A continuously variable transmission steering mechanism of a tracked vehicle, comprising a differential (1), a right drive shaft (2), a left drive shaft (3), and a continuously variable transmission (4) used for adjusting the rotational speed of the right drive shaft (2) and that of the left drive shaft (3). A left half shaft (5) and a right half shaft (6) are connected on the differential (1). The right half shaft (6) of the differential (1) is linked to the right drive shaft (2). The right drive shaft (2) rotates to drive the right half shaft (6) of the differential (1) to rotate. The left half shaft (5) of the differential (1) is linked to the left drive shaft (3). The left drive shaft (3) rotates to drive the left half shaft (5) of the differential (1) to rotate. The rotational speed ratio of the right half shaft (6) of the differential (1) to the right drive shaft (2) is equal to the rotational speed ratio of the left half shaft (5) of the differential (1) to the left drive shaft (6). The employment of the continuously variable transmission steering mechanism of the tracked vehicle, by means of continuously and precisely adjusting the rotational speeds of the left and right half shafts of the differential via the continuously variable transmission (4), implements precise turning of tracks, thus increasing the safety of the tracked vehicle traveling at a high speed.

A continuously variable transmission steering mechanism of a tracked vehicle, comprising a differential (1), a right drive shaft (2), a left drive shaft (3), and a continuously variable transmission (4) used for adjusting the rotational speed of the right drive shaft (2) and that of the left drive shaft (3). A left half shaft (5) and a right half shaft (6) are connected on the differential (1). The right half shaft (6) of the differential (1) is linked to the right drive shaft (2). The right drive shaft (2) rotates to drive the right half shaft (6) of the differential (1) to rotate. The left half shaft (5) of the differential (1) is linked to the left drive shaft (3). The left drive shaft (3) rotates to drive the left half shaft (5) of the differential (1) to rotate. The rotational speed ratio of the right half shaft (6) of the differential (1) to the right drive shaft (2) is equal to the rotational speed ratio of the left half shaft (5) of the differential (1) to the left drive shaft (6). The employment of the continuously variable transmission steering mechanism of the tracked vehicle, by means of continuously and precisely adjusting the rotational speeds of the left and right half shafts of the differential via the continuously variable transmission (4), implements precise turning of tracks, thus increasing the safety of the tracked vehicle traveling at a high speed.

A bogie axle assembly having a housing, a spindle, a drive sprocket unit, and a planetary gear set. The drive sprocket unit may be fixedly disposed on a planet gear carrier of the planetary gear set. The spindle may be fixedly disposed on the housing. The drive sprocket unit may be rotatably supported by at least one roller bearing assembly that may be disposed between the spindle and the drive sprocket unit.

Provided is a grip heater apparatus for a construction machine that can improve operability by heating the grip portions of left and right operating levers and maintaining a favorable operating environment for the left and right operating levers when work is carried out in a cold region and the operator's hands get cold. The grip heater apparatus includes: left and right grip heaters 31 and 32 provided in grip portions of left and right operation levers 26 and 28, respectively; a battery supplying electric power to the left and right grip heaters; a heater switch 34 for instructing the left and right grip heaters to be turned on or off; and a control device supplying the electric power from the battery to the left and right grip heaters only when the engine is running, the gate lock lever 27 is at a getting-on/off prevention position, and the heater switch instructs the left and right grip heaters to be turned on.

A tractor has a base for supporting a motive power source, left and right driven wheels, and left and right transmissions for the respective left and right wheels; a handle structure coupled to the base for grasping by an operator from behind the tractor; a drive system for driving each of the left and right transmissions with motive power from the motive power source; wherein the left and right transmissions are hydrostatic transmissions, further having a speed regulator control lever on each transmission that allows seamless control of the transmission from reverse speed through neutral into forward speed; and a transmission control coupled to each speed regulator control lever; further wherein there is a longitudinally disposed space between the left and right transmissions, and a power take off shaft is disposed in the space extending anteriorly and driven by the motive power source for powering a powered attachment arranged to be attached at the anterior of the tractor, further including a shaft extension of said power take off shaft extending posteriorly for driving a rear power take off for powering a rear mounted powered attachment.

A tractor has a base for supporting a motive power source, left and right driven wheels, and left and right transmissions for the respective left and right wheels; a handle structure coupled to the base for grasping by an operator from behind the tractor; a drive system for driving each of the left and right transmissions with motive power from the motive power source; wherein the left and right transmissions are hydrostatic transmissions, further having a speed regulator control lever on each transmission that allows seamless control of the transmission from reverse speed through neutral into forward speed; and a transmission control coupled to each speed regulator control lever; further wherein there is a longitudinally disposed space between the left and right transmissions, and a power take off shaft is disposed in the space extending anteriorly and driven by the motive power source for powering a powered attachment arranged to be attached at the anterior of the tractor, further including a shaft extension of said power take off shaft extending posteriorly for driving a rear power take off for powering a rear mounted powered attachment.

A method for controlling propulsion of a drilling rig. The drilling rig includes a right propulsion unit and a left propulsion unit and mutually independent speed control and a transmission for driving the right propulsion unit and the left propulsion unit. The transmission provides at least two gear states of a gear box. A propulsion speed is request for the right propulsion unit and for the left propulsion unit. A difference is determined between a requested propulsion speed of the right propulsion unit and the left propulsion unit. A suitable gear state is determined based on the determined difference. Also a computer program product including program code for a computer for implementing the method. A system and a drilling rig equipped with the system.

A method for controlling propulsion of a drilling rig. The drilling rig includes a right propulsion unit and a left propulsion unit and mutually independent speed control and a transmission for driving the right propulsion unit and the left propulsion unit. The transmission provides at least two gear states of a gear box. A propulsion speed is request for the right propulsion unit and for the left propulsion unit. A difference is determined between a requested propulsion speed of the right propulsion unit and the left propulsion unit. A suitable gear state is determined based on the determined difference. Also a computer program product including program code for a computer for implementing the method. A system and a drilling rig equipped with the system.

A steering lever system includes a pair of lever bodies, a pivotal body coupled to each of the lever bodies and a neutral position detector. The pivotal body includes a first boss portion and a second boss portion. The lever body is pivotable about a first pivot axis of the first boss portion from a neutral position to a neutral end position. The lever body is also pivotable about a second pivot axis of the second boss portion from a forward traveling end position through a neutral position to a reverse traveling end position. The neutral position detector is responsive to a detected portion provided in an auxiliary member fixed to the lever body, at the neutral end position of the lever body. The detected portion is offset from a pivotal locus of the lever body about the first pivot axis.

A steering lever system includes a pair of lever bodies, a pivotal body coupled to each of the lever bodies and a neutral position detector. The pivotal body includes a first boss portion and a second boss portion. The lever body is pivotable about a first pivot axis of the first boss portion from a neutral position to a neutral end position. The lever body is also pivotable about a second pivot axis of the second boss portion from a forward traveling end position through a neutral position to a reverse traveling end position. The neutral position detector is responsive to a detected portion provided in an auxiliary member fixed to the lever body, at the neutral end position of the lever body. The detected portion is offset from a pivotal locus of the lever body about the first pivot axis.