GB2563014A

GB2563014A - A method of manufacturing a sump, a sump, and a vehicle comprising a sump

Info

Publication number: GB2563014A
Application number: GB1708422.9A
Authority: GB
Inventors: John Desmond Alexander
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2017-05-26
Filing date: 2017-05-26
Publication date: 2018-12-05
Also published as: DE102018206692A1; GB201708422D0

Abstract

A method of manufacturing a structural sump 100 for an engine comprises placing a support frame 102 into a mould. A mouldable material 120 is supplied into the mould to at least partly encapsulate the support frame. The mouldable material may be a polymer and may encapsulate some or all of the support frame. The cured mouldable material may form a liner of the sump, for holding an engine lubricant. Alternatively, prior to supplying the mouldable material into the mould, a liner may be placed into the mould with the support frame, the mouldable material at least partly encapsulating the liner. The method may include removing the sump from the mould after the mouldable material is sufficiently cured or set; and machining the sump to final dimensions. The mouldable material may be a polymer and supplying the mouldable material into the mould may comprise injecting. The mouldable material may be an expanding foam. The support frame may be aluminium or an aluminium alloy. The sump may include a first mounting means for mounting a drive unit.

Description

TECHNICAL FIELD

The present disclosure relates to sumps, such as those used with internal combustion engines.

Aspects of the invention relate to a method of manufacturing sump, a sump, and a vehicle comprising a sump.

BACKGROUND

Sumps (sometimes called “oil pans”) are reservoirs used to hold an engine lubricant such as oil. Typically, the sump is a separate component that is attached to an engine during manufacture. In some cases, the sump may provide rigidity to the connection between the engine and transmission.

In front-engined four-wheel-drive vehicles, drive from the engine is usually provided to a transfer case by way of a main drive shaft from a transmission. The transfer case has a rear drive shaft that provides drive to a rear differential for driving the rear wheels, and a forward drive shaft that provides drive to a front drive unit for driving the front wheels. Due to the driveline loads that it receives, the front drive unit may be mounted to the engine block or the vehicle chassis.

There is a general drive to reduce the weight of vehicles, at least partly to help improve fuel economy. Even modest per-component weight savings can add up to significant overall improvements in fuel economy. Such weight savings, however, must be balanced against the need to maintain strength and rigidity.

It is an object of the present invention to address disadvantages associated with the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a method of manufacturing sump, a sump, and a vehicle comprising a sump.

In accordance with an aspect of the invention, there is provided a method of manufacturing a structural sump for an engine, the method comprising:

placing a support frame into a mould; and supplying a mouldable material into the mould to at least partly encapsulate the support frame.

The method may comprise:

removing the sump from the mould after the mouldable material is sufficiently cured or set; and machining the sump to final dimensions.

The machining may comprise machining the support frame and the cured or set mouldable material.

The mouldable material may be a polymer, and supplying the mouldable material into the mould may comprise injecting.

The method may comprise encapsulating at least all internal surfaces and edges of the support frame.

The method may comprise encapsulating at least all external surfaces and edges of the support frame.

The cured mouldable material may form a liner of the sump, for holding an engine lubricant.

The method may include, prior to supplying the mouldable material into the mould, placing a liner into the mould with the support frame, the mouldable material at least partly encapsulating the liner.

The method may comprise placing the liner into the mould such that there is a space between the liner and the support frame, the mouldable material at least partly filling the space.

The mouldable material may encapsulate a majority of the outer surface of the liner.

The mouldable material may be an expanding foam.

The support frame may be formed from a metal or metal alloy.

The support frame may be formed from aluminium or an aluminium alloy.

The support frame may be at least partly skeletal.

The support frame may be continuous.

In accordance with another aspect of the invention, there is provided a sump manufactured in accordance with the method according to the previous aspect.

In accordance with another aspect of the invention, there is provided a sump, comprising: a support frame comprising a first material; and a liner comprising a second material, the liner being at least partly supported by the support frame.

The support frame may be metallic.

The support frame may be aluminium or an aluminium alloy.

