Anti-friction ring for a developer roller in a liquid electrophotographic printer
In one example, a sealing system for a developer roller in a liquid electrophotographic printer includes a pair of arcuate seals each with an annular sealing surface to seal one end of the developer roller; a pair of washers each having a low friction surface to contact one of the sealing surfaces; and a pair of retainers each to hold one of the washers flat against the end of the roller.
1. A sealing system for a developer roller in a liquid electrophotographic printer, comprising:
a pair of arcuate seals each with an annular sealing surface to seal one end of the developer roller;
a pair of washers each having a low friction surface to contact one of the sealing surfaces, each washer pre-flexed with a concave shape; and
a pair of retainers each to hold one of the washers flat against the end of the roller.
2. The sealing system of claim 1 , where the developer roller includes a shaft and each retainer comprises a push-on retainer to bear on the shaft to hold the corresponding washer flat against the end of the roller.
3. A group of parts for a developer unit in a liquid electrophotographic printer, comprising:
a developer roller;
a shaft extending axially from each end of the roller;
multiple anti-friction rings each having a low friction surface to encircle the shaft at one end of the developer roller; and
multiple push-on retainers each to press one of the anti-friction rings against one end of the developer roller.
4. The group of claim 3 , where each anti-friction ring is concave to be flattened against the end of the developer roller with one of the retainers.
5. The group of claim 3 , where an outer diameter of each anti-friction ring is less than an outer diameter of the developer roller.
6. A developer roller assembly for liquid electrophotographic printing, comprising:
a developer roller including a conductive core and a compliant exterior surrounding the core;
a shaft extending axially from each end of the developer roller;
a flat anti-friction ring encircling the shaft on each end of the developer roller, each anti-friction ring having a low friction outboard surface facing away from the end of the roller; and
a push-on retainer pressing each anti-friction ring against the corresponding end of the developer roller.
7. The roller assembly of claim 6 , comprising a seal pressed against the low friction surface of the anti-friction ring at each end of the developer roller.
8. The roller assembly of claim 6 , where each anti-friction ring comprises a washer pre-flexed to a concave shape and flattened against the end of the developer roller with one of the retainers.
9. The roller assembly of claim 6 , where the low friction surface on each anti-friction ring is made of polytetrafluoroethylene.
10. The roller assembly of claim 9 , where each anti-friction ring is made of polytetrafluoroethylene.
11. The roller of claim 6 , where the compliant exterior wraps around the ends of the conductive cylinder and each anti-friction ring is pressed against the compliant exterior.