Abstract: A milling machine includes a rotor drive transmission having a plurality of gears disposed between a prime mover and a cutting rotor. The rotor drive transmission is associated with a rotor transmission hydraulic circuit including a hydraulic gearshift actuator to engage the plurality of gears in one or more gear ratios and a gearshift directional control valve to direct hydraulic fluid to and from the hydraulic gearshift actuator. In occurrence of a fault condition, the rotor transmission hydraulic circuit includes a gearshift trapping valve to maintain hydraulic pressure in the hydraulic gear actuator and the engaged gear ratio of the rotor drive transmission.

Abstract: A power transmission apparatus for vehicle, incorporated in a vehicle equipped with a transmission, includes a forward-reverse switching mechanism with start function produced by adding a function of a vehicle start clutch to the forward-reverse switching mechanism. Additionally, a power transmission system for vehicle includes an internal combustion engine that is a power source for vehicle driving, the transmission, a torsional vibration damper that transmits torque of the internal combustion engine to the transmission, and the forward-reverse switching mechanism with start function of the power transmission apparatus for vehicle. The forward-reverse switching mechanism with start function is disposed between the transmission, and the internal combustion engine and the torsional vibration damper.

Abstract: In a hydraulic control device and a hydraulic control method of a transmission, in a case that an oil supplying section is supplying a first oil to a continuously variable transmission mechanism, a TCU outputs, to an LC control valve of the oil supplying section, a control signal for giving a command to start supply of a second oil to a torque converter if a pulley pressure detected by a pressure sensor reaches a pressure threshold value.

Abstract: A control device for a continuously variable transmission includes a lock-up clutch of a torque converter which is arranged to connect and disconnect a power transmission between a power source and the driving wheel, and a control section configured to output a hydraulic pressure command value. The control section is configured to control a transmission gear ratio of the continuously variable transmission and an engagement state of the lock-up clutch in accordance with a traveling state of a vehicle. The control device includes a learning control section configured to perform a learning control of the engagement state of the lock-up clutch with respect to the hydraulic pressure command value, an oil vibration sensing section configured to sense oil vibration of a line pressure, and a learning control prohibiting section configured to prohibit the learning control when the oil vibration sensing section senses the oil vibration.

Abstract: A hydraulic control device for an automatic transmission where the spool is locked at the first position and the switching pressure can regulate the belt holding force of the primary pulley or the secondary pulley without switching a position of the spool when the engagement pressure is supplied to the second working oil chamber, and the spool is not locked at the first position and the switching pressure can switch the spool to the second position against the urging member when the engagement pressure is not supplied to the second working oil chamber.

Abstract: If the difference between output torque output from an engine and load torque from drive wheels is large and torque input to a lockup clutch is large, since a value of lockup command pressure at which lockup engagement pressure in lockup end control becomes constant standby pressure is set to be high, fast release of the lockup clutch or racing of the engine is suppressed during the lockup end control. If torque input to the lockup clutch is small, the value of the lockup command pressure at which the lockup engagement pressure in the lockup end control becomes the constant standby pressure is set to be low, and a hydraulic pressure output period during which hydraulic pressure is output to the lockup clutch is set to be short.

Abstract: A belt-type continuously variable transmission is equipped with a belt wrapped around across a primary pulley and a secondary pulley, and a CVT control unit for controlling pulley hydraulic pressures to the primary pulley and the secondary pulley. The CVT control unit determines whether an operating state is a driving state where the direction of an input torque inputted to the belt-type continuously variable transmission is from a driving source or a coasting state where the input torque direction is from drive road wheels. The pulley hydraulic pressure for the input torque for when it is determined that the operating state is the coasting state is set higher than the pulley hydraulic pressure for the input torque for when it is determined that the operating state is the driving state, thereby suppressing a slippage of the belt.

