JP2015121127A - Gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas compressor equipped with an oil separator capable of further improving the oil separation performance for separating mixed refrigerating machine oil from discharged refrigerant gas.SOLUTION: A gas compressor includes an oil separator 18 separating an oil component mixed in a discharged medium discharged into a discharge chamber 17 from a compressor body 4 through a discharged gas communication passage 28a, 28b from the discharged medium by colliding the discharged medium against a wall surface. The oil separator 18 includes a discharge pipe 29a, 29b extending from a circumference of the discharged gas communication passage 28a, 29b toward a bottom inner wall 2b of a main body case 2; and a cylindrical portion 30 covering a circumference of the discharge pipe 29a, 29b so as to form a passage between an outer end surface 15a of a rear side block 15 and the cylindrical portion 30 from a distal end of the discharge pipe 29a, 29b along an outer circumferential surface of the discharge pipe 29a, 29b on a distal end of an inner wall protrusion 31a, 31b extending from the bottom inner wall 2b in the main body case 2, the discharged medium passing through the passage.

Description

  The present invention relates to a gas compressor installed in an air conditioner mounted on a vehicle, for example.

  For example, vehicles such as automobiles are provided with an air conditioner for adjusting the temperature in the passenger compartment. Such an air conditioner has a loop-like refrigerant cycle in which refrigerant (cooling medium) is circulated, and this refrigerant cycle is provided with an evaporator, a gas compressor, a condenser, and an expansion valve in this order. ing. The gas compressor of the air conditioner compresses the gaseous refrigerant evaporated by the evaporator into a high-pressure refrigerant gas and sends it to the condenser.

  As such a gas compressor, conventionally, a rotor having a plurality of vanes provided in a cylinder having a substantially elliptical inner peripheral surface, the tip portion of which is in sliding contact with the inner peripheral surface of the cylinder and provided so as to protrude and be housed. A vane rotary type gas compressor that is rotatably supported is known (for example, see Patent Document 1).

  A vane rotary type gas compressor described in Patent Document 1 includes a rotor that can rotate integrally with a rotating shaft, a cylinder that has a contoured inner peripheral surface that surrounds the outer periphery of the rotor, and a cylinder that extends from the outer peripheral surface of the rotor. A plurality of vanes provided so as to protrude toward the inner peripheral surface, and two side blocks (a front side block and a rear side block) which block the both ends of the rotor and the cylinder and rotatably support both sides of the rotating shaft. The compressor main body which has is provided.

  This compressor body was introduced into the compression chamber by reducing the volume of the compression chamber formed between the rotor outer peripheral surface and the cylinder inner peripheral surface with the rotation of the rotor by two adjacent vanes. The low-pressure refrigerant gas is compressed, and the compressed high-pressure refrigerant gas is discharged to the outside.

  By the way, the high-pressure refrigerant gas compressed in the compression chamber in the cylinder is mixed with refrigerating machine oil for vane back pressure that has leaked into the compression chamber. For this reason, a pipe-shaped oil separator is provided in the discharge chamber formed in the case (compressor case) on the outer surface side of the rear side block so as to protrude from the outer end surface of the rear side block.

  Then, the high-pressure refrigerant gas (refrigeration oil mixed) compressed in the compression chamber of the compressor body is caused to collide with the inner wall of the case from the front end opening of the oil separator through the pipe-shaped oil separator. Thus, the refrigerant gas is separated from the refrigerating machine oil. The separated refrigerating machine oil accumulates in the housing case by gravity.

JP 2001-329981 A

  By the way, in Patent Document 1, as described above, high-pressure refrigerant gas (which contains refrigeration oil) collides with the inner wall of the case (compressor case) from the tip opening of the pipe-shaped oil separator, and refrigerant gas Refrigerating machine oil is separated from the inside.

  Thus, since the refrigerating machine oil of patent document 1 makes high pressure refrigerant gas (refrigerating machine oil is mixed) collide with an inner wall, that is, it makes it collide only once, the separation performance of refrigerating machine oil by collision is not enough. Needless to say, in order to increase the cooling capacity of the refrigerant gas discharged from the gas compressor, further improvement of the refrigerating machine oil separation performance is required.

  Then, an object of this invention is to provide the gas compressor provided with the oil separator which can further improve the oil separation performance which isolate | separates the refrigerating machine oil mixed from the refrigerant gas discharged.

