A drive sheave assembly of a continuously variable transmission is provided that includes a post, a fixed sheave, a movable sheave assembly, a sleeve and an engine braking assembly. The engine braking assembly includes an axial activation member, a one-way engagement member and a flange. The axial activation member is statically mounted within a central recess of the fixed sheave. The axial activation member is movably connected with the one-way engagement member. A central passage of the one-way engagement member is configured to engage a portion of the sleeve. The flange is coupled to the one-way engagement member to selectively engage a side of an endlessly looped member with axial movement of the one-way engagement member during an engine braking condition.

A drive sheave assembly of a continuously variable transmission is provided. A fixed sheave of the assembly includes a central recess. A plurality of sheave ramps are located within the central recess. A one-way engagement collar is configured to rotate freely on an end portion of a sleeve when the sleeve rotates in a first direction and lock onto rotation of the sleeve when the sleeve rotates in a second direction. The one-way engagement collar further has a plurality of ramp pockets. A ramp member is received within each ramp pocket of the plurality of ramp pockets in the one-way engagement collar. Each ramp member is configured to engage an associated sheave ramp of the plurality of sheave ramps in the central recess of the fixed sheave and move the one-way engagement collar axially to engage a side of a belt when the sleeve rotates in the second direction.

Methods and systems are provided for operating a continuously variable transmission (CVT) of a driveline of a vehicle during a request for engine compression braking. In one example, a method may include, responsive to an engine compression braking request, operating a CVT via a controller to adjust engine speed according to an engine speed-to-vehicle speed profile selected based on a power-based target engine speed for the engine compression braking request. The power-based target engine speed may vary continuously with driver demanded power and a battery charge power limit of the vehicle.

Methods and systems are provided for operating a continuously variable transmission (CVT) of a driveline of a vehicle during a request for engine compression braking. In one example, a method may include, responsive to an engine compression braking request, operating a CVT via a controller to adjust engine speed according to an engine speed-to-vehicle speed profile selected based on a power-based target engine speed for the engine compression braking request. The power-based target engine speed may vary continuously with driver demanded power and a battery charge power limit of the vehicle.

A transmission control method has a normal stepless manner transmission mode and a pseudo-stepped downshift mode for controlling a continuously variable transmission connected to an input side of an engine. A downshift target rotational speed and a lower-limit target rotational speed used for the pseudo-stepped downshift are set to values in an engine rotational speed region in which an engine output becomes greater than or equal to a prescribed value. When a mode transition condition is satisfied during deceleration by selecting the normal transmission mode, the mode is shifted to the pseudo-stepped downshift mode to start the pseudo-stepped downshift. When the pseudo-stepped downshift is initiated, an increase to the downshift target rotational speed and a decrease to the lower-limit target rotational speed of the primary rotational speed are repeated, until the mode cancellation condition, including the re-acceleration request, is satisfied.

A drive sheave assembly of a continuously variable transmission is provided. A fixed sheave of the assembly includes a central recess. A plurality of sheave ramps are located within the central recess. A one-way engagement collar is configured to rotate freely on an end portion of a sleeve when the sleeve rotates in a first direction and lock onto rotation of the sleeve when the sleeve rotates in a second direction. The one-way engagement collar further has a plurality of ramp pockets. A ramp member is received within each ramp pocket of the plurality of ramp pockets in the one-way engagement collar. Each ramp member is configured to engage an associated sheave ramp of the plurality of sheave ramps in the central recess of the fixed sheave and move the one-way engagement collar axially to engage a side of a belt when the sleeve rotates in the second direction.

A drive sheave assembly of a continuously variable transmission is provided that includes a post, a fixed sheave, a movable sheave assembly, a sleeve and an engine braking assembly. The engine braking assembly includes an axial activation member, a one-way engagement member and a flange. The axial activation member is statically mounted within a central recess of the fixed sheave. The axial activation member is movably connected with the one-way engagement member. A central passage of the one-way engagement member is configured to engage a portion of the sleeve. The flange is coupled to the one-way engagement member to selectively engage a side of an endlessly looped member with axial movement of the one-way engagement member during an engine braking condition.

A speed change ECU for a CVT sets a target input rotational speed (Nin*) such that the speed ratio of the CVT is varied stepwise a plurality of times consecutively to the downshift side in response to an operation to depress a brake pedal by a driver, and sets the target input rotational speed (Nin*) such that the time interval between consecutive downshifts becomes longer as the number of times of execution of downshifts is increased on the basis of intershifting times (tint(1)), (tint(2)), . . . while downshifts in which the speed ratio is varied stepwise are executed consecutively.

A system, method, and apparatus for controlling acceleration of a machine when the machine exits a grade. The system, method, and apparatus may determine a virtual gear having a maximum speed limit equivalent that matches the speed of the machine as the machine exits the grade. The system, method, and apparatus may also deactivate an automatic retarding control (ARC) strategy, which may be activated when the machine is on the grade to reduce and limit the speed of the machine to no more than a set speed, if the ARC strategy is active as the machine exits the grade. The system, method, and apparatus may also control automatic downshift of a transmission system to the virtual gear if the ARC mode was activing during the exit from the graded surface and is now deactive.

A transmission control method has a normal stepless manner transmission mode and a pseudo-stepped downshift mode for controlling a continuously variable transmission connected to an input side of an engine. A downshift target rotational speed and a lower-limit target rotational speed used for the pseudo-stepped downshift are set to values in an engine rotational speed region in which an engine output becomes greater than or equal to a prescribed value. When a mode transition condition is satisfied during deceleration by selecting the normal transmission mode, the mode is shifted to the pseudo-stepped downshift mode to start the pseudo-stepped downshift. When the pseudo-stepped downshift is initiated, an increase to the downshift target rotational speed and a decrease to the lower-limit target rotational speed of the primary rotational speed are repeated, until the mode cancellation condition, including the re-acceleration request, is satisfied.