Abstract: A mounting arrangement for a tensioning device with a tensioning unit in a side carrier of a crawler of a tracked undercarriage in a large machine is disclosed. The tensioning unit is arranged in a side carrier compartment in the side carrier of the crawler, wherein a mounting opening is arranged in the side carrier on the outside thereof in an installation area of the tensioning unit for allowing removal of the tensioning unit, when installed, from the side carrier compartment through the mounting opening transversely to a track running direction.

Abstract: A vehicle track assembly includes an endless track having a first surface displaying a series of ground engaging profiles longitudinally spaced along the first surface and a second surface displaying a series of wheel engaging drive lugs spaced longitudinally along the second surface, a drive wheel for engaging the drive lugs and at least one idler wheel defining an inside diameter and an outside diameter, where the inside diameter of the at least one first idler wheel is greater than the outside diameter of the first idler wheel per meter of idler wheel width. The at least one idler wheel is a plurality of idler wheels, which may include a first idler wheel and a second idler wheel. The first and second idler wheels may be parallel one another, and may be separated by a distance of greater than the width of the drive lugs.

Abstract: An integrated track adjustment/recoil unit is compressed between a front track roller frame and rear track roller frame of telescopic track roller frame during a recoil event. The integrated track adjustment/recoil unit defines an oil volume separated from a gas volume by a recoil piston, which moves closer to the idler along a recoil line responsive to a recoil event.

Abstract: A device for tensioning chains on crawler-type or tracked vehicles, in particular the chains of hydraulic excavators, comprises a first cylinder arranged in an area of the chassis for the tracked vehicle, and operatively connected via a piston rod to a guide wheel to tension the chain. A second cylinder forms a spring cylinder and is operatively connected to the first cylinder. The second cylinder concentrically encloses the first cylinder to form a double cylinder and each cylinder is provided with a separate hydraulic connection. At startup of the tracked vehicle, the hydraulic connections of the double cylinder are admitted with a specifiable pre-tensioning pressure. The spring cylinder can be moved with maximum spring travel to its end position because of its larger cross-sectional surface, and the tensioning cylinder pre-tensions the chain with a force that corresponds to the pre-tensioning pressure.

Abstract: An automatic track tensioning system is provided for use with a track-type work vehicle for automatically tensioning an endless track chain of the work vehicle.

Abstract: A machine including: a frame assembly including one or more drive wheels and one or more idler wheels affixed to the frame assembly; a track belt disposed about the drive and the idler wheel; a hydraulic actuator arrangement including a hydraulic cylinder and accumulator affixed to the idler wheel that provides a force to tension the track belt; and a tension management system in operable communication with the hydraulic cylinder that maintains a pressure inside the hydraulic cylinder within a specified range.

Abstract: A hydraulic recoil and adjustment mechanism is provided for a track assembly having an idler. The mechanism includes a recoil cylinder configured to contain a quantity of hydraulic fluid. A rod element is coupled to the idler and configured to reciprocate within the recoil cylinder. The idler is configured to exert a force on the rod element to drive hydraulic fluid from the recoil cylinder when the force exceeds a predetermined force. An accumulator includes a piston and is configured to contain a quantity of gas under pressure on one side of the piston, and to receive from the recoil cylinder a quantity of the hydraulic fluid on the other side of the piston when the force exceeds the predetermined force. An adjustment mechanism includes a reservoir for hydraulic fluid, and is configured to deliver hydraulic fluid from the adjustment mechanism to the recoil cylinder under sufficient pressure to move the rod element and the idler.

Abstract: A management system is disclosed for controlling the tension of an endless track by regulating the hydraulic pressure in a hydraulic jack acting on a roller serving to tension the track. The tension management system comprises two accumulators of different capacity that are connected to the jack. Both accumulators are in permanent direct communication with the jack and the larger accumulator is preloaded to a higher pressure than the smaller accumulator.

