An undercarriage assembly for a work machine including a drive wheel; front and rear idler wheels; an endless track belt about the drive and idler wheels; mid-rollers located between the front and rear idler wheels to engage the endless track belt; a track roller frame mounted on the machine at a main pivot, between front and rear ends of an elongate member, with the front idler wheel connected near the front end of the roller frame; a major bogie connected to the roller frame at a major bogie pivot, and the rear idler wheel connected to a trailing arm of the major bogie; a minor bogie, mounted on a forward arm of the major bogie, and pivotably connected to the major bogie at a minor bogie pivot, and including front and rear axles, supported by a suspension that provides damping between the front and rear axles and the minor bogie pivot.

An undercarriage assembly for a work machine including a drive wheel; front and rear idler wheels; an endless track belt about the drive and idler wheels; mid-rollers located between the front and rear idler wheels to engage the endless track belt; a track roller frame mounted on the machine at a main pivot, between front and rear ends of an elongate member, with the front idler wheel connected near the front end of the roller frame; a major bogie connected to the roller frame at a major bogie pivot, and the rear idler wheel connected to a trailing arm of the major bogie; a minor bogie, mounted on a forward arm of the major bogie, and pivotably connected to the major bogie at a minor bogie pivot, and including front and rear axles, supported by a suspension that provides damping between the front and rear axles and the minor bogie pivot.

A snowmobile has a rear suspension assembly including at least one slide rail, a plurality of idler wheels, a front suspension arm having first upper and lower ends, and a rear suspension arm having second upper and lower ends. The first upper end is connected to a tunnel of the snowmobile. The first lower end is selectively connected to the at least one slide rail. The first lower end is connectable to the at least one slide rail at first and second positions. The first position of the first lower end is vertically higher from a bottom surface of the at least one slide rail than the second position of the first lower end. The second upper end is connected to the tunnel.

A snowmobile has a rear suspension assembly including at least one slide rail, a plurality of idler wheels, a front suspension arm having first upper and lower ends, and a rear suspension arm having second upper and lower ends. The first upper end is connected to a tunnel of the snowmobile. The first lower end is selectively connected to the at least one slide rail. The first lower end is connectable to the at least one slide rail at first and second positions. The first position of the first lower end is vertically higher from a bottom surface of the at least one slide rail than the second position of the first lower end. The second upper end is connected to the tunnel.

A levelling assembly is provided, for levelling an upper carriage assembly of a machine with respect to an undercarriage assembly having a first track roller frame and the second track roller frame. A levelling body is rotatably coupled to the first track roller frame and the second track roller frame and defines a first side and a second side laterally opposite to the first side. The levelling assembly includes a first pair of fluid actuators for movably coupling first side of the levelling body with the first track roller frame and a second pair of fluid actuators for movably coupling second side of the levelling body with the second track roller frame. The first and the second pair of fluid actuators move the levelling body between a fore tilted position and an aft tilted position relative to the first and the second track roller frames.

A levelling assembly is provided, for levelling an upper carriage assembly of a machine with respect to an undercarriage assembly having a first track roller frame and the second track roller frame. A levelling body is rotatably coupled to the first track roller frame and the second track roller frame and defines a first side and a second side laterally opposite to the first side. The levelling assembly includes a first pair of fluid actuators for movably coupling first side of the levelling body with the first track roller frame and a second pair of fluid actuators for movably coupling second side of the levelling body with the second track roller frame. The first and the second pair of fluid actuators move the levelling body between a fore tilted position and an aft tilted position relative to the first and the second track roller frames.

A track-module apparatus comprising: (a) idler-arm axle structure for a vehicle and having leading and trailing idler-arm axles; (b) a leading idler arm rotatably attached to the leading idler-arm axle and extending forwardly to a leading-arm distal end at which a leading ground-engaging idler wheel is rotatably attached and rearwardly to a rearward suspension end; (c) a trailing idler arm rotatably attached to the trailing idler-arm axle and extending rearwardly to a trailing-arm distal end at which a trailing ground-engaging idler wheel is rotatably attached and forwardly to a forward suspension end; (d) bogie-axle structure (i) affixed to one of the idler arms, (ii) having at least one bogie-arm axle, and (iii) positioning the at least one bogie-arm axle adjacent to and below the idler-arm axle of the idler arm to which it is affixed; (e) leading-arm and trailing-arm suspension elements rotatably attached to and extending downwardly from the rearward and forward suspension ends, respectively, and each having a lower end; (f) front and rear bogie connecting arms rotatably attached to the front and rear axles, respectively, and extending forwardly and rearwardly to rotatable attachments at the leading-arm and trailing-arm suspension-element lower ends, respectively; (g) front and rear ground-engaging bogie-wheel sets rotatably attached to distal ends of the front and rear bogie connecting arms, respectively; and (h) an endless track extending around the wheels.

A track-module apparatus comprising: (a) idler-arm axle structure for a vehicle and having leading and trailing idler-arm axles; (b) a leading idler arm rotatably attached to the leading idler-arm axle and extending forwardly to a leading-arm distal end at which a leading ground-engaging idler wheel is rotatably attached and rearwardly to a rearward suspension end; (c) a trailing idler arm rotatably attached to the trailing idler-arm axle and extending rearwardly to a trailing-arm distal end at which a trailing ground-engaging idler wheel is rotatably attached and forwardly to a forward suspension end; (d) bogie-axle structure (i) affixed to one of the idler arms, (ii) having at least one bogie-arm axle, and (iii) positioning the at least one bogie-arm axle adjacent to and below the idler-arm axle of the idler arm to which it is affixed; (e) leading-arm and trailing-arm suspension elements rotatably attached to and extending downwardly from the rearward and forward suspension ends, respectively, and each having a lower end; (f) front and rear bogie connecting arms rotatably attached to the front and rear axles, respectively, and extending forwardly and rearwardly to rotatable attachments at the leading-arm and trailing-arm suspension-element lower ends, respectively; (g) front and rear ground-engaging bogie-wheel sets rotatably attached to distal ends of the front and rear bogie connecting arms, respectively; and (h) an endless track extending around the wheels.

A harvester and a method for harvesting a crop is disclosed. The harvester includes two track drives positioned on opposite ends of a front axle of the harvester, each of the track drives including two main wheels that are arranged successively in the driving direction of the harvester, at least one auxiliary wheel positioned between the main wheels, and at least one track that surrounds the main wheels. The auxiliary wheel can interact with a bottom section of the track so that the forces to be deflected via the particular track drive into ground can be deflected at least proportionately using the auxiliary wheel. To reduce the shearing forces into the ground when the harvester turns, a control unit, depending on the steering angle of the harvester, controls a lifting unit to lift a front main wheel of a particular track drive from its home position to a lifted position.

A harvester and a method for harvesting a crop is disclosed. The harvester includes two track drives positioned on opposite ends of a front axle of the harvester, each of the track drives including two main wheels that are arranged successively in the driving direction of the harvester, at least one auxiliary wheel positioned between the main wheels, and at least one track that surrounds the main wheels. The auxiliary wheel can interact with a bottom section of the track so that the forces to be deflected via the particular track drive into ground can be deflected at least proportionately using the auxiliary wheel. To reduce the shearing forces into the ground when the harvester turns, a control unit, depending on the steering angle of the harvester, controls a lifting unit to lift a front main wheel of a particular track drive from its home position to a lifted position.