GB1585163A

GB1585163A - Universal joint and shaft assemblies

Info

Publication number: GB1585163A
Application number: GB26244/76A
Authority: GB
Original assignee: GKN Transmissions Ltd
Current assignee: GKN Automotive Ltd
Priority date: 1976-06-24
Filing date: 1976-06-24
Publication date: 1981-02-25
Also published as: SE7707130L; IN150877B; FR2356048A1; CA1083371A; IT1083363B; CA1068501A; ES470893A1; NL7706993A; DE2728306C2; SE432133B; JPS53361A; DE2728306A1; FR2356048B1; JPS6154965B2; ES459998A1

Description

(54) IMPROVEMENTS RELATING TO UNIVERSAL JOINT AND SHAFT ASSEMBLIES (71) We, GKN TRANSMISSIONS LIMITED, a British Company of P.O. Box 405, Chester Road, Erdington, Birmingham B24 ORB, West Midlands, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to universal joint and- shaft assemblies and methods of making same. The invention -has been developed primarily for application to assemblies of this kind for use in motor road or other automotive vehicles for transmitting the drive from the prime mover to driving wheels either at the rear or at the front of the vehicle.

It is desirable to avoid or minimise vibration due to an out-of-balance mass in such assembly, a condition which exists when the combined centre of mass of the universal joint and the shaft member is offset radially from, i.e. is eccentric with respect to, the axis about which the shaft member and the member of the universal joint to which the shaft is secured rotate.

Such eccentricity can be brought about by the following causes. Firstly, the axis about which the assembly of shaft member and the member of the universal joint connected thereto actually rotates is determined by the axis of rotation of the other member of the universal joint, and eccentricity may be produced by the dimensional tolerance in the universal joint itself and the accuracy of fit of the universal joint members with respect to each other, i.e. presence or absence of any radial play or lost motion. Secondly, eccentricity may be produced by reason of lack of accuracy with which the shaft member is connected to that part of the universal joint member to which it is connected and- which usually is in the form of a stub . shaft or spigot (of which the geometrical axis -should ideally be coaxial with the actual axis of rotation of the universal joint). Thirdly, eccentricity may be produced by the actual centre of mass of the- shaft member not lying on the geometrical axis of the shaft member, i.e.

being offset radially therefrom.

In many cases the universal joint and shaft assembly is required to transmit drive to the input element of a combined reduction and differential gear, the output elements of which are connected respectively to drive shafts which in turn are connected to the driving wheels of the vehicle, usually but not invariably at the rear thereof.

In such cases thé. shaft member which forms part of said assembly is normally termed the propeller shaft and rotates at an appreciably higher speed than does either of the drive shafts, typically three -or four times as high, and consequently the elimination or minimisation of eccentricity giving rise to vibration is especially important.

Whilst- - continuous research and development has been directed to the elimination of the first cause of eccentricity referred to above, it is still necessary to accept that because of production -tolerances a significant number of assemblies will present some eccentricity arising from the first cause but within said production tolerances. Furthermore, although normal methods of joining the shaft member to the universal joint member to which it is required to be connected, and in particular welding methods, have been carefully designed to avoid or minimise the second cause of eccentricity, here again it has to be accepted that in mass production some of the assemblies produced will exhibit eccentricity through this second cause.

-With regard to the third cause of eccentricity, minimisation of this is often somewhat beyond the control of a manufacturer of assemblies of the kind specified in that reliance has to be placed upon the adherence to accurate tolerances by the suppliers of tubular stock from which such shaft members are made. Accuracy in this respect is closely related to price and for the price which is acceptable, having regard to the product to be produced and its intended use, for example in mass produced motor vehicles, it is clearly necessary to tolerate some eccentricity from this third cause.

The present invention is based upon the concept that vibration arising from all three causes of eccentricity is capable of being reduced if the overall mass of the assembly, and in particular the shaft member, can be reduced.

Conventional practice is to make the shaft member and the universal joint member to which it is to be connected of a ferrous metal such as steel or cast iron, and to join these members to each other by welding.

The use of welding technique for this purpose does represent a design constraint by reason of the fact that the metals employed for two members.must then necessarily be selected to have welding compatability. Further, the use of a ferrous metal for the manufacture of the universal joint member (or indeed the universal joint as a whole) is consequent upon the necessity in a large number of applications, such as propeller shaft in universal joint assemblies for motor vehicles, to comply with strength requirements which have to be met.

The present invention is based upon the concept of reducing the overall mass of the assembly and involves the provision of a mode of securement of the shaft member to the universal joint member which overcomes the compatability constraint.

