Compressor unit, housing for a compressor unit and vehicle

Abstract

The invention relates to a compressor unit (10) for providing compressed air. The compressor unit (10) comprises an air compressor (20) and a housing (40) configured to enclose the air compressor (20), the air compressor (20) having a first active cooling unit (21) with a compressor fan (22) and the housing (40) having a second active cooling unit (41) with a housing fan (42). The housing (40) comprises a first air opening (43) and a first airflow duct (44) fluidically connecting the first air opening (43) with the compressor fan (22). The housing (40) comprises a second air opening (45) and a second airflow duct (46) fluidically connecting the second air opening (45) with the housing fan (42). At least one of the first airflow duct (44) and the second airflow duct (46) comprises at least one airflow deflecting section (47). Furthermore, the invention relates to a housing (40) for a compressor unit (10) and to a vehicle (60), in particular a commercial vehicle (60a), comprising a compressor unit (10).

Description

[0001] COMPRESSOR UNIT, HOUSING FOR A COMPRESSOR UNIT AND VEHICLE

[0002] The present disclosure relates to a compressor unit for providing compressed air. Furthermore, the present disclosure relates to a housing for a compressor unit and to a vehicle, in particular a commercial vehicle, comprising a compressor unit.

[0003] Compressor units for providing compressed air are generally known. Compressor units usually comprise an air compressor and a housing and may require a technical cooling concept to prevent overheating of compressor components during operation of the air compressor. Furthermore, operation of the air compressor may lead to sound emission, and it may be desirable for at least some air compressor applications to reduce the sound emission of the air compressor.

[0004] In US 2019 / 0 039 589 A1 , an air supply system to be mounted in or on a railway vehicle or commercial vehicle is described, the air supply system comprising a compressor device for producing compressed air, an air dryer device for dehumidifying the compressed air, and a housing for enclosing the compressor device and the air dryer device. Furthermore, a cooling is provided which can be operated independently of the operating mode of the compressor device.

[0005] Since heat dissipating and sound reducing requirements may increase with available compressor capacities, it may be desirable to provide improved technical cooling concepts and enhanced sound absorption measures for compressor units.

[0006] In view of the above, it is an object of the present invention to provide a compressor unit with an efficient cooling and effectively reduced sound emission. It is a further object of the present invention to provide a housing for such a compressor unit and a vehicle comprising such a compressor unit.

[0007] Aspects and embodiments of the invention provide a compressor unit, a housing and a vehicle as indicated in the appended claims. According to a first aspect of the present invention, there is provided a compressor unit for providing compressed air, the compressor unit comprising an air compressor and a housing configured to enclose the air compressor, the air compressor having a first active cooling unit with a compressor fan and the housing having a second active cooling unit with a housing fan,

[0008] - wherein the housing comprises a first air opening and a first airflow duct fluid ically connecting the first air opening with the compressor fan;

[0009] - wherein the housing comprises a second air opening and a second airflow duct fluidically connecting the second air opening with the housing fan; and

[0010] - wherein at least one of the first airflow duct and the second airflow duct comprises at least one airflow deflecting section.

[0011] In conclusion, a compressor unit combining two active cooling units for the air compressor and an interior space of the housing of the compressor unit is provided, wherein at least one active cooling unit comprises an airflow duct configured to deflect air flowing through the airflow duct. By combining two active cooling units, the cooling of the air compressor and the compressor environment in the housing may be significantly improved. By providing airflow ducts and at least one airflow deflecting section, sound emission may be effectively reduced by airflow deflection within the housing. The airflow ducts and the airflow deflecting section may allow for an indirect air supply to at least one of the air compressor and the interior space of the housing, thus reducing direct travelling pathways for airborne sound waves to the exterior. Hence, temperature and noise reduction may be beneficially combined by the provided compressor unit.

[0012] Within the present disclosure, an air compressor may be a machine that takes ambient air from the surroundings and discharges it at a higher pressure. For instance, the air compressor may be a reciprocating air compressor. Preferably, the air compressor may be an electrically driven air compressor. According to an embodiment, the air compressor may comprise a plurality of air compressing cylinders, e.g. four air compressing cylinders. Preferably, the air compressor may be an air-cooled air compressor using ambient air for cooling of the air compressor. Nevertheless, conceivable embodiments may comprise additional water cooling provided to the air compressor. As indicated above, the first active cooling unit may comprise a compressor fan. The compressor fan may be configured to direct an airflow to a compressor component, in particular to a cylinder head of the air compressor. For instance, the compressor fan may be an axial-flow fan. Preferably, the compressor fan may be attached to or form an integral part of the air compressor. According to an advantageous embodiment, the air compressor may comprise a plurality of, which means at least two, compressor fans. For instance, there may be provided at least one compressor fan directed to each cylinder head of the air compressor. Each compressor fan may be connected to individual first air openings or to a common first air opening via a respective first airflow duct. For example, two or more compressor fans may share a common first air opening, wherein being connected to the first air opening via individual first airflow ducts which optionally may share joint duct sections.

