The present invention relates to a magnetic wedge used in a magnetic circuit of a dynamo-electric machine, a dynamo-electric machine, and a method for manufacturing the magnetic wedge.
In a general radial gap type dynamo-electric machine, a stator and a rotor are disposed coaxially, and a plurality of teeth with coils wound therearound is disposed at equal intervals in a circumferential direction on the stator around the rotor. Further, a magnetic wedge may be disposed at tips of the teeth on the rotor side to connect the tips of the adjacent teeth to each other. In this case, the magnetic wedge is used without winding the coil around the magnetic wedge itself, unlike a coil part and the like.
A magnetic flux reaching the coil from the rotor can be magnetically shielded by disposing such a magnetic wedge, and eddy current loss of the coil can be curbed. Further, by disposing the magnetic wedge, a magnetic flux distribution (particularly, a magnetic flux distribution in the circumferential direction) in a gap between the stator and the rotor can be smoothed, and rotation of the rotor can be smoothed. It is possible to obtain a high-efficiency and high-performance dynamo-electric machine by disposing the magnetic wedge in this way (for example, Patent Literature 1).
Further, as a conventional magnetic wedge, a composite material made of a ferromagnetic powder such as iron powder and a thermosetting resin is known. In a manufacturing method for the magnetic wedge, ferromagnetic powder and a thermosetting resin are kneaded into a paste phase, a sheet-like base material is produced by compression forming and thermosetting it in a thickness direction of the magnetic wedge, and then machined into dimensions and a shape required for the magnetic wedge.
Such a conventional magnetic wedge is usually machined to have an elongated rectangular parallelepiped (a rectangular shape) or a trapezoidal or convex cross section perpendicular to a lengthwise direction, is inserted into a groove or the like provided at a tip of a tooth in the lengthwise direction of the magnetic wedge, and is fitted and fixed.
As described above, the conventional magnetic wedge has a machined finish, so that end surfaces thereof usually have an angular shape with sharp corners. When the magnetic wedge is inserted into the groove or the like at a tooth tip in this state, the corners will be scraped and the magnetic wedge will be damaged, and iron powder will be scattered, causing contamination. Furthermore, when the magnetic wedge is inserted, the corners of the magnetic wedge may become caught and bend, making insertion difficult, and in the worst case, causing the magnetic wedge to break.
Therefore, an objective of the present invention is to provide a magnetic wedge that allows the magnetic wedge to be inserted into a tooth tip more smoothly, and a method for manufacturing the magnetic wedge.
The present invention is a magnetic wedge to be installed in a slot opening of a stator of a dynamo-electric machine, wherein defining that a dimension of the magnetic wedge in a circumferential direction of the dynamo-electric machine is a width, a projection shape of the magnetic wedge projected onto a plane perpendicular to a width direction is a rectangle, a parallelogram, or a right angle trapezoid, and corners of the rectangle, the parallelogram, or the right angle trapezoid have a rounded shape.
Further, the magnetic wedge may include a plurality of soft magnetic particles and an electrically insulating substance between the soft magnetic particles.
Further, the soft magnetic particles may be Fe-based soft magnetic particles, the Fe-based soft magnetic particles may contain an element M that is more easily oxidized than Fe, the electrically insulating substance may be an oxide phase containing the element M, and the Fe-based soft magnetic particles may be bound by the oxide phase.
Further, the element M may be at least one selected from a group consisting of Al, Si, Cr, Zr, and Hf.
Further, in the magnetic wedge, the Fe-based soft magnetic particles may be Fe—Al—Cr alloy particles.
Further, the magnetic wedge may have a shape with a width that differs in the thickness direction of the magnetic wedge.
A dynamo-electric machine of the present invention has a stator for a dynamo-electric machine which has a plurality of teeth and a plurality of slots formed by the plurality of teeth and in which any one of the above-described magnetic wedges is fitted between tips of the teeth adjacent to each other, and a rotor disposed at a position by which an axis is shared.
A method for manufacturing a magnetic wedge of the present invention is a method for manufacturing a magnetic wedge that is to be installed in a slot opening of a stator of a dynamo-electric machine, including, defining that a dimension of the magnetic wedge in a circumferential direction of the dynamo-electric machine is a width, a pressing step of pressing raw material powder containing soft magnetic particles in a width direction to obtain a green compact, wherein, in the pressing step, a die having a rectangular, parallelogram, or right angle trapezoidal opening with rounded corners and a punch configured to be inserted into the opening of the die are used.
