COMBINED OIL SEPARATOR AND MUFFLER FOR REFRIGERANT COMPRESSOR

Abstract

A casing for use with a refrigerant compressor of an air conditioning unit in a vehicle is disclosed, wherein the casing facilitates a maximization of pressure pulsation attenuation and an oil separation of a refrigerant/oil mixture flowing therethrough, and a space required thereby is minimized.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the invention will become readily apparent to those skilled in the art from reading the following descriptions of several embodiments of the invention when considered in the light of the accompanying drawings in which:

FIG. 1 is a schematic representation of a casing adapted to be coupled to a crankcase of a refrigerant compressor according to an embodiment of the invention; and

FIG. 2 is a front cross sectional view of a casing adapted to be coupled to a crankcase of a refrigerant compressor according to another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed and illustrated, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.

FIG. 1 shows a casing 1, which is adapted to be coupled to a crankcase (not shown) of a refrigerant compressor (not shown). The casing 1 shown is generally cylindrical in shape but may have any suitable shape as desired. The casing includes a first chamber 3 having a substantially tangential inlet 2 in fluid communication with a refrigerant/oil mixture. The inlet includes two cylindrical apertures that are formed in parallel with respect to each other. The first chamber 3 is bordered by a third chamber 6, which is disposed above the first chamber 3, and a second chamber 4, which is disposed below the first chamber 3. The third chamber 6 has an outlet 7 that extends substantially parallel to the inlet 2 in the embodiment shown. The three chambers 3, 4, 6 of the casing 1 are separated from each other by a hollow flow guiding device 9. Starting from the second chamber 4, the flow guiding device 9 extends substantially coaxially with a longitudinal axis 15 of the casing 1 through the first chamber 3 and up to the third chamber 6.

A first end region 10 of the flow guiding device 9, which is disposed between the first chamber 3 and the third chamber 6, is formed as partition 11 which, on the one hand, holds the flow guiding device 9 within the casing 1 and, on the other hand, separates the first chamber 3 from the third chamber 6 to create a substantially fluid tight seal therebetween.

A second end region 12 of the flow guiding device 9, which is disposed between the first chamber 3 and the second chamber 4, is formed as a funnel portion 13. An annular gap 14 is formed between a funnel edge and a casing inner wall 8. A spacing of the annular gap 14 between the funnel edge and the casing inner wall 8 varies around a circumference of the funnel portion 13 in the embodiment shown. The annular gap 14 forms a flow path for the oil/refrigerant mixture from the first chamber 3 to the second chamber 4. The funnel portion 13 facilitates a flow of a refrigerant portion of the oil/refrigerant mixture from the second chamber 4 into the hollow interior portion of flow guiding device 9 and into the third chamber 6.

In use, the oil/refrigerant mixture flows at a high flow velocity tangentially from the inlet 2 into the first chamber 3. In the first chamber 3, which is established as an expansion space, the oil/refrigerant mixture is cooled and the flow velocity thereof is reduced. A reflection of the pressure waves within the first chamber also attenuates the pulsation of the pressure of the oil/refrigerant mixture. Thus the first chamber 3 additionally acts as an expansion silencer. The inflowing oil/refrigerant mixture attaches to the casing inner wall 8 of the first chamber 3 as a result of a centrifugal force. The oil/refrigerant mixture, following gravity, now passes through the annular gap 14 between the funnel edge of the flow guiding device 9 and the casing inner wall 8 and is accelerated, which decreases the hydrostatic pressure thereof.

In the second chamber 4, which is established as a second expansion space, the oil/refrigerant mixture is cooled and the flow velocity thereof is reduced. A reflection of the pressure waves within the second chamber also attenuates the pulsation of the pressure of the oil/refrigerant mixture. The flow of the oil/refrigerant mixture is reversed at an acute angle at the casing inner wall 8 and/or the distal end of the second chamber 4. Thereby the oil portion of the oil/refrigerant mixture is centrifuged towards the casing inner wall 8 due to its higher inertia and the gaseous refrigerant portion of the oil/refrigerant mixture flows over the funnel portion 13 of the flow guiding device 9 into the hollow interior of the flow guiding device 9, which reduces the hydrostatic pressure thereof. The separated oil flows along the casing inner wall 8 in the direction of the distal end of the second chamber 4 down to an oil drain 5 formed in the second chamber 4, which is coupled to an oil drain channel (not shown).

The hollow interior of the flow guiding device 9 again causes attenuation of the pressure pulsations by a reflection of the pressure waves within the hollow interior of the flow guiding device 9. The gaseous refrigerant portion of the oil/refrigerant mixture now flows from the flow guiding device 9 into the third chamber 6 and is relieved there, which further attenuates pressure pulsations by a reflection of the pressure waves within the third chamber 6. The gaseous and oil-free refrigerant leaves the casing 1 through the outlet 7.

Function of the casing 1 facilitates a pressure pulsation attenuation in all three chambers 3, 4, 6 and in the flow guiding device 9, and an oil separation in the second chamber 4. Attenuation of the pressure pulsation is achieved by design in that utilizing constrictions immediately before the inflow of the oil/refrigerant mixture into the three chambers 3, 4, 6 the hydrostatic pressure of the oil/refrigerant mixture is decreased and the hydrodynamic pressure increased. Oil separation is achieved by tangential injection, expansion and cooling of the oil/refrigerant mixture over the inlet 2 of the casing 1 into the first chamber 3, utilizing the centrifugal force, gravity and a nozzle effect acting at the inlet 2 and the annular gap 14 in the second chamber 4. Further, a space requirement for the casing 1 is minimized.

