Rotor core and rotor, motor and electronic pump

Abstract

The present invention discloses a rotor core, a rotor having the same, and a motor and an electronic pump. The rotor core comprises: an integrally formed core having a central axis hole in the middle thereof; a plurality of magnet slots spaced circumferentially along the inner or outer periphery of the core, each magnet slot being axially disposed, and the spacing angles between adjacent magnet slots being different; a plurality of permanent magnets, each of the permanent magnets being inserted into the magnet slots in a one-to-one correspondence; and a plurality of lightening holes, the lightening holes being axially disposed on the core and unevenly distributed. The present invention reduces cogging torque and torque ripple without adding additional assembly costs, labor costs, or product costs.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic pumps, and in particular to a rotor core, a rotor having the rotor core, and a motor and an electronic pump. Background Art

[0002] The automotive industry is developing rapidly. As automobile performance develops towards safer, more reliable, more stable, fully automatic, intelligent, environmentally friendly and energy-saving directions, electronic oil pumps and electronic water pumps (hereinafter referred to as electronic pumps) are widely used in automobile lubrication systems and cooling systems, and can well meet market requirements.

[0003] Electronic pumps primarily provide power for a vehicle's lubrication and cooling systems and require an electric motor to operate. Cogging torque and torque ripple can cause motor vibration and noise. Because the torque of an electronic pump motor is relatively low, the resulting vibration and noise are more pronounced. Existing motors mostly use rotor pole skewing or uneven air gaps to reduce cogging torque and torque ripple, but both methods increase product, assembly, and labor costs. Therefore, designing a motor rotor with a simple structure that reduces cogging torque and torque ripple is a pressing technical challenge.

[0004] The existing patent application number is 201710538258.0, which discloses a skewed pole rotor core and its core punchings, a skewed pole rotor and a motor. The skewed pole rotor core includes: multiple core segments, multiple core segments are coaxially arranged in sequence, each core segment includes multiple axially stacked core punchings, the outer peripheral edge of each core punching has multiple convex portions distributed along its circumference and protruding outward, each core punching is provided with multiple axial through holes spaced apart along its circumference and corresponding to the multiple convex portions one by one, each convex portion and each axial through hole are asymmetric in the circumferential direction of the core segment, the convex portions and axial through holes on each core segment overlap respectively, the convex portions and axial through holes on multiple core segments are staggered in the circumferential direction of the core segment and the axial through holes on multiple core segments overlap to form a magnet slot extending along the axial direction of the core segment; multiple permanent magnets, multiple permanent magnets are inserted into the multiple magnet slots in a one-to-one correspondence. The outer protrusions and the axial through holes in the oblique pole structure disclosed in this patent application are asymmetrical in the circumferential direction of the core segment. This special structure greatly increases the production cost and labor cost of the motor.

[0005] There is also a patent application with patent application number 201921431214.9, which discloses an improved motor rotor structure, characterized in that it includes a rotor core; the rotor core is provided with a plurality of permanent magnet slots, and the plurality of permanent magnet slots are circumferentially distributed around the center of the rotor core; the outer sides of the adjacent permanent magnet slots are provided with V-shaped grooves, and a magnetic isolation bridge is formed between the V-shaped grooves and the permanent magnet slots; the outer side wall of the rotor core at the V-shaped grooves is also provided with grooves. This utility model effectively reduces the width of the magnetic isolation bridge by providing V-shaped grooves and grooves on the rotor core, thereby reducing magnetic leakage, reducing cogging torque, reducing noise, improving efficiency, and reducing costs. However, the rotor is cylindrical and not fully circular, which increases the difficulty and cost of manufacturing the core.

[0006] Therefore, to reduce motor cogging torque and torque ripple, the industry generally adopts skewed poles or uneven air gaps. However, the unique structure of skewed poles significantly increases motor assembly and labor costs, and some low-power motors are not suitable for skewed pole designs due to size limitations. Furthermore, the uneven air gap method results in the rotor's outer contour being non-circular, which increases the difficulty and expense of manufacturing the rotor core, further increasing product cost.

[0007] Therefore, for electronic pump motors, it is particularly important to design a rotor with a simple structure that can reduce cogging torque and torque ripple. Summary of the Invention

[0008] In view of the above-mentioned problems existing in the prior art, the present invention aims to provide a rotor core and a rotor, a motor and an electronic pump having the rotor core. This solution is easy to assemble, and the outer circle of the rotor is a full circle, which does not increase additional assembly costs, labor costs and product costs while reducing the cogging torque and torque fluctuations.

