JPS59209035A - Motor protector of enclosed motor-driven compressor - Google Patents

Abstract

PURPOSE:To switch a large current by an electric contact of small capacity by branching part of a current flowed to a load to a heater for heating a bimetal disc to deform the bimetal by the quantity of heat generated from the heater and switching a control circuit. CONSTITUTION:A heater 4 is contacted under pressure with a connecting terminal 2 of a motor protector case 1 and a connecting plate 5 is contacted via a bimetal disc 6 with a connecting terminal 3. The heater 4 is insulated via an insulator 8 from the plate 5. Part of a current flowed to a load, not shown, (a motor of an enclosed motor driven compressor) is branched to the heater 4. Initially, the bimetal 6 is energized to close the contacts 2, 3 as shown, but when the temperature of the heater 4 exceeds the threshold value, the bimetal 6 is deformed, the contacts 2, 3 are opened to control a control circuit, not shown, connected to the contact 3, thereby interrupting the current of the load. In this manner, a large current can be switched by the electric contact of small capacity.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a motor protector for a hermetic electric compressor.
In particular, the present invention relates to a motor protector suitable for use in a hermetic electric compressor with a large output.

[Background of the invention]

The motor protector of a conventional hermetic electric compressor passes the entire current flowing through the motor coil to the heater inside the motor protector, and when a large current such as an overload current or a locking current flows, the bimetallic disk is heated and the corresponding The deformation of the bimetallic disk cuts off the power supply to the motor, thereby protecting the motor.

However, compressors with high output have large current values, so
There is a problem that the electrical capacity of the connection terminal to the motor coil is insufficient, making it unusable for high-output compressors.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor protector that solves the problems of the prior art and can also be used for high-output compressors.

[Summary of the invention]

In order to achieve this objective, the motor protector of the hermetic electric compressor of the present invention includes a heater that contacts the connection terminal to the motor coil, a coverlet plate that contacts the connection terminal to the control circuit, and a a bimetallic disc held in the motor coil, the heater and the coverall plate being integrally coupled to the bimetallic disc in an insulating state, the bimetallic disc having a connection terminal to the motor coil that allows the current flowing through the motor coil to be connected to the motor coil. When a part of the bimetallic disk flows, the heater and the cover plate are deformed in a direction away from their respective connection terminals due to the heat of the heater or the heat of the motor coil, and when the temperature of the bimetal disk itself decreases, the heater and the coverlet plate deform. It is characterized in that it is adapted to be restored in the direction of contacting the respective connection terminals.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a cross-sectional view of the motor protector according to the present invention, FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1, and FIG. The case of the motor protector, 2, 2 and 3.3 are connection terminals to the motor coil attached to the case 1 and connection terminals to the control circuit, 4 is a heater in contact with the connection terminals 2 and 2;
5 is a cover plate that contacts the connection terminals 3, 3, 6 is a holder 7
It is a bimetallic disc held within the case 1 via the.

in contact with the four heater bimetal discs 6;
The cover plates 5 and the heater 4 are each integrally connected to a bimetallic disk 6 with an insulating material 8 interposed therebetween. In the non-heated state (low temperature state), the bimetal disc 6 is in a restored state in which the heater 4 and the cover plate 5 are brought into contact with the respective connection terminals 2, 2 and 3, 3, as shown in the figure. , 2 is heated by the heater 4 due to a portion of the current flowing through the motor coil, the heater 4 and the cover plate 5 are deformed in the direction of separating them from the respective connection terminals 2, 2 and 3.3. It has become. Then, when the heater 4 and the cover plate 5 are separated from the respective connection terminals, the control circuit is turned off and the power supply to the motor is completely cut off.

However, in the motor protector of the present invention, when a flow of the mork coil flows through the connection terminals 2, 2,
The bimetal discs are deformed (7) The heater 4 and the connecting terminals 2, 2 and the cover plate 5 and the connecting terminals 3, 3 are separated and the control circuit is cut off, and the power to the motor is cut off, so the connecting terminal 2 .2 requires only a small electric capacity. Therefore, it can be used as a motor protector for a high output compressor.

In the above embodiment, the heater 4 is used to heat the bimetallic metal.
Although an example has been shown in which the disk 6 is heated, the bimetallic disk 6 may be deformed by applying heat from a motor coil to the bimetallic disk 6.

〔Effect of the invention〕

As explained above, the present invention has the advantage that it can also be used as a motor protector for a high output compressor.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a motor protector for a hermetic electric compressor according to the present invention, FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1, and FIG. It is a diagram. 1... Motor protector case 2, 3... Connection terminal 4... Heater 5... Coverall plate 6.
・・Bimetal disc 7・Holder 8・
··Insulating material

Claims (1)

[Claims] A heater in contact with a connection terminal to a motor coil, a cover plate in contact with a connection terminal to a control circuit, and a bimetallic disk held in a Sen-Taguro Tifter case, the heater and the cover plate in contact with a connection terminal to the control circuit. are integrally coupled to bimetallic disks in an insulating state, and the bimetallic disks are heated by the heat of the heater or the motor coil when a portion of the current flowing through the motor coil flows through the connection terminal to the motor coil. The heater and the cover plate are deformed in a direction away from their respective connection terminals, and when the temperature of the bimetal disk itself decreases, the heater and coverlet plate are deformed in a direction in which they are brought into contact with their respective connection terminals. Motor protector for hermetic electric compressor.