Abstract: A coefficient of friction correction device for a belt-type continuously variable transmission is provided in which the coefficient of friction corrector calculates a coefficient of friction correction factor from the coefficient of friction calculated by the coefficient of friction calculator for a predetermined gear ratio and the default value of the coefficient of friction stored in the coefficient of friction map for the predetermined gear ratio, and uniformly corrects the default value of the coefficient of friction stored in the coefficient of friction map for each gear ratio using the coefficient of friction correction factor. This enables the default values of the coefficient of friction of all the coefficient of friction maps to be corrected by calculating just one coefficient of friction correction factor, and enables the reliability of the corrected default value of the coefficient of friction to be ensured.

Abstract: A control device for an automatic transmission including a hydraulic actuator that is actuated on the basis of a hydraulic pressure supplied and a linear solenoid valve that controls the hydraulic pressure supplied to the hydraulic actuator on the basis of a driving current of a solenoid includes an ECU that executes current feedback control over a current value of the driving current that is flowed to the solenoid using at least a proportional term and an integral term on the basis of a deviation (?I) between a target current value (Itgt) and actual current value (Ir) of the solenoid such that the hydraulic pressure supplied to the hydraulic actuator becomes a target hydraulic pressure. The ECU increases a proportional gain (Kp) in the current feedback control as a fluid temperature (To) detected by a fluid temperature sensor increases.

Abstract: A belt-type continuously variable transmission for a vehicle includes: a primary pulley including a first fixed sheave fixed to an input shaft, and a first movable sheave relatively non-rotatable and relatively movable in axial direction to the input shaft due to spline-fitting of a female spline formed on an inner circumferential portion thereof to a male spline formed on the input shaft; a secondary pulley including a second fixed sheave fixed to an output shaft in parallel with the input shaft, and a second movable sheave relatively non-rotatable and relatively movable in the axial direction to the output shaft due to spline-fitting of a female spline formed on an inner circumferential portion thereof to a male spline formed on the output shaft; and a transmission belt, the belt-type continuously variable transmission for a vehicle disposed with at least one of a first groove width defining portion disposed on the primary pulley for defining a maximum groove width of the first pulley groove and a second gr

Abstract: An element for a metallic belt in a continuously variable transmission capable of reducing misalignment while ensuring friction force in a small diameter state is provided. An element 40 for a metallic belt in a belt-type continuously variable transmission has a structure in which a side edge of the element 40 of a metallic belt 7 that contacts a drive pulley 5 and a driven pulley 8 includes: a belt radial outer portion 46b that is located on a radial outer side of the metallic belt 7 and linearly shaped to follow a radial inner portion 11a as a constant-angle inclined generatrix portion; and a belt radial inner portion 46a that is located on a radial inner side of the metallic belt 7 and curved to taper inward in the belt radial direction to gradually increase an inclination angle.

Abstract: A vehicle powertrain has an engine, a driving shaft having a passage defined therein, a driven shaft, a pump, a hydraulic fluid reservoir, and a CVT. A driving pulley of the CVT includes a fixed sheave and a movable sheave disposed on the driving shaft for rotation therewith, a spring biasing a movable sheave away from the fixed sheave, and a CVT chamber fluidly communicating with the passage of the driving shaft. The pump supplies hydraulic fluid from the reservoir to the passage in the driving shaft. The hydraulic fluid flows from the passage to the CVT chamber to create a hydraulic pressure in the CVT chamber. The hydraulic pressure in the CVT chamber biases the movable sheave toward the fixed sheave.

Abstract: An element 40 for a metallic belt in a belt-type continuously variable transmission has a structure in which: a belt radial outer portion 46b of a metallic belt 7 is linearly shaped to come into line contact with a pulley radial inner portion 11a which is a constant-angle inclined generatrix portion of a pulley 5 or 8; a projecting portion 48 located below a locking edge portion 44a and extending inward in the belt radial direction is provided at each of the lower ends of both side edges of the element 40; and when the element 40 and a pulley radial outer portion 11b which is a curved generatrix portion of the pulley 5 or 8 contact each other, the projecting portion 48 bends inward in the axial direction of the pulley 5 or 8.

