Abstract: A gear drive (12) with a first gear (10) which has first tooth flanks (26), and a second gear (30) which has second tooth flanks (32) and which engages with the first gear (10), the first gear (10) having a tip circle (14) with a tip circle radius (16), a root circle (18) with a root circle radius (20) and a modification circle (22) with a modification circle radius arranged between the tip circle (14) and the root circle (18). (24), wherein the first tooth flanks (26) between the root circle (18) and the modification circle (22) each have a recess (28) in such a way that, when the gears (10, 30) mesh, there is no contact between the first tooth flanks (26) and the second tooth flanks (32) between the root circle (18) and the modification circle (22), and a longitudinal seat adjustment for a motor vehicle with a gear drive (12).

Abstract: The present invention relates to a longitudinal seat adjustment unit (2), comprising a drive device (22), two rails (40) each with at least one spindle (42), which are arranged parallel to a longitudinal axis (X) and so as to be spaced apart from each other, and two drive trains (24) that can be driven by the drive device (22), wherein each of the drive trains (24) has a first transmission unit (31) and a second transmission unit (32), and the second transmission unit (32) is coupled to the drive device (22) via the first transmission unit (31), and wherein the second transmission unit (32) of the respective propulsion train (24) is coupled to one of the rails (40) in order to generate a propulsion in the longitudinal axis (X).

Abstract: An adjusting device for adjusting a vehicle seat along a sliding axis, having a first and a second lower rail, both of which are fixedly connected with the vehicle, a first upper rail, which is slidably supported in the first lower rail in parallel to the sliding axis and a second upper rail, which is slidably supported in the second lower rail in parallel to the sliding axis. The first lower rail and the first upper rail can enclose a first cavity and the second lower rail and the second upper rail enclose a second cavity. A first spindle can be arranged in the first cavity and non-rotatably connected to the first lower rail and a second spindle can be arranged in the second cavity and non-rotatably connected to the second lower rail.

Abstract: A gear for an adjusting device in vehicles for adjusting two vehicle parts adjustable relative to each other, in particular, for adjusting two parts of a seat adjusting device, a window lifter, or a sun roof, the gear including a drivable drive screw having gear teeth, a spindle nut, which has spindle nut teeth engaging with the screw teeth, and an internal thread, using which the spindle nut can be brought into engagement with a threaded spindle of the adjusting device, and a gear housing, which accommodates and supports the drive screw and the spindle nut. The spindle nut is made at least partially of metal, and the drive screw is made of plastic, and the gear housing includes a first bearing section made of plastic for supporting the spindle nut and a second bearing section made of metal for supporting the drive screw.