JP2019157810A - Compressor - Google Patents

Abstract

To provide a compressor which can reduce a quantity of oil flowing out to a suction chamber.SOLUTION: In a compressor 1 having a drive shaft 6, a pressure supply passage 7 and a discharge passage 8, the discharge passage 8 includes: an in-shaft passage 81 formed in the drive shaft 6, and communicating with a crank chamber 30 at its one end; a center bore internal space 82 communicating with the other end of the in-shaft passage 81, and formed between an end face of the other end side of the drive shaft 6 and a valve plate 4 in the center bore 22; and an orifice 83. The compressor also has a gas return passage 84 for making the center bore internal space 82 and the suction chamber 53 communicate with each other, the gas return passage 84 is formed in a protrusion 12 protruding to the drive shaft 6 rather than the valve plate 4 in the center bore internal space 82 out of a passage forming member 10 for forming a part of the discharge passage 8, an inside diameter of the in-shaft passage 81 is larger than an inside diameter of the gas return passage 84, and a clearance is formed between the drive shaft 6 and the protrusion 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a compressor used in, for example, a vehicle air conditioner.

As a compressor, for example, as described in Patent Document 1, a gas containing oil flows into a hole formed inside the drive shaft, and the oil is separated by receiving centrifugal force due to rotation of the drive shaft. There are things that are configured.
The gas from which the oil has been separated flows into the suction chamber. On the other hand, the oil separated from the gas flows downstream through the peripheral wall of the hole, receives the centrifugal force due to the rotation of the drive shaft, and drives from the minute gap formed between the drive shaft and the support member. It scatters into the space formed on the outer peripheral side of the shaft and returns to the crank chamber.

JP 2008-106679 A

However, the compressor described in Patent Document 1 has no space for storing oil separated from gas. For this reason, if the amount of oil contained in the gas flowing into the hole is large, the oil that exists in the minute gap formed between the drive shaft and the support member cannot be discharged in time, and the support member is formed. There is a problem that a large amount of oil flows out of the hole into the suction chamber.
The present invention has been made paying attention to the above-described problems, and an object thereof is to provide a compressor capable of reducing the amount of oil flowing out to the suction chamber.

  In order to solve the above problems, one aspect of the present invention is a compressor including a cylinder block, a front housing, a valve plate, a cylinder head, a drive shaft, a supply passage, and a discharge passage. The compressor discharges refrigerant compressed by being sucked into the cylinder bore from the suction chamber into the discharge chamber and circulates a part of the discharged refrigerant in order through the supply passage, the crank chamber, the discharge passage, and the suction chamber. Have The cylinder block is formed with a plurality of cylinder bores arranged in an annular shape, and a center bore disposed inside the plurality of cylinder bores. The front housing closes one end side of the cylinder block and forms a crank chamber together with the cylinder block. The valve plate is formed with a discharge hole and a suction hole that close the other end of the cylinder block and communicate with the cylinder bore. The cylinder head is disposed to face the cylinder block with a valve plate interposed therebetween, and a suction chamber for sucking refrigerant from the outside and a discharge chamber for discharging the refrigerant to the outside are formed. One end of the drive shaft is inserted into the center bore and is rotatably supported by the cylinder block. The supply passage communicates the discharge chamber and the crank chamber. The discharge passage communicates the crank chamber and the suction chamber, and has an in-shaft passage, a center bore inner space, and a gas return passage. The in-shaft passage is formed inside the drive shaft, and one end communicates with the crank chamber. The center bore internal space is a space that communicates with the other end of the in-shaft passage and is formed between the end surface on the other end side of the drive shaft and the valve plate inside the center bore. The gas return passage is a passage that includes an orifice and communicates the space in the center bore and the suction chamber, and is formed inside the protruding portion that is a portion protruding toward the drive shaft from the valve plate in the space in the center bore. Yes. The inner diameter of the in-axis passage is larger than the inner diameter of the gas return passage. Further, a gap is formed between the end surface on the other end side of the drive shaft and the end surface of the protruding portion on the side facing the drive shaft.

According to one aspect of the present invention, the centrifugal force generated by the rotation of the drive shaft causes the centrifugal separation action to act on the refrigerant moving through the in-shaft passage. It will flow into the inner space.
As a result, the refrigerant that has passed through the discharge passage and has moved to the suction chamber can be made into a gas flow in which most of the oil contained is separated, thereby reducing the amount of oil flowing out to the suction chamber. It is possible to provide a compressor that can.

It is sectional drawing showing the structure of the compressor in 1st embodiment of this invention. It is a figure showing the structure of a discharge passage. It is a figure showing the movement state of the oil which a refrigerant | coolant contains. It is a figure showing the modification of 1st embodiment. It is a figure showing the modification of 1st embodiment. It is a figure showing the modification of 1st embodiment. It is a figure showing the modification of 1st embodiment.

