TECHNICAL FIELD

The present invention pertains to an electric compressor equipped with a compression part compressing a refrigerant gas and an electric motor driving the compression part, and to a method for assembling same, and specifically pertains to a structure insulating a terminal used in the electric compressor.

BACKGROUND ART

An electric compressor contains a compression part and electric motor driving the compression part within a metal container. Through the operation of the compression part, refrigerant gas within the container is compressed by the compression part and expelled to outside. The metal container is shut tight. Electric power is supplied to the electric motor from an external power supply part via a terminal part provided in an opening of the container.

In circumstances where the electric compressor is used in a refrigerant circuit, when operation is stopped, a refrigerant gas within the compressor cools and condenses. In some cases, this may lead to liquid refrigerant pooling inside the container. Then, upon contact between the terminal part and the liquid refrigerant, a short circuit occurs between the metal container and the terminal part. As such, when operation of the electric compressor starts, there is a risk that current supplied to the terminal part may leak to the container through the liquid refrigerant.

Specifically, an electrical leak is more likely to occur when the lubricant used with the refrigerant is not polyolester oil (POE) but rather polyalkylene glycol (PAG) or a similar lubricant having lower volume resistivity. Thus, there is a need to ensure insulation for the terminal part.

As such, Patent Document 1 discloses technology insulating a part in which current flows by covering the part in which the current flows with resin.

Also, Patent Document 2 discloses technology extending an insulating distance between a terminal connecting part and a sealed-tight container.

CITATION LIST

Patent Literature

Patent Document 1: Japanese Patent No. 4991664Patent Document 2: Japanese Unexamined Patent Application Publication No. H6-235388A

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

However, the technology disclosed in Patent Document 1 requires covering an insulation part with resin. Also, the technology disclosed in Patent Document 2 requires forming an insulation distance extension channel to extend the insulation distance between the terminal connecting part and the sealed-tight container. Thus, a problem of poor workability arises.

In consideration of the above-described problem, the present invention aims to provide an electric compressor and an assembly method for same, in which the electric compressor is equipped with a terminal insulation structure enabling improved insulation with a simple assembly.

Means for Resolving the Problem

In order to solve the above-described problem, the present invention provides the following approach of an electric compressor and a method for assembling same.

That is, an electric compressor according to a first aspect of the present invention includes an electric motor contained in a casing and driving a compression part compressing a refrigerant guided into the casing; and a connecting part container having an external power line supplying electric power to the electric motor guided in from outside the casing, and containing a connecting part electrically connecting, within the casing, the external power line and an internal power line guided from the electric motor. The connecting part container is provided with an insertion hole. The internal power line is inserted through the insertion hole. The connecting part container is splittable at a splitting line splitting the connecting part container and splitting the insertion hole. A first rubber ring is disposed within the connecting part container and blocks off the insertion hole in a liquid-tight state. The first rubber ring is held sandwiched between split walls forming the insertion hole.

According to the first aspect of the invention, the connecting part container is split at the splitting line that splits the insertion hole, and the first rubber ring is held sandwiched between split walls forming the insertion hole, such that the interior of the container is in a liquid-tight state. Thus, blocking the infiltration of the refrigerant in the casing into the connecting part container through the insertion hole is enabled by disposing the first rubber ring so as to block the insertion hole shut in a liquid-tight state. Accordingly, the external power line connected to the connecting part container is insulated.

Also, the connecting part container is blocked shut by the first rubber ring held sandwiched between the split walls forming the insertion hole. Thus, a structure is enabled in which the first rubber ring is unlikely to fall off due to a pressure difference between the inside and outside of the connecting part container.

The electric compressor according to the first aspect of the present invention has one of an engaging protrusion and an engaging concavity formed on the split walls forming the insertion hole. The first rubber ring is provided with one of an engagement concavity engaging with the engaging protrusion and an engagement protrusion engaging with the engaging concavity.

According to the first aspect of the invention, a protrusion or a concavity corresponding to the protrusion or the concavity formed on the walls forming the insertion hole is provided on the first rubber ring. Thus, the first rubber ring may be prevented from falling from the connecting part container.

The electric compressor according to the first aspect of the present invention has the external power line with a terminal pin connected to the connecting part container. The terminal pin is covered by a second rubber ring and made liquid-tight.

According to the first aspect of the present invention, the terminal pin is covered by the second rubber ring and made liquid-tight. Thus, contact between the terminal pin and the refrigerant in the casing is avoided, which enables greater insulation for the terminal part.

The electric compressor according to the first aspect of the present invention has the connecting part container held sandwiched by the second rubber ring and the electric motor.

According to the first aspect of the present invention, the connecting part container is sandwiched by the second rubber ring and the electric motor. This enables the channel of current flow to be sealed and increases insulation. This also prevents the fitted connecting part container from detaching.

