摘要:
First and second hydraulic servo units operate respective frictional engagement elements in a transmission and each includes first and second cylinders, each having a side wall portion interposed between the two frictional engagement elements. The first cylinder has first outer and inner cylinder portions and the first hydraulic servo unit further includes a first piston having inner and outer cylindrical surfaces slidably supported by the first outer and first inner cylinder portions of the first cylinder for reciprocating axial motion into and out of engagement with one frictional engagement element. First return springs are arranged radially inward of the one frictional engagement element for returning the first piston. The second cylinder includes second outer and inner cylinder portions and the second hydraulic servo unit further includes a second piston having a larger diameter portion and a smaller diameter portion, slidably supported by the inner cylindrical surfaces of the second outer cylinder portion and the first inner cylinder portion, for reciprocating axial motion into and out of engagement with the second frictional engagement element. Second return springs are arranged around the inner circumference of the one frictional engagement element for returning the second piston.
摘要:
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.
摘要:
A five-speed automatic transmission includes a main transmission and an over-drive transmission of a front disposition type. The main transmission includes three sets of planetary gears, a clutch for engaging and disengaging speed-change elements of the planetary gear sets, and a brake for fixing and releasing the speed change elements, and provides for four forward speed ranges and one reverse speed range. In the over-drive transmission of a front disposition type, a speed change element of an over-drive planetary gear set connected to an input element of the main transmission is adapted to be engaged, disengaged and fixed for achieving either a directly coupled stage or an over-drive stage. The over-drive transmission releases the direct coupling for reverse driving operation. One of the clutches of the main transmission for achieving the directly coupled stage and one of the brakes for achieving the low speed stage are engageable in the reverse driving operation.
摘要:
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.
摘要:
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. The clutch includes a hub with an outer cylindrical surface splined to a friction plate assembly and a rim radially spaced from the hub with the friction plate assembly splined to its inner cylindrical surface. The input shaft is connected to the hub whereas one of the transmission elements is connected to the rim.
摘要:
An automatic transmission for five forward speeds equipped with a main transmission mechanism and an auxiliary transmission mechanism. The auxiliary transmission mechanism includes a multi-disc clutch and a hydraulic servo therefor arranged in a first planetary gear set. The first planetary gear set includes a first ring gear connected to an output unit of the main transmission mechanism and a first carrier connected to an output shaft and further to a first sun gear through a multi-disc clutch and a hydraulic servo for the former. The hydraulic servo for the multi-disc clutch is connected to an integral casing through a band brake and is arranged around the outer circumference of the hydraulic servo for the multi-disc clutch. A second planetary gear set is arranged on the hydraulic servo for the multi-disc clutch and includes a second ring gear connected to the output shaft, a second carrier connected to the integral casing through a multi-disc brake and a second sun gear connected to the first sun gear through the cylinder of a hydraulic servo for the multi-disc clutch. The rear casing forms part of the cylinder of the hydraulic servo for the multi-disc brake. The auxiliary transmission mechanism has a compact three-speed construction to provide five forward speeds in cooperation with the main transmission mechanism. The five-speed automatic transmission can be easily modified merely by removing the second planetary gear set and the brake for the 1st speed to provide a four-speed transmission at a reasonable cost due to the sharing of parts in common.
摘要:
A first element of a duplex planetary gear set is selectively coupled to an input shaft via a third clutch, or is selectively fixed via a first brake. A second element is selectively coupled, via a second clutch, to an intermediate shaft that is directly coupled to a speed-increasing element of a simplex planetary gear set which increases the rotational speed of the input shaft, or is selectively fixed via a second brake. A third element is directly coupled to an output shaft. A fourth element is selectively coupled to the input shaft via a first clutch. Therefore, by increasing the speed of the rotation of the input shaft by the simplex planetary gear set and transferring it to the duplex planetary gear set, it is possible to reduce the torques on individual components of an automatic transmission and therefore to reduce the sizes of the individual components and the capacities of the individual friction engagement elements.
摘要:
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.
摘要:
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.
摘要:
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.