Patent ID: 8126366

Claim:
An image forming apparatus comprising: an apparatus main body; a process unit configured to be provided in the apparatus main body and having a drive input member; and a drive transmission member provided in the apparatus main body and configured to engage with the drive input member so as to transmit a driving force to the drive input member while permitting a positional gap of the drive input member within a predetermined range, wherein the drive transmission member comprises: a guide core member comprising: a distal end core portion which is formed at an end portion lying on a downstream side in an engagement direction of the drive transmission member with the drive input member and which has a first outside diameter; and a proximal end core portion which is formed upstream of the distal end core portion in the engagement direction and which has a second outside diameter that is larger than the first outside diameter; a reciprocating member in which the guide core member is inserted along the engagement direction, the reciprocating member comprising: a distal end cylindrical portion which has a first inside diameter; and a proximal end cylindrical portion which is formed upstream of the distal end cylindrical portion in the engagement direction and which has a second inside diameter that is larger than the first inside diameter; and a pressing member disposed around the guide core member and next to the reciprocating member for connecting the guide core member and the reciprocating member, wherein an outer diameter of the pressing member is greater than the second inside diameter.