KR20150088731A - Double-headed piston type swash plate compressor - Google Patents

Abstract

A double-headed piston-type swash plate compressor comprises: a housing; and a rotational axis. The housing partitions a swash plate chamber and includes a cylinder block, a front housing member connected to a fore-end of the cylinder block, and a rear housing member connected to the rear end of the cylinder block. The rotational axis is supported by the housing. A protrusion part is arranged on a suction chamber of the rear housing member to protrude towards an opening part of an axial path formed in the rotational axis. A restrictor, which refrigerant passes when the refrigerant flows from the suction chamber to the axial path, is formed between the protrusion part and the rear-end of the rotational axis. The protrusion part has a terminal part with a size capable of being inserted into the opening part of the axial path.

Description

TECHNICAL FIELD [0001] The present invention relates to a double-headed piston type swash plate type compressor,

The present invention relates to a double-headed piston type swash plate type compressor.

The double-headed piston type swash plate type compressor includes a cylinder block, a front housing member connected to a front end of the cylinder block, and a rear housing member connected to a rear end of the cylinder block. The cylinder block defines a swash plate chamber, and the swash plate chamber receives a swash plate rotating together with the rotation axis. A double-headed piston is coupled to the swash plate. The cylinder block defines a cylinder bore accommodating a double-headed piston. Each of the double-headed pistons reciprocates in the corresponding cylinder bore in accordance with the rotation of the swash plate. The double-headed piston divides the interior of the cylinder bore into a first compression chamber at the front end and a second compression chamber at the rear end. In accordance with the reciprocating movement of the double-headed piston, the refrigerant is introduced into the first compression chamber and the second compression chamber to be compressed, the compressed refrigerant is discharged into the first discharge chamber formed in the front housing member and the second discharge chamber formed in the rear housing member And is discharged to the chamber.

The structure for introducing the refrigerant into the first compression chamber and the second compression chamber includes, for example, a structure employed in the compressor disclosed in Patent Document 1. [ The compressor of Patent Document 1 includes a first suction chamber in the front housing member and a second suction chamber in the rear housing member. The cylinder block includes a suction passage connecting the swash plate chamber to the first suction chamber and a suction passage connecting the swash plate chamber to the second suction chamber. The refrigerant is introduced into the swash plate chamber, and the refrigerant introduced into the swash plate chamber is supplied to the first suction chamber and the second suction chamber through the corresponding suction passage. In addition, when the pressure in each cylinder bore is reduced and the suction reed valve is opened, the refrigerant may enter the associated first compression chamber from the first suction chamber, or may enter the associated second compression chamber from the second suction chamber, Into the chamber.

In Patent Document 1, the refrigerant pressurizes the suction reed valve, and flows into the first compression chamber and the second compression chamber from the first suction chamber and the second suction chamber. Therefore, when the refrigerant pressurizes the suction reed valve, a suction loss of the refrigerant occurs. This consequently reduces the compression efficiency. Further, the refrigerant introduced into the swash plate chamber is heated by the heat generated in the sliding parts such as the swash plate and the rotary shaft.

For example, the compressor disclosed in Patent Document 2 includes a suction chamber only in the rear housing member, and has an axial passage formed in the rotary shaft and connected to the suction chamber. The rotary shaft includes a first rotary valve corresponding to the first compression chamber and a second rotary valve corresponding to the second compression chamber. Each rotary valve is selectively opened and closed in accordance with the rotation of the rotary shaft. As a result, the refrigerant flowing into the axial passage from the suction chamber flows into the compression chamber through the rotary valve. The compressor of Patent Document 2 eliminates the suction loss of the refrigerant generated by pressing the suction reed valve to open, and has a favorable compression efficiency. In addition, since the refrigerant is not introduced into the swash plate chamber, the refrigerant is prevented from being heated by the heat generated from the sliding parts such as the swash plate and the rotary shaft.

However, unlike the compressor of Patent Document 1, the compressor of Patent Document 2 does not introduce the refrigerant into a relatively large space like the swash plate chamber. Therefore, during the intake stroke, suction pulsation of the refrigerant tends to occur. The dimensional restriction of the double-headed piston type swash plate type compressor restricts the increase in the size of the suction chamber formed in the rear housing member, as in the structure in Patent Document 2. Therefore, the suction pulsation of the refrigerant is relatively large in the compressor of Patent Document 2.

Japanese Unexamined Patent Application Publication No. 5-133325 Japanese Patent Application Laid-Open No. 2004-278460

Accordingly, it is an object of the present invention to provide a double-headed piston type swash plate compressor in which the suction pulsation of the refrigerant is reduced.

