Metal deforming – By extruding through orifice – By rotating impeller means
Patent
1996-07-09
1999-03-30
Hail, III, Joseph J.
Metal deforming
By extruding through orifice
By rotating impeller means
B21C 2300
Patent
active
058874739
DESCRIPTION:
BRIEF SUMMARY
This invention relates to apparatus for the forming of metals by a continuous extrusion process in which feedstock is introduced into a rotating circumferential groove to pass into a passageway formed between the groove and arcuate tooling extending into the groove.
In EP-A-0 071 490 there is described continuous extrusion apparatus utilising circumferentially grooved means rotatably mounted on a bed.
According to the present invention, there is provided a continuous extrusion apparatus utilising circumferentially grooved means rotatably mounted on a bed, wherein the circumferentially grooved means comprises a circumferentially grooved cylinder carried on bearings on the bed and end coupled to a drive shaft.
In order to exploit fully the continuous extrusion forming process, very high extrusion pressures are utilised such that very high levels of stress are generated. Hitherto to operate the process a circumferentially grooved wheel mounted on a drive shaft running in associated bearings has been utilised. However, the wheel tends to orbit relative to the shaft and to deform which may lead either to damage or early failure of the wheel assembly or leakage of feedstock material and loss of extrusion pressure due to deflection of the wheel assembly under load, or both. Where the wheel is keyed or splined to the shaft, the orbiting effect may lead to fretting at the keys or splines, again leading to possible early failure.
The invention will now be described, by way of example, with reference to the accompanying, partly diagrammatic, partially axially cross-sectioned, portion of a continuous extrusion apparatus.
As shown, a circumferentially grooved cylinder 2 is mounted in bearings 4 positioned in bushes 6 carried in a frame 8 positioned on a bed 10. The cylinder is formed with a central, circumferentially grooved, portion 12 flanked by a pair of circumferential flanges 14 and a pair of outer, end, bosses 16, 18. One end boss 16 is formed with a splined recess 20 arranged to co-act with a correspondingly splined end portion 22 of a coupling shaft 24. A retaining ring 26 bears against a shoulder 28 on the coupling shaft to retain the splined end portion 22 in the splined recess 20. The other end portion 30 of the coupling shaft is splined into an output drive 32 of a gear box 34 connected to an electric motor (not shown). In an alternative arrangement (not shown) the coupling shaft is bolted to an end face of the circumferentially grooved cylinder 2.
As shown, a pre-loading tie bolt 36 is positioned centrally of a bore 38 in the cylinder 2 from a base portion 40 of the splined recess 20 to the end boss 18 and is provided with a nut 42 co-acting with a threaded portion 44 of the tie bolt. Compressive stress is induced in the cylinder by tightening the nut 42 on the tie bolt 36 against an end face 46 of the boss 18, in order that, when the apparatus is in operation and a radial loading is applied through arcuate tooling urged into contact with the cylinder 2 over a short arc, the resultant stress loading in the cylinder 2 is nontheless maintained as compressive around the full circumference. However, it is envisaged that, in some instances, it will not be necessary to apply such a compressive pre-stressing and that fabricating the cylinder 2 as a solid integer will provide a sufficiently rigid arrangement. Whilst the fatigue life of the solid cylinder may be less than the fatigue life of a pre-loaded wheel mounted on a shaft, this is not considered to be disadvantageous overall since all the material subject to high stress levels is replaced when it becomes necessary to replace a wheel and the reduced fatigue life of the present arrangement is likely to be greater than the wear out life of a wheel arrangement.
The bearings 4 include a multiplicity of rollers 48 running in a radially outer raceway 50 mounted on the bushes 6. The rollers 48 run directly on the faces 52 on the cylinder 2, with the cylinder being located axially by positioning the rollers at the boss 16 between a shoulder 54 on the cylinder 2 and a
REFERENCES:
patent: Re18710 (1933-01-01), Dunsheath
patent: 2108529 (1938-02-01), Dunsheath
patent: 2726761 (1955-12-01), Larsen
patent: 4055979 (1977-11-01), Hunter et al.
patent: 4277968 (1981-07-01), Pardoe
patent: 4566303 (1986-01-01), McKenna
BWE Limited
Hail III Joseph J.
Tolan Ed
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