In a crawler type work machine, when switching from a pivot turning mode to a straight travel mode or a slow turning mode, a controller is configured to maintain a rotation speed of the turning motor until after a first timing at which the inside steering clutch begins partial engagement.

A drive arrangement in a vehicle having front and rear ground engaging means and steering means, has a differential transmission, a differential lock, a planetary final drive on each side of the vehicle and a motor acting onto one member of the planetary final drives. The motor is controlled depending on the steering angle such, that it provides for a difference in the drive speed on the left and the right side.

When left and right steering levers are both operated and the operation amount of the left lever is larger than that of the right lever, a controller calculates a correction left operation amount of the left lever according to the operation amount of the right lever, and controls a left steering clutch so as to cause a vehicle body to turn toward the left in accordance with the correction left operation amount. When left and right steering levers are both operated and the operation amount of the right lever is larger than that of the left lever, the controller calculates a correction right operation amount of the right lever according to the operation amount of the left lever, and controls a right steering clutch so as to cause the vehicle body to turn toward the right in accordance with the correction right operation amount.

A method of controlling a transmission includes providing an input, an output, a controller, a control system, a hydrostatic unit, and a geartrain. The geartrain includes a direct drive pivot clutch and a steer drive geartrain. The method also includes receiving a pivot command by the controller from a shift selector, where the command indicates the shift selector is in a pivot position. The method further includes engaging the direct drive pivot clutch, decoupling the hydrostatic unit from a torque path defined between the input and the output, and coupling the input and the output to one another via a second torque path. The second torque path is defined through the direct drive pivot clutch and the steer drive geartrain. The transmission is controllable in a direct drive steer operation.

A method of controlling a transmission includes providing an input, an output, a controller, a control system, a hydrostatic unit, and a geartrain. The geartrain includes a direct drive pivot clutch and a steer drive geartrain. The method also includes receiving a pivot command by the controller from a shift selector, where the command indicates the shift selector is in a pivot position. The method further includes engaging the direct drive pivot clutch, decoupling the hydrostatic unit from a torque path defined between the input and the output, and coupling the input and the output to one another via a second torque path. The second torque path is defined through the direct drive pivot clutch and the steer drive geartrain. The transmission is controllable in a direct drive steer operation.

A drive assembly having a housing forming an internal sump for a transmission, and an accumulator chamber formed in the housing and in fluid communication with the sump. A piston chamber in the housing is in fluid communication with the accumulator chamber. The transmission includes a pump, a pump running surface and an internal porting system in a center section, and a pump swash plate. A piston divides the piston chamber into first and second portions. The piston is biased by a spring force to pressurize hydraulic fluid in the piston chamber and thereby pressurize the hydraulic fluid in the internal sump when pressure in the piston chamber decreases below a set level. A second transmission may also be located in the housing.

A resilient power device is adapted to drive a transmission rod of a vehicle, and includes a housing, a rotary shaft adapted to extend and be spaced apart from the transmission rod along a first axis, a power release unit including a first rod and a second rod that extend and are spaced apart from each other along a second axis parallel to the first axis, a power storage clutch adapted to be connected between the transmission rod and the rotary shaft, a power release clutch connected between the first and second rods, a first gear unit mounted to the first rod and the transmission rod, a second gear unit mounted to the rotary shaft and said second rod, and at least one resilient member connected between the housing and the rotary shaft.

A drive arrangement in a vehicle having front and rear ground engaging means and steering means, has a differential transmission, a differential lock, a planetary final drive on each side of the vehicle and a motor acting onto one member of the planetary final drives. The motor is controlled depending on the steering angle such, that it provides for a difference in the drive speed on the left and the right side.

A regenerative differential includes torque members, and a gear assembly that includes a primary gear set and a plurality of secondary gear sets. The primary gear set is configured to transfer torque between the secondary gear sets and first and second torque members. The first secondary gear set transfers torque between the primary gear set and a third torque member. The second secondary gear set transfers torque between the primary gear set and a fourth torque member. The gear assembly is configured to maintain a fixed relationship between torque member rotation velocities 1, 2, 3, and 4, such that 3=M.sub.L.sub.2+.sub.L.sub.1, .sub.4=M.sub.R.sub.2+A.sub.R.sub.1, M.sub.L and .sub.L are functions of a ratio of the first secondary gear set, and M.sub.R and .sub.R are functions of k.sub.R of a ratio of the second secondary gear set.

In an all-wheel drive arrangement with low input torque especially for the skid-steer loaders controlled by a control unit, made up of battery, frequency converter, electric joystick and/or electro-hydraulic switchgear, both sides of the vehicle control include at least two wheels, each wheel connected to a planetary gearing. The gearing equipped with the infinite gear member (e.g. belt, chain) transfers the torque from the electric motor to each wheel on one side of the vehicle controlled, whereby the planetary gear directly drives the particular wheel.