JPH0744767Y2 - Compressor oil separator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention separates lubricating oil contained in a refrigerant gas from a refrigerant gas in a high pressure part of a compressor, and separates the separated oil from a low pressure part of the compressor. The invention relates to an oil separator of a compressor configured to be returned to.

[Prior Art] In a compressor such as a swash plate compressor, lubricating oil for lubricating a movable part is contained in a refrigerant gas in a mist form. Therefore, when the refrigerant gas compressed inside the compressor is discharged and circulated to the external cooling circuit, mist-like lubricating oil is also discharged and circulated to the cooling circuit, and this lubricating oil is distributed to the inner wall of the evaporator in the cooling circuit. It adheres and hinders heat exchange.

Therefore, conventionally, an oil separator is separately provided outside the compressor, and a pipe is connected between the compressor and the cooling circuit, and when the refrigerant gas compressed inside the compressor is discharged to the cooling circuit, the refrigerant gas It has been proposed that the lubricating oil contained in (1) is separated by an oil separator and that the separated lubricating oil is returned to the inside of the compressor through an oil return pipe.

However, in this conventional configuration, since the oil separator is separately provided outside the compressor, the entire structure of the refrigeration circuit including the compressor becomes large and a large installation space is required. Piping to the compressor is required, which complicates the piping structure and
There is a disadvantage that gas leakage easily occurs from the pipe connection portion.

In order to eliminate these disadvantages, a compressor configured to separate the lubricating oil contained in the refrigerant gas from the refrigerant gas in the high pressure part of the compressor and return the separated oil to the low pressure part of the compressor. Is also proposed. In this type of compressor, a refrigerant gas containing oil is discharged from a discharge hole of the compressor through a discharge passage into an expansion chamber (volume chamber) that is bulged in the compressor casing, and enters a discharge side service flange. Oil is separated in the meantime and collects in the oil storage chamber. Then, the oil accumulated in the oil storage chamber is returned to the low pressure portion such as the swash plate chamber through the oil return passage. or,
The diameter of the oil return passage is formed to have a constant size such that the amount of oil returned during normal operation of the compressor is a predetermined amount.

[Problems to be solved by the invention] However, the discharge gas pressure is 14% during normal operation of the compressor.
The pressure is about 15 atm, but it reaches a maximum of 30 atm when the cooling load is large, such as when the road is congested in midsummer, or when the condenser is insufficiently cooled. Then, when the discharge pressure becomes higher, the pressure in the expansion chamber (volume chamber) also rises, and the oil stored in the oil storage chamber is returned to the low pressure portion of the compressor more than necessary, and as a result, the oil in the oil storage chamber is exhausted. A condition arises. In this state, part of the discharge gas will flow back to the low pressure part of the compressor,
There is a problem that not only the volume efficiency of the compressor deteriorates, but also the discharge temperature rises and the oil adhering to the swash plate and the like is washed away, resulting in the seizure of the pistons, shoes and the like.

The present invention has been made in view of the above problems,
The purpose of the compressor is to keep the amount of the oil separated from the refrigerant gas in the high pressure part of the compressor and returned to the low pressure part of the oil storage part to be substantially constant regardless of the discharge pressure. To provide an oil separator.

[Means for Solving the Problems] In order to achieve the above-mentioned object, in the present invention, the lubricating oil contained in the refrigerant gas is separated from the refrigerant gas in the high pressure portion of the compressor, and the separated oil is separated. In the compressor configured to return to the low pressure part of the compressor, the oil storage chamber provided in the high pressure part for temporarily storing the separated oil and an oil passage communicating with the low pressure part A variable orifice was provided in which the opening area was changed by directly sensing the pressure of the chamber, and the opening area was narrowed as the pressure increased.

[Operation] When the compressor equipped with the oil separator of the present invention is operated, the refrigerant gas compressed inside the compressor is guided to the oil separator provided in the high pressure part, and the oil is separated from the refrigerant gas. It is stored in the oil storage chamber. Then, the oil stored in the oil storage chamber is returned to the low pressure portion of the compressor through an oil passage that connects the oil storage chamber and the low pressure portion (for example, the swash plate chamber) of the compressor. The discharge pressure changes depending on the operating condition of the compressor, and the pressure in the oil storage chamber also changes correspondingly. The opening area of the variable orifice provided in the middle of the oil passage narrows as the pressure in the oil storage chamber rises, and widens as the pressure falls. Therefore, the amount of oil returned to the low pressure part of the compressor through the oil passage is always kept substantially constant even if the discharge pressure fluctuates, and the oil is not exhausted from the oil storage chamber.

[Example 1] An example in which the present invention is embodied in a swash plate compressor will be described below.
It will be described with reference to FIGS.

