JPH0416621Y2 - - 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 N pole, the rotor 23 starts to move from the A position in 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 and the inertial mass body, 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 a magnetic pole part, a drive coil that excites the stator, and a shaft rotatably supported on a bearing body between the magnetic pole parts. a rotor having permanent magnet poles, and a rotor fixed to a shaft integrated with the rotor on the outside of the bearing body, one of the opposing inner surfaces is flat and the other surface is provided with a plurality of hemispherical protrusions. It includes a viscous friction member and an inertial mass body loosely fitted and held in the viscous friction member, the inertial mass body is disposed as a magnetic body at a position where the magnetic force of the rotor acts, and the protrusion of the viscous friction member It is arranged on one side of the rotor away from the rotor and comes into contact with the inertial mass body.

Effect With the above configuration, the viscous friction member and the inertial mass body are brought into more reliable contact with the flat side of the viscous friction member using the magnetic force of the rotor of the inertial mass body without interfering with their functions, thereby achieving close contact. By doing so, the inertial force of the inertial mass body is sufficiently applied to the rotor to improve starting and prevent the occurrence of disturbances.

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. A viscous friction member 8 is fixed to the rotating shaft 4 on the outside of the bearing body 1 and has a substantially disc-shaped inertial mass body 7 loosely fitted therein and has opposing inner surfaces. The inertial mass body 7 is made of a magnetic material. Further, the viscous friction member 8 has one of its inner surfaces that come into contact with the inertial mass body 7 as a flat surface, and the rotor 3
A plurality of hemispherical protrusions 9 are provided on one surface remote from the inertial mass body 7 so as to come into contact with the upper surface of the inertial mass body 7.

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 in contact with one plane side of the viscous friction member 8 near the rotor 3 due to the protrusion 9 provided on the viscous friction member 8 . Further, since the inertial mass body 7 is made of a magnetic material, the inertial mass body 7 is attracted to the rotor 3, and its adhesion with the viscous friction member 8 is becoming better. 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 is sufficiently transmitted to the rotor 3 to facilitate starting.

If the movement of the inertial mass 7 is fixed by reducing the gap between the inertial mass 7 and the viscous friction member 8, the inertial mass 7 will become just a weight, and the initial This prevents vibration and makes starting difficult, but since the inertial mass 7 is brought into close contact with the viscous friction member 8 using the projections 9 provided on the viscous friction member 8 and the magnetic force acting on the inertial mass 7, the inertia The inertial force can be sufficiently transmitted to the rotor 3 without hindering the movement of the mass body 7.

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 uses a magnetic body as the inertial mass body, and has one of the opposing inner surfaces of the viscous friction member flat and the other surface provided with a plurality of hemispherical protrusions. By arranging the projections on one inner surface of the viscous friction member away from the rotor, the contact between the flat side of the viscous friction member and the inertial mass is ensured without interfering with the movement of the inertial mass, and the starting The purpose of the present invention is to provide a permanent magnet rotor type synchronous motor that is easy to operate 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, Fig. 3 is a sectional view taken along line A-A of the motor, and Fig.
The figure is a sectional view of the main parts of the same motor, Fig. 5 is a sectional view of a conventional permanent magnet rotor type synchronous motor, Figs. 6 and 7 are sectional views of the main parts of the same motor, and Fig. 8 is one side. FIG. 9 is an explanatory cross-sectional view of FIG. 8, showing a state in which the stator alternating magnetic field and the rotor rotate synchronously and a state in which the rotor rotates asynchronously. 3...Rotor, 4...Rotating shaft, 5...Stator,
5a, 5b...Magnetic pole part, 6...Drive coil, 7...
...Inertial mass body, 8...Viscous friction member, 9...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 on a bearing body between the magnetic pole parts; a viscous friction member that is fixed to a shaft integrated with the child and has one of its opposing inner surfaces flat and the other surface provided with a plurality of hemispherical protrusions; and an inertial mass body that is loosely fitted and held in the viscous friction member. The inertial mass body is provided as a magnetic body at a position where the magnetic force of the rotor acts, and the protrusion of the viscous friction member is disposed on a side facing away from the rotor so as to come into contact with the inertial mass body. Permanent magnet rotor type synchronous motor.