MXPA99000041A - Integrated device for transmission and displacement of multi-speed tree - Google Patents

Abstract

The present invention relates to a drive train assembly for a vehicle, characterized in that it comprises: a source of rotational energy, a transmission connected to the rotational energy source and operable in a plurality of transmission gear ratios; connected to the transmission and operable in a plurality of shaft gear ratios; and a controller for operating the transmission on a desired one of a plurality of transmission gear ratios and for operating the shaft assembly to a desired one of a plurality of gear ratios. shaft to supply the desired total gear ratio for the vehicle

Description

INTEGRATED DEVICE FOR TRANSMISSION AND DISPLACEMENT OF MULTIPLE SPEED TREE BACKGROUND OF THE INVENTION This invention relates generally to a drive train assembly including a transmission and a multiple speed shaft to provide a desired rate reduction gear ratio between a rotational power source and the driven wheels of the vehicle. More particularly, this invention relates to an integrated system for automatically controlling the operation of both the automated mechanical transmission and the multiple speed shaft assembly in a vehicle drive train assembly. Virtually in all land vehicles currently used, a transmission is provided in a drive train assembly between a rotational power source, such as an internal combustion engine or diesel engine, and the driven shaft, and the wheels of the vehicle. A typical transmission includes a box containing a transmission input shaft, a transmission output shaft and a plurality of geared mechanisms. Means are provided for connecting the selected geared mechanisms between the transmission input shaft and the transmission output shaft to provide the desired rate reduction gear ratio therebetween. The geared mechanisms contained within the transmission case are of variable size so as to provide a plurality of such gearing rates. By properly moving between these various gearing ratios, the acceleration or deceleration of the vehicle can be carried out in a regular and efficient manner. To facilitate the transmission of the operation, it is well known to provide a clutch between the vehicle engine and the transmission. When the clutch is engaged, the transmission is driven by the vehicle engine to operate the vehicle at the selected gear ratio. To shift the transmission of the first gear ratio to the second gear ratio, the clutch is initially decoupled so that the power is no longer transmitted from the vehicle engine to the transmission. This allows the gearing shift operation to occur within the transmission under a load condition with no torque to avoid undesirable impact of the meshing mechanism teeth. Subsequently, the clutch is coupled again so that the power is transmitted from the vehicle engine to the transmission to operate the vehicle in the second gear ratio.

