Abstract: A launch control method for a continuously variable transmission (CVT) is provided, where the CVT comprises a hydro-mechanical variator, a summing transmission connected to an output side of the variator, and a clutch for selectively connecting the summing transmission to an output member. The method determines whether a launch has been requested, and adjusts a variable displacement pump of the variator to a predetermined fixed displacement. Engagement of the clutch is commenced, and the method then determines whether a predetermined degree of slip exists between input and output elements of the clutch. The clutch is held at its present state of engagement when the predetermined degree of slip has been established, and the variator is placed into a torque control mode. The method then determines when there is zero slip between the input and output elements of the clutch, and then instructs full engagement of the clutch.

Abstract: A method for determining a control parameter of a power or torque distribution regulator for a hybrid drive of a work machine having the steps of automatically determining a work cycle that has just been performed by the work machine, and selecting of the control parameter as a function of the work cycle determined in the previous step.

Abstract: An integrated drive generator includes an input shaft and an input drive gear connected to the input shaft. The integrated drive generator also includes an input driven gear meshed with the input drive gear. The integrated drive generator also includes a hydraulic speed trimming device. The hydraulic speed trimming device includes an input shaft connected to the input driven gear, an output shaft, an accessory drive gear connected to the output shaft, and an output ring gear connected to the output shaft. The input driven gear, the accessory drive gear, and the output ring gear are coaxial and disposed proximate a first end of the hydraulic speed trimming device. The integrated drive generator also includes a pump assembly with a pump drive shaft and a pump gear connected to the pump drive shaft and meshed with the accessory drive gear.

Abstract: A transmission device (1) with secondarily coupled power splitting in which part of an applied torque can be conducted, in a first power branch (3) at least by way of a hydrostatic system (4), and the other part of the torque can be conducted in a second power branch (5) via mechanical system (6), located between a transmission input (7) and a transmission output (8). The hydrostatic system (4) of the first power branch (3) includes at least one pump (12) and at least one motor (13) that is functionally connected to the pump by way of a hydraulic circuit, and both of the pump and motor are adjustable. The two power paths (3, 5) can be summed by a summing gear system (9). The pump (12) is made smaller than the motor (13).

Abstract: Method for engaging and disengaging a hydraulic motor which is adjustable in its displacement from and to a hydrostatic drive train of a hydromechanical transmission with a closed hydraulic fluid circuit. Two adjustable hydraulic motors and a hydraulic pump are arranged in parallel in the hydrostatic drive train and connected to a mechanical drive on the output side. At least one of the two hydraulic motors is connected to the mechanical drive via an assigned clutch. As appropriate to the driving situation, during operation of the other hydraulic motor and the hydraulic pump at least one of the hydraulic motors is engaged via the assigned clutch with the hydromechanical transmission from which the hydraulic motor was previously disengaged, likewise as appropriate to the driving situation.

Abstract: An actuator displacement measuring system in an electro-hydraulic system for a construction machine is disclosed, which can detect an actuator displacement using the characteristics of an electro-hydraulic system. The actuator displacement measuring system includes controlling driving of an electric motor, determining whether the electric motor is driven, determining whether a set pressure value of a relief valve is larger than or equal to a measured pressure value of the hydraulic system if a displacement value of an actuator that is always detected deviates from a zero value of a reference position, setting the actuator displacement value to a previous value if a pressure value of the hydraulic system is larger than or equal to a pressure value of a relief valve and calculating the actuator displacement value using a rotating speed of the electric motor.

Abstract: A method for controlling a continuously variable transmission of a work machine during a shuttle shift is disclosed. The method may generally include initiating a directional swap by disengaging an off-going directional clutch of the continuously variable transmission and slipping an on-coming directional clutch of the continuously variable transmission to decelerate the work machine in an off-going direction. In addition, the method may include estimating a total amount of energy to be dissipated in the on-coming directional clutch during the shuttle shift, comparing the total amount of energy to a predetermined energy threshold and, if the total amount of energy is equal to or exceeds the predetermined energy threshold, performing the reversion action to complete the shuttle shift, wherein the reversion action corresponds to an action taken to engage one of the off-going directional clutch or the on-coming directional clutch so as to permit the shuttle shift to be completed using ratio changing.