The liner may be polymeric.

The liner may be moulded.

The liner may be overmoulded to the support frame.

The liner may be overmoulded:

at least partly inside the support frame; at least partly outside the support frame; or overmoulded so as to encapsulate at least some of the support frame.

The support frame may comprise one or more attachment points for attaching the sump to an engine.

The sump may comprise first mounting means for mounting a drive unit;

The first mounting means may be configured for use with a drive unit selected from the group consisting of:

a front drive unit; a front wheel drive unit; an electric machine; a kinetic energy recovery system; a clutch; and a drive disconnection unit.

The sump may comprise a space between the liner and the support frame, the space being at least partly filled by an expanding foam.

The expanding foam may encapsulate a majority of the outer surface of the liner.

According to another aspect of the invention, the vehicle may comprise an engine, the engine comprising the sump of any aspect of the invention.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is a front right perspective view of a sump for a vehicle according to an embodiment of the invention;

Fig. 2 is a front left perspective view of the sump of Fig. 1;

Fig. 3 is a front right inverted perspective view of the sump of Figs 1 and 2;

Fig. 4 is a front left inverted perspective view of the sump of Figs 1 to 3;

Fig. 5 is a schematic plan view showing drivetrain components of a vehicle, including a sump according to an embodiment of the invention;

Fig. 6 is a schematic side view of the drivetrain components of Fig. 5; and

Fig. 7 is a front right perspective view of the sump of Figs 1 to 4, with a front drive unit installed;

Fig. 8 is a front left perspective view of the sump of Fig. 7;

Fig. 9 is a front right perspective view of a support frame used in manufacturing the sump of Figs 1 to 4, 7 and 8;

Fig. 10 is a front left perspective view of the support frame of Fig. 9;

Fig. 11 is a front left inverted perspective view of the support frame of Figs 9 and 10;

Fig. 12 is a front right inverted perspective view of the support frame of Figs 9 to 11;

Fig. 13 is a side elevation view of a vehicle comprising an engine having a sump according to an embodiment of the invention;

Fig. 14 is a flowchart showing a method of manufacturing a sump according to an embodiment of the invention;

Fig. 15 is a mould for use with the method of Fig. 14;

Fig. 16 is a horizontal section through a portion of the sump of Figs 1 to 4;

Fig. 17 is a horizontal section through a portion of an alternative sump according to an embodiment of the invention;

Fig. 18 is a horizontal section through a portion of another alternative sump according to an embodiment of the invention;

Fig. 19 is a flowchart showing a method of manufacturing a sump according to an embodiment of the invention;

Fig. 20 is a mould for use with the method of Fig. 19; and Fig. 21 is an alternative mould for use with the method of Fig. 19.

DETAILED DESCRIPTION

Referring to the drawings, and Figs 1 to 4, and 7 to 12 in particular, there is shown a sump 100 for a vehicle, such as a car as described below and in relation to Fig. 13. The sump 100 comprises a support frame in the form of structural frame 102.

The structural frame 102 comprises first mounting means in the form of first mounting points 104. The first mounting points 104 may comprise reinforced sections of the structural frame 102. Each of the first mounting points 104 comprises one or more threaded holes 110, to receive bolts 111 when a front drive unit (FDU) is installed as described below. Alternatively, or in addition, at least one threaded stud (not shown) for receiving a nut may be positioned at each mounting point 104 to allow attachment of the FDU 128 to the sump 100. The first mounting points 104 and the structural frame 102 as a whole have sufficient strength and rigidity to allow mounting of a drive unit as described in more detail below in relation to Figs. 7 and 8.

In this embodiment, the structural frame 102 includes second mounting means in the form of a mount 112 on the opposite side of the sump 100 from the first mounting points 104. The mount 112 comprises a reinforced section of the structural frame 102. Threaded holes 130 are positioned around a far side aperture 116 formed in the mount 112. The mount 112 and the structural frame 102 as a whole have sufficient strength and rigidity to allow mounting of a bracket 118 that holds a far-side bearing 138 as described in more detail below in relation to Figs 7 and 8.

