KR102583430B1 - electric motor - Google Patents

Abstract

The electric motor 50 has a field and an armature. The armature has a core back (11), a plurality of teeth (13) extending from the core back (11) toward the field arm, and a three-phase coil (14) mounted on the plurality of teeth (13). The plurality of teeth 13 includes a tooth 13 on which only one coil 14 of three phases is mounted, and a tooth 13 on which coils 14 of a plurality of phases among three phases are mounted. The teeth 13 adjacent to each other form a slot in which the coil 14 is placed. The number of teeth 13 in the armature is an integer other than a multiple of 3. The area ratio representing the ratio of the cross-sectional area of the coil 14 to the area of the slot in the cross-section including the first direction in which the plurality of teeth 13 are lined up and the second direction in which the field and armature face each other is, It is constant in each of the plurality of slots formed by the plurality of teeth 13.

Description

electric motor

The present disclosure relates to an electric motor having a tooth and a coil mounted on the tooth.

Conventionally, the number of magnetic poles of the rotor is P, the number of teeth of the stator is N, the greatest common divisor of P and N is C, N/C=P/C±1, and N/C is any number other than a multiple of 3. An electric motor capable of reducing the cogging torque by making it a constant is known. Regarding such an electric motor, in Patent Document 1, the number of turns in a tooth on which coils of only one phase out of three phases are mounted, and the number of turns per phase in each tooth on which coils of a plurality of phases among three phases are mounted. It is disclosed that the torque ripple can be reduced by making it different from the sum of .

Patent Document 1: International Publication No. 2019/008848

In the electric motor of Patent Document 1, a coil of only one phase or a coil of a plurality of phases is disposed in a slot formed by adjacent teeth. According to the technology in Patent Document 1, since the total number of turns of coils arranged in each slot of the stator is different for each slot, there is variation in the space factor of the coils. In a slot with a lower space factor compared to other slots, the heat generation amount of the coil increases as the resistance of the coil increases. For this reason, in the technology of Patent Document 1, there was a problem that the amount of heat generated by the coil increased.

The present disclosure has been made in consideration of the above, and aims to obtain an electric motor capable of reducing the amount of heat generated by the coil.

In order to solve the above-described problems and achieve the object, the electric motor according to the present disclosure includes a field and an armature arranged to face the field. The armature has a core back, a plurality of teeth extending from the core back toward the field element, and a three-phase coil mounted on the plurality of teeth. The plurality of teeth includes a tooth on which only one coil of three phases is mounted, and a tooth on which coils of a plurality of phases among three phases are mounted. The teeth that are adjacent to each other form a slot in which the coil is placed. The number of teeth in the armature is an integer other than a multiple of 3. The plurality of slots that the armature has include slots with a total number of turns larger than the average value of the total number of turns of the coils in each of the plurality of slots, and slots with a total number of turns smaller than the average value of the total number of turns in each of the plurality of slots. . The area ratio representing the ratio of the cross-sectional area of the coil to the area of the slot in the cross section including the first direction in which the plurality of teeth is arranged and the second direction in which the field and the armature face each other is formed by the plurality of teeth. It is constant in each of the plurality of slots. For the teeth constituting the first slot, which is a slot whose total number of turns is larger than the average value of the total number of turns of the coils in each of the plurality of slots, the tooth pitch, which is the length between the center positions of the teeth, is the number of turns in the plurality of slots. It is larger than the average tee pitch. For the teeth constituting the second slot, which is a slot whose total number of turns is smaller than the average value of the total number of turns in each of the plurality of slots, the tooth pitch is smaller than the average value of the tooth pitches in the plurality of slots.

The electric motor according to the present disclosure achieves the effect of reducing the heat generation amount of the coil.

1 is a cross-sectional view of an electric motor according to Embodiment 1.
Figure 2 is a cross-sectional view of an electric motor according to the comparative example of Embodiment 1.
Fig. 3 is a diagram showing an example of the number of turns of the coil mounted on each tooth in Embodiment 1.
FIG. 4 is a diagram showing examples of the total number of turns of slots, slot area, and space ratio for each slot in the comparative example of Embodiment 1.
Fig. 5 is a diagram showing examples of the total number of turns, slot area, and space ratio for each slot in Embodiment 1.
FIG. 6 is a diagram for explaining the reduction of resistance by the electric motor according to Embodiment 1.
Figure 7 is a cross-sectional view of the electric motor according to Embodiment 2.
Figure 8 is a cross-sectional view of the electric motor according to the comparative example of Embodiment 2.
Fig. 9 is a diagram showing an example of the number of turns of the coil mounted on each tooth in Embodiment 2.
Fig. 10 is a diagram showing examples of the total number of turns, slot area, and space ratio for each slot in Embodiment 2.
FIG. 11 is a diagram for explaining the reduction of resistance by the electric motor according to Embodiment 2.
Figure 12 is a cross-sectional view of the electric motor according to Embodiment 3.
Figure 13 is a cross-sectional view of an electric motor according to the comparative example of Embodiment 3.
Fig. 14 is a diagram showing an example of the number of turns of the coil mounted on each tooth in Embodiment 3.
Fig. 15 is a diagram showing examples of the total number of turns, slot area, and space ratio for each slot in Embodiment 3.
FIG. 16 is a diagram for explaining the reduction of resistance by the electric motor according to Embodiment 3.
Figure 17 is a cross-sectional view of the electric motor according to Embodiment 4.
Figure 18 is a cross-sectional view of an electric motor according to the comparative example of Embodiment 4.
Fig. 19 is a diagram showing an example of the number of turns of the coil mounted on each tooth in Embodiment 4.
Fig. 20 is a diagram showing examples of the total number of turns, slot area, and space ratio for each slot in Embodiment 4.
FIG. 21 is a diagram for explaining the reduction of resistance by the electric motor according to Embodiment 4.
Figure 22 is a cross-sectional view of the electric motor according to Embodiment 5.
Figure 23 is a cross-sectional view of the electric motor according to Embodiment 6.
Figure 24 is a cross-sectional view of the electric motor according to Embodiment 7.
Figure 25 is a cross-sectional view of the electric motor according to Embodiment 8.
Figure 26 is a cross-sectional view of an electric motor according to the comparative example of Embodiment 8.

Below, the electric motor according to the embodiment will be described in detail based on the drawings.

Embodiment 1.

1 is a cross-sectional view of an electric motor 50 according to Embodiment 1. The electric motor 50 has a mover 1 and a stator 2. The mover 1 is arranged to face the stator 2. The stator (2) is a field. The mover (1) is an armature for obtaining propulsion through interaction with the field. The mover 1 can move in a straight direction with respect to the stator 2. The electric motor 50 is a direct-acting electric motor that moves the mover 1 in a straight line.

The stator 2 is a structure that moves the mover 1 in a longitudinal direction. The stator 2 has a stator core, a plurality of permanent magnets 21 and a mounting sheet 22 provided on the surface of the stator core. The illustration of the stator iron core is omitted. Each permanent magnet 21 is attached to a mounting sheet 22 on the surface of the stator core. In Embodiment 1, the stator 2 has four permanent magnets 21. Four permanent magnets 21 are arranged in a longitudinal direction of the stator 2.

The mover 1 has a mover iron core and a plurality of coils 14 mounted on the mover iron core. The mover iron core has a core back (11) extending in the direction in which the mover (1) moves, and a plurality of teeth (13) extending from the core back (11) toward the stator (2). In Embodiment 1, the mover 1 has five teeth 13. Five teeth 13 are lined up in the direction in which the mover 1 moves. The tip of each tooth 13 on the field side is straight. Each coil 14 is constructed by intensively winding conductive wire around teeth 13. The slot where the coil 14 is disposed is adjacent to the tooth 13 in the moving direction of the mover 1. Teeth 13 that are adjacent to each other form a slot.

Voltage is applied to the mover 1 from a three-phase alternating current power supply. The illustration of three-phase AC power is omitted. The number of magnetic poles of the mover 1 is P, the number of teeth 13 of the mover 1 is N, and the greatest common divisor of P and N is C. In Embodiment 1, P=4, N=5, C=1. In Embodiment 1, N/C=P/C±1 holds true. Also, P is an integer that is a natural multiple of 2. N/C is an integer other than a multiple of 3. That is, N is an integer other than a multiple of 3. The electric motor 50 can reduce cogging torque by satisfying these conditions.

In Embodiment 1, a tooth number is assigned to each tooth 13 of the mover 1 for convenience. To each tooth 13, tooth numbers t1, t2, t3, t4, and t5 are assigned from left to right in FIG. 1, respectively. Additionally, a slot number is assigned to each slot of the mover 1 for convenience. Slot numbers s1-1, s2, s3, s4, s5, and s1-2 are assigned to each slot from left to right in FIG. 1, respectively.

The length between the center positions of the teeth 13 constituting the slot is called the tooth pitch. Teeth pitch is the length in the first direction, which is the direction in which the plurality of teeth 13 are lined up. The first direction is also the moving direction of the mover 1. In Embodiment 1, a tooth pitch number is assigned to each tooth pitch of the plurality of teeth 13 for convenience. To each tooth pitch, from left to right in FIG. 1, tooth pitch numbers p1-1, p2, p3, p4, p5, and p1-2 are assigned, respectively.

Three-phase coils 14 are mounted on the five teeth 13. A -U-shaped coil 14 is attached to the tooth 13 of t1. A -V phase coil 14 is attached to the tooth 13 of t2. A +V phase coil 14 and a -W phase coil 14 are mounted on the tooth 13 of t3. A +W phase coil 14 is attached to the tooth 13 of t4. A +U-phase coil 14 is attached to the tooth 13 of t5. “+” and “-” indicate the winding direction of the coil 14. In addition, U-, V-, V+, W-, W+, and U+ shown in FIG. 1 represent -U phase, -V phase, +V phase, -W phase, +W phase, and +U phase, respectively.

Each of the teeth 13 of t1, t2, t4, and t5 is a tooth 13 on which only one phase of the coil 14 is mounted. The tooth 13 of t3 is a tooth 13 on which a two-phase coil 14 is mounted. That is, the plurality of teeth 13 of the mover 1 includes a tooth 13 on which only one coil 14 of three phases is mounted, and a tooth 13 on which coils 14 of a plurality of phases among three phases are mounted. Includes. The reference position A is the center position of the tooth 13 at t3. The tooth 13 of t3 is the central tooth 13 in the first direction among the five teeth 13. FIG. 1 shows a state in which the reference position A coincides with the center position of the stator 2 in the longitudinal direction of the stator 2. The central position of the stator 2 is a position between two centrally located permanent magnets 21 among the plurality of permanent magnets 21 .

The wire diameters of all coils (14) mounted on the five teeth (13) are the same. That is, all coils 14 of the mover 1 are formed by conductors of the same diameter. As a result, the time required to manufacture the mover 1 can be shortened compared to the case where it is necessary to form the coil 14 for each phase with conductors of different diameters, and the time required to manufacture the mover 1 can be reduced. Productivity can be improved.

