Actuator and vehicle door opening and closing actuator

A vehicle door opening and closing actuator, having an actuator for opening and closing a door provided in an openable and closable manner with respect to an opening portion of a vehicle, the vehicle door opening and closing actuator comprising:

• a first housing that is cylindrical;
• a second housing that is cylindrical and fitted into one end side of the first housing;
• a guide member that is cylindrical and provided in at least the second housing;
• a third housing that is cylindrical and provided in the second housing on a side opposite to the first housing and is provided so as to protrude and retract relative to the second housing;
• a motor part that is accommodated in the first housing and has a rotation shaft;
• a drive shaft that is provided at least in the third housing, is rotatably driven by receiving a rotational force of the rotation shaft of the motor, and applies power to the third housing;
• a bearing holder that is provided in the first housing and supports a bearing for rotatably supporting at least one of the rotation shaft and the drive shaft;
• a housing side clamping portion provided in the second housing;
• a guide side clamping portion that is provided in the guide member and is disposed at a position that overlaps the housing side clamping portion in an axial direction;
• a first seal portion that is provided between the housing side clamping portion and the guide side clamping portion, and is clamped by the housing side clamping portion and the guide side clamping portion;
• and
• a spring member that is provided between the second housing and the guide member, and presses one of the housing side clamping portion and the guide side clamping portion toward the other.