GB1601159A

GB1601159A - Method of establishing a joint between a driving shaft and a wheel-like machine member or part to revolve therewith

Info

Publication number: GB1601159A
Application number: GB25382/78A
Authority: GB
Original assignee: Punker GmbH
Current assignee: Punker GmbH
Priority date: 1977-06-02
Filing date: 1978-05-31
Publication date: 1981-10-28
Also published as: DE2724800C3; DE2724800A1; SE7806212L; FR2393189B1; DE2724800B2; FR2393189A1

Description

(54) METHOD OF ESTABLISHING A JOINT BETWEEN A DRIVING SHAFT AND A WHEEL-LIKE MACHINE MEMBER OR PART TO REVOLVE THEREWITH (71) We PUNKER GmbH. a body corporate organised and existing under the laws of Federal Republic of Germany, of Rendsburger Strasse, Eckernforde, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a method of establishing a joint between a driving shaft and a wheel-like machine member or part to revolve therewith, the driving collar or hub of said member or part being provided with a thin-walled neck portion whereof the internal cylindrical wall surface is to be frictionally locked about the shaft.

A method of this nature has hitherto been proposed in French patent specification No.

1,156,627. In that proposal, the frictional locking about the shaft of the thin-walled neck portion of the driving collar or hub is brought about by thrusting over the neck portion a clamping ring which has a screw extending radially of the driving shaft and two pins also extending radially of the driving shaft are arranged equidistant from one another and from the screw, so that, on tightening the screw, the latter and the pins are applied to the neck portion from without and urge the latter on to the driving shaft. It has been proved to be disadvantageous, with this proposed method of clamping a driving collar or hub on a driving shaft, that, on the one hand, the manufacture is complex and then expensive, as it calls for a clamping ring as an additional part which is of comparatively complicated design because of its screw and its pins, and, on the other hand, a hub-shaft joint of this nature has little inherent elasticity and consequently there is a danger that, with extensive use and/or fluctuations in temperature, the clamping ring and therewith the driving collar or hub may become loose.

There has, moreover, been already described, in Swiss patent specification No.

461,183, a method of clamping a machine member or part on a shaft, in which the machine member or part to be clamped has a bore the circumscribed circle of which is greater and the inscribed circle is less than the diameter of the shaft. The joining together calls for the application of external forces by means of special accessories which deform the cross-sectional area of the bore to such an extent that the two members or parts can be thrust one on to the other and there is subsequently a frictional lock between the two through neutralization of the force effect from without. In so doing, the deformation has to take place over the full length of the machine member or part to be clamped on the shaft, from which there should result an exceptionally intimate joint which is said to be suitable above all for the jointing of heavy machine members or parts. In the case of this known joint with which a start is not made from an original push fit and, moreover, not only the thinwalled neck portion is deformed, it has proved to be disadvantageous, however, that the fitting calls for a comparatively large expenditure and is difficult to accomplish, as, in the course of the total duration of the joint, at least one machine member or part must be next under constant deformation by external forces acting over its full length.

The object of the invention is, therefore, to provide a method of establishing a hubshaft joint of the kind here in question, which lends itself to simple and inexpensive manufacture with relatively simple assembly and enables the production of a tight and reliable joint, the inherent elasticity of which is relatively large and which is therefore safe to operate.

The provision which is made for the achievement of this object with regard to the method first set out hereinbefore, is that, in order to produce the joint between the driving shaft and the driving collar or hub, the driving collar or hub bore is provided with a sliding-fit seating on the driving shaft, the neck portion of the driving collar or hub is deformed over at least part of its length from its end and at at least two circumferential areas in such a way that the diameter of the imaginary cylinder inscribed within the bulged-in areas is somewhat smaller than the shaft diameter, and finally the driving collar or hub and the shaft are urged together with precise centering into and onto one another, by doing which the neck portion is re-formed to nearly its original shape. By these means the shaft-hub joint produced by the method in accordance with the invention is cheaper to establish and can be set up frictionally connected on the shaft substantially more easily. The driving collar or hub is preferably first of all produced on an automatic lathe, in order in conjunction therewith to be deformed at its neck portion by a jawed tool so that there is an imaginary inscribed cylinder which is somewhat smaller in diameter than the shaft. The forcing of the driving collar or hub on to the shaft, or the converse, then takes place, which entails a precise centering of driving collar or hub and shaft and a precise guidance, the neck portion of the driving collar or hub almost recovering its original form after the forcing thereof on to the shaft, or the converse.

Moreover, on the other hand, at least the neck portion retains a sufficiently large residual elasticity in its previously deformed resilient area, such that this joint cannot become loose even in the event of a plurality of temperature intervals or flunctuations.