According to an aspect of the present invention, there is provided a double-headed piston type swash plate compressor including a housing defining a swash plate chamber. The housing includes a cylinder block, a front housing member connected to the front end of the cylinder block, and a rear housing member connected to a rear end of the cylinder block. The compressor includes a rotating shaft supported by the housing, a swash plate accommodated in the swash plate chamber chamber and configured to rotate together with the rotating shaft, a double head piston coupled with the swash plate, a cylinder bore formed in the cylinder block, A first compression chamber partitioned by the double-headed piston at the front end of the cylinder bore, a second compression chamber partitioned by the double-headed piston at a rear end of the cylinder bore, a suction chamber formed in the rear housing member, A first rotary valve selectively connecting or disconnecting the axial passage to the first compression chamber in accordance with the rotation of the rotary shaft, and a second rotary valve connected to the suction chamber, And selectively connecting the axial passage to the second compression And a second rotary valve connected or disconnected to the chamber. The rear housing member includes a projection provided in the suction chamber and projecting toward the opening of the shaft passage. A restrictor through which the refrigerant passes when the refrigerant flows from the suction chamber to the axial passage is formed between the projection and the rear end of the rotary shaft. The projection has a distal end sized to be inserted into the opening of the axial passage.

 Other aspects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the preferred embodiments together with the accompanying drawings.
1 is a side sectional view showing a double-headed piston type swash plate type compressor according to a first embodiment.
2 is an enlarged cross-sectional view showing a protrusion and its periphery in the compressor of Fig. 1;
3 is an enlarged sectional view showing a protrusion of the double-headed piston type swash plate type compressor according to the second embodiment and its periphery.
4 is an enlarged cross-sectional view showing a protrusion of the double-headed piston type swash plate type compressor according to the third embodiment and a periphery thereof.

A double-headed piston type swash plate type compressor 10 according to a first embodiment will be described with reference to Figs. 1 and 2. Fig.

As shown in FIG. 1, the double-headed piston type swash plate type compressor 10 has a housing H. The housing H includes a front housing member 13 connected to the front end of the front cylinder block 11 and a rear housing member 13 connected to the rear end of the rear cylinder block 12, And a housing member (14). The cylinder blocks 11 and 12 and the housing members 13 and 14 are fixed together with a plurality of bolts B.

The compressor 10 includes a first valve plate 15, a first valve sub-plate 16, and a first retainer plate 17 between the front housing member 13 and the front cylinder block 11 do. The compressor 10 further includes a second valve plate 18, a second valve sub-plate 19 and a second retainer plate 20 between the rear housing member 14 and the rear cylinder block 12 . The first valve plate 15 includes a plurality of first discharge ports 15a and the second valve plate 18 includes a plurality of second discharge ports 18a. The first valve sub-plate 16 includes a plurality of first discharge valves 16a and the second valve sub-plate 19 includes a plurality of second discharge valves 19a. The discharge valves 16a and 19a selectively open and close corresponding discharge ports 15a and 18a. The first retainer plate 17 includes a plurality of first retainers 17a and the second retainer plate 20 includes a plurality of second retainers 20a. The retainers 17a and 20a regulate the opening degree of the corresponding discharge valves 16a and 19a.

The front housing member 13 and the first valve plate 15 partition the first discharge chamber 13a. The rear housing member 14 and the second valve plate 18 define the second discharge chamber 14a and the suction chamber 14b. The first discharge chamber 13a and the second discharge chamber 14a are connected to a discharge passage (not shown), and the discharge passage is connected to an external refrigerant circuit (not shown).

The cylinder blocks 11 and 12 support the rotary shaft 21 in a rotatable manner and the rotary shaft 21 has a central axial line L. [ The front end of the rotary shaft 21 is inserted into the shaft hole 11a formed in the front cylinder block 11. [ The rear end of the rotary shaft 21 is inserted into the shaft hole 12a formed in the rear cylinder block 12. [ The front end of the rotary shaft (21) is rotatably supported by the front cylinder block (11). The rear end of the rotary shaft 21 is rotatably supported by the rear cylinder block 12. [ The rear end of the rotary shaft 21 extends through the second valve plate 18, the second valve sub-plate 19, and the second retainer plate 20, and protrudes into the suction chamber 14b.

Between the front housing member 13 and the rotary shaft 21, a lip seal, which is a shaft seal 22, is provided. The shaft seal 22 is accommodated in an accommodating chamber 13b formed in the front housing member 13. [ The first discharge chamber 13a is provided around the accommodating chamber 13b.

