A vehicle drive device that includes a rotary electric machine that serves as a driving force source for wheels; a first rotation member coupled to a rotor of the rotary electric machine; and a fluid coupling that is disposed on an axial first side, which is one side in an axial direction with respect to the rotary electric machine, and that has a rotation housing.

A hydrodynamic torque converter (1) with a lock-up clutch (6) in a clutch space, (9) and with a piston (7) for activating of the lock-up clutch (6). The piston (7) separates the clutch space (9) from a piston chamber (10). The piston (7), via the application of pressure, can be moved, from a starting position in which the lock-up clutch (6) is disengaged, in the engaging direction of the lock-up clutch (6). The piston (7) has at least a closable opening (11) through which hydraulic fluid can flow from the piston chamber (10) into the clutch space (9). The opening (11) is open if either the piston (7) is away from the starting position and/or if a fluid pressure in the piston chamber (10), compared to the clutch space (9), is elevated. The closing element (12, 13) is tongue-shaped element which serves closing and opening of the opening (11).

A torque converter includes a front cover, an impeller, a turbine, and a stator. The impeller forms a fluid chamber together with the front cover. The stator is disposed between an inner peripheral part of the impeller and an inner peripheral part of the turbine. The stator regulates a flow of a fluid flowing from the turbine to the impeller. A flattening ratio is 0.5 or less. The flattening ratio is herein defined as a first ratio of an axial dimension to a radial dimension of a torus formed by the impeller, the turbine, and the stator. A flow area ratio is 0.14 or greater and 0.16 or less. The flow area ratio is herein defined as a second ratio of a minimum flow area of the impeller and the turbine to an area of an imaginary circle having the outer diameter of the torus as the diameter thereof.

A torque converter for a hybrid module may include a hydraulic coupling arrangement, a front cover, an impeller shell, and an electric rotor. The hydraulic coupling arrangement may include an impeller and a turbine. The front cover may have a first rim extending in a first axial direction. The front cover may at least partially encase the hydraulic coupling arrangement. The impeller shell may be fixed to the front cover and may at least partially encase the hydraulic coupling arrangement. The impeller shell may have a second rim extending in a second axial direction, opposite the first axial direction, a circumferential ring at a distal end of the second rim, and at least one impeller blade. The electric rotor may be fixed to the impeller shell second rim and axially retained by the circumferential ring.

A torque converter for a hybrid module may include a hydraulic coupling arrangement, a front cover, an impeller shell, and an electric rotor. The hydraulic coupling arrangement may include an impeller and a turbine. The front cover may have a first rim extending in a first axial direction. The front cover may at least partially encase the hydraulic coupling arrangement. The impeller shell may be fixed to the front cover and may at least partially encase the hydraulic coupling arrangement. The impeller shell may have a second rim extending in a second axial direction, opposite the first axial direction, a circumferential ring at a distal end of the second rim, and at least one impeller blade. The electric rotor may be fixed to the impeller shell second rim and axially retained by the circumferential ring.

A transmission includes: a torque converter; a transmission input shaft; a seal member sandwiched between the hollow shaft and the transmission input shaft; and a bush, the transmission input shaft including a large diameter portion abutted on the seal member, and a small diameter portion which is positioned on the tip end side of the large diameter portion, and which has a diameter smaller than a diameter of the large diameter portion, the seal member having a diameter larger than a diameter of the bush, and the small diameter portion having an axial length set to be longer than a length from an insertion inlet of the transmission input shaft of the bush to the seal member.

A transmission includes: a torque converter; a transmission input shaft; a seal member sandwiched between the hollow shaft and the transmission input shaft; and a bush, the transmission input shaft including a large diameter portion abutted on the seal member, and a small diameter portion which is positioned on the tip end side of the large diameter portion, and which has a diameter smaller than a diameter of the large diameter portion, the seal member having a diameter larger than a diameter of the bush, and the small diameter portion having an axial length set to be longer than a length from an insertion inlet of the transmission input shaft of the bush to the seal member.

A turbine assembly includes a turbine shell, turbine hub, and a thrust washer. The turbine hub is coupled to the turbine shell via a fastener. The thrust washer is disposed on the turbine hub and includes at least one tab configured to contact the fastener. The fastener axially and radially retains the thrust washer on the turbine hub.

A hydrodynamic clutch having an input side and an output side, the rotational motions of which are coupled to one another with a hydraulic fluid. A method for determining the degree of filling of the hydrodynamic clutch with fluid including steps of periodically sensing a fluid temperature of the hydraulic fluid, determining the thermal output supplied to the clutch on the basis of the temperature, determining a lambda value on the basis of the thermal output and determining the degree of filling on the basis of the lambda value.

A hydrodynamic clutch having an input side and an output side, the rotational motions of which are coupled to one another with a hydraulic fluid. A method for determining the degree of filling of the hydrodynamic clutch with fluid including steps of periodically sensing a fluid temperature of the hydraulic fluid, determining the thermal output supplied to the clutch on the basis of the temperature, determining a lambda value on the basis of the thermal output and determining the degree of filling on the basis of the lambda value.