JPS5827752B2 - straight electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a linear movable motor such as a linear movable motor that can obtain a linear force by supplying power, or a linear movable generator that can obtain an electrical output by applying a linear drive force from the outside. It is related to electrical machinery.

In general, linear machines with grooves in the armature core and armature windings can link more field magnetic flux to the armature core more efficiently than straight machines without grooves. This results in a linear electric machine that is small, lightweight, and can provide high output.

However, when the armature core has grooves for the windings, the armature core has a magnetically non-uniform structure, so cogging force is generated due to interaction with the field part composed of permanent magnets, etc. It has the disadvantage of causing

Furthermore, the magnetization state of the permanent magnet and the salient pole arrangement of the armature core are closely related to cogging force and output ripple, and it is difficult to reduce both at the same time. Ta.

The present invention takes such drawbacks into consideration and provides a linear electric machine that uses an armature core with a salient pole structure having grooves for windings, but simultaneously reduces cogging force and output ripple.

Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of main parts of an embodiment of the present invention.

In the figure, a field section 2 attached to a moving body 1 is composed of a flat permanent magnet having four N poles and S poles alternately arranged at equal or roughly equal pitch intervals. .

The armature core 3 has six winding salient poles 3a1.3b1.3c
1.3a.

+3b2t3c2 and five auxiliary salient poles 4a, 4b, 4c, 4. located between these winding salient poles. d, 4e, and two auxiliary flames 1t5a located at both ends of the armature core 3.
, 5b, and the tips of each winding salient pole and auxiliary salient pole face the magnetic pole surface of the field section 2 with a required gap.

The field part 2 and the armature core 3 are relatively movable, and in this embodiment, the field part 2 moves and the armature core 3 is fixed.

Salient pole for each winding 3 1,3bl j 3CI + 3a2
y3b2 y3 (72 is each wound with one armature winding 6al) 6b1, 6c1, 6b2, 6o2, windings 6ax, 6a2t 6bt j 6b2
j 6c+ 7602 is three-phase Y-connected.

FIG. 2 shows one row of drive circuits of this embodiment.

The relative position between the field part 2 and the armature core 3 is detected by a magneto-electric conversion element such as a Hall element, and the output signal of the drive phase selection means 9 which selects the phase to which current should be applied is used to select the transistor Qa+Qb? Controls QC.

As a result, driving force in a predetermined direction can be obtained.

This relationship will be explained using FIGS. 3 to 6.

Figure 3 shows salient poles for winding 3゜I, 3a2 and auxiliary salient pole 4c.
The distribution of magnetic flux in the vicinity of the winding groove between the two is representatively shown.

In the figure, most of the magnetic flux emitted from the field section 2 is absorbed by the salient poles 3C14C and 3a2 of the armature core 3, avoiding the grooves with high magnetic resistance, as shown by the arrow lines.

As a result, the effective pitch of the salient poles through which magnetic flux flows into and out of the salient poles is wider than the pitch of the tips of the salient poles, and is approximately equal to the distance between the centers of the grooves at both ends of the salient poles.

In this embodiment, each winding salient pole 3a+, 3b+t3
ct t 3a2 , 3t) The center distance between the grooves at both ends of the grooves 213c2 is equal to or approximately equal to 16/15 times the pitch T of one magnetic pole of the field section 2.

Moreover, each auxiliary salient pole 4a, 4b. 4c, 4d, 4e
The center spacing between the grooves at both ends of the groove is equal to or approximately equal to 4/15 times the pitch T of one magnetic pole.

Since the magnetic flux interlinking with the winding 6a2 is equal to the magnetic flux flowing into the winding salient pole 3a2, the effective pitch of the winding 6a2 can be said to be approximately 16T/15.

The same applies to other windings.

Therefore, the relationship between the field portion 2 and the winding 6a□ is, in principle, as shown in the schematic development diagram shown in FIG.

In the figure, the winding 6a2 has an equivalent effective pitch of 16
This is a replacement for the one-turn winding 10 of T/15.

Here, when a current {circle around (2)} flows through the winding 10, a driving force F is generated due to electromagnetic interaction with the field section 2.

Its size is proportional to the current and magnetic flux density according to Fleming's left-hand rule.

