Abstract: An assembly includes a first planetary stage, a second planetary stage, and at least one retainer plate. The first planetary stage has a planet carrier and the second planetary stage has a ring gear. The planet carrier and the ring gear are configured to be rotated about a common axis of rotation. The retainer plate is attached to the ring gear and engages in a groove in the planet carrier. The groove and the axis of rotation are at least partially skewed to each other. The retainer plate is arranged at least partially on a first side of a first plane and on a first side of a second plane. The first plane and the second plane intersect along the axis of rotation. All planet bolts fixed in the planet carrier each lie on a second side of the first plane and/or the second plane.

Abstract: A hydraulic clutch assembly includes a rotating shaft. A first clutch and a second clutch are coupled to the shaft. A first passageway located within the shaft supplies an actuating fluid to the first clutch. A second passageway located within the shaft supplies the actuating fluid to the second clutch. A first bleed passage is fluidly coupled with the first passageway. A second bleed passage is fluidly coupled to the second passageway and the first bleed passage. A first outlet is fluidly coupled to the first bleed passage. A second outlet is fluidly coupled to the second bleed passage. The first outlet and the second outlet merge together to form an outlet passage.

Abstract: An axle disconnect system for drive axles that utilizes an engagement spring, an electric motor and a slidable gear. The motor is connected to the slidable gear which moves along threads thereby engaging or disengaging clutch teeth on a first side gear which selectively engages a second side gear. The engagement spring is located between a bearing and the first side gear wherein when engagement is desired, but blocked by misalignment of the teeth, the engagement spring can apply a load to allow for engagement once alignment of the teeth is achieved. The use of a second engagement spring allows for the disengagement of the system when disengagement is typically blocked due to high driveline torques without having to reapply current to the motor.

Abstract: A planetary gear train of an automatic transmission for a vehicle is provided to improve power delivery and fuel efficiency by applying six engaging elements to five planetary gear sets to achieve ten forward speed stages and one reverse speed stage. The planetary gear train includes: an input shaft; an output shaft; first to fifth planetary gear sets each including three rotation elements; three clutches and three brakes as the six engaging elements; and first to ninth shafts. In particular, the third shaft fixedly connects seventh, tenth and thirteenth rotational elements, and the fourth shaft fixedly connects sixth and fifteenth rotational elements. In addition, the fifth shaft fixedly connects third and fourth rotational elements, the sixth shaft fixedly connects fifth and eighth rotational elements, and the seventh shaft fixedly connects ninth and eleventh rotational elements.

Abstract: A clutch assembly includes first, second and third clutches, a housing including a first projection to which the first clutch selectively produces a connection, a second projection to which the second and third clutches selectively produce connections, clutch-apply circuits each circuit corresponding to one of the clutches, and a balance volume circuit for supplying fluid to each of the clutches, and a shaft rotatably supporting the housing.

Abstract: A valve assembly includes a valve body having an input in selective communication with an output, a latching piston disposed within the valve body, a balance spring disposed between the latching piston and the valve body, and a valve piston disposed within the valve body. The input communicates with the output when the valve piston is in a first position and the input does not communicate with the output when the valve piston is in a second position. A diaphragm spring is disposed between the latching piston and the valve piston. A holding spring is disposed between the valve piston and the valve body.

Abstract: An assembly includes a valve body having an inlet in selective communication with an outlet and having an unlatch port, a latching piston disposed within the valve body, a balance spring disposed between the latching piston and the valve body, and a valve piston disposed within the valve body. The inlet communicates with the outlet when the valve piston is in a first position and the inlet does not communicate with the outlet when the valve piston is in a second position. A diaphragm spring is disposed between the latching piston and the valve piston. A holding spring is disposed between the valve piston and the valve body. An unlatching mechanism is in communication with the unlatch port of the valve body.

