Abstract: The level of quietness for an automatic transmission case is ensured by preventing vibration by improving the rigidity while suppressing the increase in the mass of a transmission case. In an automatic transmission case in which a valve body is attached to a case wall that covers the transmission mechanism, the rigidity of the automatic transmission case is increased by providing, in the case, an enclosing wall that projects out from the case wall and encloses the periphery of the valve body.

Abstract: To ensure durability of a one-way clutch, by reducing surface pressures applied to side bearings, a one-way clutch has end bearings that are disposed between an outer race and an inner race and that maintain concentricity between the races. In a supporting structure wherein one of the outer race and the inner race is fitted to a stationary member and the other race is fitted to a rotational member, a clearance of a fitting portion between the stationary member and one of the races is narrower than a clearance between the rotational member and the other race. A load resulting from whirling of the rotational member is absorbed by the greater clearance, and a high load resulting from radial movements of the race fitted to the stationary member and a weight of the race is supported by the stationary member. Thus, loads applied to the end bearings are reduced.

Abstract: A reduction in the weight and size of a speed-change mechanism is obtained by shortening a high-torque transmission system. The speed-change shock is attenuated by reducing an inertia torque in a muilti-stage vehicular automatic transmission. The vehicular automatic transmission is equipped with a planetary gear set that receives a decelerated rotation and a non-decelerated rotation as inputs and outputs a plurality of speed-change rotations, a reduction planetary gear, an input shaft that passes through an inner side of the planetary gear set, first and third clutches that couple the input shaft to two different speed-change elements of the planetary gear set respectively through the reduction planetary gear in an engageable and disengageable manner, and a second clutch that couples the input shaft to the other speed-change element of the planetary gear set in an engageable and disengageable manner.

Abstract: An automatic transmission comprises a reduction planetary gear, two clutches transmitting a decelerated rotation transmitted from the reduction planetary gear, and a planetary gear set comprising two elements to which the decelerated rotation is inputted through the two clutches. The reduction planetary gear and the two clutches are arranged in one side of the planetary gear set. The second clutch is closer to the planetary gear set than the clutch. The input side member of the first clutch is connected to an output element of the reduction planetary gear and the input side member of the second clutch. The output side member of the first clutch is extended through the radial inner space of the second clutch and connected to one of the two elements of the planetary gear set. Thus, no member is arranged in the radial outer side of the both clutches, and the both clutches are radially enlarged.

Abstract: An automatic transmission, which establishes automatic shifts in a multiple gear stages by selectively inputting a plurality of input rotations to a planetary gear set, includes first and third clutches connected through a reduction planetary gear to an input shaft and transmits a decelerated rotation to the planetary gear set and a second clutch directly connected to the input shaft and transmits a non-decelerated rotation to the planetary gear set. The reduction planetary gear is arranged on the end of a boss portion of a transmission case wall and the one element is fixed to the end of the boss portion, hydraulic servos of the first and third clutches are arranged on the boss portion, a hydraulic servo of a second clutch is arranged in the other side of the reduction planetary gear from the hydraulic servos, and the hydraulic paths for the hydraulic servos are formed in the boss portion.

Abstract: An automatic transmission establishing multiple gear stages includes a reduction planetary gear, at least two clutches transmitting a decelerated rotation transmitted from the reduction planetary gear, and a planetary gear set inputted the decelerated rotation transmitted through the two clutches. The reduction planetary gear and the two clutches are arranged in one side of the planetary gear set. The reduction planetary gear is arranged between the clutches.

Abstract: An automatic transmission includes a planetary gear set inputted a decelerated rotation and a non-decelerated rotation and outputting a plurality of shift rotations, a reduction planetary gear, an input shaft, first and third clutches which are able to engage/disengage for connecting the input shaft through the reduction planetary gear to two different decelerated rotation input elements of the planetary gear set individually, and a second clutch which is able to engage/disengage for connecting the input shaft to a non-decelerated rotation input element. The first clutch, the third clutch and the reduction planetary gear are arranged together, and the second clutch is arranged in the other side of the planetary gear set.