A typical structure for a vehicle clutch includes a cover that is connected to a fixed flywheel to the end of the output shaft of the vehicle engine for rotation therewith. A pressure plate is placed inside the clutch between the cover and the engine flywheel. The pressure plate is connected for rotation with the engine flywheel and the cover, but it is allowed to move axially in relation thereto. Therefore, the motor wheel, the cover and the pressure plate are all constantly rotated by the motor of the vehicle. An impelled disk assembly is placed between the motor wheel and the pressure plate. The driven disc assembly is supported on the transmission input shaft for rotation therewith, but is allowed to move axially relative thereto. To engage the clutch, the pressure plate is moved axially towards the engine flywheel to a coupled position, where the driven disc assembly is reciprocally coupled between the engine flywheel and the pressure plate. As a result, the driven disc assembly (and the drive input shaft on which it is supported) are driven to rotate with the engine flywheel, cover and pressure plate. To uncouple the clutch, the pressure plate moves axially away from the engine flywheel to an uncoupled position. When the pressure plate moves axially to this decoupled position, the driven disc assembly is not frictionally coupled between the flywheel of the motor and the pressure plate. As a result, the driven disc assembly (and the transmission input shaft on which it is supported) are not driven to rotate with the engine flywheel, cover and pressure plate. To carry out such axial movement of the pressure plate between the coupled and uncoupled positions, most of the vehicle clutches are provided with a release assembly that includes a generally hollow cylindrical release sleeve positioned around the input shaft of transmission. The forward end of the release sleeve extends into the clutch and is connected through a plurality of levers or other mechanical mechanism to the pressure plate. In this way, the axial movement of the release sleeve causes the corresponding axial movement of the pressure plate between the coupled and uncoupled positions. Usually, one or more coupling springs are provided within the clutch to urge the pressure plate toward the engaged position. Coupling springs typically react between the release sleeve and the cover to normally maintain the clutch in the coupled condition. The rear end of the release sleeve extends outwardly from the clutch through a central opening formed through the cover. Because the release sleeve connects to the cover and the clutch pressure plate, it is also constantly driven to rotate whenever the vehicle's engine is running. Therefore, an annular release bearing is usually mounted on the rear end of the release sleeve. The release bearing is axially fixed on the release sleeve and includes an inner race which rotates with the release sleeve, an outer race which is restricted in rotation, and a plurality of bearings placed between the inner race and the raceway. outer track to allow such relative rotation. The non-rotating outer race of the release bearing is typically coupled by a drive mechanism for moving the release sleeve (and therefore the pressure plate) between the engaged and uncoupled positions to operate the clutch. In a conventional mechanical transmission, both the clutch operation and the speed change operation in the transmission is performed manually by the vehicle operator. For example, the clutch can be disengaged by pressing a clutch pedal located in the driver's compartment of the vehicle. The clutch pedal is connected through a mechanical link to the outer race of the clutch release bearing so that when the clutch pedal is depressed, the clutch pressure plate moves from the engaged position to the uncoupled position. When the clutch pedal is released, the coupling springs provided with the clutch return the pressure plate from the uncoupled position to the engaged position. Similarly, the speed change operation in the transmission can be performed when the clutch is uncoupled by manually moving the shift lever which extends from the transmission into the interior of the vehicle driver's compartment. Manually operated clutch / transmission assemblies of this type are generally well known in the art and are relatively simple, cheap and light in structure and operation. Because of this, most of the medium and heavy duty trucks currently in use have clutch / transmission assemblies and are manually operated. However, more recently, in order to improve the convenience of using manually operated clutch / transmission assemblies, various structures have been proposed to partially or completely automate the change of a transmission operated in some other manual way. In a partial or fully automated manual transmission, the clutch pedal manipulated by the driver can be replaced by an automatic clutch actuator, such as a hydraulic or pneumatic actuator. The operation of the automatic clutch actuator can be controlled by an electronic controller or other control mechanism to selectively couple or uncouple the clutch without manual effort by the driver. Similarly, the shift lever manipulated by the driver can also be replaced by an automatic transmission actuator, such as a hydraulic or pneumatic actuator which is controlled by an electronic controller or other control mechanism to select and couple the desired reductions for use. . In addition to the clutch / transmission structures described above, most land vehicles also include an axle for transmitting the rotational power from the transmission output shaft to the driven wheels of the vehicle. A typical tree assembly includes a housing containing a shaft input shaft that is connected through a differential gearing assembly to a pair of shaft output shafts. The shaft input shaft is connected by a drive shaft assembly to the transmission output shaft so that it is rotatably driven by it. The differential gear assembly divides the rotational power from the input shaft of the shaft to two shaft output arrows and, from here, rotatably drives the vehicle wheels. In some cases, the tree assembly is structured to provide only a single gear ratio of the speed between the input shaft of the shaft to the output shaft of the shaft. In other instances, however, the tree assembly is structured to provide two (or possibly more) speed reductions between the input shaft of the shaft and the output arrows of the shaft. Multiple speed shaft assemblies are desirable because they extend the amount of speed reductions beyond those provided by the transmission in a simple manner and in a cost efficient manner. For example, a four-speed transmission that operates in conjunction with a two-speed tree assembly provides a total of eight available reductions. In these multiple speed shaft assemblies, a manually operable mechanism is provided for switching between tree reductions. In the past, this manually operable mechanism includes a mechanical joint that extends from the vehicle driver's compartment to the tree's mounting. The driver of the vehicle physically moves the mechanical joint to switch between tree reductions. However, recently, this manually operable mechanism includes an electrical switch connected to operate an electric motor provided on the shaft assembly. The driver of the vehicle manually operates the electric switch to control the operation of the electric motor to switch between the tree reductions. As mentioned in the above, it is known as partially or completely automate the change of a transmission otherwise manually operated. However, a partially or fully automated transmission can not be easily used with a manually operated multiple speed shaft assembly. As mentioned before, the use of a multiple speed shaft assembly is desirable because the number of speed reductions beyond those provided by the transmission is extended in a simple manner and in a cost-efficient manner. . Therefore, it would be desirable to provide an integrated system for automatically controlling the operation of both the automated mechanical transmission and the multiple speed shaft assembly in a vehicle drive train assembly.

