JP2000120543A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably separate a refrigerant from lubricating oil irrespective of discharge quantity. SOLUTION: Out of both first and second communicating passages 122 and 123 interconnecting a discharge chamber 115 and a separate chamber 116 together, a differential pressure regulating valve 124 to open or close these discharge and separate chambers 115 and 116 by pressure differential, is installed in the second communicating passage 123. With this, if a discharge quantity is increased, this differential pressure regulating valve 124 is opened, and on the other hand, if the discharge quantity is decreased, the valve 124 is closed. Accordingly, since a pressure differential lying between both these chambers 115 and 116 is controlled so as to make it become within the specified range, such a possibility that the flow velocity of a refrigerant in time of its flow into the separate chamber 116 might to largely lowered is preventable without entailing any drop in the efficiency of a compressor 100. Therefore, the refrigerant and lubricating oil are stably separable irrespective of the discharge quantity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor, and is effective when applied to a compressor having a variable discharge flow rate such as a refrigeration cycle for a vehicle.

[0002]

2. Description of the Related Art In a compression for a refrigeration cycle, a sliding portion in a compressor is lubricated by sucking lubricating oil together with a refrigerant. However, if the refrigerant circulates through the refrigeration cycle while lubricating oil is mixed in the refrigerant, the heat exchange efficiency of the heat exchanger such as a condenser or an evaporator decreases, and the refrigeration capacity decreases. appear.

Therefore, in the invention described in, for example, JP-A-3-129273, an oil separator (oil separator) is provided on the discharge side of the compressor to separate lubricating oil from the refrigerant flowing out of the discharge chamber. Is prevented from circulating in the refrigeration cycle.

[0004]

In the oil separator, since it is necessary to flow the refrigerant into the separation chamber in a state where the flow velocity of the refrigerant is increased, the oil separator is generally connected to the discharge chamber so that the discharge chamber communicates with the separation chamber. The flow of the refrigerant is restricted in the passage, and the speed of the refrigerant flowing into the separation chamber is increased (accelerated). Therefore, for example, when the rotation speed of the compressor is low and the discharge flow rate is small, it is necessary to make the cross-sectional area of the communication passage sufficiently small in order for the oil separator to function sufficiently. However, when the cross-sectional area of the communication passage is reduced, the rotation speed of the compressor increases and the discharge flow rate increases, so that the pressure loss (hereinafter, abbreviated as pressure loss) in the communication passage increases, and the efficiency of the compressor decreases. The problem that occurs.

Conversely, when the cross-sectional area of the communication passage is set in accordance with the case where the rotation speed of the compressor is high and the discharge flow rate is large,
When the rotation speed of the compressor is low and the discharge flow rate is low, the flow rate of the refrigerant flowing into the separation chamber is low, so that the oil separator cannot function sufficiently, and the lubricating oil circulates in the refrigeration cycle together with the refrigerant. Problem occurs. Since the above problem is caused by a change in the discharge flow rate, the variable displacement compression in which the discharge capacity can be changed causes the above problem even if the rotational speed does not change.

In view of the above, it is an object of the present invention to stably separate a fluid such as a refrigerant from a lubricating oil regardless of a change in a discharge flow rate.

[0007]

The present invention uses the following technical means to achieve the above object. Claim 1,
In the invention described in Item 2, the discharge chamber (115) and the separation chamber (11)
6), a differential pressure valve (124) whose opening changes in accordance with the pressure difference between the discharge chamber (115) and the separation chamber (116) is provided in the second communication path (123). I do.

Accordingly, if the opening of the differential pressure valve (124) is increased in accordance with the increase in the pressure difference, the opening of the differential pressure valve (124) is increased in accordance with the increase in the discharge flow rate. It is possible to prevent the pressure loss when flowing into the separation chamber (116) from the chamber (115) from excessively increasing. Therefore, the lubricating oil can be separated from the fluid while preventing the efficiency of the compressor from decreasing.