In other words, the driving force generated by the energized winding is the force generated by the coil side at one end of the effective pinch of the winding (the product of current and magnetic flux density) and the force generated by the coil at the other end (the product of current and magnetic flux). It is determined by algebraic addition of the density product).

Since the direction of the current is opposite on both coil sides of the winding (see FIG. 4), the driving force is proportional to the product of the current value and the difference between the magnetic flux densities at both ends of the effective pitch of the winding.

In general, the distribution waveform of the magnetic flux density Bx generated by the field section 2 changes into a trapezoidal waveform as shown in Fig. 5, corresponding to the arrangement of the magnetic poles (if the magnetic flux density generated by the north pole is positive), (The magnetic flux density generated by the S pole is negative) Furthermore, the magnetic flux density at a position where no magnetic pole exists in the field section 2 is almost zero.

Since the windings 5a+ and 6a2 are connected in series to form a one-phase winding (see Figure 2), the winding 6al of this phase
, 5a2 is proportional to the composite magnetic flux density difference obtained by algebraically adding the difference in magnetic flux density at both ends of the effective pitch of 6al and the difference in the magnetic flux density at both ends of the effective pitch of 6a2.

Winding wire 6b1. The same applies to 6b2 and winding 6C1t 6c2.

Fixed point A of the field section 2 shown in FIG. The three-phase windings 5a1, 6 with respect to the change in the displacement difference Z between the fixed point B0 and the fixed point B0 of the armature core 3
Figure 6 shows the change in the composite magnetic flux density difference of a2,6v, 61)2.6c:+602.

At this time, as shown in FIG. 7, constant values of currents ia, ib, and ic are applied to the three-phase winding 6a126a according to the relative displacement Z.
2t 6b+ , 6b2.6c+ t 6C, 2, the driving force F becomes as shown in FIG. 8.

Since the variation in the driving force F when a constant current is applied is the output ripple of the linear motor, the output ripple in this embodiment is JF in FIG. 8, which is very small.

As is clear from the above explanation and FIGS. 6 to 8, the windings 5a+, 5a2.6b+? 6b2,
If the width X (see FIG. 6) of the flattened portion of the composite magnetic flux density difference of 5ct t 6 (!2) is increased, the output ripple will be reduced.

Since the distribution of the magnetic flux density B spread, and the output ripple decreases.

Generally, if the effective pitch of the winding salient poles is made an odd number multiple of the pitch of one magnetic pole of the field section 2, the output ripple will be reduced.

Based on this idea, in the present invention, an auxiliary salient pole is provided to prevent unnecessary magnetic flux from interlinking with the winding salient pole, and the effective pitch of the winding salient pole is adjusted to the field part 2. The pitch is made close to or equal to an odd number multiple of one magnetic pole pitch.

Next, the cogging force in this example will be explained.

Cogging force is generated when the magnetic energy stored in the magnetic field between the field part and the armature core fluctuates according to the relative displacement of the two, and in particular, it is caused by magnetic non-uniformity in the field part. (caused by the magnetic poles) and magnetic inhomogeneities in the armature core (caused by the grooves).

Since magnetic energy is an amount related to the square of the magnetic flux density generated by the field section 2, the magnetic period and waveform (waveform obtained by squaring the magnetic flux density) of the field section 2 change every one magnetic pole pitch T. It becomes a periodic waveform that is repeated.

That is, the field section 2 is based on a component with a period T, and includes harmonic components with periods T/2, T/3, T/4, . . . .

On the other hand, the magnetic fluctuations (magnetic non-uniformity) of the armature core 3 are caused by the winding groove 7 formed between the salient poles and the tip of the winding salient pole or auxiliary salient pole. This is caused by the auxiliary grooves 8 and is expressed by local variations in permeance (reciprocal of magnetic resistance) of the armature core 3 viewed from each point on the surface of the field section 2.

The cogging force is generated by the interaction between the magnetic period and waveform of the field section 2 and the magnetic fluctuations of the armature core 3, and as shown in Fig. 1, the cogging force between the field section 2 and the armature core 3 is When both have periodicity, generally a cogging force mainly occurs due to a periodic component (referred to as a matching component) that is common to both.

Since the magnetic period and waveform of the field section 2 are periodic fluctuations with one magnetic pole pitch T as the basic period, it is sufficient to consider the magnetic fluctuations of the armature core 3 in terms of each magnetic pole pitch, and in general, If the combined variation is made smaller or the pitch of the variation is made shorter (the frequency is made higher), the cogging force that is the interaction with the field section 2 becomes smaller.

