JP3203890B2 - Reciprocating compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor suitable for use in vehicle air conditioning, and more particularly to a multi-cylinder reciprocating compressor having a single-headed piston.

[0002]

2. Description of the Related Art In general, a compressor used for air conditioning of a vehicle is driven by an engine, and thus has a very wide range of fluctuations in the number of rotations. If the lubrication is not performed with sufficient lubrication, the life of the compressor will be greatly affected.

[0003] In compressors of the swash plate type and the oscillating plate type, which are known as reciprocating compressors, a crank chamber is usually provided so as to also serve as a reservoir for lubricating oil. It is performed in a form that depends exclusively on the oil component contained in the blow-by gas and reduced into the crankcase, and on the centrifugal flow of the stored oil. In addition, for a shaft sealing device into which lubricating oil does not easily enter due to its structure, an introduction hole or the like for actively guiding the lubricating oil flowing along the inner wall of the crankcase is also provided.

[0004]

However, when the compressor is operated under the above-mentioned severe conditions, the heat generated by the compressor also raises the temperature of the lubricating oil and lowers the viscosity. This could lead to accidents such as seizure and gas leaks that would impair the reliability of the compressor.

For this reason, a suction port connected to a low-pressure circuit is opened in a front housing forming a crank chamber, and a low-temperature return refrigerant (suction gas) flows from the crank chamber through a cylinder block to a suction chamber of a rear housing. It has been proposed that the oil be contained in the suction gas to lubricate with the oil component contained in the suction gas. It is difficult for the lubricating oil to remain in the lubricating oil, and when the refrigerant stagnates in the crank chamber, the lubricating oil is diluted and the lubricating function is degraded.

An object of the present invention is to ensure the reliability of a compressor under all operating conditions by improving a lubrication system.

[0007]

According to the present invention, there is provided a cylinder block having a plurality of bores, a front housing for forming a crank chamber and closing one end of the cylinder block, and an inner region. A rear housing that forms a suction chamber in an outer region, and closes the other end of the cylinder block via a valve plate having a suction hole and a discharge hole; and a drive shaft extending into the crank chamber. A reciprocating compressor comprising a swash plate element fixed to the swash plate element and a single-headed piston that moves directly in the bore in cooperation with the swash plate element, wherein a partition partitioning the suction chamber in a circumferential direction is provided. A suction port connected to the low-pressure circuit is formed in the vicinity of the cylinder block and the cylinder block and the valve plate, and a conduction path that individually communicates the region sandwiching the partition wall in the suction chamber and the crank chamber is provided in the cylinder block and the valve plate. New structure It is adopted.

In a preferred embodiment of the present invention, one of the regions sandwiching the partition wall, which is on the side remote from the suction port,
The conduction path and at least one suction hole that opens into the area may be enclosed to form a single room by a further partition, and one of the conduction paths may be provided inside the area inside the suction chamber and the front housing. The shaft sealing device may be formed so as to directly communicate with the shaft sealing device.

[0009]

When the compression work is started by the single-headed piston linked to the swash plate element rotating together with the drive shaft moving in the bore, the suction chamber defined by the partition is close to the suction port due to the flow path resistance. This creates a pressure difference between the region and the distant region. However, while the compressor is running at low speed,
Since the pressure difference between these two areas where the two passages are individually opened is relatively small, and the crank chamber pressure is high due to the blow-by gas, the blow-by gas is returned to the suction chamber from the both passages. Like the conventional device, it is sucked into each bore.

When the compressor is switched to the high-speed operation from such a state, the pressure difference between the above-mentioned two regions becomes large, and the pressure in the region far from the suction port is significantly reduced. In parallel with the normal gas flow drawn into the bore via the inlet, a flow from a region close to the suction port to the crank chamber via one of the conduction paths and the suction port from the crank chamber through the other conduction path. Two gas streams occur, with the flow going to a region farther away. As a result, the rotating sliding portion and the shaft sealing device in the crank chamber are reasonably lubricated and cooled by the low-temperature suction gas flowing through the crank chamber and the oil component contained therein.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. In FIG. 1, a front housing 2 is connected to a front end of a cylinder block 1 which forms a part of an outer shell of the compressor, and a rear housing 3 having a suction chamber 5 and a discharge chamber 6 formed at the rear end thereof is a valve plate. 4 are connected. A drive shaft 8 connected to a power source is inserted through a crank chamber 7 formed in the front housing 2.
The drive shaft 8 is rotatably supported on the cylinder block 1 and the front housing 2 via radial bearings 20 and 21, respectively. A rotary swash plate 9 is fixed on a drive shaft 8 in the crank chamber 7, and a swing plate 10 is supported on the rear surface side of the rotary swash plate 9 so as to be relatively rotatable, and a guide portion 10a provided on an outer edge portion. By engaging with the through bolt 11, the rotation is restricted, and the single-headed piston 13 in the bore 12 penetrating through the cylinder block 1 and the swing plate 10 are connected by a connecting rod 14. Therefore,
Rotational movement of the drive shaft 8 is converted into forward and backward swinging of the swinging plate 10 via the rotating swash plate 9, and the single-headed piston 13 reciprocates in the bore 12, whereby each suction hole 15 and suction valve (see FIG. The refrigerant gas sucked into the bore 12 from the suction chamber 5 through the discharge chamber 6 through the discharge valve 6 (not shown) and the discharge hole 16 is discharged into the discharge chamber 6 while being compressed.

