JPS6160272B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in lubrication in a compressor that is lubricated by lubricating oil present in the form of a mist in a compressed gas.

This type of compressor is widely used, for example, for compressing refrigerant in small-sized refrigeration equipment, because the lubricating oil pressure sending means is simplified and the device is compact. It is preferable for the lubricating oil carried in the form of a mist to be present in abundance in the compressor in terms of equipment lubrication, but on the contrary, it is desirable for the lubricating oil to be as small as possible in the refrigeration circuit. However, if lubricating oil mist gets mixed into the refrigeration circuit, it will increase the fluid flow path resistance and reduce the thermal conductivity in the evaporator etc.
12, R-22), the evaporation and liquefaction of refrigerants such as ammonia will be hindered, and the refrigerating capacity will be reduced.

A part of the mist-like lubricating oil in the suction gas is separated from the suction gas in the suction passage of such a refrigeration device,
Conventionally, the separated oil can be supplied to the sliding parts of the compressor, and the remaining mist-like lubricating oil is absorbed into the cylinder bore and used to lubricate the cylinder, piston, etc.

In this way, the lubrication of the sliding parts is improved,
The amount of lubricating oil discharged into the refrigeration circuit is reduced to some extent, but once the lubricating oil mist has passed through the discharge valve, it is carried almost unchanged to the refrigeration circuit, so there is still some lubricant that is discharged into the refrigeration circuit. There was no shortage of oil.

The present invention has been made in order to solve the above-mentioned drawbacks against the background of the above-mentioned circumstances, and has the purpose of drastically reducing the amount of lubricating oil discharged from the compressor together with the gas to be compressed such as refrigerant gas, and It is an object of the present invention to provide a compressor that can lubricate sliding parts more effectively. The gist of this is that in a type of compressor that is lubricated by lubricating oil that exists in the form of a mist in the compressed gas, the flow of the compressed gas from the discharge valve of the compressor to the compressor outlet. An oil separation chamber for separating lubricating oil contained in the compressed gas is installed in the passage, and the lubricating oil accumulated below the oil separation chamber is transferred to the cylinder bore facing the side surface of the piston through an oil guide hole. When the piston on the peripheral wall moves near top dead center, the oil is guided to the oil spout that opens at a position where it is no longer blocked by the piston, and the oil is jetted out from the oil spout based on the pressure difference between the oil separation chamber and the cylinder bore or swash plate chamber. In addition, the opening and closing of the ejection port is controlled by a piston.

Here, the "position where the piston is no longer blocked" means the position where the piston is removed from the side surface of the piston in a type of compressor where the piston is connected to a drive mechanism such as a crankshaft by a connecting rod. However, in a swash plate compressor that has a double-headed piston in which two piston heads are connected by a small diameter part, it means a position that is removed from the piston head, and from the small diameter part of the piston. This does not mean a position that is out of place.

In the compressor configured as described above, the lubricating oil discharged from the discharge valve together with the compressed gas is separated in the oil separation chamber, and is jetted out from the oil spout opening in the peripheral wall of the cylinder bore through the oil guide hole. . However, the oil spout is usually blocked by the side surface of the piston, and only during a certain period when the piston is near top dead center, the oil spout is not blocked by the piston and lubricating oil is allowed to spout. It is.

The pressure in the spaces that house the mechanisms that drive the pistons, such as the swash plate chamber and the crank chamber, is usually considerably lower than the pressure in the oil separation chamber formed on the discharge side of the compressor. If the outlet is always open, more than the appropriate amount of lubricating oil will gush out, and if the lubricating oil that has accumulated below the oil separation chamber disappears, high-pressure compressed gas will leak to the low-pressure side through the oil guide hole. However, if the oil spout is normally blocked by a piston and is allowed to develop only at certain times as the piston reciprocates, this situation can be avoided. . By appropriately selecting the formation position of the oil spout in relation to the top dead center position of the piston, it is possible to appropriately set the opening time of the oil spout.

In addition, even though the oil spout is normally closed by the piston, it does not have a sealing member, so a small amount of lubrication flows from the oil spout into the gap between the side of the piston and the circumferential wall of the cylinder bore. This does not prevent oil from leaking out, and the lubricating oil that leaks into this gap acts as a lubricant between the piston and the circumferential wall of the cylinder bore, and the high-pressure compressed gas passes through the gap between the two to the low-pressure side space. It also serves as a seal to prevent leakage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing an example in which the present invention is applied to a refrigerant compressor for vehicle air conditioning.

