Rotating electrical machines, stator and rotor core assemblies, methods for manufacturing rotating electrical machines, methods for manufacturing non-sorted grain electrical thin steel plates for stators and non-sorted grain electrical thin steel plates for rotors, methods for manufacturing stators and rotors, and assemblies of non-sorted grain electrical thin steel plates.

Abstract

Invention details;

Description

Rotating electric machine, set of stator iron core and rotor iron core, manufacturing method of rotating electric machine, manufacturing method of non-oriented electrical steel sheet for stator and non-oriented electrical steel sheet for rotor, manufacturing method of stator and rotor, and set of non-oriented electrical steel sheets

[0001] The present invention relates to a rotating electric machine, a set of a stator core and a rotor core, a method for manufacturing a rotating electric machine, a method for manufacturing a non-oriented electrical steel sheet for a stator and a non-oriented electrical steel sheet for a rotor, a method for manufacturing a stator and a rotor, and a set of non-oriented electrical steel sheets. This application claims priority based on Japanese Patent Application No. 2021-061620 filed in Japan on March 31, 2021, and Japanese Patent Application No. 2021-094807 filed in Japan on June 4, 2021, the contents of which are incorporated herein by reference.

[0002] Various techniques for improving the characteristics of motors in which a stator core is housed in a housing are known. For example, Non-Patent Document 1 describes that heat generated by copper loss in the coil wound around the teeth of the stator core is dissipated through the stator core from the housing arranged around the outer periphery of the stator core to the atmosphere or to the coolant flowing through the cooling jacket. Non-Patent Document 1 also describes that in motors mounted on vehicles, when a high torque range is frequently used, such as when climbing steep slopes, and copper loss is dominant, the temperature rise in the coil ends, which have a long heat conduction path to the housing, becomes a factor limiting the motor's output.

[0003] Non-Patent Documents 2 and 3 describe a technology for improving the heat dissipation characteristics from the coil ends by cooling the motor with ATF (Automatic Transmission Fluid), which lubricates the power motor parts, bearings, etc., in order to suppress temperature rise in the coil ends.

[0004] Various techniques are known for forming a motor stator core by stacking steel sheets that have been subjected to various forming processes, such as punching and shaving. For example, Patent Document 1 describes a technique in which a shaving process is performed on the end surface of a punched sheet, removing an area equivalent to 5 to 25% of the thickness of the sheet material per shaving process, thereby removing an area equivalent to 40 to 60% of the thickness of the sheet material. According to the technique described in Patent Document 1, by removing an area equivalent to a predetermined percentage of the thickness of the sheet material, a rotating electric core with low iron loss can be obtained without annealing the rotating electric core. However, removing the area equivalent to the predetermined percentage inevitably results in a slight decrease in yield.

[0005] Japanese Patent No. 5598062

[0006] "Study on Increasing the Power Density of Hybrid Vehicle Drive Motors", Kamiya, M., Doctoral Dissertation, 2008. "Thermal Analysis of Motor Cooling Structures Using Automatic Transmission Fluid (ATF) for Hybrid Electric Vehicles (HEVs)", Onimaru, S., Matsui, H., Taguchi, T., Otaka, K., Ichioka, E., Mizutani, T., Society of Automotive Engineers of Japan, Preprint of the Academic Conference, No. 68-06, pp. 19-24, 2006. "Development of a New Hybrid Transmission for FWD Sports Utility Vehicles", Hata, H., Kojima, M., Watanabe, H., Mizutani, T. et al., SAE Technical Paper 2005-01-0272, 2005.

[0007] In a motor, temperature increases due to iron loss, copper loss, and the like, increasing the risk of various problems such as insulation breakdown, magnet demagnetization, and increased copper loss. Therefore, it is preferable to efficiently cool the windings, stator core, and other components. Because the thermal conductivity or thermal diffusivity of the stator core is higher than that of air, much of the heat generated in the windings, stator core, and other components is dissipated to the outside of the motor via the stator core. In a motor in which the stator core is housed in a housing, good thermal conduction characteristics between the stator core and the housing are preferred, since much of the heat generated in the windings, stator core, and other components is dissipated via the housing. On the other hand, a rotor with low thermal conductivity or thermal diffusivity reduces iron loss due to temperature increases, so from this perspective, low thermal conductivity or thermal diffusivity is preferred. There are no motors that take advantage of these thermal conductivity or thermal diffusivity characteristics.

[0008] Therefore, the present invention aims to provide a technology that increases the efficiency of a motor while improving the thermal conductivity or thermal diffusion characteristics between the stator core and the housing by increasing the thermal conductivity or thermal diffusivity of the stator, which has copper wires, to prevent an increase in copper loss, and by decreasing the thermal conductivity or thermal diffusivity of the rotor to reduce iron loss due to heat generation.

[0009] In order to solve the above problems, the present invention provides the following: (1) A first aspect of the present invention comprises a stator, a rotor, and a housing that houses the stator and the rotor, Condition 1: the thermal conductivity A of the non-oriented electrical steel sheet used in the iron core of the stator is 12 to 35 W / (m·K), the thermal conductivity B of the non-oriented electrical steel sheet used in the iron core of the rotor is 10 to 33 W / (m·K), and the thermal conductivities of both satisfy the relationship of formula (1): A > B. Condition 2: the thermal diffusivity A1 of the non-oriented electrical steel sheet used in the iron core of the stator is 3.0 x 10 －６ ~9.0 x 10 －６ m ２ / sW / (m K), and the thermal diffusivity B1 of the non-oriented electrical steel sheet used in the rotor core is 2.5 × 10 －６ ~8.5 x 10 －６ m ２ / sW / (m·K), and the thermal diffusivities of both satisfy at least one of the following relationship: A1>B1. (2) The rotating electric machine described in (1) above may satisfy the condition 1. (3) The rotating electric machine described in (1) above may satisfy the condition 2. (4) In the rotating electric machine described in any one of (1) to (3) above, the chemical composition of the non-oriented electrical steel sheets used for the stator core and the rotor core is, in mass %, C: 0.0100% or less, Si: 2.6% to 4.5%, Mn: 0.1% to 3.0%, P: 0.15% or less, S: 0.0030% or less, N: 0.0040% or less, and Al: 0.1% to 2.0%. (5) In the rotating electric machine described in (4) above, the non-oriented electrical steel sheet used for the stator core may have a value of the following formula (2) lower than the value of formula (2) for the non-oriented electrical steel sheet used for the rotor core. Formula (2): 9.9 + 12.4 × Si (mass%) + 6.6 × Mn (mass%) + 10.0 × Al (mass%) (6) In the rotating electric machine described in (4) or (5) above, the chemical composition of the non-oriented electrical steel sheet may contain, in mass%, P: less than 0.03%. (7) In the rotating electric machine described in any one of (4) to (6) above, the chemical composition of the non-oriented electrical steel sheet may contain, in mass%, Cr: 0.001 to 0.400%, and satisfy formula (4). Formula (4): Cr (mass%) × O (mass%) < 8.0 × 10 －５ (8) In the rotating electric machine according to any one of (1) to (7) above, the crystal grain size of the non-oriented electrical steel sheet used for the iron core of the rotor may be less than 80 μm.

