JPH0145262Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a step motor in which the rotor is magnetized in the rotor axial direction and the upper and lower stators are arranged facing the magnetic poles on the upper and lower surfaces of the rotor. The present invention relates to a rotor shift structure that shifts the rotor position relative to the upper and lower stators in the rotational direction.

In Figure 1, the rotor is magnetized in the rotor axial direction,
This is a step motor in which upper and lower stators are placed opposite the magnetic poles on the upper and lower surfaces of the rotor.

What is indicated by the reference numeral 1 in FIG. 1 is a rotor.
The rotor 1 rotates around a rotor shaft 1a. On the outer periphery of the rotor 1, 2 (2n
+1) (n is a positive integer) polarized. Therefore, the upper and lower surfaces of the rotor 1 have 360/NS alternating magnetic poles.
They are provided every 2(2n+1) degrees, and the deviation of the magnetic poles on the upper and lower surfaces is 360/2(2n+1) degrees. Above the rotor 1 in the direction of the rotor axis 1a, a pair of plate-shaped upper stators 2a and 3a are provided side by side at right angles to the rotor axis 1a. those upper stator 2
a and 3a face each other at two driving upper slits a ₁ and a ₂ . These driving upper slits a ₁ and a ₂ are located on a straight line 1 passing through the rotor shaft 1a, and correspond to different upper surface magnetic poles of the rotor 1, respectively. On the other hand, a pair of plate-shaped lower stators 2 are disposed below the rotor 1 in the direction of the rotor axis 1a.
b, 3b are arranged side by side at right angles to the rotor axis 1a. These lower stators 2b and 3b face each other at two lower driving slits b ₁ and b ₂ . These driving lower slits b ₁ and b ₂ are located on a straight line m passing through the rotor shaft 1a, and correspond to different lower magnetic poles of the rotor 1 in sequence. The straight line m is
Driving slits for the above-mentioned upper stators 2a and 3a
It is shifted by 360/2 (2n+1) degrees from the straight line l where a ₁ and a ₂ are arranged. Therefore, when the upper driving slit _a1 of the upper stators 2a, 3a corresponds to the north pole, the other upper driving slit _a2 corresponds to the south pole. At this time, the lower driving slit b ₁ of the lower stators 2b and 3b
corresponds to the north pole, and another lower driving slit _b2 corresponds to the south pole. The reference numeral 4 in FIG. 1 is a drive coil. Drive coil 4
are the respective upper and lower stators 2a, 3a, 2b,
3b, and when an alternating pulse is applied, the upper and lower stators 2a, 3a, 2b, 3
NS polarity is alternately generated in the upper and lower stators, and the four driving upper and lower slits a ₁ , a ₂ , b ₁ , and b ₂ of the upper and lower stators attract and repel the rotor magnetic poles, and the rotor 1 is intermittently moved one pole at a time. Rotate.

In the step motor as described above, if the number of magnetic poles of the rotor 1 is six, the angle θ of the rotation of the rotor 1 from the stable position of the rotor 1 with respect to the upper and lower stators 2a, 3a, 2b, and 3b and the torque T acting on the rotor 1 are and have the relationship shown in Figure 2. Second
In the figure, the solid line represents the static torque, the dashed line represents the driving torque, and the dotted line represents their combined torque. As can be seen from FIG. 2, when θ is 0, that is, the rotor 1 is in a stable position, even if a drive pulse is sent to the drive coil 4, no drive torque acts on the rotor 1, and the rotor 1 is clearly It does not rotate.

Therefore, conventionally, the upper and lower stators 2 are
When the stable position of the rotor 1 relative to a, 3a, 2b, and 3b is shifted in the rotational direction and the rotor 1 is in the stable position, a driving pulse is sent to the drive coil 4, and a driving torque acts on the rotor 1. The rotor 1 was designed to rotate.

The purpose of this invention is to provide such a rotor shift structure.

The rotor shift structure based on this idea is
In the step motor as described above, when k is a positive integer, 360/2(2n+1)(k+1/6)≦δ≦−360/2(
2n+1) (k+2.5/6), select a δ that has a value close to 90 degrees, and shift the upper and lower stators by that amount from the upper and lower driving slits in the rotational direction of the rotor. The stator is characterized by providing upper and lower slits for shifting.

Below, based on the embodiment of this invention shown in the drawings,
This idea will be explained in detail.

