JPH0791375A - Protector for closed type motor-driven compressor - Google Patents

Abstract

PURPOSE:To secure a protector which is used on a closed type motor-driven compressor, easy of installation and high in reliability. installation and high in reliability. CONSTITUTION:A protector 11 consists of an electric insulative holder 13 and a thermally actuated switch 12 provided with a hermetically sealed vessel made of metal being stored in this holder. Each of connecting terminals 14A and 14B is conductively attached tight to two lead pins 12A and 12B of this thermally actuated switch 12. This thermally actuated switch 12 sticks fast to a step part 13A at the time of storage, partitioning the inside of the holder 13 into a thermally actuated switch storage part 13B and a terminal storage part 13C. An electric insulative filler is filled up in the terminal storage part 13C and ahrdened, whereby the thermally actuated switch 12 is clamped to the holder 13, while a sticking part between the lead terminals 12A, 12B and the connecting terminals 14A, 14B is protectively lockable. Therefore, supposing these creating terminals are directly attached to a glass sealed terminal of a closed type motor compressor, the sticking part between the lead terminal and the connecting terminal will not be deformed and broken by vibration and bending at all.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This application relates to a protector used in a hermetic electric compressor, and an object thereof is to obtain a protector which is easy to install and has high reliability.

[0002]

2. Description of the Related Art Conventionally, various heat-actuated switches have been used to protect a hermetic electric compressor from overheating due to overload, but among them, the hermetic electric motor is used because of its good heat exchange relationship with the electric motor and refrigerant. Some use a thermally actuated switch that is mounted in a closed container of a compressor. The attachment of the heat-actuated switch is fixed to the coil of the electric motor with a binding string as disclosed in Japanese Utility Model Laid-Open No. 55-87170, for example, or in Japanese Utility Model Laid-Open No. 60-95183.
As disclosed in "Overload protection device for hermetic compressor" of Japanese Patent Publication, there is a device which is mounted inside a container by an elastic body.

In the case where the protector is tied to the coil with a binding string or the like, there is a problem that the attaching work is not easy and very time-consuming. On the other hand, since the overload protection device of Japanese Utility Model Laid-Open No. 60-95183 is installed inside the airtight container with an elastic body, the work of installing the overload protection device is easy. It is necessary to install the parts for installing the device, and the sufficient insulation distance between the closed container and the motor winding is required, so consider the extra space inside the closed container of the electric compressor. Or, it is necessary to make the closed container extra large.

On the other hand, for example, JP-A-62-2967
In Japanese Patent Laid-Open No. 39 and Japanese Patent Laid-Open No. 63-28246, "Protector for Hermetically Compressed Electric Compressor", a protector is attached with a mounting terminal such as a tab or a receptacle, and the protector is housed in a socket or outside the socket. It is shown that the fixing terminal is directly attached to the pin of the glass sealed terminal of the hermetically sealed container.

[0005]

However, in the case where the mounting terminal fixed to the protector is directly attached to the glass sealed terminal of the hermetic container as described above, the protector can be easily mounted and the mounting position can be minimized. Therefore, it is not necessary to consider the extra space inside the electric compressor's airtight container or to make the airtight container extra large.However, due to vibrations during operation of the electric compressor, the joint between the protector and the mounting terminal may be twisted. There is a problem that a large load is applied by bending or bending, and sufficient strength cannot always be obtained by the conventional method.

[0006]

Therefore, a protector for a hermetic electric compressor according to the present invention has a metal hermetically sealed container and one or more conductive pins that are insulated and fixed through the hermetically sealed container. The airtight container has a thermoresponsive switch to which connection terminals are conductively fixed, and a box-shaped holder made of an electrical insulator, and the thermoresponsive switch is held in a recess of the holder. It is characterized in that a structure for preventing the deformation and destruction of each terminal and the fixed portion by filling and hardening an electrically insulating filling material in the storage portion of the fixed portion of the connection terminal and the connection terminal to reinforce the fixed portion.