According to the present invention, we provide a method of making an assembly of a shaft member and a universal joint member comprising the steps of:- (a) providing a shaft member of tubular form and a universal joint member with a part which interfits with the shaft member, (b) forming at least one of said parts to define, in combination with the other of said parts, a cavity for receiving an adhesive substance, said cavity having first and second openings communicating with it at spaced positions, (c) fitting such shaft member and the universal joint member together, (d) injecting the adhesive substance through the first said opening into the cavity, thus expelling air from the cavity until the cavity is full of the adhesive substance, (e) subjecting the assembly to treatment to cure the adhesive substance and establish a bond between the shaft and universal joint member.

Embodiments of assemblies in accordance with the invention and methods of making such embodiments will now be described, by way of example, with reference to the accompanying drawings where in:- FIGURE 1 is a view in side elevation and in vertical diametral section of a portion of a shaft and universal joint assembly showing the connection of the shaft member to one of the members of the universal joint and forming a first embodiment of the invention; FIGURES 2 and 3 are transverse crosssectional views in the planes BD, and AC respectively shown in Figure 1; FIGURE 4 is a view similar to Figure 1 illustrating a second embodiment and -method of making same; FIGURE 5 is a view illustrating the application of material to a mandrel for making the shaft member of the embodiment of Figure 4 and forming an internal cavity therein; Referring firstly to Figure 1, the assembly comprises a universal joint member 112 and a shaft member 111. For convenience only one end portion of the shaft member is shown. A like universal joint member may be provided at the opposite end or according to requirements this other end may have other means for connecting it in the drive or transmission line. The universal joint member shown is a yoke of a Hookes type joint, comprising laterally spaced - axially projecting yoke arms 114 connected by a base part 116.

The universal joint member may be formed of a ferrous metal by casting, forging or fabricating methods in order to provide the necessary strength for applications such as propeller shaft and universal joint assemblies for motor vehicles.

The shaft member 111 is formed of a light weight material, for example aluminium alloy, such shaft member being of tubular form.

The shaft member 111 and the member 112 are secured in assembled relationship by the provision of respective axially interfitting parts llla and 112a, and by the introduction of an adhesive substance between these parts which is subsequently subjected to heating to cure the adhesive.

The shaft is assembled with its part llla over the spigot 112a.

It will be noted that portions lllg, 112g and lllh, 112h of the adjacent axially and circumferentially extending surface of the parts Illa, 112a are in direct contact with each other, i.e. without the intervention of any adhesive substances, and thereby provide accurate location of the parts llla, 112a in coaxial relation.

As- a safeguard against axial separation of the parts 1-lla, 112a these are formed with mutually cooperative formations to prevent such separation. Thus, the member 112 of the universal joint is formed with a groove 125 between the spigot 1 12a and the base 116, such groove presenting an axially facing shoulder 125a directed away from the main length of the shaft member 111 and which is engaged by a lip 126 at the free end of the tubular shaft member produced by acting mechanically on the extremity of the shaft member by a pair of radially inwardly movable tools such as 126a to produce permanent inward deformation.

The deformation of the shaft may be effected after heat treatment to effect setting of the adhesive substance, or during, or. before such heat treatment as may be convenient.

If Fthe shaft member 111 is made of an aluminium alloy there will be a temperature limit above which it should not be raised in order to avoid impairment of the mechanical properties, e.g. strength of the shaft, typically this temperature would be in the region of 200"C.

Heating, therefore, would then be in the range 1700C to a temperature representing a suitable margin below 200"C, such as 1900C. Clearly the temperature would be selected to suit the particular materials involved.

The heat treatment may be effected by a batch process, i.e. placing a quantity of the universal joint and shaft assemblies in a chamber in which the atmospheric tem perature is in the range appropriate to the adhesive and materials employed, or by passing the assemblies in succession through the chamber in which the atmophere is raised to the appropriate temperature.

The external face of the spigot part 112a incorporates a passageway system for the reception of an adhesive in liquid or other flowable form. Such passageway system may comprise a series of axially spaced circumferentially extending grooves 112c to 112f. The grooves 112e, 112f and 112c, 112d are connected at their lower sides, as seen in Figure 1, by axially extending grooves such as 127 in Figure 2, while grooves 112d and 112e are connected at their upper sides by an axially extending groove such as 128a; Grooves 128b, 128c aligned with groove 128a also exist in the planes A and B to provide respect tively for the adrnission of adhesive to the groove system through an injection passageway 129, and for venting to the interior of the tubular shaft 111. Such injection can be effected by engaging an injection nozzle 129c in the entrance of the passageway 129 and operating a pump forming part of the injection means.

- The end part Illa of the shaft 111 is a close sliding fit on the spigot part 112a and is coaxially located by direct contact over portions of the adjacent internal and external faces between the grooves.

Alternatively flhe groove system may comprise a single helical groove extending glong the outerface of the spigot part 112a communicating- at one end with the pass ageway 129 and at the opposite end with a venting groove such as 128 in the plane A.