In this embodiment, the structural frame 102 is formed from an aluminium alloy. The structural frame 102 may be manufactured in any suitable manner. For example, the structural frame 102 may be high pressure die cast aluminium, using a pressure die casting alloy such as LM24, as known to those skilled in the art. Other forms of casting, such as gravity die casting or sand casting may also be used. Other alloys may also be used.

Irrespective of the alloy and/or casting process(es) used, the structural frame 102 may initially be cast to an approximate shape, followed by manual and/or CNC machining to final dimensions. Parts of the structural frame 102 may be left as originally cast, eg where the casting is sufficiently accurate and/or the precise dimensions are less critical.

The structural frame 102 may alternatively be machined from billet material. The structural frame 102 may alternatively be formed by an additive process, such as 3D printing, or may be forged or pressed. It may be constructed using composite materials such as, for example, glass-reinforced plastics. In yet other embodiments, the structural frame 102 is formed from more than one piece (not shown), the pieces being joined by any suitable means, such as welding, bonding, snap- or interference-fittings, and/or the use of fasteners such as bolts, screws, rivets, clamps or catches. The individual pieces may be constructed in any suitable fashion, such as moulding, casting, machining, additive manufacture, forging or pressing, as described above in relation to the one-piece structural frame 102.

The sump 100 also includes a liner 120 that may be at least partly supported by the structural frame 102. The liner 120 is configured to retain, in use, a volume of lubricant. Ordinarily, the lubricant will be motor oil, whether synthetic, petrochemical-derived, or a combination of the two.

The liner 120 includes a first recessed portion 106, disposed generally between the first mounting points 104. A drive-side aperture 108 is formed within the first recessed portion 106. The first recessed portion 106 defines a first annular recess 107 around the drive-side aperture 108.

Figs 3, 4, 11 and 12 additionally illustrate a gearbox mount 117 that is bolted to the structural frame 102. In practice, the gearbox mount 117 may be attached to the structural frame 102 after the liner 120 is attached to, or moulded onto, the structural frame 102.

As best shown in Figs 7 and 8, the bracket 118 is bolted to the mount 112 using the threaded holes 130. The bracket 118 includes reinforcing webbing 132. An end of the bracket 118 distal from the sump comprises a bearing holder 140 for receiving a far side bearing 138, as described in more detail below.

In this embodiment, the liner 120 is formed from glass-reinforced nylon. In other embodiments, any other suitable material or combination of materials may be used for the liner 120. For example, a different type of polymer or polymers may be used, with or without strengthening fibres. Any other polymer(s) having the required strength, rigidity, moulding and chemical characteristics may be used, with fibre or other reinforcement as required.

The liner 120 may be formed from materials other than polymers. For example, the liner may be formed from one or more metals or ceramic materials.

The liner 120 may employ multiple layers. For example, one layer may be a glass-reinforced polymer for strength, and the other layer may be an unreinforced (or differently reinforced) polymer with chemical properties better suited to long-term contact with hot lubricant.

One way of manufacturing a sump 100 with a moulded liner 120 is described below with reference to Figs 14 and 15. In other embodiments, the liner 120 may be formed other than by moulding. For example, the liner may be forged or stamped from suitable material, additively manufactured using, eg, 3D printing, machined from billet material, machined from a cast or otherwise partly-formed component, or constructed using composite techniques such as, for example, glass reinforced plastics. Other plastics forming techniques may be used, such as vacuum forming and compression moulding.

Since the structural frame does not perform the function of retaining the lubricant, it can be designed to focus on the structural requirements of the sump as a whole. In at least some embodiments, this results in the structural frame 102 comprising several relatively large open areas 164. The open areas may be at least partly defined by ribs/struts 166 that provide structure while also offering some physical protection to the relatively soft liner 120. While the primary structural function is provided by the structural frame 102, it will be appreciated that the liner 120 may contribute some strength, stiffness, and/or vibration damping characteristics to the sump 100 as a whole.