FIG. 3 shows an embodiment of this invention, which is a step motor similar to that shown in FIG. upper and lower stator 12
a, 13a, 12b, and 13b are arranged. The pair of upper stators 12a and 13a face each other at driving upper slits a ₁ and a ₂ located on a straight line l passing through the rotor shaft 11a. On the other hand, the pair of lower stators 12b and 13b face each other at lower drive slits b ₁ and b ₂ located on another straight line m passing through the rotor shaft 11a. Those straight lines l and m are deviated by 60 degrees.
However, in the staple motor shown in Fig. 3, the first
Unlike the step motor shown in the figure, upper stators 12a and 13a are provided with upper shift slits c ₁ and c ₂ , respectively, and lower stators 12b and 1
3b is also provided with lower shift slits d ₁ and d ₂ , respectively. The upper shift slits c ₁ and c ₂ are located on a straight line p passing through the rotor shaft 11a, and the lower shift slits d ₁ and d ₂ are located on another straight line q passing through the rotor shaft 11a. The straight lines p and q are deviated from the straight lines l and m, respectively, by an angle δ in the rotational direction of the rotor 11. The value of this δ is 70 to 85 degrees.

FIG. 4 shows another embodiment of this invention.
A pair of upper stators 12 of the step motor shown in the figure.
a, 13a are integrally formed, and a pair of lower stators 12b, 13b are integrally formed. The integrally formed upper stator 5 has upper drive slits a ₁ and a ₂ as well as upper shift slits.
c ₁ and c ₂ are provided. The upper shift slits c ₁ and c ₂ are provided offset from the upper drive slits a ₁ and a ₂ by an angle δ in the rotational direction of the rotor 11, respectively. On the other hand, the integrally formed lower stator 6 is also provided with lower driving slits b ₁ and b ₂ as well as lower shifting slits d ₁ and d ₂ . The shift slits d ₁ and d ₂ are arranged at the same angle δ in the rotational direction of the rotor 11 from the drive upper slits b ₁ and b ₂ respectively.
It is set at a different angle. This value of δ is determined when the rotor 11 is 6.
Since it is polarized, it is 70 to 85 degrees.

In the step motor shown in Figs. 3 and 4, if the upper and lower stators have upper and lower slits for shifting,
When the rotor 11 does not have c ₁ , c ₂ , d ₁ , d ₂ , the rotation angle from the stable position of the rotor 11 with respect to the upper and lower stators is θ, and by providing upper and lower shift slits c ₁ , c ₂ , d ₁ , and d ₂ If the rotor 11 is shifted by an angle η with respect to the upper and lower stators, the relationship between the rotation angle θ of the rotor 11 and the torque T acting on the rotor 11 at that time is as shown in FIG. The curve shown by the solid line in FIG. 5 is the static torque, the curve shown by the one-dot chain line is the driving torque, and the curve shown by the dotted line is their combined torque. As can be seen from FIG. 5, when θ is the shift angle η, that is, when the rotor 11 is in a stable position, when a drive pulse is sent to the drive coil 14, a drive torque acts on the rotor 11, and the rotor 11 is clearly Rotate.

Next, in the rotor shift structure according to this invention, the deviation angle δ of the shift slit with respect to the drive slit will be explained.

In the embodiment shown in FIGS. 3 and 4, the static torque Tk acting on the rotor 11 can be expressed by the following equation.

Tk= _T0 + _T1 =Asin6θ+Bsin6(θ−δ) Here, _T0 is the static torque when only the driving slits _a1 , _a2 , _b1 , and _b2 are provided in the upper and lower stators. T ₁ is the static torque when only the shift slits c ₁ , c ₂ , d ₁ , and d ₂ are provided in the upper and lower stators. A is a driving slit in the upper and lower stators.
This is the maximum static torque when only a ₁ , a ₂ , b ₁ , and b ₂ are provided. B is the maximum static torque when only the shift slits c ₁ , c ₂ , d ₁ , and d ₂ are provided in the upper and lower stators.

Combining the equations, we get T=√ ² + ² +26sin6 (θ−α/6)...where cosα=A+Bcos6δ/√A ² +B ² +2ABcos6δ sinα=Bsin6δ/√A ² +B ² +2ABcos6δ In other words, the equation is shown as a solid line in Figure 5. From this equation, it can be seen that the shift angle η is α/6 and the maximum static torque Tmax is √ ² + ² + 2ABcos6δ.

Now, shift angle η and maximum static torque Tmax
The relationship between δ and δ is shown in graphs as shown in FIGS. 6A to 6F. The solid curve shows the relationship between shift angle η and δ, and the dotted curve shows the maximum static torque.
The relationship between Tmax and δ is shown. Figure 6 A is B=1/2 When A, B is B=A, C is B=1.25A, D is B
= 1.5A, E indicates B = 2.0A, and F indicates B = 3.0A.

