Brother DCP-6690CW, Service Manual, Page: 87 / 506

3-33 Confidential
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Power transmission route to the head maintenance mechanism and motor rotational
direction
This mechanism draws its power from two motors--the ASF motor (DC motor) in the right rear
corner of the engine chassis and the paper feed motor (DC motor) on the left side. The ASF
motor is mounted in the ASF motor holder combined with the maintenance unit.
The power transmission route and operation mode switching are detailed in
Section 3.2.2.4 .
ASF motor
→
Maintenance unit (head capping and carriage lock mechanisms)
As shown on the next page, the rotational torque of the ASF motor is always transmitted via the
ASF/maintenance drive gear and idle gear 16 to the clutch gear L.
When the mode switching lever is in the left position (ASF mode), the clutch gear L also
meshes with the ASF changeover gear.
When the head/carriage unit moves to the right end of its travel, a tab on the carriage rear panel
pushes the mode switching lever to the right (purge mode). The clutch gear spring pushes the
clutch gear L to the right, away from the ASF changeover gear, to mesh with the cap lift cam
gear. This way, the ASF motor drives the head capping and carriage lock mechanisms. (See
page 3-35 for the related components.)
In duplex print models, if the ASF motor rotates counterclockwise, the rotational torque is
transmitted via the gear trains in the link gear holders to the duplex print mechanism (For
details, refer to
Section 3.2.2.5 .)
Paper feed motor
→
Maintenance unit (purge, air removing and head wiper mechanisms)
As shown on the next page, the paper feed motor drives the PF roller gear L that rotates the
paper feed roller. At the right end of the roller is the PF roller gear R that always meshes with
the clutch gear R.
When the mode switching lever is in the left position (ASF mode), the clutch gear R does not
mesh with the purge gear but it is just idling.
When the head/carriage unit moves to the right end of its travel, a tab on the carriage rear panel
pushes the mode switching lever to the right (purge mode). The clutch gear spring pushes the
clutch gear R to the right to mesh with the purge gear.
As the paper feed motor rotates counterclockwise, the planetary arm meshes with the purge cam
(as shown below), driving the purge mechanism (pump switching unit), air removing
mechanism and head wiper mechanism. On the contrary, the clockwise motor rotation causes
the planetary arm to mesh with the tube pump gear, driving the purge mechanism (tube pump).
(See
page 3-35 for the related components.)