JPH05195949A - Reciprocating compressor - Google Patents

Abstract

PURPOSE:To secure the appropriate return supply quantity of recovered separated oil without under-over quantity according to the operating state of a reciprocating compressor. CONSTITUTION:An oil separating chamber 32 disposed in a high pressure area in a compressor; a separated oil recovering oil reservoir chamber 40 provided in line with the oil separating chamber 32 ; an oil return hole 42 opened facing a valve seat 41 formed at the bottom part of the oil reservoir chamber 40 so as to communicate the oil reservoir chamber 40 with a low pressure area 8 in the compressor; and a valve means 43 for controlling the flow of the oil return hole 42 according to the differential pressure of both high-low pressure areas, are installed. The return supply of the recovered separated oil corresponding to the operating state of the compressor is thereby attained automatically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a reciprocating compressor having a built-in oil separation mechanism for high pressure refrigerant gas.

[0002]

2. Description of the Related Art A swash plate type mainly used for vehicle air conditioning,
In a reciprocating compressor such as an oscillating plate type, lubricating oil used for lubricating a movable part is mixed in a refrigerant gas in a mist form. Therefore, when the mixed oil particles are discharged and circulated as they are in the refrigeration circuit together with the refrigerant gas discharged from the compressor, the oil particles adhere to the inner wall of the evaporator or the like to reduce the efficiency of heat exchange.

Therefore, conventionally, an oil separator is separately provided in the high-pressure pipe from the compressor to the condenser, and the separated lubricating oil is returned to the compressor through the return oil pipe. However, in addition to the widening of the refrigeration circuit configuration due to the expansion of equipment and piping, accidents such as clogging of the return oil piping formed in a small diameter and long shape also occur. Since it is easy, it has recently been proposed that the compressor directly incorporates an oil separation mechanism.

[0004]

In the compressor having the built-in oil separation mechanism described above, the oil reservoir chamber for collecting the separated oil separated in the high pressure area in the machine and the low pressure area for returning the separated oil. (For example, the swash plate chamber) is in communication with the return oil hole. However, when maintaining an appropriate amount of return oil and when the stored oil is depleted after the machine is stopped, the high pressure refrigerant gas generated via the return oil hole Considering the point of suppressing backflow, the passage cross-sectional area of the return oil hole must be set extremely small.

Therefore, such fine oil return holes are
Anyway, there is a problem that clogging easily occurs and the return oil function is impaired, and on the other hand, also in terms of production, breakage accidents of the work piece frequently occur. Moreover, when the compressor is started in which the residual oil in the machine is boiled and discharged together with the refrigerant gas, the main movable part in the swash plate chamber temporarily falls into a non-lube state and prompt refueling is required. It is difficult to expect a satisfactory response with the oil supply capability of the oil holes.

The present invention secures a sufficient amount of return oil according to the operating condition of the compressor (the pressure difference between the high pressure region and the low pressure region), and further effectively suppresses the reverse flow of the high pressure refrigerant gas. This is a technical issue to be solved.

[0007]

In order to solve the above-mentioned problems, the present invention provides an oil separation chamber arranged in a high-pressure area in the machine, and an oil collection chamber for recovering separated oil, which is connected to the oil separation chamber. A return oil hole that opens in a valve seat surface formed at the bottom of the oil sump chamber to communicate the oil sump chamber with a low pressure region in the machine, and the return oil according to the differential pressure between the high and low pressure regions. It employs a novel configuration with valve means to control the flow rate through the holes.

[0008]

When the compressor is started with a small differential pressure between the high pressure region and the low pressure region inside the machine, the flow rate of the return oil hole is controlled to the expansion side by the valve means, especially from the initial discharge refrigerant with a large oil content. The separated recovered separated oil is rapidly and satisfactorily returned to the low pressure region (swash plate chamber) from the oil reservoir chamber through the return oil hole having the required passage cross-sectional area. After that, at the stage where the compressor sequentially shifts to steady operation, the valve means controls to gradually reduce the flow rate of the return oil hole as the differential pressure in both the high and low pressure regions rises, and the separation oil amount and the required oil supply amount. By keeping the balance with the above, an appropriate amount of stored oil is always secured.

