IL114232A - Grinding device for the processing of building elements - Google Patents

Description

A GRINDING DEVICE FOR THE PROCESSING OF BUILLDING ELEMENTS MTU MOTOREN- UND TURBINEN-UNION MUNCHEN GMBH The present invention relates to a grinding device for the processing of building elements, in which device at least one grinding disc is mounted on a driving shaft, said grinding disc being cooled by a cooling fluid in the course of the processing of the building element and with continuous buffing of its grinding plates.

Grinding devices of the above kind are used, for example, in order to process building elements of turbo machines which are very often formed in complicated manner, e.g. blades, whose feet profiles or joined or thrust rings, are to be processed finely to the basic size. In this process, high rotation velocities and cutting capacities are required and as a result thereof high temperature loads are created at the grinding disc, at its granular grinding planes and at the building element being processed. Thus, there may be caused undesired changes of the building element surfaces (cracks, defects) or building element tensions. There also may not be excluded the premature wearing out, or even breakage, of the grinding disc.

The above risks cannot be sufficiently avoided by water cooling by jet-like feeding pipes which point locally to the grinding disc. This is also due to the fact that in a device of the above kind, substantially two "temperature sources" and their risks are to be controlled. One "temperature source" is based on the buffing of the grinding disc by a diamond roller present on one side of the disc, which roller is driven independently supported by a machine. The other "temperature source" results from the building element grinding process itself mainly on the side of the grinding disc which is away from the side adjoining the diamond roller. Thus, in the above device very complicated and expensive steps are required regarding the cooling effectiveness and the requirements of the cooling liquids.

Less complicated and expensive is another known concept (DE-PS3804781) , which is provided with a covering hood on the grinding disc, from which a lubricating cooling fluid is forwarded to the working area left free by the hood.

The other known concept is provided with a pot-like grinding disc which is provided with cooling notches being part of the grinding planes which extend obliquely to the rotation direction, over which notches the cooling oil is forwarded to the grinding planes. These cooling notches result in an interruption and reduction of in the effectiveness of the grinding plane. Moreover, in said concept the main cooling is restricted to the coating zone of the grinding disc which in any case is temperature stable. A few channels which are distributed over the circumference of the edge in which the cooling oil is forwarded to the cooling notches cannot give a significant contribution to achieve an equal or planned cooling of the circumference of the grinding disc which is locally high temperature loaded, and thus to achieve an equal or planned reduced temperature process.

The known concept is provided with feeding pipes for the cooling oil which terminate substantially tangential in the rotating direction of the covering hood and at the side of the pot edge. The cooling oil which has flown to a collecting space located at the bottom of the top-like disc, should be forwarded by way of the centrifugal power, depending on the number of the rotations, to the channels.

The known concept does not give any suggestions of an assembly friendly and a building system which may be universally operated and employed. Thus, in this case the dismantling of the grinding disc is probably only possible when, first of all, the entire covering hood is removed together with the oil conduits.

The object of the present invention is therefore to construct a device, as hereinbefore defined, which enables an assembly-friendly building process, taking into consideration the formation of the cooling means conduit, and obtains optimal grinding results with high cutting capacities, with simultaneous control of the temperature loads .

The present invention thus consists in a device, as hereinbefore defined, characterized in that the grinding disc is formed ring-like, and provided with cooling channels which extend from the inner to the outer wall circumference of the disc and are distributed over the disc circumference ; the grinding disc is anchored in a fixed rotatable manner between axially detachable spacer rings at a disc carrier, which carrier is mounted axially detachable on a machine shaft; several cooling channels of the grinding disc being in contact radially inside with the channel conduits supplying the cooling fluid; channel conduits being formed between longitudinal notches at the outer circumference of the disc carrier and at the inner circumference planes of the grinding disc; and the channel conduits being connected to the feeding pipes for the cooling fluid over a ring sealing, the ring sealing being web-like formed between the disc carrier and a machine housing.

The device according to the present invention is assembly- and maintenance-friendly. After the required axial positioning of the spacer rings and of one or more grinding disc, longitudinal notches are covered from the outside so that substantially axial channel conduits are formed. Said channel conduits are in connection with a "bundle" of radial cooling channels in the grinding disc. By axial mounting of the conduit carrier on the machine shaft - e.g. in reciprocal conical corresponding plane uptake- there is simultaneously provided the web-like corresponding ring sealing and thus provided a multiple cooling means supply over the housing stable part of the ring sealing. A relatively high amount of cooling means can be provided, which is particularly adapted to a multiple number of grinding discs and which further takes into consideration the above-mentioned "temperature sources" (grinding roller/building elements processing) .

