Marine Stainless Steel Lubricating Oil Pump

I. Product Overview

Marine stainless steel lubricating oil pumps are the "lubricating heart" of ship power systems, specially designed for the lubricating oil circulation of key equipment such as diesel engines, gas turbines, and gearboxes. They adopt 316L ultra-low carbon stainless steel (022Cr17Ni12Mo2) or 304 stainless steel (06Cr19Ni10) as the core material, and realize low-pressure and precise delivery of high-viscosity lubricating oil through the principle of gear pumps or screw pumps. Its working principle is that the power source (motor or main shaft drive) drives the gears/screws to mesh and rotate, uses the volume change to generate suction, sucks the lubricating oil in the oil tank and pressurizes it, delivers it to the equipment friction pairs (bearings, pistons, etc.) after being filtered by the oil filter, and returns to the oil tank after lubrication to form a closed loop. The pump body has undergone precision machining and passivation treatment, with a corrosion-resistant service life of ≥10 years in high-temperature, high-humidity and oil mist-containing environments. It meets the IMO "Ship Mechanical Device Lubrication System Specification" and the lubrication equipment certification requirements of classification societies such as LR and ABS, and is widely used in ship equipment that requires forced lubrication such as main engines, generators, and propulsion systems.

II. Core Technologies and Material Characteristics

1.Selection and Performance of Stainless Steel Materials

2.Key Technical Parameters

Flow range: 5-200m³/h, suitable for equipment power 500-30000kW (for example, 30000kW main engine requires flow ≥100m³/h)

Pressure control: Outlet pressure 0.3-2.5MPa, pressure pulsation ≤±0.02MPa, ensuring uniform distribution of lubricating grease to each friction point

Medium compatibility: Can deliver mineral oil, synthetic oil (such as ester oil) with viscosity 10-1000cSt, and lubricating oil containing extreme pressure additives

Temperature resistance design: 316L material can withstand 150℃ continuous high temperature (instantaneous 180℃), 304 material is applicable to ≤100℃ working conditions

Cleanliness requirement: The surface roughness of the flow-through parts is Ra≤0.8μm, and a 10μm precision filter screen is built-in to ensure that the oil cleanliness reaches ISO 4406 16/13 level

3.Safety and Precision Design

Equipped with pressure sensing and flow monitoring devices, when the oil supply pressure is lower than 80% of the rated value or the flow is interrupted, it will immediately trigger an acousto-optic alarm and link to stop the machine

Adopts positive displacement structure, with flow stability ≥98% (under constant speed conditions), ensuring that the oil quantity error of each lubrication point is ≤±5%

III. Technical Advantages and Innovative Design

1. High Viscosity Oil Delivery Capacity

Dual-screw composite structure: The main and auxiliary screws adopt variable pitch design, with meshing clearance ≤0.05mm. When the viscosity is 1000cSt, the volumetric efficiency is still ≥95%, which is 15% higher than that of gear pumps, suitable for high-viscosity lubricating oil delivery during low-temperature startup.

Heating and constant temperature system: The pump body is integrated with an electric heating jacket (power 5-15kW), which can heat the lubricating oil from the ambient temperature to 50±5℃ (viscosity drops below 100cSt), ensuring smooth startup in low-temperature environments (-20℃).

2. Low Pulsation and Precision Control

Mute gear design: Adopts helical gear (helix angle 15°), with meshing overlap ≥1.8, and operating noise ≤65dB (at 1 meter), which is much lower than 80dB of spur gear, suitable for engine room noise reduction requirements.

Frequency conversion speed regulation adaptation: Adjust the speed in linkage with the equipment speed (500-3000r/min), and the oil supply flow automatically matches with the load (for example, the flow drops to 50% of the rated value when the main engine is idling), reducing energy loss.

3. Long-term Reliable Operation

No-leakage seal: The shaft seal adopts a "mechanical seal + skeleton oil seal" double structure, with static leakage ≤0.1mL/h and dynamic leakage ≤0.5mL/h, avoiding lubricating oil pollution of the engine room.