Here, before explaining the details of the electric motor 50 according to Embodiment 1, the configuration of the electric motor according to the comparative example of Embodiment 1 will be described. Figure 2 is a cross-sectional view of the electric motor 51 according to the comparative example of Embodiment 1. The mover 1 of the electric motor 51 has a region 12 where the coil 14 is not disposed.

FIG. 3 is a diagram showing an example of the number of turns of the coil 14 mounted on each tooth 13 in Embodiment 1. The example of the number of turns shown in FIG. 3 is assumed to be common to the case of the comparative example and the case of Embodiment 1 described later. Figure 3 shows the number of turns of the coil 14 for each phase in each tooth 13 and the total number of turns of each tooth 13. The number of turns shown in FIG. 3 is a standardized number of turns based on the number of turns of the plurality of teeth 13 as a whole. The total number of turns shown in FIG. 3 is the total number of turns standardized based on the number of turns of the plurality of teeth 13 as a whole. That is, the number of turns of each tooth 13 and the total number of turns are expressed by the ratio to the number of turns in the entire movable element 1.

The total number of turns in each tooth 13 at t2 and t4 is greater than 0.20, which is the average value of the total number of turns in each of the plurality of teeth 13. On the other hand, the total number of turns in each tooth 13 of t1, t3, and t5 is smaller than 0.20, which is the average value of the total number of turns in each of the plurality of teeth 13.

FIG. 4 is a diagram showing examples of the total number of turns of slots, slot area, and space ratio for each slot in the comparative example of Embodiment 1. The slot area is the area of the slot in the cross section including the first direction and the second direction. The second direction is a direction in which the mover 1 and the stator 2 face each other. The second direction can also be said to be a direction perpendicular to the surface on which the plurality of permanent magnets 21 are arranged. The cross section shown in FIG. 1 and the cross section shown in FIG. 2 are cross sections including the first direction and the second direction. Additionally, the two slots s1-1 and s1-2 are treated as one slot in calculating the total number of turns of the slot, slot area, and space ratio. s1 represents the slot of s1-1 and the slot of s1-2. p1 represents the sum of p1-1 and p1-2.

The total number of turns in the slots shown in FIG. 4 is a standardized total number of turns based on the number of turns in all of the plurality of slots. In other words, the total number of turns in a slot is expressed as a ratio to the number of turns in all of the plurality of slots. The slot area shown in FIG. 4 is a standardized slot area based on the slot area of all plural slots. That is, the slot area is expressed by the ratio of the entire plurality of slots to the slot area. The space factor represents the ratio of the cross-sectional area of the coil 14 to the slot area in the cross-section including the first direction and the second direction. Additionally, Figure 4 shows the tooth number of the tooth 13 located near each slot and the tooth pitch number corresponding to each slot.

The total number of turns in each slot of s2 and s5 is greater than 0.20, which is the average value of the total number of turns. On the other hand, the total number of turns in each slot of s1, s3, and s4 is smaller than 0.20, which is the average value of the total number of turns. Hereinafter, a slot whose total number of turns is larger than the average value of the total number of turns in each of a plurality of slots is called a first slot, and a slot whose total number of turns is smaller than the average value of the total number of turns in each of a plurality of slots is called a second slot. In Embodiment 1, each slot of s2 and s5 is the first slot. Each slot of s1, s3, and s4 is a second slot.

In the comparative example, the slot areas of each slot of s1, s2, s3, s4, and s5 are all 0.20. That is, the slot area of each slot is the same. Additionally, the tooth pitches of p1, p2, p3, p4, and p5 are all equal to the average value of a plurality of tooth pitches. In FIG. 4, “equal” indicates that the tooth pitch is equal to the average value of a plurality of tooth pitches.

In the case of the comparative example, the slot area of each slot is the same, but the total number of turns is different for each slot. While the same slot area as the first slot is secured in the second slot, the total number of turns in the second slot is smaller than the total number of turns in the first slot, so the area 12 in which the coil 14 is not provided in the second slot. This is formed. Area 12 is provided in each of the second slots s1, s3, and s4.

In this way, in the case of the comparative example, there is a deviation in the space ratio of each slot. As described above, when the wire diameters of all coils 14 are the same, the wire diameter is determined according to the slot with the largest space factor. For this reason, in the electric motor 51, the resistance of the coil 14 in slots other than the slot with the largest space factor becomes greater than the resistance of the coil 14 in the slot with the largest space factor.

Next, details of the electric motor 50 according to Embodiment 1 will be described. In Embodiment 1, the tooth pitch of each tooth 13 is adjusted so that the ratio of the total number of turns to the slot area is constant in the plurality of slots of the mover 1. That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 13 is constant. The fact that the space factor in each of the plurality of slots is constant is not limited to the case where the space rate in each of the plurality of slots is completely the same. The fact that the space rate is constant includes the case where the tooth pitch is adjusted taking into account the case where the space rate changes due to the structure of the mover 1, as will be described later.

Fig. 5 is a diagram showing examples of the total number of turns, slot area, and space ratio for each slot in Embodiment 1. The total number of turns in the slots shown in FIG. 5 is the total number of turns standardized based on the number of turns in all of the plurality of slots. The slot area is a standardized slot area based on the slot area of all plural slots. In Embodiment 1, the slot area for each slot is adjusted by adjusting the tooth pitch of each tooth 13 according to the total number of turns in each slot.

In Figure 1, position "a", position "b", position "c", and position "d" represent the center position of each tooth 13 when it is assumed that a plurality of tooth pitches are equal to each other. . Position “a” represents the hypothetical center position of the tooth 13 at t1. The position “b” represents the hypothetical center position of the tooth 13 at t2. The position “c” represents the hypothetical center position of the tooth 13 at t4. The position “d” represents the hypothetical center position of the tooth 13 at t5.

As shown in FIG. 1, the center position of the tooth 13 at t2 is on the reference position A side with respect to the position “b”. For this reason, the tooth pitch of p3 is smaller than the tooth pitch of p3 when the center position of the tooth 13 of t2 is position “b”. In FIG. 5, “small” indicates that the tooth pitch is smaller than the average value of a plurality of tooth pitches. Since the tooth pitch of p3 is “small,” the slot area in s3 is smaller than the average value of the plurality of slot areas. As shown in Fig. 5, the slot area in s3 is adjusted to 0.19, which is smaller than 0.20, which is the average value of the slot area.

As shown in FIG. 1, the center position of the tooth 13 at t1 is on the opposite side from the reference position A with respect to the position “a”. The tooth pitch of p2 is greater than the tooth pitch of p2 when the center position of the tooth 13 of t1 is position “a”. In FIG. 5, “large” indicates that the tooth pitch is larger than the average value of a plurality of tooth pitches. Since the tooth pitch of p2 is “large,” the slot area in s2 is adjusted to 0.22, which is larger than 0.20, which is the average value of the plurality of slot areas.

Like the tooth pitches of p2 and p3, the tooth pitches of p1, p4, and p5 are also adjusted according to the total number of turns in the slot. By adjusting the tooth pitches of p1, p2, p3, p4, and p5 in this way, the ratio of the total number of turns to the slot area becomes constant in all of the plurality of slots.

In this way, in Embodiment 1, among the teeth 13 constituting the first slot, the tooth pitch is greater than the average value of the tooth pitches in a plurality of slots. Additionally, among the teeth 13 constituting the second slot, the tooth pitch is smaller than the average value of the tooth pitches in a plurality of slots. As a result, the ratio of the total number of turns to the slot area becomes constant for all of the plurality of slots.

The wire diameters of all coils 14 mounted on the plurality of teeth 13 are the same, and the ratio of the total number of turns to the slot area is constant in all the plurality of slots, so that the coils in each of the plurality of slots The spot rate in (14) becomes constant. As shown in Fig. 5, the space factors of each slot are all 1.00. That is, the space rates of each slot of s1, s2, s3, s4, and s5 are the same. Since the space factors of each slot are the same, the electric motor 50 can reduce the variation in resistance in the plurality of slots and reduce the resistance of the plurality of slots as a whole.

FIG. 6 is a diagram for explaining the reduction of resistance by the electric motor 50 according to Embodiment 1. Figure 6 shows a bar graph showing the resistance value of the electric motor 51 according to the comparative example and a bar graph showing the resistance value of the electric motor 50 according to Embodiment 1. The resistance value is expressed by a ratio based on the resistance value of the electric motor 51.

In Embodiment 1, the slot area is small in slots where the total number of turns is less than the average value, and the slot area is large in slots where the total number of turns is more than the average value, so that the space ratio of each slot is constant. By adjusting the space factor of each slot in this way, the electric motor 50 can increase the average value of the space factors in a plurality of slots compared to the case of the comparative example. In the electric motor 50, the wire diameter of the coil 14 can be enlarged compared to the case of the comparative example, and resistance can be reduced.

Here, the relationship between the total number of turns of slots and the tooth pitch in Embodiment 1 will be explained. Let the average value of the total number of turns in each of the plurality of slots be Na, the total number of turns in each slot be Ns, and the average value of the tooth pitch in the plurality of teeth 13 be La, and the teeth 13 constituting each slot are L, which is the tooth pitch of , satisfies the following equation (1).

L=(Ns/Na)×La···(1)

In the electric motor 50, based on the relationship in equation (1), the tooth pitch of the teeth 13 is adjusted according to the total number of turns in the slot, so that the ratio of the total number of turns to the slot area is adjusted in all of the plurality of slots. becomes constant. As a result, the space ratio for each slot becomes equal. However, due to the structure of the mover 1, the space ratio for each slot may change. The space factor may vary depending on, for example, the thickness of the insulator in the mixed phase portion where the coils 14 of a plurality of phases are mounted. In Embodiment 1, the tooth pitch of the teeth 13 may be adjusted so as to have a margin corresponding to the amount of change in the space ratio.

In consideration of the change in space ratio, L1, which is the tooth pitch between the teeth 13 constituting the first slot, may be adjusted to satisfy the following equation (2). Additionally, L2, which is the tooth pitch between the teeth 13 constituting the second slot, may be adjusted to satisfy the following equation (3). Additionally, Ns1 is the total number of turns in the first slot. Ns2 is the total number of turns in the second slot.

La＜L1≤(Ns1/Na)×1.2×La···(2)

La＞L2≥(Ns2/Na)×0.8×La···(3)

Equations (2) and (3) represent relational expressions when a change of 0.8 to 1.2 times the space factor is taken into account. In Embodiment 1, not only the case where equation (1) is satisfied, but also the case where the amount of change in the space factor is added as in equations (2) and (3) is also included when the space rate is constant in all of a plurality of slots. Let it be done. This makes it possible to adjust the tooth pitch to reduce resistance even when the space factor changes due to the structure of the mover 1.

Additionally, the electric motor 50 is not limited to the number of turns of the coil 14 mounted on each tooth 13 being set as shown in FIG. 3 . The electric motor 50 may be one in which the number of turns on at least one of the plurality of teeth 13 is different from the total number of turns on the other teeth 13. In this case, the electric motor 50 can obtain the effect according to Embodiment 1 even if the number of turns of each tooth 13 is different from the case shown in FIG. 3. In addition, the setting of “large” or “small” tooth pitch of the plurality of teeth 13 is not limited to that shown in FIG. 5 and is assumed to be arbitrary.

