DE102016010567A1 - compressor - Google Patents

Abstract

Compressor (10), in particular refrigerant compressor, with a compressor housing (14) and at least one piston (12), which is arranged in a cylinder reciprocating and which is driven by an electric motor (16), wherein the compressor (10) a Sump lubrication, wherein the oil sump (20) in the compressor (10) from a housing bottom (22) extends to an oil level (24), the compressor (10) comprises a pressure circulation lubrication with a lubricant delivery device, wherein the lubricant delivery device with the oil sump in Connection is provided and is provided for the suction of lubricant from the oil sump, wherein the electric motor (16) has an enclosure (18) with a housing interior (26) bounded by the housing (18), the electric motor (16) in the housing interior (26). is arranged and the electric motor (16) including housing (18) hineinerstreckt into the oil sump (20) of the compressor (10), wherein the egg Housing (18) has a suction opening (28) which is provided with a suction device, which is provided for the extraction of in the housing interior (26) provided lubricant in connection, wherein the suction device and the lubricant delivery device are implemented by a single gear pump, which a first and a second suction port, wherein the first and the second suction port are separated from each other, and wherein the first suction port is provided for sucking from the housing interior (26) passing lubricant, and the second suction port for sucking lubricant from the oil sump (20 ) is provided.

Description

The present invention relates to a compressor in particular for compressing refrigerant according to the preamble of patent claim 1.

Compressors are used in many areas of modern life. An example of this is the production of compressed air (compressed air) for a variety of purposes, such as filling tires, respirators, etc. Another example is the compression of (especially technical) gases to store and transport them, for example in appropriate gas cylinders. Examples of these are nitrogen, oxygen, acetylene and other gases, which are used, for example, as combustion or protective gases in welding operations. Furthermore, compressors, in particular due to the increasing air conditioning of rooms and vehicles and also due to a steadily growing need for cooling of goods often find application in the compression or compression of refrigerants such as R134a (tetrafluoroethane) or R744 (CO ₂ ).

In many applications, in particular refrigeration and air conditioning applications, the compressors used are reciprocating compressors, examples being axial piston compressors and radial piston compressors. Such compressors usually have a compressor housing, in which at least one piston in a cylinder or a cylinder bore is arranged back and forth. The drive of the piston is often done by an electric motor. Such compressors often have an oil sump lubrication, wherein the oil sump in the compressor in an installed or working position from a housing bottom or housing lower edge extends up to a certain oil level upwards. It is important to ensure that the engine is not immersed in the oil sump, which requires a relatively large size of the corresponding compressor.

Starting from the above-discussed prior art, it is an object of the present invention to provide a compressor, in particular compressors for compressing gases, in particular for compressing refrigerant, which has a smaller or more compact size compared to compressors according to the prior art.

This object is achieved by a compressor according to claim 1.

According to the invention, a corresponding compressor, in particular compressor for compressing gases, furthermore for compressing refrigerant in particular, has a compressor housing and at least one piston which is arranged reciprocably in a cylinder and which is driven by an electric motor. The compressor further comprises an oil sump lubrication, wherein the oil sump extends in the compressor in a working position or an installation position from a housing bottom or housing lower edge up to a predetermined oil level or oil level. The compressor has a lubrication, in particular pressure circulation lubrication, with a lubricant delivery device, wherein the lubricant delivery device is in communication with the oil sump and is provided for the suction of lubricant from the oil sump. The electric motor has an enclosure which delimits a housing interior, in which the electric motor is arranged, wherein the electric motor including housing hineinerstreckt into the oil sump of the compressor and wherein the housing has a suction opening, which with a suction device for the extraction of in the The suction device and the lubricant delivery device are implemented by a single gear pump having a first and a second suction port, wherein the first and the second suction port are separated from each other, and wherein the first suction port for suction is provided by passing into the housing interior lubricant, and the second suction port is provided for the suction of lubricant from the oil sump. In other words, the electric motor of the compressor is arranged in a so-called dry sump, since oil or lubricant which reaches the interior of the housing (in particular leakage oil) can be sucked out via the suction opening arranged in the housing.

This causes the engine or parts of the engine are not in the oil, but the engine is located in the dry sump. This avoids a possible capacitor effect of the oil, which could possibly lead to fault currents, in particular when starting the compressor and thus would increase the risk of failure for the compressor.

In another possible embodiment, both the suction device and the lubricant delivery device, which are implemented by a single pump, are implemented by an internal gear pump. This represents a robust construction.

