GB2449562A

GB2449562A - Vehicle front axle transmission mounting

Info

Publication number: GB2449562A
Application number: GB0809470A
Authority: GB
Inventors: Thomas Seiler; Vadim Ababkov
Original assignee: Dr Ing HCF Porsche AG
Current assignee: Dr Ing HCF Porsche AG
Priority date: 2007-05-25
Filing date: 2008-05-23
Publication date: 2008-11-26
Anticipated expiration: 2028-05-23
Also published as: DE102007024504A1; GB0809470D0; AT505344B1; AT505344A1; JP2008290707A; GB2449562B

Abstract

The invention relates to a motor vehicle with an engine/main transmission assembly 1 located in the longitudinal direction of the vehicle, the engine being mounted by means of engine consoles 5 in the body and/or in an engine cross-member connected to the body, and also with a front-axle transmission 15 which can be driven by means of the engine/main transmission assembly. In a motor vehicle of this type, it is proposed that the front-axle transmission be mounted exclusively in the engine/main transmission assembly and be rigidly connected to at least one of the engine consoles. Owing to the configuration of the motor vehicle according to the invention, the front-axle transmission can be mounted with low structural expense, this mounting is advantageous in terms of weight and furthermore an improvement in acoustic terms can be noted as a result of optimised vibration behaviour of the rigid arrangement of engine/main transmission assembly and front-axle transmission.

Description

I

Mounting of a front-axle transmission in a motor vehicle The invention relates to a motor vehicle with an engine/main transmission assembly arranged for example, in the longitudinal direction of the vehicle, the engine, for example, being mounted by means of engine consoles in the body and/or in a subfraine connected to the body, and also with a front-axle transmission which can be driven by means of the engine/main transmission assembly.

A motor vehicle of this type is known from practical experience through the Porsche Cayenne (RTM) vehicle type. In this four-wheel drive vehicle, the front-axle transmission, which is in the form of a front- axle differential, is fastened via three rubber mountings to the subframe of the vehicle. The main transmission is connected via a connection shall to the front-axle transmission, this connection shaft being of the universal (cardan) joint type.

It is further known from practical experience to fasten the front-axle transmission, in particular the front-axle differential, directly to the engine or to the crankcase. For this, the engine has to be redesigned accordingly at high cost.

DE 19636820 C2 shows to modify the engine console such that auxiliary units can be attached to the modified engine console in the engine compartment. In such case, the modified engine console acts as an auxiliary unit carrier, the auxiliary unit being for

example a generator.

DE 19848 799 A shows to connect an engine bearing to a differential gear. In such case, the differential gear acts as a vibration absorber for the engine owing to the supplementary mass.

DE 3621 620 Al describes a vehicle with a front-mounted, transverse power unit. Part of the transfer case housing serves to fasten the transmission to the engine bracket.

An engine console in which the oil filter is an integral component of the engine console is known from DE 19741 449 Al.

The present invention seeks to overcome or ameliorate at least one of the disadvantages of the prior art. An embodiment seeks to develop the motor vehicle of the type referred to first hereinbefore such that the mounting of the front-axle transmission is ensured with low structural outlay, this mounting is advantageous in terms of weight and furthermore an improvement in acoustic tenns can be noted as the result of optimised vibrational behaviour of the arrangement of engine/main transmission assembly and front-axle transmission.

This may be achieved in a motor vehicle of the type referred to first hereinbefore in that the front-axle transmission is mounted exclusively in the engine/main transmission assembly and is rigidly connected to at least one of the engine consoles.

Owing to the configuration according to the invention of the motor vehicle, the front-axle transmission thus forms a rigid unit with the engine/main transmission assembly.

This unit can be produced by comparatively small structural modifications because the front-axle transmission is mounted not in the body or in the subframe, but in at least one of the engine consoles, specifically is rigidly connected to this at least one engine console. Since owing to this rigid connection of the engine/main transmission assembly to the front-axle transmission it is not necessary to provide a cardan shaft between the assembly and the front-axle transmission, but instead a rigid connection shaft can be used, the arrangement described is advantageous in terms of weight. This arrangement additionally as a rule permits a package which is considerably more compact and hence likewise more advantageous in terms of weight in the region of the transmission and connection shaft.

Since owing to the configuration according to the invention of the motor vehicle the reaction forces of the front-axle transmission, in particular differential gear, produced by the drive torque are supported over the large support base of the engine/main transmission assembly, significant acoustic advantages are yielded. The movements of the front-axle transmission about the front axle are greatly reduced. Additionally the reaction movements are dampened by the large mass formed by the engine/main transmission assembly and front-axle transmission. Thus the noise caused by the movements/displacemcnt.s of the front-axle transmission upon load changes is greatly reduced.