Abstract: A continuously variable transmission (CVT) for a vehicle engine which provides enhanced cold starting and reduced wear under all conditions. The transmission includes mechanical transmission components, hydrostatic transmission components, and a clutch to decouple only the mechanical transmission components from driving engagement with the engine or other power source. Decoupling allows cold starting with significantly reduced parasitic losses. The transmission may use a hydraulic circuit to re-engage the mechanical transmission components with the input power source and full driving re-engagement of the transmission with the power source, such as an engine, after the transmission reaches a desired speed.

Abstract: One disclosed embodiment relates to a propulsion system for a machine. The propulsion system may include a prime mover operatively connected through a continuously variable transmission to a propulsion device. The propulsion system may also include propulsion-system controls that control an operating parameter of the continuously variable transmission, which may include adjusting the operating parameter based on operator input. Controlling the operating parameter may also include determining an adjustment limit for the operating parameter based on one or more operating conditions and applying the adjustment limit to the operating parameter to modify at least one of acceleration and jerk of the machine based on the one or more operating conditions.

Abstract: A method for controlling an automated clutch, which comprises a hydraulic clutch actuating system having a hydrostatic actuator, the pressure of which is detected. The method includes using the pressure of the hydrostatic actuator to adapt the characteristic curve of the clutch.

Abstract: A method of controlling output torque in a hybrid or electric vehicle transmissions includes calculating a first long-term output torque constraint and a first short-term output torque constraint. A first effective output torque constraint is determined from at least one of the first long-term and short-term output torque constraints. The first effective output torque constraint is bounded by both of the first long-term and short-term output torque constraints. The method may further include calculating a rate limit, such that determining the first effective output torque constraint includes restricting the magnitude of changes in the first long-term output torque constraint to the calculated rate limit. A spread between the first short-term output torque constraint and the first effective output torque constraint may be measured, and the rate limit calculated as a function of that spread. The rate limit may also be calculated with an inversely-proportional relationship to the spread.

Abstract: A power transfer assembly for use in a four-wheel drive vehicle has a torque transfer mechanism equipped with a power-operated clutch actuator for controlling adaptive engagement of a friction clutch and a control system for controlling actuation of the clutch actuator. The control system and its method of operation are adapted to control actuation of the clutch actuator based on whether the vehicle is operating in an engine drive mode or an engine coast/braking mode.

Abstract: A method and system for executing a shift from a first fixed gear to a second fixed gear in a powertrain system comprising a two-mode, compound-split, electro-mechanical transmission operative to receive a speed input from an engine is described. It includes deactivating an off-going clutch, and generating a time-based profile for rotational speed of an oncoming clutch. The input speed is controlled based upon the rotational speed of the oncoming clutch and an output of the transmission. The oncoming clutch is actuated, preferably when the input speed is synchronized with a rotational speed of an output shaft of the transmission multiplied by a gear ratio of the second fixed gear, preferably after a predetermined elapsed period of time in the range of 500 milliseconds.

Abstract: Two parallel planetary gear sets with a common sun gear output are geared to a hydraulic pump and motor system. Input is applied to both planetary gear sets in parallel. Output is from both planetary gear sets in parallel. Two planetary gear set members, one in each set, are geared to the pump and motor and are used to control the ratio of the infinitely variable gear transmission (IVGT). The displacement ratio of the pump and motor, connected to these two members, controls the ratio of the IVGT.

Abstract: The invention combines the features of a supercharger, a turbocharger and turbo-compounding into one system, utilizing a hydraulic or mechanical continuously variable transmission to drive the turbocharger up to a specific speed or intake manifold pressure and then holding the ideal speed to keep it at the right boost pressure for the engine condition. The benefits of a supercharger, which is primarily good for high torque at low speed, and a turbocharger, which is usually only good for high horsepower at high speeds are merged. Once the exhaust energy begins to provide more work than it takes to drive the intake compressor, the invention recovers that excess energy and uses it to add torque to the crankshaft. As a result, the invention provides the benefits of low speed with high torque and the added value of high speed with higher horsepower or better fuel economy all from one system.