[0010] (9) A second aspect of the present invention is a set of a stator core and a rotor core used in the rotating electric machine according to any one of (1) to (8) above.

[0011] (10) A third aspect of the present invention is a method for manufacturing a rotating electric machine, which uses the set of the stator core and the rotor core described in (9) above.

[0012] (11) A fourth aspect of the present invention is a steel sheet having a chemical composition, in mass%, of C: 0.0100% or less, Si: 2.6% or more and 4.5% or less, Mn: 0.1% or more and 3.0% or less, P: 0.15% or less, S: 0.0030% or less, N: 0.0040% or less, Al: 0.1% or more and 2.0% or less, one or more selected from Sn and Sb: 0 to 0.200%, Cr: 0 to 0.400%, Ni: 0 to 5.0%, Cu: 0 to 5.0%, Ca: 0 to 0.010%, Mg: 0 to 0.0100%, rare earth elements (REM): 0 to 0.010%, B: 0 to 0.0050%, Ti: 0.0030% or less, O (12) In the method for producing a non-oriented electrical steel sheet for a stator of a rotating electric machine and a non-oriented electrical steel sheet for a rotor of a rotating electric machine according to (1), the non-oriented electrical steel sheet is produced by a process including steelmaking, hot rolling, hot-rolled sheet annealing, pickling, cold rolling, and finish annealing, the annealing temperature for the finish annealing is set to 600°C to 900°C and is lower than the finish annealing temperature for the non-oriented electrical steel sheet for a stator. (13) In the method for manufacturing a non-oriented electrical steel sheet for a stator or rotor of a rotating electric machine according to (11) above, the formula (3) may be satisfied. (14) In the method for manufacturing a non-oriented electrical steel sheet for a stator or rotor of a rotating electric machine according to any one of (11) to (13) above, the chemical composition of the non-oriented electrical steel sheet may contain, by mass%, less than 0.03% P. (15) In the method for manufacturing a non-oriented electrical steel sheet for a stator or rotor of a rotating electric machine according to any one of (11) to (14) above, the chemical composition of the non-oriented electrical steel sheet may contain, by mass%, 0.001 to 0.400% Cr.

[0013] (16) A fifth aspect of the present invention is a steel sheet having a chemical composition, in mass%, of C: 0.0100% or less, Si: 2.6% or more and 4.5% or less, Mn: 0.1% or more and 3.0% or less, P: 0.15% or less, S: 0.0030% or less, N: 0.0040% or less, Al: 0.1% or more and 2.0% or less, one or more selected from Sn and Sb: 0 to 0.200%, Cr: 0 to 0.400%, Ni: 0 to 5.0%, Cu: 0 to 5.0%, Ca: 0 to 0.010%, Mg: 0 to 0.0100%, and rare earth elements (REM): 0 to 0.010%, B: (17) In the method for manufacturing a stator and a rotor for a rotating electric machine according to (1) above, a non-oriented electrical steel sheet consisting of 0 to 0.0050% of manganese, 0.0030% or less of Ti, 0.0200% or less of O, and the balance being Fe and impurities, is manufactured through a process including steelmaking, hot rolling, hot-rolled sheet annealing, pickling, cold rolling, and finish annealing, a material to be used for a stator and a material to be used for a rotor are punched out from the obtained non-oriented electrical steel sheet and laminated, and stress relief annealing is performed on only the stator so as to satisfy at least one of formula (1): A > B and formula (3): A1 > B1. (17) In the method for manufacturing a stator and a rotor for a rotating electric machine according to (16) above, formula (1) may be satisfied. (18) In the method for manufacturing a stator and a rotor for a rotating electric machine according to (16) above, formula (3) may be satisfied. (19) In the manufacturing method of a stator and a rotor for a rotating electric machine according to any one of (16) to (18) above, the chemical composition of the non-oriented electrical steel sheet may contain, by mass%, less than 0.03% P. (20) In the manufacturing method of a stator and a rotor for a rotating electric machine according to any one of (16) to (19) above, the chemical composition of the non-oriented electrical steel sheet may contain, by mass%, 0.001 to 0.400% Cr.

[0014] (21) A sixth aspect of the present invention is a set of non-oriented electrical steel sheets used as iron core materials for a rotating electrical machine, wherein Condition 1: the thermal conductivity A of the non-oriented electrical steel sheets for the stator is 12 to 35 W / (m K), the thermal conductivity B of the non-oriented electrical steel sheets for the rotor is 10 to 33 W / (m K), and the thermal conductivities of both sheets satisfy the relationship of formula (1): A > B. Condition 2: the thermal diffusivity A1 of the non-oriented electrical steel sheets for the stator is 3.0 x 10 －６ ~9.0 x 10 －６ m２ / sW / (m K), and the thermal diffusivity B1 of the non-oriented electrical steel sheet for the rotor is 2.5 × 10 －６ ~8.5 x 10 －６ m ２ / sW / (m·K), and the thermal diffusivities of both sheets satisfy at least one of the following relationship: A1>B1. (22) The set of non-oriented electrical steel sheets according to (21) above may satisfy Condition 1. (23) The set of non-oriented electrical steel sheets according to (21) above may satisfy Condition 2. (24) In the set of non-oriented electrical steel sheets according to any one of (21) to (23) above, the chemical composition is, in mass%, C: 0.0100% or less, Si: 2.6% or more and 4.5% or less, Mn: 0.1% or more and 3.0% or less, P: 0.15% or less, S: 0.0030% or less, N: 0.0040% or less, Al: 0.1% or more and 2.0% or less, and the total of Sn and Sb: The alloy may be composed of one or more selected from the group consisting of 0 to 0.200%, Cr: 0 to 0.400%, Ni: 0 to 5.0%, Cu: 0 to 5.0%, Ca: 0 to 0.010%, Mg: 0 to 0.0100%, rare earth elements (REM): 0 to 0.010%, B: 0 to 0.0050%, Ti: 0.0030% or less, O: 0.0200% or less, and the balance: Fe and impurities.

[0015] According to the present invention, it is possible to improve the heat conduction characteristics between the stator core and the housing, while also improving the motor efficiency.

[0016] FIG. 2 is a partial plan view of a motor used in the embodiment.

[0017] Preferred embodiments of the present invention will be described in detail below. Unless otherwise specified, the notation "a to b" for numerical values ​​a and b means "a or more and b or less." In such notation, when a unit is assigned only to numerical value b, the unit also applies to numerical value a.

[0018] A first embodiment of the present invention is a rotating electric machine having the following configuration: The rotating electric machine includes a stator, a rotor, and a housing that houses the stator and the rotor, wherein the thermal conductivity A of the non-oriented electrical steel sheet used in the stator core is 12 to 35 W / (m·K), the thermal conductivity B of the non-oriented electrical steel sheet used in the rotor core is 10 to 33 W / (m·K), and the thermal conductivities of both satisfy the relationship of Equation (1): A > B. The first embodiment of the present invention also includes a set of the stator core and rotor core used in this rotating electric machine. The first embodiment of the present invention also includes a method for manufacturing a rotating electric machine using the set of the stator core and rotor core.

