Stern shaft seal_Marine Bearing Series_Product__Kintowe Engineering Plastic Co.,Ltd

Stern shaft seal

The stern tube seal assembly is a critical safety component in a ship's propulsion system. It ensures effective sealing at the stern tube end during navigation, effectively isolating seawater and sediment to prevent their ingress into the engine room through the stern tube. Additionally, the stern tube seal can withstand significant axial and radial displacement as well as high-frequency vibrations. Consequently, the operational performance of the stern tube seal directly impacts a vessel's ability to navigate normally. Stern tube seals are widely used in defense and military applications, law enforcement vessels, and various civilian ships.

Working conditions:

Stern shaft sealing device operates stably and safely under various environmental conditions:

a) Longitudinal tilt: ±5°, transverse tilt: ±15°;

b) Longitudinal roll: ±7.5°, transverse roll: ±22.5°;

c) Operating ambient temperature: 5°C to 55°C;

d) Operating seawater temperature: -2°C to 39°C;

e) Complies with GJB system requirements and marine standards, subject to specific technical agreements;

f) Possesses impact resistance and meets equipment requirements specified in GJB150.18-86;

g) Environmental testing conforms to GJB requirements.

Primary structural components of the product:

The stern shaft seal assembly (standard) consists primarily of: moving ring, stationary ring, fixed clamping ring, mounting base, stationary ring seat, fasteners, support spring, inflatable seal ring, O-ring seal, etc. For non-standard customization, refer to the technical documentation.

Design Introduction

The moving ring material is tin bronze (ZCuSn10P1)

This material possesses high strength and hardness, coupled with excellent toughness and wear resistance, making it resistant to seizing. This enables it to maintain stable performance even under harsh conditions such as heavy loads, high-speed operation, and frequent friction. Additionally, it exhibits favorable casting and machining properties, facilitating the production of various shapes through casting and mechanical processing. Furthermore, tin bronze demonstrates good corrosion resistance in seawater environments, maintaining stable performance and appearance over extended periods in marine conditions.

Static ring material

The company has established long-term, friendly cooperation with suppliers while accumulating extensive processing expertise, particularly in researching and mastering process data for both imported and domestic materials. This experience is crucial for the smooth integration and operation of this unit. The polymer composite stationary ring forms a water-lubricated friction pair with the metal rotating ring to achieve effective sealing of the stern tube system.

Based on customer selection, the company can provide either imported or domestically produced composite materials.

Domestic Polymer Composites

This material is a high-strength composite formed by adding a certain amount of solid lubricant to a fiber-reinforced, resin-matrix composite under specific temperature and pressure conditions. Compared to other phenolic-impregnated fabrics (cotton fiber, polyester fiber, nylon fiber, etc.), it exhibits superior compressive strength, tensile strength, abrasion resistance, flame retardancy, heat resistance, and chemical corrosion resistance. It adapts to complex working environments with diverse operational demands. It possesses excellent properties including low friction, high permeability, high abrasion resistance, and resistance to silt and sediment.

Advantages

The mounting bracket, stationary ring seat, and retaining clamp ring are fabricated from nickel-aluminum bronze castings (ZCuAl8Mn13Fe3Ni2). The stern tube sealing assembly has undergone reliability testing, obtained CCS certification, and demonstrated through long-term service data analysis that this material possesses high strength, hardness, and wear resistance, maintaining excellent mechanical properties in most operating environments. Additionally, nickel-aluminum bronze exhibits excellent corrosion resistance in atmospheric, freshwater, and seawater environments, featuring high corrosion fatigue strength and resistance to oxidation and corrosion. It also possesses outstanding fatigue resistance, enduring prolonged high-load operating conditions without fatigue failure. Furthermore, it offers favorable casting and machining properties, with a dense alloy structure ensuring excellent airtightness.

Specification

Maximum shaft diameter(dmax)	Maximum Outer Diameter of Installation Flange(D)	Center distance between mounting holes(D1)	Convex shoulder inner diameter(D2)	Axial length(L)	Number of mounting holes(n)	Installation bolt diameter(d1)	Maximum rotational speed(r/min)
161-180	340	310	275	285	8	M12	657
180-190	350	320	285	285	8	M12	618
190-208	370	340	305	285	8	M12	590
208-228	425	390	345	285	12	M16	570
228-248	445	410	365	285	12	M16	505
248-264	465	430	385	315	12	M16	488
264-284	485	450	405	315	12	M16	444
284-314	515	480	435	315	12	M16	420
314-337	565	425	475	315	12	M20	402
337-362	590	550	500	315	12	M20	360
386-380	610	570	520	315	12	M20	340
380-400	630	590	540	315	12	M20	330
400-426	684	630	575	378	12	M20	390
426-456	714	660	605	378	12	M20	375
456-475	733	680	625	378	12	M20	350
475-500	758	710	655	378	12	M20	340
500-530	820	765	700	378	12	M24	330
530-560	860	805	740	378	12	M24	320
560-590	890	835	770	378	12	M24	290
590-630	930	875	810	378	12	M24	275
630-670	990	930	865	446	16	M24	160
670-710	1030	970	905	446	16	M24	150
710-750	1090	1030	960	446	20	M24	140
750-795	1140	1080	1010	446	20	M24	130
795-840	1200	1135	1065	446	20	M24	120
840-890	1250	1185	1115	525	20	M24	215
890-940	1300	1235	1165	525	20	M24	202
940-990	1400	1325	1245	525	24	M30	190
990-1040	1460	1385	1305	525	24	M30	180

Unit: mm

For more details, please refer to：KINTOWE Stern Tube Seal