Longitudinal adjuster and vehicle seat

A longitudinal adjuster, comprising:

• one rail pair and
• a drive device for the rail pair,
• wherein the rail pair comprises a first rail and a second rail which are displaceable relative to one another,
• wherein the drive device has at least one motor, a gear unit, a spindle block which has an internal thread and is fixed to the first rail or second rail, a spindle with an external thread which is operatively connected to the internal thread of the spindle block, and a spindle bearing,
• wherein the spindle extends along a longitudinal axis and is mounted in the spindle block and the spindle bearing such that it is rotatable about a spindle axis,
• wherein the spindle bearing has at least one spindle nut which is fastened on the spindle and rotates with the spindle,
• wherein the spindle bearing is configured as an axial bearing which transmits a linear movement of the spindle to the first rail, and wherein the spindle bearing has, in the axial direction, on one side of the spindle nut a ball bearing and on the other side of the spindle nut a sliding bush with an axial play on at least one of the two sides with respect to the spindle nut.