Motor balancing plate and motor

Abstract

The present application provides a kind of motor balance plate and motor, motor balance plate is used to set in the end portion of the axial direction (A) of the rotor (11) of motor (10), the balance plate is disc-shaped, the end face of the balance plate for towards the rotor (11) partially protrudes to the rotor (11) and forms a plurality of blades (21), the plurality of blades (21) are arranged along the circumferential direction of the balance plate, the blade (21) extends from the radial inner side to the radial outer side of the balance plate and forms centrifugal blade, so that when the balance plate rotates, the blade (21) can agitate air to form air flow from the radial inner side to the radial outer side. The motor balance plate according to the present application is simple in structure and can help the motor to dissipate heat. The motor according to the present application has good heat dissipation performance.

Description

Technical Field

[0001] This invention relates to the field of electric motors (electric motors and / or generators), particularly to electric motors for pure electric vehicles or hybrid vehicles, and especially to internal rotor motors and their balance plates. Background Technology

[0002] Reference Figure 1 For example, in an internal rotor motor 10, a balance plate 20 is usually provided at the end of the rotor 11 along the axial direction A. The balance plate 20 can rotate with the rotor 11 and plays the role of adjusting the rotational inertia of the rotor 11.

[0003] However, during the high-speed rotation of motor 10, especially when operating continuously at high speed and high torque, rotor 11 will generate a large amount of heat, which will lead to a deterioration in motor operating conditions or even malfunction. Therefore, it is necessary to take effective measures to cool motor 10. Summary of the Invention

[0004] The purpose of this invention is to overcome or at least mitigate the shortcomings of the prior art and to provide a motor balance plate and a motor including the balance plate.

[0005] According to a first aspect of the present invention, a motor balance plate is provided, which is disposed at an axial end of the rotor of a motor, the balance plate being disc-shaped, wherein...

[0006] The end face of the balance plate protrudes towards the rotor to form multiple blades, which are arranged circumferentially along the balance plate. The blades extend from the radially inner side to the radially outer side of the balance plate to form centrifugal blades, so that when the balance plate rotates, the blades can agitate the air to form an airflow from the radially inner side to the radially outer side.

[0007] In at least one embodiment, the blade is a backward-facing blade with an exit angle of less than 90°, or the blade is a radial blade with an exit angle of 90°.

[0008] In at least one embodiment, the blade is curved in shape and formed as a curved blade in a cross section perpendicular to the axial direction.

[0009] In at least one embodiment, the end face of the balance plate facing the rotor is partially recessed in a direction away from the rotor to form a cavity.

[0010] In at least one embodiment, the degree of concavity of the end face increases as it moves further inward in at least a portion of the radial direction of the balance plate.

[0011] In at least one embodiment, the blade includes a first blade, and the end face is not covered by the first blade in the inner peripheral portion.

[0012] In at least one embodiment, the blade further includes a second blade that extends beyond the first blade on its inner circumferential side and is aligned with the first blade on its outer circumferential side.

[0013] In at least one embodiment, the second blade is alternately arranged with the first blade in the circumferential direction of the balance plate.

[0014] According to a second aspect of the invention, an electric motor is provided, comprising a rotor and a stator, the rotor being located on the inner circumferential side of the stator, the electric motor further comprising a motor balance plate according to the invention, the balance plate being disposed at at least one end of the rotor in the axial direction.

[0015] According to a third aspect of the present invention, an electric motor is provided, comprising a rotor and a stator, wherein the rotor is located on the inner circumferential side of the stator.

[0016] The motor also includes a motor balance plate according to the present invention.

[0017] The rotor has a plurality of through holes extending in the axial direction, the through holes being at least partially unobstructed by the first blade.

[0018] The motor balance plate according to the present invention has a simple structure and can help the motor dissipate heat.

[0019] The motor according to the present invention has good heat dissipation performance. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of a possible motor that includes a balance plate.

[0021] Figure 2 This is a cross-sectional schematic diagram of an electric motor according to one embodiment of the present invention.

[0022] Figure 3 and Figure 4 These are schematic diagrams of a balance plate from two different perspectives according to one embodiment of the present invention.

[0023] Figure 5 This is a top view schematic diagram of a balance plate according to one embodiment of the present invention.

[0024] Figure 6 This is a cross-sectional schematic diagram of the air passage formed at the balance plate of the motor according to an embodiment of the present invention.

[0025] Figure 7 This is a schematic diagram of four possible structures of the blades of the balance plate according to the present invention.