Abstract: An input pulley, an output pulley, a belt wound across the pulleys, a hydraulic cylinder provided to the input pulley, and a hydraulic servo mechanism that controls an operation of the hydraulic cylinder are provided. The hydraulic servo mechanism includes: a valve chest facing an input side movable sheave; a servo spool slidably inserted in the valve chest, and switches an oil passage in communication with a hydraulic chamber of the hydraulic cylinder; and a feedback spool disposed in such a manner that one end comes into contact with the input side movable sheave a bearing disposed in between, and configured to switch the oil passage to maintain a slid position of the input side movable sheave at a position corresponding to a slid position of the servo spool.

Abstract: A hydraulic control device includes an electric pump configured to supply oil to a belt-type continuously variable transmission mechanism of a power transmission device through a hydraulic path based on driving of a motor, and an accumulator configured to accumulate oil inside by using the oil supplied by the electric pump and supplies the oil to a control system by discharging the accumulated oil through the hydraulic path. According to such a configuration, an increase in the sizes of the electric pump and the accumulator used for hydraulic control at the time of executing an idling stop function can be suppressed.

Abstract: A hydraulic control system for a CVT includes 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.

Abstract: A power transmission device includes a belt-type continuously variable transmission; a first fluid pressure cylinder; a second fluid pressure cylinder; a pressure-adjustment and pressure-feed device; a fluid outflow/inflow device; and a control unit that controls the pressure-adjustment and pressure-feed device based on a fluid pressure that is obtained from a thrust that is required for the second pulley in accordance with a driving state and that, by controlling the pressure-adjustment and pressure-feed device in this manner, controls the fluid outflow/inflow device such that a gear ratio is varied within a permitted gear ratio range in accordance with the fluid pressure that is pressure-fed from the pressure-adjustment and pressure-feed device in conjunction with the pressure adjustment.

Abstract: A continuously-variable transmission, which has a first pulley, which has a first fixed pulley and a first mobile pulley, a second pulley, which has a second fixed pulley and a second mobile pulley, and a drive force transmitting member, which is stretched between the first pulley and the second pulley, is provided, and this continuously-variable transmission has an indicated pressure calculation section, which calculates the indicated pressure of the first pulley, a stroke speed calculation section, which calculates the stroke speed of the first mobile pulley, and an oil pressure calculation section, which, when oil is discharged from an oil chamber, calculates the amount of increase of oil pressure in a first pulley oil chamber that increases compared to the indicated pressure due to the channel resistance of the discharge path, based on the channel resistance and the stroke speed, and a correction section, which, when oil is discharged from the first pulley oil chamber, subtracts the amount of increase of

Abstract: A hydraulic control system for an automatic transmission, in which a belt is applied to at least one pair of pulleys, and in which widths of belt grooves of the pulleys, or pressures to clamp the belt by the pulleys are controlled by hydraulic pressures applied to hydraulic chambers of the pulleys. The hydraulic control system is comprised of: a control valve that controls a delivery and a drainage of hydraulic fluid to/from the hydraulic chamber; and a drive frequency setting means that determines a drive frequency of a drive signal for actuating the control valves in such a manner that a phase of a local maximum value of amplitude of the drive signal is shifted from a phase of a local maximum value of amplitude of vibrations resulting from rotating the pulleys.

Abstract: A belt type continuously variable transmission for a vehicle includes: an input shaft and an output shaft disposed in parallel with each other; a pair of groove width variable pulleys disposed on the outer circumferential sides of the input shaft and the output shaft; and a transmission belt wound around each of V-grooves of the pair of the groove width variable pulleys, the belt type continuously variable transmission for a vehicle changing a winding diameter of the transmission belt by changing the groove widths of the V-grooves so as to continuously vary a gear ratio, wherein the groove width variable pulley includes a fixed sheave fixed to an outer circumferential surface of one of the input shaft and the output shaft, and a movable sheave disposed relatively non-rotatably on the one shaft and relatively movably in the direction of the shaft center of the one shaft so as to form the V-groove with the fixed sheave, wherein the belt type continuously variable transmission for a vehicle is disposed with a pa

Abstract: In a hydraulic control apparatus for a continuously variable transmission that enables gear ratio variation by controlling supply of hydraulic oil to first and second hydraulic actuators, there are provided with first and second oil passages connecting the first and second actuators to a reservoir, a single electric hydraulic pump installed at a common portion thereof, first and second check valves installed in the first and second oil passages for blocking flow of hydraulic oil to the reservoir, first and second bypass passages formed in the first and second oil passages, a control valve installed therebetween, a fourth check valve installed in the first and second bypass passages for blocking flow of hydraulic oil to the hydraulic pump, and a controller for controlling these, thus readily enabling a configuration that reduces the number of electric hydraulic pumps to one and minimizes cost increase.

