Abstract: An outboard engine system includes a casing and an engine mounted in an upper part of the casing. The casing also contains a torque converter, and a vertically arranged output shaft connected to a crankshaft through the torque converter. In the torque converter, a turbine runner is arranged above a pump impeller and connected to the output shaft, and a transmission cover is connected to an outer periphery of the pump impeller so as to cover an upper surface of the turbine runner. A drive plate is secured at its central portion to a lower end of the crankshaft by a first bolt, and an outer peripheral portion of the drive plate is secured to the transmission cover by a second bolt. The torque converter is suspended from the crankshaft via the drive plate. Thus, it is possible to provide an outboard engine system which enables support of a torque converter without using any bearing exclusively for supporting the overall weight of the torque converter, thereby reducing the cost.

Abstract: A vertical power unit includes an input shaft and an output shaft which have axes in the vertical direction and are vertically arranged to each other; and a torque converter between the input shaft and the output shaft. The output shaft includes an upper output shaft connected to a turbine runner and a lower output shaft connected to the upper output shaft. An oil tank and an oil pump are provided outside the torque converter. The upper output shaft is provided with a vertical hole which communicates at an upper end with a circulation circuit of the torque converter so as to introduce the oil discharged by the oil pump into the circulation circuit, and a bottom wall which closes a lower end of the vertical hole. Thus, an working oil is constantly supplied to the circulation circuit of the torque converter through the interior of the output shaft, thereby cooling the working oil in the circulation circuit, and improves maintainability of loading devices driven by the output shaft.

Abstract: In a fluid transmitting device, a plurality of first power transmission claws are inserted between adjacent ones of damper springs and secure to a clutch piston; and a plurality of second power transmission claws are inserted between adjacent ones of the damper springs so as to face the first power transmission claws, and has support portions which are connected to an outer peripheral surface of a shell of a turbine impeller via a weld formed by laser beams. The weld is formed into a linear shape extending along a circumferential direction of the shell so that the weld is melt by the laser beams to extend from an outer surface of the support portion to an inner peripheral surface of the shell. Thus, it is possible to easily perform welding between the support portions of the second power transmission claws and the shell of the turbine impeller, and to easily perform a visual inspection as to whether the welding condition is good or not.

Abstract: A vertical power unit includes an input shaft and an output shaft which have axes in the vertical direction and are vertically arranged to each other; and a torque converter between the input shaft and the output shaft. The output shaft includes an upper output shaft connected to a turbine runner and a lower output shaft connected to the upper output shaft. An oil tank and an oil pump are provided outside the torque converter. The upper output shaft is provided with a vertical hole which communicates at an upper end with a circulation circuit of the torque converter so as to introduce the oil discharged by the oil pump into the circulation circuit, and a bottom wall which closes a lower end of the vertical hole. Thus, an working oil is constantly supplied to the circulation circuit of the torque converter through the interior of the output shaft, thereby cooling the working oil in the circulation circuit, and improves maintainability of loading devices driven by the output shaft.

Abstract: An outboard engine system includes a casing and an engine mounted in an upper part of the casing. The casing also contains a torque converter, and a vertically arranged output shaft connected to a crankshaft through the torque converter. In the torque converter, a turbine runner is arranged above a pump impeller and connected to the output shaft, and a transmission cover is connected to an outer periphery of the pump impeller so as to cover an upper surface of the turbine runner. A drive plate is secured at its central portion to a lower end of the crankshaft by a first bolt, and an outer peripheral portion of the drive plate is secured to the transmission cover by a second bolt. The torque converter is suspended from the crankshaft via the drive plate. Thus, it is possible to provide an outboard engine system which enables support of a torque converter without using any bearing exclusively for supporting the overall weight of the torque converter, thereby reducing the cost.

Abstract: In a fluid transmission device, a male fitting surface of a periphery of a diameter-expanded portion of a pump shell is fitted to a female fitting surface of an inner circumference of a peripheral wall portion of a cylindrical transmission cover, and a fillet weld being is formed between an end surface of the peripheral wall portion and a peripheral surface of the diameter-expanded portion along an entire circumference, thereby connecting together the pump shell and the transmission cover. An annular recess is formed in an inner circumferential surface of the peripheral wall portion to adjoin the female fitting surface on the side opposite from the fillet weld. A portion of the transmission cover corresponding to the recess constitutes an annular thin-walled portion which has a thickness smaller than the portions of the transmission cover along the opposite sides of the annular thin wall portion.

