GB1591956A

GB1591956A - Driving apparatus for automotive vehicles

Info

Publication number: GB1591956A
Application number: GB52178A
Authority: GB
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 1977-09-22
Filing date: 1978-01-06
Publication date: 1981-07-01
Also published as: DE2803840A1; FR2403907A1; DE2803840C2; FR2403907B1

Description

(54) DRIVING APPARATUS FOR AUTOMOTIVE VEHICLES (71) We, TOYOTA JIDOSHA KOGYO KABUSHIKI KAISHA, a corporation organised and existing under the laws of Japan, of 1 Toyotacho, Toyota-shi, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to driving apparatus for automotive vehicles. Embodiments of the invention are particularly suited to use in front engine-front drive (F-F) type or rear engine-rear drive (R-R) type or front-and-rear drive type automotive vehicles.

In a driving apparatus for an automotive vehicle of F-F or R-R type, it is well known for the internal combustion engine to be disposed transversely with respect to the longitudinal or fore-and-aft axis of the vehicle. An engine so disposed is often referred to as a transaxle engine. A transaxle engine is usually combined with a transaxle transmission which is also disposed transversely of the vehicle with power input and output shafts thereof extending transversely of the fore-and-aft axis of the vehicle. The output shaft of the engine is operatively and disconnectably coupled to the input shaft of the transmission through a clutch. A helical driving gear is fixedly mounted on the transmission output shaft which forms a final gear train in cooperation with a driven helical gear which serves concurrently as the driving gear of a differential gear unit for front wheel axle shafts or rear wheel axle shafts or both of them.

The arrangement of the hitherto known driving apparatus in which the internal combustion engine and the transmission are disposed transversely with respect to the fore-and-aft axis of the vehicle as described above has the advantage that a mechanism for operatively coupling the output shaft of the engine and the input shaft of the transmission to each other can be simple, because both the shafts extend in the same direction.

However, such driving apparatus has a drawback that the dimension of the whole structure of the driving apparatus in the transversal direction has to be undesirably increased with consequent increase in the track of the vehicle. Moreover. the hitherto known driving apparatus is disadvantageous in that a mechanism for translating the movement of the shift lever to shift forks upon changing the speed ratio of the transmission is relatively complicated. Also, the freedom for selectively determining total gear ratios involved in the torque path extending from the output shaft of the engine to the axle shafts of the wheels is restricted.

According to the present invention there is provided a driving apparatus for an automotive vehicle, the apparatus comprising a transversely disposed internal combustion engine installed in said vehicle with the axis of an output shaft of said engine extending transversely with respect to the length of said vehicle, a longitudinally disposed change-speed transmission installed in said vehicle with input and output shafts thereof extending lengthwise of said vehicle, a disconnectable power coupling means disposed between said engine and said transmission and having a power transmitting shaft which extends in substantially the same direction as said output shaft of said engine and is operatively disconnectable coupled to said output shaft of said engine, a first bevel gear assembly located within a housing which also houses the transmission change-speed gears and operatively connecting said input shaft of said transmission to said power transmitting shaft of said power coupling means, and a final gear train including a second bevel gear assembly which includes a driving bevel gear mounted on said output shaft of said transmission and a driven bevel gear arranged to mesh with said driving bevel gear.

According to the present invention there is also provided a driving apparatus for an automotive vehicle, the apparatus comprising a transversely disposed internal combustion engine installed in said vehicle with the axis of an output shaft of said engine extending transversely with respect to the length of said vehicle, a longitudinally disposed change-speed transmission installed in said vehicle with input and output shafts thereof extending lengthwise of said vehicle. a disconnectable power coupling means disposed between said engine and said transmission and having a power transmitting shaft which extends in substantially the same direction as said output shaft of said engine and is operatively disconnectably coupled to said output shaft of said engine, a first bevel gear assembly located within a housing which also houses the transmission change-speed gears and for operatively connecting said input shaft of said transmission and said power transmitting shaft of said power coupling means to each other, and final gear trains for driving front and rear axle shafts of said vehicle. respectively, said final gear trains comprising respectively, second and third bevel gear assemblies, wherein one end of said output shaft of said transmission is fixedly provided with a driving bevel gear of one of said final gear trains, while the other end of said output shaft of said transmission is connected to a driving bevel gear of the other final gear train through a coupling means including a propeller shaft.

The invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a top plan view illustrating schematically an arrangement of a hitherto known driving apparatus composed of a transaxle engine and transmission and installed on an automotive vehicle of (F-F) type as well as relationships between the driving apparatus, front axle shaft and front wheels; Figure 2 is a schematic elevational side view of the driving apparatus of Figure 1 to illustrate the arrangement of individual components thereof; Figure 3 is a view similar to Figure 1 but showing a driving apparatus constructed in accordance with an embodiment of the invention installed on an F-F type vehicle; Figure 4 is a schematic perspective view showing an outer appearance of the driving apparatus of Figure 3; Figure 5 is a side view showing the structure of the transmission forming a part of the driving apparatus of Figure 3 along with other structural elements of the driving apparatus with a half of the housing removed; Figure 6 is a side view of the driving apparatus of Figure 4 to illustrate the relationship between the engine, transmission.

clutch and a differential gear unit in a partially sectioned side view; Figure 7 is a schematic diagram illustrating the arrangement of a driving apparatus constructed in accordance with another embodiment of the invention; and Figure 8 shows schematically an arrangement of a driving apparatus constructed in accordance with still another embodiment of the invention.

Before entering into a detailed description of the preferred embodiments of the invention, discussion will first be made of a hitherto known apparatus, in order to have a better understanding of the invention.

Referring to Figures ] and 2, there is shown a hitherto known driving apparatus 301 which includes an internal combustion engine 302, a clutch 303 and a transmission 304. The engine 302 and the transmission 304 are disposed transversely with respect to the longitudinal axis of an automotive vehicle and are herein referred to as the transaxle engine and transmission, respec- tively. The axis represented by a dotted broken line 305' around which an output shaft or crank shaft 305 of the engine 302 is rotated as well as input and output shafts 306 and 307 of the transmission 304 extend transversely with respect to the longitudinal or fore-and-aft axis of the vehicle. The crank shaft 305 is operatively connected to the input shaft 306 of the transmission 304 through the clutch 303 in a disengageable or disconnectable manner. There is further provided a final gear unit 308 which includes a driving helical gear 309 fixedly mounted on the output shaft 307 of the transmission 304 and a driven helical gear 310 arranged to mesh with the driving helical gear 309. The driven helical gear 310 in turn forms a driving element for a differential gear unit 311. The driving apparatus 301 as illustrated is for an automotive vehicle of F-F type. Consequently, the differential gear unit 311 is arranged to drive axle shafts 312 and 312' connected to front wheels 316 and 316', respectively. In Figures 1 and 2, reference numerals 313 and 314 denote input and output gears of the transmission 304, respectively, while reference numerals 315 and 315' designate universal joints.

With the structure of the hitherto known driving apparatus such as described above, the driving apparatus 301 is not suited for use in a vehicle which has a small width and hence a small track T, because of the great length (W) of the driving apparatus in the transversal direction. For example, assuming that such driving apparatus 301 is employed in an automotive vehicle having a small track T, it will then become impossible or at least extremely difficult to assure sufficiently large gaps C and C' defined between the lateral side walls of the driving apparatus and the right and left wheels 316 and 31 6', respectively, which necessarily results in a restricted inclination a of the front wheels. as can be seen from Figure 1.

This means that the allowable minimum turning radius of the vehicle will become undesirably increased. Further, the transversal disposition of the input and output shafts 306 and 307 of the transmission 304 will disadvantageously involve a need for a particularly complicated mechanism for transmitting movement of a shift lever not shown) to transmission gear shift forks (not shown) when the speed ratio of the vehicle is to be changed. In more particular, the shifting of transmission gears for changing vehicle speed is generally effected by moving or manipulating the shift lever in the longitudinal direction of the vehicle.