Over the cooling channels arranged at the required reciprocal distance, an optimal cooling of at least one grinding disc can be, in accordance with the present invention, obtained completely over the circumference. The cooling channels are arranged in such a manner that they enclose the complete high temperature loaded outer circumference plane of the disc in the building element cooling. The number and the cross-sections of the cooling channels can be adapted to the requirements of the cooling and of the cooling fluid. By relative reciprocal distance positioning of the cooling channels, and thus of the corresponding outlet openings - for each grinding plane in axial and circumference direction - the effective grinding plane together with the opposite plane to be processed can be rinsed equally or partly, in accordance with the requirements, by lubricating cooling fluids.

The device according to the present invention is suitable for the grinding of highly complicated formed turbo machine building elements, e.g. blades, their foot- or head-plates, ring sealings or carrier and support rings. There may be used for locally different forms or profiles of building elements, contours of grinding discs in one, or preferably simultaneously multiple, disc arrangements adapted to said forms or profiles.

Hereinafter are described several advantageous embodiments of the device according to the present invention: 1. grinding device in which one or more grinding discs together with spacer rings, being axially fixed placeable at a radial circumference flange of the disc carrier, the rotatable part of the ring sealing being axially detach- ably fixed at said circumference flange; 2. grinding device in which the ring sealing is formed at the rotating and fixedly standing sealing part between axial webs which radially overlap at a distance; 3. grinding device being provided with axial channel conduits being equally distributed over the circumference, each of said conduits being in connection with several cooling channels of a grinding disc, and also being in connection, over at least one axial opening in the radial circumference flange, with a ring room of the ring sealing; 4. a grinding device in which the rotating part of the ring sealing, together with the related axial webs, is formed at a ring plate, which ring plate is screwed at the height of the lateral outer front plane of the circumference flange with a drum-like disc carrier and is provided with openings which correspond with the openings of the circumference flange; 5. a grinding device in which the fixed part of the ring sealing consists of a substantially radially outer and radially inner ring-like insert part, the radial inner insert part being screwed with the front part of the machine housing and the radial outer insert part forming radial supply lines for the cooling fluid into the ring sealing and being screwed axially with the radially inner insert part; a grinding device in which the ring room of the ring sealing being substantially formed between two axially webs, laying radially one above another at a distance, of an U-like ring being open at one side, said ring being closed between two opposite circumference planes of the radial outer and radial inner ring-like insert parts and being screwed axially into said inner insert part, said ring forming at the radially outer part local fluid connections of the radial supply lines with the ring room; a grinding device in which one or more ring-like grinding discs and spacer rings are anchored rotatably stable at a ring-like housing cover which is screwed in a frontal axial manner with the grinding carrier or screwed thereon, means being provided for the cooling fluid sealing either between opposite axial sitting planes of the discs and rings or between a ring and the cover; a grinding device in which the cooling channels of the appropriate grinding disc terminate at the outside of sections of the grinding planes angled relatively one to another; a grinding device in which the cooling channels in the grinding disc together with its outlet openings are equally distributed over the circumference in equally distanced rows; a grinding device in which the cooling channels are formed by borings; 11. a grinding device in which several rows of cooling channels together with their outlet openings are arranged over the disc circumference in a periodically changing distance; and 12. a grinding device in which the radial outer opening middle points of the cooling channels coincide with straight envelope lines, which envelope lines are, in relation to the disc- and longitudinal axis, continuously equally bevelled and distanced equally in the circumference direction.

The present invention will now be illustrated with reference to the accompanying drawings, without being limited by same. In said drawings: Fig. 1 shows the arrangement of the machinery as well as the essential basic construction of the grinding device partly in lateral- and partly in cut axial cross-section; Fig. 2 shows a radial upper and locally cut section of the device derived from the axial cross-section of Fig.l, in particular in pointing out details of the ring sealing together with related connecting means to the channel conduits and to the cooling channels connection to said channel conduits; Fig. 3 shows a lower and locally cut section of the device derived from the axial cross-section of Fig. 1, wherein in particular the cooling fluid supply of the ring sealing of the radial outer housing side part together with a conduit connecting part is pointed out; Fig. 4 shows a local disc cross-section with a top view on the inner circumference plane extending in the direction of the disc axis of said disc section with the corresponding arrangement of the cooling channels streaming thereto; Fig. 5 shows a top view of the disc section according to Fig. 4 pointing out the outlet openings of the cooling channels which are arranged at the outer circumference; Fig. 6 shows the top view of a section drawn cut on both sides in relation to the disc or machine axis of a grinding disc according to Fig. 2, and an arrangement of the cooling channels changed in relation to Figs. 4 and 5; Fig. 7 shows an axial cross-section of a diamond grinding roller shown in a side view in relation to an outwards cut ring form intermediate member and shown also in the processing position in relation to a radial outer disc section; and Fig. 8 shows a locally cut lower section of a building element as shown in Fig. 7, in point side processing position of a building element, in particular a blade covered band.

