GB2197809A

GB2197809A - Mobile arrangement for the grinding of holes

Info

Publication number: GB2197809A
Application number: GB08725340A
Authority: GB
Inventors: Milos Flaska
Original assignee: Skoda kp
Current assignee: Skoda kp
Priority date: 1986-10-30
Filing date: 1987-10-29
Publication date: 1988-06-02
Also published as: CS259116B1; DE3735624A1; GB8725340D0; CH674171A5; CS783586A1

Description

2197809 MOBILE ARRANGEMENT FOR THE GRINDING OF HOLES The invention relates

to a constructional embodiment of a mobile arrangement for grinding the 1 internal surfaces of relatively long holes, for!n rotors of turb instance of holes-made i Mes for large output, in tubes and the like.

Rotors of turbines for large output are provided with long holes serving for revision, which holes after prolonged operation become clogged with sediments. Sim-ilarly tubes for different industrial devices become in their interior rusty or clogged, or some fu..-ict-Lo-.,ia"L coating of their internal surfaces has to be renewed. In similar cases grinding devices are frequently used, clamped in machine tools, for - -L ills and the ce lathes, boring machines, dri in s t an L like, in order to resto.-e them. The part of the machine with holes to be cleaned has to be conveyed to said machine too-L'., clamped, adjusted and after operation removed and transferred back to its prope-r place. This manipulation requires frequently substantial -costs and working power and maintenance of safety conditions. It is frequently rather d2LffL--ult to grind such a hole due to its substantial -Length or in case of an unfavourable ratio of the 1 length to the required diameter of the grinding means, the shaft could start wobbling which could lead to inaccuracies and even to a damage of the worked hole.

The aim of this invention is to substantially avoid the me-ntioned drawbacks by providing a mobile arrangement for grinding holes comprising a shaft with a drive, a carrier, a joint, grL-.id-"Lng means, a thrust stabiliser and feeding elements, in which according to this invention a. carrier is situated on a shaft driven by a driving 2 1 5 uniA, whi Le behind its sleeve a transition element nating in a joint is fixed 'n order to terminate termi L - the shaft; a grinding device is f.-"Lxed to said j oint, with a thrust stabiliser shifted and fixed on its neck. According to a further development the carrier is situated on the shaft by its sleeve provided with bearings and a sleeve wih at least three contact elements is fixed on the external surface of the ca-lri.er. According to another feature of this invention the transition element is fixed by its coupling p-rovided with supply of its driving medium to the shaft end; a joint is connected to said connected to the coupling which joint is also grLndJL.-ig mea-ns. A branch Is connected to said suppIv of the d---,v2L..--ig medium, terminatIng in the thrust stabilizer. The thrust stabilizer comprises a guJLdL.-,g element and a thrust element is situated on thp neck of the grinding device by 2Lts guiding ring and thrust ring which are clamped on said neck; a CY'L-.--ider- with an inserted pIston, the head of which is provided with a thrust gui-ding and with a nut car, d gu Lnto which a slide is be fixed to sa i d i n g r - n g, J -Inserted. The driv.Lng unit can be arranged on a -a--Roe, the wheels of wh2ch travel on a bed which - -L W -L can be removably fixed to the worked part.

One embodiment of a mobile arrangement I th _Js- inven t io -,i now be d escr ibed, by a c -- 0 r d 1 -1 E-S -.) way of example, wj-th reference to the accompanying C> diagrammatic drawings, -in which:

Figure 1 shows a general view of the arrangement; and Figure 2 is a partial sect'Lo..-i at the thrust element when viewed from the grinding disk.

T h e m ob.11.1 e a r -, an g e m e.n t f o r g -- in d in, g ho 1 e s I t 9 arranged on a comprises an. electric drive u-iL 1 1 i 3 carriage 90, having a wheel on each side of the web Of a bed 7 having the shape of an I-beam. The wheels travel along the upper surface of its lower flange. The bed 7 is fixed to a beam 8 by retaining screws 80 and by a clamp 81, through which pass a screw 801 of the beam 8 and a screw 810 of the clamp 81, the latter being screwed in an internal nut 820 formed as a reduction between the part to be ground and the screw 810 of the clamp 81. The part to be ground is in the present case a turbine rotor, the revision openings of which are going to be ground by the mobile arrangement according to the invention.

The drive unit 9 is connected to a hollow shaft 1 on which is close to the driving unit 9 slid a pressure chamber 10 to which is supplied pressurized air, as in the present case a pneumatic grinding tool 5 is used. A feeding mechanism 2 is situated on the shaft 1 downstream of the pressure chamber 10, the stationary part of which is fixed to the bed 7. This feeding mechanism 2 is formed as a steady for guiding the shaft 1 and simultaneously secures a continuously adjustable feeding of the shaft 1 together with the drive unit 9 and thus also of the grinding tool 5. The end of the shaft 1 is provided with a carrier 3 and with a coupling 40 of a transition element 4.

The carrier 3 comprises a easing 32 containing bearings 30, a sleeve 31, situated externally on the casing 32, and three feelers 33. The bearings 30 contact the shaft 1 and secure the rotating movement of the shaft 1 and the stability of all components of the carrier 3. The carrier 3 simultaneously centres the shaft 1 in the worked hole.

The coupling 40 secures the transmission of 1 4 -L the torque from the shaft 1 to a joint 41 of the transition element 4. The joint 41 secures the of the grind-11119 tool 5 with the shaft 1 and thus transmits also the rotating movement of the shaft 1 to the grinding disk 50.

