AU617467B2 - Universal joint - Google Patents

Description

or other witness S required PHILLIPS ORMONDE AND FITZPATRICK TJC:AT Patent and Trade Mark Attorneys Hwth: Fee $60.00 367 Collins Street Our Ref: IRN 91202 Melbourne, Australia P17/2/83 11 i 1

AUSTRALIA

Patents Act 617467 COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Ait: a a -a 0 APPLICANT'S REF.: C.A.P. of PI 8150 Name(s) of Applicant(s): UNIDRIVE PTY. LTD.

Address(es) of Applicant(s): 45-49 McNaughton Road, Clayton, Victoria 3168, Australia Actual Inventor(s): Address for Service is: PHILLIPS, ORMONDE AND FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne, Australia, 3000 Complete Specification for the invention entitled: "UNIVERSAL JOINT" The following statement is a full description of this invention, including the best method of performing it known to applicant(s): P 9/3/84 uur Ret: IRN 91202 This invention relates to universal joints as used for connecting two rotatable members such as two sections of a drive shaft. It will be convenient to hereinafter describe the invention with particular reference to vehicle transmission shafts, but universal joints according to the invention have other uses.

Universal joints of the foregoing kind include an input member and an output member, each of which is connectable to a respective section of the drive shaft. Those two members are interconnected in such a way that each is able to rotate about a respective axis which is angularly disposed to the rotational axis of the other. In the case of a Cardan or Hooke type of universal joint, the two members are referred to as yokes and the connection between them is effected by a component called a spider. In the case of constant velocity StI Suniversal joints, the two members are identified in a variety .o0o of ways, but in one type one of the members is called an outer 0000 race and the other is called an inner race. The two race *000 members are connected through a rolling ball system which 020* enables the aforementioned angular disposition of the two rotational axes.

Universal joints of the foregoing kind are well known.

o o 0As a matter of convenience, the invention will be hereinafter described with particular reference to Cardan or 0o, Hooke type joints, and especially the yokes of such joints.

It is to be understood however, that the invention is equally applicable to constant velocity joints and in particular is 0. applicable to the member of such a joint which is the functional equivalent of the yoke of a Cardan or Hooke type joint. For the purpose of the following description, the term "primary member" is to be understood as a generic term which encompasses the yoke of a Cardan or Hooke type joint and the member of any other type of universal joint which is the functional equivalent of such a yoke.

At least one of the primary members of a universal joint is usually arranged for removable attachment to a section of the vehicle transmission system of which the joint forms part. By way of example, the primary member which forms the 39 output member of the joint may be removably attached to the drive input shaft to the vehicle differential.

In the case of the output yoke of a Cardan or Hooke type joint, the manner of removably attaching the yoke to a shaft has remained unchanged for a great many years. That attachment involves face to face clamping of two flanges, one of which forms part of the yoke and the other forms part of the shaft. It is usual to clamp the two flanges by at least four bolts arranged in a pattern around the shaft axis e.g., arranged on a circle or rectangle which is concentric with the shaft axis. The two flanges must be clamped together so that the yoke and the shaft are coaxial, and effective locating means must be provided for that purpose. Such locating means usually comprises a circular spigot on the face of one flange which locates within a corresponding circular recess of the C other flange.

Attachments of foregoing kind suffer several 00 SoO disadvantages such as the need for a large number of oo9a 000. components and the time required to secure and separate the 0* 6 two flanges. Furthermore, the two flanges must be accurately machined to ensure proper cooperation in terms of relative location and ability to properly transmit drive.

o It is an object of the present invention to provide 0* o improved means for transmitting drive between a primary member o Q of a universal joint and any other member of the rotatable system of which the joint forms part. It is a particular object of the invention to provide such means which effects axial alignment of the primary member.

otaO A universal joint primary member according to the 0440 invention is characterized in that it has a plurality of key oa a forms located radially outwards from its axis of rotation and which cooperatively engage with complementary key forms of another rotatable member. The cooperable engagement between the two groups of key forms is such as to enable transmission of torque between the two members, and to also provide a locating facility whereby the two members are automatically arranged coaxial. That is, the coaxial location occurs as a result of moving the two groups of key forms into driving engagement.

39 It is a further feature of the invention in one form that a primary member of the foregoing kind can be secured to another member by a single fastening means rather than a plurality of such fasteners as in conventional constructions.

According to the invention, there is provided a universal joint primary member including, a body having an axis of rotation, a plurality of key forms provided on said body so as to be engageable with cooperable key forms of another rotatable member and thereby permit transmission of torque between said body and said other member, each said body key form being located radially outwards of said rotational axis and having a longitudinal axis which extends at an angle to said rotational axis, and locating means which includes said body key forms and which is operative to cause said body and said other member to be located in coaxial relationship.

