JPH0533765A - Swash plate type compressor - Google Patents

Abstract

PURPOSE:To simultaneously attain formation of a discharge passage to avoid thermal influence on a suction system as possible, and mounting of a simplified oil separating mechanism. CONSTITUTION:This swash plate type compressor is constituted so that a discharge passage 40 is formed so as to include a hollow passage 41 drilled in a drive shaft 18 and providing communication between front and rear discharge chambers 11, 12, and oil content in flowing refrigerant is separated by a spiral groove 50 engraved on the circumferential wall of the hollow passage 41. Hereby, thermal influence on a suction system is avoided, and poor heat exchange in the circuit and poor lubrication of the compressor can be dissolved rationally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a swash plate type compressor suitable for vehicle air conditioning.

[0002]

2. Description of the Related Art As a conventional swash plate type compressor, Japanese Patent Laid-Open No.
The one described in Japanese Patent No. 92587 is known. In this swash plate compressor, a pair of cylinder blocks are provided in front and back, and a swash plate chamber communicating with the return refrigerant suction port is formed in the coupling portion, and both outer ends of the cylinder block are connected via valve plates. It is closed by the front and rear housings. A suction chamber and a discharge chamber are formed in both housings, and the rear discharge chamber is in communication with a discharge port for discharging the discharged refrigerant. A drive shaft is inserted and supported in a common central shaft hole of both cylinder blocks, and a swash plate fixed to the drive shaft is rotatably accommodated in a swash plate chamber. In addition, a plurality of pairs of front and rear bores arranged in parallel around the drive shaft are formed in the cylinder block, and a double-headed piston moored to a swash plate is linearly inserted into each bore via shoes. ing. Each valve plate is formed with a suction port communicating with the front and rear suction chambers via a suction valve, and a discharge port communicating with the front and rear discharge chambers via a discharge valve between the respective valve plates. Each cylinder block is formed with a plurality of suction passages that communicate the swash plate chamber and the front and rear suction chambers, and one discharge passage that communicates the front and rear discharge chambers.

In this swash plate type compressor, the return refrigerant flowing from the suction port is introduced into the swash plate chamber and is guided to the front and rear suction chambers through the respective suction passages opening in the swash plate chamber. Then, the piston directly moves in each bore through the swash plate that rotates together with the drive shaft, so that the refrigerant in both suction chambers is sucked from each suction port into each bore that is in the process of volume expansion, and then in the process of volume reduction. The compressed refrigerant in each bore is discharged from each discharge port into both discharge chambers. The compressed refrigerant discharged in this way is collected in the rear discharge chamber via the discharge passage, and is sent and circulated to the refrigeration circuit from the discharge port communicating with the discharge chamber.

[0004]

In the swash plate type compressor described above, the discharge passage is formed at a position where it does not interfere with the suction passage including the swash plate chamber in the cylinder block, but due to design restrictions such as outer dimensions. Inevitably, it must be placed very close to the suction route and the bore. Therefore, the refrigerant that sequentially flows from the refrigeration circuit through the suction port, the swash plate chamber, and the respective suction passages is easily affected by the heat of the compressed refrigerant that has been heated to a high temperature through the discharge passage. Is discharged at a higher temperature due to compression. As a result, the circulation of the high-temperature discharged refrigerant increases the load on the refrigeration circuit, and eventually reduces the cooling capacity.

Further, in the above compressor, it is possible to prevent the lubricating oil mixed in the refrigerant gas from flowing out into the circuit together with the discharged refrigerant, thereby causing a reduction in refrigeration efficiency and insufficient lubrication of the compressor due to poor heat exchange. For this reason, a technique is known in which an oil separation mechanism is installed in the high pressure part of the compressor to recirculate the separated oil component to the low pressure part, but the oil separation chamber itself also requires a considerable space. As a result, a new problem has been pointed out that the size of the aircraft is inevitable.

In the present invention, it is a technical problem to be solved to simultaneously achieve the formation of the discharge passage while avoiding the thermal influence on the suction system as much as possible and the simple installation of the oil separation mechanism. It is a thing.

[0007]

According to the present invention, in order to solve the above-mentioned problems, a discharge passage is formed in a drive shaft to include a hollow passage communicating with front and rear discharge chambers, and a peripheral wall of the hollow passage. Is provided with a spiral groove extending in the axial direction, and at least one of the discharge chamber and the swash plate chamber are communicated with each other by a fine hole for returning the oil component separated and transferred by the spiral groove. Is adopted.

[0008]

Therefore, the compressed refrigerant discharged into one of the discharge chambers is guided to the other discharge chamber through the hollow passage bored in the drive shaft, and merges with the compressed refrigerant in the discharge chamber.
Although it is delivered to the refrigeration circuit via the discharge port, since the hollow passage forming the discharge passage is especially bored inside the drive shaft, the suction passage including the swash plate chamber flows in from the suction port. The refrigerant flowing through the path is less likely to be affected by heat from the discharge passage (high-temperature refrigerant) located at a relatively separated relational position, and unnecessary heating is reasonably avoided.

