JP4158013B2 - Permanent magnet synchronous motor armature and permanent magnet synchronous motor using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an armature structure of a permanent magnet synchronous motor used for home appliances, FA, OA, electric vehicles, and the like, and a permanent magnet synchronous motor using the same.
[0002]
[Prior art]
Synchronous motors using permanent magnets are increasingly used in response to increasing needs such as miniaturization, high torque and high efficiency of motors, and in response to higher energy products of permanent magnets.
By the way, when keeping in mind to reduce cogging and torque ripple with the minimum number of coils and to maintain the linearity of torque with respect to drive current to a high level, conventionally, for example, one field pole as shown in FIG. An armature structure in which the average number of slots per phase corresponding to, that is, the number of slots q per pole and phase, is a fraction, and armature coils are wound in a distributed manner is used.
Here, FIG. 5 shows an example of a permanent magnet synchronous motor having a 4-pole 15-slot configuration, in which a field and an armature that are originally cylindrical are linearly developed. As shown in the figure, as a three-phase armature, an element coil 24 having the same winding pitch is uniformly arranged in two layers within all slots 22, and an interlayer insulation 26 is laid between the two layers of coils. In general, it is a child structure.
[0003]
[Problems to be solved by the invention]
However, in the conventional armature configuration, coils of different phases are arranged close to each other in a specific slot. Therefore, as described in FIG. 5, an insulating material or a corresponding space is provided between the element coils (interlayer insulation). There is a need. This reduces the space factor of the coil in the slot and hinders improvement in motor characteristics.
In particular, for motors with specifications for low speed and large torque, the width of the core part around the armature is made as small as possible by increasing the number of poles, and the slot cross-sectional area and gap diameter are increased accordingly. Along with this, the number of coils has increased, and this has complicated the armature coil manufacturing and laying work and has a long process.
Furthermore, the inside of the armature is filled with cores and coils, and in a fully-closed motor, there is only a means for cooling the outer surface of the armature, and it is difficult to suppress the temperature rise, which hinders downsizing and high torque of the motor. There was a problem.
Needless to say, these problems also occur when the motor structure is expanded to a linear motor.
Therefore, the present invention solves the above-mentioned problems, facilitates high space factor and armature coil production and several steps of work, has little loss, or has high torque linearity at high load. An object of the present invention is to provide an armature structure of a permanent magnet synchronous motor that can easily improve cooling performance, and a permanent magnet synchronous motor using the same.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the armature of the permanent magnet synchronous motor according to claim 1 has N (provided on a core made of a magnetic material and a field composed of P (P: even) magnetic poles by a permanent magnet). N: a multiple of 3) and a three-phase P-pole armature winding, and an average number of slots per phase of the armature winding corresponding to one field pole, Permanent magnet synchronous motor (for example, motor with 2 poles 9 slots, 4 poles 15 slots, etc.) where q = b / a = (P + 1) / P when the number q of slots per pole / phase is expressed by a fractional expression b / a ), The armature windings each of the slots on the basis of a winding form (hereinafter referred to as a reference winding form) in which N element coils are uniformly distributed in multiple layers over the entire slot. The element coils that are in the same phase within one element coil are combined into one element coil and By eliminating the interlayer insulation between the element coils and conversely eliminating the element coils that are out of phase, among the N slots, {3 × (P / a)} is an empty slot, that is, a slot that does not contain the element coil, and the number of element coils is half of the remaining number of slots, that is, {(a × N−3 × P) / (2 × a)} It is to be a piece.
According to the armature of claim 1, since one phase coil is housed in one slot and no interlayer insulation is required, the space factor is improved and the copper loss can be reduced. It becomes easy to improve. At the same time, the number of coils required to construct the armature is greatly reduced, so that the coil manufacturing and laying work can be simplified and shortened.
[0005]
The armature of the permanent magnet synchronous motor according to claim 2 is the armature of the permanent magnet synchronous motor according to claim 1, when the width of the slot in the reference winding form is described as Ws0, as viewed from the gap surface. When all the gaps between the openings of the slot are made uniform, the width of the empty slot is Ws1, and the width of the slots other than the empty slot is Ws2.
Ws1 <Ws0 <Ws2 (2)
The distance between the slots, that is, the so-called slot pitch is made non-uniform so as to satisfy Expression (2).
According to the armature of the second aspect, since the slot area is further increased in addition to the armature of the first aspect, the coil insertion work is facilitated accordingly. Alternatively, it is possible to use a conductor having a larger area than the conventional one while having the same space factor as the conventional one, and the copper loss can be reduced. Or the characteristic similar to the past can be acquired, without making an effort to raise a space factor.
The armature of the permanent magnet synchronous motor according to claim 3 is the armature of the permanent magnet synchronous motor according to claim 1, wherein the width of the slot in the reference winding form is Ws0, the width of the empty slot is Ws1, When the width of slots other than the empty slot is Ws2,
Ws1 <Ws0 <Ws2 (2)
The distance between the slots, that is, the so-called slot pitch is made non-uniform so as to satisfy Expression (2).
