Abstract: A clutch assembly for starting a vehicle without using a torque converter has a simple structure yet providing high reliability. In the clutch assembly (11, 12, 13), a clutch (10) and a damper device (121, 122) are housed in a housing (2) connected to a crank shaft of an engine. A boss (30) serving as an output member is connected to an input shaft (28) of an automatic transmission. An output of the engine is connected/disconnected to/from the input shaft (28) upon engagement/disengagement of the clutch (10). The clutch (10) includes a friction member (14) and a piston (20) fit oil tightly with the housing (2) so as to apply pressure to the friction member (14). One end of the damper device (121, 122) is connected to a clutch hub (16), and the other end is connected to the output member (30). The clutch (10) and the damper device (121, 122) are aligned on the axis of the housing (2).

Abstract: A transmission case is provided with a housing enclosing a clutch and/or torque converter connected to an engine, and a shifting mechanism case enclosing a shifting mechanism in an oil-tight state that is connected to the housing. A focus for stress resulting from an impact load acting on the transmission case is formed as a frangible portion in the housing. Thus, damage to the transmission from an excessive load is limited to the housing, and by absorbing the impact from that damage, damage to the shifting mechanism case is prevented and oil leakage from the transmission case is avoided.

Abstract: A multi-stage automatic transmission using a reduction planetary gear and a planetary gear set in which the respective thrust forces generated thereat are supported by a low bearing load or a low case load. The automatic transmission is provided with a reduction planetary gear, coupled to an input shaft to fix a reaction force element so as to output a reduction rotation to an output element, and a planetary gear set, that outputs a speed shift rotation upon input of the subsequent reduction rotation. During at least first gear driving, there is provided a force transmission route in which thrust forces generated at one element of the reduction planetary gear and one element of the planetary gear set, respectively, are transmitted. In that route, a torsion direction of the helical teeth of the respective elements are set such that a direction of a thrust force of the element and a direction of the thrust force of the other element are different from each other during first gear driving.

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: In a breather device linking a space within a transmission case (1) to outside air, a breather (10) is provided at a middle position in a lengthwise direction on an upper portion of the transmission case, in particular, at a position displaced in an axial direction from a middle position in the lengthwise direction, and opens to outside air via a ventilating mechanism (2) that extends in a direction opposite this displaced direction.

Abstract: At the time of the 6→3 speed shift, an automatic transmission achieves a 6→4→3 speed shift by controlling the servo pressures of four engageable elements. A control apparatus controls the servo pressure of one engageable element in accordance with the servo pressures of other engageable elements. The engagement and release timings are adjusted by determining and controlling the oil pressures of the hydraulic servos, taking into consideration the 6→4 shift state (torque sharing) during a shift transitional period. Therefore, engine blow and prolongation are prevented during the 6→3 shift control.

Abstract: A shift control apparatus that advances activation of an engagement element to be engaged during a shift requiring engagement and release of four engagement elements, thereby reducing the shift time. The automatic transmission achieves a sixth-to-fourth-to-third shift by controlling servo pressures for the four engagement elements. The control apparatus starts, during the time of the sixth-to-third shift, supply of the hydraulic pressure for activating the engagement element to be engaged at the time of the fourth-to-third shift, thereby advancing the establishment of the engagement stand-by state at the time of the fourth-to-third shift. Accordingly, the reduction in the servo pressure of the engagement element to be released at the time of the fourth-to-third shift can be advanced, thereby reducing the time for the sixth-to-third shift.

Abstract: A planetary gear set comprises a plurality of pinions P1, P2 meshing with a sun gear, and a carrier C that shaft-supports the pinions. The carrier has an annular peripheral wall 12 that extends entirely around outer peripheries of the plurality of pinions. Thin-wall portions 12a receded at a radially inner side are formed in the annular peripheral wall, at circumferential-direction positions corresponding to the positions of the pinions. The circumferential continuity of the annular peripheral wall secures a carrier rigidity. The formation of the thin-wall portions avoids interference between each pinion and the annular peripheral wall without involving an increased diameter of the carrier. The pinions P1 have a smaller diameter than the pinions P2. A platy wall portion 32 of a bridge portion 3 extends in the direction of a circumference of the carrier, outwardly of the pinions P1.

