Compressor oil recovery device and compressor system with such a compressor oil recovery device

Description

[0001] The present invention relates to a compressor oil receiving device for a compressor system for filling with a compressor oil for further distribution into the compressor system and to a compressor system with such a compressor oil receiving device.

[0002] Depending on the type of compressor, such as oil-lubricated screw compressors, components of the compressor system are lubricated and / or cooled by compressor oil. During maintenance, the oil level is checked regularly and topped up with new compressor oil if necessary. For this purpose, the compressor oil is poured into a receiving volume through an oil filler opening. The receiving volume is larger than the maximum oil level intended for consumption. If more compressor oil is poured into the receiving volume than is required for the maximum oil level, overfilling may occur, which can disrupt operation or damage components.

[0003] For example, US 4,478,054 A relates to a screw compressor for a closed-circuit refrigeration system, such as an air conditioning system for a bus or similar vehicle. The screw compressor is connected in series with a condenser and an evaporator, the evaporator being in an elevated position relative to the compressor, and uses an evaporable refrigerant miscible with a lubricating oil used to lubricate the moving components of the screw compressor. The screw rotors are mounted in parallel, intersecting bores in the compressor housing. A vane lies below the intermeshing rotors and forms part of the screw compressor shell, with the rotors leading to a suction port connected to the outlet side of the evaporator above the rotors.A high-pressure outlet at one end of the meshing rotors leads to an auxiliary chamber containing a relief cylinder that drives the vane and discharges into a casing outlet at the top, leading to the condenser. An oil separator is located in the auxiliary chamber above the relief cylinder. An oil drain port leads from the auxiliary chamber to an oversized oil pan in the casing below the rotors. The vane slides in a recess within the casing below the rotors. On the suction side of the recess, another drain port leads to the sump through a drain check valve.

[0004] US 4 475 876 ​​A relates to a system for flushing lubricating oil from oil connecting lines and a cooler of an oil circulation system for a screw compressor when the compressor is switched off, wherein the lubricating oil is pressed into a container arranged within a heated housing so that when the compressor is restarted in extremely cold weather, no cold, viscous oil is present in the oil connecting lines and the cooler, thus avoiding delays in starting up the compressor.

[0005] EP 0 030 619 A1 relates to a rotor compressor, in particular a screw compressor with lubricant supply to and drainage from the shaft bearings. Each rotor shaft is surrounded by an annular drainage chamber for discharging lubricant and gas leakage between the shaft bearing and the working chamber of the compressor accommodating the rotor, and by a sealing arrangement sealing the shaft. The drainage chambers are connected via drainage openings to closed collecting chambers subject essentially to the intake pressure of the compressor, from which gas is returned to the intake side or the working chamber of the compressor, and lubricant is returned to the lubricant circuit. A short sealing element is arranged between each drainage chamber and the working chamber of the compressor.The collecting chambers next to the bearings, which are located on the side facing away from the working chamber, are also arranged to collect the lubricant escaping on this side. According to one embodiment, the collecting chambers or a channel connecting them are connected to a separator tank via an optionally closable opening. The gas chamber of this separator tank is connected to a lubricant circuit via a lubricant line. On the pressure side of the compressor, another separator tank is arranged for lubricants carried along by the gas flow. This separator tank is connected to the first separator tank via a connecting line with a valve actuated by a level switch.

[0006] In view of the above statements, the object of the present invention is to provide a compressor oil receiving device for a compressor system for filling with a compressor oil for forwarding into the compressor system and a compressor system with such a compressor oil receiving device, by means of which the risk of overfilling a receiving volume for a compressor oil can at least be reduced.

[0007] This object is achieved by a compressor oil collecting device and a compressor system comprising such a compressor oil collecting device according to the independent claims. Advantageous developments of the invention are contained in the dependent claims.

