DE102006038726B4 - Refrigerant compressor for air conditioning and method for oil separation and pressure pulsation damping this - Google Patents

Abstract

Refrigeration compressor for oil separation and noise control air conditioning systems for use in vehicles, comprising at least one housing (1) coupled to the crankcase of the refrigerant compressor, the interior of which is divided into three mutually communicating chambers (3, 4 and 6) using a flow guide (9), characterized in that the housing (1) is formed as a hollow cylinder and by the in the housing (1) insertable flow guide (9) is divided into:
a. a first annular cylindrical chamber (3) with a tangential inlet (2) for the oil / refrigerant mixture,
b. a second circular cylindrical chamber (4) arranged downstream of the first chamber (3) and having an oil outlet (5) for the separated oil placed at the lowest point in terms of gravity;
c. a third circular cylindrical chamber (6) adjoining the second chamber (4) and having an outlet (7) for the gaseous refrigerant
d. wherein the flow guide (9) separating the three chambers (3, 4 and 6) is placed coaxially with the longitudinal axis (15) of the housing (1) ...

Description

The invention relates to a refrigerant compressor for air conditioning systems, in particular a sound-damped refrigerant compressor with oil separation for use in vehicles, according to the preamble of patent claim 1, and a method for oil separation and Druckpulsationsdämpfung this.

For the purpose of achieving high reliability and service life of refrigerant compressors, the same oil is used for lubrication to reduce wear. In addition to the required lubrication, the oil also performs a sealing function, especially between the piston and the cylinder wall, and also dissipates frictional heat.

The oil is stored in the foot area of the housing of the refrigerant compressor, especially in the crankcase, in an oil sump and transported by the compression of the refrigerant in the compressor block upwards.

However, it is necessary that the refrigerant / oil mixture separates before leaving the refrigerant compressor housing, i. H. the oil is safe from the refrigerant, eg. As gas, deposited, and returned to the oil sump of the crankcase. Cyclone separators, separators with filter technology and calming chambers for reducing the flow velocity are previously known as oil separators.

Another requirement is that the refrigerant compressor during its operation should only cause a low perceptible noise by the vehicle occupants in the vehicle interior. Operating noise of the refrigerant compressor is mainly due to the pressure pulsation caused by the compression. To reduce these pressure pulsations various structures are used in practice, but primarily chambers in which the pressure wave is attenuated by expansion.

From the US 2,692,655 A For example, there is known an oil and moisture separator from compressed air comprising an inlet chamber having an inlet, an adjoining chamber having an oil drain at the lowest point, and an outlet chamber having an outlet. The chambers are delimited from each other by a flow guide, which forms an annular gap between the first and the second chamber by means of funnel shape. The separator is optimized to release larger volumes of compressed air from oil droplets and moisture. Noise protection measures are not provided in the separator.

The DE 2201 877 A discloses a venting device for the crankcase valve-controlled internal combustion engine with a leading from the crankcase via an oil separator to the intake pipe vent line. It is characteristic that the oil separator is designed as a centrifugal separator whose oil collecting space communicates with the crankcase via a riser pipe immersed in an oil sump.

After DE 197 39 279 C2 a compressor for generating compressed air is arranged in a screw housing with compressor screws with a separating container for separating oil from an oil-air mixture and with an air outlet to a pressure accumulator known, wherein a pressure port is provided, which is the separator a compacted by the compressor screws Oil-air mixture feeds.

From the prior art is the DE 36 43 567 A1 previously known, in which a muffler for hermetically sealed compressors is disclosed. The muffler has two sections, the first section causing the pulsations to attenuate and the oil separating from the cooling gas, and in the second section the gas pulsations are damped. To achieve the damping of the gas pulsations, a porous material is provided in the second section, which forms cavities and fills the second section. For the separation of oil from the first or second portion of the muffler, a small tube is provided, through which the oil can be drained.