The joint in accordance with the invention therefore has a high degree of operating reliability on account of its relatively large inherent elasticity. Beyond that, it is quickly assembled as screwing or other timeconsuming steps are not required and/or one or both of the machine members or parts does or do not have to be kept deformed by accessories engaging from without during the assembly.

In a preferred embodiment of the invention, the neck portion is encircled by a guard ring spaced therefrom but integral with the driving collar or hub, the front surface of the guard ring projecting beyond the front of the neck portion. The function of this guard ring is to be seen in that, on the one hand, it forms a stop or contact surface the advantage of which is to be seen in facilitating the assembly of driving collar or hub and shaft, and, on the other hand, it protects the neck portion against damage.

It is proposed for a joint established bv the method in accordance with the invention, that the neck portion be formed integral with a driving collar or hub portion of hollow conical shape. This makes it possible to insert a collar portion of the wheel disk into the hollow cone.

Further features and developments of the invention can be gathered from the following description, in which the invention is described and explained in more detail by embodiments shown in the accompanying drawing, in which: Fig. 1 is a longitudinal section, partly broken away through an impeller provided with a hub-shaft connection according to a first embodiment of the present invention; Fig. 2 is a section on a larger scale, along the line II-II in Fig. 1; Fig. 3 is a section, similar to Fig. 2, but through the hub alone and showing the deformation carried out; Fig. 4 is a longitudinal section through a hub-shaft connection according to a second embodiment of the present invention; Fig. 5 is a longitudinal section through a hub-shaft connection according to a third embodiment of the present invention; and Fig. 6 is a longitudinal section through a hub-shaft connection according to a fourth embodiment of the present invention.

The hub-shaft connection according to the invention, several embodiments of which are shown in the drawing, serves for the frictional transfer of force from a drive shaft 12 to ahub 13 of an impeller 14, which in the embodiment shown consists of an impeller disk 16 frictionally connected with the hub 13, and of an annular set of vanes 17 at the outer periphery. The impeller 14 may by these means be in the form of a radial or axial impeller. The connection between hub 13 and impeller disk 16 may likewise be effected in a known way.

As the individual embodiments of the hub-shaft connection 11 according to the invention are substantially identical with regard to production and construction of the frictional connection, the essence of the invention will be explained with reference to the first embodiment in Figs. 1 to 3. The hub 13, which is manufactured as a turned part on an automatic lathe, has a shoulder portion 21 on to which the impeller disk 16 is frictionally secured, and a thin-walled collar portion 22, formed on the shoulder portion 21, away from the wheel disk 16 and tapers conically towards its free end. The relatively thin-walled collar portion 22, just like the shoulder portion 21, is provided with an internal bore 23 corresponding to the diameter d of the shaft 12. This internal bore 23 receives, during manufacture, an accurate push fit tolerance, which is in harmony with the shaft 12. The turned part or hub 13 having been made with the bore fit, the collar portion 22, as is shown diagrammatically in Fig. 3, is held between the jaws 26 of a tool 27. In the embodiment shown.

the tool 27 has three jaws 26 which are uniformly spaced around the circumference and are moved radially in unison in the directions of the arrows A. In this way the collar portion 22 of the hub 13 is deformed at three circumferential places in the embodiment. It is clear that the deformation may be carried out at two or more than three places. This deformation, shown in exaggerated form for reasons of clarity in Fig. 3, causes corresponding deformation of the internal bore 23 in the region of the collar portion 22 in such a way that, at the three compressed points, there results a common inner ring envelope 28 shown in chain-dotted lines and the diameter dl of which is somewhat smaller than the diameter d of the internal bore 23 at the undeformed collar portion 22 or the diameter of shaft 12.

The shaft 12 which has at one end a chamfer 29 or a small cone, is pushed or pressed from the shoulder portion 21 into the hub 13 deformed in this way and shown in Fig. 3 within the limits of the collar portion 22. It is clear that this procedure may also be effected in reverse, i.e. that the hub 13 with its shoulder portion 21 is firstly pushed over the shaft 12. Because of the diameter relationship of the collar 22 and the shaft 12, in this procedure reference is made to pressing the hub 13 on to the shaft 12, the shaft 12 being essentially accurately centred and guided and the collar portion 22 of the hub 13 almost recovering its original shape. This is shown to some extent in Fig.