Further, in the method for manufacturing a magnetic wedge, a plurality of the soft magnetic particles and an electrically insulating substance between the soft magnetic particles may be included.
Further, in the method for manufacturing a magnetic wedge, the raw material powder may be mixed powder of a binder and powder of Fe-based soft magnetic particles containing an element M that is more easily oxidized than Fe, and after the pressing step, a heat treatment step of heat-treating the green compact to form a surface oxide phase of the Fe-based soft magnetic particles that binds the Fe-based soft magnetic particles together between the Fe-based soft magnetic particles may be provided.
Further, in the method for manufacturing a magnetic wedge, the element M may be at least one selected from a group consisting of Al, Si, Cr, Zr, and Hf.
Further, in the method for manufacturing a magnetic wedge, the Fe-based soft magnetic particles may be Fe—Al—Cr alloy particles.
Further, in the method for manufacturing a magnetic wedge, the punch may have a punch surface that is asymmetrical with respect to a center line in a thickness direction of the magnetic wedge.
According to the present invention, it is possible to obtain a magnetic wedge that can be easily installed in a tooth portion.
Embodiments of the present invention will be described in detail below with reference to the drawings, but the present invention is not limited to these embodiments. Further, descriptions of overlapping parts will be omitted.
An embodiment of the present invention is a magnetic wedge that is to be installed in a slot opening of a stator of a dynamo-electric machine, and defining that a dimension of the magnetic wedge in a circumferential direction of a dynamo-electric machine is a width, a projection shape of the magnetic wedge projected on a plane perpendicular to a width direction is a rectangle, a parallelogram, or a right angle trapezoid, and corners of the rectangle, parallelogram, or right angle trapezoid have a rounded shape. In other words, in the magnetic wedge according to the embodiment of the present invention, since the corners of the cross section perpendicular to the width direction of the magnetic wedge are rounded, the corners are not scraped and iron powder or the like is not scattered. Furthermore, when the magnetic wedge is inserted into a tip of a tooth, insertion can be performed more smoothly without the corners of the magnetic wedge getting caught and the magnetic wedge being bent, making it difficult to insert the wedge, or causing the magnetic wedge itself to break.
Here, the tip of the tooth (a tooth tip) refers to the tip side of the tooth, and is not particularly limited to an end. Further, the projection shape of the above-described magnetic wedge may be any shape as long as at least one pair of opposite sides are parallel. Further, the stator of the dynamo-electric machine has a plurality of teeth and a plurality of slots formed between the adjacent teeth, and a magnetic wedge having one of the projection shapes described above is fitted between the tips of the adjacent teeth, that is, opening portions of the slots (slot openings).
Next, specific embodiments will be described.
When the magnetic wedge 10 is installed in a radial gap type dynamo-electric machine, the lengthwise direction of the magnetic wedge (the y direction in
When the shape of the magnetic wedge becomes elongated, the risk of breakage during installation increases, and thus it is also possible to prepare a magnetic wedge that is shorter than a thickness of a stator in advance and to insert it in a row. In this case, the length of the magnetic wedge is approximately 100 mm or less.
The magnetic wedge 10 can be a green compact made of soft magnetic particles (hereinafter, also referred to as soft magnetic powder), such as iron powder or Fe-based soft magnetic alloy powder, or both. By making the magnetic wedge 10 from such a material, it becomes possible to manufacture it by powder pressing, and as a result, the R can be easily formed without using machining as described below.
Here,
The upper punch 21 and the lower punch 22 each have a rounded rectangular cross-sectional shape perpendicular to a pressing direction that is equal to the cross-sectional shape of the magnetic wedge 10. In other words, the upper punch 21 and the lower punch 22 are approximately rectangular with corners having the R and are approximately the same shape as the opening 23 of the die 20. However, in order to enable the upper punch 21 and the lower punch 22 to be inserted into the opening 23 of the die 20, dimensions thereof are several micrometers smaller than a dimension of the opening.
A method for manufacturing the magnetic wedge according to the embodiment of the present invention is a method for manufacturing a magnetic wedge that is to be installed in a slot opening of a stator of a dynamo-electric machine, and includes a pressing step of obtaining a green compact by pressing raw material powder containing soft magnetic particles in the width direction, defining that the dimension of the magnetic wedge in the circumferential direction of the dynamo-electric machine is the width, wherein, in the pressing step, a die having a rectangular, parallelogram, or right trapezoidal opening with rounded corners and a punch that can be inserted into the opening of the die are used.