[0013] As further indicated above, the second active cooling unit comprises a housing fan. The housing fan may be configured to direct an airflow to or through the interior space of the housing, thus providing cooling and enhanced air exchange to the internal housing space. For instance, the housing fan may be an axial-flow fan. Preferably, the housing fan may be attached to or form an integral part of the housing. According to an advantageous embodiment, the air compressor may comprise a plurality of, which means at least two, housing fans. For instance, there may be provided at least one housing fan for each interior space part on opposite sides of the air compressor. Each housing fan may be connected to individual second air openings or to a common second air opening via a respective second airflow duct. For example, two or more housing fans may share a common second air opening, wherein being connected to the second air opening via individual second airflow ducts which optionally may share joint duct sections.

[0014] In accordance with the compressor unit suggested above, the housing comprises a first air opening and a first airflow duct fluid ically connecting the first air opening with the compressor fan. Thus, the compressor fan is spaced from the first air opening via the first airflow duct. The first air opening may connect the interior space of the housing to an environment of the compressor unit. Hence, the compressor fan may be connected to the environment in an indirect manner by means of the first airflow duct, thus dampening airborne sound waves leaving the housing through the first air opening. The first airflow duct may, for instance, comprise a channel section with a closed or partially closed circumferential wall. According to an embodiment, the first airflow duct may be formed between a housing wall configured as an exterior wall and a housing wall configured as a partition wall.

[0015] In accordance with the compressor unit suggested above, the housing comprises a second air opening and a second airflow duct flu idical ly connecting the first air opening with the housing fan. Thus, the housing fan is spaced from the second air opening via the second airflow duct. The second air opening may connect the interior space of the housing to the environment. Hence, the housing fan may be connected to the environment in an indirect manner by means of the second airflow duct, thus dampening airborne sound waves leaving the housing through the second air opening. The second airflow duct may, for instance, comprise a channel section with a closed or partially closed circumferential wall. According to an embodiment, the second airflow duct may be formed between a housing wall configured as an exterior wall and a housing wall configured as a partition wall.

[0016] As further indicated above, at least one of the first airflow duct and the second airflow duct comprises at least one airflow deflecting section. An airflow deflecting section may be a duct part configured to deflect airflow for changing a main flow direction of the airflow. Preferably, the airflow deflecting section may be configured to deflect airflow with an angle of at least 45°, in particular of at least 70°. For instance, the airflow deflecting section may comprise an angulation or bending in order to deflect a passing airflow.

[0017] The suggested compressor unit may be configured as a ready-to-use unit with a plug-and-play configuration. For this, the compressor unit may, for instance, comprise at least one of a mechanical and an electrical interface structure arranged on an outer surface of the housing.

[0018] According to an embodiment of the first aspect of the present invention, the first airflow duct and the second airflow duct may each comprise at least one airflow deflecting section. By this, the sound reducing effect of the suggested compressor unit may be further improved. The airflow deflecting sections allow for an indirect air supply both to the air compressor and to the interior space of the housing, thus eliminating direct travelling pathways for airborne sound waves to the exterior. Preferably, the airflow deflecting sections may be configured to deflect airflow with an angle of at least 45°, in particular of at least 70°. For instance, the airflow deflecting sections may each comprise an angulation or bending in order to deflect a passing airflow.

[0019] According to an embodiment of the first aspect of the present invention, the first air opening may be configured as an air inlet and the compressor fan may be configured as a cooling fan. Within the present disclosure, a cooling fan may be a fan configured to convey cool ambient air to an object to be cooled. Hence, the compressor fan may be configured to convey cool ambient air from the first air opening to the air compressor. In this case, the first air opening may be operated as an air inlet to the first airflow duct. In accordance with the suggested embodiment, the air compressor may be effectively cooled by conveyance of cool ambient air to the air compressor.

[0020] According to an embodiment of the first aspect of the present invention, the first air opening may be configured as an air outlet and the compressor fan may be configured as a venting fan. Within the present disclosure, a venting fan may be a fan configured to dissipate hot air from an object to be cooled. In particular, the venting fan may be configured to vent the dissipated hot air to the environment. Hence, the compressor fan may be configured to convey hot air from the air compressor to the first air opening. In this case, the first air opening may be operated as an air outlet or exhaust of the first airflow duct. In accordance with the suggested embodiment, the air compressor may be effectively cooled by removal of hot air from the air compressor. If a plurality of compressor fans is provided within the compressor unit, cooling fans and venting fans may optionally be implemented in a mixed manner such that it is not excluded to use a first compressor fan as a cooling fan and a second compressor fan as a venting fan.