BRIEF DESCRIPTION OF THE INVENTION This invention relates to an integrated system for automatically controlling the operation of both the automated mechanical transmission and the multiple speed shaft assembly in a vehicle drive train assembly. The system includes a transmission actuator for operating the transmission in any of a plurality of transmission reductions. The system further includes a shaft actuator for operating the shaft assembly in any of a plurality of shaft reductions. An electronic controller is provided to operate the transmission in a desired of a plurality of transmission reductions and to operate the shaft assembly in a desired of a plurality of shaft proportions to provide a desired total gear ratio for the vehicle. To accomplish this, the electronic controller responds to one or more input signals representing vehicle operating parameters. When it is determined that a change in the total gear ratio of the vehicle is necessary, the electronic controller operates one or both of the drive actuators and the shaft driver to obtain the desired total gear ratio. The determination of whether the drive actuator is only actuated, whether the shaft drive is only driven, or both the drive actuator and the shaft drive are actuated, will depend on the specific reductions provided by the drive and shaft drive, the current total gear ratio, the desired total gear ratio and other factors. Various objects and advantages of this invention will become apparent to those familiar with the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of a vehicle drive train assembly including an integrated system for automatically controlling the operation of both the automated mechanical transmission and the multiple speed shaft assembly. Fig. 2 is a flow chart illustrating a simplified algorithm for controlling the operation of the electronic controller illustrated in Fig. 1.

DESCRIPTION DETAIL OF THE PREFERRED MODALITY Referring now to the drawings, a block diagram of a vehicle drive train assembly, generally indicated with the numeral 10, according to this invention is illustrated in FIG. The drive train assembly 10 includes a conventional motor 11 or other source of rotational energy. The motor 11 is connected through an output shaft, such as a crankshaft of the motor 11, to a clutch 12. The clutch 12 is also conventional in the art and functions to selectively connect the output arrow 11 of the motor 11 to an input arrow 13a of a transmission 13. The transmission 13 contains a plurality of geared mechanisms (not shown) that selectively connect between the input arrow 13a and the output arrow 13b. The geared mechanisms contained within the transmission 13 are of variable size so as to provide a plurality of such reductions. By properly changing between these various reductions, a desired speed reduction can be provided between the input arrow 13a and the output arrow 13b of the transmission 13. The output arrow 13b of the transmission 13 is connected through a drive shaft. conventional (not shown) to a conventional multiple speed shaft assembly 14. The shaft assembly 14 includes one or more wheels (not shown) that are rotationally driven by the engine 11 as long as the clutch 12 is engaged. The multiple speed shaft assembly 14 also contains a plurality of meshing mechanisms (not shown) that selectively connect between the output shaft 13b of the transmission 13 and the wheels of the vehicle. The geared mechanisms contained within the multiple speed shaft assembly 14 are of variable size so as to provide a plurality (typically 2) of such reductions. By appropriately switching between these various reductions, a desired reduction in speed between the output shaft 13b and the transmission 13 and the wheels of the vehicle can be provided. By properly changing between the various speed reductions provided in the transmission 13 and the multiple speed shaft assembly 14, the acceleration and deceleration of the vehicle can be carried out in a regular and efficient manner. This general structure for a drive train assembly 10 described so far is well known in the art. The transmission 13 illustrated can be a mechanical transmission partially or completely automated. In a partially typical automated manual transmission, a shift lever manipulated by the driver (not shown) engages and moves certain of a plurality of shift rails contained within the transmission to couple a first set of reductions for use. However, a shift transmission actuator 15 is automatically provided in the transmission 13 for coupling and moving the remaining shift rails to couple a second set of reductions for use. For example, it is known to provide a partially automated manual transmission where minor changes are manually selected and coupled by the driver of the vehicle using the shift lever, while the higher reductions are automatically selected and coupled by the driver 15 of the vehicle. transmission. An example of a partially automated manual transmission typical of this general structure is described in detail in U.S. Patent No. 5,450,767, assigned to the assignee of this application. The description of that patent is incorporated herein by reference. In a fully automated manual transmission, the shift lever is operated by the driver and is usually replaced by a drive actuator 15. The drive actuator 15 operates to change all of the change rails contained within the transmission so that all available reductions are selected and coupled. The aforementioned patent discusses the adaptability of a partially automated drive actuator 15, described, to fully automate the transmission change described herein. However, it will be appreciated that this invention can be carried out with any desired structure for the transmission 13 and the drive actuator 15.

