Abstract: A method of operating a valve system of a transmission comprising part of the vehicle drive train through a valve unit and said valve unit's electro-magnetic activator configuration. In a transmission's hydraulic system and is part of the vehicle drive train, its hydraulic pressure value (p_EDS) can be employed and adjusted through a valve unit configuration by applying a pulse-width-modulated current signal (i_EDS) to the electro-magnetic activator system. The pulse-width modulated current signal (i_EDS) and its amplitude (A) and/or its pulse duration (pw1) will periodically change, during the applied Dither-Modulation, by maintaining the required pressure value (p_EDS) at the same time, whereby a lengthwise movable anchor, which is attached a valve shaft of the valve system, receives hereby an imposed vibrating oscillation. According to the invention, the Dither-Modulation is activated or deactivated during pre-defined operating conditions of the vehicle drive train.

Abstract: When a speed ratio (ip) at a stopping time of the vehicle cannot be stored, an operating position of a step motor (27) is initialized to a home position such that a primary pulley pressure (Ppri) is completely drained, a secondary pulley pressure (Psec) is increased to a predetermined pressure (P1), and a pulley ratio (the speed ratio (ip)) between a non-rotating primary pulley (2) and a non-rotating secondary pulley (3) is set at a lowest speed ratio. As a result, the primary pulley pressure (Ppri) is supplied reliably, and the startability of the vehicle improves.

Abstract: A conical disk assembly including a shaft carrying an axially movable disk and having a fixed disk rigidly connected to the shaft. A support ring having first ramp surfaces facing the axially movable disk is carried on the shaft, and a rotatable sensing piston having second ramp surfaces that face the first ramp surfaces is axially movable along the shaft. Rolling elements are positioned between the ramp surfaces, and when the ramp surfaces are rotated relative to each other, the rolling elements move the sensing piston axially along the shaft. A guide ring is rigidly operatively connected to the axially movable disk and includes guide surfaces associated with the ramp surfaces for radially supporting the rolling elements. The guide ring and the support ring are connected with each other in a non-rotatable and axially movable manner to facilitate assembly of the conical disk assembly.

Abstract: A power unit for a motorcycle having a continuously variable transmission, which is housed in a transmission chamber inside a engine body and which accomplishes stepless changes in the transmission of power from a drive pulley shaft to a driven pulley shaft by changing the effective diameter with which a belt actually wraps around each of the drive and the driven pulleys. An input clutch is set between a crankshaft and a drive pulley and is provided on the drive pulley shaft. A starter clutch is set between a driven pulley shaft and a rear wheel and is provided on the driven pulley shaft. The switching between the engagement and disengagement of one of the input clutch and the starter clutch is hydraulically controlled. Meanwhile, the switching between the engagement and disengagement of the other one of the input clutch and the starter clutch is mechanically controlled.

Abstract: A flow control valve is provided in a primary pulley that is a rotor, and includes a first port; a second port; a working fluid channel formed between the first port and the second port and through which working oil passes; a check valve that is formed in the working fluid channel and is opened toward a first-port-side channel from a second-port-side channel of the working fluid channel; and a valve-opening control section (a guide member, a spool, a cylinder, and a drive pressure chamber) that is arranged at the check valve at the side of the second port, that forcibly opens the check valve when discharging the working fluid from the first port to the second port, and increases a channel resistance of the second-port-side channel as an opening amount of the check valve is small. The flow control valve can prevent over-discharge of the working fluid at the beginning of opening the valve.

Abstract: The invention relates to a hydraulic system for actuating a continuously variable belt-driven conical-pulley transmission having two conical pulleys encircled by an endless torque-transmitting means, each of which comprises two conical disks, one of which is axially movable depending on the pressure in an associated pressing chamber, and having a torque sensor which includes a torque sensing chamber that is connected to a hydraulic energy source and is linked with the pressing chambers. The invention is distinguished by the fact that the pressing chambers are connected via a first hydraulic resistance element to the torque sensing chamber, and via a second hydraulic resistance element to an additional pressure chamber, in which a lower pressure prevails than in the pressing chambers and/or the torque sensing chamber.

