Assembly for a synchronization unit of a variable ratio gear transmission. Assembly has a synchronizer ring and a friction ring. The friction ring has a friction surface and an installation surface and the synchronizer ring has a contact surface directed toward the installation surface. To allow a high efficiency of the synchronizing unit and simultaneously a functionally safe and comfortable operation of the variable ratio gear transmission, the synchronizer ring and the friction ring are configured and arranged such that the geometrical shape of the installation surface of the friction ring differs from the geometrical shape of the contact surface of the synchronizer ring in a relief state of a synchronizing process; and that the geometrical shape of the installation surface of the friction ring corresponds to the geometrical shape of the contact surface of the synchronizer ring in a load state of the synchronizing process.

A lay-shaft assembly for use in a vehicle transmission, including a lay-shaft which is rotatable around a central axis, a first gearwheel rotatable around the lay-shaft and the central axis, a second gearwheel fixedly connected to the lay-shaft and rotatable with the lay-shaft around the central axis, and a clutching assembly rotatable around the lay-shaft and the central axis. The clutching assembly includes a driven gearwheel and clutching mechanism for selectively coupling the rotation of the driven gearwheel to either the first gearwheel or the second gearwheel. The clutching assembly has a first axial end and a second axial end opposite the first axial end. The first gearwheel and the second gearwheel are arranged on a part of the lay-shaft extending from the first axial end of the clutching assembly.

Provided is a synchronizer device and method for a manual transmission, having a sliding sleeve which includes an internal toothing having sliding sleeve teeth, a clutch body, the clutch body having an external toothing having a multitude of clutch body teeth for internal toothing of the sliding sleeve to engage therein, and a synchronizer unit. The clutch body teeth at the axial tooth ends adjacent the sliding sleeve and/or at least some of the sliding sleeve teeth at the axial tooth ends adjacent the clutch body each include at least one convex end face which extends in the circumferential direction from a root point adjacent to a tooth flank of the respective tooth via an axially protruding apex portion as far as to a root point adjoining an opposite tooth.

A transmission device includes a first rotating member and a ring for synchronizing the first rotating member and a second rotating member relative to each other. The first rotating member is provided with a plurality of first recesses for receiving a plurality of protrusions provided on the synchronizing ring. The first rotating member has one said first recess for each of said protrusions. The first rotating member is provided with one or more second recesses making the total number of first and second recesses exceeding the number of said protrusions.

A lay-shaft assembly for use in a vehicle transmission, including a lay-shaft which is rotatable around a central axis, a first gearwheel rotatable around the lay-shaft and the central axis, a second gearwheel fixedly connected to the lay-shaft and rotatable with the lay-shaft around the central axis, and a clutching assembly rotatable around the lay-shaft and the central axis. The clutching assembly includes a driven gearwheel and clutching mechanism for selectively coupling the rotation of the driven gearwheel to either the first gearwheel or the second gearwheel. The clutching assembly has a first axial end and a second axial end opposite the first axial end. The first gearwheel and the second gearwheel are arranged on a part of the lay-shaft extending from the first axial end of the clutching assembly.

Provided is a transmission which eliminates torque loss during gear shift and with which the processing of components can be simplified. An axial force is generated in a protrusion by means of a first portion during gear shift from a low gear to a high gear, and when a low-speed transmission gear and a clutch ring separate from each other, a high speed transmission gear and the clutch ring interlock. Since relative movement of the protrusion in a neutral direction is suppressed by means of a first retaining portion during coasting, gear disengagement whereby the transmission gears and the clutch ring separate from each other can be suppressed. Since the first retaining portion can be formed in a first wall when providing a groove portion, an increase in the component processing workload can be suppressed.

A vehicle including a coupling device that includes (a) an engagement clutch mechanism for coupling an input side engagement member that is coupled to a drive power source of the vehicle and an output side engagement member that is coupled to a drive wheel of the vehicle; and (b) a cam mechanism for assisting engagement of the input and output side engagement members depending on a differential torque by which the input and output side engagement members are rotated differentially. The vehicle includes a control device configured, when the engagement of the input and output side engagement members is to be released, to cause a braking force to be applied to one of the input and output side engagement members such that the differential torque is reduced.

A gear wheel for a transmission includes a first member having a body for receiving a shaft and gear teeth for engagement with a further gear wheel, and a second member having a ring-shaped portion and teeth for engagement with a rotating component. The first member and the second member are rotationally locked relative to each other by means of an engagement means for transferring torque between the first member and the second member. The ring-shaped portion has a protrusion protruding in an axial direction in parallel with a rotational axis of the gear wheel and the body has an undercut receiving the protrusion. At least one part of the engagement means is arranged on the protrusion and inside the undercut.

Various aspects of the present disclosure are directed to a gear shifting device for a transmission. In some embodiments, the gear shifting device includes at least one rotatably mounted transmission element and at least one transmission element fixed to a housing, and including at least one braking device for holding the at least one rotatably mounted transmission element. The braking device has a sliding sleeve connected to the at least one transmission element of the transmission in an axially displaceable manner. In a first switched position of the sliding sleeve, a rotatably mounted first transmission element is connected non-rotatably to the transmission element fixed to the housing and. In a second switched position of the sliding sleeve, the rotatably mounted first transmission element is separated from the transmission element fixed to the housing. The braking device including at least a first and/or second synchronizer ring.

A transmission device includes a first rotating member and a ring for synchronizing the first rotating member and a second rotating member relative to each other. The first rotating member is provided with a plurality of first recesses for receiving a plurality of protrusions provided on the synchronizing ring. The first rotating member has one said first recess for each of said protrusions. The first rotating member is provided with one or more second recesses making the total number of first and second recesses exceeding the number of said protrusions.