  In order to solve the above-mentioned problems, a gas compressor according to the present invention includes a compressor main body arranged in a main body case, which compresses a supplied medium and discharges a compressed high-pressure medium, and the compressor Two side blocks provided so as to respectively close both side end surfaces of the main body, a discharge chamber provided between the closed one end side inner wall surface of the main body case and one of the side blocks, and the one side A discharge medium communication path provided in the block and communicating with the compressor main body side and the discharge chamber side to discharge the medium compressed by the compressor main body to the discharge chamber; and provided in the discharge chamber, the compressor An oil separator that separates mixed oil by colliding the discharge medium with a wall surface from the discharge medium discharged from the main body into the discharge chamber through the discharge medium communication path, and the oil separator The one side A discharge pipe on the discharge chamber side end face of the closed block extending from the periphery of the discharge medium communication path toward the inner wall surface side of the one end side end, and an opening pipe opened from the inner wall surface of the one end side end portion toward the discharge pipe side A cylindrical portion that is integrally formed on the front end side of the inner wall protruding portion that extends toward the periphery and that is provided so as to cover the vicinity of the discharge chamber side end surface of the discharge pipe, and the discharge pipe and the A passage through which the discharge medium passes is formed between the front end side of the discharge pipe and the outer peripheral surface of the discharge pipe toward the discharge chamber side end surface of the one side block between the cylindrical portion. It is characterized by.

  According to the gas compressor of the present invention, the high-pressure discharge medium discharged from the compressor main body is caused to collide with the inner wall surface in the cylindrical portion through the discharge pipe from the discharge medium communication path, and further through one side through the path. Since it can be made to collide with the discharge chamber side end surface of the block, the oil separation performance can be further improved as compared with the case where the oil is separated by colliding the discharge medium once.

The figure which showed the main body case and oil separator of the gas compressor (vane rotary type gas compressor) which concern on embodiment of this invention as a cross-sectional shape. AA sectional view taken on the line AA of FIG. The perspective view which shows the outer side end surface side of the rear side block in this embodiment. The schematic perspective view which shows the discharge chamber side in a main body case. The figure which showed the oil separation operation | movement by the oil separator of this embodiment. The figure which showed the throttle | throttle part provided in the 1st channel | path of the oil separator of this embodiment.

  Hereinafter, the present invention will be described based on the illustrated embodiments. FIG. 1 is a diagram showing, as a cross-sectional shape, a main body case and an oil separator of a vane rotary type gas compressor (hereinafter referred to as “compressor”) as a gas compressor according to an embodiment of the present invention. It is the sectional view on the AA line of FIG.

(Overall configuration of compressor 1)
The illustrated compressor 1 is configured as a part of an air conditioning system (hereinafter referred to as an “air conditioning system”) that performs cooling by using the heat of vaporization of a cooling medium, for example, and is a condensing component that is another component of the air conditioning system It is provided on the circulation path of the cooling medium together with a condenser, an expansion valve, an evaporator, etc. (all not shown). In addition, as such an air conditioning system, the air conditioning apparatus for adjusting the temperature in the vehicle interior of a vehicle (automobile etc.) is mentioned, for example.

  The compressor 1 compresses the refrigerant gas as a gaseous cooling medium taken from the evaporator of the air conditioning system, and supplies the compressed refrigerant gas to the condenser of the air conditioning system. The condenser liquefies the compressed refrigerant gas and sends it to the expansion valve as a high-pressure liquid refrigerant. The high-pressure and liquid refrigerant is reduced in pressure by the expansion valve and sent to the evaporator. The low-pressure liquid refrigerant absorbs heat from ambient air and vaporizes in the evaporator, and cools the air around the evaporator by heat exchange with the heat of vaporization.

  As shown in FIG. 1, the compressor 1 includes a substantially cylindrical main body case 2 that is open at one end side (left side in FIG. 1) and closed at the other end side, and a front that closes an opening at one end side of the main body case 2. Drive power from a compressor body 4 housed in a housing constituted by the head 3, the connected main body case 2 and the front head 3, and a vehicle (automobile) engine (not shown) as a drive source. An electromagnetic clutch 5 for transmission to the compressor body 4 is provided.