Abstract: A continuously variable automatic transmission having a direction selection mechanism with both friction and binary torque transmitting devices. The transmission includes a torque converter which drives a ring gear of a planetary gear assembly. The sun gear of the planetary assembly drives the input of a variable ratio device. In one embodiment, the friction brake is disposed between a planetary gear carrier and a stationary housing or ground and is engaged to provide reverse direction of travel. The binary clutch is disposed between the ring gear and the planet carrier and, when engaged, locks the planetary gear assembly and provides forward direction of travel. In other embodiments, a binary brake is disposed between the planetary gear carrier and the housing and is engaged to provide reverse travel and a friction clutch is disposed between the ring gear and the planet carrier and, when engaged, locks the planetary assembly and provides forward travel.

Abstract: A mower blade speed control system with an electronic control unit providing engine speed commands to an internal combustion engine having a maximum power speed and a reduced economy speed, and a continuously variable transmission with variable displacement providing rotational power from the engine to a plurality of mower blades. The electronic control unit monitors engine load and automatically adjusts engine speed and the displacement of the continuously variable transmission in response to engine load to achieve a constant rotational speed of a plurality of mower blades at different engine speeds.

Abstract: A control device for a belt-type continuously variable transmission CVT includes an engine 1, a belt-type continuously-variable transmitting mechanism 4; a forward/reverse switching mechanism 3 including a forward clutch 31 and a reverse brake 32; and a hydraulic control circuit 71 configured to control a pulley hydraulic pressure and engagement-element pressures for the forward clutch 31 and the reverse brake 32. The control device includes a selection control means for outputting a pulley hydraulic command to obtain an idle-time clamping pressure which is higher than an idle-time minimum pressure (idle-time MIN-pressure) calculated from an input torque, to the hydraulic control circuit 71, when the engine 1 is in operation during a selection of N-range. A position of an element clearance generated in the belt can be maintained even if drag torque is inputted.

Abstract: A hydraulic control system for a CVT may include a pressure regulator subsystem, a ratio control subsystem, a torque converter control (TCC) subsystem, a clutch control subsystem, and is enabled for automatic engine start/stop (ESS) functionality. A system and method are provided for performing an engine auto-stop in a vehicle having a CVT transmission and using an accumulator to fill the pulleys and clutches of the CVT, at least in part, during engine restart.

Abstract: An abnormality detection device for a continuously variable transmission includes: an acquisition module that acquires a control variable for controlling an operation of a forward and reverse switching mechanism that is provided between an engine and a driving wheel to switch between forward rotation and reverse rotation of the driving wheel; and a determination module that determines the control variable for the forward and reverse switching mechanism to be abnormal in the case where a traveling range is selected by the selection unit, a vehicle speed detected by the vehicle speed detection unit is higher than or equal to a predetermined speed, and the control variable for the forward and reverse switching mechanism, acquired by the acquisition module has a value that does not allow a driving force of the engine to be transmitted.

Abstract: A hydraulic pressure control apparatus for an automatic transmission may include a first hydraulic pump connected with an oil tank to receive oil from the oil tank, having a first motor, and adapted to generate a low pressure through an operation of the first motor, a second hydraulic pump connected with the first hydraulic pump to receive the low pressure, having a second motor, and adapted to generate a high pressure through an operation of the second motor, a first regulating valve adapted to receive the low pressure from the first hydraulic pump and to regulate a first operating pressure to supply to the torque converter, and a second regulating valve adapted to receive the high pressure from the second hydraulic pump and to regulate a second operating pressure to supply to the powertrain.

Abstract: A control apparatus for a vehicle provided with an internal combustion engine, an oil pump actuated by said engine for pressurizing operation oil, and a belt-type continuously variable transmission to which the operation oil pressurized by said oil pump is supplied, is provided. A transmission control is performed by controlling an operation oil pressure supplied to said continuously variable transmission, and an automatic stop of said engine is performed when a predetermined condition is satisfied. A transmission ratio of said continuously variable transmission is detected, and a continuable time period of the automatic stop of said engine is set according to the detected transmission ratio upon automatically stopping said engine. The automatic stop of said engine is controlled to end when a continuation time period of the automatic stop of said engine reaches the continuable time period.

