Abstract: A tandem drive axle mechanical shift assembly including a first shift rail assembly having a first shift rail actuated via a first pneumatic actuator, and a shift fork having a first end coupled with the first shift rail and a second end coupled with an engagement selector. A second shift rail assembly having a second shift rail actuated via a second pneumatic actuator, and a second shift fork having a first end coupled with the second shift rail and a second end coupled with an inter-axle differential lock-up clutch. First and second primary valves in fluid communication with a reservoir, and a secondary valve in fluid communication with the reservoir and in selective fluid communication with the second pneumatic actuator. A first actuation valve operated by the first shift rail and in selective fluid communication with the first and second primary valves, and the first and second pneumatic actuators.

Abstract: A hydrostatic driveline and method of operating a hydrostatic driveline is provided. The hydrostatic driveline comprises a power source, hydrostatic pump, a hydrostatic motor, a direct drive link, a first transmission portion, and a second transmission portion. The direct drive link is in driving engagement with at least one of the power source and the hydrostatic pump. The first transmission portion is in driving engagement with a vehicle output and the hydrostatic motor. The second transmission portion is in driving engagement with the direct drive link and at least one of the vehicle output and the first transmission portion. The hydrostatic pump, the hydrostatic motor, and the first transmission portion form a first power path for the hydrostatic driveline and the direct drive link and the second transmission portion form a second power path for the hydrostatic driveline.

Abstract: A tandem drive axle mechanical shift assembly including a first shift rail assembly having a first shift rail actuated via a first pneumatic actuator, and a shift fork having a first end coupled with the first shift rail and a second end coupled with an engagement selector. A second shift rail assembly having a second shift rail actuated via a second pneumatic actuator, and a second shift fork having a first end coupled with the second shift rail and a second end coupled with an inter-axle differential lock-up clutch. First and second primary valves in fluid communication with a reservoir, and a secondary valve in fluid communication with the reservoir and in selective fluid communication with the second pneumatic actuator. A first actuation valve operated by the first shift rail and in selective fluid communication with the first and second primary valves, and the first and second pneumatic actuators.

Abstract: A vehicle driveline torque managing process provides a motor driven actuator that manages clamping forces exerted on a clutch pack and regulates a coupling of power between a driveshaft and one of the axles of a vehicle, based on clutch positions. The process derives coupling torque values by stepping a motor from a maximum clutch separation position through a series of clutch positions while recording a motor driven commanded torque value at each step, up to a maximum clutch compression position having a maximum commanded motor torque value. Then, each motor driven commanded torque value is converted into respective clutch force values as a function of clutch position, thereby relating each clutch torque to a clutch position based on conversion tables stored in a controller that are associated with physical factors that influence clutch torque for each of the respective clutch actuator positions.

Abstract: A drive axle system (10) and a method for adapting a shift schedule of a drive axle system (10) based on an input is provided. The drive axle system (10) comprises a first shaft (18), a first axle assembly (14), a second axle assembly (16), a clutching device (28), a controller (55), and a plurality of sensors (75). The plurality of sensors (75) are in communication with the controller (55) for sensing at least one of an environmental condition and at least one operating condition the drive axle system (10). Based on the information from the plurality of sensors (75) the controller (55) selects one of a plurality of shift schedules and places the clutching device (28) in one of a first position and a second position.

Abstract: A vehicle driveline torque managing process provides a motor driven actuator that manages clamping forces exerted on a clutch pack and regulates a coupling of power between a driveshaft and one of the axles of a vehicle, based on clutch positions. The process derives coupling torque values by stepping a motor from a maximum clutch separation position through a series of clutch positions while recording a motor driven commanded torque value at each step, up to a maximum clutch compression position having a maximum commanded motor torque value. Then, each motor driven commanded torque value is converted into respective clutch force values as a function of clutch position, thereby relating each clutch torque to a clutch position based on conversion tables stored in a controller that are associated with physical factors that influence clutch torque for each of the respective clutch actuator positions.

Abstract: A hierarchical control system for a tandem axle assembly for a vehicle is provided. The hierarchical control system includes a vehicle level controller, an actuator, a shift controller, and a sensor. The shift controller is capable of placing the tandem axle assembly in at least a first operating condition and a second operating condition using the actuator. In response to the sensor and an operating condition of at least one of the power source and the transmission of the vehicle, the shift controller adjusts a manner of placing the tandem axle assembly in at least one of the first operating condition and the second operating condition. The hierarchical control system facilitates performing a shifting procedure in an automatic manner or as desired by an operator of the vehicle without excessively increasing a cost and a complexity of the tandem axle assembly.

Abstract: A tandem axle system has a forward axle system and a rear axle system. A method of selectively driving one or both of the axle systems is described.

Abstract: A hierarchical control system for a tandem axle assembly for a vehicle is provided. The hierarchical control system includes a vehicle level controller, an actuator, a shift controller, and a sensor. The shift controller is capable of placing the tandem axle assembly in at least a first operating condition and a second operating condition using the actuator. In response to the sensor and an operating condition of at least one of the power source and the transmission of the vehicle, the shift controller adjusts a manner of placing the tandem axle assembly in at least one of the first operating condition and the second operating condition. The hierarchical control system facilitates performing a shifting procedure in an automatic manner or as desired by an operator of the vehicle without excessively increasing a cost and a complexity of the tandem axle assembly.

