Abstract: A fastener assembly includes a bolt having a shaft and a head. The shaft has proximal and distal shaft ends and a shaft body, with the head at the proximal shaft end. At least a bondable portion of the shaft body is at least partially made of a bondable material. At least one collar has proximal and distal collar ends longitudinally separated by a collar body which includes a longitudinally oriented collar aperture extending through a thickness thereof between proximal and distal collar surfaces. The collar aperture defines an inner collar wall having a bondable portion which is at least partially made of a bondable material. At least the bondable portion of the shaft body is located inside the collar aperture. The bondable material of both of the inner collar wall and the shaft body is activated to bond the shaft and the collar into an integral fastener assembly structure.

Abstract: A fastener arrangement comprising a main body having a driving head, a central bore with an inner thread opening out into a front face of the driving head, and a collar, axially protruding from the front face of the driving head and being coaxially arranged to the inner thread. The fastener arrangement further comprises a spring element axially abutting against the front face of the driving head having a central through hole which is coaxially arranged to the inner thread of the driving head and a bearing element axially abutting against the spring element having a central through hole which is coaxially arranged to the inner thread of the driving head. The collar axially protrudes through the through hole of the spring element and into the through hole of the bearing element, and wherein the collar at its end facing away from the driving head, which end is positioned inside the through hole of the bearing element, provides a locking section radially extending outwardly.

Abstract: A bonding washer for making electrical connection between two metal pieces that are to be mechanically fastened together. The washer, to be interposed between the two metal pieces, may be constructed so as to fasten to one of the pieces before the two pieces are joined. Teeth on the washer, positioned at right angles to the plane of the washer, are forced into each of the two metal pieces when the fastener is tightened, making electrical connection between the two metal pieces.

Abstract: An accessory attachment has a housing with a top end and a bottom end, at least one locking member, and a spring-biased retractor apparatus. The retractor apparatus interfaces with the locking member to move the locking member from an engaged position to a disengaged position. The accessory attachment may be attached to, or removed from, a mounting receptacle by moving the retractor apparatus toward or away from either end of the housing.

Abstract: A shank (110) comprises a captive portion (116) comprising a longitudinal central axis (112), a captive end (118), a first set (117) of first structures (120a), and a second set (119) of second structure (120b). The second set (119) of the second structures (120b) is closer to the captive end (118) than the first set (117) of the first structures (120a). The first set (117) of the first structures (120a) has a first axial compliance coefficient along the longitudinal central axis (112). The second set (119) of the second structures (120b) has a second axial compliance coefficient along the longitudinal central axis (112). The first axial compliance coefficient of the first set (117) of the first structures (120a) is greater than the second axial compliance coefficient of the second set (119) of the second structures (120b).

Abstract: An embodiment includes a method, comprising: applying an overlay material to a portion of a rotatable shaft; directing a pulse of laser energy to contact the overlay material to produce a shock wave; and re-positioning one or more of the portion of the rotatable shaft and the pulse of laser energy to contact the overlay material at different positions to create a laser peened surface on the portion of the rotatable shaft; the pulse of laser energy comprising a pulse sufficient to create the laser peened surface having residual compressive stress to a depth exceeding about 3 mm. Other aspects are described and claimed.

Abstract: A piston engine crankshaft made from carbon composite molded in two separate moldings is disclosed. According to a preferred embodiment, the first mold takes the top dead center piston ignition load. The second molding takes the dynamic piston and rod load and contains the counterweight. Accordingly, carbon fiber filaments are aligned in preferred directions to optimally absorb loads at different areas of the crankshaft.

Abstract: A rocking journal bearing is provided in a piston coupling mechanism of a two-stroke cycle engine. The bearing includes a sleeve and a wristpin constructed with two sets of eccentrically-disposed bearing surfaces which alternate in accepting a compressive load during an operational cycle of the bearing. The sleeve includes a network of grooves to transport oil to the bearing surfaces. Lubricating oil flow through the bearing is minimized by limiting provision of pressurized oil from the wristpin to the network of grooves to portions of the cycle when one or the other of the sets of bearing surfaces receives the compressive load.

