Patent Description:
Gas turbine engines use lubricant to distribute heat, lubricate bearings, reduce friction, etc. This lubricant is circulated through the engine and can carry physical contaminants, such as carbon particles, metal particles, dirt, etc. Accordingly, lubricant is periodically passed through a lubricant filtration unit comprising one or more filters in order to remove at least a portion of the contaminants from the lubricant before the lubricant is circulated back into the engine.

<CIT> discloses a filter sealing system for heating- or air-conditioning installations.

<CIT> discloses a filter insert and a filter arrangement.

In one aspect, there is provided a filter assembly for an engine in accordance with claim <NUM>.

<FIG> illustrates a gas turbine engine <NUM> of a type preferably provided for use in subsonic flight, generally comprising in serial flow communication a fan <NUM> through which ambient air is propelled, a compressor section <NUM> for pressurizing the air, a combustor <NUM> in which the compressed air is mixed with fuel and ignited for generating an annular stream of hot combustion gases, and a turbine section <NUM> for extracting energy from the combustion gases. The fan <NUM>, the compressor section <NUM>, and the turbine section <NUM> are rotatable about a central axis <NUM> of the gas turbine engine <NUM>.

The gas turbine engine <NUM> may include a lubrication system S that may include a pump (not shown), lubrication conduits <NUM>, a lubricant reservoir (not shown), and a filter assembly <NUM>. The lubrication system S may also include additional components such as valve(s) (not shown), heat exchangers, etc. The lubricant reservoir may be in fluid flow communication with one or more components of the engine <NUM> in need of lubrication, such as, for instance, bearing cavity(ies), gearbox(es), and so on. The pump induces a flow of the lubricant from the lubricant reservoir, to the one or more components of the engine <NUM> in need of lubrication, back from the one or more components toward the reservoir and through the filter assembly <NUM>. The filter assembly <NUM> is used to remove contaminants from the lubricant before flowing the lubricant towards the one or more components.

In some configurations, a lubricant filter assembly, which includes a filter cartridge and a housing containing the filter cartridge, are secured to a gas turbine engine in such a way that replacement of the filter cartridge includes pulling the whole filter assembly downward. However, in some other configurations, the location of the lubricant filter assembly is such that there is no room to allow the lubricant filter cartridge to be moved downwardly and must be changed from a top. Moreover, care should be taken to ensure that there are no debris that falls into a clean lubricant outlet of the filter assembly when changing the filter cartridge. There is disclosed herein a filter assembly that may alleviate at least some of the aforementioned problems. More specifically, the disclosed filter assembly uses a filter housing defining a lower section for receiving the filter cartridge and an upper section for receiving a filter cover that is securable to the filter housing and to the filter cartridge. The upper section has a greater diameter than that of the lower section for creating a shoulder against which the filter cover abuts. A keyway engagement may be defined between the filter cartridge and the filter cover to secure the filter cartridge to the filter cover and to create a sealing engagement therebetween.

The clean lubricant outlet of the filter housing may be defined through a peripheral wall of the filter housing. This may prevent debris from falling into said outlet since the outlet may be out of reach of the debris that would fall vertically with gravity upon removal of the filter cartridge and filter cover.

Referring now to <FIG>, the filter assembly <NUM> is shown in greater detail. In the embodiment shown, the filter assembly <NUM> includes a filter housing <NUM>, a filter cover <NUM>, and a filter cartridge <NUM>. The filter cartridge <NUM> may be removably secured to the filter cover <NUM>. The filter housing <NUM> is configured to contain the filter cartridge <NUM> and the filter cover <NUM> is configured to sealingly engage the filter housing <NUM> to create a filter internal volume, or cavity, C within which the lubricant circulates through the filter cartridge <NUM>; the filter cartridge <NUM> being contain within the filter internal volume C of the filter housing <NUM>. In the depicted embodiment, the filter assembly <NUM> has a generally cylindrical shape and extends about a longitudinal axis L.