When the stored oil is depleted after the machine is stopped, even if a situation in which the high pressure refrigerant gas flows backward due to the differential pressure remaining between the condenser side and the evaporator side, the differential pressure itself Controls the flow rate of the return oil hole through the valve means, so that the existing problems such as the generation of abnormal noise and the temperature rise of the evaporator can be suppressed to a substantially harmless degree.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a swash plate type compressor embodying the present invention will be described below with reference to FIGS. The figure shows a swash plate type compressor with five cylinders on each side. Both ends of cylinder blocks 1 and 2 which are opposed to each other at the front and rear have valve plates 3 at the front and rear, respectively.
It is closed by front and rear housings 5 and 6 via 4, and these are connected by a plurality of bolts 7 inserted into the bolt insertion holes 1a and 2a. A swash plate chamber 8 is formed in the connecting portion of the cylinder blocks 1 and 2, and central shaft holes 1b and 2b of the cylinder blocks 1 and 2 are formed therein.
A swash plate 10 fixed to a drive shaft 9 penetrating therethrough is housed. Five pairs of cylinder bores 11 are formed in the cylinder blocks 1 and 2 in parallel with the drive shaft 9 and at radial positions around the drive shaft 9, and a double-headed piston 12 is inserted into each cylinder bore 11. Thus, each piston 12 is anchored to the swash plate 10 via a hemispherical shoe 13.

The front and rear housings 5 and 6
The suction chambers 14 and 15 are formed on the center side of each of them, and the discharge chambers 16 and 17 are formed on the outer peripheral side thereof. The front and rear valve plates 3 and 4 have suction chambers 14 and 15 respectively.
From each of the cylinder bores 11 into the low pressure refrigerant gas G, and a discharge port 20 from each of the cylinder bores 11 to discharge the compressed high pressure refrigerant gas G into the discharge chambers 16 and 17. , 21 are formed. Furthermore, the cylinder blocks 1, 2 of the valve plates 3, 4
Suction valve mechanisms 22 and 23 are provided on the side, and discharge valve mechanisms 24 and 2 are provided on the sides of the housings 5 and 6 of the valve plates 3 and 4, respectively.
5 are provided.

As shown in FIG. 2, a projecting portion 26 is provided on the upper portion of the rear cylinder block 2, and a suction port (not shown) that opens to the swash plate chamber 8 is bored in the projecting portion 26. A plurality of suction passages 28 and 29 that communicate the swash plate chamber 8 with the suction chambers 14 and 15 are formed between the cylinder bores 11 in both cylinder blocks 1 and 2, and the suction passages are sucked into the swash plate chamber 8 through the suction ports. The refrigerant gas G is introduced into the suction chambers 14, 15 through the suction passages 28, 29.

As shown in FIGS. 2 and 3, the protrusion 2 is formed.
A shell 31 is attached to 6, and a cyclone type oil separation chamber 32 is formed inside thereof. The oil separation chamber 3
Reference numeral 2 denotes a bottomed circular hole-shaped separating portion 32a, and a guide portion 32b which is processed into a curved counterbore hole and opens substantially tangentially to the upper half of the separating portion 32a. The through hole 33 that opens to the curved edge is connected to the pair of discharge passages 34 formed in the rear cylinder block 2 and is connected to the discharge chamber 1.
A plurality of oil holes 35 communicating with the oil reservoir chamber described later are provided at the periphery of the bottom wall of the separating portion 32a. The cover plate 36 that covers and closes the shell 31 has a discharge pipe 37 that extends into the center of the separating portion 32a.
Is fixed, and the outer end of the discharge pipe 37 is connected to an external refrigeration circuit (not shown).

