Abstract: A planetary gear mechanism includes a plurality of planetary gears, an outer gear, a sun gear, a carrier, and a stick mount. The outer gear meshes with the plurality of planetary gears. The sun gear is coaxially disposed on the same axis as the outer gear and transmits force to the planetary gears. The carrier rotatably supports the plurality of planetary gears and is rotatably and floatingly supported. The carrier includes a hole through which a stick member penetrates in a direction of axis of rotation of the carrier. The stick member penetrates through the hole and is mounted on the stick mount. The stick mount is disposed opposite the carrier. The outer gear and the sun gear are held such that one of the outer gear and the sun gear does not rotate.

Abstract: A sheet conveying device, which is incorporated in an image forming apparatus, includes a first detector to detect an angle deviation of a recording medium to a sheet conveying direction, a second detector to detect a lateral shift of the recording medium to a width direction, a third detector to detect at least one of the angle deviation and the lateral shift after correction of the angle deviation detected by the first detector and the lateral shift detected by the second detector, and a rotary body to perform a primary movement by (1) rotating in the sheet conveying direction and returning to a reference position and by (2) moving in the width direction and returning to the reference position, and a secondary movement by performing at least one of (1) and (2) after the primary movement.

Abstract: A power transmission device includes a drive coupling, a driven coupling, and an intermediate transmission member. The drive coupling receives power from a drive source and rotates. The driven coupling is disposed coaxially on a first rotary shaft of the drive coupling and detachably attachable relative to the main body of the image forming apparatus. The intermediate transmission member meshes with the drive coupling and the driven coupling and is held by one of the drive coupling and the driven coupling in a state in which the driven coupling is disengaged from the main body. One of the drive coupling and the driven coupling, whichever holds the intermediate transmission member, constitutes a retaining coupling including an attachment member attached to one of a drive-side device and a driven-side device, and a stopper assembly facing the intermediate transmission member in an axial direction of the first rotary shaft.

Abstract: A reduction gear unit incorporatable in an image forming apparatus includes planetary gear mechanisms each including a sun gear, an outer gear, planetary gears arranged between the outer gear and the sun gear at equal intervals and meshing with the sun gear and the outer gear, and a carrier rotatable coaxially with the sun gear and the outer gear to rotatably support the planetary gears. An extreme upstream mechanism in the drive transmission direction includes an input element connected to a drive source. An extreme downstream mechanism includes an output element connected to a member outputting the drive force to a rotary member. Any mechanism other than the extreme downstream mechanism includes an output element connected to an input element of an adjacent mechanism located downstream of any other mechanism. The sun gear of the extreme downstream mechanism has a larger pitch diameter than any other mechanisms.

Abstract: A transfer device includes at least one pair of lateral plates, an intermediate transfer belt, a plurality of rollers, and a dynamic vibration absorber. The intermediate transfer belt is formed into an endless loop and is entrained about the plurality of rollers. The dynamic vibration absorber is disposed on at least one of the plurality of rollers and includes an inertial body. The inertial body is disposed inside the endless loop of the intermediate transfer belt, and both ends of the inertial body in an axial direction of the inertial body are rotatably supported by the at least one pair of lateral plates via shaft bearings.

Abstract: A driving device includes a drive source, a planetary gear decelerator, a drive-target shaft, a rotation speed detector, and a sensor mount. The planetary gear decelerator includes a planetary gear mechanism equipped with an output shaft, a sun gear, an outer gear, a plurality of planetary gears, and a rotatable first carrier. The outer gear is made of resin and includes a deformable portion at a drive target side, and the deformable portion is elastically deformable in a radial direction. The plurality of planetary gears engages the sun gear and the outer gear. The rotatable first carrier rotatably supports the planetary gears. The rotation speed detector detects a rotation speed of the planetary gear decelerator, and includes a sensor and a detection target disposed coaxially on the output shaft. The sensor mount supports the sensor and moves in the radial direction in accordance with elastic deformation of the outer gear.

Abstract: A rotating-body driving device that includes a rotating body; a driving source; a reduction gear that includes an output shaft and a gear rotating at a non-integer ratio of rotation period to a rotation period of the output shaft, and the reduction gear reducing rotation speed of the driving source; a pulse-signal generating unit; a pulse-count storage unit; a speed-fluctuation storage unit that stores therein a rotation speed fluctuation of the output shaft; and a driving-source control unit. The driving-source control unit detects the speed fluctuation information associated with the accumulated number of pulse signals from the speed-fluctuation storage unit, and performs for the driving source a feedforward control to set off the rotation speed fluctuation.

