A process cartridge includes a frame, a photosensitive drum supported by the frame, and a developing roller supported by the frame. A coupling is operatively connected to the photosensitive drum, with the coupling being rotatable about an axis thereof, and with the coupling being positioned (i) at a first end of the photosensitive drum, (ii) coaxial with the photosensitive drum, and (iii) at a side of the process cartridge. A helical gear is positioned at the side of the process cartridge, the helical gear being rotatable about an axis thereof, the helical gear having a plurality of teeth, with at least some of the teeth being exposed teeth that are uncovered by the frame and exposed to outside of the process cartridge. As measured in an axial direction of the photosensitive drum, at least a part of the exposed teeth of the helical gear is positioned farther from the second end of the photosensitive drum than a tip of a projection of the coupling is positioned from the second end of the photosensitive drum.