[0008] According to the invention, a compressor oil receiving device for a compressor system for filling with compressor oil for further supply to the compressor system comprises a housing that forms a receiving volume for the compressor oil, and an oil filler neck with a filler opening on a side facing away from the receiving volume and an outlet opening on a side facing the receiving volume. The oil filler neck forms a housing opening for filling the receiving volume with the compressor oil, and the outlet opening is arranged such that, by filling the receiving volume, an air volume enclosed by the housing on the one hand and the filled compressor oil on the other hand can be formed in the receiving volume.

[0009] Overfilling of the receiving volume is thus prevented by the fact that the air volume enclosed by the housing on the one hand and the filled compressor oil on the other hand forms an air cushion in the receiving volume, which limits the filling of the exception volume.

[0010] The oil filler neck can be formed by an opening in the housing, with the filler opening being formed by a housing wall facing away from the receiving volume, and the outlet opening being formed by a housing wall facing the receiving volume. The extension of the oil filler neck perpendicular to the opening surfaces of the filler opening and the outlet opening thus corresponds to the thickness of the housing wall in this area. However, the oil filler neck preferably has a greater extension in a direction perpendicular to the opening surfaces, so that upon reaching the intake limit, the compressor oil does not immediately flow out of the oil filler neck on a side facing away from the receiving volume due to the trapped air.

[0011] The outlet opening of the oil filler neck can be arranged such that the opening surface of the outlet opening faces the level surface of the compressor oil being filled or to be filled into the receiving volume, in particular substantially parallel thereto. Alternatively, the outlet opening can also extend in the direction of the rise height of the compressor oil.

[0012] In one embodiment, the oil filler neck extends at least partially into the enclosed air volume.

[0013] The intended extension of the oil filler neck can thus be achieved with a reduced interference contour by the oil filler neck on a side of the housing facing away from the receiving volume. In particular, if the outlet opening of the oil filler neck is opposite the level of the compressor oil being filled or to be filled into the receiving volume, the air volume enclosed by the housing on the one hand and the filled compressor oil on the other hand can be easily formed between the outlet opening and a housing area adjoining the outlet opening in the direction of the compressor oil rise. The housing can thus also be easily retrofitted by inserting a suitable oil filler neck.

[0014] In particular, the filling opening and the outlet opening are arranged at different heights in the direction of a rising height of the compressor oil in the receiving volume and the distance of the filling opening to the respective level of the compressor oil in the receiving volume is greater than the distance of the outlet opening to this respective level, at least until a specified maximum oil level is reached.

[0015] In the direction of gravity, the filling opening is thus located above the outlet opening. The filling process therefore requires no additional aids such as pumps or the like. In particular, with appropriate alignment, air can continue to escape until the outlet opening is completely covered by the compressor oil level in the intake volume. Once the outlet opening is covered, the trapped air volume can then be formed in the intake volume.

[0016] According to one embodiment, the position of the outlet opening corresponds to the maximum oil level.

[0017] The maximum oil level refers to the maximum oil level specified for a particular compressor or compressor system and / or the particular operation to support trouble-free operation. Accordingly, the specified maximum oil level can be directly determined by the position of the outlet opening relative to the housing. In other words, the position of the outlet opening of the oil filler neck not only defines a maximum filling volume, but also specifically the specified maximum oil level.

[0018] According to a further development, the position of the outlet opening is adjustable.

[0019] The maximum oil level or the maximum filling volume for the compressor oil can also be adjusted accordingly. For example, the housing can have multiple receptacles for the oil filler neck, allowing the outlet opening to be positioned at different locations. Any receptacles not provided for can be closed with a blind plug, for example.

[0020] In particular, the oil filler neck is movable at least in part in the direction of the rising height of the compressor oil in the receiving volume.

[0021] For example, the oil filler neck can be screwed into the housing, so that the position of the outlet opening in the housing's receiving volume, the maximum oil level, or a maximum filling volume can be specified via the screw-in depth. Alternatively or additionally, the oil filler neck can also be rotatably mounted about an axis perpendicular to its direction of extension from the filler opening to the outlet opening and parallel to the level surface of the compressor oil, in order to be movable in the direction of the compressor oil rise. Such a pivot point is preferably located substantially at the height of the oil filler neck's receptacle in the housing, for example to keep the sealing effort to a minimum and to ensure the enclosed air volume.

