Abstract: A hydrostatic/mechanical branch power split transmission for power vehicles is disclosed. The transmission includes an infinitely variable hydrostatic converter having a first hydrostatic unit of adjustable volume and a second hydrostatic unit. The transmission also includes a power distribution system whereby the driving power is split into a hydraulic and a mechanical branch and is summed again before the transmission output. The transmission permits various driving strategies or driving programs which can be conveniently adjusted and accessed. There is also a hydrostatic connection which can be switched at several gear racial points. The breaking capacity of the engine and the maximum breaking effect through continuous hydrostatic converter can be utilized and easily controlled. A further variant also enables breaking energy to be recuperated with the hydrostatic converter. The continuous converter can be precisely adjusted to optimize gear shift range selection.

Abstract: A hydrostatic/mechanical branch power split transmission for power vehicles is disclosed. The transmission includes an infinitely variable hydrostatic converter having a first hydrostatic unit of adjustable volume and a second hydrostatic unit. The transmission also includes a power distribution system whereby the driving power is split into a hydraulic and a mechanical branch and is summed again before the transmission output. The transmission permits various driving strategies or driving programs which can be conveniently adjusted and accessed. There is also a hydrostatic connection which can be switched at several gear ratio points. The braking capacity of the engine and maximum braking effect through the continuous hydrostatic converter can be utilized and easily controlled. A further variant also enables braking energy to be recuperated with the hydrostatic converter. The continuous converter can be precisely adjusted to optimize gear shift range selection.

Abstract: Stepless hydromechanical mechanism with multiple power-transmission paths, more particularly for motor vehicles, having at least two switching ranges in which the stepless control of the mechanism is effected by a hydrostatic transmission, in which the specific requirements on the hydrostatic unit are reduced to a minimum. The hydrostatic power content is reduced. The parameters determining noise, efficiency and service life, i.e., hydrostatic pressure, hydrostatic speed, as well as the values of these components and their arrangement are brought into acceptable and technically feasible bounds.

Abstract: A hydromechanically infinitely variable transmission with power splitting for motor vehicles with at least five gearshift ranges. The transmission can be infinitely varied by means of a hydrostatic transmission. A hydrostat transmission, a multi-shaft summation planetary transmission and at least two downstream planetary transmission units constitute basic components which can be mutually coupled in transmission combinations of various configurations. The power summarized in the summarization planetary transmission is transmitted alternately through an intermediate shaft or coupling shaft and clutches to a planetary transmission unit. In at least one gearshift range, a shaft of the summarization planetary transmission is connected directly via a clutch to the output shaft. Depending on the embodiment, one to three reverse gear ranges can be incorporated in the transmission.

Abstract: A branched, infinitely variable hydromechanical transmission with multiple power-transmission paths for motor vehicles has an expanded first shift range to facilitate broadening of the overall gear-shift range to achieve higher power density and eliminates the need for a starting clutch. The transmission includes a first hydrostatic unit with an adjustable volume, a second hydrostatic unit, preferably with a constant volume, and one or more summation gear trains for adding together the power transmitted from the transmission input along hydraulic and mechanical power-transmission paths. The input shaft of the transmission is connected directly to the drive motor.

Abstract: A clutch mechanism, particularly for automatically operated automotive transmissions, for engaging shift ranges of continuously variable transmissions or step-by-step variable transmissions, and having at least two independently axially movable clutch rings with clutch profiles which cooperate with respective corresponding mating clutch rings clutch profiles, a clutch carrier mounted on a transmission element for rotation therewith in a fixed axial position, and having fluid actuated pressure pistons for shifting the movable clutch rings toward the mating rings. The clutch system can be disengaged under load and requires a small construction space. It can be produced at low cost and is almost free from drag losses. Clutch times and clutch travels are short. The shift pressures are very low. In addition, several clutches can be combined into a compact and relatively small clutch assembly.

Abstract: An infinitely variable driving and steering gear for track-laying vehicles has a hydrostatic/mechanical overlaying steering gear. The mechanism includes a hydrostatic unit and a summation gear train for summing hydrostatic and mechanical input power. The summation gear train has one or more summed power outlet shafts. The drive mechanism also includes a first multiple shaft steering summation transmission that is operably coupled to the summed power outlet shafts and which has left and right steering output shafts. The drive mechanism also includes a second multiple shaft steering summation transmission having respective output shafts that are operably connected to first steering summation transmission. The shafts of the summation gear train of the driving transmission and the shafts of the first steering summation transmission are all coaxially arranged for rotation about a common axis.

Abstract: A continuously variable split-path transmission particularly for motor vehicles comprises a stepless converter with a summation planetary gear unit for adding up the power which is split at the input shaft of the transmission into two power transmission paths. The specific requirements imposed on the stepless converter are minimal, and thus the efficiency values are favorable. The primary and secondary components of the stepless converter are small and can be advantageously incorporated into a modular unit. It is also possible to adapt such components to the specific requirements of different motor vehicles. The summation planetary gear is linked via a series of clutches to a second planetary gear unit having planetary elements which can be reciprocally coupled to each other.

Abstract: Infinitely variable hydromechanical transmission with multiple power-transmission paths for motor vehicles having at least two gear-shift ranges, in which the infinitely variable control of the transmission is effected by a hydrostatic transmission. The transmission system manages with fewer hydrostatic units than heretofore. Its power-to-weight ratio and volume are lower. Its efficiency is increased six to ten times compared to a hydrostatic transmission. A hydrostatic package, a summation planetary gear train, and a second planetary gear train form the basic units which are constantly interconnected in any combination of transmissions. Depending on the range shifted, clutches connect the output shaft to one of the shafts of the summation planetary gear train or to a shaft of the second planetary gear train.