Abstract: A rotational direction of a rotational element at a high speed gear stage is different from a operational direction of a reaction torque at a low speed gear stage. The rotation by the reaction torque at the low speed gear stage is stopped with a self-energizing operation of a band brake operated by a hydraulic servo. A waiting pressure, which is lower for a predetermined amount than a engagement pressure at the self-energizing operation, and with which a basis of a racing amount occurs after a synchronizing point, is applied to the hydraulic servo until the synchronization is determined. The waiting pressure increases to the engagement pressure after determining the synchronization so that the rotational element is stopped gradually as preventing a long shift time.

Abstract: A lubricant control apparatus for an automatic transmission including a lubricating unit for feeding the lubricating oil to the portions of a speed change mechanism so that the heat to be generated in the speed change mechanism may be absorbed and recovered by the lubricating oil. The lubricant control apparatus includes a detector that detects the acting state of the speed change mechanism; a determiner that determines a necessary lubricating oil flow on the basis of the calorific value in the speed change mechanism, the calorific value being calculated from the detected acting state of the speed change mechanism; and a structure for feeding the lubricating oil to the speed change mechanism on the basis of the determined necessary lubricating oil flow. The lubricant control apparatus feeds an optimum lubricating oil flow according to the acting state of the speed change mechanism.

Abstract: A control system for a vehicular automatic transmission includes a speed change mechanism including an output element that is connected to the drive shaft of a vehicle to transmit power, and a rotary element connected to the output element. A control system for the speed change mechanism is also provided. The control system includes a hydraulic servo actuated brake for retaining the rotary element to check the rotation of the output element in a vehicle roll back direction. The brake includes a band brake that establishes different application forces depending on whether the brake operates by a self-energizing action or a de-energizing action according to the rotational direction of the rotary element.

Abstract: To reduce dispersion in an engagement stroke amount caused by error in manufacturing parts and to reduce the stroke amount in a stationary cylinder type clutch device, the clutch device includes a hub, a drum, friction coupling elements connecting thereto such that rotational power can be transmitted, a pressing member and a reaction force member arranged at opposite ends of the clutch device in the axial direction, and a hydraulic servo for engaging and disengaging the friction coupling elements where the hydraulic servo is installed to a fixed member, a servo force is transmitted to the friction coupling elements via the pressing member and the reaction force caused by the engagement is supported by the fixed member via the reaction force member.

Abstract: A hydraulic servo device for an automatic transmission is presented with a reduced axial length as a result of the manner in which oil pressure is fed into the cylinder. The hydraulic servo device includes a cylinder, a piston position to slide within the cylinder, a rod connected to the piston, and a cover member for closing the open end of the cylinder. The cover member, in association with the cylinder and the piston, defines an oil chamber in the cylinder. An oil passage for feeding an oil pressure to the oil chamber is formed by an opening in the cover member.

Abstract: A hydraulic servo unit for a vehicular power transmission system having a helical gear, including a clutch for connecting predetermined rotary elements to each other and a hydraulic servo for applying the clutch, the hydraulic servo including a cylinder, a piston fitted in the cylinder, a push member abutting against the piston through a bearing for transmitting the push force of the piston to the clutch, and a return spring for the piston, one of the rotary elements including a reaction member opposed to the push member for transmitting the push force of the piston to a case, and the cylinder is a stationary cylinder formed in the case. Further, the return spring is arranged between the push member and the reaction member and is loaded to apply a load higher than the thrust force of the helical gear, as acting upon the reaction member.

Abstract: An automatic transmission for a vehicle with a reverse gear brake that includes a case. A predetermined rotational element, having gear teeth and an axis, is disposed within the case. The predetermined rotational element only operates as a rotational element when achieving a reverse gear mode. A brake has a gear member. The gear member is attached to the case so that it cannot rotate relative to the case, but is movable along the axis of the predetermined rotational element so that it can be engaged and disengaged with the teeth of the predetermined rotational element. The predetermined rotational element is fixed to the case so that it cannot rotate relative to the case when the gear teeth engage the gear member.

