A control device controls a driving force transmission device that presses a main clutch using an actuator that generates a pressing force according to a supply current. The control device includes a current command value setting unit that sets a current command value based on I-T characteristic information indicating the relationship between a current supplied to the actuator and a driving force transmitted, a correction duration setting unit that sets a correction duration based on a responsiveness related value related to the responsiveness of the main clutch when an increase in the driving force to be transmitted by the main clutch becomes greater than or equal to a threshold, a correction unit that increases and corrects the current command value for the set correction duration, and the current control unit that performs current feedback control such that a current corresponding to the current command value is supplied to the actuator.

A control device controls a driving force transmission device that presses a main clutch using an actuator that generates a pressing force according to a supply current. The control device includes a current command value setting unit that sets a current command value based on I-T characteristic information indicating the relationship between a current supplied to the actuator and a driving force transmitted, a correction duration setting unit that sets a correction duration based on a responsiveness related value related to the responsiveness of the main clutch when an increase in the driving force to be transmitted by the main clutch becomes greater than or equal to a threshold, a correction unit that increases and corrects the current command value for the set correction duration, and the current control unit that performs current feedback control such that a current corresponding to the current command value is supplied to the actuator.

A brake assembly is suitable for use with a vehicle wheel that has a rim rotatably mounted to an axle. The brake assembly includes a housing fixedly positioned relative to the axle and a plurality of disks disposed within the housing and fixedly positioned relative to the rim. A fluid is disposed within the housing and has a selectively variable viscosity. The viscosity of the fluid is selectively increased to increase a braking force applied to the wheel.

A brake assembly is suitable for use with a vehicle wheel that has a rim rotatably mounted to an axle. The brake assembly includes a housing fixedly positioned relative to the axle and a plurality of disks disposed within the housing and fixedly positioned relative to the rim. A fluid is disposed within the housing and has a selectively variable viscosity. The viscosity of the fluid is selectively increased to increase a braking force applied to the wheel.

A ball and ramp assembly including a first plate, a second plate and one or more rolling elements between the first and second plates. The first plate includes a shoulder portion that extends from a first side of the first plate. Additionally, the first plate includes an increased diameter portion that extends from an outer surface of the first plate. Extending inward from a second side of the first plate is a receiving portion with a substantially vertical wall portion having one or more non-circular first plate grooves. The second plate has one or more non-circular second plate grooves that extend along a first side of the second plate. The second plate grooves are a reverse mirror image of the first plate grooves. Radially outboard from the shoulder portion is a thrust bearing and integrally connected to the outer surface of the first plate is a first plate gear portion.

A ball and ramp assembly including a first plate, a second plate and one or more rolling elements between the first and second plates. The first plate includes a shoulder portion that extends from a first side of the first plate. Additionally, the first plate includes an increased diameter portion that extends from an outer surface of the first plate. Extending inward from a second side of the first plate is a receiving portion with a substantially vertical wall portion having one or more non-circular first plate grooves. The second plate has one or more non-circular second plate grooves that extend along a first side of the second plate. The second plate grooves are a reverse mirror image of the first plate grooves. Radially outboard from the shoulder portion is a thrust bearing and integrally connected to the outer surface of the first plate is a first plate gear portion.

A clutch system includes a friction clutch and a ramp system. The friction clutch is a multiplate clutch, for example, for transmitting a torque between a torque-introducing element (i.e., an engine drive shaft) and a torque-discharging element (i.e., a transmission input shaft). The ramp system includes an input ramp, an output ramp, a pilot clutch, an actuation element, and a freewheel. The output ramp is rotatable relative to the input ramp to change an axial extent of the ramp system. The pilot clutch is for initiating rotation of the input ramp relative to the output ramp when there is a differential speed between the torque-introducing element and the torque-discharging element. The actuation element is for actuating the pilot clutch. The freewheel is arranged in a torque path in parallel with the friction clutch, and arranged to transmit a torque flow from the torque-introducing element to the torque-discharging element and interrupt a torque flow from the torque-discharging element to the torque-introducing element.

A clutch system includes a friction clutch and a ramp system. The friction clutch is a multiplate clutch, for example, for transmitting a torque between a torque-introducing element (i.e., an engine drive shaft) and a torque-discharging element (i.e., a transmission input shaft). The ramp system includes an input ramp, an output ramp, a pilot clutch, an actuation element, and a freewheel. The output ramp is rotatable relative to the input ramp to change an axial extent of the ramp system. The pilot clutch is for initiating rotation of the input ramp relative to the output ramp when there is a differential speed between the torque-introducing element and the torque-discharging element. The actuation element is for actuating the pilot clutch. The freewheel is arranged in a torque path in parallel with the friction clutch, and arranged to transmit a torque flow from the torque-introducing element to the torque-discharging element and interrupt a torque flow from the torque-discharging element to the torque-introducing element.

Provided herein is a method for calibrating a clutch by searching for the minimum of a multi-dimensional surface including determining the error between a spline function and recorded data relating to clutch characteristics, creating a multi-dimensional surface corresponding to the error values, determining the minimum of the multi-dimensional surface using the steps of performing a Steepest Gradient & Direction determination step and conducting a Golden Section Search and Switch Direction Step to find a minimum that meets a predetermined closing condition. Additionally, provided herein is a computer-implemented system for calibrating the clutch.

A power transmitting component that includes a clutch, a valve and a ball ramp mechanism. The clutch has a hub, a housing, a clutch pack and an apply plate. The clutch pack has sets of friction plates that are mounted to the hub and the housing. The valve includes a valve element, which is received in a bore in the hub, an inlet and an outlet. The ball ramp mechanism has first and second ball ramp rings and is operable for selectively translating the apply plate to compress the friction plates against the housing as well as for translating the valve element to open the valve. The second ball ramp ring is coupled to the hub for rotation therewith. The first ball ramp ring is rotatable relative to the second ball ramp ring.