The filter housing <NUM>, referred simply as housing <NUM> herein below, is configured to receive the filter cartridge <NUM> therein. The filter housing <NUM> has an inlet (not shown) configured for receiving lubricant to be filtered and has an outlet 32a for outputting a flow of filtered lubricant. The housing <NUM> has an upper section 32b (<FIG>) and a lower section 32c (<FIG>). The lower section 32c is configured to receive a major portion, that is more than half herein, of the filter cartridge <NUM>. The outlet 32a of the housing <NUM> is defined at the upper section 32b of the housing <NUM>.

In the embodiment shown, the housing <NUM> has a circumferential wall 32d and an end wall 32e secured to an end of the circumferential wall 32d. The circumferential wall 32d extends circumferentially around the longitudinal axis L of the filter assembly <NUM> and may be cylindrical. The outlet 32a of the housing <NUM> is defined through the circumferential wall 32d at the upper section 32b of the housing <NUM>. Having the outlet 32a of the housing <NUM> locating as such may avoid contaminant to fall into the outlet 32a upon removal of the filter cover <NUM> and filter cartridge <NUM> during maintenance and replacement of the filter cartridge <NUM>.

As shown more clearly in <FIG>, the outlet 32a of the housing <NUM> is hydraulically connected with a line <NUM>, which may be part of the housing <NUM>. The line <NUM> may extend substantially perpendicularly to the circumferential wall 32d of the housing <NUM> such that the lubricant exits the filter assembly <NUM> in a radial direction, depicted by arrow A on <FIG>, relative to the longitudinal axis L. Alternatively, the line <NUM> may define an angle different than <NUM> degrees relative to the circumferential wall 32d of the housing <NUM>. Arrows A' and A" in <FIG> show that the line <NUM>, and the flow of lubricant exiting the filter housing <NUM>, may circulate in a radial direction combined with an axial and/or a circumferential direction relative to the longitudinal axis L. The angle the line <NUM> defines with respect to the housing <NUM> may depend upon a location where the filter assembly <NUM> is installed in the engine <NUM>.

Still referring to <FIG>, the housing <NUM> defines a shoulder <NUM> at an intersection between the upper and lower sections 32b, 32c of the housing <NUM>. In the embodiment shown, a diameter D1 of the upper section 32b is greater than a diameter D2 of the lower section 32c thereby creating the shoulder <NUM>. As shown in <FIG>, the upper and lower sections 32b, 32c of the housing <NUM> may be cylindrical and may be radially offset from one another. In other words, the upper and lower sections 32b, 32c may not be concentric. Alternatively, the upper and lower sections 32b, 32c may be concentric. In a particular embodiment, this offset between the upper and lower sections 32b, 32c of the housing <NUM> may create additional space to slide the cartridge <NUM>, when said cartridge <NUM> is secured to the cover <NUM>, within the housing <NUM>. This space may be obtained by having the upper and lower sections 32b, 32c of the housing <NUM> being concentric and by increasing a diameter of the upper section 32b relative to that of the lower section 32c. In a particular embodiment, this offset between the upper and lower sections 32b, 32c of the housing <NUM> creates the shoulder near the outlet of the housing and may help in protecting the outlet from contaminants that may be released during removal of the filter assembly.

Referring more particularly to <FIG>, the filter cartridge <NUM> may include any suitable filtering medium known in the art. In the embodiment shown, the filter cartridge <NUM> has an annular shape and has an outer wall 36a, an inner wall 36b located radially inwardly of the outer wall 36a relative to the longitudinal axis L of the filter assembly <NUM>. Herein, both the outer and inner walls 36a, 36b extends circumferentially about the longitudinal axis L. Herein, the outer and inner walls 36a, 36b are cylindrical, but other shapes are contemplated. The filter cartridge <NUM> may define a central passage 36c that may extend from a lower end 36d to an upper end 36e of the filter cartridge <NUM>. The filter cartridge <NUM> has an inlet 36i and an outlet 36o. In the embodiment shown, the inlet 36i of the filter cartridge <NUM> corresponds to the outer wall 36a, such that the lubricant enters in the filter cartridge <NUM> in a substantially radial direction relative to the longitudinal axis L of the filter assembly <NUM>, and the outlet 36o of the filter cartridge <NUM> corresponds to the central passage 36c at the upper end 36e of the filter cartridge <NUM>, such that the lubricant exits the filter cartridge <NUM> in a substantially axial direction relative to the longitudinal axis of the filter assembly <NUM>. It is understood that the expressions "upper" and "lower" may be interchanged and that the disclosed filter <NUM> may be used upside down, or at any other angle.