Abstract: A rotating clutch operably disposed between two rotating components includes a hydraulic operator having a piston and, on one side of the piston, an apply chamber or cavity and, on the opposite side of the piston, a balance chamber or cavity. The apply chamber is selectively provided with pressurized hydraulic fluid to engage and release the clutch to couple and de-couple the two rotating components. The balance chamber is provided with a flow of pressurized hydraulic fluid from the transmission lubrication system that flows through the transmission main shaft and flow restricting passages to the balance chamber. An exhaust port downstream of the balance chamber releases excess hydraulic fluid flow. Thus, whether, the clutch is rotating or not, hydraulic pressure is maintained in the balance chamber and proper clutch operation is assured.

Abstract: An automatic transmission damper mechanism provided between a first hydraulic passage (23) to which an oil (L) is supplied and a second hydraulic passage (24) from which the oil (L) is supplied to a friction element (18) has: a container (8) provided between the first and second hydraulic passages (23, 24); a slide member (11) provided in the container (8) such that it can slide therein; and an elastic member (9) provided between an inner face of the container (8) and the slide member (11). The container (8) has a pressure chamber (28) defined by an inner face of the container (8) and the slide member (11) and communicating with a branch hydraulic passage (25) branching from the first hydraulic passage (23), and the slide member (11) has a communication hole (15) through which the first and second hydraulic passages (23, 24) are placed in communication by the elastic member (9) contracting under the pressure of the oil (L) supplied into the pressure chamber (28) through the branch hydraulic passage (25).

Abstract: An arrangement which comprises at least one claw clutch for the shiftable coupling and decoupling of a shaft (1), in an automatic transmission of a planetary design, with at least one component. The shaft can be connected to a component of the planetary gearset (4) and the claw clutch is arranged centrally, substantially inside a sun gear (3) of the planetary gearset (4).

Abstract: A clutch assembly for a hybrid vehicle includes a clutch assembly including a first housing comprising a first clutch, a first clutch actuator and a second housing having the first clutch actuator at least partially disposed therein so that said first clutch actuator selectively engages the first clutch.

Abstract: An automatic transmission includes first and second clutches, a clutch drum, a piston, a plurality of friction plates, a hydraulic oil chamber, a cancel oil chamber, a return spring, and a cancel plate, wherein a plate member that forms a cylinder portion of the hydraulic oil chamber is provided between the piston and the clutch drum of the first clutch that is located on an inner diameter side, and an oil passage that supplies an oil to the cancel oil chamber of the second clutch that is located on an outer diameter side is formed between the clutch drum and the plate member.

Abstract: A speed change apparatus includes a first clutch having a first clutch drum, in which an annular clutch plate is spline-fitted to an inner peripheral surface of the first clutch drum, and a clutch piston formed with a spline on an inner peripheral surface of the clutch piston is provided to slide in an axial direction and press the clutch plate; and a second clutch having a second clutch drum, which is disposed in the clutch piston of the first clutch concentrically with the first clutch, and in which a spline is formed on inner and outer peripheral surfaces of the second clutch drum such that outer peripheral surface spline teeth form inner peripheral surface spline grooves. Wherein the outer peripheral surface of the second clutch drum is spline-fitted to the inner peripheral surface of the clutch piston and an annular clutch plate is spline-fitted to the inner peripheral surface of the second clutch drum.

Abstract: An automatic transmission including a first clutch, a second clutch, a first drum in which a first piston of the first clutch is axially slidably received and that cooperates with the first piston to define a first oil chamber, a second drum disposed coaxially with the first drum, so as to accommodate the first drum, and in which a second piston of the second clutch is axially slidably received, the second drum cooperating with the second piston to define a second oil chamber, a first fluid supply portion for feeding a working fluid into the first oil chamber through the first drum and the second drum, to operate the first piston, and a second fluid supply portion for feeding the working fluid into the second oil chamber through the second drum, to operate the second piston, and wherein the second fluid supply portion is located radially outwardly of the first fluid supply portion.

