Man Nutzfahrzeuge Gmbh

M.a.n. Maschinenfabrik Augsburg-nurnberg A.g.

Hydromatik Gmbh

Stefan Martini

Faust Hagin

Hans J Drewitz

Wolfgang Reistle

Thomas Sommer

A drive system, comprising a driving motor whose speed can be adjusted by means of an operating member, an adjustable hydrostatic transmission with a pump and a hydraulic motor of which the volume throughput can be adjusted, followed by a change-speed gear, in particular one which can be shifted under load, connected to the hydrostatic transmission, wherein a control device is associated with the hydrostatic transmission, and an operating member is provided to initiate a gear shift, is arranged so that while ensuring a simple regulating concept, it exhibits subjectively good shifting behavior without costly auxiliary devices having to participate in the control response of the continuously adjustable hydrostatic transmission. This is achieved by the fact that associated with the control device is a device for determining the direction of transmission of power between the driving motor and the change-speed gear, and that after the initiation of a gear-change to a lower gear when the direction of transmission is from the change-speed gear to the driving motor, the control device adjusts the transmission ratio of the hydrostatic transmission towards a decrease in the driving speed of the hydraulic motor and that the shift can only take place at the earliest when the direction of transmission has come to be from the driving motor to the change-speed gear.

Drive system comprising a variable speed driving motor, an adjustable

In a system for varying the output flow from a constant rate feed pump with low losses by chopping the said output flow into one flow fraction supplied to the load as a power flow and into another flow fraction returned as a pressureless flow, the loads are aperiodically supplied with proportionated amounts of fluid by chopping, the respective amounts of fluid and the chop frequency being inherently controlled in way dependent on the instantaneous requirement of the load in the system. The system for performing the method has a housing with a number of pressure spaces arranged to be acted upon by different flows and with one or more pressureless spaces, a piston with a piston rod arranged in a piston space, a compression spring preferably arranged in a hole in said piston rod and adapted to act against the sum of the hydraulic forces acting on the piston and spool. The method is applicable to complex hydraulic systems and more especially to hydrostatic drives.

Low-loss cyclically-operating pressure-responsive bypass valve for fixed

The hydromechanical transmission is all in all designed as a power splitting transmission having at least two hydraulic machines adapted to selectively act as pumps and motors, a control or connecting block, epicyclic gearing and various clutches, the hydraulic machines adapted to selectively act as pumps and motors forming a preassembled unit or subassembly with the control or connecting block. The subassembly, the epicyclic gearing, the clutches and any intermediate shaft required are arranged in a unitary manner in a common housing, in which the various elements are surrounded with a small clearance. the hydraulic machines adapted to selectively act as pumps and motors are arranged within the overall length of the epicyclic gearing and are axially parallel thereto.

Hydromechanical transmission for motor vehicles

In a hydrostatic drive one hydrostatic machine (2 and 4) is adapted for absorbing the sustained braking power or energy. The transmission is furthermore provided with a cooler (9) whose two sides are respectively connected via a threshold pressure valve (7 and 8) with one of two branch ducts (3 and 5) which connect the said hydrostatic machine with a second such machine adapted to act as a drive. The pressure threshold valve is made up of a pressure limiting and check valve.

Hydrostatic drive

The invention relates to a fluid tight pipe connection having an intermediate ring between the two pipe ends. By making the two surfaces of the ring complementary to the pipe end faces the ring may be displaced in relation to one pipe end and may be moved pivotally in relation to the other pipe end to enable the connection to allow for angular misalignment and parallel offset of the pipe axes while still maintaining a sealing joint.

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Ulm, Germany

Stefan Martini