Abstract: A method of operating a vehicle drive-train during a starting process. The drive-train has a drive mechanism which can couple a continuously-variable power-branched transmission in which a plurality of transmission ratios can be engaged. The transmission ratios can be varied continuously by adjusting a variator, the transmission driving a drive output. A force flow between the drive mechanism and the drive output can be produced by a frictional shifting element by appropriately adjusting the transmission capacity of the shifting element. When a start command is issued, a starting transmission ratio is engaged in the area of the transmission device. During the engagement of the starting transmission ratio the transmission capacity of the frictional shifting element is adjusted to values greater than zero.

Abstract: An example method of operation comprises, selectively shutting down engine operation responsive to operating conditions and without receiving an engine shutdown request from the operator, maintaining the automatic transmission in gear during the shutdown, and during an engine restart from the shutdown condition, and with the transmission in gear, transmitting reduced torque to the transmission. For example, slippage of a forward clutch of the transmission may be used to enable the transmission to remain in gear, yet reduce torque transmitted to the vehicle wheels.

Abstract: A vehicle control system and a vehicle control device can switch control of a supporting device for support a drive of a vehicle between an ordinary travel in which the vehicle travels in a state that a power source for causing the vehicle to travel is operated and an inertia travel in which the vehicle travels in a state that an operation of the power source is stopped. Accordingly, since the vehicle control system and the vehicle control device switch the control of the supporting device between the ordinary travel and the inertia travel, the vehicle control system and the vehicle control device achieve an effect that the vehicle can be caused to appropriately travel by inertia.

Abstract: A method for controlling the pressure of hydraulic fluid supplied within a transmission of a work vehicle. The method may generally include receiving a signal associated with a load condition of the work vehicle, determining a desired pressure for the hydraulic fluid supplied within the transmission based on the load condition and controlling a valve such that hydraulic fluid is supplied within the transmission at the desired pressure, wherein the transmission includes an input shaft, a counter shaft and at least two driven shafts extending parallel to the input and counter shafts.

Abstract: A method for controlling a gear ratio rate of change in a machine having a continuously variable transmission includes moving an operator input device to a changed position, receiving electronic data indicative of the changed position, and determining a non-limited desired gear ratio based on the changed position. A maximum gear ratio rate of change corresponding to the non-limited desired gear ratio and an actual gear ratio of the continuously variable transmission is selected from an electronically stored gear ratio rate map. A current desired gear ratio is determined based on a previous desired gear ratio and the maximum gear ratio rate of change. A commanded gear ratio of the continuously variable transmission is changed to the current desired gear ratio using electronic signals.

Abstract: A hydraulic control system for an automatic transmission. The hydraulic control system is applied to an automatic transmission adapted to vary a torque capacity of a transmission member by an actuator. The hydraulic control system includes: a discharging device configured to discharge compressible gas entrained in the hydraulic fluid in the actuator; an interrupting device that interrupts power transmission; and a controller configured to determine an entrainment of the compressible gas in the hydraulic fluid, disconnect the power transmission via the interrupting device in a case that an entrained compressible gas is determined, and cause the entrained compressible gas to be removed from the hydraulic fluid by rotating the actuator while interrupting the power transmission.

Abstract: A control apparatus for a vehicular power transmitting apparatus includes a first valve that controls the supply of hydraulic fluid to a running clutch in connection with the switching of the operating state of a first solenoid valve; a second valve that controls the supply of hydraulic fluid to a lockup clutch in connection with the switching of the operating state of a second solenoid valve; and a linear solenoid valve that selectively controls the apply force of the running clutch and the lockup clutch according to the supply of control pressure to the first valve and the second valve. The control apparatus detects a failure state of a part related to the operation of the power transmitting apparatus by the operating state of the running clutch and the operating state of the lockup clutch.

