SE543690C2

SE543690C2 - A grommet assembly and a vehicle comprising a power train component with a grommet assembly

Info

Publication number: SE543690C2
Application number: SE1951186A
Authority: SE
Inventors: Albin Einarsson; Jim Francis; Magnus Nilsson
Original assignee: Scania Cv Ab
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2021-06-08
Also published as: DE102020125275A1; SE1951186A1

Abstract

A grommet assembly (1) is described. The grommet assembly (1) comprises a grommet (3) made of an elastomer material and arranged to be tightly mounted in an aperture of a housing and a supporting unit (7). The grommet (3) comprises a plurality of holes (5), where each hole (5) is configured for sealably housing one of a plurality of cables through the hole (5), and a supporting unit (7) configured for supporting the grommet (3) in the aperture. The supporting unit (7) comprises a plurality of openings (9), where each opening (9) is configured for housing one of the cables through the opening (9). The supporting unit further comprises a positioning member (13) configured for positioning of the grommet (3) in an axial position in relation to the supporting unit (7) by cooperating with a positioning part (15) of the grommet (3) and an attaching means (11) for attaching of the supporting unit (7) to the wall of the housing. A vehicle (8) is also described.

Description

AND PRIOR ART A power train of a vehicle usually comprises an engine, a transmission, driveshafts, differentials and drive wheels. Many components and functions of amodern power train are controlled electrically. For example, fuel injectors in anengine are electrically controlled in order to inject fuel into cylinders at rightpoint in the time. Fuel injectors are arranged in an engine camshaft housing.One or several injectors can be controlled by a control unit sending signals tothe injector or to several injectors via cables. Because the control unit is oftenlocated outside of the engine the cables need to be led into the enginecamshaft housing through an aperture in the engine camshaft housing. Duringnormal operation of a combustion engine the temperature within the enginecamshaft housing can reach 120 ° C. Several components of the combustionengine require oil in order to lubricate the components. Consequently, thetemperature and the presence of oil in the camshaft housing set high demandson sealing of the cables led-through into the camshaft housing to prevent oilleakages. Oil leakages can contribute to damage of the control unit or of otherelements arranged at the combustion engine. Therefore, there is a need ofsealings around the cables led into the engine camshaft housing. Efforts havebeen made to develop sealing means for cables, and grommets for injectioncables have been recently used.

WOO163716 is an example of prior art describing a multiple lead-throughflange arranged to be sealably mounted in a wall. The lead through flangecomprises an elastomeric member and a plastic body for supporting of theelastomeric member. However, the problem of providing an effective sealing ofseveral cables led-through an aperture still exists. lt is therefore desirable to provide an improved grommet assembly enablingeffective sealing of cables.

SUMMARY OF THE INVENTION An object of the present disclosure is to provide an improved grommetassembly enabling effective sealing of a p|ura|ity of cables led-through anaperture in a wall of a housing of a power train component. A further object ofthe present disclosure is to provide a grommet assembly that may be easilyassembled and mounted in the aperture of the housing, in particular agrommet assembly comprising few ingoing parts that are easy to beassembled without need of assembly tools. A yet further object of the presentdisclosure is to provide an improved vehicle with a power train componentcomprising an improved grommet assembly.

At least the above mentioned objects are achieved by the grommet assemblydefined in claim 1 and by the vehicle defined in claim 18.

Thus, the above mentioned objects are achieved by grommet assemblyconfigured for permitting lead-through of a p|ura|ity of cables into an interior ofa housing of a power train component along an axial direction. The p|ura|ity ofcables can extend along the axial direction through the grommet assemblyfrom an exterior of the housing of the power train component into the interior ofthe housing of the power train component. Further, the grommet assembly isconfigured to be mounted at an aperture in a wall of the housing, which meansthat the grommet assembly is arranged to be partly arranged in the apertureand partly outside the aperture whereby the aperture can be sealed by meansof the grommet assembly.

The grommet assembly comprises a grommet made of an elastomer materialand arranged to be tightly mounted in the aperture. The elastomer material ofthe grommet enables an elastic deformation of the grommet. Further, the sizeof the grommet is adapted to the size of the aperture to receive the grommet.An outer dimension of the grommet is larger than a dimension of the aperture.ln this way the grommet will be elastically deformed when the grommet hasbeen mounted in the aperture. Thereby, a tight connection between the grommet and the aperture is achieved when the grommet has been mountedin the aperture. By the tight connection between the grommet and the aperturea Ieakage of a liquid or a gas between the grommet and the aperture can beprevented. Thus, a sealing between the aperture and the grommet is obtained.The grommet comprises a plurality of holes, where each hole is configured forsealably housing one of the cables through the hole. Thus, each of the pluralityof cables can be led-through a respective hole of the plurality of ho|es.Because each of the plurality of cables is sealably housed in each hole, i.e.each of the plurality of cables is tightly surrounded by each hole, a Ieakage ofa liquid or a gas through the ho|es can be prevented.