Abstract: A diagnostic device for a shift control actuator of a CVT includes: a variator; a chamber that is filled with and discharges hydraulic fluid for an upshift and a downshift, respectively; an upshift control valve for filling hydraulic fluid into the chamber; a downshift control valve for discharging hydraulic fluid from the chamber; a fail-safe valve for suspending the discharge of hydraulic fluid from the chamber when the upshift control valve is in a filling state; actuators for driving the upshift and downshift control valves; and a shift controller for controlling the actuators so that an actual shift ratio approaches a target ratio. The shift controller determines the state of the actuators with the information on the actual shift ratio when the controller instructs a downshift or an upshift.

Abstract: When the vehicle is stationary, the gear ratio is shifted to a Low side by controlling the position of a shift actuator such that a shift control valve is controlled to a position in which a first oil pressure shifts toward a neutral position side by a predetermined amount from a maximum discharge side position and a controlling secondary pulley pressure control unit to increase a second oil pressure to a predetermined oil pressure.

Abstract: Surplus pressure is obtained from a difference between a hydraulic pressure value detected by a hydraulic pressure sensor and a target supplied hydraulic pressure. A determination is made about whether or not a possible hydraulic pressure in a prescribed time will become lower than a minimum required hydraulic pressure based on a current surplus pressure and a changing rate of the surplus pressure. If the possible hydraulic pressure is lower than the minimum required hydraulic pressure, correction is conducted to increase supplied hydraulic pressure. Accordingly, control is conducted so that the regularly required surplus pressure can be reduced to a minimum required amount.

Abstract: A method of controlling a hydraulic CVT of a vehicle comprises: determining a speed of rotation of a driving shaft; determining a speed of rotation of a driven shaft; determining a ratio of the speed of rotation of the driving shaft versus the speed of rotation of the driven shaft; determining an engine torque; determining a base clamping force to be applied by the driving pulley onto the belt based on the ratio and the engine torque; determining a desired speed of rotation of the driving shaft; determining a corrective clamping force by comparing the speed of rotation of the driving shaft to the desired speed of rotation of the driving shaft; and controlling a hydraulic pressure applied to a movable sheave to apply a sum of the base and corrective clamping forces onto the belt. A vehicle having a CVT controlled by the method is also disclosed.

Abstract: When a driver returns an accelerator pedal, preliminary pressure increase apparatus 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. 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 apparatus further increases the line pressure from the preliminary pressure increase value to a slip preventing pressure increase value. The line pressure is increased to a preliminary pressure increase value when it is predicted that braking will be carried out subsequent to an accelerator pedal return operation, when subsequently there is sudden braking it becomes possible to increase the line pressure to a slip preventing pressure increase value that can prevent an endless belt from slipping accompanying sudden braking.

Abstract: A control device of a continuously variable transmission for a vehicle has a pair of variable pulleys and a transmission belt, and the control device respectively controls input-side and output-side thrust forces of input-side and output-side variable pulleys to set an actual gear ratio to a target gear ratio, prevents a slip of the transmission belt, and determines a lowest-speed-side gear ratio. When it is determined that a detection value of a rotation speed for calculating the actual gear ratio does not reflect an actual rotation speed, target input-side and output-side thrust forces are set to be target thrust forces for maintaining the lowest-speed-side gear ratio and preventing the slip of the transmission belt, and based on whether the actual gear ratio is already the lowest-speed-side gear ratio, values of the input-side and output-side thrust forces are changed for obtaining the target thrust forces.