Abstract: A method for achieving high quality shifts with one hydraulic unit near zero displacement when using dog clutches. This method includes selecting the proper displacement and vocation (whether the hydrostatic unit works as a pump or motor) of a low displacement hydraulic unit during the shift, selecting the appropriate speed differential between the clutch elements, selecting the proper vehicle speed at which to make the shift, and sequencing the displacement changes of the hydraulic units with a controller in order to achieve the desired shift conditions.

Abstract: A power train control system for a mobile machine is disclosed. The power train control system has a power source configured to produce a power output, a transmission device operatively connected to receive the power output and propel the mobile machine, and a control module. The control module is configured to receive an indication of a power demand, receive an indication of a current travel speed of the mobile machine, and reference the power demand and the current travel speed with a power train efficiency map to determine a desired power source speed. The power train control system is also configured to control operation of the transmission device to bring a speed of the power source within a predetermined amount of the desired power source speed.

Abstract: An axial piston pump and an axial piston motor, mounted in a housing each have a rotating element and a non-rotating element. Each non-rotating element is mounted for tilting movement about axes transverse to the axes of rotation of the rotating element, on trunnions in its own respective pair of mounting journals in the housing for controlling the transmission ratio. The pump and the motor are disposed side-by-side in the housing with the axes of rotation approximately parallel to each other. A stationary manifold, fixed to the housing, has surfaces in contact with the rotating pump element and the rotating motor element. Fluid passages open in the surfaces in fluid communication with the pump and motor cylinders through a pump/manifold interface. Internal fluid passages in the stationary manifold convey fluid pressurized in the pump directly to the motor, and convey spent fluid displaced from the motor back to the pump.

Abstract: The method serves for the shift sequence control of a continuous automatic transmission, especially of a motor vehicle, having gear-stage switchover. The transmission ratio of the automatic transmission is adjustable within a set gear stage by means of an adjusting unit. Here, it is provided that a coordinated, data-dependent control of the gear stage switchover and the continuous transmission ratio adjustment takes place with the aid of a common shift sequence control system.

Abstract: A PTO transmission includes a split power transmission unit having an output member connected to a PTO shaft, a first input connected to an engine output shaft and a second input connected the output of a variable speed drive unit. A control unit controls the speed of the variable speed drive unit as a function of sensed engine speed and maintains the PTO shaft at a constant speed. The split power transmission is preferably a planetary gear unit. The variable speed drive unit preferably includes a variable displacement hydrostatic pump driving a fixed displacement hydrostatic motor which drives a sun gear of the planetary gear unit. This system transmits power to the PTO shaft from both the engine and from the variable speed drive unit. The control unit may also control the variable speed drive unit so that the speed of the PTO shaft is maintained at a desired ratio with respect to the ground speed, or so that the speed of the PTO shaft is maintained at a speed set by an operator.

Abstract: A method and system for controlling a transmission in a work machine is provided. The output of a hydrostatic transmission having a source of pressurized fluid is combined with the output of a mechanical transmission having at least one engaged clutch. An operational speed of an engine that provides an input to both the hydrostatic transmission and the mechanical transmission is sensed. The at least one clutch of the mechanical transmission is disengaged and the displacement of the source of pressurized fluid is modified when the operational speed of the engine drops below a stall limit. The disengagement of the at least one clutch and the modification of the displacement of the source of pressurized fluid allow the operational speed of the engine to rise above the stall limit.

Abstract: A parallel hydromechanical continuously variable transmission has a housing (107) that holds a make-up pump (52), and has internal cavities for holding operating assemblies of the transmission, including an axial piston pump (50) and an axial piston motor (60). The pump (50) and motor (60) each has a rotating element (206) and a non-rotating element (258). Each non-rotating pump element is mounted for tilting movement on trunnions (258P) in its own respective pair of mounting journals in the housing (107). The tilting axes of the non-rotating elements (258) lie transverse to the axes of rotation of the rotating elements (206). The pump (50) and the motor (60) are disposed side-by-side in the housing (107) with the axes of rotation approximately parallel to each other. A stationary manifold (70), fixed to the housing (107), has one surface in contact with the rotating pump element (206P) and a second surface in contact with the rotating motor element (206M).

