Toyota Jidosha Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Susumu Okawa

Masami Sugaya

Yasunobu Jufuku

Yoshinobu Soga

Katsumi Kouno

Shigeru Okuwaki

Hideaki Matsui

Yuudai Tatara

Daisaku Sawada

Yasunori Nakawaki

Yudai Tatara

Kiyoomi Sato

Izumi Ogino

Toshimi Kato

Shigenori Nakata

Toshiya Endo

Takayoshi Kondou

A hydraulic control device for controlling a belt-and-pulley type continuously variable transmission for a motor vehicle which has two variable-diameter pulleys connected by a belt, and two hydraulic actuators for changing effective diameters of the pulleys. The hydraulic control device includes a first and a second pressure regulating valve for adjusting a pressure of a fluid supplied from a hydraulic power source, respectively to a first line pressure and a second line pressure lower than the first line pressure, and a CVT shift control valve device for controlling a speed ratio of the transmission. The valve device includes a shift-direction switching directional control valve and a shift-speed control flow control valve. The directional control valve is operable between a first position in which one of the hydraulic actuators communicates with a first pressure line having the first line pressure, while the other actuator communicates with an atmosphere or a second pressure line having a second line pressure, and a second position in which the above-indicated one actuator communicates with the atmosphere or second pressure line while the other actuator communicates with the first pressure line. The flow control valve controls rates of flows of the fluid to and from the actuators, in response to an operation of the directional control valve.

Hydraulic control device for belt-and-pulley type continuously variable

A pair of pulleys for a belt-and-pulley type continuously variable transmission wherein the pulleys are connected by a transmission belt such that the belt is partially in contact with contact surfaces of the pulleys. At least one of the pair of pulleys has a contact surface which has a plurality of raised and recessed portions that are spaced apart from each other at irregular angular intervals in a circumferential direction of the pulley.

Pulleys for belt-and-pulley type continuously variable transmission

A hydraulic control device for controlling a belt-and-pulley type continuously variable transmission for an automotive vehicle which includes an input and an output shaft, a pair of variable-diameter pulleys provided on the input and output shafts, respectively, a transmission belt connecting the pair of pulleys, and a pair of hydraulic actuators for changing effective diameters of the variable-diameter pulleys. The hydraulic control device further includes a shift control valve device for controlling pressures applied to the hydraulic actuators, to change the speed ratio of the continuously variable transmission over a mechanically defined range, and a controller for applying a drive signal to the shift control valve device. The controller includes a device for limiting a value of the drive signal, so as to prevent the actual speed ratio of the transmission from reaching upper and lower limits of the mechanically defined range.

Control device for belt-and-pulley type continuously variable

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 a discharge flow of the fluid flowing from the above-indicated other cylinder through the shift-control valve, and thereby establishing a second line pressure lower than the first line pressure.

Hydraulic control system for continuously variable transmission for

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.

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.

A chain belt comprises a plurality of V-shape blocks and connecting means. The V-shape block includes a pair of lateral side surfaces, a first contacting surface and a second contacting surface. An opening is defined within the first and second contacting surfaces of the V-shape block. The connecting means connects the plurality of V-shape blocks to each other, and forms a continuous loop. The connecting means includes a plurality of links and a plurality of pins. The link is inserted in the opening of the V-shape block. The link includes a pair of ends and an intermediate portion. The intermediate portion of the link is positioned in the opening of the V-shape block. The ends of the link are located on opposite sides of the V-shape block. An aperture is defined within each of the ends of the link. An outer projection extends outwardly from at least one of the ends of the link toward the outside of the continuous loop. The outer projection of the link includes a first contacting edge and a second contacting edge. The first contacting edge of the outer projection of the link is in contact with the first contacting surface of the V-shape block and the second contacting edge of the outer projection of the link is selectively in contact with the second contacting surface of an adjacent V-shape block. The pin is inserted into the apertures of the links.

Chain belt

This invention relates to a continuously variable transmission which increases the range of potential transmission ratios and thereby decreases the fuel consumption rate, and which is compact in size and thereby increases space in a passenger compartment. The continuously variable transmission has low and high gear trains and a reverse gear train. Each of the low and high gear trains has a pair of meshed gears and a one-way clutch which controls the direction of transmitting the generated torque. The high gear train further has a clutch which engages at a medium or high vehicle speed and disengages at a low vehicle speed. A jaw clutch is slidably mounted on an output shaft and is located in either a first position or a second position. The jaw clutch forms the low gear train when the jaw clutch is in the first position, and the reverse gear train when the jaw clutch is located on the second position.