A first embodiment of the present invention will be described below with reference to the drawings. In the description of the drawings referred to in the following description, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and it should be noted that the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. Moreover, it is a matter of course that the drawings include portions having different dimensional relationships and ratios.
Furthermore, the first embodiment shown below exemplifies a configuration for embodying the technical idea of the present invention, and the technical idea of the present invention is the material of the component parts, their shapes, The structure, arrangement, etc. are not specified below. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims. Further, the directions of “left and right” and “up and down” in the following description are merely definitions for convenience of description, and do not limit the technical idea of the present invention. Thus, for example, if the paper is rotated 90 degrees, “left and right” and “up and down” are read interchangeably, and if the paper is rotated 180 degrees, “left” becomes “right” and “right” becomes “left”. Of course it becomes.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
(Constitution)
As shown in FIG. 1, the compressor 1 includes a cylinder block 2, a front housing 3, a valve plate 4, a cylinder head 5, a drive shaft 6, a supply passage 7, and a discharge passage 8.
The cylinder block 2, the front housing 3, the valve plate 4, and the cylinder head 5 are fastened by a through bolt 9 via a gasket (not shown) to form a housing of the compressor 1.
The cylinder block 2 is formed with a plurality of cylinder bores 21 arranged in an annular shape and a center bore 22 arranged inside each cylinder bore 21.
A piston 23 is disposed inside the cylinder bore 21.

In addition to this, the cylinder block 2 is formed with an oil return passage 24 communicating with a center bore inner space 82 described later, and an oil storage chamber 25.
The oil return passage 24 is formed around the center bore inner space 82 and communicates the center bore inner space 82 with a crank chamber 30 described later. In the drawing, a configuration in which only one oil return passage 24 is formed in the cylinder block 2 is shown, but a configuration in which a plurality of oil return passages 24 are formed in the cylinder block 2 may be employed.

Further, the return side communication path 26, which is a communication path that connects the oil return path 24 and the center bore inner space 82, is formed on the inner wall surface of the center bore inner space 82 that is positioned below the center axis of the drive shaft 6 in the vertical direction. It is open. Further, the return side communication path 26 is opened at a position of the cylinder block 2 that is closed by the valve plate 4.
Further, the inner diameter of the return side communication passage 26 is smaller than the inner diameter of the oil return passage 24.

For example, a plurality of the oil storage chambers 25 are formed around the radial direction of the center bore inner space 82 and communicate with the center bore inner space 82. The plurality of oil storage chambers 25 may be configured to communicate with each other. Alternatively, only one oil storage chamber 25 may be formed in the cylinder block 2.
Further, the storage side communication passage 27, which is a communication passage that allows the oil storage chamber 25 and the center bore internal space 82 to communicate with each other, is opened at a position of the cylinder block 2 that is closed by the valve plate 4.
The front housing 3 closes one end side of the cylinder block 2. The front housing 3 forms a crank chamber 30 together with the cylinder block 2.
The crank chamber 30 is a space formed by the front housing 3 and the cylinder block 2, and a swash plate 31 is disposed therein.

The swash plate 31 is connected to the drive shaft 6 via a rotor 32 and a link mechanism 33 fixed to the drive shaft 6. Further, it is possible to change the inclination angle (inclination angle) of the swash plate 31 with respect to the axis of the drive shaft 6 by changing the pressure (internal pressure) of the crank chamber 30.
Further, a through hole 34 is formed in the swash plate 31 in a shape that allows the swash plate 31 to tilt within a range of a maximum inclination angle and a minimum inclination angle. The through hole 34 is formed with a minimum inclination angle restricting portion (not shown) that contacts the drive shaft 6. When the swash plate 31 has an inclination angle of 0 [°] when the swash plate 31 is orthogonal to the drive shaft 6, the minimum inclination restriction unit can displace the swash plate 31 to an inclination of almost 0 [°]. It is made possible.

Between the rotor 32 and the swash plate 31, an inclination reduction spring 35 that urges the swash plate 31 in a direction to reduce the inclination angle is mounted until the swash plate 31 reaches the minimum inclination angle. Further, between the swash plate 31 and the spring support member 36, an inclination angle increasing spring 37 that biases the swash plate 31 in the direction of increasing the inclination angle is mounted.
The biasing force of the tilt angle increasing spring 37 at the minimum tilt angle is set larger than the biasing force of the tilt angle decreasing spring 35. For this reason, when the drive shaft 6 is not rotating, the swash plate 31 is positioned at an inclination angle at which the urging force of the inclination angle decreasing spring 35 and the urging force of the inclination angle increasing spring 37 are balanced.

