JPH11303745A - Sealed motor-driven compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the power consumption of a PTC relay at a low cost without providing a timing circuit by providing a switch opened or closed when detecting the temperature of a main winding on the auxiliary winding of an electric element in a sealed motor-driven compressor started by the PTC relay. SOLUTION: When a sealed motor-driven compressor is started, the main winding 16 and auxiliary winding 17 of a motor element are excited to rotate a rotor, a piston is reciprocated in a cylinder by the rotation via a connecting rod fitted to the eccentric section of a shaft, and a coolant is sucked, compressed and discharged. A PTC relay 19 is self-heated to increase temperature when the auxiliary winding 17 is excited, and the current of the auxiliary winding 17 is decreased. The main winding 16 is continuously excited, the main winding 16 is self-heated to increase temperature, a bimetal stored in it reaches the reverse temperature and opens the contact point of a switch 1. When the operation of the compressor is stopped and the temperature is lowered, the switch 1 is returned before a restart.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for improving the efficiency and cost reduction of a hermetic electric compressor connected to a refrigeration cycle of an electric refrigerator or the like.

[0002]

2. Description of the Related Art Conventionally, an electric circuit of a hermetic electric compressor is disclosed in Japanese Patent Application Laid-Open No. 8-154467.

FIG. 5 shows a circuit diagram of a conventional hermetic electric compressor, in which 16 is a main winding, 17 is an auxiliary winding, 18 is a sealed container, 19 is a PTC relay, and 19 is a PTC relay.
Are connected in series with the auxiliary winding 17. Reference numeral 20 denotes an overload protection device for preventing abnormal heating of the main winding 16. Reference numeral 21 denotes a timed circuit, which includes a triac 22, a resistor 23, a CR absorber 24, and an auxiliary PTC 25.

In the circuit of the hermetic electric compressor constructed as described above, not only the main winding 16 but also the auxiliary winding 17 is energized at startup, and the PTC relay 19
The PTC relay 19 has a high resistance due to self-heating and a rise in temperature, and the current becomes small. However, a voltage almost the same as the power supply voltage is applied to both ends of the PTC relay 19, so that power of 2 W to 4 W is applied. Continue to consume.

In order to reduce the power consumption, a time limit circuit 21 is provided, and the power supply to the PTC relay 19 is cut off after the start-up.

[0006]

However, in the above-described conventional configuration, a separate circuit must be prepared in a place where the ambient temperature is not affected by the heat of the hermetic electric compressor and the ambient temperature is low. The wiring must be provided in the storage section or the like, and the wiring needs to be extended significantly more than when the timed circuit is not provided.

An object of the present invention is to provide a refrigeration system which can reduce the power consumption of a PTC relay by providing a switch inside a hermetic electric compressor, and further does not provide a timed circuit. An object of the present invention is to produce at low cost by using the same wiring length.

[0008]

According to the present invention, a switch is provided in an auxiliary winding of an electric element for sensing and opening a temperature of a main winding.

Thus, without providing a timed circuit,
The power consumption of the PTC relay can be reduced at low cost.

[0010]

According to the first aspect of the present invention, the auxiliary winding of the electric element is provided with a switch for opening and closing by detecting the temperature of the main winding. Can be reduced at a low cost.

According to a second aspect of the present invention, the switch uses a bimetal, and has a function of inverting the current when the temperature rises and interrupting the current, and inverting the current when the temperature falls and inverting the current. Therefore, there is an effect that the cost can be further reduced.

According to the third aspect of the present invention, the switch uses a trimetal, and since the tolerance of the temperature at which the switch is reversed is smaller than that of the bimetal, the switch can be opened and closed with high accuracy. Have.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same parts as in the conventional example are denoted by the same reference numerals,
Detailed description is omitted.

FIG. 1 is a circuit diagram of a hermetic electric compressor according to an embodiment of the present invention, wherein 1 is a switch using a bimetal.

FIG. 2 is a sectional view of the hermetic electric compressor according to the first embodiment of the present invention. Reference numeral 2 denotes a cylinder head having a suction chamber (not shown) and a discharge chamber (not shown). )have. 3 is a block, 4 is a shaft, 5 is an eccentric part of the shaft 4, 6 is a connecting rod, 7 is a piston,
8 is a cylinder chamber, and 9 is a rotor. Reference numeral 10 denotes a stator having a main winding 16 and an auxiliary winding 17.

