetic bearing suspends the flywheel rotor, thereby reducing the difficulty of controlling the magnetic bearings, reducing the cost of the flywheel, and improving product reliability.

Description

Technical Field

[0001] The present application relates to the field of energy storage flywheels, and in particular to a mechanically supported energy storage flywheel device that utilizes axial magnetic bearings for unloading. Background Art

[0002] Electricity is the most in-demand energy source in today's society. With the increasing reliance on electricity, power systems are increasingly relying on energy storage technologies to regulate peaks and valleys and reduce energy consumption. Flywheel energy storage utilizes the inertia of the flywheel rotor, converting electrical energy into kinetic energy through a motor-driven high-speed rotation for charging. When needed, the motor converts the kinetic energy back into electrical energy for discharge. Compared to chemical batteries, flywheel energy storage offers advantages in terms of high energy storage density, high energy conversion rate, short charge and discharge times, and long service life. However, its disadvantage is its high cost.

[0003] Flywheel rotor support technology is a key technology for energy storage flywheels and also a key factor affecting the cost of energy storage flywheel devices. The main support methods are mechanical bearings and magnetic bearings. Mechanical bearings have the advantages of low cost, simple and reliable structure, but are subject to wear and require lubrication. Magnetic bearings have the advantages of being contactless, requiring no lubrication, and having a long lifespan. However, their disadvantages are high cost, complex structure, high reliability requirements for the controller system, and the risk of bearing damage.

[0004] A Chinese invention patent application (publication number CN105811646B, publication date: March 1, 2019) discloses an energy storage flywheel device with a hybrid magnetic and mechanical bearing support, comprising a base, a flywheel rotor, a motor stator, an axial magnetic bearing, a radial magnetic bearing, and a mechanical bearing. This application employs an axial magnetic bearing to attract the flywheel rotor, a radial magnetic bearing to provide radial flexible support at the upper end, and upper and lower mechanical bearings to achieve rigid support for the flywheel. The magnetic bearings are used to unload the rotor's weight, thereby extending the service life of the mechanical bearings and improving the reliability of the flywheel system.

[0005] The existing technology has the following shortcomings: the flywheel rotor axial suspension has no damping support, and the flywheel rotor radially has both magnetic bearings for elastic support and mechanical bearings for rigid support. On the one hand, the magnetic bearing control system is more difficult, and on the other hand, it increases the cost of the energy storage flywheel device. Summary of the Invention

[0006] In view of this, the present invention proposes a mechanically supported energy storage flywheel device that utilizes axial magnetic bearings for unloading.

[0007] In order to achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A mechanically supported energy storage flywheel device utilizing axial magnetic bearing unloading comprises a flywheel support assembly and a flywheel rotor assembly in the center; the flywheel support assembly comprises a bottom support assembly, a middle housing assembly and a top support assembly; the bottom support assembly is provided with a flywheel base, a bottom support seat, a flywheel rotor bottom support bearing assembly, an axial magnetic bearing stator insert and a suspended bearing assembly; the flywheel rotor bottom support bearing assembly is provided with an axial disc spring, a mechanical bearing, a mechanical bearing seat and a bottom end cover; the suspended bearing assembly is provided with a protective bearing and a positioning end cover; the middle housing assembly is used to connect the top support assembly and the bottom support assembly, and is provided with a middle housing, an axial magnetic bearing stator insert and an axial displacement sensor; the top support assembly is provided with a top support seat, a motor housing assembly, a motor stator insert and a flywheel rotor top support bearing assembly; the motor housing assembly is provided with a motor housing and a cooling water jacket; the flywheel rotor top support bearing assembly is provided with an axial disc spring, a mechanical bearing, a mechanical bearing seat, a top end cover and a rotary encoder; the flywheel rotor assembly comprises a flywheel and a motor rotor.

[0009] The bottom and top support bearing assemblies are in rigid contact with the flywheel rotor assembly. The bottom and top support assemblies are provided with mechanical bearing seats and mechanical bearings, wherein the bottom support seat and the mechanical bearing seat in the bottom support assembly are clearance-fitted and can slide axially; the top support seat and the mechanical bearing seat in the top support assembly are clearance-fitted and can slide axially.