A boss portion 1a projecting into the crank chamber 7 is formed in the axial center portion of the cylinder block 1, and the radial bearing 20 is press-fitted into a central shaft hole formed in the boss portion 1a. The rear end of the drive shaft 8 supported by the radial bearing 20 is supported by a thrust trace 22 and a disc spring 23 housed in a center shaft hole, and the urging force of the disc spring 23 is It is received by a thrust bearing 24 interposed between the rotating housing 9 fixed to the drive shaft 8 and the front housing 2. Reference numeral 17 denotes an introduction hole for actively guiding the oil-containing refrigerant to the shaft sealing device 18 provided in the front housing 2.

Next, the lubrication system utilizing the suction refrigerant, which is the most characteristic of the present invention, will be described in more detail. As can be understood from FIG. 2 showing a cross section taken along the line AA of FIG. 1 and FIG. 3 showing a cross section developed along the line BB of FIG. 2, the annular suction chamber 5 recessed in the rear housing 3 is Partitioned in the circumferential direction by a partition wall 30 formed to correspond between the bores,
A suction port 19 connected to a low-pressure circuit is opened on the bottom wall of the suction chamber 5 located near the partition 30. In the cylinder block 1 and the valve plate 4, there are formed through-holes for individually communicating the two areas sandwiching the partition wall 30 in the suction chamber 5 with the crank chamber 7. The first conduction path 31a is opened in the near area P, and the second conduction path 31a is opened in the area Q far from the suction port 19.
This is the conduction path 31b.

Therefore, when the single-headed piston 13 linked with the swash plate element (rotating swash plate 9 and swing plate 10) rotating together with the drive shaft 8 moves directly in the bore 12, compression work is started. In the suction chamber 5 partitioned by the partition 30, a pressure difference is generated between a region P near the suction port 19 and a region Q far from the suction port 19 due to flow path resistance. However, while the compressor is operating at low speed, the first and second passages 31a,
These two regions P and Q are individually opened at 31b.
Is relatively small and the crank chamber pressure is high due to the blow-by gas. Therefore, the blow-by gas is returned to the suction chamber 5 from both the conduction paths 31a and 31b, and is sucked into the respective bores 12 as in the conventional device. You. Then, when the compressor is switched to the high-speed operation from such a state, the pressure difference between the two regions P and Q described above increases, and the pressure in the region Q far from the suction port 19 drops significantly. Area P> Crank chamber 7> between crank chamber 7>
A pressure gradient in the region Q occurs, and the suction chamber 5 is moved from
In parallel with the normal gas flow drawn into the bore 12 via
And a flow from the crank chamber 7 to the region Q via the second passage 31b. As a result, the low-temperature suction gas flowing through the crank chamber 7 and the oil component contained in the low-temperature suction gas and the oil component contained in the rotation sliding portion and the shaft sealing device 18 in the crank chamber 7 are supplied directly or through the introduction hole 17.
And acts more effectively on lubrication and cooling of the main part.

FIG. 4 shows another embodiment of the present invention.
In the present embodiment, the regions P and Q sandwiching the partition 30A in the suction chamber 5 are described.
Among them, a region Q far from the suction port 19 is formed by enclosing the second conduction path 31b and at least one suction hole 15 opened in the region Q, and is made into a private room by a further partition 30B. In other words, both regions P and Q where the first and second conduction paths 31a and 31b are opened by dividing the region Q into individual chambers.
A more reliable pressure difference is generated between the suction chamber 5 and the crank chamber 7, and the pressure gradient of the region P> the crank chamber 7> the region Q caused between the suction chamber 5 and the crank chamber 7 is increased to increase the pressure gradient of the suction gas passing through the crank chamber 7. This is to ensure a sufficient flow rate.

If the region Q divided by the partition walls 30A and 30B is completely separated from the remaining region including the region P, the first and second conduction paths 31a,
If the passage cross-sectional area of the passage 31b is insufficient, the suction efficiency is reduced in the bore 12 corresponding to the suction hole 15 opened in the region Q, so that at least one of the partition walls 30A and 30B (both in the figure). Is provided with a gap S allowing a proper flow between the region Q and the remaining region including the region P.