A plug <NUM> is secured to the filter cartridge <NUM> at the lower end 36d thereof. The plug <NUM> may be used to prevent lubricant to enter the filter cartridge <NUM> via an annular end face located at the lower end 36d of the filter cartridge <NUM>. In other words, the plug <NUM> may be used to prevent the lubricant from entering the filter cartridge <NUM> in a substantially axial direction. The plug <NUM> may ensure that the oil passes through the filter cartridge <NUM>. Stated differently, the plug <NUM> may prevent lubricant from penetrating the seal from an axial end face of the cartridge <NUM>. The filter cartridge <NUM> may be free of the plug <NUM> by having the filter cartridge <NUM> in abutment against a bottom of the housing <NUM> to avoid oil from bypassing the cartridge <NUM>. As shown more clearly on <FIG>, a annular groove 38a is defined by the plug <NUM> and may be configured for receiving a seal, such as an O-ring or any other suitable sealing member, therein.

Referring to <FIG> and <FIG>, for installing a cartridge assembly <NUM> of the filter cover <NUM> and the filter cartridge <NUM> inside the filter housing <NUM>, the cartridge assembly <NUM> is inserted into the housing <NUM> substantially along an axial direction relative to the longitudinal axis L via an open end 32f (<FIG>) of the filter housing <NUM>. The cartridge assembly <NUM> is moved relative to the filter housing <NUM> along the axial direction toward the end wall 32e (<FIG>) of the filter housing <NUM> until the cover <NUM> is in abutment against the shoulder <NUM> (<FIG>) defined by the housing <NUM>.

As shown in <FIG>, the filter cover <NUM> has an annular flange 34a at a top end thereof and the filter housing <NUM> has an annular flange <NUM> at the open end 32f thereof. Once the cartridge assembly <NUM> is received within the filter housing <NUM>, the annular flanges <NUM>, 34a of the housing <NUM> and cover <NUM> may be secured to one another to hold the cartridge assembly <NUM> in place relative to the filter housing <NUM>. Any suitable means to secure the annular flanges <NUM>, 34a to one another may be used. In a particular embodiment, a sealing engagement is created between the annular flanges <NUM>, 34a. Herein, the annular flanges <NUM>, 34a have substantially circular shapes, but other shapes are contemplated. Captive fasteners may be used to assemble the cover <NUM> to the housing <NUM> in order to reduce the chances of FOD. A quick release latch for a tool may be used to secure the cover <NUM> to the housing <NUM>.

Alternatively, or in combination, a sealing engagement may be created between the cover <NUM> and the housing <NUM> at a location proximate the shoulder <NUM> of the housing <NUM>. As shown in <FIG>, an annular groove 34b is defined by the cover <NUM> at a lower end thereof and extends substantially all around the longitudinal axis L. The annular groove 34b is configured to receive a sealing member, such as an O-ring (not shown), therein. In the embodiment shown, the annular groove 34b faces the radial direction such that the sealing member received therein may be compressed radially between the cover <NUM> and the peripheral wall 32d of the housing <NUM>. Alternatively, the annular groove 34b may be defined at an axial end face of the cover <NUM> such that the annular groove 34b faces the axial direction and faces the shoulder <NUM> of the housing <NUM> such that the sealing member received within the annular groove 34b is compressed axially between the housing at the shoulder <NUM> and the cover <NUM>. The cover <NUM> may define two annular grooves each receiving a respective one of two sealing members; the two annular grooves facing respectively in the radial and axial directions relative to the longitudinal axis L.