Abstract: A system for controlling a transmission including a fluid pump and a fluid motor operably coupled to one another in a fluid circuit is disclosed. The system includes a controller configured to receive signals indicative of operator inputs, and determine a variable pressure limit in the fluid circuit based on the signals indicative of operator inputs. The controller is further configured to control displacement of at least one of the fluid pump and the fluid motor based on the variable pressure limit, such that a pressure level in the fluid circuit is maintained below the variable pressure limit.

Abstract: A vehicle includes a clutch set, a tank with fluid, an auxiliary battery, an electric fuel pump, and a controller. The electric fluid pump delivers some of the fluid from the tank to a designated oncoming clutch of the clutch set. The controller calculates a predicted flow value for the oncoming clutch during the shift event, and selectively controls the speed of the pump using the predicted flow value during the shift event. The controller controls the pump using an actual flow value when the vehicle is not executing a shift event, i.e., when holding torque. The speed of the electric fluid pump is increased to a first calculated speed determined using the predicted flow value when the shift event is initiated and before filling of the oncoming clutch commences, and is reduced to a second calculated speed determined using the actual flow value when the shift event is complete.

Abstract: Systems and methods for assisted direct start control are provided. An example method varies engine torque, forward clutch engagement pressure, and wheel brake pressure during a vehicle launch responsive to longitudinal vehicle grade to improve launch performance.

Abstract: A power transmitting apparatus for a vehicle mounted with a torque converter and an idle-stop mechanism can be configured to improve fuel economy without cancelling a fuel-cut-off during vehicle speed reduction and to reduce the manufacturing cost by eliminating an electrically-driven oil pump. A power transmitting apparatus can comprise a torque converter, a clutch mechanism, an oil pump, a continuously variable transmission, a clutch control device, an engine control device, and a flow control device. The flow control device can be configured to limit or prevent the supply of oil to the torque converter by the oil pump and to prioritize the supply of oil to the clutch mechanism and the continuously variable transmission when the vehicle speed is reduced below a predetermined value with fuel being cut off by the engine control device during vehicle speed reduction.

Abstract: A hydraulic system for controlling a belt-driven conical-pulley transmission. A pump draws a working medium from a working medium tank or through a cooler return valve from a cooler return line. The cooler return valve is a minimum pressure valve that holds closed a connection between the cooler return line and a pump inlet line through the cooler return valve, as long as the pressure in the cooler return line remains below a specified minimum pressure. The cooler return valve also opens the connection between the cooler return line and the pump inlet line through the cooler return valve as soon as the specified minimum pressure in the cooler return line is exceeded.

Abstract: The line hydraulic pressure setting portion sets the line hydraulic pressure PL, which is the base pressure for the required shift control pressure Pin and the required belt clamping pressure Pd, based on the higher of the required pressures Pin and Pd. At this time, if the continuously variable transmission is to be shifted up, the required Pin calculating portion calculates the required shift control pressure Pin based on one of the target speed ratio ?* and the actual speed ratio ? with which the required shift pressure Pv is calculated to be higher than with the other. As such, the required shift control pressure Pin is set to the minimum necessary level for shifting up the continuously variable transmission and the line hydraulic pressure PL is appropriately set to a level for obtaining the required shift control pressure Pin.

Abstract: A vehicle drive control device includes a continuously variable transmission mechanism (hereinafter referred to as CVT (6) of a torque control type capable of continuously varying a transmission gear ratio, and a controller (34) which controls operations of the CVT (6) and an engine (2). The controller (34) includes a first control section (43; 43A) which controls a torque of the CVT (6) based on a target transmission input torque (TTRN,T), and a second control section (44) which controls a torque of the engine (2) based on a target engine rotation speed (?e,T).