Accordingly, in the case of the transaxle transmission having the input and output shafts extending transversely of the vehicle, a mechanism has to be provided which serves to translate the movement of the shift lever in the longitudinal direction to the movement of the shift forks in the transversal direction.

It will additionally be noted that, in the case of the hitherto known driving apparatus, the rotational speed of the crank shaft 305 is changed at two points, i.e.

through the transmission 304 and the final gear unit 308. Accordingly, when transmissions of the identical structure are used for different automotive vehicles and it is desired that the total speed change ratio corresponding to a sum of the speed changing gear ratio of the transmission 304 and the gear ratio of the final gear unit 308 be increased in a certain vehicle, then the gear ratio of the final gear unit 308 of that vehicle has to be increased, since the transmission 304 is assumed to be of identical structure common to all the vehicles. In order to increase the gear ratio of the final gear unit 308, the diameter of the driven gear 310 thereof may be correspondingly enlarged, which will however be disadvantageously accompanied with a decrease in a minimum height H of the driving apparatus 301 relative to the ground (Figure 2). Thus, the freedom of selecting the total speed changing gear ratio is restricted in the hitherto known driving apparatus, as a result of which the use of the transmission of the same structure and dimensions for different vehicles will encounter some inconveniences.

Now, the invention will be described with reference to embodiments thereof illustrated, by way of example only, in the drawings.

Figures 3 to 6 show a driving apparatus according to a first embodiment of the invention. Referring first to Figures 3 and 4, the driving apparatus 1 comprises an internal combustion engine 2, a disconnectable power coupling unit including a clutch 3, a transmission 4 and a differential gear unit 11 including a final gear unit described hereinafter which are assembled together in an integral or common unit. The driving apparatus 1 is assumed to be used in an automotive vehicle of F-F drive type and to this end is arranged to drive front wheels 16 and 16' through front axle shafts 12 and 12', respectively. In Figure 4, reference numerals 15 and 15' denote universal joints, 48 denotes an oil pan, and 47 and 49 denote an outer shift lever and an outer select lever.

An arrow A represents the direction towards the front of the vehicle.

Referring to Figures 4, 5 and 6, it will be noted that the engine 2 is mounted as a transversely disposed engine with the rotational axis 5' of the output shaft or crank shaft 5 extending transversely with respect to the longitudinal or fore-and-aft axis of the vehicle, while the transmission 4 is mounted as a longitudinally disposed transmission with the input and output shafts 6 and 7 thereof extending in the longitudinal direction of the vehicle. The clutch 3 is disposed between the transmission 4 and the engine 2 at a side thereof and has a power transmitting shaft 17 which extends in substantially the same direction as the output shaft 5 of the engine and is operatively disengageably connected to the latter.

As described hereinbefore, the clutch 3, transmission 4, differential gear unit 11 and so forth are assembled together in a unit and accommodated within a housing 18 which is forward by two housing portions 18a and 1 8b bolted together at 19 with the housing portion 18b being fixedly secured to the housing of the engine 2 by means of bolts 20 (refer to Figure 4). As can be seen from Figure 5, the boundary plane between the housing portions 18a and 18b is coincident with a plane including the axes of the input and output shafts 6 and 7 of the transmission.

Referring to Figure 5, the input shaft 6 and the output shaft 7 of the transmission 4 are accommodated within the housing 18 as supported rotatably through respective bearings 22; 22' and'23; 23'. The input shaft 6 of the transmission carries input gears 24, 25, 26, 27, 28 and 29 which form, respectively, a part of the torque delivery paths for fifth speed ratio drive (over-drive), first speed ratio drive, reverse drive, second speed ratio drive, third speed ratio drive and fourth speed ratio drive (top speed ratio drive). In a similar manner, the output shaft 7 of the transmission 4 carries output gears 30, 31, 32, 33, 34 and 35 which form, respectively, a part of the torque delivery paths for the fifth speed ratio drive, the first speed ratio drive, the reverse drive, the second speed ratio drive, the third speed ratio drive and the fourth speed ratio drive. In Figure 5, reference numerals 36, 37 and 38 denote synchronizers for the fifth speed ratio drive, the first and second speed ratio drives, and the third and fourth speed ratio drives, respectively. Reference numeral 39 designates an idler gear, while reference numeral 40 denotes an end cover of the transmission 4.