Referring more particularly to <FIG>, the cover <NUM> may be used to change a direction of the lubricant from being substantially axial relative to the longitudinal axis L to being substantial radial. As aforementioned, the lubricant exits the filter cartridge <NUM> via its outlet 36o along a direction that is substantially axial and the outlet 32a of the filter housing <NUM> is defined through the peripheral wall 32d and may have at least a radial component relative to the longitudinal axis L. In the embodiment shown, the cover <NUM> is used to redirect the flow of lubricant from being substantially axial to being substantially radial. The filter cover <NUM> may be used to impart at least a radial and/or at least a circumferential component to the flow of lubricant.

In the depicted embodiment, the cover <NUM> has an internal passage 34c that fluidly connects an inlet 34i of the cover <NUM> to an outlet 34o thereof. The inlet 34i of the cover <NUM> is in fluid communication with the outlet 36o of the filter cartridge <NUM> and the outlet 34o of the cover <NUM> is in fluid communication with the outlet 32a of the housing <NUM> and with the line <NUM> that extends therefrom. The internal passage 34c may be defined by two bores extending partially through a body of the cover <NUM>. Herein, the internal passage 34c includes: a first bore extending substantially axially relative to the longitudinal axis L from the outlet 36o of the filter cartridge <NUM> toward a top end of the cover <NUM> without extending fully through the cover <NUM>; and a second bore extending from the outlet 34o of the cover <NUM> in a substantially radial direction to a distal end of the first bore such that the first and second bore are in fluid communication with one another. Other configurations are contemplated. The shape of the internal passage 34c and its orientation inside the cover may vary, including straight holes, smooth cores.

The circulation of the lubricant through the filter assembly <NUM> is depicted with arrows in <FIG>. The lubricant enters the internal volume C defined by the filter housing <NUM> and passes through the filter cartridge <NUM> in a substantially radial direction relative to the longitudinal axis L and toward the longitudinal axis L to reach the central passage 36c of the filter cartridge. The lubricant flows axially along the central passage <NUM> toward the cover <NUM>, enters the internal passage 34c of the cover <NUM> in a substantially axial direction and is re-oriented, within the internal passage 34c of the cover <NUM>, in a direction having at least a radial component relative to the longitudinal axis L. The lubricant exits the filter assembly <NUM> via the outlet 32a of the housing <NUM> and is directed toward other components indeed of lubrication via the line <NUM> that is hydraulically connected to the housing <NUM>.

With time, the filter cartridge <NUM> may decrease in efficiency and may become partially clog by the contaminants it has removed from the lubricant circulating therethrough. Consequently, it may be required to periodically disassemble the filter assembly <NUM> to replace the filter cartridge <NUM>. It may be beneficial to remove the cartridge assembly <NUM> as a single unit.

Referring to <FIG>, while removing the filter cartridge <NUM> from the housing <NUM>, care should be taken to avoid contact between the cartridge <NUM> and the housing to avoid rubbing or scrapping the cartridge <NUM> against the peripheral wall 32d of the housing <NUM> which may cause contaminants picked up by the cartridge <NUM> to detach therefrom an to fall into the housing <NUM>. In the embodiment shown, a guiding feature <NUM> is secured to an end of the cartridge <NUM> that is located at the bottom of the housing <NUM> upon the cartridge assembly <NUM> received therein. More specifically, and in the embodiment shown, the guiding feature <NUM> is secured to the plug <NUM> at an external periphery thereof. The guiding feature <NUM> may be provided in the form of one or more tab(s) <NUM> circumferentially distributed about the longitudinal axis L and that bridge a gap G located radially between the filter cartridge <NUM> and the housing <NUM> relative to the longitudinal axis L. The guiding feature <NUM> may therefore limit contacts between the cartridge <NUM> and the housing <NUM>. The guiding feature may have various alternative shapes and length. It may be displayed in a circular pattern, or it can be a plate on the whole circumference with slots to allow fluid to pass.