Fig. 1 illustrates the main basic features of the grinding device. Two grinding discs 2,3 are, e.g. mounted on driving shaft 1. Said grinding discs 2,3 are mainly manufactured from "Corundum" and may be cooled in the course of the processing of the building elements, with continuous buffing of its grinding planes, by a cooling fluid. The cooling fluid may be, e.g. cooling water, or a lubricating cooling fluid such as a cooling oil. The working material "CORUNDUM" may be, for example a so-called "Electrocorund-um(AL203)" or a sintered ceramic material, e.g. sintered corundum (SG) . Grinding discs 2,3 are formed ring-like and are provided with cooling channels K, K' . Said cooling channels K, K' extend substantially radially from the inner to the outer wall circumference of the disc and are distributed along the disc circumference. Grinding discs 2,3 are anchored rotatably fixed between axially detachable spacer rings 4,5,6 at drum-like disc carrier 7. Said disc carrier 7 is located axially detachable on machine shaft 1. Several cooling channels Κ,Κ' of grinding discs 2,3 are radially inside in connection with channels conduit 8 supplying the cooling fluid. Channel conduits 8 are formed between longitudinal notches 9 at the outer circumference of disc carrier 7 and at the inner circumference planes of grinding discs 2,3 and spacer rings 4,5,6. Channel conduits 8 are connected to web-like corresponding axial ring sealing 10 (see also Figs. 2 and 3). A fixed part of ring sealing 10 is detachably connected with shaft co-axial housing section 11 of the machine and is provided with several supply conduits 12 for the cooling fluid distributed over the circumference thereof. This is performed in the form of radial passage openings which are in connection with a screwed off conduit connection L (Fig. 3) .

Both grinding discs 2,3 are together with spacer rings 4,5,6 axially fixed at radial circumference flange 13 of disc carrier 7. The rotating part (ring plate 16 - Figs. 2 and 3) of ring sealing 10 can be axially detachably be fixed at circumference flange 13.

Essentially, ring sealing 10 is formed at the rotating and fixed sealing part between axial webs S,S' (Figs. 2 and 3) which overlap radially at a distance.

Channel conduits 8 of the grinding device (Fig. 1) , which substantially extend axially, are distributed in equal distances over the circumference. Each channel conduit 8 is in connection with several cooling channels Κ,Κ' of both grinding discs 2,3. Moreover, each channel conduit 8 is in connection, over at least one axial opening 14 (Fig. 2) in radial circumference flange 13, with ring room 15 of ring sealing 10.

The rotating part of ring sealing 10 together with the related axial webs S (Fig. 2) are formed at ring plate 16. Ring plate 16 is axially screwed with drum like disc carrier 17 at the height of the lateral outer front plane of circumference flange 13 (position SR) and is provided with openings 17 which correspond to axial openings 14 of circumference flange 13.

The fixed part of ring sealing 10 (Fig. 1) consists of substantially radial outer and radial inner ring-like insert parts 18, 19 (Figs. 2 and 3). Radial insert inner part 19 is screwed with the front end of machine housing 11 (position SR' - Fig. 3) . Radial outer insert part 18 forms radial supply conduits 12 for the cooling fluid into ring sealing 10 (Fig. 3) and is screwed axially with radially inner part 19 (Fig. 2) in accordance with position SR".

In particular in accordance with Fig. 2, ring room 15 of ring sealing 10 is formed substantially between two axial webs S', laying radially one upon another at a distance, of U-like ring 20 which is open at one side. Said ring 20 is enclosed between opposite circumference planes of the radially outer and the radial inner ring-like insert parts 18,19 and screwed axially with insert part 19. At the radially outer side ring 20 forms local fluid connection of the radial supply pipes 12 with ring room 15 (Fig. 3).

According to Fig. 1 grinding discs 2,3 and spacer rings 4,5,6 are anchored rotatably stable at a ring-like housing cover 21 being screwed with disc carrier 7 or screwed upon it. Means for cooling fluid sealings are provided between either opposite axially sitting planes of the discs and the rings, or between ring 4 and cover 21. As sealing means there may be used paste-like means or rubber elastic sealing discs or the like.

In accordance with Figs. 1 and 8, cooling channels Κ,Κ' of appropriate grinding discs 2 , 3 may terminate at the outside of sections of the grinding planes angled relatively one to another.

According to Figs. 4 and 5, there are, for example, cooling channels Κ,Κ' of grinding disc 3 with their outlet openings are equally distributed over the circumference in two equally distanced rows.

Cooling channels Κ,Κ' may be formed by borings.

Several rows of cooling channels may be arranged together with their outlet openings may be arranged over the disc circumference at periodic variable distances. As can be seen in Fig. 6, the radial outer opening points of cooling channels Κ,Κ' ,Κ' ' may coincide with straight envelope lines M, which envelope lines are, in, relation to the disc- and longitudinal axis L, continuously equally bevelled and distanced equally in the circumference direction. Thus, there may be supplied in the course of the grinding process, for a given plane, relatively large amounts of cooling means.