Abstract: A power transmission device for an astride-riding vehicle is provided, the power transmission device including a torque converter T and a clutch C disposed in series in a transmission route between an engine E and a gear speed change device M. The torque converter T is arranged so that a pump capacity ? is a maximum at a speed ratio e=0, and gradually decreases in response to an increase in the speed ratio e. Linear properties in which both the engine rotational speed and the turbine rotational speed increase substantially linearly in response to an acceleration operation of the engine can therefore be obtained, thereby providing good drivability.

Abstract: In a fluid transmitting device, a plurality of first power transmission claws are inserted between adjacent ones of damper springs and secure to a clutch piston; and a plurality of second power transmission claws are inserted between adjacent ones of the damper springs so as to face the first power transmission claws, and has support portions which are connected to an outer peripheral surface of a shell of a turbine impeller via a weld formed by laser beams. The weld is formed into a linear shape extending along a circumferential direction of the shell so that the weld is melt by the laser beams to extend from an outer surface of the support portion to an inner peripheral surface of the shell. Thus, it is possible to easily perform welding between the support portions of the second power transmission claws and the shell of the turbine impeller, and to easily perform a visual inspection as to whether the welding condition is good or not.

Abstract: In a fluid transmission device, a male fitting surface of a periphery of a diameter-expanded portion of a pump shell is fitted to a female fitting surface of an inner circumference of a peripheral wall portion of a cylindrical transmission cover, and a fillet weld being is formed between an end surface of the peripheral wall portion and a peripheral surface of the diameter-expanded portion along an entire circumference, thereby connecting together the pump shell and the transmission cover. An annular recess is formed in an inner circumferential surface of the peripheral wall portion to adjoin the female fitting surface on the side opposite from the fillet weld. A portion of the transmission cover corresponding to the recess constitutes an annular thin-walled portion which has a thickness smaller than the portions of the transmission cover along the opposite sides of the annular thin wall portion.

Abstract: A lockup clutch for a torque converter includes a pump extension, a receiving plate connected to the pump extension defining a hydraulic pressure chamber communicating with a portion between a pump impeller and a turbine impeller, a pressing plate opposed to the receiving plate for movement toward and away from the receiving plate, an annular friction clutch plate interposed between the receiving plate and the pressing plate and connected to the turbine impeller, a return spring for biasing the pressing plate in a retracting direction, and an escape bore permitting the inside and outside of the receiving plate to communicate with each other on the side of an inner periphery of the friction clutch plate. When the rotational speed of the pump impeller is increased to a value equal to or higher than a predetermined value, the pressing plate clamps the friction clutch plate in cooperation with the receiving plate under the action of a centrifugal hydraulic pressure within the hydraulic pressure chamber.

Abstract: A power transmission device for an astride-riding vehicle is provided, the power transmission device including a torque converter T and a clutch C disposed in series in a transmission route between an engine E and a gear speed change device M. The torque converter T is arranged so that a pump capacity &tgr; is a maximum at a speed ratio e=0, and gradually decreases in response to an increase in the speed ratio e. Linear properties in which both the engine rotational speed and the turbine rotational speed increase substantially linearly in response to an acceleration operation of the engine can therefore be obtained, thereby providing good drivability.

Abstract: A lockup clutch for a torque converter includes a pump extension, a receiving plate connected to the pump extension defining a hydraulic pressure chamber communicating with a portion between a pump impeller and a turbine impeller, a pressing plate opposed to the receiving plate for movement toward and away from the receiving plate, an annular friction clutch plate interposed between the receiving plate and the pressing plate and connected to the turbine impeller, a return spring for biasing the pressing plate in a retracting direction, and an escape bore permitting the inside and outside of the receiving plate to communicate with each other on the side of an inner periphery of the friction clutch plate. When the rotational speed of the pump impeller is increased to a value equal to or higher than a predetermined value, the pressing plate clamps the friction clutch plate in cooperation with the receiving plate under the action of a centrifugal hydraulic pressure within the hydraulic pressure chamber.

Abstract: A lock-up clutch of a torque converter includes an annular clutch outer mounted in a side cover, a clutch inner connected to a turbine impeller, a driving friction plate axially movably connected to the clutch outer, first and second follower friction plates connected to the clutch inner for movement toward and away from each other with the driving friction plate interposed therebetween, an inner chamber defined between the first and second follower friction plates, and an outer chamber faced by outer sides of the first and second follower friction plates. When the inside of the outer chamber is put at a pressure higher than that in the inner chamber, the follower friction plates are brought into pressure contact with the driving friction plate, and an urging force on the follower friction plates is not applied to the side cover.