In the DE 198 00 556 A1 discloses a compressor which also includes the functions of oil separation and pressure pulsation damping. For this purpose, it is proposed that in the multi-part crankcase of the compressor both operating means for suction, compression and delivery of a cooling gas and oil separation means are arranged in the form of a labyrinth. The oil separation means are each integrally formed on the outer portions of the crankcase and are adjacent to each other and in contact with each other such that an inner space in at least one of the oil separation means is closed by another oil separation means, thereby forming a separation chamber for the discharged cooling gas. The oil separation means are integrally provided with passage-forming members which divide the separation chamber from its inlet to its outlet partially such that a serpentine-like separation flow path for the discharged cooling gas is formed while the separation chamber communicates with the crank chamber via an oil return passage.

Furthermore, from the EP 0 926 341 A2 a compressor with oil separation previously known, which has two channels and openings interconnected chambers. While both chambers of the compressor are used for pressure pulsation damping, only the first rectangular-shaped chamber for oil separation is provided.

Other generic solutions are in the US 6,523,455 B1 , of the US 2005/0072307 A1 and the DE 101 567 85 A1 described.

The main disadvantages of the previously known from the prior art solutions are that the Ölabscheidevorrichtungen and the muffler require a considerable space within the compressor, which is usually associated with high production costs. In addition, large-capacity compressors are subject to certain installation restrictions with regard to packaging in small engine compartment of vehicles.

The object of the invention is now to propose a silenced refrigerant compressor with oil separation for air conditioning systems of vehicles, which requires only a small space with a more efficient Druckpulsationsdämpfung and oil separation.

According to the concept of the invention, the refrigerant compressor for air conditioners comprises a soundproofed refrigerant compressor with oil separation for use in vehicles, at least one housing coupled to the crankcase of the refrigerant compressor, the interior of which is divided into a plurality of communicating chambers. According to the invention, the housing in the flow direction of the oil / refrigerant mixture comprises a first chamber with an inlet for the oil / refrigerant mixture. Downstream of the first chamber is a second chamber with a gravity-deposited at the lowest point outlet for the separated oil. The second chamber is followed by a third chamber with an outlet for the gaseous refrigerant. In addition, a three-chamber separating flow guide is provided, which extends - starting from the second chamber - channel-like through the first chamber to the third chamber. The end region of the flow-guiding device facing the third chamber is formed as a dividing wall and the end region of the flow-directing device placed between the first chamber and the second chamber is formed as a funnel with an annular gap forming between the funnel edge and the inner wall of the housing.

With the solution according to the invention, a refrigerant compressor, in particular for gaseous refrigerant, is provided, with which both an efficient oil separation of oil / refrigerant and a compression pulsation damping caused by compression can be realized in a confined space. While the oil separation takes place by utilizing the centrifugal and nozzle principle or the coalescing principle with nozzle injection in the second chamber, the pressure pulsation damping is performed in each of the three chambers by means of pressure expansion. The latter is achieved structurally by lowering the hydrostatic pressure of the same and increasing the hydrodynamic pressure using cross-sectional constrictions immediately before the oil / refrigerant mixture enters the three chambers.

The training, d. H. the cross-section, the length and the orientation, the flow guide is measured according to design specifications in terms of the permissible overall size of the refrigerant compressor and the desired degree of oil separation. In the embodiment according to the invention, the channel-like flow guiding device is placed coaxially with the longitudinal axis of the housing coupled to the crankcase of the refrigerant compressor, wherein a circular shape is selected for the cross section of the flow guiding device.

The intended for the oil / refrigerant mixture inlet of the first chamber is particularly preferably arranged orthogonal to the longitudinal axis of the channel-like flow guide in the housing wall. The inlet is preferably formed as one or more bore (s), which is arranged tangentially to the first chamber. Thus, the incoming oil / refrigerant mixture can make use of the centrifugal force to the housing inner wall of the first chamber. After the acceleration in the annular gap forming in the transition region between the first and the second chamber and the subsequent flow direction reversal, the oil is physically separated from the oil / refrigerant mixture according to the principle of gravitational force due to the inertia.

In a particularly advantageous embodiment of the invention, an oil filter is placed on the housing inner wall of the second chamber in the region of the annular gap, or immediately below, which is coupled to the oil drain passage. This oil filter can be completely or only partially annular, z. B. point, on the housing inner wall.

In addition or as an alternative to the oil filter, it is possible to provide a fibrous material or fiber weft suitable for agglomeration of the oil droplets, which fiber material is placed in the second chamber, preferably in the lower region of the second chamber.

