JPH0767256B2 - Hermetic protector for electric compressor - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a hermetically-sealed electric compressor that uses a heat-responsive body made of a metal such as a bimetal that changes its shape depending on different temperatures in order to protect the motor from overload. A mechanism for driving the movable contact to open and close the current flowing to the electric motor between the movable contact and the fixed contact forming a pair is provided in the sealed outer box, and a protector is attached to a part of the outer box and the compressor. It proposes a protector for a hermetic electric compressor provided with an improved mechanism for facilitating.

[Background technology]

Conventionally, the protector of this type hermetic electric compressor is embedded in the coil end part of the stator winding of the electric motor housed in a hermetic container, or tightly fixed on the coil end and tied with a thread. The method was adopted. Then, when an abnormality in the electric current or temperature of the electric motor is detected, the electric current supplied to the electric motor is shut off to protect the winding of the electric motor from overheating, and it automatically recovers to supply the electric current to the electric motor. Continue operation and shut off again if there is an abnormality
The operation is performed as a protection switch that repeats energization. Recently, due to the miniaturization of the hermetic electric compressor, the space for mounting the protector on the coil end portion has become narrower, or the process of tying the protector to the coil end with a thread is troublesome.

[Outline of Invention]

The protector of the present invention includes a mechanism in which a pair of contacts can be opened and closed by a thermo-responsive body such as a bimetal in a hermetically sealed outer casing made of metal, and the outer casing as one terminal and the outer casing as the other terminal. It has at least one terminal pin that is airtightly fixed to a part by an electrically insulating material such as glass, and a receptacle as described later is fixed to the outer box. In a hermetic electric compressor using this protector, the stator of the electric motor is fixed directly to the inner surface of the hermetic container, the rotor is rotatably supported by the magnetic field of the stator, and the compressor is mounted on the rotating shaft. Are connected to each other, and heat medium gas such as Freon gas in the closed container is sent to the outside from the discharge pipe of the closed container to perform work, and then the heat medium gas is returned to the compressor again. A cluster in which a plurality of conductive pins for connecting the motor windings to an external power source are sealed in a metal annular body with an insulating material such as glass is arranged in the closed container, and one of the conductive pins is provided. The position of the protector in the closed container can be determined by fitting the receptacle of the protector to. On the other hand, since the stator of the winding of the electric motor is directly fixed to the inner surface of the closed container, the positions of both the main winding and the auxiliary winding, which are wound around the stator in an insulated manner, are of course fixed. Since the rotor and its windings are also fixed in position, the temperature correlation between the protector and the motor windings has a significant correlation and is an easy-to-install and economical seal for protecting the motor windings. Type protector for electric compressor can be obtained.

Example of Invention

In FIG. 1, a closed container 10 is a robust iron container part 11
And a lid portion 12. Motor rotor R
A compressor P is arranged near the lower end of the rotary shaft S fixed to the, and an outer peripheral portion PO thereof is fixed below the closed container 10.
An electric motor stator F, which is arranged so as to surround the rotor R, has its outer periphery fixed from the center of the container portion 11 to the vicinity of the seam end E. When the inner surface of the closed container 10 is a circle, the outer periphery of the stator F is formed into a polygonal shape so that a gap is formed in the axial direction rather than being in close contact with the entire surface. The stator windings are electrically insulated and wound around the stator F, and the coil ends W of the stator F are extended to the upper and lower ends of the stator F as shown in the figure, which are formed by binding with a nylon thread, for example. . Although the heat medium gas such as Freon is not shown, the lubricating oil O is shown in the lower part of the closed container 10. A discharge pipe 17 through which the heat medium gas is delivered by the compressor P is provided at the upper part of the closed container 10. A cluster 16 hermetically sealed with glass for electrically insulating and supporting the conductive pins 16A, 16B, and 16C is hermetically fixed to a lid portion 12 of the closed container 10 in a metal annular body. Cluster 16 conductive pins 16A / 16B / 16
A receptacle as shown in FIG. 2 and FIG. 3 is fitted to C inside the closed container.

2 to 4, a protector 30 has a mechanism in which a movable contact CM is driven by a thermo-responsive body T such as a bimetal in a sealed outer casing 31 made of metal, and a fixed contact CF that makes a pair with the movable contact. The external box that is equipped with
The reference numeral 31 indicates that the electric circuit is opened and closed with the terminal pin 32 fixed by the electric insulating material 33.
Receptacle 13A is fixed to this by connecting metal fitting 34 by a method such as welding. The lead wire 13 is connected to the terminal pin 32, which is the other end, and the other end of the lead wire 13 is connected to a common end, which is one end of the main winding M and the auxiliary winding A of the motor. ing. Lead wires 14 and 15 are connected to the other receptacles 14A and 15A, respectively, and the other ends thereof are connected to the other end of the main winding M and the other end of the auxiliary winding A, respectively. The receptacles 13A, 14A, and 15A are housed in a socket 20 made of an electrically insulating material, for example, phenol resin, and are provided with electrically insulating partition walls 22 and 23, respectively. The upper part 21 of the socket 20 has a through hole 21 for the conductive pin of the cluster 16.
A ・ 21B ・ 21C are provided, and the three receptacles 13A ・ 14A ・ 15A by the socket 20 are conductive pins 16A ・ 16B, respectively.
・ Can be fitted to 16C at the same time. The connection fitting 34 is made of, for example, a phosphor bronze plate and one end thereof is a protector.
30 is welded to the rounded side surface of the outer box, and the other end is welded to the side of the receptacle 13A to which the lead wire is normally connected, that is, the upper portion in FIG. Is shaped so as to be in close contact with the inner surface of the square hole where the lead wire is pulled out, so that the position of the protector with respect to the socket 20 can be reliably determined. If the shape of the receptacle 13A welded to the protector 30 is changed from the other receptacles 14A and 15A and the shape of the receptacle 13A and the connection fitting 34 is integrated, the receptacle is directly welded to the protector. Makes sense. Of the matters described above, the electrical connection can be more easily understood with reference to FIG. Therefore, in response to the current flowing in the thermal actuator T and the ambient temperature, the movable contact separates from the fixed contact to interrupt the current during abnormal operation of the electric motor, and if the electric motor is normal, the movable contact maintains contact with the fixed contact. It can be seen that it supplies current to the electric motor.

