FR2727482A1 - SYNTHETIC RESIN TREE REINFORCED BY FIBERS - Google Patents

Abstract

The shaft of synthetic resin reinforced by coiled fibers comprising integrated angular compensating elements, comprises a section of cylindrical tube, at least one end of which is provided with a deformable elastic coupling flange. The fibers, wound up crossing at a determined angle with respect to the axis of the shaft, stretch over the entire length of the section of cylindrical tube as far as the free end of the coupling flange; the flange forms a collar (8) curved at 180 deg. with a substantially constant inner radius (R1); the free end of the collar covers the section of cylindrical tube, which has a cylindrical annular section (10), and the flange is connected, via this cylindrical annular section, to a connecting element (12) in the form bowl, the inner wall of which covers the cylindrical annular section from the outside.

Description

i "Tree made of synthetic resin reinforced with fibers" This

  The invention relates to a fiber-reinforced synthetic resin shaft comprising at least one flange acting

  as an angular compensating element.

  EP 0 443 470 discloses a shaft comprising at least one flange, and a device and a method for implementing said shaft. The aforementioned shaft comprises a radial flange whose outer contour is provided with connecting bores. Since the section of each pipe section and each flange is identical to the overall section of all the fibers, this coincides with a thinning of the fiber portion towards the outer periphery of the flange, which is related to a thinning of the fiber portion towards the outer periphery of the flange. This thinning makes it possible to obtain the desired influence, since the thickness of the flange is continuously reduced as a function of the radius, without resulting in a reduction in the shear stresses that can be transmitted. This results in a lower deformation work in the outer area of the flange, which is essential for the angular compensation effect of the shaft and, as a result, a lower heat development. In addition, the torque pitch decreases outwardly, which causes a uniform stress on the surface of the flange. In addition, the outer diameter of the flange depends on the bending stresses tolerated. Therefore, in cases where a metallic transmission shaft is to substitute for cardan joints, the diameters of the flanges can reach too large dimensions for the halls of

existing construction.

  US-PS 4,173,128 discloses a tube-shaped shaft including integral compensating elements; said shaft is made of fiber-reinforced synthetic resin, its ends are provided with metal connecting flanges, which penetrate the ends of the shaft via a tubular appendage. The ends of the shaft are provided on the outside with a metal ring, the flanges are joined to the shaft by radial rivets, which engage through the outer ring, the shaft and the tubular appendix of the flange. The compensating elements are in pairs in the form of annular bellows, bulging outwardly whose section is partially circular. The fiber reinforcement consists of fibers arranged at an angle of + 45 and fibers

  unidirectional that extend in the longitudinal direction of the shaft.

  The bellows-shaped compensating elements certainly make it possible to obtain a local reduction in the desired bending resistance for the angular compensation. However, this decrease in flexural strength is perceptible over the entire shaft, which

  makes it sensitive to alternating efforts.

  JP-3,223,516 A - Japanese Patent Abstracts - Section M, Vol. 15 (1991), No. 509 (M-1195) discloses a fiber-reinforced synthetic resin cylindrical shaft, the ends of which are connected, via resilient annular webs, to a metal connecting flange to the cylindrical walls, whose ends

  cover the tree at a radial distance.

  The object of the present invention is to design a shaft of this type, so that it can be executed with a smaller diameter for a predefined angular offset with a transmission.

predefined power.

  This object is solved according to the present invention by the features presented in the characterizing part of claim 1. Rational embodiments of the shaft and a device

  for the manufacture of said shaft are the subject of the subclaims.

  The present invention is explained in detail below in support of the drawings. These are: Figure 1: The section of the end of a tree with a flange that

  plays the role of an angular compensator element.

  Figure 2: the diagram of the manufacture of a tree with two

flanges to form on this tree.

  FIG. 3 is a diagram on a larger scale of a spacer member which acts as a forming element in a device intended for the manufacture of shafts having flanges acting as

  angular compensation elements.

  4: the section of a spacer member according to FIG. 3 and of a forming tool mounted on the tubular portion of FIG.

Shaft.

  Figure 5 the manufacture of a collar.

  Figure 6 Another step in the process of drawing fibers. Figure 7 is a half-section of a modified embodiment of a

  spacer member in a position corresponding to Figure 5.

  Figure 8: a blank of a flange made with an organ

  of spacing according to Figure 7.

  Figure 9: The previous finished flange.

  Figure 10: a front view of a tree with elements of

  connection, side view of the shaft.

