| 摘要 |
<p>PURPOSE:To sufficiently absorb a fluctuation in a rotation speed even when a pulse motor is directly coupled and to perform stable conveyance of a sheet by positioning the rotation force of the pulse motor to a drive roller through a friction member and suppressing the slip of the member by oil. CONSTITUTION:Rotation dynamic torque of a drive roller is set to a value lower than torque by which a roller 31 and a casing 32, between which a packing 33 is nipped, starts to slip. When no fluctuation in a rotation speed is produced at a pulse motor 20, the motor is run regardless of the presence of oil at the interior. In which case, when a fluctuation in rotation of the pulse motor 20 is produced, a slip is generated through a packing 33 and the fluctuation in a rotation speed is not transmitted to a drive roller 2. A slip generated once is suppressed by sealed oil and the pulse motor is returned to a state where no slip is generated. This constitution absorbs the fluctuation in the rotation speed of the pulse motor 20 by a coupling part 30 and the drive roller 2 is rotated at a constant speed.</p> |