In the embodiment illustrated in Figure 4-and the method of making it illustrated in Figure 5, parts corresponding to those already described in preceding embodiment are designated by like reference numbers with the prefix 2 and the preceding description is to be deemed to apply, reference being made now principally to the differences.

The tubular shaft member 211 which is made of an epoxy resin mixture reinforced with longitudinally extending fibres, for example carbon fibres, incorporates in its end part 21 la a relatively wide shallow groove 230 of helical form for the reception of the adhesive substance 224, the latter being injected through an opening 229 in the opposite end of the groove 230 providing venting to the interior of the shaft member 211.

As seen in Figure 5, the groove 230 is formed by winding a strip 231 of a material helically around a part of mandrel 232 upon which the shaft member 211 is moulded.

A suitable material for the helical strip 231 is a tape woven of a fibre. capable of withstanding temperatures involved in curing the resin component of the shaft member. A possible alternative to form the tape would be a metal foil.

The shaft member 211 may be formed by - winding reinforcing fibres, for example glass fibres and/or carbon fibres 233, helically around the mandrel and over the strip 231, alternate layers being preferably wound helically in opposite hands or directions. This step of the method is continued until a thickness nearly equal to the desired thickness of the shaft member is achieved and then axially extending reinforcement materials such as carbon fibres or glass fibres 234 are laid axially over the helical winding 233 already referred to and the whole is impregnated with the epoxy resin mixture, for example by applying it in fiowable form by means of a brush 236.

The shaft member thus formed, and still retained on the mandrel 232, is then subjected to heating, e.g. by passing through an oven heated to a temperature of the order of 180 C- to effect curing.

The mandrel 232 is then removed axially leaving the strip 231 in place.

The strip 231 may be left in place until the shaft member is actually required to be assembled with its end part 211a in axially interfitting relationship with the part 212a of the associated universal joint.

The tape is then effective to prevent contamination of the groove 230 by air borne dirt and/or moisture or other contaminants.

Immediately preparatory to axially interfitting assembly of said parts, the strip 231 is removed to expose a helical passageway 230 and axial interfitment is effected with the end of the shaft member abutting a flange portion 235 of the universal joint member 212. An adhesive substance 224, as previously mentioned, is then injected through the passageway 229a, air being expelled through vent open- ing 229b at the opposite end of the pass ageway 230 and the resultant assembly subjected to suitable treatment, e.g. heat- ing, to set the adhesive and secure the shaft member and universal joint member together.

Instead of a woven tape, any suitable strip material capable of holding its shape under the conditions of moulding and after winding onto the mandrel may be em ployed, provided it is sufficietly flexible to permit it to be removed after the shaft member has been formed. Again, whilst the helical winding of the- strip material is especially convenient, removable material applied in a configuration to produce a passageway system of some configuration other than helical may be employed if desired.

Furthermore, alternatively or in addi- tion the part 212a of the universal joint member may incorporate a groove in its exterior surface, which groove may be defined by a removable strip.

Although in the foregoing description reference has been made to the formation of the universal joint members from a ferrous metal, e.g. cast iron or steel, it is to be understood that where the torque to be transmitted admits the universal joint member could itself be formed of a light weight (low density) material. This could be an aluminium alloy. The universal joint member may be formed as a casting, and the joint between the shaft member and the universal joint member could be effected as shown in any one of the preceding embodiments.

Further, the invention is of applica tion to an assembly of a shaft with some other form of universal joint member, e.g.

one from a constant velocity universal joint having inner and outer members and torque- transmitting - rotary elements such as balls engaging in formations such as grooves in the inner and outer members.

It is to be understood that, when we refer to the shaft member being made of a material having a substantially lower density than a ferrous metals of which such member is normally made, we refer to the average is density of the shaft member as a whole. In the case of a shaft member formed of a composite material, a component or components of the shaft may, taken individually, present a density of the order of, or even greater than, the density of ferrous metals, and yet the shaft member as a whole having an average density less than that having of such ferrous metals.

In the embodiment shown in Figure 4, a sealing component shown of suitable form may be provided, if necessary, between the end of the shaft part 211a and the flange portion 235 of the universal joint member 212, to prevent leakage of adhe sive at this point.

Another construction of shaft member with which the invention may be utilised is that of a -carbon fibre reinforced alu minium tube WILT WE CLAIM IS : - 1. A method of making an assembly of a shaft or member and a universal joint member comprising the steps joint (a) providing a shaft member of tubular form and a universal joint member or with a part which universal with the shaft mem ber, (h) forming at least one of said parts to define, in combination with the other of said parts, a cavity for receiving an adhesive substance, said cavity for having first and second openings communicating with it at spaced positions, (c) fitting such shaft member and the universal joint member and together, (d) injecting the adhesive substance through the first said opening into the cavity, thus expelling air from the cavity until the cavity is full of the adhesive substance.