The sump 100 may comprise means for allowing a transfer shaft to traverse the sump 100. In this embodiment, the means for allowing a transfer shaft to traverse the sump 100 takes the form of the drive-side aperture 108, a duct 122 that traverses the sump 100, and the farside aperture 116. The duct 122 links the drive-side aperture 108 and the far-side aperture 116, and is sized to allow a drive shaft to pass through it, as described below in relation to Figs 7 and 8. The duct 122 may be formed of the same polymeric material as the liner 120, and in at least some embodiments is moulded in one piece with the liner 120. In other embodiments, the duct 122 may be omitted.

The structural frame 102 comprises attachment points in the form of through holes 124 formed through a flange 126 formed around an upper edge of the sump 100. In the illustrated embodiment, the flange 126 is formed from overlapping portions of the structural frame 102 and the liner 112. In other embodiments, the flange 126 may be formed from one or the other of the structural frame 102 and the liner 112. A gasket 129 extends around portions of the flange 126 that engage corresponding surfaces on the engine block.

Turning to Figs 5 to 8, in the embodiment shown, the drive unit takes the form of a front drive unit (FDU) 128. FDUs are used in four-wheel-drive vehicles where an engine, such as engine 152 in Figs 5 and 6, drives a transfer case 154 via a gearbox 156. The gearbox 156 may be automatic or manual, and a suitable clutch or torque converter (not shown) may be employed between the engine 152 and the gearbox 156. The transfer case 154 outputs a rear drive shaft 158 that provides drive to a rear differential (not shown) for driving rear wheels (not shown) of the vehicle, and a forward drive shaft 160 that provides drive to the FDU 128. The FDU 128 splits the torque provided by the forward drive shaft 160 between front wheels 162 of the vehicle. As known by those skilled in the art, the transfer case 154 may provide drive to the FDU 128 at all times, or alternatively may only selectively do so when required due to, for example, low traction conditions.

Referring to Figs 7 and 8, the FDU 128 may be mounted to the sump 100 either before or after the sump 100 is mounted to the engine 152. A transfer shaft in the form of right driveshaft 134 is lubricated if required and then inserted through the duct 122 as the FDU 128 is brought into position against the first mounting points 104. Bolts 111 are used to attach the FDU 128 to the first mounting points 104 via the threaded holes 110, with the FDU 128 partly sitting within the recess 107. The bracket 118 is attached to the mount 112 with suitable bolts (not shown). The bearing holder 140 is fastened onto the end of the bracket 118. A far side bearing 138 is slid over the end of the right driveshaft 134 and pressed into position within the bearing holder 140. This order of assembly is exemplary only, and the skilled person will appreciate that the components may be assembled in any suitable order.

The sump 100 may be mounted to the engine 152 before or after the engine is installed into a vehicle. To install the sump 100, it is offered up to the bottom of a engine 152. Bolts (not shown) are inserted through the through holes 124 and tightened. The sump 100 is engineered to transfer to the engine block driveline loads applied to the FDU 128, and (in this embodiment) the drive-side bearing 136 and far-side bearing 138, as described in more detail below.

In the embodiments described so far, the drive unit (i.e., the FDU 128) is attached directly to the sump 100. In other embodiments, the drive unit is attached by way of one or more intermediate brackets (not shown) that attach to the first mounting means (ie, mounting points 104 in the illustrated embodiments). Similarly, although the embodiments described so far show the far side bearing 138 as being supported by the structural frame 102 by way of the bracket 118, in other embodiments, the far side bearing 138 may be supported directly by the sump, for example by being mounted within a housing integrally formed in the structural frame 102.

In the embodiment of Figs 1 to 4 and 7 to 12, the drive-side bearing 136 is retained within the FDU 128. In other embodiments, the drive side bearing 136 may be positioned outside of the FDU. For example, the drive side bearing 136 may be housed directly within the sump 100. In that case, the first mounting means may include a bearing recess in the structural frame 102 for housing the drive side bearing 136. Additional reinforcement may be required in this area, due to the need for the loads placed on the drive side bearing 136 to be borne by the structural frame 102 directly rather than the FDU 128.