Abstract: Each of first and second multi-plate clutches comprises a clutch outer cylinder portion provided to be coaxial with the input shaft and connected with a first or second rotational element, a clutch inner cylinder portion provided to be coaxial with an input shaft, plural clutch plates provided between these cylinder portions to slide in an axial direction of the input shaft within the clutch outer or inner cylinder portion, and a clutch piston provided to slide in the axial direction and press the clutch plates for connecting the clutch outer cylinder portion with the clutch inner cylinder portion. The clutch outer and inner cylinder portions of each of the first and second multi-plate clutches are provided in the axial direction, and there is provided a support wall portion that is connected with the input shaft and supports the clutch inner cylinder portion of each of the multi-plate clutches.

Abstract: An automatic transmission that includes one clutch that includes a clutch drum; a piston that forms a hydraulic oil chamber using a part of the clutch drum as a cylinder; a plurality of friction plates that engage with the clutch drum; and a cancel oil chamber that is provided on a rear side of the piston and that cancels a centrifugal oil pressure that acts on the hydraulic oil chamber. Oil is supplied to the cancel oil chamber from a boss portion formed in the clutch drum on a radially inner side, and the oil is discharged from discharge holes formed in the boss portion to an outside of a hydraulic oil chamber side of the clutch drum.

Abstract: An arrangement is proposed for a planetary gearset (2) with an axially adjacent shift element in a housing (1) of a transmission of a vehicle, such that the planetary gearset (2) is connected to the shift element for torque transfer, and such that a non-destructively detachable connection is provided between the shift element and the planetary gearset (2).

Abstract: A power take off device includes input and output shafts and an integral planetary gear set. The power take off device may be a single speed or a two speed device. The input shaft and the output shaft are mechanically connected through the planetary gear set. In one mode of operation of the power take off device, a substantial speed reduction and torque increase is provided between the input shaft and the output shaft. The power take off device may change to a second mode of operation without stopping to provide a direct one to one speed and torque ratio between the input shaft and the output shaft. A planetary gear set clutch unit includes a two direction actuator that provides fluid pressure actuation and release of the clutch unit with a single input signal.

Abstract: A transmission system without dynamic seals, specifically, an actuator for a vehicle transmission including a first rotating clutch pack engageable with a planetary gearset a first non-rotating actuator piston for engaging the clutch pack and a first bearing for isolating a first rotation of the clutch pack from the piston. A transmission system is provided using an electromechanical system for shifting the clutches, allowing a smaller pump only for lubrication of the transmission and the torque converter flow.

Abstract: A transmission includes two blocking valves that control fluid pressure to a plurality of clutches. The blocking valves are characterized by a plurality of states that result in at least three transmission operating conditions. Each of the three operating conditions is characterized by fluid pressure being unavailable to a respective one of the plurality of clutches.

Abstract: The present invention provides an automatic transmission having a main bearing disposed between the inner surface of a boss portion of a first drum and the outer surface of a cylindrical support, for rotatably supporting the first drum. An auxiliary bearing is press-fit into one end of the interior of the boss portion of the first drum and surrounds the cylindrical support with an annular gap therebetween. The auxiliary bearing contacts the cylindrical support only when the first drum tilts relative to the central axis of the transmission, and has a shorter axial length than that of the main bearing.

Abstract: A connection structure for an automatic transmission includes a drum member that includes a base portion, an outer diameter portion that extends from an outer diameter side of the base portion in an axial direction, and a collar portion that extends from an inner diameter side of the base portion in the axial direction; a base member that includes a raised portion, an outer diameter portion that extends from an outer diameter side of the raised portion in the axial direction, a boss portion that extends from an inner diameter side of the raised portion in the axial direction, and a connection portion that extends from an end of the outer diameter portion; and a ring gear of a planetary gear that includes a spline groove and a circular concave groove on an end portion of an inner peripheral face.