Abstract: Surplus pressure is obtained from a difference between a hydraulic pressure value detected by a hydraulic pressure sensor and a target supplied hydraulic pressure. A determination is made about whether or not a possible hydraulic pressure in a prescribed time will become lower than a minimum required hydraulic pressure based on a current surplus pressure and a changing rate of the surplus pressure. If the possible hydraulic pressure is lower than the minimum required hydraulic pressure, correction is conducted to increase supplied hydraulic pressure. Accordingly, control is conducted so that the regularly required surplus pressure can be reduced to a minimum required amount.

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: Pneumatic/hydraulic assisted mechanisms that can be used to move an object of considerable weight in quick and accurate steps. Said mechanisms comprise of an index wheel mechanism that is rotated by pre-tensioned springs (see FIG. 15). For a said index wheel mechanism that is powered by a pneumatic linear actuator, the shock loads that occur during the operation of said index wheel mechanism can be damped using a pneumatic Recovery System (see FIG. 27). For a said index wheel mechanism that is powered by a hydraulic linear actuator, the shock loads that occur during the operation of said index wheel mechanism can be damped using a hydraulic Recovery System (see FIG. 29).

Abstract: Provided is a belt-type continuously variable transmission which may prevent a servo spool from sliding even when a movable sieve slides due to reduced pressure in a hydraulic cylinder. A hydraulic servo mechanism comprises a servo spool and a feedback spool, and contiguous members coming into contact with the feedback spool (84) between a hydraulic cylinder and the feedback spool The present invention also comprises a spool position maintaining unit that makes it possible for the contiguous members to slide in relation to a movable side cylinder case when pressure in the hydraulic cylinder is lower than a predetermined value.

Abstract: Conical disk pairs of a belt-driven conical-pulley transmission include an axially fixed disk and an axially movable disk that are situated on respective shafts on the input side and the output side and are connectable by an endless torque-transmitting component for transmitting torque. At least one of the shafts has at least one axial bore from which at least one connecting bore extends to the surface of the shaft. The outlet of the connecting bore is in a region that is covered by the movable disk independent of the latter's axial position. An annular chamber formed between the shaft outer surface and a radially inner surface of the axially movable disk can be subjected to hydraulic pressure through the connecting bore. A discharge groove is provided for bleeding air bubbles from the annular chamber.

Abstract: Pneumatic/hydraulic assisted mechanisms that can be used to move an object of considerable weight in quick and accurate steps. Said mechanisms comprise of an index wheel mechanism that is rotated by pre-tensioned springs (see FIG. 15). For a said index wheel mechanism that is powered by a pneumatic linear actuator, the shock loads that occur during the operation of said index wheel mechanism can be damped using a pneumatic Recovery System (see FIG. 27). For a said index wheel mechanism that is powered by a hydraulic linear actuator, the shock loads that occur during the operation of said index wheel mechanism can be damped using a hydraulic Recovery System (see FIG. 29).

Abstract: A stepless speed-change power transmission for a vehicle includes a driving pulley disposed on an input shaft, and including a fixed driving pulley half and a movable driving pulley half, a driven pulley disposed, on an output shaft and including a fixed driven pulley half and a movable driven pulley half, and an air guide unit. The air guide unit includes a curved first air guide wall and a curved second air guide wall that are disposed around the fixed driving pulley half to form first and second notches between the first and second air guide walls. The first notch guides air from the fixed driving pulley half onto the driven pulley. The second notch guides air from the fixed driving pulley half onto the movable driving pulley half.

Abstract: A belt-driven continuously variable transmission adapted to prevent a tilting motion of a sheave under high temperature. The belt-driven continuously variable transmission is comprised of a pair of pulleys individually comprised of a fixed sheave rotated integrally with a rotary shaft and a movable sheave fitted onto the rotary shaft while being allowed to reciprocate thereon, and a driving belt applied to the pulleys to transmit power therebetween. a stopper member is disposed on an outer circumferential side and in a side where the driving belt is not contacted with the movable sheave so as to prevent the movable sheave from being tilted to widen a width between the fixed sheave and the movable sheave holding the driving belt by a load from the driving belt.