It is regarded as particularly advantageous if the front-axle transmission is ngidly connected to at least two, in particular two, engine consoles. This means that torques can be introduced into the engine at different points via the front-axle transmission. It is regarded as particularly advantageous if the front-axle transmission is rigidly connected to engine consoles which are located on different sides of the engine. One engine console bears in particular the engine, relative to the longitudinal direction of the vehicle, for example, in the right-hand region of the vehicle, and the other engine console bears the engine in the left-hand region of the vehicle.

According to a preferred structural embodiment of the motor vehicle, provision is made for the front-axle transmission to be located beneath the respective engine console. This permits simple mounting and dc-mounting of the front-axle transmission, in particular when the front-axle transmission is connected by screws to the respective engine console.

In the context of the present invention it is not necessary for the front-axle transmission to be exclusively connected rigidly to at least one of the engine consoles. There is certainly the possibility of additionally connecting the front-axle transmission rigidly to the main transmission, in particular of connecting it to the main transmission by screws.

The invention thus proposes modifying or configuring one or more engine consoles such that they serie both to receive the engine, specifically the engine block, and to receive the front-axle transmission.

Further features of an embodiment of the invention will become apparent from the dependent claims, the following description of the drawings and the drawings themselves.

A preferred example of an embodiment of the invention is explained in the drawing and is described in greater detail in the following description.

Fig. 1 depicts a three-dimensional view of the engine/main transmission assembly and front-axle transmission and also their mounting, from the side, viewed obliquely from above, Fig. 2 depicts the arrangement shown in Figure 1, viewed from the side, Fig. 3 depicts a three-dimensional view of the two engine bearings for holding the front-axle transmission and the front-axle transmission held thereby, the engine being only partially shown, viewed obliquely from above and from the rear, Fig. 4 depicts the arrangement shown in Figure 3, viewed obliquely from below and from the side, Fig. 5 depicts the arrangement depicted in Figures 3 and 4, viewed obliquely from below and from the rear.

Figs. 1 and 2 illustrate, for a motor vehicle, an engine/main transmission assembly 1 arranged in a longitudinal direction of the vehicle, the upper part of the suinp 2, the crankcase lower half 3 located thereon and also the crankcase upper half 4 located thereon, which are each connected together by screws, being shown with respect to the engine. What is not shown is the oil pan located beneath the upper part of the sunip2 and connected thereto and also the cylinder heads connected to the crankcase upper half.

Relative to the longitudinal direction of the vehicle, the engine has on its right-hand and left-hand sides in each case an engine console 5, the respective engine console 5 being connected to the engine in the present embodiment by screws. Specifically, two screws 6 are provided for screwing the engine console 5 to the crankcase lower half 3 and four screws 7 for connecting the engine console S to the crankcase upper half 4. The respective engine consoleS has a front projection 8, in the region of which the engine console 5 is mounted via a rubber mounting 9 in an engine cross-member 10 (not shown). The main transmission 11 is connected by screws to the oil-conducting housing 2, the crankcase lower half 3 and the crankcase upper half 4. In the region of the end remote from the engine, the main transmission 11 has a transmission outlet 12 for a drive shaft (not shown) for the rear wheels of the motor vehicle and also a transmission outlet 13 for the front wheels of the vehicle. A rigid connection shaft 14 connected to the transmission outlet 13 connects the main transmission 11 to a front-axle transmission 15 in the form of a front-axle differential gear, which is connected rigidly exclusively to the two engine consoles 5 or additionally to the main transmission 11.

The engine/main transmission assembly 1 and the front-axle transmission 15 thus form a rigid unit, the rigid connection shaft 14 connecting the transmission outlet 13 to the front-axle transmission 15. Beneath the rigid connection shaft 14, above the subframe 15, there is positioned a power steering system 16 located in the transverse direction of the vehicle.

With regard to the further description, reference will be made to the illustration of Figs. 3to5: These Figures show only the region of the motor vehicle which is relevant to the invention, with the engine being shown only in the region of the upper part of the sump 2 for better clarity, without the relevant components of the engine located above the upper part of the sump 2, namely the crankcase lower half 3 and the crankcase upper half 4, to which upper half the engine consoles 5 are connected.

What is shown is the plane separating the upper part of the sump2 and the crankcase lower half 3 which is to be located above the upper part of the sump 2. The screws 6 for fastening the respective engine console 5 to the case lower half 3 are inserted through the two lower bores 17 in this engine console 5; the screws 7 for fastening this engine console 5 to the case upper half 4 are inserted through the four upper bores 18 in the respective engine console 5. This brings about the rigid connection of the two engine consoles 5 to the engine. What is shown is furthermore the rubber mountings 9 which are connected to the engine consoles 5 and via which the engine is mounted in an engine cross-member 10 (not shown).