Abstract: The output speed of a hydrostatic unit in a transmission is determined using a pair of variable reluctance sensors, one on a gear driven by the hydrostatic unit output and the other on the carrier of the planetary system. One of the two sensors will always be measuring a relatively high speed from which the hydro output is directly determined or indirectly determined using the current engine speed. Thus the frequency of the speed sensor used to determine the hydrostatic unit output speed is not decreased at slow hydrostatic unit output speeds.

Abstract: A continuously variable hydrostatic transmission in which a fixed displacement hydraulic pump and a variable displacement hydraulic motor are disposed on a drive axle, and connected via a closed hydraulic circuit. The continuously variable hydrostatic transmission shifts gears by changing the inclination angle of a movable swashplate provided for the variable displacement the hydraulic motor. The continuously variable hydrostatic transmission may perform a correction control, where the movable swashplate is moved to the TOP side, and the maximum value of the shift amount is obtained. Then, the movable swashplate is moved to the LOW side, and the minimum value is obtained. By storing the maximum and minimum values, correction data is derived. After that, the TOP and LOW transmission gear ratios are determined on the basis of the correction data.

Abstract: An apparatus, for controlling a plurality of hydraulic motors and a clutch for driving a drive shaft, can prevent a speed change shock and a load slip of a hydraulic motor as well as making a structure simple. The apparatus includes: a first volume variable hydraulic motor (1), connected to the drive shaft (3) through the clutch (5); a second volume variable hydraulic motor (2), which is always connected to the drive shaft (3); first tilt rotation control means (7, 8), for controlling a tilt rotation amount (a discharge volume cc/rev) of the first hydraulic motor by receiving a drive side pressurized oil (Pac) of the first hydraulic motor; and a zero tilt rotation holding means (10, 10A), for holding the tilt rotation amount of the first hydraulic motor at substantially zero in a state wherein the tilt rotation amount of the first hydraulic motor is controlled to be substantially zero.

Abstract: A transmission assembly having a hydrostatic transmission with a variable displacement hydraulic device which controls a motor speed ratio. The transmission assembly further includes a mechanical transmission coupled to the hydrostatic transmission and having a first range and a second range and an output shaft driven at a travel speed ratio. The torque through the hydrostatic transmission reverses when the mechanical transmission shifts from the first range to the second range. A synchronous travel speed ratio is the motor speed ratio which produces the same travel speed ratio in both the first gear range and the second gear range. An equal displacement travel speed ratio is the travel speed ratio at which a displacement of the variable displacement device in the second gear range is the same as the displacement in the first gear range. A travel speed ratio differential is a difference between the synchronous speed ratio and the equal displacement travel speed ratio.

Abstract: The invention is based on a continuously variable transmission comprising a mechanical power branch and an electronically controlled hydraulic power branch which can be adjusted via a swash plate (7), a summarizing transmission and a multi-stage transmission with hydraulically actuated, force-locking shift elements (11-14). The shift signals of the shift elements (11-14) are generally triggered when a shift or synchronizer speed is reached. Thereafter elapses a response or reaction time and an adjusting time until the shift elements (11-14) are engaged. This results in long clutch shift processes. It is proposed that the response and engagement times of the shift elements (11-14) be compensated by a control unit.

Abstract: A hydrostatic/mechanical multiple path power transmission comprises an adjustable hydrostat unit (4), a summing planetary gearbox (10) with two input shafts (6, 8) and at least two output shafts, and a step gearbox (11) connected to the output shafts. In order to adjust low speeds and standstill precisely and rapidly, the following method is specified: rotational speed signals are formed by sensors (50, 51) on the two input shafts (6, 8) of the summing planetary gearbox (10), and are compared with each other by counters (61, 62); the actual pulse count difference formed in this way is compared with a desired pulse count difference, and a controller [sic] and the output signal of a controller (66) that responds to the result of this comparison effects adjustment of the hydrostat (4).

Abstract: A mechanical transmission (3; MT) is interposed between an input shaft (1) and an output shaft (2), and a hydrostatic transmission (4; HST) is disposed in parallel with the MT (3). Between the input shaft (1) and the input side of the MT, a third planetary gear set (15) is interposed for reducing input shaft rpm to reduced rpm corresponding to a predetermined reduction gear ratio. A fourth selectively-engageable clutch (13) for applying rotation at the reduced rpm in low to intermediate change gear ratio ranges and a fifth selectively-engageable clutch (14) for applying rotation at the input shaft rpm in a high change gear ratio range are provided, so that the number of modes of operation is increased.

