Belt unit and image forming apparatus

An image forming apparatus, comprising:

• an image forming unit configured to form an image on a sheet;
• and
• a belt unit, comprising:
• an endless belt comprising a belt strip and a guided section, the guided section protruding from an inner circumferential surface of the belt strip at one of widthwise sides along a widthwise direction of the belt strip;
• a first roller and a second roller, around which the endless belt is strained;
• and
• a guiding member arranged on one of axial-end sides of the first roller along an axial direction of the first roller coaxially with the first roller, the guiding member being formed to have a groove, in which the guided section is set,
• wherein the groove comprises a first face and a second face, which face each other along a direction in parallel with a central axis of the first roller, the first face being arranged in a position closer to the one of widthwise sides with respect to the second face along the direction in parallel with the central axis,
• wherein the guiding member comprises a first piece containing the first face and a second piece containing the second face, the first piece and the second piece being separately molded and subsequently assembled to form the guiding member, and the first face protrudes outwardly with respect to the inner circumferential surface of the belt strip, and
• wherein the first piece is molded so as to have a parting line on an end of an axially extending and radially outmost edge of the first piece, the end of the edge being spaced from the first face.