CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 119(a) to Korean Patent Application No. 10-2019-0052426, filed on May 3, 2019, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

This disclosure relates to an electric compressor, and in some embodiments, to an electric compressor capable of effectively reducing vibration occurred in a motor and obtaining improved insulation performance.

2. Description of the Related Art

Compressors that compress refrigerant in vehicle air conditioning systems have been developed in various forms. Recently, along with the trend of electrification of vehicle components, electric compressors which are driven by an electric motor have been actively developed.

An electric compressor mainly employs a scroll compression method suitable for a high compression ratio operation. Such a scroll-type electric compressor (hereinafter, referred to as “electric compressor”) is provided with a motor part, a compression part, and a rotational shaft connecting the motor part and the compression part.

Specifically, the motor part is configured as a rotary motor or the like and provided in a hermetic casing. The compression part is located at one side of the motor part, and includes a fixed scroll and an orbiting scroll. The rotational shaft is configured to transmit a rotational force of the motor part to the compression part.

A refrigerant compressed in the compression part is discharged to outside of the electric compressor through an exhaust port. The discharged refrigerant is utilized for operating a vehicle air conditioning system.

The motor part includes a stator and a rotor. A plurality of coils is wound on the stator. In addition, the rotor is provided with a magnet. The magnet provided in the rotor is generally a permanent magnet.

When power is applied to the motor part, a magnetic field is formed by the plurality of coils wound around the stator. The formed magnetic field exerts electromagnetic force on the magnet provided on the rotor. Accordingly, the rotor with the magnet is rotated according to the strength and direction of the electromagnetic force.

In recent years, demands for electric vehicles have rapidly increased, and developments for increasing a travel distance (driving distance) have been actively conducted. Several factors have to be considered to increase the travel distance of the electric vehicle. An increase in compression capacity of the electric compressor is also one of the factors to be considered.

As one method for increasing the capacity of the electric compressor, a method of applying a high voltage to the electric compressor, for example, may be explained. When high input power is applied, the output of the electric compressor may also be increased accordingly.

However, when a high voltage is applied to the motor part, a rotation speed, the number of turns (revolution) and the like are increased. As the high voltage is applied, the possibility that an unintended current leakage occurs goes up. In addition, heat is more generated as the motor part operates.

Therefore, in order to prevent this, an insulation distance is generally ensured by spacing the motor part apart from an inverter applying power to the motor part and the compression part.

However, this insulation distance should be increased as the magnitude of a voltage applied to the motor part is increased. This may cause an increase in an overall size of the electric compressor.

In addition, when the electric compressor is operated by a high voltage, more vibration may be generated than when the electric compressor is operated by a low voltage. The generated vibration is transmitted to an inverter part accommodating an inverter device which may be easily damaged due to heat and impact, which may cause failure and damage of the inverter device.

Accordingly, technologies for reducing vibration inside the electric compressor and improving insulation performance have been introduced.

Korean Patent Registration Application No. 10-0396780 discloses a scroll compressor having a structure that can reduce vibration of the compressor. Specifically, the patent document discloses a scroll compressor having a structure capable of preventing vibration occurred in a driving motor from being transferred from an inner casing accommodating the driving motor therein to an outer casing, by way of connecting the outer casing and the inner casing using an elastic member.

However, this type of scroll compressor can reduce the vibration to some extent according to the operation of the driving motor, but has a limitation in that there is no consideration about a method of preventing leakage of heat and current generated in response to the operation of the driving motor.

Korean Utility Model Registration No. 20-0143541 discloses an insulation device for a compressor. Specifically, the patent document discloses an insulation device for a compressor having a structure capable of preventing coil slippage, by way of forming a plurality of bent portions on an insulator wound with the coil in an axial direction of the insulator.

However, the insulation device of the compressor of this type can prevent the coil slippage, but has a limitation in that there is no consideration about an insulation structure, irrespective of the outside of the stator, namely, the coil slippage. In addition, there is a difficulty in finding a solution for vibrations that may occur as the electric compressor operates.

PRIOR ART DOCUMENTS

Patent Documents

Korean Patent Registration Application No. 10-0396780 (Sep. 2, 2003)

Korean Utility Model Registration No. 20-0143541 (Jun. 15, 1999)

SUMMARY

The present disclosure is directed to providing an electric compressor having a structure that can solve the above-mentioned problems.

First, one aspect of the present disclosure is to provide an electric compressor having a structure, capable of effectively dissipating heat generated in a motor part and effectively preventing current leakage, without increasing a size of the electric compressor.

Another aspect of the present disclosure is to provide an electric compressor having a structure, which is simplified and capable of effectively dissipating heat generated in a motor part and effectively preventing current leakage.

Still another aspect of the present disclosure is to provide an electric compressor having a structure, which can be easily fabricated, effectively dissipate heat generated in a motor part, and effectively prevent current leakage.