Abstract: A second clutch piston formed of a plurality of members including a cylindrical cylinder member, a disc-shaped bottom plate member that fits in one end portion of that cylinder member, and a snap ring, has a plurality of long positioning protrusions provided on an inner peripheral surface of the cylinder member. By abutting the disc-shaped bottom plate member against end surfaces of these positioning protrusions, the bottom plate member can be fit into the one end portion of the cylinder member without having to provide notches therein, which enables durability against a pulling force generated in the cylinder member when the friction apply device is applied to be maintained.

Abstract: A universal two speed gearbox for driving high speed vehicles under high temperature operating conditions, and other devices which require variable operating two speed bearing thrust.

Abstract: A piston for an automatic transmission including a pair of mutually meshing gears such as counter drive and driven gears mounted on respective two parallel shafts, the piston including a bottom portion, and a cylindrical portion to be disposed radially outwardly of one of the mutually meshing gears, wherein the cylindrical portion has not only a cutout formed in a first circumferential part thereof for permitting mutual meshing engagement of the mutually meshing gears such that a point of the mutual meshing engagement is located within a circumference of the cylindrical portion, but also a through-hole formed in a second circumferential part thereof so that a speed sensor extends through the through-hole, for detecting the rotating speed of the above-indicated one gear disposed radially inwardly of the cylindrical portion. This arrangement of the cylindrical portion permits size reduction of the cutout, and assures sufficiently high degrees of strength and rigidity of the piston.

Abstract: A power transmission, for a vehicle, provides seven forward speeds and a reverse speed. The transmission has three planetary gearsets and has one sun gear member, which is held stationary for six of forward speeds and the reverse speed. The sun gear member is connected through a shaft to a torque-transmitting mechanism, which is disposed forward of an oil distribution snout and rearward of the vehicle engine.

Abstract: In a friction engagement device of an automatic transmission, a brake piston is actuated by an oil pressure and a friction disc is pressed by the brake piston. The friction engagement device of an automatic transmission includes an oil pressure chamber extending in an annular shape and a main oil pressure supply path and a secondary oil pressure supply path each extending separately to supply oil to the oil pressure chamber. Each of the main oil pressure supply path and secondary oil pressure supply path connects to the oil pressure chamber in a position different from each other in a circumferential direction of the oil pressure chamber. With a construction as such, a friction engagement device of an automatic transmission is provided which prevents a load to the friction disc from locally increasing and attains a smooth speed-changing operation.

Abstract: An apply piston for a torque-transmitting mechanism in a power transmission includes a first circumferential periphery and a second circumferential periphery radially inward of the first circumferential periphery and axially displaced therefrom. The apply piston has a generally radially-extending face between the two peripheries. The two peripheries and the radially-extending face cooperate with a transmission case to form a fluid-filled chamber that is selectively expandable to direct fluid force to the piston for engagement of the torque-transmitting mechanism.

Abstract: A hydraulic stroking device that performs stroking action by adjusting a pressure of hydraulic fluid in a fluid chamber is disclosed. The hydraulic device includes a hydraulic piston, a sealing member, and a variable sealing performance mechanism. The piston is provided in a fluid chamber, and receives the pressure of hydraulic fluid and is moved by the pressure. The sealing member seals between a circumferential surface of the piston and an inner surface of the fluid chamber. When the piston is not moving with the hydraulic fluid being pressurized, the variable sealing performance mechanism enhances the sealing performance of the sealing member compared to the sealing performance in a state when the piston is being moved.

Abstract: A forward/reverse change-over mechanism (3) of an automatic transmission comprises a forward clutch (5) inside a drum (7) with the base (7c) which rotates together with an input shaft (1). The forward clutch (5) engages by driving a piston (9) housed in the drum (7) by the oil pressure of an oil chamber (10) between a base (7c) and the piston (9). Projecting bearings (16) which seat the piston (9) are formed by press-forming at equal angular intervals concentrically with the axial center of the drum (7) in the base (7c). By installing a sensor body (18) which responds to the passage of depressions (17) formed underneath the bearings (16), the forward/reverse change-over mechanism (3) can be made compact and manufactured with a small number of parts and machining steps.