Abstract: A control apparatus for an automatic transmission includes a control section having a target secondary pressure setting section configured to set a target secondary pressure within a strength limit of the belt, and an operation switching section configured to switch a shift operation from a normal speed to a high speed higher than the normal speed when a predetermined condition is satisfied. The control section is configured to control the secondary pressure regulating valve by a feedback control based on the target secondary pressure and the actual secondary pressure sensed by the hydraulic pressure sensor. The target secondary pressure setting section is configured to modify the target secondary pressure by adding a predetermined quantity when a correction initiation condition is satisfied, the condition initiation including a first condition that the shift operation is performed at a high speed by switching of the operation switching section.

Abstract: In an engine load control device of a work vehicle, an output of an engine is transmitted to a hydraulic actuator via a variable displacement type hydraulic pump. A controller is configured to calculate, based on a target rotational speed of the engine detected by a target rotational speed detecting portion and an actual rotational speed of the engine detected by an actual rotational speed detecting portion, a variation rate per unit time of a difference between the detected results, and to adjust the maximum absorbing torque of the hydraulic pump according to the magnitude of the variation rate.

Abstract: A simplified continuously variable transmission system control provides a variable clamping force and a differential cylinder pressure manipulation to change sheave ratios. The system control uses two pumps. The first pump provides the variable clamping force. The second pump provides pressure changes to effect ratio changes. The clamping force can be varied based upon operator demand on an associated engine.

Abstract: A belt type CVT, which has a variable drive pulley controlling a transmission gear ratio by varying a diameter and a variable driven pulley connected to the variable drive pulley by a belt and controlling a tension of the belt by varying a diameter in a manner opposite to that of the variable drive pulley, in which each of the variable drive and driven pulleys includes belt supports movably installed between a pair of pulley plates, and transmission plates mounted to outside surfaces of respective pulley plates and rotated in opposite directions, thereby moving the plurality of belt supports in the radial directions, and the inner surface of the belt is provided with ratchet gear parts engaged with the belt holding ratchet gear parts of the belt supports, so that the diameters of the variable drive pulley and the variable driven pulley can be more easily and efficiently varied.

Abstract: A medium pressure control device of a continuously variable transmission includes a pump unit capable of switching a discharge volume of an operating medium to a control system, which controls a contacting surface pressure of rotation members and a transmitting member and the transmission ratio by a pressure of the operating medium, in plural stages; and a transmission ratio control unit that controls the control system and relatively delays a transmission shift when the discharge volume of the operating medium to the control system by the pump unit switches from a relatively small volume to a relatively large volume with the transmission shift.

Abstract: A motorcycle capable of reducing and minimizing a period of time in which air that is immixed into hydraulic oil due to a vehicle body being inclined in a left-right direction stays in the hydraulic oil, includes an oil pump to feed hydraulic oil to an oil chamber of a primary pulley and an oil chamber of a secondary pulley, and a first control valve. The first control valve includes a discharge port to discharge the hydraulic oil from a first oil passage continuously from the oil pump to the oil chamber. Under normal control, the controller operates the first control valve based on the driving state of the motorcycle. Further, the controller determines whether or not the inclination of the motorcycle exceeds a predetermined threshold, and when the inclination of the motorcycle exceeds the predetermined threshold, the controller operates the first control valve such that the discharge port is prevented from being closed.

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 sensing device integrated into a conical disk pair includes a sensing piston that is axially movable relative to the input shaft over a radially stepped guide surface that is formed on a shaft on which the sensing device is carried, and a corresponding opposing stepped surface formed on the sensing piston. The steps define a damping chamber between the guide surface and the opposing surface, whose volume changes when the sensing piston moves axially relative to the shaft.

Abstract: A continuously variable transmission in which a sliding member is prevented from inclining is provided. The continuously variable transmission has a first oil passage provided in a movable sheave, and a second oil passage provided in a primary shaft supporting the movable sheave and connected in series to the first oil passage. A working oil is discharged from a hydraulic chamber via the first and second oil passages. The working oil is more difficult to discharge from the second oil passage than the first oil passage.

