CuSn12 Oil-Grooved Bushings for Mixer Discharge Door Trunnions
Send a drawing for a CuSn12 tin-bronze sleeve supporting a mixer discharge door trunnion outside the product chamber. The existing spiral oil-grooved sleeve family provides the construction reference. This is a lubricated plain bearing enquiry for a limited-angle pivot, not a rotating mixer-shaft seal or a product-contact liner.
Design the lubricant route around oscillation and contamination
The gate may dwell closed under material pressure and move only briefly during discharge. Supply the pressure resultant, door geometry, actuator attachment and trunnion reactions. Show which trunnion locates the door axially and which position accommodates expansion. Small oscillations and long dwell should be described directly instead of being converted into an unexplained average RPM.
Specify CuSn12 with its product form and standard; do not replace it with C90700 by a closest-grade table. The bore groove needs a defined feed connection, end positions and sufficient bearing land. State whether the approved system uses oil or grease. A helical groove does not prove that lubricant reaches both loaded regions during a short swing, and does not make a plain bronze sleeve dry-running.
Application boundaries to confirm
The sleeve is not a seal against powder, abrasive mix or cleaning liquid. Define separate seals or guards and the permissible leakage path. Do not infer food-contact, chemical compatibility or pressure-boundary approval from the material name or the photograph.
Dimensions and drawing-based quotation checklist
| Review item | Information required |
|---|---|
| Pivot geometry | Bore, OD, length, shoulders, pin finish, housing tolerance and door alignment datums. |
| Groove and feed | Profile, width/depth/pitch, handedness, end lands, feed-hole coordinates and lubricant. |
| Gate conditions | Pressure resultant, opening angle, dwell, cycles, pivot temperature and contamination. |
| Purchasing | CuSn12 standard and form, new-part tolerances, quantity, drawing revision and requested documents. |
Identify metric or inch units and distinguish worn sample measurements from intended new-part dimensions. Include the mating-part drawing and requested material or dimensional documents; their scope and availability are confirmed with the quotation.
Installation and selection checks
Clear all feed passages and protect groove edges during fitting. Measure the installed bore, not just the loose sleeve, and verify alignment between the two trunnion seats. Confirm lubricant arrival before operating the gate and check that seal compression does not bind the pivot.
Frequently asked questions
Does the groove pump oil in both directions?
No pumping direction or flow rate is guaranteed by its appearance. The complete groove and feed system needs review for reversing motion.
Is CuSn12 interchangeable with C90700?
No automatic equivalence is declared. Keep the exact grade, casting route and acceptance requirements on the purchase order.
Can the bushing also seal the chamber?
A running-clearance bushing is not a substitute for a defined process seal. Provide the seal assembly separately.
Request a drawing-based replacement quotation
Send the drawing and duty to BONIU, identifying CuSn12 tin bronze, quantity and revision. Material route, fit, manufacturing feasibility and inspection scope are reviewed before the quotation is confirmed.