[0022] In a further development, the oil filler neck has a position indicator device configured to indicate a position of the outlet opening.

[0023] The position indicator device can be a visual, acoustic and / or other signaling or indication device that allows an indication and / or inference to be made regarding a position of the outlet opening and / or a maximum filling volume, in particular a maximum oil level. For example, at least one distance sensor can be provided at the outlet opening, which detects the distance between the outlet opening and a housing wall opposite it at the height of the compressor oil rise, or another reference point. The distance can be displayed in analog form, for example as an absolute value, or digitally with regard to predetermined target values ​​or limit values, i.e. reaching the target value or limit value or deviation therefrom. The indication can be provided visually by a display and / or a signal light and / or acoustically by a signal tone, for example with a different frequency depending on the distance.Alternatively or additionally, a signaling connection of a blocking device can be provided which, if the outlet opening is not positioned correctly, blocks the filling via the oil filler neck, for example by closing it, and only releases it again when the position is within a permissible range.

[0024] In particular, the filling opening protrudes beyond a side of the housing facing away from the receiving volume at least until a predetermined depth of movement of the oil filler neck into the receiving volume is reached and has a scale as a position indicator in this projecting area.

[0025] The scale is thus readable from the outside and allows for easy checking of the position of the oil filler neck's outlet opening. The scale can be continuous or in predetermined increments. For example, the scale can directly indicate a screw-in depth and thus a corresponding position change, or it can directly indicate a filler volume tailored to the respective housing or intake volume. The scale can also include multiple scales, allowing the oil filler neck to be used for different housings or intake volumes of different compressor systems.

[0026] In one embodiment, the compressor oil receiving device has a level indicator which indicates at least a minimum oil level and / or the maximum oil level.

[0027] Similar to the position indicator for the outlet opening of the oil filler neck, the fill level indicator can indicate a fill level using optical, acoustic, and / or other signaling techniques. For example, a float can be provided that activates a corresponding switch when the specified minimum and / or maximum oil level is reached. The activation of the switch can then, in turn, be converted into an optical and / or acoustic signal. Alternatively or additionally, a distance sensor can be used that detects the distance to a level surface in the direction of the rise of the compressor oil in the receiving volume or to a corresponding float. The acoustic and / or visual indication of the fill level, in particular at least the minimum and / or maximum oil level, can also be analog or digital.Likewise, if the level indicator is connected to a blocking device via a signal, it can block further oil filling via the oil filler neck when the maximum oil level is detected and / or activate a pumping device to drain excess compressor oil.

[0028] In particular, the level indicator is designed as at least one oil sight glass in the housing, which extends at least in the area of ​​the minimum oil level and / or the maximum oil level in the direction of the rising height of the compressor oil in the receiving volume.

[0029] The oil sight glass allows the minimum and / or maximum oil levels to be easily read directly from the outside. Specifically, the oil sight glass extends from the minimum oil level to the maximum oil level in the direction of the compressor oil rise. The beginning of the oil sight glass, pointing downwards in the direction of gravity, corresponds to the minimum oil level, for example, while the end of the oil sight glass, pointing upwards in the direction of gravity, corresponds to the maximum oil level.

[0030] According to a further development, the oil sight glass is arranged and / or dimensioned in such a way that the position of the outlet opening of the pressure nozzle in the receiving volume can also be seen via the oil sight glass.

[0031] The oil sight glass can thus be used both as a level indicator for the compressor oil in the intake volume and as a position indicator for the discharge port. In particular, it can also be used to detect a leak in the housing if the compressor oil level continues to rise above the discharge port of the oil filler neck, contrary to the intended design.

[0032] In one embodiment, the oil sight glass and / or an adjacent area of ​​the housing has a scale.

[0033] The scale preferably includes at least the minimum and / or maximum oil levels. The oil sight glass with the corresponding scale preferably extends beyond the minimum and maximum oil levels at the height of the compressor oil level rise, in order to better observe the level line in the area of ​​the minimum and maximum oil levels.

