JPS63171155A - Rectilinear electric machine - Google Patents

Abstract

PURPOSE:To reduce the cogging force while the decrease of effective flux and drop in efficiency are prevented, by partially widening the surface area of the region facing the field of armature. CONSTITUTION:An armature 12 has three salient poles 121a-121c arranged to face the field 11 in the limits of a pair of poles, N-and S-poles in field 11, and also has grooves for winding 123a-123c between these salient poles 121a-121c respectively. To each salient pole 121a-121c protrusions 122a-122c are formed which protrude in the direction orthogonal to the rectilinear moving direction. The surface area of a part of the surface facing the field 11 of each salient pole 121a-121c is thereby set wider than other regions. The cogging force produced in the grooves for winding 123a-123c is set off by the cogging force produced in this region.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a linear electric machine with reduced cogging force.

(Prior art) In a linear electric machine with a salient pole structure, the armature core has a magnetically non-uniform structure due to the formation of winding grooves, so there is a problem with the field part consisting of permanent magnets etc. There is a problem in that a cogging force is generated due to the interaction, and smooth straight movement of the mover is impaired.

Therefore, in the past, protrusions or dummy slots for reducing cogging were provided at the portions of the salient poles of the armature that faced the field.

FIG. 7 shows an example of the above-mentioned conventional linear electric machine, in which reference numeral 1 denotes a field consisting of flat permanent magnets magnetized to even-numbered poles, 2 an armature, and a salient pole 2a and these A groove 2b for winding is provided between the salient poles 2a. A protrusion 2b is provided at a portion of each salient pole 2a of the armature 2 facing the field 1 so as to protrude toward the field 1 side and is provided in a direction parallel to the winding groove 2C. The cogging force generated by the protrusions 2b is offset by the cogging force generated by each protrusion 2b.

FIG. 8 shows another example of a conventional linear electric machine,
Reference numeral 5 is a field, and 6 is an armature. The armature 6 has salient poles 6a arranged to face the field 1 and a winding groove 60.

A plurality of dummy slots 6b are formed in the portion of each salient pole 6a facing the field 1 in a direction parallel to the winding groove 60, so as to offset the cogging force generated by the winding groove 6C. .

(Problems to be Solved by the Invention) In conventional linear electric machines, the height of the protrusion provided on the salient pole of the armature needs to be high enough to offset the cogging force due to the winding groove. Alternatively, the depth of the dummy slot formed in the salient pole of the armature needs to be deep enough to offset the cogging force due to the winding groove. As a result, the gap between the salient poles and the field becomes larger as a whole, resulting in a decrease in effective magnetic flux and lower efficiency. In other words, effective magnetic flux and efficiency were sacrificed in order to prevent cogging. In addition, the winding space becomes smaller because it is necessary to move the entire final part closer to the armature body by the amount of the protrusion or dummy slot, and the winding jig has to have a complicated shape to form the protrusion. There's a problem.

The present invention has been made to solve these conventional problems, and is capable of reducing cogging force while preventing a decrease in effective magnetic flux and efficiency, and also prevents the winding space from becoming smaller. The purpose is to provide a linear electric machine that can

(Means for Solving the Problems) The present invention comprises a field magnetized to an even number of poles, and an armature having a winding groove and a salient pole arranged opposite to the field magnet. In a linear electric machine in which one of the field and the armature is moved in a straight line relative to the other, the magnetic pole pitch or this is the part of the armature that faces the field and is relative to the position of the winding groove. The present invention is characterized in that the surface area of the salient pole at a portion shifted by an integer multiple or the magnetic pole pitch with respect to the position of the winding groove or a plurality of locations shifted by an integer multiple is made larger than other portions of the salient pole.

(Function) The cogging force generated by the magnetic pole pitch or a portion shifted by an integral multiple of this with respect to the position of the winding groove is larger than the cogging force generated by other portions of the salient pole, and this cogging force and the armature winding The cogging force generated by the irrigation groove is canceled out.

