MXPA97005631A - Transmission for vehicles with displacement in the four rue - Google Patents

Abstract

The present invention relates to the transmission for a four-wheel drive vehicle having a motor and front and rear drive lines, the transmission is characterized in that it comprises: a feed arrow moved by the motor with respect to a first rotary axis a transfer arrow supported for rotation with respect to a second rotary axis, a tubular main shaft rotatably supported on the transfer shaft, a plurality of constant coupling gear sets, each having a feed gear fixed to the feed shaft and a speed gear rotatably supported on the main shaft, a plurality of synchronizing clutches for selective engagement of one of the speed gears with the main shaft, to move the main shaft at a predetermined speed ratio relative to the feed shaft, to establish a plurality of advance gears and reverse, a tubular shaft rotatably supported on the transfer arrow adjacent to the main shaft, a gear reduction unit having a feed member displaced by the main shaft and an output member displaced at a reduced speed ratio relative to the feeder member: a range clutch for selective coupling of the tubular shaft to any of the main shaft where a displacement connection with direct speed ratio is established in the output member of the gear reduction unit in which establishes the impulse or displacement connection with reduced speed ratio, a rear output arrow adapted for connection to the rear impulse line and which is commonly aligned with the transfer arrow for rotation with respect to the second rotary axis, a front output arrow adapted for connection to the frontal impulse line and which is held for rotation with respect to a third rotary axis, a transfer mechanism that connects the front output arrow for common rotation with the transfer arrow, and a differential between axes to allow speed differentiation between the rear output arrow and the transfer arrow, the differential between axes includes a first planetary gear for rotation with the transfer arrow, a second fixed planetary gear for rotation with the rear output arrow and a fixed planetary carrier for rotation with the tubular shaft and which rotatably holds the planetary gear means coupling with the first and second planetary gears

Description

TRANSMISSION FOR VEHICLES WITH DISPLACEMENT IN THE FOUR WHEELS BACKGROUND OF THE INVENTION The present invention relates in general to transmissions for use in vehicles with displacement on all four wheels. More particularly, the present invention is directed to a transmission having a multi-speed gear train and a power transfer assembly contained in a single gearbox. As is known, most four-wheel drive vehicles are equipped with a transfer enclosure mounted to a multi-speed transmission to direct power to all four wheels. To allow or accommodate different road conditions and surfaces, many transfer enclosures are equipped with a gear reduction unit that can be moved by the vehicle operator to establish high range (ie direct) and low range travel modes. (ie reduced ratio) with four wheels. Likewise, some transfer enclosures are equipped with an inter-row differential to supply torque of impulse torque to the front and rear drive lines of the vehicle displaced with the four wheels, while allowing differentiation of speed between them.

In an effort to minimize the overall size of the drive train used in four-wheel drive vehicles, it has been proposed to use a transmission of a type of drive axles normally used to move the front wheels of a vehicle with wheel displacement. such as a four-wheel drive gear train. In particular, British Patent No. 2,035,930 issued to Jones et al. Illustrates the rotation of a front wheel drive train (i.e. motor and drive shaft) such that the outputs of the drive shaft can be interconnected to the front pulse lines and back of the motor vehicle. While this assembly can provide an economical drive train arrangement for a full-time four-wheel drive vehicle, practical applications for that structure are severely limited. For example, this assembly does not allow the operator of the vehicle selectively to switch between travel modes with four high and low wheels. Accordingly, there is a need for a transmission that can be employed in most conventional four wheel drive applications and that allows the vehicle operator to selectively shift between the gear ratios and the available pulse modes.

COMP NOTE OF THE INVENTION Therefore, an object of the present invention is to provide a transmission for use with four-wheel drive vehicles having a multi-speed gear train and a power transfer structure integrated into a single transmission. gearbox. The present invention is directed to a transmission having a feeding arrow adapted to move with respect to a first rotary axis, a first output shaft supported for rotation with respect to a second rotary axis, a second output shaft supported for rotation with respect to a third rotary axis. The gear train is operable to selectively supply pulse torque from the feed shaft to the power transfer structure at one of a plurality of forward and reverse gear ratios. In turn, the structure for power transfer selectively provides pulse torque to each of first and second output arrows. In a preferred form, the power transfer assembly is equipped with a gear reduction unit, a differential between axes, and a mechanism for displacement or range change, which are cooperatively operable to establish low and high range pulse modes full-time four-wheel range, and a neutral non-displaced mode.

A further object of the present invention is to provide the structure for power transfer with a synchronized range-switching mechanism to allow the vehicle op- erator to change "on-flight" between low range and high range travel modes with four wheel. According to yet another feature, the transmission of the present invention is equi with an apparatus for torque transfer to control the torque bypass through the differential between axes in response to speed differentials between the front output arrows And later. According to an alternate embodiment, the power transference structure is equi with an apparatus for torque transfer that is operatively located between the first and second output arrows to establish low range and high range drive modes for four wheels before demand. The transmission of the present invention includes a multi-speed gear train of a feed shaft, a main shaft, and a plurality of constant coupling gear assemblies, to selectively couple the main shaft with the feed shaft for displaced rotation to various speed relationships. The main shaft can be selectively coupled to the power transfer assembly to establish two alternate power transmission paths. In particular, the range shift mechanism is provided to establish a high-range power transmission path, and a low-range power transmission path, from the main arrow to a tubular arrow, which in turn shifts the differential. between axes. The torque provided by the tubular shaft is divided by the wheelbase differential between the front and rear drive lines to set the low range and high range travel modes for four full-time wheels. Optionally, the torque transfer apparatus may be provided to control differentiation of speed through the differential between axes or instead of the differential between axles for four-wheel drive operation upon demand. As an additional objective, the apparatus for torque transfer may be a speed sensitive device or an electronically controlled transfer clutch. BRIEF DESCRIPTION OF THE DRAWINGS Additional objectives, characteristics and advantages of the present invention will be apparent to those with skill in the specialty from studying the following description and the accompanying drawings wherein: Figure 1 is a functional illustration of a motor vehicle equi with a 4WD transmission of the present invention; Figure 2 is a full sectional view of the transmission constructed in accordance with an embodiment of the present invention; Figures 3 to 5 are enlarged enlarged partial views of Figure 2, showing various components of the transmission in greater detail; Figure 6 is a partial section view of the transmission showing components of the range shift mechanism; Figure 7 is a partial view of the transmission equi with a unit for alternating gear reduction and range clutch; Figure 8 is a partial view of the transmission still equi with another gear reduction unit and a mechanism for synchronized range shift; Figure 9 is a partial sectional view showing the transmission equi with an apparatus for torque transfer, to automatically control the differentiation of speed and torque derivation through the differential between axes; Figure 10 is a partial sectional view showing an alternate axle differential and a clutch for electronically controlled torque transfer for use in transmission; Figure 11 is a block diagram for a clutch. electronically controlled transfer, adapted for use with the full-time 4WD transmission of Figures 2 to 9 and the 4 D transmission on demand of Figure 10; and Figure 12 is a partial schematic illustration of a 4WD assembly on demand for the transmission of the