In FIG. 1, reference numerals 1 and 2 indicate cylinder blocks, and a compressor main body 3 is constructed by combining two cylinder blocks 1 and 2 of mutually symmetrical shapes. Three cylinder bores 1a, 2a are formed in each cylinder block 1, 2, and a double-headed piston 4 is slidably fitted into these cylinder bores 1a, 2a. A rotating shaft 5 is inserted through the center hole 3a of the compressor main body 3 and rotatably supported by bearings 6 and 7. A swash plate 8 is fixed to the center of the rotating shaft 5 by a spring pin 9. When the swash plate 8 rotates, the piston 4 is moved into the cylinder bores 1a, 2a via two pairs of shoes and balls 12. It is designed to be able to make reciprocating movements within the chamber. 13 and 14 are thrust bearings.

A front housing 20 is fixed to the end face of the cylinder block 2 with a suction valve seat 15, a valve seat 16, and a gasket 17 sandwiched therebetween. Three suction ports 16a and three discharge ports 16b are formed in the valve plate 16, and three suction valves 18 and three discharge valves 19 are formed in cooperation with the suction valve seat 15 and the discharge valve reed 19a, respectively. It consists of
Each suction valve 18 is provided at a position where it can suck refrigerant gas from a common suction chamber 21 formed in the front housing 20, and each discharge valve 19 is located at a position where it can discharge refrigerant gas into a common discharge chamber 22. It is provided.

The rotating shaft 5 passes through the center of the front housing 20 and projects to the outside, and is connected to a drive source at this projecting end. The rotating shaft 5 and the front housing 20 are kept airtight by a shaft sealing device 23.

On the other hand, a rear housing 34 is fixed to the end face of the cylinder block 1 with a suction valve seat 31, a valve plate 32, and a gasket 33 in between. It is connected to a discharge chamber 38 via a discharge valve 37.

Further, a top head 51 is fixed to the upper end of the compressor main body 3 with bolts via a gasket and a base plate 50. This top head 51 is provided with a suction port 54 for sucking refrigerant gas and a discharge port 55 (compressor outlet) for discharging refrigerant gas, and the suction port 54 is connected to a sub-suction chamber 55 as shown in FIG.
2. It is communicated with the suction chambers 21 and 36 shown in FIG. 1 through the vertical holes 56a, 56b and the suction passage 56 shown in FIG. Further, the discharge chambers 22 and 38 shown in FIG. 1 are different from the discharge passage 5 shown in FIG.
7 and 3 are connected to an auxiliary discharge chamber 53 (oil separation chamber), respectively, and communicated with the discharge port 55.

The sub-discharge chamber 53 of the top head 51 is 53
It is composed of four chambers a, 53b, 53c, and 53c, and an overchamber 53c has a filter A arranged on both sides of the passage 53b located at a position corresponding to the T-shaped leg of the T-shaped gas passages 53a and 53b. 53c is provided. A filter B is provided on the surface where the passage 53b contacts the passage 53a.
The floor surfaces of the chamber 3a and the overchamber 53c are perforated through which the separated oil can pass.

Cylinder block 1 below this perforated floor surface,
As shown in FIG. 2, oil reservoirs 58 are arranged at the front and rear of the oil reservoir 2, and an oil equalizing hole 5 is provided to connect both oil reservoirs 58 in order to equalize the amount of separated oil collected.
9 is provided. And this oil puddle 58.5
8 and the upper cylinder bores 1a, 2a, respectively, are provided in the cylinder blocks 1 and 2, and the opening 61 of the oil guide hole 60 is
The (oil spout) is provided on the cylinder bore circumferential wall at a position where the piston 4 located at the top of the compressor is at the top dead center and is no longer blocked by the piston 4 and is opened to the swash plate chamber 62.