Abstract: A method of changing the range of a hydrostatic/mechanical power split transmission is specified: firstly, the command to engage the clutch for the next range is given, then the transfer of the load to this clutch is carried out and then the command to disengage the clutch for the old range (V.sub.x) is given if, during the load transfer, a characteristic speed value of the summing planetary gearbox (10), for example the speed of the planet carrier (25), remains constant. In this way, the sensors for the clutches are dispensed with and quicker changes of range are made possible.

Abstract: The present invention provides a method for determining the presence of a target organic molecule in a sample which comprises either (A): first, adding a substrate molecule to the sample, the substrate molecule being a conjugate of the target organic molecule and a reporter molecule; second, adding a catalytic monoclonal antibody to the sample which (1) recognizes and binds the target organic molecule when the target organic molecule is present in the sample and (2) recognizes and binds the substrate molecule when the target organic molecule is not present in the sample; and third detecting a change in the sample signifying the absence of the target organic molecule, the change being the product of an antibody-catalyzed reaction and thereby determining the presence of an organic molecule in the sample; or (B): first adding a substrate molecule to the sample, the substrate molecule being a conjugate of a molecule complementary to the target molecule and a reporter molecule; second adding a catalytic monoclonal

Abstract: A control system designed such that if a heavy load is imposed on a vehicle during running and a hydraulic relief state in which an oil pressure in a hydraulic circuit for a hydrostatic transmission unit exceeds a relief pressure is detected, the angle of a discharge controlling swash plate for a pump is reduced to a specified value (e.g., 50% of the maximum angle) or less, whereby the stall of the vehicle and the overheat of machine parts are prevented.

Abstract: The present invention relates to a method and system for controlling a split torque transmission having a hydrostatic transmission and a mechanical transmission. The control system employs a transmission control and includes a transmission input speed sensor, a transmission output speed sensor, a motor speed sensor, a speed input mechanism, a direction control mechanism, and a range selector mechanism. A microprocessor including a fuzzy controller controls the transmission in response to a input from the speed sensors and the speed input mechanism, the direction control mechanism and the range control mechanism.

Abstract: A propulsion unit, preferably a propulsion unit for a utility vehicle, as well as a method for controlling same are disclosed. The propulsion unit comprises an engine, a transmission and a power take-off unit having a power take-off shaft. A first fraction of the engine output power is directed to the transmission, whereas a second fraction is directed to the power take-off shaft. At least one of the power fractions is detected by means of measuring units. The power fraction transmitted to the transmission is limited to a predetermined limit value. It is, therefore, possible to install a propulsion unit with an engine, the output power of which being higher than the admissible input power of the transmission.

Abstract: A response control system for a hydrostatic-mechanical transmission. In this system, it is determined in digging/moving operation whether an actual speed ratio which is the ratio of the revolution speed of the output shaft to the revolution speed of the power source is equal to a specified value or less, and if so, a target speed ratio which is a target value for the ratio of the revolution speed of the output shaft to the revolution speed of the power source is set, limiting the amount of change in the target speed ratio per unit time. Based on the target speed ratio thus set, the angle of at least either of discharge controlling swash plates is controlled, thereby reducing vehicle acceleration at the primary stage of digging. In order to slow down the response to a change in load during digging operation, a constant indicating the response to a change in engine revolution is set small in proximity to a target engine revolution speed.

Abstract: A continuous-variable ratio transmission comprising a ratio-varying unit ("variator"), and an epicyclic unit having three outputs arranged concentrically. Two of those outputs are connected respectively in fixed ratio to opposite ends of the variator, so that as the variator ratio changes, the speed of one of these outputs always rises and that of the other falls. These two outputs are also connected by appropriate gearing and clutches to the CVT output shaft. Successive regimes of operation, so extending the overall ratio range of the CVT, are obtained by alternatively connecting each of the two epicyclic outputs to the CVT output. Ratios and other parameters are chosen so that regime changes are synchronous.

