Rotor and electric machine with reduced vibration and noise

Abstract

The utility model discloses a rotor of reducing vibration and noise, include: including the lamination of a plurality of rotor punching piece in proper order, the rotor punching piece includes the punching piece body, the center through -hole for cooperating with motor shaft is established to the punching piece body center, the center through -hole is circular shape, and the center through -hole is surrounded and is arranged with a plurality of waist type ventilation hole, the outer periphery edge of punching piece body is by a plurality of uneven air gap unit sequentially connected and is formed, corresponding in the inside of uneven air gap unit, and the surface of punching piece body has a plurality of magnet groove along the circumference distribution, the position of uneven air gap unit with magnet groove corresponds. The utility model forms uneven air gap area between the rotor outer periphery and the stator inner diameter, and the air gap magnetic field distribution is optimized, and the overall operation state of motor is obviously improved, and vibration and noise are reduced, and can be widely applied to the application scene of higher requirement of low noise, low vibration to electric automobile air conditioner compressor, industrial motor etc.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a rotor and motor that reduce vibration and noise, which is suitable for applications such as electric vehicle air conditioning compressors and industrial motors that have high requirements for low noise and low vibration. Background Technology

[0002] In permanent magnet motors, cogging torque and air gap magnetic field harmonics are the main factors causing vibration and noise (vibration and noise problems). Cogging torque causes fluctuations in the motor's output torque, thus exacerbating motor vibration and noise. The air gap magnetic field contains a large number of harmonics, resulting in a high harmonic content in the electromotive force, increasing the motor's harmonic current and additional harmonic iron and copper losses, which is a factor affecting motor efficiency. Since noise and vibration directly affect the ride comfort and perceived quality of a car, effectively reducing these adverse factors has become a crucial issue that automakers and parts suppliers need to address and solve.

[0003] Traditional motors typically employ a uniform air gap structure, but due to uneven magnetic field distribution, they are prone to generating significant torque ripple and electromagnetic noise, affecting motor operation smoothness and user experience. Existing technologies also employ methods such as skewed poles and segmented magnetic poles to reduce cogging torque, but these methods may increase manufacturing costs or reduce motor efficiency. Utility Model Content

[0004] The purpose of this invention is to provide a motor rotor structure that can effectively reduce vibration and noise without increasing cost or affecting motor performance, thereby reducing motor cogging torque, optimizing air gap magnetic field distribution, and thus reducing vibration and noise and improving motor running stability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A rotor for reducing vibration and noise includes a plurality of rotor laminations stacked sequentially. Each rotor lamination includes a lamination body. The lamination body has a central through hole for cooperating with a motor shaft. The central through hole is circular in shape, and a plurality of waist-shaped ventilation holes are arranged around the central through hole. The outer peripheral edge of the punch body is composed of several uneven air gap units connected in sequence; Corresponding to the inner side of the non-uniform air gap unit and distributed circumferentially on the surface of the lamination body, there are several magnetic grooves. The non-uniform air gap unit corresponds to the position of the linear magnet groove.

[0006] Preferably, the non-uniform air gap unit includes a first circular arc and a second circular arc. The first arc is an outwardly convex arc whose center is inside the circumference of the lamination body but does not pass through the central through hole on the rotor lamination. The first arc is divided into two identical segments with the center line of the magnet groove as the axis of symmetry L. The second arc is a convex arc centered on the central through hole; The first arc and the second arc are connected by a transition section.

[0007] Preferably, the transition portion includes a first arc segment, a first straight segment, and a second arc segment, wherein the second arc segment connects to the first straight segment, and the second arc segment connects to the first straight segment. The first arc segment is a convex arc whose center is inside the circumference of the lamination body; The second arc segment is a concave arc whose center is on the outer side of the circumference of the lamination body.

[0008] Preferably, the second arc is tangent to the first arc segment; The first straight line segment is tangent to both the first circular arc segment and the second circular arc segment; The first arc is tangent to the second arc segment.

[0009] Preferably, the second arc, the first arc segment, the first straight line segment, the second arc segment, and the first arc are connected sequentially to form a non-uniform air gap unit. With the center line of the magnet groove as the axis of symmetry L, the non-uniform air gap unit is divided by the axis of symmetry L, and the non-uniform air gap units located on both sides of the axis of symmetry L constitute a non-uniform air gap region. The angle of the non-uniform air gap region is 45°.

[0010] Preferably, the number of non-uniform air gap units is the same as the number of motor poles.

[0011] In a preferred embodiment, an electric motor is provided, comprising the rotor described in the above technical solutions.