The arrangement of the coils 14 in the plurality of teeth 13 may be the same as the case in which the phase order in the moving direction of the mover 1 is shown in FIG. 1 . As long as the order of the images is the same as in the case shown in FIG. 1, the image located at the end in the moving direction may be any image.

In Embodiment 1, the mover 1 was configured to satisfy P = 4, N = 5, and C = 1. The mover 1 may have two or more units, with the units P = 4, N = 5, and C = 1. In other words, C may be a natural number greater than 1. The electric motor 50 can achieve the same effect as when C is 1 even when C is a natural number greater than 1.

Each of the plurality of teeth 13 is not limited to having a straight tip on the field side. The tip of the tooth 13 on the field side may be formed with a protrusion or a depression facing in the direction of travel. The electric motor 50 can achieve the same effect even when the teeth 13 are formed with protrusions or depressions as when the teeth 13 are straight.

In Embodiment 1, a configuration was described in which a plurality of permanent magnets 21 are attached to the mounting sheet 22 on the surface of the stator core. However, in the electric motor 50, a plurality of permanent magnets 21 are attached to the inside of the stator core. It may be of a landfill configuration. The electric motor 50 can achieve the same effect even when the plurality of permanent magnets 21 are embedded inside the stator core as when the plurality of permanent magnets 21 are provided on the surface of the stator core.

According to Embodiment 1, the tooth pitch of the plurality of teeth 13 of the electric motor 50 is adjusted so that the ratio of the total number of turns of the coil 14 to the slot area is constant in the plurality of slots. That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 13 is constant. The electric motor 50 can reduce the resistance of the coil 14 in each slot by maintaining a constant space factor in each of the plurality of slots. Thereby, the electric motor 50 achieves the effect of being able to reduce the amount of heat generated by the coil 14.

Embodiment 2.

Figure 7 is a cross-sectional view of the electric motor 52 according to Embodiment 2. In Embodiment 2, the order of phases in the moving direction of the mover 1 is different from Embodiment 1. In Embodiment 2, the same components as in Embodiment 1 above are given the same reference numerals, and configurations different from Embodiment 1 are mainly explained.

The configuration of the mover 1 of the electric motor 52 is the same as that of the mover 1 in Embodiment 1, except that the arrangement of the coil 14 is different. The structure of the stator 2 of the electric motor 52 is the same as that of the stator 2 in Embodiment 1. In Embodiment 2, like Embodiment 1, each tooth 13 of the mover 1 is assigned a tooth number t1, t2, t3, t4, and t5. Each slot of the mover 1 is assigned slot numbers s1-1, s2, s3, s4, s5, and s1-2. To each tooth pitch of the mover 1, tooth pitch numbers p1-1, p2, p3, p4, p5, and p1-2 are assigned.

A +U-phase coil 14 is attached to the tooth 13 of t1. A +V phase coil 14 and a -U phase coil 14 are mounted on the tooth 13 of t2. A -V-phase coil 14 is attached to the tooth 13 of t3. A +V phase coil 14 and a -W phase coil 14 are mounted on the tooth 13 of t4. A +W phase coil 14 is attached to the tooth 13 of t5.

Each of the teeth 13 of t1, t3, and t5 is a tooth 13 on which only one phase of the coil 14 is mounted. Each tooth 13 of t2 and t4 is a tooth 13 on which a two-phase coil 14 is mounted. That is, the plurality of teeth 13 of the mover 1 includes a tooth 13 on which only one coil 14 of three phases is mounted, and a tooth 13 on which coils 14 of a plurality of phases out of three phases are mounted. ) includes. All coils 14 of the mover 1 are formed of conductors of the same diameter.

Here, before explaining the details of the electric motor 52 according to Embodiment 2, the configuration of the electric motor according to the comparative example of Embodiment 2 will be described. Figure 8 is a cross-sectional view of the electric motor 53 according to the comparative example of Embodiment 2. The mover 1 of the electric motor 53 has a region 12 where the coil 14 is not disposed.

FIG. 9 is a diagram showing an example of the number of turns of the coil 14 mounted on each tooth 13 in Embodiment 2. The example of the number of turns shown in FIG. 9 is assumed to be common to the case of the comparative example and the case of Embodiment 2 described later. Figure 9 shows the number of turns of the coil 14 for each phase of each tooth 13 and the total number of turns of the coil 14 of each tooth 13. The number of turns shown in FIG. 9 is a standardized number of turns based on the number of turns of the plurality of teeth 13 as a whole. The total number of turns shown in FIG. 9 is a standardized total number of turns based on the number of turns of the plurality of teeth 13 as a whole. That is, the number of turns of each tooth 13 and the total number of turns are expressed by the ratio to the number of turns in the entire movable element 1.

The total number of turns in each tooth 13 of t1, t3, and t5 is greater than 0.20, which is the average value of the total number of turns in each of the plurality of teeth 13. On the other hand, the total number of turns in each tooth 13 at t2 and t4 is smaller than 0.20, which is the average value of the total number of turns in each of the plurality of teeth 13.

In the electric motor 53 according to the comparative example, like the comparative example of Embodiment 1, the slot areas of each slot of s1, s2, s3, s4, and s5 are all the same. In addition, in the electric motor 53, like the comparative example of Embodiment 1, each tooth pitch of p1, p2, p3, p4, and p5 is equal to the average value of a plurality of tooth pitches. In the electric motor 53, the slot area of each slot is the same, but the total number of turns is different for each slot, so there is variation in the space ratio of each slot. For this reason, in the electric motor 53, the resistance of the coil 14 increases.

Next, details of the electric motor 52 according to Embodiment 2 will be described. In Embodiment 2, the tooth pitch of each tooth 13 is adjusted so that the ratio of the total number of turns to the slot area is constant in the plurality of slots of the mover 1.

Fig. 10 is a diagram showing examples of the total number of turns, slot area, and space ratio for each slot in Embodiment 2. The total number of turns in the slots shown in FIG. 10 is a standardized total number of turns based on the number of turns in all of the plurality of slots. The slot area is a standardized slot area based on the slot area of all plural slots. In Embodiment 2, the slot area for each slot is adjusted by adjusting the tooth pitch of each tooth 13 according to the total number of turns in each slot.

The total number of turns in the slot of s1 is greater than 0.20, which is the average value of the total number of turns. On the other hand, the total number of turns in each slot of s2, s3, s4, and s5 is smaller than 0.20, which is the average value of the total number of turns. In Embodiment 2, the slot of s1 is the first slot, and each of the slots of s2, s3, s4, and s5 is the second slot.

In Figure 7, position "a", position "b", position "c", and position "d" represent the center position of each tooth 13 when it is assumed that a plurality of tooth pitches are equal to each other. . Position “a” represents the hypothetical center position of the tooth 13 at t1. The position “b” represents the hypothetical center position of the tooth 13 at t2. The position “c” represents the hypothetical center position of the tooth 13 at t4. The position “d” represents the hypothetical center position of the tooth 13 at t5.

As shown in Fig. 7, the center position of the tooth 13 at t2 is on the reference position A side with respect to the position “b”. For this reason, the tooth pitch of p3 is smaller than the tooth pitch of p3 when the center position of the tooth 13 of t2 is position “b”. Since the tooth pitch of p3 is “small,” the slot area in s3 is smaller than the average value of the plurality of slot areas. As shown in Fig. 10, the slot area in s3 is adjusted to 0.194, which is smaller than 0.200, which is the average value of the slot area.

As shown in Fig. 7, the center position of the tooth 13 at t1 is on the reference position A side with respect to the position “a”. The center position of the tooth 13 at t5 is on the reference position A side with respect to the position “d”. For this reason, the tooth pitch of p1 is greater than the tooth pitch of p1 in the case where the center position of the tooth 13 of t1 and the center position of the tooth 13 of t5 are at position “a” and position “d”, respectively. . Since the tooth pitch of p1 is “large,” the slot area in s1 is larger than the average value of the plurality of slot areas. As shown in Fig. 10, the slot area in s1 is adjusted to 0.219, which is larger than 0.200, which is the average value of the slot area.

Like the tooth pitches of p1 and p3, the tooth pitches of p2, p4, and p5 are also adjusted according to the total number of turns in the slot. By adjusting the tooth pitches of p1, p2, p3, p4, and p5 in this way, the ratio of the total number of turns to the slot area becomes constant in all of the plurality of slots.

In this way, in Embodiment 2, among the teeth 13 constituting the first slot, the tooth pitch is greater than the average value of the tooth pitches in a plurality of slots. Additionally, among the teeth 13 constituting the second slot, the tooth pitch is smaller than the average value of the tooth pitches in a plurality of slots. As a result, the ratio of the total number of turns to the slot area becomes constant for all of the plurality of slots.

The wire diameters of all coils 14 mounted on the plurality of teeth 13 are the same, and the ratio of the total number of turns to the slot area is constant in all the plurality of slots, so that the coils in each of the plurality of slots The spot rate in (14) becomes constant. As shown in Fig. 10, the space factors of each slot are all 1.00. That is, the space rates of each slot of s1, s2, s3, s4, and s5 are the same. Since the space factors of each slot are the same, the electric motor 52 can reduce the variation in resistance in the plurality of slots and reduce the resistance of the plurality of slots as a whole.

FIG. 11 is a diagram for explaining the reduction of resistance by the electric motor 52 according to Embodiment 2. Figure 11 shows a bar graph showing the resistance value of the electric motor 53 according to the comparative example and a bar graph showing the resistance value of the electric motor 52 according to Embodiment 2. The value of resistance is expressed by a ratio based on the resistance value of the electric motor 53.

In Embodiment 2, the slot area is small in slots where the total number of turns is less than the average value, and the slot area is large in slots where the total number of turns is more than the average value, so that the space ratio of each slot is constant. By adjusting the space factor of each slot in this way, the electric motor 52 can increase the average value of the space factors in a plurality of slots compared to the case of the comparative example. In the electric motor 52, the wire diameter of the coil 14 can be enlarged compared to the case of the comparative example, and resistance can be reduced.

The electric motor 52, like the electric motor 50 according to Embodiment 1, satisfies the above equation (1). As a result, the space ratio for each slot becomes equal. Alternatively, the electric motor 52 satisfies the above equations (2) and (3), similarly to the electric motor 50 according to Embodiment 1. This makes it possible to adjust the tooth pitch to reduce resistance even when the space factor changes due to the structure of the mover 1.

Additionally, the electric motor 52 is not limited to the number of turns of the coil 14 mounted on each tooth 13 being set as shown in FIG. 9 . The electric motor 52 may be one in which the number of turns on at least one of the plurality of teeth 13 is different from the total number of turns on the other teeth 13. In this case, the electric motor 52 can obtain the effect according to Embodiment 2 even if the number of turns of each tooth 13 is different from the case shown in FIG. 9. In addition, the setting of “large” or “small” tooth pitch of the plurality of teeth 13 is not limited to that shown in FIG. 10 and is assumed to be arbitrary.