[0019] The rotating electric machine according to this embodiment will be described in detail below. The rotating electric machine according to this embodiment has at least a stator, a rotor, and a housing that houses the stator and rotor. The stator, rotor, and housing are not particularly limited in terms of their shapes or configurations, and have ordinary shapes and configurations except for the configurations (e.g., thermal conductivity and thermal diffusivity) that will be described later.

[0020] In this embodiment, the non-oriented electrical steel sheet used for the stator core has a thermal conductivity A of 12 to 35 W / (m K), and the non-oriented electrical steel sheet used for the rotor core has a thermal conductivity B of 10 to 33 W / (m K), and the thermal conductivities of both satisfy the relationship A > B (Condition 1) of Equation (1). Here, thermal conductivity is the ratio of heat flow density to temperature gradient. In this embodiment, the thermal conductivities of the non-oriented electrical steel sheet used for the stator core and the non-oriented electrical steel sheet used for the rotor core can be measured by the following method.

[0021] Thermal conductivity is measured as follows using samples obtained by disassembling the stator core and rotor core of a rotating electrical machine into multiple core materials. Note that in this application, thermal conductivity refers to the thermal conductivity at room temperature in the in-plane direction of the non-oriented electrical steel sheet that constitutes the iron core of the rotating electrical machine. Furthermore, if the non-oriented electrical steel sheet has an insulating coating on its surface, the measurement is performed with the insulating coating in place.

[0022] Thermal conductivity is not measured directly, but is calculated using the following formula: Thermal conductivity = thermal diffusivity x specific heat x density

[0023] Thermal diffusivity is determined by the laser flash method. Specifically, measurements are performed in the atmosphere using a laser flash thermal property measuring device LFA-502 manufactured by Kyoto Electronics Manufacturing Co., Ltd. The sample shape is a disk with a diameter of 10 mm and a plate thickness, and the sample is measured as a single steel plate without overlapping.

[0024] The specific heat is determined by differential scanning calorimetry (DSC). Specifically, the measurement is performed in an Ar atmosphere using a DSC3500 Sirius manufactured by NETZSCH. The flow rate of the atmospheric gas is 50 mL / min. The sample shape is a disk with a diameter of 5 mm and a plate thickness, and two of these samples are stacked during measurement.

[0025] The density is calculated by dividing the mass of the sample by the volume, and the thickness of the sample is measured with a micrometer.

[0026] The thermal conductivity A of the non-oriented electrical steel sheet used in the stator core is in the range of 12 to 35 W / (m·K). If the thermal conductivity A is less than 12 W / (m·K), the stator temperature rises, resulting in increased copper loss. If it exceeds 35 W / (m·K), the alloy amount must be reduced to achieve this, resulting in increased iron loss. The thermal conductivity A is preferably in the range of 15 to 33 W / (m·K), and more preferably in the range of 17 to 26 W / (m·K).

[0027] The thermal conductivity B of the non-oriented electrical steel sheet used in the rotor core is in the range of 10 to 33 W / (m·K). If the thermal conductivity B is less than 10 W / (m·K), the heat generated by the rotor is transferred to the stator via the air, resulting in increased copper loss. If the thermal conductivity B exceeds 33 W / (m·K), the rotor itself becomes less likely to generate heat, and the iron loss reduction effect cannot be achieved. The thermal conductivity B is preferably in the range of 12 to 30 W / (m·K), and more preferably in the range of 15 to 24 W / (m·K).

[0028] In this embodiment, it is important that the non-oriented electrical steel sheets used in the cores of the stator and rotor each have the thermal conductivity range described above, and that the thermal conductivities of both satisfy the relationship of Equation (1): A > B. When the thermal conductivities of both satisfy the relationship of Equation (1): A > B, the thermal conductivity of the stator is greater than that of the rotor, making it easier for the stator's temperature to be released to the outside through the case, etc., thereby suppressing the temperature rise of the motor. At the same time, the thermal conductivity of the rotor is smaller than that of the stator, so the rotor's temperature rises more than the stator, reducing iron loss in the rotor. These effects result in higher motor efficiency than conventional motors. It is more preferable to satisfy the relationship of A > 1.003 × B.

[0029] On the other hand, if A = B, the above effect cannot be obtained. Also, if the thermal conductivities of the two are in a relationship of A < B, the temperature of the stator rises more easily than that of the rotor, making it impossible to suppress the temperature rise of the motor. At the same time, since the thermal conductivity of the rotor is greater than that of the stator, the iron loss reduction effect of raising the rotor temperature cannot be achieved.

[0030] In addition, as another aspect of the present invention, the thermal diffusivity A1 of the non-oriented electrical steel sheet used for the stator core is 3.0 × 10 －６ ~9.0 x 10 －６ m ２ / sW / (m K), and the thermal diffusivity B1 of the non-oriented electrical steel sheet used in the rotor core is 2.5 × 10 －６ ~8.5 x 10 －６ m ２ / sW / (m·K), and the thermal diffusivities of both satisfy the relationship of Equation (3): A1 > B1 (Condition 2). In other words, by satisfying at least one of Condition 1 and Condition 2, the efficiency of the motor can be increased.

[0031] The thermal diffusivity A1 of the non-oriented electromagnetic steel sheet used in the stator core is 3.0 × 10 －６ ~9.0 x 10 －６ m ２ / sW / (m K). The thermal diffusivity A1 is 3.0 × 10 －６ m ２If it is less than / sW / (m·K), the temperature of the stator rises, which leads to an increase in copper loss. －６ m ２ If the thermal diffusivity A1 exceeds 3.5 × 10, the amount of alloy must be reduced to achieve this, resulting in an increase in iron loss. －６ ~8.5 x 10 －６ m ２ / sW / (m·K), and more preferably 4.0×10 －６ ~8.0 x 10 －６ m ２ / sW / (m·K) range.

[0032] The thermal diffusivity B1 of the non-oriented electrical steel sheet used in the rotor core is 2.5 × 10 －６ ~8.5 x 10 －６ m ２ / sW / (m K). The thermal diffusivity B1 is 2.5 × 10 －６ m ２ If the value is less than 8.5×10 / sW / (m·K), the heat generated by the rotor is transmitted to the stator through the air, etc., resulting in an increase in copper loss. －６ m ２ If the thermal diffusivity B1 exceeds 3.0 × 10 / sW / (m·K), the rotor itself becomes difficult to generate heat, and the iron loss reduction effect cannot be obtained. －６ ~8.0 x 10 －６ m ２ / sW / (m·K), and more preferably 3.5×10 －６ ~7.5 x 10 －６ m ２ / sW / (m·K) range.