One of the power supplies is connected to the conductive pin 16A of the cluster 16, and the other of the power supplies is connected to the conductive pin 16B via a conductive pin 16B and a capacitor.
When it is connected to and energized, the rotor R of the electric motor rotates and the compressor P is driven by the rotation shaft S. The heat medium gas is discharged from the discharge pipe 17 by the compressor P through the gap between the stator F of the electric motor and the inner surface of the airtight container 10 and the gap between the stator F and the rotor R in the axial direction, and is not shown. After working through the device, it returns to the compressor P and circulates again. Here, the compressed heat medium gas flows through the motor in the axial direction and is discharged from the discharge pipe 17 provided at the upper part of the closed container, and In a hermetic electric compressor in which the motor stator is fixed to the inner surface of the hermetic container, the thermal relationship between the motor winding and the protector due to the heat medium gas is almost equal to that of the structure in which the protector is bound on the stator winding. It should be noted that since the relationship can be inferior to that of the motor, the protection performance against the abnormality of the electric motor is excellent and the protector can be mounted very easily.

As another embodiment of the present invention, as shown in FIGS. 5 and 6, the protector 30A insulates one terminal box 32 electrically insulated from one outer case 31A and another terminal pin 32A. Material 33A
The items provided by This terminal pin 32A
A heating element 37 made of, for example, a nichrome wire having a relatively high resistance is connected to one end inside the outer casing 31A, and the other end is connected to a terminal pin 32. This heating element 37 is a thermal actuator T
Are arranged so as to have a heat exchange relationship with. The terminal pins 32 are connected to the lead wires 13 as shown in FIG.
Is connected to one end of the main winding M of the motor by a terminal pin
32A is connected to one end of the auxiliary winding A by a lead wire 13A. Other symbols are the same as those in FIG. 4, and the same symbols represent equivalent substances. Compared with the case shown in FIG. 4, this protector 30A has a protection characteristic suitable for responding to changes in the auxiliary winding current because the current flowing through the auxiliary winding A flows through the heating element 37 having a relatively high resistance. You can have it.

〔The invention's effect〕

The protector for the hermetic electric compressor of the present invention described above is
Positioning of the protector by conductively fixing one of the receptacles to be fitted to the conductive pin of the cluster necessary for power supply to the motor to the outer box of the protector, and fitting this receptacle to the conductive pin It is designed so that it can be fixed and electrically connected.It is much less troublesome than the conventional method of binding to the winding of the electric motor, and in the case of a small electric motor, the coil end of the winding is small. Moreover, there is an excellent effect that it is possible to reduce the size of the protector without using an extra space for binding the protector as in the conventional case.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a hermetic electric compressor according to an embodiment of the present invention. FIG. 2 is a plan view in which the outer shell upper part 21 of the socket for housing the receptacle is removed,
FIG. 3 shows a perspective view of the protector and the socket as seen from diagonally above. FIG. 4 is a wiring diagram schematically showing electrical connection. FIG. 5 is a perspective view showing a protector according to another embodiment. FIG. 6 is a connection diagram schematically showing electrical connection when the protector shown in FIG. 5 is used. 10 …… Airtight container, 13A ・ 14A ・ 15A …… Receptacle, 16
…… Cluster, 16A / 16B / 16C …… Conductive pin, 30 ・ 30A…
… Protector, 31 ・ 31A …… Outer box, 32 ・ 32A …… Terminal pin, F …… Motor stator, P …… Compressor, R …… Motor rotor, S …… Rotary shaft, W …… Coil end .

 ─────────────────────────────────────────────────── ─── Continuation of the front page Examiner Minoru Shimizu (56) References JP-A-56-107990 (JP, A)

Claims (1)

[Claims] 1. A hermetic electric compressor in which a stator of an electric motor is fixed to an inner surface of a hermetic container, a rotor is rotatably supported at the center of the hermetically sealed container, and the compressor is operated by the rotation of the rotor. A cluster consisting of a plurality of conductive pins for connecting the winding of the electric motor to an external power source is hermetically fixed on a hermetically sealed container, and has a metal hermetic outer box with good thermal conductivity as one terminal. And a heat-actuated protector having one or more terminal pins electrically insulated from the outer casing as the other terminals, and the other terminals having the other terminals through one end of each of the main winding and the auxiliary winding of the motor winding and a lead wire. The outer box has a receptacle that is fitted to one of the conductive pins of the cluster, and the other conductive pin of the cluster is connected via a lead wire to the main winding of the motor and the auxiliary. Each of the windings And the receptacle of the protector is fitted and connected to the conductive pin of the cluster, so that the protector is easily positioned and fixed so that heat exchange with the refrigerant gas is improved. Machine protector.