As is shown in Figures 5 and 6, a torque or power transmitting shaft 17 of the clutch 3 is operativelly connected to the input shaft 6 of the transmission 4 through a first bevel gear assembly 41 which comprises a driving bevel gear 42 fixedly mounted on the power transmitting shaft 1 7 at one end thereof and a driven bevel gear 43 fixedly mounted on the input shaft 6 of the transmission 4. It is to be noted that the bevel gears 42 and 43 are formed, respectively. by a spiral bevel gear. The output shaft 7 of the transmission 4 is operatively coupled to the front wheel axle shafts 12 and 12' through the diffcrential gear unit 11 including the final gear assembly, which in turn comprises a driving bevel gear 45 fixedly mounted on the output shaft 7 at an end thereof and a second bevel gear assembly including a driven bevel gear 46 which is arranged to mesh with the driving bevel gear 45 and forms the ring gear of the differential gear unit 11. In Figure 6, reference numerals 51, 52 and 53 designate bearings.

In the illustrated embodiment. it will be noted that the driven bevel gear 43 of the first bevel gear assembly 41 is fixedly mounted on the input shaft 6 of the transmission 4 at a position adjacent to the input gear 29 for the top or fourth speed ratio drive. With such arrangement of the driven gear 43 which is engaged with the driving bevel gear 42, it is possible to dispose the power transmitting shaft 17 of the clutch 3 as well as the crank shaft 5 at a position displaced towards the rear of the vehicle or to the right-hand side as viewed in Figure 5, whereby the engine 2 and the clutch 3 can be conveniently installed with the degree of projection thereof to the front of the vehicle being advantagcously reduced. On the contrary, if the driven bevel gear 43 was located at a position adjacent to the input gear for the lower speed ratio drive such as the input gear 25 for the first speed ratio drive, for example, the degree of projection of the engine 2 to the left as viewed in Figure 5 (towards the front of the vehicle) would be increased. Further, as can be seen from Fig ure 6 the driven bevel gear 46 of the second bevel gear assembly 44 is disposed at the position off-set towards the engine 2 or to the left-hand side as viewed in Figure 6 rela tivc to the centre axis 45' of the driving gear 45 and is arranged to mesh with the latter.

This arrangement alloy s a compact driving apparatus to be obtained in which the differential gear unit 11 is closely juxtaposed to the engine 2 in the direction transversal to the fore-and-aft axis (or longitudinal axis) of the vehicle.

In the case of the illustrated embodiment, the driving bevel gear 45 and the driven bevel gear 46 of the final gear train are formed, respectively, by hypoid gears. As is well known in the art, a pair of hypoid gears meshing with each other can be so arranged that the axes of these gears will not intersect with each other. In particular, as is shown in Figure 5, the centre axis 45' of the driving bevel gear 45 is spaced upwardly from the centre axis 46' of the driven bevel gear 46 by a distance B. By virtue of the use of such hypoid gears in the arrangement described above, it is possible appropriately to select the position of the driving bevel gear 45 rclative to the driven bevel gear 46 and hence the positions of the engine 2 and the clutch 3 relative to the differential gear unit 11 and the axle shafts 12 and 12'. In this manner, there can be obtained an advantage that the driving apparatus can easily be so designed that it may be installed in a restricted occupation space of any specific vehicles.