[0033] It is important that the stator and rotor each have the thermal diffusivity ranges described above, and that their thermal diffusivities satisfy the relationship of Equation (3): A1 > B1. When the thermal diffusivities of both satisfy the relationship of Equation (3): A1 > B1, the thermal diffusivity of the stator is greater than that of the rotor, making it easier for the stator's temperature to be released to the outside through the case, etc., thereby suppressing temperature rise in the motor. At the same time, the thermal diffusivity of the rotor is smaller than that of the stator, so the rotor's temperature rises more than the stator, reducing iron loss in the rotor. These effects result in higher motor efficiency than conventional motors. It is more preferable to satisfy the relationship of A1 > 1.005 × B1.

[0034] On the other hand, if A1 = B1, the above effect cannot be obtained. Furthermore, if the thermal diffusivities of the two are in a relationship of A1 < B1, the stator temperature rises more easily than the rotor, making it impossible to suppress the temperature rise of the motor. At the same time, the thermal diffusivity of the rotor is greater than that of the stator, making it impossible to enjoy the iron loss reduction effect of increasing the rotor temperature.

[0035] The thermal conductivity A of the non-oriented electrical steel sheet used for the stator core is 12 to 35 W / (m K), the thermal conductivity B of the non-oriented electrical steel sheet used for the rotor core is 10 to 33 W / (m K), and the thermal conductivities of both satisfy the relationship of formula (1): A > B (condition 1), and the thermal diffusivity A1 of the non-oriented electrical steel sheet used for the stator core is 3.0 x 10 －６ ~9.0 x 10 －６ m ２ / sW / (m K), and the thermal diffusivity B1 of the non-oriented electrical steel sheet used in the rotor core is 2.5 × 10 －６ ~8.5 x 10 －６ m ２ It is more preferable that the thermal diffusivities of the two components satisfy the relationship A1>B1 (condition 2) of formula (3). In this case, the heat of the stator is more easily released to the outside.

[0036] The relationship between the thermal conductivity or thermal diffusivity of the stator and rotor of the rotating electrical machine described above can be achieved, for example, by controlling the chemical composition of the non-oriented electrical steel sheets used in the stator and rotor.

[0037] That is, the chemical composition of these non-oriented electrical steel sheets is, in mass%, C: 0.0100% or less, Si: 2.6% to 4.5%, Mn: 0.1% to 3.0%, P: 0.15% or less, S: 0.0030% or less, N: 0.0040% or less, Al: 0.1% to 2.0%, one or more selected from Sn and Sb: 0 to 0.200%, Cr: 0 to 0.400%, Ni: 0 to 5.0%, Cu: 0 to 5. 0%, Ca: 0-0.010%, Mg: 0-0.0100%, rare earth elements (REM): 0-0.010%, B: 0-0.0050%, Ti: 0.0030% or less, O: 0.0200% or less, and the balance: Fe and impurities, and the value of the following formula (2) of the non-oriented electrical steel sheet used for the stator core is lower than the value of the following formula (2) of the non-oriented electrical steel sheet used for the rotor core. Formula (2): 9.9 + 12.4 × Si (mass %) + 6.6 × Mn (mass %) + 10.0 × Al (mass %)

[0038] C: 0.0100% or less C is contained as an impurity. To reduce iron loss, the content is preferably 0.0100% or less. The upper limit is more preferably 0.0025%, and even more preferably 0.0020%.

[0039] Si: 2.6% or more and 4.5% or less Si is an element that increases the strength of steel sheet. It is also an element that increases resistivity and is included to reduce iron loss. It is also effective in improving the strength of steel sheet. From the viewpoint of this effect and preventing a decrease in saturation magnetic flux density and embrittlement of steel, the content is preferably 2.6 to 4.5%. The lower limit is more preferably 2.8%, and even more preferably 3.0%. The upper limit is more preferably 4.2%, and even more preferably 4.0%.

[0040] Mn: 0.1% or more and 3.0% or less Like Si and Al, Mn has the effect of increasing resistivity, and is therefore included to reduce iron loss. It is also an element that increases the strength of the steel sheet. From the viewpoint of this effect and preventing a decrease in saturation magnetic flux density and embrittlement of the steel, the content is preferably 0.1 to 3.0%. The lower limit is more preferably 0.6%, and even more preferably 0.8%. The upper limit is more preferably 2.8%, and even more preferably 2.5%.

[0041] P: 0.15% or less P is an element that improves the strength of steel sheet. Since the strength of steel sheet can also be improved by Si or Mn, P does not need to be contained. From the viewpoint of preventing embrittlement of the steel sheet, the content is preferably 0.15% or less. The upper limit is more preferably 0.08%, even more preferably 0.06%, and even more preferably 0.03%.

[0042] S: 0.0030% or less S is contained as an impurity. To reduce iron loss, the content is preferably 0.0030% or less. The upper limit is more preferably 0.0025%, and even more preferably 0.0020%.

[0043] N: 0.0040% or less Nitrogen (N) is an impurity. N reduces the magnetic properties after additional heat treatment. Therefore, the N content is 0.0040% or less. The N content is preferably 0.0020% or less.

[0044] Al: 0.1% or more and 2.0% or less Al is an element that increases resistivity like Si, and is contained to reduce iron loss. Since the effect of reducing iron loss can also be obtained with Si, Al does not need to be contained. From the viewpoint of preventing a decrease in saturation magnetic flux density, the content is preferably 2.0% or less. The upper limit is more preferably 1.8%, and even more preferably 1.5%.

[0045] One or more selected from Sn and Sb: 0 to 0.200% Sn is an element that develops a crystal orientation favorable for magnetic properties. Sn does not need to be contained, and the lower limit of its content is 0. While the effects of Sn inclusion can be obtained even in small amounts, to ensure the effects of inclusion, the content is preferably 0.01% or more, and more preferably 0.02% or more. From the viewpoint of preventing deterioration of magnetic properties, the upper limit of its content is preferably 0.200%, and more preferably 0.100%. Sb is an element that develops a crystal orientation favorable for magnetic properties. Sb does not need to be contained, and the lower limit of its content is 0. While the effects of Sb inclusion can be obtained even in small amounts, to ensure the effects of inclusion, the content is preferably 0.01% or more, and more preferably 0.02% or more. From the viewpoint of preventing deterioration of magnetic properties, the upper limit of its content is preferably 0.200% ...

[0046] Cr: 0 to 0.400% Cr is an element that improves corrosion resistance and high-frequency characteristics. Cr does not need to be contained, and the lower limit of its content is 0.01%. Although the effects of Cr can be obtained even with trace amounts, to ensure the effects of its inclusion, the content is preferably 0.01% or more, and more preferably 0.02% or more. From the perspective of product cost, the upper limit of the content is 0.400%, preferably 0.300%, and more preferably 0.200%. Furthermore, Cr of 0.001% or more is even more preferable because it can increase the thermal conductivity and thermal diffusivity of the rotor and stator.

[0047] Ni: 0 to 5.0% Ni is an element that increases the electrical resistance of the steel sheet and reduces iron loss. Ni does not need to be contained, and the lower limit of its content is 0. Although the effect of containing Ni can be obtained even with a small amount, in order to reliably obtain the effect of containing Ni, the content is preferably 0.01% or more, and more preferably 0.02% or more. From the viewpoint of product cost, the upper limit of the content is 5.0%, preferably 0.5%, and more preferably 0.4%.

