Compressor having a stepped suction passage

The present invention discloses a compressor comprising: a fixed scroll including a suction communication passage that is formed so that refrigerant flowing through a suction pipe is guided to a compression chamber. The suction communication passage is formed so that the cross-sectional shape of the suction communication passage includes a step-like portion that is formed by multiple steps.

CROSS REFERENCE TO RELATED APPLICATION

This application is a U.S. national stage application of PCT/IB2023/053162 filed on Mar. 30, 2023 the contents of which are incorporated herein by reference.

FIELD OF INVENTION

The present invention relates to a compressor.

BACKGROUND OF THE INVENTION

A compressor is known in which a suction communication passage is provided in a fixed scroll so that refrigerant flowing through a suction pipe is guided to a compression chamber, as disclosed in Japanese Unexamined Patent Application Publication No. 2017-53279A hereinafter called PTL1.

In PTL1, to suppress suction pressure loss in the suction communication passage, an upper portion of the suction communication passage is formed so that the cross-sectional shape of the suction communication passage is flat and slope-shaped in a vertical cross sectional view taken along a plane in the direction of the flow path passing through the suction communication passage.

However, it is difficult to form a flat and slope-shaped suction communication passage in the fixed scroll using conventional processing methods such as an end mill machining method.

Therefore, the development of the compressor, that can suppress the suction pressure loss in the suction communication passage as well as that can easily form the suction communication passage in the fixed scroll, is required.

CITATION LIST

Patent Literature

SUMMARY OF THE INVENTION

It is an objective of the present inventions to provide a compressor that can suppress the suction pressure loss in the suction communication passage as well as that can easily form the suction communication passage in the fixed scroll.

In order to achieve the above objective, an embodiment of the present invention provides a compressor comprising: a sealed container; a motor element housed in the sealed container; a scroll compression element housed in the sealed container and configured to be driven by a crankshaft of the motor element; a suction pipe mounted penetratingly the sealed container, in which gas refrigerant sucked from outside flows into the scroll compression element, and wherein the scroll compression element including a fixed scroll including a first scroll body and an orbiting scroll including a second scroll body configured to be engaged with the first scroll body to form a compression chamber between the first scroll body and the second scroll body, the orbiting scroll being configured to orbit opposed to the fixed scroll, wherein the fixed scroll includes a suction communication passage that is formed so that refrigerant flowing through the suction pipe is guided to the compression chamber, and wherein the suction communication passage is formed so that the cross-sectional shape of the suction communication passage includes a step-like portion that is formed by multiple steps in a vertical cross-sectional view taken along a plane in the direction of the flow path passing through the suction communication passage.

Firstly, according to the embodiment of the present invention, the cross-sectional shape of the suction communication passage includes the step-like portion that is formed by multiple steps in a vertical cross sectional view taken along a plane in the direction of the flow path passing through the suction communication passage.

As such, the suction pressure loss can be suppressed by suppressing a sudden change in the flow path of the refrigerant in the suction communication passage.

Secondly, since the cross-sectional shape of the suction communication passage includes the step-like portion that is formed by multiple steps, the suction communication passage including the step-like portion can be formed more easily compared to form a flat, slope-shaped suction communication passage.

Therefore, according to the embodiment of the compressor of the present invention, it is possible to suppress the suction pressure loss in the suction communication passage as well as to easily form the suction communication passage in the fixed scroll.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

FIG.1is an explanation view illustrating a schematic configuration of a scroll compressor1according to the embodiment. The scroll compressor1is a fluid machine configured to compress and discharge a fluid (i.e., gas refrigerant), and can be a component of a refrigeration cycle apparatus. The scroll compressor1according to the embodiment is a vertically-mounted shell compressor.

As shown inFIG.1, the scroll compressor1includes a sealed container10, a suction pipe12mounted penetratingly a top face of the sealed container10and formed as a hollow cylindrical pipe, a discharge pipe14discharging the gas refrigerant to the outside, a scroll compression element20configured to compress a low-pressure gas refrigerant in a compression chamber28, and a motor element30configured to drive the scroll compression element20which is housed in the sealed container10.

The upper portion of the compression element20is supported by a middle shell10aof the sealed container10. The compression element20is fixed to the middle shell10aof the sealed container10through shrink fit or other methods. A sub-frame16is provided below the motor element30. The sub-frame16is fixed to the inner circumferential surface of the sealed container10.

The suction pipe12configured to suck a low-pressure gas refrigerant into the compression element20from outside is connected to a side surface of the sealed container10. The discharge pipe14configured to discharge a high-pressure gas refrigerant to the outside of the scroll compressor1is connected to the side face of the sealed container10.

The compression element20is accommodated in the sealed container10and configured to compress the refrigerant sucked from the suction pipe12through rotation of a crankshaft36that is driven by the motor element30. As shown inFIG.1, the compression element20includes a fixed scroll22and an orbiting scroll26.

As shown inFIG.1andFIG.2A, the fixed scroll22is fixed to the middle shell10aat a lower end portion of the fixed scroll22. The fixed scroll22includes a fixed scroll base plate22aand a fixed scroll spiral wrap22bhaving an involute curve shape so as to form a spiral body and erected on one surface of the fixed scroll base plate22a. A discharge port24configured to discharge a compressed refrigerant is formed in a central part of the fixed scroll22.

Moreover, the fixed scroll22includes a suction communication passage40that is formed so that the refrigerant flowing through the suction pipe12is guided to the compression chamber28.