Thus, a Ieakage between the grommet and the aperture and a Ieakage througheach of the plurality ho|es can be prevented.

Further, the grommet assembly comprises a supporting unit configured forsupporting the grommet in the aperture. ln this way any undesired movementsof the grommet in relation to the aperture can be prevented and the grommetcan be held in a desired position in the aperture. An undesired movement ofthe grommet in relation to the aperture may cause leakages between thegrommet and the aperture. Thus, an improved grommet assembly is obtainedwith improved sealing characteristics.

The supporting unit comprises a plurality of openings wherein each opening isconfigured for housing one of the cables through the opening. Thereby, eachof the plurality of cables can be led-through a respective opening of theplurality of openings of the supporting unit.

The supporting unit comprises also a positioning member. The positioningmember is configured for positioning of the grommet in an axial position inrelation to the supporting unit by cooperating with a positioning part of thegrommet. ln this way the grommet can be positioned along an axis extendingalong the axial direction through the supporting unit. For example, thepositioning member can be arranged for positioning of the grommet coaxiallyin relation to the supporting unit. The positioning unit can be arranged to beinserted into the positioning part or vice versa. The grommet positioned in anaxial position in relation to the supporting unit facilitates mounting of the grommet assembly at the aperture. With a properly mounted grommetassembly, risks for leakage through the grommet assembly can be minimized.

Further, the supporting unit comprises an attaching means for attaching of thesupporting unit to the wall of the housing. Thus, the supporting unit can beattached to the wall of the housing and can be removed from the wall of thehousing in a simple manner by using the attaching means. Further, a positionof the supporting unit in relation to the wall can be maintained thanks to theattaching means. As a result any undesired movements of the supporting unitcan be prevented which contributes to minimizing of risks for leakages throughthe grommet assembly.

Consequently, an improved grommet assembly is provided considering i.e.preventing leakages through the grommet assembly and thereby havingimproved sealing characteristics. Further, a grommet assembly is providedcomprising few ingoing parts that are easy to be assembled without need ofassembly tools. Because the grommet assembly comprises few ingoing partsthe manufacturing costs of the grommet assembly may be lowered, which mayreduce the price of the grommet assembly. The price of the grommet assemblymay also be reduced due to less metal parts comprised by the grommetassembly comparing to prior art solutions. Thereby, the above mentionedobjects are achieved.

According to an embodiment, in the axial position, the grommet and thesupporting unit are arranged next to each other such that one hole, of theplurality of holes, and a corresponding one of said openings form a channel, ora straight channel, for one cable of the plurality of cables. With the wordingnext to each other is meant that the grommet and the supporting unit can bearranged after each other and in the vicinity of each other. For example, thegrommet may have contact with the supporting unit. Thus, the supporting unitcan be arranged partly outside the aperture which facilitates access to thesupporting unit for service and for mounting of the supporting unit to the wall.Further, the channel formed by a hole and the corresponding openingfacilitates the lead through of a cable through the grommet assembly.

According to an embodiment the grommet comprises at least two external ribsextending outwards from and around an outer surface of the grommet. The atleast two external ribs will abut the surface of the aperture and will create anadditional obstruction for liquid and gas when the grommet has been mountedin the aperture. Thus, because of the at least two external ribs the grommetcan be mounted in the aperture in a yet improved liquid and gas tight manner.ln this way yet improved sealing characteristics of the grommet can beobtained. Further, the at least two external ribs facilitate holding of thegrommet in the axial position in the aperture. ln this way any undesiredmovements of the grommet in the aperture can be prevented. Thereby, thesealing characteristics of the grommet can be yet improved.

According to an embodiment each of the holes comprises at least one internalrib extending inwards from and around an inner surface of the hole. Thus, acable led-through a hole can be surrounded in a yet improved liquid and gastight manner because the at least one internal rib will abut the cable creatingan additional obstruction for liquid and for gas. Thereby, yet improved sealingcharacteristics of the grommet can be obtained.