Fig. 7 illustrates diamond grinding roller 22 in a radial outer processing position in relation to e.g. appropriate grinding disc 3. Grinding roller 22 can be in connection with further grinding disc 2 (Fig. 1) over connection- or distance ring 23.

In the example of grinding disc 3, Fig. 8 embodies a relative processing position in relation to building part B in the course of the plane processing of sealing points of a blade cover band. One realizes that radially outer part sections of cooling channel K' are guided up to the point side building part planes to be processed.

The grinding device according to the invention provides that the cooling fluid, e.g. cooling water, is forwarded via corresponding supply connections L (Fig. 3) and supply lines 2 under a given pressure and that the cooling fluid is caused to flow outside over cooling channels K, K' (Figs. 1, 4 and 5) or K', K" (Fig. 6) by the effect of the centrifugal power.

Claims (1)

1. A grinding device for the processing of building ele-ments, in which device at least one grinding disc , is mounted on a driving shaft, said grinding disc being cooled by a cooling fluid in the course of the processing of the building element and with continuous buffing of its grinding plates, characterised in that the grinding disc is formed ring-like, and provided with cooling channels which extend from the inner to the outer wall circumference of the disc and are distributed over the disc circumference; the grinding disc is anchored in a fixed rotatable manner between axially detachable spacer rings at a disc carrier, which carrier is mounted axially detachable on a machine shaft; several cooling channels of the grinding disc being in contact radially inside with the channel conduits / supplying the cooling fluid; channel conduits being formed between longitudinal notches at the outer circumference of the disc carrier and at the inner circumference planes of the grinding disc; and the channel conduits being connected to the feeding pipes for the cooling fluid over a ring sealing, the ring sealing being webrlike. formed between the disc carrier and a machine housing. A grinding device according to dlaim 1, characterized in that one or more grinding discs together with spacer rings, being axially fixed placeable at a radial circum- ference flange of the disc carrier, the rotatable part of the ring sealing being axially detachably fixed at said circumference flange. A grinding device according to claim 1 or 2, characterized in that the ring sealing is formed at the rotating and fixedly standing sealing part between axial webs which radially overlap at a distance. A grinding device according to any of claims 1 to 3 , being provided with axial channel conduits being equally distributed over the circumference, each of said conduits being in connection with several cooling channels of a grinding disc, and also being in connection, over at least one axial opening in the radial circumference flange, with a ring room of the ring sealing. A grinding device according to claim 2, characterized in that the rotating part of the ring sealing, together with the related axial webs, is formed at a ring plate, which ring plate is screwed at the height of the lateral outer front plane of the circumference flange with a drum-like disc carrier and is provided with openings which correspond with the openings of the circumference flange. A grinding device according to any of claims 1 to 5, characterized in that the fixed part of the ring sealing consists of a substantially radially outer and radially inner ring-like insert part, the radial inner insert part being screwed with the front part of the machine housing and the radial outer insert part forming radial supply lines for the cooling fluid into the ring sealing and being screwed axially with the radially inner insert part. A grinding device according to any of claims 1 to 6, characterized in that the ring room of the ring sealing being substantially formed between two axially webs, laying radially one above another at a distance, of a U-like ring being open at one side, said ring being closed between two opposite circumference planes of the radial outer and radial inner ring-like insert parts and being screwed axially into said inner insert part, said ring forming at the radially outer part local fluid connections of the radial supply lines with the ring room. A grinding device according to claim 1, characterized in that one or more ring-like grinding discs and spacer rings are anchored rotatably stable at a ring-like housing cover which is screwed in a frontal axial manner with the grinding carrier or screwed thereon, means being provided for the cooling fluid sealing either between opposite axial sitting planes of the discs and rings or between a ring and the cover. A grinding device according to any of claims 1 to 8, characterized in that the cooling channels of the appropriate grinding disc terminate at the outside of sections of the grinding planes angles relatively one to another . A grinding device according to any of claims 1 to 9, characterized in that the cooling channels in the grinding disc together with its outlet openings are equally distributed over the circumference in equally distanced rows. A grinding device according to any of claims 1 to 10, characterized in that the cooling channels are formed by borings. A grinding device according to any of claims 1 to 11, characterized in that several rowsd of cooling channels together with their outlet openings are arranged over the disc circumference in a periodically changing distance. A grinding device according to any of claims 1 to 12, characterized in that the radial outer opening middle points of the cooling channels coincide with straight envelope lines, which envelope lines are, in relation to the disc- and longitudinal axis, continuously equally bevelled and distanced equally in the circumference direction. For the Applicant: Dr. Yitzhak Hess