Motor Rotor and Self-Starting Synchronous Reluctance Motor

Abstract

The present application provides a motor rotor and a self-starting synchronous reluctance motor. The motor rotor includes a rotor core (1), and a filling groove and a slit groove (2) are provided on the rotor core (1). The filling groove includes an inner filling groove (7) and an outer filling groove. The inner filling groove (7) is located between the slit groove (2) and the rotor shaft hole (6) of the rotor core (1). The inner filling groove (7) and the outer filling groove are filled with a conductive and non-magnetic material, and are short-circuited through end rings (8) located at both ends of the rotor core (1) to form a squirrel-cage structure. According to the motor rotor of the present application, the motor pull-in synchronization ability can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of motors, and particularly to a motor rotor and a self-starting synchronous reluctance motor. Background Art

[0002] Based on the synchronous reluctance motor, the self-starting synchronous reluctance motor combines the advantages of the asynchronous motor and realizes self-starting through the asynchronous torque generated by the rotor bars without the need for a frequency converter drive. Compared with the asynchronous motor, the motor can achieve constant-speed operation, with low rotor loss and improved efficiency during synchronous operation; compared with the asynchronous starting permanent magnet synchronous motor, the motor does not use permanent magnet materials, has a low cost, and there is no risk of permanent magnet demagnetization. However, the self-starting synchronous reluctance motor has the problem that during the load starting process, the ability to pull into synchronization is weak and it is difficult to reach the synchronous speed, which limits the application of this type of motor in a wider range of fields. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present application is to provide a motor rotor and a self-starting synchronous reluctance motor, which can effectively improve the ability of the motor to pull into synchronization.

[0004] To solve the above problems, the present application provides a motor rotor, including a rotor core, on which a filling groove and a slit groove are provided. The filling groove includes an inner filling groove and an outer filling groove. The inner filling groove is located between the slit groove and the rotor shaft hole of the rotor core. The inner filling groove and the outer filling groove are filled with a conductive and non-magnetic material and are short-circuited through end rings located at both ends of the rotor core to form a squirrel-cage structure.

[0005] Preferably, the outer filling groove includes an outer non-independent filling groove and an outer independent filling groove. The outer non-independent filling groove is arranged on the same layer as the corresponding slit groove, and the outer independent filling groove is located outside the slit groove along the q-axis direction.

[0006] Preferably, the minimum distance from the inner filling groove to the rotor shaft hole is h3, and 10σ ≤ h3 ≤ 25σ, where σ is the air-gap width between the stator and the rotor.

[0007] Preferably, the thickness of the inner filling groove located on the q-axis along the q-axis direction is h1, and the thickness of the inner filling groove located on the d-axis along the d-axis direction is h2, and h1 < h2.

[0008] Preferably, the minimum distance from the inner filling groove to the rotor shaft hole is h3, 0.5h3 ≤ h1 ≤ h3, and under one pole, the central angle α1 occupied by the inner filling groove located on the q-axis satisfies 0.2α ≤ α1 ≤ 0.4α, where α is the central angle corresponding to one magnetic pole of the rotor.

[0009] Preferably, the minimum distance from the inner filling groove to the rotor shaft hole is h3, h3≤h2≤1.2h3, and under one pole, the center angle α2 occupied by the inner filling groove located on the d-axis satisfies 0.2α≤α2≤0.4α, where α is the center angle corresponding to one magnetic pole of the rotor.

[0010] Preferably, the ratio of the area of the inner layer filling groove located on the q-axis to the area of the inner layer filling groove located on the d-axis is 0.5 to 0.8.

[0011] Preferably, the ratio of the area of the inner layer filling groove located on the q-axis to the area of the inner layer filling groove located on the d-axis is 0.6-0.7.

[0012] Preferably, the ratio of the total area of the inner layer filling slots to the total area of the filling slots is 0.2-0.4.

[0013] Preferably, the ratio of the total area of the inner layer filling slots to the total area of the filling slots is 0.25 to 0.35.

[0014] Preferably, the outer layer non-independent filling grooves and the slit grooves in the same layer form a U-shaped magnetic barrier layer.

