WO2013119628A1

WO2013119628A1 - Lubricant oil filter with continuous release additive vessel

Info

Publication number: WO2013119628A1
Application number: PCT/US2013/024883
Authority: WO
Inventors: Manish Patel; Dakota L. JOHNSON; R. Douglas HUDGENS; Peter K. Herman; John M. TURNEY
Original assignee: Cummins Filtration IP Inc
Current assignee: Cummins Filtration IP Inc
Priority date: 2012-02-06
Filing date: 2013-02-06
Publication date: 2013-08-15
Anticipated expiration: 2014-08-06
Also published as: DE112013000347T5; CN104024587A; US20130199983A1

Description

LUBRICANT OIL FILTER WITH CONTINUOUS RELEASE ADDITIVE

VESSEL

Field

An oil filter containing a continuous release additive vessel that releases an additive into the oil to extend oil drain intervals.

Background

Current lubricating oils do not meet the engine manufacturer's desired oil drain intervals because of limits in ash content placed upon the latest oil category. The inability of the oil to remain useful for extended service intervals is due to multiple changes in both the oil and the engine over the past few years. For example, many modern diesel engines are now equipped with exhaust gas recirculation (EGR) systems and diesel particulate filters (DPF), have reduced oil sump volumes, use lower viscosity oils, and use ultra low sulfur diesel (ULSD) and alternative fuels or coolants (including non-aqueous), all of which change the operating conditions of the engine and the rate of oil degradation.

The latest oil category, CJ-4, CI-4, limits the ash and sulfur content of new oil to 1.0% and 1.5%, respectively, which in turn limits the amount of high performance anti- wear additives (for example zinc dialkyldithiophosphates (ZDDP)) and over-based detergents (for example magnesium or calcium sulfonate or salicylate ) because of the metal present in the chemical composition. It is expected that these limits will continue to decrease or at least remain the same as future oil categories are launched, continuing to limit the oil manufacturer's abilities to extend the oil's useful life.

The need for additional additives is driven by the reactions occurring in the crankcase of a diesel engine. The primary limiting factor of oil life that is most commonly seen is the inability for the total base number (TBN) to remain above the condemning limit of 2.5 mgKOH/g or alternatively at a level higher than that of the total acid number (TAN). This can be due to a variety of chemical reactions that occur in the crankcase including oxidation of the oil from high temperature and pressure

environments, and the formation of both strong and weak acids in the oil from fuel blow- by (including biodiesel), coolant leaks, moisture and other contamination, sludge or soot formation and a variety of other mechanism.

Weak acids (such as acetic acid, methyl acetate, ethyl acetate, carboxylic acids, etc.) are formed due to the blow-by of combustion products of biodiesel based fuels. These acids are best neutralized by weak bases (such as metal oxide or methyl amine).

Strong acids are also formed and are best neutralized by strong base material in the oil thus depleting the initial TBN value.

Other reasons preventing the oil from reaching the desired drain intervals include thickening or thinning of the oil viscosity (e.g. maximum excursion equals ± one grade), the inability to disperse soot and particulates in the oil, and excessive nitration. With the past oil category, CI-4, ash content of up to 1.5% was acceptable with no limit on the sulfur content. This allowed an additive to include higher levels of over-based detergent and other additives and reach longer service intervals. Because additives are depleted continuously over time in the oil in part due to acid neutralization and by reacting with peroxides (a product of oxidation) generated in the engine oil, an improved technique of continually metering additives into the oil to extend the oil's useful life would be useful.

Summary

An engine oil filter is described that will continually release highly concentrated additives into the engine oil to reduce maintenance costs by reducing oil usage through extended oil drain intervals. The additives may include, but are not limited to, overbased detergents, weak base materials, anti-oxidants, anti-wear additives, friction modifiers, dispersants, viscosity modifiers, anti-foam additives, nano additives, or other additives beneficial to engine oil, individually or in various combinations.

In one embodiment, the oil filter includes a housing defining an interior chamber and having a first end and a second end, an oil inlet and an oil outlet at the first end of the housing, and oil flow pathway between the inlet and the outlet for oil flowing through the interior chamber. Filter media is disposed within the interior chamber in the oil flow pathway between the inlet and the outlet, and the filter media configured to filter oil flowing through the interior chamber. An additive vessel is disposed in the interior chamber and is configured to introduce additive material contained therein into oil flowing through the interior chamber.

