Abstract: The gear machine according to the invention includes a driving gear wheel (1) and a driven gear wheel (2) having meshing gear teeth (21,22) having a special novel shape designed to provide improved gear wheel kinematics as well as minimal volume flow rate fluctuations. A correction of the gear teeth side geometry is performed by local limited adjustment of the basic transmission function i for eliminating volume flow rate fluctuations so that a discontinuity-free transmission is attained which results in an improved motion of the driven gear wheel with reduced acceleration changes. In order to accomplish this improvement in kinematics, the shape of the flanks or sides (25,26) of the engaging or meshing gear teeth (21,22) is such that the transmission function i depends on a spacing (g.sub..alpha.

Abstract: A gear pump or motor, has two rotatively guided toothed or gear wheels in a housing, the teeth of which are mutually engaged and separate a compression chamber from a suction or discharge chamber. Depending on the rotation angle .phi.1 of a torque-transmitting gear wheel, an instantaneous hydraulic medium volume flow V is displaced and the mutually engaging gears wheels have a gear ratio i=.phi.1/.phi.2, where .phi.2 is the rotation angle of the non-torque transmitting gear wheel. In order to avoid pressure fluctuations and the resulting sound projection, the instantaneous gear ratio i over the whole angle of rotation .phi.1 of the torque-transmitting gear wheel is selected in such a way that the non-torque-transmitting gear wheel is driven at a constantly changing, periodically returning angular speed by tooth pitch, thus totally or partially compensating by an output increase or reduction the volume flow pulsation caused by the constant change in the position of the sealing limit at the teeth contact point.

Abstract: This invention is for a hydrostatic-mechanical transmission system of the power-branching type having a "neutral" operating mode. An assembly of a hydrostatic transmission including a variable displacement pump and a hydraulic motor is connected to the input shaft of a mechanical transmission. The mechanical transmission has a speed-range selector defining a first low-speed range for the gearing and a second high-speed range for the gearing. Two planetary gear sets in succession are coupled to the transmission such that the transmission ratios of the hydrostatic transmission and the mechanical transmission establish a neutral mode in each speed range a zero output contribution by the mechanical transmission.