The outer peripheral portion of the swash plate 31 is accommodated in the inner space of the end portion of the piston 23 protruding toward the crank chamber 30 side. Thereby, the swash plate 31 is configured to be interlocked with the piston 23 via the pair of shoes 38. Therefore, the piston 23 can reciprocate inside the cylinder bore 21 by the rotation of the swash plate 31.
The valve plate 4 closes the other end side of the cylinder block 2. Further, the valve plate 4 is formed with a discharge hole 41 and a suction hole 42.

The discharge hole 41 and the suction hole 42 communicate with the cylinder bore 21, respectively.
The cylinder head 5 is disposed to face the cylinder block 2 with the valve plate 4 interposed therebetween.
Further, the cylinder head 5 is formed with a suction port 51, a suction passage 52, a suction chamber 53, a discharge chamber 54, a discharge passage 55, and a discharge port 56.
The suction chamber 53 is connected to an external refrigerant circuit on the suction side via a suction port 51 and a suction passage 52, and sucks refrigerant (refrigerant gas) from the external refrigerant circuit.
The suction chamber 53 communicates with the cylinder bore 21 through a suction hole 42 provided in the valve plate 4 and a suction valve (not shown).
The discharge chamber 54 communicates with the cylinder bore 21 via a discharge valve (not shown) and a discharge hole 41 provided in the valve plate 4.

The discharge chamber 54 is connected to an external refrigerant circuit on the discharge side via a discharge passage 55 and a discharge port 56.
A check valve 57 is disposed between the discharge chamber 54 and the discharge passage 55.
The check valve 57 operates in response to a pressure difference between the discharge chamber 54 (upstream side) and the discharge passage 55 (downstream side). The check valve 57 blocks the discharge chamber 54 and the discharge passage 55 when the pressure difference is smaller than a preset threshold pressure. On the other hand, the check valve 57 communicates between the discharge chamber 54 and the discharge passage 55 when the pressure difference is larger than the threshold pressure.
Accordingly, the refrigerant (refrigerant gas) is discharged to the external refrigerant circuit via the check valve 57, the discharge passage 55, and the discharge port 56.
Further, the cylinder head 5 is provided with a control valve 58.
The control valve 58 controls the amount of refrigerant (introduction amount) introduced into the crank chamber 30 by adjusting the opening of the supply passage 7 that communicates the discharge chamber 54 and the crank chamber 30.

Therefore, by controlling the amount introduced into the crank chamber 30 by the control valve 58, the stroke of the piston 23 can be changed by changing the pressure of the crank chamber 30 and changing the inclination angle of the swash plate 31. Become. When the stroke of the piston 23 is changed, the discharge capacity of the compressor 1 (the flow rate of the discharged refrigerant) can be variably controlled.
For example, when the air conditioner is in operation, that is, when the compressor 1 is in operation, the energization amount of the solenoid built in the control valve 58 is adjusted based on a signal received from the outside. Thereby, the discharge capacity of the compressor 1 is variably controlled so that the pressure in the suction chamber 53 becomes a predetermined value. At this time, the control valve 58 can control the suction pressure to an optimum value according to the external environment.

Further, for example, when the air conditioner is not in operation, that is, when the compressor 1 is not operated, the supply passage 7 is forcibly opened by not energizing the solenoid built in the control valve 58, and the compressor The discharge capacity of 1 is controlled to the minimum.
The drive shaft 6 is disposed inside the front housing 3 and the cylinder block 2 and is rotatably supported by the cylinder block 2.
One end of the drive shaft 6 is inserted into the center bore 22. A first slide bearing 61 is disposed between the drive shaft 6 and the center bore 22. The first plain bearing 61 supports the drive shaft 6 so as to be rotatable from the radial direction.
The end surface of the drive shaft 6 facing the valve plate 4 is supported by an annular thrust plate 62.

The contact state (gap) between the drive shaft 6 and the thrust plate 62 is adjusted by the attachment state of the adjustment screw 63 to the cylinder block 2.
The adjustment screw 63 is formed in an annular shape, and a male screw (not shown) is formed on the outer diameter surface. Further, on the surface of the center bore 22 that faces the outer diameter surface of the adjusting screw 63, a female screw (not shown) that fits with the male screw formed on the adjusting screw 63 is formed.
Therefore, the adjustment screw 63 is disposed inside the center bore 22 at a position closer to the valve plate 4 than the drive shaft 6 by fitting the male screw to the female thread of the center bore 22.
Moreover, the space | gap part which the adjustment screw 63 has is formed circularly.

The other end of the drive shaft 6 protrudes outside the front housing 3 and is connected to a power transmission device (not shown). The power transmission device is connected to a driving force generation source (not shown) such as an engine via a belt. Therefore, when the driving force generated by the driving force generation source is transmitted to the power transmission device, the drive shaft 6 can rotate in synchronization with the rotation of the power transmission device.
A second sliding bearing 64 is disposed between the drive shaft 6 and the front housing 3. The second plain bearing 64 supports the drive shaft 6 so as to be rotatable from the radial direction. Further, the load in the thrust direction toward the other end of the drive shaft 6 is supported by the thrust bearing 65 via the rotor 32.

