Ricoh A028 Service Training Manual page 68

OPC Unit
2.3.7 Belt tension mechanism
The tension springs on the front and rear of the OPC
tracking unit provide tension to the OPC belt. Operation
of the handle, release lock, and release cam are the
same as the operation of the backup roller mechanism.
The release hook is fastened to the shaft of the OPC
tracking unit. One hook of the tension spring is hooked
to the release hook and the other is hooked to the stud
on the side plate of the unit.
When the handle is moved to the set position, the
separation turn roller always pulls the OPC belt by the
tensile force of the spring. When it is turned to the
release position, tension is relieved and the OPC belt
can be removed.
2.3.8 OPC unit drive
The OPC motor, built into the OPC unit, drives only the
drive roller via a timing belt. Usually, the OPC belt is
rotated by the OPC motor at a speed of approximately
20 rpm. In the OPC cleaning brush mode, the speed of
the OPC belt is reduced to one turn every 5 minutes to
prolong the cleaning time per unit area of the OPC belt.
A rubber roller with a high coefficient of friction is used
as a drive roller to prevent the belt from slipping.
Three positioning studs are mounted on the rear side
plate of the OPC unit to position the unit on the rear side
plate of the main body.
Release hook
Release cam
OPC motor
2-32
1 July 1994
Tracking roller
OPC tracking unit
Tracking
adjusting nut
Tension spring
Handle
Set
Release
OPC belt
OPC sensor
Drive roller
Positioning stud
Timing belt