Abstract:
A fluid filter includes a filtered flow and a bypass flow. In particular, a fluid filter insert includes a first end cap, a second end cap, a screen disposed between the first and the second end caps, and a filter media surrounding the screen. Further, a method of filtering a fluid includes passing a first portion of the fluid through a fluid filter inlet, passing a second portion of the fluid through a filter media, and passing the first and the second portions through a filter outlet. In addition, a fluid filter includes a bypass inlet, a filter media inlet coaxial with the bypass inlet, an outlet axially spaced from the bypass inlet, and a housing surrounding the bypass inlet, the filter media inlet and the outlet. Further, the fluid filter provides that the bypass inlet is dimensioned to permit a predetermined amount of flow.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to automotive fluid circuits. More particularly, the present invention relates to an in-line fluid filter for automotive fluid circuits.  
       BACKGROUND OF THE INVENTION  
       [0002]     An automobile&#39;s engine and transmission can create a great deal of heat. In particular, heat can degrade the engine or transmission lubricant. Such lubricant degradation may have negative consequences, potentially causing catastrophic damage to the engine or transmission. Other types of machinery also require heat removal.  
         [0003]     Therefore, cooling systems have been provided to remove excessive heat created by engines, transmissions or machinery. Specifically, coolants may be passed through a heat exchanger to remove this heat. A heat exchanger for an engine is commonly referred to as a radiator. A heat exchanger for a transmission is commonly referred to as an oil cooler.  
         [0004]     Coolants are circulated through the radiator or oil cooler and may collect debris as they are circulated. As such, these coolants require filtration. However, excessive filtration may retard the flow of the coolant through the heat exchanger, causing excessive heat and overheating the engine or transmission. To alleviate this challenge, these coolant filters have sometimes been provided with bypass valves. However, these bypass valves may function improperly. At times, the valves are left open, preventing the coolant from being filtered. At other times, the valves remain closed, cutting off the coolant from circulating, thus over-heating the engine or transmission. Further, bypass valves may be large and cumbersome to place in the coolant line and increase cost and complications during installation. They may also need to be replaced often, leading to increased cost and time spent on replacements and repair.  
         [0005]     Accordingly, it is desirable to provide an apparatus and method to filter coolants, while ensuring that the coolant adequately flows through the heat exchanger. Moreover, it is desirable to provide an apparatus and method to filter coolants inline, in an inexpensive and efficient manner.  
       SUMMARY OF THE INVENTION  
       [0006]     The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments filters fluid while ensuring adequate fluid flow to a heat exchanger, transmission, engine or other machinery. In particular, in some embodiments, the fluid filter provides that a portion of the fluid is filtered while another portion of the fluid bypasses the filter.  
         [0007]     In accordance with one embodiment a fluid filter insert includes a first end cap, a second end cap, a screen disposed between the first and the second end caps, and a filter media surrounding the screen. Further, the fluid filter insert provides that the first end cap, the second end cap, the screen and the filter media are surrounded by a filter housing having a first end and a second end wherein the housing includes a housing inlet at the first end and a housing outlet at the second end. In addition, the housing inlet is axially spaced apart from the first end cap of the filter insert.  
         [0008]     In accordance with another embodiment, a method of filtering a fluid includes passing a first portion of the fluid through a fluid filter inlet, passing a second portion of the fluid through a filter media, and passing the first and the second portions through a filter outlet. Further, the method provides that the filter media, the screen and the filter inlet and the filter outlet are placed in a filter housing wherein the filter housing includes a first end having a housing inlet and a second end having a housing outlet. In addition, the method includes the step of passing the first and second portions of the fluid through the housing inlet and the housing outlet wherein the filter inlet and the filter outlet comprise a first end cap having a first orifice and a second end cap having a second orifice, respectively.  
         [0009]     In accordance with yet another embodiment of the present invention, a system for filtering fluid includes means for passing a first portion of the fluid through a fluid filter inlet, means for passing a second portion of the fluid through a filter media, and means for passing the first and the second portions through a filter outlet. Further, the system provides that the filter inlet and the filter outlet comprise a first end cap having a first orifice and a second end cap having a second orifice, respectively.  
         [0010]     In accordance with still another embodiment of the present invention, a fluid filter includes a bypass inlet, a filter media inlet coaxial with the bypass inlet, an outlet axially spaced from the bypass inlet, and a housing surrounding the bypass inlet, the filter media inlet and the outlet. Further, the fluid filter provides that the bypass inlet is dimensioned to permit a predetermined amount of flow.  
         [0011]     There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.  
         [0012]     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.  
         [0013]     As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  is a schematic view of a fluid filter in use in an automobile cooling system.  