At this point, it should be mentioned that the term "bevel gear" as herein used means a gear which has generally a frusto-conical outer profile and is formed with teeth in the slanted peripheral surface. Thus, with the term "bevel gear", it is intended that the ordinary bevel gear as well as the hypoid gears to be so arranged that the centre axes will not intersect with each other be covered or encompassed by the concept of "bevel gear". Accordingly, an arrangement may be made such that the axis of the power transmitting shaft 17 of the clutch 3 will not intersect with the axis of the input shaft 6 of the transmission 4 by using hypoid gears for the driving bevel gear 42 and the driven bevel gear 43 of the first bevel gear assembly 41.

In operation of the driving apparatus in accordance with fhe first embodiment of the invention described above, the rotation or torque transmitted to the power transmitting shaft 17 of the clutch 3 from the crank shaft 5 of the internal combustion engine is transmitted to the input shaft 6 of the transmission 4 through the driving bevel gear 42 and the driven bevel gear 43 of the first bevel gear assembly 41 and hence transmitted to the output shaft 7 of the transmission 4 through the input and output gears thereof. The output shaft 7 of the transmission 4 in turn drives the differential gear unit ]1 through the final gear assembly 44 formed by the driving bevel gear 45 and the driven bevel gear 46, whereby the front axle shafts 12 and 12' and hence the front wheels 16 and 16' are correspondingly driven through the differential gear unit 11.

As will be appreciated from the foregoing description, the driving apparatus according to the invention can be implemented with the transversal length W thereof (Figure 3) being significantly reduced as compared with the hitherto known driving apparatus in which both of engine and the transmission are disposed transversely with respect to the longitudinal axis of the vehicle, by virtue of such arrangement that the transmission 4 is disposed longitudinally or along the aforeand-aft axis of the vehicle. In this manner, the disadvantage of the hitherto known driving apparatus of being unsuitable for use in the vehicle having a narrow width and hence a small track T as described hereinbefore can be substantially reduced. Further, even when a multi-cylinder engine having a relatively large transversal dimention is used, the driving apparatus as a whole can be realized with the transversal length thereof being kept to a minimum.

It should be further noted that the input and output shafts of the transmission 4 extend in the longitudinal or afore-and-aft axial direction of the vehicle, i.e. in the same direction as the shift lever (not shown) is operated for changing speed. Thus, the mechanism for operatively coupling the shift lever and the shift forks (not shown) can be advantageously implemented in a much simplified arrangement. Additionally, by virtue of the connection between the power transmitting shaft 17 and the input shaft 6 of the transmission through the first bevel gear assembly 41, the rotational speeds of the crank shaft 5 and the power transmitting shaft 17 can be appropriately changed and then transmitted to the input shaft 6 of the transmission by selecting the gear ratio between the driving bevel gear 42 and the driven bevel gear 43 of the first bevel gear assembly 42. In other words, the freedom for determining the total gear ratio of the whole torque delivery path extending from the crank shaft 5 to the front axle shafts 12 and 12' is significantly larger than the freedom available in the hitherto known driving apparatus in which the rotation of the power transmission shaft is directly transmitted to the input shaft of the transmission.

In the illustrated embodiment, the differential gear unit 11 is juxtaposed adjacent to the engine 2 in the transversal direction relative to the longitudinal axis of the vehicle. Thus, the flange portion (not shown) formed in the oil pan 48 for securing the latter to the bottom of the engine 2 will never come into contact with the differential gear unit 11, when the engine 2 is slanted towards the rear of the vehicle as indicated by an arrow D in Figure 4. Consequently, the slant angle can be selected to have a sufficiently great value. Also, it is apparent that the engine 2 may be sufficiently slanted towards the front of the vehicle.