Abstract: A method is disclosed for controlling the shift points in a continuously variable transmission having a closed loop control wherein the output of the continuously variable transmission is generated by a hydrostatic transmission or by a combination of the hydrostatic transmission and a mechanical transmission having a summing planetary and high and low speed clutches.

Abstract: A target engine revolution speed is calculated based on the throttle position of an engine such that the amount of change in the target engine revolution speed with respect to time is limited. According to the target engine revolution speed thus calculated, a target motor speed ratio, which is a target value for the ratio of the revolution speed of a motor in a hydrostatic transmission unit to the revolution speed of the engine, is set. With this target motor speed ratio, the angle of at least either of discharge controlling swash plates is adjusted.

Abstract: An apparatus for torque-converter clutch transmission includes a final output planetary gear, at lease a braking pump, a compound planetary gear train, an oil path system, and a centrifugal pump. The final output planetary gear includes a sun gear mounted on an engine crankshaft, a planetary carrier mounted on an output shaft, and a ring gear. The compound planetary gear train includes first and second planetary gears which together share a common ring gear. The first planetary gear further includes a sun gear mounted to the engine crankshaft and a planetary carrier connected to a rotor shaft of the braking pump, and a ring gear, while the second planetary gear further includes a sun gear connected to the ring gear of the final output planetary gear and a planetary carrier fixedly mounted to an inner wall of a gear box.

Abstract: A process and device for controlling a hydrostatic positioning mechanism (HG) of a hydrostatic/mechanical, continuous output-distributing power shift gear in which after an engagement of a clutch (K2, K3) of a new gear in a load-free synchronous condition, the positive displacement volume is respectively continuously triggered for a change until the gear branch, which is still running, is released triggering by the clutch (K2, K3) to be disengaged respectively in the disengaging direction and by monitoring a setting signal of a clutch setting sensor (KS2, KS3) of the clutch (K2, K3) to be disengaged until a setting change is signaled.

Abstract: An infinitely variable hydrostatic torque-routing transmission with at least two operating ranges shiftable via switching elements includes a first, mechanical part, including a planetary differential gear, and a second, hydrostatic part, including two adjustable hydrounits. The hydrounits are coupled to each other energetically, are operable in both directions as pump or motor, and are coupled to the mechanical part. The ring gear is coupled, in the various operating ranges, for control of the direction of rotation and speed of rotation of the transmission output shaft, to a first hydrounit, and with the second hydrounit being in the first operating range in drive connection with the transmission output shaft via an alternating switching element, while the first hydrounit, connected to the ring gear, operates as a pump and the second hydrounit as a motor.

Abstract: A method is disclosed for providing a smooth power transition between a variable displacement pump and a variable displacement motor when a mechanical feedback is not provided. The method includes sensing and comparing the speeds of the variable displacement pump and the variable displacement motor based on known maximum volumetric displacements and reducing the rate of change of displacement of one of the variable displacement pump or the variable displacement motor when it is determined that the one is near its maximum displacement position and simultaneously initiating a change in displacement of the other thereof. The subject arrangement ensures that there is no detrimental interruptions of power during the transition of changing of displacement of one of the variable displacement pump and the variable displacement motor to changing the displacement of the other one thereof.

Abstract: A control mechanism for a hydrostatic-mechanical power transmission system having a mechanical transmission unit driven through an input shaft connectable to a power source, and a hydrostatic transmission unit that is connectable to the input shaft and includes a pump and a motor each having a displacement setting swash plate. The control mechanism further includes a differential unit for connecting an output shaft to the mechanical transmission unit and the hydrostatic transmission unit to drive. At least either of the displacement setting swash plates is variable in angle.

Abstract: Upon detection of execution of operation for stopping a vehicle during its running state and of a drop in an actual speed ratio below a predetermined value, the actual speed ratio being the actual ratio of the revolution speed of an output shaft to the revolution speed of a power source, a feedback amount is determined, setting the integral component of the difference between a target motor speed ratio and an actual motor speed ratio to zero. Based on the feedback amount thus determined, an operation amount for controlling the angle of a swash plate is computed. With this amount, the angle of the swash plate is controlled.