In a further possible embodiment, the gear pump has at least two gears, which have gear teeth, wherein the gear teeth have a tooth width, which is measured in particular at its base or at its half-height, wherein the first and the second suction from each other at least one tooth width are separated from each other.

The gear pump may have a pressurized kidney to discharge discharged oil. Furthermore, the gear pump as first and second suction port having a first and a second Saugniere, wherein the first Saugniere via a first suction line with the Einhausungsinnenraum in communication or fluid communication and wherein the second Saugniere via a second suction line extending into the oil sump of the Compressor hineinerstreckt, with the oil sump in connection. It should be noted at this point that the first suction kidney and / or the second suction kidney can alternatively be directly in communication with the housing interior / oil sump or can be arranged on or in the same. The position of the suction kidneys is determined by the relative amount of the fluid to be suctioned off at the respective suction openings.

In a possible embodiment, the gear pump in a normal operation, a working direction of rotation or conveying direction in which the promotion of the medium to be conveyed takes place, wherein seen in terms of working direction first Saugniere has a smaller extent in the circumferential direction than that in Regarding the working direction, second suction kidney. The position of the suction kidneys relative to an expansion space in the pump, the respective volumes and the delivery behavior of the pump can be influenced, the above arrangement leads to a safe maintenance of the dry sump while good absorption of still needed lubricant from the oil sump. As a result, a good lubrication performance is ensured, the dry sump remains oil-free.

The internal gear pump preferably has a pump housing which defines the same at least in sections outwardly, and an internal rotor and an external rotor, both of which are provided with teeth. The inner rotor is usually designed as an external gear, that is as a gear, which has a tooth whose tooth tips are aligned radially outward, whereas the external rotor is usually designed as an internal gear, that is as a wheel-shaped device which radially inwardly directionally recessed and externally has an inwardly directed toothing. The first and second suction kidneys are disposed in the pump housing and are separated from each other by at least a distance corresponding to a width of an intermeshing tooth pair of the outer rotor and the inner rotor. Preferably, both the first and the second suction kidney in a pump cover, that is arranged on the same side of the pump.

The compressor optionally has a suction gas supply into the compressor housing, through which gas to be compressed, in particular refrigerant, is supplied into the compressor housing, and a Sauggasauslass the Sauggaszuführung inside the compressor housing, wherein the Sauggasauslass is arranged on a compressor top. In a further possible embodiment, the housing has a suction gas inlet, via which suction gas can enter into the housing interior, in particular for cooling the electric motor, wherein the suction gas inlet is arranged on an upper side of the housing interior. Thus, in each case installation or operation of the compressor in an inclined position is made possible up to relatively large angles of inclination.

Alternatively or additionally, the Sauggasauslass is arranged such that the suction gas enters the same tangential to the compressor housing. Due to the tangential suction gas inlet into the compressor housing or compressor outer housing, an oil separation of over 90% of the oil present in the suction flow is already achieved. In the further course, a gravity separation takes place until the suction gas reaches the suction gas inlet of the housing (the intake opening in the motor housing). In the enclosure, additional oil that is still in the suction gas is injected by the centrifugal action of the rotor to the stator, where it can coagulate and run to the housing bottom. Here it is sucked off by the suction device or dry sump pump. In this respect, the two housings also form an excellent oil separator.

Further, the compressor may have a high pressure volume into which the compressed medium, in particular refrigerant is ejected after the compression process, wherein the high pressure volume is associated with a pulsation damper for damping pulsations in the ejected medium.

The compressor is configured in an optional embodiment for compressing CO ₂ .

Further features of the invention are specified in the subclaims.

The invention will be described below with reference to the accompanying drawings by means of exemplary embodiments. In the drawings show:

1 a sectional view of a first embodiment of a compressor according to the invention, wherein the cutting plane is directed in an axial direction of the compressor;

2 a section of the 1 ;

3 a view of the compressor of the 1 again in section, but with the cutting plane directed in a radial direction;

4 a detailed view of the 1 ;

5 again a section in a radial direction of the compressor, the cutting plane extending through an oil pump cover thereof;

6 a plan view of an oil pump of the compressor, wherein the oil pump cover is shown transparent;

7 a drive shaft of the compressor with piston and balance weight according to the compressor shown in the preceding figures;

