EP3507493A1

EP3507493A1 - Compressor

Info

Publication number: EP3507493A1
Application number: EP17761188.6A
Authority: EP
Inventors: Alexander LIBERT; Markus BESEMER; Wolfgang SANDKÖTTER
Original assignee: GEA Bock GmbH
Current assignee: Bock GmbH
Priority date: 2016-09-02
Filing date: 2017-08-31
Publication date: 2019-07-10
Anticipated expiration: 2037-08-31
Also published as: WO2018041403A1; CN109642562B; DE102016010567A1; EP3507493B1; CN109642562A

Abstract

The invention relates to a compressor (10), particularly a refrigerant compressor, comprising a compressor housing (14) and at least one piston (12) arranged in a cylinder in a reciprocal manner and driven by an electric motor (16), said compressor (10) having an oil sump lubrication, the oil sump (20) extending in the compressor (10) from a housing lower side (22) to an oil filling level (24), and a force-feed lubrication with a lubricant pumping device, the lubricant pumping device being connected to the oil sump and used to suck lubricant out of the oil sump, the electric motor (16) comprising a casing (18) with a casing interior (26) defined by the casing (18), the electric motor (16) being arranged in the casing interior (26) and the electric motor (16) together with the casing (18) extending into the oil sump (20) of the compressor (10). The casing (18) comprises a suction opening (28) connected to a suction device used to suck up lubricant that reaches the casing interior (26), the suction device and the lubricant pumping device being operated by a single toothed wheel pump (32) having a first (34) and a second (36) suction opening, where the first and the second suction openings are separate from each other, and the first suction opening (34) is used to suck up lubricant reaching the casing interior (26), and the second suction opening (36) is used to suck up lubricant from the oil sump (20).

Description

compressor

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 generation of compressed air (compressed air) for a variety of purposes, such as filling tires, respirators, etc. Another example is

Compressing (in particular technical) gases for storage and transport thereof, for example in corresponding 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, especially due to the increasing air conditioning of rooms and vehicles and also due to a steadily growing need for cooling of goods often

Application in the compression or compression of refrigerants such as R134a (tetrafluoroethane) or R744 (C0 ₂ ).

In many applications, in particular refrigeration and air conditioning applications, compressors used are reciprocating compressors, by way of example

1

CONFIRMATION COPY Axial piston compressors and radial piston compressors may be mentioned. 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.

Based on the above-discussed prior art, it is the task of

present invention, a compressor, in particular compressors for compressing gases, continue to specify 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, in particular for compressing refrigerant

Compressor housing and at least one piston, the back in a cylinder and

is arranged movable and which is driven by an electric motor on. The compressor further comprises an oil sump lubrication, wherein the oil sump in the

Compressor extends in a working position or an installation position of a lower housing or lower housing 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, the one

Enclosed interior limited in which the electric motor is arranged, wherein the electric motor together with housing hineinerstreckt into the oil sump of the compressor and wherein the housing has a suction opening, which provided with a suction device for the extraction of passing into the housing interior lubricant is in communication with the suction device and the

Lubricant conveying 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 is provided for the extraction of entering into the housing interior lubricant, and the second suction port for suction is provided by lubricant from the oil sump. In other words, the electric motor of the compressor is in a so-called. Dry sump arranged because of the arranged in the housing

Suction opening Oil or lubricant, which gets into the interior of the housing (especially leak) can be sucked off.

This causes the engine or parts of the engine are not in the oil, but the engine is located in the dry sump. This will be a possible

Condensation effect of the oil avoided, which could possibly lead to fault currents, especially when starting the compressor and thus increase the Ausfa! L risk 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 half its height, wherein the first and the second suction from each other by at least one tooth width from each other are separated.

The gear pump may have a pressurized kidney to discharge discharged oil.

