The belt conveyance device includes a plurality of rollers, a belt, a meandering correction part, and an adjustment part. The rollers are disposed at intervals each other and rotate around axes. The belt is disposed around the plurality of rollers and travels. The meandering correction part shifts one end portion in an axial direction of a tension roller included in the plurality of rollers in a radial direction within a predetermined range to correct a meandering of the belt. The adjustment part shifts the other end portion in the axial direction of the tension roller in the radial direction such that a position of the one end portion of the tension roller is variable under a state where the meandering of the belt is corrected.

A sheet conveying apparatus including: a pair of inlet rollers; a pair of outlet rollers; a pair of movable rollers disposed between the inlet rollers and the outlet rollers; a moving unit configured to move the movable rollers; a pair of upstream rollers disposed between the inlet rollers and the movable rollers; a pair of downstream rollers disposed between the movable rollers and the outlet rollers; a first conveyance belt passed over a first inlet roller, a first outlet roller, a first movable roller, a first upstream roller, and a first downstream roller; and a second conveyance belt passed over a second inlet roller, a second outlet roller, a second movable roller, a second upstream roller, and a second downstream roller. A diameter of the pair of upstream rollers and a diameter of the pair of downstream rollers are smaller than a diameter of the pair of movable rollers.

A driving apparatus includes an endless belt, a belt roller which engages the endless belt, a steering member and an adjustment member. The belt roller has a rotation shaft. The steering member contacts the endless belt at the inner side of the endless belt. The adjustment member is supported rotatably. The adjustment member receives a force in response to the endless belt moving in a longitudinal direction of the rotation shaft of the belt roller, and generates a pressing force that tilts the steering member via a rotational movement of the adjustment member.

An image forming apparatus includes an image forming portion, an endless belt and a plurality of stretching rollers. The stretching rollers includes a tiltable steering roller, a sliding member, a first stretching roller having a smallest diameter, and a second stretching roller having a largest diameter of the diameters. With respect to rotational axis directions of the stretching rollers, lengths of contact portions of the stretching rollers with the belt are shorter than a width of the belt, the length of the contact portion of the first stretching roller with the belt is a first length, the length of the contact portion of the second stretching roller with the belt is a second length shorter than the first length, and end positions of the contact portions of the first and second stretching rollers with respect to the rotational axis direction are different from each other.

A medium transport device includes a transport belt that is disposed in such a manner as to face an image holding unit holding an image and that is capable of moving circularly so as to transport a medium, a first stretching roller that stretches a portion of the transport belt and that is disposed in such a manner as to face the image holding unit, the first stretching roller being configured to transport the medium by nipping the medium between the image holding unit and the transport belt and configured to transfer the image held by the image holding unit onto the medium, a second stretching roller that stretches a portion of the transport belt that is located downstream from the portion of the transport belt stretched by the first stretching roller in a transport direction of the medium, a contact adjusting unit that causes a second end of the first stretching roller in an axial direction of the first stretching roller to swing while a first end of the first stretching roller serves as a fulcrum and adjusts a contact state between the image holding unit and the transport belt in a longitudinal direction of a contact region between the image holding unit and the transport belt, and a position adjusting unit that keeps a distance between the center of the first stretching roller and the center of the second stretching roller constant and adjusts a position of the second stretching roller with respect to the first stretching roller by causing a second end of the second stretching roller to swing while a first end of the second stretching roller serves as a fulcrum.

A driving apparatus includes an endless belt, a belt roller which engages the endless belt, a steering member and an adjustment member. The belt roller has a rotation shaft. The steering member contacts the endless belt at the inner side of the endless belt. The adjustment member is supported rotatably. The adjustment member receives a force in response to the endless belt moving in a longitudinal direction of the rotation shaft of the belt roller, and generates a pressing force that tilts the steering member via a rotational movement of the adjustment member.

In some examples, a sheet-processing machine includes a transport unit for transporting sheets. The transport unit includes a feed roller configured as an infeed roller and a feed roller configured as a diverting roller, which define a transport plane of sheets. At least two further feed rollers of the transport unit are arranged outside the transport plane. At least one feed roller of the at least two further feed rollers is configured as a pivoting roller that pivots and/or that can be pivoted about a pivot axis. The pivot axis of the pivoting roller is an axis that is normal of an axis of rotation of the pivoting roller, and the pivoting roller is configured to automatically pivot about the pivot axis.

The belt conveyance device includes a plurality of rollers, a belt, a meandering correction part, and an adjustment part. The rollers are disposed at intervals each other and rotate around axes. The belt is disposed around the plurality of rollers and travels. The meandering correction part shifts one end portion in an axial direction of a tension roller included in the plurality of rollers in a radial direction within a predetermined range to correct a meandering of the belt. The adjustment part shifts the other end portion in the axial direction of the tension roller in the radial direction such that a position of the one end portion of the tension roller is variable under a state where the meandering of the belt is corrected.

A medium transport device includes a transport belt that is disposed in such a manner as to face an image holding unit holding an image and that is capable of moving circularly so as to transport a medium, a first stretching roller that stretches a portion of the transport belt and that is disposed in such a manner as to face the image holding unit, the first stretching roller being configured to transport the medium by nipping the medium between the image holding unit and the transport belt and configured to transfer the image held by the image holding unit onto the medium, a second stretching roller that stretches a portion of the transport belt that is located downstream from the portion of the transport belt stretched by the first stretching roller in a transport direction of the medium, a contact adjusting unit that causes a second end of the first stretching roller in an axial direction of the first stretching roller to swing while a first end of the first stretching roller serves as a fulcrum and adjusts a contact state between the image holding unit and the transport belt in a longitudinal direction of a contact region between the image holding unit and the transport belt, and a position adjusting unit that keeps a distance between the center of the first stretching roller and the center of the second

A sheet conveying device includes a first conveyer and a second conveyer, each including a upstream-side pulley and a downstream-side pulley with respect to a conveying direction, an endless belt stretched around these pulleys, and a suction mechanism provided on an inner periphery relative to a conveying surface of the endless belt, along the conveying direction, wherein a third conveyer including a upstream-side pulley and a downstream-side pulley relative to the conveying direction and an endless belt stretched around these pulleys is provided between the first conveyer and the second conveyer, and in a state where the third conveyer is viewed from a side of the conveying surface, the upstream-side pulley of the third conveyer is arranged to be overlapped with the downstream-side pulley of the first conveyer, and the downstream-side pulley of the third conveyer is arranged to be overlapped with the upstream-side pulley of the second conveyer.