Abstract: The present invention is directed to methods and systems for improving the operation of transmissions for automotive vehicles, and in particular the “factory installed” automotive transmissions installed by the original automobile manufacturer. The methods and systems in accordance with the present invention modify both the structural components and the hydraulic circuitry of the original automotive transmissions to enhance the operation of the modified transmissions. The improvements to the operation of the “factory installed” transmissions, and in particular the Allison transmission, include modification of the flow control valve to increase line pressure during lockup; modifications to the rotating clutch module to increase the torque held by the clutch and prevent clutch slippage, and modifications to the trim valves to adjust the pressure applied to the clutches for more efficient operation of the transmission.

Abstract: A transmission includes a plurality of fluid passages configured to transmit fluid through the transmission for operating the transmission. A miniature electric motor is operatively connected to a moveable blocker positioned in one of the passages for actuating movement of the blocker between an open position in which fluid is allowed to flow through the passage, and a closed position in which the passage is blocked.

Abstract: A multiple speed transmission for a motor vehicle includes a speed reduction gear set driveably connected to an input shaft, a planetary gear set having elements selectively driveably connected to the speed reduction gear set and input shaft, a first clutch and a second clutch, each clutch connected through the speed reduction gear set to the input shaft, a source of hydraulic fluid, and a first servo having a first fluid path connecting the fluid source and the first clutch, and a second fluid path connecting the fluid source and the second clutch, and a third fluid path connecting the lubrication fluid source and the lubrication circuit.

Abstract: A servo system employs at least two multiple disk clutches arranged in series to each other in an axial direction and at least two pistons used for engagement and disengagement of the respective clutches and arranged to be nested each other so that one of the pistons fits inside the other. Also provided is a servo system control device with a piston-stroke order control section. The piston-stroke order control section determines a timing of operation of each of the pistons for engagement of the respective clutches so that the pistons are operated in a specified order that the outside piston is operated prior to the inside piston.

Abstract: A friction disc in a tandem frictional engagement device, that is spline-fitted to a first coupling members is pressed by a first piston in a first direction, wherein the friction disc and another friction disc on the side of a first coupled member are clamped between the first piston and a first stopper member. A friction disc that is spline-fitted to a second coupling member is pressed by a second piston in an opposite direction, wherein the friction disc and another friction disc on the side of a second coupled member are clamped between the second piston and a second stopper member. A leading end of a first fitting portion of the first coupling member to which the friction disc is spline-fitted is the second stopper member and substantially abuts a second fitting portion of the second coupling member to which the friction disc is spline-fitted.

Abstract: An automatic transmission apparatus comprising, a first member rotating integrally with an input shaft and including a first cylindrical portion having an inner spline at an inner peripheral surface, a second member including a second cylindrical portion having an outer spline for engaging with the inner spline of the first member and a depressed portion formed on the second member and a clearance, which establishes a communication between an inner portion surrounded by the first and the second members and an outer portion of the first and the second members, is formed between the depressed portion of the second member and the inner surface of the first member.

Abstract: A transmission includes at least one planetary gear set, a first clutch pack having a plurality of first clutch plates, and a second clutch pack located in series axially with the first clutch pack. The second clutch pack has a plurality of second clutch plates. A clutch apply member associated with the second clutch pack protrudes through the first clutch plates of the first clutch pack. A substantially cylindrical seal member is positioned between the first clutch pack and second clutch pack for preventing substantial flow of cooling fluid between the first and second clutch packs to direct cooling fluid through the second clutch pack when the second clutch pack is applied by the clutch apply member.

Abstract: A shiftable transmission in which at least two clutches (2, 7) actuated in closing direction by spring force and in opening direction by the exertion of pressure are arranged, wherein output of the transmission is stopped by unpressurized shifting of both actuation devices (9, 13) thereby closing both clutches (2, 7). When pressure is exerted upon the second actuation device (13), the actuation force of the first actuation device (9) is composed of a spring force of the first actuation device (9) and a hydraulic force from the pressurization of the second actuation device (13). The clutch belonging to the first actuation device can thus be impinged upon with different forces depending on whether or not the second actuation device is impinged upon with pressure.