According to the idea of the invention, the oil / refrigerant mixture within the housing in the second chamber is subjected to a flow direction reversal. For this purpose, both the funnel-shaped end portion of the flow guide and the housing inner wall are formed or formed accordingly. Also by a factory predefined inclination of the funnel flanks a desired degree of oil separation is achieved.

In practice, the three chambers of the housing coupled to the crankcase of the refrigerant compressor are each circular in cross-section, wherein the position of the first chamber in the housing - namely anaxially between the second and third chamber - this is formed as a cylinder. The distal ends of the second and third chambers are preferably formed as a spherical cap or cylindrical with rounded edges for flow reasons and for reasons of compressive strength.

The method for oil separation and pressure pulsation damping within a refrigerant compressor is effected according to the invention in that the pressure pulsation damping takes place by reflection of the pressure waves in each of the three chambers communicating with one another using the flow cross section which changes the flow cross section. Through a targeted cross-sectional constriction between the chambers and an adjoining cross-sectional widening in the chambers, the pressure wave occurring during compression in the refrigerant compressor is weakened or completely degraded.

Oil separation, on the other hand, is accomplished by tangentially injecting, expanding and cooling the oil / refrigerant mixture through the inlet of the housing into the first chamber and utilizing the centrifugal force, gravity, and nozzle action in the second chamber at the inlet and annular gap.

Alternatively or additionally, oil drops are agglomerated via a fiber material or fiber fabric placed within the second chamber and separated by utilizing gravity and the pressure gradient. This fiber material or Fasergewirk is preferably designed as a filter fabric.

• – effiziente Trennung des Öls vom Kältemittel, wodurch eine gute Schmierwirkung und damit eine hohe Lebensdauer des Kältemittelverdichters erzielt wird,
• – effiziente Reduzierung der Druckpulsation des Kältemittels führt zu einem geringeren wahrnehmbaren Betriebsgeräusch im Fahrzeug,
• – geringer Raumbedarf des Kältemittelverdichters durch Funktionsintegration, wodurch der Einsatz des Kältemittelverdichters auch in kleineren Motorräumen ermöglicht wird und
• – niedrige Fertigungskosten durch reduzierten Materialeinsatz, Fertigungsaufwand und Zukauf von Fremdteilen.

The significant advantages and features of the invention over the prior art are essentially:

• - efficient separation of the oil from the refrigerant, whereby a good lubricating effect and thus a long service life of the refrigerant compressor is achieved,
• Efficient reduction of the pressure pulsation of the refrigerant leads to a lower perceptible operating noise in the vehicle,
• - Low space requirement of the refrigerant compressor through functional integration, whereby the use of the refrigerant compressor is made possible even in smaller engine compartments and
• - low production costs due to reduced material usage, production costs and purchase of foreign parts.

The objectives and advantages of this invention will become better understood and appreciated after a careful study of the following detailed description of the preferred non-limiting example embodiments of the invention herein, together with the accompanying drawings, in which:

1 : schematic representation of coupled to the crankcase of the refrigerant compressor housing and

2 : Representation of coupled to the crankcase of the refrigerant compressor housing in a detailed view.

The 1 illustrates a schematic representation of coupled to the crankcase of the refrigerant compressor housing 1 , The essentially cylindrical housing 1 comprises a first chamber through which the oil / refrigerant mixture flows 3 comprising a tangential inlet consisting of two parallel cylindrical bores 2 includes. The first chamber 3 is in axial extension through one above the first chamber 3 placed third chamber 6 and through one below the first chamber 3 placed second chamber 4 flanked. The third chamber 6 has an outlet 7 for the oil-free gaseous refrigerant, which in the scheme shown parallel to the inlet 2 extends. The three chambers 3 . 4 . 6 of the housing 1 are in turn by a flow guide according to the invention 9 separated from each other. The flow guide 9 extends from the second chamber 4 channel-like through the first chamber 3 through to the third chamber 6 coaxial to the longitudinal axis 15 of the housing 1 , The third chamber 6 facing first end region 10 the flow guide 9 is as a partition 11 formed by the one hand, the flow guide 9 inside the case 1 is held and on the other hand, the first chamber 3 from the third chamber 6 is demarcated. The one between the first chamber 3 and the second chamber 4 placed second end area 12 the flow guide 9 is on the other hand a funnel 13 with a between the hopper edge and the housing inner wall 8th forming annular gap 14 shaped. By a factory preset inclination of the funnel edges forms a different sized annular gap 14 between the hopper edge and the housing inner wall 8th out, through which the oil / refrigerant mixture from the first chamber 3 in the second chamber 4 flows. The funnel 13 has a double effect, as it is the one from the first chamber 3 in the second chamber 4 flowing oil / refrigerant mixture and the other from the second chamber 4 in the channel-like middle section of the flow guide 9 flowing refrigerant gas accelerates, whereby the hydrostatic pressure decreases.