FIG. 5 shows still another embodiment of the present invention. In this embodiment, either one of the first and second conduction paths 31a and 31b is extended and the area inside the suction chamber 5 is increased. P, Q
And a shaft sealing device 1 housed in the front housing 2
8 is formed so as to directly communicate with the reference numeral 8. That is, for example, the first conduction path 31a shown in the previous embodiment is connected to the sub-conduction path 31a 'formed in the front housing 2 without being opened to the crank chamber 7, and is connected to the housing chamber of the shaft sealing device 18. Specifically, a part of the inner wall of the crank chamber 7 is swelled like a local cross section indicated by a dashed line in the figure, and a perforation provided in the swelling portion 2 a and an outer shell of the front housing 2 are formed. The sub-conducting path 31a 'is formed by sequentially connecting the perforations provided along the path. In addition, 35 is a blind lid.

Therefore, the first region from the region P in the suction chamber 5
The suction gas guided by the conduction path 31a and the sub-conduction path 31a 'is preferentially supplied to the shaft sealing device 18 and further lubricates and cools these elements while passing through the radial bearing 21 and the thrust bearing 24. After that, the air is sucked into the corresponding bore 12 through the crank chamber 7, the second conduction path 31b, the region Q, and the suction hole 15. In other words, in this embodiment, the shaft sealing device 18 that is likely to cause an accident such as gas leakage due to heat deterioration due to poor lubrication is more actively protected, and is extremely effective in extending the life of the compressor. It should be noted that the direct connection with the shaft sealing device 18 is not limited to the first conduction path 31a forming the outward path of the suction gas, but may be replaced with the second conduction path 31b constituting the return path. is there.

In each of the above embodiments, only a small part of the intake gas is introduced into the crank chamber 7. Compared with the system in which the entire amount of the intake gas is introduced into the crank chamber 7 as described at the beginning, the amount of the intake gas is reduced. The amount of the oil component accompanying the flow is extremely small, and the problem of the effect on the residual oil amount in the crank chamber 7 and the problem of dilution of the lubricating oil by the stagnant refrigerant are substantially insignificant.

[0020]

As described in detail above, the present invention is configured so that a part of the suction gas flows around the crank chamber in a bypass flow by utilizing the pressure difference actively generated in the suction chamber. Thus, the low-temperature suction gas and the oil component contained in the low-temperature suction gas can favorably lubricate and cool the rotary sliding portion particularly at high rotation speed.

Further, in the case where the suction gas is configured to pass directly through the shaft sealing device, the shaft sealing device which is extremely susceptible to deterioration can be preferentially and effectively protected.

[0022]

[Brief description of the drawings]

[0023]

FIG. 1 is a cross-sectional view showing the entire configuration of a compressor according to an embodiment of the present invention.

[0024]

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

[0025]

FIG. 3 is a developed sectional view taken along the line BB of FIG. 2;

[0026]

FIG. 4 is a sectional view similar to FIG. 2 showing another embodiment of the present invention.

[0027]

FIG. 5 is a partially cutaway sectional view showing a main part of still another embodiment of the present invention.

[0028]

[Explanation of symbols]

1 is a cylinder block, 2 is a front housing, 3 is a rear housing, 4 is a valve plate, 5 is a suction chamber, 7 is a crank chamber, 12 is a bore, 15 is a suction hole, 18 is a shaft sealing device, 19
Is a suction port, 30 is a partition, 31a is a first conduction path, 31b is a second conduction path.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takahiro Hamaoka 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (72) Inventor Akihiro Amano 2-1-1 Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (72) Inventor Eiji Tokunaga 2-1-1 Toyota-machi, Kariya City, Aichi Prefecture Inside Toyota Industries Corporation (58) Fields investigated (Int. Cl. ⁷ , DB name) F04B 27/08

Claims (3)

(57) [Claims] 1. A cylinder block having a plurality of bores arranged side by side, a front housing forming a crank chamber and closing one end of the cylinder block, a discharge chamber in an inner area, and a suction chamber in an outer area. A rear housing for closing the other end of the cylinder block through a valve plate having a suction hole and a discharge hole, a swash plate element fixed to a drive shaft extending into the crank chamber, and the swash plate element A reciprocating compressor having a single-headed piston that moves directly in the bore in cooperation with a partition provided in the suction chamber to partition the suction chamber in the circumferential direction, and a suction port connected to a low-pressure circuit is provided near the partition. With opening,
A reciprocating compressor in which the cylinder block and the valve plate penetrate through a conduction path that individually communicates a region interposing the partition in the suction chamber with the crank chamber. 2. One of the regions sandwiching the partition wall, which is located on the side remote from the suction port, is enclosed by the partition wall so as to enclose the conduction path and at least one suction hole opened in the region, and is made into a private room by a further partition wall. The compressor according to claim 1, comprising: 3. The compression system according to claim 1, wherein one of the conduction paths is formed so as to directly communicate an area in the suction chamber with a shaft sealing device provided in the front housing. Machine.