[0009] The specific technical solutions are as follows:

[0010] A rotor core, comprising:

[0011] An integrally formed iron core, wherein a central axial hole is provided in the middle of the iron core, and a plurality of magnet slots are provided on the inner or outer periphery of the iron core and spaced apart along the circumference thereof, each magnet slot being arranged along the axial direction;

[0012] A plurality of permanent magnets, wherein the plurality of permanent magnets are inserted into the magnet slots in a one-to-one correspondence;

[0013] A plurality of weight-reducing holes are provided on the iron core along the axial direction, and the weight-reducing holes are unevenly distributed.

[0014] Compared with the existing technology, the positive effects of the above technical solution are:

[0015] 1) The motor rotor design of the present invention changes from the original structure in which permanent magnets are evenly distributed within the rotor to a structure with regular uneven distribution. This structural change can suppress harmonics, improve air gap flux density, and achieve the effect of reducing cogging torque and torque ripple.

[0016] 2) Due to the uneven distribution of permanent magnets, the center of mass of the rotor deviates from the geometric center, causing increased centrifugal force on the rotor, increasing damage to the motor bearings and shortening the motor's service life. The present invention provides weight-reducing holes to make the center of mass of the rotor coincide with the geometric center, thereby achieving dynamic balancing of the rotor.

[0017] 3) The iron core of the present invention adopts an integrally formed structure, which avoids the assembly of multiple iron core segments in the inclined pole structure, reducing assembly costs, labor costs and product costs;

[0018] 4) The outer contour of the core in the present invention is a full circle, which avoids the non-full-circular structure of the rotor core in the uneven air gap structure and reduces the manufacturing difficulty and cost of the rotor.

[0019] 5) The permanent magnet installation methods in the present invention include surface-mounted and built-in types. The surface-mounted type is that a plurality of magnet slots are distributed along the circumference of the iron core at intervals. The built-in type is that a plurality of magnet slots are opened on the inner circumference of the iron core at intervals along the circumference, and the permanent magnets are inserted into the magnet slots.

[0020] Furthermore, the spacing angle between one of the magnet slots and the magnet slots on both sides is the same, with a value of b, and the spacing angles between the other magnet slots are the same, with a value of a, and a is not equal to b.

[0021] This is a preferred solution for unevenly distributing the permanent magnets on the rotor. This uneven distribution means that the angles between the permanent magnets vary, but except for one permanent magnet, the angles between the remaining permanent magnets are the same. Preferably, the optimal effect is achieved when the plurality of permanent magnets have the same structure and are eight in number. In this case, a is equal to 7° and b is equal to 17°. In the present invention, the permanent magnets are of the same size, but of course, they can also be of different sizes.

[0022] Of course, the number of permanent magnets is not limited to 8. It can also be an even number such as 2, 4, 6, or 10, which can be selected according to actual needs. Accordingly, when the number of permanent magnets changes, the spacing angle between the permanent magnets also needs to change.

[0023] Furthermore, the circumferential cross-section of the permanent magnet is rectangular, or may be other geometric shapes. When a rectangular permanent magnet is used in the present invention, the effect of reducing cogging torque and torque ripple is best.

[0024] Furthermore, the number of the weight-reducing holes is the same as the number of the permanent magnets. Moreover, the structure and position of the weight-reducing holes located radially inside the larger or smaller permanent magnet interval are different from the structure and position of the other weight-reducing holes. Preferably, the weight-reducing holes are circular in shape, and the diameter of the weight-reducing holes located radially inside the larger or smaller permanent magnet interval is different from that of the other weight-reducing holes. More preferably, the diameter of the circle where the center of the weight-reducing holes located radially inside the larger or smaller permanent magnet interval is located can be the same as or different from the diameter of the circle where the center of the other weight-reducing holes is located.

[0025] The present invention adjusts the diameter and center position of the weight-reducing hole so that the center of mass of the rotor coincides with the geometric center, thereby solving the problem of the center of mass of the rotor deviating from the geometric center due to the uneven distribution of permanent magnets, thereby achieving dynamic balance of the rotor.

[0026] The shape of the weight-reducing holes in the present invention is not limited to a circle, and can be any other shape.

[0027] The present invention also provides a rotor comprising the above-mentioned rotor core structure.

[0028] The present invention also provides a motor, comprising a rotor having the above rotor core structure.

[0029] The present invention also provides an electronic pump including a motor using a rotor having the rotor core structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the overall structure of the built-in permanent magnet according to Example 1 of the present invention;

[0031] Figure 2 This is a front view of the overall structure of the built-in permanent magnet according to embodiment 1 of the present invention;

[0032] Figure 3 This is a schematic diagram of the overall structure of the surface-mounted permanent magnet according to embodiment 2 of the present invention;

[0033] Figure 4 This is a front view of the overall structure of the surface-mounted permanent magnet according to embodiment 2 of the present invention;

[0034] Figure 5 1 is a comparison diagram of the cogging torque between the design solution of Example 1 of the present invention and the traditional design solution;

[0035] Figure 6 This is a comparison diagram of torque fluctuations between the design of Example 1 of the present invention and the traditional design;

[0036] Figure 7 A comparison diagram of the cogging torque between the design solution of Example 2 of the present invention and the traditional design solution;

[0037] Figure 8 2 is a comparison diagram of torque fluctuations between the design scheme of Example 2 of the present invention and the traditional design scheme.