Furthermore, the gear pump as the first and second intake ports, a first and a second Saugniere, wherein the first Saugniere via a first suction line with the Einhausungsinnenraum in communication or, fluid communication is 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 Saugniere and / or the second Saugniere alternatively directly with the Housing interior / oil sump may be in communication or may be arranged on or in selbigem. 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 Respect to the

Working direction seen second suction kidney. Due to the position of the suction kidneys relative to an expansion space in the pump, the respective volumes and

Conveying behavior of the pump influenced, the above arrangement leads to a safe maintenance of the dry sump at the same time good absorption of still needed lubricant from the oil sump. This is also a good one

Lubricating guaranteed, 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 spaced from each other by at least a distance corresponding to a width of an intermeshing tooth pair of the outer rotor and the outer

Internal rotor corresponds, separated from each other. 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 feed 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 on a compressor top

is arranged. In a further possible embodiment, the housing has a Suction gas inlet, via which suction gas into the housing interior, in particular for cooling the electric motor, can occur, wherein the suction gas inlet is arranged on an upper side of the Einhausungsinnenraums. 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. Through the tangential

Suction gas entering the compressor housing or compressor outer housing is already achieved an oil separation of over 90% of the oil in the suction flow. 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 in an optional embodiment for compressing C0 ₂

educated.

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:

Fig. 1 is a sectional view of a first embodiment of an inventive

Compressor, wherein the cutting plane is directed in an axial direction of the compressor; Fig. 2 shows a detail of Fig. 1;

Fig. 3 is a view of the compressor of Figure 1, again in section, but with the cutting plane directed in a radial direction.

Fig. 4 is a detail view of Fig. 1;

5 again shows a section in a radial direction of the compressor, wherein the sectional plane extends through an oil pump cover thereof;

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

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

The compressor 10 shown in the figures is a

Reciprocating compressor, more specifically a radial piston compressor, which

(compare in particular FIG. 7) has six pistons 12, which in

corresponding cylinders (not shown) are arranged back and forth. The compressor has a compressor housing 14, which this in the illustrated

Fully embed embodiment. To drive the piston 12 is an electric motor 16, which is housed by means of an enclosure 18. The described compressor 10 is a compressor 10 with oil sump lubrication, wherein a

Oil sump 20 (in a working or operating position or an installation position of the

Compressor 10) from a housing bottom 22 to a predetermined oil level (oil level) 24 extends toward. The electric motor 16 is arranged in a housing interior 26 delimited by the housing 18 and extends together with the housing 18 into the oil sump 20 of the compressor 10. The housing interior 26 is oil-free or oil sump-free. As an alternative to the feature that the housing interior 26 is oil-free or oil-sump-free, it could also be said that the electric motor 16, which is arranged in the housing interior 26, in a dry sump in the

Housing interior 26 is arranged. The housing 18 has a suction opening 28 in the form of a recess, which is in communication or fluid communication by means of a first suction line 30 with a suction device or pump in the form of an internal gear pump 32. The first suction line 30 connects the suction opening 28 to a first suction opening in the form of a first suction kidney 34 of the internal gear pump 32

Extraction of oil, which in particular from the lubricant circuit of the compressor can penetrate into the housing 18 ensured.

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

It remains to mention at this point that the compressor 10 a

Pressure circulation lubrication, which by means of the lubricant conveying device by promoting lubricant (oil) from the Öisumpf, which is formed in the present embodiment by the internal gear pump 32, the lubrication of the lubrication points, in particular bearings and the like ensures. In the presently described embodiment, the internal gear pump 32 simultaneously serves as

Suction device, by means of which possibly in the housing interior 26th

penetrating oil can be sucked off. Due to the dual function of

Internal gear pump 32 is in a structurally simple design, both a good lubricating performance and a reliable maintenance of the dry sump, in which the electric motor 16 is arranged, that is, therefore, a reliable

Ensuring the oil sump of the housing interior 26 of the compressor 10, ensured.

The internal gear pump 32 has to discharge discharged oil on a pressure kidney 40, which via corresponding lines (not shown) with lubrication points,

In particular bearing points which are to be lubricated, in conjunction or

Fluid communication is.

The internal gear pump 32 has a pump housing 42 with a pump cover 44. Both the pump housing 42 and the pump cover 44 limit the Internal gear pump 32 to the outside. In the described embodiment of a compressor 10 according to the invention, both the first suction kidney 34 and the second suction kidney 36 and the pressure kidney 40 in the pump cover 44 are each in shape

arranged 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 is not arranged on the pump cover 44 but on the pump housing 42, for example on a side opposite the pump cover 44. In the described embodiment, the first suction kidney 34 and the second suction kidney 36 are spaced apart from each other. The distance is at least one width of a tooth of either an external rotor 46 of the internal gear pump 32 or an internal rotor 48 of 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 ensures that the volume associated with the first suction kidney 34 and the volume associated with the second suction kidney 36 in the pump passing through the outer runner 46 and the second suction kidney 36

Internal rotor 48 are formed, remain separated from each other and the

Internal gear pump 32, provided they are in a working direction (in the here

described embodiment, the pump rotates to the right, i. from the first

Saugniere 34 in the direction of the second suction kidney 36) is operated, first sucks oil from the housing interior 26 and then obtains oil from the oil sump.