Abstract: When a vehicle decelerates rapidly, a lower limit secondary pulley pressure (Plmt) is calculated on the basis of a primary pulley rotation speed (Npri) detected by a primary pulley rotation sensor. When a deceleration speed (Gdata) is greater than a predetermined deceleration speed (G1) and a secondary pulley pressure (Psec) detected by a secondary pulley pressure sensor is lower than the lower limit secondary pulley pressure (Plmt), it is determined that slippage is about to occur in a V-belt 4 on a primary pulley side in particular, and therefore speed ratio fixing control is performed.

Abstract: A continuously variable belt transmission for a vehicle which can generate a cancellation hydraulic pressure for cancellation with a simple construction, as well as urge a movable sheave in the direction for producing a belt pressing force even at the time a vehicle is towed. A member to form a first hydraulic chamber P1 where a pressing force acting on the movable sheave is generated and a circular member forming a part of a second hydraulic chamber P2 where a hydraulic pressure is generated to cancel a centrifugal hydraulic pressure generated in the first hydraulic chamber P1 are provided, wherein the circular member is formed of an elastic member urging the movable sheave in the direction for generating the belt pressing force at a position of the movable sheave in a predetermined gear ratio.

Abstract: A hydraulic control system for a vehicular drive system including a hydraulically operated belt-and-pulley type continuously variable transmission and a hydraulically operated frictional coupling device engaged for running of a vehicle, the hydraulic control system including: a first solenoid valve for regulating a belt-tensioning hydraulic pressure for tensioning a belt of the transmission, a second solenoid valve for regulating a transient coupling hydraulic pressure to be applied to the frictional coupling device in the process of an engaging action, a line-pressure regulating valve for regulating a line pressure used for hydraulically operated devices of the mechanism, and a hydraulic-circuit switching device operable to apply a control pressure of the second solenoid-operated valve to the line-pressure regulating valve after the frictional coupling device has been placed in a fully engaged state, and to apply a first control pressure of the first solenoid-operated valve to the line-pressure regulating va

Abstract: Safety as well as the minimum driving performance is secured by preventing abrupt down-shifting if a line pressure valve or a primary pressure control valve fails. A line pressure path connected to an oil pump is connected with a line pressure control valve. A first primary pressure path branched from the line pressure path is connected with a hydraulic fluid chamber through a fail-safe valve, and a secondary pressure path branched from the line pressure path is connected to a hydraulic fluid chamber. The line pressure control valve is connected with a second primary pressure path in communication with a hydraulic fluid chamber, and this secondary primary pressure path is provided with a primary pressure control valve and a limiter valve.

Abstract: When a driver returns an accelerator pedal, preliminary pressure increase means increases a line pressure to a preliminary pressure increase value according to the speed of return of an accelerator pedal detected by an accelerator pedal return speed sensor, and subsequently when a braking state sensor detects that the speed of depression of a brake pedal is a predetermined value or above, pressure increase when braking means further increases the line pressure from the preliminary pressure increase value to a slip preventing pressure increase value.

Abstract: A conical pulley assembly with integrated torque sensor. A torque-dependent force is transmitted through a transmitting component to a sensing piston whose position determines the pressure in a sensing chamber. The transmitting member is connected to the movable disk, and is formed in such a way that it transmits the torque-dependent force to the sensing piston in a manner that is dependent on the position of an axially movable disk of the conical pulley.

Abstract: If it is determined that a malfunction has occurred in an electrical hydraulic pump and the hydraulic fluid is not supplied to a high hydraulic pressure supplied portion from the electrical hydraulic pump, the hydraulic fluid is supplied to the high hydraulic pressure supplied portion from a mechanical hydraulic pump that usually supplies the hydraulic fluid to a low hydraulic pressure supplied portion. In this case, the hydraulic pressure that is generated by the mechanical hydraulic pump is increased by increasing the output from the engine that drives the mechanical hydraulic pump.