Here, in the pressing step, a green compact of the magnetic wedge 10 can be obtained using, for example, a die and a punch. The method for forming the magnetic wedge 10 using the die 20, the upper punch 21, and the lower punch 22 is as follows. First, only the lower punch 22 is inserted into the die 20, and the cavity is filled with raw material powder containing soft magnetic powder. Then, the upper punch 21 is inserted into the opening and applied with a predetermined pressure. At this time, a direction in which the pressure is applied (a pressing direction) is the width direction of the magnetic wedge 10. The pressurized raw material powder is consolidated and becomes a green compact 11. The obtained green compact 11 has a shape having the R 24. The magnetic wedge 10 can be obtained by subjecting the green compact 11 to a heat treatment or the like to solidify it.
In addition to the above-described width direction, it is also theoretically possible to apply pressure in the thickness direction or lengthwise direction during pressing. However, when pressure is applied in the thickness direction, a pressing surface becomes an x-y plane in
A pressing pressure can be adjusted as appropriate according to the material and properties of the raw material powder, but when it is too low, a density of the green compact will be too low and a strength of the green compact will be insufficient, and in addition to causing problems in handling in subsequent steps, the density may become low even after the heat treatment, causing problems such as insufficient strength and inability to obtain desired magnetic properties. Therefore, the pressing pressure is preferably 0.1 GPa or more, preferably 0.2 GPa or more, and even more preferably 0.3 GPa or more. On the other hand, when the pressing pressure is too high, the load on the tooling will increase, making wear and tear more likely to occur, and the life of the tooling will be shortened. From such a viewpoint, the pressing pressure is preferably 3 GPa or less, more preferably 2 GPa or less, and even more preferably 1 GPa or less.
Further, in order to extend the life of the tooling, it is preferable that at least portions of the die 20, the upper punch 21, and the lower punch 22 that come into contact with the green compact 11 be formed of cemented carbide.
As described above, according to the manufacturing method of this embodiment, the R shape can be formed at the end portion of the magnetic wedge 10 without machining, and the magnetic wedge 10 that can be easily fitted and installed in a dynamo-electric machine can be manufactured at low cost. Furthermore, since the opening of the die has a rounded rectangular shape, the R shape alleviates stress concentration at the corners caused by the pressing pressure, which is also effective in improving the life of the tooling. In order to enjoy the above-described effects more reliably, a radius of the R is preferably 0.1 mm or more, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more.
On the other hand, from the viewpoint of ensuring an effective length of the magnetic wedge 10, the radius of the R is preferably 50% or less of the thickness of the magnetic wedge 10, more preferably 40% or less, and even more preferably 30% or less.
On the other hand, by making the R smaller, a gap between the magnetic wedge and the tooth tip in this portion is reduced, fixation of the magnetic wedge is strengthened, and disturbances in distribution of magnetic flux that occur around the gap are curbed, and as a result, the magnetic wedge also contributes to improving motor efficiency. From this point of view as well, the radius of the R is preferably 50% or less of the thickness of the magnetic wedge 10, more preferably 40% or less, and even more preferably 30% or less.
Further, the magnetic wedge 10 can be made of a composite material made of soft magnetic particles and an electrically insulating substance. The composite material is a material in which an electrically insulating substance is present between multiple soft magnetic particles to bind the soft magnetic particles to each other and to electrically isolate the particles, and can curb eddy current loss that occurs in the magnetic wedge 10 by increasing an electrical resistance of the magnetic wedge 10.
An average particle diameter (a median diameter d50 in the cumulative particle size distribution) of the soft magnetic particles is preferably 200 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less, because if it is too large, the electrical resistance will decrease and the eddy current loss will increase. On the other hand, in order to maintain high magnetic permeability and to enhance the effects of the magnetic wedge, the average particle diameter of the ferromagnetic particles is preferably 2 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more.
Both organic and inorganic substances can be used as the electrically insulating substance, and for example, an epoxy resin, a phenol resin, polyimide, polyphenylene sulfide, polyamide, polyamideimide, a silicone resin, colloidal silica, low melting point glass, or the like can be used. When they are used, the ferromagnetic powder and these electrically insulating substances are mixed, and then it can be produced by methods such as transfer molding, injection molding, hot pressing, or the like, in addition to the powder pressing described above.