[0038] In the accompanying drawings, 1, iron core; 1.1, central axis hole; 1.2, magnet slot; 2, permanent magnet; 3, weight reduction hole. DETAILED DESCRIPTION

[0039] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the following embodiments are combined with the accompanying drawings to specifically illustrate the present invention.

[0040] The present invention provides a rotor core 1, such as Figures 1 to 4 Shown, including:

[0041] An integrally formed iron core 1 has a central axis hole 1.1 in the middle thereof. A plurality of magnet slots 1.2 are provided along the inner or outer periphery of the iron core 1 and are spaced apart along the circumference thereof. The arrangement of the magnet slots 1.2 along the inner periphery of the iron core 1 is suitable for a built-in permanent magnet 2 structure, while the arrangement of the magnet slots 1.2 along the outer periphery of the iron core 1 is suitable for a surface-mounted permanent magnet 2 structure. Each magnet slot 1.2 is provided along the axial direction.

[0042] Multiple permanent magnets 2 are inserted into the magnet slots 1.2 in a one-to-one correspondence;

[0043] A plurality of weight-reducing holes 3 are provided on the iron core 1 along the axial direction, and the weight-reducing holes 3 are unevenly distributed.

[0044] The present invention changes the original structure in which the permanent magnets 2 are evenly distributed in the rotor to a structure with regular uneven distribution. Through this structural change, harmonics can be suppressed, the air gap flux density can be improved, and the cogging torque and torque fluctuation can be reduced. Due to the uneven distribution of the permanent magnets 2, the center of mass of the rotor deviates from the geometric center, resulting in an increase in the centrifugal force of the rotor, which affects the service life of the motor. The present invention also provides weight-reducing holes 3 to make the center of mass of the rotor coincide with the geometric center, thereby achieving dynamic balance of the rotor.

[0045] Specifically, one magnet slot 1.2 is spaced at the same angle as the adjacent magnet slots 1.2 on both sides, with a value of b. The remaining magnet slots 1.2 are spaced at the same angle as each other, with a value of a, where a is not equal to b. The multiple permanent magnets 2 have the same structure, facilitating the placement of the magnet slots 1.2. The circumferential cross-section of the permanent magnets 2 is rectangular, but other shapes are also possible.

[0046] Furthermore, the number of the weight-reducing holes 3 is the same as the number of the permanent magnets 2, and the weight-reducing holes 3 are opened on the iron core 1. Preferably, the weight-reducing holes 3 are located below the two permanent magnets 2 or below the permanent magnets 2. The structure and position of the weight-reducing holes 3 located radially inside the larger or smaller permanent magnet 2 interval are different from those of the other weight-reducing holes 3. Preferably, the shape of the weight-reducing holes 3 is circular, and the diameter of the weight-reducing holes 3 located radially inside the larger or smaller permanent magnet 2 interval is different from that of the other weight-reducing holes 3. The diameter of the circle where the center of the weight-reducing holes 3 located radially inside the larger or smaller permanent magnet 2 interval is located can be the same as or different from the diameter of the circle where the center of the other weight-reducing holes 3 is located. The form of the weight-reducing holes 3 is not limited to a circle, and can be any other shape.

[0047] The present invention adjusts the diameter and center position of the weight-reducing hole 3 so that the center of mass of the rotor coincides with the geometric center, thereby solving the problem of the center of mass of the rotor deviating from the geometric center due to the uneven distribution of the permanent magnets 2, thereby achieving dynamic balance of the rotor. Example

[0048] Taking the internal permanent magnet 2 structure as an example, the specific structure is as follows:

[0049] like Figure 1 and Figure 2 The figure shows a rotor core 1, comprising an integrally formed core 1. A central axial hole 1.1 is provided in the middle of the core 1. Eight magnet slots 1.2 are provided along the inner circumference of the core 1, spaced apart along the circumference. Each magnet slot 1.2 is axially extending and has the same dimensions. Permanent magnets 2 are inserted into the magnet slots 1.2 in a one-to-one correspondence, i.e., there are eight permanent magnets 2. The circumferential cross-section of the permanent magnets 2 is rectangular. The spacing angle between one permanent magnet 2 and the adjacent permanent magnets 2 is the same, at 17 degrees. The spacing angles between the other permanent magnets 2 are also the same, at 7 degrees.