Abstract: A belt-driven continuously variable transmission adapted to reduce a frictional resistance between the movable sheave and the rotary shaft. The pulley includes the fixed sheave rotated integrally with the rotary shaft, and the movable sheave engaged with the rotary shaft in a manner to slide axially and to be rotated integrally with the rotary shaft. The driving belt is applied to the belt groove formed between the movable sheave and the fixed shave to transmit torque. The transmission is provided with the a passage for delivering fluid to the engagement mechanism engaging the rotary shaft with the movable sheave while allowing relative axial movement therebetween.

Abstract: A belt-driven continuously variable transmission having a downsized torque cam assembly for creating forward thrust to push a movable sheave toward a fixed sheave. The belt-driven continuously variable transmission is adapted to output a torque while changing a speed ratio continuously by altering an effective diameter position of a driving belt.

Abstract: A belt type continuously variable transmission that includes a primary pulley; a secondary pulley; a belt where the primary pulley and the secondary pulley are bound; a positioning hydraulic chamber that presses a primary movable sheave to a primary fixed sheave; a supply-side valve that permits working oil to be supplied from the outside to the positioning hydraulic chamber; and a discharge-side control valve that controls permission or prohibition of discharge of the working oil from the positioning hydraulic chamber to the outside. The discharge-side control valve prohibits discharge of the working oil from the positioning hydraulic chamber to the outside when a position of the primary movable sheave is kept constant in the axial direction with respect to the primary fixed sheave.

Abstract: A chain belt-type continuously variable transmission in which ratchet-type chain belts are wound on driving and driven pulley devices, each of which has a variable diameter, in order to control the shift ratio. Driving belt supports are disposed in a driving pulley device so as to radially contract and expand. Driven belt supports are disposed in a driven pulley device so as to radially contract and expand. Teeth in the front portions of the driving belt supports and the driven belt supports and teeth in the rear portions of the driving belt supports and the driven belt supports are oriented in opposite directions. Front and rear ratchet gears formed on the driving belt supports and the front and rear ratchet gears formed on the driven belt supports are oriented in opposite directions and are arranged in alternating positions without being formed at corresponding positions in a line.

Abstract: A continuously variable transmission configured to reduce response delay and hunting due to overshooting. The continuously variable transmission is electronically controlled by a control unit. The control unit is connected to an actuator for moving a moving flange of a primary sheave and controls the output of the actuator in such a manner as to vary between upshift and downshift of the continuously variable transmission.

Abstract: The present invention provides an anti-rotation structure for a balance chamber snap ring of a belt type continuously variable transmission having a balance chamber that balances a centrifugal oil pressure generated in an oil pressure chamber formed on a movable sheave back surface. A projecting portion, which comes into contact with an end portion of the balance chamber snap ring when the balance chamber snap ring rotates independently within a ring groove about a secondary shaft, thereby restricting independent rotation of the balance chamber snap ring, is provided on a latch portion of a cover member. As a result, independent rotation of the balance chamber snap ring can be prevented, thereby preventing the cover member and the balance chamber snap ring from becoming worn.

Abstract: In a vehicular belt-driven continuously variable transmission, belt squeezing force is inhibited from becoming excessive and a safety factor, with respect to belt slip, of belt squeezing force applied to a transmission belt (48) is reduced to a value that is less than or equal to 1.5 by reducing a pressure receiving area (SOUT) of an output side hydraulic cylinder (46c). As a result, a centrifugal hydraulic pressure canceller chamber on a secondary pulley side (46) can be eliminated thus simplifying the structure of the vehicular belt-driven continuously variable transmission, while belt squeezing force can be appropriately controlled.

Abstract: In a controller for a belt-type continuously variable transmission including a hydraulic actuator that changes a groove width of a primary pulley, a hydraulic actuator that changes a groove width of a secondary pulley, and a belt clamping pressure control solenoid that controls the hydraulic pressure supplied to the hydraulic actuator of the secondary pulley, a mechanism calculates a transmission ratio between the primary pulley and the secondary pulley and determines whether or not there is belt slippage based on that calculated transmission ratio, and a mechanism determines normalcy of the belt clamping pressure control solenoid. The input torque when belt slippage has actually occurred, i.e., when a failure has been determined, is used as a condition when performing the normalcy determination.