Abstract: A control system in which a judgment is made such that (i) a vehicle is in a forward drive control state, on condition that the forward/reverse drive lever is placed in the forward drive position and the actual speed ratio exceeds a specified small value in a forward drive direction, (ii) the vehicle is in a reverse drive control state on condition that the lever is placed in the reverse drive position and the actual speed ratio exceeds a specified small value in a reverse drive direction, (iii) the vehicle is in an engine brake control state, on condition that the lever is placed in the neutral position and the actual speed ratio exceeds the specified small value in the forward or reverse drive direction, (iv) the vehicle is in an FR shift control state, on condition that the lever is placed in the forward or reverse drive position and the actual speed ratio exceeds the specified small value in the reverse or forward drive direction, and (v) the vehicle is in a neutral control state, on condition that the le

Abstract: The maximum value of target motor speed ratio is calculated from the allowable revolution speed of a motor, and based on the maximum value, an allowable value of target speed ratio is set. Target speed ratio is then limited to the allowable value or less. This enables it to prevent overrun occurring e.g., when the vehicle rolls down a hill.

Abstract: A speed change gear control system, wherein gear shift control for shifting the transmission from an arbitrary speed range into a higher speed range which provides higher absolute speed than the arbitrary speed range is performed, provided that the actual speed ratio e of the transmission satisfies .vertline.E.sub.1 .vertline.<.vertline.e.vertline.<.vertline.E.sub.0 .vertline. where E.sub.0 is a speed ratio for a shifting point at which the transmission is shifted from the arbitrary speed range into the higher speed range; and E.sub.1 is a specified speed ratio, or provided that .vertline.e.vertline.+(.DELTA.e/.DELTA.t).times.T.sub.1 >.vertline.E.sub.0 .vertline.-.DELTA.E.sub.1 where .DELTA.e is an increase in the speed ratio e over a period of time .DELTA.t; T.sub.1 is the filling time required for supplying hydraulic oil to a clutch which shifts the transmission from the arbitrary speed range to the higher speed range; and .DELTA.E.sub.1 is a specified small speed ratio.

Abstract: A transmission and control mechanism for a hydrostatic-mechanical power transmission system, provided with a mechanical transmission driven through an input shaft connected to a engine, a hydrostatic transmission connected to the input shaft, and a differential unit for connecting an output shaft to the mechanical and hydrostatic transmissions. The hydrostatic transmission includes a swashplate type pump and motor, with at least one of the swashplates being variable in angle. There is an engine revolution speed sensor, a target motor speed ratio setting device for setting a target motor speed ratio based on whether the engine speed is above, below or within a predetermined speed range, and a swashplate angle controller for controlling the swashplates according to the target motor speed ratio.

Abstract: The gearbox includes a multi-shaft toothed-wheel planetary gearing and a continuously adjustable hydrostatic transmission having toothed-wheel auxiliary transmission stages and gear-changing clutches. The hydrostatic transmission is associated with a displacement-type machine with constant displacement volume. In the planetary gearing, one shaft forms the input shaft to which the adjustable displacement-type machine is connected. A second shaft of the planetary gearing is connected to the constant-volume displacement-type machine. Third and fourth shafts of the planetary gearing represent coupling shafts. The coupling shafts alternately act via at least two auxiliary transmission stages, also called gears, on the output shaft. The coupling shafts change their speeds in such a manner that one coupling shaft becomes steadily faster and the other one becomes steadily slower. They behave in such a manner that they exhibit equal speeds in one extreme position.

Abstract: The gearing consists of a four-shaft toothed-gear planetary (epicyclic) transmission and a parallel, infinitely variable hydrostatic transmission, as well as additional gear wheels; toothed clutches achieve the various gears (speeds), whereas the hydrostatic transmission effectuates the infinitely variable adjustment of the infinitely variable transmission of the entire gearing; the gear shifting takes place at a synchronous speed of rotation, load-free, and without interrupting the tractive force. The special characteristic consists in the design of the toothed clutches and the control that has been provided for the shifting action, the effect being that the shifting into a new gear and out of the previous one is completely smooth and free of jolts. Apart from provding this comfortable and easy shifting action, the gearing also possesses an extensive range, overall, of transmission adjustment capability, as well as a good efficiency factor. Thus, it is very suitable for application in motor vehicles.