[0012] The beneficial effects of this utility model are: This utility model discloses a rotor for reducing vibration and noise. Its ingenious design significantly reduces overall motor losses and improves vibration and noise levels. The rotor comprises several rotor laminations stacked sequentially. Each lamination includes a lamination body with a central through-hole that mates with the motor shaft, waist-shaped ventilation holes surrounding the central through-hole, magnetic grooves distributed circumferentially along the surface of the lamination body, and several non-uniform air gap units forming the outer periphery of the lamination body. Each non-uniform air gap unit is composed of a second arc, a first arc segment, a first straight line segment, a second arc segment, and a first arc connected together, forming a non-uniform air gap region between the rotor's outer diameter and the stator's outer circumference. Compared to a uniform air gap structure, this utility model optimizes the air gap magnetic field distribution through the non-uniform air gap unit design, thereby effectively reducing cogging torque, mitigating noise and vibration. The optimized air gap magnetic field also effectively reduces harmonic losses, improves overall motor efficiency, enhances the overall operating condition of the motor, and improves the smoothness of motor operation. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a rotor that reduces vibration and noise according to this utility model; Figure 2 This is a partial schematic diagram of a rotor for reducing vibration and noise according to the present invention. Figure 3 This is a partially enlarged schematic diagram of the non-uniform air gap unit shown in this utility model; Figure 4 These are simulation comparison diagrams of cogging torque tested under the motor rotor structure described in this utility model; Figure 5 These are comparison images of motor operating noise tested under the motor rotor structure described in this utility model; The components in the attached diagram are labeled as follows: 1. Central through hole; 2. Rivet hole; 3. Ventilation hole; 4. Magnet groove; 5. First arc; 6. Second arc; 7. Transition section; 7-1. First arc segment; 7-2. First straight segment; 7-3. Second arc segment; 8. Stator; 9. Lamination body. Detailed Implementation

[0014] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0015] Example: This embodiment describes a rotor that reduces vibration and noise.

[0016] like Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a rotor for reducing vibration and noise according to this utility model. The rotor for reducing vibration and noise includes: a plurality of rotor laminations stacked sequentially; each rotor lamination includes a lamination body; the lamination body has a central through hole 1 for cooperating with a motor shaft; the central through hole 1 is circular; and a plurality of waist-shaped ventilation holes 3 are arranged around the central through hole 1. In this embodiment, four ventilation holes are provided, which serve to allow refrigerant (refrigeration oil) to pass through, reduce weight, and optimize magnetic flux density. Rivet holes 2 are also arranged around the central through hole 1 on the rotor; in this embodiment, four rivet holes are provided, each located between the four ventilation holes, for riveting.

[0017] The outer periphery of the lamination body is composed of several uneven air gap units connected in sequence; Correspondingly, a plurality of magnetic slots 4 are evenly distributed along the circumference on the inner side of the non-uniform air gap unit and on the surface of the lamination body, for placing and fixing magnets. In this embodiment, the motor is 12 slots and 8 poles, that is, the number of magnetic slots is 8, and the corresponding number of non-uniform air gap units is also 8.

[0018] The outer periphery of the rotor lamination is composed of eight non-uniform air gap units in sequence. The rotor is located inside the stator 8. Under the action of the non-uniform air gap units, an air gap region with an optimized air gap magnetic field path is formed between the stator and the rotor.

[0019] In this invention, by designing the outer periphery of the rotor lamination body as a series of continuously connected non-uniform air gap units, an irregular circular edge is formed, thereby creating a region of non-uniform air gap between the rotor and the stator. Compared with the regular circular rotor laminations in the prior art, this design can effectively reduce cogging torque, improve efficiency, thereby reducing noise and vibration, and improving the overall operating condition of the motor.

[0020] In a preferred embodiment, a single non-uniform air gap unit includes a first arc 5 and two segments of second arc 6. The first arc 5 is divided into left and right segments by the second axis L2 of the magnet groove 4. For ease of understanding, it can be understood as being divided by the second axis L2 and then referred to as the first segment of the first arc and the second segment of the first arc, respectively. like Figure 2 As shown, the first arc 5 is an outwardly convex arc with its center O1 inside the circumference of the lamination body but not beyond the central through hole 1 of the rotor. The first arc 5 takes the center line of the magnet groove 4 as its axis of symmetry, which is denoted as the second axis L2. The second axis is the longitudinal center line of the magnet groove that is set therewith. The first arc 5 is divided into two identical left and right segments by the second axis L2. The two second arcs 6 and the two transition segments 7 are set in a mirror symmetry with respect to the second axis.