[0026] Figure 8 This is a schematic diagram of four possible structures of the air passage formed at the balance plate by the motor according to the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 10. Motor; 11. Rotor; 12. Stator;

[0029] 20 Balance plate; 21 Blade; 211 Long blade; 212 Short blade;

[0030] 11f front dial; 20r rear dial;

[0031] θ is the exit angle; L1 is the first ray; L2 is the second ray; E is the exit end; C is the exit circle;

[0032] R is radial; A is axial. Detailed Implementation

[0033] Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement the present invention, and are not intended to exhaustively describe all possible ways of the invention, nor to limit the scope of the invention.

[0034] Unless otherwise specified, refer to Figure 1 , Figure 2 , Figure 6 and Figure 8 A represents the axial direction of motor 10 and balance plate 20, and R represents the radial direction of motor 10 and balance plate 20.

[0035] Reference Figure 2 The motor 10 according to the present invention includes a rotor 11, a stator 12 and a balance plate 20.

[0036] The stator 12 is torsionally (non-rotatable) disposed relative to the housing of the motor 10, and the rotor 11 is disposed on the inner circumferential side of the stator 12, and the rotor 11 can rotate relative to the stator 12.

[0037] At least one end of the rotor 11 along the axial direction A is provided with a balance plate 20. The balance plate 20 is connected to the rotor 11 in a way that prevents relative rotation. That is, the balance plate 20 will rotate with the rotor 11 during the rotation of the rotor 11.

[0038] Simultaneously refer to Figures 3 to 5 The balance plate 20 is roughly disc-shaped, and the center of the balance plate 20 has a through hole for the spindle to pass through.

[0039] The end face of the balance plate 20 facing the rotor 11 is partially recessed in a direction away from the rotor 11. Considering the structure of the centrifugal blade described below, this end face is referred to as the rear disc face 20r, and the axial end face of the rotor 11 opposite to the rear disc face 20r is referred to as the front disc face 11f. Due to the recess of the rear disc face 20r, a cavity is formed between the rear disc face 20r and the front disc face 11f.

[0040] The rear disc surface 20r partially protrudes from the front disc surface 11f to form multiple blades 21. The blades 21 extend from the radially inner side to the radially outer side, and the multiple blades 21 are arranged circumferentially along the balance plate 20. Because it is similar to the blades of a centrifugal fan, this type of blade 21 is also called a centrifugal blade.

[0041] In this embodiment, the blade 21 includes a long blade (second blade) 211 and a short blade (first blade) 212, which are alternately arranged in the circumferential direction. The long blade 211 and the short blade 212 are aligned on the outer circumferential side, that is, the radially outer ends of the long blade 211 and the short blade 212 are located on the same circumference; the long blade 211 extends beyond the short blade 212 on the inner circumferential side, that is, in the radial direction R of the balance plate 20, the long blade 211 extends into a more inward region than the short blade 212. The arrangement of the short blade 212 is to avoid obstruction of the airway inlet described below.

[0042] Because the balance plate 20 is almost in close contact with the end of the rotor 11, a relatively independent air passage is formed in the axial direction A between the rear disc surface 20r and the front disc surface 11f, and in the circumferential direction between two adjacent blades 21. (Refer to...) Figure 5 When the balance plate 20 rotates clockwise in the direction indicated by the hollow arc arrow in the figure, the blades 21 agitate the air, causing the air to pass through the air passage in a centrifugal manner (i.e., in the direction indicated by the hollow straight arrow in the figure).

[0043] It should be understood that, due to the influence of the manufacturing process, the blade 21 is usually very close to the front disk surface 11f in the axial direction A, but there may still be a gap between the blade 21 and the front disk surface 11f in the axial direction A. Since the gap is very small, it does not affect the formation of centrifugal airflow.

[0044] It is worth noting that, since it is desired that the air passes through the air passage in a centrifugal manner, each air passage is continuous in the direction from the inner peripheral side to the outer peripheral side. This means that the air passage has an airflow inlet on the inner peripheral side and an airflow outlet on the outer peripheral side, and the airflow inlet and airflow outlet are defined by the gap between the surface of the balance plate 20 and the surface of the rotor 11.

[0045] At the air passage inlet, for various reasons, the rotor 11 has several through holes formed in the axial direction A. These through holes communicate at least partially with the air passage and define the air passage inlet. In order to ensure a sufficiently large area of ​​the air passage inlet, some blades 21 are configured as short blades 212 as described above, so that the through holes of the rotor 11 in the axial direction A are not blocked at least partially by the blades 21.

[0046] refer to Figure 6 Airflow can flow in from the inner periphery of the airway and out from the outer periphery of the airway.

[0047] Refer again Figure 2 For the entire motor 10, when the rotor 11 drives the balance plate 20 to rotate, the centrifugal airflow formed by the blades 21 stirring the air will cause the air near the rotor 11 to flow in the direction indicated by the hollow straight arrow in the figure. The flowing air can carry away the heat inside the rotor 11 and also cool down the components near the rotor 11.