In the compressor configured as described above, the refrigerant gas and mist of lubricating oil discharged from each cylinder through the discharge valves 19 and 37 are discharged into the discharge chambers 22 and 3.
8 to the discharge passage 57 and vertical holes 57a, 57b.
It is guided to the sub-discharge chamber 53 through the. This sub-discharge chamber 5
In the sub-discharge chamber 53, lubricating oil in the discharged gas is separated by filters A and B and stored in two oil reservoirs 58, 58 at the front and rear of the sub-discharge chamber 53. That is, in this embodiment, the sub-discharge chamber 53
constitutes the oil separation chamber. The amount of oil stored in the oil reservoirs 58, 58 is averaged by the oil distribution through the oil equalizing hole 59. And this oil is oil sump 5
8 and 58 to respective openings 61 by respective oil guide holes 60. When the piston 4 reaches one top dead center in this state, the opening 61 is opened by the piston 4, and oil is jetted into the swash plate chamber 62 from the opening 61 located at the top of the compressor.
Therefore, the lubricating oil is alternately injected into the swash plate chamber 62 from the front and rear openings 61, 61 as the piston 4 reciprocates, and is further scattered by the rotation of the swash plate 8 to lubricate each sliding part. be. This injection of lubricating oil is based on the pressure difference between the sub-discharge chamber 53 and the swash plate chamber 62, which receive discharge pressure. Note that the discharged gas after most of the lubricating oil has been separated is discharged from the discharge port 55 toward the refrigeration circuit.

On the other hand, suction gas containing mist-like lubricating oil enters the sub-suction chamber 52 from the suction port 54, is divided into two parts, and is guided to the suction chambers 21, 36 via the vertical holes 56a, 56b and the suction passage 56. On the other hand, the oil that has lubricated the inside of the swash plate chamber 62 flows from the swash plate chamber 62 through the oil pan 63 and into the suction chambers 21 and 36 together with the blow-by gas.
The air is drawn into the cylinder bores 1a, 2a through the respective intake valves 18, 35.

In this way, the refrigerant gas and lubricating oil are circulated within the compressor main body 3, and the oil is separated on the high pressure side.
The separated oil is supplied to the sliding parts, and the refrigerant gas containing only a small amount of oil is sent under pressure to the refrigeration circuit.

The above-mentioned communication hole 60 is normally closed by the piston 4 and is opened when the piston 4 is near the top dead center, so by appropriately selecting the position of the opening 61, the opening 61 by the piston 4 can be Since the opening time can be changed, the amount of lubricating oil supplied into the swash plate chamber 62 can be adjusted by controlling the opening time.

Furthermore, when the compressor stops at the position where this opening 61 is open, the pressure in the discharge passage 57 and the pressure in the suction passage 56 become approximately equal over time, so the pressure in the swash plate chamber is also the same. After the pressure increases and the differential pressure between the discharge passage pressure and the swash plate chamber pressure disappears, the lubricating oil in the oil reservoir 58 is not sprayed into the swash plate chamber, and the lubricating oil remains in the oil reservoir 58. A portion of the lubricating oil sprayed into the swash plate chamber until the differential pressure becomes equal is stored in the oil pan 63 below the swash plate chamber 62, so there is no possibility of an accident in which the lubricating oil is compressed in the cylinder. There is no risk of this occurring.

As described above, in this example, since the amount of lubricating oil contained in the gas flowing into the circuit is small, not only the flow resistance in the pipe is reduced, but also
Heat exchange between the condenser and evaporator also improves, and cooling capacity is improved. In addition, oil can be supplied to the sliding parts better, improving anti-seizure performance, and it is possible to lubricate the lower cylinder bore simply by injecting oil into the upper cylinder bore. Yet another oil puddle 5
8 and the opening 61 are close to each other, the oil supply path is short and small and the structure is simple, and the amount of oil supplied can be controlled by the position of the piston 4 and the opening 61. be.

Another embodiment in which the separated oil supply path is different from the above embodiment is shown in FIGS. 4 and 5.

In FIG. 4, a suitable circular oil groove 70 is formed inside the O-ring groove on the mating surfaces of the cylinder blocks 1 and 2. A point 7 where this circular oil groove 70 intersects with a vertical plane passing through the axis of the rotating shaft 5
0a, circular oil grooves 7 at three points 70b and 70c 120 degrees and 240 degrees apart from this point around the axis.
Oil holes 71 are branched from 0 to both sides and parallel to the axis.
a, 71b, 71c (71b, 71c are not shown) are further bent at each end to open into the wall surface of the cylinder bores 1a and 2a, but the openings 72a, 72
b, 72c (72b, 72c are not shown) are configured such that when the piston 4 is at the top dead center, the openings near the top dead center are released from being blocked by the piston 4.

The oil accumulated in the oil reservoir 58 is guided to the oil hole 73 and the oil groove 70 based on the pressure difference between the oil reservoir 58 and the swash plate chamber 62, and is pumped to points 70a, 70b, and 70c. As shown in FIGS. 4 and 5, when the front head of the upper piston 4 is at the top dead center, the oil is forced from the point 70a to the opening 72a via the oil hole 71a, and from the opening 72a the piston 4 has a small diameter. The liquid is injected into the gap between the portion 4a and the cylinder bore 2a in the direction of the arrow (both sides in the circumferential direction). Similarly, when the rear head of the piston 4 is at the top dead center, the rear opening 7
It goes without saying that the fuel is injected from 2a, and the same injection is also performed for the two cylinders located below.