  The end of the shaft 2, shown in Figure 1, forms a section 4, preferably annular, cylindrical, which extends to the line 6, formed of dashes and dots, with a length L1, a diameter inside D3, outside diameter D4 and wall thickness d. The tubular section 4 ends with the flange 8 which forms a collar with a change of direction of the fibers of 180 and with an inner diameter R1. The free end of the flange forms a cylindrical or tubular annular section which extends over the end of the tubular section 4 of the shaft 2. The flange thus formed is connected to a connection element 12 in the form of a bowl. or bell, whose cylindrical wall, preferably tubular, covers from outside the tubular section of the flange and which, in the embodiment shown in FIG. 1, is connected to the section of the flange by the intermediate of fasteners 16 to positive engagement - rivets in this case - arranged radially. In a preferred embodiment, an annular support member 18 is mounted on the inner face and is supported from the inside against the cylindrical section 10 of the coupling flange and into which

  the fixing elements 16 are arranged radially.

  It is possible to mount a flange on one or both ends of the finished shaft, depending on the requirements it must meet. The bottom 21, transverse to the axis 20, of the connecting element 12 is provided with bores 24 for receiving the fastening elements. It is possible to possibly fix nuts 25 on the inner wall intended to receive fixing screws, as shown in FIG. 1. The connecting element 12 makes it possible to connect the shaft to a flange of the motor shaft and / or the output shaft. A passage opening 26, made in the middle of the connecting element, is intended to receive a centering pin formed

on the connection flange.

  Instead of making a rigidly positive engagement assembly between the section 10 of the flange and the wall of the connecting element, it is also possible to provide in the direction of the periphery a flexible assembly by means of a ring elastic band fixed by vulcanization. It is possible to fix the connecting element on the section 10 of the flange in the overlap area by gluing or vulcanization. Another way of

  a positive engagement assembly will be described below.

  below with reference to Figures 7 to 10.

  The shaft is made of a fiber-based composite material. The fibers for transmitting the torsional forces are wound by crossing at a given angle with respect to the axis 20, preferably with an angle of + 45. To increase the resistance to bending, it is also possible to provide in the area of the section

  cylindrical unidirectional fibers (parallel to the axis).

  The overall section of all the fibers of the cross winding is identical in the zone of the tubular section 4, in the zone of the

  flange 8 and in the region of the section 10 of the cylindrical end.

  In the area of the flange, an enlargement of the diameter of the edge leads to a thinning of the fiber layers. This thinning is related to a corresponding decrease in the thickness of the wall, as has been described in detail in EP 0 443 470 in support of Figures 18 and 19. As a result, the inner radius R1 of the flange is based on the diameter D1 which, by a value equal to the difference of the thickness of the wall of the flange on the inside or outside diameter, is greater than the diameter D2, on which the radius is based

outside R2 of the collar.

  Figure 2 shows a diagram showing a first step of the manufacture of a shaft 2, the two ends are provided with a flange. The device for the manufacture of the shaft comprises a cylindrical winding core 30 with an axis 31, whose outer diameter is equal to the inner diameter D3 of the U-shaped tubular section of the shaft. Both ends of the winding core are clamped in movable clamping chucks 32 of a not shown winding machine, controllable from a program defining the desired winding pattern. The fibers 34 are placed above the wire guide system, movable

in the direction of the axis.

  A winding core, provided with a spacer 38, is mounted on each zone forming the end of the shaft to be wound. The spacers are guided on the winding core in the

  direction of the axis of the winding core 30.

  As shown in FIG. 3, an annular profiled recess is formed in the opposite end walls of spacers 38. The bottom of the profiled recess has a semi-cylindrical concave curved section with a radius R2 and extends towards the surface. frontal 44 of the spacer member by a hollow cylindrical section 42. The profile, formed by the outer contour of the winding core, the profiled recess 40 and the consecutive cylindrical section 42, corresponds to the shape of the outer wall of

the collar.

  Rolling studs 46, which involve the fibers in a directional change during winding, are mounted radially projecting outwardly on the outer wall of the spacer, at a determined distance from the curved front surface. 44. The transition zone of the winding between the cylindrical section 48 and the conical section 50 is preferably made in the manner described in patent EP 0 443 470 - Pabsch et al. - Referring to Figures 18 and 19. The fibers used are preferably very strong fibers, such as carbon fibers, which are preferably wound with

  the synthetic resin in which they are impregnated.