Referring now to <FIG>, a cover and a filter cartridge in accordance with another embodiment are shown generally at <NUM> and <NUM>, respectively. And, referring concurrently to <FIG> that illustrate steps of assembly the cover <NUM> to the filter cartridge <NUM>. To create a locking engagement E (<FIG>) between the cover <NUM> and the filter cartridge <NUM>, the filter cartridge <NUM> defines a tab or a flange 136t that may extend circumferentially around the longitudinal axis L. In the embodiment shown, the flange 136t is located at a distal end of the filter cartridge relative to a distance from the end wall 32e (<FIG>) of the housing <NUM> (<FIG>) in which the cartridge <NUM> may be received. The flange 136t has a thickness t1 (<FIG>) taken along the longitudinal axis L. The flange 136t is configured to be received within a groove <NUM> defined by the cover <NUM>. The groove <NUM> is shown in dashed line in <FIG>. The groove <NUM> may have a depth d1 (<FIG>) taken along the longitudinal axis L and that may corresponds substantially to the thickness t1. As shown more particularly on <FIG>, the groove <NUM> is located axially between an axial end face <NUM> of the cover <NUM> and a lip <NUM>, which extends partially around the longitudinal axis L. The groove <NUM> extends radially outwardly relative to the longitudinal axis from an edge of the lip 136t. The cover <NUM> thereby defines an opening <NUM>, a periphery of which is depicted in <FIG> with a dashed line. The periphery of the opening <NUM> is defined partially by the lip 134t. As shown in <FIG>, the periphery of the opening <NUM> has a shape that corresponds substantially to a shape of the periphery of the flange 136t of the filter cartridge <NUM>. It is understood that the groove and the flange may be defined by the filter cartridge and by the cover in an alternate embodiment without departing from the scope of the present disclosure. In a particular embodiment, the flange 136t may define a chamfer to ease its insertion in the groove.

As shown more specifically in <FIG>, with continued reference to <FIG>, to assemble the filter cartridge <NUM> to the cover <NUM>, the cartridge <NUM> and the cover <NUM> are moved one relative to the other along the longitudinal axis L from a disengaged position shown in <FIG> until the flange 136t is received through the opening <NUM> defined by the cover <NUM>, which corresponds to an intermediate position shown in <FIG>. At which point, a sealing member SM, in this case an o-ring <NUM>, which is received within a groove <NUM> (<FIG>) of the filter cartridge <NUM>, becomes biased between the filter cartridge <NUM> and the axial end face <NUM> of the cover. The cartridge <NUM> may be in abutment against the axial end face <NUM> of the cover <NUM> upon the o-ring <NUM> biased therebetween. The sealing member SM may create a sealing engagement between the cover <NUM> and the cartridge <NUM> to limit fluid that circulates through the central passage 136c (<FIG>) of the filter <NUM> and toward the cover <NUM> from leaking at an interface between the cover and cartridge <NUM>, <NUM>. The sealing member SM may alternatively be a packing, a c-seal, a piston ring with or without a spring, a spring washer, a magnetic seal, or any other type of axial seal.

Referring more particularly to <FIG>, the cover <NUM> may be moved relative to the cartridge <NUM> from the intermediary position shown in <FIG> to a locked position shown in <FIG>. In the embodiment shown, falling within the wording of the claims, the cover <NUM> and cartridge <NUM> are moved one relative to the other along a radial direction R (<FIG>) relative to the longitudinal axis L. In other words, the cover <NUM> and the cartridge <NUM> are translated one relative to the other to move them from the intermediary position to the locked position of <FIG>. In the locked position, at least a portion of the flange 136t is received within the groove <NUM> of the cover <NUM>. This creates the locking engagement E that may limit axial movement of the cover <NUM> relative to the cartridge <NUM> along the longitudinal axis L. The cooperation of the flange 136t and the groove <NUM> may block axial movements of the cover and cartridge <NUM>, <NUM> one relative to the other. In the embodiment shown, the flange 136t becomes sandwiched between the lip <NUM> of the cover <NUM> and the axial end face <NUM> of the cover <NUM>. In the embodiment shown, in the locked position depicted in <FIG>, the lip <NUM> of the cover is slidingly received within a groove <NUM> defined by the cartridge proximate the flange 136t upon the flange 136t received within the groove <NUM> of the cover <NUM>.

