JP3259404B2 - Vibration suppressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration suppressing device for a rotating body suitable for use in, for example, a high-speed electric motor of a textile machine.

[0001]

2. Description of the Related Art The structure of a conventional general motor, particularly a high-speed motor used in a textile machine will be described with reference to FIG. In the electric motor shown in this figure, a substantially hollow cylindrical roller 2 rotates with respect to a shaft 1 having both ends fixed.
Outer rotor motor. The roller 2 is rotatably attached to the shaft 1 via bearings 3 at both end surfaces. A rotor core 5 is attached to the inner peripheral surface of the roller 2 via a magnet 4, while a stator core 6 is fixed to the shaft 1 with a gap facing the rotor core 4. A rotating magnetic field is generated in the stator core 6 by current supply from a cable 7 that is passed through a hollow portion provided at one end of the shaft 1.

That is, an induction synchronous motor is constituted by the magnet 4, the rotor core 5 and the stator core 6 (an induction motor may be employed as the electric motor), and the roller 2 rotates with respect to the shaft 1. It has become. Then, by pressing the outer peripheral surface of the rotating roller 2 against, for example, a bobbin,
It is configured to wind up a thread. Therefore, according to such a configuration, the peripheral speed of the rotating roller 2 is
It is almost proportional to the winding speed of the yarn.

On the other hand, recently, there is a demand to increase the yarn winding speed in order to improve productivity, and therefore, a high peripheral speed is required for the roller 2. For example, the peripheral speed of the roller 2 needs to be about 6,000 [m / min]. This includes
There are two approaches: That is, the outer diameter of the roller 2 is increased, or the rotation speed of the roller 2 is increased. In the above method, not only the problem that the roller 2 itself is enlarged, but also the bearing 3
There is a problem that accuracy that can cope with the increase in weight is required. Therefore, conventionally, the method described above has been used and the diameter of the shaft 1 has been reduced, so that a bearing 3 having a small maximum load and a small inner and outer diameter can be used.

[0004]

However, as the diameter of the shaft 1 becomes smaller, the frequency of the natural vibration generated in the shaft 1 decreases.
In combination with the high rotation speed of the roller 2, there is a problem that the rotation speed is lower than the rotation speed that satisfies the above peripheral speed. Here, the natural vibration will be described. In general, natural vibration refers to a characteristic mechanical property of a structure. When the structure is excited at a natural frequency, a resonance phenomenon occurs, and the structure vibrates with a very large amplitude. I do.

FIG. 8 shows the natural vibration of the shaft 1 and
The vibration mode is shown. Since the roller 2 has much higher rigidity than the shaft 1, the natural frequency of the roller 2 is also much higher than that of the shaft 1. Therefore, when looking at the entire electric motor, the natural vibration of the roller 2 can be ignored, and only the natural vibration of the shaft 1 can be considered. As shown in this figure, when the rotation of the roller 2 is stopped, the shaft 1 naturally does not generate any vibration. However, when the roller 2 starts to rotate, the shaft 1 is excited by the vibration caused by the rotation. When the rotation speed of the roller 2 reaches 7,980 [rpm] (in this example), the shaft 1 ends up rotating.
Generates a natural vibration (in this example, a frequency of 133 Hz) whose fixed points at both ends are “nodes” (primary vibration mode).
In this case, the roller 2 vibrates vertically as a whole according to the vibration of the shaft 1.

Further, when the rotation speed of the roller 2 rises and reaches 16,080 [rpm], the shaft 1 is provided with a fixed point at both ends and a bisecting point (that is, a middle point) at each node. (In this example, the frequency is 268 Hz)
Occurs (secondary vibration mode). In this case, roller 2
Since the two ends of the roller 2 vibrate in opposite phases in accordance with the vibration of the shaft 1, they vibrate like a seesaw. Similarly, as the rotation of the roller 2 rises, the shaft 1 sequentially generates natural vibrations having the fixed points at both ends and the n-equivalent points as "nodes" (n-order vibration mode). However, n is an integer equal to or greater than “1”, and as n becomes higher, the natural vibration of elements other than the shaft 1 cannot be ignored.

