A drive force distribution method and a drive force distribution control device is provided for a front and rear wheel drive vehicle provided with a drive force distribution device that controls a distribution of a drive force generated by a drive force source to main drive wheels and auxiliary drive wheels. A present distribution of the drive force to an auxiliary drive wheel side is increased by a first predetermined amount upon determining the rotational speed difference between the rotational speeds of the main drive wheels and the auxiliary drive wheels has been determined to not be smaller than a predetermined rotational speed difference. The present distribution of the drive force to the auxiliary drive wheel side is reduced by a second predetermined amount when the rotational speed difference has been determined to be smaller than the predetermined rotational speed difference.

A drive force distribution method and a drive force distribution control device is provided for a front and rear wheel drive vehicle provided with a drive force distribution device that controls a distribution of a drive force generated by a drive force source to main drive wheels and auxiliary drive wheels. A present distribution of the drive force to an auxiliary drive wheel side is increased by a first predetermined amount upon determining the rotational speed difference between the rotational speeds of the main drive wheels and the auxiliary drive wheels has been determined to not be smaller than a predetermined rotational speed difference. The present distribution of the drive force to the auxiliary drive wheel side is reduced by a second predetermined amount when the rotational speed difference has been determined to be smaller than the predetermined rotational speed difference.

A hydraulic control device for a vehicle is provided wherein a determination of “base neutral” is made when a difference between a command hydraulic pressure and an actual hydraulic pressure of a hydraulic clutch is within a predetermined minute value range, and when the difference is out of the minute value range, a determination of “base raising” is made if the command hydraulic pressure is larger than the actual hydraulic pressure, and a determination of “base lowering” is made if the command hydraulic pressure is smaller than the actual hydraulic pressure. The determination of “sub raising” is made when an inclination of command torque subjected to low-pass filter processing is positive for a predetermined time or more, and the determination of “sub lowering” is made when the inclination is negative for the predetermined time or more, whereby a rising or dropping tendency of the command torque is determined.

A hydraulic control device for a vehicle is provided wherein a determination of “base neutral” is made when a difference between a command hydraulic pressure and an actual hydraulic pressure of a hydraulic clutch is within a predetermined minute value range, and when the difference is out of the minute value range, a determination of “base raising” is made if the command hydraulic pressure is larger than the actual hydraulic pressure, and a determination of “base lowering” is made if the command hydraulic pressure is smaller than the actual hydraulic pressure. The determination of “sub raising” is made when an inclination of command torque subjected to low-pass filter processing is positive for a predetermined time or more, and the determination of “sub lowering” is made when the inclination is negative for the predetermined time or more, whereby a rising or dropping tendency of the command torque is determined.

An axle assembly having an input shaft, an output shaft, and an interaxle differential unit. The interaxle differential unit includes first and second side gears, a case, and a pinion gear that is rotatably disposed on a pinion pin. The case extends from the input shaft. The pinion pin extends from the case and is spaced apart from the input shaft.

A drive wheel conversion system for self-propelled hydrostatic wheel driven riding/standing lawn care equipment platforms that provide a quick and easy conversion of conventional trailing caster wheel assemblies to independent driven power drive wheels. Such conversion enables a four-wheel drive lawn care vehicle that has interchangeable mower attachments capable for a wide variety of operable use, as needed, on an existing standard lawncare self-propelled platform.

A drive wheel conversion system for self-propelled hydrostatic wheel driven riding/standing lawn care equipment platforms that provide a quick and easy conversion of conventional trailing caster wheel assemblies to independent driven power drive wheels. Such conversion enables a four-wheel drive lawn care vehicle that has interchangeable mower attachments capable for a wide variety of operable use, as needed, on an existing standard lawncare self-propelled platform.

When evacuation travel is performed using only a drive power from one drive power source of an engine and a rotary machine, a drive power distribution device is prohibited from switching to a four-wheel-drive state and thus evacuation travel is performed in a two-wheel-drive state in which a loss in a power transmission device is relatively small. Accordingly, in a four-wheel-drive vehicle, it is possible to increase an evacuation-travelable distance when evacuation travel is performed using only the drive power from one drive power source of the engine and the rotary machine.

When evacuation travel is performed using only a drive power from one drive power source of an engine and a rotary machine, a drive power distribution device is prohibited from switching to a four-wheel-drive state and thus evacuation travel is performed in a two-wheel-drive state in which a loss in a power transmission device is relatively small. Accordingly, in a four-wheel-drive vehicle, it is possible to increase an evacuation-travelable distance when evacuation travel is performed using only the drive power from one drive power source of the engine and the rotary machine.

An axle assembly having an input shaft, an output shaft, and an interaxle differential unit. The interaxle differential unit includes first and second side gears, a case, and a pinion gear that is rotatably disposed on a pinion pin. The case extends from the input shaft. The pinion pin extends from the case and is spaced apart from the input shaft.