As described above, the supply passage 7 allows the discharge chamber 54 and the crank chamber 30 to communicate with each other.
The discharge passage 8 allows the crank chamber 30 and the suction chamber 53 to communicate with each other.
Further, the discharge passage 8 has an in-shaft passage 81, a center bore inner space 82, and a gas return passage 84 including an orifice 83.
The in-axis passage 81 is formed inside the drive shaft 6 and is formed in parallel with the axial direction of the drive shaft 6.
One end of the in-shaft passage 81 is open to the side surface of the drive shaft 6. One end of the in-shaft passage 81 communicates with the crank chamber 30 through the introduction passage 85.
The other end of the in-shaft passage 81 opens on the end face of the drive shaft 6 on the side facing the valve plate 4.

The center bore inner space 82 communicates with the other end of the in-shaft passage 81. Further, the center bore internal space 82 is a space formed between the valve plate 4 and the end face on the other end side of the drive shaft 6 (end face facing the valve plate 4) inside the center bore 22.
Further, a passage is formed between the center bore space 82 and the shaft passage 81 by a gap portion of the thrust plate 62 and a gap portion of the adjustment screw 63. The inner diameter of the gap portion of the thrust plate 62 is larger than the inner diameter of the in-axis passage 81. The inner diameter of the gap portion of the adjustment screw 63 is larger than the inner diameter of the gap portion of the thrust plate 62.

The gas return passage 84 is formed inside the passage forming member 10 and communicates the center bore inner space 82 and the suction chamber 53.
The orifice 83 is formed inside the protruding portion 12 of the passage forming member 10, and forms part of the gas return passage 84 on the side of the center bore inner space 82.
That is, the orifice 83 included in the gas return passage 84 is formed in the center bore inner space 82 side inside the protruding portion 12.
The inner diameter of the orifice 83 is less than the inner diameter of the in-axis passage 81. That is, the inner diameter of the in-axis passage 81 is larger than the inner diameter of the orifice 83.

The passage forming member 10 is attached to the valve plate 4 and forms a part of the discharge passage 8.
The passage forming member 10 includes a cylindrical portion 11 and a protruding portion 12.
The cylindrical portion 11 is formed in a cylindrical shape and includes an in-cylinder passage 13.
The in-cylinder passage 13 is formed inside the cylindrical part 11 and is formed in parallel with the axial direction of the cylindrical part 11.
The inner diameter of the in-cylinder passage 13 is larger than the inner diameter of the orifice 83 and smaller than the inner diameter of the in-axis passage 81.
Further, the cylindrical portion 11 is fixed to the valve plate 4 with the axial direction oriented parallel to the thickness direction of the valve plate 4.

  The passage forming member 10 is formed using, for example, a metal material or a resin material. When the passage forming member 10 is formed of a metal material, for example, a hole penetrating the valve plate 4 is formed in the valve plate 4, and the tubular portion 11 is press-fitted and fixed in the hole formed in the valve plate 4. . On the other hand, when the passage forming member 10 is formed of a resin material, for example, a hole penetrating the valve plate 4 is formed in the valve plate 4, and the tubular portion 11 is fitted into the hole formed in the valve plate 4. And fix.

The protruding portion 12 is formed integrally with the cylindrical portion 11, and protrudes toward the drive shaft 6 from the valve plate 4 in the center bore inner space 82.
That is, the gas return passage 84 is formed inside the protruding portion 12.
Moreover, the protrusion part 12 is formed in the truncated cone shape, and has the front end surface 14, the inclined surface 15, and the orifice 83 as represented in FIG.
Therefore, the gas return passage 84 includes the in-cylinder passage 13 and the orifice 83.
Further, the inner diameter of the in-axis passage 81 is larger than the inner diameter of the gas return passage 84 including the in-cylinder passage 13 and the orifice 83.
The front end face 14 faces the end face of the drive shaft 6 on the side facing the valve plate 4.
The outer diameter of the distal end surface 14 is less than the inner diameter of the in-axis passage 81.

Further, a gap is formed between the distal end surface 14 and the adjustment screw 63 when viewed from the radial direction of the drive shaft 6. That is, a gap is formed between the end surface on the other end side of the drive shaft 6 and the end surface of the protruding portion 12 on the side facing the drive shaft 6.
The inclined surface 15 forms a portion on the outer diameter side of the protruding portion 12 with respect to the distal end surface 14, and is inclined linearly into a shape in which the outer diameter increases as it approaches the valve plate 4 from the distal end surface 14. That is, the surface (inclined surface 15) facing the drive shaft 6 of the protruding portion 12 is formed in a tapered shape whose outer diameter increases from the side near the other end of the drive shaft 6 (tip surface 14) toward the valve plate 4. Has been.

