A work vehicle includes a rotary member, a support member, a sealing ring, a pressure controller, and a vehicle speed determination component. The rotary member has a first hydraulic fluid supply channel to supply the hydraulic fluid to the steering clutch, and is rotated by power from the transmission when the steering clutch is engaged. The sealing ring is disposed between the rotary member and the support member and is mounted adjacent to the connected part between the first hydraulic fluid supply channel and the second hydraulic fluid supply channel. The pressure controller controls the engagement pressure to be a specific first pressure when the vehicle speed is determined not to be equal to or greater than a specific speed, and controls the engagement pressure to decrease from the first pressure when the vehicle speed is determined to be equal to or greater than a specific speed.

A clutch includes a clutch disk that rotates by receiving motive power from an engine and a clutch plate switched between an engaged state in which it is engaged with the clutch disk and a disengaged state in which it is not engaged with the clutch disk. A controller calculates a coefficient of friction μ between the clutch disk and the clutch plate based on a time period Δt elapsed from a first time point when the number of relative rotations of the clutch disk and the clutch plate attains to a first number of rotations to a second time point when a second number of rotations smaller than the first number of rotations is attained, in a state in which the clutch disk rotates while transfer of motive power from the engine to the clutch disk is cut off and in the engaged state.

A clutch-side transmission circuit transmits, from a clutch pedal, a restoring action of the depressed clutch pedal. A switching device connects a first clutch-side hydraulic circuit to the pedal-side hydraulic circuit when a shift lever SL is tilted forwards and connects a second clutch-side hydraulic circuit to the pedal-side hydraulic circuit when the shift lever SL is tilted rearwards. A first clutch is engaged in response to the restoring action of the clutch pedal being transmitted from the first clutch-side transmission circuit. A second clutch is engaged in response to the restoring action of the clutch pedal being transmitted from the second clutch-side transmission circuit.

The present disclosure relates to a method and an apparatus for controlling a lubricant flow rate in a wet clutch. The method comprising: determining a clutch state as an open state, a closed state or a slipping state; determining a clutch temperature and a sump lubricant temperature; based at least on the clutch state, the clutch temperature and the sump lubricant temperature, selecting one out of a plurality of maps, wherein each map maps one or more operating parameters of the clutch on a target lubricant flow rate; determining a target lubricant flow rate based on the one or more operating parameters according to the selected map; and controlling a lubricant flow control device based on the determined target lubricant flow rate.

A work vehicle monitoring system includes a work vehicle and a monitoring device provided on an exterior of the work vehicle. The work vehicle includes a steering clutch, a rotary member having a first hydraulic fluid supply channel, a drive unit, a support member having a second hydraulic fluid supply channel, a sealing ring disposed between the first hydraulic fluid supply channel and the second hydraulic fluid supply channel, a controller that controls a pressure of a hydraulic fluid inside the first hydraulic fluid supply channel and the second hydraulic fluid supply channel, and an external output component that outputs data related to the pressure, a rotational speed, and a time. The monitoring device accepts the data from the external output component and outputs maintenance information about the sealing ring when a predicted wear amount of the sealing ring obtained from the determination basis data exceeds a specific threshold.

A rear axle drive (2) for an AWD vehicle is presented. The rear axle drive (2) is connected to an hydraulic AWD coupling (3), wherein the rear axle drive (2) comprises a lubrication valve (4) for controlling the level of lubricant in at least one lubricant reservoir (6, 7) of the rear axle drive (2) for providing lubricant to gears and/or bearings of the rear axle drive (2). The lubrication valve (4) is functionally connected to a shut-off valve (5) of the AWD coupling (3) and the lubrication valve (4) of the rear axle drive (3) is controlled by movement of an actuating member (51, 54) of the AWD coupling (3).

A work vehicle monitoring system includes a work vehicle and a monitoring device provided on an exterior of the work vehicle. The work vehicle includes a steering clutch, a rotary member having a first hydraulic fluid supply channel, a drive unit, a support member having a second hydraulic fluid supply channel, a sealing ring disposed between the first hydraulic fluid supply channel and the second hydraulic fluid supply channel, a controller that controls a pressure of a hydraulic fluid inside the first hydraulic fluid supply channel and the second hydraulic fluid supply channel, and an external output component that outputs data related to the pressure, a rotational speed, and a time. The monitoring device accepts the data from the external output component and outputs maintenance information about the sealing ring when a predicted wear amount of the sealing ring obtained from the determination basis data exceeds a specific threshold.

A work vehicle includes a rotary member, a support member, a sealing ring, a pressure controller, and a vehicle speed determination component. The rotary member has a first hydraulic fluid supply channel to supply the hydraulic fluid to the steering clutch, and is rotated by power from the transmission when the steering clutch is engaged. The sealing ring is disposed between the rotary member and the support member and is mounted adjacent to the connected part between the first hydraulic fluid supply channel and the second hydraulic fluid supply channel. The pressure controller controls the engagement pressure to be a specific first pressure when the vehicle speed is determined not to be equal to or greater than a specific speed, and controls the engagement pressure to decrease from the first pressure when the vehicle speed is determined to be equal to or greater than a specific speed.

A method of predicting the health of and controlling a hydraulic pressure actuated torque converter lock-up clutch includes determining rotational input and output speeds of the torque converter. The method also includes determining a magnitude of the hydraulic pressure. The method additionally includes determining a level of performance of the clutch across multiple torque converter operating modes using the determined input and output torque converter speeds and the determined magnitude of the hydraulic pressure. The method also includes calculating a numeric state of health (SOH) coefficient of the clutch that quantifies a relative severity of degradation of a plurality of clutch characteristics across the multiple torque converter operating modes. Furthermore, the method includes executing a control action relative to the clutch when the calculated numeric SOH coefficient for specified torque converter operating mode(s) is less than a calibrated SOH threshold.

The present disclosure relates to a method and an apparatus for controlling a lubricant flow rate in a wet clutch. The method comprising: determining a clutch state as an open state, a closed state or a slipping state; determining a clutch temperature and a sump lubricant temperature; based at least on the clutch state, the clutch temperature and the sump lubricant temperature, selecting one out of a plurality of maps, wherein each map maps one or more operating parameters of the clutch on a target lubricant flow rate; determining a target lubricant flow rate based on the one or more operating parameters according to the selected map; and controlling a lubricant flow control device based on the determined target lubricant flow rate.