摘要:
The continuously variable belt transmission is provided with a fixed sheave and a movable sheave provided on a secondary shaft, a first hydraulic chamber that presses the movable sheave in an axial direction, a second hydraulic chamber that gives the movable sheave a pressing force acting in a direction opposite the pressing force given by the first hydraulic chamber, an oil passage connected to the second hydraulic chamber, and an oil receiver disposed along a path from the oil passage to the second hydraulic chamber. The oil receiver is attached to the secondary shaft, a bearing and a bulkhead are disposed on both sides of the oil receiver, an oil passage is provided in the secondary shaft, and a grooved portion provided in the oil receiver connects the second hydraulic chamber and the oil passage.
摘要:
A continuously variable transmission includes a transmission ratio changing unit that can change a transmission ratio as a rotation speed ratio of an input disc and an output disc by tiltably rotating a power roller, a nip-press unit that can apply nip-pressure that nips the power roller between the input disc and the output disc by a pressure of a working medium supplied from a hydraulic pressure controlling unit that controls the pressure of the working medium to a nip-pressure generation hydraulic chamber via a coupling oil passage, and a pressure release unit which is disposed to the coupling oil passage and can release the pressure of the working medium of the nip-pressure generation hydraulic chamber via the release unit in response to an operation state, wherein since the release unit is positioned upward in a vertical direction of the nip-pressure generation hydraulic chamber in a state that the pressure release unit is mounted on a vehicle, the pressure release unit can appropriately prevent an unintentional transmission shift.
摘要:
A shift control apparatus for controlling a continuously variable transmission device including a continuously variable transmission mechanism having rotary elements and operable to transmit a rotary motion of a drive power source of an automotive vehicle to a drive wheel of the automotive vehicle, such that a speed ratio of said mechanism is continuously variable, the shift control apparatus includes a power-transmission-state determining device for determining whether the mechanism is placed in a non-power-transmitting state, a speed-ratio determining device for determining whether the mechanism is placed in a lowest-speed position, a rotation-stop detecting device for determining whether the rotary elements are at rest, and a compulsory-speed-ratio-change implementing device for effecting a compulsory shift-down action of the mechanism toward the lowest-speed position when the mechanism is placed in the non-power-transmitting state while the mechanism is not placed in the lowest-speed position and while the rotary elements of the mechanism are at rest.
摘要:
A hydraulic control apparatus for controlling a vehicle power transmitting system including a belt-and-pulley type continuously variable transmission and a torque converter provided with a lock-up clutch. The transmission includes a pair of hydraulic actuators one of which receives a belt tensioning pressure for controlling a tension of a transmission belt. The hydraulic control apparatus includes a lock-up clutch control valve which is selectively placed in an engaging and a releasing position for engaging and releasing the lock-up clutch, respectively, a slip control valve for controlling an amount of slipping of the lock-up clutch until the clutch is fully engaged, a pressure control device for raising the belt tensioning pressure so as to increase the tension of the transmission belt; and a pilot-pressure generating device for applying a pilot pressure simultaneously to the slip control valve and the pressure control means, so that the belt tensioning pressure is raised while the slip control valve controls the amount of slipping of the lock-up clutch.
摘要:
A hydraulic control apparatus for a power transmitting system for an automotive vehicle having a continuously variable transmission which has a first and a second shaft, a pair of variable-diameter pulleys provided on the first and second shafts, a belt connecting the pulleys, and a pair of hydraulic actuators for changing diameters of the pulleys, wherein a tension of the belt is controlled by regulating an actuating pressure in a driven side actuator of the hydraulic actuators which is provided on a driven one of the two shafts. The apparatus includes a pressure regulating valve which has a valve spool for regulating the actuating pressure in the driven side actuator, and a pressure-reducing chamber for receiving a pressure-reducing pilot pressure for biasing the spool for reducing the actuating pressure. The apparatus further includes a pilot pressure generator for generating the pressure-reducing pilot pressure to be applied to the pressure-reducing chamber, when the detected vehicle running speed exceeds a predetermined value.