[0034] If the scale is provided on the oil sight glass, the scale can be easily adapted to different conditions and / or specifications by replacing the oil sight glass.

[0035] In a further aspect, the present invention relates to a compressor system having a compressor oil receiving device as described above, wherein the receiving volume for the compressor oil is formed at least partially by an oil sump of the compressor system.

[0036] The compressor oil collection device can thus be installed directly in existing areas of the compressor system, enabling a compact design. In particular, the compressor system's oil sump can be easily retrofitted with a suitable oil filler neck.

[0037] In one embodiment, the compressor system comprises a screw compressor.

[0038] The screw compressor is specifically an oil-lubricated screw compressor.

[0039] Further configurations and advantages of the compressor system arise analogously to the possible configurations and advantages of the compressor oil collection device. Corresponding features can therefore also be directly transferred to the compressor system when using the compressor oil collection device.

[0040] The invention is explained in more detail below using exemplary embodiments with reference to the accompanying figures. The figures show in detail: Figure 1 a schematic cross-sectional view of a compressor oil collecting device according to an exemplary prior art; Figure 2 a schematic cross-sectional view of a compressor oil collecting device according to a first exemplary embodiment of the present invention; and Figure 3a schematic cross-sectional view of a compressor oil receiving device according to a second exemplary embodiment of the present invention.

[0041] Figure 1shows a schematic cross-sectional view of a compressor oil holding device according to an exemplary prior art. The compressor oil holding device has a compressor housing A, which forms a holding volume for a compressor oil C. In an upper region of the housing in the direction of gravity during correct use, a housing opening is designed as an oil filler opening B, through which the compressor oil C can be filled into the holding volume of the compressor housing. The oil filler opening B is arranged above a maximum oil level E in the direction of gravity during correct use of the compressor. Accordingly, compressor oil can also be filled into the holding volume above the maximum oil level E. A filling quantity exceeding the maximum oil level E can disrupt the operation of the compressor.To monitor the level of compressor oil C in the receiving volume of compressor housing A, compressor housing A has an oil sight glass D as a level indicator, which has a scale that indicates at least a minimum oil level F and a maximum oil level E. Avoiding overfilling therefore requires constant observation of the level of compressor oil C in the receiving volume of compressor housing A via oil sight glass D during a filling process. Damage to and / or contamination of the oil sight glass as well as subjective viewing angles during observation and lighting conditions can influence the readability and accuracy.

[0042] To reduce or even avoid the risk of overcrowding, Figure 2a schematic cross-sectional view of a compressor oil receiving device 10 according to a first exemplary embodiment of the present invention. The compressor oil receiving device 10 has a compressor housing 1, which forms a receiving volume for a compressor oil 3. In addition, the compressor oil receiving device 10 has an oil filler neck 2, which is formed integrally with the compressor housing 1. The integral formation of the oil filler neck 2 with the compressor housing 1 improves the tightness of the connection, so that the risk of leakage, in particular with regard to the escape of air, is reduced or avoided via the connection. In the direction of the rising height of the compressor oil 3 in the receiving volume, the oil filler neck 2 has an outlet opening 22 facing the level of the compressor oil 3 and a filler opening 21 facing away from the level of the compressor oil 3.The filler opening 21 is, for example, flush with the side of the compressor housing 1 facing away from the receiving volume for the compressor oil 3. In alternative embodiments, the filler opening 21 or the area of ​​the oil filler neck 2 with the filler opening 21 can also protrude on a side of the compressor housing 1 facing away from the receiving volume. The filler opening 21 can be closed using a cover (not shown). The oil filler neck 2 extends in the direction of gravity or in the direction of the rise of the level of the compressor oil 3 into the receiving volume of the compressor housing 1. The outlet opening 22 is thus arranged below the filler opening 21 in the direction of gravity. Furthermore, the outlet opening 22 is arranged in the direction of gravity between an upper and lower volume limitation of the receiving volume for the compressor oil 3 formed by the compressor housing 1.The position of the outlet opening 22 in the direction of gravity corresponds to a maximum oil level 5, which is predetermined to prevent overfilling. The compressor housing 1 of the compressor oil receiving device 10 also has an oil sight glass 4 as an indicator device for the level of the compressor oil 3 in the receiving volume. The oil sight glass 4 extends in the direction of the rise of the level of the compressor oil 3 in the receiving volume over an area that covers a minimum oil level 6 and the maximum oil level 5. The minimum oil level 6 and the maximum oil level 5 correspond to a corresponding scale on the oil sight glass 4. In alternative embodiments, further scale information can be provided on the oil sight glass 4. The position of the outlet opening 22 can also be seen via the oil sight glass 4, which also extends beyond the maximum oil level 5.

