AU2003213514A1 - Device for Holding a Universal Joint Yoke - Google Patents

Description

S&F Ref: 637590

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Dana Australia Pty Ltd 39-45 Wedgewood Road Hallam Victoria 3803 Australia Ian M. George Andrew N. Dougan Spruson Ferguson St Martins Tower Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Device for Holding a Universal Joint Yoke The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845c DEVICE FOR HOLDING A UNIVERSAL JOINT YOKE Field of the Invention The present invention relates to drive shaft universal joints and particularly relates to a device for holding a drive shaft universal joint yoke.

Background of the Invention Motor vehicle drive shafts must be manufactured to close runout tolerances, particularly to avoid vibration and associated component damage. During quality control inspections, drive shafts are typically mounted on a measurement stand and rotated about a central axis-whilst measurements are taken about the circumference of the shaft along its length to enable determination of shaft runout.

The drive shaft is typically mounted on the measurement stand by way of the universal joint yokes fixed to each opposing end of the drive shaft.

To provide accurate results, it is important that the drive shaft is mounted such that the shaft is centred with respect to the measurement stand mounts such that the shaft is is rotated about a central axis extending between the centres of the universal joint yokes.

Two popular forms of yokes are "full-round" yokes which have a circular bore, provided in each of the opposing arms of the yoke, to which are mounted the universal joint cross member and bearing cups, or a "half-round" yoke where the opposing arms are each provided with a semi-cylindrical recess within which the cross member and bearing cups are mounted.

Current yoke holding devices for mounting drive shafts typically only suit "halfround" universal joint yokes or have an asymmetric design which does not provide for self-centring of the yoke.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.

Summary of the Invention There is disclosed herein a device for holding a universal joint yoke fixed to a drive shaft having a central drive axis, said yoke having a pair of opposing yoke arms each provided with a circular bore, said bores having a common central bore axis extending [I\Day Lib\LIBLL] 14501 .doc:klp therethrough and intersecting said drive shaft drive axis at a midpoint between said yoke arms, said device comprising: a pin adapted to axially extend through said yoke arm bores; means for axially fixing said pin in a pre-determined axial position in relation to said yoke arms; a mounting fixture adapted to engage said pin and to rotate about a rotation axis; alignment means provided on said mounting fixture and adapted to engage complimentary alignment means provided on said pin to thereby align said mounting fixture rotation axis with said bore axis midpoint.

Preferably, said mounting fixture is adapted to engage said pin by way of a semicircular mounting surface provided on said mounting fixture.

Typically, said mounting fixture rotation axis passes through said mounting fixture alignment means and said pin complimentary alignment means is located on said pin at an axial position corresponding to said central bore axis midpoint.

Typically, said mounting fixture alignment means comprises a recess formed in said mounting surface of said mounting fixture and said pin complimentary alignment means comprises a projection provided on said pin.

Preferably, said projection is an annular projection.

Alternatively, said mounting fixture alignment means comprises a projection formed on said mounting surface of said mounting fixture and said pin complimentary alignment means comprises a recess provided in said pin.

Preferably, said recess is an annular recess.

Typically, said means for axially fixing said pin comprises an annular ridge provided adjacent to each opposing end of said pin and each adapted to engage a corresponding surface feature provided in the corresponding said yoke bore.

In one form, said surface feature is an annular groove.

In another form, said surface feature is a surface bordering said yoke bore and an adjacent outer face of said yoke arm.

Brief Description of the Drawings A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Figure 1 is a perspective view of a device for holding a universal joint yoke and an end portion of a drive shaft assembly.

[:\DayLib\LIBLL] 14501 .doc:klp Figure 2 is a partially cross sectioned side elevation view of a device for holding a bearing plate style universal joint yoke in an unassembled state.

Figure 3 is a partially cross sectioned side elevation view of the device of Figure 2 in an assembled state.

Detailed Description of the Preferred Embodiments Referring to accompanying Figure 1, a drive shaft assembly comprises a drive shaft 1 having a universal joint yoke 2 fixed to each opposing end thereof Each yoke 2 has a pair of opposing yoke arms 3. Each of the yoke arms 3 is provided with a circ'ular bore 4.

The bores 4 have a common central bore axis 5 extending therethrough. When the drive 1o shaft assembly is mounted in a motor vehicle during use a universal joint cross member and bearing cups are mounted on the drive shaft assembly by way of the yoke bores 4.