[0021] According to an embodiment of the first aspect of the present invention, the second air opening may be configured as an air inlet and the housing fan may be configured as a cooling fan. Hence, the housing fan may be configured to convey cool ambient air from the second air opening to the interior space of the housing. In this case, the second air opening may be operated as an air inlet to the second airflow duct. In accordance with the suggested embodiment, the compressor environment within the housing may be effectively cooled by conveyance of cool ambient air to the interior space of the housing.

[0022] According to an embodiment of the first aspect of the present invention, the second air opening may be configured as an air outlet and the housing fan may be configured as a venting fan. Hence, the housing fan may be configured to dissipate hot air from the interior space of the housing to the second air opening. In this case, the second air opening may be operated as an air outlet of the second airflow duct. In accordance with the suggested embodiment, the interior space of the housing may be effectively cooled by removal of hot air from the interior space of the housing. If a plurality of housing fans is provided within the compressor unit, cooling fans and venting fans may optionally be implemented in a mixed manner such that it is not excluded to use a first housing fan as a cooling fan and a second housing fan as a venting fan. If a venting fan and a cooling fan are combined, a pressure level in the interior space of the housing may be advantageously maintained on a substantially constant level.

[0023] Generally, the housing may comprise further auxiliary air openings in addition to the first and second air openings for additional air exchange with the environment. Auxiliary air openings may be air openings which are not associated with a compressor fan or a housing fan via a dedicated airflow duct. Preferably, auxiliary air openings may be also shielded from a direct sound travelling path from the interior space of the housing to the environment by a suitable airflow deflection structure, thus providing an indirect access to the interior space of the housing for reduced sound emission.

[0024] According to an embodiment of the first aspect of the present invention, the housing may further comprise a third active cooling unit with a motor fan configured to provide cooling air to or to dissipate heat from a compressor motor of the air compressor. By this, an additional motor cooling option may be provided in order to further improve the overall cooling efficiency of the compressor unit. The compressor motor may be a compressor component configured to drive the compressing system of the compressor, for instance a piston-cylinder system of a reciprocating compressor.

[0025] According to a refined embodiment, the housing may comprise a third air opening and a third airflow duct fluidically connecting the third air opening with the motor fan, wherein the third airflow duct may comprise at least one airflow deflecting section. By this, beneficial sound reduction may be also provided for the additional motor cooling option.

[0026] According to a non-limiting, highly feasible example, the compressor unit may comprise four compressor fans and first airflow ducts leading to two first air openings, two housing fans configured as venting fans in order to exhaust hot air from the housing and a motor fan configured as a cooling fan in order to supply cool ambient air to the compressor motor, thus providing a balanced and efficient cooling concept which may be easily implemented at moderate cost.

[0027] According to an embodiment of the first aspect of the present invention, at least one of the compressor fan, the housing fan and the motor fan may be configured as a reversible fan. In this context, a reversible fan may be configured to be selectively operated as a cooling fan or as a venting fan. In other words, the reversible fan may be operable according to two opposite flow directions. For instance, the flow direction may be changed by reversing a rotation direction of the reversible fan. By implementing a reversible fan, increased flexibility may be achieved, and cooling concepts may be individually controlled according to sensed conditions such as temperature conditions or power consumption conditions, according to predefined control instructions or according to specific customer requirements.

[0028] According to an embodiment of the first aspect of the present invention, the compressor unit may be configured to generate a cooling airflow or a venting airflow with an airflow velocity of at least 4 m / s. By this, a highly effective cooling may be provided to the air compressor. For instance, at least one of the compressor fan, the housing fan and the motor fan may comprise a suitable nominal power for airflow acceleration to reach the suggested minimum velocity. In addition or alternatively, at least one of the first, second and third airflow duct may comprise an airflow acceleration section such as a nozzle section. The compressor unit may be configured to reach the suggested minimum velocity at a specific compressor component to be cooled, e.g. at a cylinder head of a compressor cylinder.

[0029] According to an embodiment of the first aspect of the present invention, at least one of the first air opening, the second air opening and the third air opening lead to an open environment of the compressor unit, such that at least one of the first airflow duct, the second airflow duct and the third airflow duct are configured to provide fresh atmospheric air to at least one of the compressor fan, the housing fan and the motor fan or to exhaust hot air to the environment. By this, a highly effective cooling may be provided to air compressor components and to the interior housing space surrounding the air compressor.

