Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
  • F01M11/00—Component parts, details or accessories, not provided for in, or of interest apart from, groups F01M1/00 - F01M9/00
  • F01M11/03—Mounting or connecting of lubricant purifying means relative to the machine or engine; Details of lubricant purifying means

Definitions

• the present invention relates to a device comprising a by-pass hydraulic filter configuration as defined in the preamble of claim 1.
• Such devices are generally known, e.g. in the form of combustion engines and of transmissions for automotive vehicles.
• the lifetime and quality of operation of such a device is considerably enhanced by the presence and use of a by-pass configuration filter.
• Such type of filters due to their nature, operate at a filtering level that is considerably more refined than standard so called in-line filters, but also have a relatively slow pace of flow through it.
• Reason for this is that standard alternatively denoted full flow filters mainly function on the basis of a surface based filtering principle, while by-pass filters, very often also micro-filters, function on the basis of an in-depth filtering principle, at which the oil is filtered within a thick and relatively dense layer of filter material.
• the feature of relatively low flow of fluid per minute directs the micro-filters towards application in a said by-pass configuration.
• the by-pass configuration may be made as a separate hydraulic circuit having a separate pump for providing a pressure required for the oil to pass through the micro-filter.
• additional pump is saved in case such by pass is favourably made over a part of such hydraulic means using mechanical device.
• Such part could e.g. be a cooler part of such mechanical device and could be used as a suitable location for a by-pass configuration at which a separate pump and extensive amounts of connections are saved.
• Relevant criteria in this respect are the presence of a supply and a discharge line, and a pressure difference caused by the part that is by-passed.
• the filter applied in such by-passing configuration is to be adapted to and restricted by the nature of such mechanical device part to be by passed.
• the filter should not be designed or chosen to allow a pass through of too large a flow, i.e. not over a predefined value determined for the specific configuration. Passing such predefined maximum allowed amount of flow would in such by-pass configuration draw away fluid from the device that is by-passed, and would set it at the risk of ceasing to function properly.
• an object of the current invention to promote the functional quality of such by-pass configurations, in particular to maximise the amount of flow passed through the by-pass filter, and thereby to improve the lifetime and functional quality of the mechanical device it is serving.
• the measure according to the invention as defined in the characterising portion of the following claim 1.
• an improved by-pass filter i.e. a by-pass filter allowing a considerably larger flow that the predefined maximum for the configuration.
• a hydraulic flow restricting means incorporated in a connection line connecting the supply line and the by-pass filter, i.e. including the entry opening of the by-pass filter.
• the restriction is configured to bring down the flow through of the improved flow filter to said allowed maximum under the most favourable conditions i.e. at maximum operating temperatures and at maximum value of occurring flow within the relevant part of the device.
• Figure 1 is a schematic example of a typical prior art by-pass filtering configuration for a mechanical device using hydraulic fluid at operation;
• Figure 2 is a scheme according to figure 1 in which the structural part of the improvement according to the invention is represented;
• Figure 3 in a graphical representation represents the functional part of the improvement according to the invention at a common operational temperature of 90 degrees Celsius.
• Figure 4 is a representation according to figure 3 at a temperature of 40 degrees
• Figure 1 represents a portion of a mechanical device using hydraulic fluid to be filtered for the benefit of the operation and lifetime of the device.
• the device part includes a supply line 1, supplying hydraulic means from another part, e.g. a transmission casing to a device part 2, in this example a fluid cooler, and a hydraulics return line 5 returning the fluid passed through the device part to the mechanical device.
• the passage of oil through part 2 may be for use or for treatment thereby.
• Supply and discharge lines 3 and 4 respectively represent the lines for coolant medium for heat exchange with the hydraulic fluid for the mechanical device.
• a pressure difference Pd over the part 2 allows the hydraulic fluid to pass through the part 2.
• This pressure difference is provided by another part of the device, not depicted in the drawing, e.g. by a pump.
• the existing pressure difference and the existing hydraulic supply and return lines are favourable used in this example to create a by pass filter configuration using these existing means.
• a micro filter 7 is connected in parallel to the device part 2 via a supply line 6 connected to the supply line 1 and a return line 8 connected to the return line 5.
• the whole of the represented structure may be provided as an integrated unit.
• the filter is designed to allow a predefined maximum amount of flow of oil to pass through it, so as not to take too much oil away from the part 2 of the mechanical device, and thereby so as not to jeopardise the operation said part 2 and/or the mechanical device.
• the depicted configuration though economically and spatially favourable by its design, is functionally limited in filtering capacity. This condition may therefor in practice hamper the inclusion of a by pass filter in certain applications. It is however an object of the invention to increase the functional quality of the current configuration without undue effort, thereby increasing the chances for apply a micro filter or thereby increasing the performance of an existing by-pass configuration, all while maintaining the existing advantages and safeguards within the configuration.
• the above aim is, at hindsight in a surprisingly simple manner achieved by applying a restriction means in the manner as provided by figure 2, i.e. in the supply line 6 connecting the supply line 1 of the configuration with the by-pass filter 7.
• the restriction may alternatively also favourably be included in the the filter device itself, i.e. at the entrance thereof.
• micro high efficiency filter can be optimised regarding flow performance by which for example a relation is obtained for an "improved flow element".
• a normal restriction for example a small hole, can be characterised by:
• the added restriction is applied in series with a flow improved micro high efficiency filter.
• the oil flow through the by-pass circuit - thus through the filter element 7 and through the restriction 9 when inco ⁇ orated - would decrease, e.g. because of a lowered total pressure difference Pd or because of a higher oil viscosity
• the combination of restriction and flow improved micro high efficiency filter will result in a higher oil flow through the filter element 7 and thus better filtration performance, as when compared to the common prior art configuration reflected by figure 1.
• a main benefit of the novel configuration is improved filter performance at lower pressure differences and lower oil temperatures - related to a reference maximum pressure difference and corresponding maximum oil flow through the filter element at a reference oil temperature.
• Figure 3 and 4 illustrate the above numerical example, and the improvement gained by inclusion of the restriction means, in a graphical manner for temperatures at 90 degrees and 40 degrees Celsius.
• the oil flow Fo is plotted in liter per minute (l/min)
• the pressure difference Pd over the by-pass configuration filter is provided in units of Bar.
• the uppermost line 10 in the graphs represents the characteristic of a standard filter element within the present configuration.
• the line 11 represents the flow characteristic of the improved flow filter element, which allows a larger flow at lower pressure differences.
• Line 12 represents the flow characteristic of the restriction, while line 13 represents the characteristic of the combined effect of restriction and improved flow filter in the present configuration.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fluid-Pressure Circuits (AREA)
• Filtration Of Liquid (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2003
  • 2003-10-24 WO PCT/IB2003/004728 patent/WO2004038190A2/en not_active Application Discontinuation
  • 2003-10-24 EP EP03758415A patent/EP1613844A2/de not_active Withdrawn
  • 2003-10-24 AU AU2003274436A patent/AU2003274436A1/en not_active Abandoned

Non-Patent Citations (1)

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