Abstract: An oil pump apparatus for supplying an oil to a vehicular transmission, includes a pump to suck the oil from an oil reservoir through an inlet port into a pumping chamber, and an intake circuit to convey the oil sucked from the oil reservoir to the inlet port. The intake circuit includes a proximal segment, an intermediate segment and a distal segment. The proximal segment extends from the inlet port, to the intermediate segment. The intermediate segment extends upwards from the proximal segment. The distal segment extends downwards from a first connecting end portion connected with the intermediate segment to a end portion formed with an suction opening to suck the oil from the oil reservoir into the intake circuit.

Abstract: A torque converter defines an ellipticity lower than or equal to 0.23 which is an outermost length of the torque converter in an axial direction, divided by an outermost diameter of the torque converter in a radial direction. The torque converter includes: a pump impeller connecting to an input shaft; a turbine runner opposed to the pump impeller and connecting to an output shaft; and a stator disposed between an inlet of the pump impeller and an outlet of the turbine runner, by way of a one way clutch which allows a one way rotation. The torque converter transmits a power by circulating a fluid through the pump impeller, the turbine runner and the stator. A first area ratio A is: 0.23?A?0.45, A second area ratio B is: 0.23?B?0.45, and A third area ratio C is: 0.15?C<0.23.

Abstract: In a torque converter comprised of three major rotating elements, namely a pump impeller formed integral with a converter cover, a turbine runner to which a driving power is transmitted through a working fluid from the pump impeller, and a stator disposed between the pump impeller and the turbine runner, the stator is supported on a transmission case via a one-way clutch and has a plurality of stator blades. In order to balance the enhanced vehicle's startability and improved fuel economy at idle, the ratio W/D of a stator-blade axial length W to a torque-converter nominal diameter D is set to satisfy a predetermined inequality 0.030?W/D?0.052.

Abstract: In a torque converter comprised of three major rotating elements, namely a pump impeller, a turbine runner to which a driving power is transmitted through a working fluid from the pump impeller, and a stator disposed between the pump impeller and the turbine runner, a flattening ratio L/D of a sum L of an pump-impeller axial length and a turbine-runner axial length to a torque-converter nominal diameter D is set to be less than or equal to 0.21. In order to balance contradictory requirements, namely reduced curvature loss, i.e., enhanced converter efficiency, proper rate-of-change in working-fluid flow passage area, and proper breakaway of working fluid from each turbine blade, a ratio r/R of a radius of curvature r of a turbine-core outer peripheral curved surface to a radius of curvature R of a turbine-shell outer peripheral curved surface being set to satisfy a predetermined inequality 0.3≦r/R≦0.5.

Abstract: A torque converter defines an ellipticity lower than or equal to 0.23 which is an outermost length of the torque converter in an axial direction, divided by an outermost diameter of the torque converter in a radial direction. The torque converter includes: a pump impeller connecting to an input shaft; a turbine runner opposed to the pump impeller and connecting to an output shaft; and a stator disposed between an inlet of the pump impeller and an outlet of the turbine runner, by way of a one way clutch which allows a one way rotation. The torque converter transmits a power by circulating a fluid through the pump impeller, the turbine runner and the stator. A first area ratio A is: 0.23≦A≦0.45, A second area ratio B is: 0.23≦B≦0.45, and A third area ratio C is: 0.15≦C≦0.23.

Abstract: In a torque converter comprised of three major rotating elements, namely a pump impeller, a turbine runner to which a driving power is transmitted through a working fluid from the pump impeller, and a stator disposed between the pump impeller and the turbine runner, a flattening ratio L/D of a sum L of an pump-impeller axial length and a turbine-runner axial length to a torque-converter nominal diameter D is set to be less than or equal to 0.21. In order to balance contradictory requirements, namely reduced curvature loss, i.e., enhanced converter efficiency, proper rate-of-change in working-fluid flow passage area, and proper breakaway of working fluid from each turbine blade, a ratio r/R of a radius of curvature r of a turbine-core outer peripheral curved surface to a radius of curvature R of a turbine-shell outer peripheral curved surface being set to satisfy a predetermined inequality 0.3≦r/R≦0.5.

Abstract: In a torque converter comprised of three major rotating elements, namely a pump impeller formed integral with a converter cover, a turbine runner to which a driving power is transmitted through a working fluid from the pump impeller, and a stator disposed between the pump impeller and the turbine runner, the stator is supported on a transmission case via a one-way clutch and has a plurality of stator blades. In order to balance the enhanced vehicle's startability and improved fuel economy at idle, the ratio W/D of a stator-blade axial length W to a torque-converter nominal diameter D is set to satisfy a predetermined inequality 0.030≦W/D≦0.052.