Abstract: A control device of a continuously variable transmission for a vehicle having a pair of variable pulleys with variable effective diameters of an input-side variable pulley and an output-side variable pulley and a transmission belt wound around between the pair of the variable pulleys, the continuously variable transmission respectively controlling an input-side thrust force in the input-side variable pulley and an output-side thrust force in the output-side variable pulley to set an actual gear ratio to a target gear ratio while preventing a slip of the transmission belt, the continuously variable transmission includes: a hydraulic control circuit capable of accurately controlling one of the input-side variable pulley and the output-side variable pulley in terms of thrust force as compared to the other, in the case that a target thrust force on the one side for assuring belt slip prevention of the both pulleys on the one side is set, based on a target thrust force on the one side, a target thrust force on the

Abstract: A hydraulic control system adapted to carry out a speed change in case of rotating a wrapping transmission under the situation where solenoid valves for controlling a pressure in a hydraulic chamber cannot be energized. A pair of pulleys individually provided with hydraulic chambers to vary a width of a groove holding a belt. Those hydraulic chambers are connected with a hydraulic source through electrically controlled feeding control valves, and also connected with drain portions through electrically controlled relief control valves. The hydraulic control system includes a communicating passage connecting the hydraulic chambers, and the hydraulic control system disconnects the hydraulic chambers from the hydraulic source and the drain portions in case none of the feeding control valves and the relief control valves can be energized.

Abstract: A continuously variable transmission is provided with i) a primary pulley that is formed by a driving-side fixed sheave that is fixed to a drive shaft, a driving-side movable sheave, and a driving-side cylinder member, and has a driving-side cylinder, ii) a secondary pulley that is formed by a driven-side fixed sheave that is fixed to a driven shaft, a driven-side movable sheave, and a driven-side cylinder member, and has a driven-side cylinder, and iii) a drive belt. The drive shaft has a drive shaft internal fluid passage for supplying hydraulic fluid to the driving-side cylinder. A driving-side communicating fluid passage that communicates the drive shaft internal fluid passage with the driving-side cylinder is formed between the driving-side cylinder member and the driving-side movable sheave.

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.

Abstract: A belt type continuously variable transmission includes a primary shaft and a secondary shaft, wherein the primary shaft is supported on a case via a first rolling element bearing, and the secondary shaft is supported on the case via a second rolling element bearing, the case is formed with a bolt hole at each of an even number of locations in a region separate from a shaft center plane, which is a plane that passes through a shaft center of the primary shaft and a shaft center of the secondary shaft, and first and second stopper plates that each hold down outer races of the first and second rolling element bearings are fixed to the case by bolts mounted in the bolt holes.

Abstract: A hydraulic control system of continuously variable transmission includes: a first sheave pressure regulating valve (17) that regulates a line pressure (Pl), which is used for hydraulic control as a source pressure, to obtain a first sheave pressure (Pin); a fail-safe valve (19) that selects and outputs any one of the first sheave pressure (Pin) or a fail-safe hydraulic pressure (second sheave pressure Pout) that is applied to a drive pulley (21) at the time of a failure due to an excessive first sheave pressure (Pin) to the drive pulley (21); and an orifice (25) that is provided in an oil passage (24) between the fail-safe valve (19) and the drive pulley (21). Then, a hydraulic pressure in the oil passage (24) on the drive pulley (21) side of the orifice (25) is supplied to the first sheave pressure regulating valve (17) as a feedback pressure.

Abstract: A belt type continuously variable transmission for a vehicle such as a motorcycle includes a primary sheave and a secondary sheave each having a pair of flanges axially movable relative to each other. A belt is wound around the sheaves. An actuator controlled by a control device moves the flanges. The control device includes a determination section for determining whether the actual gear ratio of the belt type continuously variable transmission has become a predetermined gear ratio for TOP or LOW, and a first correction section for correcting an operation amount of the actuator based on the determination made by the determination section. Control accuracy in a region where the gear ratio is TOP or LOW is thereby improved.

