A synchronizer is provided for torsionally connecting a gear to an axially aligned shaft. The synchronizer includes a hub connected with the shaft, a sleeve having an inner diameter with spline teeth for torsional connection with the hub being axially movable upon the hub, a blocking ring torsionally connected on the hub having an angular lost motion relationship with the sleeve, the blocking ring having at least a first annular conical friction surface orientated radially inward and axially toward the hub and a second annular conical friction surface oriented radially inward and axially outward from the hub, the blocking ring having blocking cogs preventing axial movement of the sleeve toward the gear when the gear is in a non-synchronous condition, and an engagement ring for fixed connection with the gear, the engagement ring having a complementary annular conical friction surfaces.

In a claw-type gearshift, a blocking ring is arranged axially between a hub body having a sliding sleeve and a clutch body such that it is rotatable between a release position and two locking positions. The blocking ring is adapted to be displaced toward the clutch body until conical friction surfaces on the blocking ring and on the clutch body come into contact. The blocking ring constitutes a form-locking blockade for the sliding sleeve against displacement of the sliding sleeve teeth between the clutch body teeth when an axial shifting force is applied in the non-synchronized state. When the claw clutch is shifted, a difference in speed between the clutch body and the hub body is reduced and the sliding sleeve is deflected in the axial direction toward the speed change gear to be shifted, as a result of which a friction surface of the blocking ring and a mating friction surface of the clutch body come into contact.

Provided is a dog clutch mechanism that can guarantee a successful engaging operation regardless of relative rotational positions of a sleeve and a transmission gear, with a simple and inexpensive configuration. When sliding of a sleeve (20) toward a transmission gear (30) involves contact (abutting) between dog teeth (21b) of the sleeve (20) and key members (50), an engaged state is achieved so that a rotation shaft (2) and the transmission gear (30) integrally rotate, with the key members (50) retracted toward the transmission gear (30) to a retracted position against biasing force of a coil spring (55), and the dog teeth (21b) fit in keyway (51) between the plurality of key members (50). Thus, the dog clutch mechanism (1) guarantees the successful engagement with only a single engagement operation.

A method for shifting a gear in a synchronizer comprising a synchronizer body arranged on a transmission shaft, a first and a second synchronizer associated to a first and a second transmission gear, wherein the synchronizer has a sliding sleeve and at least one thrust piece which is shiftably arranged on the synchronizer body and can exert an axial compressive force on the corresponding synchronizer ring. The synchronizer includes an elastic actuating element active between the sliding sleeve and the thrust piece, and the sliding sleeve has a detent recess for the neutral position and a release contour that can cooperate with the actuating element such that when the sliding sleeve is shifted for being engaged with one of the transmission gears, the thrust piece is urged away from the corresponding synchronizer ring.

A synchronizer of a transmission may include a lower key disposed slidable in a radial direction of a hub; an upper key disposed at an external side of the lower key in the radial direction to be slidable in an axial direction of the hub; a sleeve disposed at an external side of the hub to slide the upper key in the axial direction while being slid in the axial direction thereof, pressing the upper key toward a synchronizer ring; a key spring disposed between the lower key and the hub to press the lower key and the upper key toward an internal surface of the sleeve; and a displacement converting device converting relative displacement generated in a circumferential direction of the hub between the upper key and the lower key into relative displacement of the upper key in axial direction toward the synchronizer ring with respect to the lower key.

A clutch may include a hub configured to be constrained to a rotation shaft; a sleeve configured to be straight slidably disposed on an external circumferential surface of the hub; a clutch gear configured to be disposed to be relatively rotatable with respect to the rotation shaft; a first friction ring configured to be mounted between the clutch gear and the hub; a key configured to be mounted between the sleeve and the hub; and a displacement changing portion configured to change a relative rotation displacement of the first friction ring with respect to the hub to an axial linear displacement of the first friction ring.

A synchronizer of a transmission may include bottom key disposed on a hub to be slidable in a radial direction of the hub; a top key disposed radially outside the bottom key to be slidable in an axial direction of the hub; a sleeve disposed outside the hub and sliding in the axial direction to slide the top key in the axial direction to press a synchro-ring; a key spring disposed between the bottom key and the hub to press the bottom key and the top key toward an internal side of the sleeve; and a motion converting portion converting relative motion generated in a circumferential direction of the hub between the top key and the bottom key into axial relative motion of the top key to the bottom key toward the synchro-ring.

An automotive synchronizer slider assembly includes a slider body with two connecting grooves symmetrically arranged thereon. The slider body has a top, a bottom, and a middle. A first boss and a second boss are provided on the top of the slider body. The first boss and the second boss have mounting grooves for a steel ball, and the first boss has provided on a top thereof two or more clips. Pressure plates are provided at the bottom of the slider body. A mounting part has a top and a bottom, and a spring mounting hole positioned between the top and the bottom. The top of the mounting part is connected to the second boss, and the bottom of the mounting part has a hole therein. A steel ball is mounted in the mounting grooves and retained in the slider body by the two clips. A fastening spring having a top and a bottom is mounted in the spring mounting hole. The bottom of the fastening spring abuts the bottom of the mounting part proximate the hole therein, and the top of the fastening spring abuts the steel ball.

A synchronizing device, for a vehicle gearbox, with a synchronizer body which can be mounted rotationally fixedly on an axial shaft, and a shift sleeve which is connected rotationally fixedly to the synchronizer body and can be moved axially along an outer periphery of the synchronizer body and which, to perform a synchronizing process, can be brought from a neutral position into rotationally fixed engagement in a first shift phase with an axially displaceable synchronizer ring and in a second shift phase with a clutch body adjacent to the synchronizer ring. During the first shift phase, the synchronizer ring can be moved in the direction of the adjacent clutch body by the shift sleeve using pressure pads arranged axially displaceably in the synchronizer body, and hence can be brought into frictional engagement with the adjacent clutch body for the purpose of pre-synchronization.

A synchronizer device for a manual transmission, having a shaft and a selector gear that is mounted on the shaft. The synchronizer device includes a hub, which can be connected to the shaft in a rotationally locked fashion, a slider sleeve, which is supported on the hub in a rotationally locked fashion, and can be slid in the axial direction, a locking element that is designed to limit the slidability of the slider sleeve in a locked position, a friction package, which has an outer synchro ring, an inner synchro ring, and an intermediate ring, which is positioned between the outer synchro ring and the inner synchro ring, with the outer synchro ring and inner synchro ring being able to rotate relative to each other, and a servo unit having a first servo surface on a first component and having a second servo surface on a second component, which rests against the first servo surface, and a torque between the first component and second component causes the first servo surface to slide along relative to the second servo surface, which produces an axially acting servo force on the friction package. According to this invention, the servo force is introduced into the friction package by the outer synchro ring and the outer synchro ring is able to rotate relative to the locking element.