A ball screw nut (3) in which multiple balls (7) are disposed in rolling tracks configured from shaft-side thread grooves (4A) and nut-side thread grooves (6A), and the threaded shaft (4) or the nut (6) is provided with a deflector member (15) in which multiple circulation grooves that make the rolling tracks into circling paths are formed. In the ball screw nut: one circumferential direction end of at least one of the multiple circulation grooves is disposed at a position that is shifted in one circumferential direction or the other with respect to the one circumferential direction ends of the other multiple circulation grooves. The invention addresses the problem of providing a deflector-type ball screw capable of improving durability with respect to radial loads and moment loads without enlarging the overall shape or providing multiple deflector members.

A connecting structure includes a first member having a male screw portion on its outer-circumferential surface, a second member having a female screw portion on its inner-circumferential surface that is screwed with the male screw portion, a rotation restraining member placed between the first member and the second member and preventing relative rotation between the first member and the second member, and an elastic member applying elasticity in the axial direction between the first member and the second member.

A work vehicle includes a hydrostatic continuously variable transmission to output power, an electric motor to perform shifting, a linkage mechanism to link a shifting shaft of the electric motor with a trunnion shaft of the hydrostatic continuously variable transmission the linkage mechanism, including a first linkage section linked with the shifting shaft, and a second linkage section linked with the trunnion shaft, and a biasing mechanism to press and bias a second gear of the second linkage section that meshes with a first gear of the first linkage section against the first gear such that a tooth flank of the second gear abuts with a tooth flank of the first gear in a rotation direction reverse to a rotation direction of the first gear.

Provided is a transmission control system that enables more precise control of the transmission ratio. This transmission control system is provided with a motor, an actuator, a transmission, a position sensor, a current sensor, and a control unit. The control unit includes: a drive unit that drives the motor while the vehicle is stopped; and a first estimation unit that estimates the initial transmission ratio, which indicates the transmission ratio when the ignition switch is turned on, on the basis of a rotation position detected by the position sensor, a load current detected by the current sensor, and a characteristic curve over a period during which the drive unit is operating.

A gearbox (1) is placed in a drive train between an electric motor (12) and an engine (13) of a vehicle. The gearbox (1) is placed in direct connection to an output shaft (2) of the electric motor (12). The gear box (1) has means to place it in three different modes.

A pulley for a continuously variable transmission (CVT) and a method of controlling the pulley. The pulley has a main shaft, a fixed sheave, a mobile sheave and a cam system. The fixed sheave is fixedly mounted on the main shaft and has a fixed belt groove portion. The mobile sheave is movably mounted on the main shaft and has a mobile belt groove portion, the mobile sheave is mounted on the main shaft such that the fixed belt groove portion and the mobile belt groove portion form a riding path for a drive belt and is axially movable with respect to the main shaft such as to vary an effective diameter of the pulley by increasing or decreasing an axial space between the mobile sheave and the fixed sheave. The cam system is mounted at one end via a bearing fitted around the primary shaft to the mobile sheave. The cam system is adapted to provide an axial movement to the mobile sheave in order to increase or decrease the axial space between the mobile sheave and the fixed sheave.

A drum cam is connected to a first annular member in a ball cam provided on a rear wheel-side output shaft. Furthermore, linear motion of a second annular member in the ball cam provided on the rear wheel-side output shaft is transmitted to a front wheel-driving clutch via a first transmission mechanism.

In general, this disclosure involves a pulley system that includes a plurality of fixed sheaves arranged to at least partially encircle an output shaft, a plurality of traveling sheaves coupled to the output shaft. The output shaft can be configured to pass through the fixed sheaves and translate along an axis of travel and the plurality of traveling sheaves can be arranged such that a geometric average of belt tension created by spans of belt between the plurality of traveling sheaves and the plurality of fixed sheaves is approximately coincident with a centerline of the output shaft. The system further includes a belt extending between and around the plurality of fixed sheaves and the plurality of traveling sheaves such that the belt flexes toward a single surface of the belt.

A belt-type continuously variable transmission capable of continuously changing a speed reduction ratio of a driven pulley to a drive pulley, has a speed reduction ratio regulation mechanism that regulates a minimum speed reduction ratio of the driven pulley to the drive pulley. The driven pulley includes a fixed sheave, a movable sheave displaceable in an axial direction with respect to the fixed sheave, and a coil spring that urges the movable sheave toward the fixed sheave. The speed reduction ratio regulation mechanism has a swing arm that adjusts an allowable range in which moving away in an axial direction of the movable sheave with respect to the fixed sheave is possible, and a regulation drive section that drives the swing distal end portion of the swing arm to swing continuously.

A powertrain has a continuously variable transmission including a shaft rotatable about an axis. The CVT further comprises a variator assembly that includes a pulley supported on the shaft. The pulley has a movable sheave with a ramp surface. The movable sheave is axially movable on the shaft. The variator assembly also includes an endless rotatable device frictionally engaged with the movable sheave. An actuator mechanism includes a wedge component supported on the shaft. The wedge component has a wedge surface that automatically engages the ramp surface when torque on the shaft is in a first direction. The wedge surface applies a wedge force on the ramp surface. The actuator mechanism further includes an actuator that is operatively connected to the movable sheave and is activatable to apply a force on the movable sheave.