In addition, the differential pressure valve (12
If the pressure is reduced in 4), the opening of the differential pressure valve (124) is reduced in accordance with the decrease in the discharge flow rate.
The flow velocity at the time of flowing into the separation chamber (116) from 5) can be prevented from being excessively reduced, and the lubricating oil can be reliably separated from the fluid. As described above, according to the present invention, the fluid and the lubricating oil can be stably separated irrespective of the change in the discharge flow rate.

According to the third aspect of the present invention, the discharge chamber (11
5) A differential pressure valve (124) whose degree of opening changes in accordance with the pressure difference between the separation chamber (116) is provided in the communication path (123) for communicating the discharge chamber (115) and the separation chamber (116). It is characterized by the following. This makes it possible to stably separate the fluid and the lubricating oil irrespective of a change in the discharge flow rate, as in the first aspect of the present invention.

In the invention according to claim 4, the discharge chamber (11
5) A difference for controlling the communication state of the communication paths (122, 123) for communicating the discharge chamber (115) and the separation chamber (116) such that the pressure difference between the separation chamber (116) and the pressure within the predetermined range. A pressure valve (124) is provided. Thereby, regardless of the discharge flow rate, the discharge chamber (115) and the separation chamber (1)
Since the pressure difference is controlled so as to be within the predetermined range, the flow velocity of the fluid flowing from the discharge chamber (115) into the separation chamber (116) is within the predetermined range. Therefore, it is possible to stably separate the fluid and the lubricating oil irrespective of the change in the discharge flow rate.

Incidentally, the reference numerals in parentheses of the above-mentioned means are examples showing the correspondence with specific means described in the embodiments described later.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present embodiment, a compressor according to the present invention is a variable displacement swash plate compressor (hereinafter abbreviated as a compressor) for a vehicle refrigeration cycle (hereinafter abbreviated as a refrigeration cycle). FIG. 1 shows a compressor 1
FIG. 2 is a schematic diagram of a refrigeration cycle including 00. In FIG. 1, 2
Reference numeral 00 denotes a radiator (condenser) that cools the refrigerant (fluid) discharged from the compressor 100, and 300 separates the refrigerant flowing out of the radiator 200 into a gas-phase refrigerant and a liquid-phase refrigerant, and separates only the liquid-phase refrigerant. Is a receiver (liquid receiver) for discharging excess refrigerant and storing excess refrigerant in the refrigeration cycle.

A decompressor 400 decompresses the liquid refrigerant flowing out of the receiver 300, and a depressurizer 500
The evaporator evaporates the liquid-phase refrigerant depressurized at 00. The decompressor 400 is a so-called temperature-type expansion valve whose depressurization degree (opening degree) is adjusted so that the degree of superheat of the refrigerant on the outlet side of the evaporator 500 becomes a predetermined value. Next, the compressor 100 will be described.

FIG. 1 is an axial cross-sectional view of a compressor 100. Reference numeral 101 denotes a shaft which rotates by obtaining driving force from a traveling engine (not shown).
Front housing 102 and middle housing 103
It is rotatably supported by radial bearings 104 and 105 provided therein. And the middle housing 10
3, a plurality of cylinder bores (cylindrical spaces) 106 extending in a direction parallel to the shaft 101 are formed around the shaft 101, and a piston 107 reciprocates in the cylinder bore 106 in a direction parallel to the shaft 101. It is slidably disposed.

Reference numeral 108 denotes a rotor that rotates integrally with the shaft 101. A protrusion that projects radially outward of the rotor 108 toward the piston 107 and that is provided with an oblong elongated hole 108b. The part 108a is integrally formed. Reference numeral 109 denotes a swash plate connected to one end side (the rotor 108 side) of the piston 107 via a pair of shoes 110. The swash plate 109 is connected to the rotor 108 via a pin 111 penetrating the elongated hole 108b. Are displaceably connected.

