Motor and method for adjusting the performance of a motor

Abstract

This invention provides a motor with a simple structure that can suppress the stall torque of the motor without reducing the motor's efficiency, and a method for adjusting the performance of the motor. [Solution] The motor 1 comprises a stator core 2, which is a stator; a rotor core 3, which is a rotor; a shaft 4 that rotates together with the rotor core 3; a bearing 5 that holds the shaft 4; a bracket 6 that supports various components; and a cover 7 that houses the various components. The rotor core 3 is provided with a plurality of slots arranged radially and containing dielectrics such as permanent magnets, which are formed by punching. The outer diameter side of each slot opens as an opening that gradually narrows as it moves radially outward, and the angle between the side of each slot that extends inclined toward the center of the rotor core 3 from the opening and the radial line passing through the center of each slot from the center of the rotor core 3 is in the range of 12° to 70°.

Description

Technical Field

[0001] The present invention relates to a motor and a method for adjusting performance of a motor.

Background Art

[0002] Conventionally, there has been known a configuration in which when a motor is used, the current value is reduced to suppress the stall torque of the motor, so that the motor is connected to other components such as another motor or a gear. For example, Patent Document 1 describes a configuration that suppresses the current supplied to a motor in accordance with a relatively low-efficiency motor when connecting motors having different efficiencies.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, the above-mentioned conventional motors have a problem that a separate configuration of an electric system and / or a control system for adjusting the current value is additionally required to suppress the stall torque, which increases the manufacturing cost of the motor.

[0005] Therefore, an object of the present invention is to provide a motor and a performance adjustment method for a motor that can suppress the stall torque of the motor without reducing the efficiency of the motor with a simple structure.

Means for Solving the Problem

[0006] To achieve the above objective, the invention described in claim 1 is a motor having a rotor core in which a plurality of slots are arranged radially, wherein the outer diameter side of each slot is opened as an opening that gradually narrows as it moves radially outward, and the angle between the side of each slot that extends inclined toward the center of the rotor core from the opening and the radial line passing through the center of each slot from the center of the rotor core is in the range of 12° to 70°. Furthermore, the invention described in claim 2 is a method for adjusting the performance of a motor, wherein the motor has a rotor core in which a plurality of slots are arranged radially, and the outer diameter side of each slot in the rotor core is opened as an opening that gradually narrows as it moves radially outward, and the stall torque and maximum output are increased or decreased by changing within a predetermined range the angle between the side of each slot that extends inclined toward the center of the rotor core from the opening and a radial line passing through the center of each slot from the center of the rotor core. Furthermore, the invention described in claim 3 is characterized in that, in the invention described in claim 2, the predetermined range is in the range of 12° to 70°. [Effects of the Invention]

[0007] According to the present invention, the rotor core has openings that gradually narrow as the outer diameter side moves radially outward, and the angle between the side extending inclined from each opening toward the center of the rotor core and the radial line passing from the center of the rotor core through the center of each slot is in the range of 12° to 70°. Therefore, it is possible to suppress the stall torque of the motor without reducing the motor's efficiency, eliminating the need for a separate control unit that suppresses stall torque by adjusting the current supplied to the motor. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing the motor of the present invention. [Figure 2] This is a diagram showing the rotor core. [Figure 3]This is an enlarged view of section A in Figure 2. [Figure 4] This graph shows the correlation between the angle θ and the motor's efficiency. [Figure 5] This graph shows the correlation between the angle θ and the stall torque of the motor. [Figure 6] This graph shows the correlation between the angle θ and the motor efficiency in the motor of modification example 1. [Figure 7] This graph shows the correlation between the angle θ and the stall torque of the motor in modification example 1. [Figure 8] This graph shows the correlation between the angle θ and the motor efficiency in the motor of modification example 2. [Figure 9] This graph shows the correlation between the angle θ and the stall torque of the motor in the modified example 2. [Figure 10] This is an explanatory diagram showing the state when the angle θ is changed. [Modes for carrying out the invention]

[0009] Hereinafter, an example of a motor 1 according to an embodiment of the present invention and a method for adjusting the performance of the motor 1 will be described with reference to the drawings. Figure 1 is a cross-sectional view showing the motor 1 of the present invention. Figure 2 is a diagram showing the rotor core 3. Figure 3 is an enlarged view of portion A in Figure 2. Figure 4 is a graph showing the correlation between the angle θ of the motor 1 and the efficiency of the motor 1 in this embodiment. Figure 5 is a graph showing the correlation between the angle θ of the motor 1 and the stall torque of the motor 1 in this embodiment. Figure 6 is a graph showing the correlation between the angle θ and the efficiency of the motor in Modification Example 1. Figure 7 is a graph showing the correlation between the angle θ and the stall torque of the motor in Modification Example 1. Figure 8 is a graph showing the correlation between the angle θ and the efficiency of the motor in Modification Example 2. Figure 9 is a graph showing the correlation between the angle θ and the stall torque of the motor in Modification Example 2. Figure 10 is an explanatory diagram showing the state in which the angle θ is changed in the slot 21 of the rotor core 3. Note that the dielectric 20 is omitted in Figures 3 and 10.

[0010] (Motor configuration) The configuration of motor 1 will now be described. Motor 1 is an example of an induction motor, and as shown in Figure 1, it has a stator core 2 which is a stator, a rotor core 3 which is a rotor rotatably supported by the stator core 2, a shaft 4 which is held by the rotor core 3 and rotates together with the rotor core 3, a bearing 5 which holds the shaft 4, a bracket 6 which supports various components, and a cover 7 which houses the various components. The stator core 2 is composed of an inner core 8 and an outer core 9, and a coil 11 wound on a bobbin 10 is attached to it. In this embodiment, the output of motor 1 is 200 [W].

