JPH0416623Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a small synchronous motor using a permanent magnet as a rotor.

Conventional technology Conventionally, permanent magnet rotor type synchronous motors have generally incorporated a squirrel cage conductor into the permanent magnet rotor and started as an induction motor, but the structure has been made as simple as possible with a very small capacity. Therefore, the stator had two poles with salient poles and concentrated winding, and the rotor was composed of a single cylindrical magnet.

Problems to be Solved by the Invention However, this type of permanent magnet rotor type synchronous motor had only alternating torque and had difficulty in starting rotation. Further, there is a problem in that variations in the rotational angular velocity, that is, disturbances, occur due to load variations, power supply voltage variations, etc., resulting in abnormal vibrations in the motor. Therefore, as shown in FIGS. 5 to 7, an inertial mass body 22 loosely fitted into a viscous friction member 21 is fixed to the shaft 24 of the rotor 23 to improve the starting characteristics and prevent the disturbance phenomenon. It was hot.

Figure 8 A shows the alternating magnetic field of one stator magnetic pole generated by an AC power source, B shows the rotor 23 rotating synchronously in synchronization with this alternating magnetic field, and C shows the rotor 23. 23 is unable to synchronize with the alternating magnetic field and a disturbance phenomenon occurs.

As shown in FIGS. 8 and 9, the N pole of the rotor 23 is stopped near the approximate center of the magnetic pole portion 25 before driving. Next, when a voltage is applied to the drive coil 26, a stator magnetic flux is generated, and when the magnetic pole portion 25 is at the north pole, the rotor 23 starts to move from the position A to the direction B or C in FIG. 9 due to the repulsive force. Further, the rotational vibration angle θ is increased by the alternating magnetic field, and when the N pole of the rotor 23 reaches the Z-Z axis position clockwise or counterclockwise from the A position, it exits the repetitive motion and starts rotating.

Here, to explain the action of the viscous friction member 21 and the inertial mass body 22, in response to abnormal vibrations of the rotor 23, that is, changes in angular velocity, the inertial mass body 22 uses its inertia to respond to abnormal vibrations of the rotor 23 through friction with the viscous friction member 21. to apply a restraining action and shift the abnormal vibration to a presser foot synchronized state.

Furthermore, during startup, when the N pole of the rotor 23 is at position B, as shown in FIG. When returning to position A, the magnetic pole part 25
changes from N pole to S pole. Further, when the magnetic pole portion 25 changes from the S pole to the N pole, the remaining mechanical angle to the Z-Z axis is less than 90°, so the rotor 23 can shift to starting rotation due to repulsive force.

However, the viscous friction member 21 as shown in FIG.
deformation of the viscous friction member 21 as shown in FIG.
If the fit between the inertial mass body 22 and the inertial mass body 22 is poor, the adhesion will be poor and the stopping action will not work sufficiently.

Therefore, there was a problem that the starting characteristics could not be sufficiently improved and the disturbance phenomenon could not be sufficiently prevented.

The present invention eliminates the above-mentioned conventional drawbacks.
This improves the close contact between the viscous friction member 21 and the inertial mass body 22, improves the starting characteristics, and prevents disturbances.

Means for Solving the Problems In order to solve the above problems, the present invention provides a stator having magnetic pole parts, a drive coil for exciting the stator, and a permanent shaft rotatably supported between the magnetic pole parts. a rotor having magnetic poles; a viscous friction member having opposing inner surfaces fixed to the rotor or a shaft integrated with the rotor and retaining elasticity; the viscous friction member has one of its inner surfaces that abuts the inertial mass body flat, the other side is provided with a radial collar, and a plurality of viscous friction members that abut the inertial mass body are provided on the collar. It has hemispherical protrusions.