[0015] Preferably, the outer layer non-independent filling slots are separated from the slit slots and the outer circle of the rotor by dividing ribs, and the width k of the dividing ribs satisfies 0.5σ≤k≤2.5σ, where σ is the air gap width between the stator and the rotor.

[0016] Preferably, the outer independent filling groove is U-shaped, and the outer independent filling groove under each pole is separated at the q-axis position and between the outer independent filling groove and the outer circle of the rotor by dividing ribs.

[0017] Preferably, the slit groove is in a straight line shape, an arc shape, or a combination of a straight line shape and an arc shape.

[0018] Preferably, the rotor core is provided with a groove at the outer circle of the rotor in the q-axis direction, and the maximum distance between the contour line of the outer circle of the rotor and the bottom of the groove is d, k≤d≤5k, where k is the width of the dividing rib between the outer filling groove and the outer circle of the rotor.

[0019] Preferably, at the same pole, the center angle occupied by the groove is β, the center angle corresponding to one magnetic pole of the rotor is α, and 0.1α≤β≤0.25α.

[0020] Preferably, 0.15α≤β≤0.2α.

[0021] Preferably, the end ring covers all the filling slots and avoids all the slit slots.

[0022] According to another aspect of the present application, a self-starting synchronous reluctance motor is provided, comprising a motor rotor, which is the motor rotor described above.

[0023] The motor rotor provided by the present application includes a rotor core, and a filling groove and a slit groove are provided on the rotor core. The filling groove includes an inner filling groove and an outer filling groove. The inner filling groove is located between the slit groove and the rotor shaft hole of the rotor core. The inner filling groove and the outer filling groove are filled with a conductive and non-magnetic material, and are short-circuited through end rings located at both ends of the rotor core to form a squirrel-cage structure. By arranging the inner filling groove on the inner peripheral side of the slit groove, the filling groove area on the rotor core can be effectively increased, the aluminum casting area on the rotor core can be improved, and the motor pull-in synchronization ability can be enhanced. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the motor rotor of an embodiment of the present application after removing the end rings;

[0025] Figure 2 It is a schematic structural diagram of the motor rotor of an embodiment of the present application after removing the end rings;

[0026] Figure 3 It is a schematic structural diagram of the motor rotor of an embodiment of the present application;

[0027] Figure 4 It is a comparison diagram of the pull-in synchronization ability between the motor of the embodiment of the present application and the motor of the related technology.

[0028] The reference numerals are represented as:

[0029] 1. Rotor core; 2. Slit groove; 3. Outer non-independent filling groove; 4. Outer independent filling groove; 5. Partition rib; 6. Rotor shaft hole; 7. Inner filling groove; 8. End ring; 9. Groove. Detailed Embodiments

[0030] Referring to Figures 1 to 4 As shown, according to the embodiment of the present application, the motor rotor includes a rotor core 1, and a filling groove and a slit groove 2 are provided on the rotor core 1. The filling groove includes an inner filling groove 7 and an outer filling groove. The inner filling groove 7 is located between the slit groove 2 and the rotor shaft hole 6 of the rotor core 1. The inner filling groove 7 and the outer filling groove are filled with a conductive and non-magnetic material, and are short-circuited through end rings 8 located at both ends of the rotor core 1 to form a squirrel-cage structure.

[0031] By arranging the inner filling groove 7 on the inner peripheral side of the slit groove 2, the filling groove area on the rotor core 1 can be effectively increased, the aluminum casting area on the rotor core 1 can be improved, and the motor pull-in synchronization ability can be enhanced. The formation of the rotor squirrel-cage structure provides an asynchronous torque for the motor during the starting stage, enabling the motor to have self-starting ability.

[0032] The above-mentioned conductive and non-magnetic material is preferably selected as aluminum or aluminum alloy material. Metal aluminum has good electrical conductivity and low price, and is suitable for applications in the field of industrial motors. Both ends of the filling slots are short-circuited and connected through the end ring 8 to form a rotor squirrel-cage structure. The material used for the end ring 8 is the same as the material filled in the filling slots. The end ring 8 shorts the filling slots to form a squirrel cage, and only then can the current in the filling slots flow to form a loop. The squirrel cage is also called a starting cage, which provides asynchronous torque during the motor starting stage, enabling the motor to have self-starting ability. The conductive and non-magnetic material can also be made of materials such as pure copper.