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

If one were to turn the direction of rotation of the pump, the larger (second) suction chamber 36 corresponding large chamber would first be filled with oil, and then when the first (smaller) Saugniere 34 associated opening is reached, the oil has the chance in to escape this direction. This results in a lower

Capacity. This applies if the Hauptölansaugung from the second Saugniere associated chamber and the dry sump is only a subset of

Lubricant brings. The subset is in particular 0% - 50%, preferably 0% - 40%, still preferred 0% - 25%.

The compressor 10 further has a suction gas feed 50, which passes from the outside through the compressor housing 14 and opens into the interior of the compressor housing 14. The suction gas supply 50 is arranged such that a Sauggasauslass 52 of the Sauggaszuführung 50 ensures a tangential gas flow in the compressor 10 for improved oil separation. The Sauggasauslass 52 is thus arranged such that the suction gas enters the compressor housing 14 tangentially thereto. That in the

Compressor housing 14 introduced suction gas is then via a in the form of a

Recess in the housing 18 trained Sauggaseintritt 54 in the

Housing interior 26, in which the electric motor 16 is arranged, guided, wherein the suction gas passes through the electric motor 16 and thereby cools. This can be seen in particular from Figure 2, where the suction gas flow is illustrated by corresponding arrows 56, 58 and 60. After flowing through the electric motor 16, the suction gas is sucked into the cyuters of the compressor 10 to then be discharged in a compressed state into a high-pressure volume 62.

The high-pressure volume 62 has for damping pulsations, which by the

Compression process, in particular the discharge of the pressurized gas or refrigerant are caused in the high-pressure volume 62, a

Pulsation damper 64 on. This ensures at the same time for a low noise.

In the presently described embodiment, the compressor 10 is designed as a compressor for C0 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 can be designed both hermetically and semi-hermetically.

It remains to be noted at this point that the pistons 12 in the above

described embodiment are made of steel. This leads to a significantly reduced thermal expansion compared to aluminum pistons. Particularly when C0 _{2 is used} as a refrigerant, steel pistons are highly suitable for absorbing or coping with the resulting forces. Also ensures the low thermal Expansion of the steel for a high level of operational reliability even at high levels

Compression ratios where a large heat release is expected.

Reference should be made at this point explicitly to the figures 3, 5 and 6, from which the arrangement of the first suction kidney 34 and the second suction kidney 36 and the pressure kidney 40 is clearly visible. From Figure 6, the interior of the internal gear pump 32 can be further detected, since in this figure, the pump cover 44 is shown transparent.

As a result, the interaction of outer rotor 46 and inner rotor 48 can be seen very well, which cause the oil production. In particular, the distance between the first suction kidney 34 and the second suction kidney 36 can be seen from FIG. 6, which, as already mentioned above, amounts to at least one tooth width.

Finally, it should be noted that only in the 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 14 is at low pressure (suction pressure).

From Fig. 7, the construction of the drive device (drive shaft 68) together with the piston, which are reciprocated by means of connecting rods 70 in a radial direction, can be seen. To increase the smoothness, mass balance takes place by means of appropriate suitable mass balance weights 72 and 74.

Although the invention will be described with reference to an embodiment with a fixed combination of features, it also includes the conceivable further advantageous

Combinations as specified in particular, but not exhaustive, by the subclaims. All features disclosed in the application documents are claimed as essential to the invention insofar as they are novel individually or in combination with respect to the prior art.

