JP2000262025A - Capacitor motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a capacitor motor which can be restored to normal operation when the cause of abnormality is removed, without employing expensive temperature-sensitive type fuses and relays. SOLUTION: Charging of a specific inductive capacity of insulating material employed in a capacitor 32 at a certain temperature is utilized. More specifically, insulating material whose specific inductive capacity is reduced at a temperature which is slightly lower than a certain temperature (overheating temperature) is employed. That is, by reducing the capacity of the capacitor 32, the impedance of the capacitor 32 is increased and a current flowing into the capacitor 32 is suppressed. The capacitor 32, insulated by the insulating material whose specific inductive capacity is reduced by overheating, is arranged close to a motor coil 28 which is the heating part of a motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condenser motor used for home electric appliances and the like.

[0002]

2. Description of the Related Art A well-known condenser motor (single-phase induction motor) is used in various home appliances. If it is anticipated that the above-mentioned overheating condition that may lead to the burnout of the capacitor motor may occur during the use of home appliances, take measures to protect against overheating by attaching a temperature-sensitive fuse or relay to the motor coil, etc. I do.

[0003]

However, temperature-sensitive fuses and relays are generally expensive and occupy a large portion of the motor cost, despite the purpose of protecting them from burning during abnormal use.

[0004] Further, there is a problem that a temperature-sensitive fuse does not recover once it has been exposed to an overheated state and operated.

In view of the above problems, the present invention provides an expensive temperature-sensitive capacitor motor that does not use a fuse or relay and that returns to normal operation when the cause of the abnormality is eliminated. It is intended for that purpose.

[0006]

According to a first aspect of the present invention, there is provided a capacitor motor, wherein a capacitor is formed of an insulating material whose dielectric constant decreases when overheated, and the capacitor is disposed near a heat generating portion of the motor. It is characterized by.

[0007] In the capacitor motor of the second aspect,
Claim 1 is characterized in that the capacitor is arranged near the motor coil.

According to such a capacitor motor, when the motor is heated to an overheated temperature, the dielectric constant of the insulating material of the capacitor decreases, that is, the capacitance of the capacitor decreases, thereby increasing the impedance of the capacitor.
The current flowing through the condenser motor is reduced, thereby preventing the condenser motor from rising above a certain temperature.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a cross-sectional view of a condenser motor 10, in which a pair of brackets 12 and 14 forming an outer shell are fixed by a fixture 16, and a rotating shaft 18 penetrates the center of both brackets 12 and 14. Are a pair of bearings 20,
22 is rotatably supported by the shaft. The rotating shaft 18
A substantially circular rotor yoke 24 is fixed to a substantially central part of the rotor yoke.

A stator core 26 having an inner peripheral surface corresponding to the outer peripheral surface of the cage rotor 24 is fixed to the inner peripheral surfaces of the brackets 12 and 14. This stator core 2
A motor coil 28 is wound around the outside of the lead wire 6, and a lead wire 3 connected to a commercial power source from an end of the motor coil 28 is provided.
0 has been derived. Further, the capacitor 32 of the present invention is disposed near the motor coil 28.

The rotation operation of this type of condenser motor 10 is a well-known matter, and a description thereof will be omitted.

FIG. 2 shows a connection diagram of a general condenser motor 10, and shows a divided motor coil 28. As shown in FIG.
_1, which was connected in parallel a series circuit of a capacitor 32 and the motor coil 28 _2, the parallel circuit is a commercial power source AC
Is to be connected to. Further, FIG. 3 shows the case of a series connection, the motor coil 28 ₁ and 28 ₂ divided connected in series, the capacitor 32 is connected in parallel to the motor coil 28 _1. Then, the motor coil 28 ₁ ,
28 _second series circuit the commercial power source AC is connected to.

Here, the dielectric constant of the insulating material used for the capacitor 32 of the present invention is changed from a certain temperature. Specifically, as shown in FIG.
An insulating material that decreases the dielectric constant from just before a certain temperature (overheating temperature) is used. That is, the dielectric constant decreases from just before the temperature at which the overheating occurs, that is, by decreasing the capacitance of the capacitor 32, the impedance of the capacitor 32 is increased, and the current value flowing into the capacitor 32 is reduced. ing.

As shown in FIG. 1, a capacitor 32 made of an insulating material whose dielectric constant decreases when overheated is arranged close to a motor coil 28 which is a heat generating portion of the motor. The position of the condenser 32 may be anywhere as long as it is a heat-generating part in the condenser motor 10.
A preferred example is a motor coil 28 which normally generates a temperature change sensitively. When the capacitor motor 10 is operated in an abnormal state such as a lock, the capacity of the capacitor 32 rapidly decreases, and the current I2 shown in FIGS. 2 and 3 decreases.
The heat generation of the capacitor motor 10 is suppressed, and as shown in FIG. 5, the temperature of the capacitor motor 10 does not rise above a certain temperature.

As described above, in this embodiment, since the capacitor 32 is formed of an insulating material that reduces the capacity when overheated, even if an abnormal state occurs, the temperature of the capacitor motor 10 does not exceed a certain temperature. It does not rise. This eliminates the need for expensive and temperature-sensitive fuses and relays that have been used in the past, thereby suppressing an increase in cost. Further, when the cause of the abnormality is removed, it is possible to return to the normal operation unlike the related art.

[0017]

As described above, the capacitor motor according to the present invention does not require an expensive temperature-sensitive type fuse or relay. Even if the motor is overheated due to an abnormal operation such as a lock, a constant temperature is maintained. If the temperature does not rise above the temperature and the cause of the abnormality is eliminated, the normal operation can be resumed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a condenser motor according to an embodiment of the present invention.

FIG. 2 is a connection diagram of a general condenser motor according to an embodiment of the present invention.

FIG. 3 is a connection diagram of a general capacitor motor in which a series connection is made according to the embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between the temperature of an insulating material used for a capacitor according to an embodiment of the present invention and the dielectric constant / capacitance.

FIG. 5 is a diagram illustrating a relationship between time and motor temperature according to the embodiment of the present invention.

[Explanation of symbols]

 10 Condenser motor 28 Motor coil 32 Capacitor

Claims (2)

[Claims] 1. A capacitor motor comprising: a capacitor formed of an insulating material whose dielectric constant decreases when overheated; and wherein the capacitor is disposed near a heating portion of the motor. 2. The condenser motor according to claim 1, wherein the condenser is arranged near the motor coil.