Abstract: A lockup clutch for a torque converter includes a pump extension, a receiving plate connected to the pump extension defining a hydraulic pressure chamber communicating with a portion between a pump impeller and a turbine impeller, a pressing plate opposed to the receiving plate for movement toward and away from the receiving plate, an annular friction clutch plate interposed between the receiving plate and the pressing plate and connected to the turbine impeller, a return spring for biasing the pressing plate in a retracting direction, and an escape bore permitting the inside and outside of the receiving plate to communicate with each other on the side of an inner periphery of the friction clutch plate. When the rotational speed of the pump impeller is increased to a value equal to or higher than a predetermined value, the pressing plate clamps the friction clutch plate in cooperation with the receiving plate under the action of a centrifugal hydraulic pressure within the hydraulic pressure chamber.

Abstract: A torque converter includes a pump impeller, a turbine impeller, a stator impeller disposed between the pump impeller and the turbine impeller, and a free wheel which is interposed between the stator impeller and a stationary case and operable to lock the stator impeller in order to allow the stator impeller to bear a reaction force generated with the amplification of torque between the pump and turbine impellers. In this torque converter, a stator shaft connected to the stator impeller is disposed with its tip end being passed through a turbine shaft to protrude outside the turbine shaft. The free wheel is interposed between the tip end of the stator shaft and the stationary case. Thus, it is possible to reduce the diameter of the stator impeller and thus, the diameter of the entire torque converter, irrespective of the presence of the free wheel inhibiting the rotation of the stator impeller.

Abstract: A torque converter includes a turbine impeller integrally connected to a pump impeller, a side-cover having a boss and covering the turbine impeller, and a turbine shaft extending through the boss and connected to the turbine impeller. A radial bearing and a one-way clutch are disposed axially adjacent to each other between the boss of the side-cover and the turbine shaft. The radial bearing serves to retain the boss and the turbine shaft concentrically, and the one-way clutch connects the turbine shaft and the side-cover to each other, when a back load is applied to the turbine shaft. Therefore, a load received by a clutch element of the one-way clutch such as a sprag between the turbine shaft and the side-cover is equalized. Thus, when a back load is applied to the turbine shaft, a slipping between the turbine impeller and the pump impeller is prevented, thereby providing a good engine brake effect.

Abstract: A transmitting system for a small-sized vehicle having an engine and a multi-stage transmission comprising a crankshaft of the engine, an input shaft of the multi-stage transmission, a shifting clutch and a primary reducing device. The input shaft is disposed in parallel to the crankshaft and the crankshaft and input shaft are connected to each other through a fluid transmitting means. The fluid transmitting means including a pump impeller leading to the engine, and a turbine impeller leading to the multi-stage transmission. The fluid transmitting means and the shifting clutch are mounted on the crankshaft of the engine and connected in series to each other. One of the fluid transmitting means and the shifting clutch is connected to the crankshaft, and the other is connected to the input shaft of the multi-stage transmission through the primary reducing device.

Abstract: In a transmitting system for a small-sized vehicle in which a crankshaft and an input shaft of a transmission are connected to each other through a fluid transmitting device such as a torque converter. A primary reducing device, the fluid transmitting device and a shifting clutch are disposed on the crankshaft sequentially from one side of a crankcase supporting the crankshaft with a bearing interposed therebetween toward the outside, and the axial movements of the input member, the pump impeller and the turbine impeller on the crankshaft are restrained by the bearing and a nut threadedly fitted at a tip end of the crankshaft. Thus, a creep phenomenon of the fluid transmitting device can be eliminated by controlling the shifting clutch, and the shifting operation of the transmission can be conducted lightly. Moreover, the transmitting system is of a simple construction and improved in assemblability.

Abstract: In a transmitting system for a small-sized vehicle in which a crankshaft of an engine and an input shaft of a multi-stage transmission are connected to each other through a fluid transmitting device, a shifting clutch is interposed between the crankshaft of the engine and the multi-stage transmission in a series relation to the fluid transmitting device. A lock-up clutch is interposed between a pump impeller and a turbine impeller of the fluid transmitting device. Thus, when the multi-stage transmission is to be shifted, the shifting operation can be conducted lightly, in spite of a creep phenomenon of the fluid transmitting device, by bringing the shifting clutch into an OFF state. Moreover, during cruising of the vehicle, the slipping of the fluid transmitting device can be inhibited by the OFF state of the lock-up clutch to enhance the transmitting efficiency.

Abstract: In a transmitting system for a small-sized vehicle in which a crankshaft of an engine and an input shaft of a multi-stage transmission are connected to each other through a fluid transmitting device, the fluid transmitting device including a pump impeller leading to the engine, and a turbine impeller leading to the transmission, a shifting clutch is interposed between the crankshaft of the engine and the multi-stage transmission in a series relation to the fluid transmitting device. Thus, a creep phenomenon of the fluid transmitting device can be eliminated, and the shifting operation of the transmission can be conducted lightly, by bringing the shifting clutch into its OFF state.