  The front head 3 is formed in a lid shape that closes the opening end surface of the main body case 2, and is fastened and fixed around the opening end on one end side of the main body case 2 with a plurality of bolts. The front head 3 has a suction port 7 for sucking a low-pressure refrigerant gas G1 from an evaporator (not shown) of the air conditioning system, and the housing case 2 has a high-pressure refrigerant gas G2 compressed by the compressor body 4. Is discharged to a condenser (not shown) of the air conditioning system.

  As shown in FIG. 2, the compressor body 4 includes a substantially cylindrical rotor 11 that rotates integrally with the rotary shaft 10, and a substantially elliptical inner peripheral surface that surrounds the rotor 11 from the outside of the outer peripheral surface 11 a. The cylinder 12 having 12a, the five plate-like vanes 13 provided so as to protrude from the outer peripheral surface 11a of the rotor 11 toward the inner peripheral surface 12a of the cylinder 12, and both end surfaces of the rotor 11 and the cylinder 12 are closed. Two side blocks (a front side block 14 and a rear side block 15 (see FIG. 1)) are provided. In FIG. 2, the main body case 2 on the outer peripheral surface side of the compressor main body 4 is omitted.

  An O-ring 16 as a seal member is provided on the outer peripheral surfaces of the front side block 14 and the rear side block 15 over the entire circumference (the O-ring on the front side block 14 side is not shown), and the front side block 14 side A suction chamber (not shown) formed between the front head 3 and the housing 2 and a discharge chamber 17 formed in the housing 2 on the rear side block 15 side are partitioned in an airtight manner.

  An oil separator 18 is provided on the outer end face 15 a side of the rear side block 15 so as to be positioned in the discharge chamber 17. Details of the oil separator 18 which is a feature of the present invention will be described later.

  The front side block 14 is fastened and fixed to the inner peripheral surface around the opening end of the front head 3 with a plurality of bolts. On the other hand, as shown in FIG. 1, the rear side block 15 is press-fitted (fitted) to the inner peripheral surface 2 a of the housing 2 at the end portion side of the outer peripheral surface (outside the O-ring 16 installed along the outer peripheral surface). ) Thus, the compressor main body 4 housed in the main body case 2 is fastened and fixed to the front head 3 by bolts on the front side block 14 side, and the rear side block 15 side is press-fitted (fitted) to the inner peripheral surface 2a of the main body case 2. ) Is held as it is.

  The electromagnetic clutch 5 is installed on the outer surface side of the front head 3, and the rotational driving force of the engine is transmitted to the pulley 20 via a belt (not shown). One end side (left side in FIG. 2) of the rotating shaft 10 is fitted in the central through hole of the armature 21 of the electromagnetic clutch 5. The rotating shaft 10 is pivotally supported by the central through holes of the front side block 14 and the rear side block 15.

  During operation of the compressor 1 (compressor main body 4), the armature 21 is attracted to the side surface of the pulley 20 by excitation of an electromagnet (not shown) in the pulley 20, so that the pulley 20 is passed through a belt (not shown). Is transmitted to the rotary shaft 10 (rotor 11) via the armature 21.

(Configuration and operation of compressor body 4)
As shown in FIG. 2, in the space between the inner peripheral surface 12a of the cylinder 12, the outer peripheral surface 11a of the rotor 11, and both side blocks 14, 15 (see FIG. 1), five vanes installed at equal intervals. A plurality of compression chambers 22 a and 22 b partitioned by 13 are formed.

  Each vane 13 is slidably installed in a vane groove 23 formed in the rotor 11, and outwards from the outer peripheral surface 11 a of the rotor 11 due to back pressure by refrigerating machine oil supplied to the bottom of the vane groove 23. Protrusively. In FIG. 2, the compression chamber formed in the upper space between the inner peripheral surface 12a of the cylinder 12 and the outer peripheral surface 11a of the rotor 11 is referred to as a compression chamber 22a, and the compression chamber formed in the lower space. Is a compression chamber 22b.

  The cylinder 12 has an inner peripheral surface 12 a having a substantially elliptical cross-sectional contour that surrounds the outer periphery 11 a of the rotor 11. Each of the compression chambers 22a and 22b repeatedly increases and decreases in volume in the refrigerant gas suction process and the compression process as the rotor 11 rotates. In addition, the compressor 1 (compressor main body 4) of this embodiment has the suction | inhalation process and compression process of 2 times, while the rotor 11 carries out 1 rotation.