FIG. 3 is a plan view of a stator according to an embodiment of the present invention.
Is fixed.

FIG. 4A is a sectional view of a switch 1 using a bimetal according to one embodiment of the present invention.
Reference numeral 2 denotes a bimetal, 13 denotes a contact, and 14 denotes a case formed of an insulator. FIG. 4B is a cross-sectional view of a switch using a trimetal according to one embodiment of the present invention. Reference numeral 15 denotes a trimetal. The bimetal is formed by rolling two metals having different coefficients of thermal expansion, and the trimetal is formed by rolling three metals having different coefficients of thermal expansion. The trimetal has a higher accuracy of the reversal temperature.

With the above configuration, when the hermetic electric compressor starts to start, the main winding 16 and the auxiliary winding 17 are energized, and the rotor 9 starts rotating. This rotation rotates the shaft 4, and the piston 7 changes the volume of the cylinder chamber 8 of the block 3 by the connecting rod 6 attached to the eccentric part 5 of the shaft. When the cylinder chamber 8 becomes large, a refrigerant (not shown) is sucked from a suction pipe (not shown) attached to the closed container 18 through a suction chamber in the cylinder head 2, and when the cylinder chamber 8 becomes small, Is compressed by sending refrigerant through a discharge chamber of the cylinder head 2 to a discharge pipe (not shown) of a closed container.

When power is supplied to the auxiliary winding 17 and the PTC
The temperature of the relay 19 rises due to self-heating and the auxiliary winding 17
Current becomes small. On the other hand, since the main winding 16 continues to be energized, the temperature of the main winding rises due to the self-heating of the main winding 16, and the temperature of the built-in bimetal 12
Reaches the reversing temperature and the contact of the switch 1 is opened.

Since the temperature of the main winding is kept high during operation, the contact 13 of the switch 1 remains open.

When the operation of the hermetic electric compressor stops, the temperature of the hermetic electric compressor decreases. PTC relay 19 is 7
The internal resistance greatly changes from 0 ° C. to 130 ° C., and is several kΩ or more above the temperature, and several Ω to several tens Ω below the temperature.
Therefore, before the internal resistance of the PTC relay 19 decreases, the temperature at which the bimetal reverses so that the bimetal 12 reverses before the internal resistance of the PTC relay 19 decreases may be set to be several degrees higher than the resistance change temperature of the PTC relay 19. Since the switch 1 returns before the restart, there is no problem in the restart.

Further, a switch 1 using a trimetal 15
Since the temperature tolerance can be reduced, it is possible to operate quickly at the time of start-up to reduce power consumption and to surely reverse the state before restarting.

[0023]

As is apparent from the above embodiment, according to the first aspect of the present invention, there is obtained an advantageous effect that the power consumption of the PTC relay can be reduced at a low cost without providing a time limiting circuit. Can be

According to the second aspect of the present invention, the PT
Since the contact is opened after the C relay has high resistance and the current flowing through the auxiliary winding has become small, there is no problem even if the contact and bimetal are made small. This has the advantageous effect of being able to perform.

Further, according to the third aspect of the present invention, there is obtained an advantageous effect that more power consumption can be reduced and a more reliable restart can be obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a hermetic electric compressor according to an embodiment of the present invention shown in claim 1;

FIG. 2 is a sectional view of the hermetic electric compressor according to one embodiment of the present invention shown in claim 1;

FIG. 3 is a plan view of the stator according to the embodiment of the present invention shown in FIG. 1;

FIG. 4 is a cross-sectional view of a switch using a bimetal or a trimetal according to an embodiment of the present invention.

FIG. 5 is a circuit diagram of a conventional hermetic electric compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switch 12 Bimetal 15 Trimetal 16 Main winding 17 Auxiliary winding 19 PTC relay

Claims (3)

[Claims] 1. A hermetic electric compressor started by a PTC relay, wherein a switch is provided on an auxiliary winding of an electric element of the hermetic electric compressor to open and close by detecting a temperature of a main winding. Hermetic electric compressor. 2. The switch according to claim 1, wherein the switch uses a bimetal.
The hermetic electric compressor as described. 3. A switch using a trimetal.
The hermetic electric compressor as described.