GB2230473A

GB2230473A - Oil filter coupling

Info

Publication number: GB2230473A
Application number: GB9007756A
Authority: GB
Inventors: Katharina Koterewa; Zwetko Zwetkow
Original assignee: Medizin und Labortechnik Leipzig VEB
Current assignee: Medizin und Labortechnik Leipzig VEB
Priority date: 1989-04-05
Filing date: 1990-04-05
Publication date: 1990-10-24
Also published as: GB9007756D0; DE4002247A1; FR2645588A1; DD281219A5

Description

1 A connector coupling for oil filters on powered or processing machines

The invention relates to a connector coupling f or oil f ilters on powered or processing machines. The connector coupling is suitable for all powered and processing machines, in which the operating oil from an easily exchangeable external oil filter has to be cleaned.

Equipping a powered or operating machine with an oil filter is always necessary when there is the danger of fairly heavy soiling of the operating oil by solid particles. In many machines it is sufficient, to undertake the exchange of the filter inserts after switch off. The continuous operation of some machines, for example vacuum pumps in plant construction, however demands their exchange during operation. Thus it is known, to guide the circulation of oil via two orifices to the outside and to equip them in each case with one part of a hose coupling (CH-PS 371 858). Making the connection to the filter device takes place via two hoses, which in each case have a complementary hose coupling which close the circulation of oil of the vacuum pump via the filter device. Changing a filter takes place as follows: initially the hose couplings are released. This simultaneously closes the hoses and the pump-side orifices of the oil circuit. The filter may then be exchanged. The hose couplings are susceptible to faults because of their relatively complicated construction. In effect, they represent four valves loaded with helical springs, the components 2 of which are subjected during normal operation directly to a f low of oil loaded for example with corrosive impurities.

A connector coupling as described in DE-OS 3 436 079, F 04 C-27/02 is simpler and more operationally reliable. It is intended for the connection of a f ilter to the oil circuit routed to the outside via two orifices. In order to avoid leakage of oil during the filter change, the coupling includes a valve disc associated with the two orifices and rotatable with the aid of an actuating device. The latter has two through bores f or making the connection between the oil circuit and the f ilter during normal operation. Moreover, the valve disc is provided on the pump side with a groove, which is approximately perpendicular to the line connecting the through bores, for severing the connection between and for short circuiting, the pump-side orifices during the filter change.

This connector coupling is located almost completely outside the pump casing so that it is not protected f rom damage due to shock and impact in practice. Furthermore, the relatively large spacing of the filter from the casing together with the shaking of the pumps subjects the coupling to permanent flexural stress. After lengthy operation this leads to leakages. Some parts require a high finishing cost. It requires an actuating device and moreover is not easy.

It The invention aims to protect the connector coupling from shock and impact damage, to suppress as far as possible the flexural stress, to avoid leakages, to simplify handling and to reduce the finishing costs.

0 3 The object underlying the invention was to develop a connector coupling for oil filters on rotary slide valve vacuum pumps, which is located as far as possible inside the oil casing of the pump, and which does not leak after lengthy operation, is constructed from simply finished parts and is easily used.

Accordingly, the invention proposes a coupling for a plug-in oil filter for a machine, wherein the machine has a female coupling within its casing and the filter has a male coupling, comprising a sprung piston in the coupling, which piston seals the coupling when disconnected and permits short circuit of the oil outward and return flow connections, and which is displaced by the insertion of the male coupling to allow communication of the connections with channels within the male coupling leading to the filter.

Preferably, the male coupling itself has a sprung piston/sleeve combination which when disconnected ensures that said channels are closed to the outside so that oil cannot leak from the filter.

Appropriate embodiments of these features are explained in the following example of embodiment. In the accompanying drawing:

Fig. 1 shows the section through the connector coupling in the coupled state Fig. 2 shows the section through the socket member of the connector coupling in the uncoupled state Fig. 3 shows the section through the coupler of the 4 connector coupling in the uncoupled state The connector coupling of an oil f ilter with a rotary slide valve vacuum pump was selected as the example.

