The present invention is generally related to crankcase ventilation systems, and more specifically to automotive crankcase ventilation systems.
It has been an interest in reducing emissions produced by internal combustion engines, ICEs, for decades. Reductions have been achieved in various ways, such as by using catalytic converters and improving the efficiency of ICEs to reduce the consumption of fuel. However, such reductions mainly target exhaust gases that would be discharged through an exhaust pipe of the ICE. Thus, there has been an increased interest in reducing the emissions of other exhaust gases, such as crankcase blow-by gases. Additionally, vehicle emission standards are starting to include standards for all vehicle emissions, thereby including emissions from crankcase blow-by gases, which further increases the interest in reducing such emissions.
It is of interest to provide a crankcase ventilation system for separating oil particles from crankcase blow-by gases of an internal combustion engine which may reduce crankcase blow-by gas emissions. It is a further interest to provide an improved quality, i.e. less oil particles, of crankcase blow-by gas which is released to the atmosphere, or sent back to a combustion chamber of an ICE. These interests are met by providing an arrangement having the features in the independent claims. Preferred embodiments are defined in the dependent claims.
Hence, according to an aspect of the present disclosure, there is provided a crankcase ventilation system for separating oil particles from crankcase blow-by gases of an internal combustion engine, ICE. The system comprises a housing and a disc stack separator. The disc stack separator may be arranged within the housing. The disc stack separator comprises a chamber and a rotor. The chamber may be arranged within the disc stack separator. The rotor comprises an oil separating element arranged within the chamber and spaced from one or more walls of the chamber, and a shaft configured to rotatably mount the oil separating element. The oil separating element may comprise a plurality of stacked plates, wherein the plates may be conical. The disc stack separator further comprises a first gas inlet for supplying the crankcase blow-by gases to the oil separating element along the shaft, and a first gas outlet for discharging the at least partially oil separated gases. The system further comprises a filter element. The filter element comprises a second gas inlet, a second gas outlet, and a filter arranged between the second gas inlet and the second gas outlet. The first gas inlet is configured to be connected to a crankcase blow-by crankcase outlet of the ICE. The first gas outlet is connected to the second gas inlet.
The present disclosure is based on the concept of using a disc stack separator connected to a filter element to increase the separation of oil particles from crankcase blow-by gases. A disc stack separator provides a filtration rate of substantially 100% for particles having a size above 0.6 μm. The filtration rate may further be dependent on a flow rate of the crankcase blow-by gases, such that a filtration rate of substantially of 100% may be achieved for particles having particles having a size below 0.6 μm, such as below 0.5 μm, 0.4 μm or 0.3 μm, when the flow rate is reduced. Further, a disc stack separator may not require regular service. However, the filtration rate of a disc stack separator may decrease with regards to particles having a size less than, for example, 0.6 μm. On the other hand, a filter element has a filtration rate of substantially 100%, regardless of the size of the particles. However, a filter element inherently has a low loading capacity, a short lifetime and requires regular service or replacement. By first using a disc stack separator to separate oil particles having a size above 0.6 μm before the crankcase blow-by gases are sent to the filter element, the load for the filter element is greatly reduced. In other words, the amount of particles which has to be separated by the filter element, in comparison to only using a filter element, is greatly reduced. Thereby, the lifetime of the filter element is extended. The lifetime of the filter element may be increased at least 25 times. Further, the loading capacity of the filter element is increased. In other words, the filter element may be used for a longer time before a maximum capacity of the filter element is reached. Alternatively, the size of the filter of the element may be decreased without decreasing the required service interval. Thus, combining a disc stack separator and a filter element achieves a synergistic effect as the advantages of both technologies are present.
