Yamaha Hatsudoki Kabushiki Kaisha

Yousuke Ishida

Akifumi Oishi

Toshinori Inomori

Takuji Murayama

Tatsuya Masuda

Masaru Oosuga

Akifumi Ooishi

Soichiro Matsumoto

Hiroyuki Suzuki

Shintarou Satou

A centrifugal clutch is disclosed. The centrifugal clutch has a first plate provided in a clutch housing, a second plate provided in a clutch boss, a pressure plate capable of being moved close to and away from the first and second plates, and a centrifugal weight arranged to push the pressure plate toward the first and second plates by receiving centrifugal force. The centrifugal clutch is arranged so that torque T transmitted between the first and second plates is temporarily reduced and then increased as an engine rotational speed is increased from a time when an engine is stopped.

Motorcycle including centrifugal clutch

A straddle-type vehicle is disclosed. The straddle-type vehicle has a planetary gear mechanism having a ring gear rotatable with a crankshaft, a sun gear, and at least two planetary gears. The straddle-type vehicle also has a planetary carrier, a rotary shaft rotating with the sun gear, an output shaft rotating with the planetary carrier, and a CVT having a primary shaft rotatable with the rotary shaft. The straddle-type vehicle further has a primary pulley, a secondary shaft rotatable with the crankshaft, a secondary pulley, and a belt. The straddle-type vehicle additionally has an actuator configured to change a transmission gear ratio of the CVT. The crankshaft, the planetary gear mechanism, the rotary shaft, and the belt-type continuously variable transmission form a cyclic power transmission passage. A centrifugal clutch is disposed within the passage.

Straddle-type vehicle

A belt-type continuously variable transmission includes a primary sheave including a pair of first clamp surfaces, a secondary sheave including a pair of second clamp surfaces, and a belt endlessly wound between both of the primary and secondary sheaves. The belt includes contact surfaces clamped between the first clamp surfaces and between the second clamp surfaces. Powder having infusibility as a friction enhancing material is held on at least one of the first clamp surfaces of the primary sheave, the second clamp surfaces of the secondary sheave, and the contact surfaces of the belt.

Belt-type continuous stepless speed changer

A centrifugal clutch is provided with a clutch housing, a clutch boss, a plate group, a pressure plate, a roller retainer, a disc spring, a pressing body and a clutch release mechanism. The pressure plate is displaced on one side in the direction of an axis line and configured to directly or indirectly press the plate group and transition the same into a pressed-contact state. The disc spring extends in a direction of being inclined to the direction of the axis line from a first end portion toward a second end portion in a centrifugal direction. The first end portion of the disc spring is directly or indirectly fixed to the clutch housing. The second end portion of the disc spring directly or indirectly biases the roller retainer toward the plate group.

Centrifugal clutch and vehicle provided with the same

A friction clutch has a clutch housing including a friction plate, a clutch boss including a clutch plate, and a pressure plate causing the friction plate and the clutch plate to contact each other by moving in a predetermined direction. A clutch spring applies a biasing force in a direction of causing the pressure plate to press the friction and clutch plates into contact with each other. An annular retainer receives a reaction force to the biasing force of the clutch spring by supporting one end of the clutch spring opposite to the pressure plate. A circlip of a notched ring shape is fitted into an inner peripheral side of the clutch housing. The circlip locks the retainer to the clutch housing by abutting on an opposite side of the retainer. The retainer is configured to suppress radially inward deformation of the circlip when a vehicle engine is driven.

Friction clutch

An off-road vehicle having a belt type continuously variable transmission and an air intake path. A four cycle type engine includes a crank case and a cylinder extending upward from the crank case. A belt type continuously variable transmission is provided on one end of the crank case in a vehicle width direction. A belt chamber is formed inside a transmission case for housing the belt type continuously variable transmission. A part of the transmission case in front of a rear end of the cylinder is connected to an intake path for leading air to the belt chamber. The intake path extends upward from the transmission case.

Motorcycle

According to some preferred embodiments, a clutch housing () of a clutch () has a bottom portion () in a closed-end cylindrical shape, a plurality of arms () extending along an axial direction from the bottom portion () and provided along a circumferential direction centering on an axial center (C) of the clutch shaft (), and a plurality of gaps () formed between adjacent arms (). Off-springs () are arranged in the gaps and extend along the axial direction.