present invention. r > The present invention relates to a multi-speed transmission for use in four-wheel drive vehicles. In general, the transmission integrates a multi-speed gear train, and a power transfer structure in a common gearbox that is adapted to be used with a longitudinally aligned motor. More particularly, the gear train can be manually moved to provide a plurality of feed and reverse gear gears. The power of the gear train is supplied to the power transfer assembly for distribution to the front and rear drive lines of the vehicle. The power transfer assembly includes a gear reduction unit and a range shift mechanism that cooperate to allow the vehicle to travel between high range (i.e. direct speed ratio) and low range (i.e. reduced speed ratio) ). The range shift mechanism can be synchronized to allow range shifting "on-the-fly". Additionally, the structure for power transfer includes a differential between axes that interconnects the output of the unit for reduction of gears to the front and rear impulse lines to establish low range and high range travel modes with four full-time wheels ( that is to say "differentiated") as an additional option, an apparatus for torque transfer can also be provided to control speed differentiation and torque derivation through the differential between axes. Finally, the power transfer assembly can incorporate a structure on demand, to automatically transfer power from the gear train to a normally non-displaced impulse line, to establish a four-wheel drive mode on demand. As will be understood, the novel transmission that will be described below is illustrated in a simply exemplary vehicle application to which modifications can be made. With reference to Figure 1, a vehicle 10 is schematically illustrated as being in agreement for use with the present invention. The vehicle 10 has a front thrust line 12 and a rear thrust line 14, movable by connection to a power train 16. The power train 16 includes a motor 18 and a transmission 20. The motor 18 is mounted on a line or longitudinal orientation on the long axis of the vehicle 10, and its output is selectively coupled by a conventional clutch to the transmission power 20. As will be detailed below with greater specificity, the power to the transmission 20 is commonly aligned with the output of the motor 18 for rotation with respect to a first rotary axis, denoted by the reference letter "I". The front drive line 12 includes a pair of front wheels 24 connected at opposite ends of a front axle assembly 26 having a front difference 28 coupled to one end of a front drive shaft 30. The opposite end of which is coupled to a front output arrow 32 of the transmission 20. As seen, the front output arrow 32 is supported in the transmission 20 to rotate with respect to a second rotary axis denoted by the reference letter "F". Similarly, the rear thrust line 14 includes a pair of rear wheels 34 connected at opposite ends of a rear axle assembly 36 having a rear differential 38 coupled to an end of a rear thrust arrow 40, the opposite end of which is interconnects to a rear exit arrow 42 of the transmission 20. The rear exit arrow 42 is likewise illustrated supported within the transmission 20 for rotation with respect to a third rotary axis denoted by the reference letter "R". With particular reference to Figures 2 to 5, the transmission 20 is illustrated to include two primary sections, i.e. a multi-speed gear train 44 and a power transfer structure 46. The gearing train 44 includes a feed shaft 48 which is rotatably displaced by the output of the transmission. motor 18, the main shaft 50 and a series of constant coupling gear sets 52, 54, 56, 58 and 60. Each gear set can be selectively engaged to couple the main shaft 50 to the feed shaft 48 for rotation to a speed ratio or pre-determined gear. In this way, the power of the motor 18 is selectively supplied from the feed shaft 48 to the main shaft 50 through the gear sets. The power is then supplied from the main arrow 50 to the front and rear exit arrows 32 and 42 through the power transfer assembly 46. The power transfer structure 46 includes a gear reduction unit 62 displaced by the arrow main 50, a differential between axes 64 having outputs coupled to the front output shaft 32 and a rear output shaft 42 for distributing the pulse torque and allowing speed differentiation between them, a tubular shaft 66 coupled to the feed of the differential between axes 64 and a mechanism for displacement or change of range 68 having a range clutch 70, which is movable to selectively couple the tubular shaft 66 with either the main shaft 50 or the gear reduction unit 62. As Diagrammatically illustrated in Figure 1, the displacement or range change mechanism 68 also includes an actuator of change 72 to move the range 70 clutch in response to a feed by the vehicle operator to set one of three available modes. These modes include low range and high range travel modes, shifted by all four full-time wheels, and a neutral non-offset mode. A mode selection mechanism 74 is manipulated by the vehicle operator to signal the shift actuator 72 of the selected particular mode. With continued reference to Figures 2 to 5, the transmission 20 is illustrated which includes a housing 76 defined by a series of housing sections that are interconnected by fasteners 78. The feed shaft 48 is shown supported on the housing 76 by mounts of bearings 80 and 82 for rotation with respect to a rotary axis "I". The main shaft 50 is an elongated tubular shaft that concentrically surrounds and rotatably holds on a transfer shaft 84, with the main shaft 50 being held in the housing 76 by the bearing assemblies 86 and 88. Likewise, one end of the shaft The transfer shaft 84 is rotatably held in the housing 76 by the bearing assembly 90 while its opposite end is piloted in a bore 92 formed in one end of the rear output shaft 42. The rear output shaft 42 is held in the housing 76 through bearing assembly 94. A rear yoke 96 is illustrated attached to the opposite end of the rear output shaft 42 for connection to the rear pulse line 14 in a conventional manner. In this way, the main arrow 50, the transfer arrow 84 and the rear exit arrow 42 are commonly aligned for rotation with respect to the rotary axis "R". As best seen from Figure 3, the transmission 20 includes a front transfer mechanism 98 that is provided to transfer impulse torque from the transfer shaft 84 to the front output shaft 32. More particularly, the transfer mechanism front 98 includes a fixed (ie slotted) pulse input wheel 100 to the transfer shaft 84, a second offset gear 102 that is formed integrally with the front output shaft 32 and a pulse chain 104 that interconnects the wheel toothed driven 102 to the driving sprocket 100. The front output shaft 32 is shown supported from the housing 76 by a pair of axially spaced bearing assemblies 106 and 108 for rotation relative to the rotating shaft "F". A front yoke 110 is illustrated attached to the front output arrow 32 for connection to the rest of the front pulse line 12. With reference to Figures 2 and 4, the first set of gears 52 is illustrated to include a first feed gear 114 that is attached to the pulse shaft 48 and a first speed gear 116 that is rotatably mounted to the main shaft 50 by a suitable bearing assembly 118. The first feed gear 114 and the first speed gear 116 are in constant coupling to define a first power transmission path from the feed shaft 48 to the main shaft 50 to the first speed ratio. The second gear set 54 includes a second feed gear 120 which is attached to the feed shaft 48 and a second speed gear 122, which is rotatably mounted to the main shaft 50 by a suitable bearing structure 124. The second gear power 120 and second speed gear 122 are in constant coupling to define a second power transmission from the feed shaft 48 to the main shaft 50 at a second speed ratio. The third gear set 56 includes a third feed gear 126 which is fixed to the feed shaft 48 and a third speed gear 128 which is rotatably mounted to the main shaft 50 by a suitable bearing assembly 130. The third gear of feed 126 and third speed gear 128 are in constant coupling to define a third power transmission path from feed arrow 48 to main shaft 50 at a third speed ratio. The fourth gear set 58 includes a fourth feed gear 132 which is fixed to the feed shaft 48 and a fourth speed gear 134, which is rotatably mounted to the main shaft 50 by a suitable bearing assembly 136. The gear of fourth speed 132 and fourth supply gear 136 are in constant coupling to define a fourth power transmission path at a fourth speed ratio. The fifth gear set 60 includes a fifth feed gear 138 which is fixed to the feed shaft 48 and a fifth speed gear 140, which is rotatably held on the main shaft 50 by the suitable bearing structure 142. The fifth gear The power supply 138 and the fifth speed gear 140 are in constant coupling to define a fifth path for power transmission at a fifth speed ratio. These five gear sets are provided to set five forward gears for transmission 20. Finally, a set of reverse gears 144 is provided to reverse the rotary direction of the main shaft 50. For this purpose, a