By the term “oil particles” it is meant, for example, oil droplets and/or oil mist. The disc stack separator may comprise rotating means configured for rotating the shaft of the disc stack separator. The rotating means may comprise a turbine wheel, or an electric motor. The turbine wheel may be configured to be operated, for example, with oil, i.e. being oil-powered, via a belt, or a gear. The disc stack separator may be attached to an engine block of the ICE. The disc stack separator may be attached to, or integrated with a part of the engine block of the ICE, such as, for example, a cam cover. However, the disc stack separator may be a standalone component, i.e. not integrated with the engine block of the ICE. The first gas inlet may be connected to the crankcase blow-by outlet of the ICE, or the engine block, via an adapter conduit. The adapter conduit may be customizable, such that the system may be connected to many different kinds of ICEs. The system may be configured to release the filtered crankcase blow-by gases from the second gas outlet to an external space, such as the atmosphere.
The filter may be composed of a layer of arranged fibers, wherein the fibers may comprise polypropylene and/or fiberglass. The filter may be an Efficient Particulate Air, EPA, filter, high-efficiency particulate air, HEPA, filter or an Ultra Low Particulate Air, ULPA, filter. Thereby the filtration capacity of the system may be increased. An EPA filter may have a retention rate between 85% to 99%. A HEPA filter may have a retention rate between 99.95% to 99.999%. An ULPA filter may have a retention rate which is higher than a HEPA filter. A higher filter retention rate may lead to the filter reaching a maximum load capacity quicker. Thus, using disc stack separator may allow for using filters having a higher retention rate, thereby increasing the retention of particles.
One way of preventing crankcase blow-by gases from being released into the atmosphere has been by sending the crankcase blow-by gases back to a combustion chamber of the ICE. The second gas outlet may be configured to be connected to an intake manifold or an intake side of the ICE. Thus, the crankcase blow-by gases which has been cleaned by the system may be fed back to the ICE via the intake manifold. The intake manifold may be connected to combustion chambers of the ICE. Oil particles being present in the gas fed to the ICE may reduce the efficiency of the ICE and/or increase the risk of a malfunction of the ICE. Thus, the present system may improve the performance of the ICE.
The filter element may further comprise a pressure regulation valve. The first gas outlet may be connected to the second gas inlet via the pressure regulation valve. Alternatively, the second gas outlet may be connected to the pressure regulation valve. The pressure regulation valve may comprise a diaphragm. The pressure regulation valve may further comprise a spring configured to pre-load the pressure regulation valve. The pressure regulation valve may allow for a more efficient feeding of cleaned crankcase blow-by gases to the intake manifold, or intake side, of the ICE.
The filter element may comprise a positive crankcase ventilation, PCV, valve, wherein the first gas outlet may be conned to second gas inlet via the PCV valve. The PCV valve may provide an alternative way to allow for a more efficient feeding of cleaned crankcase blow-by gases to the intake manifold, or in intake side, of the ICE.
The pressure regulation valve may be arranged within the housing. Correspondingly, the PCV valve may be arranged within the housing. Thereby providing a more robust and compact system, which may increase the durability of the system. The housing may comprise a detachable portion, a lid, or a latch, which may allow a user to access the pressure regulation valve. The system may further comprise one or more bypass valves. The one or more bypass valve(s) may be configured to, for example, allow gas to be released if a pressure difference between two sides of a bypass valve exceeds a threshold, or if a gas flow level of the system is exceeded.
The first gas outlet may be arranged through a wall of the housing. For example, the first gas outlet may be connected to an opening in a wall of the housing. Thereby, the second gas inlet of the filter element may be securely connected to the housing and thereby to the first gas outlet. The pressure regulation valve may comprise an outlet, wherein the outlet may be arranged through a wall of the housing, or be connected to an opening in a wall of the housing, and thereby connectable to the first gas outlet.
The chamber may be formed by the housing. In other words, the housing may comprise the chamber. The chamber being formed, or comprised, by the housing may be understood as, for example, internal walls of the housing forming the chamber.
The housing may further comprise an oil reservoir. By the term “oil reservoir” is further meant, for example, oil chamber, or drive oil chamber. The disc stack separator may be configured to discharge oil separated from the crankcase blow-by gases into the oil reservoir. Thus, the disc stack separator may be configured to collect the separated oil into the oil reservoir. The oil reservoir may be connected to the chamber of the disc stack separator. The system may be configured to deliver oil from the oil reservoir to the ICE.
