Abstract:
The invention concerns an engine-rpm-dependent arrest device to prevent non-permitted down shifts in motor vehicle gearboxes, comprising a pilot valve (1) and a control valve (2), both of which have two positions. The control valve (2) is switched into one position by the pressure acting on the surface (36) of the control-valve piston (31), when this pressure exceeds a given pressure produced by a low-pressure pump (20) operating in dependence on engine rpm. The control valve (2) is only in contact with the pressure medium conveyed by the low-pressure pump (20) and controls the large end surface (40) and the annular surface (41) of the stepped-design pilot-valve piston (38). If, with a high gear engaged and motor rpm above a given limit, the gear-shift valve (7) is shifted to its low-gear position, the pilot valve (1) prevents pressure acting on the low-gear activation device (15). At the same time, pressure continues to act on the high-gear activation device (16), thus keeping the gearbox in the high gear.
Abstract:
Ein Getriebe weist ein Planetengetriebe (3) auf, dessen inneres Zentralrad (2) den Antrieb bildet und dessen Planetenträger (6) den Abtrieb bildet, welcher mit einem Stirnrad (10) eines Stirnradgetriebes verbunden ist und welcher über eine Lagerung (13) im Gehäuse (5) des Getriebes gelagert ist. Die Lagerung (13) befindet sich im Bereich der Verzahnung (12) des Stirnrades (10), wodurch ein in seiner Baulänge sehr kompaktes Getriebe geschaffen wird.
Abstract:
Described is a drive device with applications in particular in mobile excavators, wheeled loaders and similar plant, which comprises a power-shift planetary gearbox (4) driven by a hydraulic motor (3). The gearbox (4) preferably has two gears which can be alternately engaged and disengaged hydraulically by means of friction clutches (12, 13). The two clutches (12, 13) are spring-loaded and controlled by oil pressure generated by an oil pump (21) and supplied to both clutches (12, 13) via a gear-shift valve (23). One of the clutches (13) is designed as a brake and has a static leakage-oil-free oil supply. When the pressure generated by the oil pump (21) sinks below a given value, the gear-shift valve (23) is switched into its 2nd-gear position in which only the brake is acted on by the oil pressure. In an emergency in which only a limited amount of hydraulic oil is available, this device makes it possible for the machine to continue operating for a certain length of time since only one almost leakage-oil-free clutch is acted on by the hydraulic oil.
Abstract:
Eine Antriebsvorrichtung weist eine erste Schalteinrichtung (9) und eine zweite Schalteinrichtung (11) auf, welche jeweils mit hydraulischem Druck im Öffnungssinne und über Federkraft im Schliesssinne betätigbar sind und welche eine Vorrichtung (26) aufweisen, über welche die erste Schalteinrichtung (9) und die Zweite Schalteinrichtung (11) bei im Schliesssinne betätigten Schalteinrichtungen im Öffnungssinne zu betätigen sind.
Abstract:
A powershift reversing transmission (1) has a hydrodynamic torque converter and at least two clutches (17, 18) for shifting the forward/rear driving directions. The clutches are designed as negative clutches. A reservoir (33) from which hydraulic medium flows through an aperture (37) is provided to modulate the pressure when reversing the transmission. A throttle (39) with a variable cross-section is provided for inching. A back pressure may be applied to the clutches (17 or 18) through said throttle. This reversing transmission is particularly useful for driving lift trucks or as an entry unit for a multispeed reversing transmission.
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 to a diesel motor (24) downstream of it. In order to change gears in a power shift planetary transmission unit (2), gear shift valves (34, 40) are provided. A brake (14) can be operated by a brake switch valve (30). The brake switching valve (30) is connected via line sections (33, 39) to the gear shift 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, which is designed for dynamic deceleration. Deceleration always takes place in a higher gear, thereby preventing unacceptably high values.
Abstract:
In einem schaltbaren Getriebe sind mindestens zwei durch Federkraft im Schliesssinne und durch Druckbeaufschlagung im Öffnungssinne betätigbare Kupplungen (2, 7) angeordnet, wobei der Abtrieb des Getriebes durch Drucklosschalten beider Betätigungsreinrichtungen (9, 13) und somit Schliessen beider Kupplungen (2, 7) gebremst wird. Bei druckbeaufschlagter zweiter Betätigungseinrichtung (13) setzt sich die Betätigungskraft der ersten Betätigungseinrichtung (9) aus einer Federkraft der ersten Betätigungseinrichtung (9) und einer hydraulischen Kraft aus der Druckbeaufschlagung der zweiten Betätigungseinrichtung (13) zusammen. Somit kann die zur ersten Betätigungseinrichtung gehörende Kupplung, je nachdem, ob die zweite Betätigungseinrichtung mit Druck beauschlagt ist oder nicht, mit verschiedenen Kräften beaufschlagt werden.
Abstract:
A drive mechanism with a two-speed clutch (4) which can be engaged under load, in the form of a planetary gear driven by a hydraulic motor (3), in particular for mobile dredgers and similar building machines, has two gear steps which can be alternately engaged and disengaged by means of hydraulic friction clutches (9, 10). The two friction clutches (9, 10) are designed as spring accumulator clutches controlled by oil pressure. The two friction clutches (9, 10) are arranged radially one inside the other and can be used to change the gears and as parking brakes and auxiliarly brakes.
Abstract:
A driving mechanism (1), particularly usable as a traction motor or as a servo motor, is of a particularly compact design and allows to use a flat, simple driving wheel such as for example a wheel-drum (4). The compact construction is made possible by a reduced number of construction elements consisting for most of them of single part elements, such as an inner toothing wheel (3) intended to reduce the torque and to the mounting of the driving wheel (5, 6) driven by the mechanism, a hub support (13) intended to the housing of the inner toothing wheel (3) as well as a gear box casing cover (12) comprising also a housing for a portion of the gear box. A hydraulic motor (2) is sound-proof mounted inside the driving mechanism (1), a security brake (15) is arranged about a portion of the hydraulic motor (2) so as to obtain a reduced size construction. The driving mechanism (1) of which the axial length does not exceed the width of a caterpillar is well protected when used as a driving motor of a track vehicle.