Drive configurations for skid steered vehicles

A drive configuration for a skid steered vehicle comprising a respective drive member adapted to be located at each side of the vehicle, each drive member engaging with a track or wheel of the vehicle;

• at least one propulsion motor in operable communication with said drive members operable to drive the tracks or wheels of the skid steered vehicle;
• at least one steer motor in driveable communication with a controlled differential positioned between and connecting a pair of primary shafts and in driveable communication with each primary shaft, the ends of each primary shaft remote from the controlled differential forming an output of the transmission and being in driveable communication with the drive members;
• wherein the at least one propulsion motor is provided on a secondary shaft remote from the primary shafts.

A controlled differential adapted to couple two shafts and steer input, such as those provided in a drive configuration for a skid steered vehicle, the controlled differential comprising:

• a pair of planet carriers arranged to turn with respective shafts;
• a pair of ring gears interconnected by a cross-shaft such that the ring gears rotate in common;
• planet gears and a pair of sun gears, the sun gears being coupled to at least one steer motor to enable rotation of the sun gears in mutually opposite senses upon input from the steer motor.

A controlled differential adapted to couple two shafts comprising:

• first and second outer ring gears arranged to turn with respective shafts;
• first and second inner ring gears interconnected by a cross-shaft such that the inner ring gears rotate in common;
• planet gears and planet carriers, the carriers being coupled to at least one steer motor whereby operation of the steer motor enables rotation of the carriers in mutually opposite senses and a corresponding change in rotation of the one or each shaft via the ring and planet gears.

A drive configuration for a skid steered vehicle comprising:

• a respective drive member adapted to be located at each side of the vehicle, each drive member engaging with a track or wheel of the vehicle;
• at least one propulsion motor in operable communication with said drive members operable to drive the tracks or wheels of the skid steered vehicle;
• at least one steer motor in driveable communication with the controlled differential, a controlled differential being positioned between and connecting two shafts and being in driveable communication with each shaft, the ends of each shaft remote from the controlled differential forming an output from the transmission and being in driveable communication with the drive members, wherein at least part of the output of the controlled differential connects directly to the transmission output.

A controlled differential adapted to couple two shafts and a steer input, such as those provided in a drive configuration for a skid steered vehicle, the controlled differential comprising:

• a planet carrier arranged to turn with one of said shafts and being in direct communication with an output carrier of a first output gear reduction stage;
• a first controlled differential sun gear arranged to turn with the other of said shafts and being in direct operable communication with a second sun gear of a second output gear reduction stage;
• a ring gear being coupled to at least one steer motor through a series of gear reduction stages to enable a differential torque to be applied at the first sun gear and planet carrier.

A controlled differential adapted to couple two shafts and steer input, such as those provided in a drive configuration for a skid steered vehicle, the controlled differential comprising a pair of planetary gear sets comprising at least a pair of planet carriers, planet gears and ring gears, at least one of the pairs being arranged to turn with respective shafts, at least one of the other pairs being interconnected by a cross-shaft such that these gears rotate in common and the gears of at least one of another pair being coupled to at least one steer motor to enable rotation of these gears in mutually opposite senses upon input from the steer motor, the controlled differential further comprising a releasable locking mechanism for temporary locking of the cross-shaft whereby the at least one steer motor provides torque and power through the controlled differential.