[0030] According to an embodiment of the first aspect of the present invention, at least one housing wall of the housing may comprise a sound insulation element. By this, a sound level emitted by the compressor unit may be further reduced by materialbased sound absorption or dampening. For instance, the sound insulation element may be attached to a bottom wall, a top wall, a side wall or a partition wall of the housing. According to an example, the sound insulation element may be a textile layer, thus providing a substantially flat and effective sound insulation element which may be easily attached to a housing wall.

[0031] According to an embodiment of the first aspect of the present invention, at least one of the first airflow duct, the second airflow duct and the third airflow duct may comprise a sound insulation element. By this, a sound level emitted by the compressor unit may be further reduced by material-based sound absorption or dampening directly at the airflow-guiding housing structures. Hence, the airflow ducts may not only contribute to a reduced sound level by flow deflection but also by a material-based sound absorbing effect. This combination highly promotes the noisereducing effect, in particular if the sound insulation element is placed at or near an airflow deflecting section. According to a refined embodiment, the sound insulation element may be a foam lining. By this, a sound insulation element with beneficial sound absorbing properties and easy implementation may be applied.

[0032] According to an embodiment of the first aspect of the present invention, the housing may be configured as a multi-component housing and at least two housing components may be sealed against each other by means of a vibration absorbing element. By this, minimization of vibration and noise leakage in connecting areas of housing components can be achieved. For instance, a vibration absorbing element may be a sealing tape or a gasket. According to a refined embodiment, at least one housing component of the multi-component housing may additionally comprise a sound insulation element, in particular a foam lining, for further sound reduction as indicated above.

[0033] According to an embodiment of the first aspect of the present invention, the compressor unit may comprise a wiring harness guided from an interior space of the housing to an outside surface of the housing, wherein the housing may comprise a rubber grommet for guiding the wiring harness. By implementing such a rubber grommet, the housing can be further optimized by substantially soundproof components.

[0034] According to a second aspect of the present invention, there is provided a housing for a compressor unit according to any of the aforementioned features, wherein the housing comprises

[0035] - an active cooling unit section comprising a fan compartment for a housing fan;

[0036] - a first air opening and a first airflow duct;

[0037] - a second air opening and a second airflow duct flu idical ly connecting the fan compartment with the second air opening; and wherein at least one of the first airflow duct and the second airflow duct comprises at least one airflow deflecting section.

[0038] With the suggested housing according to the second aspect of the present invention, it is possible to provide efficient cooling to an air compressor to be enclosed by the housing and to obtain enhanced sound emission properties with regard to a formed compressor unit. By providing airflow ducts and at least one airflow deflecting section, sound emission may be effectively reduced by airflow deflection within the housing. The airflow ducts and the airflow deflecting section may allow for an indirect air supply to the interior space of the housing, thus reducing direct travelling pathways for airborne sound waves to the exterior. Hence, temperature and noise reduction may be beneficially combined by the provided housing.

[0039] The housing according to the second aspect of the present invention may comprise at least one of the features described above in relation to the compressor unit according to the first aspect. For instance, the first airflow duct and the second airflow duct may each comprise at least one airflow deflecting section. A housing fan may be arranged in the fan compartment of the active cooling unit section. The housing fan may be configured as a cooling fan, wherein the second air opening may be configured as an air inlet. The housing fan may be configured as a venting fan, wherein the second air opening may be configured as an air outlet. Optionally, the housing fan may be a reversible fan. Generally, the housing may comprise more than one fan compartment. Consequently, more than one housing fan may be arranged in the provided fan compartments, the housing fans selectively being configured as cooling fans or venting fans. Furthermore, the housing may comprise an additional motor cooling unit section comprising a motor fan compartment for a motor fan, the motor fan configured to provide cooling air to or dissipate heat from a compressor motor of an air compressor arranged in the housing. In this case, the housing may comprise a third air opening and a third airflow duct fluidically connecting the third air opening with the motor fan, wherein the third airflow duct may comprise at least one airflow deflecting section.

[0040] For further enhanced sound properties, the housing according to the second aspect of the present invention may comprise a housing wall with a sound insulation element as explained above. Furthermore, at least one of the first, second and third airflow duct may comprise a sound insulation element. The addressed sound insulation element may be a foam lining. The housing may be configured as a multi-component housing, wherein at least two housing components are sealed against each other by means of a vibration absorbing element. The housing may comprise a rubber grommet for guiding a wiring harness from an interior space of the housing to an outside surface of the housing.

