Production assembly and method for hybrid composite driveshaft tube

Abstract

A driveshaft has an elongated monolithic composite tube with a front joint at one end thereof and a rear joint at an opposite end thereof. The tube has an inner layer formed of glass fibers coaxially wound on top of one other. The tube has outer layer wound directly on the inner layer. The outer layer is formed substantially of carbon fibers. A ratio of a thickness of the outer layer to the thickness of the inner layer is between 0.8 and 1.2.

Claims

1. A driveshaft comprising: an elongated monolithic composite tube with a front joint at one end of said elongated monolithic composite tube and a rear joint at an opposite end of said elongated monolithic composite tube, the front joint having a tube yoke, the rear joint being spaced by a distance from the front joint, said elongated monolithic composite tube having only an inner layer and an outer layer, the inner layer formed of glass fibers coaxially wound on top of one another, the outer layer wound directly on the inner layer, the outer layer being substantially formed of carbon fibers, wherein a ratio of thickness of the outer layer and a thickness of the inner layer is between 0.8-1.2.

2. The driveshaft of claim 1, wherein the outer periphery of said elongated monolithic composite tube is entirely on an outer facing side of the outer layer.

3. The driveshaft of claim 1, wherein the glass winding is a helical winding.

4. A method of manufacturing the driveshaft of claim 1 comprising: fiber winding the inner layer so as to have a hollow cylindrical configuration; filament twisting so as to create a winding thickness of the carbon fibers onto an outer side of the inner layer; and securing the front joint and the rear joint along a connection part to the respective ends of said elongated monolithic composite tube.

5. The method of claim 4, wherein the thickness of the outer layer is substantially equal to the thickness of the inner layer.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a front view of a representative embodiment of the composite driveshaft of the present invention.

(2) FIG. 2a is a cross-sectional illustration of the composite driveshaft shown in FIG. 1.

(3) FIG. 2b is a cross-sectional illustration of a composite driveshaft with increased carbon layer thickness.

(4) FIG. 3a is a detailed isometric view of FIG. 2a.

(5) FIG. 3b is a detailed isometric view of FIG. 2b.

(6) FIG. 3c is an isometric view of FIG. 2a.

(7) FIG. 3d is an isometric view of FIG. 2b.

DETAILED DESCRIPTION OF THE INVENTION

(8) In this detailed description, the inventive subject matter has been described with reference for examples, such that there is no restriction and only to better describe the subject matter.

(9) In FIG. 1, a driveshaft comprising a one-piece composite tube (20) is shown from the front. A tube yoke (12) is secured coaxially to the inner cavity of the composite tube (20) from one end by a known securing method, for example welding, shape bonding, etc. From the other end, a rear joint (40) is secured by a welding seam (32) circumferentially arranged on a connection part (30). A universal joint (14) on the tube toke (12) enables a flange yoke (16) to be attached to the composite tube (20) from the front joint (10).

(10) In FIG. 2a, the composite tube (20) used in a driveshaft is shown in cross-section. Inner layer (24) is obtained in a hollow cylindrical form by winding the glass fiber onto a mandrel (not shown) at a 45? angle (eg 100 rpm). The outer layer (22) is obtained by winding the carbon fiber onto the inner layer (24), again at a speed of winding the inner layer (24), at an angle of 45?. Carried out experiments showed that a composite tube (20) where the ratio of glass fiber winding thickness (h1) to carbon fiber winding thickness (h2) and glass fiber and carbon fibers having different characteristic mechanical properties have an effective resistance against fatigue compared to other composite tubes. In FIG. 2b, winding thicknesses are designed differently. The ratio (h1/h2) of the carbon fiber winding thickness (h1) to the glass fiber thickness (h2) is selected as 0.1. In this case, too, the laminate thickness ratio provided an application in which the driveshaft twisting strength is sufficient compared to a two-part steel driveshaft and the natural bending frequency remains small.

(11) In composite structures, including driveshaft tubes, the mechanical properties are mainly determined by the mechanical properties of the fibers and the orientation of the fibers within the tube. The fibers providing the best in strength, stiffness and cost have been selected in the driveshaft composite tube (20). The fiber orientation can be varied and calculated to provide the desired torque force and axial stiffness.

(12) TABLE-US-00001 REFERENCE NUMBERS 10 Front joint 12 Tube yoke 14 Universal joint 16 Flange yoke 20 Composite tube 22 Outer layer 24 Inner layer 30 Connection part 32 Weld 40 Rear joint