From past experience, it has been found that when the rotor is magnetized with six poles, the value of η is preferably around 15 degrees. Therefore, the maximum static torque when η is 15 degrees
When Tmax is determined from FIGS. 6A to 6F, the value of η does not reach 15 degrees when B=1/2A, and Tmax becomes 0 when B=A. At B=1.25A, Tmax is 0.7A, B=
1.5A is 1.1A, B=2.0A is 1.7A, and B=
At 3.0A it becomes 2.8A. However, it is desirable that the value of A be as small as possible because if A is made large, power consumption increases, for example.
Considering this point, if B<1.5A, the maximum static torque Tmax will be too small. Therefore, B
It turns out that it must be ≧1.5A.

Now, if we show the relationship between the shift angles η and δ when B≧1.5A in a single graph, it will be as shown in FIG. 7. If the value of δ is determined from this Figure 7 so that the shift angle η is 15 ± 5 degrees, δ will be approximately 70 to 85
range of degrees. Therefore, it can be seen that in a step motor using a six-pole rotor, δ is best in the range of 70 to 85 degrees.

The above is δ for a six-pole rotor as shown in FIGS. 3 and 4. If we extend this idea and apply it similarly to a step motor using a 2(2n+1) pole rotor, the value of δ will be in the following range.

360/2 (2n+1) (k+1/6)≦δ≦ 360/2 (2n+1) (k+2.5/6) Here, k is a positive integer.

Note that when δ is close to 90 degrees, the driving torque based on the shift slit becomes 0, so a value close to 90 degrees must be selected from among δ within the above range.

The rotor shift structure according to this invention as explained above is easy to manufacture and does not require adjustment.
This has the advantage that the labor involved in assembly is greatly reduced. There is also the advantage that design is easy.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a step motor having only upper and lower driving slits. Figure 2 shows the rotation angle θ of the rotor in the step motor shown in Figure 1.
FIG. 3 is a relationship diagram between the torque T and the torque T received by the rotor. FIG. 3 shows an embodiment of this invention, and is a plan view of a step motor having a rotor shift structure according to this invention. FIG. 4 shows another embodiment of this invention, and is a plan view of a step motor having a rotor shift structure according to this invention. FIG. 5 is a diagram showing the relationship between the rotation angle θ of the rotor and the torque T received by the rotor in the step motor shown in FIGS. 3 and 4. FIG. 6A to 6F are relationship diagrams between the shift angle η and the maximum static torque Tmax in the step motor shown in FIGS. 3 and 4, and the shift angle δ of the shift slit, where A is B=1/2A When, B is when B=A, C is when B=1.25A, D is when B=1.5A, E is when B=2.0A,
And F indicates when B=3.0A. Figure 7 shows
FIG. 6 is a relationship diagram between the shift angle η and the shift angle δ of the shift slit when B≧1.5A. 11a... Rotor shaft, 11... Rotor, a ₁ , a ₂
... Upper slit for driving, 12a, 13a, 5...
Upper stator, b ₁ , b ₂ ...Lower slit for drive, 12
b, 13b, 6...Lower stator, 14...Drive coil, _c1 , _c2 ...Upper slit for shift, _d1 , _d2 ...
...Lower slit for shift, l, m...straight line.

Claims (1)

[Claims for Utility Model Registration] A rotor comprising a rotor, an upper stator, a lower stator, and a drive coil, the rotor having magnetic poles, each magnetic pole being arranged at a circumferential position centered on the rotor axis, etc. 2 (2n+1) in the interval (n is a positive integer)
The poles are magnetized and alternately parallel to the rotor axis.
The upper stator is disposed above the rotor in the rotor axial direction and parallel to the upper surface of the rotor, and has an upper slit for driving and an upper slit for shifting, and the upper stator has an upper slit for driving and an upper slit for shifting; Two upper slits are arranged on a straight line passing through the rotor axis, and each corresponds to a different upper surface magnetic pole of the rotor, and the lower stator is disposed below the rotor in the rotor axial direction, and the lower stator is disposed below the rotor in the rotor axial direction. It is arranged parallel to the lower surface and has a lower drive slit and a lower shift slit, and the two lower drive slits are arranged in a straight line passing through the rotor axis, and each corresponds to a different lower surface magnetic pole of the rotor. However, the straight line on which the lower driving slit is arranged is deviated from the straight line on which the upper driving slit is arranged by 360/2 (2n+1) degrees, and the upper and lower shift slits are deviated from the upper and lower driving slits of the upper and lower stators. Each is shifted by δ in the rotational direction of the rotor, and when k is a positive integer, 360/(2n+1)(k+1/6)≦δ≦360/(2n+1
)(k+2.5/6), the drive coil is magnetically coupled to the upper and lower stators and receives alternating drive pulses, A rotor shift structure of a step motor that rotates the rotor by alternately generating NS magnetic poles in the stator.