In one embodiment, the additive material includes an over-based detergent and optionally one or more of: a weak base additive, an anti-oxidant additive, an anti-wear additive, a friction modifier additive, a dispersant additive, an anti-foam additive, a nano- additive, a corrosion inhibitor additive, a pour point depressant additive and a surfactant additive. For example, in one example, the additive material comprises the over-based detergent for example in an amount ranging from about 10% to about 90% by weight of the additive material, a friction modifier additive for example in an amount ranging from about 0.2 % to about 3% by weight, an anti-oxidant additive for example in an amount ranging from about 0.5% to about 3% by weight, an anti-wear additive for example in an amount ranging from about 1.0% to about 5% by weight, and an inert solvent for example in an amount ranging from about 0 to about 88.3% by weight.

Other additives and additive amounts can be used depending upon factors including, but not limited to, the type of oil, the oil category, the properties of the oil that one wants to improve, and the effectiveness of the additive(s). The additives can be used singly by themselves or in a multi-component mixture at any desired ratio. The additives may be combined with an inert solvent, such as base oil, for viscosity adjustment.

In one embodiment, the oil filter includes a full flow pleated filter media, a bypass media, a venturi nozzle, and the additive vessel which continuously releases an oil additive into the oil flowing through the oil filter. However, other combinations of elements are contemplated including, but not limited to: a) an oil filter containing the full flow pleated media, a venturi, and the additive vessel; b) by-pass media and the additive vessel; and c) a full flow pleated filter media, a by-pass media, and the additive vessel.

Drawings

Figure 1 illustrates an example of an oil filter with an additive vessel as described herein.

Figure 2 illustrates the operation of the additive vessel of the oil filter in Figure 1. Figure 3 is a cross-sectional view of another example of an oil filter with an additive vessel. Description

With reference to Figure 1, a lubricating oil filter 10 is depicted that incorporates the concepts described herein. The filter 10 is a spin-on oil filter that includes a housing 12 having an open first end and a dome-shaped, closed second end defining an interior chamber 14 along with a nut plate 16 that is secured to an open first end of the housing 12. A filter element 18, for example a fibrous, pleated, full flow filter media, is disposed within the chamber 14 for filtering contaminants from the oil. The filter element 18 includes a hollow interior, a lower endplate 20, and an upper endplate 22. The two endplates are sealed across their corresponding filter element ends in order to prevent fluid flow out through the ends of the filter element 18.

Next to the filter element 18 is a by-pass filter media section 24. The by-pass filter media 24 can comprise, for example, an assembly of stacked, ring-shaped discs made of, for example, cellulose material. The by-pass filter media 24 is configured to filter the oil as the oil flows through the by-pass media toward a central oil passageway 26 thereof. The by-pass filter media 24 abuts up against the lower endplate 20 and includes an enclosing base endplate 28. The filter 10 may include any ratio of full flow filter media 18 to by-pass filter media 24.

The filter element 18 includes an inner sleeve 30 that supports the interior surface of the filter media and defines an interior space 32. The lower endplate 20 is open at its center and is formed with a short, cylindrical conduit 34 that extends upwardly into the interior space 32. A tube 36 fits around the conduit 34 and provides fluid flow communication from the central oil passageway 26 of the by-pass filter media 24 into a venturi nozzle 38 disposed within the interior space 32.

The upper endplate 22 is formed with an inner annular lip 40 which provides an anchor for an inner seal 42. The venturi nozzle 38 includes an outwardly flared end that fits around the inner annular lip. When the filter 10 is mounted during use, an inside annular surface of the inner seal 42 fits up against a stem of a filter head as described in US 5,906,736. The nut plate 16, which may be stamped, molded, or machined, is internally threaded and is assembled to an externally-threaded portion of the filter head. The housing 12 is metal and has a substantially cylindrical sidewall which includes a formed upper lip which is shaped with an inverted receiving channel. Tightly and securely anchored into the channel is an annular upper, outer lip of the nut plate 16.

The nut plate 16 is provided with at least one oil inlet opening 48 to allow oil to be filtered to enter the filter. The nut plate 16 also defines a central, threaded outlet opening 50 by which the filter is threaded onto a corresponding threaded mounting post on the filter head and through which oil exits the filter. Further details on the general construction and operation of this type of filter can be found in US 5,906,736 which is incorporated herein by reference in its entirety.

An additive vessel 60 is disposed within the chamber 14 next to the by-pass filter media 24 between the by-pass filter media and the second end of the housing 12. The additive vessel 60 contains one or more additive materials and is configured to continuously release the additive into the oil at a controlled rate.

A coil spring 62 within the housing 12 pushes directly or indirectly against the bottom of the additive vessel 60 which forces the additive vessel 60 into engagement with the endplate 28.