[0041] According to a third aspect of the present invention, there is provided a vehicle, in particular a commercial vehicle, comprising a compressor unit according to any one of the aforementioned features. A vehicle equipped with the suggested compressor unit may provide increased driver and passenger comfort due to reduced perceivable compressor noise as well as enhanced air compressor performance due to the improved cooling concept. The described vehicle may be a motor vehicle of any type designed to transport people and / or cargo. In particular, the vehicle may be a commercial vehicle as e.g. a truck or a bus. For commercial vehicles, the advantage of an efficiently improved compressor unit may, due to a generally higher consumption of compressed air, significantly increase the operating efficiency of the vehicle. Hence, the present invention may be beneficially applicable to commercial vehicles.

[0042] According to an embodiment of the third aspect of the present invention, the vehicle may be configured as an electrically driven vehicle. An electrically driven vehicle may be a motor vehicle with an electric drive, which may be optionally combined with a combustion drive to form a hybrid vehicle. In this context, low-noise compressor unit concepts may be in particular desired for electrically driven vehicles which generally show a reduced driving sound level, thus providing enhanced comfort for drivers and passengers. For instance, the vehicle may be an electrically driven bus for commercial passenger transport.

[0043] The above and other characteristics will become clear from the following description of illustrative, non-restrictive examples, which will be further outlined with reference to the appended drawings. The drawings are not necessarily to scale. Some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art. Fig. 1 shows an exploded view of a compressor unit according to a first embodiment.

[0044] Fig. 2 illustrates an exploded back view of a first housing component of the compressor unit according to the first embodiment.

[0045] Fig. 3 provides an enlarged detail view of a second housing component of the compressor unit according to the first embodiment.

[0046] Fig. 4 depicts a perspective view of the compressor unit according to the first embodiment.

[0047] Fig. 5 shows a sectional perspective view of the compressor unit depicted in Fig. 2.

[0048] Fig. 6 illustrates a simplified schematic view of a housing component of the compressor unit according to a first configuration.

[0049] Fig. 7 illustrates a simplified schematic view of a housing component of the compressor unit according to a second configuration.

[0050] Fig. 8a provides a perspective view of the housing component of the compressor unit, the housing component comprising a vibration absorbing element.

[0051] Fig. 8b provides an enlarged detail view of the housing component according to Fig. 8a.

[0052] Fig. 9a depicts a perspective view of the compressor unit with a housing comprising a rubber grommet.

[0053] Fig. 9b provides an enlarged detail view of the housing according to Fig. 9a.

[0054] Fig. 10 shows a simplified schematic view of a vehicle comprising a compressor unit.

[0055] Fig. 1 schematically illustrates a compressor unit 10 according to a first embodiment. The compressor unit 10 comprises an air compressor 20 and a housing 40 configured to enclose the air compressor 20. The housing 40 is configured as a multicomponent housing 40 and comprises two first housing components 40a and a second housing component 40b according to the depicted example. The housing 40 comprises an outside surface 40d. The first housing components 40a are sealed against the second housing component 40b by means of a vibration absorbing element 52, e.g. a gasket (see also Fig. 8b). The air compressor 20 according to the depicted embodiment is configured as an electrically driven reciprocating air compressor 20 comprising four air compressing cylinders with air cooling. According to the depicted embodiment, the air compressor 20 comprises four first active cooling units 21 each having a compressor fan 22. The compressor fans 22 are each directed to a cylinder head of the air compressor 20. The compressor fans 22 are configured as axial-flow fans.

[0056] According to the depicted embodiment, the housing 40 comprises two second active cooling units 41 each having a housing fan 42. The housing fans 42 are configured to direct an airflow to or through the interior space 40c of the housing 40. As apparent from Fig. 1 , each housing 42 is attached to a first housing component 40a, thus providing active cooling units 41 on opposite housing sides of the housing 40. The first housing components 40a may each comprise a respective active cooling unit section 41a with a fan compartment 42a for receiving the housing fan 42. The housing fans 42 are configured as axial-flow fans according to the depicted example.

[0057] As illustrated, the housing 40 comprises a plurality of first air openings 43 and a first airflow duct 44 fluidically connecting the first air opening 43 with the compressor fan 22, see also the detail view in Fig. 3. The compressor fan 22 is spaced from the first air openings 43 via the first airflow duct 44, thus providing an indirect air supply to the compressor fan 22. Although not visualized in detail, all four compressor fans 22 shown may be connected by individual first airflow ducts 44 with associated first air openings 43.