As shown in FIG. 4, both ends of the cylinder blocks 1 and 2 arranged in front and back are closed by front and rear housings 5 and 6 via valve plates 3 and 4, respectively, and these are formed by a plurality of bolts 7 Are joined by. A swash plate chamber 8 is formed in the connecting portion of the cylinder blocks 1 and 2, and a swash plate 10 fixed to a drive shaft 9 penetrating through the central shaft holes 1a and 2a of both cylinder blocks 1 and 2 is formed in the swash plate chamber 8. It is housed.
As shown in FIGS. 4 to 6, five pairs of cylinder bores 11 are formed in each of the cylinder blocks 1 and 2 in parallel with the drive shaft 9 and at a radial position around the drive shaft 9, and
A double-headed piston 12 is fitted and inserted in 11. Each piston 12
Is moored to the swash plate 10 via the shoe 13, and is reciprocated in the cylinder bore 11 by the swing of the swash plate 10 accompanying the rotation of the drive shaft 9.

Suction chambers 14 and 15 are formed on the center sides of the front and rear housings 5 and 6, respectively, and discharge chambers 16 and 17 are formed on the outer peripheral sides thereof. The valve plates 3 and 4 are formed with suction ports 18 and 19 and discharge ports 20 and 21, respectively. Further, intake valves 22 and 23 are provided on the cylinder blocks 1 and 2 side of the valve plates 3 and 4, respectively, and the housings of the valve plates 3 and 4 are provided.
Discharge valves 24 and 25 are provided on the fifth and sixth sides.

A protrusion 26 for sucking in and discharging the refrigerant gas G is provided on the upper portion of the rear cylinder block 2, and a gas inlet 27 opening to the swash plate chamber 8 is provided in the protrusion 26 as shown in FIG. Has been formed. Five suction passages 28 and 29 for communicating the swash plate chamber 8 with the suction chambers 14 and 15 are formed between the cylinder bores 11 of the cylinder blocks 1 and 2, respectively. The refrigerant gas G sucked in is introduced into the suction chambers 14, 15 through the suction passages 28, 29.

As shown in FIGS. 1, 5 and 6, a shield plate 31 is provided on the protrusion 26.
The shell 33 is attached through the pore forming plate 32, and the expansion chamber 34 is formed inside the shell 33. In the expansion chamber 34, a pair of discharge pipes 35 are laterally projected on the shield plate 31, and the upper ends of the discharge pipes 35 are opened toward the center of the expansion chamber 34. A pair of gas outlets 36 is formed in the rear cylinder block 2 so as to connect the discharge pipes 35 and the discharge chambers 16 and 17, and the compressed refrigerant gas is discharged from the discharge chambers 16 and 17 to the gas outlets 36 and discharge. It is discharged into the expansion chamber 34 through the pipe 35.

A suction pipe 37 is projected from the shell 33, and is connected to the gas inlet 27 at the base end thereof. Further, the shell 33 has a discharge pipe 38 whose end is the discharge pipe in the expansion chamber 34.
The refrigerant gas flow, which is fixed so as to project downward from the opening of 35, is guided from the discharge pipe 35 through the expansion chamber 34 to the discharge pipe 38, collides with the lower end 38a of the discharge pipe 38,
The mist-like oil O contained in the gas flow is the lower end portion 38a.
It is attached to the outer periphery of and separated and collected. Further, the refrigerant gas in the expansion chamber 34 is supplied to an external cooling circuit (not shown) via the discharge pipe 38.

In the lower part of the expansion chamber 34, the rear cylinder block 2
An oil storage chamber 39 for storing the separated and recovered oil O is formed on the protruding portion 26. A through hole 40 is formed in the shielding plate 31 between the expansion chamber 34 and the oil storage chamber 39 so as to be located immediately below the lower end portion 38a of the discharge pipe 38, and dust and the like mixed in the oil O is formed under the through hole 40. A filter 41 is attached for the purpose. As shown in FIG. 6, through holes
A pair of pores 42 are formed in the pore forming plate 32 so as to correspond to the outer peripheral edge of 40, and the expansion chamber 34 and the oil reservoir chamber are formed through the pores 42.
It is in communication with 39. An oil passage 43 is formed between the bottom portion of the oil storage chamber 39 and the swash plate chamber 8 serving as a low pressure portion so as to extend therebetween so as to extend substantially vertically.
The oil in 39 is dropped and supplied into the swash plate chamber 8 through the oil passage 43.