  Other elements that make up the device are the forming tools 52 which, after completion of the winding, are mounted on the ends of the tubular section 48 of the winding. The forming tools 52 are separated in a plane 53 traversed by the axis 31 of the winding core 30. It is possible to mount them radially on the finished winding, as shown by the arrow C in FIG. 3, and in their final position, the cylindrical inner wall 55 of their two halves 54, 56 completely envelop the finished winding to the line 6 of FIG. 1. The front wall of the forming tools 52, facing towards the body of FIG. 38 is provided with an annular shoulder 58. The section of the shoulder 58 is a rounded convex semi-cylindrical section of inner radius R1 and extends on the outer wall of the forming tool 52 by a cylindrical section 60. The shape of the shoulder 58 coincides with the contour concave interior of the flange 8. The forming tool covers with the shoulder 58 the end of the cylindrical section 48 of

  l winding on a length equal to the radius Rj.

  The device is described below with reference to one of the two couplings formed by the spacer member 38 and the tool

forming 52.

  To achieve the winding, the spacers 38 are mounted on the winding core at a distance corresponding to the length of the shaft and locked on each winding core in the direction of the axis. After the completion of the winding, the forming tools 52 separated in two in the plane of the axis 53 are mounted on the winding core so that they envelop the ends of the tubular section 4 of the winding and that their rounded shoulder is placed above the conical conical section of the winding. In this position, shown in Figure 4, the forming tools are locked against each other and in the relatively axial direction relative to the winding core. Then, the spacers 38 are loosened so that it is

  it is possible to move them axially on the winding core 18.

  The spacers 38 are displaced by means of drive systems - shown schematically in the present case by assembly bolts 62 and clamping washers or clamps 64, 66 -, which allow to move the spacers 38 axially on the forming tools 50, in the direction of the arrow B in FIG. 5. During the displacement, the conical section of the winding is wrapped around the shoulder 58 of the forming tool, on which it is put under prestressing and brought to the installation. In addition, the fiber winding scheme remains

substantially reproducible.

  In the final position, shown in FIG. 5, the section of the end of the shaft 2 is formed between the forming zones of the winding core 30, the spacer member 38 and the tensioning tool. 52. The applied preload enables the winding structure to be compacted in the region of the collar and to regulate the

  amount of synthetic resin needed.

  To exert an axial stress along the entire length of the winding, which is related to an elongation of the fibers even in the tubular section 4 of the shaft, it is intended to mount other drive systems, which allow to separate from each other the two units securely connected and formed by the spacer 38 and the forming tool 52. The drive systems shown in Figure 6 are assembly bolts 70 which extend the bolts. assembly 62 and which, in this case, act simultaneously with a clamping flange 68 locked on the winding core. The axial displacement in the direction of the arrow A, shown in FIG. 6, exerts a tensile force on the fibers, which makes it possible to stretch the fibers. At the same time, the reaction force exerted on the forming tools 52, rendered movable in the direction of the axis for the drawing, makes it possible to increase the drawing force exerted on the region of the flange of the winding. . Just apply the pulling force to one end of the shaft. In this case, it is necessary to maintain in fixed position in the direction of the axis the forming tool mounted on

  the opposite end of the winding core 30.

  When the synthetic resin has reached the final tension, it will be subjected to a suitable curing treatment by the rotation of the shaft and the influence of the temperature. After curing the synthetic resin, the resulting tree blank is removed from the winding core. The free edge of the tubular section is treated and the shaft and the connecting element are made up. With regard to the production of trees with only one end provided with a collar, the tubular section must be separated from the

the appropriate length.

  It is possible to design various variants for the drive systems and the locking systems of the forming tools, used to perform the described functions, in particular in the

  sense of wide automation of each manufacturing step.

  Figure 10 shows an embodiment in which has been

  modified the assembly between the flange and the connecting element.

  Between the tubular section of the flange 8 and the inner face of the wall 14 of the connecting element 12, which covers this section, it is intended to mount a multi-groove assembly 72, which makes it possible to obtain the profile of a grooved tree with oblique parallel flanks, but also with involute flanks. It is also possible to represent the multi-groove profile as

a splined assembly.

  The profile of the multi-groove assembly of the shaft flange, also the profile of the shaft, can preferably be formed on a thin-walled bushing 74, connected to the outer wall of the section.

cylindrical ring.

  The profile of the multi-groove assembly on the cylindrical inner face of the connecting element may also be formed on a thin-walled socket 76, connected in a fixed position to the inner wall of the connecting element. But it is also possible to form the profile directly in the cylindrical inner wall of the connecting element, by mandrinage, by

example.

  If bushings are used whose inside or outside face is grooved, the bushings should be designed as thin as possible so that the outside diameter of the connecting element, necessarily enlarged by the corrugated assembly, remains as low as possible. It is rational in this case to design a large number of relatively low oblique flanks or

low height.

