DE102010006012A1 - Universal joint fork-drive shaft for motor car, has reinforcing insert e.g. solid cylinder or pipe, axially oriented along longitudinal axis of shaft and extended by part of cylindrical section and/or by part of shoulder - Google Patents

Abstract

The shaft (1) has a cylindrical section (2) extended over a shoulder (6) into a joint head (3) by two fork legs (4, 5). The shaft comprises a reinforcing insert (7) e.g. solid cylinder or pipe, which is axially oriented along a longitudinal axis of the shaft. The reinforcing insert is extended by a part of the cylindrical section and/or by a part of the shoulder. The reinforcing insert consists of metal e.g. steel and aluminum, or non-metal e.g. fiber composite and polyurethane foam. The joint head and the cylindrical section of the shaft consist of a cast material.

Description

The invention relates to a weight-optimized reinforced universal joint drive shaft for motor vehicles.

In order to achieve a reduction in fuel consumption and thus a reduced carbon dioxide emissions at the highest possible performance by reducing the weight of a motor vehicle, the aim is to realize possible components in the automotive industry by lightweight construction. The mechanical strength and load capacity of the respective vehicle component must be taken into account. For example, components used in areas with critical component geometry, such as a cardan shaft with a universal joint fork, which is used as part of the drive train in the high-power sector, set particularly high demands in terms of strength, so that production of such components in lightweight construction is a challenge.

From the prior art is with the DE 197 07 999 A1 a sliding universal joint fork with recesses, which thus provides, in addition to a reduced weight, especially outer surfaces, which are provided for welding counterweights in balancing the shaft assembly. These recesses extend between the cylindrical body and the openings in the fork legs, the universal joint fork is to be given sufficient strength by the struts, which are provided between and laterally of the recesses.

Based on this prior art, it is desirable to provide a weight-optimized universal joint fork hinge shaft with at the same time an improved strength with respect to its component geometry.

This object is achieved by a universal joint yoke PTO shaft with the features of claim 1. Further developments are set forth in the subclaims.

A first embodiment of the invention relates to a propeller shaft with universal joint fork, which at one - or both - ends of a cylindrical shaft portion has a condyle, which consists of two fork legs, via a shoulder, respectively via a shoulder-like connection region of the condyle to the cylindrical portion are connected. In order to reduce the weight of the kingpin shaft without reducing the strength at the shoulder, a reinforcing insert oriented axially along the longitudinal axis of the universal joint fork pivot shaft and integrated through at least a part of the universal joint is incorporated into the kingpin cylindrical portion and / or extending through at least a portion of the shoulder.

The reinforcing insert can be cylindrically shaped in one embodiment and depending on whether the propeller shaft is provided as a hollow or solid shaft, be formed as a solid cylinder or tubular, the favored lightweight variant provides the tubular reinforcing insert for reasons of material savings.

Through the sandwich construction technique for the cardan shaft with universal joint yoke, which may be a cast material, by suitable choice of material of the reinforcing insert, both the strength and the total weight of the universal joint cardan shaft can be reduced by substituting not only casting material for the reinforcing insert, but a further reduction allows the cast wall thickness by a reinforcing material of higher strength.

Thus, the reinforcing insert can insert a metal insert from a steel or aluminum sheet. The use of a non-metal insert made of a fiber-reinforced composite, for example, is also conceivable.

The choice of materials and the use of a pipe as a reinforcing insert in connection with the sandwich construction, the strength of the universal joint yoke drive shaft can be improved, the reinforcing insert can be integrated with the use of casting as material material for the universal joint yoke hinge shaft already during casting in the propeller shaft. If the reinforcing insert is cast in, then after the solidification of the cast material, the cylindrical section and the connection area are connected in an axially form-fitting manner to the reinforcing insert.

Since waves are stressed by the torque transmission and torsion, in a further embodiment, the reinforcing insert may have recesses which are arranged distributed over its lateral surface and open radially to the longitudinal axis. Thus, when molding the reinforcing insert with the casting material to form the universal joint fork hinge shaft, a radial positive engagement of the reinforcing insert with the surrounding cylindrical portion and the connection region is also created by the casting material entering the recesses. As a result, the reinforcing insert is dovetailed in the universal joint fork drive shaft.

These and other advantages will be set forth by the following description with reference to the accompanying figure. The reference to the figure in the description is to support the Description and facilitated understanding of the subject. The 1 is merely a schematic representation of an embodiment of the invention. It shows a perspective partial sectional view of an embodiment of a universal joint fork propeller shaft according to the invention.