reverse feed gear 146 is fixed to the feed shaft 48, a reverse speed gear 148 is rotatably supported by the bearing structure 150 on the main shaft 50 and a secondary reverse gear (not shown) is in constant engagement, both with the gear reverse feed 146 as the reverse speed gear 148. In this way, reverse gear set 144 sets the reverse gear. To provide means for selectively setting the forward and reverse gears, each set of gears 52, 54, 56, 58, 60 and 144 is associated with a synchronizing clutch selectively engageable to move between the various gears. Specifically, the gear train 44 of the transmission 20 is a five-speed assembly having three synchronizing clutch structures that are displaced by the vehicle operator that manipulates a gear shift lever 152 (Figure 1) in a well-known manner. . For this purpose, a first synchronizer clutch assembly 154 is illustrated operatively installed between the first set of gears 52 and the second set of gears 54 on the main shaft 50 and includes a hub 156 fixed for rotation with the main shaft 50 and a sleeve of clutch 158 which is supported for rotation with and bi-directional axial movement in the hub 156. The first synchronizer clutch assembly 154 is a double action assembly with each synchronizer which is preferably of the double cone type as illustrated. Nevertheless, it will be understood that the synchronizing clutch assembly 154 as well as each of the synchronizing assemblies subsequently discussed for effecting gear changes between the feed shaft 48 and the main shaft 50 (may be of any convenient type conventionally employed in manual transmissions of When the clutch sleeve 158 is moved backward from the centered neutral position shown to its first gear position, the first gear 116 is coupled to the main arrow 50, thereby coupling the first path for power transmission and establishing the ratio of the first speed of advance This movement of clutch sleeve 158 to the first gear causes the speed synchronization between the arrow -main 50 and the first-speed gear 116 thereby allowing the clutch sleeve 158 to move in engagement locked with the teeth of an e-ring mbrague 160 which is fixed to the first speed gear 116. On the contrary, when the clutch sleeve 158 moves forward from its central neutral position to its second gear position, it engages the gear at second speed 122 to the main arrow 50 , thereby coupling the second path for power transmission and establishing, the second forward speed ratio. The movement of the clutch sleeve 158 to its second gear position causes speed synchronization between the main shaft 50 and the second speed gear 122, thereby allowing the clutch sleeve 158 to move in a locked or locked engagement with the teeth of a clutch ring 162 that is fixed to the second speed gearing 122. The clutch sleeve 158 is movable axially relative to the hub 156 in a well-known manner by a first shift fork, illustrated partially with the reference number 164, which is operatively interconnected to the gear change lever 152 by a convenient gear change mechanism illustrated diagrammatically by the block 166 in Figure 1. A second dual action synchronizing clutch assembly 170, preferably of the single cone type, is operatively illustrated in the main arrow 50, between the third set of gears 56 and the fourth set d and gears 58. The synchronizer clutch assembly 170 includes a hub 172 fixed for rotation with the main shaft 50 and a clutch sleeve 174 which is held for rotation with bidirectional axial movement in the hub 172. When the clutch sleeve 174 is moves backward from its illustrated centered neutral position to its third gear position, engages the third speed gear 128 with the main arrow 50, thereby coupling the third path for power transmission and setting the third forward speed ratio. The teeth of a clutch ring 176 fixed to the third speed gear 128 are selectively engageable with the clutch sleeve 174, when after synchronization, the clutch sleeve 174 moves to its third gear position, to engage the third gear. speed 128 with the main arrow 50. In contrast, when the clutch sleeve 174 moves forward to its fourth gear position, it engages the fourth speed gear 134 to the main arrow 50, to couple the fourth transmission path. power and establish the fourth speed ratio. The teeth of a clutch ring 177 fixed to the fourth speed gear 134 are selectively engageable with a clutch sleeve 174 when after synchronization, the clutch sleeve 174 moves to its fourth gear position to engage the gear at a fourth speed 134. to the main shaft 50. The clutch sleeve 174 is axially movable between its third and fourth gear positions, by means of a second shift fork, partially illustrated at 178, which also engages the gear change mechanism 166. A third dual action synchronizing clutch assembly 180, also preferably of the single cone type includes a cone 182 which is fixed for rotation with the main shaft 50. A clutch sleeve 184 engages for rotation with axial movement in the hub 182. The central movement of the clutch sleeve 184 from its centered neutral position illustrated in its fifth gear position causes the clutch sleeve engage the teeth of a clutch ring 186 fixed to the fifth speed gear 140, to engage the fifth set of gears 60 with the main date to couple the fifth power transmission path and establish the fifth forward speed ratio . Finally, the clutch sleeve 184 moves to its reverse gear position where it engages the teeth in the clutch ring 187 in response to displacement of the gear train 44 to its reverse clutch to engage in the reverse speed gear. 148 of the gear set 144 of the main arrow 50. The clutch sleeve 184 is axially movable between its positions of fifth gear and reverse gear by a third shift fork, especially illustrated at 168 which is also connected to the shift mechanism. gear 166. As noted, the pulse torque delivered by the gear train 44 on the main date 50 is transferred by the power transfer assembly 46 to the output arrows 32. In operation, the unit for reduction of gear 62 will be apt to selectively connect tubular shaft 66 to main shaft 50 for displaced rotation in any of a speed ratio. ad direct or reduced. For this purpose, Figure 5 shows the reduction and gearing unit 62 which is a supplementary gear set having a solar or planetary gear 120 fixed to the main shaft 50, a ring gear 192 fixed to housing 176 and a planetary carrier 194. which rotatably holds a plurality of pinion gears 196 which are in constant engagement with both the planetary gear 190 and the gear ring 192. As such, the planetary gear 190 is moved directly by the main shaft 50 while a planetary carrier 194 is displaced at a reduced speed ratio with respect to it. The range clutch 70 is grooving the tubular shaft 166 for rotation therewith and sliding axial movement. The range 170 clutch is movable between 3 different portions to set the high range shift mode, the low range shift mode, and the neutral non-shifted mode. In particular, the movement of a range clutch 70 to its illustrated high range position is denoted by the construction line "H", causes the clutch teeth 198 in the range clutch 70 to engage the clutch teeth 200 in the planetary gear 190 thereby establishing the direct speed relation connection (i.e. high range) between the main shaft 50 and the tubular shaft 66, likewise the backward movement of the range clutch 70, to its low range position as denoted by the construction line "N" causes its clutch teeth 198 to engage the clutch teeth 202 in the planetary carrier 194, thereby establishing the reduced speed ratio (i.e., low-range) connection between the main arrow 50 and the tubular thread 66. Finally, the movement of the range clutch 70 to its central position as denoted by the construction line "N", disconnects the tubular shaft 66 from the offset connection with the main arrow 50 to set the neutral non-offset mode. To provide means to establish full-time 4-wheel drive mode (ie, differentiated) wherein the pulse torque is supplied to both the front drive line 12 and the rear drive line 14, the transmission is equipped with an axle differential 64 having its feed member moved by the arrow tubular 66 and exit members that displace or are displaced by the front and rear exit arrows 32 and 42, respectively. Referring continuously to Figure 5, the axle differential 64 illustrates a dual planetary gear set including a first sun gear 204 held by a redoubled connection 206 to the rear end of the transfer shaft 84, a second gear to raise it 208 fixed by a resumed connection 210 to the rear exit arrow 42 and a planetary carrier 212 which rotatably interconnects the tubular arrow 66 to the planet gears 204 and 208. In particular, the planetary carrier 212 includes a first carrier ring 214 and a second carrier ring 216 interconnected with fasteners 218. The first carrier ring 214 is illustrated coupled by a slotted connection 220 to the tubular shaft 66. A set of first or second stage planetary gears 222 are rotatably held between the carrier ring 214 and 216 and mated with the first planetary gear 204. A set of second planetary gears or of integral length 224, they are rotatably held between the carrier rings 214 and 216 and coupled