In the compressor shown in the figures 10 it is a reciprocating compressor, more precisely a radial piston compressor, which (compare in particular 7 ) six pistons 12 which are arranged in corresponding cylinders (not shown) back and forth. The compressor has a compressor housing 14 on, which completely einhaust this in the illustrated embodiment. To drive the pistons 12 serves an electric motor 16 which by means of an enclosure 18 is housed. In the described compressor 10 it is a compressor 10 with oil sump lubrication, with an oil sump 20 (In a working or operating position or an installation position of the compressor 10 ) from a housing bottom 22 up to a predetermined oil level (oil level) 24 extends. The electric motor 16 is in one by the enclosure 18 limited housing interiors 26 arranged and extends together with the enclosure 18 in the oil sump 20 of the compressor 10 into it. The housing interior 26 is oil-free or oil sump-free. Alternatively to the feature that the housing interior 26 oil-free or Ölsumpffrei is, one could also say that the electric motor 16 in the interior of the housing 26 is arranged in a dry sump in the housing interior 26 is arranged.

The enclosure 18 has a suction opening 28 in the form of a recess which, by means of a first suction line 30 with a suction device or pump in the form of an internal gear pump 32 is in communication or fluid communication. The first suction line 30 connects the suction opening 28 with a first suction opening in the form of a first suction kidney 34 the internal gear pump 32 , As a result, a safe extraction of oil, which in particular from the lubricant circuit of the compressor in the enclosure 18 can penetrate ensured.

The internal gear pump 32 also has a second suction opening in the form of a second suction kidney 36 on, which via a second suction line 38 with the oil sump 20 is in fluid communication. This provides a reliable delivery of oil through the internal gear pump 32 ensured.

It remains at this point to mention that the compressor 10 a pressure circulation lubrication, which by means of the lubricant conveying device by conveying lubricant (oil) from the oil sump, which in the present embodiment by the internal gear pump 32 is formed, the lubrication of the lubrication points, in particular bearings and the like ensures. In the presently described embodiment, the internal gear pump is used 32 at the same time as a suction device, by means of which possibly in the Einhausungsinnenraum 26 penetrating oil can be sucked off. Due to the dual function of the internal gear pump 32 In a structurally simple embodiment, both a good lubricating performance and a reliable maintenance of the dry sump, in which the electric motor 16 is arranged, so that means a reliable assurance of oil sump clearance of the housing interior 26 of the compressor 10 , guaranteed.

The internal gear pump 32 has a pressure kidney for the removal of extracted oil 40 on, which via corresponding lines (not shown) with lubrication points, in particular bearing points which are to be lubricated, is in communication or fluid communication.

The internal gear pump 32 has a pump housing 42 with a pump cover 44 on. Both the pump housing 42 as well as the pump cover 44 limit the internal gear pump 32 outwardly. In the described embodiment of a compressor according to the invention 10 are both the first suckling kidney 34 as well as the second suckling kidney 36 as well as the print kidney 40 in the pump cover 44 each arranged in the form of corresponding recesses. In alternative embodiments, it would also be conceivable that the first suction kidney 34 and / or the second suction kidney 36 and / or the pressure kidney 40 not on the pump cover 44 but on the pump housing 42 for example on a pump cover 44 opposite side is / are arranged. In the described embodiment, the first suction kidneys 34 and the second suckling kidney 36 spatially spaced from each other. The distance is at least one width of a tooth of either an external rotor 46 the internal gear pump 32 or an indoor runner 48 the internal gear pump 32 (which are identical). The width of the tooth is defined as the extension at the base of the tooth. This will ensure that the first suckling kidney 34 associated volume and that of the second Saugniere 36 allocated volume in the pump, which is through the external rotor 46 and the inner rotor 48 be formed, stay separate from each other and the internal gear pump 32 if it is in a working running direction (in the embodiment described here, the pump rotates to the right, ie from the first suction kidney 34 in the direction of the second suction kidney 36 ), first oil from the interior of the housing 26 sucks and then oil from the oil sump refers.

The gear pump has, as mentioned above, in a normal operation, the working direction of rotation and seen in relation to the working direction first Saugniere, in the presently described embodiment of the first Saugniere 34 corresponds, has a smaller extent in the circumferential direction than the second suction kidney seen in relation to the working direction, which in the presently described embodiment of the second suction kidney 36 equivalent.

If you turned the direction of rotation of the pump, so would first of the larger (second) Saugniere 36 corresponding large chamber filled with oil, and then if that of the first (smaller) Saugniere 34 associated opening, the oil has the chance to escape in that direction. This results in a lower delivery rate. This applies when the Hauptölansaugung from the second Saugniere associated chamber and the dry sump brings only a subset of the lubricant. The subset is in particular 0% -50%, preferably 0% -40%, further preferably 0% -25%.

