Elastic joint body

An elastic joint body for a shaft arrangement, for the articulated connection of two shaft sections, including a plurality of bushes which are arranged at predetermined angular intervals in the peripheral direction with respect to a central axis of the joint body, a plurality of sets of loops, each set of loops wraps around two adjacent bushes, wherein the bushes and sets of loops are arranged in such a way that a central aperture which extends through the joint body in the direction of the central axis of the latter is formed in the joint body, and at least one gate land on at least one peripheral face that extends in the axial direction, and wherein the bushes and the sets of loops are sheathed, at least partially, with a rubbery-elastic sheathing, starting from the at least one gate land.

TECHNICAL FIELD

The present invention relates to an elastic joint body for a shaft arrangement, for the articulated connection of two shaft sections, the joint body having a plurality of bushes which are arranged at predetermined angular intervals in the peripheral direction with respect to a central axis of the joint body, and a plurality of sets of loops, wherein each of the sets of loops wraps around two adjacent bushes. The bushes and sets of loops are arranged in such a way that a central aperture which extends through the joint body in the direction of the central axis of the latter is constructed in the joint body.

BACKGROUND OF RELATED ART

Joint bodies of this kind, which are also often referred to as “joint discs”, are known from the prior art and are disclosed, for example, in document DE 27 05 598 A1. The joint body disclosed in that document comprises bushes which are arranged at regular angular intervals around the axis of the joint body and which are wrapped around, two at a time, by filament windings. The bushes and filament windings are embedded together in an elastomeric material. Even the regions between the individual outer bushes are filled up with the elastomeric material in which the filament windings are embedded.

On their faces which extend perpendicularly to the central axis of the joint body, i.e. the axial faces of the joint body, the joint bodies which are known from the prior art have gate features which originate from a point-type or continuous gate. The filament windings and outer bushes are sheathed with the elastomeric material, starting from these gate locations on the axial faces of the joint body. As a result of the sheathing operation from the direction of the central axis of the joint body, the elastomeric material comes into direct contact with the filament windings, which affects the flow behaviour or spreading behaviour of the elastomeric material. Because of these influences, defective configuration of the elastomeric sheathing or of the elastic body of the joint body, and unwanted air inclusions in the elastomeric sheathing, can occur in individual cases. Since the elastomeric sheathing of the bushes and of the filament windings is extremely important to the functioning, including the compensation for angular offsets between shaft sections and the lifespan of the joint body, both elastomeric sheathing of faulty construction and multiplied air inclusions in the elastomeric body can lead to a reduction in the lifespan as well as to impairment of the functioning of the joint body.

SUMMARY

An object of the present invention is to provide a joint body of the kind initially referred to, in which the lifespan can be increased and the functioning of the joint body can be ensured.

In order to achieve the above object, the joint body according to the invention has at least one gate land on at least one peripheral face that extends in the axial direction. The bushes and the sets of loops are sheathed, at least partially, with a rubbery-elastic sheathing, starting from the at least one gate land.

The at least one gate land on at least one peripheral face that extends in the axial direction of the joint body guarantees a more uniform and more reliable construction of the rubbery-elastic sheathing. By means of the at least one gate land, it is possible to better take into account the influence of the sets of loops and bushes when forming the rubbery-elastic sheathing. In addition, it is thereby possible to reduce the occurrence of air inclusions in the rubbery-elastic sheathing.

The rubbery-elastic sheathing of the joint body, which sheathing is of uniform and complete construction, leads to an increased lifespan of the joint body and contributes to ensuring functioning of the joint body which is satisfactory on a long-term basis.

According to one embodiment of the invention, the at least one gate land may extend in the direction of the central axis of the joint body.

Furthermore, according to another embodiment of the invention, the at least one gate land may extend in the peripheral direction of the joint body.

The two embodiments described above do not necessarily represent alternatives to one another, but may also be combined. Accordingly, the joint body according to the invention may have both at least one gate land that extends in the axial direction and also at least one gate land that runs in the peripheral direction on the peripheral faces of the joint body.

According to a further development of the invention, the at least one gate land may completely surround at least one of the peripheral faces of the joint body. In other words, the joint body may comprise a circumferential gate land on at least one peripheral face.

According to one embodiment of the invention, a plurality of gate lands may extend in the peripheral direction of the joint body on at least one of its peripheral faces. In this case, each gate land of the plurality of gate lands may also span only a partial region of at least one of the peripheral faces of the joint body.

The individual gate lands of the plurality of gate lands may also be offset in the axial direction in relation to one another.

According to one embodiment of the invention, the at least one gate land may be provided in the region of the central aperture on an inner peripheral face. By means of the central aperture of predetermined construction and dimensions, the at least one axial gate land may be formed via a central gate system. The sets of loops and the bushes are thus sheathed starting from the axial gate land in the region of the central aperture. As the central gate system, use may be made, for example, of a film gate system in which the rubbery-elastic sheathing is formed in the shape of a film or a strip, starting from the at least one gate land that extends in the axial direction.

In addition to, or as an alternative to, the axial gate land in the region of the inner peripheral face of the central aperture, at least one axial gate land may be provided on an outer peripheral face of the joint body.