[0021] The second arc 6 is a convex arc centered at the center O of the central through hole 1; such as Figure 2 As shown, two adjacent magnet grooves 4 are symmetrically arranged about the first axis L1; one end of the second arc is the intersection point of the first axis and the outer peripheral edge of the lamination body. The two ends of the first arc 5 are respectively connected to the corresponding second arc 6 through corresponding transition parts 7.

[0022] like Figure 3 As shown, Figure 2 This is a partially enlarged structural diagram of the non-uniform air gap shown in this utility model. The transition part 7 includes a first arc segment 7-1, a first straight segment 7-2, and a second arc segment 7-3. The second arc 6 is connected to the first straight segment 7-2 through the first arc segment 7-1, and the first straight segment 7-2 is connected to the first arc 5 through the second arc segment 7-3. The first arc segment 7-1 is a convex arc whose center is inside the circumference of the lamination body; The second arc segment 7-2 is a concave arc whose center is on the outer side of the circumference of the lamination body.

[0023] The number of non-uniform air gap units is the same as the number of poles of the motor. In this embodiment, the motor is 8-pole, so eight non-uniform air gap units are set accordingly, and they are regularly distributed on the lamination body.

[0024] The non-uniform air gap unit, as part of the rotor's outer diameter, is designed as described above to create a non-uniform but regular structure for the rotor, forming multiple regions with uneven air gap distribution. The second arc 6, the first arc segment 7-1, the first straight line segment 7-2, the second arc segment 7-3, and the first arc 5 are connected sequentially to form a non-uniform air gap unit. With the center line of the magnet groove 4 as the axis of symmetry, denoted as the second axis L2, the non-uniform air gap unit is divided by the second axis L2 and located on both sides of it. This structure constitutes a non-uniform air gap region between the rotor's outer diameter and the stator's outer circumference. The angle θ of a single non-uniform air gap unit is 45°, meaning that a single non-uniform air gap unit divides the circumference into 8 equal parts. The included angle obtained by connecting the two ends of each non-uniform air gap unit to the center O of the central through hole 1 is 45°.

[0025] Furthermore, such as Figure 2 As shown, the center O1 of the first arc 5 is located on the outer circumference of the central shaft hole, the radius is denoted as R1, and its central angle β is 35-39°, that is, the included angle obtained by connecting the two ends of the first arc 5 to the center O of the central through hole 1 is 35-39°; while the center of the second arc 6 coincides with the center O of the central shaft hole, the radius is denoted as R2, and its central angle α is 3-5°, that is, the included angle obtained by connecting the two ends of the second arc 6 to the center O of the central through hole 1 is 3-5°.

[0026] In this embodiment, taking an 8-pole magnet as an example, there are a total of 8 non-uniform air gap units on the outer diameter of the lamination body, evenly distributed on the circumference of the rotor outer diameter along the outer side of the magnet slots. In other words, the non-uniform air gap units are evenly distributed at adjacent locations of each magnet slot, thus forming a continuous and regular non-uniform gap structure on the outer circumference of the rotor. Under the action of these non-uniform air gap units, the air gap between adjacent magnet slots initially decreases, then increases again after a short straight transition, and finally decreases again after the first arc.

[0027] For ease of understanding, this embodiment combines Figures 1 to 3 This section explains how the non-uniform air gap unit changes the air gap size. Specifically, it follows a clockwise direction, combined with... Figures 1 to 3 As shown, the rotor's outer diameter begins from the second arc 6 in the non-uniform air gap unit divided by the axis of symmetry L (for ease of understanding, the air gap at the beginning of the second arc is referred to as the initial air gap, and its value is large), transitions through the first arc segment 7-1 (convex arc), the first straight line segment 7-2, and the second arc segment 7-3 (concave arc) to the first arc 5. The air gap first decreases from the initial air gap through the first arc segment 7-1, then gradually increases through the first straight line segment 7-2 to the second arc segment 7-3, before gradually decreasing again upon transitioning to the first arc 5. Similarly, the air gap region continues to change, and then through the other non-uniform air gap unit divided by the axis of symmetry L, the first arc 5 continues to transition and connect with the second arc segment 7-3, at which point the air gap increases again. Then, when passing through the first straight line segment 7-2 to the first arc segment 7-1, the air gap decreases, and then gradually increases again upon transitioning to the second arc 6. As explained above, the non-uniform air gap unit on the outer diameter of the rotor regularly and continuously alters the distribution of the air gap magnetic field. In production, applying this rotor structure with the non-uniform air gap unit to motors has yielded excellent results. It not only reduces vibration and noise, but the optimized air gap magnetic field also reduces harmonic losses, improves overall motor efficiency, and enhances motor operational stability.