An oil storage chamber 40 for collecting and storing the separated lubricating oil 0 is provided in the protruding portion 26 of the rear cylinder block 2 located below the oil separation chamber 32, and the deepest portion of the bottom wall thereof is provided. Is formed on a conical valve seat 41 having a relatively shallow angle, and a return oil hole 42 communicating with the swash plate chamber 8 is provided at the center of the valve seat 41. Reference numeral 43 denotes a float valve for flow rate control, which is enlarged and shown in FIG. 4, and the float valve 43 is made of a circular spring steel plate, and has a plurality of (four in the figure) angular protrusions 43a on its periphery. Are formed. Therefore, in the state where it is placed on the valve seat 41,
When the differential pressure between the oil separation chamber 32 belonging to the high pressure region in the machine and the swash plate chamber 8 belonging to the low pressure region is zero or relatively small, the float valve 43 is attached to the valve seat 41 only by the outer edge of the projection 43a. When seated, the arcuate peripheral surface 43b forms an appropriate space between the arcuate peripheral surface 43b and the surface of the released valve seat 41 to allow a proper flow of the stored oil. Then, as the pressure difference between the high and low pressure regions increases, the protrusion 43a is elastically deformed preferentially to closely fit the surface of the valve seat 41, and the gap between the arcuate peripheral surface 43b and the surface of the valve seat 41 is generated. Is gradually reduced to both sides 43b, 4
1 comes into contact with each other almost linearly, and the flow rate of the stored oil is regulated to the minimum (Fig. 4).
(B)). Reference numeral 44 is a mesh member that is mounted so as to cover and close the upper portion of the valve seat 41, and prevents excessive float movement of the float valve 43.

This embodiment is constructed as described above,
When the swash plate 10 is rotated by the rotation of the drive shaft 9, each piston 12 is reciprocated in the cylinder bore 11, whereby the refrigerant gas G is sucked, compressed and discharged. The compressed high-pressure refrigerant gas G is introduced into the oil separation chamber 32 from the discharge chambers 16 and 17 through the discharge passage 34 and the through hole 33.
That is, the refrigerant gas G guided from the through hole 33 to both end portions of the guiding portion 32b flows into the arc-shaped separating portion 32a from a substantially tangential direction by the guide of the curved wall formed in the guiding portion 32b. The mixed oil particles in the refrigerant gas G are effectively separated by the centrifugal force given by the rotating flow shown in FIGS. Since the pulsation of the refrigerant gas G is physically calmed down through such an oil separation process, the refrigerant gas G is sent to the refrigeration circuit in an extremely stable state, while being separated from the refrigerant gas G. The oil particles flow down the peripheral wall of the separating portion 32a, drop from the oil hole 35 penetrating the bottom wall, and are collected and stored in the oil reservoir 40.

Therefore, in the state immediately after the operation of the machine base is started, the differential pressure between the oil separation chamber 32 belonging to the high pressure region and the swash plate chamber 8 belonging to the low pressure region is extremely small, and the difference in the protrusion 43a of the float valve 43 is small. Although a slight deformation occurs due to the pressure, the arcuate peripheral surface 43b secures an appropriate conduction gap between the arcuate peripheral surface 43b and the free valve seat 41 surface. As a result, the recovered separated oil 0 separated from the initial refrigerant gas G having a particularly high oil content due to the bumping of the residual oil in the machine at the time of start-up is returned from the oil reservoir 40 with the above-mentioned communication gap and the required passage cross-sectional area. The swash plate 1 is quickly and amply supplied to the swash plate chamber 8 through the oil hole 42.
It is used for lubrication of the main movable parts such as 0 and shoe 13.

Thereafter, at the stage where the compressor sequentially shifts to the steady operation, the projection 43a of the float valve 43 is closely fitted to the surface of the valve seat 41 as the differential pressure between the oil separation chamber 32 and the swash plate chamber 8 increases. However, the degree of deformation is preferentially increased, and the amount of oil returned through the communication gap is controlled to be gradually reduced to return the amount of oil suitable for steady operation to the swash plate chamber 8. In this case, there is a large disparity between the required return oil amount at the initial stage of startup and the required return oil amount at the time of steady operation, and the deformation characteristics of the float valve 43 based on the pressure difference between the high and low pressure regions and the accompanying characteristics. The change width of the communication gap is set on the condition that the separation capacity of the oil separating means, the required amount of returned oil, the amount of stored oil, and other factors are harmonized.

