GB2211575A

GB2211575A - Fluid feed device

Info

Publication number: GB2211575A
Application number: GB8824566A
Authority: GB
Inventors: Klaus Matthees
Original assignee: Barkas Werke VEB
Current assignee: Barkas Werke VEB
Priority date: 1987-10-22
Filing date: 1988-10-20
Publication date: 1989-07-05
Anticipated expiration: 2008-10-20
Also published as: GB2211575B; DD272779A3; GB8824566D0; DE3833684A1; DE3833684C2

Description

1 "2 7 FLUID FEED DEVICE The present invention relates to a fluid feed

device, especially for independent feeding of pressure spaces in a rotating system.

In DD-PS 127 307 there is disclosed a rotary two-channel feedthrough with a first central feed channel in the form of a stand pipe which projects through the hub. The second feed channel is an annular channel, the cross-section of which is formed between thewall of a bore in the hub and the circumference of the central pipe. The pipe is sealed off axially by way of a pressed profile seal. The feed space for the second feed channel is sealed off by way of a liner and a radial sealing ring, both sealing elements co-operating with the hub. It is disadvantageous in this system that a high axial accuracy between the rotary system and the housing of the fluid feed device is necessary. This mode of construction is not suitable for arrangements which have cumulative tolerances of different kinds and axial inaccuracies.

Rotary two-channel fluid feed devices are also known, in which the first and the second feed channel are each surrounded by a rotating liner and sealed off by axial sealing discs of graphite (sliding ring seals). The annular members or housings of these devices are mounted in ball bearings on the outer liner and retained in compensating manner by way of flexible hoses of the pressure connections. This is possible due to the small frictional moments in the precise construction of the device; cf. Catalogue 825 D (1986 issue) of the firm of Deublin Company, North Brooks Illinois, USA, page 33.

The mounting of a rotary fluid feed device by way of flexible hoses is not desirable in closed housings for a hydraulic system to be fed by way of two channels. It is known for single-channel feed 1 devices to have axially tightened ball sealing elements with transverse bore, which are preferably mounted eccentrically; cf. DD-PS 723 144, and o + p: M1hydraulik und pneumatik 2C, (1985), No. 7, page 553. This arrangement is capable of compensating for axial displacement between feed and rotary system, but it must include a force-locking axial tightening.

There is thus a need for a fluid feed device which can be small in size, can compensate for radial and axial tolerances resulting from production and/or assembly, and which has fluid feeds which can be fast with a housing.

According to the present invention there is provided a fluid feed device comprising a rotary hub provided with first and second fluid feed passages for the feed of fluid respectively to first and second pressure chambers, a stationary annular member surrounding the hub and provided with two spaced-apart first projections extending in a first direction and with first and second fluid transfer ducts respectively extending in the two first projections and respectively communicating with the first and second feed passages, an end member arranged adjacent to the annular member and provided with two spaced-apart second projections extending in a second direction opposite to the first direction and with first and second inlet ducts respectively extending in the two second projections, and a coupling member provided with four slots respectively slidably receiving the four projections and with a first connecting duct communicating with the first inlet duct and first transfer duct at the walls of the slots receiving the associated projections and at overlying faces of those projections and a second connecting duct communicating with the second inlet duct and second 3 transfer duct at the walls of the slots receiving the associated projections and at overlying faces of those projections.

In a preferred embodiment, a preferably central feed passage in the hub opens into a first pressure space and a further feed passage is or parallel further feed channels are arranged around the central feed passage channel and serves or serve for feed to a second pressure space. The central feed passages is supplied by way of bores and annular grooves in the hub and in the non-rotating member, which surrounds the hub, by means of the transfer ducts in this annular lo member. The end member, for example a substantially coaxial cover arranged in axial proximity of the annular member, and the annular member each have a respective pair of claws, which are each oriented towards the other and are disposed in slidable engagement in a crossslotted sheave. A respective one of the duct arrangements opens out in each of the claws, wherein these duct arrangements are connected by means of connecting ducts which open out in slot faces of the sheave, which are covered by the claws. Such a feed device may be capable of compensating for axial displacement and assembly and component tolerances. Sealing of the duct transitions in the sheave relative to the claws may be advantageously achieved if the transitions are surrounded by resilient sealing means, preferably prestressed seals, in the slots.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional view of the fluid feed device embodying the invention, the section in part - 4 being in a different plane which runs through a fluid inlet duct; Fig. 2 is an end view of the device; Fig. 3 is a cross-section along the line A-A of Fig. 1; and Fig. 4 is an end view of another fluid feed device embodying the invention, with an electromagnetic routing valve arranged in a cover of the device.