In Figure 7, there is schematically shown an arrangement of a driving apparatus 101 implemented as an automatic transmission in accordance with the second embodiment of the invention. In place of the clutch as well as the manually manipulated transmission of the first embodiment, the driving apparatus 101 comprises a torque converter 103, an auxiliary transmission composed of a planetary gear unit 104 and a hydraulic control system (not shown). The torque converter 103 has a power transmitting shaft 117 which extends in substantially the same direction as the output shaft 105 of a transversely disposed engine 102 and is operatively connected to the output shaft 105 in a disconnectable manner. The auxiliary transmission 104 is disposed longitudinally with input and output shafts 106 and 107 thereof extending in the longitudinal direction of the vehicle (vertical direction as viewed in Figure 7).

Mounted on the left end of the power transmission shaft 117 (as viewed in Figure 7) is a driving bevel gear 142 which is arranged to mesh with a driven gear 143 mounted on an interlocked shaft 153 extending parallel to the input and output shafts of the auxiliary transmission 104. The shaft 153 is operatively connected to the input shaft 106 of the auxiliary transmission 104 through a spur gear assembly 150 which comprises a driving spur gear 154 secured to the interlocked shaft 153 substantially coaxially with the driven bevel gear 143 and a driven spur gear 155 fixedly secured to the input shaft 106 of the auxiliary transmission at an end thereof. The driving bevel gear 142 cooperates with the driven bevel gear 143 to form a first bevel gear assembly 141 for operatively connecting the power transmitting shaft 117 to the input shaft 106 of the auxiliary transmission 104 through the interlocked shaft 153 and the spur gear assembly 150.

The output shaft 107 of the auxiliary transmission 104 is operatively connected to axle shafts 112 and 112' for the front wheels (not shown) through the differential gear unit 111 including a final gear train 144 which is formed by a second bevel gear assembly comprising a driving bevel gear 145 fixedly secured to the output shaft 107 of the automatic transmission at the rear end thereof (lower end as viewed in Figure 7) and a driven bevel gear 146 disposed coaxially with the front axle shafts 112 and 112'. In Figure 7 reference numeral 115 and 115' denote, respectively, universal joints.

In operation of the driving apparatus described above according to the second embodiment of the invention, the rotation of the power transmitting shaft 117 is transmitted to the input shaft 106 of the auxiliary transmission through the first bevel gear assembly 141, the interlocked shaft 153 and the spur gear assembly 150, thereby to drive the output shaft I 07 of the auxiliary transmission, the rotation of which in turn is transmitted to the second bevel gear assembly to drive the differential gear unit Ill and hence the front axle shafts 112 and 112' for the front wheels. The remaining arrangement of the driving apparatus shown in Figure 7 is substantially the same as the corresponding arrangement of the first embodiment described hereinbefore in conjunction with Figures 3 to 6. It will be sclf-explanatory that the driving apparatus constructed according to the second embod imcnt of the invention will bring about similar advantages as those of the first embodiment of the invention.

The embodiments of driving apparatus according to the invention described so far are assumed to be used in a vehicle of the F-F type. However, it will be readily appreciated that the driving apparatus can be implemented for use in vehicles of the R-R type or of midship engine type. Of course, it is also possible to arrange the driving apparatus for a vehicle of the rcar-andfront drive system.

Figure 8 shows a driving apparatus for the rcar-and-front drive type vehicle constructed in accordance with the third embodiment of the invention. This driving apparatus 201 principally diffcrs from the first embodiment of the invention in that the rear end portion of the output shaft of the longitudinally disposed transmission is operatively connected to the final gear assembly for the rear wheels. In more particular, the rear end (right end as viewed in Figure 8) of the output shaft 207 of the longitudinally disposed transmission 204 is operatively coupled through a coupling apparatus 260 to a driving shaft 259 of a driving bevel gear 258 belonging to a final gear train formed by a third bevel gear assembly 256 for driving rear wheels 257. A driven bevel gear 261 of the third bevel gear assembly 256 in turn forms a ring gear of a differential gear unit for the rear wheels 257. The coupling apparatus 260 comprises universal joints 262 and 263 connected.