Abstract: A hydraulic arrangement for controlling a transmission connected downstream of an internal combustion engine having a start-stop device. A hydraulic energy source provides hydraulic energy, an energy accumulator is connected downstream of the hydraulic energy source for storing and dispensing hydraulic energy provided by the hydraulic energy source, and a hydraulic controller is associated with the hydraulic energy source and the energy accumulator for controlling the transmission. The energy accumulator is associated with the hydraulic controller by a branch line to a pilot control circuit.

Abstract: In one embodiment, an oil pressure control apparatus includes a belt-driven continuously variable transmission, a lockup clutch provided in a torque converter, a primary regulator valve that regulates a line oil pressure that becomes a source pressure of oil pressure of various parts, and a clamping oil pressure control valve that supplies a clamping oil pressure to a driven-side pulley of the belt-driven continuously variable transmission. Control of the primary regulator valve is performed with a control oil pressure of a linear solenoid valve that controls the clamping oil pressure control valve, and a control oil pressure of a linear solenoid valve that controls engagement/release of the lockup clutch.

Abstract: A hydraulic actuator for a belt type continuously variable transmission, with which a smooth operation is secured and both superior productivity and reduced manufacturing costs can be expected, includes a first cylinder provided on a movable sheave, a drum having a first drum portion that covers the first cylinder and a second drum portion that is fitted to a boss portion of the movable sheave and formed with a plurality of projections, a first plunger having a cylindrical portion that is fitted to the first cylinder and the second drum portion to form a first hydraulic chamber, and a second plunger fitted to the cylindrical portion and the first cylinder to form a second hydraulic chamber. An oil passage connecting the first hydraulic chamber and the second hydraulic chamber is formed by a gap between the second drum portion and cylindrical portion, which are fitted together.

Abstract: In a control device for an automatic transmission having a flow control mechanism that causes a part of a working oil discharged from a mechanical oil pump to flow into the mechanical oil pump when a differential pressure between an upstream side and a downstream side of a narrowed portion increases beyond a predetermined value, the narrowed portion being provided in a discharge passage through which the working oil discharged from the mechanical oil pump flows, a line pressure is raised when an oil temperature of the working oil is equal to or higher than a predetermined oil temperature and an engine torque is equal to or smaller than a predetermined engine torque.

Abstract: A snowmobile is disclosed having improved drive train including a continuously variable transmission (CVT) having a drive belt looped around a driving pulley and a driven pulley, and a transversely arranged jackshaft wherein the driven pulley is connected directly onto the outer surface of one end of the jackshaft. The transverse jackshaft is preferably made from a thin-walled hollow tube and the driven pulley is preferably press fitted thereon. A method of assembling a snowmobile drive train is also disclosed.

Abstract: An oil pressure control apparatus includes a belt-driven continuously variable transmission, a primary regulator valve that regulates a line oil pressure that becomes a source pressure of oil pressure of various parts, and a gear oil pressure control valve that supplies gear oil pressure to a driving-side pulley of the belt-driven continuously variable transmission. A failsafe valve is provided between the gear oil pressure control valve and the driving-side pulley. When the gear oil pressure control valve or a linear solenoid valve that controls the gear oil pressure control valve fails, the failsafe valve is switched so as to supply the line oil pressure to the driving-side pulley, and other than during such the gear oil pressure control valve's failure or the electromagnetic valve's failure, the failsafe valve is switched so as to supply the gear oil pressure to the driving-side pulley.

Abstract: A control system for controlling a belt-type continuously variable transmission having a pulley capable of varying its groove width to which a belt is applied, in which the pulley is provided with an oil chamber to which the oil pressure is fed so that the pulley clamps the belt, in which the capacity of the oil chamber is varied in accordance with a change in the groove width, and in which the oil pressure in the oil chamber is controlled in accordance with a deviation between a target oil pressure and an actual oil pressure, comprising: a pressure-receiving capacity change detecting device for detecting a change in the capacity of the oil chamber; and an oil pressure control contents altering device for altering a degree to reflect the deviation on the oil pressure control of the oil chamber on the basis of a change in the capacity.