with the second planetary gear 208. Furthermore, each of the first planetary gears 222 engages with one of the second planet gears 224 in such a way that they are arranged as pairs coupled around the circumference of the planetary carrier 212. In this way, when the range clutch 70 is located in its "H" position, the full-time four-wheel high-range shift mode is established. Likewise, when the clutch of range 70 is located in its "L" position, the low-range displacement mode with four full-time wheels is established. Finally, when the range clutch is in its position 70 is in its "N" position, the tubular arrow 66 is decoupled from the main arrow 50, whereby no impulse torque is supplied to the front output arrows and rear 32 and 34 respectively, through the inter-axle differential 64. As will be understood, the specific gear geometry associated with the inter-coupled gears of the differential between axes 64, will determine the torque distribution ratio between the front output arrow 32. and the rear exit arrow 42.To provide means for moving the range clutch 70 between its three different positions, the displacement or range shift mechanism 68 is illustrated in Figure 6 to include a range fork 230 that engages the range 70 clutch and a derived apparatus. spring 232, for axially moving the range fork 230. The spring-loaded apparatus 232 is mounted on a shift rail 234 attached to the housing 76 includes a clamp 236 slidably mounted on the rail 234 and a pair of springs 238. The springs 238 act between the 236 clamp and the 230 range fork to apply directional bypass loads on the 230 range fork. This mount is adapted to bypass the 230 range fork to ensure movement of the range 70 clutch to any of its fully engaged positions. coupled "L" or "H". A range pin is attached to the clamp 236 and extends to a range slot 242 formed in a sector plate 244. The outline of the range slot 242 is designed to control the amount and direction of axial movement of the clamp 236. and fork of range 230 in response to the amount of direction of rotation of the sector plate 244. In the particular embodiment illustrated, the shift actuator 72 is an encoder / electric gearmotor assembly assembly 246 having a rotary exit arrow 248 that it is coupled to the sector plate 244. In this way, the encoder assembly / geared motor unit 246 is operable to controllably rotate the sector plate 244 in any direction, between positions corresponding to the three positions of the range clutch 70 in FIG. response to control signals that are sent to the encoder / geared motor unit assembly 246 from a remote controller unit, illustrated diagrammatically by block 250. The unit ad controller 50 generates the control signals in response to the signals so that they are supplied when the vehicle operator operates the mode selection mechanism 74 which in this case includes appropriate oppression buttons or switches that are mounted in the compartment for vehicle passengers. Preferably, the controller unit 250 also receives other signals, such as vehicle speed to control the specific operating parameter during which range changes are allowed. In an alternate manually operated version, the shift actuator 72 will include a mechanical articulation assembly or structure operable to rotate the sector plate 244 and a mode selection mechanism 74 will include a manually operated shift lever. With reference to Figure 7, an alternate construction for the gear reduction unit 62 is illustrated by the reference number 62A. For clarity, common reference numbers are used to identify similar components while premium reference numbers are used to designate those components that have been modified to incorporate the gear reduction unit 62A in the transmission 20. In general, the gear reduction unit 62A is adapted to be used in substitution by gear reduction unit 62. In particular, gear reduction unit 62A includes a supplementary gear 252, rotatably supported on main shaft 50 'having clutch teeth 254 formed therein that align with the clutch teeth 256 formed in the main arrow 50 '. The tubular shaft 66 'rotatably holds the transfer shaft 84 and has external clutch teeth 258 therein formed which are located adjacent to and aligned with the main arrow clutch assembly 256. A radial bearing assembly 260 is disposed between the main shaft 50 'and the tubular arrow 66' to facilitate relative rotation between them. The gear reduction unit 62A also includes a ring gear 192 which is fixed to the housing 76 so as to be stationary relative to it. each of the plurality of pinion gears 196 (only one is illustrated) is rotatably held between the front and rear carrier rings of the planetary carrier 194. The pinion gears 196 engage the planetary gear 252 and the ring gear 192. The clutch range 70 'includes a pair of sleeves 262 and 264 that are selectively coupled with one or more of planetary gear 252, main arrow 50 'and tubular arrow 66' to establish the two differential displacement connections between them. In particular, the outer sleeve 262 has internal clutch teeth 266 that are in constant engagement with the clutch teeth 258 in the tubular shaft 66 '. Similarly, the outer sleeve 262 has external clutch tabs 268 formed in a drum-like axial extension that selectively engages the clutch teeth 202 in the planetary carrier 194. The inner sleeve 264 is rotatably supported against an inner bearing surface formed in the axial extension portion of the outer sleeve 262 and is retained relative to it by a quick coupling ring 70. The inner sleeve 264 includes internal clutch teeth 272 which engage continuously with the external teeth 256 of the main shaft 50 'and which also they are selectively engageable either with the planetary gear clutch teeth 254 or tubular arrow clutch teeth 258 depending on the axial position of the range clutch 70 '. Due to the coupled connection between the outer sleeve 262 and the tubular shaft 66 ', and the connection engaged between the inner sleeve 264 and the main shaft 50', the range clutch 70 'can slide axially between a low range position (" L "), a neutral position (" N ") and a high-rank position (" H "). When the range clutch 70 'is placed in its "L" position as illustrated in the lower half of Figure 7, the clutch teeth 272 of the inner sleeve 264 couple both the clutch teeth of the planetary gear 254 and the teeth of the main arrow clutch 256. In addition, the outer clutch teeth 268 on the outer sleeve 262 engage the planetary carrier clutch teeth 202 while their internal clutch teeth 266 engage the tubular arrow clutch teeth 258. As such, the inner sleeve 264 engages planetary gear 252 for common rotation main shaft 50 '. In this way, the planetary gear 252 moves the pinion gears 196 around the ring gear 192 in such a manner that the planetary carrier 194 travels at a reduced speed ratio respect to the main shaft 50 '. Furthermore, due to the connection of the planetary carrier 194 the tubular shaft 66 'via the outer sleeve 262 of the range clutch 70', the tubular shaft 66 'also moves at a reduced speed ratio respect to the main shaft 50'. to establish the low range offset connection between them. When the range clutch 70 'moves from its low range position to its neutral position, the clutch teeth 272 of the inner sleeve 264 are decoupled from the planetary gear teeth 254 and only engage the teeth of the main arrow 256. Still further, the clutch teeth 268 in the outer sleeve 262 are decoupled from the planetary carrier teeth 202 while their internal clutch teeth 266 only engage the tubular arrow teeth 258. In this neutral position, the inner sleeve 264 is free to rotate respect to the outer sleeve 262. As such, there is no displacement connection between the main shaft 50 'and the tubular shaft 66', whereby the neutral non-displaced mode is established. Finally, when the range clutch 70 'moves from its neutral position to its high range position as illustrated in the upper half of Figure 7, a direct connection is established between the tubular arrow 66' and the main arrow 50 ' . Specifically, the outer sleeve 262 is uncoupled from the planetary carrier 194 and its clutch teeth 266 are held in engagement the tubular arrow teeth 258. Furthermore, the clutch teeth 272 of the inner sleeve 264 engage the main arrow teeth 256. and the tubular arrow teeth 258 for directly coupling the tubular shaft 66 'to the main shaft 50' for common rotation, thereby establishing the high range displacement connection therebetween. As before, the range fork 230 engages the range clutch 70 'to control its axial movement. It is contemplated that a displacement mechanism of rank similar to that described in Figure 6 will be employed the contour of the range slot 242 which controls the movement of the range fork 230 in response to rotation of the sector plate 244 by drive of the gearmotor unit 246. reference to Figure 8, a transmission 20 is again illustrated alternately equipped a gear reduction unit 62B and a synchronized range shift mechanism 274 that allows "on-the-fly" travel between modes of high range displacement and low range of four wheels. As schematically illustrated, the gear reduction unit 62B is a planetary gear assembly having a