Abstract: A variator torque control system adjusts a variator output so that the actual output torque of the variator closely matches an expected output torque. In an example, pressure values of an existing torque control map are supplemented in real time with calculated pressure supplement values based on the current operation of the variator. The pressure supplement value for each mapped pressure value may be derived based on a prior application of the same or another map value.

Abstract: A method for controlling restart of an engine in a hybrid electric powertrain includes stopping the vehicle and engine, initiating the restart, estimating time required to restart the engine after the restart is initiated, filling and stroking launch elements of a transmission, when the estimated time substantially equals a second estimated time required to fill and stroke said launch elements, and increasing the torque capacity of the launch elements to accelerate the vehicle.

Abstract: An ECU executes a program including the steps of: learning a differential pressure of a lock-up clutch; determining whether or not learning has been completed when a vehicle is in a coasting state and a brake is applied; lowering the lock-up differential pressure such that the lock-up clutch can be disengaged immediately and prohibiting or suppressing control for increasing transmission gain when learning has been completed; and increasing a lower limit guard value for the lock-up differential pressure and performing control for increasing the transmission gain when learning has not been completed.

Abstract: A travel operation structure of a work vehicle, comprising a pair of left and right side brake pedals disposed on either the left or right of a steering wheel; a hydro static transmission for changing the speed of travel; and a stop operation pedal disposed on the other of the left and right of the steering wheel; wherein the corresponding left or right side brake is applied when one of the pair of left and right side brake pedals is depressed, and when both the left and right side brake pedals are depressed, both the left and right side brakes operate, and travel is stopped; and when the stop operation pedal is depressed, operating oil of the continuously variable speed change device is directed into an oil tank, and the continuously variable speed change device is switched to a neutral stop position for blocking transmission of power to the travel device.

Abstract: In one embodiment, when a condition (specifically, brake ON) of rising of a source pressure (line pressure) of a lock-up control valve is satisfied during deceleration lock-up control, a lock-up differential pressure instruction value is corrected to a low side with that source-pressure rising amount taken into consideration.

Abstract: A vehicle is described having a continuously variable transmission by means of which torque is transmitted from an engine to drive wheels of the vehicle, a braking system for applying a braking force to the drive wheels and a controller for setting the transmission ratio of the transmission in such a manner as to maintain a desired speed of the drive wheels or of the engine. In the invention means are provided for applying to the controller a signal indicative of the engine applied torque, and means for supplying to the controller a signal to indicate application of wheel brakes. The controller is operative when the brakes are applied to discontinue setting the transmission ratio in dependence upon the speed of the drive wheels and to set the transmission ratio instead in such a manner as to minimise the absolute value of the engine output torque or the torque transmitted through the transmission or to follow a desired torque setpoint.

Abstract: A vehicle mounted with a continuous stepless transmission having a continuous stepless transmission and a controlling section for performing speed-changing operation of the continuous stepless transmission, the speed change ratio of the continuous stepless transmission being switchable by a speed change operation section, includes: a shift-mode-switching section which switches the mode of a speed change ratio switching, the speed change ratio switching being performed by the speed change operation section, between a first mode for switching the speed change ratio in stages among a plurality of preset speed change ratios and a second mode for switching the speed change ratio continuously or substantially continuously; in which the controlling section further includes a vehicle speed setting section which sets a target vehicle speed at least based on the speed change operation signal detected by operating the speed change operation section and a mode signal detected by switching the shift-mode-switching section

Abstract: In a continuously variable transmission apparatus, by adjusting the transmission ratio of a toroidal continuously variable transmission, an output shaft can be stopped while an input shaft is left rotating in one direction by a drive source. And, when, while the vehicle is running, a select lever is operated to a select position in the reverse direction to the vehicle running direction, in a state where a clutch device is connected, the speed ratio of the continuously variable transmission apparatus is changed from a value corresponding to the vehicle running state to a value 0 capable of realizing the above-mentioned stopping state along a preset condition.