[0033] Referring to Figure 4 As shown, the figure is a rotational speed curve graph of the motor using the motor rotor of the embodiment of the present application and the motor of the related technology during the starting process. It can be seen that under the condition of the same load, the motor using the rotor structure of the embodiment of the present application can be pulled into the synchronous speed, while the motor of the prior art is in an out-of-step state, indicating that the motor using the motor rotor of the embodiment of the present application has a stronger ability to pull into synchronization.

[0034] In one embodiment, the outer filling slots include an outer non-independent filling slot 3 and an outer independent filling slot 4. The outer non-independent filling slot 3 is arranged on the same layer as the corresponding slit slot 2, and the outer independent filling slot 4 is located outside the slit slot 2 along the q-axis direction.

[0035] In one embodiment, the minimum distance from the inner filling slot 7 to the rotor shaft hole 6 is h3, and 10σ ≤ h3 ≤ 25σ, where σ is the air gap width between the stator and the rotor. In this embodiment, the inner layer of the rotor core 1 is arranged with inner filling slots on both the d-axis and q-axis axis positions, which can make full use of the internal space of the rotor core 1, thereby increasing the amount of cast aluminum on the rotor core 1 and improving the motor's ability to pull into synchronization. Limiting the minimum distance between the filling slot and the rotor shaft hole 6 aims to ensure the structural safety of the rotor core 1.

[0036] In one embodiment, the thickness of the inner filling slot 7 located on the q-axis along the q-axis direction is h1, and the thickness of the inner filling slot 7 located on the d-axis along the d-axis direction is h2, and h1 < h2. For the motor rotor of a synchronous reluctance motor, the structure and structural arrangement relationship between the slit slot 2 and the outer filling slots result in a smaller thickness of the iron core inside the slit slot 2 in the q-axis direction where the slit slot 2 is located, and a larger thickness of the iron core inside the slit slot 2 in the d-axis direction. Therefore, in order to make more full use of the space of the rotor core 1 inside the slit slot 2 and more effectively increase the cast aluminum area, for the rotor core 1 at the position with a thinner thickness, the thickness of the inner filling slot 7 thereon can be smaller, and for the rotor core 1 at the position with a larger thickness, the thickness of the inner filling slot 7 thereon can be larger, so as to maximize the utilization of the structure of the rotor core 1 without affecting the structural strength of the rotor core 1 and effectively improve the motor efficiency.

[0037] In one embodiment, the minimum distance from the inner filling groove 7 to the rotor shaft hole 6 is h3, 0.5h3 ≤ h1 ≤ h3, and under one pole, the central angle α1 occupied by the inner filling groove 7 located on the q-axis satisfies 0.2α ≤ α1 ≤ 0.4α, where α is the central angle corresponding to one magnetic pole of the rotor.

[0038] The minimum distance from the inner filling groove 7 to the rotor shaft hole 6 is h3, h3 ≤ h2 ≤ 1.2h3, and under one pole, the central angle α2 occupied by the inner filling groove 7 located on the d-axis satisfies 0.2α ≤ α2 ≤ 0.4α, where α is the central angle corresponding to one magnetic pole of the rotor.

[0039] The inner filling groove 7 is arranged at the inner layer position of the rotor between the slit groove 2 and the rotor shaft hole 6, and needs to be reasonably arranged. It is required that the inner filling groove 7 has a certain filling area, and there is also a certain distance between the inner filling groove 7 and the slit groove 2 and the rotor shaft hole 6, so as to ensure the safety of the rotor structure.

[0040] In one embodiment, the ratio of the area of the inner filling groove 7 located on the q-axis to the area of the inner filling groove 7 located on the d-axis is 0.5 to 0.8.

[0041] Preferably, the ratio of the area of the inner filling groove 7 located on the q-axis to the area of the inner filling groove 7 located on the d-axis is 0.6 to 0.7.

[0042] The area of the q-axis axis region near the inner side of the rotor is smaller than the area of the d-axis axis region. In order to make full use of the inner layer space of the rotor, it is more appropriate to take the above values for the area ratio of the two inner filling grooves 7, so that the space of the rotor core 1 in each region can be more fully utilized.

[0043] In one embodiment, the proportion of the total area of the inner filling groove 7 in the total area of the filling grooves is 0.2 to 0.4.

