— More about Epson WF-4830/4820 series Mechanism, click here
Epson WF-4830/4820 Series Paper loading Driving Path
- The WF-4830 Series has functionality to load paper using three motors.
- The PF motor drive force is conveyed through the PF timing belt to the PF roller and EJ roller, carrying out paper loading before and after printing.
- The ASF motor drive force is separated into the auto duplex print unit and 1st cassette pickup assy.
- The 2nd ASF motor drive force drives the 2nd cassette pickup assy.
- The WF-4820 Series has functionality to load paper using two motors (PF motor/ASF motor).
Drive path from PF motor
Drive path from ASF motor
- The middle roller always rotates in a set direction (paper feed direction) because of the planet gear, regardless of the ASF motor rotational direction.
- The pickup roller also uses a oneway clutch to always rotate in a set direction (paper feed direction) only.
— Epson WF 4830/4820 series Paper feed, paper loading mechanism, click here
- From above picture, can see the sequence of all the gears interact with each others:
- The ASF motor with the force to rotate and pull all the gears behind to work that on Duplex gear, Planet gear, Sun gear, Combination gear B to Oneway clutch.
- Through the Pickup shaft, the force continue pull the Pickup Assy and Spur gear 22 and work with Pickup Roller.
— Epson WF 4830/4820 series Printhead and Paper feed, click here
Principle of a oneway clutch
- A oneway clutch comprises an outer gear, an inner gear, and three planet gears.
- Rotation of the planet gear controls the drive of the inner gear.
- If the ASF motor rotates clockwise when viewed from the output shaft
- The teeth of the planet gears catch on the outer gear ratchet, meaning that the inner gear rotates together with the outer gear. The inner gear rotation is conveyed to the pickup roller, and the pickup roller rotates in the direction of paper loading.
- If the ASF motor rotates counter-clockwise when viewed from the output shaft
- The planet gears are not fixed, therefore the planet gears rotate freely around the inner gear together with the outer gear. Accordingly, the inner gear does not rotate, and the ASF motor drive force is interrupted, and the pickup roller does not rotate.
Drive path from 2nd ASF motor
(WF-4830 Series only)
- The pickup roller uses a oneway clutch to always rotate in a set direction (paper feed direction) only.
How Paper Stopper Assy Works
- At the inner end of the cassette of the front paper loading mechanism, the paper stopper assy is mounted and it prevents the paper in the cassette from getting out into the printer when the cassette is inserted suddenly or in a similar situation, and also aligns the paper to the specified position.
- When cassette is inserted, it pushes cassette slider. But because the resistance of grease in the slider section of slider base and cam slider is large, cam slider and paper stopper do not fall so soon.
In the meantime, paper stopper prevents paper from getting out into the printer due to the inertia of cassette insertion, and also aligns paper at the position of paper stopper.
- Then, reaction force of compression spring between cam slider and cassette slider slides cam slider to the rear of the printer, and paper stopper fall slowly.
— About Epson XP 15000 | XP series, click here