planetary gear 276 rotatably displaced by the main shaft 50 '., a ring gear 278 and a planetary carrier 194 having a plurality of planetary gears 196 rotatably supported and which couple the planet gear 276 and the ring gear 278. The planetary carrier 194 is engaged by a slotted connection 280 for rotation with the tubular arrow 66 '. The displacement mechanism 274 includes the bidirectional clutch apparatus having a clutch hub 282 fixed for rotation with the ring gear 278 and a range clutch 284 supported for rotation and axially sliding movement in the clutch hub 282. As seen , a bell-shaped reaction member 286 is provided for engaging the clutch hub 282 in the ring gear 278. The range clutch 284 is movable between its centered neutral position (N) which is illustrated either at a position of Low range (L) or a high range position (H). In particular, when moving to its low range position, the range clutch 284 couples the clutch hub 282 with a stationary brake plate 288 fixed to the housing 76. As such, the ring gear 278 is held stationary, so such that the planetary carrier 194 rotates at a reduced speed ratio relative to the main arrow 50 'to establish the low range shift connection between the main shaft 50' and the tubular shaft 66 '. The range clutch 284 can also be moved to its high range position by coupling the clutch hub 282 to a clutch plate 290 which is held by a slotted connection 292 to the tubular shaft 66 '. As such, the range clutch 184 couples the ring gear 278 for common rotation with the planetary carrier 194. In this manner, the planet gear 276, the planet gears 96 and a ring gear 278 are effectively locked together to rotate as a common unit for directly transferring torque from the main shaft 50 'to the tubular shaft 66'. When the range clutch 284 is placed in its neutral position, the ring gear 278 is disengaged from the brake plate 288 and the clutch plate 290. As such, rotation of the main shaft 50 'causes the planetary gear 276 rotate, which in turn causes the planet gears 196 to rotate relative to their respective pinion arrow which in turn causes the ring gear 278 to rotate. As a result, the planetary carrier 194 does not rotate in response to rotation of the planet gear 276, whereby the tubular arrow 66 'is maintained in an undisplaced state.

To provide means for displacing the clutch sleeve 284 in-flight between its three distinct positions, the range clutch 284 is coupled to the range fork 230. Still further, the synchronized shift mechanism 74 includes a first synchronizer 294 operatively located between the clutch hub 282 and the brake plate 288, and a second synchronizer 296 operatively located between the clutch hub 282 and the clutch plate 290. The first synchronizer 294 is operable to cause speed synchronization between the ring gear 278 and the brake plate 288 before movement of a range clutch 284 to its low range position and to complete this speed synchronization therebetween before the range clutch 284 engages the clutch teeth 298 on the brake plate 288 Similarly, the second synchronizing assembly 296 is operable to cause speed synchronization between the ring gear 278 and the carrier planetary gear 194, in response to movement of the range clutch 284 to its high range position, and to complete speed synchronization between them before the range clutch 284 engages in engagement with the clutch teeth 300 on the plate of clutch 290. It is contemplated that the synchronizers 294 and 296 may be any convenient synchronizing clutch apparatus known in the art to facilitate speed synchronization between relatively rotatable components.

Referring to Figure 8, the transmission 20 is illustrated in another modified version wherein a torque transfer apparatus has been operatively installed to automatically control the torque shunt through the differential between axes 64 in response to differentials. of speed (ie, slip between axes) between the front output arrow 32 and the rear output arrow 42. Again, since many of the components illustrated in Figure 9 are identical to those previously described, those that have been modified Now they are identified with a reference number with premium. According to the particular embodiment illustrated, the torsional transfer apparatus 310 is a viscous coupling having an inner drum 312 fixed by a slotted connection 312 to the transfer shaft 84 'and a cover assembly 316 supported and sealed with respect to the inner drum 312 for rotation with respect to it. In particular, the cover assembly 316 includes an outer drum 318 in which a front end plate 320 and a rear end plate are fastened. The front end plate 320 is illustrated as being fixed by a slotted connection 324 for rotation with the second planetary gear 208 'of the axle differential 64. The second planetary gear 208' is illustrated as being held in the transfer arrow 84 '. In addition, the rear end plate 322 is illustrated fixed by a slotted connection 326 to the rear exit arrow 42. A clutch gasket is retained within the sealed chamber formed between the cover assembly 316 and the inner drum 312 and includes a interior clutch plate assembly 328 fastened for rotation with the inner drum 312 and a set of outer clutch plates 330 held for rotation with the outer drum 318. The inner and outer clutch plates 328, 330 are alternately interposed and the sealed chamber it is filled with a predetermined volume of a viscous fluid. Since the viscous coupling 310 is a speed dependent device, increasing the relative rotation between the seal drum 318 and the inner drum 312 results in the shearing of viscous fluid within the sealed chamber to transfer torque through the packing of clutch interleaved with the minor rotation component, thereby automatically deriving the displacement torque transferred through the 64th inter-axle differential., torque bypass is on demand and progressive based on the speed difference between axes through viscous coupling 310. US Pat. No. 5,148,900 commonly owned, describes the operation of this viscous coupling in more detail and is here expressly incorporated by reference. Still further, it is contemplated that another torque-on-demand transfer apparatus may be replaced by viscous coupling. For example, U.S. Pat. No. 5,456,642 issued to Frost of common property, discloses a gear-coupled drive unit that can be easily adapted for use in transmission 20 as a slip-limiting device. Thus, it is contemplated that any self-contained demand apparatus currently known in the power transmission art to progressively transfer displacement torque due to speed differentials, is a device equivalent to viscous coupling 310. Now with particular reference to the Figure 10, another partial view of the transmission 20 is illustrated as being alternately equipped with an electronically controlled torque transfer apparatus, hereinafter referred to as a transfer clutch 332, which is operable to control the speed differentiation and Torque bypass through an axle differential 334. The axle differential 334 includes a planetary carrier 336 fixed by a slotted connection 338 to the tubular shaft 66, a fixed planetary gear 340 by a slotted connection 342 to the shaft transfer 84 and a fixed ring gear 344 by a slotted connection 346 to the rear exit arrow 42. The planetary carrier 336 supports a plurality of pinion gears 48 held steerably at arrows 350 and mating with ring gear 344 and planetary gear 340. Ring gear 344 is formed from as part of an outer drum structure including an outer drum 352 and an end plate 354. The end plate 354 is fixed to the outer drum 352 and is coupled to the rear output shaft 42 by the slotted connection 346. As such , the displaced rotation of the planetary carrier 336 causes the torque to be distributed between the output arrow ppsterior 42 and the front output arrow 32 (via the transfer arrow 84) at a ratio determined by the gear geometry of the components interacolated. To provide means for deriving torque through the inter-axle differential 334, the transfer clutch 32 illustrates that it is operatively disposed between the tubular shaft 66 and the rear output shaft 42. In particular, the transfer clutch 332 includes a hub of inner clutch 356 fixed by a slotted connection 358 to tubular shaft 66, a clutch packing 360 extending between clutch hub 356 and outer drum 352, and an impulse mechanism 362, for applying a clutch engagement force of compressor in the clutch packing 360. The clutch packing 360 includes a series of inner clutch plates 364 fixed to the clutch hub 356 and alternately interspersed with a series of outer clutch plates 366 fixed to the outer drum 352. Impulse mechanism 362 is slidably held in the tubular shaft 66 and includes an inner bearing support 368 rotatably supported on the arrow t ubular 66, an outer bearing support 370 coupled for rotation with the inner clutch hub 356 and a thrust bearing assembly 372 retained therebetween. As seen, the axially extending end segment 374 of the inner clutch hub 356 is retained in an opening 376 formed in the outer bearing support 370. The outer bearing support 370 includes a radially extending plate segment 378. that, before axial sliding movement of the impulse mechanism 