Pressurized air enters from the pressure chamber 10 through openings (not shown) in the wall of the shaft 1 into the hollow passing through the shaft 1, and flows up to its end, to which a branch 42 is connected. Pressur,Lzed air passes through this branch 42 i-nto a cylinder 611 of a thrust element 61 of a thrust stabilizer 6. The thrust stabilizer 6 comprises two rings 605, 650, one of wh-.L--h LS Lng element indicated in the drawing as part of a guidL 60 a-nd the second as part of the thrust eleme-nt 61.

Both said elements 60, 61 are situated on and are fixed to the neck 51 of the grinding to31 5, namely the guidIng element 60 by its guid A-ng ring 605 and the thrust element 61 by its thrust ring 650. A nut 601 is fixed on the guiding ring 605, into WhLch a guide 600 is screwed in, Drovided with a slide 603 which slides along the internal surface of the ground hole, which guide 600 is secured by a safety nut 602.

The cylinder 611 is fixed to the thrust ring 650. In the cylinder 611 is a piston 612 provided with a thrust guLde 610. The piston 612 is sealed in the 11 - ' U - - - 1. U. - - - - The mobile arrangement for the grinding of holes according to this invention is fixed to the part to be ground such that first the internal nut 820 is screwed into a threaded opening which in the present case is already present in the turbine rotor for other purposes, or wh21--ch has to be made in, other cases. The bed 7 is thereafter placed by Lts beam 8 against the part to be ground and fixed to it by the 1 1 clamp 81 by a screw 801 of the beam 8 and the whole is fastened by the screw 810 of the clamp 81. The bed 7 is thereafter supported, initially adjusted and the carriage 90 with the mobile arrangement is slid on the bed 7. The bed 7 is then provided with a stop 70 and is finally adjusted so that the shaft 1 is coaxial with the hole to be ground. The feelers 33 are thereafter adjusted to be in contact with the inner surface of the hole and the mobile arrangement Ls caused to leave the hole in order to enable the adjustment of the thrust stabilizer 6. The adjustment is accomplished so that a suitable angle ais provided between the axis of the grinding d.-"Lsk 50 and the guiding element 60, the guide 600 of which is shifted so that the slide 603 is 21n contact with the hole to be ground. The axis of the thrust element 6 ls thereafter adjusted through an angle B from the axis of the guJLd.'L.--ig element 60.

It is advantageous to move the grinding disk 50 with the corresponding part of the mobile arrangement up to the end of the hole to be ground and adjust the feeding mechanism 2 for a suitable d isplacement. The driving unit 9 is then Switched on and P-. essu--4Lzed air, JIL.e. the driving medium, is allowed to enter the pressure chamber 10 and through individual parts up to the air-operated grinding tool 5. When the pressure of the driving medium reaches a certain value, it passes, by way of the branch 42, into the cylinder 611 of the thrust element 61, forces out the piston 612 and the thrust stabilizer 6 and the grinding disk-50 are pressed against the internal surface of the hole. The magnitude of the thrust and the stability of the system are determ-ined by the magnitude of the angles cf-, B of the parts of the thrust stabilizer 6. Starting operatio-n of the 6 gr Lnd ing d Isk 50 from the more d 2Lsta..,,t end of the hole has the advantage that chips and grin-ding grains, separated 2Lri the course of g- --.LridJL-,.g are thrown out by the expelled air of the drive of the grinding tool 5 beyond the parts in contact with the surface of the ground hole.

The mobile arrangement for the grinding of holes can be used either independently or in connection with an automatic cycle in case limit sw. itches are provided on the bed 7, whIch can Lnfluence either the driving unit 9 or the feeding mechanism 2 as regards the feeding direction. Other p3ssJLbi-li--ies of applLcation of the mob.LLe arrangement a.-cord'L,-ig to this -Lnventir, is its operation wthout a driving uri2L-t 9 and a bed 7, when the shaft 1 is fixed to a shaft of a machi.ne tool, for instance of a horizontal b,)rLng ma-hine, it Is also possible to clamp the shaft 1 to the cone of a headsto--k of a lathe o-- to a shaft of a deep boring machi-ne and finish the surface of a bored hole.

7

Claims

Mobile arrangement for the grinding of J holes, COMP-LLSing a shaft, a drive unit, a carrier, a joint, a grinding tool, a thrust stabilizer, a car-,Lage and power supply elements, wherein the shaft Ls driven by the drive unit and the carrier is situated thereon, the carrier - including a casing downstream of which a transition unit is fixed to the end of the shaft, the transition unit terminating in a joinfto which a grinding tool-is attached, which has a -neck on which a thrust stabilizer-is situated and fixed.
2. Mobile arrangement according to Claim 1 wherein the carrier is slid on the shaft by its casLng which is provided with bearings and on its " suexternal. Lface is fixed a sleeve provided with at I least three feelers.
3. Mobile arrangement according to Claim I or 2 wherein the transition unit is fixed to the end of of the shaft by a coupling provided with a supply condui.t for the driving medium, and to the coupling Ls connected a joint which is further connected to the grinding tool and a branch terminating in a thrust stabilizer is connected to said supply conduit.

Mobile arrangement according to Claim 1, 2 or.3 wherein the thrust stabilizer, comprising a thrust element and a guiding element, is slid on the neck of the grinding tool by a guiding ring and a thrust ring which are clamped on said neck of the grinding tool, a cylinder containing a piston being fixed to the thrust ring, the head of the piston being provided with a thrust guide, while a nut into. which a slide is inserted, is fixed to the guiding r Lng.

R 5. Mobile arrangement accordi.ng to any one of Claims 1 to 4 wherein the driving unit is supported by the carriage, the wheels of which travel on a bed which is in use removably fixed to the worked part. 6. Mobile arrangement for the grinding of holes constructed, arranged and adapted to operate substantially as herein described with reference to, and as shown in, the accompanying drawings. 7.

m An object comprising a hole ground by a obile arrangement according to any one of Claims 1 -L -L 1 -L to 6.