[0048] It should be understood that when balance plates 20 are provided at both ends of rotor 11, airflow can flow into the through hole of rotor 11 and further into the air passage through the gaps between the layers of rotor 11 in the axial direction A.

[0049] Figure 3 and Figure 5 The blade 21 shown is a backward-facing blade. It should be understood that in other possible embodiments, the blade 21 may also follow other orientations.

[0050] For example, Figure 7 The diagram schematically illustrates four different orientations of centrifugal blades. These four centrifugal blades can agitate the air and cause it to flow radially outward along the tangent of the blades, regardless of whether they rotate clockwise or counterclockwise. However, the wind force and noise levels produced by the different blade shapes are different.

[0051] Figure 7 In the forms (a) and (b), the blade 21 is straight in the cross section perpendicular to the axial direction A, and is therefore called a straight blade; in the forms (c) and (d), the blade 21 is curved (arc) in the cross section perpendicular to the axial direction A, and is therefore called a curved blade.

[0052] In addition, the exit angle θ of blade 21 in form (a) is equal to 90°, so it is also called a radial blade; the exit angle θ of blade 21 in forms (b) and (c) is less than 90°, so it is also called a backward blade; the exit angle θ of blade 21 in form (d) is greater than 90°, so it is also called a forward blade.

[0053] The exit angle θ is the angle between the first ray L1 and the second ray L2. The outermost end of the blade 21 in the radial direction R constitutes the exit end E. During the rotation of the blade 21, the trajectory of the exit end E forms the exit circle C. A ray drawn radially outward along the tangent of the blade 21 from the exit end E constitutes the first ray L1. A ray drawn tangent to the exit circle C in the opposite direction of the rotation direction of the blade 21 (indicated by the hollow arrow in the figure) from the exit end E constitutes the second ray L2.

[0054] According to experiments, for motors with an average speed greater than 12,000 rpm and a maximum speed greater than 19,000 rpm, the backward curved blades in form (c) produce the least noise and provide sufficient centrifugal force in application, and are therefore the preferred blade form used in this embodiment.

[0055] Furthermore, comparing these four types of blades 21, they are arranged in descending order of the wind force they provide, as type (d), type (a), type (c), and type (b); and in descending order of the noise they produce, as type (d), type (a), type (b), and type (c). In particular, the radial straight blades, such as type (a), produce the same wind force and noise level during clockwise and counterclockwise rotation.

[0056] Since both the magnitude of centrifugal wind force and the noise generated need to be considered in practical applications, different types of blades can be selected according to application requirements.

[0057] Reference Figure 6 and Figure 8 The cross-sectional shape of the air passage along axis A affects the airflow direction around rotor 11. This cross-sectional shape is influenced by the shapes of the rear disc surface 20r and the front disc surface 11f. Since the front disc surface 11f is usually planar, the influence of different shapes of the rear disc surface 20r on the airflow can be discussed in a simplified manner.

[0058] Figure 8 The diagram shows the air passages corresponding to four different possible forms of the rear disc surface 20r.

[0059] In form (a), the rear disc surface 20r is a plane perpendicular to axis A in the region where the airway is located.

[0060] In form (b), the rear disc surface 20r is a plane that is inclined relative to the plane perpendicular to the axial direction A in the region where the air passage is located. The entire rear disc surface 20r of the corresponding balance plate 20 is partially concave in the direction away from the rotor 11. The concavity increases as it goes further in the radial direction, and the increment of concavity per unit distance in the radial direction remains constant.

[0061] In form (c), the rear disc surface 20r is curved in the area where the air passage is located. The entire rear disc surface 20r of the corresponding balance plate 20 is partially concave in the direction away from the rotor 11. The concavity increases as it goes further in the radial direction, and the increment of concavity per unit distance in the radial direction increases.

[0062] In form (d), the rear disc surface 20r is curved in the area where the air passage is located. The entire rear disc surface 20r of the corresponding balance plate 20 is partially concave in the direction away from the rotor 11. The concavity increases as it moves radially inward, and the increment of concavity per unit distance in the radial direction decreases.

[0063] According to the experiment, the air passages of forms (b), (c) and (d) become narrower as they move radially outward, which keeps the pressure of the airflow rising along the path of centrifugal motion. As a result, the pressure of the airflow flowing out from the radially outward outlet of the air passage is greater than the surrounding air pressure, preventing air from reversing and entering the air passage from the outlet. That is, the airflow can flow around the rotor 11 along the expected path.