In the method for manufacturing the magnetic wedge that is the embodiment of the present invention, the raw material powder is a mixed powder of a binder and Fe-based soft magnetic particles containing an element M that is more easily oxidized than Fe, and a heat treatment step of subjecting the green compact to heat treatment to form a surface oxide phase of the Fe-based soft magnetic particles that binds the Fe-based soft magnetic particles together between the Fe-based soft magnetic particles is provided after the pressing step.
Further, the magnetic wedge 10 is a consolidated body of the plurality of Fe-based soft magnetic particles 1 containing the element M that is more easily oxidized than Fe. Here, the “element M that is more easily oxidized than Fe” is an element of which standard Gibbs energy of formation of an oxide is lower than that of Fe2O3. As the element M, at least one selected from a group consisting of Al, Si, Cr, Zr, and Hf can be used. One form of the magnetic wedge 10 is an Fe-based alloy in which the soft magnetic particles contain the element M that is more easily oxidized than Fe, and may also be a form in which an oxide phase of the element M is generated between the soft magnetic particles to bind the particles to each other. As a method for manufacturing the magnetic wedge 10 of this form, the oxide phase of the element M can be grown at a grain boundary by heat-treating the soft magnetic particles in an atmosphere involving oxygen after pressing them using the above method, and according to this form, a ratio of the electrically insulating material at the grain boundary can be minimized, resulting in high density, high strength, and high magnetic permeability, which is more preferable.
Further, not only one type of element M but also two or more types of elements M due to a combination of Al and Cr, Si and Cr may be selected. For example, two types of Al and Cr may be selected, and the Fe-based soft magnetic particles 1 may be formed of Fe—Al—Cr based alloy particles. In this way, the magnetic wedge 10 can have high bending strength and high electrical resistance. The Fe—Al—Cr based alloy is an alloy in which the elements having the next highest content after Fe are Cr and Al (in no particular order), and other elements may be contained in a smaller amount than Fe, Cr, and Al. A composition of the Fe—Al—Cr alloy is not particularly limited, but for example, the content of Al is preferably 2.0% by mass or more, and more preferably 5.0% by mass or more. From the viewpoint of obtaining the high saturation magnetic flux density, the content of Al is preferably 10.0% by mass or less, and more preferably 6.0% by mass or less. A content of Cr is preferably 1.0% by mass or more, and more preferably 2.5% by mass or more. From the viewpoint of obtaining the high saturation magnetic flux density, the content of Cr is preferably 9.0% by mass or less, and more preferably 4.5% by mass or less.
When two or more elements are selected as the element M, a total content thereof is preferably 1.0% by mass or more and 20% by mass or less, as in the case in which one element is selected.
Further, the Fe-based soft magnetic particles may be surface-treated particles using a chemical method, heat treatment, or the like. Furthermore, the Fe-based soft magnetic particles can also be configured of a plurality of types of Fe-based soft magnetic particles having different compositions.
When the magnetic wedge 10 of the second embodiment is installed in a dynamo-electric machine, preferably, it is installed in a direction in which an upper side of the trapezoid in the x-y cross section faces a rotor, as shown in
As schematically shown in
The shape of the magnetic wedge 10 of the second embodiment in the x-z cross section is not limited to the approximately trapezoidal shape shown in
As a pressing method, a pressing method (a single-stage pressing) in which compression is simply performed using the upper punch 21 and the lower punch 22 as shown in
On the other hand, due to a structure of the stator, the value of W1/W2 may have to be set to 60% or less. In such a case, it is possible to produce a shape in which W1/W2 is 60% or less, or 50% or less, or even 40% or less using the multi-stage pressing method.
Further, a modified example of this embodiment is shown in
Furthermore, when a plurality of magnetic wedges 10 are inserted in a row into one tooth tip, the magnetic wedges 10 of the third embodiment are installed in the manner shown in
As described above, in the configuration in which a plurality of magnetic wedges 10 having a parallelogram or right angle trapezoidal cross-sectional shape are installed in a row, an effect in which the magnetic wedges 10 are pressed against each other in the overlapping portion, regardless of the presence or absence of the R 24 is produced, and thus this in itself can be regarded as an invention that makes the fixation of the magnetic wedge 10 stronger. That is, a dynamo-electric machine includes a stator for a dynamo-electric machine having a plurality of teeth and a plurality of slots formed by the plurality of teeth and in which a plurality of magnetic wedges each having a parallelogram or right angle trapezoidal cross-sectional shape in the lengthwise direction of the magnetic wedges are installed in a row between the tips of the adjacent teeth, and a rotor disposed at a position by which an axis is shared with the stator for the dynamo-electric machine.