The additive(s) released into the oil are intended to improve oil quality in some manner including, but not limited to, replenishing reserve alkalinity (RA), reducing oxidation and wear, stabilizing oil viscosity, and/or neutralizing acids in the oil. One example by which an additive may improve an oil's useful life is illustrated through the reaction of a sulfonate and carboxylate acid to create a neutral salt and water as shown below, thus preventing the TAN of the oil from increasing.

The additive may include, but is not limited to, any of the following additives which may be combined with a base oil or solvent for viscosity adjustment: Table 1 : Potential Oil Additives - Example A

Potential Oil Additives - Example B

The percentages in Table 1 are by volume or by weight. One or more of the listed additives may be blended with an inert solvent, such as base oil, to reach 100% composition. The listed additives can be used individually as one pure additive or in any combinations to form a multi-component mixture at any ratio.

One exemplary embodiment of a multi-component additive mixture that is believed to be useful is listed in Table 2 (by volume % or by weight %), which may or may not be mixed with an inert solvent such as a base oil to adjust viscosity.

Table 2

Example A

Example B

Tables 3-6 shown below indicate possible additive compositions for the additive vessel. All compositions and treat rates (TR) are in % by volume or % by weight (both are applicable). The mixtures below may also be blended with an inert solvent, such as base oil, to reach 100% composition.

Table 3 (Overbased detergents/Strong bases)

A highly concentrated base with a TBN of 10-500mgKOH/g should be present with a concentration range of approximately 80% to 90% of the fully formulated additive Example A

Example B

Table 4 (antioxidants)

The function of the antioxidant is to reduce the rate of oxidation in the oil, which will in turn help reduce acid formation, increase oil life and control viscosity.

Example A

Aminic Antioxidant 0 5 I Phenolic Antioxidants 0.5 3

A min c & H. Mo. Wt. Phenolic antioxida nts 0.5

H M >. W1 :. Phe nolic antioxidants 0 5 3

A mm atic r inn ?s 0 1 Example B

Table 5 (multi-functional friction modifiers)

The multi-functional friction modifier can be present to reduce engine wear and friction, leading to fuel economy improvements.

Example A

Example B

Table 6 (anti-wear additives)

An anti-wear additive can be present to help reduce engine wear during extended oil drain intervals.

Liquid ashless Butylated Triphenyl Phosphorothionate 1 I

Liquid ashless dithiophosphate 1

Liquid Mixture of amine phosphates I I

Alkyl Zinc Dialkyldithiophosphates 1

2 Ethyl hexyl zinc DialkyI thiophospates I

2 Ethyl hexyl Molydenum DialkyI thiophospates 1 5

Ashles Amine DialkyI dithiophosphate I I

Zinc Dialkyldithiocarbamate 1 5

Atimony Dialkydithiocarbamate 1

Methylene bis dialkyldithiocarbamate 1 5 Molybdeum Phosphorodithioate I

Molybdeum Dithiocarbamate 1 5 Example B

With reference to Figure 2, the additive vessel 60 includes a one-way valve 70 and a capillary tube 72 to effect release of the additive from the interior of the additive vessel. The capillary tube includes an inlet end 74 disposed inside the additive vessel and an outlet end 76 disposed within the center oil passageway 26 of the by-pass media. A hollow sleeve 78 is formed on and extends upwardly from the vessel 60, and a removable plug 80 fits into and seals with the sleeve 78 to close off the sleeve 78. The capillary tube 72 extends through the sleeve 78 and the plug 80. As shown in Figure 1, when the vessel 60 is in place in the filter, the plug 80 and the sleeve 78 extend into the center oil passageway 26 through the bottom of the by-pass filter media 24 so that the outlet end 76 of the capillary tube is disposed in and discharges into the passageway 26. In addition, the plug 80 is removable from the sleeve 78 to permit filling and refilling of the vessel 60.

Figure 3 illustrates a variation of a filter 10' that is similar to the filter 10. The filter 10' includes an additive vessel 60' with a one-way valve 70' and a capillary tube 72'. However, in the filter 10', the by-pass filter 24' is shorter in axial length than the by-pass filter 24. In addition, the end of the capillary tube 72' is disposed adjacent to the bottom of the vessel 60'. The tube 36' is also provided with a flow restriction. The filter 10' in Figure 3 operates in much the same way as the filter 10 operation discussed below.