Referring now to the drawings, there is shown in Figs. 1 to 3 a fluid feed device in the form of a hydraulic injection adjuster which is mounted on the camshaft of an injection pump and driven from the auxiliary drive of an internal combustion engine, pressure medium being fed in two channels by way of a hub 2 of the device. A central feed bore or channel 3, and spaced-apart feed bores or channels 4 radially spaced from and parallel to this, in the hub 2 respectively feed an inner pressure chamber 5 and outer pressure chambers 6 of a rotary system 1. The hub 2 is surrounded by and is slidable in a stationary annular member 7. One channel arrangement for the feed channel 3 opens out in one claw 10 of the annular member 7, by way of channels 31 in the hub, oppositely disposed annular grooves 32 at adjacent surface portions of the hub and the annular member, and channels 33 and 34 in the annular member. In similar manner, another channel arrangement for the parallel feed channels 4 opens out in another claw 10 of the annular member 7, by way of a channel 41, annular grooves 42, and channels 43 and 44 in the annular member.

A cover 8, in which a housing 9 surrounding the system 1 is mounted, also has two claws 11. The claws 10 and 11 of the annular member 7 and the cover 8, respectively, engage in opposed orientation axially into slots in a cross-slotted sheave 12, the claws of each of the member 7 and the cover 8 being disposed substantially diametrically opposite each other and the four slots in the sheave being disposed at angular spacings of substantially 90. Arranged between neighbouring cross- slots are connecting channels 35 and 45, which each open out in the region of the channels 34, 36 or 44, 46 of the claws 10 and 11, respect ively (see Fig. 3).

A communication between connections 38 and 48 of the cover 8 is provided in the cover by way of channels 37 and 47.

Thus, by virtue of the described channel arrangements, the inner pressure chamber 5 is fed from the connection 38 and the outer pressure chambers 6 from the connection 48. Arranged in recessed manner around the channels 34 and 44, or 36 and 46, respectively, are central resilient sealing rings 13, which lie under bias against the adjoining slot faces and surround the channels 35 and 45 opening out therein.

In departure from the two-duct connection shown in Fig. 2, the device of Fig. 4 has an electromagnetically controlled routing valve flanged onto the cover 8, connected by only one pressure medium connect- ion and oil return control directly into the housing 9. An arrangement of that kind entails not only constructional advantages, but also favourably influences the dynamics of the system.

The embodiment hereinbefore described may have the advantage that the axial and radial displacement between the pressure medium ducts, fast with the housing, in the cover and the rotary system can be compensated for and that the pressure medium is fed to the rotary system exclusively in channels in fixed components.

Claims

- 6 CLAIMS

1 A fluid feed device comprising a rotary hub provided with first and second fluid feed passages for the feed of fluid respectively to first and second pressure chambers, a stationary annular member surrounds ing the hub and provided with two spaced-apart first projections extending in a first direction and with.first and second fluid transfer ducts respectively extending in the two first projections and respectively communicating with the first and second feed passages, an end member arranged adjacent to the annular member and provided with two spacedapart second projections extending in a second direction opposite to the first direction and with first and second inlet ducts respectively extending in the two second projections, and a coupling member provided with four slots respectively slidably receiving the four projections and with a first connecting duct communicating with the first inlet duct and first transfer duct at the walls of the slots receiving the associated projections and at overlying faces of those projections and a second connecting duct communicating with the second inlet duct and second transfer duct at the walls of the slots receiving the associated projections and at overlying faces of those projections.

2. A device as claimed in claim 1, wherein the first feed passage comprises an axial bore in the hub and the second feed passage comprises at least one bore disposed in the hub at a radial spacing from the axial bore.

3. A device as claimed in claim 2, wherein the second feed passage comprises a plurality of parallel bores disposed in the hub at a radial spacing from and at spacings around the axial bore.

4. A device as claimed in any one of the preceding claims, wherein the feed passages and transfer ducts comprise annular channels at adjacent surface portions of the hub and the annular member.

5. A device as claimed in any one of the preceding claims, wherein the two first projections are arranged substantially diametrically opposite each other and the two second projections are arranged substantially diametrically opposite each other, the four slots being disposed at angular spacings of substantially 90.

6. A device as claimed in any one of the preceding claims, comprising resilient sealing means arranged at the points of communication of the connecting ducts with the inlet ducts and transfer ducts.

7. A fluid feed device substantially as hereinbefore described with reference to the accompanying drawings.

Published 1989 at The Patent Office, StateHouse, 667=7=7--7:- 171 HighHolburn, London YIr,1R4TP.FLuther copies maybe obtainedfrom The Patent Office. Sales Branch, St Mary Cray, Orpingtori, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent, Con. 1187