Liquid purification or separation – Structural installation – Closed circulating system
Reexamination Certificate
1997-06-30
2001-02-20
Savage, Matthew O. (Department: 1723)
Liquid purification or separation
Structural installation
Closed circulating system
C210S188000, C210S320000, C210S335000, C210S445000, C210S455000, C210S456000, C210S489000, C096S219000, C096S220000
Reexamination Certificate
active
06190546
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to an oil suction filter, in particular for automatic gearboxes, having a housing which holds a filter and has an oil intake opening on its base surface.
Such filters are generally known. They are used to remove impurities from oil, sucked out of an oil sump, for example. For this reason, the oil suction filter is arranged with its oil intake opening pointing downward in the oil sump. The oil is thus sucked out from the underside of the housing through the filter into a duct which leads on and is arranged for example on the upper side of the housing.
In this process, air bubbles, which accumulate on the underside of the housing, also pass into the filter and ultimately also to the pump. The air bubbles themselves arise as a result of mechanical components, for example gear wheels of an automatic gearbox, which rotate in the oil sump and thus “beat” air into the oil, or as a result of splash oil which is used for cooling and is thus fed back into the oil sump.
The air which is also sucked in leads to increased generation of noise in the pump and to increased wear of the pump.
SUMMARY OF THE INVENTION
The object of the invention is to provide an oil suction filter which reduces the wear of the pump and reduces the production of noise.
This object is achieved by means of an oil suction filter which has an air diverting device that at least partially surrounds the oil intake opening. This prevents air bubbles which accumulate on the underside of the housing and which join together to form large air bubbles from passing into the filter together with the sucked in oil.
In a preferred exemplary embodiment, the air diverting device completely surrounds the oil intake opening. In this embodiment, the oil intake opening is completely shielded, so that no air bubbles which are located on the underside of the housing can penetrate into the oil suction filter.
In a further preferred exemplary embodiment, the oil intake opening is arranged in an edge region of the underside of the housing. Here, air bubbles are prevented from being sucked in even if the air diverting device does not completely surround the oil intake opening. The part which lies nearest to the edge of the housing does not necessarily have to be shielded by the air diverting device. Air bubbles do then also pass into the filter from the edge region. Since this edge region is small in comparison to the entire area of the underside, the quantity of air bubbles is also so small that a significant reduction in noise is achieved.
The air diverting device is preferably designed as a ring which completely surrounds the intake opening. The outer surface of the ring and its central axis extend essentially perpendicularly with respect to the base surface of the housing. This embodiment can be realized simply and cost effectively.
In a particularly preferred embodiment of the oil suction filter, there is provision for beads with an open edge to be provided in the base surface. This has the advantageous effect that the air bubbles rising from the bottom to the top accumulate in the beads and are directed to the edge of the oil suction filter. Since the beads are open here, the air bubbles are directed past or around the oil suction filter.
In a further preferred exemplary embodiment, the air diverting device protrudes at least approximately 3 mm beyond the base surface, that is, the height of the air diverting device is at least approximately 3 mm. It has in fact been found that the layer of air bubbles forming on the underside is usually not more than 3 mm. It is therefore essential for the height to be matched to the thickness of the layer of air bubbles.
Moreover, the object is achieved by an oil suction filter having a housing with an oil discharge opening, wherein the filter is arranged between the oil intake opening and the oil discharge opening and an oil deflection device is assigned to the oil intake opening and/or the oil discharge opening. This ensures that an inner space of the oil suction filter has a uniform flow through it, so that accumulation of air within the filter housing is avoided. The air is continuously transported away in the form of small air bubbles. This prevents a large number of small air bubbles from joining together to form a large undesired air bubble, in particular in a region with low oil flow which is also referred to as a dead region.
In a preferred embodiment, the oil deflection device comprises a wall region which runs essentially transversely with respect to the inflow or outflow direction. This has the effect that oil which is flowing into the oil suction filter cannot flow directly to the oil discharge opening but instead is deflected into the inner space, so that a lengthened flow path of the oil is produced and accumulations of air are avoided.
Finally, the object is to provide an oil suction filter which has various hydraulic resistances, so that a flow can be formed in the entire inner space of the oil suction filter. In addition, the flow velocity can be influenced selectively by means of the various hydraulic resistances. Consequently, direct discharge of oil from the oil intake opening to the oil discharge opening, as well as accumulations of air, are avoided.
In a preferred embodiment, the filter is formed from a filter cloth which has zones of different density and/or thickness in order to generate the various hydraulic resistances.
When a filter according to the invention is used, it produces a very uniform flow through the filter so that the formation of large air bubbles is essentially avoided. Moreover, the filtering action of the filter is extremely effective, that is, essentially all impurities are filtered out of the oil.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
REFERENCES:
patent: 1460867 (1923-07-01), Strowbridge
patent: 1488671 (1924-04-01), Hale
patent: 2665009 (1954-01-01), Harstick
patent: 2727634 (1955-12-01), O'Meara
patent: 3371793 (1968-03-01), Fowler
patent: 3384241 (1968-05-01), Nostrand
patent: 3480149 (1969-11-01), Houser
patent: 3513982 (1970-05-01), Carter et al.
patent: 3640839 (1972-02-01), Ochiai
patent: 4402827 (1983-09-01), Joseph
patent: 4450081 (1984-05-01), Anderson et al.
patent: 4828694 (1989-05-01), Leason
patent: 4889621 (1989-12-01), Yamada et al.
patent: 5494575 (1996-02-01), Kitajima et al.
patent: 5538633 (1996-07-01), Kitajima et al.
patent: 3906313 (1990-02-01), None
patent: 0396385 (1990-11-01), None
Luk Fahrzeug--Hydraulik GmbH & Co. KG
Ostrolenk Faber Gerb & Soffen, LLP
Savage Matthew O.
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