Axial flux flywheel energy storage motor

Abstract

The utility model belongs to the field of flywheel energy storage, and particularly relates to an axial magnetic flux flywheel energy storage motor. The upper end cover and the lower end cover respectively cover the upper end and the lower end of the shell; bearings are arranged on the bottom surface of the upper end cover and the top surface of the lower end cover; the flywheel rotor, the upper end cover, the lower end cover and the shell are all made of magnetic materials; the two rotating shafts are respectively connected with the bearings of the upper end cover and the lower end cover; the stator core is arranged on the top surface of the lower end cover; the armature winding is arranged on the stator iron core; the outer magnetic ring and the inner magnetic ring are fixed on the bottom surface of the upper end cover, and the outer magnetic ring is sleeved on the outer circle of the outer magnetic ring; and the excitation winding is sleeved outside the flywheel rotor and is fixed on the inner wall of the shell. According to the utility model, the flywheel rotor is subjected to an axially upward electromagnetic force, the axial electromagnetic force on the flywheel rotor is kept unchanged during charging and discharging operation, only a pair of mechanical bearings is needed for positioning, and the motor is simple and compact in overall structure, low in cost and convenient to process.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the flywheel energy storage field, concretely relates to an axial flux flywheel energy storage motor. BACKGROUND

[0002] Flywheel energy storage technology has broad development prospects as an environmental protection, short charging and discharging time, long service life and high efficiency energy storage technology. Flywheel energy storage motor as the core component of system energy conversion directly affects the charging and discharging performance of the whole system. Permanent magnet motor has the advantages of simple structure and high efficiency, and is widely used in flywheel energy storage system. However, when the flywheel energy storage system is in long time standby operation state, the permanent magnet flux continuously generates electromagnetic loss in the iron core, and the electromagnetic loss increases with the increase of the rotating speed, resulting in low utilization rate of flywheel energy storage energy. In addition, the flywheel energy storage system generally uses at least one axial magnetic bearing and two radial magnetic bearings, resulting in high complexity and high cost of the system.

[0003] In a flywheel energy storage device with large energy storage capacity and small power, in order to obtain high energy storage density, the mass of flywheel rotor is heavy, and the outer diameter is large. If the radial armature winding in the prior art is used, there are defects such as short axial length of stator core, long end of armature winding, large copper loss of motor, large amount of copper, poor performance of system and the like. UTILITY MODEL CONTENTS

[0004] The axial flux flywheel energy storage motor provided by the utility model can effectively solve the problems in the background art.

[0005] The axial flux flywheel energy storage motor provided by the utility model comprises a shell, an upper end cover, a lower end cover, a flywheel rotor, a stator core, an armature winding, an outer magnetic ring, an inner magnetic ring and an excitation winding.

[0006] The shell is sleeve-shaped; the upper end cover and the lower end cover are respectively covered on the upper end and the lower end of the shell; the bottom surface of the upper end cover and the top surface of the lower end cover are both provided with bearings;

[0007] The flywheel rotor is arranged in the shell, the flywheel rotor is provided with shafts at the upper end and the lower end, and the two shafts are respectively connected with the bearings of the upper end cover and the lower end cover; the flywheel rotor, the upper end cover, the lower end cover and the shell are all made of magnetic material;

[0008] The stator core is arranged on the top surface of the lower end cover; the armature winding is arranged on the stator core;

[0009] The outer magnetic ring and the inner magnetic ring are fixed on the bottom surface of the upper end cover, and the outer magnetic ring is sleeved on the outer ring of the outer magnetic ring;

[0010] The excitation winding is sleeved on the flywheel rotor and fixed on the inner wall of the shell;

[0011] The lower end surface of the flywheel rotor is provided with a first groove, and a protrusion is arranged in the groove corresponding to the position of the armature winding.

[0012] As further optimization of the utility model, the flywheel rotor is made of alloy steel.

[0013] As further optimization of the utility model, the upper end surface of the flywheel rotor is provided with a second groove.

[0014] As further optimization of the utility model, the protrusion is in rectangular shape, circular arc shape or sine function shape.

[0015] As further optimization of the utility model, the stator core is composed of a plurality of silicon steel sheets.

[0016] As further optimization of the utility model, the armature winding and the stator core are fixed by epoxy resin; the excitation winding and the outer wall of the shell are fixed by epoxy resin.

[0017] As further optimization of the utility model, it further comprises a permanent magnet ring and an aluminum ring; the permanent magnet ring is arranged between the inner magnet ring and the upper end cover; the aluminum ring is arranged on both sides of the permanent magnet ring to enclose the permanent magnet ring between the inner magnet ring and the upper end cover.

[0018] As further optimization of the utility model, the surface of the stator core is flat and has no groove.