During operation of the ICE and the crankcase ventilation system, the filter element may be continuously filtering the crankcase blow-by gases and thereby retain oil particles. When the amount of oil particles retained by the filter reaches a certain level, the filter needs service or replacement. The arrangement of the filter element according to the present disclosure provides a more accessible filter element, and thereby provides easier replacement of a filter of the filter element. The present crankcase ventilation system may further be configured to collect oil, or oil particles, from the filter element. Further, the system may comprise an oil drain channel configured to deliver the collected oil to the oil reservoir. The filter element may be configured to allow retained oil to drain, or flow, into the oil drain channel. The drainage of flow may be higher when the ICE is not operating. Further, the force of gravity may assist the drainage of oil from the filter element. Thus, the crankcase ventilation system allows for drainage of the filter element, especially when the ICE is not operating. Thereby, the time before a filter needs to be serviced or replaced may be increased.
The first gas outlet may be connected to the second gas inlet via a gas conduit, thereby providing the ability of arranging the housing and the filter housing at a distance from each other. The gas conduit may further be configured as, for example, a pipe, a tube, such as a connecting tube, or a channel. A system comprising a pressure regulation valve, or a PCV valve, for which the first gas outlet is connected to the second gas inlet via the pressure regulation valve, or the PCV valve, may comprise at least one gas conduit which may be arranged between the first gas outlet and the pressure regulation valve, or the PCV valve, and/or between the pressure regulation valve, or the PCV valve, and the second gas outlet.
The filter element may comprise a filter housing. The filter may be arranged within the filter housing. Thus, the system may comprise a housing, in which the disc stack separator is arranged, and a filter housing, in which the filter element is arranged. A system having two separate housings allows for an increased flexibility when connecting the system to an ICE. As there is limited amount of space in a vehicle, it may be hard to fit a crankcase ventilation system into such a space. Further, the temperatures in some of the spaces around an ICE may not be suitable for all components of a crankcase ventilation system. Thus, by providing a system split into two housings the system can be placed more optimally with regards to fitting inside the space and/or with regards to temperatures inside the space.
The filter element may comprise a filter chamber, in which the filter may be arranged within the filter chamber. The second inlet may be arranged through a first wall of the filter chamber. The second outlet may be arranged through a second wall of the filter chamber. The second wall may be the same wall as the first wall, or a different wall than the first wall. Therefore, the second inlet and the second outlet may be arranged through the same wall, or through different walls. The filter chamber may be comprised by the housing. Thus, the housing, which may comprise a plurality of parts which may be welded and/or fastened together, may comprise the filter chamber of the filter element and the chamber of the disc stack separator. At least one side of the filter chamber may comprise a shape which is adapted to fit to a side of the chamber of the disc stack operator. A housing comprising the chamber and the filter chamber may be understood as an integrated solution, in which both of the disc stack separator and the filter element are realized within the same arrangement, or component. Thus, a more compact system may be provided. The arrangement comprising both of the technologies further may provide an easier installation of the system as fewer components need to be attached to an ICE.
The filter chamber may comprise a detachable cover. The filter chamber may comprise six sides. The detachable cover may form one of the six sides. Further, the detachable cover may form one of the six sides and portions of sides neighboring the side formed by the detachable cover. For example, The detachable cover may form a first side, and portions of the four sides neighboring the first side. The detachable cover may be attached to the rest of the filter chamber by fastening means, such as, for example, screws or bolts. Further, the detachable cover may be attached to the rest of the filter chamber via a hinge. The detachable cover may allow for a user to access the filter within the filter chamber, thereby providing easier replacement of a filter.
The second outlet may be arranged through the detachable cover. Alternatively, the second outlet may be arranged through a side, or a wall of the filter chamber.
At least a portion of the chamber of the disc stack separator may be abutting at least a portion of the filter chamber. The at least a portion of the filter chamber may comprise at least a portion of one or more sides of the chamber, and the at least a portion of the filter chamber may comprise at least a portion of one or more sides of the filter chamber. Thus, a more compact system may be provided.
This and other aspects of the present disclosure will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the disclosure.