According to an embodiment the supporting unit comprises a rotary restrictingmember configured to cooperate with a rotary restricting part of the grommetfor positioning of the grommet in a rotary direction in relation to the supportingunit. The rotary restricting member may be arranged to be inserted into therotary restricting part or vice versa. Thus, positioning of the grommet in therotary direction in relation to the supporting unit can be facilitated whichfacilitates mounting of the grommet assembly. Further, the rotary restrictingmember and the rotary restricting part may prevent a rotation of the grommetin relation to the supporting unit during use of the grommet assembly. Thus,the grommet can be kept in a desired position in relation to the supporting unitwith respect to the rotary direction. Thereby, a yet improved grommetassembly can be provided because any undesired movements of the grommetin relation to the supporting unit and thereby inside the aperture can beprevented. ln this way the sealing characteristics can be improved.

According to an embodiment the supporting unit comprises a mounting plate,wherein the positioning member is arranged on an abutment surface of the mounting plate. The abutment surface of the mounting plate is arranged toabut a corresponding abutment surface of the grommet when the grommet hasbeen connected to the supporting unit. Because the positioning member maybe arranged perpendicularly to the abutment surface of the mounting plate themanufacturing of the supporting unit can be simplified and thereby made moreeffective. Further, the grommet can be easily positioned in the axia| positionrelatively the supporting unit thanks to the positioning member arrangedperpendicularly to the abutment surface of the mounting plate.

According to an embodiment the positioning member extends axially from theabutment surface. Thus, positioning of the grommet in the axia| positionrelatively, the supporting can be yet simplified.

According to an embodiment the positioning member comprises an elongatedrod and the positioning part of the grommet comprises a positioning holearranged to receive the elongated rod in the axia| position. ln this way theelongated rod can be inserted into the positioning hole in order to position thegrommet in the axia| position in relation to the supporting unit. Thereby,positioning of the grommet in the axia| position relatively, the supporting canbe yet simplified.

According to an embodiment the positioning hole comprises at least oneinternal sealing rib extending inwards from and around an inner surface of thepositioning hole. ln this way, a space between the positioning hole and theelongated rod can be sealed by the sealing rib. ln this way a leakage of a liquidor gas between the positioning hole and the elongated rod can be prevented.

According to an embodiment the elongated rod is arranged at a centralposition of the supporting unit. Thus, the rod can be inserted into a centrallypositioned positioning hole of the grommet in order to position the grommet inthe axia| position relatively the supporting unit. Further, manufacturing of thepositioning member of supporting unit can be simplified with the elongated rodarranged at the central position of the supporting unit.

According to an embodiment the positioning member comprises a lockingelement arranged to lock the grommet at the supporting unit. ln this way thegrommet can be secured at the supporting unit and an undesired disassembling of the grommet assembly can be prevented. Thus, a yetimproved grommet assembly can be obtained where the position of thegrommet in relation to the supporting unit can be ensured.

According to an embodiment the locking element comprises a disassemblypart permitting separation of the grommet and the supporting unit from theaperture in the wall of the housing when a pressure force is applied to thesupporting unit through the disassembly part. Thereby, the grommet and thesupporting unit can be disassembled, i.e. removed from the aperture simply byapplying the pressure force to the disassembly part. ln this way, for example,service of an old grommet assembly can be facilitated.

According to an embodiment the grommet has an oval, in particular anelliptical cross section profile. When the grommet has the elliptical crosssection the aperture may also have an elliptical cross section adapted to thecross section of the grommet. An elliptical cross section profile comprises asemi-minor axis and a semi-major axis. The aperture can be arranged suchthat the semi-minor axis of the elliptical cross section extends along a heightdirection of the housing of the power train component. For example the semi-minor axis may extend vertically along the housing. Because the semi-minoraxis is shorter than the semi-major axis the grommet with the elliptical crosssection takes less space in the height direction of the housing. This isadvantageous because in a modern power train component, as for example,an internal combustion engine, there is a number of equipment around theengine that also require space. Thus, a higher number of cables can beorganized on the same surface area of the housing as according to prior artsolutions. ln other words, the same number of cables than in prior art solutionscan be organized on a smaller surface area of the housing thanks to thegrommet assembly according to present disclosure. This means that a smallersize aperture, for example a lower or thinner aperture, in the housing isrequired for leading-through the same number of cables comparing to prior artsolutions. ln this way, the strength of the housing may be improved as well asmore electrical functionality can be routed through the housing.

According to an embodiment the mounting plate has an oval cross sectionprofile. The cross section of the mounting plate may be partly elliptical. ln thisway also the mounting plate requires less space in the height direction of the housing which is advantageous considering, inter alia, mounting of thesupporting unit at the wall of the housing.

According to an embodiment the supporting unit comprises a holding meansarranged for holding a cover for the p|ura|ity of cables. ln this way the p|ura|ityof cables can be held together and be protected by the cover. As an effect therisk for cable damage can be decreased and thereby the operational lifetime ofthe cables can be prolonged.