Now, as shown in FIG. 3, most of the magnetic flux flowing into the winding groove 7 avoids the groove with rough magnetic resistance and is attracted to the salient pole of the armature core 3, as shown by the arrow line. Be taken.

As a result, the magnetic flux penetrating deeper than the illustrated broken line H1°112 becomes extremely small.

Therefore, even though the depth of the winding groove 7 is deeper than the broken lines H, , H2, it is magnetically almost the same as that of the broken lines H0, H2.

Therefore, as illustrated in FIG. 1, the winding salient poles 3a, +
, 3t) + t 3c: + t 3a2 y3b2,3
If C2 and the auxiliary salient poles 5a and 5b at both ends are provided with auxiliary grooves 8 in the form of shallow open grooves that have almost the same magnetic effect as the winding grooves, the magnetic average property of the armature core 3 will be reduced. Conditions change.

In the embodiment of the present invention illustrated in this FIG. Auxiliary salient poles 4a and 4b located between.

The center spacing between the grooves at both ends of 4c, 4d, and 4e is 4T/15, and the auxiliary groove 8 is arranged at a position that equally divides the center spacing between the grooves at both ends of the winding salient pole into four.

In other words, the entire groove consisting of the winding groove and the auxiliary groove is
They are arranged at an approximately equal pitch (4T/15 in this example).

Therefore, when the part of the armature core 3 facing the magnetic pole surface of the field section 2 in this embodiment is viewed on the basis of one magnetic pole pitch T, the variation of the composition is shown by the solid line in Fig. 9a. As shown by M, there are small fluctuations mainly having 15 peaks and valleys.

In addition, the dashed-dotted line m1 in FIG.

Depending on the relative position of the field part 2 and the armature core 3, the field part 2
Although the groove facing the magnetic pole changes, the fluctuation amplitude and the period of the fluctuation of the resultant fluctuation are approximately constant.

Cogging force occurs when the magnetic period and waveform of the field portion match the magnetic fluctuations of the armature core.

Therefore, the cogging force of this embodiment is small, with the direction of the force mainly changing 15 times (30 times) for each movement of one magnetic pole pitch of the field section 2.

FIG. 9 shows the composite magnetic fluctuation of the armature core 3 when the auxiliary groove 8 is not provided.

In this case, the composite fluctuation is the sum of only the magnetic fluctuation due to the winding groove 7 formed between the salient poles [ml in Fig. 9a], and is the sum of the three peaks and valleys. This results in large fluctuations.

As a result, the cogging force also becomes so large that the direction of the force changes three times (six times) with respect to the movement of one magnetic pole pitch of the field section 2.

Comparing Figures 9a and 9b, we can see that by providing the auxiliary groove 8, the magnitude of the magnetic fluctuation is reduced, and the period of the dominant component of the magnetic fluctuation is also 15 times higher order. There is.

In general, the magnitude of each component of cogging force is related to the product of the magnitude of the component in the armature core and the magnitude of the component in the permanent magnet that is the field part, and the smaller the product, the more cogging The magnitude of the corresponding component of force also becomes smaller.

Further, the magnitude of the components of a permanent magnet usually decreases more rapidly as the components become higher-order components.

Therefore, the cogging force in the embodiment of the present invention shown in FIG. 1 is extremely small due to the small magnitude of the magnetic fluctuation component on the armature core and the short period of the dominant component of the fluctuation. It has become.

That is, if the state of magnetic fluctuation of the armature core is changed by providing an auxiliary groove as in the present invention and the period of the dominant component of the cogging force is shortened, the cogging force is reduced.

Note that in the embodiment of the present invention shown in FIG. 1, the armature core 3 is used as a stator and the field section 2 is moved. There is no difference in the effect.

Further, the embodiment shown in FIG. 1 can also be used as a linear generator as it is.

That is, if the moving body 1 is driven by an external force, the windings 5al and 6a2.

A three-phase power generation voltage can be obtained at 6bl + 6b226c1 j 6c2.

Therefore, for example, if the three-phase generated voltage is supplied to each cathode of three diodes whose anodes are commonly connected and rectified, a DC voltage corresponding to the moving speed can be obtained from the anode.