  In the cylinder 12, each suction hole (not shown) for sucking the low-pressure refrigerant gas G1 into each compression chamber 22a, 22b and the high-pressure refrigerant gas G2 compressed in each compression chamber 22a, 22b are discharged. The discharge holes 24a and 24b are provided.

  Specifically, in the process of increasing the volume of the compression chambers 22a and 22b, low-pressure refrigerant gas is sucked into the compression chambers 22a and 22b through the respective suction holes (not shown) formed in the front side block 14, and the volume is increased. In the process of decreasing the refrigerant gas, the refrigerant gas confined in the compression chambers 22a and 22b is compressed, whereby the refrigerant gas becomes high temperature and high pressure. The high-temperature and high-pressure refrigerant gas G2 is discharged through the discharge holes 24a and 24b into discharge chambers 25a and 25b, which are spaces surrounded by the cylinder 12, the main body case 2, and the side blocks 14 and 15, respectively. Is done.

  Each discharge chamber 25a, 25b is provided with a discharge valve 26 for preventing the refrigerant gas from flowing back to the compression chambers 22a, 22b, and a valve support 27 for preventing excessive deformation (warping) of the discharge valve 26. . The high-temperature and high-pressure refrigerant gas discharged from the discharge holes 24a and 24b to the discharge chambers 25a and 25b is provided in the discharge chamber 17 in the main body case 2 through the discharge gas communication passages 28a and 28b formed in the rear side block 15. It introduce | transduces into the oil separator 18 mentioned later. As shown in FIG. 1, the discharge holes 24 a and 24 b are arranged in parallel along the longitudinal direction of the rotor 11 (the axial direction of the rotating shaft 10).

  The oil separator 18 is used for a first collision, which will be described later, with respect to the discharged refrigerant gas mixed with refrigeration oil (such as vane back pressure oil leaked from the vane groove 23 formed in the rotor 11 to the compression chambers 22a and 22b). Refrigerating machine oil mixed in the refrigerant gas is separated in two stages by causing the surface 30a and the second collision surface 15a ′ (see FIG. 5) to collide twice.

  As shown in FIG. 1, the refrigerating machine oil R separated from the refrigerant gas by the oil separator 18 is accumulated at the bottom of the discharge chamber 17, and the high-pressure refrigerant gas G <b> 2 after the refrigerating machine oil is separated is discharged from the discharge chamber 17. From the discharge port 8 to the condenser (not shown). The discharge port 8 is provided in the upper part of the main body case 2 on the side away from the outer end face 15a of the rear side block 15.

  The refrigerating machine oil R that accumulates at the bottom of the discharge chamber 17 is oil passages, salai grooves (not shown), etc. formed in both side blocks 14 and 15 due to the high-pressure atmosphere of the high-pressure refrigerant gas discharged into the discharge chamber 17. Is supplied to the vane groove 23 for back pressure.

(Structure of oil separator 18)
Next, the structure of the oil separator 18 will be described.

  3 is a schematic perspective view showing the outer end surface 15a side of the rear side block 15, and FIG. 4 is a schematic perspective view showing the discharge chamber 17 side in the main body case 2. As shown in FIG.

  The oil separator 18 provided in the discharge chamber 17 in the main body case 2 includes discharge pipes 29a and 29b with open ends and inner wall projections 31a and 31b formed with a concave cylindrical portion 30 with an open end on the tip side. And.

  The discharge pipes 29a and 29b are arranged from the periphery of the discharge gas communication passages 28a and 28b opened to the outer end face 15a side of the rear side block 15 to the bottom inner wall 2b on the front side (right side in FIG. 1) in the main body case 2. (See FIG. 1).

  The cylindrical portion 30 is formed on the distal end side of the inner wall protruding portions 31a and 31b so as to cover the periphery of the discharge pipes 29a and 29b up to the vicinity of the outer end surface 15a of the rear side block 15.

  On the outer end surface 15a of the rear side block 15, the ribs 32a and 32b projecting forward so as to be positioned outside the cylindrical portion 30 are formed around the lower side (gravity direction side) of the discharge pipes 29a and 29b. Has been. As shown in FIG. 5, the ribs 32 a and 32 b are inclined so that the tip side is slightly inclined downward, and the separated oil (refrigerant oil R) moves smoothly to the bottom of the discharge chamber 17. Yes.