According to an embodiment the holding means is arranged at a side surfaceof the mounting plate, wherein the side surface is arranged on an oppositeside of the mounting plate in relation to the abutment surface of the mountingplate. Thus, the cover can be fastened on the holding means on the outside ofthe housing and thereby the cables can be protected on the outside of thehousing.

According to an embodiment, the attaching means comprises at least oneattaching hole configured to receive a snap locking means, a screw, or a rivet.ln this way the supporting unit can be attached to the wall of the housing in aneasy and effective manner.

The initially mentioned objects are also achieved by a vehicle comprising apower train component comprising a housing with an aperture in a wall of thehousing, wherein a grommet assembly according to any of the abovedescribed embodiments has been arranged at the aperture. The grommetassembly having several advantages considering, inter alia, sealingcharacteristics can contribute to decrease of risks for damages in the vehicle.Thereby, by using the improved grommet assembly the operational lifetime ofthe vehicle can be prolonged.

BRIEF DESCRIPTION OF THE DRAWINGS ln the following preferred embodiments of the invention are described withreference to the attached drawings, on which: Fig. 1.Fig. 2. is a perspective view of a grommet assembly,is a cross sectional view of the grommet assembly in Fig. 1, Fig. 3. is a cross sectional view of the grommet assembly in Fig. 2,assembled, Fig. 4. is a perspective view of the grommet assembly in Fig. 1,assembled and with a cover, and Fig. 5. is a perspective view of a vehicle.

DETAILED DESCRIPTION OF PREFERRED E|\/|BOD|I\/IENTS OF THEINVENTION Fig. 1 shows a grommet assembly 1 in a perspective view. ln the figure thegrommet assembly 1 is illustrated before it has been assembled.

The grommet assembly 1 is configured for permitting lead-through of a pluralityof cables (not illustrated) into an interior of a housing of a power traincomponent 2 (illustrated in Fig. 5). The cables are permitted to be led-throughalong an axial direction x. The power train component can be, for example, aninternal combustion engine, and more specifically a camshaft housing of theinternal combustion engine. The engine can be arranged at a vehicle 8. Thevehicle 8 is illustrated in Fig. 5.

A grommet assembly 1 comprises a grommet 3 and a supporting unit 7. Thegrommet 3 can be made of an elastomer material such as rubber while thesupporting unit 7 can be made of a harder material such as a hard-plasticmaterial or a metal. Other suitable materials for the grommet 3 and for thesupporting unit 7 can also be used.

The grommet 3 is arranged to be tightly mounted in an aperture 4 in a wall 6(shown in Fig. 3) of the power train component 2. This means that thegrommet 3 is adapted to the aperture 4 such that when the grommet 3 hasbeen mounted in the aperture 4 an outer surface 21 of the grommet 3 abuts aninner surface 10 of the aperture 4 in a liquid and gas tight manner. Thereby, asealing between the grommet 3 and the aperture 4 is achieved. The grommet3 can be tightly mounted in the aperture 4 thanks to the flexibility of thegrommet 3, where flexibility is achieved by using an elastomer materialenabling an elastic deformation of the grommet 3. The cross sectional profileof the grommet 3 may comprise a first diameter d1 and a second diameter d2.

The first diameter d1 may be larger than the second diameter d2 resulting inan elliptical cross sectional profile of the grommet 3. Thus, the cross sectionalprofile of the aperture 4 may comprise a corresponding third diameter and afourth diameter respectively. ln a similar way to the first diameter d1 and thesecond diameter d2, the third diameter may be larger than the fourth diameterresulting in an elliptical cross sectional profile of the aperture 4. The third andthe fourth diameters are not shown in Fig. 1. The grommet 3 can be mountedin the aperture 4 in the liquid and gas tight manner because the first diameterd1 and the second diameter d2 are larger than the third diameter and thefourth diameter respectively. ln this way, the grommet 3 can be compressedwhen mounted in the aperture 4. The magnitude of the third diameter may bebetween 94 and 98 °/> of the first diameter d1. ln a similar way the magnitudeof the fourth diameter may be between 94 and 98 °/-.. of the second diameterd2. The grommet 3, tightly mounted in the aperture 4 is illustrated in Fig. 3.

The grommet 3 may have an oval or elliptical cross section profile. Themounting plate 31 may also have an oval cross section that may be partlyelliptical. Other suitable cross sectional profiles such as for example a squareor an oval elongated cross sectional profile also can be used.