Therefore, the present invention is applicable not only to linear motors but also to linear generators.

Further, in the above-mentioned embodiments, an electronic commutator type linear motor was explained as an example, but the drive phase may be switched using a brush or the like.

Furthermore, the present invention applies not only to a simple and stable field part using permanent magnets, but also to other structures.
Any field part that generates a fixed magnetic field can be applied.

Furthermore, as shown in the embodiments of the present invention, if the depth of the auxiliary groove is made shallow and the base of the salient pole is made narrower than the tip, the space for storing the winding wire can be increased, which improves efficiency. It becomes a good straight-line electric machine.

Furthermore, if the width of the auxiliary groove is made approximately equal to the groove width between the salient poles, approximately the same magnetic effect can be easily obtained.

Of course, the structure of the auxiliary groove may be substantially the same as the groove between the salient poles.

In addition, if the armature core is constructed by punching thin sheets of silicon steel plate with a die and fixing them in a stack in the direction perpendicular to the drawing in Figure 1, the arrangement precision of each salient pole and groove will be improved, and the auxiliary grooves will be Mass production with stable effects becomes easy.

FIG. 10 shows a main part configuration diagram of another embodiment of the present invention.

In the actual mf+lJ, the opposing length of the field portion is longer than the opposing length of the armature core.

In the figure, a field part 12 made up of flat permanent magnets attached to a moving body 11 has N poles and S poles arranged alternately at equal pitch intervals T or approximately equal pitch intervals. ing.

The electric machine f iron core 13 has two winding salient poles 13a and 13b,
Auxiliary salient pole 14 located between them and armature core 13
It has auxiliary salient poles 15a and 15b located at both ends.

Each winding salient pole 13a, 13b has a winding 16a, 15
b are wound, and the magnetic turrets intersecting them have a false position difference of one magnetic pole bit T.

Therefore, if the winding to which the current is applied and the current direction are switched depending on the relative position between the field section 12 and the armature core 13, a sustained driving force in a predetermined direction can be obtained.

In this embodiment, each winding salient pole 13a.

Two auxiliary grooves 18 are provided at the tip of armature core 13b.
The magnetic fluctuation of the composite of 3 is reduced.

These auxiliary grooves 18 are the winding grooves 1 formed between the salient poles.
7, and the entire groove consisting of the auxiliary groove 18 and the winding wire 17 is arranged at a pitch of 3T/8.

Further, the auxiliary salient poles 15a and 15b at both ends are tapered so that the opposing gap with the field part 12 becomes dog-like toward the ends, and as a result, the cogging force in this embodiment is reduced. .

Incidentally, in the above embodiment, the effective pitch of each winding salient pole is approximately equal to the pitch of one magnetic pole of the field section, but the present invention is not limited to such a case; Also the pitch of one magnetic pole in the field part.

As in the case of 1/, , , , , etc., the general σ is
This method can be implemented even when the effective pitch of the winding salient poles is close to an odd multiple of the pitch of one magnetic pole in the field section.

Of course, the pitch may be equal to an odd number multiple of one magnetic pole pitch, and the cogging force can be reduced by arranging the auxiliary groove.

Generally, if the auxiliary groove is provided so that the pitch between the center of the auxiliary groove and the center of the adjacent groove (winding groove or auxiliary groove) is different from an integral multiple of the pitch of one magnetic pole in the field part, the cogging force will be increased. can be made smaller.

In addition, there are many possible variations in the arrangement of the auxiliary grooves that reduce the cogging force. However, if the number of auxiliary grooves is equal to or greater than the number of winding grooves, the valley grooves should be made shallower.
Moreover, since it can be made small, fluctuations in magnetic flux in the auxiliary groove portion are reduced, and the performance of the linear electric machine is improved.

Furthermore, if the same number of auxiliary grooves are arranged symmetrically on each salient pole for windings, there will be no variation in the magnetic flux flowing in and out of each salient pole for windings, and the performance of the linear electric machine will be improved.

As shown in the above-mentioned embodiment, an auxiliary groove having an effect magnetically equal to or almost equal to that of the winding groove is provided at the tip of the salient pole, and the entire groove (the winding groove and the auxiliary groove) is The cogging force can be easily reduced if they are arranged at equal pitches or at approximately equal pitch intervals.