[0058] Furthermore, the housing 40 comprises a plurality of second air openings 45 and a second airflow duct 46 as depicted in Fig. 2, wherein the second airflow duct 46 is fluidically connecting the second air openings 45 with the housing fan 42. The housing fan 42 is spaced from the second air openings 45 via the second airflow duct 46, thus providing an indirect air supply to the housing fan 42. Although depicted for only one housing fan 42 in Fig. 2, both housing fans 42 illustrated in Fig. 1 may be connected by individual second airflow ducts 46 with associated second air openings 45.

[0059] As apparent from Fig. 1 , the first air openings 43 and the second air openings 45 lead an open environment 80 of the compressor unit 10, such that the first airflow duct 44 and the second airflow duct 46 may provide fresh atmospheric air to the compressor fan 22 and the housing fan 42 or, alternatively, may exhaust hot air to the environment 80.

[0060] As apparent from Figs. 1 and 2, the first airflow duct 44 and the second airflow duct 46 each comprise airflow deflecting sections 47 in which an airflow direction of a passing airflow is forced to change (see also Figs. 5 to 7). In particular, the airflow deflecting sections 47 may cause a direction change of a passing airflow of an angle of at least 45°, in particular of at least 70°. For instance, in Fig. 2 a schematical illustration of air outflows 71 from the housing fan 42 to the second air openings 45 is provided, the air outflows 71 being deflected at a plurality of airflow deflecting sections 47 before exiting the housing 40. As apparent from Fig. 2, the housing fan 42 is configured as a venting fan 42c and the second air openings 45 are configured as an air outlet 45b. As such, the venting fan 42c is configured to vent dissipated hot air from the air compressor 20 via the second air openings 45 to the environment 80. As illustrated in Fig. 2, the second airflow duct 46 may be formed between a housing wall 50 configured as an exterior wall 50a and a housing wall 50 configured as a partition wall 50b.

[0061] As furthermore depicted in Fig. 1 , the housing 40 comprises a bottom plate 55 into which a third active cooling unit 48 with a motor fan 49 is embedded in order to provide cooling air to or to dissipate heat from a compressor motor 23 of the air compressor 20, thus allowing for an additional motor cooling option in order to further improve the overall cooling efficiency of the compressor unit 10. Although not depicted in the illustrated embodiment, the housing 40 may comprise a third airflow duct flu idical ly connecting a third air opening with the motor fan 49, wherein the third airflow duct may comprise at least one airflow deflecting section.

[0062] Fig. 3 provides a detailed view of the housing 40 according to the section A indicated in Fig. 5, thus illustrating an enlarged view of the second housing component 40b with the first airflow duct 44. The second housing component 40b comprises a housing wall 50 configured as an exterior wall 50a and a housing wall 50 configured as a partition wall 50b. The space between the exterior wall 50a and the partition wall 50b forms the first airflow duct 44 configured to flu idical ly connect the first air openings 43 with the compressor fan 22. The first airflow duct 44 comprises air flow deflecting sections 47 for deflecting an airflow through the first airflow duct 44, thus reducing sound energy while the airflow passes the first airflow duct 44. Furthermore, a foam lining forming a sound insulation element 51 is attached to the partition wall 50b, thus providing additional material-based sound absorption or dampening.

[0063] By combining a first active cooling unit 21 and a second active cooling unit 41 , a cooling of the air compressor 20 and the space surrounding the air compressor 20 may be beneficially improved. By providing a first airflow duct 44 and a second airflow duct 46 with an air deflecting section 47 for providing indirect airflow access to and from the first and second active cooling units 21 , 41 , the sound level of the compressor unit 10 may be significantly decreased. Hence, the described compressor unit 10 enables an efficient combination of temperature and noise reduction.

[0064] Figs. 4 and 5 illustrate further views of the compressor unit 10As depicted in Fig. 5, the housing 40 also comprises first air openings 43 and first airflow ducts 44 fluid ically connecting the first air openings 43 with the compressor fans 22. According to the depicted embodiment in Fig. 5 and as apparent from the visualized air inflow 70, the first air openings 43 may be configured as an air inlet 43a and the compressor fans 22 may be configured as cooling fans 22a. Hence, the compressor fans 22 may be configured to convey cool ambient air from the first air openings 43 to the air compressor 20. The first airflow ducts 44 comprise airflow deflecting sections 47 for providing indirect airflow access to the compressor fans 22, thus reducing direct travelling pathways for sound waves in order to provide noise reduction in an environment 80 of the compressor unit 10.