As shown inFIG.1andFIG.4, the orbiting scroll26is configured to orbit opposed to the fixed scroll22without rotating, by a non-illustrated Oldham mechanism. The orbiting scroll26includes an orbiting scroll base plate26aand an orbiting scroll spiral wrap26bhaving an involute curve shape so as to form a spiral body and erected on one surface of the orbiting scroll base plate26a. An orbiting bearing26cformed in a bottomed cylindrical shape is formed in a substantially central part on an undersurface of the orbiting scroll base plate26a. An eccentric shaft portion36binstalled on an upper end of a main shaft portion36adescribed later is inserted in the orbiting bearing26c, in order to cause the orbiting scroll26to orbit.

The orbiting scroll spiral wrap26bis configured to be engaged with the fixed scroll spiral wrap22bto form the compression chamber28between the fixed scroll spiral wrap22band the orbiting scroll spiral wrap26b. The orbiting scroll26is configured to orbit opposed to the fixed scroll22.

The motor element30includes an electric motor stator32fixed to the inner circumferential surface of the sealed container10through shrink fit or other methods, an electric motor rotor34rotatably housed on an inner circumferential side of the electric motor stator32, and the crankshaft36(main shaft portion36a) fixed to the electric motor rotor34through shrink fit or other methods. The electric motor rotor34is configured to rotate as electric power is supplied to the electric motor stator32and transmit a driving force to the orbiting scroll26through the crankshaft36.

The eccentric shaft portion36blocated above the electric motor rotor34in the crankshaft36is rotatably supported in a radial direction by the cylindrical orbiting bearing26cinstalled under the orbiting scroll base plate26a. The main shaft portion36ais fitted in a main bearing39and slides along the main bearing39by an oil film of lubricating oil. The eccentric shaft portion36beccentric to the main shaft portion36ais installed on the upper end of the crankshaft36.

Next, the suction communication passage40formed in the foxed scroll is described in detail with reference toFIG.2AtoFIG.2BandFIG.3.

As shown inFIG.2AtoFIG.2BandFIG.3, the suction communication passage40is formed so that the refrigerant flowing through the suction pipe12is guided to the compression chamber28. A suction hole22eis formed in the upper portion of the fixed scroll22(SeeFIG.3). InFIG.2AandFIG.2B, the circumference of the suction hole22eis shown as a circle drawn with the dashed line in order to show the positional relationship between the suction hole22eand the suction communication path.

The suction pipe12is fitted in the suction hole22e. The suction hole22eis provided with a check valve25for preventing reverse flow of the refrigerant. The check valve25includes a valve body25aand a spring25bthat urges the valve body25atoward the side of the suction pipe12. The refrigerant flowing through the suction pipe12is led to the compression chamber28via the suction hole and the suction communication passage40.

As shown inFIG.3that is the longitudinal cross sectional view taken along a plane in the direction of flow path of the refrigerant flowing through the suction communication passage40, the suction communication passage40is formed so that the cross-sectional shape of the suction communication passage40includes a step-like portion42that is formed by multiple steps44in a vertical cross sectional view taken along a plane in the direction of the flow path passing through the suction communication passage40. The step-like portion42is colored by light gray inFIG.2AandFIG.2B.

As shown inFIG.2B, when viewed from a side where the fixed scroll22is engaged with the orbiting scroll26, the step-like portion42is formed so that the cross-sectional shape of the suction communication passage40becomes lower for each step44and so that with respect to the center of the fixed scroll22, the length of a curve on which an outermost point of each step44is located is longer than the length of a curve on which an innermost point of each step44is located along an outer wall22dof the fixed scroll22.

As such, the innermost point of each step44is located along the involute curve of the outer wall22dof the fixed scroll22. By forming each step44in the same shape, when viewed from a side where the fixed scroll22is engaged with the orbiting scroll26, the area surrounded by the outermost points and the inner points of the steps44and is formed almost sectorially.

As such, the suction pressure loss can be suppressed by suppressing a sudden change in the flow path of the refrigerant in the suction communication passage40. Therefore, it is possible to reduce the loss that occurs during the process of sucking the gas refrigerant through the suction communication passage40.

Moreover, since the cross-sectional shape of the suction communication passage40includes the step-like portion42that is formed by multiple steps44, the suction communication passage40including the step-like portion42can be formed more easily by using conventional processing methods such as an end mill machining method, compared to form a flat, slope-shaped suction communication passage40.

Next, the method for manufacturing the suction communication passage40of the scroll compressor1.

Firstly, the fixed scroll22formed with the fixed scroll base plate22aand the fixed scroll spiral wrap22bis prepared. And then, to process the fixed scroll22using the end mill machining method, the fixed scroll22is fixed to a predetermined fixture.

Next, the multiple steps44for the suction communication passage40of the fixed scroll22are cut from a side where the fixed scroll22is engaged with the orbiting scroll26. During the period when the end mill machining method was applied to the fixed scroll22, the step-like portion42of the suction communication passage40is formed by cutting the suction communication passage40for each step44. Therefore, the suction communication passage40including the step-like portion42can be formed more easily by using conventional processing methods such as an end mill machining method, compared to form a flat, slope-shaped suction communication passage40.

In particular, the suction communication passage40is cut for each step44from a lower step to a higher step in order, from the side where the fixed scroll22and orbiting scroll26are engaged. Therefore, the moving distance of the end mill can be shortened, and thereby the manufacturing time can be shortened.

Although specific embodiments of the invention have been disclosed and described as well as illustrated in the companying drawings, it is simply for the purpose of better understanding of the principle of the present invention and it is not as a limitation of the scope and spirit of the teaching of the present invention. Adaption and modification to various structures such as design or material of the invention, mounting mechanism of various parts and elements or embodiments are possible and apparent to a skilled person without departing from the scope of the present invention which is to be determined by the claims.

LIST OF REFERENCES