2, illustrating the assembled condition of the frictional connection 11. It can be seen that hub 13 consists of a metal which may be deformed plastically, yet also elastically up to a certain degree. The result of this is that after pressing of the hub 13 on to the shaft 12, the elastic region, i.e. the collar portion 22, has still a sufficiently large residual elasticity to ensure that the collar portion 22 of the hub 13 clamps around or bears on the shaft 12 in the directions of arrows B in an active radial manner at the deformed places.

This also guarantees that the connection 11 according to the invention cannot become loose even after frequent and considerable temperature intervals, shocks, starting or like operational characteristics.

The second embodiment shown in Fig. 4 differs from the first only in that the hub 13 additionally has a ring 31 formed integrally thereon, which surrounds the collar portion 22 with clearance, the front 32 of the ring 31 projecting beyond the front edge of the collar portion 22 and thus providing a stop or bearing surface for producing the frictional rivet joint 33 between the impeller disk 16 and the shoulder portion 21. At the same time, the ring 31 provides protection against damage for the collar portion 22. The frictional connection 11 is provided in this embodiment in the same way as described with reference to Figs. 1 to 3.

In the third embodiment of the present invention shown in Fig. 5, the hub 13 has, apart from the collar portion 22 which links up integrally with one end of the shoulder portion 21, a second collar portion 36, shaped integrally at the other end of the shoulder portion 21 and extends within the rivet joint 33 and projects therebeyond. The collar portion 36, like the collar portion 22, is provided with a push-fit tolerance with the internal bore 23, and, in order to form the frictional connection 11 with the shaft 12, is deformed by a tool 27 in such a way that the internal diameter of the bore 23 there also has a smaller ring envelope than corresponds to the diameter of shaft 12. In this embodiment, therefore a twofold frictional connection 11 is produced by reason of the fact that the frictional connection operates at both collar portions 22 and 36, so that in this embodiment the impeller 14 may be driven from the shaft 12 with a higher torque. the In the fourth embodiment of the present invention shown in Fig. 6, the shoulder portion 41 of hub 13' adjoining the collar portion 22 is in the form of a hollow cone, the bent-over and flattened end 42 of which is secured by the rivets 43 to the impeller disk 46. The wheel disk 46 is provided through noncutting shaping with a collar portion 47 projecting into the hollow shoulder portion 41. This collar portion 47, in a way corresponding to the sleeve portions 22 and 36 of the hubs 13, provides a frictional connection 11' with the shaft 12. The collar portion 47 therefore likewise receives an internal diameter 48 with a push-fit tolerance and is subsequently deformed in a tool in conformity with Fig. 3, whereupon the impeller 46 with the hub 13 is pressed on to the shaft 12.

In the embodiment shown the hub 13' may also be manufactured through noncutting shaping. There results a particularly simple and inexpensive embodiment of the frictional connection 11 according to the invention, which has a twofold action because of the deformation of the hub 13' and of the additional impeller hub in the form of the collar portion 47.

WHAT WE CLAIM IS: 1. A method of establishing a joint between a driving shaft and a wheel-like machine member or part to revolve therewith, the driving collar or hub of said member or part being provided with a thin-walled neck portion whereof the internal cylindrical wall surface is to be frictionally locked about the shaft, in which, in order to produce the joint between the driving shaft and the driving collar or hub, the driving collar or hub bore is provided with a sliding-fit seating on the driving shaft, the neck portion of the driving collar or hub is deformed over at least part of its length from its end and at at least two circumferential areas in such a way that the diameter of the imaginary cylinder inscribed within the bulged-in areas is somewhat smaller than the shaft diameter, and finally the driving