  As shown in FIG. 5, in front of the tip opening 29a ′ (29b ′) of the discharge pipe 29a (29b), a first collision surface 30a facing the back side (right side in FIG. 5) in the cylindrical portion 30. The first passage a1 is provided between the outer peripheral surface of the discharge pipe 29a (29b) and the inner peripheral surface of the cylindrical portion 30. Further, a second passage a <b> 2 is provided between the tip opening 30 b of the cylindrical portion 30 and the outer end surface 15 a of the rear side block 15. Further, a third passage a3 is provided between the lower outer peripheral surface of the cylindrical portion 30 and the inner peripheral surface of the rib 32a (32b).

  Therefore, the end opening 29a ′ (29b ′) side of the discharge pipe 29a (29b) is inside the main body case 2 through the first passage a1 and the second passage a2, and the first passage a1 and the third passage a3. The discharge chamber 17 communicates with the discharge chamber 17. Although FIG. 5 shows the discharge pipe 29a side, the discharge pipe 29b has the same configuration.

  In addition, although the 1st collision surface 30a in the cylindrical part 30 was made into planar shape, the center part side of this 1st collision surface 30a is good also as a slightly convex shape.

(Oil separation operation by the oil separator 18)
Next, the oil separation operation by the oil separator 18 will be described with reference to FIG. In the following, the oil separation operation on the discharge pipe 29a side will be described, but the same oil separation operation is performed on the discharge pipe 29b side.

  As shown in FIG. 5, the high-pressure refrigerant gas G2 compressed and discharged in the compression chambers 22a and 22b passes through the discharge pipe 29a (29b) from the discharge gas communication path 28a (28b) of the rear side block 15, and is tubular. Colliding with the first collision surface 30a in the portion 30 (first collision).

  In this first collision, the refrigeration oil mixed in the refrigerant gas (such as vane back pressure oil leaked from the vane groove 23 formed in the rotor 11 to the compression chambers 22a and 22b) is separated (primary separation). . Most of the contained refrigeration oil is separated by the collision of the refrigerant gas G2 with the first collision surface 30a. The refrigerating machine oil R separated by the collision at the first collision surface 30a moves along the surface of the rib 32a (32b) from the lower first passage a1 through the second and third passages a2 and a3. Thus, it collects at the bottom of the discharge chamber 17 (see FIG. 1).

  Then, the refrigerant gas after having collided with the first collision surface 30a (the refrigeration oil still remains a little) passes through the first passage a1 and the second of the outer end face 15a facing the front of the first passage a1. Colliding with the collision surface 15a ′ (second collision). In this second collision, the refrigerating machine oil R still remaining in the refrigerant gas is further separated (secondary separation), and the separated refrigerating machine oil R passes through the second and third passages a2 and a3 on the lower side. It moves along the surface of the rib 32a (32b) and accumulates at the bottom of the discharge chamber 17 (see FIG. 1).

  On the other hand, the refrigerant gas G2 from which the refrigerating machine oil is almost separated moves to the upper side of the discharge chamber 17 through the second passage a2 and the third passage a3, and is discharged to the condenser (not shown) through the discharge port 8. . At this time, the discharge port 8 is separated from the outer end face 15 a of the rear side block 15. Therefore, even if a part of the refrigerating machine oil separated by the collision at the second collision surface 15a 'of the outer end surface 15a is diffused around, it is possible to reduce leakage from the discharge port 8 to the outside.

  In this way, the high-pressure refrigerant gas G2 discharged from the compression chambers 22a and 22b collides with the first collision surface 30a in the cylindrical portion 30 through the discharge gas communication path 28a (28b) and the discharge pipe 29a (29b). (First collision), and further, the refrigerant gas is caused to collide once by colliding with the second collision surface 15a ′ on the outer end surface 15a side of the rear side block 15 through the first passage a1 (second collision). Thus, the oil separation performance can be further improved compared to the case of oil separation.

  When the oil separation performance by the oil separator 18 is improved, the high-pressure refrigerant gas not mixed with the refrigerating machine oil is discharged to the condenser (not shown) through the discharge port 8, so that the cooling efficiency in the air conditioning system can be further increased. .

  In addition, by providing ribs 32a and 32b around the lower side of the discharge pipes 29a and 29b (second passage a2) on the outer end surface 15a of the rear side block 15, the second collision surface 15a ′ can be It is possible to prevent the refrigerant gas from being injected toward the lower direction of the second passage a2 (the bottom of the discharge chamber 17).