Incidentally, the shoe 110 is rotatably in contact with the piston 107 at a spherical spherical sliding portion, and is in slidable contact with the swash plate 109 on a planar sliding surface. Therefore, when the shaft 101 rotates, the swash plate 109 rotates while being inclined with respect to the shaft 101 via the rotor 108, and the radially outer side of the swash plate 109 swings, so that the piston 107 reciprocates.

In the compressor 100 according to the present embodiment, the swash plate is changed by changing the pressure in a space 126 in which the swash plate 109 is provided (hereinafter, this space 126 is referred to as a swash plate chamber 126). 109, the stroke (stroke) of the piston 107 is changed, and the compressor 1
The discharge capacity of 00 is changed. Reference numeral 112 denotes one end of the cylinder bore 106 (the other end of the piston 107).
The valve plate 112, the cylinder bore 106 and the piston 107 constitute a working chamber V for sucking and compressing the refrigerant. That is, in the present embodiment, the swash plate type compression mechanism Cp is configured by the shaft 101, the swash plate 109, the piston 107, and the like.

Reference numeral 113 denotes a suction chamber 114 for distributing refrigerant to a plurality of working chambers V, a discharge chamber 115 for collecting and collecting the refrigerant discharged from each working chamber V, and an oil separator OS for separating lubricating oil from the refrigerant. And an oil storage chamber 117 for storing the lubricating oil separated by the oil separator OS. The valve plate 112 is provided with a suction port 118 for communicating the working chamber V with the suction chamber 114 and a discharge port 119 for communicating the working chamber V with the discharge chamber 115. Is provided with a reed valve-shaped suction valve (not shown) for preventing the backflow of the refrigerant from the working chamber V to the suction chamber 114. The discharge port 119 is provided with a reed valve in which the refrigerant flows back from the discharge chamber 115 to the working chamber V. (Not shown). Reference numeral 120 denotes a valve stop plate (stopper) for regulating the maximum opening of the discharge valve.

As shown in FIG. 3, the separation chamber 116 is a columnar space having an inner wall surface 116a formed in a circular shape. The separation chamber 116 is concentric with the separation chamber 116. The arranged discharge pipe 121 is inserted and fixed. In addition, the discharge pipe 121 is connected to the refrigerant inflow side of the radiator 200. Further, in FIG.
Reference numeral 3 denotes first and second communication paths for communicating the discharge chamber 115 and the separation chamber 116, and the first and second communication paths 122, 1
As shown in FIG. 3, the separation chamber 116 has an inner wall 1
It is open in the tangential direction of 16a. And the second
As shown in FIG. 2, the communication passage 123 is provided with a differential pressure valve 124 whose opening changes according to the pressure difference between the discharge chamber 115 and the separation chamber 116.

The differential pressure valve 124 is connected to the second communication passage 123
Spherical valve element 124 for adjusting the communication state (open / closed state) of
a, a coil spring (elastic member) 124b for applying an elastic force in the direction of closing the second communication passage 123 (hereinafter, this force is referred to as a valve closing force) to the valve element 124a, and a valve seat 124c of the valve element 124a. Have been. Incidentally, reference numeral 125 denotes a lip seal that seals a gap between the shaft 101 and the front housing 102 and prevents the refrigerant from leaking out of the swash plate chamber 126 in which the swash plate 109 is disposed.

Next, the characteristic operation of the compressor 100 will be described. 1. At the time of maximum displacement operation (see FIG. 2) At the time of maximum displacement operation, as shown in FIG.
7, the amount of refrigerant (discharge flow rate) discharged during one rotation of the shaft 101 becomes larger than that during variable displacement operation described later.

As a result, the flow velocity of the refrigerant flowing through the first communication passage 122 increases, so that the pressure loss of the refrigerant in the first communication passage 122 increases (substantially in proportion to the square of the flow velocity).
5 becomes higher than the internal pressure of the separation chamber 116,
The pressure difference increases. Here, the force acting on the valve element 124a due to the pressure difference between the discharge chamber 115 and the separation chamber 116 is a force that increases (opens) the degree of opening of the second communication passage 123. The force acting on the valve body 124a due to the pressure difference between the valve body 124a and the separation chamber 116 is referred to as the valve opening force.