As described above, when the natural vibration is generated in the shaft 1 and the roller 2 vibrates in accordance therewith, the textile machine has a problem that the vibration propagates to the bobbin and the quality of the yarn is deteriorated. Was. Further, due to the natural vibration, the rotor core 5 and the stator core 6 (see FIG. 7)
However, there is a problem that the electric motor may come into contact with the electric motor and damage the electric motor itself. The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vibration suppression device for a rotating body that can significantly reduce the amplitude of natural vibration due to rotation.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is provided with a substantially hollow cylindrical rotating body.
A vibration suppression device for a fixed support shaft,
Installed at a position on the fixed support shaft according to the motion mode
It has a yoke, on the inner peripheral surface side opposite directions of the rotating body
A plurality of sets of electromagnets a pair of electromagnets which Aspirate the set, the displacement amount with respect to the reference value of the rotary member and the stationary support shaft
Comprising a plurality of detecting means for detect, a plurality of detection
Means to calculate the displacement amount detected by
According to the result of the arithmetic processing.
Attraction by one of a pair of electromagnets in the same set of stones
It is characterized in that the force is increased and the suction force by the other is reduced .

[0009]

According to the present invention, the displacement amounts of the fixed support shaft and the rotating body with respect to the reference value in two different axial directions passing through the center of rotation of the rotating surface are detected by the first and second detecting means, respectively. Is done. Here, when the amount of displacement detected by the first detection means increases, one of the first set of electromagnets
While increasing the attraction force to the rotating body in a direction to cancel the increase in the displacement, the other of the same set of electromagnets reduces the attraction force to the rotating body, so the rotating body and the fixed support shaft are:
They are mutually attracted so that the increase in the displacement amount decreases. The same applies to the second detecting means and the second set of electromagnets. Thus, the displacement between the fixed support shaft and the rotating body is always kept at the reference value. Also, if the displacement amounts detected by the first and second detection means are respectively reference values,
The attraction force of each of the first and second sets of electromagnets becomes constant, and the support shaft and the rotating body are kept in equilibrium.

[0010]

An embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a side end view showing a schematic configuration of this embodiment. In this figure, the vibration suppressing device 10 of this embodiment is added to FIG. 7, and the vibration suppressing device 10 includes a primary yoke 11, a secondary yoke 12, a coil 13, a sensor 14, and a driving circuit 15. Consists of In FIG. 1, the same portions as those in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted.

Next, a detailed configuration of this embodiment will be described. FIG. 2 is an end view taken along line AA ′ in FIG.
As shown in this figure, the shaft 1, a primary yoke 11 having a magnetic pole 11 ₁ to 11 ₈ are arranged radially mounted, each of these pole coils _{131-134 8} is wound around each I have. In these coils, coils 13 ₁ ,
13 ₂ are electrically connected in series or in parallel, and similarly, coils 13 ₃ and 13 ₄ , 13 ₅ and 13 ₆ , 1
3 ₇ and the 13 ₈ are electrically in series or connected in parallel.

On the other hand, the inner peripheral surface of the roller 2 has a magnetic pole 11 _1.
Opposed to the secondary yoke 12 is attached to to 11 _8. This secondary yoke 12 can be omitted if the roller 2 is made of a magnetic material. When eddy current loss is a problem, the eddy current loss can be reduced by forming the primary yoke 11 and the secondary yoke in a laminated structure. Then, by supplying a current to the coils _{131-134 8,} the magnetic pole 11 ₁ to 11 ₈ and the secondary yoke 12, an electromagnetic force to form a magnetic line of force shown in FIG., Namely, the suction force to the secondary yoke 12 Is to occur.