The drive shaft 1 has a drive axis 6 extending between the centres of the opposing yokes 2 (and thereby extending along the centre line of the drive shaft 1 if the drive shaft 1 is straight). The drive axis 6 intersects the central bore axis 5 at a midpoint 7 between is the yoke arms 3. It is about this drive axis 6 that the drive shaft 1 is driven in normal use.

For accurate run out measurement it is also desired that the drive shaft 1 is rotated about this drive axis 6 during measurement on a measurement stand.

In the specific form of standard yoke 2 depicted, a snap ring groove 8 is provided toward the outer axial end of the peripheral wall of each of the yoke bores 4. In normal use these grooves 8 retain snap rings which are fitted once the universal joint cross member and bearing cups have been mounted in the yoke bores 4, thereby fixing the same in place between the snap rings.

A device for holding the universal joint yoke 2 comprises a pin 9 and a mounting fixture 10. The pin 9 axially extends through the yoke arm bores. An annular ridge 11 is provided towards each opposing axial end of the pin 9. These ridges 11 form a means for axially fixing the pin 9 in a pre-determined axial position in relation to the yoke arms 3 by engaging the snap ring grooves 8 provided in the yoke bores 4. In the depicted example the ridges 1 1 are located such that the pin 9 is axially positioned centrally with respect to the yoke arms 3, although it is envisaged that the pins 9 may (less desirably) be axially offset, so long as they are fixed in a pre-determined position.

The mounting fixture 10 is mounted in a measurement stand (not depicted) and, in use, is rotated about a rotation axis 12 extending through the centre of the rotation fixture The mounting fixture 10 is provided with a mounting block 13 on the end face of [1:\DayLib\LIBLL] 14501 .doc:klp which is provided a semi-circular mounting surface 14 having a diameter equal to that of the pin 9 to thereby enable secure engagement of the pin 9 by the mounting surface 14.

The mounting fixture 10 is provided with alignment means in the form of a recess extending transversely across the mounting surface 14. A complimentary alignment means, in the form of an annular projection 16, is provided on the pin 9.

In use, the mounting fixture 10 is axially driven along the mounting fixture rotation axis 12 towards the drive shaft assembly by the measurement stand such that the mounting surface 14 engages the pin 9 with the recess 15 and projection 16 aligned and therefore engaged. The recess 15 and projection 16 are positioned such that, upon aligned 0to engagement of the mounting surface 14 and pin 9 the mounting fixture rotation axis 12 is aligned with the central bore axis mid point 7. Here the mounting fixture recess 15 is located at the mounting fixture rotation axis 12 and the pin projection 16 is located at an axial position corresponding to the central bore axis mid point 7, thereby ensuring the alignment between the mounting fixture rotation axis 12 and central bore axis mid point is 7. Alternatively, the mounting fixture recess 15 and pin projection 16 could be offset an equal distance from the central positions described above, thereby still providing the required alignment.

When the drive shaft assembly is clamped between the mounting fixture mounting surfaces 14 of two opposing mounting fixtures 10 at each end of the drive shaft assembly, the drive shaft drive axis 6 will become coaxially aligned with the mounting fixture rotation axis 12, thereby providing for rotation of the drive shaft 6 about the drive shaft drive axis for conducting measurements as required.

The pin 9 is configured such that the ridges 11 and projection 16 have a diameter very slightly less than the diameter of the yoke arm bores 4, enabling the pin 9 to just fit through the yoke arm bores 4. The depth of the ridges 11 and projection 16, and thus the diameter of the main body of the pin 9, are dictated by the depth required to provide sufficient engagement between the ridges 11 and snap ring grooves 8 as well as between the projection 16 and mounting fixture recess 15. As a result of the depth of the ridges 11 and the projection 16, the main body of the pin 9 has a reduced diameter as compared to the diameter of the yoke bore holes 4, resulting in a loose fit therebetween. This loose fit is overcome, however, by the application of axial force along the mounting fixture rotation axis 12 by the mounting fixture 10, securely holding the pin 9 and ridges 11 against the wall of the yoke bores 4 and snap ring grooves 8 respectively. Whilst a more complicated arrangement providing a close fit tolerance between the main body of the pin [I:\DayLib\LIBLL] 14501 .doc:klp 9 and yoke bore holes 4 could be provided, the arrangement described provides for rapid mounting and dismounting of the drive shaft assembly.

