Segmented Filter Unit for Ship Gear Lubrication

Solution Overview

Problem

Existing filter units for lubricating oil in ship gears are bulky, heavy, and expensive due to their dual cartridge design, and edge filters lack the necessary filter fineness for effective filtration.

Innovation Solution

A filter unit with a main cartridge for continuous fine filtration and a smaller auxiliary cartridge for temporary coarse filtration during replacement, allowing for in-service maintenance while reducing size and weight, and incorporating a differential pressure switch for alarm triggering when the main filter is dirty.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a double switch filter with two identical filter cartridges is used to enable filter replacement during machine operation, then the filter can be changed while running, but the filter unit becomes bulky, heavy, and expensive

Engineering Contradiction:

Improvefilter replacement during operationVSAvoidfilter unit weight

Core Design Contradiction:

Ease of operationVSWeight of stationary object

Solution Approach 1:

The filter system is segmented into two distinct cartridges: a main cartridge with a fine filter element for continuous operation and an auxiliary cartridge with a coarse filter element for temporary use during replacement. This segmentation allows each cartridge to be optimized for its specific function, with the auxiliary cartridge being smaller and lighter since it only needs to handle coarse filtration temporarily.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different filter elements with different properties are placed in different cartridges: the main cartridge contains a fine filter element (10 μm) for high-quality continuous filtration, while the auxiliary cartridge contains a coarse filter element (40 μm) for temporary coarse filtration. This local quality differentiation allows the auxiliary cartridge to be smaller and lighter while still fulfilling its temporary function.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If a double switch filter with two identical filter cartridges is used to enable filter replacement during machine operation, then the filter can be changed while running, but the filter unit becomes bulky and requires more installation space

Engineering Contradiction:

Improvefilter replacement during operationVSAvoidinstallation space

Core Design Contradiction:

Ease of operationVSArea of stationary object

Solution Approach 1:

The filter system is segmented into two distinct cartridges: a main cartridge with a fine filter element for continuous operation and an auxiliary cartridge with a coarse filter element for temporary use during replacement. This segmentation allows each cartridge to be optimized for its specific function, with the auxiliary cartridge being smaller since it only needs to handle coarse filtration temporarily.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different filter elements with different properties are placed in different cartridges: the main cartridge contains a fine filter element (10 μm) for high-quality continuous filtration, while the auxiliary cartridge contains a coarse filter element (40 μm) for temporary coarse filtration. This local quality differentiation allows the auxiliary cartridge to be smaller and require less installation space.

Inventive Principle:

Principle #3Local quality

3Ease of operation

If a double switch filter with two identical filter cartridges is used to enable filter replacement during machine operation, then the filter can be changed while running, but the filter unit becomes expensive

Engineering Contradiction:

Improvefilter replacement during operationVSAvoidfilter material quantity

Core Design Contradiction:

Ease of operationVSQuantity of substance

Solution Approach 1:

The filter system is segmented into two distinct cartridges: a main cartridge with a fine filter element for continuous operation and an auxiliary cartridge with a coarse filter element for temporary use during replacement. This segmentation allows the auxiliary cartridge to use less expensive coarse filter material since it only needs to handle temporary coarse filtration.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different filter elements with different properties are placed in different cartridges: the main cartridge contains a fine filter element (10 μm) for high-quality continuous filtration, while the auxiliary cartridge contains a coarse filter element (40 μm) for temporary coarse filtration. This local quality differentiation allows the auxiliary cartridge to use less material and be more cost-effective.

Inventive Principle:

Principle #3Local quality

4Weight of stationary object

If an edge filter is used to reduce filter unit size and weight, then the filter unit becomes more compact, but a maximum filter fineness of about 50 μm cannot be achieved

Engineering Contradiction:

Improvefilter unit weightVSAvoidfilter fineness

Core Design Contradiction:

Weight of stationary objectVSManufacturing precision

Solution Approach 1:

The filter system is segmented into two distinct cartridges: a main cartridge with a fine filter element for continuous operation and an auxiliary cartridge with a coarse filter element for temporary use during replacement. This segmentation allows the main cartridge to achieve high filter fineness (10 μm) while the auxiliary cartridge uses a coarser filter (40 μm) that can be smaller and lighter.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different filter elements with different properties are placed in different cartridges: the main cartridge contains a fine filter element (10 μm) for high-quality continuous filtration, while the auxiliary cartridge contains a coarse filter element (40 μm) for temporary coarse filtration. This local quality differentiation allows the main cartridge to achieve the required 10 μm fineness while the auxiliary cartridge can be more compact.

Inventive Principle:

Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables efficient lubricating oil filtration with reduced installation space and cost, ensuring continuous operation and preventing gearbox damage during filter changes by using a coarse filter for short periods and a fine filter for normal operation.

Implementation Method 1

a fine filter element (10 μm), which is intended for continuous operation, is provided in the main cartridge

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

a coarse filter (40 μm), which is only required for the period in which the main cartridge is being replaced

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 3

the pressure drop in the auxiliary cartridge is set to the same threshold value as the pressure drop in the main cartridge when the fine filter is dirty, at which point the differential pressure switch responds and triggers an alarm

Methodology Applied

Scientific EffectPressure differential measurement: Pressure Drop

Data Source

PatentEP2675544B1Filter unit and method for operating the filter unit

Publication Date: 2016.10.05 ZF FRIEDRICHSHAFEN AG

Figure 1~2
Figure 3
Figure 4

AI summary

The invention relates to a filter unit comprising an inlet (12) and an outlet (13) for a flow medium to be filtered, a first filter cartridge (14) with a first filter element, a second filter cartridge (15) with a second filter element and a switching device (16) which allows alternate filter operation of the first or second filter cartridge (14, 15). It is proposed that the first filter cartridge be configured as the main cartridge (14), the first filter element as a fine filter, the second filter cartridge as an auxiliary cartridge (15) and the second filter element as a coarse filter.