Another feature is that at least one of the connection terminals is directly connected to the conductive terminal of the glass sealed terminal of the hermetic electric compressor, and the holder is provided with a holding portion for restricting the movement of the conductive terminal. The purpose is to reduce the load on the conductive terminals due to vibration of the electric motor and prevent the conductive terminals from being deformed or damaged.

Another feature is that only the storage portion of the fixing portion between the heat-actuated switch and the connection terminal is hardened and fixed by an electrically insulative filling material, and the other portion of the heat-actuated switch is exposed to a space through which a refrigerant can flow. By doing so, it is possible to increase the area in which the heat-actuated switch and the refrigerant come into direct contact with each other, thereby facilitating heat exchange and improving the responsiveness to overheating of the refrigerant when an abnormality occurs.

[0009]

EXAMPLES Examples will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a hermetic electric compressor having a so-called high-pressure housing to which a protector for a hermetic electric compressor of the present invention (hereinafter referred to as a protector) is attached, and FIG. It is a sectional view taken along the line A-A. The hermetic electric compressor 1 constitutes a hermetic container composed of a lid 2 and a lower container 3, and an electric motor 4 having a well-known structure is provided in the hermetic container.
And the compressor 5 is housed and fixed. A suction pipe 6 for introducing a refrigerant sent from a heat exchanger (not shown) to the compressor 5 is connected through the closed container, and the refrigerant compressed by the compressor 5 is discharged into the closed container. Then, it flows around the electric motor and is sent again from the discharge pipe 7 to the heat exchanger. A through hole is provided in a part of the closed container, that is, the lid 2 in the embodiment, and a glass sealed terminal 8 for connecting the electric motor 4 inside the closed container to an external power source is hermetically fixed by welding or the like in this through hole. Has been done. Lubricating oil 9 for the electric motor 4 and the compressor 5 is enclosed in the closed container.

In the embodiment, the glass sealed terminal 8 has three conductive terminals 8A, 8B and 8C, and each conductive terminal is hermetically fixed through an electrically insulating material such as glass.
In addition, each conductive terminal has a tab terminal for connection inside the airtight container, two of which, 8B, 8C.
Is connected to the lead wire 10 from the winding of the electric motor, and the protector 11 is connected to the remaining 8A.

This protector 11 is shown in FIGS.
Will be described with reference to. 3 is a plan view of the protector 11 in a temporarily fixed state before being filled with an electric insulating material described later, and FIG. 4 is a BB of FIG. 3 after being filled with the electric insulating material.
It is a principal part cross-section arrow view of a cross section. The protector 11 is configured such that a heat-actuated switch 12 having a metal-made airtight housing having a well-known structure as shown in FIG. 5 (A) is housed and fixed in an electrically insulating holder 13 as shown in FIG. 5 (B). ing. The heat-actuated switch 12 has a well-known structure using a heat-actuated element such as bimetal, and the description of the structure will be omitted, but it is described in, for example, Japanese Patent Application Laid-Open No. 2-227928 and Japanese Patent Application Laid-Open No. 5-36335. It is shown.

Lead terminal pins 12A and 12B are hermetically fixed to the thermally actuated switch 12 by penetrating the hermetic housing by an electrically insulating sealing material 12C such as glass or ceramics. Connection terminals 14A and 14B for connection with the above-mentioned glass sealed terminal 8 and the lead wire 10 from the electric motor are conductively connected and fixed to each lead terminal by welding or the like. In this embodiment, the connection terminal 1
4A is connected to the conductive terminal 8A of the glass sealed terminal, and the connection terminal 14B is connected to the lead wire 10 from the electric motor.

The holder 13 has a substantially box shape, and a step portion 13A provided inside the holder 13 accommodates the heat-actuated switch in the accommodating portion 13B so as to be divided into a terminal accommodating portion 13C. A connection terminal holding portion 13D that holds a connection portion between the connection terminal 14A and the conductive terminal 8A of the glass sealed terminal 8 is provided on the outer circumference.