[0010] The positioning end cover and the flywheel rotor are interference fitted, and the axial position of the flywheel rotor is limited by the protective bearing of the suspension bearing assembly.

[0011] The axial disc springs at both ends of the flywheel rotor are respectively installed on the bottom support seat and the top support seat, and respectively press the bottom end cover and the top end cover.

[0012] Four axial displacement sensors are installed on the middle housing, and signal transmission is achieved through aviation plugs.

[0013] The motor rotor in the flywheel rotor assembly is a tile-shaped structure, which is directly attached to the outer edge of the main shaft. The outer surface of the motor rotor is prestressed with carbon fiber.

[0014] The motor housing is provided with a water cooling channel, which is spiral and used for cooling the motor stator wire.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The patented invention utilizes axial magnetic bearings to suspend the flywheel rotor, so that the support bearings of the flywheel rotor do not bear the weight of the rotor, reducing the power consumption of the mechanical bearings. It utilizes the axial disc springs in the flywheel rotor support bearing assembly to provide axial suspension damping, reducing the difficulty of magnetic bearing control, reducing flywheel costs, and improving product reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the application and, together with the description, serve to explain the principles of the application.

[0018] Figure 1 A cross-sectional view of the structure created by the present invention;

[0019] Figure 2 A cross-sectional view of the flywheel rotor and support bearing assembly rigidly contacting and the axial disc spring installation created by the present invention;

[0020] Figure 3 A schematic diagram of the flywheel rotor assembly created by the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of the axial displacement sensor created by the present invention;

[0022] Figure 5 A schematic diagram of the motor rotor structure created by the present invention;

[0023] Figure 6 Schematic diagram of the cooling water channel created by the present invention.

[0024] Description of Reference Numerals

[0025] 1-Bottom end cover; 2-Mechanical bearing; 3-Mechanical bearing seat; 4-Bottom support seat; 5-Flywheel base; 6-Axial magnetic bearing stator wire; 7-Flywheel rotor assembly; 71-Flywheel; 72-Motor rotor; 8-Middle housing; 9-Motor housing; 10-Cooling water jacket; 11-Motor stator wire; 12-Flywheel end cover; 13-Top support seat; 14-Rotary encoder; 15-Top end cover; 16-Axial displacement sensor; 17-Protective bearing; 18-Positioning end cover; 19-Axial disc spring; 20-Rotating shaft; 21-Permanent magnet; 22-Carbon fiber; 23-Magnetic isolation strip. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0027] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0028] In describing the present invention, it should be noted that the term "exemplary" means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or preferable to other embodiments. The term "connected" should be understood broadly, encompassing fixed connections, detachable connections, or integrated connections. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0029] The present invention is described in detail below with reference to examples.

[0030] A mechanically supported energy storage flywheel device using axial magnetic bearing unloading, such as Figures 1 to 6 As shown, it includes a flywheel support assembly and a flywheel rotor assembly in the center; the flywheel support assembly includes a bottom support assembly, a middle housing assembly and a top support assembly; the bottom support assembly is provided with a flywheel base 5, a bottom support seat 4, a flywheel rotor bottom support bearing assembly, an axial magnetic bearing stator insert 6 and a suspension bearing assembly; the flywheel rotor bottom support bearing assembly is provided with an axial disc spring 19, a mechanical bearing 2, a mechanical bearing seat 3, and a bottom end cover 1; the suspension bearing assembly is provided with a protective bearing 17 and a positioning end cover 18; the middle housing assembly is used to connect the top support assembly and the bottom support assembly, and is provided with a middle housing 8, an axial magnetic bearing stator insert and an axial displacement sensor 16; the top support assembly is provided with a top support seat 13, a motor housing assembly, a motor stator insert 11, and a flywheel rotor top support bearing assembly; the motor housing assembly is provided with a motor housing 9 and a cooling water jacket 10; the flywheel rotor top support bearing assembly is provided with an axial disc spring, a mechanical bearing, a mechanical bearing seat, a top end cover 15 and a rotary encoder 14; the flywheel rotor assembly includes a flywheel 71 and a motor rotor 72.