The grommet 3 may comprise at least two external ribs 19 extending from andaround the outer surface 21 of the grommet 3. Thus, the first diameter d1 andthe second diameter d2 may be defined by the external ribs 19, i.e. the firstdiameter d1 and the second diameter d2 can be measured between outeredges of each rib 19. According to the embodiment illustrated in Fig. 1-Fig. 4the grommet 3 comprises four external ribs 19 evenly distributed along theouter surface 21 of the grommet 3. The grommet 3 may comprise a highernumber of ribs 19 than four. The at least two external ribs 19 can contribute toimproved sealing characteristics of the grommet 3. Further, the at least twoexternal ribs 19 facilitate holding of the grommet 3 in the axial position in theaperture 4, whereby undesired movements of the grommet 3 in the aperture 4can be prevented.

The grommet 3 comprises a plurality of holes 5. The number of holes 5corresponds to the number of cables that are intended to be led-through thegrommet 3. For example, the grommet 3 may comprise seven or nine holes 5.Thus, the cables can be led-through the holes 5 into, for example, an engine 11 camshaft housing, in order to be connected to one or several fuel injectors.Because several cables can be led-through the grommet 3, fewer apertures inthe camshaft housing need to be manufactured comparing to solutions wherea grommet is adapted to only one or very few cables. Thereby, the strength ofthe camshaft housing can be improved as well as risks for leakage can bedecreased because of a fewer number of apertures in the camshaft housing.

Each hole 5 is configured for sealably housing one of the cables through thehole 5. Because the grommet 3 can be made of an elastomer material eachhole 5 may expand a bit when a cable is led-through the hole 5. The holes 5has a fifth diameter d5. The fifth diameter d5 of the hole 5 is adapted to thediameter of the corresponding cable intended to be led-through respective hole5 such that the fifth diameter d5 is smaller than the diameter of thecorresponding cable. The fifth diameter d5 may be, for example between 94and 98 °/> of the diameter the cable intended to be led-through the hole 5.

Each hole 5 is arranged to surround a respective cable in a liquid and gas tightmanner by abuting an outer surface of the cable thanks to the elastomermaterial of the grommet and thanks to the diameter ratio between the fifthdiameter d5 and the diameter of the cables. The diameter ratio has beendescribed above.

All the holes 5 may have the same diameter or the diameter of the holes 5 canbe different for each hole 5 or for a group of holes 5. Thus, different cableswith different diameters can be led-through the holes 5.

The supporting unit 7 is configured for supporting of the grommet 3 in theaperture 4. Thus, the supporting unit 7 is arranged to hold the grommet 3 inthe aperture 4. The supporting unit 7 comprises a plurality of openings 9,where each opening 9 is configured for housing one of the cables through theopening 9. The openings 9 may have different cross section forms. Forexample the cross section of the openings 9 may have form of a trapezium, asquare, a triangle or a circle. 12 Further, the supporting unit 7 comprises a positioning member 13 configuredfor positioning of the grommet 3 in an axial position in relation to the supportingunit 7 by cooperating with a positioning part 15 of the grommet 3.

As illustrated in Fig. 1 the positioning member 13 may comprise an elongatedrod 13 and the positioning part 15 of the grommet 3 may comprise apositioning hole 15 arranged to receive the elongated rod 13 in the axialposition along the axial direction x defined by an axis x. The elongated rod 13may be arranged at a central position of the supporting unit 7. Then, thepositioning hole 15 is arranged at a central position of the grommet 3 tocooperate with the centrally positioned elongated rod 13. The positioning holemay be a through hole extending through the grommet 3.

The holes 5 for housing cables may be distributed around the positioning hole15, for example along a circle or an ellipse. The holes 5 may be evenly orunevenly distributed around the positioning hole 15 depending on the desiredneeds of leading-through the cables. For example, when the cables need to begrouped, then a number of holes 5 for these cables may be arranged closer toeach other and may be separated from another group of holes 5. The holes 5may be enumerated, i.e. there may be a number at each hole 5 indicatingwhich cable, for example with a corresponding number or a color, should belead-through the corresponding hole 5. Thus, a process of leading- throughcables through the grommet 3 may be facilitated.

According to an embodiment the elongated rod 13 may have a circular crosssectional profile. The cross sectional profile of the elongated rod 13 may alsohave a form of an ellipse, a square, a triangle a trapezium or similar.

The positioning hole 15 may comprise at least one internal sealing rib 35extending inwards from and around an inner surface 37 of the positioning hole15.

Further, the supporting unit 7 may comprise a mounting plate 31. Theelongated rod 13 may then be arranged on an abutment surface 33 of themounting plate 31 and may extend axially along the axial direction x from theabutment surface 33. The elongated rod 13 may be arranged perpendicularly 13 to the abutment surface 33. The mounting plate 31 is arranged to bepositioned at the aperture and to attach the supporting unit 7 to the wall 6 ofthe housing of the power train component 2.