[0019] The axial flux flywheel energy storage motor has low eddy current loss; the flywheel rotor is subjected to upward electromagnetic force in the axial direction, the axial electromagnetic force acting on the flywheel rotor remains unchanged during charging and discharging operation, the load and loss of the bearing are small, the motor has high operation stability and high energy utilization rate; the flywheel rotor is free of winding and permanent magnet, and has reliable structure and high mechanical strength; the flywheel rotor is integrated, the flywheel rotor can be subjected to electromagnetic force in the axial direction during energy storage standby and charging and discharging, only one pair of mechanical bearings is needed for positioning, the overall structure of the motor is simple and compact, the cost is low, and the motor is convenient to process; the axial flux stator core and the armature winding are adopted, and the motor is suitable for flywheel energy storage occasions with large energy storage capacity and small power. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a cross-sectional structure schematic view of an embodiment;

[0021] Figure 2 is Figure 1 a flywheel rotor structure schematic view;

[0022] The shell 1, the upper end cover 2, the lower end cover 3, the flywheel rotor 4, the rotating shaft 4a, the first groove 4b, the second groove 4c, the protrusion 4d, the armature winding 5, the stator core 6, the outer magnet ring 7, the inner magnet ring 8, the excitation winding 9, the permanent magnet ring 10, the aluminum ring 11, the permanent magnet main magnetic flux path 12 and the excitation main magnetic flux path 13. DETAILED DESCRIPTION

[0023] As shown in the figure, the embodiment includes a shell 1, a lower end cover 3, an upper end cover 2, a flywheel rotor 4, an armature winding 5, a stator core 6, an outer magnetic ring 7, an inner magnetic ring 8 and an excitation winding 9. Figure 1

[0024] The shell 1 is sleeve-shaped. The upper end cover 2 and the lower end cover 3 are respectively covered on the upper and lower ends of the shell 1. In the embodiment, the upper end cover 2, the lower end cover 3 and the shell 1 are all made of magnetic material to play a role of magnetic conduction.

[0025] In the embodiment, the flywheel rotor 4 is made of alloy steel material of magnetic material, and specifically made of 40Cr. The flywheel rotor 4 is arranged in the shell 1, and the flywheel rotor 4 is provided with rotating shafts 4a at the upper and lower ends. The rotating shafts 4a are made of non-magnetic material, and the rotating shafts 4a are connected with the flywheel rotor 4 in an interference fit. The two rotating shafts 4a are respectively connected with the upper end cover 2 and the lower end cover 3 through bearings. Specifically, the bearings are respectively embedded in the bottom surface of the upper end cover 2 and the top surface of the lower end cover 3, and the two rotating shafts 4a are respectively inserted into the two bearings. That is, the flywheel rotor 4 can rotate around the axis of the two rotating shafts 4a in the shell 1.

[0026] The excitation winding 9 is wound by flat copper wire into a ring shape, and the excitation winding 9 is sleeved on the flywheel rotor 4 and fixed on the inner wall of the shell 1. Specifically, the excitation winding 9 and the inner wall of the shell 1 are bonded by epoxy resin.

[0027] In the embodiment, the stator core 6 is fixed on the top surface of the lower end cover 3, and the stator core 6 is stacked by a plurality of silicon steel sheets. The stator core 6 is surface-free to reduce the eddy current loss of the flywheel rotor 4. The armature winding 5 is bonded on the upper surface of the stator core 6 by epoxy resin. The stator core 6 and the lower end surface of the flywheel rotor are provided with an axial air gap.

[0028] As shown in the figure, the lower end surface of the flywheel rotor 4 in the embodiment is provided with a first groove 4b, and a protrusion 4d is arranged in the groove corresponding to the position of the armature winding. The protrusion 4d in the embodiment is a circle formed by two circular arcs. In other embodiments, the protrusion 4d can also be in the shape of a rectangle or a sine function. Figure 2 Due to the existence of the protrusion 4d, the axial air gap of the stator core 6 can generate a periodically changing magnetic field under the action of the excitation winding 9. The first groove 4b in the embodiment reduces the leakage magnetic flux from the side surface of the stator core 6. Preferably, the second groove 4c is further arranged on the upper end surface of the flywheel rotor 4 to further reduce the leakage magnetic flux.

[0029]

[0030] ​​The outer magnetic ring 7 and the inner magnetic ring 8 are fixed to the bottom surface of the upper end cover 2, the outer magnetic ring 7 is sleeved on the outer ring of the outer magnetic ring 7, and the outer magnetic ring 7 and the inner magnetic ring 8 are both provided with an axial air gap on the upper end surface of the flywheel rotor 4, and the air gap is about 2mm.

[0031] The embodiment further comprises a permanent magnetic ring 10 and an aluminum ring 11. The permanent magnetic ring 10 is arranged between the inner magnetic ring 8 and the upper end cover 2, and the aluminum ring 11 is arranged on both sides of the permanent magnetic ring 10 to enclose the permanent magnetic ring 10 between the inner magnetic ring 8 and the upper end cover 2. There is an air gap of 40mm between the permanent magnetic ring 10 and the outer magnetic ring 7.