The primary member can be a yoke of the kind used in a ,o Cardan or Hooke type universal joint, or a functional equivalent of such a yoke as used in any other universal joint 0 00 0. including constant-velocity types.

0o 0 An embodiment of the invention is described in detail in 0200 the following passages of the specificaton which refer to the accompanying drawings. The drawings, however, are merely .0 illustrative of how the invention might be put into effect, so Od 0 0o that the specific form and arrangement of the various features as shown is not to be understood as limiting on the invention.

S0oo In the drawings: Figure 1 is an elevation view of one form of universal joint yoke to which is applied an example embodiment of the 0000o invention, 0 Figure 2 is an end view of the yoke of Figure 1 looking e in a direction from the right hand side of Figure 1, Figure 3 is an enlarged view of a key form as shown in Figure 2, Figure 4 is a cross-sectional view taken along line IV-IV of Figure 3, Figure 5 is an assembly including the yoke of Figures 1 and 2, Figure 6 is a universal joint assembly including a form of yoke different to that shown in Figures 1 and 2.

39 Figure 7 is a view similar to Figure 5 but showing a constant velocity type universal joint.

The universal joint yoke 1 shown in Figures 1 and 2 is intended for use in a Cardan or Hooke type of universal joint, but the invention is applicable to other types of universal joints. By way of example, the invention is applicable to universal joints of the constant-velocity type, including those used in front wheel drive vehicle transmissions.

The yoke 1 of Figure 1 includes a body 2 having an axis of rotation 3, and two arms 4 extending from the body 2 in spaced relationship so that each is located on a respective opposite side of the axis 3. Each arm 4 has an opening which enables connection of the yoke 1 to a joint spider (not shown). Such an arrangement is conventional.

A series 6 of key forms 7 is formed on or attached to 0000 the end of the body 2 which is remote from the arms 4. As 0000 °oo best seen in Figure 2, that series 6 comprises an annular oo array of key forms 7, but other arrangements could be 0°0 adopted. Also, the key forms 7 are shown as standing proud 0000 from a surface 3 of the body 2 so as to form an end extremity of the yoke 1, whereas in other arrangements the key forms 7 could be positioned axially inwards from the adjacent end of the yoke i.

00 to An annular series 6 of key forms 7 as shown has the advantage of enabling almost infinite adjustment of the opo relative rotational positions of the yoke 1 and a connected member 9, as shown in Figure 5. Such adjustment may be desirable to balance the rotary system of which the yoke 1 OOO forms part. Nevertheless, in a simple form, a yoke according 0000 Sto the invention could have two key forms 7 only, each of which would preferably be located on a respective opposite side of the axis 3.

Each key form 7 is located radially outwards from the axis 3, and in the particular arrangement shown, the annular series 6 is substantially concentric with the axis 3. Each key form 7 has a longitudinal axis 10 (Figure 3) which extends at an angle to the rotational axis 3. Reference to a longitudinal axis does not necessarily mean that the key form 7 has a greater extent in the direction of that axis than in a 39 direction transverse thereto. The axis 10 is simply a datum which establishes a reference for the direction in which the key form 7 imparts a driving force, and that direction is generally transverse to the axis 10. In the particular arrangement shown, the axis 10 intersects the axis 3, but that is not essential.

The actual configuration of each key form 7 can vary according to requirements, but one particularly satisfactory configuration is shown by Figures 3 and 4. It is a feature of the configuration shown that it serves as part of locating means which is operative to locate the yoke 1 in coaxial relationship with another rotatable member, such as the member 9. In the construction shown, that locating function is achieved by the varying width nature of each key form 7. That 0 is, as best seen in Figure 3, the radially inner end 11 of each key form 7 is narrower than the radially outer end 12.

In the particular construction shown, the two side .o surfaces 13 of each key form 7 are substantially straight in the longitudinal direction, and a longitudinal continuation of 0000 non~ 00 0 each side surface 13 would substantially pass through the axis 200 3. That is, each side surface 13 lies on a straight line extending radially from the axis 3. Such an arrangement 0o automatically creates a locating facility as referred to CO 0 o0 o above. Each side surface 13 of the key form 7 forms a driving or driven face for the purpose of transmitting torque between 0: the yoke 1 and the member 9, and each lies on a respective opposite side of the axis The cross-sectional shape of the key form 7 as shown in 0.3oO Figure 4 is preferred, but not essential. That shape has the 0000 advantage of facilitating mating engagement with the osoa cooperative key forms of the member 9.

Figure 5 shows an assembly including the yoke 1 and the member 9, which in this case is shown as a splined sleeve intended for connection to the differential pinion of a vehicle transmission system. That sleeve 9 has a series 14 of key forms 15 which cooperatively engage with the yoke key forms 7. In particular, recesses (radial grooves) between each two adjacent key forms 15 are substantially complementary to the key forms 7 so as to achieve the necessary mating 39 engagement and locating function as previously described.