The supporting unit 7 can be manufactured as one unit, i.e. the mounting plate31 and the positioning member 13 can be manufactured as one unit, forexample by molding. As an alternative the mounting plate 31 and thepositioning member 13 can be manufactured separately and can beassembled afterwards. For example the mounting plate 31 may comprise ahole with threads and the positioning member 13 may be configured to bescrewed into the hole of the mounting plate 31.

Further, the supporting unit 7 comprises an attaching means 11 for attachingof the supporting unit 7 to the wall of the housing. The attaching means 11may comprise at least one attaching hole 11 configured to receive a snaplocking means, a screw, or a rivet. Thus, the supporting unit 7 can be attachedto the wall of the housing in a simple and efficient manner. ln Fig. 3 thesupporting unit 7 is illustrated attached to the wall 6 by means of screws 12screwed into the wall 6. According to the embodiment illustrated in Fig. 1 toFig. 4 the supporting unit 7 comprises two holes 11 arranged to receive arespective screw 12. However, more than two holes 11 may also be arranged.Around each hole 11 a reinforcement disk 14 can be arranged in order toincrease the strength of the area around the opening 11. ln case when thesupporting unit 7 has been manufactured of a plastic material thereinforcement disk 14 can comprise a metal. The reinforcement disk 14 maybe of a harder metal comparing to the supporting unit 7 when the support unithas been manufactured of a metal.

The supporting unit 7 may comprise a rotary restricting member 27 configuredto cooperate with a rotary restricting part 29 of the grommet 3 for positioning ofthe grommet 3 in a rotary direction rd in relation to the supporting unit 7. Therotary direction rd may be a rotational direction around the axial direction x ofthe axis x. As illustrated in Fig. 1 the rotary restricting member 27 may bearranged as a rectangular element protruding from the abutment surface 33 ofthe supporting unit 7. The rotary restricting member 27 may be made of thesame material as the supporting unit 7, i.e. of a hard-plastic material or of a 14 metal. The rotary restricting member 27 may also have other forms and crosssections, for example a circular cross section.

Further, the positioning member 13 of the supporting unit 7 may comprise alocking element 39 arranged to lock the grommet 3 at the supporting unit 7.The function of the locking member 39 is described in details in conjunction toFig. 2 and Fig. 3 below.

The locking element 39 may comprise a disassembly part 41 permittingseparation of the grommet 3 and the supporting unit 7 from the aperture 4 inthe wall 6 of the housing when a pressure force is applied to the supportingunit 7 through the disassembly part 41. The disassembly part may be arrangedas a recess or a track in the locking element 39. The disassembly part 41 maybe arranged to receive, for example, a screwdriver in order to apply thepressure force to the supporting unit 7. ln this way a user can separate of thegrommet 3 and the supporting unit 7 from the aperture 4 in a simple mannerfor service of the grommet assembly 1 or in order to replace an old grommetassembly.

Further, as shown in Fig. 2, each of the holes 5 may comprise at least oneinternal rib 23 extending inwards from and around an inner surface 25 of thehole 5. Thus, the sealing between each of the holes 5 and a respective cableled-though the hole 5 can be yet improved thanks to the at least one internalrib 23 that will create an additional sealing between the hole 5 and the cable.The at least one internal rib 25 will be elastically deformed when the cable hasbeen led-through the hole 5.

The supporting unit 7 may comprise a holding means 43 arranged for holdinga cover 47 (shown in Fig. 4) for the plurality of cables. The holding means 43may be arranged at a side surface 45 of the mounting plate 31, wherein theside surface 45 is arranged on an opposite side of the mounting plate 31 inrelation to the abutment surface 33 of the mounting plate 31. The holdingmeans 43 may protrude from the side surface 45 and may have a C-shapedcross section enabling mounting of the cover 47 on the holding means 43.

Fig. 2 shows the grommet assembly in Fig. 1 in a cross sectional view. Thegrommet 3 and the supporting unit 7 have been positioned axially in relation to each other, i.e. the grommet 3 and the supporting unit 7 have been positionedalong the axial direction x.