A swash plate 23, which rotates together with the rotating shaft 21, is mounted on the rotating shaft 21. The swash plate 23 is accommodated in the swash plate chamber 24 partitioned in the internal space of the cylinder blocks 11 and 12, that is, the housing H. The swash plate (23) includes an annular base (23a) around the rotary shaft (21). A first thrust bearing 25 is provided between the front cylinder block 11 and the base 23a of the swash plate 23. [ A second thrust bearing 26 is provided between the rear cylinder block 12 and the base 23a of the swash plate 23. [ The thrust bearings 25 and 26 sandwich the swash plate 23 so as to limit the movement of the swash plate 23 along the central axis L of the rotation shaft 21.

The front cylinder block 11 includes a plurality of through holes 11h (only one is shown in Fig. 1) disposed around the rotating shaft 21. [ The rear cylinder block 12 includes a plurality of through holes 12h (only one is shown in Fig. 1) disposed around the rotational shaft 21. [ One of the front passage holes 11h and one of the associated rear passage holes 12h form a cylinder bore 27. [ Each of the cylinder bores 27 accommodates the double-headed piston 28 so as to reciprocate in the front-rear direction. Each of the double-headed pistons 28 is engaged with the swash plate 23 through a pair of shoes 29. The swash plate 23 rotates integrally with the rotating shaft 21. [ The rotation of the swash plate 23 is transmitted to the respective double-headed piston 28 through the associated pair of shoes 29 and reciprocates the double-headed piston 28 back and forth at the associated cylinder bore 27.

In the front section of each cylinder bore 27, the first valve plate 15 and the associated double-headed piston 28 define a first compression chamber 27a. In the rear section of each cylinder bore 27, the second valve plate 18 and the associated double-headed piston 28 define a second compression chamber 27b.

The inner circumferential surfaces of the shaft holes 11a and 12a have sealing circumferential surfaces 11b and 12b. The rotary shaft 21 is directly supported by the cylinder blocks 11 and 12 on the sealing peripheral surfaces 11b and 12b. The rotary shaft 21 includes an axial passage 21a inside the rotary shaft 21. The shaft passage 21a has an opening 211a that opens toward the rear of the rotary shaft 21, that is, toward the rear housing member 14. [ The opening 211a is opened in the suction chamber 14b. That is, the axial passage 21a is connected to the suction chamber 14b through the opening 211a.

The rotary shaft (21) includes a first introduction passage (31) at a position corresponding to the front cylinder block (11) in the axial direction. The first introduction passage 31 connects the shaft passage 21a to the outer periphery of the rotary shaft 21. [ The rotary shaft 21 also includes a second introduction passage 32 at a position corresponding to the rear cylinder block 12 in the axial direction. The second introduction passage 32 connects the shaft passage 21a to the outer periphery of the rotary shaft 21. [

The front cylinder block 11 includes a plurality of first intake passages 33 (only one is shown in FIG. 1), and each of the first intake passages 33 has a shaft hole 11a at the front end portion of the corresponding cylinder bore 27, . Each of the first suction passages 33 has an opening which opens to the sealing peripheral surface 11b and connects the first suction passage 33 to the shaft hole 11a. 1) and each of the second suction passages 34 has a rear end portion of the corresponding cylinder bore 27 communicated with the axial hole 12a, . Each of the second suction passages 34 has an opening portion that opens to the sealing circumferential surface 12b and connects the second suction passage 34 to the shaft hole 12a.

The first introduction passage 31 is formed at a position where the first introduction passage 31 is intermittently connected to the first suction passage 33 in accordance with the rotation of the rotary shaft 21. [ The second introduction passage 32 is formed at a position where the second introduction passage 32 is intermittently connected to the second suction passage 34 in accordance with the rotation of the rotary shaft 21. The first introduction passage 31 is disposed at the same position as the opening of the suction passage 33 in the axial direction of the rotary shaft 21 and the second introduction passage 32 is disposed at the same position as the opening of the suction passage 33, Is disposed at the same position as the opening of the passage (34). The rotary shaft 21 includes the first rotary valve 35 at a portion surrounded by the sealing peripheral surface 11b and the first rotary valve 35 is formed integrally with the front portion of the rotary shaft 21 do. The rotary shaft 21 also includes a second rotary valve 36 at a portion surrounded by the sealing peripheral surface 12b and the second rotary valve 36 is integrally formed with a rear portion of the rotary shaft 21, .