To facilitate the automatic change of the transmission 15, the clutch 12 is provided with a clutch actuator 16. The structure and operation of the clutch actuator 16 are conventional in the art. Briefly, the clutch actuator 16 is provided to replace a clutch pedal manipulated by the driver in a manner that partially or completely automates the operation of the clutch 12. The clutch actuator 16 is effective to operate the clutch 12 in a coupled or decoupled mode . When the clutch 12 is engaged, the transmission 13 is driven by the vehicle engine 11 to operate the vehicle at a selected reductions. To change the transmission 13 from a first reduction to a second reduction, the clutch 12 is initially decoupled so that the energy is no longer transmitted from the engine 11 of the vehicle to the transmission 13. This allows the transmission actuator 15 to carry the speed change operation within the transmission 13 under a load condition without torque to avoid undesirable impact of the teeth of the geared mechanism. Subsequently, the clutch 12 is coupled again so that energy is transmitted from the vehicle engine 11 to the transmission 13 to operate the vehicle at a second reduction. A structure that has been found to be acceptable for a clutch actuator 16 is disclosed in commonly assigned U.S. Patent Application Serial No. 08 / 891,625, filed on July 9, 1997, the description of which is incorporated in FIG. present as a reference. However, it will be appreciated that this invention can be practiced with any desired structure for the clutch 12 and the clutch actuator 16. To facilitate the automatic change of the multiple speed shaft assembly 14, a shaft driver 17 is provided. The structure and operation of the shaft driver 17 are conventional in the art. Briefly, the shaft driver 17 is provided to replace a mechanical joint manipulated by the conductor or an electric switch / motor assembly in a manner that automates the operation of the shaft assembly 14. The shaft driver 17 may include an electric motor (not shown) that is effective to operate the shaft assembly 14 at a desired reduction. Typically, the shaft assembly 14 is capable of providing two reductions, a relatively low first reduction and a relatively high second reduction. Therefore, when the first reduction is engaged, the wheels of the vehicle are driven by the engine 11 of the vehicle to operate the vehicle at a relatively low reduction with respect to the rotational speed of the output arrow 13b of the transmission 13. Similarly, when the second reduction is engaged, the wheels of the vehicle are driven by the motor 11 of the vehicle to operate the vehicle at a relatively high reduction with respect to the rotational speed of the output arrow 13b of the transmission 13. The driver 17 is provided with shaft for moving the shaft assembly 14 between the first and second reductions in the manner described below. A structure that has been found to be acceptable for the shaft driver 17 is described in the commonly assigned US Patent Application No. 4,793,458, issued December 27, 1988, the description of which is incorporated herein by reference. reference. However, it will be appreciated that this invention can be carried out with any desired structure for the shaft assembly 14 and the shaft driver 17. The operation of the clutch actuator 16, the drive actuator 15 and the shaft driver 17 are controlled by an electronic controller 20. The electronic controller 20 can be constituted of any conventional microprocessor or similar computing apparatus which can be programmed to operate the clutch actuator 16 (to perform automatic coupling and disengagement of the clutch 12), the drive actuator 15 (for carrying out the automatic transmission transmission 13 when the clutch 12 is decoupled) and the shaft driver 17 (for carrying out the automatic change of the shaft assembly 14) as described above. The operation of the electronic controller 20 will be described in detail below. The operation of the electronic controller 20 will be described in detail below. A transmission output arrow speed sensor 21 provides an input signal to the electronic controller 20. The transmission output speed sensor 21 is conventional in the art and is adapted to generate an electrical signal which is representative of the actual rotational speed of the output arrow 13b of the transmission 13. A clutch position sensor 22 also provides an input signal to the electronic controller 20. The structure and operation of the clutch position sensor 22 is conventional in the art and is adapted to provide an electrical signal to the electronic controller 20 which is representative of the actual position of the clutch 12 as it moves between the engaged and uncoupled positions. A motor controller 23 is provided to control the operation of the motor 11 of the vehicle. The motor controller 23 can also be modified like any conventional microprocessor or