[0032] In the embodiment, during the energy storage standby period, the excitation winding 9 is not electrified, the permanent magnetic main magnetic flux path 12 generated by the permanent magnetic ring 10 is: the permanent magnetic ring 10, the axial air gap, the flywheel rotor 4, the axial air gap, the outer magnetic ring 7, the upper end cover 2, and the permanent magnetic ring 10. The magnetic flux acts on the surface of the flywheel rotor 4 to provide an electromagnetic force upward on the flywheel rotor 4, so as to partially or completely offset the gravity of the flywheel rotor 4, thereby reducing the load borne by the bearing. Since the magnetic flux of the permanent magnetic ring 10 passes through a long closed path of the stator core 6, and the air gap magnetic resistance of the surface of the stator core 6 is large, the surface air gap magnetic density of the stator core 6 is very small, the stator core loss and the eddy current loss of the rotor surface are very small, the motor loss is low, and the energy utilization rate of the flywheel rotor 4 is high.

[0033] In the embodiment, during the energy storage standby period, the excitation winding 9 is not electrified, the permanent magnetic main magnetic flux path 12 generated by the permanent magnetic ring 10 is: the permanent magnetic ring 10, the axial air gap, the flywheel rotor 4, the axial air gap, the outer magnetic ring 7, the upper end cover 2, and the permanent magnetic ring 10. The magnetic flux acts on the surface of the flywheel rotor 4 to provide an electromagnetic force upward on the flywheel rotor 4, so as to partially or completely offset the gravity of the flywheel rotor 4, thereby reducing the load borne by the bearing. Since the magnetic flux of the permanent magnetic ring 10 passes through a long closed path of the stator core 6, and the air gap magnetic resistance of the surface of the stator core 6 is large, the surface air gap magnetic density of the stator core 6 is very small, the stator core loss and the eddy current loss of the rotor surface are very small, the motor loss is low, and the energy utilization rate of the flywheel rotor 4 is high.

[0034] The embodiment greatly reduces the bearing load and friction loss, the overall structure of the motor is simple, compact and low in cost, the rotor dynamics is good, the processing is convenient, and the motor is very suitable for flywheel energy storage occasions.

[0035] It should be noted that the up, down, top, bottom and other orientation expressions described in the embodiment are all based on the drawings of the specification and are only used to describe the technical solutions, but do not represent the limitation of the protection scope.

[0036] It should be explained finally that the above embodiment is only used to illustrate the technical scheme of the utility model, and is not the limit of the protection scope of the utility model, although the utility model is explained in detail with reference to the preferred embodiment, the ordinary skilled in the art should understand that the technical scheme of the utility model can be modified or replaced equivalently, and does not deviate from the essence and scope of the technical scheme of the utility model.

Claims

1. An axial flux flywheel energy storage motor, characterized by, The flywheel rotor, the upper end cover, the lower end cover, the shell, the stator core, the armature winding, the outer magnetic ring, the inner magnetic ring and the excitation winding are all made of magnetic material. The shell is sleeve-shaped, and the upper end cover and the lower end cover are respectively arranged at the upper end and the lower end of the shell. The flywheel rotor is arranged in the shell, and the flywheel rotor is provided with rotating shafts at the upper end and the lower end, and the rotating shafts are respectively connected with the bearings of the upper end cover and the lower end cover. The flywheel rotor, the upper end cover, the lower end cover and the shell are all made of magnetic material. The stator core is arranged on the top surface of the lower end cover. The outer magnetic ring and the inner magnetic ring are fixed on the bottom surface of the upper end cover, and the outer magnetic ring is sleeved on the outer ring of the outer magnetic ring. The excitation winding is sleeved on the flywheel rotor and fixed on the inner wall of the shell.

2. An axial flux flywheel energy storage motor according to claim 1, wherein, The lower end surface of the flywheel rotor is provided with a first groove, and a protrusion is arranged in the groove corresponding to the position of the armature winding.

3. An axial flux flywheel energy storage motor according to claim 1, wherein, The flywheel rotor is made of alloy steel.

4. An axial flux flywheel energy storage motor according to claim 1, wherein, The upper end surface of the flywheel rotor is provided with a second groove.

5. An axial flux flywheel energy storage motor according to claim 1, wherein, The protrusion is rectangular, circular arc or sinusoidal function.

6. An axial flux flywheel energy storage motor according to claim 1, wherein, The stator core is made of a plurality of silicon steel sheets.

7. An axial flux flywheel energy storage motor as claimed in claim 1, wherein, The armature winding is fixed with the stator core by epoxy resin, and the excitation winding is fixed with the outer wall of the shell by epoxy resin.

8. An axial flux flywheel energy storage motor according to claim 1, wherein, The flywheel rotor, the upper end cover, the lower end cover, the shell, the stator core, the armature winding, the outer magnetic ring, the inner magnetic ring and the excitation winding are all made of magnetic material. The surface of the stator core is flat and has no slot.

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