The elongated rod 13 of the supporting unit 7 has been positioned to beinserted into the positioning hole 15 of the grommet 3 in order to support thegrommet 3 in the aperture 4. As mentioned before the elongated rod 13 mayhave a circular formed cross section with a sixth diameter d6. The sixthdiameter d6 of the elongated rod 13 corresponds to an eighth diameter d8 ofthe positioning hole 15. The eighth diameter d8 may be smaller than the sixthdiameter d6 of the elongated rod 13 enabling a liquid and gas tight connectionbetween the elongated rod 13 and the positioning hole 15 when the elongatedrod 13 has been inserted into the positioning hole 15. Further, the positioninghole 15 may comprise at least one internal sealing rib 35 extending inwardsfrom and around an inner surface 37 of the positioning hole 15. Thus, thesealing between the elongated rod 13 and the positioning hole 15 can be yetimproved thanks to the at least one internal sealing rib 35 that will create anadditional sealing between the elongated rod 13 and the positioning hole 15when the elongated rod 13 has been inserted into the positioning hole 15. Theat least one internal sealing rib 35 will be elastically deformed when theelongated rod 13 has been inserted into the positioning hole 15.

The cross section of the elongated rod 13 may have a seventh diameter d7greater that the sixth diameter d6. Thus, a part of the length of the elongatedrod 13 may have the sixth diameter d6 and the remaining part of the elongatedrod 13 may have the seventh diameter d7. The part of the elongated rod 13having the sixth diameter d6 may be an outermost part of the elongated rod 13seeing from the abutment surface 33 of the mounting plate 31. Accordingly,the part of the elongated rod 13 with the seventh diameter d7 may be thenearest part of the elongated rod 13 seeing from the abutment surface 33 ofthe mounting plate 31. The positioning hole 15 may then have a portion with aninth diameter d9 corresponding to the seventh diameter d7 of the elongatedrod 13.

By arranging the elongated rod 13 and the positioning hole 15 with differentdiameters along the axis x the supporting of the grommet 3 in the aperture 4can be facilitated. Further, also sealing between the elongated rod 13 and the 16 positioning hole 15 can be improved because of a first transition surface 14 ofthe elongated rod 13 created between the part of the length of the elongatedrod 13 having the sixth diameter d6 and the remaining part of the elongatedrod 13 having the seventh diameter d7. ln a similar way the positioning hole 15comprises a second transition surface 14” arranged to cooperate with the firsttransition surface 14. Because the first transition surface 14 and the secondtransition surface 14” are angled in relation to the axial direction x an additionalobstruction for a liquid and a gas trying to pass the grommet 3 will be createdby the first transition surfaces 14 and the second transition surface14”.

As mention above, the positioning member 13 of the supporting unit 7 maycomprise a locking element 39 arranged to lock the grommet 3 at thesupporting unit 7. According to the embodiment illustrated in Fig. 1-Fig. 3 thelocking element 39 is arranged as an outer part of the elongated rod 13. Thelocking element 39 has been arranged at a first distance I1 from the abutmentsurface 33 of the mounting plate 31 of the supporting unit 7. The lockingelement 39 may have a circular cross section with a diameter larger than thesixth diameter d6 of the elongated rod 13 and larger than the eighth diameterd8 of the positioning hole 15 as described above. The diameter of the lockingelement 39 enables insertion of the elongated rod 13 through the positioninghole 15. Further, the diameter of the locking element 39 is adapted to thepositions of the holes 5 such that the locking element 39 does not obstruct theholes 5 and cables through the holes 5. The diameter of the locking element39 may be smaller than a diameter or diameters of the line along which theholes 5 has been distributed around the positioning hole 15.

Further the grommet 3 may have a length l2, which length l2 corresponds tothe thickness of the wall 6 and thereby to the depth of the aperture 4 in the wall6. Because the length l2 of the grommet 3 is equal to or slightly larger than thefirst distance I1, the grommet 3 can be locked at the supporting unit 7 bymeans of the locking element 39 extending through the positioning hole 15when the elongated rod 13 has been inserted into the positioning hole 15 inorder to position and to support the grommet 3 at the aperture 4. 17 Fig. 3 is a cross sectional view of the grommet assembly in Fig. 2 illustrated asbeing assembled together and being attached to the wall 6 by means ofscrews 12.

As illustrated in Fig. 3, in the axial position the grommet 3 and the supportingunit 7 may be arranged next to each other such that each hole 5 and thecorresponding opening 9 form a channel 17 for each cable of the plurality ofcables.

According to an embodiment, the grommet assembly 1 comprises a fillingcompound 16 arranged between the grommet 3 and the supporting unit 7when the grommet assembly 1 has been assembled. Thus, the grommet 3may comprise a recession 18 to receive the filling compound 16. Therecession 18 may have an oval cross sectional profile. The filling compound 16may have a corresponding cross sectional profile enabling a tight positioning ofthe filling compound 16 within the recession 18. The filling member 16 may bemade of a plastic material, for example rubber, and is arranged to provide anadditional protection from leakage through the grommet assembly 1. Further,thanks to the filling compound 16 risks for cable chafing may be reduced.Thus, a yet improved grommet assembly may be provided. ln Fig. 4 the grommet assembly 1 has been illustrated assembled and with thecover 47 mounted at the supporting unit 7.

