C95500 Nickel-Aluminium-Bronze Sleeve Bushings for Marine Winch Drums
A proposed C95500 nickel-aluminium-bronze sleeve for a marine winch drum must be reviewed by operating state and rope layer. Line pull, drum torque and journal reaction are different quantities. Define the moving sleeve interface, loaded holding periods, hauling and payout conditions before selecting the alloy, running clearance and lubrication arrangement.
Identify which drum interface is actually a plain bearing
A winch can use rolling bearings, plain sleeves or a combination at different locations. This guide concerns a drawing-defined cylindrical drum support that already calls for a copper-alloy sliding bearing. It does not recommend replacing a winch’s rolling bearings or redesigning its brake.
Show whether the drum rotates on a stationary pin with a sleeve fixed in the drum hub, or whether the shaft rotates inside a sleeve fixed in a frame. Identify every radial support and any separate thrust face. The relative motion at the sleeve may differ from the motor or gearbox speed, especially when a clutch disconnects the drive.
Concast identifies C95500 as nickel-aluminium bronze, lists bearing and marine uses and notes that heat-treated material is also available.[1] That is base-alloy information, not approval of this particular marine winch bearing. Specify the casting standard, route, condition and required records; do not assume C95500, C95800 and CuAl10Ni5Fe5 are interchangeable.
Build a duty table before requesting an allowable load
| State | Journal question | Information required |
|---|---|---|
| Hauling | Which contacts slide while the rope loads the drum? | Line pull by rope layer, speed, load direction, duty cycle and support reactions |
| Loaded holding | What remains loaded while relative sliding speed is zero? | Sustained reactions, dwell, corrosion exposure and subsequent breakaway |
| Controlled payout | Does the sleeve move with the drive connected or released? | Payout speed, brake state, rope load and thermal conditions |
| Free rotation or slack-line recovery | Can the drum turn faster than in normal hauling? | Maximum relative sleeve speed and approved lubrication conditions |
Zero sliding speed during holding gives zero PV by arithmetic, but it does not remove contact stress, pin deflection or the next startup. Conversely, a low-load free-rotation condition can impose a speed requirement absent from a high-line-pull specification. Request an operating envelope rather than a single “heavy duty” label.
Rope layers change the torque question
Thern’s hydraulic-winch information distinguishes its own first-layer, mid-drum and full-drum capacities.[2] It demonstrates that the drum fill condition belongs in a winch load description. The cited Thern model uses ball bearings; it is not evidence for a C95500 sleeve application, and none of its capacities is used as a BONIU limit.
Illustrative geometry: assume a tangential 40 kN line force. At an effective rope radius of 0.20 m, drum torque is 8 kN·m. At 0.35 m, the same line force requires 14 kN·m. Conversely, an assumed constant 8 kN·m torque gives 40 kN at 0.20 m and about 22.9 kN at 0.35 m, before losses or control limits.
These are assumed values illustrating T = F × r, not winch capacities, brake settings or bushing ratings. A “40 kN winch” description is incomplete unless it identifies the rope layer and governing operating condition.
Do not divide drum torque by sleeve area to obtain bearing pressure. The journal reactions require a free-body analysis including rope lead direction, drum weight, support spacing, drive forces and any axial load. Rope fleet angle and the force application point may also matter. Use designer-supplied reactions for each support, with the associated duty state identified.
Specify marine exposure without assuming seawater lubrication
Describe the actual contact environment: enclosed and greased, exposed to salt spray, intermittently flooded or intentionally wetted. A component on a ship is not automatically a water-lubricated bearing. Keep the chosen lubricant route and the corrosion review explicit.
State the mating pin or shaft alloy, hardness, finish and any coating. Review seals, drainage, storage and shutdown exposure. A corrosion-resistant base alloy does not prevent every form of wear or damage in a contaminated sliding pair; the complete contact and lubricant system must suit the application.
C95500’s as-cast and heat-treated supply conditions must not be mixed silently in a quotation comparison. Obtain the required condition and acceptance properties from the controlled specification. Do not treat a hardness value as a direct allowable bearing pressure or a basis for increasing the machine’s load rating.
Fit and commissioning follow the approved winch arrangement
- Inspect the drum hub, pin and supporting structure. Record ovality, alignment and wear rather than copying only a damaged sleeve’s bore.
- Specify housing fit, installed running clearance, geometric tolerances and axial location. Review fit effects in the actual hub, including distortion from assembly.
- Show lubricant holes, grooves and their feed connections. Protect finished surfaces and use controlled, aligned installation tooling.
- Keep sleeve retention distinct from the winch’s shaft retention, clutch and brake functions. Do not introduce an unintended axial sliding face.
- Agree dimensional and operational acceptance under the specified duty states. Qualified personnel must follow the winch maker’s isolation, commissioning and load-test procedures.
The RFQ can define component inspection and material records. Winch capacity, marine classification, brake holding and complete-machine certification require their own approved scope. No such approval or customer installation is implied by this technical guide.
Frequently asked questions
Does rated line pull equal the force on each bushing?
No. Bearing reactions depend on the complete support and force geometry. Obtain them for the individual journal locations and load cases.
Does a holding drum have no bearing load because PV is zero?
No. Sustained contact load and the subsequent startup remain design questions even when relative speed is zero.
Can C95800 be supplied against a C95500 drawing?
Only after an explicit approved substitution review. Similar nickel-aluminium-bronze names do not establish identical specifications or conditions.
Can the torque example be used as a winch rating?
No. It is an idealised geometry example with assumed inputs. It omits losses, controls, brakes, structural limits and the bearing analysis.
Technical sources
- Wieland Concast: C95500. Base-alloy, application and condition reference; no finished-sleeve or winch rating adopted.
- Thern: Hydraulic Winches. Manufacturer example of capacity distinguished by drum layer; its ball-bearing winch is not a bronze-sleeve reference design.
Source documents describe their own materials, products or engineering scope. The application analysis and illustrative calculations above are not BONIU test results or guaranteed performance.
Request a drawing review
Send the winch drum and support sections, sleeve drawing, C95500 standard and condition, moving/fixed interface, shaft and hub tolerances, designer-supplied reactions by support and operating state, line pull by rope layer, speed, dwell, lubrication, salt-water exposure, quantity and inspection requirements. BONIU confirms the proposed material and component manufacturing scope after review; C95500 stock or a complete winch assembly is not assumed.