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. three places. This deformation, shown in exaggerated form for reasons of clarity in Fig. 3, causes corresponding deformation of the internal bore 23 in the region of the collar portion 22 in such a way that, at the three compressed points, there results a common inner ring envelope 28 shown in chain-dotted lines and the diameter dl of which is somewhat smaller than the diameter d of the internal bore 23 at the undeformed collar portion 22 or the diameter of shaft 12. The shaft 12 which has at one end a chamfer 29 or a small cone, is pushed or pressed from the shoulder portion 21 into the hub 13 deformed in this way and shown in Fig. 3 within the limits of the collar portion 22. It is clear that this procedure may also be effected in reverse, i.e. that the hub 13 with its shoulder portion 21 is firstly pushed over the shaft 12. Because of the diameter relationship of the collar 22 and the shaft 12, in this procedure reference is made to pressing the hub 13 on to the shaft 12, the shaft 12 being essentially accurately centred and guided and the collar portion 22 of the hub 13 almost recovering its original shape. This is shown to some extent in Fig. 2, illustrating the assembled condition of the frictional connection 11. It can be seen that hub 13 consists of a metal which may be deformed plastically, yet also elastically up to a certain degree. The result of this is that after pressing of the hub 13 on to the shaft 12, the elastic region, i.e. the collar portion 22, has still a sufficiently large residual elasticity to ensure that the collar portion 22 of the hub 13 clamps around or bears on the shaft 12 in the directions of arrows B in an active radial manner at the deformed places. This also guarantees that the connection 11 according to the invention cannot become loose even after frequent and considerable temperature intervals, shocks, starting or like operational characteristics. The second embodiment shown in Fig. 4 differs from the first only in that the hub 13 additionally has a ring 31 formed integrally thereon, which surrounds the collar portion 22 with clearance, the front 32 of the ring 31 projecting beyond the front edge of the collar portion 22 and thus providing a stop or bearing surface for producing the frictional rivet joint 33 between the impeller disk 16 and the shoulder portion 21. At the same time, the ring 31 provides protection against damage for the collar portion 22. The frictional connection 11 is provided in this embodiment in the same way as described with reference to Figs. 1 to 3. In the third embodiment of the present invention shown in Fig. 5, the hub 13 has, apart from the collar portion 22 which links up integrally with one end of the shoulder portion 21, a second collar portion 36, shaped integrally at the other end of the shoulder portion 21 and extends within the rivet joint 33 and projects therebeyond. The collar portion 36, like the collar portion 22, is provided with a push-fit tolerance with the internal bore 23, and, in order to form the frictional connection 11 with the shaft 12, is deformed by a tool 27 in such a way that the internal diameter of the bore 23 there also has a smaller ring envelope than corresponds to the diameter of shaft 12. In this embodiment, therefore a twofold frictional connection 11 is produced by reason of the fact that the frictional connection operates at both collar portions 22 and 36, so that in this embodiment the impeller 14 may be driven from the shaft 12 with a higher torque. the In the fourth embodiment of the present invention shown in Fig. 6, the shoulder portion 41 of hub 13' adjoining the collar portion 22 is in the form of a hollow cone, the bent-over and flattened end 42 of which is secured by the rivets 43 to the impeller disk 46. The wheel disk 46 is provided through noncutting shaping with a collar portion 47 projecting into the hollow shoulder portion 41. This collar portion 47, in a way corresponding to the sleeve portions 22 and 36 of the hubs 13, provides a frictional connection 11' with the shaft 12. The collar portion 47 therefore likewise receives an internal diameter 48 with a push-fit tolerance and is subsequently deformed in a tool in conformity with Fig. 3, whereupon the impeller 46 with the hub 13 is pressed on to the shaft 12. In the embodiment shown the hub 13' may also be manufactured through noncutting shaping. There results a particularly simple and inexpensive embodiment of the frictional connection 11 according to the invention, which has a twofold action because of the deformation of the hub 13' and of the additional impeller hub in the form of the collar portion 47. WHAT WE CLAIM IS:

1. A method of establishing a joint between a driving shaft and a wheel-like machine member or part to revolve therewith, the driving collar or hub of said member or part being provided with a thin-walled neck portion whereof the internal cylindrical wall surface is to be frictionally locked about the shaft, in which, in order to produce the joint between the driving shaft and the driving collar or hub, the driving collar or hub bore is provided with a sliding-fit seating on the driving shaft, the neck portion of the driving collar or hub is deformed over at least part of its length from its end and at at least two circumferential areas in such a way that the diameter of the imaginary cylinder inscribed within the bulged-in areas is somewhat smaller than the shaft diameter, and finally the driving

collar or hub and the shaft are urged together with precise centering into and onto one another, by doing which the neck portion is re-formed to nearly its original shape.

2. A method in accordance with claim 1, including forming the neck portion integral with a driving collar or hub portion of hollow conical shape.

3. A method in accordance with claim 2, including inserting a collar portion of the wheel disk into the hollow cones.

4. A method of establishing a joint between a driving shaft and a wheel-like machine member or part to revolve therewith, substantially as hereinbefore described with reference to Figs. 1 to 3 of the accompanying drawings.

5. A method of establishing a joint between a driving shaft and a wheel-like machine member or part to revolve therewith, substantially as hereinbefore described with reference to Fig. 4 of the accompanying drawings.

6. A method of establishing a joint between a driving shaft and a wheel-like machine member or part to revolve therewith, substantially as hereinbefore described with reference to Fig. 5 of the accompanying drawings.

7. A method of establishing a joint between a driving shaft and a wheel-like machine member or part to revolve therewith, substantially as hereinbefore described with reference to Fig. 6 of the accompanying drawings.

8. A joint between a driving shaft and a wheel-like machine member or part, when established by the method claimed in any one of the preceding claims.