[0048] Cu: 0 to 5.0% Cu is an element that increases the electrical resistance of the steel sheet and reduces iron loss. Cu does not need to be contained, and the lower limit of its content is 0. The effect of containing Cu can be obtained even with a small amount, but to ensure the effect of containing Cu, the content is preferably 0.01% or more, and more preferably 0.02% or more. From the viewpoint of product cost and preventing embrittlement of the steel, the upper limit of the content is 5.0%, preferably 0.5%, and more preferably 0.4%.

[0049] Ca: 0 to 0.010% Ca is an element that coarsens sulfides, improves the growth of crystal grains during heat treatment, and contributes to low iron loss. Ca does not need to be contained, and the lower limit of its content is 0. The effect of containing Ca can be obtained even with a small amount, but to ensure the effect of its inclusion, the content is preferably 0.005% or more, and more preferably 0.0010% or more. From the viewpoint of preventing deterioration of magnetic properties, the upper limit of the content is 0.010%, preferably 0.0050%, and more preferably 0.0030%.

[0050] Mg: 0 to 0.0100% Mg is an element that reduces iron loss by promoting the growth of crystal grains, and also improves fatigue strength by converting sulfides in inclusions into harder inclusions containing Mg. To achieve this effect, and taking cost into consideration, the content is preferably set to 0 to 0.0100%. The lower limit is more preferably 0.0005%, and even more preferably 0.0010%. The upper limit is more preferably 0.0040%, and even more preferably 0.0030%.

[0051] Rare earth elements (REM): 0 to 0.010% Rare earth elements (REM) coarsen sulfides, improve grain growth during heat treatment, and contribute to low iron loss. Rare earth elements (REM) do not need to be present, and the lower limit of their content is 0. Although the effects of containing rare earth elements (REM) can be obtained even in trace amounts, to ensure the effects of their inclusion, the content is preferably 0.005% or more, and more preferably 0.0010% or more. From the viewpoint of preventing deterioration of magnetic properties, the upper limit of the content is 0.010%, preferably 0.0050%, and more preferably 0.0030%. Note that REM stands for Rare Earth Metal and refers to Sc, Y, and elements belonging to the lanthanide series.

[0052] Ti: 0.0030% or less Ti is an element contained as an impurity. Ti combines with C, N, O, etc. in the base steel to form fine precipitates such as TiC, TiN, and Ti oxides, which inhibit the growth of crystal grains during annealing and deteriorate magnetic properties, so the content is preferably 0.0030% or less. The upper limit is more preferably 0.0020%, and even more preferably 0.0010%. Since Ti does not need to be contained, the lower limit of the content is 0. In consideration of refining costs, the lower limit may be 0.0003% or 0.0005%.

[0053] B: 0 to 0.0050% A small amount of B contributes to an increase in thermal conductivity and thermal diffusivity. Therefore, B may be contained. To obtain the above effect, the B content is preferably 0.0001% or more. Since B does not need to be contained, the lower limit of the content is 0. On the other hand, if the B content exceeds 0.0050%, B compounds inhibit grain growth during annealing, resulting in finer crystal grain sizes and increased iron loss. Therefore, the B content is set to 0.0050% or less.

[0054] O: 0.0200% or less O combines with Cr in the steel and ２ O ３ This Cr ２ O ３O contributes to increasing the thermal conductivity and thermal diffusivity. Therefore, O may be contained. To obtain the above effect, the O content is preferably 0.0010% or more. On the other hand, when the O content exceeds 0.0200%, Cr ２ O ３ O inhibits grain growth during annealing, resulting in a finer grain size and an increase in iron loss. Therefore, the O content is set to 0.0200% or less.

[0055] The contents of Cr and O preferably satisfy the following formula (4): Cr (mass%)×O (mass%)<8.0×10 －５ If formula (4) is not satisfied, Cr ２ O ３ inhibits grain growth during annealing, resulting in a finer grain size and an increase in iron loss. Therefore, it is preferable that formula (4) is satisfied.

[0056] The balance of the chemical composition is Fe and impurities. The impurities are components contained in raw materials or components mixed in during the manufacturing process, but are not intentionally contained in the steel sheet.

[0057] The chemical components of the base steel sheet described above may be measured by a common analytical method. For example, the steel components may be measured using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Note that C and S may be measured using a combustion-infrared absorption method, N may be measured using an inert gas fusion-thermal conductivity method, and O may be measured using an inert gas fusion-non-dispersive infrared absorption method.

[0058] The stator and rotor of the rotating electric machine of the first embodiment are non-oriented electrical steel sheets having the above chemical composition, and are characterized in that the value of the following formula (2) for the non-oriented electrical steel sheet used for the stator core is lower than the value of the following formula (2) for the non-oriented electrical steel sheet used for the rotor core: Formula (2): 9.9 + 12.4 × Si (mass %) + 6.6 × Mn (mass %) + 10.0 × Al (mass %)

[0059] The value of equation (2) is closely related to the thermal conductivity (or thermal diffusivity) of the resulting non-oriented electrical steel sheet. In other words, equation (2) is a rough estimate of the resistance value of a non-oriented electrical steel sheet at room temperature. In metals, both electrical conduction and thermal conduction (or thermal diffusion) are carried out by free electrons, and the two are correlated. This relationship is formulated by the Wiedenmann-Franz law, which states that thermal conductivity (or thermal diffusivity) and resistance are inversely proportional at the same temperature.

[0060] Therefore, by controlling the chemical composition of the non-oriented electrical steel sheets used in the stator and rotor and making the value of equation (2) for the non-oriented electrical steel sheets used in the stator core lower than the value of equation (2) for the non-oriented electrical steel sheets used in the rotor core, it is possible to more reliably obtain the relationship of the thermal conductivity of the two sheets, as expressed in equation (1): A > B.

[0061] In the first embodiment, a rotating electric machine is manufactured using the rotor and stator described above, which allows both the stator and rotor to have good magnetic properties and improve motor efficiency.

[0062] The second embodiment of the present invention relates to a method for manufacturing a non-oriented electrical steel sheet for a rotor and a non-oriented electrical steel sheet for a stator used in the rotating electric machine described in the first embodiment. The relationship between the thermal conductivity or thermal diffusivity of the stator and rotor of the rotating electric machine of the first embodiment can also be achieved by controlling the finish annealing temperature in the manufacturing process of the non-oriented electrical steel sheet used for the stator and rotor.