Abstract: In a speed ratio control device for a belt continuously variable transmission according to this invention, when a speed ratio is subjected to feedback control on the basis of a difference between an actual speed ratio and a target speed ratio, pressure supplied to a primary pulley is corrected through feedforward (S17, S18) in order to suppress variation in the groove width of the primary pulley caused by a rapid variation in an input torque into the primary pulley (S17) while traveling in a fixed speed ratio mode (S14) in which the target speed ratio is held at a fixed value.

Abstract: A control valve switches between the (A) state where the first oil passage to which a hydraulic pressure obtained by decreasing a line pressure is supplied is in communication with the fifth oil passage for supplying the hydraulic pressure to a forward clutch or a reverse brake and the third oil passage to which a hydraulic pressure controlled by an SLP linear solenoid valve is supplied is in communication with the sixth oil passage for supplying the hydraulic pressure to a primary pulley, and the (B) state where the second oil passage to which a hydraulic pressure controlled by an SLT linear solenoid valve is supplied is in communication with the fifth oil passage and the fourth oil passage for supplying the hydraulic pressure to a secondary pulley is in communication with the sixth oil passage. The fourth oil passage has an orifice.

Abstract: A control device includes an arrangement for deriving an input torque input to a belt-type continuously variable transmission based on a control amount of a first actuator. The continuously variable transmission includes a first actuator that is provided on a one movable sheave side, that presses the one movable sheave toward one fixed sheave, and that can generate a belt pinching pressure on the one movable sheave side, and a second actuator and a torque cam that are provided on the other movable sheave side, that press the other movable sheave toward the other fixed sheave, and that can generate a belt pinching pressure on the other movable sheave side.

Abstract: An input-side drive arrangement for a belt-driven conical-pulley transmission includes an input shaft that is rigidly connected to an axially fixed disk, and an axially movable disk that can be shifted axially on the shaft and is rotationally fixed to the shaft. A torque-sensing device has a first shaped surface that is rigidly connected to the shaft and a second shaped surface that is rigidly connected to a sensing piston that surrounds the shaft and is rotatable and axially movable relative to the shaft. The sensing piston engages a rotationally drivable input wheel and can be subjected to hydraulic pressure from the side facing the movable disk. The rotationally fixed and axially movable engagement between the sensing piston and the input wheel is such that the engagement is disconnected when there is torque acting from the movable disk and the sensing piston is not under hydraulic pressure.

Abstract: In a stepping motor cooling apparatus for a belt-type continuously variable transmission, a pair of primary and secondary pulleys are disposed inside a transmission case, and a forward/backward switching unit is disposed coaxially to the primary pulley, furthermore, a stepping motor is disposed below the forward/backward switching unit. An inner case originating from the transmission case surrounds a circumference of the forward/backward switching unit. Through the inner case, a dripping hole is formed at an inner case's portion directly above the stepping motor so that working fluid drained from the forward/backward switching unit can drip on the stepping motor. In order to further improve the cooling effect of the stepping motor, a recess portion is formed immediately below the stepping motor at an upper surface of a valve body disposed under the stepping motor.

Abstract: The invention concerns a continuously variable cone disc transmission with sets of discs mounted on drive and driven shafts. The sets of discs are each hydraulically adjustable axially in their distance from each other whereby the traction train circulating between them is able to adjust to different running circles and thereby enabling a continuously variable transmission. The pressure fluid needed for the hydraulic actuation is supplied to the pressure cylinders by a pump through a control valve. This control valve is actuated hydraulically by a pressure supply that is need-adjusted by a proportional-pressure reduction valve. In the event of a functional failure and consequent loss of the regulating pressure, the control valve is automatically arrested in position, so that the control valve is prevented from giving a command for the sudden change of the transmission ratio into an extreme position.