In an alternate embodiment falling outside of the wording of the claims, the cover and cartridge <NUM>, <NUM> may be rotated one relative to the other about the longitudinal axis L to move the cover and cartridge from the intermediate position to the locked position. Other configurations are contemplated without departing from the scope of the present disclosure. Once the cover <NUM> and the cartridge <NUM> are in the locked position, the filter cartridge assembly may be moved within the housing <NUM> (<FIG>) using a handle <NUM> (<FIG>) located on top of the cover <NUM>. Other means of manipulating the cartridge assembly are contemplated.

Referring back to <FIG>, the shape of the opening <NUM> is configured to maximize a surface contact, or retention surface, area between the lip <NUM> and the flange 136t of the cover and cartridge <NUM>, <NUM> respectively. In the embodiment shown, the opening <NUM> defines at least one tooth 134t, two teeth 134t in the embodiment shown, and at least one slot <NUM>, two slots <NUM> in the embodiment shown. Correspondingly, the flange <NUM> may define at least one slot <NUM>, two in the embodiment shown, and at least one tooth 136q, two teeth 136q in the embodiment shown. The teeth 136q of the flange 136t are slidably received within the slots <NUM> of the opening <NUM> and the teeth 134t of the opening <NUM> are slidingly receive within the slots <NUM> of the flange 136t. In other words, the opening <NUM> may have a keyway shape corresponding to a shape of the flange 136t to allow one to be received within the other. In the embodiment shown, the opening <NUM> and the flange 136t are non-axisymmetric and may define a symmetry plane containing the longitudinal axis L.

Referring now to <FIG>, alternative embodiments of the cover are shown generally at <NUM> and <NUM>, respectively. The cover <NUM>, <NUM> may different from the cover <NUM> of <FIG> by the shape of their opening <NUM>, <NUM>. As shown, a number of teeth/slot may be varied. Any other suitable shape may be used. The shape of the opening of the cover and that of the flange may be used to ensure that the filter cartridge and cover are matingly engageable to one another solely in one orientation of the cover relative to the filter cartridge.

Referring more particularly to <FIG>, the opening <NUM> includes first and second curved sections 234m1, 234m2 diametrically opposed to one another; a diameter the first curved section 234m1 being greater than that of the second section 234m2. The first and second sections 234m1, 234m2 are connected via a middle section 234m3. The middle section 234m3 defines two slots 234m4 and two teeth 234m5; the two slots facing one another and the two teeth facing one another. In the embodiment shown, the middle section is tangent to the second section. Other configurations are contemplated. For instance, in <FIG>, the middle section is straight and a junction between the middle and second sections defines a kink. Referring more particularly to <FIG>, the opening <NUM> is similar to the opening <NUM> described above with reference to <FIG>, but the middle section 334m3 is free of the teeth and slot.

The different shapes of the opening and corresponding flange may be selected to provide a uniformity of a biasing force exerted by the interaction of the cover and filter cartridge on the sealing member when in the locked position shown in <FIG>. The shape of the opening may dictate a surface area used to retain the filter as well as its disposition near the seal. The shape shown in <FIG> may offer a larger retaining surface. The teeth may be used as a mean to prevent or limit the rotation of the filter cartridge <NUM> relative to the cover <NUM> should a sliding motion is used to disassemble the cartridge <NUM> from the cover <NUM>.

Referring to <FIG>, a cartridge assembly in accordance with another embodiment is shown generally at <NUM>. The cartridge assembly <NUM> includes a cover which may correspond to the cover <NUM> described above with reference to <FIG> and a filter cartridge <NUM> in accordance with another embodiment. In some cases, it may be required to grab the cartridge <NUM> for either assisting its removal from the housing <NUM> (<FIG>) and/or to orient it with respect to the cover <NUM>. However, the filtering medium of the cartridge may be soft and grabbing it directly may deform it, which may impair its filtering efficiency.