[0064] In particular, the rear disc surface 20r with arc-shaped air passages, as in forms (c) and (d), is less prone to turbulence. Less turbulence results in less noise and vibration from the airflow, therefore, air passages of forms (c) and (d) are preferred. Especially, the rear disc surface 20r with an air passage of form (d) makes the balance plate 20 easier to mold, therefore, in this embodiment, the rear disc surface 20r more preferably adopts the design shown in form (d).

[0065] It should be understood that the aforementioned airway with a change in cross-sectional area along the radial direction R, especially the outer peripheral portion of the airway. For example, refer to... Figure 6 The cavity formed by the balance plate 20 has a greater degree of concavity towards the radially inward side in its outer peripheral portion; however, for ease of processing, the inner peripheral portion of the cavity is rounded and does not follow the above shape limitation. Therefore, it is also said that in at least a portion of the radial R region, the concavity of the rear plate surface 20r increases towards the radially inward side.

[0066] This invention has at least one of the following advantages:

[0067] (i) This invention retains the original function of the balance plate while enabling it to help dissipate heat from the motor.

[0068] (ii) The centrifugal blades formed on the balance plate generate an airflow in a specific direction during rotation, which can pump out the hot air inside the rotor, thereby dissipating heat from the rotor.

[0069] (iii) The airflow generated by the centrifugal blades can also bring the cooler air outside the stator into the inner circumference of the stator, so that the stator can dissipate heat during the process of cold air being pressed in and hot air being pumped out.

[0070] (iv) The airflow generated by the centrifugal blades can further promote the flow of air near the motor housing, which helps to dissipate heat from the housing.

[0071] (v) The balance plate according to the invention can increase the volume of the motor by no means or only a small amount, and because the motor has good heat dissipation performance, it can increase the heat capacity without increasing the volume. Therefore, the motor can be designed to have a small volume, which helps the motor to be integrated into the application system.

[0072] (vi) The rotation of the centrifugal blades is followed by the balance plate, and the torque comes from the main shaft of the system, for example. The rotation of the blades is synchronized with the rotor without the need for an additional control system.

[0073] (vii) The balance plate according to the present invention has a simple structure and can be formed by casting, eliminating the need for machining processes.

[0074] (viii) Through simulation tests, the operating temperature of the motor system according to the present invention is reduced by about 10 degrees Celsius compared with the previous scheme.

[0075] (ix) The motor according to the present invention has low noise and low vibration based on the use of centrifugal airflow for cooling.

[0076] Of course, the present invention is not limited to the above embodiments. Those skilled in the art can make various modifications to the above embodiments of the present invention under the guidance of the present invention, without departing from the scope of the present invention.

[0077] For example, in the motor according to the present invention, the balance plate according to the present invention can be provided only at one end in the axial direction, while there is no limitation on whether the balance plate is provided at the other end in the axial direction or what form the balance plate is.

Claims

1. An electric motor comprising a rotor (11) and a stator (12), the rotor (11) being located on an inner peripheral side of the stator (12), characterized by, The motor further comprises a motor balance plate according to the application, which is arranged at at least one end portion of the rotor (11) in the axial direction (A), which balance plate is in the form of a disc, wherein The balance plate has an end face arranged toward the rotor (11), which end face is partially convex toward the rotor (11) to form a plurality of vanes (21) arranged in the circumferential direction of the balance plate, the vanes (21) extending from the radially inner side to the radially outer side of the balance plate to form centrifugal vanes, so that when the balance plate rotates, the vanes (21) can agitate air to form an air flow from the radially inner side to the radially outer side, at least a portion of the air flow passing not only in the axial direction through the rotor (11) but also through the gap between the rotor (11) and the stator (12).

2. The electric machine of claim 1, wherein, The vanes (21) are backward vanes with an outlet angle of less than 90°, or the vanes (21) are radial vanes with an outlet angle of 90°.

3. The electric machine of claim 1 or 2, characterized in that In a cross section perpendicular to the axial direction (A), the vanes (21) are in the form of a curve to form curved vanes.

4. The electric machine of claim 1 or 2, wherein, The end face is partially concave in the direction away from the rotor (11) to form a cavity.

5. The electric machine of claim 4, wherein, In at least a portion of the radial direction (R) of the balance plate, the degree of concavity of the end face increases toward the radially inner side.

6. The electric machine of claim 1 or 2, wherein, The vanes (21) include first vanes (212), and the end face is not covered by the first vanes (212) at the inner circumferential portion.

7. The electric machine of claim 6, wherein, The vanes (21) further include second vanes (211), which second vanes (211) extend beyond the first vanes (212) at the inner circumferential side and are aligned with the first vanes (212) at the outer circumferential side.

8. The electric machine of claim 7, wherein, In the circumferential direction of the balance plate, the second vanes (211) are arranged alternately with the first vanes (212). In the circumferential direction of the balance plate, the second vanes (211) are arranged alternately with the first vanes (212).

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