The person skilled in the art will appreciate various possible modifications and alterations to the above described holding device.

For example, the recess 15 and projection 16 provided on the mounting fixture and pin 9 respectively could be interchanged. Other means for aligning the axial position of the pin in relation to the mounting fixture, such as any suitable key type arrangement, could also be provided as an alternative alignment means.

Similarly, rather than providing the ridges 11 on each opposing end of the pin 9 to 1o axially fix the pin, standard snap rings could be utilised to maintain a shorter pin between the snap ring grooves 8 of the yoke bores 4, however assembly of such an arrangement would be more time consuming than the preferred configuration described above.

For yoke configurations not provided with snap ring grooves 8, other means for axially fixing the pin in a pre-determined axial position in relation to the yoke arms 3 may be provided. An example of such a yoke configuration, being a bearing plate style full round yoke 102, is depicted in Figures 2 and 3 along with an associated device for holding the yoke 102. The bearing plate style yoke 102 is not provided with snap rings to secure the universal joint cross member and bearing cups. In this yoke configuration, bearing plates (not depicted) are secured to the outer faces of the yoke arms 103 by way of fastener holes 117. The bearing plates cover the yoke arm bores 104, thereby retaining the universal joint cross member and bearing cups. The intersection bordering the yoke arm bores 104 and the outer end faces of the yoke arms 103 will typically be in the form of chamfered surface 108.

A device for holding the bearing plate style yoke 102 comprises a pin 109 and mounting fixture of the same basic form of Figure 1. For this particular device depicted, the alignment means of the mounting surface 114 of the mounting block 113 is in the form of an annular projection 115 which engages a complimentary annular recess 116 provided on the pin 109. The pin 109 is provided with an annular ridge 111 at each opposing axial end thereof. The edges of the ridges 111 are chamfered so as to define a tapered shoulder 118 between each ridge 111 and the main body of the pin 109. Similar to pin 9 of the device of Figure 1, the annular ridges 111 have a diameter very slightly less than the diameter of the yoke arm bores 104, enabling the pin 109 to just fit through the yoke arm bores 104. As best depicted in Figure 3, showing the pin 109 fitted to the yoke 2 and the mounting surface 114 of the mounting block 113 engaging the pin 109, the [I:\DayLib\LIBLL] 14501.doc:klp tapered shoulders 118 of the pin annular ridges 111 engage the yoke bore hole chamfered surfaces 108 when the pin 109 is engaged by the mounting block 113 with the application of axial force along the mounting fixture rotation axis.

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Claims (7)

1. 2. The device of claim 1 wherein said mounting fixture is adapted to engage said 1s pin by way of a semi-circular mounting surface provided on said mounting fixture.
2. 3. The device of either of claims 1 and 2 wherein said mounting fixture rotation axis passes through said mounting fixture alignment means and said pin complimentary alignment means is located on said pin at an axial position corresponding to said control bore axis midpoint.
3. 4. The device of any one of claims 1 to 3 wherein said mounting fixture alignment means comprises a recess formed in said mounting surface of said mounting fixture and said pin complimentary alignment means comprises a projection provided on said pin. The device of claim 4 wherein said projection is an annular projection.
4. 6. The device of any one of claims 1 to 3 wherein said mounting fixture alignment means comprises a projection formed on said mounting surface of said mounting fixture and said pin complimentary alignment means comprises a recess provided on said pin.
5. 7. The device of claim 6 wherein said recess is an annular recess. [1I\DayLib\LIBLL 14501 .doc:klp
6. 8. The device of any one of claims 1 to 7 wherein said means for axially fixing said pin comprises an annular ridge provided adjacent to each opposing end of said pin and each adapted to engage a corresponding surface feature provided in the corresponding said yoke bore. s 9. The device of claim 8 wherein said surface feature is an annular groove. The device of claim 8 wherein said surface feature is a surface bordering said yoke bore and an adjacent outer face of said yoke arm.
7. 11. A device for holding a universal joint yoke, said device being substantially as hereinbefore described with reference to Figure 1 or Figures 2 and 3 of the accompanying 1o drawings. Dated 17 July, 2003 Dana Australia Pty Ltd Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [l:\DayLib\LIBLL] 14501 .doc:klp