The operation explained below facilitates the understanding of the sound-damped refrigerant compressor according to the invention with oil separation.

The oil / refrigerant mixture flows tangentially across the inlet at a high flow rate 2 in the first chamber 3 one. In this designed as an expansion chamber first chamber 3 the oil / refrigerant mixture is cooled and its flow rate is lowered. This also reduces the pulsation of the pressure of the oil / refrigerant mixture. The first chamber 3 thus acts as an expansion silencer. The inflowing oil / refrigerant mixture follows the centrifugal force and lies against the inside wall of the housing 8th the first chamber 3 at. The gravity-following oil / refrigerant mixture now passes between the funnel 13 the flow guide 9 and the housing inner wall 8th trained annular gap 14 and is accelerated there, which is accompanied by a decrease in hydrostatic pressure. in the second expansion chamber designed as the second chamber 4 place. as well a cooling of the oil / refrigerant mixture and a reduction of its flow velocity instead. The flow of the oil / refrigerant mixture is at an acute angle to the housing inner wall 8th and / or at the distal end of the second chamber 4 diverted. In this case, the oil content with higher mass due to its inertia against the housing inner wall 8th spun and the gaseous portion of the oil / refrigerant mixture flows over the hopper 13 the flow guide 9 in the channel-like portion of the flow guide 9 , The separated oil flows on the inside of the housing 8th towards the distal end of the second chamber 4 down to the oil drain 5 which is coupled to an unillustrated oil drain channel. The channel-like section of the flow guide 9 again causes a damping of the pressure pulsation. The gaseous portion of the oil / refrigerant mixture then flows out of the flow guide 9 in the third chamber 6 and is relaxed there, which leads to a further damping of the pressure pulsation. About the outlet formed as a bore 7 The gaseous and oil-free refrigerant leaves the housing 1 , The oil separation from the oil / refrigerant mixture was in the second chamber 4 made, while the pressure pulsation damping in all three chambers 3 . 4 . 6 as well as in the flow-guiding device 9 took place.

In the 2 is the coupled to the crankcase of the refrigerant compressor housing 1 shown in a detailed view. Basically, the structure of the housing corresponds 1 the the 1 , In addition to those in the 1 described components is in the housing 1 to 2 an oil filter 16 provided in the second chamber 4 is placed. The oil filter 16 is coupled here with an unillustrated oil drain channel. The oil filter 16 causes using its Fasergewirks an increase in size of droplets, so that the enlarged drops from the flow of the oil / refrigerant mixture excreted. In addition to 1 is in 2 also the flow pattern 17 drawn the oil / refrigerant mixture or the oil-free refrigerant. As can be seen, the distal ends of the second chamber 4 and the third chamber 6 formed for fluidic reasons and reasons of compressive strength cylindrical with rounded edges. In practice, the subject invention is regularly made of three parts, namely the housing 1 with the inlet 2 , Outlet 7 and oil drain 5 , one with the housing 1 coupling insert, which already has the separation function between the first chamber 3 and the second chamber 4 takes over, and the flow guide 9 , which is locked on the insert.

