摘要:
Provided are gearboxes including compound planet gear assemblies as well as methods of using such gearboxes. A gearbox includes at least a first ring gear and a second ring gear. Depending on the current gear selection, one of these ring gears may be engaged with a shifting mechanism or not engaged with any ring gears when in a neutral gear. The first ring gear may be constantly engaged with a first planet gear of a compound planet gear assembly, while the second ring gear may be constantly engaged with a second planet gear of the same compound planet gear assembly. The first planet gear may be also engaged with a sun gear coupled to a shaft. Another shaft is coupled to the shifting mechanism. Different gear selections of the gearbox engage different ring gears to the shifting mechanism thereby changing the rotational speed ratio of the two shafts.
摘要:
Provided are gearboxes including compound planet gear assemblies as well as methods of using such gearboxes. A gearbox includes at least a first ring gear and a second ring gear. Depending on the current gear selection, one of these ring gears may be engaged with a shifting mechanism or not engaged with any ring gears when in a neutral gear. The first ring gear may be constantly engaged with a first planet gear of a compound planet gear assembly, while the second ring gear may be constantly engaged with a second planet gear of the same compound planet gear assembly. The first planet gear may be also engaged with a sun gear coupled to a shaft. Another shaft is coupled to the shifting mechanism. Different gear selections of the gearbox engage different ring gears to the shifting mechanism thereby changing the rotational speed ratio of the two shafts.
摘要:
A method of commanding a synchronous gear shift begins by receiving a request to shift from a third gear to a first gear, and skipping a second gear having a gear ratio between the gear ratio of the first gear and the gear ratio of the third gear. Subsequently the method includes: reducing a torque command to a predetermined value; opening a clutch disposed on the input shaft of the transmission to decouple the transmission from the engine; transitioning the engine from a torque-control mode into a speed-control mode; commanding the engine to rotate at a speed dictated by the motion of the vehicle and the gear ratio of the first gear; closing the clutch to couple the transmission and the engine; and transitioning the engine back into the torque-control mode.
摘要:
Switching conditions are defined by a threshold α1 for switching from “power OFF control” to “power ON control”, and a threshold α2 for switching from the “power ON control” to the “power OFF control”. During a period of a shift operation, the thresholds are changed toward thresholds β1 and β2 smaller than α1 and α2 depending on a shift progress degree PRG, respectively.
摘要:
A powertrain includes an electromechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member. A method for controlling the powertrain includes commanding a shift from a first operating range state to a second operating range state, identifying an off-going clutch, controlling torque output from said electric machine to offload reactive torque transmitted through said off-going clutch, selectively applying an oncoming clutch to offload reactive torque transmitted through said off-going clutch, and reducing a clutch torque capacity of said off-going clutch when said reactive torque transmitted through said off-going clutch is substantially zero.
摘要:
A control system for a transmission of a vehicle comprises an actuation module and an upshift control module. The transmission has a first gear that corresponds to a first transmission ratio and a second gear that corresponds to a second transmission ratio that is less than the first transmission ratio. The actuation module controls an amount torque transferred to the second gear using a friction device. The upshift control module selectively increases the amount of torque transferred to the second gear based on a comparison of the first transmission ratio and a measured transmission ratio at a predetermined period of time after an upshift to the second gear is commanded, wherein the measured transmission ratio is determined based on an input speed of the transmission divided by an output speed of the transmission.
摘要:
Riding comfort of a vehicle is improved by reducing deceleration and acceleration exceeding the expectation of a rider due to gear changes. A gear change control device calculates current torque being transmitted from a drive-side member of a clutch to a driven-side member of the clutch, and calculates post-completion torque estimated to be transmitted from the drive-side member to the driven-side member after the completion of engagement of the clutch. The gear change control device then controls the degree of engagement of the clutch according to the difference between the current torque and the post-completion torque, and receives a next gear change command according to the difference between the current torque and the post-completion torque.
摘要:
A control system for a drive unit of a vehicle, including a reaction force establishing device controlling a speed change ratio of a continuously variable transmission, and a clutch mechanism arranged on a power transmission route from the continuously variable transmission to a wheel and in which a torque capacity thereof is controllable. A first input torque control mechanism lowers a torque to be inputted to the clutch mechanism through the continuously variable transmission, by controlling a torque of the reaction force establishing device while the torque capacity of the clutch mechanism is being controlled. The system reduces a change in a torque inputted to a clutch mechanism, in case of carrying out a speed change operation of a continuously variable transmission and engaging the clutch mechanism.
摘要:
An automatic transmissions control system varies times to start a shift to securing a good response in engagement pressure for an engagement-side frictional element as well as suppressing occurrence of hydraulic pressure vibrations at low temperatures. The control system has an engagement pressure at-low-temperature regulation section that selectively controls at least one of the first and second engagement-pressure regulator valves, when the oil temperature is detected to be lower than a predetermined oil temperature and the shift condition is determined to exist requiring a shift operation such that the first engagement-pressure regulator valve provides a maximum hydraulic pressure to engage the first frictional element to start a shift with the maximum hydraulic pressure being continuously provided until the shift ends, and/or the second engagement-pressure regulator valve provides a minimum hydraulic pressure to obtain complete disengagement of the second frictional element to start a downshift as the shift operation.
摘要:
A hydraulic pressure of each corresponding one of a plurality of friction elements of a gear shift mechanism of the automatic transmission is controlled to downshift the gear shift mechanism from a current gear stage to a next gear stage, at which an engine brake is operated, upon receiving a driver's demand for deceleration. An engine output of the engine is increased by increasing a throttle opening degree of the engine in at least two steps in an absence of a driver's operation on an accelerator of the vehicle at the time of the downshifting of the gear shift mechanism from the current gear stage to the next gear stage.