Fig. 5 illustrates a vehicle 8 comprising a power train component 2 arrangedwith a grommet assembly 1 according to the embodiments of the presentdisclosure. The power train component 2 may be an internal combustionengine of the vehicle 8.

Claims

18 Claims

1. _ A grommet assembly (1) configured for permitting lead-through of a plurality of cables into an interior of a housing of a power train component along an axial direction (x) and configured to be mounted at an aperture in a wall of said housing, the grommet assembly (1) comprising: - a grommet (3) made of an elastomer material and arranged to be tightlymounted in said aperture, wherein the grommet (3) comprises a pluralityof holes (5), where each hole (5) is configured for sealably housing oneof said cables through the hole (5), and - a supporting unit (7) configured for supporting the grommet (3) in saidaperture, wherein the supporting unit (7) comprises: - a plurality of openings (9), where each opening (9) is configured forhousing one of said cables through the opening (9), - a positioning member (13) configured for positioning of the grommet (3)in an axial position in relation to the supporting unit (7) by cooperatingwith a positioning part (15) of the grommet (3) and - an attaching means (11) for attaching of the supporting unit (7) to saidwall of the housing.

2. _ The grommet assembly (1) according to claim 1, wherein in said axial position the grommet (3) and the supporting unit (7) are arranged next toeach other such that one hole (5) and a corresponding one of saidopenings (9) form a channel (17) for one cable of the plurality of cables.

3. _ The grommet assembly (1) according to claim 1 or 2, wherein the grommet (3) comprises at least two external ribs (19) extending outwards from andaround an outer surface (21) of the grommet (3).

4. _ The grommet assembly (1) according to any of claims 1 to 3, wherein each of the holes (5) comprises at least one internal rib (23) extending inwardsfrom and around an inner surface (25) of the hole (5).

5. _ The grommet assembly (1) according to any of claims 1 to 4, wherein the supporting unit (7) comprises a rotary restricting member (27) configured to 19 cooperate with a rotary restricting part (29) of the grommet (3) forpositioning of the grommet (3) in a rotary direction (rd) in relation to thesupporting unit (7).

6. The grommet assembly (1) according to any of claims 1 to 5, wherein thesupporting unit (7) comprises a mounting plate (31), wherein the positioningmember (13) is arranged on an abutment surface (33) of said mountingplate (31).

7. The grommet assembly (1) according to claim 6, wherein the positioningmember (13) extends axially from the abutment surface (33).

8. The grommet assembly (1) according to any of claims 1 to 7, wherein thepositioning member (13) comprises an elongated rod and the positioningpart (15) of the grommet (3) comprises a positioning hole arranged toreceive the elongated rod in said axial position.

9. The grommet assembly (1) according to claim 8, wherein the positioninghole comprises at least one internal sealing rib (35) extending inwards fromand around an inner surface (37) of the positioning hole.

10.The grommet assembly (1) according to claim 8 or 9, wherein saidelongated rod is arranged at a central position of the supporting unit (7).

11.The grommet assembly (1) according to any of claims 1 to 10, wherein thepositioning member (13) comprises a locking element (39) arranged to lockthe grommet (3) at the supporting unit (7).

12.The grommet assembly (1) according to claim 11, wherein the lockingelement (39) comprises a disassembly part (41) permitting separation ofthe grommet (3) and the supporting unit (7) from said aperture in the wall ofsaid housing when a pressure force is applied to the supporting unit (7)through the disassembly part (41 ).

13.The grommet assembly (1) according to any of claims 1 to 12, wherein thegrommet (3) has an oval cross section profile.

14.The grommet assembly (1) according to any of claims 6 to 13, wherein themounting plate (31) has an oval cross section profile.

15.The grommet assembly (1) according to any of claims 1 to 14, wherein thesupporting unit (7) comprises a holding means (43) arranged for holding acover (47) for the plurality of cables.

16.The grommet assembly (1) according to claim 15 and any of claims 6 to 14,wherein the holding means (43) is arranged at a side surface (45) of themounting plate (31 ), wherein the side surface (45) is arranged on anopposite side of the mounting plate (31) in relation to said abutment surface(33) of the mounting plate (31).

17.The grommet assembly (1) according to any of claims 1 to 16, wherein saidattaching means (11) comprises at least one attaching hole configured toreceive a snap locking means, a screw, or a rivet.

18.A vehicle (8) comprising a power train component (2) comprising a housingwith an aperture in a wall of the housing, wherein a grommet assembly (1)according to any of claims 1 to 17 has been arranged at said aperture.