Abstract: The present invention discloses an adjustable ball-type universal joint, which is distinct from the conventional ball-type universal joint where the ball-type joint is hard to rotate stably or fixed securely. In the present invention, an elastic element is added to the bottom of the ball-type joint, providing elastic resilience to stabilize the rotation of the ball-type join and secure the fixation of the ball-type joint. Therefore, the present invention can improve performance and quality, save manpower and materials, reduce fabrication cost, and upgrade commercial competitiveness for the ball-type universal joint.

Abstract: A foil bearing (thrust foil bearing (40)) includes a foil holder (41) and a plurality of foils (42) arrayed in a circumferential direction. Each of the foils (42) includes a body portion (42a) having a thrust bearing surface (S2) and an extended portion (42b) extending from the body portion (42a) to a radially outer side. An end portion (42d) of the body portion (42a) of each of the foils (42) on one circumferential side is arranged so as to be overlapped on the body portion (42a) of adjacent one of the foils (42). The extended portions (42b) of the plurality of foils (42) are fixed onto the same plane of the foil holder (41).

Abstract: A wheel bearing arrangement for a vehicle, having rotatable and statically fixed components, and at least two rolling body bearings arranged radially between the rotatable and statically fixed components for rotatably mounting the rotatable component. The at least two rolling body bearings have in each case an inner ring, an outer ring, and a rolling body row arranged therebetween. A spacer sleeve is arranged at end sides of the respective inner rings for axially securing the two inner rings. A respective securing ring is arranged fixedly on the respective inner rings so as to rotate therewith. The securing rings each have a substantially axially configured lug with a respective radial embossment arranged in a respective groove configured on an outer circumferential face of the spacer sleeve, in order to connect the respective inner rings axially to the spacer sleeve via the respective securing rings.

Abstract: A method for replacing a portion of a first outer bearing assembly for a generator with a second outer bearing assembly. The first outer bearing assembly includes a first liner and a first outer bearing race. The method includes removing the first outer bearing race and the first liner and inserting a second liner. The second liner is matched to a given diameter such that the second outer bearing assembly fits within the generator. A position ring of the second outer bearing assembly is inserted against the machined second liner and a generator housing. A second bearing race of said second outer bearing assembly is inserted against the position ring. The second bearing race of the second outer bearing assembly is connected against the position ring and against a generator housing.

Abstract: An oil delivery system is provided. The system may comprise a bearing housing comprising an oil delivery cavity. A bearing may be pressed against the bearing housing. The bearing may comprise an outer ring with a passage formed through the outer ring. A bearing is also provided. The bearing may include an outer ring, and a passage formed through the outer ring.

Abstract: A rolling bearing apparatus includes: a bearing portion having an inner ring, an outer ring, a plurality of balls, and a cage; and a lubrication unit that is provided adjacently to an annular space formed between the inner ring and the outer ring and that has a pump that feeds a lubricant into the annular space. The pump has a main body portion having an internal space in which the lubricant is retained and being open at one end of the main body portion, a metal diaphragm fixed to a fixation portion that is a part of the main body portion so as to close the opening of the main body portion, and a piezoelectric element fixed to the diaphragm. At least the fixation portion of the main body portion is formed of metal, and the fixation portion and the diaphragm are fixed together by metal joining.

Abstract: A rolling bearing apparatus includes a bearing portion and a lubrication unit. The lubrication unit is provided adjacently to an annular space in an axial direction. The annular space is formed between an inner ring and an outer ring, and the lubrication unit has a tank storing lubricant that is supplied to the annular space. The tank has an outer wall on a radially outer side, and a space formed on a radially inner side of the outer wall is a storage portion for storing the lubricant. An oil supply hole that is used to refill the storage portion with the lubricant is provided passing through the outer wall. The oil supply hole is open to the radially outer side.

Abstract: A retention assembly for handling cyclical axial loads is disclosed. The retention assembly comprises a bearing, a motor, and a bushing element. The bearing is mounted around an axis of a shaft The motor is adapted to operate the shaft through a coupler. The bushing element is mounted around the axis of the shaft. The bushing element has a hollow cylindrical configuration defining an internal volume for accommodating the coupler and a portion of the shaft therein. An internal diameter of the bushing element is larger than an external diameter of each of the coupler and the shaft respectively. One end of the bushing element is in a contacting relationship with the bearing. The bushing element is adapted to hold the bearing in place through an interference fit with a motor housing ID for withstanding the cyclical axial loads.

