Refrigerant scroll compressor for motor vehicle air conditioning system including at least one sealing means for bottom surface sealing of orbiting scroll

Abstract

A refrigerant scroll compressor for a motor vehicle air conditioning system having a fixed scroll, a orbiting scroll engaging with the fixed scroll, wherein the fixed scroll and the orbiting scroll cooperate to compress a refrigerant gas. An intermediate pressure chamber is disposed adjacent the orbiting scroll, an oil return duct provides fluid communication between the intermediate pressure chamber and a high pressure area of the refrigerant scroll compressor, and at least one intermediate pressure duct is formed in one of the orbiting scroll and fixed scroll and is in fluid communication with the intermediate pressure chamber.

Claims

1. A scroll compressor for a motor vehicle air conditioning system comprising: a stationary housing including an outer surface; a fixed scroll overlying and having engaging contact with the stationary housing; an orbiting scroll engaging the fixed scroll and including an outer surface defining an annularly extending groove formed therein, wherein the fixed scroll and the orbiting scroll cooperate to compress a refrigerant gas; an intermediate pressure chamber disposed adjacent the orbiting scroll; at least one sealing means to seal the orbiting scroll including an annularly extending gasket and an annularly extending O-ring overlying the annularly extending gasket and having engaging contact therewith, the at least one sealing means extending from the outer surface of the stationary housing to the orbiting scroll wherein the annularly extending gasket is positioned adjacent the stationary housing and has engaging contact therewith and an entirety of the annularly extending O-ring is disposed in the annularly extending groove of the orbiting scroll; and at least one intermediate pressure duct formed in the orbiting scroll, the intermediate pressure duct being in fluid communication with the intermediate pressure chamber.

2. The scroll compressor of claim 1, wherein the annularly extending O-ring contacts at least one inner face of the orbiting scroll located within and adjacent the groove.

3. The scroll compressor of claim 1, wherein a cross-section of the annularly extending gasket taken through a plane parallel to a longitudinal axis of the scroll compressor is rectangular in shape.

4. The scroll compressor of claim 1, wherein a cross-section of the annularly extending O-ring taken through a plane parallel to a longitudinal axis of the scroll compressor is circular in shape.

5. The scroll compressor of claim 1, wherein the sealing means encircles the at least one intermediate pressure duct.

6. A scroll compressor for a motor vehicle air conditioning system comprising: a stationary housing including an outer surface; a fixed scroll overlying and having engaging contact with the stationary housing; an orbiting scroll orbiting with respect to the fixed scroll, the fixed scroll and the orbiting scroll cooperating to compress a gas and the orbiting scroll including an outer surface facing the outer surface of the stationary housing, the outer surface of the orbiting scroll defining an annularly extending groove formed therein; an intermediate pressure chamber defined by the stationary housing adjacent the orbiting scroll; and at least one sealing means extending from the outer surface of the stationary housing to the outer surface of the orbiting scroll, at least a portion of the at least one sealing means disposed in the annularly extending groove, the at least one sealing means including an annularly extending gasket and an annularly extending O-ring overlying the annularly extending gasket and having engaging contact therewith wherein the annularly extending gasket is positioned adjacent the stationary housing and has engaging contact therewith, wherein an entirety of the annularly extending O-ring is disposed in the annularly extending groove.

7. The scroll compressor of claim 6, wherein the annularly extending O-ring contacts at least one inner face of the orbiting scroll located within and adjacent the annularly extending groove.

8. The scroll compressor of claim 6, wherein a cross-section of the annularly extending gasket taken through a plane parallel to a longitudinal axis of the scroll compressor is rectangular in shape.

9. The scroll compressor of claim 6, further comprising at least one intermediate pressure duct formed in the orbiting scroll, the intermediate pressure duct being in fluid communication with the intermediate pressure chamber.