The arrangement of the coils 14 in the plurality of teeth 13 may be the same as the case in which the phase order in the moving direction of the mover 1 is shown in FIG. 7 . If the order of the phases is the same as in the case shown in FIG. 7, the phase located at the end in the traveling direction may be any phase.

The mover 1 may have two or more units, with the units P = 4, N = 5, and C = 1. In other words, C may be a natural number greater than 1. The electric motor 52 can achieve the same effect as when C is 1 even when C is a natural number greater than 1.

A protrusion or a depression facing in the direction of travel may be formed on the distal end of the tooth 13 on the field side. The electric motor 52 can achieve the same effect even when the teeth 13 are formed with protrusions or depressions as when the teeth 13 are straight.

The electric motor 52 may have a configuration in which a plurality of permanent magnets 21 are embedded within the stator core. The electric motor 52 can achieve the same effect even when the plurality of permanent magnets 21 are embedded inside the stator core as when the plurality of permanent magnets 21 are provided on the surface of the stator core.

According to Embodiment 2, in the electric motor 52, the tooth pitch of the plurality of teeth 13 is adjusted so that the ratio of the total number of turns of the coil 14 to the slot area is constant in the plurality of slots. . That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 13 is constant. The electric motor 52 can reduce the resistance of the coil 14 in each slot by maintaining a constant space factor in each of the plurality of slots. Thereby, the electric motor 52 achieves the effect of being able to reduce the amount of heat generated by the coil 14.

Embodiment 3.

Figure 12 is a cross-sectional view of the electric motor 54 according to Embodiment 3. In Embodiment 3, the order of phases in the moving direction of the mover 1 is different from Embodiment 1 or 2. In Embodiment 3, the same components as those in Embodiment 1 or 2 above are given the same reference numerals, and configurations different from Embodiment 1 or 2 are mainly explained.

The configuration of the mover 1 of the electric motor 54 is the same as that of the mover 1 in Embodiment 1 except that the arrangement of the coil 14 is different. The structure of the stator 2 of the electric motor 54 is the same as that of the stator 2 in Embodiment 1. In Embodiment 3, like Embodiment 1, each tooth 13 of the mover 1 is assigned a tooth number t1, t2, t3, t4, and t5. Each slot of the mover 1 is assigned slot numbers s1-1, s2, s3, s4, s5, and s1-2. To each tooth pitch of the mover 1, tooth pitch numbers p1-1, p2, p3, p4, p5, and p1-2 are assigned.

The +U phase coil 14 and the -W phase coil 14 are mounted on the tooth 13 of t1. A +V phase coil 14 and a -U phase coil 14 are mounted on the tooth 13 of t2. A -V-phase coil 14 is attached to the tooth 13 of t3. A +V phase coil 14 and a -W phase coil 14 are mounted on the tooth 13 of t4. The +W phase coil 14 and the -U phase coil 14 are mounted on the tooth 13 of t5.

The tooth 13 of t3 is a tooth 13 on which only one phase of the coil 14 is mounted. Each of the teeth 13 of t1, t2, t4, and t5 is a tooth 13 on which a two-phase coil 14 is attached. That is, the plurality of teeth 13 of the mover 1 includes a tooth 13 on which only one coil 14 of three phases is mounted, and a tooth 13 on which coils 14 of a plurality of phases out of three phases are mounted. ) includes. All coils 14 of the mover 1 are formed of conductors of the same diameter.

Here, before explaining the details of the electric motor 54 according to Embodiment 3, the configuration of the electric motor according to the comparative example of Embodiment 3 will be described. Figure 13 is a cross-sectional view of the electric motor 55 according to the comparative example of Embodiment 3. The mover 1 of the electric motor 55 has a region 12 where the coil 14 is not disposed.

FIG. 14 is a diagram showing an example of the number of turns of the coil 14 mounted on each tooth 13 in Embodiment 3. The example of the number of turns shown in FIG. 14 is assumed to be common to the case of the comparative example and the case of Embodiment 3 described later. Figure 14 shows the number of turns of the coil 14 for each phase of each tooth 13 and the total number of turns of the coil 14 of each tooth 13. The number of turns shown in FIG. 14 is a standardized number of turns based on the number of turns of the plurality of teeth 13 as a whole. The total number of turns shown in FIG. 14 is a standardized total number of turns based on the number of turns of the plurality of teeth 13 as a whole. That is, the number of turns of each tooth 13 and the total number of turns are expressed by the ratio to the number of turns in the entire movable element 1.

The total number of turns in each tooth 13 of t1, t3, and t5 is greater than 0.20, which is the average value of the total number of turns in each of the plurality of teeth 13. On the other hand, the total number of turns in each tooth 13 at t2 and t4 is smaller than 0.20, which is the average value of the total number of turns in each of the plurality of teeth 13.

In the electric motor 55 according to the comparative example, like the comparative example of Embodiment 1, the slot areas of each slot of s1, s2, s3, s4, and s5 are all the same. In addition, in the electric motor 55, like the comparative example of Embodiment 1, each tooth pitch of p1, p2, p3, p4, and p5 is equal to the average value of a plurality of tooth pitches. In the electric motor 55, the slot area of each slot is the same, but the total number of turns is different for each slot, so there is variation in the space ratio of each slot. For this reason, in the electric motor 55, the resistance of the coil 14 increases.

Next, details of the electric motor 54 according to Embodiment 3 will be described. In Embodiment 3, the tooth pitch of each tooth 13 is adjusted so that the ratio of the total number of turns to the slot area is constant in the plurality of slots of the mover 1.

Fig. 15 is a diagram showing examples of the total number of turns, slot area, and space ratio for each slot in Embodiment 3. The total number of turns in the slots shown in FIG. 15 is a standardized total number of turns based on the number of turns in all of the plurality of slots. The slot area is a standardized slot area based on the slot area of all plural slots. In Embodiment 3, the slot area for each slot is adjusted by adjusting the tooth pitch of each tooth 13 according to the total number of turns in each slot.

The total number of turns in each slot of s3 and s4 is equal to 0.20, which is the average value of the total number of turns. The total number of turns in the slot of s1 is greater than 0.20, which is the average value of the total number of turns. The total number of turns in each slot of s2 and s5 is smaller than 0.20, which is the average value of the total number of turns. In Embodiment 3, the slot of s1 is the first slot, and each of the slots of s2 and s5 is the second slot.

In FIG. 12, position "a" represents the center position of the tooth 13 at t1 when it is assumed that a plurality of tooth pitches are equal to each other. The position “d” represents the hypothetical center position of the tooth 13 at t5.

As shown in FIG. 12, the center position of the tooth 13 at t1 is on the reference position A side with respect to position “a”. The center position of the tooth 13 at t5 is on the reference position A side with respect to the position “d”. For this reason, the tooth pitch of p1 is greater than the tooth pitch of p1 in the case where the center position of the tooth 13 of t1 and the center position of the tooth 13 of t5 are at position “a” and position “d”, respectively. . Since the tooth pitch of p1 is “large,” the slot area in s1 is larger than the average value of the plurality of slot areas. As shown in Fig. 15, the slot area in s1 is adjusted to 0.206, which is larger than 0.200, which is the average value of the slot area.

Like the tooth pitch of p1, the tooth pitch of p2 and p5 is also adjusted according to the total number of turns in the slot. The total number of turns in each slot of s3 and s4 is equal to the average value of the total number of turns. Each tooth pitch of p3 and p4 is equal to the average value of a plurality of tooth pitches. The area of each slot of s3 and s4 is equal to the average value of the slot area. By adjusting the tooth pitch of p1, p2, and p5, the ratio of the total number of turns to the slot area becomes constant in all of the plurality of slots.

In this way, in Embodiment 3, among the teeth 13 constituting the first slot, the tooth pitch is greater than the average value of the tooth pitches in a plurality of slots. Additionally, among the teeth 13 constituting the second slot, the tooth pitch is smaller than the average value of the tooth pitches in a plurality of slots. As a result, the ratio of the total number of turns to the slot area becomes constant for all of the plurality of slots.

The wire diameters of all coils 14 mounted on the plurality of teeth 13 are the same, and the ratio of the total number of turns to the slot area is constant in all the plurality of slots, so that the coils in each of the plurality of slots The spot rate in (14) becomes constant. As shown in Fig. 15, the space factors of each slot are all 1.00. That is, the space rates of each slot of s1, s2, s3, s4, and s5 are the same. Since the space factors of each slot are the same, the electric motor 54 can reduce the variation in resistance in the plurality of slots and reduce the resistance of the plurality of slots as a whole.

FIG. 16 is a diagram for explaining the reduction of resistance by the electric motor 54 according to Embodiment 3. Figure 16 shows a bar graph showing the resistance value of the electric motor 55 according to the comparative example and a bar graph showing the resistance value of the electric motor 54 according to Embodiment 3. The value of resistance is expressed by a ratio based on the resistance value of the electric motor 55.

In Embodiment 3, the slot area is small in slots where the total number of turns is less than the average value, and the slot area is large in slots where the total number of turns is more than the average value, so that the space ratio of each slot is constant. By adjusting the space factor of each slot in this way, the electric motor 54 can increase the average value of the space factors in a plurality of slots compared to the case of the comparative example. In the electric motor 54, the wire diameter of the coil 14 can be enlarged compared to the case of the comparative example, and resistance can be reduced.

The electric motor 54, like the electric motor 50 according to Embodiment 1, satisfies the above equation (1). As a result, the space ratio for each slot becomes equal. Alternatively, the electric motor 54, like the electric motor 50 according to Embodiment 1, satisfies the above equations (2) and (3). This makes it possible to adjust the tooth pitch to reduce resistance even when the space factor changes due to the structure of the mover 1.

Additionally, the electric motor 54 is not limited to the number of turns of the coil 14 mounted on each tooth 13 being set as shown in FIG. 14 . The electric motor 54 may be one in which the number of turns on at least one of the plurality of teeth 13 is different from the total number of turns on the other teeth 13. In this case, the electric motor 54 can obtain the effect according to Embodiment 3 even if the number of turns of each tooth 13 is different from the case shown in FIG. 14. In addition, the setting of "large", "small" or "equal" of the tooth pitch of the plurality of teeth 13 is not limited to that shown in FIG. 15 and is assumed to be arbitrary.

The arrangement of the coils 14 in the plurality of teeth 13 may be the same as the case in which the phase order in the moving direction of the mover 1 is shown in FIG. 12. If the order of the phases is the same as in the case shown in FIG. 12, the phase located at the end in the traveling direction may be any phase.

The mover 1 may have two or more units, with the units P = 4, N = 5, and C = 1. In other words, C may be a natural number greater than 1. The electric motor 54 can achieve the same effect as when C is 1 even when C is a natural number greater than 1.

A protrusion or a depression facing in the direction of travel may be formed on the distal end of the tooth 13 on the field side. The electric motor 54 can achieve the same effect even when the teeth 13 are formed with protrusions or depressions as when the teeth 13 are straight.

The electric motor 54 may have a configuration in which a plurality of permanent magnets 21 are embedded within the stator core. The electric motor 54 can achieve the same effect even when the plurality of permanent magnets 21 are embedded inside the stator core as when the plurality of permanent magnets 21 are provided on the surface of the stator core.