When the first introduction passage 31 is connected to one of the first suction passages 33 in accordance with the rotation of the rotary shaft 21, the first rotary valve 35 is connected to the axial passage 21a < / RTI > associated with the first compression chamber 27a. When the first introduction passage 31 and the first suction passage 33 are disconnected in accordance with the rotation of the rotary shaft 21, the first rotary valve 35 is connected to the axial passage 21a ) And the first compression chamber 27a. The first rotary valve 35 can selectively connect or disconnect the axial passage 21a to or from the first compression chamber 27a in accordance with the rotation of the rotary shaft 21. [

When the second introduction passage 32 is connected to one of the second suction passages 34 in accordance with the rotation of the rotary shaft 21, the second rotary valve 36 is connected to the axial passage (not shown) through the passages 32, 21a < / RTI > and the associated second compression chamber 27b. When the second introduction passage 32 and the second suction passage 34 are disconnected in accordance with the rotation of the rotary shaft 21, the second rotary valve 36 is connected to the axial passage 21a ) And the second compression chamber 27b. The second rotary valve 36 can selectively connect or disconnect the axial passage 21a to or from the second compression chamber 27b in accordance with the rotation of the rotary shaft 21. [

The rear housing member 14 includes an introduction port 37 connected to the suction chamber 14b. The introduction port 37 is connected to the external refrigerant circuit, and the refrigerant flows from the external refrigerant circuit to the suction chamber 14b. The introduction port 37 extends in the direction perpendicular to the axial direction of the rotary shaft 21, that is, in the radial direction of the rotary shaft 21.

2, the rear housing member 14 includes a conical protrusion 40 protruding toward the opening 211a of the axial passage 21a in the suction chamber 14b. The protrusion 40 is integrally formed with the inner wall of the rear housing member 14 which faces the rear end of the rotary shaft 21 and divides the suction chamber 14b through die casting. The protrusion 40 is tapered toward the distal end 40e and has a diameter reduced toward the distal end 40e. The distal end 40e of the projection 40 has a flat cross-section. The distal end 40e of the projection 40 extends into the axial passage 21a. Between the protrusion 40 and the rear end of the rotary shaft 21 or more specifically between the protrusion 40 and the periphery of the opening 211a located around the protrusion 40 an annular restricting portion 41 Is formed. The restrictor 41 restricts the flow of the refrigerant flowing through the restrictor 41. The cross sectional area of the distal end 40e of the projection 40 perpendicular to the central axis L of the rotary shaft 21 is determined by the axial passage 21a perpendicular to the central axial line L of the rotary shaft 21, Is smaller than the cross-sectional area of the opening 211a. That is, the distal end portion 40e of the protruding portion 40 is sized such that the distal end portion 40e can be inserted into the axial passage 21a.

The operation of the first embodiment will be described.

When the refrigerant flows into the suction chamber 14b from the external refrigerant circuit through the introduction port 37, the refrigerant flowing into the suction chamber 14b collides with the projection 40. [ The refrigerant is guided toward the axial passage 21a along the protrusion and flows to the axial passage 21a through the restrictor 41. [ When the first rotary valve 35 and the second rotary valve 36 are opened in accordance with the rotation of the rotary shaft 21, the refrigerant flowing into the axial passage 21a flows into the second compression chamber 27a associated with the associated first compression chamber 27a, (27b). While the refrigerant is sucked from the suction chamber 14b into the first compression chamber 27a and the second compression chamber 27b, the refrigerant passes through the restrictor 41 and suction pulsation of the refrigerant is reduced.

The first embodiment has the following advantages.

(1) The rear housing member 14 has a protruding portion 40 protruding toward the opening 211a of the axial passage 21a in the suction chamber 14b. The restrictor 41 is formed between the protruding portion 40 and the rear end of the rotary shaft 21. This structure allows the refrigerant to flow into the suction chamber 14b and flow through the restrictor 41 to the axial passage 21a. When the first rotary valve 35 and the second rotary valve 36 are opened in accordance with the rotation of the rotary shaft 21, the refrigerant flowing into the axial passage 21a flows into the second compression chamber 27a associated with the associated first compression chamber 27a, (27b). While the refrigerant is sucked from the suction chamber 14b into the first compression chamber 27a and the second compression chamber 27b, the refrigerant passes through the restrictor 41 and the suction pulsation of the refrigerant is reduced.

(2) The distal end 40e of the projection 40 extends into the axial passage 21a. This structure is advantageous in that the restrictor 41 can be easily formed when the distal end portion 40e of the protruding portion 40 is extended in the axial direction to the same position as the rear end of the rotary shaft 21 and does not extend into the axial passage 21a . As a result, the suction pulsation of the refrigerant is further reduced in an appropriate manner.