In addition, the shape of the inclined surface 15 is not limited to the shape inclined linearly, For example, it is inclined stepwise (stepwise) even if it is the shape inclined curvedly. It is good also as a shape.
The orifice 83 passes through the center of the projecting portion 12, and connects the center bore inner space 82 and the in-cylinder passage 13.
Accordingly, the refrigerant in the crank chamber 30 flows to the suction chamber 53 via the discharge passage 8.
As described above, the compressor 1 has the first fluid movement path and the second fluid movement path.

  The first fluid movement path is a path for discharging the refrigerant sucked into the cylinder bore 21 from the suction chamber 53 and compressed into the discharge chamber 54. The second fluid movement path is a path through which a part of the discharged refrigerant is circulated in order through the supply passage 7, the crank chamber 30, the discharge passage 8, and the suction chamber 53. That is, the second fluid movement path forms an internal circulation path for circulating a part of the discharged refrigerant through the supply passage 7, the crank chamber 30, the discharge passage 8, and the suction chamber 53 in order.

(Operation / Action)
With reference to FIG. 1 and FIG. 2, an example of the operation performed in the compressor 1 of the first embodiment and the operation will be described with reference to FIG. 3.
When the compressor 1 is used, for example, when the control valve 58 is released from the closed state, the flow of the oil-containing refrigerant (discharge gas) that moves in the first fluid movement path and the second fluid movement A flow of refrigerant that contains oil and moves along the path is generated.
The refrigerant moving in the first fluid movement path flows into the cylinder bore 21 from the suction chamber 53 through the suction hole 42, is compressed by the piston 23, and is discharged into the discharge chamber 54.
Here, blow-by gas is generated inside the cylinder bore 21 when the piston 23 compresses the refrigerant. Then, the blowby gas moves to the crank chamber 30. For this reason, the oil contained in the blow-by gas contributes to smoothly sliding the cylinder bore 21 and the piston 23.

The oil contained in the blow-by gas that has moved to the crank chamber 30 is agitated by the rotation of the rotor 32 and the swash plate 31 and scattered around. For example, on the compression stroke side approaching in the axial direction of the drive shaft 6, This contributes to sliding the shoe 38 smoothly.
The blow-by gas generated inside the cylinder bore 21 moves to the in-shaft passage 81 via the crank chamber 30 and the introduction passage 85.

On the other hand, the refrigerant moving in the second fluid movement path flows into the crank chamber 30 from the discharge chamber 54 via the supply passage 7.
The oil contained in the refrigerant that has moved to the crank chamber 30 smoothly slides between the swash plate 31 and the shoe 38 on the compression stroke side approaching in the axial direction of the drive shaft 6, for example, as the oil contained in the blow-by gas. It contributes to that.
Then, the refrigerant that has flowed into the crank chamber 30 via the supply passage 7 moves to the in-shaft passage 81 via the introduction passage 85.
The refrigerant and blow-by gas (referred to as “refrigerant” in the following description) moved to the in-shaft passage 81 move toward the center bore inner space 82.

The refrigerant moving in the in-shaft passage 81 is subjected to a centrifugal separation action by the centrifugal force generated by the rotation of the drive shaft 6.
And since the oil contained in a refrigerant | coolant has mass larger than gas (gas), it moves with the gas flow of a refrigerant | coolant along the inner wall face of the axial channel | path 81, as represented in FIG. Then, the air flows into the center bore space 82 through a gap formed in the thrust plate 62 and the adjusting screw 63 and having a larger inner diameter than the in-axis passage 81. In FIG. 3, the movement path of the oil contained in the refrigerant is indicated by broken arrows.

The oil flowing into the center bore inner space 82 is directly scattered on the inner wall surface of the center bore inner space 82 by the centrifugal force generated by the rotation of the drive shaft 6. Further, a part of the oil flowing into the center bore space 82 collides with the tip surface 14 and the inclined surface 15 and then moves (returns) to the crank chamber 30 via the return side communication passage 26 and the oil return passage 24. ).
Further, a part of the oil flowing into the center bore inner space 82 moves to the oil storage chamber 25 via the storage side communication passage 27 and is temporarily stored in the oil storage chamber 25. The oil stored in the oil storage chamber 25 depends on the state of the center bore inner space 82 and the oil return passage 24 (residual amount of oil, etc.), the storage side communication passage 27, the center bore inner space 82, the return side communication passage 26, and the oil. It moves to the crank chamber 30 via the return passage 24.