Abstract: A motorcycle including a power transmission device including a continuously variable transmission having a belt wound around a drive pulley and around a driven pulley and a hydraulically-operated clutch provided on at least one of a drive pulley shaft and a driven pulley shaft and an internal combustion engine wherein a supply of working oil to the clutch and of lubricating oil to a continuously variable transmission is enabled while avoiding a complication of an oil passage configuration and an increase in the diameter of the pulley shaft. A clutch control oil passage directs working oil to a clutch and a lubricating oil passage directs lubricating oil to a continuously variable transmission are provided in the particular pulley shaft on which the clutch is provided, so as to be coaxial with each other and be axially isolated from each other.

Abstract: In one embodiment, an oil pressure control apparatus includes a belt-driven continuously variable transmission, a lockup clutch provided in a torque converter, a primary regulator valve that regulates a line oil pressure that becomes a source pressure of oil pressure of various parts, and a lockup control valve that performs switching when controlling engagement/release of the lockup clutch. Control of the primary regulator valve and control of the lockup control valve are performed with a single linear solenoid valve. In this case, control of the primary regulator valve and control of the lockup control valve are performed in different ranges.

Abstract: To discharge a pressure from a hydraulic chamber of a belt-type continuously variable transmission certainly. A pulley 2 to which a belt 7 is applied includes a fixed sheave 5 and a movable sheave 6 being opposed to the fixed sheave 5. A flow path 38 is arranged to discharge a pressure fluid from a hydraulic chambers 16A and 16B pushing the movable sheave 6 toward the fixed sheave 5. A valve element 41 is arranged on the flow path 38 to close the flow path 38 when pushed in a direction against a pressure from the hydraulic chambers 16A and 16B, and a valve closing mechanism 43 is also arranged on the flow path 38 to generate a thrust force for pushing the valve element 41 in the direction against a pressure from the hydraulic chambers 16A and 16B.

Abstract: A hydraulic control apparatus includes a continuously-variable transmission; a line-pressure control section configured to produce a line pressure by adjusting a discharge pressure of an oil pump; a first hydraulic-pressure control section configured to adjust a first hydraulic pressure based on the line pressure, the first hydraulic pressure being supplied to the drive pulleys; and a second hydraulic-pressure control section configured to adjust a second hydraulic pressure based on the line pressure, the second hydraulic pressure being supplied to the driven pulleys. The continuously-variable transmission includes a pair of drive pulleys including a first movable pulley and a first fixed pulley; a pair of driven pulleys including a second movable pulley and a second fixed pulley; and a belt wound between the pair of drive pulleys and the pair of driven pulleys.

Abstract: In a line pressure control device for a belt type continuously variable transmission according to this invention, when a line pressure is feedback-controlled to equal a target line pressure which is equal to or greater than the larger of oil pressures supplied to a primary pulley and a secondary pulley (S1), and it is determined that the target line pressure has fallen below a first low pressure, leading to a divergence between the target line pressure and the actual line pressure (S6), the target line pressure is restricted such that the target line pressure does not fall below a lower limit value (S7).

Abstract: A hydraulic control unit (18), for a power transmission system having an oil receiving device (26,37), which controls a power transmitting condition of the power transmission system, and an oil reserving device for feeding the oil to the oil receiving device, wherein the oil reserving device comprises a piston (59) in which a diametrically large portion and a diametrically small portion are arranged integrally and coaxially, a first hydraulic chamber (57) in which the diametrically large portion, and a second hydraulic chamber (58) in which the diametrically small portion are housed liquid-tightly and movably back and forth; and an oil feeding amount control device for feeding the oil of the first hydraulic chamber to the oil receiving device, by raising the oil pressure in the second hydraulic chamber (58) to operate the piston (59).

Abstract: A hydraulic system for actuating at least two valves, particularly for actuating a conical-pulley continuously variable transmission of a motor vehicle having a continuously variable transmission ratio (CVT), and with a control valve that controls at least two control valves by controlling total control pressure. Between the control valve and a first valve of at least two valves a cutoff valve is connected, through which the total control pressure provided above a switching threshold can be reduced to minimum control pressure acting at least on the first valve or to zero by means of the control valve.