(Example) Hereinafter, an example of a linear electric machine according to the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, reference numeral 11 is a field made of a flat permanent magnet magnetized with even number of poles in the longitudinal direction, and 12 is an armature. The armature 12 has three salient poles 121a, 121b, and 121c arranged opposite to the field 11 within the range of a pair of magnetic poles, the N pole and the S pole of the field 11, and a winding wire between these salient poles. It has grooves 123a, 123b, and 123c. Either one of the field 11 and the armature 12 can move linearly relative to the other in the longitudinal direction of the field 11, that is, in the arrangement direction of each salient pole of the armature I2. Fourth
The figure shows the entire embodiment, in which the armature 12 is fixed and the field 11 is moved linearly in the longitudinal direction of the armature 12. The field 11 is guided by guide rollers 13 and moves in a straight line.

Each of the salient poles 121a, 121b, and 121c of the armature 12 has a protrusion 122a that protrudes on both sides, that is, in a direction perpendicular to the rectilinear movement direction, at the longitudinal center of each of the salient poles.
By forming 122b and 122c, the surface area of a part of the surface of each salient pole facing the field 11 is larger than that of other parts of the salient pole. As shown in FIG. 3(a), when the magnetic pole pitch of the field 11 is P, each protrusion 122a of each of the salient poles 121a, 121b, and 121c is
.

122b and 122c are the respective winding grooves 123a and 12
3b and 123c are provided at positions shifted by the magnetic pole pitch P. To explain more specifically, the protrusion 122c corresponds to the winding groove 123a, and the protrusion 122c corresponds to the winding groove 123a.
The protrusion corresponding to 3b is 122a, and the protrusion corresponding to the winding groove 123c is 122b, and the surface area of the salient pole at the portion where these protrusions are formed is larger than the surface area of other parts of the salient pole. .

According to the above embodiment, each protrusion 122a among the salient poles 121a, 121b, and 121c facing the field 11 of the armature 12.

The cogging force generated in the portion where the surface area is expanded by forming the salient poles 121a, 121b,
It becomes larger than the cogging force generated in other parts of 121c.

The protrusions 122a, 122b, and 122C are provided at positions shifted by the magnetic pole pitch P from the positions of the winding grooves 123a, 123b, and 123c, so that the surface area is expanded by forming the protrusions. The cogging force generated in each winding groove 123a, 123b, 123
The cogging forces generated by c are opposite to each other and cancel each other out, thereby reducing the cogging forces.

Further, according to the above embodiment, there is no need to provide a protrusion protruding toward the field side on the surface of each salient pole facing the field, and there is no need to provide a dummy slot. It will not retreat to the armature body side. Therefore, the winding space is not limited, and cogging force can be reduced while preventing a decrease in efficiency.

The part of the armature 12 that faces the field 11 and should have a large surface area, that is, the protrusion 122a in the above embodiment.
, 122b, 122C forming portions should basically be made the same as the width of the winding grooves 123a, 123b, 123C, but cogging can be prevented even if the phase of the protrusion and the winding groove is slightly shifted. To be effective, the width of the protrusion may be about 0.4 to 2.5 times the width of the winding groove.

The surface shape of the armature for partially widening the surface area of the portion of the armature facing the field is not limited to the shape of the above embodiment, but may be of the shape shown in FIGS. 3(b), (C), and (d). It may be modified as follows. (b) is a shape in which a part of the salient pole of the armature is protruded only on one side in the width direction, (C) is a shape in which the longitudinal middle part of the salient pole that is part in the width direction is connected by a protrusion, (
d) is a shape in which the longitudinal intermediate portions of salient poles that are separated in the width direction are connected by a protrusion, and a portion of the salient pole is made to protrude only on one side in the width direction. In order to obtain armatures of various shapes, cores of different lengths may be combined and laminated, or a core and a yoke plate with a protrusion may be combined.

Next, another embodiment of the present invention will be described. In FIG. 5, numeral 21 is a field magnetized to even-numbered poles, and 22 is an armature. The armature 22 has three salient poles 221a, 221b,
221c and winding grooves 233a, 233 between these salient poles.
b.

233c. The three salient poles are located within the range of the four magnetic poles of the field 21.

Field 2 of each of the salient poles 221a, 221b, 221c
1, there are protrusions 222a and 222b that partially extend in the width direction, that is, in a direction orthogonal to the rectilinear movement direction.
, 222c are provided, so that the surface area of that portion is larger than that of the other portions of the salient pole.

