JPS6027260B2 - synchronous motor - Google Patents

Description

[Detailed description of the invention] The present invention relates to a synchronous mode external device.

Conventionally, this type of surface-facing synchronous motor, especially a shaded coil-less multi-pole inductor synchronous motor, has a low temperature of minus 1.
It is necessary to guarantee dynamic characteristics at ambient temperatures ranging from 500°C to high temperatures plus 80°C.

In this case, as shown in FIG. 5, the output torque Tq3 of the synchronous motor repeats its amplitude every half cycle of the AC input current waveform AC. Therefore, the rotor corresponds to the synchronous speed SP,
Microscopically, at room temperature, it rotates like a cocking mechanism. On the other hand, as the ambient temperature rises, the thrust friction loss torque that occurs during the frictional movement between the thrust washer integrated with the rotor and the bearing press-fitted into the stator cylinder decreases, so the rotor becomes even more twitching as shown in r2. If this continues, it will lead to a loss of synchronicity. The present invention eliminates the above-mentioned drawbacks and provides a synchronous motor that can prevent step-out using a magnetic brake. The synchronous motor of the present invention will be explained below along with the drawings.

1 and 2, reference numeral 1 denotes a coil frame around which a coil 2 is wound, into which an oilless sintered bearing 3 is press-fitted, and a rotating shaft 4 is pivotally supported in the oilless sintered bearing 3. A multi-pole magnetized rotor 7, which faces the magnetic pole tooth surfaces 6 of the stator 5, is integrated into the rotating shaft 4.

In addition, a cover 9 is attached to the motor case 8 that surrounds the coil frame 1.
A bimetal 10 is attached to the inner upper surface of the cover 8, and a stator 5 is attached to the bimetal 10.
A control permanent magnet 12 is fixedly installed so as to face the magnetic pole surface 11 of the rotor 7 on the opposite side of the magnetic pole tooth surface 6 . In this case, as shown in FIG. 3, magnetic pole teeth 13 of the same polarity are formed on the braking permanent magnet 12 toward the magnetic pole surface 11, and each magnetic pole 13 is arranged between two magnetic poles of the rotor. and each magnetic pole tooth 1 is spaced apart from the other magnetic pole teeth of the stator 5.
3 will face the same pole or different pole at the same time. Furthermore, as shown in FIG. 4, the bimetal 10 is set so that the amount of displacement at an ambient temperature of +80 qo is extremely large and approximately at its maximum, compared to when the ambient temperature is -15 qo. Further, a thrust washer 14 is interposed between the oilless sintered bearing 3 and the rotor 7. Furthermore, the operation of the present invention will be explained in detail.If the coil 2 is excited, the fifth
As shown in the figure, an output torque Tq3 is generated by combining the excitation torque Tq and the reluctance torque Tq2 generated by the magnetic force of the rotor. On the other hand, if the ambient temperature increases and the viscosity of the enclosed lubricating oil decreases, the thrust friction loss torque decreases. At this time, as the temperature rises, the bimetal 10 begins to be displaced toward the magnetic pole surface 11 of the rotor 7, and the braking permanent magnet 12 approaches the magnetic pole surface 11 of the rotor 7. Therefore, attraction or anti-travel occurs between the braking permanent magnet 112 and the rotor 7, and a reverse torque is applied by the braking permanent magnet 12 as shown at Tq4 in FIG. The peak value of the output torque is flattened and lowered, and the degree of cocking is greatly improved as shown in r3. In this case, since the bimetal 10 is displaced according to the ambient temperature, a large control force is applied at high temperatures, but at low temperatures, the permanent magnets 12 are separated from the rotor 7, so the control force becomes extremely small. According to the synchronous motor of the present invention configured as described above, good rotational output can be obtained without being affected by the ambient temperature, and reliability can be significantly improved. achieve.

[Brief explanation of drawings]

FIG. 1 is a simplified sectional view of the synchronous motor of the present invention, FIG. 2 is a simplified plan view of the same portion, and FIGS. 3 to 5 are explanatory views of the same. 1... Coil frame, 2... Coil, 3... Bearing, 4
... Rotating shaft, 5... Bearing, 6... Magnetic pole tooth surface, 7.
...Rotor, 8...Motor cover, 9...Cover, 10...Bimetal, 11...Magnetic pole surface, 12...Permanent magnet for braking, 11...Magnetic pole tooth, 14...Thrust washer. 1st
Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. A control permanent magnet is disposed opposite to a multi-pole magnetized rotor that faces the magnetic pole tooth surfaces of the stator, and the braking permanent magnet faces the rotor. A synchronous motor, characterized in that it is fixed to a displaceable thermally responsive element. 2. Claim 1, in which the thermally responsive element is fixed to the upper surface inside the cover and is located on the opposite side from the stator.
Synchronous motor as described in section.