The oil passage 43, as shown in FIGS.
A large-diameter portion 43a having a substantially elliptical cross-section is formed toward the side, and a small-diameter portion 43b having a circular cross-section is formed continuously with the large-diameter portion 43a. In the large diameter portion 43a, a variable orifice 33 is provided, the opening area of which changes in response to the pressure change in the oil storage chamber 39, and the opening face width of which narrows as the pressure rises. The variable orifice 44 is formed of a pipe 45 made of a rigid body such as metal that guarantees a minimum opening area, and a flow rate adjusting body 46 made of elastic foam synthetic resin having open cells fitted on the outer periphery of the pipe 45. It is fitted into the oil passage 43 with one end abutting the lower end of the large diameter portion 43a. A gap δ is formed between both outer peripheral side surfaces of the flow rate adjuster 46 and the inner surface of the large diameter portion 43a.

Next, the operation of the device configured as described above will be described.

When the swash plate 10 is rotated by the rotation of the drive shaft 9, each piston 12 is reciprocated in the cylinder bore 11 in the left-right direction in FIG. 4, so that the refrigerant gas G is sucked, compressed, and discharged. The compressed refrigerant gas G is discharged into the expansion chamber 34 from the discharge chambers 16 and 17 through the gas outlet 36 and the discharge pipe 35, and the flow velocity is reduced in the expansion chamber 34, and then the discharge pipe 38.
And is supplied to an external cooling circuit (not shown). When the refrigerant gas G is discharged from the opening end of the discharge pipe 35 into the expansion chamber 34, the refrigerant gas flow collides with the lower end portion 38a of the discharge pipe 38, thereby forming a mist shape in the gas flow. Oil O adheres to the outer periphery of the lower end portion 38a and is separated and collected. The oil O that has been separated and collected falls from the lower end portion 38a to the bottom portion of the expansion chamber 34, and the through hole 40, the filter 41, and the pores.
It is dripped and stored in the oil storage chamber 39 through 42. Further, the stored oil O is dripped and supplied to the swash plate chamber 8 of the compressor through the oil passage 43, and is used for lubricating movable parts such as the piston 12.

The oil dripped and supplied from the oil storage chamber 39 to the swash plate chamber 8 through the oil passage 43 partially passes through the pipe 45 and partially through the flow rate adjuster 46 when passing through the variable orifice 44. When the pressure in the oil storage chamber 39 is low, the flow rate adjuster 46 is in a state of being expanded in the radial direction by its elastic force, and the open area of the open cells is large. The same pressure as that in the oil storage chamber 39 is applied to the outer circumference of the flow rate adjusting body 46 via the oil O existing in the gap δ with the large diameter portion 43a. Therefore, as the pressure in the oil storage chamber 39 rises, the flow rate adjuster 46 directly senses this pressure and is pressed and contracted in the radial direction against its elasticity, and the open area of the open cells is reduced and the open cells are reduced. When the amount of oil O that can pass through the portion decreases and the discharge pressure reaches the maximum, the open air bubble portion is almost closed and the oil O is supplied to the swash plate chamber 8 only through the pipe 45.

If the opening area of the oil passage 43 is constant, the oil storage chamber
As the pressure in 39 increases, the flow rate of oil O in the oil passage 43 increases, and the oil O may disappear from the oil storage chamber 39. However, since the variable orifice 44 provided in the oil passage 43 operates as described above, the flow rate of the oil O passing through the oil passage 43 becomes substantially constant even if the pressure in the oil storage chamber 39 changes. Therefore, the oil storage chamber 39
Since the oil O is exhausted inside and the discharge gas flows back into the swash plate chamber 8, the volume efficiency is deteriorated and the piston 12 and the shoe are
The seizure of 13 etc. is surely prevented.

Further, in this embodiment, the oil passage 43 is the oil storage chamber.
Since it is formed so as to extend substantially vertically at the shortest distance between the swash plate chamber 39 and the swash plate chamber 8, the oil passage 43 is unlikely to be clogged.

[Second Embodiment] Next, a second embodiment will be described with reference to FIG. In this embodiment, only the structure of the variable orifice 44 is different from that of the previous embodiment. That is, the pipe 47 that constitutes the variable orifice 44 is formed such that the inner diameter thereof becomes the minimum at the center in the axial direction and gradually increases toward both ends, and the flanges 47a are formed at both ends and the peripheral wall is formed. A through hole 47b extending in the axial direction of the pipe 47 is formed. A cylindrical flow rate adjuster 48 made of elastic foam synthetic resin, rubber or the like is fitted around the outer periphery of the pipe 47.
A gap 49 communicating with the through hole 47b is formed between the outer peripheral surface of the inner peripheral surface and the inner peripheral surface of the flow rate adjusting body 48.

