Abstract: Systems and methods for a multi-speed electric axle are provided. The multi-speed electric axle includes an electric motor that is rotationally coupled to an input shaft. The multi-speed electric axle also includes a planetary gearset connected to the input shaft via an input gear reduction, a lower-speed clutch that selectively grounds a ring gear in the planetary gearset to a housing, and a higher-speed clutch that selectively connects a sun gear to a carrier.

Abstract: A drive device comprises a first switchgear (9) and a second switchgear (11) which can be actuated respectively hydraulic pressure in an opening direction and via spring force in a closing direction, and which are provided with a device (26) by which the first switchgear (9) and the second switchgear (11) are to be actuated in the opening direction when the switchgears are actuated in the closing direction.

Abstract: A brake release unit is provided between a transmission control unit for controlling a transmission and a clutch device. Pressure oil supplied from a hydraulic pressure source to the clutch device is also guided to an accumulator of the brake release unit. When the engine is stopped, pressure oil from the clutch device is collected in a reservoir, and the transmission operates as a parking brake. Pressure oil accumulated in the accumulator is kept as it is. If a solenoid switching valve of the brake release unit is driven as a result of operation of a switch in the operator's cabin, pressure oil accumulated in the accumulator is supplied to the clutch device. As a result, it is possible to easily release the parking brake.

Abstract: The invention relates to a drive system for a motor vehicle, in particular for a construction machine. A hydrostatic transmission unit comprising a variable displacement pump (25), a variable displacement motor (1) and a feed pump (26), is connected downstream of a diesel motor (24). In order to change gears in a powershiftable planetary transmission unit (2), gear-shift valves (34, 40) are provided. A brake (14) can be operated by a brake switching valve (30). The brake switching valve (30) is connected via line sections (33, 39) to the gearshift valves. When the brake switching valve (30) is in one switching position, a reservoir (37) is filled with hydraulic fluid. When in another switching position, a connection is made between the reservoir and a brake pressure chamber (20). During normal running of the machine, the reservoir is filled constantly with hydraulic fluid. When the brakes are operated, an adjustable residual pressure always acts on the brake. The brake is designed for dynamic deceleration.

Abstract: A driving device, in particular for driving the wheels of a motor vehicle, is provided with a drive and a mechanical gear downstream thereof and two hydraulically shiftable friction clutches (3) or friction brakes (4) for connecting the drive with the gear and for carrying out the functions of a parking brake. The friction clutches (3) or friction brakes (4) are connected, by control pressure lines (27, 28), with auxiliary pistons (15, 16) cooperating therewith, and when the accumulator piston (7) is actuated by the gearshift pistons (15, 16), the volume of the accumulator piston (7) is supplied by the control pressure lines (27, 28) to the gearshift pistons (15, 16) in order to uncouple them.

Abstract: The invention relates to hydraulically engaged by means of two friction clutches (9 and 10). For that purpose, friction elements (outer and inner disks 13, 14 and 19, 20) are alternatively engaged and disengaged by the force exerted by plate springs (16, 22) or by hydraulic fluid. A mechanism associated with one of the friction clutches (9 or 10) prevents the full force of the spring from acting on the friction elements when the gear is shifted down from a higher to a lower step. An accumulator (30) is preferably used to influence the torque transmission during a downshift. An essential advantage of the disengaged arrangement consists in the smoothness of the shifting operation during downshifts, avoiding a particularly disagreeable hard shifting which is otherwise felt.

Abstract: A drive device specially used in mobile excavators, wheeled loaders and similar work machines contains a power-shiftable transmission (4) designed as planetary transmission and driven by a hydraulic motor (3). The transmission (4) preferably has two speed levels which are alternatively engageable and disengageable via hydraulically shiftable friction clutches (12, 13). Both friction clutches (12, 13) are designed as spring-accumulator clutches and are controllable by oil pressure generated by an oil pump (21) and both friction clutches (12, 13) are controlled via a gear-shift valve (23). One of the two friction clutches (13) is designed as brake and has a static, leakage-oil-free oil supply. When the oil pressure generated by the oil pump (21) falls below a specific value, the gear-shift valve (23) is engaged into its 2nd-gear position in which only the brake is actuatable with oil pressure.

Abstract: A driving mechanism, specially for mobile excavators and similar construction machines, having a power-shiftable two-gear transmission (4) constructed as planetary gear and driven by a hydromotor, includes two speed levels alternatively engageable and disengageable via hydraulically shiftable friction clutches (9, 10). Both friction clutches (9, 10) are designed as spring accumulator clutches controllable by oil pressure. Both friction clutches (9, 10) are radially telescoped and are to be used both for shifting the gears and as parking brake and auxiliary service brake.

Abstract: A two-ratio planetary hub utilizes spring applied pressure release clutches between the sun gear and planet carrier and ring gear to stationary housing to provide selectable ratios, braking and neutral functions.