Anti-fouling design: The inner surface of the flow-through parts is electrolytically polished, and the oil fouling adhesion rate is 60% lower than that of ordinary stainless steel. After long-term operation, the flow stability is still maintained (attenuation ≤5%/year).

IV. Typical Application Scenarios

1. Lubrication of Main Engine and Power Equipment

Low-speed diesel engine lubrication: 12-cylinder low-speed diesel engines are equipped with 316L stainless steel screw-type lubricating oil pumps, with a flow rate of 80-150m³/h and a pressure of 1.5MPa. They deliver 120℃ high-temperature lubricating oil to crankshaft bearings and crosshead sliders, ensuring that the friction coefficient of piston movement is ≤0.001.

Gas turbine lubrication: LNG ship gas turbines use high-temperature lubricating oil pumps with a flow rate of 30-80m³/h and a pressure of 2.0MPa. They deliver synthetic ester oil (viscosity 46cSt/100℃) to turbine blade bearings, withstanding a medium temperature of 150℃.

2. Auxiliary Engine and Transmission System

Generator bearing lubrication: 1000kW diesel generators are matched with 304 stainless steel gear pumps, with a flow rate of 10-30m³/h and a pressure of 0.6MPa. The lubricating oil is accurately distributed to the front and rear bearings through the oil distribution valve, and the oil temperature is controlled at 40±5℃.

Propulsion shafting lubrication: The controllable pitch propeller (CPP) system adopts double pumps in parallel, with a single pump flow rate of 20-50m³/h and a pressure of 1.0MPa, providing continuous lubrication for shafting seals and hydraulic servo mechanisms, with a response time ≤1 second.

3. Lubrication of Special Equipment

Low-temperature lubrication of polar ships: In a -30℃ environment, the lubricating oil pump heats the low-temperature lubricating oil with a viscosity of 500cSt to 30℃ (viscosity drops to 80cSt) through pump body insulation and electric heating, with a flow rate of 5-20m³/h, to lubricate deck machinery such as windlasses and winches.

Lubrication of diesel engines on drilling platforms: The main diesel engine of offshore platforms uses 316L stainless steel lubricating oil pumps with a flow rate of 50-100m³/h. It operates stably in a high-humidity (95%) and salt spray concentration of 30mg/m³ environment, and the bearing temperature rise is controlled within 35K.

V. Selection and Maintenance Specifications

1. Key Selection Parameters

Equipment type: 316L stainless steel is selected for main engines and high-temperature equipment, and 304 stainless steel is selected for auxiliary engines and normal-temperature equipment

Lubrication requirements: Configure the flow rate according to 10 times/hour of the total oil quantity of the equipment friction pair. For example, 100L total oil quantity requires flow rate ≥1m³/h

Medium characteristics: 316L material is selected for conveying synthetic oil or high-temperature oil, and wear-resistant gear pumps are selected for those containing solid additives (such as MoS₂)

2. Maintenance Points

Daily monitoring: Check the outlet pressure (fluctuation ≤±0.05MPa), oil temperature (≤120℃) and filter pressure difference (≤0.1MPa) every 500 hours

Regular maintenance: Clean the suction filter monthly, replace the mechanical seal (using fluororubber + silicon carbide material) every 2000 hours, and check the gear clearance annually (allowable ≤0.1mm)

In-depth maintenance: Conduct disassembly inspection every 3 years, passivate 316L components, and re-calibrate the accuracy of gears/screws (tooth profile tolerance ≤0.01mm)

VI. Compliance and Certification

International standards: Compliant with ISO 3914 lubricating oil pump performance standards and IMO MSC.337(91) ship mechanical lubrication system requirements

Classification society certification: Passed the type approval of lubricating pumps by LR, ABS, CCS (including 1000-hour high-temperature operation test)

Environmental requirements: 100% recyclable pump body materials, and the leaked oil collection device meets the anti-pollution specifications of MEPC.107(49)