similar computing apparatus which can be programmed to operate the motor 11 in a desired manner. Mainly, the motor controller 23 controls the operation of the motor 11 in response to an input signal generated by an accelerator pedal position sensor 24. The accelerator pedal position sensor 24 is conventional in the art and is adapted to generate an electrical signal which is representative of the actual position of the accelerator pedal (not shown) of the vehicle. As is well known, the accelerator pedal is physically manipulated by the foot of the driver of the vehicle to control the operation of the same. The accelerator pedal is pressed by the driver when it is desired to increase the speed of the engine 11 and move the vehicle. Conversely, the accelerator pedal is released when it is desired to decrease the speed of the engine 11 to decrease or stop the movement of the vehicle. Therefore, the motor controller 23 controls the speed of the motor 11 in response to the signal from the accelerator pedal position sensor 24 so that the vehicle operates as the driver desires. If desired, the accelerator pedal position sensor 24 can be replaced by a throttle position sensor (not shown) or another sensor that responds to the driver which generates a signal which is representative of the desired speed or mode of operation of the vehicle. A second entry to motor controller 23 is a motor output arrow speed sensor 25. The output speed sensor of the motor is conventional in the art and is adapted to generate an electrical signal which is representative of the actual rotational speed of the output arrow of the motor. motor 11. The electronic controller 20 and the motor controller 23 communicate with each other by means of a common data link line 26 extending therebetween. In a manner which is generally conventional in the art, the controller The electronic and the motor controller 23 are programmed to communicate and cooperate with each other so as to control the operation of the vehicle in a manner desired by the driver of the vehicle. Specifically, the electronic controller 20 and the motor controller 23 are effective to control the operation of the motor 11, the clutch 12, the transmission 13 and the shaft assembly 14, so that the vehicle can be started and stopped only by manipulation Physics of the accelerator and brake pedals, similar to a conventional automatic transmission in a passenger car. To accomplish this, the signals from the decelerator pedal position sensor 24 and the engine output arrow speed sensor 25 are available to the electronic controller 20 on the common data link line 26. Alternatively, the signals from the accelerator pedal position sensor 24 and the engine output arrow speed sensor 25 can be fed directly to the electronic controller 20. In the illustrated embodiment, the electronic controller 20 responds to the input signals generated by the speed sensor 21, the clutch position sensor 22, and the motor controller 23 to control the operation of the clutch actuator 16, the actuator 15. of transmission and the shaft driver 17. However, the electronic controller 20 can respond to any desired amount of input signals, which include those representing vehicle operating parameters other than those specifically shown, to control the operation of the clutch actuator 16, the transmission actuator 15 and the shaft driver 17. The specific nature of the algorithm or program executed by the electronic controller varies to some extent from one vehicle to another. However, in general, the electronic controller 20 responds to the input signals to cause the change to occur either in either or both of the transmission 13 and the shaft assembly 14 to obtain the overall reduction desired for the vehicle. By an appropriate change of the transmission 13 and the shaft assembly 14, the acceleration and deceleration of the vehicle can be carried out in a regular and efficient manner. Figure 2 is a flow chart, generally indicated with the number 30, illustrating a simplified algorithm for controlling the operation of the electronic controller 20 illustrated in Figure 1. In the first step 31 of the algorithm, the electronic controller 20 reads part or all the input signals supplied to it. Then, the algorithm 30 introduces a decision point 32 where the electronic controller 20 determines whether a change in the total reduction of the vehicle is necessary, based on the predetermined criteria. Typically, these predetermined criteria are stored in a permanent memory of the electronic controller. As mentioned before, the specifications of the predetermined criteria vary from vehicle to vehicle. This invention contemplates that any desired predetermined criteria can be used to determine whether a change in the overall reduction of the vehicle is necessary. If the electronic controller determines that a change in the total reduction of the vehicle is not currently necessary., the