[0028] In this utility model, we will also demonstrate the difference between applying the above rotor structure to a motor and the rotor structure using a uniform gap structure in the prior art, as follows: Through the above design of the rotor structure, significant improvements have been achieved in both cogging torque and motor operating efficiency. Figure 4 As shown, Figure 4This is a simulation comparison chart of cogging torque tested under the rotor structure of the motor described in this utility model. The orange line shows the non-uniform air gap, and the blue line shows the uniform air gap. By optimizing the air gap magnetic field distribution, torque pulsation is reduced. Simulation data shows that the peak cogging torque of the motor using the non-uniform air gap unit is reduced by 0.15 to 0.2 compared to the motor with the uniform air gap structure.

[0029] For rotors with uneven gap structures, the motor operating noise was also tested in the preferred embodiment. Figure 5 This is a comparison chart of motor operating noise under the rotor structure described in this utility model. In the chart, the non-uniform air gap unit is represented by orange / gray lines, and the uniform air gap structure by blue lines. In the compressor's 24-order measured noise data, blue represents the uniform air gap data, while orange and gray represent data 1 and data 2 of the non-uniform air gap. Through actual measurement, the motor operating noise with the rotor using the non-uniform air gap unit is significantly lower than that with the rotor using the uniform air gap structure, as can be seen from the data. The non-uniform air gap unit is 2-8 decibels lower than the uniform air gap structure.

[0030] This invention cleverly improves the motor's rotor structure by designing it with a non-uniform gap structure. By creating a non-uniform air gap region between the rotor's outer circumference and the stator's inner diameter, the distribution of the air gap magnetic field is optimized, significantly improving the overall motor operation and reducing vibration and noise. Furthermore, it is of great significance for reducing overall motor losses and improving vibration and noise levels, and can be widely applied to applications requiring low noise and low vibration, such as electric vehicle air conditioning compressors and industrial motors.

[0031] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A rotor for reducing vibration and noise, characterized in that, It includes several rotor laminations stacked in sequence. Each rotor lamination includes a lamination body. The lamination body has a central through hole (1) for cooperating with the motor shaft. The central through hole (1) is circular in shape, and several waist-shaped ventilation holes (3) are arranged around the central through hole (1). The outer peripheral edge of the punch body is composed of several uneven air gap units connected in sequence; Corresponding to the inner side of the non-uniform air gap unit and distributed circumferentially on the surface of the lamination body, there are several magnetic grooves (4).

2. The rotor for reducing vibration and noise according to claim 1, characterized in that, Each of the non-uniform air gap units includes a first arc (5), two second arcs (6), and two transition portions (7) for connecting the first arc (5) and the corresponding second arc (6); two adjacent magnet slots are symmetrically arranged with respect to a first axis; one end of the second arc is the intersection point of the first axis and the outer peripheral edge of the lamination body; the first arc (5) is symmetrically arranged with respect to a second axis, which is the longitudinal center line of the magnet slot corresponding to it; the two second arcs (6) and the two transition portions (7) are mirror-symmetrically arranged with respect to the second axis.

3. The rotor for reducing vibration and noise according to claim 2, characterized in that, The transition section (7) includes a first straight segment (7-2); the two ends of the first straight segment (7-2) are connected to the first arc (5) and the second arc (6) respectively.

4. A rotor for reducing vibration and noise according to claim 3, characterized in that, The transition section (7) further includes a first arc segment (7-1) and a second arc segment (7-3), the second arc (6) being connected to the first straight line segment (7-2) via the first arc segment (7-1); the second arc segment (7-3) being connected between the first straight line segment (7-2) and the first arc (5); The first arc segment (7-1) is a convex arc whose center is inside the circumference of the rotor lamination body; The second arc segment (7-3) is a concave arc whose center is on the outer side of the circumference of the rotor lamination body.

5. A rotor for reducing vibration and noise according to claim 2, characterized in that, The second arc (6) is centered on the center of the central through hole (1); the center of the first arc (5) is located on the outer circumference of the central through hole.

6. A rotor for reducing vibration and noise according to claim 2, characterized in that, The number of the non-uniform air gap units is 8, and the central angle of a single non-uniform air gap unit is 45°; the central angle of the second arc (6) is 3 to 5°; and the central angle of the first arc (5) is 35 to 39°.

7. An electric motor, characterized in that, Including the rotor for reducing vibration and noise as described in any one of claims 1 to 6.

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