[0065] The compressor unit 10 according to the depicted embodiment may be configured to generate a cooling airflow or a venting airflow with an airflow velocity of at least 4 m / s, thus providing a highly effective cooling. For instance, at least one of the compressor fan 22 and the housing fan 42 may comprise a suitable nominal power for sufficient airflow acceleration to reach the minimum velocity. Figs. 6 and 7 schematically illustrate a housing component of a housing 40 of the compressor unit 10 according to a first and second configuration. The housing component may, for instance, be a first housing component 40a or a second housing component 40b as further explained above. The housing component comprises a housing wall 50 configured as an exterior wall 50a with a second air opening 45 and a housing wall 50 configured as a partition wall 50b arranged opposite to the exterior wall 50a. As depicted, a second active cooling unit 41 comprising a housing fan 42 is embedded in the partition wall 50b. According to the first configuration depicted in Fig. 6, the second air opening 45 forms an air outlet 45b and the housing fan 42 is configured as a venting fan 42c. By this, an air outflow 71 of hot air from an interior space 40c of the housing 40 is vented to an environment 80 of the housing 40.

[0066] According to the second configuration depicted in Fig. 7, the second air opening 45 forms an air inlet 45a and the housing fan 42 is configured as a cooling fan 42b. By this, an air inflow 70 of cool ambient air from the environment 80 is aspirated by the cooling fan 42b and forwarded to the interior space 40c of the housing 40. The housing fan 42 and the second air opening 45 are fluidically connected by a second airflow duct 46 comprising airflow deflection sections 47, at which the air outflow 71 according to Fig. 6 and the air inflow 70 according to Fig. 7 are deflected by approximately 90°. By this, sound energy is reduced while the airflow passes the second airflow duct 46 and direct travelling pathways for sound waves are reduced. Furthermore, a sound insulation element 51 may be attached to at least one of the exterior wall 50a as depicted in Fig. 6 and to the partition wall 50b as depicted in Fig. 7, thus providing additional material-based sound absorption or dampening.

[0067] Fig. 8a provides a perspective view of the first housing component 40a of the housing 40 of the compressor unit 10. Fig. 8b provides an enlarged detail view of the first housing component 40a according to the section C indicated in Fig. 8a. As depicted, a vibration absorbing element 52 as for example a gasket is attached to the first housing component 40a, thus further enhancing the sound emission properties of the compressor unit 10.

[0068] Fig. 9a depicts a perspective view of the compressor unit 10 showing a connection side of the housing 40. Fig. 9b shows an enlarged detail view of the second housing component 40b of the housing 40, the second housing component 40b comprising a rubber grommet 54. The rubber grommet 54 serves for guiding a wiring harness 53 from an interior space 40c of the housing 40 (see Fig. 1 ) to an outside surface 40d of the housing 40, while forming a substantially soundproof element of the housing 40. The wiring harness 53 may form an electrical interface structure accessible on the outside surface 40d, such that the compressor unit 10 may be configured as a ready- to-use unit with a plug-and-play configuration.

[0069] Fig. 10 provides a simplified schematic view of a vehicle 60 comprising a compressor unit 10. As apparent from Fig. 10, the vehicle 60 is configured as a commercial vehicle 60a, here shown as a bus for passenger transport. According to the depicted embodiment, the compressor unit 10 is arranged in a rear end of the vehicle 60 on a vehicle chassis 62 and may be configured to supply compressed air to a compressed air buffer 61 or, in addition or alternatively, to compressed air consumers such as an air suspension system (not shown). In accordance with the example provided in Fig. 10, the vehicle 60 comprises an electric drive 63. The suggested low-noise compressor unit 10 may be advantageous in particular for such an electrically driven vehicle 60 which generally shows a reduced driving sound level, thus providing enhanced comfort for drivers and passengers.

[0070] List of reference numerals (part of the application):

[0071] 10 compressor unit

[0072] 20 air compressor

[0073] 21 first active cooling unit

[0074] 22 compressor fan

[0075] 22a cooling fan

[0076] 23 compressor motor

[0077] 40 housing

[0078] 40a first housing component

[0079] 40b second housing component

[0080] 40c interior space

[0081] 40d outside surface

[0082] 41 second active cooling unit

[0083] 41a active cooling unit section

[0084] 42 housing fan

[0085] 42a fan compartment

[0086] 42b cooling fan

[0087] 42c venting fan

[0088] 43 first air opening

[0089] 43a air inlet

[0090] 44 first airflow duct

[0091] 45 second air opening

[0092] 45a air inlet

[0093] 45b air outlet

[0094] 46 second airflow duct

[0095] 47 airflow deflecting section

[0096] 48 third active cooling unit

[0097] 49 motor fan

[0098] 50 housing wall

[0099] 50a external wall

[0100] 50b partition wall

[0101] 51 sound insulation element

[0102] 52 vibration absorbing element wiring harness rubber grommet bottom plate vehicle a commercial vehicle compressed air buffer vehicle chassis electric drive air inflow air outflow environment