algorithm 30 branches back to the first stage 31, where the electronic controller 20 again reads part or all of the input signals supplied thereto. However, if the electronic controller 20 determines that a change in the total reduction of the vehicle is currently necessary, the algorithm 30 branches to an instruction point 33 where a drive actuator 15 and a shaft driver 17 are operated. to obtain the desired reduction. The determination if the drive actuator 15 is driven only, if the shaft drive 17 is actuated only or both the drive actuator 15 and the shaft drive 17, will depend on the specific reductions provided by the transmission 13 and the drive 14 of the drive. tree, the current total reduction, the total reduction desired and other factors that are well known in the art. Usually, the clutch actuator 16 is initially driven by the electronic controller 20 to disengage the clutch 12 before actuating the drive actuator 15 to change the transmission 13. The shaft actuator 14 can be driven at the same time the change occurs. under a load condition without torque. Alternatively, the shaft driver 17 may be constituted using a conventional spring-loaded structure where it previously deflects the shaft assembly 14 to automatically shift or change as long as the magnitude of the torque thereof decreases below a predetermined threshold. After an appropriate change has been made, the algorithm 30 branches back to the first stage 31, where the electronic controller 20 again reads part or all of the input signals supplied thereto. For purposes of illustration, assume that the transmission 13 is capable of providing four different direct gear ratios referred to as first, second, third and fourth transmission gear ratios. Assume further that the shaft assembly 14 is capable of providing two different gear ratios designated as low and high gear ratios, and that the difference between the shaft gear ratios is greater than the difference between any of the gear ratios of adjacent transmission. If the vehicle is at rest, when the accelerator pedal is depressed, the electronic controller 20 will determine that the vehicle is operated on a first gear ratio. To accomplish this, the electronic controller 20 initially drives the drive actuator 15 to change the transmission 13 to a first transmission gear ratio and the shaft driver 17 to change the shaft assembly 14 to the shaft gear ratio. low. The combination of the first transmission gear ratio and the low shaft gear ratio provides the first total gear ratio. If the vehicle accelerates gradually, the electronic controller 20 will subsequently determine that the vehicle must be operated sequentially through the second, third and fourth proportions of general gears. This is accomplished by actuating the drive actuator 15 to change the transmission 13 to a second, third and fourth proportions of transmission gears, while maintaining the shaft assembly 14 in the low shaft engagement ratio. In order to reach the fifth general gear ratio, the electronic controller will then drive the drive actuator 16 to change the transmission 13 back to the first transmission gear ratio, while driving the shaft driver 17 to change the drive assembly 14. tree to the high tree gear ratio. Subsequently, the electronic controller 20 will drive the transmission driver 16 to change the transmission 13 sequentially through the second one., third and fourth transmission gear ratios while holding the shaft assembly 14 in the high shaft gear ratio to obtain the sixth, seventh and eighth general gear ratios. Downward changes can be carried out in a similar way. It will be appreciated that one or more gear ratios may be skipped, based on the operating conditions of the vehicle. It will also be further appreciated that the change of the transmission 13 and the shaft assembly 14 may vary from that mentioned above, based on the specific gear ratios provided in this manner. It can be seen that the electronic control system described above provides an integrated system for automatically controlling the operation of both the automated mechanical transmission 13 or the multiple speed shaft assembly 14 in the vehicle drive train assembly 10. As a result, the number of total meshing ratios that are provided extend much further than those provided individually by the transmission 13 and the shaft assembly 14. Furthermore, by providing these additional general gear ratios, it is carried out in a relatively simple manner and in a cost-efficient manner, while at the same time allowing partial or fully automatic change of both the transmission 13 and the transmission. 14 tree assembly. In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention has been explained and illustrated in its preferred embodiment. However, it should be understood that this invention can be practiced otherwise than specifically explained and illustrated, without departing from its spirit or scope.