The central aperture of the joint body, which aperture is of predetermined construction, may be of substantially round or even multi-angular (polygonal) construction. In this case, its inner peripheral face extends in the direction of the central axis of the joint body.

The at least one gate land that extends in the direction of the central axis of the joint body runs substantially parallel or obliquely to the central axis of the joint body.

Depending upon the shape or dimensioning of the joint body, the at least one gate land that extends in the axial direction may extend over the entire axial extension of the joint body, or only over a part thereof. Accordingly, the extension of the at least one gate land in the axial direction of the joint body may be smaller than the entire extension of the joint body in the axial direction. As an alternative to this, the at least one gate land may extend over the entire axial extension of the joint body in the direction of the central axis.

According to one embodiment of the present invention, at least six gate lands are provided on the inner peripheral face of the central aperture of the joint body. All of the six gate lands may extend in the axial direction of the joint body. The at least six gate lands that extend in the axial direction of the joint body may be arranged around the central axis of the joint body at regular angular intervals in relation to one another. In other words, the bushes and the sets of loops are sheathed with the rubbery-elastic sheathing, starting from the six axial gate lands. The axial gate lands, which are arranged so as to be offset in relation to one another, lead to a rubbery-elastic sheathing of uniform construction, with a reduced occurrence of air inclusions.

According to one embodiment of the invention, when the joint body is formed, a plurality of bushes and a plurality of sets of loops that wrap around two adjacent bushes are arranged in an injection mould. The elastomer composition that forms the rubbery-elastic sheathing can then be introduced into the injection mould, starting from the central aperture which is to be constructed in the joint body, in such a way that at least one gate land that extends in the axial direction of the joint body is formed on the inner peripheral face of the central aperture of the joint body. Starting from the at least one axial gate land, the sets of loops and the bushes are sheathed, at least partially, by the elastomer composition that forms the rubbery-elastic sheathing.

With the aid of the at least one axially extending gate land, the bushes and the sets of loops can be sheathed in a uniform manner, virtually over the entire axial extension of the elastic joint body, with the rubbery-elastic sheathing. What can also be achieved by means of the at least one axial gate land is that the rubbery-elastic sheathing is formed by means of a displacement flow and, in that way, sheathes the sets of loops and the bushes. A displacement flow that is made possible by the at least one axial gate land leads to more uniform, and thereby improved, flow behaviour of the elastomer composition, so that the rubbery-elastic sheathing is formed in a uniform and complete manner with a simultaneous reduction in the risk of air inclusions.

According to one embodiment of the invention, there may be associated with each bush flanged bushes which are provided at the axial ends, in each case, of the bushes and which are sheathed, at least partially, by the rubbery-elastic sheathing. The flanged bushes serve, inter alia, to support the sets of loops in the axial direction of the bushes and to thus better retain the sets of loops in their predetermined position on the bushes.

According to the invention, provision may be made for the rubbery-elastic sheathing of the joint body to have, on each of its faces that run perpendicularly to the central axis of the joint body, at least one clearance in the region between two adjacent bushes. These clearances on the axial faces of the joint body lead to the possibility of the rubbery-elastic sheathing deforming in the region between the bushes when the joint body is in operation, i.e. when torque is being transmitted. Furthermore, the clearances may also extend in a region between two strands of a set of loops that wraps around two adjacent bushes.

The present invention also relates to a shaft arrangement, in particular a drive line of a vehicle having a joint body of the kind described above.

DETAILED DESCRIPTION

FIG. 1shows a perspective view of a first embodiment of the elastic joint body10according to the invention, with six bushes14which are sheathed by a rubbery-elastic sheathing12. The bushes14are arranged at predetermined angular intervals on the joint body10in the peripheral direction with respect to a central axis M. In that region of the joint body10acts cording toFIG. 1which is represented in cut-away form in the drawing, there can be seen the flange elements16on the bushes14, which elements are provided for axially supporting the sets of loops18,20and22. Both the flanged bushes16and the sets of loops18,20and22are sheathed by the rubbery-elastic sheathing12.

It can also be seen fromFIG. 1that an individual bush14is wrapped around, in each case, by a number of sets of loops18,20or20,22. As shown, the loop20wraps around two adjacent bushes14and loop18wraps around two adjacent bushes14. Under these circumstances, provision may be made for the sets of loops18,22to be stressed by a tensile force when the joint body10is in the installed condition in a shaft arrangement, while the set of loops20and another, parallel set of loops, which is not shown inFIG. 1but which is sheathed by the rubbery-elastic sheathing12, is loaded in compression or shear.

The rubbery-elastic sheathing12may be formed of an elastomer composition that is introduced into an injection mould (not shown) in such a way that a gate land24is formed on the inner peripheral faces26of the joint body10. The joint body10additionally has gate lands24which extend in the direction of the central axis M. The axial gate lands24may be provided on an inner peripheral face26of a central aperture28in the joint body10or joint disc and on an outer peripheral face30of the joint body10. However it is sufficient, for the design and manufacture of the joint body10, if the axial gate lands24are arranged either on the inner peripheral face26of the central aperture28or the outer peripheral face30of the joint body10. According to this embodiment of the invention, the gate lands24extend parallel to the central axis M. The bushes14, the flanged bushes16and the sets of loops18,20,22are sheathed, starting from the gate lands24, with the rubbery-elastic sheathing12.