Abstract: A hydromechanical transmission has an engine-driven power shaft connected to a variable-volume pump forming the input side of a hydrostatic unit whose output side comprises a constant-volume motor connected to this pump. A summing planetary-gear train has a first ring gear connected directly to the power shaft, a second ring gear connected to the hydraulic motor and a planet carrier with two interengaging sets of planet gears, one set meshing with the first ring gear and the other set meshing with the second ring gear as well as with a sun gear. An output shaft of the transmission can be connected via a high-range clutch to the sun gear of the summing train or via a low-range clutch to the planet carrier thereof to provide a speed ratio which is steplessly variable in two ranges.

Abstract: In order to control an infinitely-variable transmission of a vehicle engine, a memory stores an optimum fuel consumption curve by which signal transmission is modified through the throttle valve control line or an adjustment regulating valve line for a servomotor connected between the accelerator pedal and the transmission whose ratio is controlled by the servomotor.

Abstract: A drive system for a track-laying vehicle has a main drive shaft connectable to an engine and to primary inputs of right and left summing transmission having secondary inputs and having outputs connected to the secondary inputs of the summing transmissions so that when the compensating shaft is rotated in one direction the one input is rotated one way and the other the opposite way and vice versa. A planetary-gear transmission has a pair of separate inputs and an output connected to the compensating shaft. A variable speed hydrostatic transmission has its input connected to the main drive shaft and its output connected to one of the inputs of the planetary-gear transmission. A first clutch has one side connected to the output of the hydrostatic transmission and to one input of the planetary-gear transmission and another side connected to the compensating shaft.

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.

Abstract: A hydrostatic-mechanical gear unit wherein input power is divided into an hydraulic power branch and a mechanical power branch. The hydraulic branch includes two hydrostatic units in tandem. Through gearing the hydraulic branch is directed to a first internal gear for transmitting the rotational hydraulic power. The mechanical branch through gearing leads to a second internal gear for transmitting rotational mechanical power. The internal gears together with pinions form part of a planetary wheel set for integrating the mechanical power and the hydraulic power. An intermediate shaft connected to the pinion carrier conveys power to an output shaft through a coupling in a first forward driving stage and in the reverse driving stage, and a coaxial shaft connected with a sun wheel conveys power to the output shaft through a coupling in a second forward driving stage.

Abstract: A hydrostatic transmission coupled with a gear transmission for operating a motor vehicle driven by an internal combustion engine has its accelerator pedal connected to the throttle valve of the engine and to the servovalve of the stepless hydrostatic transmission via an engine characteristic storage which modulates the accelerator travel signal applied to the servovalve to optimize the fuel consumption. The servovalve also receives input from an electric signal comparator which compares the engine speed with an output signal from the output unit of the hydrostatic transmission or the output shaft of the gear transmission.

Abstract: A composite transmission with power branching between a hydrostatic transmission and a mechanical summing transmission in which the hydrostatic transmission has a variable displacement unit. The input shaft is connected to the variable displacement unit and to a ring gear on the four-shaft summing transmission of which the ring gear and sun gear are selectively connectible by respective clutches to the constant displacement hydraulic unit. The planet carrier of the summing transmission is connected to the output shaft. The output shaft can also be directly coupled to the input shaft by a clutch and a further planetary can be provided between the fourth shaft of the summing transmission and the output shaft.

Abstract: A hydromechanical drive has an input shaft connected permanently to the input of a variable-volume hydraulic pump and to the planet carrier of a summing transmission. The pump in turn drives a motor which in turn rotates the sun gear of this summing transmission, which has a first planet gear meshing with the sun gear and with a respective ring gear and a second planet gear meshing with the first planet gear and with a respective ring gear. A planetary-gear output transmission has its planet carrier connected to the ring gear of the second planet gear of the summing transmission and a planet carrier connected permanently to the output shaft of the drive and connectable through an openable clutch to the ring gear of the first planet gear of the summing transmission. In addition this output transmission has a first planet gear meshing with the respective sun gear and with a respective ring gear and a second planet gear meshing with the respective first planet gear and with its own ring gear.

Abstract: A steplessly adjustable hydrostatic-mechanical composite transmission in which an input shaft is connected to one shaft of a multishaft summing transmission and to one unit of a hydrostatic transmission whose two units are connected in a hydraulic circuit. One of the hydrostatic units is of the variable displacement type while the other is of the constant displacement type and can be connected by selective actuation of respective clutches to two other input elements of the multishaft planetary summing transmission. The latter has, in accordance with the invention, two output members, each of which is connected to a respective input shaft of an after transmission which can be of the planetary or fixed gear pair type. The latter transmission can also be used to effect reversing of the output shaft which is driven thereby.

Abstract: A hydromechanical drive comprises an input shaft connected to the input side of a hydrostatic transmission having an output side and comprising a pair of hydraulically interconnected hydraulic machines one of which is of variable volume to vary the transmission ratios between its input and output sides. A cam-type summing transmission has one input element connected to the output side of the hydrostatic transmission, another input element connected to the input shaft of the drive, and an output element connected to the output shaft of the drive. A brake is connected to the output side of the hydrostatic transmission for retarding same and thereby reducing the load on the hydrostatic transmission. This brake may be of the torque-converter type that applies increasing resistance to rotation as rotation speed increases.

Abstract: An axle housing which encloses a transmission for the drive of a pair of traction wheels, e.g. as used on a fork-lift truck, has an upper recess flanked by cheeks of enlarged housing extremities which accommodate respective planetary-gear trains. One of the cheeks carries a vertical supporting plate for a hydrostatic drive motor whose shaft enters the axle housing through that cheek and carries a pinion meshing with a toothed ring on a differential-gear housing. The latter housing may be rotatable about a vertical axis through 180.degree. to accommodate motors of different axial length.