Assuming that the magnetic pole pitch of the field 21 is P, the protrusions are provided at positions shifted from the positions of the respective winding grooves by the magnetic pole pitch P and integral multiples thereof, 2P and 3P. That is, in this embodiment, a plurality of portions with large surface areas are provided for one winding groove.

In the case of the above-mentioned embodiment, the cogging force reduction effect is achieved similarly to the case of the above-mentioned embodiment. In the case of this embodiment, there are multiple parts with a large surface area for one winding groove, so
The ratio of the area of the wide portion to the area of the narrow portion can be reduced, and the overall width can be reduced.

FIG. 6 shows various modifications of the armature for providing a plurality of portions with large surface areas for one winding groove. (a) is a shape in which a part of the armature facing the field protrudes only to one side in the width direction, and (b) is a shape in which the part of the armature facing the field is partially protruded in the width direction at multiple locations. Connected shape, (C)
is a shape in which the part of the armature that faces the field is divided in the width direction and connected at a plurality of points, and protrudes only on one side in the width direction. Specific means for obtaining armatures of various shapes as described above can be obtained by combining cores of different lengths or by combining cores and yoke plates.

In addition, the width direction dimension of the part with a wide surface area of the armature is basically twice the size of the other parts of the salient pole if the wide part has the same number as the winding grooves, or the width of the wide part. If the number of the wide portions is twice that of the winding grooves, the dimension is 1.5 times that of the other parts of the salient pole, and if the number of the wide parts is three times the number of the winding grooves, then the dimension of the other parts of the salient pole is 1.5 times that of the other parts of the salient pole. It is preferable to make the size approximately .33 times larger in order to reduce the cogging force. However, the configuration of the magnetic circuit, such as the widthwise dimension of the field, differs from one individual to another, and as mentioned above, the linear dimension of the protrusion to partially widen the armature surface area cannot be uniformly determined. However, since various other design conditions differ from one another, the optimum width and longitudinal dimensions of the large surface area portion of the armature vary depending on the above-mentioned conditions.

In the linear electric machine according to the present invention, any one of the field and the armature may move linearly relative to the other.

(Effects of the Invention) According to the present invention, the surface area of the portion of the armature that faces the field is partially widened, and the cogging force generated in this portion cancels out the cogging force generated in the winding groove. Because of that,
There is no need to provide a protrusion toward the field on the surface of the armature that faces the field, and there is no need to provide a dummy slot 1-, which reduces the cogging force while preventing a decrease in effective magnetic flux and efficiency. It is possible to reduce the Furthermore, since the winding space can be increased, winding is easier and the magnetic force of the armature can be increased. The surface of the armature facing the field can be formed flat without any protrusions.
The shape of the winding jig can be simplified.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment of the linear electric machine according to the present invention, Fig. 2 is a front view of the armature in the above embodiment as seen from the field side, and Fig. 3 is applicable to the above embodiment. 4 is a perspective view of the above-mentioned embodiment, and FIG. 5 is a diagram showing the relationship between the field and the armature showing another embodiment of the linear electric machine according to the present invention. Fig. 6 is a front view showing various modifications of the armature applicable to the above embodiment, Fig. 7 is a front view showing an example of a conventional linear electric machine, and Fig. 8 is a front view showing another example of a conventional linear electric machine. FIG. 11.21...field, 12.22...armature, 121
a, 121b, 121c, 221a, 221b, 22
1c = salient pole, 123a, 123b, 123c, 223
a, 223b, 223c... Grooves for winding.

Claims (1)

[Claims] It is equipped with a field magnetized to an even number of poles, and an armature having a winding groove and salient poles arranged opposite to the field, and one of the field and the armature is connected to the other. In a linear electric machine that moves in a straight line with respect to, a part of the armature that faces the field and is shifted from the magnetic pole pitch or an integral multiple of this position with respect to the position of the above-mentioned winding groove, or with respect to the position of the above-mentioned winding groove. A linear electric machine characterized in that the surface area of the salient pole at a plurality of portions shifted from the magnetic pole pitch or an integer multiple thereof is larger than other portions of the salient pole.