Still another aspect of the present disclosure is to provide an electric compressor having a structure, capable of effectively reducing vibration generated as the motor part operates.

Still another aspect of the present disclosure is to provide an electric compressor having a structure, capable of effectively dissipating heat generated in a motor part by using refrigerant introduced into the electric compressor.

Still another aspect of the present disclosure is to provide an electric compressor having a structure, capable of simplifying an electric connection between a motor part and an inverter device.

Still another aspect of the present disclosure is to provide an electric compressor having a structure, capable of facilitating a stator, a rotor and a member for insulation, all constructing a motor part, to be assembled in a correct direction.

Still another aspect of the present disclosure is to provide an electric compressor having a structure, capable of facilitating installation of a motor part in a housing.

In order to achieve the above aspects and other advantages according to the embodiments, there is provided an electric compressor, comprising a main housing extending in a lengthwise direction, a motor part disposed in the main housing and comprising a stator comprising a rotor accommodating portion, and a rotor rotatably disposed in the rotor accommodating portion of the stator, a compression part rotatably connected to the motor part and configured to receive a rotational force from the motor part and compress a refrigerant, and an inverter part electrically connected to the motor part and configured to apply power to the stator. The motor part may be disposed in a motor room formed inside the main housing. The stator may comprise a plurality of insulating protrusions protruding from an outer circumferential surface of the stator to increase a surface area of the outer circumferential surface. The plurality of insulating protrusions may be configured to be brought into contact with an inner circumferential surface of the motor room.

The outer circumferential surface of the stator of the electric compressor may comprise a first region comprising the plurality of insulating protrusions is spaced apart from one another by a predetermined distance, and a second region comprising adjacent insulating protrusions, among the plurality of insulating protrusions, spaced apart from each other by another predetermined distance different from the predetermined distance.

Here, a coupling protrusion may be configured to protrude from the inner circumferential surface of the motor room. The coupling protrusion may be configured to allow the plurality of insulating protrusions to be brought into contact, and may be inserted into a coupling space formed between the adjacent insulating protrusions located in the second region and spaced apart from each other by the another predetermined distance.

The stator of the electric compressor may have a cylindrical shape extending in a lengthwise direction thereof. The plurality of insulating protrusions may be configured to extend from the outer circumferential surface of the stator in the lengthwise direction of the stator, so that a refrigerant flows from the motor part toward the compression part through spaces formed by the plurality of insulating protrusions spaced apart from one another.

An insulating unit may be coupled to an end portion of the stator in the lengthwise direction of the stator. The insulating unit may be configured to insulate the stator and may comprise a cross-section corresponding to the stator.

The stator of the electric compressor may comprise a coupling groove recessed by a predetermined distance into one side surface of the stator facing the insulating unit, and the insulating unit may comprise a coupling protrusion protruding by the predetermined distance from one side surface of the insulating unit facing the stator. The coupling protrusion may be configured to be inserted into the coupling groove.

The stator of the electric compressor may comprise an outer circumferential portion defining an outer circumference of the stator, and a plurality of teeth protruding radially inward from the outer circumferential portion of the stator. A plurality of coupling grooves may be provided on one side surface of each of the plurality of teeth facing the insulating unit. A number of the plurality of coupling grooves formed in one of the plurality of teeth may be different from a number of the plurality of coupling grooves formed in another one of the plurality of teeth.

The insulating unit of the electric compressor may comprise an insulation outer circumferential portion defining an outer circumference of the insulating unit; and a plurality of insulating teeth protruding radially inward from the insulation outer circumferential portion of the insulating unit. A plurality of coupling protrusions may be provided on one side surface of each of the plurality of insulating teeth facing the stator. A number of the plurality of coupling protrusions formed on one of the plurality of insulating teeth may be different from a number of the plurality of coupling protrusions formed on another one of the plurality of insulating teeth.

An insulating housing configured to cover the insulating unit may be coupled to an end portion of the stator, to which the insulating unit is coupled, in the lengthwise direction of the stator.

A coupling key may protrude from one side of the insulating housing facing the insulating unit, and a coupling slot may be recessed into one side of the insulating unit facing the insulating housing. The coupling key may be configured to be inserted into the coupling slot when the insulating housing covers the insulating unit.

The electric compressor may further comprise a connector unit configured to electrically connect the inverter part and the motor part. The connector unit may include a support member defining a body of the connector unit, and an electric member coupled to the support member in a penetrating manner. One side of the electric member may be electrically connected to the inverter part and another side of the electric member may be electrically connected to the motor part.