Further, when the compressed refrigerant flows in the hollow passage, a secondary flow which is orthogonal to the flow is generated in the compressed refrigerant due to the spiral grooves having different passage cross-sectional areas, and the secondary flow interferes with the groove wall. Thus, the oil component in the compressed refrigerant is separated. Then, the separated oil component is transferred to the other discharge chamber according to the lead of the spiral groove while being supported by the rotational centrifugal force of the drive shaft, and is stored in the bottom of the discharge chamber, and then the refrigerant gas is not allowed to blow through. Since it is returned to the swash plate chamber through the small pores, it is mixed with the suction refrigerant again and used for lubrication of the swash plate, the shoe, and the like.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a pair of cylinder blocks 1 and 2 arranged in front and back are provided with a swash plate chamber 4 communicating with an inlet (not shown) of a return refrigerant at a connecting portion thereof. Both outer ends of the front housing 7 and the rear housing 8 via the valve plates 5 and 6, respectively.
Is blocked by. Front and rear housing 7, 8
The annular suction chambers 9 and 10 occupying the outer region thereof and the circular discharge chambers 11 and 12 occupying the inner region thereof are defined and formed (FIG. 2), and the front discharge chamber 11 is driven later. Axis 18
It is arranged so as to surround the periphery of.

A drive shaft 18 is inserted into and supported by a common central shaft hole of both cylinder blocks 1 and 2 via radial bearings 14 and 15 and sealing devices 16 and 17.
8 passes through the through hole 5c of the valve plate 5 at the front part, and the shaft sealing device 19
Is extended to the outer end side of the front housing 7.
The swash plate 23 is rotatably attached to the drive shaft 18 in the swash plate chamber 4.
Is fixed to the thrust bearing 21.
It is sandwiched between both cylinder blocks 1 and 2 via 22. In addition, a plurality of pairs of front and rear bores 1a, 2a arranged in parallel around the drive shaft 18 are formed in both cylinder blocks 1, 2, and a pair of shoes 24, 24 are provided on a swash plate 23 in each bore 1a, 2a. A double-headed piston 25 moored through is fitted in such a way that it can move linearly. Each valve plate 5 and 6 has a bore 1
a, 2a, and suction ports 5a, 6a communicating with front and rear suction chambers 9, 10 via suction valves 26, 27,
Discharge ports 5b and 6b that communicate with the front and rear discharge chambers 11 and 12 via the discharge valves 30 and 31 are formed. The swash plate chamber 4 is provided outside the cylinder blocks 1 and 2.
And a plurality of suction passages 32 that communicate the suction chambers 9 and 10 with each other.
Is formed by surrounding the through bolt 33. The rear discharge chamber 12 is electrically connected to the central shaft hole of the cylinder block 2 by a through hole 6c penetrating the valve plate 6.

The discharge passage 40, which is a characteristic construction of the compressor of the present invention, is bored on the axial center of the drive shaft 18, and one of the discharge passages 40 is formed in the central shaft hole at the rear end face of the drive shaft 18. A hollow passage 41 that opens into the front discharge chamber 11 via a through hole 41b that penetrates the drive shaft 18 in the radial direction, and a discharge passage that is connected to the front discharge chamber 11 and the refrigeration circuit. It is formed by a passage 42 connecting the outlet 28.

On the peripheral wall of the hollow passage 41, there is formed a spiral groove 50 having an axially extending lead having a direction in which the compressed refrigerant flows in the forward direction with respect to the rotation of the drive shaft 18. , The end of the spiral groove 50 is a through hole 51.
It is opened to the shaft sealing chamber 13 via. Reference numeral 52 is a pore for separating and transferring by the spiral groove 50 and for returning the oil component accumulated in the discharge chamber 11 at the front portion to the swash plate chamber 4 and having a diameter that does not substantially allow blow-through of the refrigerant gas. Is selected. The oil component separated by the spiral groove 50 can be positively supplied to the radial bearing portion appropriately through, for example, the guide hole 53 shown in the drawing.

Therefore, the refrigerant returned from the refrigeration circuit through the suction port (not shown) is introduced into the swash plate chamber 4, and is subsequently guided to the front and rear suction chambers 9 and 10 through the respective suction passages 32. Then, the pistons 25 linearly move in the bores 1a, 2a through the swash plate 23 that rotates together with the drive shaft 18, so that the refrigerant in the suction chambers 9, 10 is discharged into the valve plates 5, 6 respectively.
Via the suction ports 5a, 6a of the valve, the compressed refrigerant is sucked into the respective bores 1a, 2a in the process of expanding the volume, and then the compressed refrigerant is discharged from the respective bores 1a, 2a in the process of reducing the volume of the valve plates 5, 6 respectively. It is discharged to the front and rear discharge chambers 11 and 12 via. In this way, the compressed refrigerant discharged into the rear discharge chamber 12 is guided into the hollow passage 41 from the opening 41a, merges with the compressed refrigerant inside the front discharge chamber 11 through the through hole 41b, and further passes through the passage. The gas is discharged and circulated from the discharge port 28 to the refrigeration circuit via 42.