In the embodiments above, the drive unit is described as being a front drive unit (FDU) 128 for accepting drive from a transfer case 154 in a four-wheel-drive vehicle. The drive unit may take other forms. For example, in a front-engined, front-wheel-drive car, the drive unit may take the form of a front wheel drive unit. This has a similar function to the FDU, but is driven directly from the transmission (not shown), which is typically directly attached to the engine.

In other embodiments, the drive unit may comprise an electric machine (not shown) that is used for driving and/or enabling regenerative braking through one or more associated driveshafts. For example, in a front-wheel-drive car, the electric machine may be attached to the first mounting points 104 to provide drive and/or regenerative braking. Such an electric machine may be attached to, or form part of, a front drive unit or front wheel drive unit. More than one electric machine may be provided. For example, a first electric machine may be mounted to the first mounting points 104 and a second electric machine may be mounted to the mount 112.

In yet other embodiments, the drive unit may comprise a kinetic energy recovery system (KERS) (not shown). KERS devices are known in the art, and typically include a flywheel and a mechanical or electrical drive mechanism for selectively converting a vehicle’s momentum into kinetic energy that is stored by the flywheel during regenerative braking. Again, such a KERS unit may be attached to, or form part of, a front drive unit or front wheel drive unit, for example.

In yet other embodiments, the drive unit may comprise a clutch (not shown). The clutch may be mechanical or hydraulic, for example. The clutch may be used to selectively and progressively engage drive to, for example a front drive unit or front wheel drive unit, or to one or more driveshafts driven by such a unit.

In yet other embodiments, the drive unit may comprise a drive disconnection unit (not shown). The drive disconnection unit may be similar to a clutch, but without the progressive engagement characteristics. A drive disconnection unit may be used to completely selectively disconnect drive to, for example, the front wheels of a four-wheel-drive car when four-wheel-drive operation is not required.

It will be appreciated that the embodiments so far have all been front-engined. Similar principles apply to rear- and mid-engined arrangements, which can similarly have a drive unit mounted directly to the sump.

In the embodiment described above, the means for allowing the transfer shaft (ie, right driveshaft 134) to traverse the sump comprises the drive-side aperture 108 and the far-side aperture 116 on each side of the sump 100, through which the right driveshaft 134 may pass. In other embodiments, one or the other of the apertures may be replaced by, for example a recess or notch. Such a recess or notch may be formed, for example, in the structural frame 102 and/or the liner 120, as required.

In the embodiment described above, the drive-side aperture 108 and a far-side aperture 116 are formed respectively between the first mounting points 104 and the mount 112. In other embodiments, either or both of the drive-side aperture 108 and the far-side aperture 116 may instead be formed adjacent the respective first mounting points 104 and mount 112. That is, it is not strictly necessary for any recess or aperture to pass through the or each of the mounting means.

In various embodiments, a driveshaft such as right driveshaft 134 may pass under the sump, in front of the sump, behind the sump, through the sump or partially through the sump. This traversal of the sump by a driveshaft is common in north-south engine installations with allwheel drive. In front engine (eg, east-west) front wheel drive installations, the drive shaft typically does not need to traverse the sump, in which case means for traversing the sump need not be provided.

Referring to Fig. 13, there is shown a vehicle 142 comprising the engine 152. The engine 152 comprises an embodiment of a sump 100 according to the invention. The sump 100 may take the form of, for example, any of the above-described embodiments, or any other embodiment falling within the scope of the appended claims.

Referring to Figs. 14 and 15, there is described a method 146 of manufacturing a sump 100 according to an embodiment of the invention. The embodiment may take the form of, for example, any of the above-described embodiments, or any other embodiment falling within the scope of the appended claims.

The method comprises placing 148 a structural frame 102 into a mould 150. The mould 150 may be of any suitable type, such as an injection mould as is commonly used in the automotive industry. The structural frame 102 comprises first mounting means in the form of first mounting points 104 for mounting a drive unit.