It should be noted that, after the machine stand is stopped, the stored oil 0 is exhausted before the pressure in the circuit is equilibrated due to the continuation of the returned oil via the return oil hole 42, and the difference remaining between the condenser side and the evaporator side. Even if the pressure causes a backflow of the high-pressure refrigerant gas G, the differential pressure itself is controlled via the float valve 43 so as to reduce the conduction gap, so that abnormal noise is generated and the evaporator is cooled. Past problems such as temperature rise are suppressed to a substantially harmless degree.

FIG. 5 shows another embodiment of the valve means.
In the present embodiment, the valve seat 51 in which the oil return hole 42 is opened is formed in a flat surface, and the lead valve 50 is curved on the valve seat 51 in advance so as to keep the opening of the oil return hole 42 to the maximum. Is fixed. The deformation characteristics of the lead valve 50 made of a spring steel plate are set under the same conditions as those of the float valve 43 described above, but the opening of the return oil hole 42 is increased due to the increase of the differential pressure in both the high and low pressure regions. Even if the lead valve 50 is deformed to such an extent that it is closed, consideration is given to maintain the minimum required amount of returned oil by, for example, the positive roughening R around the opening shown in the figure. Is desirable.

In yet another embodiment shown in FIG. 6, instead of the roughening R shown in FIG. 5, a stepped shape H is formed around the opening of the valve seat 51.
In addition, it was designed to secure the minimum amount of returned oil. The specific configuration of the oil separation mechanism is not limited to the cyclone system shown in the above embodiment, and it goes without saying that the oil separation mechanism can be implemented in different modes.

[0021]

As described above in detail, since the present invention has the constitution described in the claims, it has the following excellent effects. (1) Since the valve means that responds to the differential pressure in both the high and low pressure regions in the machine can automatically control the amount of recovered stored oil returned to the low pressure region (swash plate chamber), a start requiring a large amount of oil supply It is possible to secure an adequate amount of oil supply without excess or deficiency, and to ensure the lubrication of the main moving parts especially at the time of start-up and in any situation during steady operation where a remarkably small amount of oil is sufficient compared to the time of start You can

(2) Since the passage cross-sectional area of the return oil hole itself does not control the return oil flow rate, the diameter of the return oil hole is not forced to be extremely small, and the concern about breakage of the processing blade is completely eliminated. .. (3) Even after the machine stand is stopped, while the differential pressure remains in the circuit pressure, the valve means operates to control the degree of flow to the low pressure region through the oil return hole, so that the high pressure refrigerant gas The adverse effects on the low-pressure system due to backflow and blow-by are well prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the entire structure of a compressor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the essential part showing the oil separation and the return structure of the separated oil.

FIG. 3 is a plan view particularly showing an oil separation chamber

4A and 4B show an embodiment of a float valve, FIG. 4A is a plan view, and FIG.

FIG. 5 is a sectional view showing an embodiment of a lead valve.

FIG. 6 is a sectional view showing another embodiment of the lead valve.

[Explanation of symbols]

8 is a swash plate chamber, 32 is an oil separation chamber, 40 is an oil reservoir chamber, 41, 5
1 is a valve seat, 42 is an oil return hole, 43 and 50 are valve means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tetsuya Takashima 2-chome Toyota-cho, Kariya city, Aichi stock company Toyota Industries Corporation

Claims (1)

[Claims] 1. An oil separation chamber disposed in a high pressure region of the machine,
An oil sump chamber for recovering separated oil, which is connected to the oil separation chamber, and a return valve which opens to a valve seat surface formed at the bottom of the oil sump chamber to communicate the oil sump chamber with a low pressure region in the machine. A reciprocating compressor comprising an oil hole and valve means for controlling the flow rate of the oil return hole in accordance with the pressure difference between the high and low pressure regions.