362, applies the clutch engagement force to the clutch packing 360. A return spring 380 is arranged to normally divert the thrust mechanism 362 in a direction to the opposite application of the clutch engagement force to the clutch packing 360. In In the illustrated embodiment, the displacement actuator 72 serves the dual purpose of controlling the axial movement of the range clutch 70, 70 'or 284 between its three distinct range positions as well as a pivotal control movement of a lever assembly 382, for controlling the amount of engaging engagement force exerted on the clutch packing 360. The lever assembly 382 includes an elongated lever arm 384 having a bifurcated end segment 386 surrounding the tubular shaft 66 that pivotally supports a rail 388 retained in the housing 76 and a flanged end segment 390. The lever assembly 382 also includes a crown roller 392 that is assembled by a pin 394 in the flanged segment 390 in the lever arm 384. The crown roller 392 is retained in a mode slot 396 formed in the sector plate 244 '. In general, the contour of the mode slot 396 is configured to control the direction and amount of pivotal movement of the lever arm 384, in response to the direction and amount of rotation of the setor plate 244 'to control the magnitude of the clutch engagement force exerted on the clutch pack 360. While not illustrated, the buttons on the bifurcated segment 386 of the lever arm 384 engage the inner bearing bracket 368 to cause axial sliding movement of the thrust mechanism 368 in response to pivotal movement of lever arm 384. As seen, flanges 398 extending from inner bearing bracket 368 engage lever arm 384 to inhibit rotation of inner bearing bracket 368. To control clutch engagement force generated by the transfer clutch 332 and in turn the torque derivation through the inter-axes differential 334, the shift actuator 7 2 is employed in conjunction with an electronically controlled power transfer system 400. The power transfer system 400 is illustrated as a block diagram in Figure 11. In its most basic form, the power transfer system 400 includes a front speed sensor 402 for measuring the rotational speed of the front output shaft 32 (or transfer shaft 84 or front thruster shaft 30) a rear speed sensor 400 for measuring the rotational speed of the rear output shaft 42 (or arrow) rear propulsion 40) and controlled unit 250. The speed signals of the sensors 402 and 404 are supplied to the controller 250 which determines a speed differential signal based on these. If the speed differential signals exceed a predetermined threshold value, the controller 250 operates the geared motor encoder / group 246 to apply a clutch engagement force on the clutch packing 360, thereby transferring the pulse torque to the slower spin arrow of the output arrows 32 and 42. The threshold value can be stored in search tables or calculated from stored algorithms. The drive of the geared motor encoder / group 246 may be of the on / off type or the adaptive type. Under the on / off control scheme, the transfer clutch 332 is normally maintained in a non-driven state but is shifted to its fully activated state when the speed differential signal exceeds the threshold value. Once the speed differential signal is reduced to a magnitude less than the predetermined threshold value, the transfer clutch 332 is returned to its non-activated state. With the transfer clutch 332 in its non-activated state, speed differentiation through the axle differential is allowed. NeverthelessWhen the transfer clutch 332 is fully actuated, the relative rotation through the wheelbase 334 is inhibited. Under the ADAPTIVE control scheme, the magnitude of the clutch coupling force is varied as a function of changes in the magnitude of the speed differential signal to progressively control the actuated condition of the transfer clutch 332 between its non-driven states and fully powered. As such, the derivation through the inter-axes differential 334 can be continuously modulated. Detector power signals '' • n? Additional, cumulatively illustrated by block 408, may also be fed to controller 250 to modify the operating parameters of the vehicle under which the transfer clutch 332 is controlled. These detectors may include a vehicle speed detector, a brake detector , an acceleration detector and the like. An adaptive control system suitable for use with the present invention is described in U.S. Pat. No. 5,411,110 of common property, the entire description of which is hereby incorporated by reference. As an additional option, due to the use of the mode selection mechanism 74, the vehicle operator is allowed to select one in an AUTOMATIC mode and ENCLAVED OR STRETCHED mode. In automatic mode, the transfer clutch 332 is controllably actuated in accordance with any of the ON / OFF or ADAPTIVE control schemes described above, without further additional power required from the vehicle operator. In this way, the vehicle operator can choose between full-range and low-range full-time pulse modes with any torque derivation through the automatically controlled inter-axes differential 334 ("on demand") to be transparent to the vehicle. operator of the vehicle. However, when the ACROSSED shift mode is chosen, the transfer clutch 332 intentionally shifts and maintains in its fully actuated state to lock the inter-axle differential 334, to provide undifferentiated displacement to the output arrows 32 and 42. STRETCHED mode is provided to allow for enhanced traction when the motor vehicle is operated off-road or in severe road conditions. In locked mode, the transmission 20 is capable of allowing the vehicle operator to select low range or high range travel mode with four part-time (i.e., non-differentiated) wheels. In this way, the transmission 20 is capable of providing five different modes of travel other than which the vehicle operator can potentially choose via the mode selection mechanism 74. Obviously, the amount of different travel modes available can be selected to adjust to each particular vehicular application. It will be understood that the contour of the mode slot 396 and the range slot 242 are engineered in such a way that the transfer clutch 332 normally operates in its non-actuated state during range travel to eliminate the possibility of overloading the vehicle. transfer clutch 332. In this manner, the clutch engagement force can be controllably modulated between the non-driven and fully actuated states of the transfer clutch 332 when the clutch reduction unit has set any of the high displacement modes rank or bass tango. Now with reference to Figure 12, a partial schematic view of an alternate construction for the transmission 20 is illustrated. In general, the modified construction removes the differential between axes and arranges the viscous coupling 310 between the transfer shaft 84 and the rear output shaft 42 to provide a 4 D power transfer system "on demand". The viscous coupling 310 is again described as having an inner drum 312 fixed for rotation with the transfer arrow 84, a cover assembly 316 circumscribed and sealed relative to the inner drum 312, and a clutch packing of interposed friction clutch plates 328 and 330. The cover assembly 316 includes an output drum 318, a front end plate 320 which it is attached to the output drum 318 and coupled to the tubular shaft 66, and a rear end plate 322, also attached to the outer drum 318 and which is coupled to the rear output shaft 42. In this way, the cover assembly 318 is arranged to directly transfer the pulse torque from the tubular shaft 66 to the rear output shaft 42. In operation, the pulse torque is normally supplied only to the rear output shaft 42, thereby establishing a displacement mode with two wheels. However, when the loss of traction in the rear casings 32 causes the rear exit arrow 42 to pass the front exit arrow 32, the viscous clutch 310 is operative to automatically transfer impulse torque to the transfer arrow 84 and in this manner to the front output arrow 32 to establish a four-wheel drive mode "on demand". As will be appreciated, the progressive torque transmission characteristics of the viscous coupling can be "tuned" for each particular vehicular application to determine at what value of the speed difference, the transmission of torque will occur. While not shown, it is clear that a modified version of the viscous coupling can be arranged to normally transfer torque of impulse torque to the transfer shaft 84, with torsion torque supplied on demand to the rear output shaft 42, if so you want An electronically controlled transfer clutch, similar to the transfer clutch 332, may also be employed in viscous coupling 310 to control four-wheel drive operation upon demand under any of the ON / OFF or ADAPTIVE control schemes and the AUTOMATIC or ACERROJADO discussed above. The above discussion describes and illustrates exemplary embodiments of the present invention. A person skilled in the art will readily recognize from said discussion and the appended drawings and claims, that various changes and modifications may be practiced without departing from the real spirit and fair scope of the invention as defined in the following claims.

