A hydraulic synchronizer selectively couples one or more gears to a drive shaft. The synchronizer has a shaft hub with a splined annulus and a fluid passage. A ring is disposed about the shaft hub and movable along a rotation axis of the shaft hub. A shift collar is fixedly coupled to the ring and has a splined annulus engaged with the splined annulus of the shaft hub. The shift collar is configured to engage splines of a gear when the ring is in an engaged axial position and to disengage the splines of the gear when the ring is in a neutral position. The shift collar transmits rotational input from the shaft hub to the gear when the ring is in the engaged axial position. Hydraulic chambers receive hydraulic fluid from the fluid passage and move the ring to the engaged and neutral positions.

A first rotating shaft (22) and a second rotating shaft (43) are connected so as to be capable of transmitting rotation by engagement of a first pawl portion (38) of a piston (32) and a second pawl portion (47) of the second rotating shaft (43) based upon delivery of hydraulic oil to an oil chamber (37). The first pawl portion, when in engagement with the second pawl portion based upon the delivery of the hydraulic oil, is engaged with a third pawl portion (52) of a synchronizer ring (51) prior to the engagement with the second pawl portion. Engagement surfaces of the first and second pawl portions are formed as inclination surfaces so that a force is applied to the first pawl portion and the second pawl portion in a direction of axially moving away from each other when the rotation is transmitted between the first and second rotating shafts.

A first rotating shaft (22) and a second rotating shaft (43) are connected in a state of being capable of transmitting rotation by the engagement of a first pawl portion(38) of a piston (32) and a second pawl portion(47) of the second rotating shaft (43) based upon the delivery of hydraulic oil to an oil chamber (37). The first pawl portion(38) of the piston (32), when being engaged with the second pawl portion(47) of the second rotating shaft (43) based upon the delivery of hydraulic oil to an oil chamber (37), is engaged with a third pawl portion(52) of a synchronizer ring (51) prior to the engagement with the second pawl portion(47). Engagement surfaces of the first pawl portion(38) and the second pawl portion(47) are formed as inclination surfaces so that a force is applied to the first pawl portion(38) and the second pawl portion(47)in a direction of axially moving away from each other when the rotation is transmitted between the first rotating shaft (22) and the second rotating shaft (43).

A synchronizer assembly includes a pair of engageable members each including an exterior cone surface and first exterior splines. A central synchronizer ring is disposed between the pair of engageable members and having second exterior splines. A pair of synchronizer cone rings are disposed on opposite sides of the central synchronizer ring and each include third exterior splines and an interior cone surface that oppose the exterior cone surface of respective ones of the pair of engageable members. A sliding synchronizer sleeve engages the second exterior splines of the central synchronizer ring and movable for engaging the third exterior splines of the pair of synchronizer cone rings and the first exterior splines of the pair of engageable members. A plurality of interlocking clips engage the pair of synchronizer cone rings.

A synchronizer assembly includes a pair of engageable members each including an exterior cone surface and first exterior splines. A central synchronizer ring is disposed between the pair of engageable members and having second exterior splines. A pair of synchronizer cone rings are disposed on opposite sides of the central synchronizer ring and each include third exterior splines and an interior cone surface that oppose the exterior cone surface of respective ones of the pair of engageable members. A sliding synchronizer sleeve engages the second exterior splines of the central synchronizer ring and movable for engaging the third exterior splines of the pair of synchronizer cone rings and the first exterior splines of the pair of engageable members. A plurality of interlocking clips engage the pair of synchronizer cone rings.

A collar and a torque transmission apparatus having a collar. The collar may have a set of collar teeth. Each collar tooth may include a first end surface, a second end surface, a first collar side surface, and a second collar side surface. The first and second collar side surfaces may be concave from the first end surface to the second end surface.

A collar and a torque transmission apparatus having a collar. The collar may have a set of collar teeth. Each collar tooth may include a first end surface, a second end surface, a first collar side surface, and a second collar side surface. The first and second collar side surfaces may be concave from the first end surface to the second end surface.

A hydraulic synchronizer selectively couples one or more gears to a drive shaft. The synchronizer has a shaft hub with a splined annulus and a fluid passage. A ring is disposed about the shaft hub and movable along a rotation axis of the shaft hub. A shift collar is fixedly coupled to the ring and has a splined annulus engaged with the splined annulus of the shaft hub. The shift collar is configured to engage splines of a gear when the ring is in an engaged axial position and to disengage the splines of the gear when the ring is in a neutral position. The shift collar transmits rotational input from the shaft hub to the gear when the ring is in the engaged axial position. Hydraulic chambers receive hydraulic fluid from the fluid passage and move the ring to the engaged and neutral positions.

A transmission includes a primary gear including primary teeth, each having a primary surface; a secondary gear including secondary teeth; an intermediate gear including intermediate teeth, each comprising a primary intermediate part having a primary intermediate surface and a secondary intermediate part having a secondary intermediate surface, where the primary intermediate part is axially offset from the secondary intermediate part. The intermediate gear is axially displaceable to an engaged position. The primary surface contacts the primary intermediate surface in a contact region and the secondary intermediate surface contacts one of the secondary teeth. In the engaged position, one primary tooth and one intermediate tooth form an overlap, radially inside the contact region, for preventing the intermediate gear from being displaced from the engaged position to a disengaged position.