Abstract: A hydraulic control apparatus for an automatic transmission including a hydraulic pressure source, hydraulic paths, hydraulic servos for operating friction elements which are coupled with the hydraulic source an the hydraulic paths, a control device arranged on the hydraulic paths for operating engagement release through supply/removal of hydraulic pressure to the hydraulic servos and valves which are arranged on the hydraulic path for cutting off hydraulic pressure from the hydraulic pressure source to the hydraulic servo with hydraulic pressure in the downstream side of the control device as signal pressure.

Abstract: A multi-speed automatic transmission improves transmission efficiency by reducing drag loss due to high speed rotation of a freely rotating element of a planetary gear set. An automatic transmission for a vehicle includes: an input path T1 of a first speed ratio; an input path T2 which has a larger speed ratio than this input path T1; a planetary gear set of four elements, wherein the four elements are a first element, a second element, a third element, and a fourth element following an order of elements on a speed diagram; a clutch C-2 transmitting a rotation of the input path T2 to the first element S3; a clutch C-1 transmitting the rotation from the input path T2 to the fourth element S2; a clutch C-4 transmitting a rotation from the input path T1 to the first element; a clutch C-3 transmitting the rotation from the input path T1 to the second element C3; a brake B-1 engaging the fourth element; a brake B-2 engaging the second element; and an output member coupled with the third element R3.

Abstract: To make it possible to maintain speeds during failures in an automatic transmission that does not have exclusive friction elements corresponding to the attainment of each speed. The hydraulic control apparatus of an automatic transmission, provided with control means 71-74 for supplying regulated pressure to each of the hydraulic servos 81-84 that are first through fourth friction elements to which hydraulic pressure is supplied from the oil path L1, and provided with switching valves (1)-(5) for cutting off the supply of hydraulic pressure to friction elements other than the friction elements that engage in each speed, on the upstream side of the supply paths L31, L32, L10, L11 and L12. Each switching valve is switched by hydraulic pressure (C1-C3, B1 pressures) regulated by the control means that achieve regulated pressure operating conditions during failures, and selective application of signal pressure (Sol, SolB, SoIC pressures) output by the control means as operating means.

Abstract: The invention has been made to eliminate a feeling of two-phase speed-change operations by causing a speed-change operation to proceed continuously when the speed-change operation is performed through two-phase control of engagement and release of four engagement elements. To accomplish this purpose, the invention provides a control apparatus for an automatic transmission wherein a predetermined speed-change operation is achieved through a pre-phase speed-change operation in which a first engagement element and a third engagement element are released and engaged respectively and through a post-phase speed-change operation in which a second engagement element and a fourth engagement element are released and engaged respectively. The control apparatus sets a target rotational acceleration of an input shaft of the transmission, and controls release of the second engagement element for a transition to the post-phase speed-change operation in accordance with the target rotational acceleration.

Abstract: The invention eliminates the feeling of two-phase speed-change operations by causing a speed-change operation to proceed continuously when the speed-change operation is performed through two-phase control of engagement and release of four engagement elements. An automatic transmission is such that a predetermined speed-change operation is achieved through a pre-phase speed-change operation in which a first engagement element and a third engagement element are released and engaged respectively and through a post-phase speed-change operation in which a second engagement element and a fourth engagement element are released and engaged respectively.