(3) The protrusion 40 is tapered. This structure allows the refrigerant to flow into the suction chamber 14b and be guided toward the axial passage 21a by the projection 40. [ Therefore, the refrigerant smoothly flows from the suction chamber 14b to the axial passage 21a. This reduces the suction loss of the refrigerant and also reduces the suction pulsation of the refrigerant.

(4) The introduction port 37 extends in a direction perpendicular to the axial direction of the rotary shaft 21. This structure allows the refrigerant to flow from the introduction port 37 into the suction chamber 14b and to move along the projection 40 along the axis of the rotation shaft 21 as compared with the case where the introduction port 37 extends parallel to the axial direction of the rotary shaft 21. [ So that it is guided more smoothly toward the passage 21a.

(5) The protrusion 40 is formed integrally with the inner wall of the rear housing member 14. This structure improves the productivity of the protrusion 40, for example, when the protrusion formed of the member separated from the rear housing member 14 is attached to the rear housing member 14. [

The first embodiment can be modified as follows.

As in the second embodiment shown in FIG. 3, the distal end 40e of the protrusion 40 may be semi-spherical. This structure allows the refrigerant to smoothly flow around the distal end portion 40e of the projection 40 and further reduces the suction loss of the refrigerant.

As in the third embodiment shown in Fig. 4, the projections 40 may be columnar. That is, the protrusion 40 does not need to be tapered. The protrusion 40 may be a column extending in the axial direction of the rotary shaft 21 or more specifically the protrusion 40 may have a constant cross sectional shape and a cross sectional area in the axial direction of the rotary shaft 21. [ Further, the distal end 40e of the columnar projection 40 may be hemispherical as shown in Fig.

The introduction port 37 can extend in the direction crossing the axial direction of the rotary shaft 21. [

The introduction port 37 can extend in a direction parallel to the axial direction of the rotary shaft 21. [

The distal end 40e of the projection 40 does not necessarily have to extend into the axial passage 21a but can extend to the same position as the rear end of the rotary shaft 21 in the axial direction. That is, the distal end 40e of the protrusion 40 can be positioned at any position where the restrictor 41 can be formed between the protrusion 40 and the rear end of the rotation shaft 21. [

The projecting portion 40 may be formed as a member separated from the rear housing member 14. [

Accordingly, the examples and embodiments should be regarded as illustrative rather than restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.

Claims (7)

A housing including a cylinder block, a front housing member connected to a front end of the cylinder block, and a rear housing member connected to a rear end of the cylinder block, the housing defining a swash plate chamber;
A rotating shaft supported by the housing;
A swash plate housed in the swash plate chamber and configured to rotate with the rotation axis;
A double-headed piston engaged with the swash plate;
A cylinder bore formed in the cylinder block and accommodating the double-headed piston;
A first compression chamber defined at the front end of the cylinder bore by the double-headed piston;
A second compression chamber partitioned at a rear end of the cylinder bore by the double-headed piston;
A suction chamber formed in the rear housing member;
An axial passage formed in the rotary shaft and connected to the suction chamber, the axial passage including an opening portion opened to the suction chamber;
A first rotary valve selectively connecting or disconnecting the axial passage to the first compression chamber in accordance with rotation of the rotary shaft;
A second rotary valve selectively connecting or disconnecting the axial passage to the second compression chamber in accordance with rotation of the rotary shaft; And
And a protrusion provided in the suction chamber and protruding toward the opening of the shaft passage,
A restrictor through which the refrigerant passes when the refrigerant flows from the suction chamber to the axial passage is formed between the protruding portion and the rear end of the rotary shaft,
Wherein the projecting portion has a distal end portion of a size that can be inserted into the opening portion of the axial passage. The method according to claim 1,
And the distal end of the protrusion is inserted into the axial passage. The method according to claim 1,
Wherein the protruding portion is tapered. The method according to claim 1,
Wherein the protrusions extend in the axial direction of the rotary shaft and have a constant cross-sectional shape and a cross-sectional area in the axial direction of the rotary shaft. The method according to claim 1,
Wherein the distal end of the protrusion is semi-spherical. ≪ RTI ID = 0.0 >< / RTI > The method according to claim 1,
Wherein the projecting portion is formed integrally with the rear housing member. 7. The method according to any one of claims 1 to 6,
Wherein the rear housing member includes an introduction port for introducing the refrigerant into the suction chamber,
Wherein the introduction port extends in a direction crossing the axial direction of the rotary shaft.

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