Abstract: A power transmission device includes a drive coupling, a driven coupling, and an intermediate transmission member. The drive coupling receives power from a drive source and rotates. The driven coupling is disposed coaxially on a first rotary shaft of the drive coupling and detachably attachable relative to the main body of the image forming apparatus. The intermediate transmission member meshes with the drive coupling and the driven coupling and is held by one of the drive coupling and the driven coupling in a state in which the driven coupling is disengaged from the main body. One of the drive coupling and the driven coupling, whichever holds the intermediate transmission member, constitutes a retaining coupling including an attachment member attached to one of a drive-side device and a driven-side device, and a stopper assembly facing the intermediate transmission member in an axial direction of the first rotary shaft.

Abstract: A rotator driving system for driving a rotator with a motor includes a dynamic vibration absorber attached to a rotary shaft of the rotator. The dynamic vibration absorber includes an inertia body, a viscosity-providing component to provide a viscosity, and a torsion spring unit to function as a torsion spring that includes a boss fixed to the rotary shaft. Multiple spokes extend radially outward from the boss. Multiple seats are provided at respective tips of the multiple spokes to fix the inertia body. The torsion spring unit is fixed by both the rotary shaft of the rotator and the boss fixed to the rotary shaft therebetween. The viscosity-providing component supports the inertia body via the multiple seats provided at the respective tips of the multiple spokes.

Abstract: A drive transmission device that transmits rotation from a drive source of an image forming apparatus to a rotary body detachably attachable relative to a main body thereof in an axial direction includes two external gears, a cylindrical member, and an intermediate-body retainer. The two external gears include teeth on an outer circumferential surface thereof extending in an axial direction. The cylindrical member includes an internal gear formed on an inner circumferential surface thereof to mesh with the external gears, and a flange on a portion of an outer circumferential surface of the cylindrical member, the flange including a projection. The intermediate-body retainer includes a depression to fit with the projection of the flange to prevent the cylindrical member from getting disengaged from the external gears. The external gears constitute a two-stage spline joint that meshes with the internal gear of the cylindrical member.

Abstract: A rotary body driver includes a driving source and a planetary gear transmission to receive a driving force from the driving source. The planetary gear transmission includes a sun gear rotatable by the driving force received from the driving source, a plurality of planet gears meshed with and surrounding the sun gear with an identical interval between the adjacent planet gears, a rotatable carrier to rotatably support the plurality of planet gears, an outer gear encircling and meshed with the plurality of planet gears, and an output shaft combined with and supporting the carrier. A rotary body shaft mounting a rotary body is connected to the output shaft of the planetary gear transmission to transmit the driving force received from the output shaft to the rotary body. The outer gear is made of resin and the output shaft and the carrier are made of metal.

Abstract: A drive transmission unit includes a planetary gear mechanism. The planetary gear mechanism includes an outer gear rotatably disposed on a shaft, a sun gear rotated by a power source, coaxially disposed on the same shaft as the outer gear, multiple planetary gears to engage the sun gear and the outer gear, disposed along an inner circumferential surface of the outer gear, a carrier rotatable on the same shaft as the outer gear to rotatably support the planetary gears, a contact member that contacts the sun gear as the sun gear moves in a direction of thrust due to engagement with the plurality of planetary gears, and a grease retaining portion to retain grease near a contact portion at which the sun gear contacts the contact member as the sun gear moves in the direction of thrust. The outer gear, the sun gear, and the planetary gears are helical gears.

Abstract: A drive device including a planetary gear reduction device having at least two stages and an output shaft, and a driven shaft to support a driven member rotatively driven by torque reduced by the planetary gear reduction device and transmit the torque from the output shaft to the driven member. Each stage of the planetary gear reduction device includes a sun gear, an outer gear, multiple planetary gears, a carrier, and a support shaft. The output shaft is provided to the carrier of the last stage. Central axes of the sun gear, the outer gear, the carrier, the output shaft, the driven shaft, and the driven member are all arranged coaxially with one another and at least one carrier is floatingly supported relative to the outer gear. The carrier is formed as a single integrated unit having holes into which both ends of the support shaft are fitted.