10. A scroll compressor for a motor vehicle air conditioning system comprising: a first housing including a high pressure chamber; a stationary second housing including an outer surface; a fixed scroll overlying and having engaging contact with the stationary second housing; an orbiting scroll orbiting with respect to the fixed scroll, the fixed scroll and the orbiting scroll cooperating to compress a gas and the orbiting scroll including an outer surface facing the stationary second housing, the outer surface of the orbiting scroll defining an annularly extending groove formed therein; an intermediate pressure chamber defined by the stationary second housing adjacent the orbiting scroll; and at least one sealing means extending from the outer surface of the stationary second housing to the outer surface of the orbiting scroll, the at least one sealing means including an annularly extending gasket and an annularly extending O-ring overlying the annularly extending gasket and having engaging contact therewith wherein the annularly extending gasket is positioned adjacent the stationary housing and has engaging contact therewith, wherein an entirety of the annularly extending O-ring is disposed in the annularly extending groove.

11. The scroll compressor of claim 10, wherein the annularly extending O-ring contacts at least one inner face of the orbiting scroll located within and adjacent the annularly extending groove.

12. The scroll compressor of claim 10, wherein a cross-section of the annularly extending gasket taken through a plane parallel to a longitudinal axis of the scroll compressor is rectangular in shape.

13. The scroll compressor of claim 10, further comprising at least one intermediate pressure duct formed in the orbiting scroll in fluid communication with the intermediate pressure chamber.

14. The scroll compressor of claim 10, wherein a cross-section of the annularly extending O-ring taken through a plane parallel to a longitudinal axis of the scroll compressor is circular in shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further particulars, features and advantages of the embodiments of the invention result from the subsequent description of embodiments with reference to the associated drawings. The drawings show:

(2) FIG. 1 is a schematic cross-section of a refrigerant scroll compressor;

(3) FIG. 2 is a plan view of an orbiting scroll with an intermediate pressure duct, and

(4) FIG. 3 is an embodiment of a refrigerant scroll compressor as a cross-section in a lateral view.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

(5) 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.

(6) FIG. 1 shows a highly schematic cross-section of a refrigerant scroll compressor. For this purpose, and according to the functional principle, an orbiting scroll 2 is located in a fixed scroll 1. The orbiting scroll 2 moves in an oscillating manner in the fixed scroll 1 such that between the scrolls 1, 2, cavities are formed which decrease radially from the outside to the inside, in which the refrigerant gas is compressed from the outside to the inside and the compressed refrigerant gas inside is finally discharged axially into the high-pressure chamber. FIG. 1 illustrates an intermediate pressure chamber 3 below the scrolls 1, 2, in which the refrigerant gas exists at an intermediate pressure. The resulting intermediate pressure in the intermediate pressure chamber 3 acts on the orbiting scroll 2 and is constituted such that a resulting axial force results from the forces which act from the intermediate pressure chamber 3 on the orbiting scroll 2 and the opposite forces between the orbiting scroll 2 and the fixed scroll 1 act oppositely. In the representation according to FIG. 1, the orbiting scroll 2 is pressed by the resulting axial force from the bottom against the fixed scroll 1. The orbiting scroll 2 on the side of the intermediate pressure chamber 3 is sealed with respect to a stationary housing 14 by an O-ring 7.

(7) In the fixed scroll 1 and in the housing, which is not described in further detail, an oil return duct 4 is realized, by means of which the oil enters at a reduced flow into the intermediate pressure chamber 3 from the high-pressure area of the refrigerant circuit in a first expansion device 5. The oil from the intermediate pressure chamber 3 reaches the suction side, and/or the suction chamber of the compressor, via an oil extraction duct 6 with a second expansion device 9. The orbiting scroll 2 is supported and sealed by means of a gasket 7a and the O-ring 7 on its side facing the housing.

(8) Decisive for the functionality according to the invention is that an additional intermediate pressure duct 8 be provided, which results in that the refrigerant gas arrives directly at the intermediate pressure chamber 3 through the cavities which form between the scrolls, and that an intermediate pressure results. In the illustrated embodiment pursuant to FIG. 1, the intermediate pressure duct 8 is designed for penetrating the bottom of the orbiting scroll 2 as a bore, which directly connects an inner area between the scrolls 1, 2 with the intermediate pressure chamber 3.