Heat-actuated switch housing 13B of holder 13
A pressing part 13E is provided on the inner wall of the pressing part 1E.
Due to 3E, the end face of the housing of the heat-actuated switch is stepped 13A.
The heat-actuated switch is temporarily fixed to the holder by this pressing force as soon as it is pressed against.

The heat-actuated switch 12 has connection terminals 14A, 14
After fixing B to the predetermined lead terminals 12A and 12B, respectively, the tip of the connection terminal 14A is inserted into the connection terminal holding portion 13D of the holder 13, and at the same time, the thermoresponsive switch 12 main body is placed in the thermoresponsive switch storage portion 13B. The side where the lead terminal and the connection terminal are fixed is inserted into the terminal housing 13C and temporarily fixed. In this state, the terminal storage portion 13C of the holder 13
Then, a liquid electrically insulative filling material 15 such as an epoxy resin mixed with a hardening agent is injected and cured so as to cover the fixed portions of the lead terminals 12A, 12B and the connection terminals 14A, 14B of the thermoresponsive switch 12. Then, the heat-actuated switch 12 is fixed to the holder 13. This state is shown in FIGS.

At this time, the electrically insulative filling material 15 may flow into the heat responsive switch housing portion 13B side, but in the embodiment, the housing end face of the heat responsive switch 12 is provided with the step portion 13A of the holder 13 as described above. By making it adhere to
It is possible to prevent the electrically insulative filling material 15 from flowing into the heat responsive switch housing portion 13B. Therefore, the filling material 15
In addition to saving energy, the refrigerant flows through the space around the thermally responsive switch 12 in the storage portion 13B, so that the heat exchange efficiency is improved and the responsiveness to heat generation due to overheating of the electric motor or abnormality of the compressor is improved. Further, as shown in FIG. 7, by providing the ventilation hole 13F in the wall of the holder on the side of the heat-responsive switch housing portion, the heat exchange efficiency between the refrigerant and the heat-responsive switch can be further improved.

In order to improve the adhesion between the heat-actuated switch 12 and the holder 13, a thin plate portion 13A1 is provided elastically by providing a thin plate portion 13A1 on the stepped portion 13A of the holder 13 as shown in the enlarged view of the essential part of FIG. The electrically insulative filling material 15 is provided so as to be in close contact with the heat-actuated switch 12 or an elastic body such as silicone rubber is provided in this portion, so that the heat-actuated switch storage portion 13B is provided.
Can be prevented from flowing into. Alternatively, the holder 13 may be formed of a material having sufficient elasticity.

By thus fixing the area around the fixed portion between the lead terminal and the connection terminal of the heat-actuated switch with the hardened electrically insulating filler, the heat-actuated switch is directly connected to the conductive terminal of the glass sealed terminal. However, the force such as twisting or bending due to the vibration of the electric motor is not applied to the fixing portion, so that the connection terminal can be prevented from coming off from the heat responsive switch. At the same time, by adopting such a structure, it is possible to reduce the load due to the vibration transmitted to the electrically insulating sealing material such as glass or ceramics holding the lead terminals 12A and 12B of the heat responsive switch 12. It is possible to prevent cracks from being generated in the sealing material and impair the airtightness of the heat responsive switch 12.

Further, since the protector 11 is connected to the glass-sealed terminal with only one connecting terminal 14A, the load is concentrated on the bent portion 14A1 of the connecting terminal 14A and the bent portion is deformed or broken by the weight of the protector. There is a possibility that it will end up. However, the holder 13 is connected to the connection terminal holder 13
By providing D, it is possible to prevent the connection terminal 14A from substantially moving and reduce the load on the connection terminal, and to prevent the bent portion 14A1 from being deformed or damaged.

Although the electric compressor having a high pressure housing has been described as an example in the embodiment, the present invention is not limited to this, and the present invention can be similarly applied to a so-called low pressure electric compressor. . Further, the type of the compressor is not limited, and it goes without saying that it may be a rotary type compressor such as a rotary type or a scroll type, or a reciprocating type compressor such as a reciprocating type.

