A bi-directional pump connected to a motor by a pair of supply/discharge lines; a regulator changes the bi-directional pump tilting angle; and a controller controls the regulator based on a turning signal outputted from a turning operation valve. At the turning acceleration, at which the signal increases, the controller calculates a motor flow rate passing through the motor and an instruction flow rate determined based on the turning signal. If the instruction flow rate is greater than a reference flow rate obtained by adding a predetermined value to the motor flow rate, the controller controls the regulator so the bi-directional pump tilting angle is adjusted to a tilting angle realizing the reference flow rate. If the instruction flow rate is not greater than the reference flow rate, the controller controls the regulator so the bi-directional pump tilting angle is adjusted to a tilting angle realizing the instruction flow rate.

A compact hydraulic transmission assembly using an axial piston pump disposed on a center section that also provides a cylindrical running surface for a radial piston motor. This design provides for a compact and low profile assembly, while the combination of an axial piston pump with a radial piston motor provides improved efficiency for higher torque output. The radial piston motor includes a lower mass piston block that improves performance. The center section includes an extension extending outwardly from its circumference and including a check port; and a mounting lobe for securing the center section is secured to the pump housing.

A compact hydraulic transmission assembly using an axial piston pump disposed on a center section that also provides a cylindrical running surface for a radial piston motor. This design provides for a compact and low profile assembly, while the combination of an axial piston pump with a radial piston motor provides improved efficiency for higher torque output. The radial piston motor includes a lower mass piston block that improves performance. The center section includes an extension extending outwardly from its circumference and including a check port; and a mounting lobe for securing the center section is secured to the pump housing.

Hydraulic transmission apparatus (20) including a pump (24) having a variable cylinder capacity and feeding one or more hydraulic motors (26A, 26B), and a control unit (50). In the apparatus, the feed and discharge orifices of the motors are arranged in such a manner that, when the pressures at said orifices are equal, the outlet torque from the motors is zero. To make the apparatus inactive, without physically bypassing the motors, the control unit is suitable for operating the apparatus in a torque-free mode by regulating the cylinder capacity of the pump in such a manner that the pressures at said feed and discharge orifices remain substantially equal.

Hydraulic transmission apparatus (20) including a pump (24) having a variable cylinder capacity and feeding one or more hydraulic motors (26A, 26B), and a control unit (50). In the apparatus, the feed and discharge orifices of the motors are arranged in such a manner that, when the pressures at said orifices are equal, the outlet torque from the motors is zero. To make the apparatus inactive, without physically bypassing the motors, the control unit is suitable for operating the apparatus in a torque-free mode by regulating the cylinder capacity of the pump in such a manner that the pressures at said feed and discharge orifices remain substantially equal.

A dynamic vibration absorbing device includes a guide member having an annular shape. The dynamic vibration absorbing device also includes at least one mass body that rolls along the guide member. In addition, the dynamic vibration absorbing device includes at least one elastic member non-rotatable relatively to the guide member, the at least one elastic member disposed to restrict the at least one mass body from rotating relatively to the guide member.

A dynamic vibration absorbing device includes a guide member having an annular shape. The dynamic vibration absorbing device also includes at least one mass body that rolls along the guide member. In addition, the dynamic vibration absorbing device includes at least one elastic member non-rotatable relatively to the guide member, the at least one elastic member disposed to restrict the at least one mass body from rotating relatively to the guide member.

A work vehicle according to the present invention includes an engine installed in a traveling machine body supported by traveling units, and a transmission case incorporating a hydraulic continuously variable transmission. The transmission case incorporates a forward/backward traveling switching mechanism. The work vehicle includes forward traveling valves for forward traveling hydraulic clutches, a backward traveling valve for a backward traveling hydraulic clutch, and a master valve configured to control hydraulic oil supplying to the forward traveling valves and the backward traveling valve. A part of a hydraulic circuit is formed on a front lid member of the transmission case. The forward traveling valves, the backward traveling valve, and the master valve are attached on a front surface side of the front lid member.

A work vehicle according to the present invention includes an engine installed in a traveling machine body supported by traveling units, and a transmission case incorporating a hydraulic continuously variable transmission. The transmission case incorporates a forward/backward traveling switching mechanism. The work vehicle includes forward traveling valves for forward traveling hydraulic clutches, a backward traveling valve for a backward traveling hydraulic clutch, and a master valve configured to control hydraulic oil supplying to the forward traveling valves and the backward traveling valve. A part of a hydraulic circuit is formed on a front lid member of the transmission case. The forward traveling valves, the backward traveling valve, and the master valve are attached on a front surface side of the front lid member.

A hydrokinetic torque coupling device comprises a casing, a torque converter, a torsional vibration damper and a lockup clutch disposed within the casing. The torque converter comprises an impeller and a turbine-piston coaxially aligned with the impeller and axially movable toward and away from the casing to position the hydrokinetic torque coupling device into and out of a lockup mode in which the turbine-piston is non-rotatably frictionally coupled to the casing. The torsional vibration damper comprises an input member non-moveably secured to the turbine-piston, a first retainer plate and the elastic members elastically coupling the input member to the first retainer plate. The input member includes an actuating portion configured to actuate the lockup clutch. The lockup clutch is disposed within the casing between the actuating portion of the input member and a cover shell of the casing for frictionally coupling the casing and the turbine-piston.