According to Embodiment 3, in the electric motor 54, the tooth pitch of the plurality of teeth 13 is adjusted so that the ratio of the total number of turns of the coil 14 to the slot area is constant in the plurality of slots. . That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 13 is constant. The electric motor 54 can reduce the resistance of the coil 14 in each slot by maintaining a constant space factor in each of the plurality of slots. Thereby, the electric motor 54 achieves the effect of being able to reduce the amount of heat generated by the coil 14.

Embodiment 4.

Figure 17 is a cross-sectional view of the electric motor 56 according to Embodiment 4. In Embodiment 4, the number of teeth 13 in the mover 1 is different from Embodiments 1 to 3. Additionally, in Embodiment 4, the number of permanent magnets 21 in the stator 2 is different from Embodiments 1 to 3. In Embodiment 4, the same components as those in Embodiments 1 to 3 above are given the same reference numerals, and configurations different from those in Embodiments 1 to 3 are mainly explained.

In Embodiment 4, the mover 1 has four teeth 13. The stator 2 has three permanent magnets 21. In Embodiment 4, P=3, N=4, C=1. In Embodiment 4, N/C=P/C±1 holds true. Also, N/C is an integer other than a multiple of 3. That is, N is an integer other than a multiple of 3. The electric motor 56 can reduce cogging torque by satisfying these conditions.

In Embodiment 4, tooth numbers t1, t2, t3, and t4 are assigned to each tooth 13 of the mover 1. Each slot of the mover 1 is assigned slot numbers s1-1, s2, s3, s4, and s1-2. To each tooth pitch of the mover 1, tooth pitch numbers p1-1, p2, p3, p4, and p1-2 are assigned.

A +U-phase coil 14 is attached to the tooth 13 of t1. A +V phase coil 14 and a -U phase coil 14 are mounted on the tooth 13 of t2. A +W phase coil 14 and a -V phase coil 14 are mounted on the tooth 13 of t3. A -W-phase coil 14 is mounted on the tooth 13 of t4.

Each tooth 13 of t1 and t4 is a tooth 13 on which only one phase of coil 14 is mounted. Each tooth 13 of t2 and t3 is a tooth 13 on which a two-phase coil 14 is mounted. That is, the plurality of teeth 13 of the mover 1 includes a tooth 13 on which only one coil 14 of three phases is mounted, and a tooth 13 on which coils 14 of a plurality of phases among three phases are mounted. Includes. All coils 14 of the mover 1 are formed of conductors of the same diameter.

Here, before explaining the details of the electric motor 56 according to Embodiment 4, the configuration of the electric motor according to the comparative example of Embodiment 4 will be described. Figure 18 is a cross-sectional view of the electric motor 57 according to the comparative example of Embodiment 4. The mover 1 of the electric motor 57 has a region 12 where the coil 14 is not disposed.

FIG. 19 is a diagram showing an example of the number of turns of the coil 14 mounted on each tooth 13 in Embodiment 4. The example of the number of turns shown in FIG. 19 is assumed to be common to the case of the comparative example and the case of Embodiment 4 described later. Figure 19 shows the number of turns of the coil 14 for each phase in each tooth 13 and the total number of turns of the coil 14 of each tooth 13. The number of turns shown in FIG. 19 is a standardized number of turns based on the number of turns of the plurality of teeth 13 as a whole. The total number of turns shown in FIG. 19 is the total number of turns standardized based on the number of turns of the plurality of teeth 13 as a whole. That is, the number of turns of each tooth 13 and the total number of turns are expressed by the ratio to the number of turns in the entire movable element 1.

The total number of turns in each tooth 13 at t1 and t4 is greater than 0.25, which is the average value of the total number of turns in each of the plurality of teeth 13. On the other hand, the total number of turns in each tooth 13 at t2 and t3 is smaller than 0.25, which is the average value of the total number of turns in each of the plurality of teeth 13.

In the electric motor 57 according to the comparative example, like the comparative example of Embodiment 1, the slot areas of each slot of s1, s2, s3, and s4 are all the same. In addition, in the electric motor 57, like the comparative example of Embodiment 1, each tooth pitch of p1, p2, p3, and p4 is equal to the average value of a plurality of tooth pitches. In the electric motor 57, the slot area of each slot is the same, but the total number of turns is different for each slot, so there is variation in the space ratio of each slot. For this reason, in the electric motor 57, the resistance of the coil 14 increases.

Next, details of the electric motor 56 according to Embodiment 4 will be described. In Embodiment 4, the tooth pitch of each tooth 13 is adjusted so that the ratio of the total number of turns to the slot area is constant in the plurality of slots of the mover 1.

Fig. 20 is a diagram showing examples of the total number of turns, slot area, and space ratio for each slot in Embodiment 4. The total number of turns in the slots shown in FIG. 20 is a standardized total number of turns based on the number of turns in all of the plurality of slots. The slot area is a standardized slot area based on the slot area of all plural slots. In Embodiment 4, the slot area for each slot is adjusted by adjusting the tooth pitch of each tooth 13 according to the total number of turns in each slot.

The total number of turns in each slot of s2 and s4 is equal to 0.25, which is the average value of the total number of turns. The total number of turns in the slot of s1 is greater than 0.25, which is the average value of the total number of turns. The total number of turns in the slot of s3 is smaller than 0.25, which is the average value of the total number of turns. In Embodiment 4, the slot at s1 is the first slot, and the slot at s3 is the second slot.

In Figure 17, position "a", position "b", position "c", and position "d" represent the center position of each tooth 13 when it is assumed that a plurality of tooth pitches are equal to each other. . Position “a” represents the hypothetical center position of the tooth 13 at t1. The position “b” represents the hypothetical center position of the tooth 13 at t2. Position “c” represents the hypothetical center position of the tooth 13 at t3. The position “d” represents the hypothetical center position of the tooth 13 at t4.

As shown in Fig. 17, the center position of the tooth 13 at t1 is on the reference position A side with respect to the position “a”. The center position of the tooth 13 at t4 is on the reference position A side with respect to the position “d”. For this reason, the tooth pitch of p1 is greater than the tooth pitch of p1 in the case where the center position of the tooth 13 of t1 and the center position of the tooth 13 of t4 are at position “a” and position “d”, respectively. . Since the tooth pitch of p1 is “large,” the slot area in s1 is larger than the average value of the plurality of slot areas. As shown in Fig. 20, the slot area in s1 is adjusted to 0.27, which is larger than 0.25, which is the average value of the slot area.

As shown in Fig. 17, the center position of the tooth 13 at t2 is on the reference position A side with respect to the position “b”. The center position of the tooth 13 at t3 is on the reference position A side with respect to the position “c”. For this reason, the tooth pitch of p3 is smaller than the tooth pitch of p3 in the case where the center position of the tooth 13 of t2 and the center position of the tooth 13 of t3 are position “b” and position “c”, respectively. . Since the tooth pitch of p3 is “small,” the slot area in s3 is smaller than the average value of the plurality of slot areas. As shown in FIG. 20, the slot area in s3 is adjusted to 0.23, which is smaller than 0.25, which is the average value of the slot area.

The total number of turns in each slot of s2 and s4 is equal to the average value of the total number of turns. Each tooth pitch of p2 and p4 is equal to the average value of a plurality of tooth pitches. The area of each slot of s2 and s4 is equal to the average value of the slot area. By adjusting the tooth pitch of p1 and p3, the ratio of the total number of turns to the slot area becomes constant in all of the plurality of slots.

In this way, in Embodiment 4, among the teeth 13 constituting the first slot, the tooth pitch is greater than the average value of the tooth pitches in a plurality of slots. Additionally, among the teeth 13 constituting the second slot, the tooth pitch is smaller than the average value of the tooth pitches in a plurality of slots. As a result, the ratio of the total number of turns to the slot area becomes constant for all of the plurality of slots.

The wire diameters of all coils 14 mounted on the plurality of teeth 13 are the same, and the ratio of the total number of turns to the slot area is constant in all the plurality of slots, so that the coils in each of the plurality of slots The spot rate in (14) becomes constant. As shown in Fig. 20, the space factors of each slot are all 1.00. That is, the space rates of each slot of s1, s2, s3, and s4 are the same. Since the space factors of each slot are the same, the electric motor 56 can reduce the variation in resistance in the plurality of slots and reduce the resistance of the plurality of slots as a whole.

FIG. 21 is a diagram for explaining the reduction of resistance by the electric motor 56 according to Embodiment 4. Figure 21 shows a bar graph showing the resistance value of the electric motor 57 according to the comparative example and a bar graph showing the resistance value of the electric motor 56 according to Embodiment 4. The resistance value is expressed by a ratio based on the resistance value of the electric motor 57.

In Embodiment 4, the slot area is small in slots where the total number of turns is less than the average value, and the slot area is large in slots where the total number of turns is more than the average value, so that the space ratio of each slot is constant. By adjusting the space factor of each slot in this way, the electric motor 56 can increase the average value of the space factors in a plurality of slots compared to the case of the comparative example. In the electric motor 56, the wire diameter of the coil 14 can be enlarged compared to the case of the comparative example, and resistance can be reduced.

The electric motor 56, like the electric motor 50 according to Embodiment 1, satisfies the above equation (1). As a result, the space ratio for each slot becomes equal. Alternatively, the electric motor 56, like the electric motor 50 according to Embodiment 1, satisfies the above equations (2) and (3). This makes it possible to adjust the tooth pitch to reduce resistance even when the space factor changes due to the structure of the mover 1.

In addition, the electric motor 56 is not limited to the number of turns of the coil 14 mounted on each tooth 13 being set as shown in FIG. 19. The electric motor 56 may be one in which the number of turns on at least one of the plurality of teeth 13 is different from the total number of turns on the other teeth 13. In this case, the electric motor 56 can obtain the effect according to Embodiment 4 even if the number of turns of each tooth 13 is different from the case shown in FIG. 19. In addition, the setting of "large", "small", or "equal" of the tooth pitch of the plurality of teeth 13 is not limited to that shown in FIG. 20 and is assumed to be arbitrary.

The arrangement of the coils 14 in the plurality of teeth 13 may be the same as the case where the phase order in the moving direction of the mover 1 is shown in FIG. 17. If the order of the phases is the same as in the case shown in FIG. 17, the phase located at the end in the traveling direction may be any phase.

The mover 1 may have two or more units, with the units P = 3, N = 4, and C = 1. In other words, C may be a natural number greater than 1. The electric motor 56 can achieve the same effect as when C is 1 even when C is a natural number greater than 1.

A protrusion or a depression facing in the direction of travel may be formed on the distal end of the tooth 13 on the field side. The electric motor 56 can achieve the same effect even when the teeth 13 are formed with protrusions or depressions as when the teeth 13 are straight.

The electric motor 56 may have a configuration in which a plurality of permanent magnets 21 are embedded within the stator core. The electric motor 56 can achieve the same effect even when the plurality of permanent magnets 21 are embedded inside the stator core as when the plurality of permanent magnets 21 are provided on the surface of the stator core.