The compressor 10 also has a suction gas supply 50 on, which from the outside through the compressor housing 14 passes through and inside the compressor housing 14 empties. The suction gas supply 50 is arranged such that a Sauggasauslass 52 the suction gas supply 50 a tangential gas flow in the compressor 10 ensures improved oil separation. The suction gas outlet 52 is therefore arranged such that the suction gas tangential to the compressor housing 14 enters the same. That in the compressor housing 14 Introduced suction gas is then via a in the form of a recess in the enclosure 18 trained suction gas inlet 54 in the housing interior 26 in which the electric motor 16 is arranged, guided, wherein the suction gas is the electric motor 16 goes through and this cools. This is especially out 2 can be seen where the suction gas flow through corresponding arrows 56 . 58 and 60 is clarified. After flowing through the electric motor 16 the suction gas gets into the cylinder of the compressor 10 sucked, then in a compressed state in a high-pressure volume 62 to be expelled.

The high pressure volume 62 has for damping pulsations caused by the compression process, in particular the discharge of the pressurized gas or refrigerant in the high-pressure volume 62 caused in, a pulsation damper 64 on. This ensures at the same time for a low noise.

In the presently described embodiment, the compressor is 10 designed as a compressor for CO ₂ and formed in a hermetic construction. In alternative embodiments, a semi-hermetic design of the compressor is conceivable. It can therefore be stated that a compressor 10 According to the present invention, both hermetically and semi-hermetically.

It remains to be noted at this point that the pistons 12 are made of steel in the embodiment described above. This leads to a significantly reduced thermal expansion compared to aluminum pistons. Particularly when CO _{2 is used} as a refrigerant, steel pistons are highly suitable for absorbing or coping with the resulting forces. The low thermal expansion of the steel also ensures high operational reliability even at high compression ratios, where a large heat release is to be expected.

It is at this point explicitly on the 3 . 5 and 6 referred, from which the arrangement of the first Saugniere 34 and the second suckling kidney 36 as well as the print kidney 40 is clearly visible. Out 6 may also be the interior of the internal gear pump 32 be recognized, since in this figure the pump cover 44 is shown transparently. As a result, the interaction of external rotor can be very well 46 and inner rotor 48 recognize, which cause the oil production. In particular, it can be 6 the distance between the first suction kidney 34 and the second suckling kidney 36 recognize, as already mentioned above, at least one tooth width.

Finally, it should be noted that only in high-pressure volume 62 and the associated high-pressure line 66 , which serves to discharge the compressed medium from the compressor, high pressure is applied. Otherwise, the entire remaining interior of the compressor housing is located 14 at low pressure (suction pressure).

Out 7 is the construction of the drive device (drive shaft 68 ) including the piston, which by means of connecting rods 70 in a radial direction are reciprocated, can be seen. To increase the smoothness finds a mass balance by means of appropriate appropriate mass balance weights 72 and 74 instead of.

Although the invention is described with reference to an embodiment with a fixed combination of features, but it also includes the conceivable further advantageous combinations, as they are given in particular, but not exhaustive, by the dependent claims. All disclosed in the application documents features are claimed as essential to the invention, as far as they are new individually or in combination over the prior art.

LIST OF REFERENCE NUMBERS

10

compressor

12

piston

14

compressor housing

16

electric motor

18

housing

20

oil sump

22

Housing bottom

24

oil level

26

Housing interior

28

suction

30

First suction line

32

Internal gear pump

34

First suckling kidney

36

Second suckling kidney

38

Second suction line

40

pressure kidney

42

pump housing

44

pump cover

46

external rotor

48

internal rotor

50

Sauggaszuführung

52

Sauggasauslass the Sauggaszuführung 50

54

suction gas

56, 58, 60

arrow

62

High volume printing

64

pulsation dampers

66

High-pressure line

68

drive shaft

70

pleuel

72, 74

Counterbalancing weight

Claims (11)