Abstract: A vehicle planetary gear device including a sun gear, a carrier, a ring gear, a clutch drum, clutch plates axially slidably fitted in the drum, a backing plate fixedly disposed in the drum on one side of a series of clutch plates, and a piston axially movable fitted in the drum and disposed on the other side of the series of clutch plates, and wherein the ring gear is fixedly fitted in the drum with its engaging teeth held in engagement with engaging grooves of the drum, and at least one retainer ring is fixed on the drum and disposed in contact with the teeth of one-piece member consisting of the ring gear and the backing plate, whereby axial movements of the backing plate and the ring gear relative to the drum are prevented by the at least one retainer ring.

Abstract: A system and method is disclosed for providing multiple classes of communication services on a high-speed, high capacity communication platform over Wave Division Multiplexing (WDM) networks. A predetermined set of light channels of a WDM network is partitioned into one or more sub groups based on their wavelengths, each sub group is assigned for providing exclusively one communication service such as video, audio or data communication services. Each light channel is modulated by a predetermined set of orthogonal codes so that neighboring channel interferences can be minimized. Further, the predetermined set of orthogonal codes can be further divided into an even group and an odd group. These two groups of codes are assigned to two immediate neighboring light channels.

Abstract: A high performance intermediate servo assembly wherein the servo piston has been modified to provide at least a 17% increase in surface apply area and a corresponding increase in hydraulic pressure delivered to the 2nd gear clutch band which it actuates is disclosed. The present servo piston is reconfigured to an overall length equivalent to the assembled stack-up dimensions of the original equipment servo piston, accumulator, accumulator spring, and spring retainer components and integrates the critical working surfaces thereof to retain proper function. Such original equipment components have been eliminated to simplify the intermediate servo assembly operation since shift feel is not a concern in this application. Further, the standard O-ring seals on the original equipment servo piston are replaced by high performance seals such as quad-lobed seals to ensure the hydraulic integrity of the present intermediate servo assembly under the increased fluid pressure generated.

Abstract: In a transmission with a built-in planetary gear mechanism which has an element to be fixed to a casing of the transmission, inner elements are sub-assembled by mounting a plurality of transmission constituting members inclusive of the planetary gear mechanism. After containing the inner elements inside the casing, the element to be fixed is arranged to be fixable to the casing from a peripheral wall portion of the casing. The element to be fixed is fixed to the cylinder portion of a hydraulic brake to be built in the transmission. The cylinder portion is fixed to the casing by means of fixing members which are inserted into the casing from an outside of the peripheral wall portion of the transmission casing.

Abstract: A power train for an automotive transmission includes first and second planetary gear sets disposed around an input shaft. The first and second planetary gear sets include a first sun gear, a first planet carrier, and a first ring gear. The second planetary gear set includes a second sun gear, a second planet carrier, and a second ring gear; the first planet carrier being fixedly connected to the second ring gear. The first sun gear is connected to the input shaft with a first clutch interposed between the first sun gear and the input shaft. The second planet carrier is connected to the input shaft with a second clutch interposed between the second planet carrier and the input shaft, and the second sun gear is connected to the input shaft with a third clutch interposed between the second sun gear and the input shaft. The fourth clutch and the second one-way clutch are disposed spaced away from each other in the axial direction of the input shaft.

Abstract: An automatic transmission is adjusted by changing the longitudinal position of a pin relative to a hydraulically-actuated piston, the pin being threaded into the piston. A holding socket engages the piston and prevents it from rotating while the pin is being adjusted. The holding socket engages a support guide which is contained within the transmission casing. The combination of the holding socket and the support guide replaces a spanner wrench, used in the prior art, and eliminates the need to disassemble the transmission to perform the adjustment, and also provides a more convenient way of making the adjustment in the cramped environment of an automatic transmission. The process therefore substantially reduces the time required to adjust an automatic transmission, and also reduces the likelihood of harm to the transmission, or injury to the technician, during the adjustment process.