[0011] The rotor core 3 is a component used in the motor 1 as a rotor, and is formed by laminating electromagnetic steel sheets. As shown in Figure 2, the rotor core 3 has multiple slots 21, 21... arranged radially and housing dielectrics 20 such as permanent magnets, which are provided by punching. In this embodiment, the rotor core 3 has 28 slots 21.

[0012] Each slot 21 that houses the dielectric 20 is opened as an opening 22, as shown in Figure 3, where the outer diameter side gradually narrows as it extends radially outward. The angle θ is defined as the angle between the side 23 that extends inclined from each opening 22 toward the center of the rotor core 3 and the radial line L that passes from the center of the rotor core 3 through the center of each slot 21. Here, as the area between the outer diameter ends of adjacent slots 21 increases, the stall torque of the motor 1 also increases. Therefore, as the angle θ decreases, the area and the stall torque of the motor 1 tend to increase. The shape and dimensions of the slots 21 are determined so that the angle θ falls within a predetermined range. The predetermined range is the range in which the efficiency of the motor 1 is maintained within 0.5% of the maximum value and the stall torque of the motor 1 is 350% or less of the rated torque. The specific value of the predetermined range is from 12° to 70°. This can be read from Figures 4 and 5, which are verified by changing the angle θ. Figure 4 shows that in the range where the angle θ is between 12° and 70°, the efficiency of motor 1 falls within 0.5% of the maximum value (88.0-88.4%). Also, Figure 5 shows that in the range where the angle θ is between 12° and 70°, the stall torque output is 350% or less of the rated torque.

[0013] Within a given range, the same trend is observed even when the status differs, such as the number of slots 21 or the dimensions of the various configurations of motor 1. For example, Figures 6 and 7 are graphs showing the correlation with angle θ in a motor of modification example 1, which has a capacity of 2200 [W], an outer diameter of stator core 2 of φ178 [mm], and 28 slots 21 in rotor core 3. Similar to Figures 4 and 5, within a predetermined range, the motor efficiency falls within 0.5% of the maximum value (90.0 to 90.5%), and the stall torque output is 350% or less of the rated torque. Further, FIGS. 8 and 9 are graphs showing the correlation with the angle θ in the motor of Modification 2, which has a capacity of 200 [W], an outer diameter of the stator core 2 of φ120 [mm], and 22 slots 21 in the rotor core 3. Similar to FIGS. 4 and 5, within a predetermined range, the efficiency of the motor falls within a range of 0.5% or less from the maximum value (72.1 to 72.6%), and the output of the stall torque relative to the rated torque is 350% or less.

[0014] According to the motor 1 described above, the rotor core 3 is formed with openings 22 that gradually narrow toward the radially outer side on the outer diameter side. The shape and dimensions of the openings 22 are determined such that an angle θ formed between a side 23 extending obliquely from each opening 22 toward the center of the rotor core 3 and a radial straight line L passing through the center of the rotor core 3 and the center of each slot 21 falls within a predetermined range of 12° to 70°. Therefore, the motor 1 can suppress the stall torque of the motor 1 without reducing the efficiency of the motor 1, so that a separate component such as a control unit that suppresses the stall torque by adjusting the current value supplied to the motor 1 is not required.

[0015] (Motor Performance Adjusting Method) A method for adjusting the performance of the motor 1 by changing the angle θ of the rotor core 3 within a predetermined range will be described. As shown in FIGS. 10(a) to 10(c), the performance of the motor 1 is adjusted by changing the angle θ in the slots 21 of the rotor core 3 within a predetermined range. In FIG. 10, (a) shows the case where the angle θ is 40°, (b) shows the case where the angle θ is 50°, and (c) shows the case where the angle θ is 60°. As shown in FIGS. 5, 7 and 9, since the angle θ and the stall torque are in a proportional relationship, any desired stall torque can be output by adjusting the angle θ. Further, since this is an adjusting method of changing the angle θ within a predetermined range, the efficiency of the motor 1 is maintained as shown in FIGS. 4, 6 and 8.

[0016] According to the performance adjustment method for motor 1 described above, by changing the angle θ within a predetermined range, it becomes possible to output any desired stall torque while maintaining the efficiency of motor 1. Therefore, since the stall torque and maximum output can be easily adjusted to match the existing gear configuration, there is no need to provide separate parts such as gears to match the stall torque.

[0017] Furthermore, the motor and motor performance adjustment method according to the present invention are not limited in any way to the embodiments described above, and the overall configuration of the motor and motor performance adjustment method, as well as various other configurations, can be modified as needed. [Explanation of Symbols]

[0018] 1. Motor, 2. Stator core, 3. Rotor core, 4. Shaft, 5. Bearing, 6. Bracket, 7. Cover, 8. Inner core, 9. Outer core, 10. Bobbin, 11. Coil, 20. Inductor, 21. Slot, 22. Opening, 23. Side.

Claims

1. It has a rotor core in which multiple slots are arranged along the radial direction, In the rotor core, the outer diameter side of each slot is opened as an opening that gradually narrows as it moves radially outward. A motor characterized in that the angle between the side of each slot, which extends inclined from the opening toward the center of the rotor core, and the radial line passing from the center of the rotor core through the center of each slot is in the range of 12° to 70°.

2. In a motor having a rotor core in which multiple slots are arranged radially, In the rotor core, the outer diameter side of each slot is opened as an opening that gradually narrows as it moves radially outward, A method for adjusting the performance of a motor, which involves changing the angle between the sides of each slot that extend inclined from the opening toward the center of the rotor core and the radial line passing through the center of each slot from the center of the rotor core within a predetermined range to increase or decrease the stall torque and maximum output.

3. The motor performance adjustment method according to claim 2, characterized in that the predetermined range is in the range of 12° to 70°.

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