LIST OF REFERENCE NUMBERS

1

casing

2

inlet

3

first chamber

4

second chamber

5

oil drain

6

third chamber

7

outlet

8th

Housing inner wall

9

flow guide

10

End region of the flow-guiding device 9

11

partition wall

12

End region of the flow-guiding device 9

13

funnel

14

annular gap

15

Longitudinal axis of the housing 1

16

oil filter

17

flow path

Claims (8)

Refrigerant compressor for air conditioning systems with oil separation and sound damping for use in vehicles, at least comprising a coupled to the crankcase of the refrigerant compressor housing ( 1 ), whose interior is using a flow guide ( 9 ) into three communicating chambers ( 3 . 4 and 6 ), characterized in that the housing ( 1 ) hollow cylindrical and through which in the housing ( 1 ) usable flow guide ( 9 ) is divided into: a. a first annular cylindrical chamber ( 3 ) with a tangential inlet ( 2 ) for the oil / refrigerant mixture, b. one of the first chambers ( 3 ) Subordinate second circular cylindrical chamber ( 4 ) with an oil drain placed at the lowest point in terms of gravity ( 5 ) for the separated oil, c. one to the second chamber ( 4 ) subsequent third circular cylindrical chamber ( 6 ) with an outlet ( 7 ) for the gaseous refrigerant d. wherein the flow guiding device ( 9 ), which are the three chambers ( 3 . 4 and 6 ) separated from each other, coaxial with the longitudinal axis ( 15 ) of the housing ( 1 ) and starting from the second chamber ( 4 ), channel-like through the first chamber ( 3 ) through to the third chamber ( 6 ), wherein the third chamber ( 6 ) facing end region ( 10 ) of the flow guiding device ( 9 ) as a partition ( 11 ) and between the first chamber ( 3 ) and the second chamber ( 4 ) placed end area ( 12 ) of the flow guiding device ( 9 ) as a funnel ( 13 ) with a between the funnel edge and the housing inner wall ( 8th ) forming annular gap ( 14 ), wherein the flow guiding device ( 9 ) for pressure pulsation damping respectively cross-sectional constrictions before the entry of the oil / refrigerant mixture in the second and the third chamber ( 4 . 6 ) trains. Refrigerant compressor according to claim 1, characterized in that the end region ( 10 ) of the flow guiding device ( 9 ) partially through an opening in the wall of the housing ( 1 ) and thereby within this opening the inlet ( 2 ) and the outlet ( 7 ) separated from each other. Refrigerant compressor according to claim 1 or 2, characterized in that provided for the oil / refrigerant mixture inlet ( 2 ) of the first chamber ( 3 ) orthogonal to the longitudinal axis of the channel-like flow guide ( 9 ) or the longitudinal axis ( 15 ) of the housing ( 1 ) is formed in the housing wall. Refrigerant compressor according to one of claims 1 to 3, characterized in that a on the housing inner wall ( 8th ) of the second chamber ( 4 ) in the region of the annular gap ( 14 ) placed oil filter ( 16 ) is provided, which is coupled to an oil drain passage. Refrigerant compressor according to one of claims 1 to 4, characterized in that a suitable for agglomeration of the oil droplets fiber material, Fasergewirk or Filtergewirk is provided which in the second chamber ( 4 ) is placed. Refrigerant compressor according to one of claims 1 to 5, characterized in that both the funnel-like end region ( 12 . 13 ) of the flow guiding device ( 9 ) as well as the housing inner wall ( 8th ) of the second chamber ( 4 ) for the flow direction reversal of the oil / refrigerant mixture within the housing ( 1 ) are provided. Method for oil separation and pressure pulsation damping within a refrigerant compressor according to at least one of claims 1 to 6, characterized in that a. the pressure pulsation damping by a reflection of the pressure waves in each of the three communicating chambers ( 3 . 4 and 6 ) using the flow cross section changing flow guide ( 9 ) and b. the oil separation by the tangential injection, expansion and cooling of the oil / refrigerant mixture via the inlet ( 2 ) of the housing ( 1 ) into the first chamber ( 3 ) and taking advantage of centrifugal force, gravity and the inlet ( 2 ) as well as at the annular gap ( 14 ) occurring nozzle effect in the second chamber ( 4 ) he follows. A method according to claim 7, characterized in that an oil separation by the flow through the oil filter ( 16 ) and the associated increase in the drop in the fiber material of the oil filter ( 16 ) he follows.

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