[0044] Preferably, the proportion of the total area of the inner filling groove 7 in the total area of the filling grooves is 0.25 to 0.35.

[0045] The purpose of limiting the proportion of the total area of the inner filling groove 7 in the total area of the filling grooves is to ensure that the filling area of the inner filling groove 7 does not affect the structural safety of the rotor, and at the same time improve the pull-in synchronization ability of the motor.

[0046] In one embodiment, the outer non-independent filling groove 3 and the slit groove 2 of the same layer form a U-shaped magnetic barrier layer or a U-shaped-like magnetic barrier layer. Such a setting can form a multi-layer magnetic barrier structure, which is beneficial to increasing the inductance difference between the d-axis and q-axis of the motor, thereby making full use of the reluctance torque.

[0047] In one embodiment, the outer non-independent filling slot 3 is separated from the slit slot 2 and the outer circle of the rotor by a dividing rib 5, and the width k of the dividing rib 5 satisfies 0.5σ≤k≤2.5σ, where σ is the air gap width between the stator and the rotor, thereby ensuring that the width of the dividing rib 5 is within an appropriate range, which can ensure that the motor has a certain salient pole ratio and that the structural strength of the rotor is ensured.

[0048] In one embodiment, the shape of the outer independent filling slot 4 is U-shaped or quasi-U-shaped, and the outer independent filling slot 4 under each pole is separated at the q-axis position and between the outer independent filling slot 4 and the outer circle of the rotor by a dividing rib 5. The shape of the outer independent filling slot 4 is designed to have a similar shape to the magnetic barrier layer composed of the outer non-independent filling slot 3 and the slit slot 2, so that the magnetic resistance torque brought by the difference in inductance between the d and q axes can be more fully utilized, and the dividing rib 5 also ensures the structural strength of the rotor.

[0049] In one embodiment, the slit groove 2 is in a straight line shape, an arc shape, or a combination of a straight line shape and an arc shape.

[0050] In one embodiment, the rotor core 1 is provided with a groove 9 on the rotor outer circle in the q-axis direction, and the maximum distance between the contour line of the rotor outer circle and the bottom of the groove 9 is d, k≤d≤5k, where k is the width of the dividing rib 5 between the outer filling groove and the rotor outer circle.

[0051] At the same pole, the center angle occupied by the groove 9 is β, the center angle corresponding to one magnetic pole of the rotor is α, and 0.1α≤β≤0.25α.

[0052] Preferably, 0.15α≤β≤0.2α.

[0053] By providing the groove 9 at this position and limiting the size of the groove 9, the magnetic resistance in the q-axis direction can be further increased, so that the salient pole ratio of the motor is increased, which is beneficial to the utilization of the magnetic resistance torque.

[0054] In one embodiment, the end ring 8 covers all the filling slots and avoids all the slit slots 2. The motor rotor formed by such an arrangement can not only form a good starting performance by using the squirrel cage structure, but also use the slit slots 2 as flow holes to increase the air flow area of the motor rotor and improve the heat dissipation performance of the motor rotor.

[0055] In one embodiment, the inner filling groove 7 is trapezoidal; or, the inner filling groove 7 is circular and / or elliptical.

[0056] When the inner filling slot 7 is circular and / or elliptical, the shape of the inner filling slot 7 can be made more regular, thereby reducing the difficulty of machining the rotor core and improving the machining efficiency.

[0057] According to an embodiment of the present application, the self-starting synchronous reluctance motor includes a motor rotor, which is the above-mentioned motor rotor.

[0058] It is easily understood by those skilled in the art that, on the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0059] The above are only the preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art, several improvements and variations can be made without departing from the technical principle of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A motor rotor, characterized in that, It includes a rotor core (1), and a filling groove and a slit groove (2) are provided on the rotor core (1). The filling groove includes an inner filling groove (7) and an outer filling groove. The inner filling groove (7) is located between the slit groove (2) and the rotor shaft hole (6) of the rotor core (1). The inner filling groove (7) and the outer filling groove are filled with a conductive and non-magnetic material. A groove (9) is provided at the outer circumference of the rotor in the q-axis direction of the rotor core (1), and short-circuit connection is performed through end rings (8) located at both ends of the rotor core (1) to form a squirrel-cage structure; The outer filling groove includes an outer non-independent filling groove (3) and an outer independent filling groove (4). The outer non-independent filling groove (3) is arranged in the same layer as the corresponding slit groove (2), and the outer independent filling groove (4) is located outside the slit groove (2) along the q-axis direction; The thickness of the inner filling groove (7) located on the q-axis along the q-axis direction is h1, and the thickness of the inner filling groove (7) located on the d-axis along the d-axis direction is h2, and h1 < h2.