In this embodiment, when the pressure in the oil storage chamber 39 is low, the flow rate adjusting body 48 is held in a cylindrical shape without being deformed, and the oil O passing through the variable orifice 44 is formed in the central portion of the pipe 47 and the wall surface. It passes through both the formed through hole 47b. On the other hand, when the pressure in the oil storage chamber 39 becomes high, the flow rate adjusting body 48 bends inward in the radial direction by the action of the pressure applied to the outer peripheral surface thereof, and the opening area of the gap 49 becomes smaller. Therefore, even in the case of this embodiment, even if the pressure in the oil storage chamber 39 changes, the amount of oil O returned to the swash plate chamber 8 through the oil passage 43 becomes substantially constant.

[Third Embodiment] Next, a third embodiment will be described with reference to FIG. In this embodiment, the variable orifice 44 is constituted only by the flow rate adjusting body 50 made of elastic foam synthetic resin or rubber having open cells, and the large diameter portion 43a of the oil passage 43 is formed in a circular cross section. This is different from both of the above embodiments. The flow rate adjuster 50 is formed in a hemispherical shape on the oil storage chamber 39 side. In this embodiment, when the pressure in the oil storage chamber 39 is low, the opening area of the passage 50a formed in the center of the oil storage chamber 39 is maximized, and the flow rate adjuster 50 is compressed as the pressure in the oil storage chamber 39 increases. The opening area of the passage 50a is reduced. Therefore, also in this embodiment, the oil storage chamber
Even if the pressure in 39 changes, the amount of oil O returned to the swash plate chamber 8 through the oil passage 43 becomes substantially constant. Also, in the case of this embodiment, unlike both the above-mentioned embodiments, since the diameter of the passage 50a changes, it is possible to prevent clogging even when foreign matter is present in the oil O.

The present invention is not limited to the above embodiments,
For example, the oil O in the oil storage chamber 39 is not returned directly to the swash plate chamber 8 but is returned to the swash plate chamber 8 via a low pressure portion communicating with the swash plate chamber 8, or the structure for separating the oil O from the refrigerant gas is different. The structure of may be adopted. Further, it may be applied to a compressor other than the swash plate compressor.

[Effects of the Invention] As described in detail above, according to the present invention, the oil is separated from the refrigerant gas in the high pressure portion of the compressor and is disposed in the oil passage for returning the oil stored in the oil storage chamber to the low pressure portion. Due to the action of the variable orifice, the amount of oil returned to the low pressure part is kept almost constant regardless of the fluctuation of the discharge pressure, and even when the discharge pressure becomes extremely high, the oil in the oil storage chamber does not run out, and the oil Part of the discharge gas flows back to the low pressure part of the compressor from the return passage of the compressor, the volumetric efficiency of the compressor deteriorates, the discharge temperature rises and the oil adhering to the swash plate is washed away and the piston and shoe It is possible to reliably prevent the occurrence of seizure.

In addition, the present invention has a structure in which the opening area of the variable orifice is adjusted by directly detecting the pressure of the oil storage chamber associated with the discharge pressure. Therefore, even if the discharge pressure fluctuates due to fluctuations in heat load or other reasons, Properly adjust the area,
The amount of oil returned to the low pressure part can be kept substantially constant.

[Brief description of drawings]

1 to 6 show a first embodiment embodying the present invention. FIG. 1 is a partial sectional view showing the structure of an oil separator, FIG. 2 is an enlarged sectional view of an oil passage, and FIG. 2 is a sectional view taken along line III-III in FIG. 2, FIG. 4 is a sectional view showing the entire compressor, FIG. 5 is a sectional view taken along line VV in FIG. 1, and FIG. 6 is shown in FIG. FIG. 7 is a sectional view taken along line VI-VI, FIG. 7 is a sectional view of an essential portion of the second embodiment, and FIG. 8 is a sectional view of an essential portion of the third embodiment. Cylinder blocks 1 and 2, swash plate chamber 8 as a low pressure part of the compressor, expansion chamber 34, discharge pipe 38, oil storage chamber 39, oil passage 43, large diameter portion 43a, small diameter portion 43b, variable orifice 44, pipe 45, 47, flow rate adjusters 46, 48, 50, gap δ, refrigerant gas G, oil O.

Claims (1)

[Scope of utility model registration request] 1. A compressor configured to separate lubricating oil contained in a refrigerant gas from a refrigerant gas in a high pressure portion of a compressor and return the separated oil to a low pressure portion of the compressor. The oil storage chamber provided in the high pressure part for temporarily storing the stored oil and the oil passage communicating with the low pressure part, the pressure of the oil storage chamber is directly sensed, the opening area changes, and the pressure rises. An oil separator for a compressor provided with a variable orifice whose opening area becomes narrower as a result.