(9) The schematically illustrated expansion devices 5, 9 are preferably cost-effectively designed as orifice plates. The principle according to the invention of separating the oil flow from the flow of the refrigerant gas within the compression process can be realized with the illustrated embodiment. The oil return duct 4 and the oil extraction duct 6 therefore function only for recirculating the oil, whereas the refrigerant gas enters the intermediate pressure chamber 3 by means of the intermediate pressure duct 8 to generate the axial sealing pressure. By decoupling the oil return and the gas flow for the intermediate pressure chamber 3, the process can be controlled much more effectively.

(10) FIG. 2 illustrates an orbiting scroll 2 and an intermediate pressure duct 8 indicated in the bottom of the scroll as an intermediate pressure bore. Intermediate pressures with a pressure ratio of 3:15 of low pressure to high-pressure and of 5.9 to 7.6 bar can be achieved with the modified refrigerant scroll compressor. At a pressure ratio of 3:25 bar, the intermediate pressure will rise from 6.8 up to 8.6 bar, depending on how the intermediate pressure duct 8 is positioned, and on the rotational speed.

(11) In some embodiments, the intermediate pressure duct 8 has a cross-section that is 10 times larger than the first expansion device 5. In this manner, the pressure in the intermediate pressure chamber 3 can be superbly controlled by the refrigerant gas. The closer that the intermediate pressure duct 8 is formed to the inner area of the scroll, the greater is the influence at different final compression pressures.

(12) The pressure differential between high pressure outlet and intermediate pressure results in delivering the oil through the first expansion device 5 into the intermediate pressure chamber 3, which is filled as a result thereof. The pressure differential between the intermediate pressure chamber 3 and the suction area of the refrigerant compressor delivers the oil through the oil extraction duct 6 and through the second expansion device 9. Any oil that remains in the intermediate pressure chamber 3 flows back through the intermediate pressure duct 8 into the scroll package 1, 2 to provide same with lubrication.

(13) FIG. 3 illustrates the structural design of the refrigerant scroll compressor a little better than a mere schematic. The refrigerant/oil mixture from the high-pressure chamber 10 of the refrigerant scroll compressor is separated in the oil separator 11, and the liquid oil flows into the oil return duct 4 by means of a connection pipe 12. A first expansion device 5, designed as a restriction orifice, is arranged upstream of the oil entry into the oil return duct 4. This decompresses the refrigerant oil and it enters the intermediate pressure chamber 3.

(14) Refrigerant gas from the compression process, passing from the compression chamber 13 formed between the fixed scroll 1 and the orbiting scroll 2, enters via the intermediate pressure duct 8 into the intermediate pressure chamber 3 parallel to the oil flow from the high-pressure chamber 10 of the refrigerant scroll compressor. An intermediate pressure of the refrigerant gas/oil mixture results in the intermediate pressure chamber 3.

(15) In certain operational situations, a desirable return flow of the refrigerant oil from the intermediate pressure chamber 3 into the compression chamber 13 occurs, as a result of which improved lubrication of the scrolls 1, 2 is achieved.

(16) The refrigerant gas/oil mixture exits the intermediate pressure chamber 3 via the second expansion device 9, which is again designed as a restriction orifice in the embodiment, and is discharged via the oil extraction duct 6.

(17) An alternative embodiment that is not illustrated consists in that the oil return duct 4 is directed without a connection to the intermediate pressure chamber 3 directly towards the suction side of the compressor.

(18) This form of design compared to designs from the prior art moreover results in a reduced number of components, and it is also possible to use standard components cost-effectively.

(19) 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.

LIST OF REFERENCE SYMBOLS

(20) 1 Fixed scroll 2 Orbiting scroll 3 Intermediate pressure chamber 4 Oil return duct 5 First expansion device, restriction orifice 6 Oil extraction duct 7 O-ring 7a Gasket 8 Intermediate pressure duct 9 Second expansion device, restriction orifice 10 High-pressure chamber 11 Oil separator 12 Connection line 13 Compression chamber 14 Stationary housing