The oil remaining in the center bore inner space 82 without moving to the oil return passage 24 and the oil storage chamber 25 circulates in the center bore inner space 82 by the gas flow of the refrigerant flowing out from the opening of the shaft inner passage 81. To do. For this reason, it is possible to suppress the oil remaining in the center bore inner space 82 from entering the orifice 83.
Thus, the refrigerant that has moved from the in-shaft passage 81 to the center bore inner space 82 becomes a gas flow in which most of the contained oil is separated in the center bore inner space 82 and is sucked through the orifice 83 and the in-cylinder passage 13. Move to chamber 53. Therefore, the in-shaft passage 81, the center bore inner space 82, and the discharge passage 8 including the orifice 83 form an oil separator that separates the oil from the refrigerant containing the oil.

That is, the refrigerant that has moved from the crank chamber 30 to the discharge passage 8 and has passed through the discharge passage 8 to the suction chamber 53 becomes a gas flow in which most of the contained oil is separated. Therefore, the refrigerant having a small oil content is supplied to the suction chamber 53.
Thus, even when a large amount of oil is contained in the refrigerant flowing into the in-shaft passage 81, the amount of oil that moves to the suction chamber 53 can be reduced. It is possible to reduce the amount of oil circulating in the circuit. For this reason, it becomes possible to suppress that the efficiency of an air conditioner falls.
The above-described first embodiment is an example of the present invention, and the present invention is not limited to the above-described first embodiment, and the present invention may be applied to other forms than this embodiment. Various modifications can be made according to the design or the like as long as they do not depart from the technical idea.

(Effects of the first embodiment)
If it is the compressor 1 of 1st embodiment, it will become possible to show the effect described below.
(1) The discharge passage 8 includes an in-shaft passage 81, a center bore inner space 82, and an orifice 83, and has a gas return passage 84 that allows the center bore inner space 82 and the suction chamber 53 to communicate with each other. In addition to this, a gas return passage 84 is formed in the projecting portion 12 projecting toward the drive shaft 6 from the valve plate 4 in the center bore inner space 82. Further, the inner diameter of the in-axis passage 81 is larger than the inner diameter of the gas return passage 84. Further, a gap is formed between the end surface on the other end side of the drive shaft 6 and the end surface of the protruding portion 12 on the side facing the drive shaft 6.

For this reason, the centrifugal force generated by the rotation of the drive shaft 6 causes a centrifugal separation action to act on the refrigerant moving in the in-axis passage 81, so that oil having a mass larger than that of the gas is separated from the refrigerant and enters the center bore inner space 82. Will flow in.
As a result, the refrigerant that has passed through the discharge passage 8 and moved to the suction chamber 53 can be made into a gas flow in which most of the contained oil is separated, so that the amount of oil that flows out to the suction chamber 53 It is possible to provide the compressor 1 capable of reducing the above.

Further, an opening portion of the gas return passage 84 that faces the drive shaft 6 opens to the protruding portion 12 that protrudes into the center bore inner space 82. For this reason, it is possible to suppress the oil that has bounced off the valve plate 4 and the inner wall surface of the center bore inner space 82 from flowing into the gas return passage 84.
Therefore, even when a large amount of oil flows into the in-shaft passage 81, the amount of oil that moves from the crank chamber 30 to the suction chamber 53 can be reduced, so that the external refrigerant circuit of the air conditioner is circulated. The amount of oil to be reduced can be reduced. For this reason, it becomes possible to suppress that the efficiency of an air conditioner falls.
Even if the volume of the center bore space 82 is small, the oil can be effectively separated from the refrigerant moving in the shaft passage 81.

Furthermore, compared to the case where the inner diameter of the in-shaft passage 81 is equal to or smaller than the inner diameter of the gas return passage 84, it is possible to suppress the inflow of oil from the center bore inner space 82 to the gas return passage 84. The amount of oil flowing out to the suction chamber 53 can be further reduced.
Further, in comparison with the case where no gap is formed between the end surface of the drive shaft 6 facing the valve plate 4 and the end surface of the projecting portion 12 facing the drive shaft 6, an in-shaft passage is provided. It is possible to increase the amount of oil flowing from 81 into the center bore inner space 82.

(2) The surface (inclined surface 15) facing the drive shaft 6 of the protrusion 12 is formed in a tapered shape whose outer diameter increases as it approaches the valve plate 4 from the side close to the drive shaft 6 (tip surface 14). Yes.
For this reason, the flow of the refrigerant containing oil that flows out from the in-shaft passage 81 and collides with the protrusion 12 becomes a flow toward the inner wall surface of the center bore inner space 82 as the valve plate 4 is approached by the inclined surface 15. .
As a result, the flow of the refrigerant containing oil can be guided toward the inner wall surface of the center bore inner space 82, and the flow away from the opening of the orifice 83 can be achieved. As a result, the oil can be prevented from flowing into the orifice 83 from the center bore inner space 82, so that the amount of oil flowing out to the suction chamber 53 can be further reduced.