  A fluted toothing has the advantage of ensuring that the radial forces exert on the flange and / or the inner wall of the connecting element, which discharges the bonded assembly. For the bushes 74, 76, synthetic materials with high rigidity, high hardness and good resistance to alternating forces, such as fluorinated polymers or copolymers of acetal on a trioxane base, are used. Preferably, synthetic materials are used which make it possible to produce the sockets with external toothing and / or internal oblique or grooved by the method of

injection molding.

  FIG. 7 shows a possibility for assembling a socket, comprising an outer assembly with multiple grooves, with the

flange.

  An annular recess 78 contiguous to the front face 44 of the spacer member is provided on the cylindrical inner face of the annular wall of the spacer disc. The corrugated sleeve 74 of the splined assembly is placed in this recess prior to the application of the winding. When the forming tool 52 and the spacer member 38 come into contact with each other, the conical section 50 of the winding contacts the inner wall of the sleeve 74. It is possible, in this case, secure it firmly to the flange during curing, by the resin or, if appropriate, by an adhesive agent applied to the inner wall of the sleeve 76. The flange will obtain the shape in which it will be removed at the hardened state of the winding device, as shown in FIG. 8. The rearwardly curved section 78 is separated at the free end face of the bushing 74. FIG. 9 shows the flange 8 thus obtained, on which is

fixed sleeve 74.

  In the embodiment according to FIG. 10, the connecting element 12 can be moved in the axial direction relative to the flange 8 of the shaft, via the corrugated assembly. In order to avoid the involuntary withdrawal of the connecting element, it is possible to mount on the corrugated assembly the locking cams on one of the elements and these recesses contained in the other element.

Claims (15)

  1. Tree made of synthetic resin reinforced with coiled fibers comprising integrated angular compensating elements, formed of a section of cylindrical tube of which at least one end is provided with a deformable elastic coupling flange, in which the fibers, wound in intersecting at a given angle relative to the axis of the shaft, extend over the entire length of the cylindrical tube section to the free end of the coupling flange, the flange forms a collar (8 ) curved at 180 with a substantially constant inner radius (R1), the free end of the flange covers the cylindrical tube section, which has a cylindrical annular section (10), and the flange is connected, via this cylindrical annular section with a bowl-shaped connecting element (12) whose inner wall covers the ring section from outside cylindrical.   2. Shaft according to claim 1, characterized in that these fastening elements (16) to positive engagement through the radial direction constitute a fastening system between the element of   connection and the cylindrical annular section of the collar.   3. Shaft according to claim 2, characterized in that a support ring (18), in which the fastening elements (16) engage, is placed against the inner wall of the annular section (10). cylindrical collar (8).   4. Shaft according to claim 1, characterized in that the connecting element (12) is vulcanized, with the aid of an elastomeric intermediate layer, on the cylindrical annular section (10) of the collar (8).   Shaft according to Claim 4, characterized in that the elastomeric intermediate layer arranged in the circumferential direction   is an elastically deformable layer.   Shaft according to Claim 1, characterized in that a multi-groove connection is provided on the outer wall of the cylindrical section of the collar and the inner face.   of the cylindrical annular wall of the connecting element.   Shaft according to Claim 6, characterized in that the shaft and the connecting element can be displaced towards each other in the direction of the axis via the multi-groove connection. Shaft according to Claim 6, characterized in that the profile of the multi-groove joint of the shaft flange is formed on a thin-walled bushing which is connected to the outer wall.   of the cylindrical section of the collar.   9. Shaft according to claim 6, characterized in that the profile of the multi-groove connection of the inner wall of the connecting element is formed on a thin-walled socket, which   is fixedly connected to the inner wall.   10. Shaft according to claim 6, characterized in that the profile of the multi-groove joint is formed in the inner wall.   cylindrical of the connecting element.   Shaft according to Claim 6, characterized in that the multi-groove joint is formed by the profile of a shaft   fluted with oblique parallel flanks.   Shaft according to Claim 6, characterized in that the multi-groove joint is formed by the profile of a shaft   fluted with involute flanks.   13. Shaft according to claim 6, characterized in that the assembly with multiple grooves is formed as a splined assembly. Shaft according to Claim 9, characterized in that the bush is formed from a synthetic material having a   high rigidity, hardness and resistance to alternating forces.   Tree according to Claim 10, characterized in that the bush is formed of a synthetic material having a   high rigidity, hardness and resistance to alternating forces.