In the embodiment shown, the filter cartridge <NUM> includes at least one, two in the embodiment shown, holding tabs 436n, each of which may be L-shaped including a radial protrusion 436n1 extending radially away from a proximal end of the cartridge <NUM> and an axial protrusion 436n2 protruding axially from a distal free end of the radial protrusion 436n1. The axial protrusions 436n2 defines a surface 436n3 against which a user may lay his/her finger to manipulate the filter cartridge <NUM>. In the embodiment shown, the axial protrusions 436n2 extends axially relative to the longitudinal axis L toward the end wall of the housing <NUM> (<FIG>) when received therein. As shown in <FIG>, the holding tabs 436n are axially offset from the flange 136t and groove <NUM> defined by the cartridge <NUM>.

The support or holding tabs 436n may be used if the pinch (e.g. biasing force) between the filter cover <NUM> and the sealing member SM (<FIG>) is high enough to expect a deformation of the filter cartridge <NUM> during assembly. The tabs 436n may ease the grip by hand or tool and may be configured to re-direct the load path outside the filter element (e.g. filtering medium). The support may or may not serve as a filter guiding feature once in the locked position. In other words, the tabs may be in abutment against the wall of the housing to maintain the cartridge concentric with the housing.

Referring to <FIG>, another embodiment of a cartridge assembly is shown generally at <NUM>. The assembly <NUM> includes a cover <NUM> and a filter cartridge <NUM>. In the embodiment shown, the cover <NUM> defines two tabs 534t that are diametrically opposed to one another and the filter cartridge <NUM> defines two grooves <NUM> that are diametrically opposed to one another. Each of the tabs <NUM> of the cover <NUM> may be slidingly received within a respective one of the grooves <NUM> of the cartridge <NUM>. It is understood that the cover may define the grooves and the cartridge may define the tab in an alternate embodiment.

<FIG> illustrate the assembly <NUM> in the disengaged position and <FIG> illustrates the assembly in the locked position in which the sealing member SM is compressed between the cover and cartridge <NUM>, <NUM>. To create the locking engagement E between the cover <NUM> and the cartridge <NUM>, the cover and cartridge are moved one relative to the other until the grooves <NUM> are in register with the tabs 534t. At which point, the cover and the cartridge <NUM>, <NUM> are moved one relative to the other in a radial direction R relative to the longitudinal axis L to slide the tabs 534t within the grooves <NUM>.

Referring to <FIG>, another embodiment of a cartridge assembly is shown generally at <NUM>. The assembly <NUM> includes a cover <NUM>, a cartridge <NUM>, and a locking member also referred to as a fork <NUM>. In the embodiment shown, the cover <NUM> defines an elongated slot <NUM> dimensioned for receiving the fork <NUM>. The cartridge <NUM> defines a tab 636t at an extremity of the cartridge <NUM>. A recess 636r is defined by the cartridge <NUM> proximate the tab 636t. The cover <NUM> has an opening <NUM> suitably dimensioned for receiving the tab 636t of the cartridge <NUM>.

To create the locking engagement E between the cover and cartridge <NUM>, <NUM>, the cover and cartridge <NUM>, <NUM> are moved one relative to the other along the longitudinal axis L until the tab 636t of the cartridge <NUM> is received within the opening <NUM> of the cover <NUM>. At which point, the fork <NUM> may be inserted in the elongated slot <NUM> of the cover <NUM> in a radial direction R relative to the longitudinal axis L. The fork <NUM> thereby locks the tab 636t of the cartridge <NUM> within the cover <NUM>. More specifically, the fork <NUM> has an inner dimension suitably dimensioned to be able to be received within the recess 636r of the cartridge <NUM> and that is less than a diameter of the tab 636t, and has an outer dimension that is greater than a dimension of the opening <NUM> of the cover <NUM> such that, upon the fork <NUM> received within the elongated slot <NUM> of the cover <NUM>, movement of the cover <NUM> relative to the filter cartridge <NUM> along the longitudinal axis L is limited by the fork <NUM> and, more specifically, limited by the interaction of the fork <NUM> with the tab 636t of the cartridge <NUM> and with an annular flange 634f of the cover <NUM>, which defines the opening <NUM> of the cover <NUM>. In other words, the fork <NUM> is configured to be in abutment with both of the tab 636t of the cartridge <NUM> and with the annular flange 634f of the cover <NUM> to limit movements of the cover <NUM> relative to the cartridge <NUM>.