The vessel 60 utilizes the pressure gradient across the filter element in addition to the vacuum effect created by the venturi 38 on the clean side of the pleated filter media 18 to drive the additive up the capillary tube 72 and into the oil. The release rate of the additive is controlled by careful selection of the capillary inner diameter (release rate goes with fourth power of inner diameter ID) and capillary length (release rate goes with inverse proportion of length) according to the well-known Hagen-Poiseuille equation for laminar flow in capillary tubes:

where;

AP is tie pressure drup

L is the length of pipe

With reference to Figures 1 and 2, dirty oil passes through the one way valve 70 into the additive vessel 60. The pressure in region 1 will be referred to as PI . The oil mixes with additive in the vessel (region 2). The oil/additive mixture then flows through the capillary tube 72 (region 3) into the passageway 26 in the center of the by-pass media

(region 4). The oil/additive mixture then combines with the clean oil and is dispensed from the filter. The pressure in region 4 will be referred to as P2.

The difference between Pi and P₂ changes over the life of the filter 10 as the filter media becomes more plugged. However, Pi will always be greater than P₂. As Pi-P₂ increases, the additive release rate will also increase, thus compensating for the dilution of the additive. Approximately 85-95% of the oil flows through the filter media 18, and most of the remainder flows through the by-pass media 24 except for the small amount that flows into the additive vessel.

The very small inner diameter of the capillary tube 72 makes it intolerant of particulates which may plug or damage the tube. Therefore, the additive(s) in the vessel 60 is in liquid form.

The venturi 38 helps to drive flow through the capillary tube 72. In addition, it is beneficial if the by -pass filter media not include additive material intended to be introduced into the oil. The use of a stationary additive material in the by-pass filter media section can lead to a decrease in media capacity due to reduced porosity.

Therefore, eliminating an additive material from the by-pass media would allow for equivalent capacity using a reduced by-pass media area, thus allowing for a larger chemical vessel. In addition, using a liquid additive in the vessel 60 will have improved reactivity when compared to use of a stationary additive in the by-pass media due to the fact that the active sites of an additive chemical contained in the by-pass media become coated with soot, sludge, and other contaminants and therefore have a reduced ability to neutralize acids. Nonetheless, if one finds it advantageous to do so, the by-pass media or the full flow filter media may include an optional stationary additive material, for example a strong or weak base additive material in particulate form, intended to be introduced into the oil.

Also, the central oil passageway 26 in the by-pass media is advantageous.

Without this open flow path, the pressure across the capillary tube will be very similar on the dirty side and clean side, so there will be no force to drive liquid flow through the capillary. The lack of such a central passageway 26 also minimizes the effect of the venturi tube 38 on the additive vessel, further hindering the driving force of the flow.

While the filter 10 has been described with the additive vessel at the bottom of the filter, the filter 10 can include other configurations such as with the additive vessel in other locations in the filter, for example located between the by-pass media 24 and the full flow media 18.

In addition, although the filter 10 has been described as having a combination of the full flow filter media 18, the venturi 38, the by-pass media 24, and the additive vessel 60, other configurations are possible. For example, the filter can include the full flow pleated media 18, the venturi 38, and the additive vessel 60, without the by-pass media. In another example, the filter can include the by-pass media 24 and the additive vessel 60 without the pleated media 18. In another example, the filter can include the full flow pleated filter media 18, the by-pass media 24, and the additive vessel 60, without the venturi nozzle 38 and the sleeve 30. Other configurations and combinations of elements are possible.

The invention may be embodied in other forms without departing from the spirit or novel characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims

1. An oil filter, comprising:

a housing defining an interior chamber and having a first end and a second end, an oil inlet and an oil outlet at the first end of the housing, and an oil flow pathway between the inlet and the outlet for oil flowing through the interior chamber;

filter media disposed within the interior chamber in the oil flow pathway between the inlet and the outlet, the filter media configured to filter oil flowing through the interior chamber;

an additive vessel in the interior chamber, the additive vessel configured to introduce additive material contained therein into oil flowing through the interior chamber, the additive material includes an over-based detergent and optionally one or more of: a weak base additive, an anti-oxidant additive, an anti-wear additive, a friction modifier additive, a dispersant additive, an anti-foam additive, a nano-additive, a corrosion inhibitor additive, a pour point depressant additive and a surfactant additive.

2. The oil filter of claim 1, wherein the filter media comprises a pleated filter media and a by-pass media disposed between the pleated filter media and the second end, the by-pass media includes a center oil passageway extending therethrough that is in communication with an interior of the pleated filter media, and the by-pass media does not include additive material intended to be introduced into the oil;

a venturi disposed within the interior of the pleated filter media;

the additive vessel includes a capillary tube with an inlet end disposed inside the additive vessel and an outlet end disposed within the center oil passageway of the by-pass media, and a one-way oil inlet that communicates the interior chamber of the housing with the inside of the additive vessel.