[0063] That is, in mass%, C: 0.0100% or less, Si: 2.6% to 4.5%, Mn: 0.1% to 3.0%, P: 0.15% or less, S: 0.0030% or less, N: 0.0040% or less, Al: 0.1% to 2.0%, one or more selected from Sn and Sb: 0 to 0.200%, Cr: 0 to 0.400%, Ni: 0 to 5.0%, Cu: 0 to 5.0%, Ca: 0 to 0.010%, Mg: 0 to 0.0100%, rare earth elements (REM): 0 to 0.010%, B: 0 to 0.0050%, Ti: 0.0030% or less, O: 0.0200 % or less, and the balance: Fe and impurities, is manufactured by a process including steelmaking, hot rolling, hot-rolled sheet annealing, pickling, cold rolling, and finish annealing, and two annealing temperatures for the finish annealing are set so as to satisfy formula (1): A > B or formula (3): A1 > B1, and the finish annealing temperature of the non-oriented electrical steel sheet for the rotor is set to 600°C to 900°C, which is lower than the finish annealing temperature of the non-oriented electrical steel sheet for the stator, thereby obtaining the relationship between the thermal conductivity or thermal diffusivity of the stator and rotor of the rotating electrical machine described in the first embodiment. Therefore, a set of non-oriented electrical steel sheets in which the thermal conductivity A of the non-oriented electrical steel sheet for the stator is 12 to 35 W / (m K) and the thermal conductivity B of the non-oriented electrical steel sheet for the rotor is 10 to 33 W / (m K), and the thermal conductivities of both satisfy the relationship of formula (1): A > B, or a set in which the thermal diffusivity A1 of the non-oriented electrical steel sheet for the stator is 3.0 x 10 －６ ~9.0 x 10 －６ m ２ / sW / (m K), and the thermal diffusivity B1 of the non-oriented electrical steel sheet for the rotor is 2.5 × 10 －６ ~8.5 x 10 －６ m ２ A set of non-oriented electrical steel sheets is obtained in which the thermal diffusivities of the two steel sheets satisfy the relationship of formula (3): A1>B1.

[0064] The manufacturing method according to the second embodiment of the present invention involves steps including steelmaking, hot rolling, hot-rolled sheet annealing, pickling, cold rolling, finish annealing, and skin-pass rolling, which is performed as needed. No particular restrictions are imposed on the steps other than the aforementioned finish annealing, but the following conditions can be adopted in each step.

[0065] The slab heating temperature for hot rolling may be a standard condition of 1000 to 1200° C. However, the coiling temperature is preferably 600° C. or less, more preferably 550° C. or less, from the viewpoint of toughness of the hot-rolled sheet.

[0066] The thinner the thickness of the hot-rolled sheet, the more advantageous it is in preventing cracks and breakages during pickling and cold rolling. Therefore, the thickness can be adjusted appropriately taking into consideration the toughness and production efficiency of the hot-rolled sheet.

[0067] From the viewpoint of magnetic properties, it is preferable to anneal the hot-rolled sheet at 900°C or higher and 1100°C or lower for 30 seconds or longer to grow the crystal grain size before cold rolling to about 50 to 300 μm. However, since the ductility of the hot-rolled sheet decreases, the conditions should be determined taking into consideration the components and productivity.

[0068] For the finish annealing after cold rolling, two annealing temperatures are set depending on the required thermal conductivity or thermal diffusivity. The finish annealing temperature for the non-oriented electrical steel sheet for the rotor is set to 600°C to 900°C, which is lower than the finish annealing temperature for the non-oriented electrical steel sheet for the stator. The finish annealing temperature is closely related to the thermal conductivity or thermal diffusivity of the resulting non-oriented electrical steel sheet. In other words, if the finish annealing temperature for the non-oriented electrical steel sheet for the rotor is set in the range of 600°C to 900°C, which is lower than the finish annealing temperature for the non-oriented electrical steel sheet for the stator, the crystal grain size of the non-oriented electrical steel sheet for the rotor will become finer, increasing the lattice defects (grain boundaries) in the steel and lowering the thermal conductivity or thermal diffusivity. Therefore, by lowering the finish annealing temperature of the non-oriented electrical steel sheet used for the rotor below that of the non-oriented electrical steel sheet used for the stator, the relationship of thermal conductivity (Equation (1): A > B) or the relationship of thermal diffusivity (Equation (3): A1 > B1) can be obtained. To improve strength and magnetic properties, the crystal grain size of the non-oriented electrical steel sheet used for the rotor is preferably less than 80 μm, and more preferably less than 70 μm. The crystal grain size can be determined by using the average value of the crystal grain size measured by a cross-section method in the thickness direction and the rolling direction in a longitudinal cross-sectional structural photograph. Optical microscope photographs, such as those taken at a magnification of 50x, can be used as the longitudinal cross-sectional structural photograph.

[0069] The final annealing temperature range for non-oriented electrical steel sheets for rotors is 600°C to 900°C. Temperatures below 600°C are undesirable because strain introduced during cold rolling remains and the steel sheet becomes embrittled. Temperatures above 900°C are also undesirable because the crystal grain size becomes coarse and the thermal conductivity or thermal diffusivity increases. A particularly preferred range for the final annealing temperature for non-oriented electrical steel sheets for rotors is 750°C to 850°C.

[0070] The relationship between the thermal conductivity or thermal diffusivity of the stator and rotor of the rotating electric machine of the first embodiment can also be obtained by punching and stacking a material to be used for the stator and a material to be used for the rotor from a non-oriented electrical steel sheet obtained by manufacturing using a process including ordinary steelmaking, hot rolling, hot-rolled sheet annealing, pickling, cold rolling, and finish annealing, and then performing stress relief annealing on only the stator so that formula (1): A > B or formula (3): A1 > B1 is satisfied, without particularly controlling the finish annealing temperature in the manufacturing process of the non-oriented electrical steel sheet used for the stator and rotor described above.

[0071] Regarding the stress relief annealing performed on only the stator after punching, it is preferable to perform annealing for 120 minutes or more at a temperature range of 700°C to 900°C to release punching strain. When strain is imparted by skin-pass rolling, it is particularly preferable to anneal at a high temperature for a long time. In this way, by appropriately performing stress relief annealing on only the stator, the relationship of Equation (1): A > B or the relationship of Equation (3): A1 > B1 can be obtained between the stator and rotor after stress relief annealing.

[0072] Hereinafter, the embodiments of the present invention will be further described using examples. Note that the conditions used in the examples are merely examples for confirmation purposes, and the present invention is not limited to these examples. Various conditions can be adopted as long as they do not deviate from the present invention and the object of the present invention is achieved.

[0073] FIG. 1 is a partial plan view of the motor. The motor 300 is an IPM motor manufactured based on the Institute of Electrical Engineers of Japan (IEICE) Model D. The outer diameter of the stator core 3 is 112 mmφ, the outer diameter of the rotor 302 is 54 mmφ, and the stack height of the stator core 3 is 100 mm. There are 24 slots. The stator core 3 is fixed to the housing 301 by shrink fitting. The outer diameter of the rotor 302 is 54 mmφ, the inner diameter of the stator core 3 is 55 mmφ, and the gap between the rotor 302 and the stator core 3 is 0.5 mm. The outer diameter of the stator core 3 is 112 mmφ (= 54 mm + 0.5 mm × 2 + 28.5 mm × 2). The stator core has 24 slots, the number of turns per phase of the copper wire wound around the teeth of the stator core is 35, and the magnetic flux density Br of the rotor magnet is 1.25 T.

[0074] In this example, a winding current with a peak value of 3 A was passed through at a phase angle of 30 degrees, and the loss generated in the motor when the motor was driven at a rotation speed of 1500 RPM for 60 minutes was determined as the motor loss (W).