Abstract: A constant-velocity joint includes: an outer joint member; an inner joint member that is placed in the outer joint member and that can be angled with respect to the outer joint member; and balls that roll between the outer joint member and the inner joint member to transmit torque. First outer larger diameter portions and second outer larger diameter portions are formed alternately in the circumferential direction in the inner peripheral surface of the outer joint member. The center of an arc radius of a track of the center of the ball rolling on the first outer larger diameter portion and the center of an arc radius of a track of the center of the ball rolling on the second outer larger diameter portion are located on different sides with respect to the joint center in the axial direction of the outer joint member.

Abstract: A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins. The first hub can be mounted with the input shaft. The second hub can be mounted with the rotor shaft. The first side coupling assembly can have a first side coupling body and a first side elastomeric insert. The second side coupling assembly can have a second side coupling body and a second side elastomeric insert. The central hub can define central hub bores therein. The plurality of coupler pins can be received in the central hub bores. The first and second side elastomeric inserts provide dampening between (i) the first side coupling body and the central hub and (ii) the second side coupling body and the central hub.

Abstract: A flexible coupling comprises a flexible torque disc (24) having a first plurality of fixing points (24a) whereby it can be mounted upon a first rotatable component (12), in use, and a second plurality of fixing points (24b) whereby it can be mounted upon a second rotatable component (14), in use, a support ring (26), and mounting means (34) whereby the flexible torque disc (24) is secured to the support ring (26), the mounting means (34) restricting deflection of the flexible torque disc (24) relative to the sup port ring (26).

Abstract: A dog clutch for an automatic transmission includes a mating clutch that defines a plurality of helical splines and a sliding clutch that defines a plurality of helical splines. The helical splines of the sliding clutch mesh with the helical splines of the mating clutch in an engaged configuration. The dog clutch also includes a synchronizer positioned at the sliding clutch. A related automatic transmission is also provided.

Abstract: A clutch assembly for transmitting power from an output shaft of an engine to an input shaft of a gearbox includes annular friction surfaces on at least one of the flywheel and the pressure plate. The annular friction surface has a plurality of grooves that extend across the annular friction surface away from an inner rim of the friction surface toward an outer rim of the friction surface to prevent a reduction in friction caused by outgassing or abraded particles trapped between engaging friction surfaces.

Abstract: A hydrostatically operated clutch system having a hydrostatic clutch actuator for hydrostatically operating a clutch, in particular a pulse separation clutch of a hybrid drive, such that the hydrostatic clutch actuator is combined with a valve arrangement which is to be opened actively and enables the clutch to be engaged rapidly.

Abstract: An installation structure of a one-way clutch in which torque transmission is limited to one direction includes a flywheel, first and second rotary structures, housing and stopper plates, and a rivet. The first rotary structure is arranged coaxially with the flywheel while connected to an engine block. The second rotary structure is arranged coaxially with the first rotary structure while connected to the flywheel. The housing plate is disposed between the flywheel and the first and second rotary structures and arranged coaxially while connected to the second rotary structure. The stopper plate is attached to the second rotary structure to hold first rotary structure with the housing plate. The rivet fastens the stopper plate, the second rotary structure, and the housing plate. A first clearance between one face of the flywheel and a top face of a head of the rivet is narrower than a thickness of the stopper plate.

Abstract: An actuator for connecting and disconnecting a dog clutch between two coaxial shafts (1, 2) by means of an axially movable clutch sleeve (3) comprises an electric motor. A motor shaft (8) of the motor is connected to a rotatable actuator rod (7). This rod (7) is provided at its end with an eccentric pin (5) for such cooperation with the clutch sleeve (3) that a rotation of the actuator rod (7) 180° or less by means of the motor from a rotational position corresponding to one axial end position of the clutch sleeve (3) to a rotational position corresponding to the other axial end position of the clutch sleeve (3) leads to a connection or disconnection of the dog clutch.

Abstract: A rotational fixing for a guide pin of a disc brake and method for fixing a guide pin of a disc brake. The rotational fixing includes a guide sleeve having a sleeve portion, a receiving portion of a brake carrier, and an inter-connection. The receiving portion receives the sleeve portion. The inter-connection engages the sleeve portion and the receiving portion and restricts rotation of the guide sleeve relative to the brake carrier when the sleeve portion is received by the receiving portion.