Continuously variable transmission

An endless belt for the power transmission, wherein a plurality of block bodies each comprising a body member formed of a highly rigid material and provided at opposite side portions thereof with inclined surfaces being in frictional engagement with pulleys and a clamp member formed separately of said body member are arranged in a row and adjacent to one another on a belt-shaped endless carrier formed of fabric in such a manner that the endless carrier is clamped between the body members and the clamp members, the endless belt being of such an arrangement that the belt-shaped endless carrier formed of fabric is woven by warps disposed in the longitudinal direction and wefts disposed in the widthwise direction, with the wefts restraining the warps.

Endless belt for power transmission

A V-belt assembly trained over V-belt wheels which includes a flexible endless belt, a plurality of rigid suspension members secured fixedly to the endless belt perpendicularly to the longitudinal direction of the endless belt and approximately U-shaped rigid transmission pieces pivotably supported by pivotal projections projecting sidewise from both sides of the respective suspension members and capable of engaging V-shaped grooves in the V-belt wheels. The central axis of the pivotal projections passes through the approximately central portion of the thickness of the endless belt. In the ends of both legs of the U-shaped transmission piece are formed grooves for receiving the pivotal projection of the suspension member, and lids for covering respectively these grooves are secured fixedly to the ends of the legs. Further, the transmission pieces except for at least one piece are formed with a square notch opening to the end face of both legs of 'U' configuration and the surface opposed to the adjacent transmission piece and an arcuate surface-like groove formed on a portion of one of angled sides of this notch reaching the end face of the leg to contact the other side, the arcuate surface-like grooves of these transmission pieces being fitted onto the respective pivotal projections of the suspension members.

V-belt assembly for transmitting power

A V-belt assembly for transmitting power, which includes a V-belt assembly trained over a V-belt wheel; a flexible endless belt; a plurality of suspension members slidably mounted on the endless belt in a longitudinal direction thereof and which includes a pin member and a U-shaped member connected to said pin, and a plurality of U-shaped transmission pieces separated from the U-shaped member, having side surfaces corresponding to side walls of a V-shaped groove of the V-belt wheel and supported swingably by the suspension members, respectively.

A continuously variable belt transmission device, including driving and driven pulley assemblies on parallel axes. Each pulley assembly includes an axially fixed and an axially movable pulley member with confronting conical face which define a V-shaped groove between them whose width is variable according to axial movement of the movable pulley member wherein the axial orders of the fixed and movable pulley members are opposite in the two pulley assemblies. An endless belt assembly is fitted in a power transmitting manner in the V-shaped grooves of the driving and driven pulley assemblies, and thus by alteration of the widths of the grooves the power transmission ratio can be varied. When the widths of the two V-shaped grooves of the two pulley assemblies are substantially equal, with the endless belt assembly being substantially taut between the pulley assemblies, the axial center of the V-shaped driving pulley groove of the driving pulley assembly is, relative to the axial center of the V-shaped driven pulley groove of the driven pulley assemblies, offset towards the axially movable driven pulley member along the axial direction. The maximum amount of skewing of the endless belt assembly is thereby reduced.

Continuously variable belt transmission device with pulleys axially

A V-belt assembly trained over U-belt wheels for transmitting power and which includes a flexible endless belt, a plurality of rigid suspension members secured fixedly to the endless belt perpendicularly to the longitudinal direction of the endless belt and rigid transmission pieces surrounding the respective suspension members in the section perpendicular to the longitudinal direction of the endless belt, supported pivotal projections projecting sideways from both sides of the suspension members and capable of engaging V-shaped grooves in the V-belt wheels. This rigid transmission piece is shaped in the generally rectangular form constituted from two generally U-shaped pieces. At least one of the pivotal projections of the suspension member and holes in the transmission piece located approximately in the center of a space between the top surface and the bottom surface of the transmission piece fitted on the pivotal projections of the suspension member is coated with an antifriction material layer. Two generally U-shaped pieces of the transmission piece are coupled with each other by a joint member in at least one of the top and bottom of these pieces.

A belt means for transmitting torque between pulleys in a continuously variable transmission. The belt means comprises a plurality of abutting hoops superimposed inside of each other, with no clearance being provided between abutting hoops because the outer circumferential diameter of an inner hoop is greater than or equal to an inner diameter of an outwardly located hoop, whereby, the tensile stresses on the innermost hoop are decreased to enhance the durability and increase the service-life of the inner hoop.

Continuously variable transmission means

A hydraulic apparatus for a continuously variable transmission, through which the RPM ratios of a driving pulley to a driven pulley is consecutively varied. Such RPM ratios are varied by electrically controlling the volume of hydraulic fluid supplied to or drained from a cylinder of a driving pulley.

Growing community of inventors

Aichi, Japan

Susumu Okawa