[0075] Example 1 Molten steel was continuously cast to prepare a 250 mm thick slab having the chemical composition shown in Tables 1 and 2 below. The slab was then hot-rolled to produce a hot-rolled sheet. The slab reheating temperature was 1200°C, the finish temperature in finish rolling was 850°C, the coiling temperature was 650°C, and the finished sheet thickness was 2.0 mm. Next, the hot-rolled sheet was subjected to hot-rolled sheet annealing, where annealing was performed for 1 minute at the temperatures shown in Tables 1 and 2, followed by descaling by pickling and cold rolling to a thickness of 0.35 mm. The sheet was then subjected to finish annealing at 800°C for 30 seconds.

[0076] Next, the magnetic properties of iron loss W15 / 50 (iron loss at a maximum magnetic flux density of 1.5 T and a frequency of 50 Hz) were measured. 55 mm square specimens were taken as measurement samples, and the average values ​​of the properties in the rolling direction and width direction were calculated. Magnetic measurements were performed using a device capable of measuring 55 mm square specimens conforming to the electromagnetic circuit described in JIS C 2556 (2015) and even smaller specimens. The measurement results are shown in Tables 1 and 2. The thermal conductivity and thermal diffusivity of the material were also measured. The measurements were performed using the method described above.

[0077] Materials A to X shown in Tables 1 and 2 were prepared for the motor stator and rotor, respectively. Materials A' to X' had approximately the same composition and iron loss, but also had low thermal conductivity. Materials A' to X' were subjected to a higher final annealing temperature than those used for materials A to X. The grain size of materials A to X was approximately 30 μm, while that of materials A' to X' was approximately 40 μm. Stator and rotor cores were fabricated from these materials, and motors were constructed. Tables 3 and 4 show the materials used for the stator and rotor, whether Equations (1) to (3) hold, and motor loss. The motors of the invention examples had lower motor loss than other motors (comparative examples) using the same iron loss material. In Comparative Examples 167 to 169, the iron loss of the material (W, W') was good, but the thermal conductivity and thermal diffusivity were outside the ranges of the present application, and when operated as a motor, heat was trapped and the motor loss was poor. In particular, Comparative Example 168 shows that even if formula (1) and formula (3) are established, if the thermal conductivity and thermal diffusivity are outside the ranges of the present application, the motor loss will be poor.

[0078]

[0079]

[0080]

[0081]

[0082] (Example 2) Using the cold-rolled materials A, B, C, D, and M shown in Example 1, finish annealing was performed for 30 seconds at the temperatures shown in Tables 5 and 6. Note that Material A was used for motors 201-203 and 216-224, Material B for motors 204-206, Material C for motors 207-209, Material D for motors 210-212, and Material M for motors 213-215. The iron loss, thermal conductivity, thermal diffusivity, and motor loss of the materials were determined in the same manner as in Example 1. The material with a final annealing temperature of 600°C had an average crystal grain size of approximately 20 μm, the material with a final annealing temperature of 700°C had an average crystal grain size of approximately 25 μm, the material with a final annealing temperature of 800°C had an average crystal grain size of approximately 30 μm, the material with a final annealing temperature of 900°C had an average crystal grain size of approximately 65 μm, and the material with a final annealing temperature of 1000°C had an average crystal grain size of approximately 120 μm.

[0083] Motors 203, 206, 209, 212, 215, 218, 221, and 224, which are examples of the invention, had lower motor loss than other motors (comparison examples) using the same components.

[0084]

[0085]

[0086] (Example 3) As shown in Table 7, the materials A, B, C, D, and M used in Example 1 were used for the stator and rotor of the motor. Iron cores were punched from these materials by machining, and then stress relief annealing was performed under the conditions shown in Table 7. In this case, stress relief annealing was performed at 800°C for 2 hours. For the conditions under which stress relief annealing was performed, stress relief annealing was also performed on sample pieces for measuring thermoelectric efficiency and iron loss. The iron loss, thermal conductivity, thermal diffusivity, and motor loss of the materials were determined in the same manner as in Example 1. The material that was not subjected to stress relief annealing had an average crystal grain size of approximately 30 μm, and the material that was subjected to stress relief annealing had an average crystal grain size of approximately 120 μm.

[0087] The motors 303, 306, 309, 312, and 315, which are examples of the invention, had lower motor loss than other motors (comparison examples) that used the same iron loss material.

[0088]

[0089] 3 stator core 300 motor 301 housing 302 rotor

Claims

DEPCT6725 / 10 / 25661. A rotating electrical machine, which consists of: a stator; a rotor; and a casing that houses the stator and rotor, which satisfies at least one of the conditions of Condition 1: the thermal conductivity A of the non-oriented electrical steel sheet used for the stator core is in the range of 12 to 35 W / (m•Kelvin), the thermal conductivity B of the non-oriented electrical steel sheet used for the rotor core is in the range of 10 to 33 W. / (m•Kelvin), and these two thermal conductivity conditions have the relationship of expression(1)A>B, and condition 2: the heat dissipation condition A1 of the non-sorted grain electrical steel sheet used for the stator core is in the range of 3.0x10⁻⁶ to 9.0x10⁻⁶ sq m / s W / (m•Kelvin), the heat dissipation condition B1 of the non-sorted grain electrical steel sheet used for the rotor core is in the range of 2.5x10⁻⁶ to 8.5x10⁻⁶ sq m / s W / (m•Kelvin), and these two heat dissipation conditions have the relationship of expression(3)A1>B12.Rotating electromechanical device under Reputation 1, which corresponds to condition 13. Rotating electromechanical device under Reputation 1, which corresponds to condition 24. Rotating electromechanical device under any one of Reputations 1 through 3, where the chemical composition of each non-grained electrical thin steel sheet used for the stator core and rotor core consists of (in percentage by mass) C: 0.0100 percent or less, Si: 2.6 percent or more and 4.5 percent or less, Mn: 0.1 percent or more and 3.0 percent or less, P: 0.15 percent or less, S: 0.0030 percent or less, N: 0.0040 percent or less, Al: 0.1 percent or more and 2.0 percent or less, one or more elements selected from Sn and Sb: 0 percent to 0.200 percent, Cr: 0 percent to 0.400 percent, Ni: 0 percent to 5.0 percent, Cu: 0 percent to 5.0 percent, Ca: 0 percent to 0.010 percent, Mg: 0 percent to 0.0100 percent, Rare Earth Elements (REM): 0 percent to 0.0.10%, B: 0% to 0.0050%, Ti: 0.0030% or less, O: 0.0200% or less, and the remainder consists of Fe and impurities.

5. Rotating electromechanical devices under claim 4 where the value of expression (2) below for non-grained electrical thin steel sheets used for the stator core is lower than the value of expression (2) for non-grained electrical thin steel sheets used for the rotor core. Expression (2): 9.9 + 12.4 x Si (percent by mass) + 6.6 x Mn (percent by mass) + 10.0 x Al (percent by mass).