Because of the non-regular width of the key forms 7, and the complementary recesses of the series 14, it is not possible to properly engage the two key form series 6 and 14 unless the yoke 1 and the sleeve 9 are substantially coaxial.

Thus, the process of engaging those two series 6 and 14 automatically aligns the yoke 1 and sleeve 9 in coaxial relationship.

A key form 7 or 15 as described can be produced by forging, casting, or machining. It is preferred, however, to produce the key forms 7 and 15 by an orbital forging process which produces an accurate shape without the need for finishing by machining) in many cases.

It will be appreciated that key forms other than that *o particularly described and shown could be employed. The qualifying parameter for the key form is that it is able to 00 0 oo transmit drive from one member to another and has a S configuration such as to function as locating means, at least for relative radial location of the two rotatable members.

The yoke 1 and the sleeve 9 can be secured together in 020' any appropriate fashion. In the particular arrangement shown by Figure 5, that is achieved by use of two clamping studs 16 located on respective opposite sides of the axis 3. It is o preferred that the head 17 of each stud 16 has a frusto-conical undersurface which mates within a substantially o complementary recess of a washer 18. The stud shank 24 threadably engages within the yoke body 2 and the washer 18 overlies part of a flange 19 of the sleeve 9 so as to clamp n* the sleeve 9 to the yoke 1. Obviously, it would be possible 0040 to rearrange the studs so that each shank 24 threadably engaged within the sleeve 9 and each washer 18 clamped against a surface of the yoke body 2.

It is a feature of the foregoing attachment between the yoke 1 and the sleeve 9 that it does not compromise the ability to achieve the rotational adjustment previously referred to.

Another universal joint assembly incorporating an embodiment of the invention is shown by Figure 6. Components of that assembly which correspond to components shown in 39 Figure 5 are given like reference numerals, but which are in -7the number series 100 to 199.

In the Figure 6 arrangement, the cooperable key forms 107 and 115 may be substantially as described in relation to Figures 1 to 4. The principal difference between the arrangements of Figures 5 and 6 is the way in which the yokes 1 and 101 are connected to the members 9 and 109 respectively.

The member 109 is mounted on a differential drive shaft 120, and an axial extension 121 of that shaft 120 projects through a central opening 122 in the yoke body 102. A nut 123 engages with a screw thread formed on that extension 121 so as to hold the yoke 101 against the member 109. That arrangement enables rapid connection and separation of the universal joint to and from the drive shaft 120 and also enables the universal joint and the drive shaft member 109 to be secured together at a large number of different positions of relative rotation.

044 a That enables the universal joint to be attached at a rotational position of optimum balance so as to minimize vibration problems. Because of the limited number of 0004 S rotational positions of attachment in conventional assemblies 020' it is seldom possible to correct vibration problems by rotational positioning alone.

oa Figure 7 is included simply to illustrate application of S the invention to a constant velocity type of universal joint.

The outer race 201 of that joint is the functional equivalent oo* of the yoke 1 of the Figure 5 arrangement. As in the Figure arrangement, the outer race 201 is connected to a splined sleeve 209 through two engaging series of key forms as oo previously described.

0040 Various alterations, modificaticns and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from trhe spirit or ambit of the invention as defined by the appended claims.

39 -8-

Claims (8)

1. 4. A primary member according to any preceding claim, wherein each said side surface lies on a straight line which passes through said rotational axis.
2. 5. A primary member according to any preceding claim, wherein said primary member forms the yoke of a Cardan or Hooke type universal joint.
3. 6. A primary member according to any one of claims 1 to 4, wherein said primary member forms the input or output member of a constant velocity type universal joint.
4. 7. An assembly including a primary member according to any preceding claim and a said other rotational member, said cooperable key forms of the other member engaging with said "J body key forms, and securing means releasably securing said i >KH 9 I-9- A body and said other member against separation.
5. 8. An assembly according to claim 7, wherein each of at least two said body key forms engages within a substantially complementary key form recess of said other member.
6. 9. An assembly according to claim 7 or 8, wherein said securing means includes two clamping studs which are operable to releasably clamp said body and said other member against separation, and which do not need to be removed from said assembly when released to permit such separation.
7. 10. An assembly according to claim 7 or 8, wherein said securing means includes a shaft to which said other member is connected, an axial extension of that shaft projecting axially through said body, and a screw threaded nut threadably engaging with said shaft extension and engaging said body. 35 11. A universal joint primary member substantially as herein a*€ l particularly described with reference to any one of the embodiments as shown in the accompanying drawings.
8. 12. A universal joint assembly substantially as herein particularly described with reference to any one of the 20 embodiments as shown in the accompanying drawings. S. DATED: 9 September, 1991 UNIDRIVE PTY. LTD. By its Patent Attorneys: PHILLIPS, ORMONDE FITZPATRICK 7774k 39 3 9 10