Claims (20)

1. CLAIMS 1.- A transmission for a four-wheel drive vehicle having a motor and front and rear drive lines, the transmission is characterized in that it comprises: a feed arrow displaced by the motor with respect to a first rotary axis; a main arrow supported for rotation with respect to a second rotary axis; constant coupling gear sets supported between the feed shaft and the main shaft; synchronizing clutches for selectively coupling the gear sets to move the main shaft at speed ratios relative to the feed shaft to establish feed gears and a reverse gear; a rear output arrow adapted for connection to the rear pulse line and which is commonly aligned with the main arrow for rotation with respect to the second rotary axis; a front output arrow adapted for connection to the front pulse line and which is supported for rotation with respect to a third rotary axis; an axle differential to allow speed differentiation between the rear exit arrow and the front exit arrow, the axle differential includes a feed member displaced by the main arrow, a first fixed exit member for rotation with the exit arrow later and a second exit member; and a transfer mechanism that connects the front output arrow for common rotation with the second output member.
2. 2.- The transmission in accordance with the claim 1, characterized in that it further comprises a gear reduction unit having a first gear component displaced by the main shaft and a second gear component displaced at a reduced speed ratio relative to the first gear component, a range clutch for coupling selective of the inter-axle differential feed member for rotation with the main arrow, to establish a displacement connection with direct speed ratio, the range clutch is further operable to selectively couple the inter-axle differential feed member with the second component of gear to establish a reduced ratio impulse connection.
3. 3.- The transmission in accordance with the claim 2, caracerized because the gear reduction unit includes a fixed planetary gear for rotation with the main shaft, a stationary ring gear and a planetary carrier having pinion gears coupled with the planetary gear and the ring gear, the range clutch it is movable between a first position in which the range clutch engages the planetary gear with the differential supply to establish the direct speed ratio shift connection, a second position in which the range clutch couples the planetary carrier to the arrow of the differential to establish the reduced speed ratio travel connection and a third position in which the range clutch is decoupled from the planetary gear and the planetary carrier to disconnect the differential feed from the offset coupling with the main arrow destabilizing from this way an undisplaced mode neutral
4. 4. The transmission according to claim 2, characterized in that the gear reduction unit includes a planetary gear rotatably supported on the main shaft, a non-rotating ring gear and a planetary carrier having pinion gears coupled with the gear wheel. ring and the planetary gear, and wherein the range clutch is movable between a first position in which it directly couples the differential supply with the main arrow to establish the direct speed relation impulse connection, a second position in which it couples the planetary gear with the main shaft and the planetary carrier with the differential supply to establish the reduced speed ratio impulse connection and a third position in which the differential supply is decoupled from the main shaft.
5. 5. The transmission according to claim 2, characterized in that the gear reduction unit includes a fixed planetary gear for rotation with the main shaft, a ring gear and a fixed planetary carrier for rotation with the differential supply and having pinion gears coupled with the planetary gear and the gear of ring, and wherein the range clutch is held for rotation with the ring gear and is movable between a first portion in which the range clutch engages the ring gear with the differential supply, to establish the pulse connection of direct speed ratio, a second position for coupling the ring gear with a stationary member to establish the reduced speed ratio drive connection, and a third position in which the ring gear is allowed to rotate relative to the planetary carrier and the planetary gear to establish a neutral mode.
6. 6. The transmission according to claim 1, characterized in that it further comprises an apparatus for torque transfer to inhibit the differentiation of speed through the differential between axes in response to excessive speed differentials between the front output arrows and later.
7. 7.- A transmission for a vehicle displaced by four wheels that has front and rear displacement lines and motor, the transmission is characterized because it comprises: a power arrow displaced by the engine; a main arrow; a plurality of constant coupling gear sets supported between the feed shaft and the main shaft; a plurality of clutches for selectively coupling one of the sets of gears to move the main shaft at a predetermined speed ratio relative to the supply shaft in such a way that advance gears and a reverse gear are set; a gear reduction unit displaced by the main shaft at a reduced speed relation to it; a differential between axes that has a power supply and first and second outputs; a range clutch for selectively coupling the inter axle differential supply to either the main arrow where a slip connection with direct speed ratio is established or the gear reduction unit in which a slip connection is established with reduced speed ratio; a rear output arrow coupled with the first inter-axes differential output and adapted for connection to the rear pulse line; a front output arrow adapted for connection to the front displacement line; and a transfer mechanism that connects the front output arrow with the output of the differential between axes.
8. 8. The transmission according to claim 7, characterized in that the unit for gear reduction includes a fixed planetary gear for rotation with the main shaft, a stationary ring gear and a planetary carrier having pinion gears coupled with the planetary gear. and the ring gear, the range clutch is set for rotation with the differential supply and is movable between a first position in which the range clutch is coupled with the planetary gear with the feed to establish the displacement connection with respect of direct speed, a second position in which the range clutch couples the planetary carrier with the supply to establish the reduced speed ratio boost connection, and a third position in which the range clutch is decoupled from the planetary gear and the planetary carrier to disconnect the power supply of the coupling with the main arrow, thus establishing a neutral non-displaced mode.
9. 9.- The transmission in accordance with the claim 7, characterized in that the gear reduction unit includes a planetary gear rotatably held in the main shaft, a non-rotatable ring gear and a planetary carrier having pinion gears coupled with the planetary gear and the ring gear, and wherein the range clutch is movable between a first portion in which the feed is directly coupled to the main shaft to establish the displacement connection with direct speed ratio, a second position in which it engages the planetary gear with the main shaft and the planetary carrier with the power to establish the displacement connection with reduced speed ratio, and a third position in which the power is decoupled from the main shaft.