The sensor 14x detects how much the gap dx between the primary yoke 11 and the secondary yoke 12 is displaced from the reference value in the x-axis direction shown in the figure, together with the direction of displacement. For example, the sensor 14x outputs the displacement amount as a sign (-) when the gap is displaced in a direction in which the gap becomes smaller, and outputs the displacement amount as a sign (+) when the gap dx is displaced in a larger direction. ) To output. Similarly, the sensor 14y includes the primary yoke 11 and the secondary yoke 1
The amount of displacement of the gap dy with respect to the reference value in the y-axis direction shown in the drawing is detected together with the displacement direction.

Next, the electrical configuration of this embodiment, in particular, the sensors 14x and 14y, the drive circuit 15, and the coil 13 ₁
To 13 ₈ will be described with reference to FIG. 3. In this figure, the same parts as those in FIG. 2 are denoted by the same reference numerals. As shown in this figure, the detection result of the sensor 14x is:
The signal is supplied to the controller 153 through a predetermined amplification by the sensor amplifier 151. The controller 153 performs an appropriate calculation process on the detection result by the sensor 14x, for example, a PID (proportional, integral, differential) calculation process. Then, the controller 153 the result of the calculation, one input terminal of the adder 155 ₁ (+) and one input of the adder 155 ₂ - supplying the (). Adder 15
5 _1, 155 ₂ of the other input terminal, a constant current command C is supplied.

In the adder 155 ₁ , the constant current command C
A calculation result by the controller 153 and are added, the addition result is supplied to the coil 13 _3, 13 ₄ through a current amplification by the power amplifier 157 _1. On the other hand, in the adder 155 ₁ , the controller 153
Is subtracted, and the result of the subtraction is applied to the coils 13 ₇ , 1 through current amplification by the power amplifier 157 _2.
It is supplied to the 3 _8. The power amplifiers 157 ₁ , 157
The current amplification factors in ₂ are set equal to each other.

Similarly, the detection result of the sensor 14y is processed similarly to the sensor 14x. That is, the detection result of the sensor 14y are sequentially via the PID calculation by the amplification and the controller 154 by the sensor amplifier 152, summed with a constant current command C in adder 156 _1, the addition result is the current amplification by the power amplifier 158 ₁ Are supplied to the coils 13 ₁ and 13 ₂ via the
_{In step 2} , the calculation result of the controller 154 is subtracted from the constant current command C.
_The current is supplied to the coils 13 ₅ and 13 ₆ through the current amplification by ₂ .

Next, the operation of this embodiment will be described. When the rotation of the roller 2 is stopped, or when the vibration caused by the rotation is extremely small, the primary yoke 11
Since the air gaps dx and dy of the secondary yoke 12 are reference values, the detection results of the sensors 14x and 14y are both “zero”.
Also becomes "zero". Therefore, the adder 155
₁ , 156 ₁ and the adders 156 ₂ , 15
Since the result of the subtraction by 6 ₂ is only the constant current command C, the coils 13 ₁ , 13 ₂ , 13 ₃ , 13 ₄ , 1
3 _5, 13 and _6, 13 _7, 13 ₈ and a current value supplied to the
Each will be the same. As a result, the coils 13 ₁ , 13
₂ and 13 ₅ , 13 ₆ , the respective attractive forces to the secondary yoke 12 cancel each other, and similarly, the coils 13 ₃ , 1
And 3 _4, the suction force to the secondary yoke 12 by a 13 _7, 13 ₈ also cancel each other. That is, the attraction force to the secondary yoke 12 by each coil is in the x direction in FIG.
Since the balance is made in both the y direction, the air gaps dx and dy are kept at the reference values.