According to Embodiment 4, in the electric motor 56, the tooth pitch of the plurality of teeth 13 is adjusted so that the ratio of the total number of turns of the coil 14 to the slot area is constant in the plurality of slots. . That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 13 is constant. The electric motor 56 can reduce the resistance of the coil 14 in each slot by maintaining a constant space factor in each of the plurality of slots. Thereby, the electric motor 56 achieves the effect of being able to reduce the amount of heat generated by the coil 14.

Embodiment 5.

Figure 22 is a cross-sectional view of the electric motor 58 according to Embodiment 5. In Embodiment 5, the tooth pitch at the end portion of the teeth 13 on the core back 11 side is adjusted, and on the stator 2 side, a plurality of teeth 13 have the same pitch. In Embodiment 5, the same components as those in Embodiments 1 to 4 above are given the same reference numerals, and configurations different from those in Embodiments 1 to 4 are mainly explained.

The configuration of the mover 1 of the electric motor 58 is the same as that of the mover 1 in Embodiment 1, except that the mode of tooth pitch adjustment is different. The structure of the stator 2 of the electric motor 58 is the same as that of the stator 2 in Embodiment 1. In Embodiment 5, like Embodiment 1, each tooth 13 of the mover 1 is assigned a tooth number t1, t2, t3, t4, and t5. Each slot of the mover 1 is assigned slot numbers s1-1, s2, s3, s4, s5, and s1-2. To each tooth pitch of the mover 1, tooth pitch numbers p1-1, p2, p3, p4, p5, and p1-2 are assigned.

The arrangement of the coils 14 on the plurality of teeth 13 is the same as in Embodiment 1. As in the case of Embodiment 1, the plurality of teeth 13 of the mover 1 includes a tooth 13 on which only one coil 14 of the three phases is mounted, and a plurality of coils 14 of the three phases. It includes mounted teeth (13). All coils 14 of the mover 1 are formed of conductors of the same diameter.

In Embodiment 5, the tooth pitch at the end on the core back 11 side among the plurality of teeth 13 is adjusted so that the ratio of the total number of turns to the slot area is constant in the plurality of slots of the mover 1. It is adjusted.

Examples of the total number of turns of slots, slot area, and space ratio in Embodiment 5 are the same as those in Embodiment 1 shown in FIG. 5. In FIG. 5, “small” or “large” shown for each tooth pitch of p1, p2, p3, p4, and p5, in Embodiment 5, refers to the core back 11 side among the plurality of teeth 13. Applies to tooth pitch at the end. On the other hand, among the plurality of teeth 13, the tooth pitches at the ends on the stator 2 side are all equal to the average value of the tooth pitches.

In Figure 22, position "a", position "b", position "c", and position "d" represent the center position of each tooth 13 when it is assumed that a plurality of tooth pitches are equal to each other. . Position “a” represents the hypothetical center position of the tooth 13 at t1. The position “b” represents the hypothetical center position of the tooth 13 at t2. The position “c” represents the hypothetical center position of the tooth 13 at t4. The position “d” represents the hypothetical center position of the tooth 13 at t5.

The center position of the end portion on the core back 11 side of the teeth 13 at t2 is on the reference position A side with respect to the position “b”. Among the teeth 13 of t2 and t3 constituting the slot of s3, the tooth pitch of p3, which is the tooth pitch at the end of each tooth 13 on the core back 11 side, is smaller than the average value of the tooth pitch. . Additionally, the center position of the end portion of the teeth 13 at t2 on the stator 2 side coincides with the position “b”. For the teeth 13 of t2 and t3, the tooth pitch at the end of each tooth 13 on the stator 2 side is equal to the average value of the tooth pitch. That is, among the teeth 13 of t2 and t3, the tooth pitch at the end of each tooth 13 on the stator 2 side is larger than the tooth pitch on the core back 11 side.

The center position of the end of the tooth 13 at t1 on the core back 11 side is on the opposite side from the reference position A with respect to the position “a”. Among the teeth 13 of t1 and t2 constituting the slot of s2, the tooth pitch of p2, which is the tooth pitch at the end of each tooth 13 on the core back 11 side, is greater than the average value of the tooth pitch. . Additionally, among the teeth 13 at t1 and t2, the tooth pitch at the end of each tooth 13 on the stator 2 side is equal to the average value of the tooth pitch. That is, among the teeth 13 at t1 and t2, the tooth pitch at the end of each tooth 13 on the stator 2 side is smaller than the tooth pitch on the core back 11 side.

As with the slots s2 and s3, in the slots s1, s4, and s5, the tooth pitches of p1, p4, and p5, which are the tooth pitches at the ends of the teeth 13 on the core back 11 side, are It is adjusted. As with each slot of s2 and s3, also in each slot of s1, s4, and s5, the tooth pitch at the end of each tooth 13 on the stator 2 side is equal to the average value of the tooth pitch.

In Embodiment 5, each slot of s2 and s5 is the first slot. Each slot of s1, s3, and s4 is a second slot. In Embodiment 5, among the teeth 13 constituting the first slot, the tooth pitch at the end on the core back 11 side among the teeth 13 is larger than the average value of the tooth pitch, and the teeth ( 13) The tooth pitch at the end on the field side is smaller than the tooth pitch on the core back 11 side. In addition, among the teeth 13 constituting the second slot, the tooth pitch at the end on the core back 11 side among the teeth 13 is smaller than the average value of the tooth pitch, and the tooth pitch between the teeth 13 is smaller than the average value of the tooth pitch. The tooth pitch at the end on the field side of each is larger than the tooth pitch on the core back 11 side. As a result, the ratio of the total number of turns to the slot area becomes constant for all of the plurality of slots.

The wire diameters of all coils 14 mounted on the plurality of teeth 13 are the same, and the ratio of the total number of turns to the slot area is constant in all the plurality of slots, so that the coils in each of the plurality of slots The spot rate in (14) becomes constant. By keeping the space ratio of each slot of s1, s2, s3, s4, and s5 constant, the electric motor 58 can reduce the variation in resistance in the plurality of slots and reduce the resistance of all the plurality of slots. Additionally, the electric motor 58 can increase the average value of the space factor in a plurality of slots. The electric motor 58 can enlarge the wire diameter of the coil 14, thereby reducing resistance.

The tooth pitch of the end portion of each tooth 13 on the core back 11 side satisfies the above equation (1). As a result, the space ratio for each slot becomes equal. Alternatively, the tooth pitch of the end portion of each tooth 13 on the core back 11 side satisfies the above equations (2) and (3). This makes it possible to adjust the tooth pitch to reduce resistance even when the space factor changes due to the structure of the mover 1.

The arrangement of the coils 14 in the plurality of teeth 13 may be the same as the case in which the phase order in the moving direction of the mover 1 is shown in FIG. 22. If the order of the phases is the same as in the case shown in FIG. 22, the phase located at the end in the traveling direction may be any phase. Additionally, the arrangement of the coils 14 in the plurality of teeth 13 may be similar to the arrangement in Embodiments 2 to 4.

The mover 1 may have two or more units, with the units P = 4, N = 5, and C = 1. In other words, C may be a natural number greater than 1. The electric motor 58 can achieve the same effect as when C is 1 even when C is a natural number greater than 1.

The electric motor 58 may have a configuration in which a plurality of permanent magnets 21 are embedded within the stator core. The electric motor 58 can achieve the same effect even when the plurality of permanent magnets 21 are embedded inside the stator core as when the plurality of permanent magnets 21 are provided on the surface of the stator core.

According to Embodiment 5, the tooth pitch at the end of the teeth 13 on the core back 11 side of the electric motor 58 is adjusted, so that the ratio of the total number of turns of the coil 14 to the slot area is plural. It is constant in the slots of . That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 13 is constant. The electric motor 58 can reduce the resistance of the coil 14 in each slot by maintaining a constant space factor in each of the plurality of slots. Thereby, the electric motor 58 achieves the effect of being able to reduce the amount of heat generated by the coil 14.

Embodiment 6.

Figure 23 is a cross-sectional view of the electric motor 59 according to Embodiment 6. In Embodiment 6, the thickness of the core back 11 in the second direction is adjusted for each slot. In Embodiment 6, the same components as those in Embodiments 1 to 5 above are given the same reference numerals, and configurations different from those in Embodiments 1 to 5 are mainly explained. In the following description, the thickness of the core back 11 refers to the thickness of the core back 11 in the second direction. The end of the core back 11 is a surface of the end of the core back 11 on the stator 2 side, and is a surface that forms a slot together with the surface of the teeth 13.

The configuration of the mover 1 of the electric motor 59 is the same as that of the mover 1 in Embodiment 1, except that the thickness of the core back 11 is adjusted in place of the tooth pitch. The structure of the stator 2 of the electric motor 59 is the same as that of the stator 2 in Embodiment 1. In Embodiment 6, like Embodiment 1, each tooth 13 of the mover 1 is assigned a tooth number t1, t2, t3, t4, and t5. Each slot of the mover 1 is assigned slot numbers s1-1, s2, s3, s4, s5, and s1-2.

The arrangement of the coils 14 on the plurality of teeth 13 is the same as in Embodiment 1. As in the case of Embodiment 1, the plurality of teeth 13 of the mover 1 includes a tooth 13 on which only one coil 14 of the three phases is mounted, and a plurality of coils 14 of the three phases. It includes mounted teeth (13). All coils 14 of the mover 1 are formed by conductors of the same diameter.

In Embodiment 6, the thickness of the core back 11 is adjusted for each slot so that the ratio of the total number of turns to the slot area is constant in the plurality of slots of the mover 1. In addition, examples of the total number of turns of slots, slot area, and space ratio in Embodiment 6 are the same as those in Embodiment 1 shown in FIG. 5.

In FIG. 23, the position “f” represents the position of the end of the core back 11 when the thickness of the core back 11 is equal to the average value of the thickness of the core back 11. Position “e” is a position on the opposite side to the stator 2 with respect to position “f”. Among the core backs 11, the thickness of the portion where the end of the core back 11 is at position “e” is smaller than the average value of the thickness of the core backs 11. Position “g” is a position on the stator 2 side with respect to position “f”. Among the core backs 11, the thickness of the portion where the end of the core back 11 is at position “g” is greater than the average value of the thickness of the core backs 11.

In Embodiment 6, each slot of s2 and s5 is the first slot. That is, as shown in Fig. 5, the total number of turns in each slot of s2 and s5 is greater than the average value of the total number of turns in each of the plurality of slots. In each slot of s2 and s5, the position of the end of the core back 11 is position “e”. As a result, in each slot of s2 and s5, the slot area is adjusted to be larger than the average value of the slot area.

In Embodiment 6, each slot of s1, s3, and s4 is a second slot. That is, as shown in Fig. 5, the total number of turns in each slot of s1, s3, and s4 is smaller than the average value of the total number of turns in each of the plurality of slots. In each slot of s1, s3, and s4, the position of the end of the core bag 11 is position “g”. As a result, in each slot of s1, s3, and s4, the slot area is adjusted to be smaller than the average value of the slot area.