2. The motor rotor according to claim 1, characterized in that, The minimum distance from the inner filling groove (7) to the rotor shaft hole (6) is h3, and 10σ ≤ h3 ≤ 25σ, where σ is the air-gap width between the stator and the rotor.

3. The motor rotor according to claim 1, characterized in that, The minimum distance from the inner filling groove (7) to the rotor shaft hole (6) is h3, 0.5h3 ≤ h1 ≤ h3, and under one pole, the central angle α1 occupied by the inner filling groove (7) located on the q-axis satisfies 0.2α ≤ α1 ≤ 0.4α, where α is the central angle corresponding to one magnetic pole of the rotor.

4. The motor rotor according to claim 1, wherein, The minimum distance from the inner filling groove (7) to the rotor shaft hole (6) is h3, h3 ≤ h2 ≤ 1.2h3, and under one pole, the central angle α2 occupied by the inner filling groove (7) located on the d-axis satisfies 0.2α ≤ α2 ≤ 0.4α, where α is the central angle corresponding to one magnetic pole of the rotor.

5. The motor rotor according to claim 1, characterized in that, The ratio of the area of the inner filling groove (7) located on the q-axis to the area of the inner filling groove (7) located on the d-axis is 0.5 - 0.

8.

6. The motor rotor according to claim 5, characterized in that, The ratio of the area of the inner filling groove (7) located on the q-axis to the area of the inner filling groove (7) located on the d-axis is 0.6 - 0.

7.

7. The motor rotor according to claim 1, characterized in that, The proportion of the total area of the inner filling groove (7) in the total area of the filling groove is 0.2 - 0.

4.

8. The motor rotor according to claim 7, wherein, The proportion of the total area of the inner filling groove (7) in the total area of the filling groove is 0.25 - 0.

35.

9. The motor rotor according to claim 1, wherein The outer non-independent filling groove (3) and the slit groove (2) in the same layer form a U-shaped magnetic barrier layer.

10. The motor rotor according to claim 1, characterized in that, The outer non-independent filling groove (3), the slit groove (2), and the outer circumference of the rotor are separated by a dividing rib (5), and the width k of the dividing rib (5) satisfies 0.5σ ≤ k ≤ 2.5σ, where σ is the air-gap width between the stator and the rotor.

11. The motor rotor according to claim 1, characterized in that, The shape of the outer independent filling groove (4) is U-shaped, and the outer independent filling groove (4) under each pole is separated by a dividing rib (5) at the q-axis position and between the outer independent filling groove (4) and the outer circumference of the rotor.

12. The motor rotor according to claim 1, characterized in that, The slit groove (2) is in a straight line shape, an arc shape, or a combination of a straight line shape and an arc shape.

13. The motor rotor according to claim 1, characterized in that, The maximum distance between the contour line of the rotor outer circle and the bottom of the groove (9) is d, k≤d≤5k, where k is the width of the dividing rib (5) between the outer filling groove and the rotor outer circle.

14. The motor rotor according to claim 13, characterized in that, At the same pole, the center angle occupied by the groove (9) is β, the center angle corresponding to one magnetic pole of the rotor is α, and 0.1α≤β≤0.25α.

15. The motor rotor according to claim 14, characterized in that, 0.15α≤β≤0.2α。 16. The motor rotor according to claim 1, characterized in that, The end ring (8) covers all the filling slots and avoids all the slit slots (2).

17. The motor rotor according to claim 1, characterized in that, The inner layer filling groove (7) is trapezoidal; or, the inner layer filling groove (7) is circular and / or elliptical.

18. A self-starting synchronous reluctance motor, comprising a motor rotor, characterized in that, The motor rotor is the motor rotor according to any one of claims 1 to 17.

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