Abstract: In a transmitting system for a small-sized vehicle, a centrifugal clutch, and a torque converter including a pump impeller connected to an output drum of the centrifugal clutch and a turbine impeller connected to an output gear, are placed between a crankshaft of an engine and the output gear. The pump impeller and the output drum adjacent to the pump impeller are integrally coupled, with an open surface of the output drum facing to an opposite side to the pump impeller, to be constructed as a single component. Thus, occurrence of rotation vibrations and unusual noises can be prevented without requiring machining with high precision, and the numbers of components and assembling steps can be reduced while providing favorable maintainability.

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: 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: In a torque converter in which a radial bearing and a one-way clutch are disposed adjacent and concentrically with each other between a hub of a side cover and a turbine shaft extending through the hub, and a hub of an output gear is coupled to an outer end of the turbine shaft, an inner peripheral surface of the hub of the side cover is comprised of a larger-diameter inner peripheral surface portion located on the side of its base end, and a smaller-diameter inner peripheral surface portion located on the side of its tip end and connected to the larger-diameter inner peripheral surface portion through an annular step, and an outer race of the radial bearing fitted to the larger-diameter inner peripheral surface portion is clamped by the annular step and a retaining ring locked to the larger-diameter inner peripheral surface portion.

Abstract: In a transmitting system for a small-sized vehicle, a centrifugal clutch, and a torque converter including a pump impeller connected to an output drum of the centrifugal clutch and a turbine impeller connected to an output gear, are placed between a crankshaft of an engine and the output gear. The pump impeller and the output drum adjacent to the pump impeller are integrally coupled, with an open surface of the output drum facing to an opposite side to the pump impeller, to be constructed as a single component. Thus, occurrence of rotation vibrations and unusual noises can be prevented without requiring machining with high precision, and the numbers of components and assembling steps can be reduced while providing favorable maintainability.

Abstract: In a torque converter in which a radial bearing and a one-way clutch are disposed adjacent and concentrically with each other between a hub of a side cover and a turbine shaft extending through the hub, and a hub of an output gear is coupled to an outer end of the turbine shaft, an inner peripheral surface of the hub of the side cover is comprised of a larger-diameter inner peripheral surface portion located on the side of its base end, and a smaller-diameter inner peripheral surface portion located on the side of its tip end and connected to the larger-diameter inner peripheral surface portion through an annular step, and an outer race of the radial bearing fitted to the larger-diameter inner peripheral surface portion is clamped by the annular step and a retaining ring locked to the larger-diameter inner peripheral surface portion.

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: 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 and a shifting clutch are mounted on the crankshaft. One of the fluid transmitting device and the shifting clutch is connected to the crankshaft, while the other is connected to the input shaft of the multi-stage transmission through a primary reducing device. Provided in the crankshaft are an upstream supply oil passage connected to an oil pump, a downstream supply oil passage connected to portions to be lubricated of the engine, a flow-in bore which permits the upstream supply oil passage to communicate with the inside of the fluid transmitting device, and a flow-out bore which permits the inside of the fluid transmitting device to communicate with the downstream supply oil passage.

Abstract: The rotation of a first flywheel of a two-mass type of flywheel device is transmitted to a second flywheel via springs. Frictional connecting portion having a friction plate is provided between the first flywheel and the springs. A driven plate integral with the second flywheel is provided between the springs and the second flywheel. The friction plate is fitted at one end thereof to a cylindrical portion formed on a diametrically inner side of the first flywheel and is frictionally engaged with the first flywheel. The friction plate is engaged at the other end thereof with the springs. A spring holding plate is disposed to define an oil chamber together with the first flywheel for containing therein the springs, the frictional connecting portion, and the driven plate. The first flywheel and the spring holding plate are formed by pressing metallic plate members and the first flywheel and the spring holding plate are welded together at their peripheries for hermetically sealing the oil chamber.