The bushes14, the flanged bushes16and the sets of loops18,20,22are sheathed, starting from the gate lands24, with the rubbery-elastic sheathing12.

According to this embodiment of the invention, the axial gate lands24extend over the entire axial extension of the joint body10. However, the gate lands24do not necessarily have to be designed in this way, but may also extend only over partial sections of the axial extension of the joint body10.

In the region between the bushes14, the joint body10also has clearances32. The purpose of the clearances32is that the joint body10, or the rubbery-elastic sheathing12, is able to deform when in operation, i.e. when torque is being transmitted between two shaft sections (not shown). In other words, the clearances32allow individual bushes14to come closer to one another when the joint body10is in operation.

FIG. 2shows a partially cut-away top view of the elastic joint body10according toFIG. 1. In that region of the joint body10which is represented in cut-away form in the drawing, there can once again be seen the flange elements16on the bushes14, which elements are provided for axially supporting the sets of loops18,20and22.

The top view according toFIG. 2likewise shows the gate lands24. The gate lands24are ribs formed on the inner peripheral face26of the central aperture28and the outer peripheral face30. The gate lands24are arranged at regular angular intervals around the central axis M and extend in the axial direction of the joint body10.

FIG. 3shows a perspective view of a joint body110according to a second embodiment of the invention.

The joint body110corresponds, to a large extent, to the joint body10described with reference toFIGS. 1 and 2, but in the joint body110, the gate lands124are arranged in line with the axes of the bushes114.

It can also be seen inFIG. 3that, according to this embodiment, the axial gate lands124span only a partial region of the axial extension of the joint body110. Accordingly, the axial gate lands124do not reach as far as the edges of the joint body110, but extend in a central region of the axial extension of the latter.

FIG. 4shows a perspective view of a joint body210according to a third embodiment of the invention.

The gate lands224of the joint body210extend in the peripheral direction of the latter. In this instance, the gate lands224run along the inner peripheral face226of the central aperture228or along the outer peripheral face230of the joint body210. In other words, the gate lands224run completely round the inner peripheral face226and the outer peripheral face230, the gate lands224according to this embodiment being provided in a central region of the axial extension of the joint body210.

However, the gate lands224do not have to be arranged on the inner peripheral face226and on the outer peripheral face230. It is sufficient if the gate lands224that extend in the peripheral direction are arranged either on the inner peripheral face226of the central aperture228or on the outer peripheral face230of the joint body210.

FIG. 5shows a perspective view of the joint body310according to a fourth embodiment of the invention.

The joint body310comprises two gate lands324which run parallel to one another and extend in the peripheral direction of the joint body310on the inner peripheral face326and the outer peripheral face330. The gate lands324completely surround the inner peripheral face324and the outer peripheral face330.

Naturally it is also possible for more than two gate lands324to be provided on the inner peripheral face326and/or the outer peripheral face330.

FIG. 6shows a perspective view of a joint body410according to a fifth embodiment of the invention.

The joint body410comprises a plurality of gate lands424which extend in the peripheral direction of the joint body410on the outer peripheral face430and the inner peripheral face426of the central aperture428. In this instance, each of the gate lands424spans a partial region of the inner peripheral face426or of the outer peripheral face430of the joint body410.

FIG. 7shows a perspective view of a joint body510according to a sixth embodiment of the invention.

The joint body510has both gate lands524that extend in the axial direction and gate lands524that run in the peripheral direction of the joint body510along the outer peripheral face530and the inner peripheral face526. In this instance, provision may be made for the axial gate lands524to extend between the gate lands524that run in the peripheral direction of the joint body510. However, this is not obligatory.

FIG. 8shows a perspective view of a joint body610according to a seventh embodiment of the invention.

The joint body610according toFIG. 8has a gate land624, on the inner peripheral face626and on the outer peripheral face630in each case, that extends in the peripheral direction of the joint body610, i.e. equatorially. The gate lands624that extend in the peripheral direction are arranged substantially centrally on the inner peripheral face626and outer peripheral face630and thus “cross” the gate lands624that extend in the axial direction.

FIG. 9shows a perspective view of a joint body710according to an eight embodiment of the invention.

The joint body710according toFIG. 9defines a multi-angular central aperture728arranged about the central axis M. As shown inFIG. 9, the central aperture728has six inner peripheral faces726; however, it is within the scope of this disclosure for the central aperture728to have less than six inner peripheral faces726or more than six inner peripheral faces726. A gate land724may be disposed on the inner peripheral faces726and on an outer peripheral face730of the joint body710. The gate lands724extend oblique to the central axis M.

All embodiments described above can be combined with one another.

Even though, in each of the embodiment described above, gate lands were provided on the inner peripheral face and the outer peripheral face of the joint body, it is sufficient, for the design and manufacture of the joint body, if the axial gate lands are arranged either on the inner peripheral face or on the outer peripheral face of the joint body.