  Therefore, it is possible to prevent the refrigerant gas that has collided with the second collision surface 15 a ′ from being injected onto the surface of the refrigerating machine oil accumulated at the bottom of the discharge chamber 17 and soaring the refrigerating machine oil into the discharge chamber 17. When the refrigerating machine oil accumulated at the bottom of the discharge chamber 17 is lifted into the discharge chamber 17, there is a problem that the refrigerating machine oil is mixed into the refrigerant gas again.

  Further, as shown in FIG. 6, a throttle portion 33 that restricts the width (diameter) of the first passage a <b> 1 is disposed between the outer peripheral surface of each discharge pipe 29 a, 29 b and the inner peripheral surface of the cylindrical portion 30. Thereby, the flow velocity of the refrigerant gas flowing through the first passage a1 can be increased. In this way, by reducing the diameter of the first passage a1 with the restricting portion 33, the flow velocity of the refrigerant gas can be increased and caused to collide with the second collision surface 15a ′, so that the collision at the second collision surface 15a ′. The oil separation performance by can be further increased.

  In FIG. 6, the throttle portion 33 is provided in the first passage a <b> 1, but the entire width of the first passage a <b> 1 is narrowed (for example, formed by the throttle portion 33 shown in FIG. 6). For example, a function as an aperture portion).

1 Compressor (gas compressor)
2 Body case 2b Bottom inner wall (one end side inner wall)
DESCRIPTION OF SYMBOLS 3 Front head 4 Compressor main body 11 Rotor 12 Cylinder 13 Vane 14 Front side block 15 Rear side block 15a Outer end surface 15a 'Second collision surface 17 Discharge chamber 18 Oil separators 28a, 28b Discharge gas communication passage (discharge medium communication passage)
29a, 29b Discharge pipe 30 Cylindrical part 30a 1st collision surface 31a, 31b Inner wall projection part 32a, 32b Rib 33 Restriction part a1 1st channel | path a2 2nd channel | path a3 3rd channel | path

Claims (5)

A compressor main body arranged in the main body case for compressing the supplied medium and discharging the compressed high-pressure medium;
Two side blocks provided so as to respectively close both end surfaces of the compressor body;
A discharge chamber provided between one end side inner wall surface of the one end side that is closed in the main body case and one of the side blocks;
A discharge medium communication path that is provided in the one side block and communicates the compressor main body side and the discharge chamber side to discharge the medium compressed by the compressor main body to the discharge chamber;
Oil separation that is provided in the discharge chamber and separates mixed oil by colliding the discharge medium with a wall surface from the discharge medium discharged from the compressor body to the discharge chamber through the discharge medium communication path. Equipped with
The oil separator is a discharge pipe having an open end on the discharge chamber side end surface of the one side block extending from the periphery of the discharge medium communication path toward the one end side inner wall surface side; and
A cylinder that is integrally formed on the distal end side of the inner wall protrusion extending from the inner wall surface of the one end side end portion toward the discharge pipe side and that covers the periphery of the discharge pipe to the vicinity of the discharge chamber side end surface And
Between the discharge pipe and the cylindrical portion, there is a passage through which the discharge medium passes from the tip end side of the discharge pipe along the outer peripheral surface of the discharge pipe toward the discharge chamber side end surface of the one side block. A gas compressor characterized by being formed.   The oil separator causes the discharge medium discharged from the discharge pipe through the discharge medium communication path to collide with an inner wall surface facing the tip opening of the discharge pipe in the cylindrical portion, and further discharge after the collision. 2. The gas compressor according to claim 1, wherein a medium is caused to collide with the discharge chamber side end face of the one side block through the passage to separate the oil component mixed in the discharge medium.   A discharge port is provided on the side of the main body case away from the end surface on the discharge chamber side of the one side block to discharge the discharge medium from which oil has been separated by the oil separator to the outside. The gas compressor according to claim 1 or 2.   4. The rib extending from the discharge chamber side end surface to the front side is provided on the lower side of the cylindrical portion of the discharge chamber side end surface of the one side block. 5. A gas compressor according to claim 1.   The gas compressor according to any one of claims 1 to 4, wherein the passage is provided with a throttle portion that narrows the width of the passage.