A seat lifter includes: an inner link for changing a height position of an inner lower arm with respect to a floor of a vehicle; an outer link for changing a height position of an outer lower area with respect to the floor; a coupling rod that couples the inner link to the outer link; a planetary gear mechanism capable of causing the coupling rod to rotate relative to the inner lower arm and the outer lower arm; a drive unit capable of driving the planetary gear mechanism; and a power transmission rod that transmits power of the drive unit to the planetary gear mechanism. The planetary gear mechanism is disposed between the inner lower arm and the outer lower arm. The drive unit is disposed outside the inner lower arm in the width direction or outside the outer lower arm in the width direction.

A seat lifter includes: an inner link for changing a height position of an inner lower arm with respect to a floor of a vehicle; an outer link for changing a height position of an outer lower area with respect to the floor; a coupling rod that couples the inner link to the outer link; a planetary gear mechanism capable of causing the coupling rod to rotate relative to the inner lower arm and the outer lower arm; a drive unit capable of driving the planetary gear mechanism; and a power transmission rod that transmits power of the drive unit to the planetary gear mechanism. The planetary gear mechanism is disposed between the inner lower arm and the outer lower arm. The drive unit is disposed outside the inner lower arm in the width direction or outside the outer lower arm in the width direction.

A single-stage gear reduction output mechanism for an automotive seat assembly includes a gear housing bracket, gear housing, axle shaft, eccentric, and first and second gears. The axle shaft extends through the eccentric with a slip fit, the first gear rotates with the axle shaft, and the second gear is carried on a first bearing surface of the eccentric and meshingly engages the first gear in a planetary arrangement. The second gear includes an external flange with at least two guide holes. First and second support pins that are rigidly fixed in place relative to the axle shaft extend through the two guide holes in the external flange of the second gear. Forces acting at the interfaces between the first and second support pins and the two guide holes and between the eccentric and the second gear prevent the first gear from back-driving rotation of the second gear.

A single-stage gear reduction output mechanism for an automotive seat assembly including a gear housing bracket, gear housing, axle shaft, eccentric, and first and second gears. The axle shaft extends through the eccentric with a slip fit, the first gear rotates with the axle shaft, and the second gear is carried on a first bearing surface of the eccentric and meshingly engages the first gear in a planetary arrangement. A locking plate including first, second, and third slot cutouts is disposed within the gear housing. A support pin extends from the gear housing through the first slot cutout and a second bearing surface of the eccentric extends through the second slot cutout to support the locking plate and limit its movement along a lateral axis. The second gear includes a first pin that extends through the third slot cutout to prevent the first gear from back-driving the second gear.

A single-stage gear reduction output mechanism for an automotive seat assembly including a gear housing bracket, gear housing, axle shaft, eccentric, and first and second gears. The axle shaft extends through the eccentric with a slip fit, the first gear rotates with the axle shaft, and the second gear is carried on a first bearing surface of the eccentric and meshingly engages the first gear in a planetary arrangement. A locking plate including first, second, and third slot cutouts is disposed within the gear housing. A support pin extends from the gear housing through the first slot cutout and a second bearing surface of the eccentric extends through the second slot cutout to support the locking plate and limit its movement along a lateral axis. The second gear includes a first pin that extends through the third slot cutout to prevent the first gear from back-driving the second gear.

A single-stage gear reduction output mechanism for an automotive seat assembly includes a gear housing bracket, gear housing, axle shaft, eccentric, and first and second gears. The axle shaft extends through the eccentric with a slip fit, the first gear rotates with the axle shaft, and the second gear is carried on a first bearing surface of the eccentric and meshingly engages the first gear in a planetary arrangement. The second gear includes an external flange with at least two guide holes. First and second support pins that are rigidly fixed in place relative to the axle shaft extend through the two guide holes in the external flange of the second gear. Forces acting at the interfaces between the first and second support pins and the two guide holes and between the eccentric and the second gear prevent the first gear from back-driving rotation of the second gear.

When reversing a direction in which an angle is adjusted by a first adjustment section and reversing a direction in which a posture is adjusted by a second adjustment section, a control section of a seat provides, before a timing at which a driving direction of a second driving section is reversed, a stop period for stopping the second adjustment section from adjusting the posture, and the control section causes the first adjustment section to carry out a preparation operation in advance during the stop period.

Provided is a seat having improved rigidity. The seat includes: a first side frame; a second side frame, a connection body; a base member; a first drive-side link; a second drive-side link, an actuator that generates a force for changing an angle between the first drive-side link and the second drive-side link; a first driven-side link that is fixed on the second side frame side of the connection body and rotates integrally with the connection body; a second driven-side link whose first end side is rotatably connected to a second end side of the first driven-side link and whose second end side is rotatably connected to a base member; and a transmission mechanism that mechanically transmits, when a force for rotating the second driven-side link about a connection part between the second driven-side link and the base member acts on the second driven-side link, the force to the connection body.