Drive transmission device and image formation apparatus
A drive transmission device according to an embodiment may include: a driving shaft configured to be rotated by a driving source; a driven shaft; and a coupling device including a driving side coupling connected to the driving shaft and a driven side coupling connected to the driven shaft, and configured to selectively couple the driving shaft and the driven shaft with each other to transmit a rotation of the driving shaft to the driven shaft. The driving side coupling may include an Oldham's coupling including a driving side rotor, an intermediate rotor, and a driven side rotor and configured to absorb an eccentricity between the driving shaft and the driven shaft, wherein the driving side coupling further comprises a bias member provided inside of the driving side coupling, the bias member biasing the driven side rotor toward the driven side coupling.
1. A drive transmission device, comprising:
a driving shaft configured to be rotated by a driving source;
a driven shaft; and
a coupling device including a driving side coupling connected to the driving shaft and a driven side coupling connected to the driven shaft, and configured to selectively couple the driving shaft and the driven shaft with each other to transmit a rotation of the driving shaft to the driven shaft, wherein
the driving side coupling comprises an Oldham's coupling comprising a driving side rotor, an intermediate rotor, and a driven side rotor and configured to absorb an eccentricity between the driving shaft and the driven shaft, wherein
the driven side rotor of the driving side coupling includes a fitting projection projected from a part of the driven side rotor of the driving side coupling toward the driven side coupling,
the driven side coupling includes a fitting recess, wherein the fitting projection is fittable in the fitting recess,
the driving side coupling and the driven side coupling are coupled with each other with the fitting projection of the driving side coupling and the fitting recess of the driven side coupling being fit to each other, whereas the driving side coupling and the driven side coupling are not coupled with each other with the fitting of the fitting projection and the fitting recess being released, and
the driving side coupling further comprises a hollow space formed in the fitting projection of the driven side rotor and a bias member comprising a spring provided in the hollow space formed in the fitting projection of the driven side rotor, the bias member biasing the driven side rotor toward the driven side coupling.
2. The drive transmission device according to claim 1 , wherein
the bias member is provided in the hollow space and between an end of the driving shaft and an end of the fitting projection in an axial direction of the driving shaft.
3. The drive transmission device according to claim 1 , wherein
the bias member is configured, when the driven side rotor is displaced from an axis of the driving shaft, to move the driving side rotor back toward the axis of the driving shaft by a restoring force of the bias member.
4. The drive transmission device according to claim 3 , wherein
the bias member is provided on the axis of the driving shaft.
5. The drive transmission device according to claim 3 , wherein
the bias member comprises a coil spring, an axis of which is aligned with the axis of the driving shaft.
6. The drive transmission device according to claim 1 , further comprising
a transmission member comprising one of a projection and a recess formed at the driving shaft and engageable with the driving side rotor to transmit the rotation of the driving shaft to the driving side coupling.
7. The drive transmission device according to claim 6 , wherein
the driving side rotor includes an engagement part which comprises the other of the projection and the recess and which the transmission member is engageable with and disengageable from, and
by means of a bias force of the bias member, the transmission member is engaged with the engagement part.
8. The drive transmission device according to claim 1 , wherein
the driven shaft transmits the rotation to at least one of a drum and a roller rotatable in an image formation unit connected to the drive transmission device, wherein
the image formation unit includes the at least one of the drum and the roller rotatable to form an image.
9. The drive transmission device according to claim 8 , wherein
the at least one of the drum and the roller comprises a developer carrier configured to develop a latent image formed on an image carrier with a developer.
10. An image formation apparatus, comprising:
the drive transmission device according to claim 1 ; and
an image formation unit including at least one of a drum and a roller rotatable to form an image in the image formation unit, wherein the at least one of the drum and the roller in the image formation unit is connected to the driven shaft of the drive transmission device.
11. An image formation apparatus, comprising:
the drive transmission device according to claim 1 ;
an image carrier on which a latent image can be formed; and
a developer carrier configured to develop the latent image formed on the image carrier with a developer to thereby form a developer image, one of the image carrier and the developer carrier is connected to the driven shaft of the drive transmission device.