Autonomous self-cleaning high-pressure hydraulic filter with integrated bypass regeneration

Abstract

Hydraulic filter system comprising at least one filter chamber, at least one regeneration chamber and at least one dirt separation chamber, wherein the filter system: 1. is operated in the main flow of a hydraulic circuit, 2. comprises a backwashable filter medium, 3. performs automatic regeneration through a fluid-mechanically generated backwashing process, 4. is operated without exchangeable filter elements, where all the aforementioned features can be present in any suitable embodiment.

Description

[0001] The invention relates to a completely novel filter system for hydraulic working circuits, which combines the functions of conventional high-pressure, return and bypass filters in a single assembly.

[0002] Unlike conventional systems, this filter element operates without replacement filters or consumables and performs its own automatic regeneration during operation, without interrupting the hydraulic flow. The accumulated dirt can be emptied via a removable dirt collection unit.

[0003] The core of the invention is a three-chamber filter housing, consisting of: 1. a main filter chamber with a backwashable, metallic fine filter medium, 2. a regeneration chamber which is temporarily separated from the main flow via a hydraulically self-opening differential pressure valve, and 3. a dirt collection unit in which solids are permanently collected by hydrodynamic separation (e.g. by microcentrifugation).

[0004] The regeneration of the filter medium occurs solely through the pressure conditions of the system: If a defined differential pressure is exceeded, a bypass valve briefly switches the main flow and relieves the pressure on the main filter chamber. The hydraulic valve opens automatically, and the resulting pressure gradient creates a backwash flow through the filter medium. Detached solids are directed to the regeneration unit and then to the dirt collection unit, while the oil is returned to the system.

[0005] Through repeated regeneration cycles, the system can also separate the finest particles, allowing the filter to simultaneously perform the typical tasks of a high-pressure filter (coarse particles), a bypass filter (fine cleaning) and a return filter (oil conditioning return).

[0006] The invention thus creates a new category of hydraulic filter systems that did not previously exist: An autonomously operating main flow filter that cleans itself, requires no maintenance and does not have any consumable parts.

[0007] The system is particularly suitable for systems with high pressure levels, long service lives and high requirements for oil purity, as well as anywhere maintenance intervals need to be reduced or filter downtime avoided.

Claims

[1] Hydraulic filter system comprising at least one filter chamber, at least one regeneration chamber and at least one dirt separation chamber, wherein the filter system:

1. is operated in the main flow of a hydraulic circuit, 2. comprises a backwashable filter medium, 3. performs automatic regeneration through a fluid-mechanically generated backwashing process, 4. is operated without exchangeable filter elements, where all the aforementioned features can be present in any suitable embodiment. [2] Filter system according to claim 1, wherein the regeneration is triggered by a pressure difference, a hydraulic signal, a mechanical signal or an equivalent technical means, in particular but not exclusively. [3] Filter system according to one of the preceding claims, wherein the regeneration chamber can be temporarily separated from the main flow via a valve, a valve arrangement, a throttle, a membrane, a fluid logic element or another functionally equivalent control element. [4] Filter system according to one of the preceding claims, wherein the main flow is diverted during regeneration via a bypass line, secondary flow line, diverting device or another fluid-carrying element. [5] Filter system according to one of the preceding claims, wherein the backwashing process is brought about by a pressure gradient, a flow reversal, a volume displacement element, a pressure relief or an alternative fluid mechanical generation method. [6] Filter system according to any of the preceding claims, wherein the filter medium consists of metallic, ceramic, polymeric, sintered, coated, multilayer or functionally equivalent material. [7] Filter system according to any of the preceding claims, wherein the filter medium has a nominal or effective pore size between 1 µm and 100 µm. [8] Filter system according to one of the preceding claims, wherein the dirt separation is carried out by centrifugal forces, vortex flows, gravity, inertial forces, cyclone action, laminar or turbulent flow profiles or another equivalent physical principle. [9] Filter system according to one of the preceding claims, wherein the dirt separation chamber is designed as a removable, replaceable, emptied or internally integrated container. [10] Filter system according to one of the preceding claims, wherein the entire regeneration process is carried out purely hydraulically, mechanically, fluidically or by functionally equivalent means, wherein electronic controls may be used additionally or alternatively. [11] Filter system according to any of the preceding claims, comprising at least one check valve, backflow preventer, fluid logic element or a functionally equivalent structure that prevents the backflow of dirt particles. [12] Filter system according to one of the preceding claims, wherein the regeneration chamber is completely, partially or sectionally isolated from the main flow during backwashing. [13] Filter system according to one of the preceding claims, wherein the pressure reduction is effected by a deflection, a relief bore, a flexible chamber, a pressure accumulator or an equivalent hydraulic means. [14] Filter system according to one of the preceding claims, wherein the regeneration process is triggered cyclically, on demand, at intervals or on events. [15] Filter system according to one of the preceding claims, which removes both coarse and fine particles, in particular but not exclusively, regardless of whether the fine cleaning takes place in one or more regeneration cycles. [16] Filter system according to any of the preceding claims, wherein the filter system is designed in a cylindrical, prismatic, modular or any geometric shape. [17] Filter system according to one of the preceding claims, wherein the system can be integrated into existing filter housings as an insert, cartridge or retrofit module. [18] Filter system according to one of the preceding claims, wherein the bypass function is realized by a valve, a throttle, a flap, a disk, a slide arrangement or another suitable fluid-carrying structure. [19] Filter system according to any of the preceding claims, wherein the separation of particles takes place at any point within the multi-chamber system, regardless of the location, geometry or flow direction. [20] Filter system according to one of the preceding claims, designed to maintain the functionality of the filter medium in the long term by means of a fluid-mechanical self-cleaning process, comprising all technical means that achieve the same sequence of action.