respectively, to the rear end of the transmission output shaft 2()7 and the driving shaft 259 of the driving bevel gear 25tri and additionally includes a propeller shaft 264 disposed between the universal joints 262 and 263. Except for these arrangements as described above, the construction of the driving apparatus shown in Figure 8 is substantially similar to that of the driving apparatus according to the first embodiment of the invention as described hereinbefore in conjunction with Figures 3 to 6. ?'hus. a driving gear 245 of a second bevel gear assembly 244 forming the final gear train for the front wheels 265 is fixedly mounted on the transmission output shaft 207 at the front end thereof. In Figure 8, reference numerals 202 and 203 denote, respectively, a forardly

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

bevel gear assembly 141, the interlocked shaft 153 and the spur gear assembly 150, thereby to drive the output shaft I 07 of the auxiliary transmission, the rotation of which in turn is transmitted to the second bevel gear assembly to drive the differential gear unit Ill and hence the front axle shafts 112 and 112' for the front wheels. The remaining arrangement of the driving apparatus shown in Figure 7 is substantially the same as the corresponding arrangement of the first embodiment described hereinbefore in conjunction with Figures 3 to 6. It will be sclf-explanatory that the driving apparatus constructed according to the second embod imcnt of the invention will bring about similar advantages as those of the first embodiment of the invention.

The embodiments of driving apparatus according to the invention described so far are assumed to be used in a vehicle of the F-F type. However, it will be readily appreciated that the driving apparatus can be implemented for use in vehicles of the R-R type or of midship engine type. Of course, it is also possible to arrange the driving apparatus for a vehicle of the rcar-andfront drive system.

Figure 8 shows a driving apparatus for the rcar-and-front drive type vehicle constructed in accordance with the third embodiment of the invention. This driving apparatus 201 principally diffcrs from the first embodiment of the invention in that the rear end portion of the output shaft of the longitudinally disposed transmission is operatively connected to the final gear assembly for the rear wheels. In more particular, the rear end (right end as viewed in Figure 8) of the output shaft 207 of the longitudinally disposed transmission 204 is operatively coupled through a coupling apparatus 260 to a driving shaft 259 of a driving bevel gear 258 belonging to a final gear train formed by a third bevel gear assembly 256 for driving rear wheels 257. A driven bevel gear 261 of the third bevel gear assembly 256 in turn forms a ring gear of a differential gear unit for the rear wheels 257. The coupling apparatus 260 comprises universal joints 262 and 263 connected.

respectively, to the rear end of the transmission output shaft 2()7 and the driving shaft 259 of the driving bevel gear 25tri and additionally includes a propeller shaft 264 disposed between the universal joints 262 and 263. Except for these arrangements as described above, the construction of the driving apparatus shown in Figure 8 is substantially similar to that of the driving apparatus according to the first embodiment of the invention as described hereinbefore in conjunction with Figures 3 to 6. ?'hus. a driving gear 245 of a second bevel gear assembly 244 forming the final gear train for the front wheels 265 is fixedly mounted on the transmission output shaft 207 at the front end thereof. In Figure 8, reference numerals 202 and 203 denote, respectively, a forardly slanted and transversely disposed engine and a clutch.

It will now be appreciated that, in the case of the driving apparatus in accordance with the third embodiment of the invention as shown in Figure 8, the longitudinally extending disposition of the output shaft 207 of the transmission 204 is utilized for deriving the driving power for the front wheel from the front end of the output shaft 207 and at the same time for allowing the driving power for the rear wheels 261 to be derived from the rear end of the output shaft 207. In this manner, the teaching of the invention can readily be applied to a front-and-rear drive type vehicle having a transversely disposed engine. In the driving apparatus shown in Figure 8, the engine, transmission and the like components are assumed to be installed at the front of vehicle. However. it will be readily be understood that these components may be disposed at the rear of vehicle. in which case the propeller shaft is coupled to the front end of the transmission output shaft for driving the front wheels. Besides, in place of deriving the driving power from the front and rear ends of the transmission output shaft for driving the front and rear wheels, it is also Dossible to derive the driving power from either end of the output shaft, while the other end thereof is coupled to an electric generator, a pump or the like through a suitable transmission apparatus such as belt-pulley apparatus.