Abstract: A guide assembly for a disc brake. The guide assembly includes a receiving portion of a brake carrier that receives a sleeve portion of a guide pin. The sleeve portion and receiving portion have corresponding non-circular cross-sectional profiles that restrict rotation of the sleeve portion relative to the brake carrier when the sleeve portion is received and aligned in the receiving portion. The present invention further relates to a disc brake that includes a brake carrier, a caliper, and at least one guide assembly and a method of manufacture.

Abstract: A rotational speed control device includes a housing containing a viscous fluid and a shaft disposed in the housing and rotatable relative to the housing. A rotor may be movable axially on the shaft depending on the rotating speed of the shaft. The rotor is biased in a low torque direction. A braking torque between the rotor and the housing and/or between the rotor and a drive control ring is varied according to an axial position of the rotor on the shaft. The device may incorporate bypass channels to control a circulating pressure of the viscous fluid.

Abstract: A hydrodynamic machine has a vaned primary wheel and a vaned secondary wheel, which together form a toroidal working chamber filled with a working medium to form a hydrodynamic circuit flow for transmission of a drive moment. One of the two vaned wheels is driven by a drive shaft of the hydrodynamic machine via a rotary axis. The machine further has a side channel pump having a pump impeller with a plurality of pump vanes and a channel running in the circumferential direction of the pump impeller. The pump vanes are arranged in the channel such that when the pump impeller rotates, a delivery effect is generated in the channel such that at an inlet end a suction effect and at an outlet end a pressure effect is generated. The pump impeller is radially mounted, axially moveably and/or angularly tilt ably, rotationally fixedly on the drive shaft.

Abstract: A disc brake assembly includes a brake support unitarily formed from a brake carrier and an adapter portion 12. The adapter portion 12 has two lateral plates with several mounting bores on a circumference of a mounting circle. The brake carrier has a first tie bar connecting the two lateral plates and extending above the mounting circle. Two radially protruding first support stubs are formed on the two lateral plates at opposite lateral ends of the first tie bar for limiting the travel of a brake caliper. Two first guide structures for an inboard brake spreader plate are located at the opposite lateral ends of the first tie bar between the support stubs. Two guide bores laterally adjacent the support stubs are present for guide pins of the brake caliper.

Abstract: In a method for controlling a parking brake in a vehicle, in order to set a clearance between the brake pad and the brake disk, a supply voltage is first applied to an electric motor, after which the supply voltage is switched off before the brake pad comes into contact with the brake disk.

Abstract: An aircraft includes a power source arranged to provide AC electrical power of varying frequency, and a brake cooling fan including an impeller which is driven by an electric motor powered by said AC electrical power for cooling brakes of the aircrafts wheels. The brake cooling fan has an operable mode when the frequency of said AC electrical power meets certain criteria indicating that the frequency of the AC power is suitable for powering the motor, and an inoperable mode to protect against unsuitable operation of the motor. The brake cooling fan may then be safely powered with AC power direct from a wild frequency power network on the aircraft without needing a power inverter or constant power supply generator.

Abstract: The present invention provides a friction material for a disc brake pad, which is able to suppress chipping of an edge of the friction material that occurs under the high speed and high load braking conditions and further to suppress the deterioration of the braking effectiveness under the high speed and high load braking conditions while satisfying laws and regulations relating to the required amount of the content of the copper component. A friction material composition that contains 0.5-10 weight % of a resilient graphitic carbon particle relative to the total amount of the friction material composition as a carbon type lubricant and contains the total amount of a copper component contained in the friction material composition is less than 5 weight % relative to the total amount of the friction material composition.

Abstract: A suspension assembly having a shaft with a first end and a second end. The first end of the shaft is mounted to a force receiving member. The shaft is translatable within a linear bearing, which is mounted to a support member. A first magnet is mounted to the force receiving member and a second magnet is mounted to the support member. A shaft collar is mounted to the second end of the shaft. The first and second magnets are adapted to provide a magnetic force against a force applied to the force receiving member.