The latter has an oil casing 1 with an orif ice 2, to which is f ixed the socket member 3 inside the casing. The socket member 3 comprises a socket cylinder 4 provided with a flange, a piston 5, a piston rod 6 and a compression spring 8 inserted between the piston 5 and the base 7 of the socket cylinder 4. The socket cylinder 4 has bores 9; 10 at different axial spacings for the supply and return of oil. The bore 9 is surrounded by an annular magnet 11, the oil inlet line 12 ending therein. The bore 10 receives the end of the oil outlet line 13. The piston rod 6 extends to the outside through a bore in the base 7. Its free end carries a stop 14. The other portion 15 adjacent the piston 5 is reinforced. (Fig. 2) The casing 16 of the oil f ilter is equipped with a coupler 17. The coupler 17 comprises an inner coupling member 18 and an outer coupling member 19 which partially accommodates said member 18. The outer coupling member 19 has a sliding f it in an opening 20 in the cover 21 of the casing 16. The opening 20 has a seal 22. The end of the outer coupling member 19 which is located in the casing 16 is formed as a flange 23 and secures said end against sliding out of the casing 16. Longitudinally of the coupling member 19 three bores are arranged: a first bore 24 near the flange 23, a second bore 25 near its base 27 and a third bore 26 between the two bores 2C25. The inner coupling member 18 is firmly connected to an interface layer 28 surrounding it, its edges being fixed to the casing 16.

J The layer 28 covers the f ilter cartridge 29 which is housed in the casing 16 and has a large number of axial oil channels 30. The coupling member 18 has a central channel 32 which extends between the portion in the f ilter cartridge 29 and a radial bore 31 in the opposite end. Between its end face and the base 27 of the coupling member 19 is located a compression spring 33. Its outer surface is provided with a recess 34, which extends from the layer 28 and a point at a spacing 35 from the radial bore 31, which spacing is smaller than the spacing of the third bore 26 from the second bore 25, but equal to or greater than this spacing less the diameter of the third bore 26. The space delimited by the filter casing 16, the interfacing 28 and the coupling members 1C19 forms the oil chamber 36 for the filtered oil. (Fig. 3).

It is useful to arrange the second bore 25 and the third bore 26 in recesses 37; 38. The spacing between these bores 25; 26 is selected to be equal to the spacing of the bores 9; 10 of the socket cylinder 4. However because of the recesses 37; 38 this is not essential A pin 39 which may be inserted into the coupling member 19 and a covering cap 40 for the orifice 2 are provided for the uncoupled state for protection against undesired actuation.

The following mode of operation is typical of the described connector coupling:

In the uncoupled state the compression spring 8 keeps the piston 5 in a position between the f lange and the 6 bore 10 for the oil return line. The oil conveyed by an oil pump passes through the oil inlet line 12, the ring magnet 11 and the bore 9 into the closed oil chamber 41 of the socket member 3 and f rom there through the bore 10 and the oil outlet line 13 to the lubrication and sealing points of the vacuum pump. In the same state the compression spring 33 forces the coupling member 19 into its outermost position, whereby the f irst bore 24 is located in the region of the opening 20 and therefore of the seal 22 and the third bore 26 is located in the region of the undrilled portion (spacing 35). As a result, the coupler 17 is outwardly oiltight. After removing the covering cap 40 the coupler 17 is inserted into the socket member 3 through the orifice 2 for the purpose of coupling. Thus the piston 5 is forced into the socket cylinder 4 against the resistance of the compression spring 8. If it has reached the rearmost position, the coupling member 19 is displaced as compared to the coupling member 18, overcoming the resistance of the compression spring 33. When the flange 23 is positioned against the interface layer 28, coupling is complete. This position is held fixed by connecting or closure elements (not shown). It is characterised in that the bores 9; 25 and 31 and the bores 10 and 26 are opposite each other, and the bore 24 is located in the oil chamber 36. Consequently, the oil flows from the oil inlet line 12 through the bores 9; 25; 31 and the central channel 32 into the filter cartridge 29. The cleaned oil penetrates through the oil channels 30 of the interface layer 28 into the oil chambers 36, from where it flows out through the bore 24, the recess 34, the bores 26; 10 into the oil flow line 13. (Fig. 1).