As part of the regular scheduled maintenance of an aircraft turbine engine, the lubricant/fuel filters may have to be replaced. It may be important that the filters are easily accessible as this may minimize the risk of introducing debris into the engine. On a twin engine application, the filter may have to be accessible from both sides of the engine. The disclosed filter assembly may minimize the risk of disassembly or mis-assembly that may lead to improper sealing between the inlet and outlet.

In some cases, filter upright position may be the most desirable one. The outlet may need to be protected against falling debris and filter contaminants. There may be an interest to ease the maintenance by removing the filter with the filter cover. The disclosed filter assemblies may be able to hide the outlet of the filter into the filter cover; ensure a connection to the engine that may not expose the outlet; and ensure a sub-assembly (e.g., filter cartridge assembly <NUM>) between the filter cartridge and the filter cover that may be required by design to assemble the sub-assembly in the filter housing. These may be achieved by a stepped filter housing <NUM>; a filter assembly sequence that may include an axial seal and a keyway shape interface; and/or filter guiding features.

A stepped filter housing may allow a filter to be mounted vertically upwards. The cover may transfer the fluid to a horizontal connection located on the outlet bore further from the filter bore. This recess may allow the connection to be protected against the filter contaminants in case contaminants are scraped on the filter housing bore during maintenance. The horizontal orientation may minimize the possibility of introducing dirt back into the engine. This step may be achieved by two concentric or non-concentric bores, or by a stepped bore of different shape. If the filter is mounted near the top of the engine it may be equally accessible from both sides of the engine.

The filter assembly sequence may ensure a minimized disassembly or mis-assembly risk when installed in the housing while allowing to remove the filter with the filter cover. The filter may feature a keyway-shaped flange and an axial seal. The filter cover may feature a keyway-shape slot and a groove. To assemble, the keyway-shaped flange and groove may be aligned and engaged. The filter may slide transversely to apply an axial load on the seal and to fix the filter on the filter cover. The assembly sequence may ensure the axial seal is loaded and the sub-assembly can only be assembled in the housing if the second step is completed.

The filter guiding features may ensure the filter is properly assembled and sealed on the filter cover when finally assembled in the housing. If the guiding features are located at the bottom of the filter, they may ensure the filter remains concentric to the filter bore in order to reduce the risk of scraping the contaminant from the filter to the housing outlet when the filter is being removed.

The stepped housing bore may allow for additional radial space to slide the filter on the cover. The filter guiding feature may ensure the filter remains assembled after final assembly when used with a face seal.

Claim 1:
A lubricant filter assembly (<NUM>) for an engine (<NUM>), comprising:
a housing (<NUM>) having a longitudinal axis (L) and defining an internal volume (C), the housing (<NUM>) having an open end (32f); and
a cartridge assembly (<NUM>) receivable within the internal volume (C) via the open end (32f) of the housing (<NUM>) and securable to the housing (<NUM>), the cartridge assembly (<NUM>) including a filter cartridge (<NUM>) having a generally cylindrical shape extending around the longitudinal axis, a cover (<NUM>) removably secured to the filter cartridge (<NUM>), and a sealing member (SM) between the cover (<NUM>) and the filter cartridge (<NUM>), a locking engagement (E) between the cover (<NUM>) and the filter cartridge (<NUM>) to limit an axial movement of the cover (<NUM>) relative to the filter cartridge (<NUM>) upon removal of the cartridge assembly (<NUM>) from the housing (<NUM>),
wherein the locking engagement (E) is defined by a cooperation of a groove (<NUM>) defined by one of the cover (<NUM>) and the filter cartridge (<NUM>) and a tab (136t) defined by the other of the cover (<NUM>) and the filter cartridge (<NUM>),
characterized in that
the cover (<NUM>) and filter cartridge (<NUM>) are movable one relative to the other in a radial direction (R) relative to the longitudinal axis (L) into a locked position in which the tab (536t) is at least partially within the groove (<NUM>).