Generally, cardan shafts are used to transmit torques in non-aligned axes of rotation or in mutually moving parts, so that they are also subjected to torsion. A universal joint propeller shaft, also known as a cardan shaft, is used primarily in motor vehicle construction as a component of the drive train and usually consists of a hollow shaft. The universal joint at the ends of the cardan shaft allows connection to another universal joint of another shaft with little play and maintenance and high efficiency.

As an alternative or in addition to the universal joint nowadays joint discs made of rubber or other elastic material with integrated metal bushings are used for the coupling of propeller shafts, which provide by damping vibrations for a quieter running of the drive and thus for improved comfort.

Although the invention is described with reference to a cardan joint universal joint shaft, it is also conceivable to design a cardan shaft equipped with jointed disks in the sandwich construction of the cardan shaft according to the invention with a reinforcing insert, so that a weight-optimized cardan shaft can also be obtained here.

In 1 is an end piece of a universal joint fork PTO shaft 1 shown, in which from the cylindrical portion 2 the propeller shaft 1 over the shoulder 6 the two opposite fork legs 4 . 5 of the condyle 3 , shown without the necessary for coupling a second universal joint fork bearing bores, connect. The PTO shaft 2 Here is a hollow shaft in which an axially extending reinforcing insert 7 is poured, which is present as a pipe and so a through hole 8th provides. The reinforcement insert 7 is positively from the cylindrical portion of the propeller shaft 2 and the shoulder 6 surround.

The universal joint fork PTO shaft 1 is designed as a cast component, wherein in the tail of the universal joint fork propeller shaft 1 the reinforcement feeder 7 For example, made of a steel or aluminum sheet, during the casting operation of the universal joint fork-PTO shaft 1 is poured, so that by the sandwich construction of the universal joint drive shaft 1 with the reinforcement insert 7 the critical shoulder in terms of component geometry 6 optimized in terms of weight and strength. The reinforcement insert 7 may also consist of a material selected from a group of non-metals (fiber composite, PU foam, etc.).

The reinforcement insert 7 that extends from the cylindrical section 2 in the shoulder 6 of the clevis 3 extends there, replacing the otherwise existing casting material, thereby reducing the weight while at the same time providing sufficient, if not increased, strength.

To improve the positive connection between the cast universal joint drive shaft 1 and the cast-in reinforcing insert 7 , Especially in the radial direction, this may have circumferential openings - not shown in the figure - into which the casting material can enter or pass through, so that the reinforcing insert 7 also with respect to the torsional forces occurring positively in the universal joint fork drive shaft 1 is anchored.

The sandwich construction with use of the tube-like reinforcing insert in the propeller shaft, especially in the critical areas of the end pieces to the fork heads, allows the optimal use of the weight-specific component geometry and the optimization of the component critical strength ranges by selecting suitable materials by exploiting the component-specific mechanical material properties the component strength can be increased with weight-optimized component geometry.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19707999 A1 [0003]

Claims (6)

PTO shaft with a universal joint fork ( 1 ) for motor vehicles, wherein a cylindrical section ( 2 ) of the propeller shaft ( 1 ) over a shoulder ( 6 ) in a condyle ( 3 ) with two fork legs ( 4 . 5 ), characterized in that the propeller shaft with the universal joint fork ( 1 ) axially along a longitudinal axis of the kingpin shaft ( 1 ) oriented reinforcing inserts ( 7 ) which extends through at least part of the cylindrical section ( 2 ) and / or through at least part of the shoulder ( 6 ). PTO shaft with a universal joint fork ( 1 ) according to claim 1, characterized in that the reinforcing insert ( 7 ) is a solid cylinder or a pipe. PTO shaft with a universal joint fork ( 1 ) according to claim 1 or 2, characterized in that the reinforcing insert ( 7 ) is made of a metal selected from a group comprising at least one of steel and aluminum. PTO shaft with a universal joint fork ( 1 ) according to claim 1 or 2, characterized in that the reinforcing insert ( 7 ) is made of a material selected from a group of non-metals (fiber composite, PU foam, etc.). PTO shaft with a universal joint fork ( 1 ) according to at least one of claims 1 to 4, characterized in that the condyle ( 3 ) and the cylindrical section ( 2 ) of the propeller shaft ( 1 ) consist of a casting material, wherein an axial positive engagement of the reinforcing insert ( 7 ) at least with the cylindrical portion ( 2 ) of the universal joint fork propeller shaft ( 1 ) is provided by the reinforcing insert ( 7 ) in the casting material of the universal joint fork propeller shaft ( 1 ) is poured. PTO shaft with a universal joint fork ( 1 ) according to claim 5, characterized in that the reinforcing insert ( 7 ) distributed over its lateral surface and radially oriented to the longitudinal axis recesses for receiving cast material, whereby a radial positive connection between the reinforcing insert ( 7 ) and the universal joint fork propeller shaft ( 1 ) provided.

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