Pump Mechanism - Epson Stylus PHOTO 890 Service Manual

EPSON Stylus Photo 890/1280/1290

2.1.4.3 Pump Mechanism

The pump mechanism absorbs ink from the printhead and the cap assembly. The wiper
for head cleaning is included in the cap assembly.
The pump mechanism is driven by the ASF/Pump motor, a 4phase 48-pole PM type
stepping motor. See Table for the ASF/Pump motor specifications. When the torque
from the ASF/Pump motor is switched to the pump unit side, the pump mechanism acts
differently according to the directions of the ASF/Pump motor rotation, as shown in the
table below.
Table 2-11. ASF/Pump Motor Functions
Directions
• Absorbs ink.
Counterclockwise
• Sets the wiper.
• Releases tube.
Clockwise
• Resets the wiper.
Combination Gear 14, 28
Combination Gear 12, 22.4
ASF/Pump Motor Pinion Gear Combination Gear 17.19, 25.6
Figure 2-8. Torque to the Pump Mechanism
OPERATING PRINCIPLES
Corresponding Functions
Planetary Gear 15.2
A
DE Lock Lever
Tension Belt
Pump Unit Gear
o
Torque transmission to the pump unit
The torque from the ASF/Pump motor is transmitted to the pump mechanism as
described below:
1) The CR unit moves to the right end of the CR shaft, which then pushes the DE
lock lever to the right end.
2) The ASF-Pump motor rotates clockwise (viewed from the motor pinion gear
side) specified steps.
3) With the rotation of step 2), the planetary gear set in the DE unit moves toward
the combination gear (17.19, 25.6).
4) The CR unit moves specified steps from the right end of the CR shaft to the
left. With this motion, the DE lock lever fixes the planetary gear set.
5) Torque from the ASF/Pump motor is transmitted as described below.
→
Motor pinion gear
→ →
Tension belt Pump unit gear
DE pump mechanism and operating principle are as shown in the figure below.
Figure 2-9. Pump Operating Principle
1. When the pump unit rotates CCW from ASP/Pump motor side, rollers rotates
compressing a tube, and the ink in the tube is pressed from the capping unit down
to waste ink pads.
2) When the pump unit rotates CW, the rollers stop compressing the tube, and the ink
is not pressed to the waste in pack.
Overview
→
Planetary gear (15.2) Combination gear (17.19, 25.6)
→
Pump unit
Revision C
42