An oil feed structure includes: a hydraulic clutch; a power transmitting shaft coupled to the hydraulic clutch; a valve element inserted into the power transmitting shaft, and a spring configured to bias the valve element. The valve element includes: a pressure receiving surface facing in an axial direction of the power transmitting shaft and configured to receive hydraulic pressure of a hydraulic pressure oil passage; and a port communicable with a clutch lubrication hole of the power transmitting shaft. The spring biases the valve element toward the hydraulic pressure oil passage against the hydraulic pressure received by the pressure receiving surface. When clutch operating hydraulic pressure changes, the valve element moves in the axial direction to change an opening degree of communication between the port and the clutch lubrication hole.

A lubrication system (400) for a transfer case (200) includes a pump (228) selectively supplying a working fluid to a fluid reservoir of an actuator (226) configured to apply force to a clutch assembly (214) to cause the clutch assembly (214) to move between a disengaged position and an engaged position. The lubrication system also includes a relief valve (302) having a relief valve inlet fluidly coupled to the fluid reservoir of the actuator (226) which opens to receive the working fluid based on a threshold pressure level of the working fluid in the fluid reservoir. The lubrication system also includes a trough (306) fluidly coupled to a relief valve outlet of the relief valve (302). The trough (306) carries the working fluid from the relief valve outlet to a bearing assembly (227) associated with at least one of an input shaft (204) and a primary output shaft (206) of the transfer case (200) when the clutch assembly (214) is in the disengaged position.

A power transmission device includes a friction clutch, an actuator, and a controller configured to determine an approximated temperature change of the friction clutch. The controller is configured to determine a current power state of the friction clutch, determine a desired power state change based on the current power state and a previous power state, determine a plurality of thermal coefficients based on a thermal coefficient model, the desired power state change, and a set of operation variables, determine an approximated temperature change of the friction clutch based on the thermal coefficients and a friction clutch temperature model, determine an approximated clutch temperature based on the approximated temperature change and a contemporaneous value of an device ambient temperature, and control operation of the actuator based at least on the approximated clutch temperature.

A hybrid module for a drive train of a motor vehicle includes a housing, an electric machine disposed within the housing. The electric machine having a stator and a rotor arranged radially within the stator. The hybrid module having at least one hydraulically cooled friction clutch arranged radially within the rotor. A cooling device is provided that is configured to cool a plurality of friction surfaces of the at least one friction clutch and which has an annular collecting region coupled to the rotor for conjoint rotation therewith and entraining a hydraulic medium during operation, as well as a scoop section, which is secured to the housing and projects into the collecting region and via which the hydraulic medium is fed to a retaining chamber during operation.

A friction engagement device of an automatic transmission is provided with a cylindrical drum part supporting an annular friction plate. The drum part includes a cylindrical body with a spline part having serrations extending in the axial direction and depressed radially outward to fit with the friction plate, in an inner circumferential side surface, a vertical wall part provided at an end side of the cylindrical body and extending radially inward, and a corner part provided between the cylindrical body and the vertical wall part. A drum recess is formed inside the corner part, connected to the serration and depressed toward an axial end side. A cut part is provided outside the corner part, connected to the drum recess, and cut in the circumferential direction of the drum part. The drum recess is opened to an outside by the cut part to form an oil gallery.

A wet-type friction engaging device includes a first friction member and a second friction member defining a groove formed on a surface of a base facing the first friction member.

Methods and systems for a transmission are provided herein. In one example, a hydraulic system includes a lubrication valve included in a lubricant line and designed to adjust a flow of lubricant to a multi-disc wet clutch. The hydraulic system further includes a clutch line coupled to a clutch control valve, where the clutch line is in fluidic communication with a hydraulic fluid to a clutch actuator of the multi-disc wet clutch and a passive adjustment device of the lubrication valve and where the passive adjustment device transitions the lubrication valve between a limited flow state and an open flow state based on a pressure of the hydraulic fluid in the clutch line.

Dual clutch transmission system, vehicle and method of cooling. A dual clutch transmission system, including coaxial first and second engageable and disengageable torque transmitting assemblies, configured to be installed in a power train of a vehicle, the system including a main flow path for supply of cooling fluid, wherein the main flow path branches into a first flow path for supply of cooling fluid to the first torque transmitting assembly, and a second flow path for supply of cooling fluid to the second torque transmitting assembly, wherein the system includes a third flow path for supplying cooling fluid, which is discharged from the second torque transmitting assembly, to the first torque transmitting assembly, the third flow path preferably being arranged within a space defined by a housing of the dual clutch transmission system.

Methods and systems for a transmission are provided herein. In one example, a hydraulic system includes a lubrication valve included in a lubricant line and designed to adjust a flow of lubricant to a multi-disc wet clutch. The hydraulic system further includes a clutch line coupled to a clutch control valve, where the clutch line is in fluidic communication with a hydraulic fluid to a clutch actuator of the multi-disc wet clutch and a passive adjustment device of the lubrication valve and where the passive adjustment device transitions the lubrication valve between a limited flow state and an open flow state based on a pressure of the hydraulic fluid in the clutch line.

An intelligent clutch lubrication system includes a first dynamically-lubricated clutch pack, a supply pump, a first lubricant control (LC) valve, and a lubricant flow circuit having a clutch lubrication loop in which the first clutch pack is positioned. When active, the supply pump urges lubricant flow about the lubricant flow circuit and through the clutch lubrication loop. The first LC valve is positioned in the clutch lubrication loop at a location upstream of the first clutch pack, while a controller architecture is operably coupled to the first LC valve. the controller architecture is configured to control the first LC valve to temporarily boost lubricant flow to the first DL clutch pack when moving into an engaged position during operation of the intelligent clutch lubrication system.