Abstract: A method of operating a work machine having (i) a hydraulic drive system for driving a drive track chain, (ii) a track tensioning assembly for adjusting tension on the drive track chain, (iii) a hydraulic work implement for performing a work function, and (iv) a fluid supply circuit for providing pressurized hydraulic fluid to both the hydraulic drive system and the hydraulic work implement includes the step of advancing the pressurized hydraulic fluid from the fluid supply circuit to the work implement when the work machine is being operated in a work mode of operation. The method also includes the step of diverting the pressurized hydraulic fluid from the work implement to the drive system when the work machine is being operated in a travel mode of operation. The method further includes the step of detecting a fluid pressure increase within the drive system in response to diversion of the pressurized hydraulic fluid from the work implement to the drive system.

Abstract: A recoil and slack adjustment mechanism for tensioning an endless track chain of an undercarriage assembly of a work machine includes a ram assembly and an accumulator assembly. The ram assembly includes a ram housing having a ram chamber defined therein. A recoil ram is movably housed within the ram chamber. The recoil ram has a ram subchamber defined therein. The tensioning ram is movably housed within the ram subchamber and is coupled to a front idler roller of the undercarriage assembly. A check valve is disposed between the ram chamber and the ram subchamber such that fluid pressure from the accumulator assembly is selectively exerted on the tensioning ram thereby urging the front idler roller so as to bias the track chain of the undercarriage assembly. The recoil and slack adjustment assembly provides continuous, constant tensioning of the track chain, and does not require the use of live hydraulics.

Abstract: A track belt tensioning management system is provided for actively adjusting the tension on a track belt in response to the difference in linear output speed between a drive wheel and the track belt. This is accomplished by sensing the speeds of the drive wheel and the track belt and delivering the sensed signals to a controller which processes the signals and determines the difference in their respective linear output speeds. If the difference varies from a predetermined value, the controller directs appropriate signals to a hydraulic valve arrangement which controllably directs pressurized fluid to and from a hydraulic actuator arrangement to adjust the tension between the drive wheel and the track belt. The subject arrangement maintains sufficient frictional force between the drive wheel and the belt to control the slip therebetween as required while at the same time limiting the forces in order to reduce premature failures and/or wear on the track belt and other associated components.

Abstract: A hydraulic track tensioning circuit is connected to an idler wheel of a track drive mechanism to maintain a tension in a track proportional to the drawbar pull of the track drive mechanism. The tensioning circuit includes a variable pressure relief valve having a variable pressure setting controller which controls the tensioning pressure in a supply line connected to a hydraulic tensioning cylinder in response to the highest pressure in a pair of motor ports of a reversible hydraulic drive motor operative to propel the track drive mechanism.

Abstract: A hydraulic chain tensioning means for automatically tensioning the chains of crawler vehicles equipped with two-, four- or eight-wheel articulated suspension means comprises essentially two tensioning cylinders (1.1 and 1.2) and a plurality of valves (3). The two tensioning cylinders (1.1 and 1.2) are interconnected by way of ducts (4) and connected by further ducts (5) to the valves (3). The tensioning cylinders (1.1 and 1.2) are fitted to the chassis (10) of the crawler vehicle and the leading wheel of the crawler vehicle bears against the piston rods (1.1K and 1.2K) of the tensioning cylinders (1.1 and 1.2). Parallel to the tensioning cylinders (1.1 and 1.2) a soft spring (piston-type accumulator 6) is connected so that at the beginning of the chain tensioning means being put under load only a minor pressure rise occurs in the tensioning cylinders (1.1 and 1.2).

Abstract: A semiconductor integrated circuit device having internal circuits, and a test mode selecting circuit. The selecting circuit includes a first load device, a transistor having a first terminal receiving a signal via the first load device, a control terminal receiving a first voltage and a second terminal, and a second load device provided between the second terminal of the transistor and a reference voltage node. A test mode selecting signal is output via the second terminal of the transistor when a second voltage higher than the voltage of the signal applied to the first load device in a normal operation mode is applied thereto. The test mode selecting signal is applied to predetermined internal circuits among said internal circuits, so that the predetermined internal circuits are switched to states of a test mode from the normal operation mode.