Compressor ( 10 ), in particular refrigerant compressor, with a compressor housing ( 14 ) and at least one piston ( 12 ), which is arranged in a cylinder reciprocable and by an electric motor ( 16 ), wherein the compressor ( 10 ) has an oil sump lubrication, wherein the oil sump ( 20 ) in the compressor ( 10 ) from a housing bottom ( 22 ) up to an oil level ( 24 ), wherein the compressor ( 10 ) comprises a pressure circulation lubrication with a lubricant delivery device, wherein the lubricant delivery device is in communication with the oil sump and is provided for the suction of lubricant from the oil sump, characterized in that the electric motor ( 16 ) an enclosure ( 18 ) with a through the enclosure ( 18 ) limited housing interior ( 26 ), the electric motor ( 16 ) in the housing interior ( 26 ) is arranged and the electric motor ( 16 ) including housing ( 18 ) into the oil sump ( 20 ) of the compressor ( 10 ), whereby the enclosure ( 18 ) a suction opening ( 28 ) equipped with a suction device, which is used for the extraction of into the housing interior ( 26 The suction device and the lubricant delivery device are implemented by a single gear pump having a first and a second suction port, wherein the first and the second suction port are separated from each other, and wherein the first suction port for suction from into the housing interior ( 26 ) is provided lubricant, and the second suction port for sucking lubricant from the oil sump ( 20 ) is provided. Compressor ( 10 ) according to claim 1, characterized in that the gear pump is an internal gear pump ( 32 ). Compressor ( 10 ) according to one of the preceding claims, characterized in that the gear pump has at least two gears, which have gear teeth, wherein the gear teeth have a tooth width, which is measured in particular at its base or at its half-height, wherein the first and the second suction from each other are separated by at least one tooth width. Compressor ( 10 ) according to one of the preceding claims, characterized in that the gear pump is a pressure kidney ( 40 ) to the outlet of conveyed oil, and that the gear pump as a first suction port a first Saugniere ( 34 ) and as a second suction opening a second Saugniere ( 36 ), wherein the first suction kidney ( 34 ) via a first suction line ( 30 ) with the housing interior ( 26 ) and wherein the second suckling kidney ( 36 ) via a second suction line ( 38 ), which are in the oil sump ( 20 ) of the compressor ( 10 ), with the oil sump ( 20 ). Compressor ( 10 ) according to one of the preceding claims, characterized in that the gear pump in a normal operation has a working direction of rotation and that seen in relation to the working direction first Saugniere ( 34 ) a smaller extent in the circumferential direction than the second suction kidney seen in relation to the working direction ( 36 ). Compressor ( 10 ) according to one of claims 2 to 5, characterized in that the internal gear pump ( 32 ) a pump housing ( 42 ), which the internal gear pump ( 32 ) at least partially limited to the outside, and an inner rotor ( 48 ) and an external rotor ( 46 ), which are both provided with teeth, wherein the first and the second Saugniere ( 34 . 36 ) in the pump housing ( 42 ), in particular a pump cover ( 44 ) and wherein the first and the second suction kidneys ( 34 . 36 ) by at least a distance equal to the width of an intermeshing tooth pair of the outer rotor ( 46 ) and the inner rotor ( 48 ), are separated from each other. Compressor ( 10 ) according to one of the preceding claims, characterized in that the compressor ( 10 ) a suction gas supply ( 50 ) in the compressor housing ( 14 ), through which gas to be compressed, in particular refrigerant, into the compressor housing ( 14 ), and a Sauggasauslass ( 52 ) of the suction gas supply ( 50 ) inside the compressor housing ( 14 ), wherein the Sauggasauslass is arranged on a compressor top. Compressor ( 10 ) according to one of the preceding claims, characterized in that the compressor ( 10 ) a / the suction gas supply ( 50 ) in the compressor housing ( 14 ), through which gas to be compressed, in particular refrigerant, into the compressor housing ( 14 ), and a suction gas outlet (s) ( 52 ) of the suction gas supply ( 50 ) inside the compressor housing ( 14 ), wherein the Sauggasauslass ( 52 ) is arranged such that the suction gas tangential to the compressor housing ( 14 ) enters the same. Compressor ( 10 ) according to one of the preceding claims, characterized in that the enclosure ( 18 ) a suction gas inlet ( 54 ), via which suction gas into the housing interior ( 26 ), in particular for cooling the electric motor ( 16 ), wherein the suction gas inlet at an upper side of the housing interior ( 26 ) is arranged. Compressor ( 10 ) according to one of the preceding claims, characterized in that the compressor ( 10 ) a high pressure volume ( 62 ), in which the compressed medium, in particular refrigerant, is ejected after the compression process, and in that the high-pressure volume ( 62 ) a pulsation damper ( 64 ) for damping pulsations in the ejected medium. Compressor ( 10 ) according to one of the preceding claims, characterized in that the compressor ( 10 ) is adapted for compressing CO ₂ as a medium to be compressed or the compressor ( 10 ) CO _{2 has} to be compressed as a medium.

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