In this way, in Embodiment 6, in the first slot, the thickness of the core back 11 is smaller than the average value of the thickness of the entire core back 11, and in the second slot, in the second direction. The thickness of the core back 11 is greater than the average value of the thickness of the entire core back 11. As a result, the ratio of the total number of turns to the slot area becomes constant for all of the plurality of slots.

Additionally, the fact that the ratio is constant in a plurality of slots is not limited to the case where the ratio is completely the same in the plurality of slots. The fact that the ratio is constant in a plurality of slots means that, similar to the adjustment of the tooth pitch in Embodiment 1, the thickness of the core back 11 is adjusted in consideration of the case where the space ratio changes due to the structure of the mover 1. This shall include cases of adjustment.

The wire diameters of all coils 14 mounted on the plurality of teeth 13 are the same, and the ratio of the total number of turns to the slot area is constant in all the plurality of slots, so that the coils in each of the plurality of slots The spot rate in (14) becomes constant. By keeping the space ratio of each slot of s1, s2, s3, s4, and s5 constant, the electric motor 59 can reduce the variation in resistance in the plurality of slots and reduce the resistance of all the plurality of slots. Additionally, the electric motor 59 can increase the average value of the space factor in a plurality of slots. The electric motor 59 can enlarge the wire diameter of the coil 14, thereby reducing resistance.

The arrangement of the coils 14 in the plurality of teeth 13 may be the same as the case in which the phase order in the moving direction of the mover 1 is shown in FIG. 23. If the order of the phases is the same as in the case shown in FIG. 23, the phase located at the end in the traveling direction may be any phase. Additionally, the arrangement of the coils 14 in the plurality of teeth 13 may be similar to the arrangement in Embodiments 2 to 4.

The mover 1 may have two or more units, with the units P = 4, N = 5, and C = 1. In other words, C may be a natural number greater than 1. The electric motor 59 can achieve the same effect as when C is 1 even when C is a natural number greater than 1.

The electric motor 59 may have a configuration in which a plurality of permanent magnets 21 are embedded within the stator core. The electric motor 59 can achieve the same effect even when the plurality of permanent magnets 21 are embedded inside the stator core as when the plurality of permanent magnets 21 are provided on the surface of the stator core.

According to Embodiment 6, the thickness of the core back 11 of the electric motor 59 is adjusted for each slot, so that the ratio of the total number of turns of the coil 14 to the slot area is constant in a plurality of slots. That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 13 is constant. The electric motor 59 can reduce the resistance of the coil 14 in each slot by maintaining a constant space factor in each of the plurality of slots. Thereby, the electric motor 59 achieves the effect of being able to reduce the amount of heat generated by the coil 14.

Embodiment 7.

Figure 24 is a cross-sectional view of the electric motor 60 according to Embodiment 7. In Embodiment 7, the width of each of the plurality of teeth 13 in the first direction is adjusted. In Embodiment 7, the same components as those in Embodiments 1 to 6 above are given the same reference numerals, and configurations different from those in Embodiments 1 to 6 are mainly explained. In the following description, the width of the teeth 13 refers to the width of the teeth 13 in the first direction.

The configuration of the mover 1 of the electric motor 60 is the same as that of the mover 1 in Embodiment 1, except that the width of the teeth 13 is adjusted in place of the tooth pitch. The structure of the stator 2 of the electric motor 60 is the same as that of the stator 2 in Embodiment 1. In Embodiment 7, like Embodiment 1, each tooth 13 of the mover 1 is assigned a tooth number t1, t2, t3, t4, and t5. Each slot of the mover 1 is assigned slot numbers s1-1, s2, s3, s4, s5, and s1-2.

The arrangement of the coils 14 on the plurality of teeth 13 is the same as in Embodiment 1. As in the case of Embodiment 1, the plurality of teeth 13 of the mover 1 includes a tooth 13 on which only one coil 14 of the three phases is mounted, and a plurality of coils 14 of the three phases. It includes mounted teeth (13). All coils 14 of the mover 1 are formed of conductors of the same diameter.

In Embodiment 7, the example of the number of turns of coil 14 mounted on each tooth 13 is the same as that of Embodiment 1 shown in FIG. 3. The total number of turns in each tooth 13 at t2 and t4 is greater than the average value of the total number of turns in each of the plurality of teeth 13. On the other hand, the total number of turns in each tooth 13 of t1, t3, and t5 is smaller than the average value of the total number of turns in each of the plurality of teeth 13. Hereinafter, the tooth 13 having a larger number of turns than the average number of turns of the coil 14 in the plurality of teeth 13 is referred to as the first tooth, and the tooth 13 has a number of turns greater than the average number of turns of the coil 14 in the plurality of teeth 13. The teeth 13 with the smaller number of turns are called the second teeth. Each tooth 13 of t2 and t4 is the first tooth. Each tooth 13 of t1, t3, and t5 is the second tooth.

In Fig. 24, w1 is the width of each tooth 13, t2 and t4, which are the first teeth. w2 is the width of each tooth 13 of the second teeth t1, t3, and t5. w1>w2 is established. That is, in the electric motor 60, the width of the first teeth is larger than the width of the second teeth. In Embodiment 7, by adjusting the width of each tooth 13 in this way, the ratio of the total number of turns to the slot area becomes constant for all of the plurality of slots.

Additionally, the fact that the ratio is constant in a plurality of slots is not limited to the case where the ratio is completely the same in the plurality of slots. The fact that the ratio is constant in a plurality of slots means that, similar to the adjustment of the tooth pitch in Embodiment 1, the width of the teeth 13 is adjusted in consideration of the case where the space ratio changes due to the structure of the mover 1. This shall include cases where this is possible.

The wire diameters of all coils 14 mounted on the plurality of teeth 13 are the same, and the ratio of the total number of turns to the slot area is constant in all the plurality of slots, so that the coils in each of the plurality of slots The spot rate in (14) becomes constant. By keeping the space ratio of each slot of s1, s2, s3, s4, and s5 constant, the electric motor 60 can reduce the variation in resistance in the plurality of slots and reduce the resistance of all the plurality of slots. Additionally, the electric motor 60 can increase the average value of the space factor in a plurality of slots. The electric motor 60 can enlarge the wire diameter of the coil 14, thereby reducing resistance.

The arrangement of the coils 14 in the plurality of teeth 13 may be the same as the case in which the phase order in the moving direction of the mover 1 is shown in FIG. 24. If the order of the phases is the same as in the case shown in FIG. 24, the phase located at the end in the traveling direction may be any phase. Additionally, the arrangement of the coils 14 in the plurality of teeth 13 may be similar to the arrangement in Embodiments 2 to 4.

The mover 1 may have two or more units, with the units P = 4, N = 5, and C = 1. In other words, C may be a natural number greater than 1. The electric motor 60 can achieve the same effect as when C is 1 even when C is a natural number greater than 1.

The electric motor 60 may have a configuration in which a plurality of permanent magnets 21 are embedded within the stator core. The electric motor 60 can achieve the same effect even when the plurality of permanent magnets 21 are embedded inside the stator core as when the plurality of permanent magnets 21 are provided on the surface of the stator core.

According to Embodiment 7, the width of each tooth 13 of the electric motor 60 is adjusted so that the width of the first tooth is larger than the width of the second tooth, so that the total number of turns of the coil 14 relative to the slot area is adjusted. The ratio is constant in a plurality of slots. That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 13 is constant. The electric motor 60 can reduce the resistance of the coil 14 in each slot by maintaining a constant space factor in each of the plurality of slots. Thereby, the electric motor 60 achieves the effect of being able to reduce the amount of heat generated by the coil 14.

Embodiment 8.

Figure 25 is a cross-sectional view of the electric motor 61 according to Embodiment 8. The electric motor 61 according to Embodiment 8 is a rotating electric motor. In Embodiment 8, the same components as those in Embodiments 1 to 7 above are given the same reference numerals, and configurations different from those in Embodiments 1 to 7 are mainly explained.

The electric motor 61 has a stator 3 and a rotor 4. The stator (3) is a ring-shaped structure surrounding the rotor (4). The stator (3) is arranged facing the rotor (4). The rotor (4) is a field. The stator (3) is an armature to obtain driving force through interaction with the field. The rotor (4) is rotatable with respect to the stator (3). The electric motor 61 rotates the rotor 4.

The rotor 4 has a shaft 41 and a plurality of permanent magnets 42 fixed to the surface of the shaft 41. In Embodiment 8, the rotor 4 has four permanent magnets 42. The four permanent magnets 42 are arranged in the rotation direction of the rotor 4, that is, in the circumferential direction.

The stator 3 has a stator core and a plurality of coils 33 mounted on the stator core. The stator iron core has a ring-shaped core back 31 forming the outer edge of the stator 3, and a plurality of teeth 32 extending from the core back 31 toward the rotor 4. Each tooth 32 extends in the radial direction of the stator 3. In Embodiment 8, the rotor 4 has five teeth 32. Five teeth 32 are arranged in a circumferential direction. At the distal end of each tooth 32 on the field side, a protrusion facing in the direction of rotation is formed. Each coil 33 is constructed by intensively winding conductive wire around teeth 32. The slot where the coil 33 is disposed is adjacent to the tooth 32 in the circumferential direction. Teeth 32 that are adjacent to each other form a slot.

In Embodiment 8, a tooth number is assigned to each tooth 32 of the stator 3 for convenience. To each tooth 32, tooth numbers t1, t2, t3, t4, and t5 are assigned clockwise from a certain position of the tooth 32 in FIG. 25, respectively. Additionally, a slot number is assigned to each slot of the stator 3 for convenience. Each slot is assigned slot numbers s1, s2, s3, s4, and s5, respectively, clockwise from t1 and the neighboring slot.

The tooth pitch in the stator 3 is the length in the first direction, which is the direction in which the plurality of teeth 32 are aligned. The first direction is also the circumferential direction. In Embodiment 8, a tooth pitch number is assigned to each tooth pitch of the plurality of teeth 32 for convenience. To each tooth pitch, tooth pitch numbers p1, p2, p3, p4, and p5 are assigned clockwise from the tooth pitch of the teeth 32 of t5 and t1, respectively.

A voltage is applied to the stator 3 from a three-phase alternating current power supply. The illustration of three-phase AC power is omitted. The arrangement of the coils 33 in the plurality of teeth 32 is the same as the arrangement of the coils 14 in the plurality of teeth 13 in Embodiment 1. The plurality of teeth 32 of the stator 3 includes a tooth 32 on which only the coil 33 of one of the three phases is mounted, and a tooth 32 on which the coils 33 of a plurality of the three phases are mounted. do. All coils 33 of the stator 3 are formed by conductors of the same diameter.

Figure 26 is a cross-sectional view of the electric motor 62 according to the comparative example of Embodiment 8. The stator 3 of the electric motor 62 has a region 34 where the coil 33 is not disposed. In Embodiment 8 and the comparative example of Embodiment 8, examples of the total number of turns of slots, slot area, and space ratio are the same as those of Embodiment 1 shown in FIG. 5. The slot area is the area of the slot in the cross section including the first direction and the second direction. The second direction is the radial direction. The second direction is a direction in which the stator 3 and the rotor 4 face each other, and is also a direction perpendicular to the surface on which the plurality of permanent magnets 42 are arranged. The cross section shown in FIG. 25 and the cross section shown in FIG. 26 are cross sections including the first direction and the second direction.