Abstract: A tandem axle system has a forward axle system and a rear axle system. A method of selectively driving one or both of the axle systems is described.

Abstract: A method of operating a parallel hybrid electric drive train may include manually selecting a first mode by a user. The first mode include an electric mode that provides for propelling a vehicle using only an electric motor. The method may also include propelling the vehicle in the electric mode, limiting an allowed vehicle acceleration below a predetermined acceleration value, detecting a battery state of charge, and preventing an engine start during operation in the electric mode.

Abstract: A method of shifting a power distribution unit for a vehicle from a first operating state to a second operating state is provided. The method includes the step of adjusting a rotational speed of a portion of a second axle assembly using a clutching device to impart energy to a lubricant within the second axle assembly. A controller in communication with a power source of the vehicle adjusts an operating condition of the power source to facilitate moving the clutching device. The power distribution unit includes an inter-axle differential capable being placed in a locked condition by the clutching device and of accommodating a rotational difference between a first output gear and a second output gear with the inter-axle differential.

Abstract: A method of shifting a power distribution unit for a vehicle from a first operating state to a second operating state is provided. The method includes the step of adjusting a rotational speed of a portion of a second axle assembly using a clutching device to impart energy to a lubricant within the second axle assembly. A controller in communication with a power source of the vehicle adjusts an operating condition of the power source to facilitate moving the clutching device. The power distribution unit includes an inter-axle differential capable being placed in a locked condition by the clutching device and of accommodating a rotational difference between a first output gear and a second output gear with the inter-axle differential.

Abstract: A method of operating a parallel hybrid electric drive train may include manually selecting a first mode by a user. The first mode include an electric mode that provides for propelling a vehicle using only an electric motor. The method may also include propelling the vehicle in the electric mode, limiting an allowed vehicle acceleration below a predetermined acceleration value, detecting a battery state of charge, and preventing an engine start during operation in the electric mode.

Abstract: A hybrid powertrain system includes a first prime mover having an output, a second prime mover having an output, a synchronizing clutch selectively coupling the first prime mover output and the second prime mover output, a multi-ratio transmission having an input, and a planetary gear set selectively coupling the second prime mover output to the first prime mover output or the multi-ratio transmission input based on a coupling state of the synchronizing clutch.

Abstract: A power train control system for a mobile machine is disclosed. The power train control system has a power source configured to produce a power output, a transmission device operatively connected to receive the power output and propel the mobile machine, and a control module. The control module is configured to receive an indication of a power demand, receive an indication of a current travel speed of the mobile machine, and reference the power demand and the current travel speed with a power train efficiency map to determine a desired power source speed. The power train control system is also configured to control operation of the transmission device to bring a speed of the power source within a predetermined amount of the desired power source speed.

Abstract: A powertrain system is provided that includes a prime mover and a change-gear transmission having an input, at least two gear ratios, and an output. The powertrain system also includes a power shunt configured to route power applied to the transmission by one of the input and the output to the other one of the input and the output. A transmission system and a method for facilitating shifting of a transmission system are also provided.

Abstract: A pin-type, double acting synchronizer (18) with friction clutches (22,36 and 24,38), jaw clutches (26,30 and 28,31), a shift flange (32), self-energizing ramps (21a-21d) affixed to a shaft (12), and self-energizing ramps (45a-45d) affixed to a self-energizer member (34). Engagement of the ramps provides an additive axial force (F.sub.a) for increasing the engagement force of the friction clutches. The member (34) is secured for sliding movement with the flange and jaw members (30,31). The member (34) is resiliently connected for rotation with the flange by force limiting detent assemblies (50) until synchronizing torque reaches a predetermined amount. When the predetermined torque is reached, the force limiting assemblies allow the flange to rotate and engage stops (32h) for directing all torque in excess of the predetermined amount to the shaft in parallel with the self-energizing ramps.

Abstract: A pin-type, double-acting synchronizer mechanism (22) includes friction clutches (24,36 and 26,38), jaw clutches (28,14b,16b), self-energizing ramps, (13f,13g,13h,13i and 29e,29f,29g,29h), and springs (33) to limit the maximum self-energizing or additive force provided by the ramps. The ramps act between a shaft (12) and jaw clutch (28). A shift flange (32) is rotatably fixed to the jaw clutch (28) by splines which allow relative axial movement against the force of the springs (33). The jaw clutch (28) and the shaft (12) include mating splines (29,13) divided into spline portions (29a,29b,29c,29d and 13a,13b,13c,13d,13e) to define the ramps to control limited relative rotation between the jaw clutch (28) and shaft (12), and to provide surface area and structural strength for transmitting full torque to the shaft and gears.

Abstract: A system and method for decreasing the time required to complete a ratio change in an electronically enhanced powertrain system is provided. The powertrain system includes a number of devices for providing a retarding torque to engine rotation to increase the decay rate of the engine speed during an upshift. These devices include an engine brake and an input shaft brake. A retarding torque is also provided by increasing engine accessory load by controlling various engine accessories such as a cooling fan, an air compressor, a hydraulic pump, an air conditioning compressor, and an alternator.