GB2253158A

GB2253158A - Oil filter

Info

Publication number: GB2253158A
Application number: GB9104091A
Authority: GB
Inventors: Joseph Hegarty
Original assignee: HEGARTY ANTHONY; HEGARTY LYNNE MARGARET
Current assignee: HEGARTY ANTHONY; HEGARTY LYNNE MARGARET
Priority date: 1991-02-27
Filing date: 1991-02-27
Publication date: 1992-09-02
Also published as: GB9104091D0

Abstract

A spin-on oil filter comprises a wound cellulose-based filter element 30 and peripheral seals 32, 36 between element 30 and housing 12. The seal 36 at the closed end of the housing is mounted on the edge of an apertured plate 38 and is urged against the filter element and housing wall by a spring 40. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO OIL FILTERS The present invention relates to oil filters. In particular the invention relates to oil filters in which the filter element is made in a wound form from a cellulose based material.

An oil filter, whether using a filter element of this wound type or of the pleated type, usually comprises a cylindrical container in which the element is located, the element having a central cylindrical passage. The container is closed at one end and has a plate at the other end, sometimes known as a spin-on plate having a central opening in the plate, the spinon plate also having a number of circumferential openings arranged around the central opening. A further plate sometimes known as a waffle plate is located internally of the container adjacent the spin-on plate. The waffle plate also has circumferential openings aligned with the circumferential openings in the spin-on plate and one end of the filter element rests on the waffle plate.A seal is provided on the spin-on plate to prevent oil leaking from the filter and a seal is also provided between the waffle plate and the cylindrical container.

Oil to be filtered can enter through the central opening in the spin-on plate which is aligned with the cylindrical passage in the filter element and the oil can then flow through the filter element and out through the openings in the waffle plate and the spin-on plate.

Alternatively the oil can enter through the circumferentially arranged openings, pass through the openings in the waffle plate and thence through the filter element and leave the filter through the cylindrical passage in the element and the central opening in the spin-on plate.

In the case of a filter having a wound element it is important to seal between the filter element and the cylindrical container at the closed end of the container and to maintain that seal under all conditions of operation of the filter.

The present invention seeks to provide a filter having a wound filter element and a seal between the filter element and the container and to provide means for ensuring that this seal remains in position whilst the filter is in operation.

Accordingly the present invention provides an oil filter assembly comprising a casing, the casing having an inlet and an outlet and a wound filter element located in the housing between the inlet and the outlet, a sealing ring located between the filter element and the casing, and loading means urging the sealing ring into contact with the filter element and the housing.

The loading means can comprise a pressure plate in contact with the sealing ring, and spring means located between the pressure plate and the housing.

The sealing ring can be mounted on a rim of the pressure plate.

The inlet of the assembly can be aligned with a central passage in the filter element.

One end of the filter element can be in contact with an apertured waffle plate, the outlet of the assembly being formed in a plate located adjacent the waffle plate.

The assembly can include a further seal arranged between the waffle plate and one end of the filter element.

The filter element can be made from a cellulose based material.

The present invention will now be more particularly described with reference to the accompanying drawing which shows a sectional elevation of one form of filter assembly according to the present invention.

Referring to the drawing there is shown a filter assembly 10 comprising a cylindrical casing 12 having a closed end 14.

The opposite end of the casing 12 to the end 14 is closed by a plate 16 which is secured to the casing 12 and the plate 16 has a central screw threaded opening 18.

The plate 16 which is sometimes known as a spin-on plate is provided with a number of circumferential openings 20 and a seal 22 and a crimping ring 23. A collet 24 is located around the opening 18, and the collet 24 engages a central opening in a waffle plate 26 and a tube 28 located centrally in a wound filter element 30 formed from a cellulose based material. A sealing gasket 32 is provided at the rim of the waffle plate and the waffle plate is also provided with circumferential openings 34 in the same manner as the openings 20 in the spin-on plate 16.

A further sealing gasket 36 is located at the opposite end of the filter element 30 to that resting on the waffle plate 26.

The sealing gasket 36 is attached to a pressure plate 38 by the rim of the pressure plate engaging in an annular slot in the gasket 36.

A spring 40 is located between a spring collet 42 and a rim 44 formed on the pressure plate 38. The pressure plate 38 has openings 46 to allow oil to fill the space between the upper end of the filter element 30 and the closed end 14 of the container 12.

It will be appreciated that the combination of the spring 40 and the pressure plate 38 forces the sealing gasket in an outward direction against the wall of the casing 12 and downwardly into contact with the outer edge of the filter element 30 thereby preventing oil from entering any gap which may exist between the filter element and the casing.

In operation, the filter assembly 10 is attached to an oil tapping of, for example, an internal combustion engine by means of the threaded opening 18. When the engine is running oil passes through the central opening 18 and through the tube 28 and into the space between one end of the filter element and the closed end 14 of the casing 12. It will be appreciated that the oil is under pressure and will then pass down through the filter element under pressure and after being filtered will leave the filter element through the openings 34 in the waffle plate 26 and the openings 20 in the spin-on plate 16. The oil will be contained by the sealing gasket 22 and will then re-enter the engine lubricating system.

As the oil is under pressure the filter element 12 will tend to be compressed and therefore decrease in length. The arrangement of the pressure plate 38 and spring 40 will cause the sealing gasket 36 to move with the movement or shrinkage of the sealing element 12 and once the oil pressure is removed for example when the engine is switched off, the oil filter element will tend to expand against the load exerted by the pressure plate 38 and spring 40.

At all times the sealing gasket 36 will be maintained in contact both with the wall of the cylindrical casing 12 and the filter element 30.

An oil filter assembly according to the present invention can be used either to filter a bypass oil flow or to filter the full oil flow of the machine which the oil is lubricating.

The present invention is not limited to the type of filter assembly in which the oil enters through a central opening and leaves in a filtered state through a circumferential array of openings in the filter assembly and can operate in an arrangement in which the oil enters the filter assembly through a circumferential array of openings and leaves through a central opening in the filter assembly.

A filter assembly according to the present invention can also be used on any type of machine in which lubricating oil is pumped under pressure within the machine, for example internal combustion engines, machine tools and gas turbine engines.

Claims

1 An oil filter assembly comprising a casing, the casing having an inlet and an outlet, a annular wound filter element located in the housing between the inlet and the outlet, a sealing ring located between the filter element and the casing, and loading means urging the sealing ring into contact with the filter element and the housing.

2 An assembly as claimed in claim 1 in which the loading means comprises a pressure plate, the sealing ring being mounted on a rim of the pressure plate, and spring means located between the pressure plate and the housing.

3 An assembly as claimed in claim 1 or claim 2 in which the inlet of the assembly is aligned with a central passage in the filter element.

4 An assembly as claimed in any one of the preceding claims in which one end of the filter element is in contact with an apertured waffle plate, the outlet of the assembly being formed in a spin-on plate located adjacent the baffle plate and closing off one end of the casing.

5 An assembly as claimed in any one of the preceding claims including a further seal arranged between the waffle plate and one end of the filter element.

6 An assembly as claimed in any one of the preceding claims including a seal on the spin-on plate of the assembly to prevent leakage of oil from the assembly.

7 An assembly as claimed in any one of the preceding claims in which the filter element is made from a cellulose based material.

8 An oil filter assembly constructed and arranged for use and operation substantially as herein described and with reference to the accompanying drawing.