Claims

Patent claims1. A compressor unit (10) for providing compressed air, the compressor unit (10) comprising an air compressor (20) and a housing (40) configured to enclose the air compressor (20), the air compressor (20) having a first active cooling unit (21) with a compressor fan (22) and the housing (40) having a second active cooling unit (41) with a housing fan (42),- wherein the housing (40) comprises a first air opening (43) and a first airflow duct (44) flu idical ly connecting the first air opening (43) with the compressor fan (22);- wherein the housing (40) comprises a second air opening (45) and a second airflow duct (46) fluid ically connecting the second air opening (45) with the housing fan (42); and- wherein at least one of the first airflow duct (44) and the second airflow duct (46) comprises at least one airflow deflecting section (47).

2. The compressor unit (10) according to claim 1 , wherein the first airflow duct (44) and the second airflow duct (46) each comprise at least one airflow deflecting section (47).

3. The compressor unit (10) according to claim 1 or 2, wherein the first air opening (43) is configured as an air inlet (43a) and wherein the compressor fan (22) is configured as a cooling fan (22a).

4. The compressor unit (10) according to any preceding claim, wherein the first air opening (43) is configured as an air outlet and wherein the compressor fan (22) is configured as a venting fan.

5. The compressor unit (10) according to any preceding claim, wherein the second air opening (45) is configured as an air inlet (45a) and wherein the housing fan (42) is configured as a cooling fan (42b).

6. The compressor unit (10) according to any preceding claim, wherein the second air opening (45) is configured as an air outlet (45b) and wherein the housing fan (42) is configured as a venting fan (42c).

7. The compressor unit (10) according to any preceding claim, wherein the housing (40) further comprises a third active cooling unit (48) with a motor fan (49) configured to provide cooling air to or to dissipate heat from a compressor motor (23) of the air compressor (20).

8. The compressor unit (10) according to claim 7, wherein the housing (40) comprises a third air opening and a third airflow duct fluidically connecting the third air opening with the motor fan (49), wherein the third airflow duct comprises at least one airflow deflecting section.

9. The compressor unit (10) according to any preceding claim, wherein at least one of the compressor fan (22), the housing fan (42) and the motor fan (49) is configured as a reversible fan.

10. The compressor unit (10) according to any preceding claim, wherein the compressor unit (10) is configured to generate a cooling airflow or a venting airflow with an airflow velocity of at least 4 m / s.11 . The compressor unit (10) according to any preceding claim, wherein at least one of the first air opening (43), the second air opening (45) and the third air opening lead to an open environment (80) of the compressor unit (10), such that at least one of the first airflow duct (44), the second airflow duct (46) and the third airflow duct are configured to provide fresh atmospheric air to at least one of the compressor fan (22), the housing fan (42) and the motor fan (49) or to exhaust hot air to the environment (80).

12. The compressor unit (10) according to any preceding claim, wherein at least one housing wall (50) of the housing (40) comprises a sound insulation element (51 ).

13. The compressor unit (10) according to any preceding claim, wherein at least one of the first airflow duct (44), the second airflow duct (46) and the third airflow duct comprises a sound insulation element (51 ).

14. The compressor unit (10) according to claim 12 or 13, wherein the sound insulation element (51 ) is a foam lining.

15. The compressor unit (10) according to any preceding claim, wherein the housing (40) is configured as a multi-component housing (40) and wherein at least two housing components (40a, 40b) are sealed against each other by means of a vibration absorbing element (52).

16. The compressor unit (10) according to any preceding claim, wherein the compressor unit (10) comprises a wiring harness (53) guided from an interior space (40c) of the housing (40) to an outside surface (40d) of the housing (40), wherein the housing (40) comprises a rubber grommet (54) for guiding the wiring harness (53).

17. A housing (40) for a compressor unit (10) according to any of the preceding claims, wherein the housing (40) comprises- an active cooling unit section (41a) comprising a fan compartment (42a) for a housing fan (42);- a first air opening (43) and a first airflow duct (44);- a second air opening (45) and a second airflow duct (46) fluidically connecting the fan compartment (42a) with the second air opening (45); and wherein at least one of the first airflow duct (44) and the second airflow duct (46) comprises at least one airflow deflecting section (47).

18. A vehicle (60), in particular a commercial vehicle (60a), comprising a compressor unit (10) according to any one of the claims 1 to 16.

19. The vehicle according to claim 18, wherein the vehicle is configured as an electrically driven vehicle.

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