According to the armature of the third aspect, in addition to the effect of the armature of the second aspect, the cogging frequency is increased and the cogging torque can be reduced by the unequal slot pitch.
The armature of the permanent magnet synchronous motor according to claim 4 is the armature according to any one of claims 1 to 3, wherein cooling air is passed directly into the empty slot, or an air cooling pipe or a liquid cooling pipe. Is laid.
According to the armature of the fourth aspect, in addition to the effect of the armature according to any one of the first to third aspects, the armature can be directly cooled.
The permanent magnet synchronous motor according to claim 5 is a permanent magnet synchronous motor having the armature according to any one of claims 1 to 3.
According to the permanent magnet synchronous motor according to claim 5, due to the effect of the armature according to any one of claims 1 to 3, the production work is easy, the loss is small, or the linearity of the torque at high load In addition, it is possible to provide a motor that is high and that can easily improve the cooling performance of the armature.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the drawings.
FIG. 1 shows an example of a permanent magnet synchronous motor having a 4-pole 15-slot configuration according to the first embodiment of the present invention, in which a field and an armature that are originally cylindrical are linearly developed. The first embodiment of the present invention starts from FIG. 5 described as a conventional example. That is, in FIG. 5, element coils 44 are wound so that there are two layers in each slot 42 of (slot numbers) # 1 to # 15 provided on one side of the core 41, and interlayer insulation is provided between the element coils 44. 46 is laid. The jump of the element coil is such that, for example, one coil side of a certain U-phase element coil enters the upper side of the # 1 slot and the other enters the lower side of the # 5 slot. Looking closely at the arrangement of the element coils 44 in this figure, the element coils of different phases are housed in the three slots # 1, # 6, and # 11, and the other phases are in the same phase. I understand.
FIG. 1A is a diagram excluding the element coils of the # 1, # 6, and # 11 slots where these different phases are adjacent, and is drawn with the field omitted.
In FIG. 1A, the slot from which the element coil is removed becomes an empty slot 47. The element coil 44 has the same phase in all slots where the coil exists. In this case, the potential difference between the two element coils can be ignored unless the element coils adjacent to each other in the upper and lower portions in the slot 44 are connected in series so that the interlayer insulation between them is unnecessary.
FIG. 1B is a diagram in which interlayer insulation is eliminated based on this idea and the upper and lower element coils are combined into one. Here, the number of slots to be vacant slots and the number of element coils after being combined are unique depending on the relationship between the number of poles P and the number of slots N, based on the selection of coil jumps that are approximately 180 ° in electrical angle. To be determined. That is, the number of slots q per pole / phase is q = N / (3 × P) = (P + 1) / P
Q is expressed as q = b / a
In other words, the number N ′ of empty slots is as follows.
N ′ = 3 × (P / a)
The total number of element coils Nc is half the number of slots other than the empty slots, that is, Nc = (a × N−3 × P) / (2 × a).
It is expressed.
The 4-pole 15-slot configuration shown in this embodiment is
q = 15 / (3 × 4) = 5/4 = (4 + 1) / 4
It is.
Comparing the armature structure of FIG. 1B with FIG. 5, N ′ = 3 × (4/4) = 3 according to the above equation.
Nc = (4 × 15−3 × 4) / (2 × 4) = 6
Thus, three empty slots are generated, and the total number of element coils is changed from 15 to 6.
At the same time, the region of the interlayer insulation is replaced with a part of the element coil, and it can be seen that the sectional area of the element coil is enlarged, that is, the space factor is improved.
By the way, the empty slot generated in the present invention is a useless space as it is. This embodiment is effectively used in the following embodiments.
[0007]
FIG. 2 shows a second embodiment of the present invention in which the armature of a permanent magnet synchronous motor having a four-pole 15-slot configuration is linearly developed as in FIG. Here, while keeping the pitch of the teeth 43 on the side facing the field (not shown) uniform, the width of the empty slot 47 is reduced, and the width of the slot 42 containing the element coil 44 is made radial accordingly. It is an enlarged one.
In this embodiment, the cross-sectional area of the element coil 44 can be widened by increasing the slot area, and thus copper loss can be reduced. Or when using the element coil which has the same cross-sectional area as before, the insertion operation of a coil becomes easy.
[0008]
FIG. 3 shows a third embodiment of the present invention in which an armature of a permanent magnet synchronous motor having a 4-pole 15-slot configuration is linearly developed as in the past. Here, the width of the empty slot 47 is reduced, and the width of the slot 42 containing the element coil 44 is increased accordingly. In this embodiment, since the pitch of the slot openings becomes non-uniform, the magnetic flux of the permanent magnet on the field is also modulated non-uniformly. Therefore, in addition to the same effect as that of the second embodiment by expanding the slot area, it is possible to reduce the cogging torque.
