A speed reducer capable of reliably reducing and changing speed while suppressing heat generation and abrasion includes: a plurality of gears rotatably supported on an output shaft; a shifter engageable with an engagement gear selected from the plurality of gears to couple the engagement gear to the output shaft; and a plurality of bushes disposed in an annular groove formed in the shifter to move the shifter to the engagement gear and thereby engage the shifter with the engagement gear; and a bush support supporting the plurality of bushes so as to allow them to swing individually.

Disclosed is a shifting execution mechanism for a dual clutch transmission, including a front shell, a rear shell, at least two hydraulic cylinders and at least one connecting sleeve. The at least two hydraulic cylinders are mounted along the same axis, two ends of the hydraulic cylinders are clamped between the front shell and the rear shell. Each hydraulic cylinder is mounted with a shifter, a positioning seat, and two sealing plates. Every two adjacent hydraulic cylinders are connected together through one connecting sleeve. A first hydraulic chamber is defined between the connecting sleeve and the sealing plate located adjacent to the connecting sleeve in each hydraulic cylinder. A second hydraulic chamber is defined between the front shell and the sealing plate located adjacent to the front shell. A third hydraulic chamber is defined between the rear shell and the sealing plate located adjacent to the rear shell.

Various methods and systems are provided for a shift assembly for a vehicle transmission. In one example, a shift assembly for a transmission includes a first barrel cam including a first cam track; a second barrel cam arranged coaxially with the first barrel cam and including a second cam track; a first motor configured to drive the first barrel cam independent of the second barrel cam; and a second motor configured to drive the second barrel cam independent of the first barrel cam.

An axle assembly that includes a sector cam. The sector cam may be rotatable about a sector cam axis and may be operatively connected to first and second shift collars. Rotation of the sector cam about the sector cam axis may control movement of the first and second shift collars.

An axle assembly that includes a barrel cam. The barrel cam may be rotatable about a barrel cam axis and may be operatively connected to a first shift collar. Rotation of the barrel cam about the barrel cam axis may control movement of the first shift collar along a first axis.

A shifting mechanism in which an inclination of a sleeve with respect to a shift fork is reduced while maintaining a clearance between the shift fork and the sleeve. In the shifting mechanism, an engagement groove is formed entirely around a shift sleeve, and a cutout is formed on the engagement groove. A first diameter of the shift sleeve between predetermined sites of the bottom of the engagement groove within the cutouts is shorter than a second diameter of the shift sleeve between predetermined sites of the bottom of the engagement groove. A straight-line distance between the engagement ridges formed on both ends of the shift fork is longer than the first diameter but shorter than the second diameter.

A fork guide groove of a drum member guides a shift fork so that a shifter member is in a reference position not engaged with first and second speed change members when the drum member is placed in a neutral position, is movable between a first speed-change position engaged with the first speed-change member and the reference position when the drum member is placed in a first operational position, and is movable between a second speed-change position engaged with the second speed-change member and the reference position when the drum member is placed in a second operational position. A slider guide groove of the drum member guides a slider member supported by a fork shaft in an axially movable manner so as not to obstruct movement of the shifter member between the reference position and the first speed-change position when the drum member is placed in the first operational position.

A method for hysteresis compensation in an actuator and a selector fork that is adjustable by this actuator and guides a sliding sleeve, by means of a state machine, wherein the selector fork is moved by means of the actuator from a first shift position (xDecoup), namely a neutral position, into at least one second shift position (xCoup), namely a gear position, and vice versa, wherein the position of the actuator (phiAtr, phiCoup, phiDecoup), in the event of a shift request into the neutral position (xDecoup) or into the gear position (xCoup), is corrected on the basis of stored mechanical backlash (phiBL) between the actuator and the selector fork and of a sign (+1, 0, −1) generated by the state machine and associated with the particular shift request.

A gear shifting assembly of a transmission, a transmission, and an automobile. The present disclosure aims to address the problem of complicated structure existing in a gear shifting assembly or the like. To this end, the gear shifting assembly of a transmission according to the present disclosure includes a P-gear mechanism and a forward-gear mechanism, wherein the gear shifting assembly further includes a drive mechanism and a shifting mechanism, and the shifting mechanism is configured to be capable of switching the drive mechanism so that the P-gear mechanism or the forward-gear mechanism is in an operational state. By employing the common drive mechanism, the gear-shifting function of forward gears and the function of parking at the P-gear can be realized without interference, and on the basis of function integration, elements are saved so that the gear shifting assembly is made more compact in structure.

Various methods and systems are provided for a shift assembly for a vehicle transmission. In one example, a shift assembly for a transmission includes a first barrel cam including a first cam track; a second barrel cam arranged coaxially with the first barrel cam and including a second cam track; a first motor configured to drive the first barrel cam independent of the second barrel cam; and a second motor configured to drive the second barrel cam independent of the first barrel cam.