[0043] If, for example, a minimum oil level is read during a maintenance procedure, compressor oil 3 is refilled via the filler opening 21 of the oil filler neck 2. The level of compressor oil 3 in the receiving volume of the compressor housing 1 rises accordingly. The air volume displaced by the compressor oil 3 in the receiving volume can escape via the oil filler neck until the level of compressor oil 3 has risen so far that the outlet opening 22 is covered by the compressor oil. As a result, the remaining air volume in the compressor housing 1 is enclosed between the outlet opening 22 and the compressor housing 1 and forms an air cushion 7. The air cushion 7 prevents a further increase in the level of compressor oil 3 in the receiving volume. Since the outlet opening 22 is arranged here at the height of the maximum oil level 5, further filling of the receiving volume with compressor oil 3 and thus overfilling is avoided.The compressor oil 3 can then only rise in the oil filler neck 2 itself, as indicated by the arrow. This has a predetermined height between the filler opening 21 and the outlet opening 22, so that a rise in the oil filler neck 2 or the reaching of the maximum oil level 5 can be detected with sufficient tolerance without compressor oil 3 immediately escaping from the filler opening 21.

[0044] Figure 3shows a schematic cross-sectional view of a compressor oil receiving device 10' according to a second exemplary embodiment of the present invention. The second embodiment differs from the first embodiment in the design of the oil filler neck 2' and the corresponding compressor housing 1'. Otherwise, the compressor oil receiving device 10' of the second embodiment is constructed analogously to the compressor oil receiving device 10 of the first embodiment, so that the same reference numerals are used in this regard, and a description of the first embodiment can be applied to the second embodiment.

[0045] In the second embodiment, the oil filler neck 2' of the compressor oil receiving device 10' is not formed integrally with the compressor housing 1', but can be screwed into the compressor housing 1' via a threaded connection (not shown). Accordingly, the position of the outlet opening 22' of the oil filler neck 2' can be adjusted via the screw-in depth, as indicated by the double arrow in the area of ​​the filler opening 21'. Thus, the maximum oil level 5 or a maximum level of the compressor oil 3 in the receiving volume of the compressor housing 1' can also be adjusted. The threaded connection can have additional sealing means to prevent air from escaping from the air volume 7 enclosed between the compressor housing 1' on the one hand and the filled compressor oil when the outlet opening 22' overlaps.In alternative embodiments, other position adjustment mechanisms, such as clamps or the like, can also be provided instead of a screw connection.

[0046] The oil filler neck 2' also has a scale 23, which protrudes from the side of the compressor housing 1' facing away from the receiving volume, depending on the position, as a position indicator for the oil filler neck 2'. The scale, which is just not covered by the compressor housing 1', then indicates the respective screw-in depth. In alternative embodiments, the position indicator can also be provided via a distance meter, which detects a distance at the level of the rising water level between the outlet opening 22' and a reference point, for example, a compressor housing wall opposite the outlet opening at the level of rising water level. The distance signal can be displayed by a display device as an analog distance value or by differently colored illuminated displays.