When an angle (θ shown in
Preferably, the magnetic wedge 10 of the third embodiment is a green compact made of soft magnetic particles, and is produced by powder pressing. In this case, the cross-sectional shape of the magnetic wedge 10 shown in
Next, a dynamo-electric machine 300 according to a fourth embodiment of the present invention will be described together with a stator for a dynamo-electric machine that is one of components thereof.
In the dynamo-electric machine 300 of the embodiment, the magnetic wedge 10 of the first embodiment is fitted to the rotor 32 side of the slot, that is, to tips of the teeth 34 on the rotor 32 side so as to connect the tips of adjacent teeth 34.
Here, the relative permeability and saturation magnetic flux density of the teeth 34 are usually designed to be higher than those in the magnetic wedge 10. As a result, a magnetic flux from the rotor 32 reaching the magnetic wedge 10 flows into the teeth 34 via the magnetic wedge 10, the magnetic flux reaching the coil can be curbed, and the eddy current loss generated in the coil can be reduced. Further, when the dynamo-electric machine is driven, most of the magnetic flux in the teeth 34 generated by a coil current flows into the rotor 32 with an interval, but some of the magnetic flux is attracted by the magnetic wedge and spreads in the circumferential direction. Thus, a magnetic flux distribution in a gap between the stator 31 and the rotor 32 becomes gentle, and for example, in a dynamo-electric machine in which a permanent magnet is disposed in the rotor 32, cogging can be curbed, and the eddy current loss generated in the rotor 32 can be further reduced. Also, for example, in an induction type dynamo-electric machine in which a cage-shaped conductor is disposed at a rotor 32, secondary copper loss can be reduced. The loss can be reduced and the dynamo-electric machine 300 with high efficiency and high performance can be obtained by disposing the magnetic wedge 10 according to the present invention in the dynamo-electric machine as described above.
Hereinafter, an example of the second embodiment using the Fe—Al—Cr based alloy as the Fe-based soft magnetic particles will be described. However, materials, blending amounts, and the like described in this example are not intended to limit the scope of the present invention to those alone unless otherwise specified.
An alloy powder of Fe-5% Al-4% Cr (% by mass) was prepared by a high-pressure water atomizing method. Specific preparation conditions are as follows. A tapping temperature was 1650° C. (a melting point 1500° C.), a diameter of a molten metal nozzle was 3 mm, a tapping discharge rate was 10 kg/min, a water pressure was 90 MPa, and a water volume was 130 L/min. Melting and tapping of raw materials were performed in an Ar atmosphere. An average particle size (a median diameter) of the prepared powder was 12 μm, a specific surface area of the powder was 0.4 m2/g, true density of the powder was 7.3 g/cm3, and a content of oxygen of the powder was 0.3%.
Polyvinyl alcohol (PVA) and ion-exchanged water were added to this raw material powder to prepare slurry, and the slurry was spray-dried with a spray dryer to obtain granulated powder. Defining that the raw material powder is 100 parts by weight, an amount of PVA added is 0.75 parts by weight. Zinc stearate was added to the granulated powder at a ratio of 0.4 parts by weight and mixed.
The mixed powder was filled in tooling and pressed at room temperature. Here, tooling having a shape that is the same as that shown in
As can be seen from
The above die and punch were installed in a mechanical press machine with a maximum load of 20 tons, and an amount of descent of the upper punch was adjusted so that a length of the green compact in a stroke direction (a width W2 of the longer side of the magnetic wedge in
The green compact prepared as described above was heat-treated in the air at 750° C. for 1 hour. A temperature increase rate at this time was 250° C./h.
Fifty examples were created using the manufacturing method described above.
In addition, a mass of each of the magnetic wedges was measured and divided by a volume calculated from each of the dimensions to determine the density. As a result, the density was 6,150±120 Kg/m3. A space factor (relative density) which is a value obtained by dividing the density of the magnetic wedge by a true density of the powder was 84%. The reason why the density of the magnetic wedge is higher than that of the green compact is caused by an oxidation increase due to heat treatment.