Abstract: A method for controlling torque transfer between first and second friction elements in an automatic transmission having a hydraulic band brake servo in which a magnet is fixed to a displaceable piston, and a sensor producing a signal responsive to the sensed intensity of a field produced by the magnet representing the position of the servo piston, producing from the signal an indication of the position of the servo piston, determining a reference threshold servo position corresponding to incipient band brake torque capacity, and reducing pressure in the second friction element when the current servo displacement equals the threshold displacement.

Abstract: A replacement mechanism or servo assembly for applying a band to an input member of an automatic transmission includes a housing in which an apply piston is located and to which an apply pin is connected. The piston is sealably movable in the housing and includes a major piston member having a first distal reaction face and a minor piston member integral with the major piston and having a second distal reaction face. A pressure fluid distribution device applies a working fluid against both of the first distal reaction face and the second distal reaction face in order to move the piston with the resultant force of the pressures on both reaction faces and to cause the apply pin to move toward the band to compress the band about the input member with this resultant force. In a preferred embodiment, the housing further includes a pressure separator immovably disposed between the first distal reaction face and an adjacent second proximal face of the minor piston member.

Abstract: A frictional engagement device for engaging a pair of members relatively rotating around a common axis is improved to obtain a smooth action. A first frictional engaging element is fitted unrotatably and axially movably to one of the relatively rotating member. A second frictional engaging element is unrotatably and axially movably fitted to the other of the relatively rotating member and disposed engageable to the first frictional engaging element. A first cam member which is axially movably fitted to one of the relatively rotating member and disposed apart from the second frictional engaging element has a slanted cam surface. A second cam member which is disposed adjacent to the first cam member on a side of the second frictional engaging element has a slanted cam surface parallelly opposing the cam surface of the first cam member. A piston means which is fitted to the second cam member has a surface engageable with the second frictional engagement element.

Abstract: A cooling structure of an automatic transmission is provided which is capable of reducing the number of assembly parts and obtaining a high cooling efficiency by placing two heat sources away from each other. A high clutch device (15) is disposed between a front planetary gear device (13) and a rear planetary gear device (14) which is parallelly disposed in the direction in which an input shaft (4) in the front planetary gear device (13) extends. The high clutch device (15) includes a cylindrical clutch drum (15a), a clutch piston (15b) which slides in the direction of the input shaft (4) inside of the clutch drum portion (15a) and forms a piston-operating oil hydraulic chamber (20) in combination with the clutch drum portion (15a), and a plurality of clutch plates (15c) which are pressed by the clutch piston (15b) and laminated in the direction in which the input shaft (4) extends. The clutch drum (15a) is formed intetrally with a planetary carrier (18).

Abstract: A mechanical transmission for drive wheels, especially for mobile work machines, has a sprocket keyed on a drive shaft rotatably supported to a frame, an internally-cogged crown connected to a hub of a drive wheel of a work machine, and at least one intermediate gear wheel coupled to the sprocket and the crown and rotatably supported by an intermediate member. Two gear couplings are provided, each of which is equipped with own externally-activated means for command. The gear couplings connect the intermediate member with the frame and the drive shaft.

Abstract: A frictional engagement device for an automatic transmission, by which an input shaft and an output shaft are engaged or disengaged by use of oil pressure. A casing connected to an input shaft and a first piston disposed in the casing define a first oil pressure chamber. The first piston is rotationally movable by predetermined angle and is axially movable by predetermined distance relative to the casing. A second piston disposed in the first piston defines a second oil pressure chamber with the first piston, and the second piston is axially movable relative to the first piston. Separator plates axially slidably connected to the first piston and clutch discs axially slidably connected to a hub which is fixedly connected to the output shaft are engaged by a displacement of the second piston by supplying pressurized oil to the second oil pressure chamber and/or to the first oil pressure chamber.