Patent Application
20220205489
This invention relates to a connector arrangement whereby a shaft of a lightweight material such as a composite material or a plastics material can be connected to another component of, for example, a composite or plastics material.
Composite materials are in increasingly widespread use in a number of applications. By way of example, they are increasingly being used in a number of aerospace and automotive applications as an alternative to the use of metallic materials. In such applications, the use of composite materials is advantageous as they allow considerable weight savings to be made whilst maintaining component strength at an acceptable level. By way of example, they have found application in a number of designs of drive shaft, fuel pipe, suspension components and the like.
Whilst the use of composite materials has advantages in a number of applications, one disadvantage of the use of composite materials is that the connection of other components thereto is difficult. By way of example, the formation of openings in a composite material shaft may weaken the shaft to such an extent that its load transmitting properties are negatively impacted. As a consequence of this, bolting or screwing fittings to an end of a shaft is undesirable.
If two components of composite materials are to be interconnected in a load transmitting manner, this disadvantage may be exacerbated. Rather than drill or form openings in a composite material shaft in such an application, a suitable adhesive or the like may be used to bond the two components to one another. However, the use of a bonded connection may be undesirable in a number of applications.
Similar disadvantages may apply where components of other lightweight materials are to be interconnected, for example, thermoset or thermoplastic materials.
It is an object of the invention to provide a connector arrangement whereby a first component can readily be connected to a second component in a load transmitting manner.
According to the present invention there is provided a connector arrangement for interconnecting a first component and a second component, the connector arrangement comprising a connector member including a first abutment face shaped to cooperate with a face of the first component, the first abutment face being provided with a series of spline teeth formations, the dimensions of the first abutment face being selected relative to the first component such that the spline teeth formations thereof dig into the material thereof, the connector member further comprising a second abutment face shaped to cooperate with a face of the second component, the second abutment face also being provided with a series of spline teeth formations, the dimensions of the second abutment face being selected relative to the second component such that the spline teeth formations thereof dig into the material of the second component.
The first component may be of a composite material including reinforcing fibres, or may comprise a thermoset or thermoplastic material, for example. Where of a composite material, it may take a range of forms including, for example, filament wound materials, stitched preforms, braided or tape based reinforced materials or short fibre filled materials. Alternative materials include those capable of 3D printing and injection moulding. Similarly, the second component may be of these materials. The first and second components may be of the same material. However, this need not be the case and the invention may be used in the connection of components of dissimilar materials or of different physical properties or characteristics.
The first component preferably takes the form of a shaft or rod. The first abutment face may be arranged to abut part of the outer surface of the first component. Alternatively, where the first component comprises a hollow shaft, the first abutment face may be arranged to abut part of the inner surface of the first component.
The second component may comprise a flange component arranged to encircle part of the first component. By way of example, it may comprise a fitting provided with openings to allow the first component to be bolted or otherwise secured to another device or component. The second abutment face may be arranged to abut an inner peripheral surface of the second component.
Alternatively, the second component may comprise a toothed gear or the like.
In a further alternative, the second component may comprise a hollow shaft, the second abutment face being arranged to cooperate with the outer or inner peripheral surface of the second component.
The first and second abutment faces may be axially aligned with one another, or may be displaced, axially, from one another. They may comprise, respectively, the inner and outer faces of a tubular component, or may be respective parts of, for example, the outer face of a component.
The spline teeth formations of the first and second abutment faces are preferably of small height. By way of example, they may be of radial height less than 0.5 mm, and are preferably of radial height less than 0.25 mm. Such formations are sometime referred to as microsplines.
Where the loads to be transmitted between the first and second components are torsional loads, the spline teeth formations are preferably in the form of generally axially extending teeth, and assembly is achieved by press fitting. Where the loads to be transmitted between the first and second components are tensional loads, the spline teeth formations are preferably of helical form, the assembly operation involving relative rotation between the connector member and the first and second components such that the assembly is ‘screwed’ together.
It will be appreciated that the invention provides a simple and convenient technique for securing together a pair of components, for example components of lightweight materials such as composite materials or plastics materials.
The invention will further be described, by way of example, with reference to the accompanying drawings, in which:
Referring firstly to
Encircling part of the first component 12 is a connector member 16 of a metallic material. The connector member 16, in this embodiment, takes the form of a short length of a metallic tube, the inner and outer surfaces of which are each provided with respective series of small, generally axially extending spline teeth formations 18a, 18b. The spline teeth formations 18a, 18b are of a small radial height. By way of example, they may be of radial height less than 0.5 mm, and are preferably smaller than this in radial height. For example, they may be of radial height less than 0.25 mm. As noted hereinbefore, such spline formations are sometimes referred to as microsplines as a result of their being of small radial height.
The connector member 16 thus includes a first, inner abutment face 20a provided with spline teeth formations 18a which faces towards and abuts, in use, part of the outer face of the first component 12. The connector member 16 is secured to the first component 12 by being press fitted thereto.
The second component 14 includes an inner peripheral surface which, in use, faces towards and abuts a second, outer abutment face 20b of the connector member 16 provided with spline teeth formations 18b. As with the assembly of the connector member 16 to the first component 12, the second component 14 and the connector member 16 are conveniently assembled by press fitting.
During the press fitting assembly processes, the spline teeth formations 18a, 18b dig into the corresponding surfaces of the first and second components 12, 14, the combination of the fit of the connector member 16 with the first and second components 12, 14 and the engagement of the spline teeth formations 18a, 18b with the first and second components 12, 14 resulting in the formation of a good torsional load bearing connection between the first and second components.
The second component 14 is conveniently provided with a series of openings 14a or other suitable formations to allow connection of the second component 14 to other components or devices.
The invention thus allows load bearing connections to be made between a pair of components of lightweight materials such as plastics materials and composite materials in a simple and convenient manner. As the first and second components 12, 14 need not be of the same material, but rather may be of dissimilar materials, it will be appreciated that the components 12, 14 may be of materials whose characteristics are best suited to the types of loads to be borne thereby or functions to be performed thereby. By way of example, the first component 12 may be of a material of good stiffness whereas the second component 14 may be of greater flexibility.
Although in the arrangement shown in
In the arrangement of
In the arrangements described hereinbefore the spline teeth formations 18a, 18b take the form of generally axially extending spline teeth. It will be appreciated that such formations are advantageous where the loads to be transmitted are torsional loads. However, other spline formations are possible. By way of example, they may be of generally helical form, formations of this type being better suited to the transmission of tensional loads. Where generally helical spline teeth formations are provided, the assembly process should preferably be modified to introduce relative rotation between the connector member 16 and the first and second components 12, 14 during press fitting so that the connector member 16 and first and second components 12, 14 are effectively ‘screwed’ together.
Whilst the description hereinbefore is of specific embodiments of the invention, it will be appreciated that a wide range of modifications and alterations may be made thereto without departing from the scope of the invention as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1906321.3 | May 2019 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/062218 | 5/1/2020 | WO | 00 |