Abstract: Provided is a resin-made impact absorption member including: an impact absorption portion which includes a fiber-reinforced resin material containing reinforcing fibers and a thermoplastic resin and has a hollow structure including an outer cylindrical portion and a hollow portion, in which the reinforcing fiber has an average fiber length of 1 mm to 100 mm, the thermoplastic resin has a fracture elongation of 10% or more, the fiber-reinforced resin material has a compressive elastic modulus of 10 GPa or more and a compressive strength of 150 MPa to 500 MPa, and in the impact absorption portion, a maximum value of a ratio L1/t1 of a distance L1 from a position of the center of gravity to the outer cylindrical portion on a same section in a sectional shape in a direction orthogonal to an impact absorption direction, to a thickness t1 of the outer cylindrical portion, is 40 or less.

Abstract: A hydraulic damping device includes a first cylinder that houses oil, a piston rod that moves in an axial direction of the first cylinder, and a piston section that generates a damping force by a movement of the piston rod. The piston section includes a piston body formed with an oil channel through which oil flows, a base valve that opens and closes the oil channel of the piston body, a ring-shaped ring valve that is provided on the base valve, and a preload spring that has a positioning section that extends radially and determines a position of the ring valve in the radial direction.

Abstract: The present disclosure relates to an hydraulic mount for coupling first second components in a vehicle. The mount has a first elastomeric member defining a first portion of a first chamber, and a second elastomeric member defining a second portion of the first chamber and a second chamber. The chambers are each able to retain fluid in a liquid seal manner. An inner tube assembly defines an opening for receiving a bolt. The elastomeric members may be fixedly secured to an outer surface of the inner tube assembly. An inner ring is fixedly coupled to the inner tube assembly at a position between the two chambers. The second elastomeric member is fixedly secured to an outer surface of the inner ring. A decoupler is fixedly disposed within the inner ring and adapted to move between rigid surfaces adjacent the first and second chambers.

Abstract: The present invention provides a vibration mitigation device which includes a vertically extending housing and a reciprocating assembly coupled with and fully enclosed inside of the vertically extending housing. In accordance with an exemplary embodiment of the present invention, the vibration mitigation device may utilize a tension spring as the biasing member while operating in a pneumatic process, an eddy current dampening process or a hybrid combination of the two dampening processes. For low amplitude, the eddy current dampening process may provide improved vibration mitigation results and for higher amplitudes, the pneumatic process may provide improved vibration mitigation results. Other exemplary embodiments include a vibration damping element that utilizes a compression spring as a biasing member for mitigating vibrations. Further exemplary embodiments provide a vibration damping element that utilizes a compression spring and a tension spring as biasing members for mitigating vibrations.

Abstract: The disclosure relates to an attachment bracket having a pin for coupling a work tool to a machine. The attachment bracket includes a base portion coupled with the work tool, and a mounting portion extending from the base portion and coupled with the machine. The mounting portion includes a first surface, a second surface, and a bore extending between the first surface and the second surface. The attachment bracket further includes a sleeve member received through the bore, and attached with the mounting portion. The attachment bracket further includes an isolation member received within the sleeve member. The isolation member includes a first structural sleeve, a second structural sleeve, and a dampening member disposed between the first structural sleeve and the second structural sleeve. The attachment bracket further includes a restraining member for restricting axial and rotational movement of the pin with respect to the mounting portion.

Abstract: Provided is a vibration damper for a high load, including: a vibration body support portion having first shaft support portions; rotation shafts that are rotatably installed at the first shaft support portions, have eccentric portions eccentric with respect to rotation centers of the rotation shafts and are spaced a predetermined gap from each other; a support portion having second shaft support portions on which the eccentric portions are rotatably supported; an elastic member that is installed between the vibration body support portion and the support portion or between the vibration body support portion and the second shaft support portions and that elastically supports the support portion with respect to the vibration body support portion in an upward direction; and a rotation synchronization unit that is installed at the rotation shafts so as to synchronize rotation directions of the rotation shafts according to vibration.

Abstract: A dynamic damper is coupled to an intermediate member of a damper device. A drive member of the damper device has additional abutment portions coupled to end portions of vibration absorption springs of the dynamic damper before both first and second inter-element stoppers operate. The second inter-element stoppers operate before the first inter-element stoppers operate and at least by the time when the additional coupling portions are coupled to end portions of the vibration absorption springs. Outer springs and the vibration absorption springs act in parallel to transfer torque after the additional coupling portions are coupled to end portions of the vibration absorption springs.