A polymeric material 149 is injected 151 into the mould 150 via, for example, a sprue 153 to form an overmoulded liner 120. The liner 120 may be at least partly supported by the structural frame 102. As described above, the liner 120 is configured to retain, in use, a volume of lubricant.

In at least some embodiments, the method includes providing the sump 100 with means for allowing a transfer shaft to traverse the sump 100. The means for allowing a transfer shaft to traverse the sump may comprise, for example, a duct (such as duct 122 described above) and/or one or more apertures (such as drive-side aperture 108 and a far-side aperture 116) and/or recesses. Where a duct 122 is provided, it may be moulded with the rest of the liner, added as a separate component after the liner is produced, or pre-fabricated and overmoulded to the liner 120 as part of the moulding process. The duct 122 may also be partly formed from, and/or supported by, the structural frame 102.

Construction of the liner 120 may vary from embodiment to embodiment. For example in one embodiment, the liner 120 is moulded as a unitary piece that is separate from the structural frame 102. The liner 120 may installed within the structural frame 102 to form the completed sump 100 prior to installation.

In another embodiment, the liner 120 is overmoulded onto the structural frame 102. One way of achieving this is to place the structural frame 102 into a suitable mould such that when the polymer material is injected into the mould it at least partly encapsulates the structural frame 102.

As shown in Fig. 16, the encapsulation may be such that the structural frame 102 is wholly or substantially external to the liner 120 (that is the material from which the structural frame

102 is composed is exposed on the outside of the sump 100 following the moulding process). Depending upon how this is implemented, one potential advantage is that the liner 120 may be protected from, for example, stone or impact damage, by a portion of the externally exposed structural frame 102. This approach also prevents the lubricant from coming into contact with the structural frame 102.

Alternatively, as shown in Fig. 17, the encapsulation may be such that the structural frame 102 is wholly or substantially internal to the liner 120 (that is, the material from which the structural frame 102 is composed is exposed on the inside of the sump 100 following the moulding process). Depending upon how this is implemented, one potential advantage is that the liner may be thickened and/or reinforced at critical exposed portions of the sump to protect against, for example, stone or impact damage. This approach also protects the structural frame 102 from the external environment, which may help reduce corrosion of the structural frame 102 due to, for example, exposure to water and salt grit from roads.

Alternatively, as shown in Fig. 18, the encapsulation may be such that the structural frame 102 is completely enclosed by the polymer material over some or all of the structural frame’s surface. Depending upon how this is implemented, one potential advantage is that the liner 120 protects the structural frame 102 from both the lubricant and the external environment. Complete enclosing of some or all of the structural frame’s surface may be achieved by, for example, moulding an interior of the liner 120 with the structural frame 102 held against an outer surface of a mould, and then withdrawing the structural frame slightly within the mould and injecting further polymer material into the gap formed by the slight withdrawal.

Any combination of the techniques of Figs 16 to 18 may be employed in a sump 100. For example, a lower region of the structural frame 102 may be completely encapsulated by the liner 120, while an upper region nearer the engine block may only have the liner 120 on the inside of the structural frame 102 (ie, some of the structural frame 102 is exposed on the outside of the sump 100 in this region).

Turning to Fig. 19, there is described a method 246 of manufacturing a sump 200 according to an embodiment of the invention. The sump may take the form of, for example, any of the above- or below-described embodiments, or any other embodiment falling within the scope of the appended claims.

The method comprises placing 248 a structural frame 202 into a mould 250. The mould 250 may be of any suitable type, such as an injection mould as is commonly used in the automotive industry.

A mouldable material 249 is supplied 251 into the mould 250 via, for example, a sprue 253 to at least partly encapsulate the structural frame 202, such that the structural frame 202 at least partly supports the mouldable material 249. Breather holes 266 allow displacement of air as the mouldable material 249 is supplied into the mould 250.