Next, the rotation of the roller 2 causes the shaft 1 to rotate.
Will be described, and a displacement in a direction in which the gap dx becomes large occurs. In this case, the sensor 14x
Since the displacement with respect to the reference value is output with a sign (+),
The calculation result of the controller 153 also follows this. As a result, the adder 155 ₁ outputs a signal obtained by adding the calculation result to the constant current command C.
While the suction force generated by 3 ₃ and 13 ₄ increases, the adder 155 ₂ uses the constant current command C to
3 reduces the calculation result, so that the coils 13 ₇ , 1
Suction force generated by 3 ₈ is reduced. Since the stiffness of the roller 2 is higher than the stiffness of the shaft 1, the primary yoke 111 is relatively pulled toward the (+) direction (rightward) of the x-axis. That is, a suction force acts in a direction to reduce the gap dx.

Conversely, when the shaft 1 is excited by the rotation of the roller 2 and a displacement occurs in a direction in which the gap dx becomes smaller, the displacement amount with respect to the reference value has a sign (-).
, The adder 155 ₁ outputs a signal obtained by subtracting the calculation result of the controller 153 from the constant current command C, and the attractive force generated by the coils 13 ₃ and 13 ₄ decreases, while the adder 155 ₂ Then, the constant current command C
And the calculation result of the controller 153 are added, so that the attraction force generated by the coils 13 ₇ and 13 ₈ increases. As a result, the primary yoke 1 is relatively drawn in the (-) direction (rightward) of the x-axis, so that the shaft 1 has a suction force to cancel the displacement, that is, a suction force in a direction to increase the gap dx. Works.

That is, in the x-axis direction, the sensor 14x →
Drive circuit 15 → coils 13 ₃ and 13 ₄ and coils 13 ₇ and 1
By 3 ₈ and by the suction → sensor 14x (displacement detection) of the feedback loop is controlled so that the air gap dx is always kept to the reference value. A similar operation is performed in the y-axis direction. That is, control is performed such that the air gap dy is always maintained at the reference value by the feedback loop of the sensor 14y → the drive circuit 15 → the suction by the coils 13 ₁ and 13 ₂ and the coils 13 ₅ and 13 ₆ → the sensor 14y (displacement detection). Is done. Therefore, by independently controlling the displacements in the x-axis and y-axis directions, the gaps dx, dy between the primary yoke 11 and the secondary yoke 12 are always maintained at the reference values over the entire rotation plane in FIG. Thus, even when the natural vibration is generated in the shaft 1 by the excitation by the rotation of the roller 2 and the amplitude of the natural vibration reaches a peak, the amplitude can be suppressed to an extremely small value.

FIG. 4 is a characteristic diagram showing the relationship between the rotational speed of the roller 2 and the vibration amplitude at point a (one end of the outer peripheral surface of the roller 2 in FIG. 8). As shown in this figure, in the conventional example,
As the rotation speed of the roller 2 increases, the natural vibrations are sequentially generated, whereby the amplitude at the point a at one end of the outer peripheral portion sequentially peaks at the rotation speeds of 7,980 [rpm] and 16,080 [rpm]. On the other hand, in the electric motor to which this embodiment is added, the natural vibration is generated as the rotation speed of the roller 2 is increased, as in the conventional example. However, even when the amplitude reaches a peak, the amplitude is extremely suppressed. I understand. Therefore,
According to the motor loaded with this embodiment, the vibration can be reduced in the entire region up to the substantially maximum rotation speed, so that it is not necessary to use the motor while avoiding the rotation speed band in which the natural vibration occurs, and any rotation speed can be reduced. It is possible to use numbers.

In this embodiment, the installation locations of the primary yoke 11 and the secondary yoke 12 are not particularly described.
In the natural vibration of the shaft 1, it is apparent that the vibration suppressing device according to the present invention has the most effective vibration suppressing effect if the vibration suppressing device according to the present invention is installed at the “antinode” of the vibration mode to be suppressed. Further, since this embodiment is configured to be incorporated inside the electric motor, almost no external space is required.