When the valve opening force exceeds the valve closing force, the second
Since the communication path 123 is opened, the refrigerant discharged from the working chamber V to the discharge chamber 115 flows through the first and second communication paths 122 and 123 and flows into the separation chamber 116. Note that the lubricating oil in the oil storage chamber 117 separated by the oil separator OS is drawn into the suction side of the compression mechanism Cp through a passage (not shown) due to the differential pressure between the suction pressure and the discharge pressure, and is together with the refrigerant in the working chamber V Inhaled into.

2. During variable displacement operation (see FIG. 4) During variable displacement operation, as shown in FIG.
7, the amount of refrigerant (discharge flow rate) discharged during one rotation of the shaft 101 becomes smaller than that during the maximum capacity operation. Therefore, the first and second communication paths 122,
Since the flow rate of the refrigerant flowing through the flow path 123 decreases,
The pressure loss of the refrigerant in the communication passages 122 and 123 decreases, and the pressure difference between the discharge chamber 115 and the separation chamber 116 decreases.

When the valve closing force exceeds the valve opening force, the second
Since the communication passage 123 is closed, the working chamber V is connected to the discharge chamber 115.
Is discharged into the separation chamber 116 through only the first communication passage 122. Note that the lubricating oil in the oil storage chamber 117 separated by the oil separator OS is sucked into the suction side of the compression mechanism Cp by the differential pressure between the suction pressure and the discharge pressure and is discharged together with the refrigerant in the same manner as in the maximum capacity operation. It is sucked into the working chamber V.

Next, the features of this embodiment will be described. According to the present embodiment, as described above, when the discharge flow rate increases,
The refrigerant flows through two communication paths (first and second communication paths) 122 and 123.
And flows into the separation chamber 116 from the discharge chamber 115. Therefore, even if the discharge flow rate increases, the pressure loss generated when the refrigerant flows from the discharge chamber 115 toward the separation chamber 116 can be reduced. A decrease in efficiency of the compressor 100 can be prevented.

On the other hand, when the discharge flow rate decreases, the refrigerant
The discharge chamber 115 is separated from the separation chamber 1 by communicating only the communication passage 122.
16, even if the discharge flow rate decreases, the separation chamber 1
It is possible to prevent the flow velocity of the refrigerant when flowing into the fuel cell 16 from greatly decreasing, and to prevent the oil separator OS from decreasing the oil separation capacity. As described above, according to the compressor 100 of the present embodiment, the differential pressure valve 124 is opened and closed to control the pressure difference between the discharge chamber 115 and the separation chamber 116 to be within a predetermined range. It will be. Therefore, without reducing the efficiency of the compressor 100, the separation chamber 116
Therefore, it is possible to prevent the flow velocity of the refrigerant when flowing into the oil tank from dropping significantly, so that the refrigerant and the lubricating oil can be stably separated regardless of the change in the discharge flow rate.

By the way, in the above embodiment, the discharge chamber 1
Due to the pressure difference between the second communication passage 12 and the separation chamber 116.
The differential pressure valve 124 that opens and closes the third communication passage 123 is provided in the second communication passage 123. However, in the present invention, when the refrigerant flows from the discharge chamber 115 to the separation chamber 116, the pressure loss changes according to the increase and decrease of the discharge flow rate. It was made with the focus on doing
The two communication paths 122 and 123 are made into one communication path, and the communication state (opening degree) of the one communication path is set so that the pressure difference between the discharge chamber 115 and the separation chamber 116 is within a predetermined range. May be provided.