[0050] like Figure 5 As shown in FIG, a comparison diagram of the cogging torque between the conventional design scheme in which the permanent magnets 2 are evenly distributed in the rotor and the design scheme of the present invention in which the permanent magnets 2 are unevenly distributed is shown. From the comparison results in the figure, it can be seen that the design scheme of the present invention can effectively reduce the cogging torque of the motor; Figure 6 As shown in FIG, a torque fluctuation comparison diagram of a conventional design scheme in which permanent magnets 2 are evenly distributed in the rotor and a design scheme of the present invention in which the permanent magnets 2 are unevenly distributed is shown. From the comparison results in the figure, it can be seen that the design scheme of the present invention can effectively reduce the torque fluctuation of the motor. Therefore, the design scheme of the present invention can effectively suppress harmonics, improve air gap flux density, and reduce cogging torque and torque fluctuation. From a structural point of view, the design scheme of the present invention does not increase additional assembly cost, labor cost and product cost.

[0051] Uneven distribution of permanent magnets 2 can cause the rotor's center of mass to deviate from the center of the shaft hole, increasing centrifugal force and reducing the motor's service life. To address this issue, eight lightening holes 3 are unevenly distributed throughout the rotor core 1. The two holes 3 located between the larger permanent magnets 2 have a diameter of 4 mm, while the remaining holes have a diameter of 3.2 mm. The centers of these holes 3 are all on a Φ18 circle.

[0052] If the center coordinates of central axis hole 1.1 are (0, 0), then the center of mass of rotor core 1 without lightening holes 3 is at the coordinates (0.041, 0.017). After adding lightening holes 3, the center of mass of rotor core 1 is at the coordinates (0.000, 0.001). This shows that the design of the present invention effectively eliminates the adverse effects of center of mass deviation caused by the uneven distribution of permanent magnets 2.

[0053] In summary, it can be seen that the present invention adjusts the diameter and center position of the weight-reducing hole 3 so that the center of mass of the rotor coincides with the geometric center, thereby achieving dynamic balancing of the rotor. Example

[0054] Take the surface mounted permanent magnet 2 structure as an example, Figure 3 and Figure 4 As shown, the outer periphery of the core 1 is provided with 8 magnet slots 1.2 spaced apart along its circumference, and the other structures are the same as those of the built-in permanent magnet 2. After experimental testing, the above technical effects can also be obtained, such as Figure 7 As shown in FIG, a comparison diagram of the cogging torque between the conventional design scheme in which the permanent magnets 2 are evenly distributed in the rotor and the design scheme of the present invention in which the permanent magnets 2 are unevenly distributed is shown. From the comparison results in the figure, it can be seen that the design scheme of the present invention can effectively reduce the cogging torque of the motor; Figure 8 As shown in the figure, it is a torque fluctuation comparison diagram of the traditional design scheme in which the permanent magnets 2 are evenly distributed in the rotor and the design scheme of the present invention in which the permanent magnets 2 are non-uniformly distributed. From the comparison results in the figure, it can be seen that the design scheme of the present invention can effectively reduce the torque fluctuation of the motor. Therefore, the design scheme of the present invention is applicable to both the built-in permanent magnet 2 structure and the surface-mounted permanent magnet 2 structure.

[0055] The present invention protects the rotor core 1 , and also protects a specific rotor, motor, and electronic pump of the rotor core 1 , all of which are within the embodiment and protection scope of the present invention.

[0056] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A rotor core, characterized in that: include: An integrally formed iron core (1) is provided with a central axis hole (1.1) in the middle of the iron core (1), and a plurality of magnet slots (1.2) spaced apart along the circumference of the iron core (1) are provided on the inner or outer circumference of the iron core (1), each magnet slot (1.2) being arranged in the axial direction. A plurality of permanent magnets (2), wherein the plurality of permanent magnets (2) are inserted into the magnet slots (1.2) in a one-to-one correspondence; A plurality of weight-reducing holes (3), wherein the weight-reducing holes (3) are axially opened on the iron core (1), and the weight-reducing holes (3) are unevenly distributed; The spacing angle between one of the magnet slots (1.2) and the magnet slots (1.2) on both sides is the same, with a value of b; the spacing angles between the other magnet slots (1.2) are the same, with a value of a, and a is not equal to b; The number of the weight-reducing holes (3) is the same as the number of the permanent magnets (2); The structure and position of the weight-reducing hole (3) located radially inside the interval between the larger or smaller permanent magnets (2) are different from the structure and position of the other weight-reducing holes (3); The circumferential cross-section of the permanent magnet (2) is rectangular.

2. The rotor core according to claim 1, wherein: The plurality of permanent magnets (2) have the same structure and are eight in number.

3. The rotor core according to claim 2, wherein: a is equal to 7° and b is equal to 17°.

4. A rotor, characterized in that: The invention comprises the rotor core according to any one of claims 1 to 3.

5. A motor, characterized in that: Use is made of the rotor according to claim 4.

6. An electronic pump, characterized in that: Use of the motor as claimed in claim 5.

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