3. The oil filter of claim 1, wherein the filter media comprises a pleated filter media and a by-pass media disposed between the pleated filter media and the second end; the additive vessel is disposed between the by-pass media and the second end; the by-pass media includes a center oil passageway extending therethrough that is in communication with an interior of the pleated filter media; and the additive vessel includes a capillary tube with an inlet end disposed inside the additive vessel and an outlet end disposed within the center oil passageway of the by-pass media, and a one-way oil inlet that communicates the interior chamber of the housing with the inside of the additive vessel.

4. The oil filter of any preceding claim, wherein the additive material comprises the over-based detergent in an amount ranging from about 10% to about 90% by weight of the additive material, about 0.2 % to about 3% by weight of the friction modifier additive, about 0.5% to about 3% by weight of the anti-oxidant additive, about 1.0% to about 5% by weight of the anti-wear additive, and about 0 to about 88.3% by weight of an inert solvent.

5. The oil filter of any one of claims 1-3, wherein the additive material comprises the over-based detergent in an amount ranging from about 20% to about 90% by weight of the additive material, about 0%> to about 90%> by weight of hindered amines, about 0.5 % to about 30%) by weight of the friction modifier additive, about 1.0%> to about 30%> by weight of the anti-oxidant additive, about 1.0% to about 30% by weight of the anti-wear additive, and about 0 to about 77.5% by weight of an inert solvent.

6. The oil filter of any one of claims 1-3, wherein the additive material comprises the over-based detergent and one or more of: a weak base additive, the anti-oxidant additive, an anti-wear additive, a friction modifier additive, a dispersant additive, an anti- foam additive, a nano-additive, a corrosion inhibitor additive, a pour point depressant additive and a surfactant additive.

7. The oil filter of claim 6, wherein the additive material comprises the over-based detergent and two or more of: a weak base additive, the anti-oxidant additive, an anti- wear additive, a friction modifier additive, a dispersant additive, an anti-foam additive, a nano-additive, a corrosion inhibitor additive, a pour point depressant additive and a surfactant additive.

8. The oil filter of claim 1, wherein the filter media comprises a pleated filter media.

9. The oil filter of claim 1, wherein the filter media comprises stacked ring-shaped discs having a center passageway.

10. The oil filter of claim 1, wherein the additive vessel includes an inlet located at a region exposed to a first pressure and an outlet located at a region exposed to a second pressure, and the first pressure is greater than the second pressure.

11. An additive vessel configured to introduce an additive into oil in an oil filter, the additive vessel comprising:

a housing defining an interior space, a one-way oil inlet into the interior space located at a region that in use is exposed to a first pressure, and a capillary tube having an inlet end disposed within the interior space and an outlet end disposed outside the interior space at a region that in use is exposed to a second pressure; the first pressure is greater than the second pressure; and

additive material contained within the interior space, the additive material includes an over-based detergent and optionally one or more of: a weak base additive, an anti-oxidant additive, an anti-wear additive, a friction modifier additive, a dispersant additive, an anti-foam additive, a nano-additive, a corrosion inhibitor additive, a pour point depressant additive and a surfactant additive.

12. The additive vessel of claim 11, wherein the additive material comprises the over- based detergent in an amount ranging from about 10% to about 90% by weight of the additive material, about 0.2 % to about 3% by weight of the friction modifier additive, about 0.5% to about 3% by weight of the anti-oxidant additive, about 1.0% to about 5% by weight of the anti-wear additive, and about 0 to about 88.3% by weight of an inert solvent.

13. The additive vessel of claim 11, wherein the additive material comprises the over- based detergent in an amount ranging from about 20% to about 90% by weight of the additive material, about 0% to about 90% by weight of hindered amines, about 0.5 % to about 30%) by weight of the friction modifier additive, about 1.0% to about 30%> by weight of the anti-oxidant additive, about 1.0% to about 30% by weight of the anti-wear additive, and about 0 to about 77.5% by weight of an inert solvent.

14. The additive vessel of claim 11, wherein the additive material comprises the over- based detergent and one or more of: a weak base additive, the anti-oxidant additive, an anti-wear additive, a friction modifier additive, a dispersant additive, an anti-foam additive, a nano-additive, a corrosion inhibitor additive, a pour point depressant additive and a surfactant additive.

15. The additive vessel of claim 14, wherein the additive material comprises the over- based detergent and two or more of: a weak base additive, the anti-oxidant additive, an anti-wear additive, a friction modifier additive, a dispersant additive, an anti-foam additive, a nano-additive, a corrosion inhibitor additive, a pour point depressant additive and a surfactant additive.

16. The additive vessel of claim 11, wherein the capillary tube is disposed along a central axis of the housing, and the oil inlet is located radially outward of the capillary tube.