The electric compressor of the first aspect of the present invention includes an electric motor contained in a casing and driving a compression part compressing a refrigerant guided into the casing, and a connecting part container having an external power line supplying electric power to the electric motor guided in from outside the casing, and containing a connecting part electrically connecting, within the casing, the external power line and an internal power line guided from the electric motor. The external power line has a terminal pin connected to the connecting part container. The terminal pin is covered by a second rubber ring and made liquid-tight.

According to the first aspect of the present invention, the terminal pin is covered by the second rubber ring and made liquid-tight. Thus, contact between the terminal pin and the refrigerant in the casing is avoided, which enables greater insulation for the terminal part.

The electric compressor of the first aspect of the present invention provides one or both ends of the second rubber ring with one of a fitting concavity and a fitting protrusion fitting correspondingly onto a casing side and/or onto a connecting part container side. The casing side and/or the connecting part container side is provided with one of a fitting protrusion and a fitting concavity fitting correspondingly with the fitting concavity or the fitting protrusion on the second rubber ring.

Also, given that the second rubber ring is sandwiched, there is a possibility that elastic force of the second rubber ring may be excessive upon experiencing extensive sandwiching. Such circumstances may lead to breakage of the connecting part container or of a component positioned opposite, such as the glass terminal. However, a gap between the components sandwiching the second rubber ring is determined by the dimensions of the various components. As such, the tolerance for the dimensions of this gap grows large upon adding the cumulative tolerances of the components.

In order to avoid such discrepancies, intentionally lowering the rigidity of the second rubber ring and decreasing the load relative to displacement has been considered. For example, the rigidity may be lowered by simply making the entirety of the second rubber ring narrower. In such circumstances, the contact surface area between the second rubber ring and the connecting part container or between the second rubber ring and the glass terminal is reduced. However, there is a risk that the required insulation may then be insufficient where needed.

Thus, providing the fitting concavity and/or the fitting protrusion on the second rubber ring reduces the horizontal cross-section at this fitting part, which enables breakage of the connecting part container or of the glass terminal due to excessive load to be prevented without decreasing the insulation.

Also, the fitting is performed by fitting the protrusions and concavities provided between the second rubber ring and the casing and/or the connecting part container. These protrusions and concavities create a seal effect, such that the second rubber ring need not necessarily be actively sandwiched and impose a large load.

In the electric compressor according to a first aspect of the present invention, a natural length of the fitting concavity and/or the fitting protrusion with respect to an axial direction of the second rubber ring is longer than a length of the fitting protrusion and/or the fitting concavity provided on the casing side and/or the connecting part container side with respect to the axial direction.

Making the natural length of the fitting concavity and/or the fitting protrusion with respect to the axial direction of the second rubber ring longer than the fitting protrusion and/or the fitting concavity with respect to the axial direction ensures that the fitting concavity or the fitting protrusion on the second rubber ring reaches the corresponding component first. Accordingly, this enables difficult-to-measure units of tolerance and the like to be absorbed in the narrow portion of the second rubber ring, where the horizontal cross-section is smaller.

In the electric compressor pertaining to the first aspect of the present invention, a portion of the second rubber ring is narrower than another portion of the second rubber ring.

Making only one portion of the second rubber ring narrower than other portions thereof with respect to the axial direction enables breakage of the connecting part container or of the glass terminal due to excessive load to be prevented without decreasing the insulation.

The electric compressor pertaining to a first aspect of the present invention includes a resin case having a lid pressing a coil wound around an end part of the electric motor. A split portion of the connecting part container is integrated with the lid.

According to the first aspect of the present invention, a split portion of the connecting part container is integrated with the lid pressing the coil into place. Thus, an electric compressor is provided that satisfies the goal of pressing the coil while maintaining ease of assembly.

A method for assembling an electric compressor according to a second aspect of the present invention, applied to any above-described aspect of the electric compressor, involves inserting the internal power line into the first rubber ring; fitting the split connecting part container so that the first rubber ring with the internal power line inserted therein is held sandwiched between the split walls; and connecting the terminal pin, affixed to the second rubber ring and to a glass terminal plate, to the connecting part container.

According to the second aspect of the invention, the internal power line is inserted into the first rubber ring first, before fitting the split connecting part container to hold the first rubber ring sandwiched in place. Thus, the connecting part container is assembled easily and with high insulation by simply having the split connecting part container sandwich the rubber ring. Furthermore, the terminal part attached to the second rubber ring is connected to the connecting part container. This enables the electric compressor to be achieved with high insulation without sacrificing ease of assembly.

Advantageous Effects of Invention

According to the present invention, an electric compressor has an insulated terminal without hampering ease of assembly.