摘要:
A hydraulic control system for a continuously variable transmission for an automotive vehicle, the transmission having a first and a second variable-diameter pulley provided on respective first and second shafts, a belt connecting the first and second pulleys, and a first and a second hydraulic cylinder for changing effective diameters of the first and second pulleys. The control system includes a first pressure regulating valve for regulating the pressure of a fluid delivered from a pressure source, and thereby establishing a first line pressure, a shift-control valve for applying the first line pressure to one of the first and second cylinders, while simultaneously permitting a flow of the fluid from the other cylinder, thereby changing the effective diameters of the first and second pulleys, and a second pressure regulating valve for regulating the pressure of one of a first and a second discharge flow of the fluid from the respective first and second cylinders through the shift-control valve, and thereby establishing a second line pressure lower than the first line pressure. A relief line is provided for releasing the other of the first and second discharge flows of the fluid. The relief line is exposed to a substantially atmospheric pressure.
摘要:
A hydraulic control system for a continuously variable transmission for an automotive vehicle, the transmission having a first and a second variable-diameter pulley provided on respective first and second shafts, a belt connecting the first and second pulleys, and a first and a second hydraulic cylinder for changing effective diameters of the first and second pulleys. The control system includes a shift-control valve receiving a first line pressure from said pressure source to one of the cylinders, while simultaneously permitting a flow of the fluid from the other cylinder. A second pressure line is connected to the shift-control valve to receive therefrom a pressure of the fluid flowing from above-indicated other cylinder. A pressure regulating valve regulates the pressure in the second pressure line, as a second line pressure lower than said first line pressure. The control system further includes at least one one-way by-pass line or restricted by-pass line which connects the second pressure line to at least one of the two cylinders, respectively. Each by-pass line permits a flow of the fluid from the second pressure line to the corresponding cylinder, or a restricted flow of the fluid between the second pressure line and the hydraulic cylinder.
摘要:
A hydraulic control apparatus includes two oil flow control valves (30, 32) each provided with a supply control portion (36, 38, 52, 54) for controlling an oil supply from a pressurized oil source, and a discharge control portion (40, 42, 56, 58) for controlling connection with a discharge passage. One of those oil flow control valves supplies/discharges oil to/from one of hydraulic chambers (22, 24) that are oppositely formed in a hydraulic servo mechanism. An operation direction of the hydraulic servo mechanism is performed by operating one of the oil flow control valves. The other operation direction of the hydraulic servo mechanism is performed by operating the other oil flow control valve.
摘要:
A toroidal continuously variable transmission includes: an input disk; an output disk; a plurality of power rollers; a plurality of trunnions; an oil pump; a pressing hydraulic mechanism that moves and brings the input disk and output disk closer to each other; a shifting hydraulic mechanism that moves the trunnions forward and rearward; and a hydraulic control device that controls the pressing hydraulic mechanism and the shifting hydraulic mechanism by oil pressure. The hydraulic control device has an oil pressure regulation unit that sets an oil pressure in a shifting hydraulic line that is a hydraulic source of the shifting hydraulic mechanism to an oil pressure at which shifting control can be performed by the shifting hydraulic mechanism till the transmission of power between the input disk and output disk is interrupted when the operation of the oil pump is stopped.
摘要:
A hydraulic control apparatus for a power transmitting system including a continuously variable transmission, a reversing device, and an auxiliary transmission, which apparatus includes: a solenoid valve for generating a pilot pressure for selectively placing the auxiliary transmission in high- and low-gear positions; high-gear and low-gear control valves normally operable based on the pilot pressure, to control high- and low-gear coupling devices of the auxiliary transmission to establish the high- and low-gear positions. The low-gear control valve is operated to engage the low-gear coupling device, when the low-gear control valve receives a pressure to be applied to the reversing device for forward run of the vehicle. The high-gear control valve may be operated to release the high-gear coupling device, when a thrust based on a pressure applied to the low-gear coupling device exceeds a predetermined value. The hydraulic control apparatus may further include a device for increasing a torque capacity of the high-gear coupling device during an engaging action thereof when a shift lever is operated to a reverse-drive position for reverse run of the vehicle.