Abstract: By shifting a lock-up clutch of a torque converter from a released state into an engaged state on condition that a gear ratio of an input shaft of a CVT to an output shaft of the CVT is decreasing (upshift), a lock-up control at the time of an increase in vehicle speed is performed while the gear ratio is being changed in a stepped manner. Thus, it is possible to synchronize a decrease in engine rotational speed due to shifting with a decrease in engine rotational speed due to lock-up engagement. Hence, lock-up engagement may be performed so that the driver does not recognize a decrease in engine rotational speed due to the lock-up engagement and, as a result, it is possible to prevent driver's uncomfortable feeling.

Abstract: When a line pressure PL serving as a source pressure of a primary pulley (2) and a secondary pulley (3) is controlled on the basis of a control deviation ?Step, which is the deviation between a step count StepMdl of a step motor (27) corresponding to a target speed ratio I (o) and a value obtained by adding a target deviation GTstep and a starting learned value Gstep to a step count Bstep of the step motor (27) corresponding to an actual speed ratio ip, the engine torque varies dramatically beyond the range of a predetermined value T1 and a predetermined value T2 during a predetermined time period t1, a learning error determination relating to the starting learned value Gstep is prohibited for a predetermined time period t2.

Abstract: A hydrostatically powered vehicle includes an engine operatively associated with a pump that supplies fluid to a propel motor. Based on various sensed and engine operating conditions, a controller determines a desired operating condition for the engine while maintaining the travel speed of the vehicle constant.

Abstract: A hydrostatically driven vehicle has an engine operating a variable displacement propel pump, a displacement of which can vary based on an angle of a rotating swashplate, such that a fluid flow impelled by the pump transfers power to at least one propel motor rotating a wheel of the vehicle. An electronic controller of the vehicle senses an operating parameter of the system, for example, the angle of the rotating swashplate or the direction and speed of rotation of the propel motor with a sensor to yield an actual signal, and relays the actual signal to an electronic controller. The controller determines a desired angle for the rotating swashplate based on the control signal, and compares it to the actual signal from the sensor. Motion of the vehicle is stalled when the angle signal differs from the desired angle by a predetermined extent and for a predetermined period.

Abstract: A sleeve 28 making up a gear ratio control valve 21 is driven by not only a stepping motor 29 but also a secondary actuator 47. Pressure oil is made free to be introduced into the secondary actuator 47 through a manual oil pressure switching valve 37 which is switched over by a gearshift. Then, when the gearshift is operated from a non-running state to a running state, a gear ratio of a toroidal type continuously variable transmission is corrected by a predetermined amount by driving the sleeve 28 by the secondary actuator 47. As a result, while improving characteristic of a vehicle when starting from rest, the vehicle can be prevented from being reduced in speed unintentionally excessively even when the gearshift is operated while running.

Abstract: A variator torque control system and method utilize a hydraulic actuator to control the variator output via a torque control map, wherein the values of the torque control map are evaluated and modified during use of the map to improve map accuracy. In an example, errors in the map are evaluated to determine whether a system fault has occurred.

Abstract: A belt continuously variable transmission includes a primary pulley (1), a secondary pulley (2), a belt (3), a hydraulic pump (21), a speed ratio control valve (13) that regulates hydraulic pressure from the hydraulic pump (21) and supplies the hydraulic pressure to the primary pulley (1) and the secondary pulley (2), a motor (14) that drives the speed ratio control valve (13), a controller (11) that controls the motor (14), and an oil temperature sensor (26) that detects the temperature of a working fluid. The controller (11) stops energization to the motor (14) when the temperature of the working fluid becomes greater than a first predetermined temperature while the vehicle is at rest in an idling state.