Effect With the above configuration, the inertial mass body is urged against the flat side of the viscous friction member and securely contacts the viscous friction member without hindering the movement of the inertial mass body, thereby improving the close contact between the inertial mass body and the inertial mass body. The body's inertial force is fully utilized to improve starting and prevent irregularities.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. 1 to 4, reference numerals 1 and 2 designate bearing bodies that rotatably support a rotating shaft 4 integrated with a rotor 3 having permanent magnet poles, and are fixed to a stator 5. Note that the rotor 3 has a rotating shaft 4.
The rotor 3 is magnetized with two poles in the direction perpendicular to the rotor 3, that is, in the radial direction of the rotor 3. 6 is a drive coil that excites the stator 5, and 5a and 5b are magnetic pole parts. The rotating shaft 4 has an elastic viscous friction member 8 having opposing inner surfaces in which an inertial mass body 7 is loosely fitted.
is fixed. In addition, the viscous friction member 8 has one of its inner surfaces that comes into contact with the inertial mass body 7 as a flat surface, and the other side is provided with a radial collar 9, and on this collar 9, a plurality of hemispherical surfaces that come into contact with the inertial mass body 7 are provided. A projection 10 is provided.

Next, the operation of the permanent magnet rotor type synchronous motor will be explained.

When voltage is applied to the drive coil 6, stator magnetic flux is generated and the rotor 3 begins to vibrate. At this time, the inertial mass body 7 is pressed against one plane side of the viscous friction member 8 by the protrusion 10 on the collar 9 provided on the viscous friction member 8, and is in close contact with the viscous friction member 8. Since the inertial mass body 7 is in close contact with the viscous friction member 8, the inertial force of the inertial mass body 7 acts sufficiently to facilitate starting.

Here, if the function of the inertial mass body 7 is completely fixed, the inertial mass body 7 will become just a weight, which will prevent the initial vibration of the rotor 3 and make starting difficult, but the viscous friction Using the elastic force of the collar 9 provided on the member 8, the inertial mass body 7 is brought into contact with one flat side of the viscous friction member 8 by pressing by the point contact of the protrusion 10, so that the inertial mass body 7 The inertial force can be fully utilized without hindering the movement of the

In addition, since the inertial mass body 7 is in close contact with the viscous friction member 8, the inertial mass body 7 is in close contact with the viscous friction member 8, so that it can sufficiently suppress abnormal vibrations and synchronize them. state can be easily transitioned to.

Effects of the Invention As is clear from the description of the above embodiments, the present invention provides a resilient viscous friction member in which an inertial mass body is loosely fitted, one of the inner surfaces of which is flat, and the other surface of the elastic viscous friction member that is in contact with the inertial mass body. A collar with a plurality of hemispherical protrusions extends in the radial direction, and the elastic force of the collar is used to urge the inertial mass body toward the flat side of the viscous friction member. To provide a permanent magnet rotor type synchronous motor that ensures contact between the flat side of a viscous friction member and an inertial mass body without hindering body movement, is easy to start, and is less likely to cause disturbances.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a permanent magnet rotor type synchronous motor showing an embodiment of the present invention, Fig. 2 is a perspective view of the motor, and Fig. 3 is a sectional view taken along line AA of the motor shown in Fig. 1. , FIG. 4 is a sectional view of the main parts of the motor, FIG. 5 is a sectional view of a conventional permanent magnet rotor type synchronous motor, and FIGS. 6 and 7 are sectional views of the main parts of the motor.
FIG. 8 is an explanatory diagram showing a state in which the rotor rotates synchronously with one stator alternating magnetic field and a state in which it rotates asynchronously, and FIG. 9 is an explanatory cross-sectional view of FIG. 8. 3...Rotor, 4...Rotating shaft, 5...Stator,
5a, 5b...Magnetic pole part, 6...Drive coil, 7...
...Inertial mass body, 8...Viscous friction member, 9...Brim, 10...Protrusion.

Claims (1)

[Scope of utility model registration request] A stator having a magnetic pole part, a drive coil that excites the stator, a rotor having permanent magnet poles rotatably supported between the magnetic pole parts, and the rotor or a rotor integrated with the rotor. A viscous friction member having opposing inner surfaces fixed to a shaft and retaining elasticity, and an inertial mass body loosely fitted and held in the viscous friction member, the viscous friction member and the inertial mass body. A permanent magnet rotor-type synchronous motor, in which one of the abutting inner surfaces is flat, the other side has a rib extending in the radial direction, and a plurality of hemispherical projections are provided on the rib to make contact with the inertial mass body. .