The system 1 comprises a housing 10. The housing 10 comprises an upper portion 10a and a lower portion 10b. The upper portion 10a has a generally cylindrical shape comprising a top and a bottom. The lower portion 10b also has a generally cylindrical shape comprising a bottom and a top. The upper and lower portions 10a, 10b are connected and sealed together by means of fastening means 16, which are illustrated in
The system 1 further comprises a disc stack separator (not shown; see
The housing 10 may further comprise an oil reservoir (not shown; see
The system 1 further comprises a filter element 30. The filter element 30 comprises a filter housing 33 and a filter 31 arranged within the filter housing 33. The filter element 30 further comprises a gas inlet 43 and a gas outlet 44, which are arranged through opposite sides of the filter housing 33. The filter 31 is arranged between the gas inlet 43 and the gas outlet 44. Further, the filter 31 is connected between the gas inlet 43 and the gas outlet 44 such that gas inlet 43 and the gas outlet 44 are fluidly connected via the filter 31. In other words, gases have to pass through the filter 31 in order to travel from the gas inlet 43 to the gas outlet 44.
The first gas outlet 42 of the disc stack separator 20 is connected to the second gas inlet 43 of the filter element 30. In
The system 1 may further comprise an oil drain channel 32 as shown in
The second gas outlet 44 may be configured to be connected to an intake manifold (not shown) of the ICE. Thereby, the crankcase blow-by gases which have been filtered by the system 1 may be fed back into the ICE. The second gas outlet 44 may be connected to an intake manifold in a number of different ways. For example, the system 1 may comprise a secondary gas conduit configured for connecting the second gas outlet 44 to the intake manifold. In another example, the filter element 30 may be arranged at the intake manifold such that the second gas outlet 44 is connected directly to the intake manifold.
The shown cross-section of the crankcase ventilation system 1 is made along a longitudinal axis of a disc stack separator 20 of the system 1. Thereby, an inside of the disc stack separator 20 is shown. The system 1 comprises a housing 10 in which the disc stack separator 20 is arranged within. The housing 10 comprises an upper portion 10a and a lower portion 10b. The disc stack separator 20 comprises a chamber 21 and a rotor 20. The chamber 21 is at least in part defined by inner walls of the upper portion 10a of the housing 10. In other words, the chamber 21 is formed by the housing 10. The rotor 20 comprises an oil separating element 23 and a shaft 24. The oil separating element 23 is arranged within the chamber 21. The shaft 24 is arranged from a top of the upper portion 10a of the housing 10 to a bottom of the lower portion 10b of the housing 10, and is thereby arranged through the chamber 21. The oil separating element 23 is rotatably mounted on the shaft 24. Further, the oil separating element 23 is arranged within the chamber 21 and is spaced from walls of the chamber 21 such that there is space between walls of the chamber 21 and the oil separating element 23.
The disc stack separator 20 further comprises a rotating means 25. The rotating means 25 is illustrated in
The housing 10 as illustrated in
The system 1 shown in
A difference between the system 1 shown in
The pressure regulation valve 50 is arranged within the housing 10. More specifically, the housing 10 shown in
The pressure regulation valve 50 is connected to the first gas outlet (not shown; see e.g.
The system 1 may further comprise an auxiliary conduit 50b as shown in
A difference between the system 1 shown in
The pressure regulation valve 50 shown in
A difference between the system 1 shown in
The filter chamber 35 has six sides, out of which three are shown in
The filter chamber 35 comprises a detachable cover 37. The detachable cover 37 is configured to be detached in order to allow access for a user to the filter arranged within the filter chamber 35. The detachable cover 37 forms the outer side of the filter chamber 35 and portions of the four sides neighboring the outer side. It is to be understood that the present disclosure is not limited to comprising a detachable cover 37 as shown in
Another difference between the system 1 shown in
The second outlet 44 is shown to be arranged through the detachable cover 37. However, the second outlet 44 may be arranged on any of the sides of the filter chamber 35.
It is to be understood that the present disclosure is not limited to the embodiment as shown in
Number | Date | Country | Kind |
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2250255-3 | Feb 2022 | SE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2023/053837 | 2/16/2023 | WO |