Abstract: A driving device includes a drive source, a planetary gear decelerator, a drive-target shaft, a rotation speed detector, and a sensor mount. The planetary gear decelerator includes a planetary gear mechanism equipped with an output shaft, a sun gear, an outer gear, a plurality of planetary gears, and a rotatable first carrier. The outer gear is made of resin and includes a deformable portion at a drive target side, and the deformable portion is elastically deformable in a radial direction. The plurality of planetary gears engages the sun gear and the outer gear. The rotatable first carrier rotatably supports the planetary gears. The rotation speed detector detects a rotation speed of the planetary gear decelerator, and includes a sensor and a detection target disposed coaxially on the output shaft. The sensor mount supports the sensor and moves in the radial direction in accordance with elastic deformation of the outer gear.

Abstract: A rotating-body driving device comprising: a rotating body; a driving source; a reduction gear that includes an output shaft and a gear rotating at a non-integer ratio of rotation period to a rotation period of the output shaft, and the reduction gear reducing rotation speed of the driving source; a pulse-signal generating unit; a pulse-count storage unit; a speed-fluctuation storage unit that stores therein a rotation speed fluctuation of the output shaft; and a driving-source control unit, wherein the driving-source control unit detects the speed fluctuation information associated with the accumulated number of pulse signals from the speed-fluctuation storage unit, and performs for the driving source a feedforward control to set off the rotation speed fluctuation.

Abstract: A rotary drive device to drive a rotary body included in an image forming apparatus. The rotary drive device includes a drive source and a planetary gear mechanism to control torque from the drive source. The planetary gear mechanism includes a sun gear rotated by the torque, an annular gear coaxial to the sun gear and having inward-facing teeth, multiple planetary gears provided within the annular gear, and a carrier rotatable coaxially to the sun gear and the annular gear to rotatably support the multiple planetary gears. The annular gear is formed by injecting molten resin into a mold having a cylindrical cavity with teeth shapes along an inner circumference of the cavity from multiple pin gates provided to the mold at equal intervals along a circumference of the cavity. A number of pin gates is a non-integer multiple of a number of planetary gears.

Abstract: A driving device includes a planetary gear deceleration mechanism in a transmission path that transmits driving force from a driving motor to a driven member, in which the deceleration mechanism includes first and second support units into which a housing that constitutes a mechanism main body is divided, the first support unit includes carriers of at least one stage and pinion gears supported thereby, and is provided with an output unit in the carrier of the final stage, the second support unit includes an output shaft that is detachable from the output unit and a supporting unit for the output shaft, and the output shaft is supported in an insertable and removable manner with respect to the output unit of the carriers in the first and the second support units that are joined to each other.

Abstract: A planetary gear mechanism includes a plurality of planetary gears, an outer gear, a sun gear, a carrier, and a stick mount. The outer gear meshes with the plurality of planetary gears. The sun gear is coaxially disposed on the same axis as the outer gear and transmits force to the planetary gears. The carrier rotatably supports the plurality of planetary gears and is rotatably and floatingly supported. The carrier includes a hole through which a stick member penetrates in a direction of axis of rotation of the carrier. The stick member penetrates through the hole and is mounted on the stick mount. The stick mount is disposed opposite the carrier. The outer gear and the sun gear are held such that one of the outer gear and the sun gear does not rotate.

Abstract: A planetary gear unit including a sun gear rotatable by torque from a drive source, an outer gear disposed coaxially with the sun gear, multiple planetary gears disposed within the outer gear at equal intervals along an inner circumference of the outer gear to engage the sun gear and the outer gear, a carrier pin to rotatably support each of the multiple planetary gears, and a carrier rotatable coaxially with the sun gear and the outer gear to support both ends of the carrier pin. At least a first end of the carrier pin is constructed of a circular portion and a linear portion to form a first supported part. The carrier includes a first support part that supports the first supported part and is formed to position the circular portion of the first supported part downstream from the linear portion in a direction of rotation of the carrier.

Abstract: A rotary body driver includes a driving source and a planetary gear transmission to receive a driving force from the driving source. The planetary gear transmission includes a sun gear rotatable by the driving force received from the driving source, a plurality of planet gears meshed with and surrounding the sun gear with an identical interval between the adjacent planet gears, a rotatable carrier to rotatably support the plurality of planet gears, an outer gear encircling and meshed with the plurality of planet gears, and an output shaft combined with and supporting the carrier. A rotary body shaft mounting a rotary body is connected to the output shaft of the planetary gear transmission to transmit the driving force received from the output shaft to the rotary body. The outer gear is made of resin and the output shaft and the carrier are made of metal.