(3) An orifice 83 included in the gas return passage 84 is formed in the center bore inner space 82 side inside the protruding portion 12.
As a result, it is possible to suppress the oil that has bounced off the valve plate 4 and the inner wall surface of the center bore inner space 82 from flowing into the orifice 83.
(4) The outer diameter of the tip surface 14 is less than the inner diameter of the in-axis passage 81.
As a result, compared with the case where the outer diameter of the tip surface 14 is equal to or larger than the inner diameter of the in-shaft passage 81, it is possible to reduce the oil that collides with the tip surface 14, and the oil from the center bore inner space 82 has an orifice Inflow to 83 can be further suppressed.

(5) An oil storage chamber 25 communicating with the center bore space 82 is formed around the center bore space 82 in the radial direction.
As a result, compared to the case where the oil storage chamber 25 is not formed in the center bore 22, it is possible to increase the amount of oil temporarily stored and reduce the amount of oil flowing out to the suction chamber 53. It becomes possible.
(6) The passage forming member 10 which is attached to the valve plate 4 and forms a part of the discharge passage 8 includes a cylindrical portion 11 having an in-cylinder passage 13 and a protruding portion 12 having an orifice 83. .
As a result, the member including the in-cylinder passage 13 and the orifice 83 can be formed by the passage forming member 10 which is one member, and the configuration can be simplified.

(7) An oil return passage 24 that connects the center bore space 82 and the crank chamber 30 is formed around the center bore space 82. In addition to this, the return side communication passage 26 is opened in the inner wall surface of the center bore inner space 82 positioned below the central axis of the drive shaft 6 in the vertical direction.
As a result, the oil scattered in the center bore space 82 can be efficiently returned to the crank chamber 30.
(8) The return side communication passage 26 is opened at a position of the center bore 22 that is closed by the valve plate 4.
As a result, the oil scattered in the center bore space 82 can be efficiently moved to the oil return passage 24.

(Modification of the first embodiment)
(1) In the first embodiment, the compressor 1 is a variable capacity compressor. However, the present invention is not limited to this, and the compressor 1 may be a fixed capacity compressor.
(2) In 1st embodiment, although the structure of the protrusion part 12 was set as the structure which has the inclined surface 15, it is not limited to this.
That is, for example, as shown in FIG. 4, the configuration of the protruding portion 12 may be a configuration that does not have the inclined surface 15.

(3) In 1st embodiment, although the structure of the channel | path formation member 10 was set as the structure provided with the cylindrical part 11 and the protrusion part 12, it is not limited to this.
That is, for example, as illustrated in FIG. 5, the configuration of the passage forming member 10 may include only the protruding portion 12. Specifically, a communication flow path 43 that connects the center bore inner space 82 and the suction chamber 53 is formed in the valve plate 4. In addition, by processing the portion of the gasket member that seals between the cylinder block 2 and the valve plate 4 in the center bore inner space 82 of the passage forming member 10, the protruding portion 12 having the orifice 83 is formed. It is good also as a structure provided with. That is, the protrusion 12 and the passage forming member 10 may be formed integrally with the gasket member. Further, in the configuration shown in FIG. 5, the gas return passage 84 includes a communication channel 43 and an orifice 83.
In this case, a dedicated member constituting the protruding portion 12 and the passage forming member 10 is not necessary, and thus the structure can be simplified.

(4) In 1st embodiment, although the structure of the channel | path formation member 10 was set as the structure provided with the cylindrical part 11 and the protrusion part 12, it is not limited to this.
That is, for example, as illustrated in FIG. 6, the configuration of the passage forming member 10 may include only the protruding portion 12.
Specifically, the valve plate 4 is formed with an orifice 83 that allows the center bore inner space 82 and the suction chamber 53 to communicate with each other. In addition to this, the configuration of the passage forming member 10 is formed by using, for example, a resin material and formed by the protruding portion 12, the peripheral wall portion 16, and the bottom plate portion 18.
The fitting amount of the passage forming member 10 with respect to the center bore inner space 82 is set to a fitting amount such that the passage forming member 10 can be attached to and detached from the center bore inner space 82. Thereby, the structure of the channel | path formation member 10 is formed with respect to the center bore inner space 82 so that attachment or detachment is possible.

The peripheral wall portion 16 is formed in an annular shape. The outer diameter surface of the peripheral wall portion 16 is in contact with the inner wall surface of the center bore inner space 82.
The peripheral wall 16 is provided with a notch 19.
The cutout portion 19 is disposed at a position overlapping the return side communication path 26 in the peripheral wall portion 16. As a result, the oil scattered from the in-shaft passage 81 to the peripheral wall portion 16 moves to the crank chamber 30 via the notch portion 19, the return side communication passage 26 and the oil return passage 24.