In such a configuration, an auxiliary salient pole is provided between the winding salient poles,
The ratio of the effective pitch of the winding salient pole to the effective pitch of the auxiliary salient pole is L:K (here, L and K are integers), and the entire groove (winding groove and auxiliary groove) is the winding salient pole. L of effective pitch of poles
If it is placed every 1/2nd, it can be realized as a container.

Of course, the present invention is effective even when the auxiliary grooves do not have the same magnetic effect, and even when the grooves are not all arranged at equal pitches.

In addition, by arranging the auxiliary salient poles, the effective pitch of the winding salient poles can be brought closer to an odd multiple of one magnetic pole pitch, and the width and depth of the winding groove can be reduced.
The small-shaped auxiliary grooves can provide the same magnetic effect as the winding grooves, and since the number of auxiliary grooves can be increased, the cogging force can be sufficiently reduced.

That is, the auxiliary salient pole is useful for reducing output ripple as well as for reducing cogging force when introduced with the auxiliary groove.

Of course, an auxiliary groove may be provided on the auxiliary salient pole.

Furthermore, the salient poles for the winding of the armature core and the number of phases of the winding are not limited to the above-mentioned embodiments, and in general, a multi-phase linear electric machine can be realized.

Further, the present invention can be practiced not only when the salient poles for the winding of the armature core are arranged at equal pitch intervals, but also when there is a difference in pitch between the salient poles.

Further, the present invention is effective even when the magnetic poles of the field part are arranged at irregular pitch intervals and when the magnetic field part has a non-magnetic part.

As described above, the present invention can realize a linear motor or a linear generator with low cogging force, low output ripple, and high efficiency.

Therefore, when an electronic commutator-type linear electric machine for a sound device such as a record player is configured based on the present invention, vibrations and unevenness of driving force can be minimized, so that an extremely high-performance audio device can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a main part of an embodiment of the present invention, and FIG. 2 is a diagram of a drive circuit of f+1 in the same implementation = f! A diagram showing I, FIG. 3 is a diagram representatively showing the magnetic flux distribution of the main part in the same example,
Fig. 4 is a schematic development diagram of the main parts of the same embodiment, Fig. 5 is a diagram showing the magnetic flux density distribution of the field part in the same embodiment, and Figs. 6, 7, and 8 are diagrams of the same embodiment. Figures 9a and 9b are diagrams for explaining the driving operation, and Figures 9a and 9b are diagrams for comparing and explaining the cogging force reduction effect in the same embodiment. Figure 10 is a diagram showing the main part configuration of another embodiment of the present invention. be. 1.11...Moving body, 2,12...Field section, 3゜13...Armature core, 3a+,
3a2, 3b13b2.3c+, 3c2, 1
3a, 13b・------ Salient pole for winding, 4a ~ 4
e, 5a, 5b, 14, 15a. 15b...Auxiliary salient pole, 5at, 5a2, 5b
＋. 6b2.6ct, 6C2, 16a, 16b-winding, 7.17... Winding groove, 8, 18...
...Auxiliary groove, 9...Drive phase selection means, 10...
...Equivalent one turn winding.

Claims (1)

[Claims] 1. An armature core comprising: a field part having a plurality of magnetic poles; and a salient pole for winding around which an armature winding is wound, at a position facing the field part. , one of the field part and the armature core is configured to be movable in a straight line with respect to the other, and a required number of auxiliary salient poles are provided on the armature core and are located on both sides of the winding salient pole. The distance between the centers of the grooves is equal to or approximately equal to an odd number multiple of one magnetic pole pitch of the field part, and an auxiliary groove is provided at a position facing the field part of the winding salient pole, A linear electric machine characterized in that the distance between the centers of the auxiliary grooves and the centers of adjacent grooves is a non-integral multiple of one magnetic pole pitch of the field section. 2. A field part having a plurality of magnetic poles, and an armature core having a winding salient pole around which an armature winding is wound at a position facing the field part, and the field part and Either one of the armature cores is configured to be movable in a straight line relative to the other, and the armature core is provided with a required number of auxiliary salient poles adjacent to the winding salient poles, and An auxiliary groove is provided in a portion of the pole facing the field part, and the entire groove of the armature core includes the auxiliary groove and a groove formed between the winding salient pole and the auxiliary salient pole. are arranged so that the center distance between adjacent grooves is constant or almost constant.