One embodiment of a sump 200 that can be manufactured with the method shown in Fig. 19 is shown in Fig. 20. In that embodiment, the mouldable material 249 forms a liner 212 for retaining, when the sump 200 is in use, a lubricant as described above. An advantage of manufacturing a sump 200 in this manner is that the liner 212 is intimately connected to the structural frame 202. This reduces the negative effects of the relatively different thermal expansion characteristics that might exist between the structural frame 202 (which in one embodiment is an aluminium alloy, for example) and the liner 212 (which in one embodiment is a glass-reinforced plastics material, for example).

In relation to the Fig. 20 embodiment, once the mouldable material 249 has set, cooled or cured sufficiently, the method may comprise removing the sump 200 from the mould 250, and machining the sump 200 final dimensions. Either or both of the structural frame 202 and the liner 212 may be machined as part of this process. Such machining may be done manually, by CNC machinery, or any suitable combination thereof.

As with the embodiment described in relation to Fig. 15, the method may comprise encapsulating at least all internal surfaces and edges of the structural frame and/or encapsulating at least all external surfaces and edges of the structural frame.

Another embodiment of a sump 200 that can be manufactured with the method shown in Fig. 19 is shown in Fig. 21. In that embodiment, the liner 212 is a separately manufactured component. It is placed into the mould 250 with the structural frame 202. The mouldable material 249 is then supplied into the mould via sprues 253 and at least partly encapsulates the liner 212. A breather hole 266 allows displacement of air as the mouldable material 249 is injected into the mould 250.

In some embodiments, the liner 212 is placed into the mould 250 such that there is space between at least some of an outer surface of the liner 212 and at least some of an inner surface of the structural frame 202. For example, space is provided in the form of approximately 2-10mm, or more particularly approximately 5mm, clearance 264 between the liner 212 and the structural frame 202. The space or clearance 264 need not completely separate the liner 212 from the structural frame 202 across the whole of the sump 200. It is particularly useful for such space or clearance 264 to be provided along the bottom and lower sides of the completed sump, for reasons that will be explained below.

The mouldable material 249 is then supplied into the mould 250 to at least partly fill the space 264. Filling the space 264 offers several potential benefits. The properties of the mouldable material may be selected to provide thermal insulation, protection to the liner 212 where it is not protected by the structural frame 202, a reduction in noise vibration and harshness (NVH), and/or damping of any relative movement between the liner 212 and the structural frame 202 that might otherwise cause damage to the liner 212 (the liner 212 is, at least in some embodiments, made of a polymeric material that is considerably softer than the, for example, aluminium alloy from which the structural frame 202 is constructed). The existence of the mouldable material 249 within the space also prevents foreign material, such as dirt, grit or stones, from getting stuck between the liner 212 and the structural frame 202. This in turn prevents abrasion caused by such foreign material.

The mouldable material may encapsulate some, a majority, or substantially all of the outer surface of the liner 212.

The mouldable material to 249 may take the form of an expanding foam. One such expanding foam is flexible polyurethane integral foam.

Expanding foam may be used in conjunction with the overmoulded liner 120. After the liner 120 (formed from glass-reinforced nylon, for example) has been overmoulded onto the frame 102, the mould components can be parted slightly (5mm, say) to form a cavity, and the sump 100 overmoulded by injecting the cavity with an expanding foam, such as flexible polyurethane integral foam.

The embodiments described with reference to Figs 19 to 21 are applicable to all other embodiments described earlier, and vice versa.

The materials from which the structural frame 102/202 and liner 112/212 are manufactured may be selected such that their properties are optimised for their respective needs and purposes. For example, the frame may be “structural” because it provides stiffness to the powertrain structure and to withstand driveline loads. Because of the combination of components, materials that offer appropriate properties may be used in the most appropriate areas. This allows independent optimisation of factors such as weight, thermal isolation and noise. As described above, the two materials may be joined by, for example, overmoulding a polymeric material onto an aluminium alloy frame, or by interlocking a separate polymer structure onto an aluminium alloy structure. This freedom allows the structural frame to be optimised to deliver its primary function (to react to loads), leading to weight saving by avoiding unnecessarily heavy material being used to retain oil, for example. Oil retention is handled by the liner, and so the liner can be optimised for oil and temperature resistance, low weight, and reduced noise characteristics, for example.