[0047] The invention is not limited to the described embodiments. Although, for example, in the embodiments described above, the oil filler neck extends perpendicular to the oil level, the oil filler neck may also be inclined relative to this. LIST OF REFERENCE SYMBOLS

[0048] 1, 1'Compressor housing 2, 2'Oil filler neck 3Compressor oil 4Oil sight glass (level indicator) 5Maximum oil level 6Minimal oil level 7Air cushion (air volume) 10, 10'Compressor oil intake device 21, 21'Filling opening (oil filler neck) 22, 22'Outlet opening (oil filler neck) 23Scale (position indicator) ACompressor housing BOil filling opening CCompressor oil DOil sight glass (level indicator) EMaximum oil level FMinimal oil level

Claims

1. Compressor oil receiving device (10, 10') for a compressor system to be filled with a compressor oil (3) for transferring into the compressor system, comprising: a housing (1, 1') which forms a receiving volume for the compressor oil (3), and an oil-filling nozzle (2, 2') with a filling opening (21, 21') on a side facing away from the receiving volume and an outlet opening (22, 22') on a side facing the receiving volume, characterized in that the oil-filling nozzle (2, 2') forms a housing opening for filling the receiving volume with the compressor oil (3) and the outlet opening (22, 22') is arranged such that by filling the receiving volume an air volume (7), which is enclosed by the housing (1, 1') on the one hand and the compressor oil (3) that has been filled on the other hand, can be formed in the receiving volume.

2. Compressor oil receiving device (10, 10') according to claim 1, wherein the oil-filling nozzle (2, 2') extends at least partially into the enclosed air volume (7).

3. Compressor oil receiving device (10, 10') according to any one of claims 1 or 2, wherein the filling opening (21, 21') and the outlet opening (22, 22') are arranged at different heights in the direction of a rise height of the compressor oil (3) in the receiving volume, and the distance of the filling opening (21, 21') from the respective level height of the compressor oil (3) in the receiving volume, at least until an intended maximum oil level (5) has been reached, is greater than the distance of the outlet opening (22, 22') from this respective level height.

4. Compressor oil receiving device (10, 10') according to any one of the preceding claims, wherein the position of the outlet opening (22, 22') corresponds to the maximum oil level (5).

5. Compressor oil receiving device (10') according to any one of the preceding claims, wherein the position of the outlet opening (22') is adjustable.

6. Compressor oil receiving device (10') according to claim 5, wherein the oil-filling nozzle (2') can be moved at least by a movement amount in the direction of the rise height of the compressor oil (3) in the receiving volume.

7. Compressor oil receiving device (10') according to claim 6, wherein the oil-filling nozzle (2') has a position indicating device (23), which is configured to indicate a position of the outlet opening (22').

8. Compressor oil receiving device (10') according to claim 7, wherein the filling opening (21') projects beyond a side of the housing (1') facing away from the receiving volume at least until a predetermined movement depth of the oil filling nozzle (2') into the receiving volume has been reached, and has a scale (23) as a position indicating device (23) in this projecting region.

9. Compressor oil receiving device (10, 10') according to any one of the preceding claims, wherein the compressor oil receiving device (10, 10') has a filling level indicator (4), which indicates at least a minimum oil level (6) and / or the maximum oil level (5).

10. Compressor oil receiving device (10, 10') according to claim 9, wherein the filling level indicator (4) is configured as at least an oil inspection glass (4) in the housing (1, 1'), which extends at least in the region of the minimum oil level (6) and / or the maximum oil level (5) in the direction of the rise height of the compressor oil (3) in the receiving volume.

11. Compressor oil receiving device (10, 10') according to claim 10, wherein the oil inspection glass (4) is arranged and / or dimensioned such that through the oil inspection glass (4) the position of the outlet opening (22, 22') of the pressure nozzle (2, 2') in the receiving volume can be identified.

12. Compressor oil receiving device (10, 10') according to claim 10 or 11, wherein the oil inspection glass (4) and / or a bordering region of the housing (1, 1') has / have a scale (5, 6).

13. Compressor system having a compressor oil receiving device (10, 10') according to any one of claims 1 to 12, wherein the receiving volume for the compressor oil (3) is configured at least partly by an oil sump of the compressor system.

14. Compressor system according to claim 13, wherein the compressor system includes a screw compressor.