Centrifugal multi-plate friction clutch and vehicle equipped with the same

A clutchhas a clutch boss, a clutch housing, a friction plate, a clutch plate, and a pressure plate. The clutch bossis attached to the main shaftso as to be integrally rotated therewith. The clutch housingencloses the periphery of the clutch bossand is attached to the main shaftso as to be rotated with respect to the main shaft. The friction platehas a plate main body and a friction material and rotates together with the clutch housing. The clutch platefaces the plate main body via the friction material and rotates together with the clutch boss. The pressure platerotates together with one of the clutch bossthe clutch housingwhich is engaged with the friction plate

Friction clutch, vehicle equipped with the same, and assembly method of friction clutch

A cam faceand a cam faceare formed in such a manner that an angular velocity &#x3c9; represented by the following equation increases when a parameter R increases and the angular velocity &#x3c9; decreases when the parameter R decreases,&#x3c9;=(1)&#xb7;[(tan &#x3b1;+tan &#x3b2;)/where the mass of the centrifugal weight () is m, the revolution radius that is the distance from the rotation center () of the centrifugal weight () to the center of gravity of the centrifugal weight () is R, the angle formed by a radial line (L) and a tangent line (L) of a point of the cam face () being in contact with the centrifugal weight () is &#x3b1;, the angle formed by a radial line (L) and a tangent line (L) of a point in the cam face () being in contact with the centrifugal weight () is &#x3b2;, and the urging force of a Belleville spring that urges a roller retainer () is F.

Friction clutch and vehicle equipped with the same

A clutch structure, constructed without a one-way clutch, remains engaged until the input side rotational speed becomes relatively low. A pressure plate presses a group of plates directly or indirectly by moving in the direction of an axis, bringing the group of plates into a press contact state. An input side press body turns around the axis with the rotation of a clutch housing, presses the pressure plate to the side of the group of plates by centrifugal force generated during the turning, and moves in a direction away from the axis. A roller retainer presses the group of plates directly or indirectly by moving in the direction of the axis, bringing the group of plates into a press contact state. An output side press body turns around the axis with the rotation of an output side clutch member, presses the roller retainer to the side of the group of plates by centrifugal force generated during the turning, and moves in a direction away from the axis.

Clutch and vehicle having clutch

A centrifugal clutch of a motorcycle has clutch housing which includes a friction plate, a clutch boss including a clutch plate, a pressure plate that pressure-contacts the friction plate with the clutch plate, a roller weight that receives a centrifugal force and presses the pressure plate toward a plate group side. The centrifugal clutch also includes an elastic body that constantly biases the pressure plate toward the plate group side to transmit a portion of a driving force from the clutch housing to the clutch boss even when the motorcycle engine is in an idling state. The elastic body may comprise a disc spring that biases the pressure plate toward the plate group and a coil spring that biases the pressure plate away from the plate group.

Motorcycle with centrifugal clutch

A belt-type continuously variable transmission that prevents escape of noise generated by a resin block belt to the outside. The resin block belt is wound around a primary sheave and a secondary sheave. A transmission case defines a belt chamber accommodating the primary sheave, secondary sheave, and resin block belt. The transmission case includes an exhaust passage, intake passages, and a sound absorbing member. The sound absorbing member is attached to an inner wall of the exhaust passage in a position to collide with sound waves traveling through the exhaust passage. The sound absorbing member has a sound absorbing surface crossing an extending direction of the exhaust passage.

Belt-type continuously variable transmission having resin block belt and motorcycle including belt-type continuously variable transmission

An engine having an engine case on one side of which a V-belt type of continuously variable transmission is provided, the CVT being placed in a transmission case and constituted that a V-belt is routed around a drive pulley and a driven pulley, the drive pulley being attached to one end of a crankshaft, the driven pulley being attached to one end of a transmission shaft parallel to the crankshaft, characterized in that the crankshaft is supported for free rotation with the engine case, one end of the crankshaft is projected in cantilever fashion from the engine case into the transmission case, the drive pulley is attached to the projected portion, and the transmission case is made as a component separate from or independent of the engine case and supported with the engine case so that a space is present between the engine case and the transmission case.

Engine

A belt-type continuously variable transmission (CVT) with reduced vibration at high engine speeds. A secondary sheave includes a fixed sheave member, a moving sheave member, a compression coil spring, and an outside spring guide. The compression coil spring urges the moving sheave member toward the fixed sheave member. The outside spring guide prevents the compression coil spring from buckling during compression.

Growing community of inventors

Shizuoka, Japan

Yousuke Ishida