In this embodiment, the same constant current command C is added to or subtracted from the calculation result according to the displacement amount in each axial direction. However, in order to transmit the rotational force, FIG.
In the case where the roller 2 is pressed against an external device in the x-axis direction in FIG. 5, as shown in FIG. 5, the coils opposed in the x-axis direction, that is, the coils 13 ₃ and 13 ₄ and the coils 13 ₇ and 13 ₈ The constant current command C and the addition result obtained by adding the current command C ′ indicating the pressing pressure of the roller 2 to the constant current command C may be respectively added to and subtracted from the calculation result of the displacement amount by the sensor 14x. . Thereby, since the pressing pressure is offset in advance, even when the outer peripheral surface of the roller 2 is pressed against the bobbin, the load on the bearing 3 can be reduced.
Alternatively, the spring constant at the time of pressing can be arbitrarily changed.

In the above-described embodiment, the x-axis direction, y
Although one sensor was used to detect the displacement in the axial direction, as shown in FIG.
The sensor 14 'opposes the symmetric position of x and 14y, respectively.
x, 14′y may be provided, and the difference between the detection results of these opposed sensors may be obtained by the differential amplifiers 159, 160 and supplied to the sensor amplifiers 151, 152. With this configuration, not only the detection sensitivity of the displacement amount is doubled, but also noise unique to the sensor and a characteristic change due to a temperature change can be offset, so that the measurement accuracy can be improved.

[0025]

According to the present invention described above, when the displacement detected by the first or second detecting means increases, one of the first and second sets of electromagnets increases the displacement. As described above, while the attraction force to the rotating body is increased, the other of the same set of electromagnets reduces the attraction force to the rotating body, so that the rotating body and the fixed support shaft have increased displacement. As they decrease, they are sucked into each other. Therefore, even if the natural vibration accompanying the rotation occurs, the displacement amount between the fixed support shaft and the rotating body is always kept at the reference value,
Since the suction force is increased or decreased, the natural vibration can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a side end view showing a configuration of a main part of a first embodiment according to the present invention.

FIG. 2 is an end view taken along line A-A 'in FIG.

FIG. 3 is a block diagram showing an electrical configuration of the embodiment.

FIG. 4 is a characteristic diagram showing a relationship between a rotation speed of a roller 2 and a vibration amplitude in the embodiment.

FIG. 5 is a block diagram showing an electrical configuration of a second embodiment according to the present invention.

FIG. 6 is a block diagram showing an electrical configuration of a third embodiment according to the present invention.

FIG. 7 is a side end view showing a structure of a high-speed electric motor used in a conventional textile machine.

FIG. 8 is an explanatory diagram showing a natural vibration in the shaft 1 and its vibration mode.

[Explanation of symbols]

1 ... shaft (fixed support shaft), 2 ... rollers (rotating body), 11 ₃ , 11 ₄ ... magnetic poles, 13 ₃ , 13 ₄ ... coils, 11 ₇ , 11 ₈ ... magnetic poles, 13 ₇ , 13 ₈ ... coil (first set of electromagnets), 11 ₁ , 11 ₂ ... magnetic poles, 13 ₁ ,
13 ₂ …… Coil, 11 ₅ , 11 ₆ … Magnetic pole, 13 ₅ , 13
₆ ... coil (second set of electromagnets), 14x ... sensor (first detection means), 14y ... sensor (second detection means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16F 15/03 F16C 32/04 H02K 5/24

Claims (1)

(57) [Claims] 1. A substantially hollow cylindrical rotating body is attached.
A vibration suppression device for a fixed support shaft, the position on the fixed support shaft corresponding to a vibration mode to be suppressed.
Has installed yokes, and a plurality of sets of <br/> electromagnet a pair of electromagnets Aspirate was set on the inner peripheral surface side opposite directions of the rotating body, the rotation and the fixed support shaft Displacement relative to the reference value with the body
Anda plurality of detecting means for detect a respectively detected by said plurality of detecting means
Calculation processing for the amount of displacement
Accordingly, a pair of the same set of the electromagnets
Increase the attraction force of one of the electromagnets and
You and decreases the suction force by vibration suppression device.