Drive transmission device and image forming apparatus

A drive transmission device arranged to face a drive transmitted portion across a metal plate, the drive transmission device comprising:

• a gear part which is coupled to a drive source, and rotates around an axis by a driving force of the drive source;
• a coupling part which is formed into a cylindrical shape, penetrates a through-hole of the metal plate, is connected to the drive transmitted portion, and rotates around the same axis of the gear part;
• a biasing member which biases the gear part and the coupling part to a direction close to the drive transmitted portion;
• and
• a retracting part which is formed into an annular shape through which the coupling part penetrates, and rotates around the same axis as the coupling part in a reciprocating manner, wherein
• the metal plate has at least two inclined parts which are arranged across the through-hole, and protrude in a direction away from the drive transmitted portion, the inclined part being formed by deforming a part of the metal plate, and
• the retracting part rotates in one direction while in contact with the inclined part to move the gear part and the coupling part in the direction away from the drive transmitted portion against a biasing force of the biasing member.