While the previous embodiment injected oil only to the upper cylinder, this embodiment injects oil to all cylinders under the same conditions, so it has the unique effect of uniformly lubricating the cylinders, pistons, etc.

In the above embodiment, a swash plate type refrigerant compressor for vehicle air conditioning has been described, which is small and lightweight and suitable for high capacity requirements, but the present invention is by no means limited to this. The same applies to other compressors, such as compressors for refrigerated containers and general refrigerators, as long as they are lubricated by lubricating oil that exists in the form of a mist in the compressed gas. Can be applied.

As detailed above, in the compressor according to the present invention, the lubricating oil mist contained in the compressed gas discharged from the discharge valve is separated in the oil separation chamber, so that the compressor is not connected to the compressor. The amount of lubricating oil flowing into the pipe is reduced, and the flow resistance within the pipe is reduced. In addition, especially when the compressor is connected to a refrigeration circuit to compress refrigerant gas, it coats the inner surfaces of the condenser, evaporator, heat exchanger, etc. in the refrigeration circuit and reduces the heat transfer coefficient. This reduces the amount of heat generated, and the effect of improving the refrigerating capacity can be obtained.

Further, the separated lubricating oil is jetted from the oil spout into the cylinder bore, the swash plate chamber, the crank chamber, etc., thereby achieving the effect of improving the lubrication of the inner peripheral surface of the cylinder bore and the sliding parts of the piston drive mechanism. Furthermore, the timing at which lubricating oil is spouted from the oil spout is controlled by the reciprocating motion of the piston, and the piston functions as a control valve that controls the timing of lubricating oil spouting, so the amount of lubricating oil jetted out is controlled by the reciprocating motion of the piston. is properly controlled, and the lubricating oil in the oil reservoir never runs out.

Therefore, there is no communication between the auxiliary discharge chamber for oil separation and the swash plate chamber through only the refrigerant gas, and it is possible to completely prevent the discharge gas from flowing back into the swash plate chamber.

Additionally, while the lubricating oil spout is closed by the piston, a small amount of lubricating oil leaks into the gap between the piston and the circumferential wall of the cylinder bore, lubricating the gap between the two, and filling the gap between the two to form a seal. As a result, the lubricity and compression efficiency of the compressor are improved.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view (-cross section in FIG. 2) of a compressor that is an embodiment of the present invention, FIG. 2 is a cross-sectional view (-- in FIG. 1), and FIG. FIG. FIG. 4 is a front cross-sectional view of another embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along the line shown in FIG. 1, 2: cylinder block, 1a, 2a: cylinder bore, 3: compressor body, 4: piston, 5:
Rotating shaft, 8: Swash plate, 11: Shoe, 12: Ball, 18, 35: Suction valve, 19, 37: Discharge valve,
20: Front housing, 21, 36: Suction chamber, 22, 38: Discharge chamber, 34: Rear housing, 51: Top head, 52: Sub-suction chamber, 5
3: Sub-discharge chamber, 53a, 53b: Gas passage, 53
c: overchamber, 54: suction port, 55: discharge port, 5
6: Suction passage, 57: Discharge passage, 58: Oil reservoir,
59: Oil equalizing hole, 60: Oil guiding hole, 61, 72a, 7
2b, 72c: opening, 62: swash plate chamber, 63: oil pan, 70: oil groove, 71a, 71b, 71c:
Oil hole, 81: Circular oil groove, A, B: Filter.

Claims (1)

[Claims] 1. In a compressor that is lubricated by lubricating oil that exists in the form of a mist in the compressed gas,
An oil separation chamber for separating lubricating oil contained in the compressed gas is provided in the flow path of the compressed gas from the discharge valve of the compressor to the compressor outlet, and an oil separation chamber is provided to separate lubricating oil contained in the compressed gas. The lubricating oil is guided through the oil guide hole to an oil spout opening in the circumferential wall of the cylinder bore facing the side surface of the piston at a position that is released from the piston when the piston moves near top dead center. A compressor characterized in that oil is ejected from a jet port based on a pressure difference between the oil separation chamber and the cylinder bore or the swash plate chamber, and the jet port is opened and closed by the piston.