W1 and W2 shown in
An electrical resistivity of the magnetic wedge was 5×104 Ω·m. 4 mm square Ag electrodes are formed on two facing planes of the magnetic wedge by sputtering, and the electrical resistivity ρ (Ω·m) was calculated by the following Equation using a resistance value R (Ω) at the time of applying 50 V measured by a digital ultra-high resistance tester R8340 manufactured by Advantest Co.
Here, A is an area of the electrode (m2), and t is a thickness (m) of the magnetic wedge.
A three-point bending strength at room temperature was measured using a universal testing machine (Model 5969 manufactured by Instron). Measurement conditions were a load cell capacity of 500 N, a fulcrum diameter of 4 mm, an indenter diameter of 4 mm, a distance between fulcrums of 8 mm, and a test speed of 0.12 mm/min. From a load P (N) at break, the cross-sectional shape of the magnetic wedge was approximated by a trapezoid, and a three-point bending strength σ was calculated using the following Equation.
Here, L is a distance between the fulcrums, W1 and W2 are widths of the magnetic wedges (refer to
The three-point bending strength of the magnetic wedge (3 samples) measured as described above was 140 to 160 MPa, which was confirmed to be higher than a strength (about 100 MPa) normally required for a magnetic wedge.
In order to evaluate an effect of providing the R at the end portion of the magnetic wedge 10, a partial model 40 imitating the tooth 34 of a motor was created, and an installation test of the magnetic wedge 10 in this partial model 40 was conducted. A schematic diagram of the partial model 40 is shown in
A pressing force of the magnetic wedge 10 by the spring 41 can be adjusted as appropriate by using springs with different spring constants or by inserting an appropriate spacer. In this test, nine compression coil springs (D5509 manufactured by KS Sangyo; outer diameter of 3.7 mm, free length of 16 mm) with a spring constant of 1.588 N/mm were arranged and installed, and a spacer (not shown) having a thickness of 3.8 mm was further inserted between the spring and the baking plate. Therefore, an amount of compression of the spring when the magnetic wedge 10 was inserted was 3.8 mm, and the magnetic wedge 10 was pressed with a total force of 53 N from the nine springs.
A pushing force when the magnetic wedge 10 is inserted into the partial model 40 described above was measured as follows. First, two magnetic wedges each having a length of 18 mm are inserted in advance, and a third magnetic wedge is inserted 1 mm from an upper end of the partial model. In this state, using a universal testing machine (Model 6959 manufactured by Instron), the third magnetic wedge was inserted at a pushing speed of 0.1 mm/s, and a force (a pushing force) generated at that time was measured with a load cell.
As the third magnetic wedge, a magnetic wedge with an end portion having the R (left side in
A DC magnetization curve (a B-H curve) of the magnetic wedge was measured using a self-recording magnetic flux meter (TRF-5AH manufactured by Toei Kogyo Co., Ltd.). Five pieces were prepared by cutting off both ends of the above-described magnetic wedge by 4 mm in the lengthwise direction with a slicer to have a length of 10 mm, and they were glued together in the thickness direction to prepare a measurement sample. The sample was held between magnetic poles of an electromagnet and the B-H curve in the lengthwise direction was measured at a maximum applied magnetic field of 360 kA/m.
Measurement results at room temperature are shown in
Motor efficiency when a magnetic wedge having the above-described magnetic properties is installed in an induction type dynamo-electric machine was calculated using electromagnetic field simulation by a finite element method. The main specifications of the induction type dynamo-electric machine used for the electromagnetic field simulation are as follows.
A side shape of the magnetic wedge shown in
As a result of the electromagnetic field analysis, as shown in Table 1, it was found that the installation of the magnetic wedge improved motor efficiency in both cases of sine wave input and rectangular wave input. In this way, it is possible to improve the efficiency of the motor by using the magnetic wedge having the magnetic properties of this embodiment.
As described above, according to the present invention, the R shape can be formed at the end portion of the magnetic wedge 10 without machining, the magnetic wedge 10 that can be easily fitted and installed into a dynamo-electric machine can be manufactured at low cost, and the efficiency of the dynamo-electric machine can be improved.
Number | Date | Country | Kind |
---|---|---|---|
2021-165974 | Oct 2021 | JP | national |
2022-036710 | Mar 2022 | JP | national |
2022-101297 | Jun 2022 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2022/037524 | 10/6/2022 | WO |