[0031] The bottom and top support bearing assemblies are in rigid contact with the flywheel rotor assembly 7. The bottom and top support assemblies are provided with a mechanical bearing seat 3 and a mechanical bearing 2. The bottom support seat 4 and the mechanical bearing seat 3 in the bottom support assembly are clearance-fitted and can slide axially. The top support seat 13 and the mechanical bearing seat in the top support assembly are clearance-fitted and can slide axially.

[0032] The positioning end cover 18 and the flywheel rotor assembly 7 are interference fitted, and the axial limitation of the flywheel rotor assembly is achieved by the protective bearing 17 of the suspension bearing assembly.

[0033] The axial disc springs 19 at both ends of the flywheel rotor are respectively installed on the bottom support seat 4 and the top support seat 13, respectively pressing the bottom end cover 1 and the top end cover 15.

[0034] Four axial displacement sensors 16 are installed on the middle housing, and signal transmission is achieved through aviation plugs.

[0035] The motor rotor permanent magnet 21 in the flywheel rotor assembly is a tile-shaped structure, directly labeled on the outer edge of the shaft 20, with magnetic strips 23 between the permanent magnets, and the outer surface of the motor rotor is prestressed with carbon fiber 22.

[0036] The motor housing 9 is provided with a cooling water channel, which is spiral and is used to cool the motor stator wire.

[0037] In an optional embodiment, the motor housing may be made of a cast housing, which has the advantages of low cost and short processing cycle compared to a forged housing.

[0038] The middle shell is provided with a hoisting hole to facilitate product hoisting.

[0039] The patented invention utilizes axial magnetic bearings to suspend the flywheel rotor, so that the support bearings of the flywheel rotor do not bear the weight of the rotor, reducing the power consumption of the mechanical bearings. It utilizes the axial disc springs in the flywheel rotor support bearing assembly to provide axial suspension damping, reducing the difficulty of magnetic bearing control, reducing flywheel costs, and improving product reliability.

Claims

1. A mechanically supported energy storage flywheel device utilizing axial magnetic bearing unloading, comprising a flywheel support assembly and a flywheel rotor assembly located in the center; the flywheel support assembly comprising a bottom support assembly, a middle housing assembly, and a top support assembly; characterized in that: The flywheel rotor is suspended by an axial magnetic bearing. When the flywheel rotor rotates at high speed, the mechanical bearing only bears radial loads. Axial disc springs are provided at both ends of the flywheel rotor to provide elastic damping when the axial magnetic bearing suspends the flywheel rotor. The bottom support assembly comprises a flywheel base, a bottom support seat, a flywheel rotor bottom support bearing assembly, an axial magnetic bearing stator insert, and a suspension bearing assembly. The flywheel rotor bottom support bearing assembly comprises an axial disc spring, a mechanical bearing, a mechanical bearing seat, and a bottom end cover. The suspension bearing assembly comprises a protective bearing and a positioning end cover. The middle housing assembly is used to connect the top support assembly and the bottom support assembly and comprises a middle housing, an axial magnetic bearing stator insert, and an axial displacement sensor. The top support assembly comprises a top support seat, a motor housing assembly, a motor stator insert, and a flywheel rotor top support bearing assembly. The motor housing assembly comprises a motor housing and a cooling water jacket. The flywheel rotor top support bearing assembly is characterized by comprising an axial disc spring, a mechanical bearing, a mechanical bearing seat, a top end cover, and a rotary encoder. The flywheel rotor assembly comprises a flywheel and a motor rotor.

2. A mechanically supported energy storage flywheel device utilizing axial magnetic bearing unloading according to claim 1, characterized in that: The flywheel rotor is supported by mechanical bearings to achieve high-speed rotation.

3. The mechanically supported energy storage flywheel device utilizing axial magnetic bearing unloading according to claim 1, characterized in that: The motor rotor is a tile-shaped structure, which is directly attached to the outer edge of the main shaft. The outer surface of the motor rotor is prestressed with carbon fiber.

4. The mechanically supported energy storage flywheel device utilizing axial magnetic bearing unloading according to claim 1, characterized in that: The motor housing is provided with a spiral water cooling channel for cooling the motor stator wire.

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