A drive transmission unit is described that includes a drive source, and a rotatable drive transmitting member to transmit a driving force from the drive source. The drive transmitting member includes a bottom part intersecting an axis of the drive transmitting member, a circular transmitting part extending from the bottom part in an axial direction of the drive transmitting member and including an internal toothed surface on an inner circumferential surface of the transmitting part to mesh with a first member, and a first projecting part and a second projecting part projecting in opposite directions from the bottom part along the axial direction of the drive transmitting member and having different diameters.

A one-way or selectable clutch with multiple circumferential rows of ratchet elements is disclosed. The clutch may include two or more rows of ratchet elements extending between two or more races. The device may be either a one-way clutch or a selectable mechanical clutch, and afford the benefits of reduced backlash and multiple modes of operation. Those modes may include free-wheel/overrun in both clockwise and counterclockwise directions, locked/transmit torque in both directions, locked in clockwise and overrun in counterclockwise directions, and locked in counterclockwise and overrun in clockwise directions.

A drive transmission unit is described that includes a drive source, and a rotatable drive transmitting member to transmit a driving force from the drive source. The drive transmitting member includes a bottom part intersecting an axis of the drive transmitting member, a circular transmitting part extending from the bottom part in an axial direction of the drive transmitting member and including an internal toothed surface on an inner circumferential surface of the transmitting part to mesh with a first member, and a first projecting part and a second projecting part projecting in opposite directions from the bottom part along the axial direction of the drive transmitting member and having different diameters.

A drive transmission unit is described that includes a drive source, and a rotatable drive transmitting member to transmit a driving force from the drive source. The drive transmitting member includes a bottom part intersecting an axis of the drive transmitting member, a circular transmitting part extending from the bottom part in an axial direction of the drive transmitting member and including an internal toothed surface on an inner circumferential surface of the transmitting part to mesh with a first member, and a first projecting part and a second projecting part projecting in opposite directions from the bottom part along the axial direction of the drive transmitting member and having different diameters.

A clutch-controlled transfer gear having a drive shaft which is mounted so as to be rotatable by way of at least one drive shaft bearing, a primary shaft which is mounted so as to be rotatable by way of at least one primary shaft bearing, a secondary shaft which is arranged with an axial offset with respect to the drive shaft and which is mounted so as to be rotatable by way of at least one secondary shaft bearing, a transfer mechanism which is arranged between secondary shaft and drive shaft and bridges the axial offset thereof, and a clutch which is arranged between the drive shaft and an offset gear, by means of which clutch the secondary shaft is, for the operation thereof, coupled to the drive shaft and, for the deactivation thereof, decoupled from the drive shaft, as required.