10. 10. The transmission in accordance with the claim 7, characterized in that the unit for gear reduction includes a fixed planetary gear for rotation with the main shaft, a ring gear and a fixed planetary carrier for rotation with the supply and having pinion gears coupled with the ring gear and the gear planetary, and wherein the range clutch is held for rotation with the gear and is movable between a first position in which the range clutch couples the ring gear with the feed to establish the displacement connection with direct speed ratio, a second position for coupling the ring gear to a stationary member to establish the displacement connection at reduced speed ratio and a third position at which the ring gear is allowed to rotate relative to the planetary carrier and the planetary gear to establish a neutral mode
11. 11. The transmission according to claim 7, characterized in that it also comprises an apparatus for transferring torque to inhibit speed differentiation through the differential between axes in response to excessive speed differentials between the front and rear output arrows .
12. 12. The transmission for a vehicle with four-wheel drive that has a motor and front and rear drive lines, the transmission is characterized in that it comprises: a feed arrow displaced by the motor with respect to a first rotary axis; a main arrow supported for rotation with respect to a second rotary axis; constant coupling gear sets supported between the feed shaft and the main shaft; synchronizer clutches for selectively coupling the gear sets to move the main shaft at a predetermined speed relation to the feed shaft to establish a forward gear and a reverse gear; a rear output arrow adapted for connection to the rear pulse line and which is commonly aligned with the main arrow for rotation with respect to the second rotary axis; a front output arrow adapted for connection to the front impulse line and which is held for rotation with respect to a third rotary axis; a gear reduction unit displaced by the main shaft at a reduced speed relation to it; a range clutch for selectively coupling the rear output shaft to either the main shaft and the gear reduction unit; and a transfer clutch for the pulse torque from the output arrow after the front output arrow in response to a pre-determined slip between them.
13. 13. The transmission according to claim 12, characterized in that the transfer clutch is a multi-plate assembly operable to selectively transfer torque of impulse torque from the rear output arrow to the front output arrow, and where the The transmission further comprises: an actuator for varying the actuated condition of the transfer clutch between a non-driven state wherein all of the pulse torque is supplied to the rear output shaft and a fully driven state wherein the front output shaft is Coupling rigidly for common rotation with the rear exit arrow; detector means for dynamic and operational characteristics of the vehicle and generating detector power signals indicative thereof; and a controller for the operation of the actuator in response to the power signals of the detector.
14. 14. The transmission according to claim 13, characterized in that it further comprises a mechanism for mode selection to allow a vehicle operator to choose any one of a high range displacement mode with four wheels on demand and one mode of travel of low range with four part-time wheels, the mode selection mechanism is further operable to generate a signal mode indicative of the particular mode selected and fed to the controller, whereby when the mode signal indicates impulse mode selection High range for four wheels on demand, the range clutch moves for selective coupling of the rear output arrow to the main arrow to establish a displacement connection with direct speed ratio and the actuated mode of the transfer clutch is varied as a function of the magnitude of the detector's power signals and when the mod signal or indicates selection of low-range pulse mode with four part-time wheels, the range clutch moves for selective coupling of the rear output shaft to the gear reduction unit to establish the displacement connection at reduced speed ratio and the transfer clutch moves to its fully actuated state.
15. 15. The transmission for a four-wheel drive vehicle having front and rear drive lines and motor, the transmission is characterized in that it comprises: a feed arrow displaced by the motor with respect to a first rotary axis; a transfer arrow supported for rotation with respect to a second rotary axis; a tubular main arrow rotatably held on the transfer shaft; a plurality of gear sets of constant coupling each having a feed gear fixed to the feed shaft and a speed gear rotatably held on the main shaft; a plurality of synchronizing clutches for selective engagement of one of the speed gears with the main shaft, to move the main shaft at a predetermined speed ratio relative to the supply shaft, to establish a plurality of forward and reverse gears; a tubular arrow rotatably supported on the transfer arrow adjacent to the main arrow; a gear reduction unit having a feed member displaced by the main shaft and an output member displaced at a reduced speed ratio relative to the feed member; a range clutch for selective coupling of the tubular shaft to any of the main shaft where a displacement connection with direct speed ratio is established in the output member of the gear reduction unit in which the connection of impulse or displacement with reduced speed ratio; a rear output arrow adapted for connection to the rear pulse line and which is commonly aligned with the transfer arrow for rotation with respect to the second rotary axis; a front output arrow adapted for connection to the front impulse line and which is held for rotation with respect to a third rotary axis; a transfer mechanism that connects the front output arrow for common rotation with the transfer arrow; and a differential between axes to allow speed differentiation between the rear output arrow and the transfer arrow, the differential between axes includes a first planetary gear for rotation with the transfer arrow, a second fixed planetary gear for rotation with the arrow of rear outlet and a fixed planetary carrier for rotation with the tubular shaft and rotatingly supporting the planetary gear means coupling with the first and second planetary gears.
16. 16. The transmission according to claim 15, characterized in that the gear reduction unit includes a fixed planetary gear for rotation with the main shaft, a stationary ring gear and a planetary carrier having pinion gears coupled with the planetary gear and the ring gear, the range clutch is fixed for rotation with the tubular shaft and is axially movable there between a first position in which the range clutch couples the planetary gear with the tubular shaft to establish the impulse connection with direct speed ratio, a second position in which the range clutch couples the planetary carrier to the tubular shaft, to establish the impulse connection at reduced speed ratio and a third position at which the chain clutch is decoupled from the planetary gear and the planetary carrier, to disconnect the tubular shaft of the coupling displaced with the main arrow, establishing in this way a Do not neutrally displaced.
17. 17. The transmission according to claim 15, characterized in that the gear reduction unit includes a planetary gear rotationally supported in the main shaft, a non-rotatable ring gear and a planetary carrier having pinion gears coupled with the gear wheel. ring and the planetary gear and wherein the range clutch is movable between a first position in which it couples directly on the tubular shaft to the main shaft to establish the impulse connection with direct speed ratio, a second position in which it engages in the planetary gear with the main arrow and the planetary carrier with the tubular shaft to establish the impulse connection with reduced speed ratio and a third position in which the tubular shaft is decoupled from the main shaft.
18. 18. The transmission according to claim 15, characterized in that the unit for gear reduction includes a fixed planetary gear for rotation with the main shaft, a ring gear and a fixed planetary carrier for rotation with the tubular shaft and having sprocket gears coupled with the ring gear and the planetary gear, and wherein the range clutch is held for rotation with the ring gear and is movable between a first position in which the range clutch couples the ring gear with the tubular arrow to establish the impulse connection with direct speed ratio, a second position for coupling the ring gear with a stationary member to establish the impulse connection with reduced speed ratio and a third position in which the ring gear is allows it to rotate regarding the planetary carrier and the planetary gear to establish a neutral mode.
19. 19. The transmission according to claim 15, characterized in that it also comprises an apparatus for transferring torque to inhibit the differentiation of speed through the differential between axes in response to excessive speed differentials between the front output arrows and later.
20. 20. The transmission according to claim 19, characterized in that the apparatus for torque transfer is a multi-plate transfer clutch operable to selectively limit the speed differentiation between the front and rear output arrows and where the Transmission further comprises: an actuator for varying the actuated condition of the transfer clutch between a non-driven state wherein the unrestricted speed differentiation between the front and rear output arrows is allowed and a fully driven state wherein the differentiation of speed; detector means for dynamic and operational characteristics of the vehicle and generating detector power supply signals indicative thereof; and a controller for regulating the actuation of the actuator operation in response to the power supply signals of the detector, the controller causes the actuator to modulate the actuated condition of the transfer clutch as a function of the power supply signals of the detector.