Workpiece-shaping tool assembly

Abstract

A workpiece-shaping tool assembly has a drive shaft having an outer end centered on and rotatable about an axis and a tool fittable with the end of the drive shaft. A torque coupling is formed by shaft splines formed on the drive shaft and tool splines formed on the tool, complementary to the shaft splines, and interfitting with the shaft splines. A radial-force coupling is formed by an inner cylindrical shaft surface formed on the shaft axially offset from the shaft splines and centered on the axis and a respective inner cylindrical tool surface formed on the tool offset from the tool splines, centered on the axis, and radially juxtaposed and engageable with the inner shaft surface.

Claims

1. A workpiece-shaping tool assembly, the assembly comprising: a drive shaft having an outer end centered on and rotatable about an axis; a tool body fittable with the end of the drive shaft; a ring shrink-fitted in the end of the tool body; a torque coupling formed by shaft splines formed axially inward of the ring on the drive shaft and tool splines formed on the tool body, complementary to the shaft splines, and interfitting radially with the shaft splines; a radial-force coupling formed by axially spaced inner and outer cylindrical shaft surfaces on the drive shaft, axially flanking the torque coupling, and centered on the axis and complementary respective axially spaced inner and outer cylindrical tool surfaces respectively formed on the tool body and ring, axially flanking the torque coupling, centered on the axis, and radially juxtaposed and bearing radially directly on the respective inner and outer shaft surfaces; and a tension rod having an inner end threadedly received in the shaft axially inward of the inner and outer shaft and tool surfaces and an outer end bearing axially on an annular end face of the ring and through the ring on the tool body.

2. The shaping assembly defined in claim 1, wherein the cylindrical inner and outer tool surfaces are directed radially inward and the cylindrical inner and outer shaft surfaces are directed radially outward.

3. The shaping assembly defined in claim 1, wherein the tool splines are of smaller inside diameter than the inner shaft surface.

4. The shaping assembly defined in claim 1, wherein the tool body is formed with a bore in which the inner tool surface and the tool splines are formed and with a counterbore at an outer end of the bore and in which the ring formed with the outer tool surface is fitted.

5. The shaping assembly defined in claim 4 wherein the bore and counter bore form an axially outwardly directed annular shoulder face against which the ring bears axially inward.

6. The shaping assembly defined in claim 1, wherein the outer end of the tension rod is formed as a radially projecting flange formed with an annular array of axially throughgoing threaded bores, the assembly further comprising: respective screws threaded in the throughgoing bores and bearing axially on the ring.

7. The shaping assembly defined in claim 6, wherein the shaft is formed with an axially outwardly open bore in which is formed inward of the splines a screwthread threadedly engaged with the tension rod, the screws bearing axially inward on the ring.

8. The shaping assembly defined in claim 1, wherein the annular end face of the ring is centered on the axis and the tension rod extends along and is centered on the axis.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing whose sole FIGURE is a partly axially sectional side view of the tool assembly of this invention.

SPECIFIC DESCRIPTION OF THE INVENTION

(2) As seen in the drawing, an assembly 1 for shaping an unillustrated workpiece or rolled product comprises a steel drive shaft 2 that is centered on and that can rotate about an axis a and that is formed with an axially centered and outwardly open bore 20. A tool 3 in the form of a roll is attached to the axial outer end of drive shaft 2. The attachment is designed to be releasable, thereby allowing the tool 3, when worn, to be removed from the drive shaft 2 and replaced by a different one.

(3) The drive shaft 2 and tool 3 are designed so that torque can be transmitted from the drive shaft 2 to the tool 3, and radial and axial forces can be also be transmitted relative to the axis a. The couplings are designed so that torque about the axis a and radial forces can be transmitted between the drive shaft 2 and the tool 3, and also so that axial forces can be transmitted between the drive shaft 2 and the tool 3, in each case separately and isolated from each other.

(4) Specifically, the shaft 2 and tool 3 have a keyed torque-transmitting spline coupling 4 that here extends along an inner axial section 5 whose length is sufficient to enable it to reliably transmit the required torque. According to the invention the spline coupling is completely relieved here of radial and axial forces.

(5) Radial forces are transmitted through an inner axial section 6 and an outer axial section 9. The respective cylindrical surfaces in these two sections 6 and 9 are provided on the shaft 2 and also on the tool 3 that are toleranced to each other so as to provide a predefined transmission of radial forces.

(6) The shaft 2 thus has in the inner axial section 6 of the bore 20 an outwardly facing cylindrical surface 7 that interacts with a complementary inwardly facing cylindrical surface 8 of the tool 3. In the outer axial section 9 of the bore 20, however, the shaft 2 has an outwardly directed cylindrical surface 10 that interacts with a complementary inwardly directed surface 11 of the tool 3.

(7) It is evident in the outer axial section 9 that the outer but inwardly directed cylindrical surface 11 is formed on a ring 12 that is inserted into a cylindrical counterbore 13 in the main body of the roll 2, and that bears axially inward on a shoulder 19 formed at the inner end of the counterbore 13. This ring 12 is secured in the cylindrical counterbore 13 by a thermal shrinking process, that is it is made to be an exact and very tight fit, then is chilled and fitted to the counterbore 13 against the shoulder 19 so that when it warms up and expands it is locked in the body of the tool 3. Thus the ring 12 is not unitary with the main body of the tool 3, but is integral therewith as a result of the tight surface contact.

(8) The transmission of axial forces is effected exclusively and in a manner isolated from the transmission of torque and from the transmission of radial forces by a tension rod 15 that is secured in the bore 20 inward of the region 6 by inner and outer complementary screwthreads 14 of the shaft 2 and the rod 15. This tension rod 15 has at its outer end an integral flange disk 16 that bears on an end face 17 of the tool 3. This end face 17 is actually the planar and annular outer end face of the ring 12.

(9) In order to provide backlash-free axial attachment of the tool 3 on the shaft 2, the flange 16 is formed around its circumference with an annular array of axially extending and angularly equispaced threaded holes into which headless grub screws 18 are engaged. These screws 18 are tightened until their one axial ends contact the end face of ring 12 with sufficient initial tension, so that in practice the flange 16 does not bear directly on the end face 17, but via the screws 18 thereon.

(10) An inner radius r.sub.1 of the splines of the body 3 in the region 5 is smaller than the radius r.sub.2 of the cylindrical inner surfaces 7 and 8 in the inner section 6.

(11) Radius r.sub.1 of the spline coupling 4 is, however, greater than a radius r.sub.3 of the cylindrical outer surfaces 10, 11 in outer section 9. Thus r.sub.3<r.sub.1, r.sub.2.

(12) The shrinking-in of the ring 12 provides a trouble-free approach for machining the teeth of the spline coupling 4 in the tool 3. Specifically, this profile can be produced, for example by milling and/or grinding, before fitting in the shrink-fit ring 12, since without the ring 12 clearance is provided for the tool required for this purpose to pass axially through the roll tool 3. It is only after this that ring 12 is shrunk and inserted and the tool 3 is thereby completed.

(13) All of the surfaces that are under load when the assembly 1 is operating can be coated, thereby ensuring an extended service life. A lubricant can be introduced between the regions 6 and 9 and along the splines 4 to allow the spline coupling to operate optimally.