FIG. 2 shows a casing 101, which is coupled to a crankcase (not shown) of a refrigerant compressor (not shown). Similar structure to that described above for FIG. 1 includes the same reference number followed by a prime (′) symbol. The casing includes a first chamber 3′, a second chamber 104, and a third chamber 106. Distal ends of the second chamber 104 and the third chamber 106 are substantially cylindrical in shape and have rounded edges for hydrodynamic and pressure strength purposes.

The casing 101 includes an oil filter 16 that is disposed in the second chamber 104 between an annular gap 14′ formed between a funnel portion 13′ of a flow guiding device 9′ and a casing inner wall 8′. The oil filter 16 is coupled to an oil drain channel (not shown). In the embodiment shown, the oil filter 16 is formed from a knitted fiber fabric, although oil filters formed from other materials can be used as desired.

In use, the knitted fiber fabric of the oil filter 16 separates oil from the oil/refrigerant mixture. The separated oil forms into drops, which are caused to enlarge in the oil filter 16. The drops of oil are drained from the casing 101 through the oil drain channel. A flow course 17 of the oil/refrigerant mixture, and the subsequent substantially oil-free refrigerant, is shown. Remaining function of the casing 101 is substantially the same as the function of the casing 1 described above for FIG. 1.

From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.

Claims

1. A casing for use with a refrigerant compressor comprising: a first chamber having an inlet in fluid communication with a source of a mixture of oil and refrigerant;a second chamber having a drain formed therein, the second chamber in fluid communication with the first chamber;a third chamber having an outlet, the third chamber in fluid communication with the second chamber; anda flow guiding device for directing a flow of the mixture of oil and refrigerant from the first chamber to the second chamber and from the second chamber to the third chamber.

2. The casing according to claim 1, wherein the second chamber and the third chamber are disposed adjacent the first chamber.

3. The casing according to claim 2, wherein the flow guiding device includes a partition disposed between the first chamber and the third chamber and a funnel portion disposed between the first chamber and the second chamber.

4. The casing according to claim 3, wherein an annular gap is formed between the funnel portion of the flow guiding device and a casing inner wall.

5. The casing according to claim 4, wherein the flow guiding device includes a hollow interior portion for facilitating a flow of a refrigerant portion of the mixture of oil and refrigerant from the second chamber to the third chamber.

6. The casing according to claim 3, wherein the partition creates a substantially fluid tight seal between the first chamber and the third chamber.

7. The casing according to claim 1, wherein the flow guiding device is disposed coaxially with a longitudinal axis of the casing.

8. The casing according to claim 1, further comprising an oil filter disposed in the second chamber for filtering an oil portion from the mixture of oil and refrigerant.

9. The casing according to claim 8, wherein the oil filter is formed from a knitted fiber fabric material.

10. The casing according to claim 1, wherein the drain is an oil drain for facilitating drainage of an oil portion of the mixture of oil and refrigerant from the casing.

11. A casing for use with a refrigerant compressor comprising: a first chamber having an inlet in fluid communication with a source of a mixture of oil and refrigerant;a second chamber disposed adjacent the first chamber, the second chamber including an oil drain formed therein for facilitating drainage of an oil portion of the mixture of oil and refrigerant from the casing;a third chamber disposed adjacent the first chamber, the third chamber including an outlet for a refrigerant portion of the mixture of oil and refrigerant; anda flow guiding device disposed in the first chamber, the flow guiding device including a partition disposed between the first chamber and the third chamber and a funnel portion disposed between the first chamber and the second chamber, wherein the partition creates a substantially fluid tight seal between the first chamber and the third chamber and an annular gap is formed between the funnel portion of the flow guiding device and a casing inner wall.

12. The casing according to claim 11, wherein the oil drain is disposed at a lowest point of the second chamber with respect to gravity.

13. The casing according to claim 11, wherein the flow guiding device includes a hollow interior portion for facilitating a flow of the refrigerant portion of the mixture of oil and refrigerant from the second chamber to the third chamber.

14. The casing according to claim 11, wherein the flow guiding device is disposed coaxial with a longitudinal axis of the casing.

15. The casing according to claim 11, further comprising an oil filter disposed in the second chamber for filtering the oil portion from the mixture of oil and refrigerant.

16. The casing according to claim 15, wherein the oil filter is formed from a knitted fiber fabric material.

17. A method for oil separation and pressure pulsation attenuation in a casing for a refrigerant compressor, the method comprising the steps of: causing a mixture of oil and refrigerant to enter a first chamber formed in the casing;attenuating a pressure pulsation in the first chamber by a reflection of pressure waves within the first chamber;causing the mixture of oil and refrigerant to flow into a second chamber;attenuating the pressure pulsation in the second chamber by a reflection of pressure waves within the second chamber; andseparating an oil portion from a refrigerant portion of the mixture of oil and refrigerant.

18. The method according to claim 17, wherein an oil filter disposed in the second chamber separates the oil portion from the mixture of oil and refrigerant.

19. The method according to claim 17, further comprising the steps of: causing a refrigerant portion of the mixture of oil and refrigerant to flow into a hollow interior of a flow guiding device; andattenuating the pressure pulsation in the hollow interior of the flow guiding device by a reflection of pressure waves within the hollow interior of the flow guiding device.

20. The method according to claim 19, further comprising the steps of: causing the refrigerant portion of the mixture of oil and refrigerant to flow into a third chamber; andattenuating the pressure pulsation in the third chamber by a reflection of pressure waves within the third chamber.