WHAT WE CLAIM IS: 1. A driving apparatus for an automotive vehicle, the apparatus comprising a transversely disposed internal combustion engine installed in said vehicle with the axis of an output shaft of said engine extending transversely with respect to the length of said vehicle. a longitudinally disposed change-speed transmission installed in said vehicle with input and output shafts thereof extending lengthwise of said vehicle, a disconnectable power coupling means disposed between said engine and said transmission and having a power transmitting shaft which extends in substantially the same direction as said output shaft of said engine and is operatively disconnectably coupled to said output shaft of said engine, a first bevel gear assembly located within a housing which also houses the transmission change-speed gears and operatively connecting said input shaft of said transmission to said power transmitting shaft of said power coupling means. and a final gear train including a second bevel gear assembly which includes a driving bevel gear mounted on said output

shaft of said transmission and a driven bevel gear arranged to mesh with said driving bevel gear.
2. Apparatus according to claim 1 wherein said first bevel gear assembly includes a driving bevel gear mounted on said power transmitting shaft, and a driven bevel gear mounted on said input shaft of said transmission at a position adjacent to a gear for a high speed ratio drive of said transmission.
3. Apparatus according to claim 1 wherein each of said driving and driven bevel gears of said second bevel gear assembly is formed by a hypoid gear.
4. Apparatus according to claim 1 wherein said driven bevel gear of said second bevel gear assembly meshing with said driving bevel gear thereof is spaced from the centre axis of said driving bevel gear towards said internal combustion engine as viewed in the direction transversely of said vehicle.
5. Apparatus according to claim 1 wherein said power coupling means and said transmission are formed by an automatic transmission which comprises a torque converter and a longitudinally disposed auxiliary transmission, and wherein said first bevel gear assembly includes a driving bevel gear fixedly mounted on a power transmitting shaft of said torque converter and a driven bevel gear fixedly mounted on a shaft which extends substantially parailel to an input shaft of said auxiliary transmission and operatively interlocked thereto through a spur gear assembly.
6. Apparatus according to claim 1 wherein said power coupling means, said transmission and said final gear train are accommodated within a common housing which is formed by two housing portions connected together along a plane in which axes of said input and output shafts of said transmission are included.
7. Apparatus according to claim 6 wherein one of said housing portions which is located adjacent to said engine is fixedly connected to said engine.
8. A driving apparatus for an automotive vehicle, the apparatus comprising a transversely disposed internal combustion engine installed in said vehicle with the axis of an output shaft of said engine extending transversely with respect to the length of said vehicle, a longitudinally disposed change-speed transmission installed in said vehicle with input and output shafts thereof extending lengthwise of said vehicle, a disconnectable power coupling means disposed between said engine and said transmission and having a power transmitting shaft which extends in substantially the same direction as said output shaft of said engine and is operatively disconnectably coupled to said output shaft of said engine, a first bevel gear assembly located within a housing which also houses the transmission change-speed gears and for operatively connecting said input shaft of said transmission and said power transmitting shaft of said power coupling means to each other, and final gear trains for driving front and rear axle shafts of said vehicle, respectively, said final gear trains comprising, respectively, second and third bevel gear assemblies, wherein one end of said output shaft of said transmission is fixedly provided with a driving bevel gear of one of said final gear trains, while the other end of said output shaft of said transmission is connected to a driving bevel gear of the other final gear train through a coupling means including a propeller shaft.
9. A driving apparatus for an automotive vehicle, the apparatus being substantially as hereinbefore described with reference to Figures 3 to 6 of the accompanying drawings.
10. A driving apparatus for an automotive vehicle, the apparatus being substantially as hereinbefore described with reference to Figure 7 of the accompanying drawings.
11. A driving apparatus for an automotive vehicle, the apparatus being substantially as hereinbefore described with reference to Figure 8 of the accompanying drawings.