In the electric motor 62 according to the comparative example, like the comparative example of Embodiment 1, the slot areas of each slot of s1, s2, s3, s4, and s5 are all the same. In addition, in the electric motor 62, like the comparative example of Embodiment 1, each tooth pitch of p1, p2, p3, p4, and p5 is equal to the average value of a plurality of tooth pitches. In the electric motor 62, the slot area of each slot is the same, but the total number of turns is different for each slot, so there is variation in the space ratio of each slot. For this reason, the resistance of the coil 33 in the electric motor 62 increases.

Next, details of the electric motor 61 according to Embodiment 8 will be described. In Embodiment 8, the tooth pitch of each tooth 32 is adjusted so that the ratio of the total number of turns to the slot area is constant in the plurality of slots of the stator 3. That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 32 is constant.

In Figure 25, position "a", position "b", position "c", and position "d" represent the center position of each tooth 32 when it is assumed that a plurality of tooth pitches are equal to each other. . Position “a” represents the hypothetical center position of the tooth 32 at t1. The position “b” represents the hypothetical center position of the tooth 32 at t2. The position “c” represents the hypothetical center position of the tooth 32 at t4. The position “d” represents the hypothetical center position of the tooth 32 at t5. In addition, the center position refers to the center position in the circumferential direction.

In Embodiment 8, each slot of s2 and s5 is the first slot. That is, as shown in Fig. 5, the total number of turns in each slot of s2 and s5 is greater than the average value of the total number of turns in each of the plurality of slots. The center position of the tooth 32 at t1 is shifted counterclockwise from position “a”, and the center position of the tooth 32 at t2 is shifted clockwise from position “b”. As a result, the slot area of s2 is adjusted to be larger than the average value of the slot area. The center position of the tooth 32 at t4 is shifted counterclockwise from the position “c”, and the center position of the tooth 32 at t5 is shifted clockwise from the position “d”. As a result, the slot area of s5 is adjusted to be larger than the average value of the slot area.

In Embodiment 8, each slot of s1, s3, and s4 is a second slot. That is, as shown in Fig. 5, the total number of turns in each slot of s1, s3, and s4 is smaller than the average value of the total number of turns in each of the plurality of slots. By shifting the center position of each tooth 32, the slot areas of s1, s3, and s4 are adjusted to be smaller than the average value of the slot areas.

In Embodiment 8, among the teeth 32 constituting the first slot, the tooth pitch is greater than the average value of the tooth pitches in a plurality of slots. Additionally, among the teeth 32 constituting the second slot, the tooth pitch is smaller than the average value of the tooth pitches in a plurality of slots. As a result, the ratio of the total number of turns to the slot area becomes constant for all of the plurality of slots.

The wire diameters of all coils 33 mounted on the plurality of teeth 32 are the same, and the ratio of the total number of turns to the slot area is constant in all of the plurality of slots, so that the coils in each of the plurality of slots The spot rate in (33) becomes constant. By keeping the space ratio of each slot of s1, s2, s3, s4, and s5 constant, the electric motor 61 can reduce the variation in resistance in the plurality of slots and reduce the resistance of all the plurality of slots.

In Embodiment 8, the slot area is small in slots where the total number of turns is less than the average value, and the slot area is large in slots where the total number of turns is more than the average value, so that the space ratio of each slot is constant. By adjusting the space factor of each slot in this way, the electric motor 61 can increase the average value of the space factors in a plurality of slots compared to the case of the comparative example. In the electric motor 61, the wire diameter of the coil 33 can be enlarged compared to the case of the comparative example, and the resistance can be reduced.

The electric motor 61, like the electric motor 50 according to Embodiment 1, satisfies the above equation (1). As a result, the space ratio for each slot becomes equal. Alternatively, the electric motor 61, like the electric motor 50 according to Embodiment 1, satisfies the above equations (2) and (3). This makes it possible to adjust the tooth pitch to reduce resistance even when the space factor changes due to the structure of the stator 3.

The configuration of the stator 3 in Embodiment 8 is an application of the configuration of the mover 1 in Embodiment 1. The structure of the stator 3 may be an application of not only the structure of the mover 1 in Embodiment 1 but also the structure of each mover 1 in Embodiments 2 to 7.

The stator 3 may have two or more units, with P = 4, N = 5, and C = 1 as units. In other words, C may be a natural number greater than 1. The electric motor 61 can achieve the same effect as when C is 1 even when C is a natural number greater than 1.

The teeth 32 are not limited to those with protrusions formed on the distal end on the field side. A depression may be formed in the distal end of the tooth 32 on the field side. The tip of the teeth 32 on the field side may be straight. The electric motor 61 can achieve the same effect even when a depression is formed or when the tip is straight, as when a protrusion is formed.

According to Embodiment 8, the tooth pitch of the plurality of teeth 32 of the electric motor 61 is adjusted so that the ratio of the total number of turns of the coil 33 to the slot area is constant in the plurality of slots. That is, the space ratio in each of the plurality of slots formed by the plurality of teeth 32 is constant. The electric motor 61 can reduce the resistance of the coil 33 in each slot by maintaining a constant space factor in each of the plurality of slots. Thereby, the electric motor 61 achieves the effect of being able to reduce the amount of heat generated by the coil 33.

The configuration shown in each embodiment above represents an example of the present disclosure. The configuration of each embodiment can be combined with other known technologies. The components of each embodiment may be appropriately combined. It is possible to omit or change part of the configuration of each embodiment without departing from the gist of the present disclosure.

1: mover 2, 3: stator
4: rotor 11, 31: core back
12, 34: Area 13, 32: Tees
14, 33: coil 21, 42: permanent magnet
22: Mounting seat 41: Shaft
50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62: Electric motor

Claims (7)

Gyejawa,
Equipped with an armature arranged to face the field,
The armature has a core back, a plurality of teeth extending from the core back toward the field, and a three-phase coil mounted on the plurality of teeth,
The plurality of teeth includes the teeth on which only the coil of one of three phases is mounted, and the teeth on which the coils of a plurality of phases among the three phases are mounted,
The adjacent teeth constitute a slot in which the coil is placed,
The number of teeth in the armature is an integer other than a multiple of 3,
The plurality of slots included in the armature include slots with a total number of turns greater than the average of the total number of turns of the coil in each of the plurality of slots, and those with a total number of turns greater than the average of the total number of turns in each of the plurality of slots. Contains a small said slot,
The area ratio representing the ratio of the cross-sectional area of the coil to the area of the slot in the cross-section including the first direction in which the plurality of teeth are lined up and the second direction in which the field and the armature face each other is defined as a plurality of areas. is constant in each of the plurality of slots formed by the teeth,
For the teeth constituting the first slot, which is the slot whose total number of turns is greater than the average value of the total number of turns of the coil in each of the plurality of slots, the tooth pitch, which is the length between the center positions of the teeth, is: greater than the average value of the tooth pitch in a plurality of the slots,
In the teeth constituting the second slot, which is the slot whose total number of turns is smaller than the average value of the total number of turns in each of the plurality of slots, the tooth pitch is equal to the tooth pitch in the plurality of slots. An electric motor characterized by a smaller than average value. In claim 1,
The average value of the total number of turns in each of the plurality of slots is Na, the total number of turns in the first slot is Ns1, the total number of turns in the second slot is Ns2, and the average value of the tooth pitch in the plurality of teeth. Let's call it La,
L1, which is the tooth pitch between the teeth constituting the first slot, satisfies La<L1≤(Ns1/Na)×1.2×La,
An electric motor characterized in that L2, which is the tooth pitch between the teeth constituting the second slot, satisfies La>L2≥(Ns2/Na)×0.8×La. In claim 1,
In the teeth constituting the first slot, the tooth pitch at the end on the core back side among the teeth is greater than the average value of the tooth pitch, and the tooth pitch at the end on the field side among the teeth is larger than the average value of the tooth pitch. The tooth pitch is smaller than the tooth pitch on the core back side,
In the teeth constituting the second slot, the tooth pitch at the end on the core back side among the teeth is smaller than the average value of the tooth pitch, and the tooth pitch at the end on the field side among the teeth is smaller than the average value of the tooth pitch. An electric motor characterized in that the tooth pitch in the core is larger than the tooth pitch on the core back side. Gyejawa,
Equipped with an armature arranged to face the field,
The armature has a core back, a plurality of teeth extending from the core back toward the field, and a three-phase coil mounted on the plurality of teeth,
The plurality of teeth includes the teeth on which only the coil of one of three phases is mounted, and the teeth on which the coils of a plurality of phases among the three phases are mounted,
The adjacent teeth constitute a slot in which the coil is placed,
The number of teeth in the armature is an integer other than a multiple of 3,
The plurality of slots included in the armature include slots with a total number of turns greater than the average of the total number of turns of the coil in each of the plurality of slots, and those with a total number of turns greater than the average of the total number of turns in each of the plurality of slots. Contains a small said slot,
The area ratio representing the ratio of the cross-sectional area of the coil to the area of the slot in the cross-section including the first direction in which the plurality of teeth are lined up and the second direction in which the field and the armature face each other is defined as a plurality of areas. is constant in each of the plurality of slots formed by the teeth,
In the first slot, which is the slot where the total number of turns is greater than the average value of the total number of turns of the coil in each of the plurality of slots, the thickness of the core back in the second direction is the thickness of the entire core back. is smaller than the average value of
In the second slot, which is the slot where the total number of turns is smaller than the average value of the total number of turns in each of the plurality of slots, the thickness of the core back in the second direction is the average value of the thickness of the entire core back. An electric motor characterized by a larger size. Gyejawa,
Equipped with an armature arranged to face the field,
The armature has a core back, a plurality of teeth extending from the core back toward the field, and a three-phase coil mounted on the plurality of teeth,
The plurality of teeth includes the teeth on which only the coil of one of three phases is mounted, and the teeth on which the coils of a plurality of phases among the three phases are mounted,
The adjacent teeth constitute a slot in which the coil is placed,
The number of teeth in the armature is an integer other than a multiple of 3,
The plurality of slots included in the armature include slots with a total number of turns greater than the average of the total number of turns of the coil in each of the plurality of slots, and those with a total number of turns greater than the average of the total number of turns in each of the plurality of slots. Contains a small said slot,
The area ratio representing the ratio of the cross-sectional area of the coil to the area of the slot in the cross-section including the first direction in which the plurality of teeth are lined up and the second direction in which the field and the armature face each other is defined as a plurality of areas. is constant in each of the plurality of slots formed by the teeth,
The plurality of teeth includes a first tooth, which is the tooth whose number of turns is larger than the average value of the number of turns of the coil in the plurality of teeth, and wherein the number of turns is smaller than the average value of the number of turns of the coil in the plurality of teeth. It includes a second tis, which is tis,
An electric motor characterized in that the width of the first tooth in the first direction is larger than the width of the second tooth in the first direction. The method according to any one of claims 1 to 5,
An electric motor, characterized in that all of the coils mounted on the plurality of teeth have the same wire diameter. delete

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