The electric compressor may further include a terminal unit detachably coupled to the another side of the electric member and configured to electrically connect the connector unit and the motor part. An insulating unit and an insulating housing covering the insulating unit and electrically connected to the stator may be sequentially coupled to each end portion of the stator in the lengthwise direction of the stator, and a terminal accommodating may be disposed in one side of the insulating housing facing the inverter part. The insulating unit may be configured to insulate the stator and may comprise a cross-section corresponding to the stator. The terminal accommodating portion may comprise a space configured to accommodate the terminal unit.

A connector coupling portion may be disposed on one side of the inverter part facing the motor part. The connector unit may be detachably coupled to the connector coupling portion. The connector coupling portion may comprise a support member insertion groove recessed by a predetermined distance. The support member may be configured to be coupled to the support member insertion groove. An electric member insertion opening may be formed in a penetrating manner, and one side of the electric member may be configured to be inserted in the electric member insertion opening

One side of the insulating housing facing the inverter part may be configured to be brought into contact with one side of the inverter part facing the motor part when the connector unit is detachably coupled to the connector coupling portion.

The insulating housing may comprise a housing outer circumferential portion formed in a ring shape and defining a body of the insulating housing. A snap protrusion may be configured to protrude radially inward from one end portion of the housing outer circumferential portion facing the stator. The insulating unit may comprise an insulation outer circumferential portion defining an outer circumference of the insulating unit. A snap coupling portion may be recessed radially inward from one end portion of the insulation outer circumferential portion facing the stator. The snap protrusion may be fitted to the snap coupling portion when the insulating housing is coupled the insulating unit.

According to the present disclosure, the following effects can be obtained.

First, insulating units may be provided on both end portions of a stator in a lengthwise direction of the stator. The insulating unit may be configured to prevent heat generated in the stator from being transferred to outside. The insulating unit may also be configured to prevent unintended current leakage from the stator.

Accordingly, heat and current generated in a motor part can be effectively prevented from being transmitted to outside, even without increasing a spaced distance between the stator and an inverter part and a spaced distance between the stator and a compression part.

The insulating units may also be coupled to both end portions of the stator in the lengthwise direction of the stator. Insulating housings may be configured to cover the insulating units and are coupled to the both end portions of the stator in the lengthwise direction of the stator. That is, the motor part itself may be provided with members for improving an insulation effect.

Therefore, since a separate member is not necessary to be provided inside a main housing, the electric compressor can be simplified in structure and can effectively prevent heat and current generated in the motor part from being transferred to outside.

In addition, even if the insulating units and the insulating housings are coupled to the stator, an overall structure of the motor part may not be greatly changed. Therefore, the existing facilities for manufacturing a motor part can be used.

Accordingly, a separate facility for producing the motor part may not be needed, thereby enhancing productivity and manufacturing economic efficiency can be improved.

In addition, the insulating housings configured to cover the stator may be formed of a material having predetermined elasticity. Vibration generated due to an operation of the motor part can be absorbed by the insulating housings.

Therefore, even if the motor part does not secure a sufficient insulating distance from the inverter part, the compression part or an inner surface of the housing, vibration generated in the motor part can be effectively reduced.

In addition, a plurality of insulating protrusions may be spaced apart from one another by predetermined distances on an outer circumferential surface of the stator. A predetermined space may be formed between the insulating protrusions adjacent to each other, so that a refrigerant can flow.

Accordingly, the refrigerant introduced into the electric compressor can absorb heat generated in the motor part while flowing toward the compression part. In this manner, since the motor part can be cooled by the refrigerant to be compressed, heat generated in the motor part can be effectively dissipated.

In addition, the motor part may be electrically connected to an inverter device through an electric connection unit. The electric connection unit may be detachably coupled to the inverter device. In addition, the electric connection unit may also be detachably coupled to an insulating housing.

Therefore, complicated wiring may not be necessary for electric connection between the motor part and the inverter device. In addition, since the electric connection unit is electrically coupled to the inverter device and the motor part, a simple connection and disconnection may be allowed.

In addition, the stator may be provided with a stator coupling portion, the insulating unit may be provided with an insulation coupling portion, and the insulating housing may be provided with a housing coupling portion. Each coupling portion may comprise the stator, the insulating unit and the insulating housing to be coupled together in a specific direction, namely, in an accurate direction.

Therefore, even when the stator, the insulating unit and the insulating housing are formed in a circular shape that is difficult to distinguish directions, the stator, the insulating unit and the insulating housing may be coupled together only when they are aligned in the specific direction by the coupling portions. This may facilitate assembly of the motor part.

In addition, as insulating protrusions are spaced apart from each other, a coupling space may be formed in an outer circumferential surface of the stator, which may define an outer surface of the motor part. In addition, a coupling protrusion may be formed inside a motor room to correspond to the coupling space.

Accordingly, the stator can be accommodated in the motor room only in a direction in which the coupling protrusion is inserted into the coupling space. This may facilitate the motor part to be accommodated in the motor room.