Abstract: A multi-speed automatic transmission improves transmission efficiency by reducing drag loss due to high speed rotation of a freely rotating element of a planetary gear set. An automatic transmission for a vehicle includes: an input path T1 of a first speed ratio; an input path T2 which has a larger speed ratio than this input path T1; a planetary gear set of four elements, wherein the four elements are a first element, a second element, a third element, and a fourth element following an order of elements on a speed diagram; a clutch C-2 transmitting a rotation of the input path T2 to the first element S3; a clutch C-1 transmitting the rotation from the input path T2 to the fourth element S2; a clutch C-4 transmitting a rotation from the input path T1 to the first element; a clutch C-3 transmitting the rotation from the input path T1 to the second element C3; a brake B-1 engaging the fourth element; a brake B-2 engaging the second element; and an output member coupled with the third element R3.

Abstract: A planetary carrier supports a plurality of short pinions and long pinions and includes a first supporting wall supporting one ends of the short pinions and the long pinions, second supporting walls supporting the other ends of the short pinions, third supporting walls supporting the other ends of the long pinions, first connecting walls connecting the first supporting wall and the second supporting walls, pairs of second connecting walls facing each other, arranged on both sides of each long pinion in the rotational direction of the carrier, and connecting the second supporting walls and the third supporting walls, and third connecting walls connecting each pair of the second connecting walls to each other on at least one of the radial inner side and the radial outer side of each long pinion.

Abstract: A speed-reducing gear unit is provided for causing a reduced-speed rotation output member to have a reduced rotation that is slower than rotation of an input shaft. The reduced-speed rotation output member is switched between a reduced-speed rotation state and a free rotation state by rotation state switching means. The reduced-speed rotation of the reduced-speed rotation output member is selectively transferred to fourth and first elements of a speed-changing dual planetary gear unit via first and third control clutches. The rotation of the input shaft is transferred to a second element via a second control clutch. Rotations of the first and second elements are selectively restricted by first and second control brakes. A third element is connected to an output shaft.

Abstract: An automatic transmission disposed in a case with a speed change mechanism disposed around an input shaft, a gear supported to a support wall of the case so as to transmit the output of the speed change mechanism to another shaft extending along the input shaft, and a rear cover portion integrated with the case, thereby eliminating a joint portion with the support wall supporting the gear removably attachable to the case through an opening portion.

Abstract: A shift control apparatus that advances activation of an engagement element to be engaged during a shift requiring engagement and release of four engagement elements, thereby reducing the shift time. The automatic transmission achieves a sixth-to-fourth-to-third shift by controlling servo pressures for the four engagement elements. The control apparatus starts, during the time of the sixth-to-third shift, supply of the hydraulic pressure for activating the engagement element to be engaged at the time of the fourth-to-third shift, thereby advancing the establishment of the engagement stand-by state at the time of the fourth-to-third shift. Accordingly, the reduction in the servo pressure of the engagement element to be released at the time of the fourth-to-third shift can be advanced, thereby reducing the time for the sixth-to-third shift.

Abstract: At the time of the 6→3 speed shift, an automatic transmission achieves a 6→4→3 speed shift by controlling the servo pressures of the fourth engageable elements. A control apparatus controls the servo pressure of one engageable element in accordance with the servo pressures of other engageable elements. The engagement and release timings are adjusted by determining and controlling the oil pressures of the hydraulic servos, taking into consideration the 6→4 shift state (torque sharing) during a shift transitional period. Therefore, engine blow and prolongation are prevented during the 6→3 shift control.

Abstract: A multi-stage automatic transmission using a reduction planetary gear and a planetary gear set in which the respective thrust forces generated thereat are supported by a low bearing load or a low case load. The automatic transmission is provided with a reduction planetary gear, coupled to an input shaft to fix a reaction force element so as to output a reduction rotation to an output element, and a planetary gear set, that outputs a speed shift rotation upon input of the subsequent reduction rotation. During at least first gear driving, there is provided a force transmission route in which thrust forces generated at one element of the reduction planetary gear and one element of the planetary gear set, respectively, are transmitted. In that route, a torsion direction of the helical teeth of the respective elements are set such that a direction of a thrust force of the element and a direction of the thrust force of the other element are different from each other during first gear driving.