Abstract: A vehicular automatic transmission for establishing a plurality of forward gear stages, includes: a transmission case; an input shaft; a transmission mechanism connected to the input shaft and including a plurality of transmission elements; an output shaft connected to the transmission mechanism; first and second clutches at opposite ends of the transmission mechanism and drivably connecting the input shaft with at least one of the transmission elements; and first and second hydraulic servos for applying the first and second clutches responsive to feed of an oil pressure. The transmission case encloses the transmission mechanism, the clutches and the hydraulic servos, and includes axial end walls forming cylinders for the hydraulic servos.

Abstract: A vehicular automatic transmission, for establishing a plurality of forward gear stages, includes: a transmission case; an input shaft; a transmission mechanism connected to the input shaft and including a plurality of transmission elements; an output shaft connected to the transmission mechanism; a clutch drivably connecting any one of the input shaft and the transmission elements individually; and a hydraulic servo for applying the clutch responsive to an oil pressure. The transmission case encloses the transmission mechanism, the clutch and the hydraulic servo, and includes axial end walls, on one of which is formed a stationary cylinder for the hydraulic servo. A piston is slidably mounted in the cylinder and together with the cylinder, defines an oil chamber for receipt of the actuating oil pressure. A bearing is arranged between the piston and the clutch for transmitting the thrust force from the piston to the clutch, while allowing relative rotation between the piston and the clutch.

Abstract: A band brake drum supporting device for an automatic transmission having a band drum to be retained in a case by fastening a band brake which is joined to a rotary element of the automatic transmission and arranged in the case. The drum includes a band engaging portion and a cylindrical drum supporting portion extending radially inward from the band engaging portion while being offset axially with respect to the band engaging portion. The outer circumference of the drum supporting portion is supported through two axially juxtaposed bearings on a stationary support portion which extends radially outward of the drum supporting portion from the case. The stationary support portion includes a cylindrical boss portion disposed coaxially with the drum supporting portion and engaging at its inner circumference with the two bearings and a planar flange portion extending radially outward from the end portion of the boss portion which is located closer to the band brake.

Abstract: A 5-speed automatic transmission for a vehicle having a highly efficient top gear, a compact construction and a wide overall range of gear ratios. The automatic transmission has a speed changer which provides five gear stages, namely two speeds on the speed decreasing side and two speeds on the speed increasing side with a direct-coupled gear therebetween. The speed changer includes a ring gear connected to an output shaft, a first carrier, a first sun gear, a second carrier connected to the first carrier, a stepped pinion gear supported by these two carriers, and a sun gear meshing with the pinion gear. The first carrier is connected to an input shaft by a clutch and the first sun gear is connected to the input shaft by a clutch. The first sun gear may be stopped by a first brake, a second brake stops the second sun gear and a third brake is provided to stop a third sun gear. Top gear is achieved by meshing of the pinion gear with the second sun gear and the ring gear.

Abstract: An automatic transmission for a vehicle, as provided a plurality of planetary gear units in which the ratios of the tooth numbers of the sun gears to the tooth numbers of the ring gears are different from each other. In the two sets of planetary gear units in which the ratios of the tooth numbers of the sun gears to the tooth numbers of the ring gears are different from each other, the ring gears are identical to each other in the tooth number, the normal module, the normal pressure angle, the angle of torsion, the pitch radius, the base radius, the bottom diameter, the top diameter, the tooth height, the dedendum, the addendum, the lead, the coefficient of normal shift and the arcuate tooth thickness, and the pinions of those two sets of planetary gear units are identical to each other in at least the arcuate tooth thickness, the coefficient of normal shift, the dedendum, the addendum, the tooth height, the angle of torsion, the normal pressure angle and the normal module.

Abstract: A shift mechanism for an automatic transmission includes a frictional engagement element arranged between the case of the automatic transmission and one element of a planetary gear unit and a hydraulic servo unit for engaging the frictional engagement element. A one-way clutch is connected to that same one element of the planetary gear unit for selectively locking it to the case. The one-way clutch is axially spaced from the frictional engagement element with the hydraulic servo unit therebetween. Further, the one-way clutch has its outer race connected to the case and its inner race connected to the aforementioned element of the planetary gear unit through a connection member axially extending along the inner circumferential side of the hydraulic servo unit. The inner race is formed with a radial lubricating oil passage in fluid communication with an oil passage in a transmission shaft.