Abstract: A dog clutch for an automatic transmission is provided. The dog clutch includes a magnet that is mounted to a sliding clutch. A solenoid is positioned adjacent the magnet and is configured for selectively adjusting the dog clutch between an engaged configuration and a disengaged configuration. A related automatic transmission is also provided.

Abstract: A planetary gear train of an automatic transmission for vehicles may include an input shaft receiving torque of an engine, an output shaft outputting changed torque of the engine, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotation shaft, a second rotation shaft, a third rotation shaft, a fourth rotation shaft selectively connected to the input shaft, a fifth rotation shaft selectively connected to the input shaft or selectively connected to the transmission housing, a sixth rotation shaft directly connected to the output shaft to be continuously operated as an output element, a seventh rotation shaft selectively connected to the transmission housing, an eighth rotation shaft selectively connected to the third rotation shaft, a ninth rotation shaft directly connected to the input shaft to be continuously operated as an input element, and six friction elements.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving torque of an engine, an output shaft outputting changed torque of the engine, a first planetary gear set including first, second, and third rotation elements, a second planetary gear set including fourth, fifth, and sixth rotation elements, a third planetary gear set including seventh, eighth, and ninth rotation elements, a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements, and seven friction elements disposed to selectively connect the rotation elements with each other and selectively connect the rotation elements with a transmission housing.

Abstract: A transmission for a vehicle may include a first planetary gear set, a second planetary gear set, a third, planetary gear set, and a fourth planetary gear set each including three rotary elements, and a plurality of friction members, in which the friction members are connected to at least one or more of the rotary elements of the planetary gear sets and control rotation of the rotary elements.

Abstract: A transmission for a vehicle may include a first planetary gear set, a second planetary gear set, a third, planetary gear set, and a fourth planetary gear set each including three rotary elements, and a plurality of friction members, in which the friction members are connected to at least one or more of the rotary elements of the planetary gear sets and control rotation of the rotary elements.

Abstract: A transmission for a vehicle may include a first planetary gear set, a second planetary gear set, a third, planetary gear set, and a fourth planetary gear set each including three rotary elements, and a plurality of friction members, wherein the friction members are connected to at least one of the rotary elements of the planetary gear sets and control rotation of the rotary elements.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving rotary power of an engine, an output gear outputting the rotary power with rotary speed changed, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first rotating shaft, a second rotating shaft, a third rotating shaft, a fourth rotating shaft selectively connected with the third rotating shaft and a transmission housing simultaneously, a fifth rotating shaft selectively connected with the first rotating shaft and the input shaft simultaneously, a sixth rotating shaft, a seventh rotating shaft selectively connected with the sixth rotating shaft and the transmission housing simultaneously, an eighth rotating shaft selectively connected with the sixth rotating shaft and the output gear simultaneously, and six friction elements.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving power from an engine, an output shaft outputting power changed in speed, a first planetary gear set including first, second, and third rotating elements, a second planetary gear set including fourth, fifth, and sixth rotating elements, a third planetary gear set including seventh, eighth, and ninth rotating elements, a fourth planetary gear set including tenth, eleventh, and twelfth rotating elements, and seven control elements disposed between the rotating elements, and disposed at positions where the rotating elements are selectively connected to a transmission housing.

Abstract: A planetary gear train of an automatic transmission for vehicles may include an input shaft receiving power of an engine, an output shaft outputting shifted power of the engine, a first planetary gear set including first, second, and third rotational elements, a second planetary gear set including fourth, fifth, and sixth rotational elements, a third planetary gear set including seventh, eighth, and ninth rotational elements, a fourth planetary gear set including tenth, eleventh, and twelfth rotational elements, and seven control elements disposed between the rotational elements and at positions at which the rotational elements and a transmission housing are selectively connected.

Abstract: A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving torque of an engine, an output shaft outputting changed torque of the engine, a first planetary gear set including first, second, and third rotation elements, a second planetary gear set including fourth, fifth, and sixth rotation elements, a third planetary gear set including seventh, eighth, and ninth rotation elements, a fourth planetary gear set including tenth, eleventh, and twelfth rotation elements, and seven friction elements disposed to selectively connect the rotation elements with each other and selectively connect the rotation elements with a transmission housing.