cl 7 The ring magnet 11 serves for rough separation of abraded dust present in the oil, even without a coupled filter.

8

Claims

Patent Claims

1. A coupling for a plug-in oil filter for a machine, wherein the machine has a female coupling (3) within its casing and the filter has a male coupling (17), comprising a sprung piston (5) in the coupling (3), which piston seals the coupling when disconnected and permits short circuit of the oil outward and return flow connections (12,13), and which is displaced by the insertion of the male coupling (17) to allow communication of the connections (12,13) with channels (25,31,32; 34,26) within the male coupling (17) leading to the filter (29).

2. A coupling as claimed in claim 1, wherein the male coupling (17) itself has a sprung piston/sleeve combination (18,19) which when disconnected ensures that said channels are closed to the outside so that oil cannot leak from the filter.

3. A connector coupling for oil filters on powered or processing machines, characterised in that inside the machine on an orif ice (2) of the casing (1) a socket cylinder (4) is arranged, which has bores (9; 10) at a dif f erent axial spacing, f or the oil inlet line (12) and the oil outlet line (13) and has a piston (5) and a compression spring (8) inserted between this piston and its base (7), the casing (16) of the filter is equipped with an inner, f ixed coupling member (18) and an outer, movable coupling member (19), the outer coupling member (19) has a safety element (23), which engages behind the cover (21) of the casing (16), a f irst bore (24) near said (23), a second bore (25) near its base (27) and a third bore (26) placed between the j:

1 9 two, the opening (20) of the outer coupling member (19) is provided with a seal (22) through the cover (21), the inner coupling member (18) being firmly connected to an interface layer (28) surrounding it and covering the filter cartridge (29), the interfacing (28) has oil channels (30), the inner coupling member (18) has a central channel (32) between the portion located in the filter cartridge (29) and a radial bore (3) in the opposite end and a recess (34) between the interface layer (28) and a point at a spacing (35) from the radial bore (31), which spacing is smaller than the spacing of the third bore (26) from the second bore (25), but equal to or greater than this spacing less the diameter of the third bore (26), and a compression spring (33) is arranged between the end face of the inner coupling member (18) and the base (27) of the outer coupling member (19).

4. A connector coupling for oil filters according to claim 3, characterised in that the portion (15) bordering on the piston (5) is reinforced.

5. A connector coupling for oil filters according to claims 3 or 4, characterised in that the bore (9) for the oil inlet line (12) is surrounded by a ring magnet (11).

6. A connector coupling for oil f ilters according to claim 3,4 or 5, characterised in that the saf ety element of the outer coupling member (19) is formed as a flange (23).

7. A connector coupling for oil filters according to any of claims 3 to 6 characterised in that the second and the third bore (15; 26) of the outer coupling member (19) are arranged in recesses (37; 38).

8. A connector coupling for oil filters according to any, of claims 3 to 7, characterised in that the spacing of the second and third bore.(25; 26) of the outer coupling member (19) is equal to the spacing of the bores (9; 10) of the socket cylinder (4).

9. A connector coupling for oil filters substantially as herein described in the drawings.

Published 1990airnePiLlentM".SlateHouse.5671 High Rolbom.UndonWCIIR 4TP. Purther copies maybe obtained from ThePatentoffice We& Branch, St Idary Cray. Orpington, Kent BR5 3RD. Printed by MWup,ex techniques It& & Mary Cray. Xent, Con. 1187 1