Abstract: The present disclosure relates to a method and an apparatus for controlling a lubricant flow rate in a wet clutch. The method comprising: determining a clutch state as an open state, a closed state or a slipping state; determining a clutch temperature and a sump lubricant temperature; based at least on the clutch state, the clutch temperature and the sump lubricant temperature, selecting one out of a plurality of maps, wherein each map maps one or more operating parameters of the clutch on a target lubricant flow rate; determining a target lubricant flow rate based on the one or more operating parameters according to the selected map; and controlling a lubricant flow control device based on the determined target lubricant flow rate.

Abstract: A torque convertor and direct drive unit arrangement and operating methods are provided herein. In one example, a prime mover may be configured to be coupled to a transmission via one of a torque convertor and a direct drive unit, the direct drive unit including a higher range clutch and a lower range clutch.

Abstract: Methods and systems are provided for wet clutch pressure control to reduce drag and degradation of rotary seals in a transmission. In one example, a method may include determining an upper threshold pressure based on a rotational speed of a shaft of the transmission, determining a lower threshold pressure based on the rotational speed of the shaft, and adjusting a pressure of hydraulic fluid applied to the clutch to be between the upper threshold pressure and the lower threshold pressure. In this way, the pressure of the hydraulic fluid applied to the clutch may be maintained at a level that allows full torque transfer by the wet clutch while reducing drag on the rotary seals.

Abstract: A transmission, such as a transmission for a vehicle, a driveline including the transmission, and a method of performing a gear shift using the transmission. The transmission comprises a first transmission shaft, a first gear disposed on the first transmission shaft, a first wet clutch, and a first synchronizer. The first wet clutch and the first synchronizer are configured to selectively drivingly engage the first gear with the first transmission shaft and are connectable in series between the first gear and the first transmission shaft, such that the first gear is drivingly engaged with the first transmission shaft only when both the first wet clutch and the first synchronizer are engaged, and such that the first gear is drivingly disengaged from the first transmission shaft when either one or both of the first wet clutch and the first synchronizer is/are disengaged.

Abstract: A clutch assembly may have an axially slidable first plate, an axially fixed second plate disposed opposite the first plate, and a clutch pack arranged between the first plate and the second plate. The clutch pack may have a number of axially slidable consecutively arranged friction plates and separator plates. The assembly may also have an actuator axially movable between a first position and a second position, where, in the first position, the clutch pack is opened and, in the second position, the clutch pack is closed and the friction plates are frictionally engaged. The assembly may also have a return spring configured to bias the actuator in a direction away from the clutch pack towards the first position. The assembly may also have an engagement spring element configured to exert an elastic force on the clutch pack.

Abstract: A torque convertor and direct drive unit arrangement and operating methods are provided herein. In one example, a prime mover may be configured to be coupled to a transmission via one of a torque convertor and a direct drive unit, the direct drive unit including a higher range clutch and a lower range clutch.

Abstract: A torque convertor and direct drive unit arrangement and operating methods are provided herein. In one example, a prime mover may be configured to be coupled to a transmission via one of a torque convertor and a direct drive unit, the direct drive unit including a higher range clutch and a lower range clutch.

Abstract: Torque converter arrangements and operating methods are provided herein. In one example, the torque converter includes a first attachment interface designed to rotationally couple to a prime mover and a second attachment interface designed to rotationally couple to a transmission. The torque converter further includes a lock-up clutch with an engagement spring embedded in an actuation piston, a plurality of separator plates supported by one or more guiding pins that extend through the plurality of separator plates and into a casing, and a plurality of friction plates interleaved with the plurality of separator plates, where the plurality of separator plates and friction plates are axially captured between the actuation piston and an end plate.

Abstract: Torque converter arrangements and operating methods are provided herein. In one example, the torque converter includes a first attachment interface designed to rotationally couple to a prime mover and a second attachment interface designed to rotationally couple to a transmission. The torque converter further includes a lock-up clutch with an engagement spring embedded in an actuation piston, a plurality of separator plates supported by one or more guiding pins that extend through the plurality of separator plates and into a casing, and a plurality of friction plates interleaved with the plurality of separator plates, where the plurality of separator plates and friction plates are axially captured between the actuation piston and an end plate.

Abstract: The present disclosure relates to a method and an apparatus for controlling a lubricant flow rate in a wet clutch. The method comprising: determining a clutch state as an open state, a closed state or a slipping state; determining a clutch temperature and a sump lubricant temperature; based at least on the clutch state, the clutch temperature and the sump lubricant temperature, selecting one out of a plurality of maps, wherein each map maps one or more operating parameters of the clutch on a target lubricant flow rate; determining a target lubricant flow rate based on the one or more operating parameters according to the selected map; and controlling a lubricant flow control device based on the determined target lubricant flow rate.

Abstract: A clutch assembly may have an axially slidable first plate, an axially fixed second plate disposed opposite the first plate, and a clutch pack arranged between the first plate and the second plate. The clutch pack may have a number of axially slidable consecutively arranged friction plates and separator plates. The assembly may also have an actuator axially movable between a first position and a second position, where, in the first position, the clutch pack is opened and, in the second position, the clutch pack is closed and the friction plates are frictionally engaged. The assembly may also have a return spring configured to bias the actuator in a direction away from the clutch pack towards the first position. The assembly may also have an engagement spring element configured to exert an elastic force on the clutch pack.

Abstract: Methods and systems are provided for wet clutch pressure control to reduce drag and degradation of rotary seals in a transmission. In one example, a method may include determining an upper threshold pressure based on a rotational speed of a shaft of the transmission, determining a lower threshold pressure based on the rotational speed of the shaft, and adjusting a pressure of hydraulic fluid applied to the clutch to be between the upper threshold pressure and the lower threshold pressure. In this way, the pressure of the hydraulic fluid applied to the clutch may be maintained at a level that allows full torque transfer by the wet clutch while reducing drag on the rotary seals.

Abstract: A transmission, such as a transmission for a vehicle, a driveline including the transmission, and a method of performing a gear shift using the transmission. The transmission comprises a first transmission shaft, a first gear disposed on the first transmission shaft, a first wet clutch, and a first synchronizer. The first wet clutch and the first synchronizer are configured to selectively drivingly engage the first gear with the first transmission shaft and are connectable in series between the first gear and the first transmission shaft, such that the first gear is drivingly engaged with the first transmission shaft only when both the first wet clutch and the first synchronizer are engaged, and such that the first gear is drivingly disengaged from the first transmission shaft when either one or both of the first wet clutch and the first synchronizer is/are disengaged.