Both engine consoles 5. which are in the form of cast metal components, have a projection 19 which extends them to the rear, which serves for mounting the front-axle transmission 15. On the right-hand side of the vehicle, the front-axle transmission 15 has a transmission housing 20. On the side facing the left-hand side of the vehicle, the transmission housing 20 is closed with a cover 21, to which a tube 22, also known as a trumpet, is connected. This tube 22 is passed through beneath a section of the oil-conducting housing 2 which is set back at the top, onto the left-hand side of the vehicle.

The tube 22 passes through a long transmission output shaft (not shown) and the transmission housing 20 through a short transmission output shaft, likewise not shown.

Identical wheel drive shafts 29 for the front wheels of the motor vehicle can be connected to these transmission output shafts located on both sides of the engine.

In the region of the left-hand engine console 5, the front-axle transmission 15 is mounted in the region of the tube 22. For this purpose, the tube 22 is provided with a flange 23 which has two through bores for receiving two screws 24 which can be screwed into threaded bores in the projection 19 of the engine console 5 associated with this flange 23. The transmission housing 20 is likewise provided with two through bores which are penetrated by screws 25 and which can be screwed into threaded bores in the projection 19 of the engine consoleS associated with the transmission housing 20. The front-axle transmission 15 is located beneath the respective engine consoleS and is accordingly connected by screws from below. It is also conceivable to connect by screwing in a different direction.

The reference numeral 26 designates the input shaft mounted in the transmission housing 20, which shaft is connected to the rigid connection shaft 14. Finally, it is shown that the engine is located centrally over the front axle of the vehicle and the main transmission 11 in its rear region is mounted in the body via a cross-member 27.

Due to the rigid connection of the engine and main transmission, the front-axle transmission 15 may be additionally connected to the main transmission 11. Thus for example the front-axle transmission 15 can be connected rigidly to the main transmission 11 in the region of connection of the connection shaft 14 with the front-axle transmission 15. This is indicated by the screw 28, which penetrates a further bore in the front-axle transmission 15.

List of reference numerals I engine/main transmission assembly 2 upper part of sump 3 crankcase lower half 4 crankcase upper half engine console 6 screw 7 screw 8 projection 9 rubber mountings subframe 11 main transmission 12 transmission outlet 13 transmission outlet 14 rigid connection shaft front-axle transmission 16 power steeaing system 17 bore 18 bore 19 projection transmission housing 21 cover 22 tube/trumpet 23 flange 24 screw screw 26 input shaft 27 cross-member 28 Screw 29 wheel drive shaft

Claims

CJaims 1. A motor vehicle with an engine/main transmission assembly

arranged in the longitudinal direction of the vehicle, the engine being mounted by means of engine brackets in the vehicle body and/or in an engine cross-member or subframe connected to the vehicle body, and also with a front-axle transmission which can be driven by means of the engine/main transmission assembly, wherein the front-axle transmission is mounted within the engine/main transmission assembly and is rigidly connected to at least one of the engine brackets.
2. A motor vehicle according to Claim 1, wherein the main transmission is connected to the front-axle transmission via a rigid connection shaft.
3. A motor vehicle according to Claim 1 or 2, wherein the front-axle transmission is rigidly connected to at least two, in particular two, engine consoles.
4. A motor vehicle according to one of Claims 1 to 3, wherein the front-axle transmission is rigidly connected to engine consoles which are located on different sides of the engine.
5. A motor vehicle according to one of Claims 1 to 4, wherein the front-axle transmission is located beneath the respective engine console.
6. A motor vehicle according to one of Claims 1 to 5, wherein the front-axle transmission is connected to the respective engine console by screws.
7. A motor vehicle according to one of Claims 1 to 6, wherein the engine is located over the front axle of the vehicle.
8. A vehicle according to one of Claims I to 7, wherein the front-axle transmission has a transmission housing with short transmission output shaft located on one side of the engine and a trumpet with long transmission output shaft connected to the transmission housing and located beneath the engine, both transmission output shafts being able to be connected to wheel drive shafts.
9. A motor vehicle according to Claim 8, the transmission housing (20) is rigidly connected to at least one engine console and the trumpet to another engine console.
10. A motor vehicle according to one of Claims 1 to 9, wherein the front-axle transmission is rigidly connected to the main transmission.
11. A motor vehicle according to Claim 10, wherein the front-axle transmission in the region of the connection shaft is connected rigidly to the main transmission, in particular is connected to the main transmission by screws.
12. A motor vehicle according to one of Claims 1 to 11, wherein the front-axle transmission is in the form of a front-axle differential.
13. A motor vehicle according to one of Claims I to 12, wherein the vehicle has a rear-axle transmission which can be driven by means of the engine/main transmission assembly.
14. A motor vehicle, substantially as hereinbefore described with reference to the accompanying drawings.
15. An engine/main transmission assembly, substantially as hereinbefore described with reference to the accompanying drawings.