One definition of “structural” in the context of the structural frame 102/202 is capable of taking driveline loads associated with the drive unit that is mounted to the sump 100/200.

The subject matter of each and every embodiment is expressly combinable with the subject matter of each and every other embodiment, to the extent that the requirements of the different embodiments are compatible with each other.

All Figures should be considered schematic. Unless the contrary is clear from context, absolute and relative dimensions should not be inferred in a limiting manner from the drawings. Some details have been omitted for clarity. For example, seals, shims, gaskets, washers, protective boots or shields, and sub-component parts are not shown in all drawings. The positions of, for example, sprues and breather holes in moulds, as well as the relative position of the sump components within the mould are, again, schematic and not to be considered in any way limiting.

Although the invention has been described reference to a number of specific non-exhaustive and non-limiting embodiments, the skilled person will appreciate that the invention may be embodied in many other forms.

Claims

1. A method of manufacturing a structural sump for an engine, the method comprising: placing a support frame into a mould; and supplying a mouldable material into the mould to at least partly encapsulate the support frame.

2. The method of claim 1, comprising:

3. The method of claim 2, wherein the machining comprises machining the support frame and the cured or set mouldable material.

4. The method of any preceding claim, wherein the mouldable material is a polymer and supplying the mouldable material into the mould comprises injecting.

5. The method of any preceding claim, comprising encapsulating at least all internal surfaces and edges of the support frame.

6. The method of any preceding claim, comprising encapsulating at least all external surfaces and edges of the support frame.

7. The method of any preceding claim, wherein the cured mouldable material forms a liner of the sump, for holding an engine lubricant.

8. The method of claim 1, comprising:

prior to supplying the mouldable material into the mould, placing a liner into the mould with the support frame, the mouldable material at least partly encapsulating the liner.

9. The method of claim 8, comprising placing the liner into the mould such that there is a space between the liner and the support frame, the mouldable material at least partly filling the space.

10. The method of claim 8 or 9, wherein the mouldable material encapsulates a majority of the outer surface of the liner.

11. The method of any one of claims 8 to 10, wherein the mouldable material is an expanding foam.

12. The method of any one of the preceding claims, wherein the support frame is formed from a metal or metal alloy.

13. The method of claim 12, wherein the support frame is formed from aluminium or an aluminium alloy.

14. The method of any preceding claim, wherein the support frame is at least partly skeletal.

15. The method of any one of claims 1 to 13, wherein the support frame is continuous.

16. A sump manufactured in accordance with any one of the preceding claims.

17. A sump, comprising:

a support frame comprising a first material; and a liner comprising a second material, the liner being at least partly supported by the support frame.

18. The sump of claim 17, wherein the support frame is metallic.

19. The sump of claim 18, wherein the support frame is aluminium or an aluminium alloy.

20. The sump of any one of claims 17 to 19, wherein the liner is polymeric.

21. The sump of any one of claims 17 to 20, wherein the liner is moulded.

22. The sump of claim 21, wherein the liner is overmoulded to the support frame.

23. The sump of claim 22, wherein the liner is overmoulded: at least partly inside the support frame;

at least partly outside the support frame; or overmoulded so as to encapsulate at least some of the support frame.

24. The sump of any one of claims 17 to 23, wherein the support frame comprises one or more attachment points for attaching the sump to an engine.

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25. The sump of any one of claims 17 to 24, comprising a first mounting means for mounting a drive unit;

26. The sump of claim 25, wherein the first mounting means is configured for use with a drive unit selected from the group consisting of:

10 a front drive unit;

a front wheel drive unit; an electric machine; a kinetic energy recovery system; a clutch; and

15 a drive disconnection unit.

27. The sump of any one of claims 17 to 26, comprising a space between the liner and the support frame, the space being at least partly filled by an expanding foam.

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28. The sump of claim 27, wherein the expanding foam encapsulates a majority of the outer surface of the liner.

29. A vehicle comprising an engine, the engine comprising the sump of any one of claims 17 to 28.