Claims (10)

1. A drive train assembly for a vehicle, characterized in that it comprises: a source of rotational energy; a transmission connected to the rotational energy source and operable in a plurality of transmission gear ratios; a shaft assembly connected to the transmission and operable in a plurality of shaft engagement ratios; and a controller for operating the transmission on a desired one of a plurality of transmission gear ratios and for operating the shaft assembly on a desired one of a plurality of shaft gear ratios to supply the total gear ratio desired for the vehicle. .

2. The drive train assembly according to claim 1, characterized in that the transmission includes a drive actuator for changing the transmission between a plurality of transmission gear ratios, and wherein the controller operates the drive actuator.

3. The drive train assembly according to claim 1, characterized in that the shaft includes a plurality of shaft actuators for changing the shaft assembly between the plurality of shaft engaging proportions, and wherein the driver operates the shaft actuator .

4. The drive train assembly according to claim 1, characterized in that the transmission includes a drive actuator for changing the transmission between a plurality of transmission gear ratios, the shaft includes a shaft drive for moving the shaft assembly between a plurality of shaft engaging ratios, the controller operates the drive actuator and the shaft actuator.

5. The drive train assembly according to claim 1, characterized in that it includes a clutch connected between the rotational power source and the transmission.

6. The drive train assembly according to claim 5, characterized in that the clutch includes a clutch actuator for selectively connecting the rotational energy source to the transmission, and wherein the controller operates the clutch actuator.

7. The drive train assembly according to claim 5, characterized in that the clutch includes a clutch actuator for selectively connecting the rotational power source to the transmission, the transmission includes a transmission actuator for shifting the transmission through a plurality of of transmission gear ratios, the shaft includes a shaft driver for changing the shaft assembly between a plurality of shaft engagement ratios, and the controller operates the clutch actuator, the drive actuator and the shaft driver.

8. The drive train assembly according to claim 1, characterized in that the controller is an electronic controller.

9. The drive train assembly according to claim 1, characterized in that it further includes a sensor for generating a signal that is representative of a vehicle operating condition, and wherein the controller responds to a signal to operate the transmission on a desired of a plurality of transmission gear ratios and for operating the shaft assembly to a desired one of a plurality of shaft gear ratios, to provide a desired total gear ratio for the vehicle.

10. The drive train assembly according to claim 1, characterized in that it further includes a plurality of sensors for generating signals that are representative of a plurality of vehicle operating conditions, and wherein the controller responds to signals to operate the transmission in a desired of the plurality of transmission gear ratios and to operate the shaft assembly in a desired of the plurality of shaft gear ratios to provide a desired overall gear ratio for the vehicle. SUMMARY OF THE INVENTION An integrated system for automatically controlling the operation of both the automated mechanical transmission and a multiple speed shaft assembly in a vehicle drive train assembly that includes a drive actuator for operating the transmission in any of a plurality of proportions of transmission gear. The system further includes a shaft actuator for operating the shaft assembly in any of a plurality of shaft engaging ratios. An electronic controller is provided for operating the transmission on a desired one of a plurality of transmission gear ratios and for operating the shaft assembly on a desired one of a plurality of shaft gear ratios to supply a desired total gear ratio for the shaft. vehicle. To accomplish this, the electronic controller responds to one or more input signals that represent the operating parameters of the vehicle. When it is determined that a change in the overall gear ratio of the vehicle is necessary, the electronic controller operates both the drive actuator and the shaft driver to obtain the desired total gear ratio. The determination of whether the drive actuator will only be driven, the shaft drive alone or both the drive actuator and the shaft drive, will depend on the specific gear ratios provided by the drive and shaft drive, the gear ratio current total, the desired total gear ratio, and other factors.