As described above, since the hollow passage 41 forming the discharge passage 40 is formed especially inside the drive shaft 18, the suction refrigerant flowing in the swash plate chamber 4 and the suction passage 32 is
It is less susceptible to heat from the discharge passage 40 (high-temperature refrigerant) at a relatively distant relation, and unnecessary heating is reasonably avoided, and pressure influence on the bores 1a, 2a, that is, compressive deformation is similarly avoided. It

When the compressed refrigerant flows in the hollow passage 41, a secondary flow orthogonal to the flow is generated in the compressed refrigerant due to the spiral grooves 50 having different passage cross-sectional areas, and the secondary flow interferes with the groove wall. By doing so, the oil component mixed in the compressed refrigerant is separated. The separated oil component is the drive shaft 18
While being supported by the rotational centrifugal force of the spiral groove 50, it is transferred along the lead of the spiral groove 50, is stored in the discharge chamber 11 at the front part through the through hole 51 and the shaft sealing chamber 13, and is then transferred to the swash plate chamber 4 through the pore 52. As a result, the swash plate 23, the shoe 24, and the like are mixed with the suction refrigerant again and used for lubrication.

In the above-described embodiment, the discharge passage 40 is formed by the hollow passage 41 and the passage 42 connecting the discharge chamber 11 and the discharge port 28 in the front portion, and the flow of the compressed refrigerant in the hollow passage 41 is Although the configuration from the rear discharge chamber 12 to the front discharge chamber 11 has been described, for example, the discharge passage 40 is formed to include the passage connecting the rear discharge chamber 12 and the discharge port, and the compressed refrigerant in the hollow passage 41 is formed. Can also be configured to flow from the front discharge chamber 11 toward the rear discharge chamber 12. In that case, the passage communicating with the discharge port is provided in the discharge chamber 1 at the rear.
The spiral groove 5 is opened at a position eccentrically located from the center of 2.
The oil component separated and transferred by 0 is temporarily discharged from the discharge chamber 1 at the rear part.
It is desirable to consider that the wall surface of the discharge chamber 12 collides with the wall surface of No. 2 and is accumulated in the lower bottom portion of the discharge chamber 12 by gravity. Of course, it goes without saying that the stored oil component is recirculated to the swash plate chamber 4 through the pores 52 similar to the above.

Even if the spiral groove 50 is replaced with a simple annular groove and the separated oil component is supplied only to the radial bearing portion through the guide hole 53, a corresponding lubricating effect can be expected.

[0019]

As described above in detail, the compressor of the present invention is
The discharge passage is bored in the drive shaft and includes a hollow passage that connects the front and rear discharge chambers. As a result of the circulation of the discharge refrigerant at an extremely low temperature, the load on the refrigeration circuit is small, and the cooling capacity can be preferably maintained.

Moreover, since the inside of the drive shaft is utilized as the discharge passage, it is possible to expand the degree of freedom in designing the main elements including the cylinder block while reducing the size and weight. Furthermore, since the oil component in the flowing refrigerant is separated and transferred by the spiral groove formed on the peripheral wall of the hollow passage, the oil component is positively returned to the swash plate chamber through the discharge chamber and the pores. Without needing a special space
Poor heat exchange in the circuit and insufficient lubrication of the compressor can be reasonably resolved.

[Brief description of drawings]

FIG. 1 is a sectional view of a swash plate compressor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of the compressor shown in FIG.

[Explanation of symbols]

1, 2 is a cylinder block, 4 is a swash plate chamber, 7 and 8 are front and rear housings, 9 and 10 are front and rear suction chambers, 11 and 12 are front and rear discharge chambers, 18 is a drive shaft, 23 is a swash plate, and 25 is Piston, 28 is discharge port, 32 is suction passage, 40 is discharge passage, 41 is hollow passage, 50 is spiral groove, 52 is fine hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Takemoto 2-chome, Toyota-cho, Kariya city, Aichi stock company Toyota Industries Corp.

Claims (1)

Claim: What is claimed is: 1. A cylinder block having a plurality of bores and a swash plate chamber communicating with the suction port, and at least respective discharge chambers for connecting both outer ends of the cylinder block. The housing before and after closing, the drive shaft inserted into and supported by the central shaft hole of the cylinder block, and the extended end of which is sealed in the front housing, and the drive shaft fixedly attached to the drive shaft into the swash plate chamber. An intake path including a swash plate rotatably accommodated and a double-headed piston moored to the swash plate via a shoe and directly moving in each of the bores, and the refrigerant flowing from the intake port including the swash plate chamber In a swash plate compressor configured to be sucked into each of the bores through and to discharge the compressed refrigerant in each of the bores from the discharge port through the front and rear discharge chambers and the discharge passage,
The discharge passage includes a hollow passage that is bored in the drive shaft and connects the front and rear discharge chambers, and a spiral groove extending in the axial direction is formed on the peripheral wall of the hollow passage, and at least one of the hollow passages is formed. The swash plate type compressor is characterized in that the discharge chamber and the swash plate chamber are communicated with each other by pores that return the oil component separated and transferred by the spiral groove.