[0021]

As described above, the heat-actuated switch is electrically connected to the glass-sealed terminal by fixing the periphery of the fixed portion between the lead terminal and the connection terminal of the heat-actuated switch with the hardened electrically insulating filler. Even if it is directly connected to the terminal, the load due to the force such as twisting or bending due to the vibration of the electric motor is not applied to the fixed part or the sealing fixing part of the lead terminal of the heat-actuated switch. It is possible to prevent the connection terminal from being deformed or dropped, and the airtight deterioration due to damage to the sealing material of the heat-responsive switch.

Further, since the lead terminals and the connection terminals are embedded in the electrically insulating material, the distance between the terminals can be made relatively small, and the heat-responsive switch can be easily downsized.

Further, by providing the holder with the connection terminal holding portion, the connection terminal can be substantially kept stationary and the load applied to the connection terminal due to the vibration of the electric motor can be reduced, so that the conductive terminal is not deformed or damaged. Can be prevented.

Further, the outer edge of the heat-actuated switch and the inner surface of the holder are brought into close contact with each other to define the inside of the holder, and the filling material is filled only in the fixing portion between the lead terminal and the connection terminal of the heat-actuated switch to cure and fix it. In addition to saving the filling material, by providing a space for the refrigerant to flow around the heat-actuated switch in the holder, the heat exchange efficiency is improved, and heat generation due to overheating of the motor or abnormality of the compressor Responsiveness is improved. Further, by providing the ventilation hole in the wall of the holder on the side of the heat-responsive switch housing portion, the heat exchange efficiency between the refrigerant and the heat-responsive switch can be further improved.

[Brief description of drawings]

FIG. 1 shows an embodiment of a hermetic electric compressor using a protector of the present invention.

2 is a cross-sectional view taken along the line AA of the hermetic electric compressor shown in FIG.

FIG. 3 is a plan view of an embodiment of the protector of the present invention when temporarily fixed.

4 B of the protector of FIG. 3 after filling with an electrically insulating material
-B sectional arrow view.

5 is used in the embodiment of FIG. 3, (A)
Is a heat-actuated switch, and (B) is a perspective view of a holder.

6 is a perspective view of the protector of FIG. 3 after being filled with an electrically insulating material.

FIG. 7 is another embodiment of the holder used in the protector of the present invention.

FIG. 8 is an enlarged view of a main part of another embodiment of the holder.

[Explanation of symbols]

 1: Hermetic type electric compressor 8: Glass sealed terminal 11: Protector 12: Thermally actuated switch 12A, 12B: Lead terminal 12C: Electrical insulating sealing material 13: Holder 13D: Connection terminal holder 14A, 14B: Connection terminal 14A1: Bent part 15: Electrically insulating filler

Claims (3)

[Claims] 1. A thermal responsive device having a metal closed container and one or more conductive pins insulated and fixed through the closed container, and a connection terminal being conductively fixed to the conductive pin or the closed container. A switch and a box-shaped holder made of an electric insulator are provided, the heat-responsive switch is held in a recess of the holder, and an electrically insulating filling is provided in a storage portion of a fixing portion between the heat-responsive switch and a connection terminal. A hermetic protector for an electric compressor, which is characterized by being filled and hardened. 2. At least one of the connection terminals is directly connected to a conductive terminal of a glass sealed terminal of a hermetic electric compressor, and a holding portion for restricting movement of the conductive terminal and preventing deformation or damage is provided in a holder. Claim 1 characterized by having.
A hermetic protector for electric compressors. 3. A heat exchange is performed by curing and fixing only a storage portion of a fixing portion between a heat-actuated switch and a connection terminal with an electrically insulating filler and exposing the other portion of the heat-actuated switch to a space through which a refrigerant can flow. The protector for the hermetic electric compressor according to claim 1 or 2, wherein the protector is made easier.