Abstract: A hydraulic control system of continuously variable transmission includes: a first sheave pressure regulating valve (17) that regulates a line pressure (Pl), which is used for hydraulic control as a source pressure, to obtain a first sheave pressure (Pin); a fail-safe valve (19) that selects and outputs any one of the first sheave pressure (Pin) or a fail-safe hydraulic pressure (second sheave pressure Pout) that is applied to a drive pulley (21) at the time of a failure due to an excessive first sheave pressure (Pin) to the drive pulley (21); and a first regulator valve (12) and a second regulator valve (13) that regulate the line pressure (Pl). An output pressure (Psf) of the fail-safe valve (19) is supplied to the first and second regulator valves (12 and 13) in a feedback manner as a drive pulley (21) side hydraulic pressure to thereby regulate the line pressure (Pl).

Abstract: A belt-drive continuously variable transmission including a lock mechanism for locking a primary moveable sheave of a primary pulley in a highest transmission ratio position. The lock mechanism includes a fixed side axial groove extending on an outer circumferential surface of a primary fixed sheave shaft, a moveable side axial groove extending on an inner circumferential surface of a primary moveable sheave sleeve, an intervening member disposed between the axial grooves, an axial tapered groove formed as a part of at least one of the axial grooves which is disposed corresponding to a highest transmission ratio, and an intervening member displacement limiting member arranged to limit an amount of displacement of the intervening member relative to the primary fixed sheave shaft along the fixed side axial groove or the moveable side axial groove.

Abstract: A driving pulley for a CVT has a shaft, a fixed sheave mounted on the shaft, a first sleeve disposed around the shaft and being operatively connected to the shaft, a movable sheave mounted on the first sleeve, a second sleeve disposed around the first sleeve and being connected to the shaft, a spring biasing the movable sheave away from the fixed sheave, and a CVT chamber having an annular cross-section. The fixed and movable sheaves are adapted to receive a belt therebetween. The CVT chamber has at least one opening adapted for fluidly communicating the CVT chamber with a hydraulic fluid reservoir. Hydraulic pressure in the CVT chamber biases the movable sheave toward the fixed sheave. The CVT chamber has an inner wall formed by the first sleeve, an outer wall formed by the second sleeve, an outer end, and an inner end formed by the movable sheave.

Abstract: A vehicle powertrain has an engine, a driving shaft having a passage defined therein, a driven shaft, a pump, a hydraulic fluid reservoir, and a CVT. A driving pulley of the CVT includes a fixed sheave and a movable sheave disposed on the driving shaft for rotation therewith, a spring biasing a movable sheave away from the fixed sheave, and a CVT chamber fluidly communicating with the passage of the driving shaft. The pump supplies hydraulic fluid from the reservoir to the passage in the driving shaft. The hydraulic fluid flows from the passage to the CVT chamber to create a hydraulic pressure in the CVT chamber. The hydraulic pressure in the CVT chamber biases the movable sheave toward the fixed sheave.

Abstract: Provided is control device and method for a belt type continuously variable transmission which can reduce drive energy consumption by a decrease in belt friction when the estimated accuracy of belt slip condition is high and which can prevent the belt from greatly slipping during belt slip control when the estimated accuracy of belt slip condition is low. The device includes a primary pulley (42), a secondary pulley (43), and a belt (44) and controls gear ratio based on the running radius of the belt (44) on the pulley by controlling the primary oil pressure and the secondary oil pressure. A belt type continuously variable transmission (4) comprises a belt slip control means (FIG.

Abstract: Provided are control device and method for a belt type continuously variable transmission which can improve control stability of secondary hydraulic pressure with the estimated accuracy of a belt slip condition during belt slip control ensured. The device has a primary pulley (42), a secondary pulley (43), and a belt (44), and a secondary hydraulic pressure controller (92) to determine command secondary hydraulic pressure by feedback control based on the deviation (?) between target secondary hydraulic pressure and actual hydraulic pressure, and control the secondary hydraulic pressure to the secondary pulley (43). A belt type continuously variable transmission mechanism (4) includes a belt slip control means (FIG.

Abstract: Provided is control device and method for a belt type continuously variable transmission which can reduce drive energy consumption by a decrease in belt friction when the estimated accuracy of belt slip condition is high and which can prevent the belt from greatly slipping during belt slip control when the estimated accuracy of belt slip condition is low. The device includes a primary pulley (42), a secondary pulley (43), and a belt (44) and controls gear ratio based on the running radius of the belt (44) on the pulley by controlling the primary oil pressure and the secondary oil pressure.