         [0015]      FIG. 2  is a perspective view illustrating the fluid filter according to an embodiment of the invention.  
         [0016]      FIG. 3  is an exploded view of the fluid filter according to an embodiment of the invention.  
     
    
     DETAILED DESCRIPTION  
       [0017]     The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides a fluid filter, particularly a coolant filter, that ensures adequate fluid flow to a heat exchanger. The filter may be used inline in an application. Further, it may be used on the pressure side or return side of an application. The filter is of simple construction and facilitates simple installation and fewer repairs or complications during its operation.  
         [0018]     An embodiment of the present inventive apparatus is illustrated in  FIG. 1 . Specifically,  FIG. 1  is a schematic view of a fluid filter  10  in use in an automobile cooling system. The filter  10  is placed in line with a transmission  12  and a heat exchanger  14 . The heat exchanger  14  may be a cooler or a radiator. Line  20  allows filter  10  to be in fluid communication with transmission  12 , with a transmission outlet  16  and a filter inlet  18 . Line  26  allows the heat exchanger  14  to be in fluid communication with the filter  10 , with a filter outlet  22  and a heat exchanger inlet  24 . Lastly, the heat exchanger  14  and transmission  12  are in fluid communication through line  32 , with a heat exchanger outlet  28  and a transmission inlet  30 .  
         [0019]     Lines  20 ,  26  and  32  may be any type of hose or conduit that permits fluid flow. Although in this case, a transmission  12  is shown, any type of machinery may be used. In particular, machines requiring fluid filtration may be used, such as an engine for example. Also, although an automotive system is shown, to illustrate one particular application that may utilize the filter of the present invention, the filter of the present invention may be utilized with any system or application, requiring fluid filtration. For example, a power steering application may use the filter  10  of this invention. Further, the filter  10  may be placed on the pressure side or return side of any system.  
         [0020]     In the illustrated schematic diagram of  FIG. 1 , fluid constantly circulates between the transmission  12  and heat exchanger  14 , cooling the fluid. The fluid can be any type of fluid requiring filtration, for example, transmission fluid, engine oil, power steering fluid, etc. In this instance, the fluid exits the transmission  12  at the transmission outlet  16  and enters the filter  10  at the filter inlet  18 . There, the fluid is filtered, as will be described in further detail below.  
         [0021]     Thereafter, the fluid exits the filter through the filter outlet  22  and enters the heat exchanger  14  through the heat exchanger inlet  24 . While in the heat exchanger  14 , the fluid is cooled as necessary and exits the heat exchanger  14  at the heat exchanger outlet  28 . Finally, the fluid re-enters the transmission  12  via the transmission inlet  30  completing one circuit. Although,  FIG. 1  shows a simple schematic representation of the filter  10  in use, the filter  10  may be installed in a variety of systems, with great complexity, not illustrated in this schematic view.  
         [0022]      FIG. 2  is a perspective view illustrating the fluid filter  10  according to an embodiment of the invention. The filter  10  is shown having a first end cap  34 , a second end cap  36  and a filter element  38 . Specifically, the first end cap  34  may be a seat configured to hold a first end of the filter element  38 . Likewise, the second end cap  36  may be a seat configured to hold a second end of the filter element  38 . The first and second end caps  34  and  36 , respectively, may be made of any suitable material, for example, a metal.  
         [0023]     The filter element  38  may be any type of media or element capable of filtering fluid. In addition, the filter element  38  may be a fibrous media. In particular, the fibrous media may be pleated. The pleats provide greater surface area for filtration than non-pleated media. Further, the greater surface area may be placed in a smaller space.  
         [0024]      FIG. 3  is an exploded view of the fluid filter  10  according to an embodiment of the invention. Here, the first end cap  34  has a filter inlet  40 . The filter element  38  surrounds a screen  42  having apertures  44  spaced throughout the screen  42 . The second end cap  36  has a filter outlet  46 . The filter outlet  46  may be fitted with a gasket  48 .  
         [0025]     The filter inlet  40  and outlet  46  may be any kind of opening or orifice. The screen  42  may be cylindrical and hollow in nature. Hollow area  43 , created by the cylinder, serves as a bypass filter, as will be fully described below. The screen  42  may be formed of any suitable material. Preferably, the screen  42  is made of metal. The screen  42  provides structural integrity and support for the filter element  38 . The filter element  38  is shown here in its pleated form, surrounding the screen  42 .  
         [0026]     The filter  10  may be placed in its entirety in a fluid filter housing  50 . The filter housing  50  has a first end  52  and a second end  54 . At the first end  52 , the filter housing  50  has a housing inlet  56 . The housing inlet  56  is spaced apart from filter inlet  40  to permit fluid to proceed around the filter  10  and enter the filter media  38 . However, at the second end  54 , the filter housing outlet  58  may couple with the filter outlet  46  such that the filtered flow and bypass flow may exit the filter outlet  46  and the filter housing outlet  58  simultaneously.  