LIST OF REFERENCE NUMBERS

10 compressors

12 pistons

14 compressor housing electric motor

housing

oil sump

Housing bottom

oil level

Housing interior

suction

First suction line

Internal gear pump

First suckling kidney

Second suckling kidney

Second suction line

pressure kidney

pump housing

pump cover

external rotor

internal rotor

Sauggaszuführung

Sauggasauslass the Sauggaszuführung 50 Sauggaseintritt

, 58, 60 arrow

High volume printing

pulsation dampers

High-pressure line

drive shaft

pleuel

, 74 Mass balance weight

Claims

claims

1. compressor (10), in particular Kältemitteiverdichter, with a compressor housing (14) and at least one piston (12), the back in a cylinder and

is arranged movable and which is driven 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) extends to an oil level (24) wherein the compressor (10) comprises a pressure circulation lubrication with a lubricant conveying device, wherein the

Lubricant conveying 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) has an enclosure (18) with a housing interior (26) delimited by the housing (18), the electric motor (16) being arranged in the housing interior (26) and the electric motor (16) together with

Housing (18) extends into the oil sump (20) of the compressor (10), wherein. the housing (18) has a suction opening (28), which with a

Suction device, which is provided for the extraction of in the housing interior (26) passing lubricant is in communication, said

Extraction device and the lubricant delivery device are implemented by a single gear pump, which has a first and a second

Suction opening, wherein the first and the second suction port are separated from each other, and wherein the first suction port for the extraction of in the Housing interior (26) passing lubricant is provided, and the second suction port for sucking lubricant from the oil sump (20) is provided.

2. compressor (10) according to claim 1,

characterized in that

the gear pump is an internal gear pump (32).

3. compressor (10) according to any 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 half its height, wherein the first and the second suction are separated from each other by at least one tooth width.

4. compressor (10) according to any one of the preceding claims,

characterized in that

the gear pump has a pressure kidney (40) to the outlet of conveyed oil, and that the gear pump as a first suction port, a first suction kidney (34) and as a second suction port, a second suction kidney (36), wherein the first suction kidney (34) via a first suction line (30) is in communication with the housing interior (26) and wherein the second suction kidney (36) via a second suction line (38) extending into the oil sump (20) of the compressor (10), with the oil sump (20) in Connection stands.

5. compressor (10) according to any one of the preceding claims,

characterized in that

the gear pump has a working direction of rotation in a normal operation, and that the first suction kidney (34) seen in the working direction has a smaller extent in the circumferential direction than that in relation to the one

Working direction seen second suction kidney (36).

6. compressor (10) according to any one of claims 2 to 5, characterized in that

the internal gear pump (32) includes a pump housing (42) which at least partially outwardly circumscribes the internal gear pump (32), and an internal rotor (48) and external rotor (46) both provided with teeth, the first and second second suction kidney (34, 36) in the pump housing (42), in particular a pump cover (44) are arranged, and wherein the first and the second suction kidney (34, 36) by at least a distance equal to the width of an intermeshing tooth pair of external rotor (34). 46) and the inner rotor (48), are separated from each other.

7. compressor (10) according to any one of the preceding claims,

characterized in that

the compressor (10) a Sauggaszuführung (50) in the compressor housing (14) through which to be compressed gas, in particular refrigerant, in the

Compressor housing (14) is supplied, and a Sauggasauslass (52) of the

Suction gas supply (50) inside the compressor housing (14), wherein the Sauggasauslass is arranged on a compressor top.

8. compressor (10) according to any one of the preceding claims,

characterized in that

the compressor (10) a / the suction gas supply (50) in the compressor housing (14) through which to be compressed gas, in particular refrigerant, in the

Compressor housing (14) is supplied, and a / the Sauggasauslass (52) of the Sauggaszuführung (50) inside the compressor housing (14), wherein the Sauggasauslass (52) is arranged such that the suction gas tangential to

Compressor housing (14) enters it.

9. compressor (10) according to any one of the preceding claims

characterized in that

the housing (18) has a suction gas inlet (54) via which suction gas can enter into the housing interior (26), in particular for cooling the electric motor (16), the suction gas inlet at an upper side of the

Housing interior (26) is arranged.

10. compressor (10) according to any one of the preceding claims,

characterized in that

the compressor (10) has a high-pressure volume (62) into which the compressed medium, in particular refrigerant, is ejected after the compression process, and in that the high-pressure volume (62) has a pulsation damper (64) for damping pulsations in the ejected medium.

11. Compressor (10) according to one of the preceding claims,

characterized in that

the compressor (10) is adapted to compress C0 ₂ as a medium to be compressed or the compressor (10) has C0 ₂ as a medium to be compressed.