In the above embodiment, the separation chamber 116
Centrifugal oil separator OS that separates lubricating oil from the refrigerant by swirling the refrigerant along the inner wall surface 116a
However, the present invention can also be applied to a compressor having a collision-type oil separator that separates lubricating oil from the refrigerant by causing the refrigerant to collide with the inner wall surface of the separation chamber 116 at high speed. Further, in the above-described embodiment, the compressor according to the present invention has been described by taking the variable capacity type swash plate compressor as an example. However, the present invention is not limited to this. Alternatively, the present invention can be applied to other compressors such as a variable capacity scroll compressor.

The application of the compressor according to the present invention is not limited to a refrigeration cycle for a vehicle, but may be applied to other refrigeration cycles such as an electric refrigerator.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a refrigeration cycle.

FIG. 2 is a cross-sectional view of the compressor according to the embodiment during a maximum capacity operation.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a cross-sectional view of the compressor according to the embodiment during variable displacement operation.

[Explanation of symbols]

101: shaft, 102: front housing, 10
3 Middle housing, 106 Cylinder bore, 107
... piston, 108 ... rotor, 109 ... swash plate, 115 ...
Discharge chamber, 116: separation chamber, 122: first communication path, 123
... second communication passage, 124 ... differential pressure valve.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhito Miyagawa 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Co., Ltd. F-term in Japan Auto Parts Research Institute (reference) 3H003 AA03 AB05 AC03 BH05

Claims (5)

[Claims] 1. A compression mechanism (Cp) for suctioning and compressing a fluid.
And a discharge chamber (11) in which the compression mechanism (Cp) is housed, and into which fluid discharged from the compression mechanism (Cp) flows.
5) and a housing (113) in communication with the discharge chamber (115) via the first communication passage (122) and in which a separation chamber (116) for separating lubricating oil from a fluid is formed. A second communication path (123) for communicating the discharge chamber (115) with the separation chamber (116) is provided, and the discharge chamber (115) and the separation chamber (116) are further provided.
A differential pressure valve (124) whose degree of opening changes according to the pressure difference between the second communication passage (123) and the second communication passage (123). 2. An inner wall (116) of said separation chamber (116).
a) is formed in a circumferential shape, and the separation chamber (11) of the two communication passages (122, 123) is formed.
The compressor according to claim 1, wherein the side (6) is open in a tangential direction of the inner wall surface (116a). 3. A compression mechanism (Cp) for sucking and compressing a fluid.
And a discharge chamber (11) in which the compression mechanism (Cp) is housed, and into which fluid discharged from the compression mechanism (Cp) flows.
5) and the discharge chamber (11) through the communication passage (123).
5) and a separation chamber (1) for separating lubricating oil from the fluid.
16) having a housing (113) formed therein, and a differential pressure valve (124) whose degree of opening changes according to the pressure difference between the discharge chamber (115) and the separation chamber (116) is connected to the communication passage ( 123). 4. A compression mechanism (Cp) for sucking and compressing a fluid.
And a discharge chamber (11) in which the compression mechanism (Cp) is housed, and into which fluid discharged from the compression mechanism (Cp) flows.
5) a housing (113) communicating with the discharge chamber (115) through the communication passages (122, 123) and having a separation chamber (116) for separating lubricating oil from a fluid; The communication passages (122, 1 1) are arranged such that the pressure difference between the discharge chamber (115) and the separation chamber (116) falls within a predetermined range.
23) A compressor provided with a differential pressure valve (124) for controlling the communication state of (23). 5. A compression mechanism (Cp) for suctioning and compressing a fluid,
And a discharge chamber (1) that houses the compression mechanism (Cp) and into which fluid discharged from the compression mechanism (Cp) flows.
An oil separator which is applied to the compressor (100) having the above (15) and separates lubricating oil from the fluid flowing out of the discharge chamber (115), wherein the fluid flowing out of the discharge chamber (115) flows in. A member (113) constituting the separation chamber (116) is provided with a communication passage (123) for communicating the discharge chamber (115) with the separation chamber (116), and the discharge chamber (115) and the separation chamber ( An oil separator characterized in that a differential pressure valve (124) whose degree of opening changes in accordance with the pressure difference with the pressure path (116) is provided in the communication path (123).