         [0027]     In operation, fluid enters the fluid filter housing  50  through the housing inlet  56 . Part of the fluid is directed around the first end cap  34  of the filter  10  and enters the filter element  38  and is adequately cleaned. The filter element  38  may be configured to provide as much filtration as desired. For instance, the filter element  38  may be as dense or as sparse as desired, to achieve the level of filtration required. The filtered fluid then enters the hollow area  43  created by the screen  42  through apertures  44  and exits the filter  10  at the filter outlet  46 . The apertures  44  themselves act as a secondary form of filtration, catching any particles that may not have been trapped by the filter element  38 .  
         [0028]     The remainder of the fluid enters the filter inlet  40  and proceeds through the hollow space  43  created by the screen  42  and exits the filter  10  directly at the filter outlet  46 . As previously mentioned, both the filtered flow and the bypass flow exit the filter outlet  46  and the housing outlet  58  simultaneously. Thus, the remainder of the fluid is not filtered, allowing the fluid to bypass the filter element  38 . This provides that there is always some fluid reaching the heat exchanger  14  or the transmission  12 .  
         [0029]     The portion of the fluid that is filtered may be between 10 and 40 percent of the total fluid, leaving between 90 and 60 percent, respectively, of the fluid unfiltered. The preferred percentage is to filter 30% of the fluid, leaving 70% of the fluid to bypass the filter element  38 . The fluid inlet  40  may be designed to accommodate the percentage of fluid to be filtered. For example, if the size of the filter inlet  40  is very small, then more of the fluid would be directed around the first end cap  34 , enter the filter media  38  and be filtered, allowing less fluid to enter the hollow area  43  and exit the filter  10 , bypassing the filter media  38  altogether.  
         [0030]     Correspondingly, if the size of the filter inlet  40  was large, more of the fluid would enter the hollow area  43  and proceed directly to the filter outlet  46  and exit the filter  10 , bypassing the filter media  38  altogether. This in turn, directs less fluid around the first end cap  34 , to be filtered by filter element  38 . In this manner, the amount of fluid filtration can be controlled.  
         [0031]     In addition, allowing only some of the fluid to be filtered ensures that fluid communication always occurs in the application being served by the filter  10 . For instance, in the example illustrated by  FIG. 1 , allowing some fluid to bypass the filter element  38  ensures that there will be some fluid circulated between the heat exchanger  14  and the transmission  12  at all times. Other filters have been known to filter more or less of the fluid than originally intended. For instance, those filters with conventional bypass valves have been known to function improperly. This may leave less fluid to circulate, potentially causing catastrophic failure of the entire system. Correspondingly, less fluid may be filtered, allowing more debris and impurities to enter the system, also potentially causing failure of the system.  
         [0032]     In addition to ensuring adequate fluid flow to the system at all times, the partial flow through the filter media  38  extends filter life. Because all of the flow does not proceed through the filter element  38 , it does not get clogged with debris and impurities as easily and will not wear as easily. In such a manner, the life of the filter element  38  will be extended and this will result in fewer replacements of the filter  10 . Fewer replacements lead to less cost and greater efficiency.  
         [0033]     Further, the partial flow through the filter element  38  allows the filter  10  to be placed in a higher pressure application than would otherwise be possible with a conventional filter. Because only a portion of the fluid enters the filter element  38 , the filter can be placed in a higher pressure application than a filter where all of the fluid passes through the filter media.  
         [0034]     Moreover, the filter inlet  40  size can also be configured based on the pressure requirements of the application. For instance, if it is desired that 30% of the total flow be filtered through the filter element  38 , then the following procedure might be followed to determine the size of the filter inlet  40 . A filter  10  with a solid first end cap  34 , having no orifice or inlet, may be installed in a filter housing. Fluid may then be passed through the filter  10  and pressure and flow may be measured.  
         [0035]     The pressure drop across the filter element  38  may then be measured at 30% of total system fluid flow. This pressure drop across the filter element  38  may then be used to determine the filter inlet  40  size that would yield equivalent pressure drop at 70% total fluid flow. Then the filter inlet  40  size may be introduced to the first end cap  34  in any suitable manner to achieve 30% filtered flow.  
         [0036]     Although an example of the filter is shown using coolants, it will be appreciated that other fluids can be used. Also, although the filter is useful to the automotive industry it can also be used in other industries. In particular, the filter  10  may be used in heating and ventilation systems, or any system requiring fluid filtration.  
         [0037]     The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.