Abstract: A simplified continuously variable transmission system control provides a variable clamping force and a differential cylinder pressure manipulation to change sheave ratios. The system control uses two pumps. The first pump provides the variable clamping force. The second pump provides pressure changes to effect ratio changes. The clamping force can be varied based upon operator demand on an associated engine.

Abstract: To prevent engine speed from increasing during low-speed operation, a transmission includes a change-gear mechanism, a centrifugal clutch, a control unit and a secondary sheave rotation sensor. The change-gear mechanism has an input shaft, an output shaft and an actuator for changing a change-gear ratio between the input and output shafts. The centrifugal clutch is connected to the output shaft. The control unit controls the actuator. The secondary sheave rotation sensor detects and outputs a rotational speed of the output shaft to the control unit. The control unit controls the actuator based on a target change-gear ratio obtained by dividing a target rotational speed of the input shaft by the rotational speed of the output shaft.

Abstract: A speed change control device for a belt type continuously variable transmission has a speed change control unit (32) which controls an oil pressure for determining a speed ratio of the continuously variable transmission (10) by operating a step motor (40), and detects a rotation speed of a primary pulley or a secondary pulley. A driving speed of the step motor (40) is limited using two or more of a temperature of a working oil of the speed change control unit (32), the speed ratio of the continuously variable transmission (10), and the detected rotation speed as parameters.

Abstract: A simplified continuously variable transmission system control provides a variable clamping force and a differential cylinder pressure manipulation to change sheave ratios. The system control uses two pumps. The first pump provides the variable clamping force. The second pump provides pressure changes to effect ratio changes. The clamping force can be varied based upon operator demand on an associated engine.

Abstract: A continuously variable transmission has a primary pulley having a primary movable sheave that is capable of moving to change a groove width of the primary pulley, and a secondary pulley having a secondary movable sheave that is capable of moving to change a groove width of the secondary pulley. Endless flexible members are engaged with the primary pulley and the secondary pulley to transmit torque therebetween. At least one of the pulleys has a thrust applying mechanism that is capable of applying spring force and first fluid pressure force to the movable sheave of the pulley so as to narrow the groove width thereof and generating second fluid pressure force opposite to the spring force and the first fluid pressure force.

Abstract: A positional deviation ERRstep of a step motor 27 is calculated on the basis of a reference model step StepMdl, an actual speed ratio-corresponding step Bstep, and an added value obtained by adding together a target deviation GTstep, calculated in accordance with a transmission input torque Ti, and a starting learned value Gstep. When the transmission input torque Ti is large, the target deviation GTstep is increased in accordance with the transmission input torque Ti. A line pressure PL is then controlled on the basis of the positional deviation ERRstep obtained as a result.

Abstract: A shift control apparatus of a CVT installed in a non-ABS equipped vehicle is arranged to estimate a condition of a transmission ratio of the CVT, to prohibit a shift operation of varying the transmission ratio to a high-speed-side transmission ratio relative to a first predetermined transmission ratio when the driving-wheel acceleration is greater than or equal to a predetermined acceleration, and to cancel the prohibition of the shift operation when the transmission ratio is in a high speed side relative to a second transmission ratio under a condition that the driving-wheel acceleration becomes greater than or equal to the predetermined acceleration.

Abstract: A belt type continuously variable transmission includes a continuously variable shift mechanism having a primary pulley, a secondary pulley and a belt wound around the respective pulleys, a pulley thrust calculation unit that calculates a pulley thrust, which is used to bias the respective pulleys in a direction for reducing the pulley width, so as to include a predetermined margin, a hydraulic control unit that controls an oil pressure supplied to each of the pulleys on the basis of the calculated pulley thrust, and an upshift determination unit that determines whether or not an upshift, during which the speed ratio is reduced, is underway. The pulley thrust calculation unit sets the predetermined margin to be smaller when an upshift is determined to be underway than when an upshift is determined not to be underway.