The protrusion 12 is disposed at the center of the circle formed by the peripheral wall 16, and has a communication channel 43 having an inner diameter larger than that of the orifice 83. That is, in the configuration shown in FIG. 6, the gas return passage 84 includes the communication flow path 43 and the orifice 83.
Therefore, as shown in FIG. 6, the position where the orifice 83 is formed is not limited to the protruding portion 12 in the gas return passage 84.
The bottom plate portion 18 has the peripheral wall portion 16 and the protruding portion 12 continuous, and a part of the portion continuous with the peripheral wall portion 16 is in contact with the valve plate 4.
In this case, the projecting portion 12 can be provided in the compressor 1 only by fitting the passage forming member 10 into the center bore inner space 82.

(5) In the first embodiment, the inner diameter of the return side communication passage 26 is smaller than the inner diameter of the oil return passage 24. However, the present invention is not limited to this.
That is, for example, as shown in FIG. 7, a small-diameter communication path 28 having an inner diameter smaller than that of the oil return path 24 is formed between the oil return path 24 and the crank chamber 30. Accordingly, the inner diameter of the return side communication path 26 may be larger than the inner diameter of the communication path that connects the oil return path 24 and the crank chamber 30.
In this case, compared to the configuration of the first embodiment, it is possible to easily move the oil from the center bore inner space 82 to the oil return passage 24 and to temporarily store the oil in the oil return passage 24. It becomes possible.

  DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Cylinder block, 3 ... Front housing, 4 ... Valve plate, 5 ... Cylinder head, 6 ... Drive shaft, 7 ... Supply passage, 8 ... Discharge passage, 9 ... Through bolt, 10 ... Passage formation member 11 ... cylindrical part, 12 ... protruding part, 13 ... in-cylinder passage, 14 ... tip surface, 15 ... inclined surface, 16 ... peripheral wall part, 18 ... bottom plate part, 19 ... notch part, 21 ... cylinder bore, 22 ... Center bore, 23 ... piston, 24 ... oil return passage, 25 ... oil storage chamber, 26 ... return side communication passage, 27 ... storage side communication passage, 28 ... small diameter communication passage, 30 ... crank chamber, 31 ... swash plate, 32 ... Rotor, 33 ... Link mechanism, 34 ... Through hole, 35 ... Inclination reducing spring, 36 ... Spring support member, 37 ... Inclination increasing spring, 38 ... Shoe, 41 ... Discharge hole, 42 ... Intake hole, 43 ... Communication channel, 51 ... Inhalation port, 52 ... Inhalation , 53 ... suction chamber, 54 ... discharge chamber, 55 ... discharge passage, 56 ... discharge port, 57 ... check valve, 58 ... control valve, 61 ... first sliding bearing, 62 ... thrust plate, 63 ... adjusting screw, 64: Second sliding bearing, 65: Thrust bearing, 81: In-shaft passage, 82: Space in center bore, 83 ... Orifice, 84 ... Gas return passage, 85 ... Introduction passage

Claims (4)

A cylinder block formed with a plurality of cylinder bores arranged in an annular shape and a center bore disposed inside the plurality of cylinder bores;
A front housing that closes one end of the cylinder block and forms a crank chamber together with the cylinder block;
A valve plate that closes the other end of the cylinder block and has a discharge hole and a suction hole communicating with the cylinder bore;
A cylinder head disposed opposite to the cylinder block with the valve plate interposed therebetween, and formed with a suction chamber for sucking refrigerant from outside and a discharge chamber for discharging refrigerant to the outside;
A drive shaft having one end inserted into the center bore and rotatably supported by the cylinder block;
A supply passage communicating the discharge chamber and the crank chamber;
A discharge passage communicating the crank chamber and the suction chamber,
The refrigerant sucked into the cylinder bore from the suction chamber and compressed is discharged into the discharge chamber, and a part of the discharged refrigerant is circulated in order through the supply passage, the crank chamber, the discharge passage, and the suction chamber. A compressor having an internal circulation path,
The discharge passage is formed inside the drive shaft and has one end communicating with the crank chamber, the other end of the shaft passage, and the other of the drive shaft within the center bore. A center bore space that is a space formed between the end face on the end side and the valve plate, and a gas return passage that includes an orifice and communicates the space in the center bore and the suction chamber,
The gas return passage is formed in a projecting portion that is a portion projecting to the drive shaft side from the valve plate in the center bore inner space,
The inner diameter of the in-shaft passage is larger than the inner diameter of the gas return passage,
A compressor characterized in that a gap is formed between an end surface on the other end side of the drive shaft and an end surface on the side of the protruding portion facing the drive shaft.   The front end surface of the projecting portion facing the drive shaft is formed in a tapered shape whose outer diameter increases from the side close to the other end of the drive shaft toward the valve plate. The compressor described.   3. The compressor according to claim 1, wherein the orifice included in the gas return passage is formed on the inner space side of the center bore inside the protruding portion. 4.   The compressor according to any one of claims 1 to 3, wherein an outer diameter of a front end surface of the projecting portion is less than an inner diameter of the in-shaft passage.

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