Abstract: 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.

Abstract: 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.

Abstract: The invention comprises a hydro-mechanical continuously variable transmission (HMCVT) that uses a planetary gear system to provide a combination of hydraulic and mechanical power for a vehicle or stationary equipment. The invention further comprises various ancillary elements to improve the performance of the HMCVT.

Abstract: An object is to provide a steering system for a tracklaying vehicle which is capable of preventing overrun of a motor during a pivot turn irrespective of the load of the road surface and does not cause a shortage of power during a turn. The steering system is comprised of a pair of brakes for right and left output shafts and designed to transmit the driving force of a hydraulic motor to the output shafts through a planetary gear mechanism. A transmission of a driving force from the hydraulic motor to the planetary gear mechanism is interrupted after concurrently carrying out actuation of a brake for either one of the right and left output shafts and a transmission of a driving force from the hydraulic motor to the planetary gear mechanism for a specified period of time, when the vehicle carries out a pivot turn. During a pivot turn of the vehicle, the engine is controlled such that a vehicle body speed obtained by a bevel shaft rotational speed detector becomes equal to a specified value.

Abstract: A hydraulic and mechanical composite continuously variable transmission (HMT) is disclosed. The HMT includes a hydraulic continuously variable transmission (HST) and a mechanical speed change mechanism using a group of planetary gears as the differential part. The output rotation of the HST and the rotation of the input part of the mechanical speed change mechanism that receives power from the engine are transmitted to the differential part which translates the rotation to a speed change output shaft. The speed change input part is formed at one end of a pump shaft and the differential input part is coaxially formed at the other end thereof. Further, the operator may manually set the speed ratio via electrical means on the mechanical speed chance mechanism.

Abstract: A steering method and steering system which enable a minimum turn radius more than the discharge capacities of a hydraulic motor and a hydraulic pump and which positively prevent the unstable traveling and turning behavior of a vehicle when the vehicle makes a pivot turn. The vehicle is provided with a pair of brakes for right and left output shafts and designed to transmit the driving force of the hydraulic motor to the output shafts through planetary gear mechanisms. During a pivot turn of the vehicle, an operation of the brake of either one of the right and left output shafts and a transmission of a driving force from the hydraulic motor to a planetary gear mechanism are simultaneously carried out for a specified period of time and thereafter, the transmission of the driving force from the hydraulic motor to the planetary gear mechanism is interrupted.

Abstract: A transaxle apparatus is constructed so that left and right axles, two hydrostatic transmissions (HSTs), one for driving a vehicle and the other for steering it, and a differential unit for differentially connecting said axles with each other are together contained in a housing. The driving HST is disposed so that its hydraulic pump and motor are aligned along either a left or right side of the housing. The steering HST is disposed so that its hydraulic pump and motor are aligned along either a front or rear side of the housing. The differential unit is laterally opposite to the driving HST. Either the left or right axle crosses the driving HST between its hydraulic pump and motor. The two HSTs are provided with one or two flat center sections disposed in the housing. The cylinder blocks of the hydraulic pumps and motors of the two HSTs are mounted on either a top or bottom surface of the center section or sections.

Abstract: A differential steer is provided for use in a machine and includes a variable displacement motor operatively connected to a differential disposed between first and second output members. The variable displacement motor is an over-center type and the displacement thereof is varied from zero to maximum in both directions of movement. Pressurized fluid to drive the steer motor is received from the main system pump. A microprocessor senses the direction and rate of rotation of the steer motor output, the speed of the outputs from the differential, the magnitude of a steer input, and controls the output speed of the steer motor to the differential in response to the magnitude of the steer input. Consequently, the quantity of fluid taken from the main system pump is limited to only that necessary to rotate the steer motor at a rate necessary to satisfy the desired steer input.

Abstract: A hydro-mechanical steering differential for providing differential steering of the left and right hand tracks of a tractor is disclosed. The steering differential is powered by a mechanical input and a hydraulic input, and includes left and right outputs. The improved hydro-mechanical steering differential comprises a geared differential unit having a right output gear element, a left output gear element and a gear carrier element. The gear carrier element is coupled to the mechanical input and has a gear set meshed with right and left output gear elements. The left output gear element is coupled to the left output, and the right output gear element is coupled to the right output. A gearless hydro-mechanical differential unit has a rotatable motor powered by the hydraulic output. The hydro-mechanical has a drive unit coupled to the mechanical input and a driven unit coupled to the right output.

Abstract: An electric drive system for tracklaying vehicles includes a pair of electric motors and an infinitely variable speed, hydromechanical steering transmission including a pair of hydrostatic propulsion units and a plurality of planetary gears sets. The hydrostatic units are driven by one or both of the electric motors to produce separate hydrostatic propulsion outputs which are combined with the mechanical outputs of the motors by the planetary gear sets to generate separate hydromechanical propulsion outputs on right and left transmission output shafts for vehicle propulsion and steer in two speed ranges.

Abstract: In a superimposed steering gear (3) for tracklaying vehicles in which the steering power needed for turning is superimposed on the drive system via summarizing differentials and which has a hydrostatic-mechanical power branching summed up in a summarizing transmission (31), the power losses of the hydrostatic branch that works with poor efficiency are kept as small as possible and, at the same time, an infinite steering is made possible over all radial ranges. For this purpose, the summarizing transmission (31) is shiftable into steps that cover at least two radial ranges, a speed adaptation to the transmission components taking place at any given time in the shift points for an infinite transition.