6. Rotating electrical machines pursuant to claim 4 or 5 where the chemical composition of the non-sorted grain electrical thin steel sheets contains P: less than 0.03 percent (percent by mass).

7. Rotating electrical machines pursuant to one of claims 4 through 6 where the chemical composition of the non-sorted grain electrical thin steel sheets contains Cr: 0.001 percent to 0.400 percent (percent by mass), and corresponds to expression (4): Cr(percent by mass)xO(percent by mass)<8.0x10⁻⁵.

9. A stator core and rotor core set used for a rotating electrical machine under any of the claims in Cases 1 through 7 where the grain size of the electrically conductive thin steel sheet used for the rotor core is less than 80 micrometers.

10. A method for manufacturing a rotating electrical machine which includes: manufacturing a rotating electrical machine using a stator core and rotor core set under Case 9.

11. A method for manufacturing electrically conductive thin steel sheets. Non-sorted grain electrical steel for stators and non-sorted grain electrical thin steel for rotors of rotating electrical machines according to claim 1, whereby non-sorted grain electrical thin steel has a chemical composition consisting of (in percentage by mass) C: 0.0100 percent or less, Si: 2.6 percent or more and 4.5 percent or less, Mn: 0.1 percent or more and 3.0 percent or less, P: 0.15 percent or less, S: 0.0030 percent or less, N: 0.0.0040% or less, Al: 0.1% or more and 2.0% or less, one or more elements selected from Sn and Sb: 0% to 0.200%, Cr: 0% to 0.400%, Ni: 0% to 5.0%, Cu: 0% to 5.0%, Ca: 0% to 0.010%, Mg: 0% to 0.0100%, Rare Earth Elements (REM): 0% to 0.010%, B: 0% to 0.0050%, Ti: 0.0030% or less, O: 0.0-200 percent or less, and the remainder consisting of Fe and impurities, is produced by a process comprising steel production, hot rolling, hot-rolled thin steel sheet annealing, acid immersion, cold rolling, and final annealing. Two annealing temperatures for the final annealing are determined, and the final annealing temperature of non-grained electrical thin steel sheets for rotors is set at a temperature range of 600°C to 900°C, which is lower than the final annealing temperature of non-grained electrical thin steel sheets.

112. A method for the production of non-alignment grain electrical thin steel plates for the stator and non-alignment grain electrical thin steel plates for the rotor of a rotating electrical machine according to claim 11 which is consistent with expression (1).

13. A method for the production of non-alignment grain electrical thin steel plates for the stator and non-alignment grain electrical thin steel plates for the rotor of a rotating electrical machine according to claim 11 which is consistent with expression (3). 14.Methods for the production of non-alignment grain electrical steel plates for stators and non-alignment grain electrical steel plates for rotors of rotating electrical machines pursuant to one of the claims 11 through 13, where the chemical composition of the non-alignment grain electrical steel plates contains P: less than 0.03 percent (percent by mass).

15. Methods for the production of non-alignment grain electrical steel plates for stators and non-alignment grain electrical steel plates for rotors of rotating electrical machines pursuant to one of the claims 11 through 13, where the chemical composition of the non-alignment grain electrical steel plates contains P: less than 0.03 percent (percent by mass).

16. A method for manufacturing stators and rotors of rotating electrical machines according to claim 1, which includes: manufacturing of thin electrical steel sheets of non-sorted grains whose chemical composition includes (in percentage by mass) C: 0.0100 percent or less, Si: 2.6 percent or more and 4.5 percent or less, Mn: 0.1% or more and 3.0% or less, P: 0.15% or less, S: 0.0030% or less, N: 0.0040% or less, Al: 0.1% or more and 2.0% or less, one or more elements selected from Sn and Sb: 0% to 0.200%, Cr: 0% to 0.400%, Ni: 0% to 5.0%, Cu: 0% to 5.0%, Ca: 0% to 0.010%, Mg: 0% to 0.0100%, Rare Earth Elements (REM): 0% to 0.010%, B: 0% to 0.0050%, Ti: 0.0030% or less, O: 0.0.200 percent or less, and the remainder consists of Fe and impurities by a process consisting of steel production, hot rolling, hot rolled thin sheet annealing, acid immersion, cold rolling, and final annealing; hammering the material used for the stator and rotor from the obtained non-sorted grain electrical thin sheet and stacking these materials; and stress relief annealing only on the stator to satisfy at least one expression of expression(1)A>B and expression(3)A1>B117. A method for manufacturing stators and rotors according to claim 16 that satisfies expression(1).

18. A method for manufacturing stators and rotors according to claim 16 that satisfies expression(3).

19. A method for manufacturing stators and rotors of a rotating electrical machine according to one of the claims of claims 16 through 18 where the chemical composition of the non-sorted grain electrical thin sheet consists of P: less than 0.03 percent (percent by mass).20.Methods for manufacturing stators and rotors of rotating electrical machines according to any one of the claims 16 to 19 where the chemical composition of the non-oriented grain electrical steel sheets contains Cr: 0.001 percent to 0.400 percent (percent by mass).

21. Non-oriented grain electrical steel sheetsets used for core materials of rotating electrical machines which comply with at least one of the conditions of Condition 1: Thermal conductivity A of the non-oriented grain electrical steel sheets used for core materials. The thermal conductivity B of the non-grained electrical steel sheet used for the stator is in the range of 12 to 35 W / (m•Kelvin), the thermal conductivity B of the non-grained electrical steel sheet used for the rotor is in the range of 10 to 33 W / (m•Kelvin), and these two thermal conductivity conditions have the relationship of expression(1)A>B, and condition 2: the thermal conductivity A1 of the non-grained electrical steel sheet used for the stator is in the range of 3.0x10⁻⁶ to 9.0x10⁻⁶ sq m / s W / (m•Kelvin), the thermal conductivity B1 of the non-grained electrical steel sheet used for the rotor is in the range of 2.5x10⁻⁶ to 8.5x10⁻⁶ m² / s W / (m•Kelvin), and these two thermal diffusion conditions have the relationship of expression(3)A1>B122. An electrically conductive thin steel sheet of grain non-arranged according to claim 21 that corresponds to condition 123. An electrically conductive thin steel sheet of grain non-arranged according to claim 21 that corresponds to condition 224. An electrically conductive thin steel sheet of grain non-arranged according to one of claims 21 through 23 in which the chemical composition consists of (percent by mass)C:0.0100 percent or less,Si:2.6 percent. S: 0.1% or more and 4.5% or less; Mn: 0.1% or more and 3.0% or less; P: 0.15% or less; S: 0.0030% or less; N: 0.0040% or less; Al: 0.1% or more and 2.0% or less; one or more elements selected from Sn and Sb: 0% to 0.200%; Cr: 0% to 0.400%; Ni: 0% to 5.0%; Cu: 0% to 5.0%; Ca: 0% to 0.5%.0.10%, Mg: 0% to 0.0100%, Rare Earth Elements (REM): 0% to 0.010%, B: 0% to 0.0050%, Ti: 0.0030% or less, O: 0.0200% or less, and the remainder consists of Fe and impurities.

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