Abstract: There is provided an oil pressure reduction rate restricting apparatus for a V-belt type continuously variable transmission, which is comprised of a reduction rate restricting section that calculates a reduction rate restricted secondary pressure and a reduction rate restricted primary pressure by restricting respective reduction rates of the target secondary pressure and the target primary pressure when the reduction rates of the target secondary pressure and the target primary pressure calculated by a target secondary pressure calculating section and a target primary pressure calculating section, respectively, are equal to or greater than respective predetermined values. The secondary pressure and the primary pressure are controlled based on the reduction rate restricted secondary pressure and the reduction rate restricted primary pressure whose reduction rates have been restricted such that the gradient thereof are small.

Abstract: In a hydraulic system for an automatic transmission, a method for automatically draining fluid from an oil cooler and related hydraulic lines when power is off to prevent fluid leakage, escape and outflow when they are disconnected from the system. A control system includes a source of relatively high pressure when power is on, an oil cooler, fluid circuit lines for supplying transmission oil to the cooler, a source of low pressure for containing fluid, such as an oil sump, and a valve hydraulically connected to the circuit, high pressure source, and low pressure source, the valve having a first state at which a hydraulic connection through the valve between the circuit and the source of low pressure is closed when power is on, and a second state at which a hydraulic connection through the valve between the circuit and the low pressure source is open when power is off.

Abstract: A drive control apparatus for a vehicle including an engine which generates power using combustion of fuel; a hydrodynamic power transmission device which transmits an output of the engine via fluid, includes an input side and an output side which can be directly coupled; a lock-up engagement device which engages the lock-up clutch when a predetermined lock-up engagement condition is satisfied; and a lock-up restriction device which stops engagement control performed by the lock-up engagement device so as to disengage the lock-up clutch if there is a possibility that knocking will occur in the engine when the lock-up clutch is engaged by the lock-up engagement device. A shock at the time of tip-in acceleration is suppressed irrespective of knocking prevention control so as to improve riding comfort. In addition, occurrence of a droning noise is suppressed.

Abstract: A control apparatus for feedback-controlling an engaging action of a clutch disposed between an engine and a transmission of an automotive vehicle, wherein an engaging force control device is operated upon an engaging action of the clutch, for determining a control amount and feedback-controlling the engaging action on the basis of the determined control amount such that the clutch is placed in a desired state of engagement, and a control amount limiting device is operated to limit the determined control amount when the determined control amount has changed to cause an engaging force of the clutch to be reduced.

Abstract: A cruise control system for a utility vehicle, which is speed-controlled by a hydrostatic transmission, includes a controller having an input for receiving a selectable set speed signal, and an output for sending a speed control signal to at least one proportional valve of a hydrostatic transmission servo control system. The vehicle ground speed is continuously monitored by a speed sensor operatively associated with a rotating gear in the vehicle drive train that rotates in proportion to vehicle ground speed, to create a ground speed signal. The selectable set speed signal can be input to controller memory by driving the vehicle at a desired ground speed and then activating a speed set switch. The speed control algorithm of the controller thereafter compares the set speed to the ground speed signal from the speed sensor and corrects the control signal to the proportional valve to correct hydrostatic transmission speed output.

Abstract: Within the scope of the method for including the temperature in the calculation of the definite, operating-point dependent maximum and minimum adjustment speeds in a continuously variable belt-drive transmission, the actual limiting values for the maximum possible adjustment gradient are continuously calculated in every operating state by a physical-mathematical pattern wherein the hydraulic routes of the variator, the clutches integrated in the transmission and the lubrication are modeled as laminar inserts and the route of the control unit leakage as coupled laminar and turbulent hydraulic transmission elements.

Abstract: The proposal is for a process for controlling a CVT of the bevel-pulley-belt type in which, on the occurrence of a wheel-locking drive situation, a converter bridging clutch is disengaged and at the same time a forward or reverse drive clutch is disengaged. The pressure level of the secondary pulley (3) is hereby raised and the transmission ratio of the CVT is changed in accordance with a predeterminable transmission ratio change and a predeterminable gradient.