[0009]
FIG. 4 shows a fourth embodiment of the present invention, in which an armature of a permanent magnet synchronous motor having a four-pole 15-slot configuration is linearly developed. Here, in the example shown in FIG. 1, the liquid cooling pipe 48 is inserted into the empty slot, and the refrigerant liquid is allowed to flow therethrough. In this case, it becomes possible to directly cool the vicinity of the element coil which is a heating element, and the cooling performance of the motor is improved.
Although the four embodiments have been described above, the present invention is not limited to the embodiments described above, and can be arbitrarily configured in accordance with the spirit of the invention. For example, the motor is not limited to a 4-pole 15-slot configuration, and includes all configurations where q = N / (3 × P) = (P + 1) / P. In the fourth embodiment, the refrigerant may be either liquid or gas, and if gas is used, cold air may be directly passed into the empty slot without using a pipe. Furthermore, it goes without saying that the motor to which the present invention is applied may be either a rotary motor or a linear motor.
[0010]
【The invention's effect】
As described above, according to the armature of the first aspect, since the copper loss can be reduced by improving the winding space factor, the characteristics such as the motor capacity can be easily improved. At the same time, the number of coils is greatly reduced, which simplifies and shortens coil manufacturing and installation work.
According to the armature of the second aspect, since the space factor is improved in addition to the first aspect, it is possible to further improve the motor characteristics, particularly to reduce the copper loss. Or the characteristic similar to the past can be acquired, without making an effort to raise a space factor.
According to the armature of the third aspect, in addition to the same effect as that of the first aspect, the magnetic flux in the gap is unevenly modulated, so that the cogging torque can be reduced.
According to the armature of the fourth aspect, in addition to the same effect as the armature of any one of the first to third aspects, the armature can be easily cooled or the cooling performance is improved. Can be improved.
According to the permanent magnet synchronous motor of the fifth aspect, it is possible to provide a motor having the characteristics of the armature according to any one of the first to fourth aspects.
[Brief description of the drawings]
FIG. 1 is a developed cross-sectional view of a permanent magnet synchronous motor showing a first embodiment of the present invention.
FIG. 2 is a developed cross-sectional view of an armature showing a second embodiment of the present invention.
FIG. 3 is a developed cross-sectional view of an armature showing a third embodiment of the present invention.
FIG. 4 is a developed cross-sectional view of an armature showing a fourth embodiment of the present invention.
FIG. 5 is a developed cross-sectional view of a conventionally known motor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Permanent magnet synchronous motor 2, 4 Armature 21, 41 Core 22, 42 Slot 23, 43 Teeth 24, 44 Element coil 25, 45 Outer core part 26, 46 Interlayer insulation 47 Empty slot 48 Slot opening 49 Liquid cooling pipe 3 Field 31 Core 32 Permanent magnet

Claims (5)

Field magnets that make up P (P: even number) magnetic poles with permanent magnets and N-phase (N: multiple of 3) slots provided in the core made of a magnetic material and three-phase P-pole armature windings When the average number of slots per phase of the armature winding corresponding to one field pole, that is, the number of slots q per phase per pole is expressed by a fractional expression b / a,
q = b / a = (P + 1) / P (1)
In a permanent magnet synchronous motor (for example, a motor with 2 poles, 9 slots, 4 poles, 15 slots, etc.) represented by formula (1)
The armature winding is based on a winding form (hereinafter referred to as a reference winding form) in which N element coils are uniformly distributed in multiple layers over the entire slot (hereinafter referred to as a reference winding form).
A new winding configuration in which the element coils that are in the same phase in each of the slots are combined into one element coil, and interlayer insulation between the element coils is eliminated, and conversely, the element coils that are out of phase are eliminated. By doing so, among the N slots, {3 × (P / a)} located at equal intervals are used as empty slots, that is, slots that do not contain the element coils, and the number of element coils remains. An armature of a permanent magnet synchronous motor, wherein the number of slots is half, that is, {(a × N−3 × P) / (2 × a)}. When the width of the slot in the reference winding form is described as Ws0, the width of the empty slot is set to Ws1 while the intervals between the openings of the slot viewed from the gap surface are uniform, and the slots other than the empty slot When the width of Ws2 is
Ws1 <Ws0 <Ws2 (2)
The armature of a permanent magnet synchronous motor according to claim 1, wherein the interval between the slots, that is, the so-called slot pitch is made nonuniform so as to satisfy the formula (2). When the width of the slot in the reference winding form is Ws0, the width of the empty slot is Ws1, and the width of slots other than the empty slot is Ws2.
Ws1 <Ws0 <Ws2 (2)
The armature of a permanent magnet synchronous motor according to claim 1, wherein the interval between the slots, that is, the so-called slot pitch is made nonuniform so as to satisfy the formula (2). The permanent magnet synchronous motor armature according to any one of claims 1 to 3, wherein cooling air is passed directly into the empty slot, or an air cooling or liquid cooling pipe is laid. A permanent magnet synchronous motor comprising the armature according to any one of claims 1 to 4.

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