(e) subjecting the assembly to treatment to cure the adhesive substance and establish a bond the between the shaft and universal joint member.

2. A method according to claim 1 wherein at least one of said shaft member and universal joint member is pro- vided with a plurality of circumferentially extending axially spaced grooves, interconnected by axially extending grooves, to define said cavity, said first and second openings communicating with respective ones of said grooves, and wherein said adhesive substance during injection there- of successively fills: said grooves.

3. A method according to claim 1 wherein at least one of said shaft member and universal joint member is provided

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. leaving the strip 231 in place. The strip 231 may be left in place until the shaft member is actually required to be assembled with its end part 211a in axially interfitting relationship with the part 212a of the associated universal joint. The tape is then effective to prevent contamination of the groove 230 by air borne dirt and/or moisture or other contaminants. Immediately preparatory to axially interfitting assembly of said parts, the strip 231 is removed to expose a helical passageway 230 and axial interfitment is effected with the end of the shaft member abutting a flange portion 235 of the universal joint member 212. An adhesive substance 224, as previously mentioned, is then injected through the passageway 229a, air being expelled through vent open- ing 229b at the opposite end of the pass ageway 230 and the resultant assembly subjected to suitable treatment, e.g. heat- ing, to set the adhesive and secure the shaft member and universal joint member together. Instead of a woven tape, any suitable strip material capable of holding its shape under the conditions of moulding and after winding onto the mandrel may be em ployed, provided it is sufficietly flexible to permit it to be removed after the shaft member has been formed. Again, whilst the helical winding of the- strip material is especially convenient, removable material applied in a configuration to produce a passageway system of some configuration other than helical may be employed if desired. Furthermore, alternatively or in addi- tion the part 212a of the universal joint member may incorporate a groove in its exterior surface, which groove may be defined by a removable strip. Although in the foregoing description reference has been made to the formation of the universal joint members from a ferrous metal, e.g. cast iron or steel, it is to be understood that where the torque to be transmitted admits the universal joint member could itself be formed of a light weight (low density) material. This could be an aluminium alloy. The universal joint member may be formed as a casting, and the joint between the shaft member and the universal joint member could be effected as shown in any one of the preceding embodiments. Further, the invention is of applica tion to an assembly of a shaft with some other form of universal joint member, e.g. one from a constant velocity universal joint having inner and outer members and torque- transmitting - rotary elements such as balls engaging in formations such as grooves in the inner and outer members. It is to be understood that, when we refer to the shaft member being made of a material having a substantially lower density than a ferrous metals of which such member is normally made, we refer to the average is density of the shaft member as a whole. In the case of a shaft member formed of a composite material, a component or components of the shaft may, taken individually, present a density of the order of, or even greater than, the density of ferrous metals, and yet the shaft member as a whole having an average density less than that having of such ferrous metals. In the embodiment shown in Figure 4, a sealing component shown of suitable form may be provided, if necessary, between the end of the shaft part 211a and the flange portion 235 of the universal joint member 212, to prevent leakage of adhe sive at this point. Another construction of shaft member with which the invention may be utilised is that of a -carbon fibre reinforced alu minium tube WILT WE CLAIM IS : -

1. A method of making an assembly of a shaft or member and a universal joint member comprising the steps joint (a) providing a shaft member of tubular form and a universal joint member or with a part which universal with the shaft mem ber, (h) forming at least one of said parts to define, in combination with the other of said parts, a cavity for receiving an adhesive substance, said cavity for having first and second openings communicating with it at spaced positions, (c) fitting such shaft member and the universal joint member and together, (d) injecting the adhesive substance through the first said opening into the cavity, thus expelling air from the cavity until the cavity is full of the adhesive substance.

with a helical groove defining said cavity with said first and second openings communicating with respective ends of said groove, said adhesive substance during injection thereof filling said groove from one end to the other end thereof.

4. A method according to claim 1 or claim 3 further characterised by forming at least one of said shaft member and universal joint member by a moulding operation, and incorporating in said member during such moulding a piece of material which is removed to define said cavity prior to assembly of said members.

5. A method according to claim 4 wherein said shaft member is formed by applying reinforcing fibres to a mandrel, impregnating such fibres with a synthetic resin material, and curing said resin to form the shaft member, a strip of material, constituting said removable material, being wound on the mandrel prior to the application of fibres thereto.

6. An assembly of a shaft member and a universal joint member, wherein the members have axially interfitting parts with overlapping circumferentially extending faces, said faces defining a cavity in which is received an adhesive substance which secures said members together said cavity being of elongate form having an inlet opening and a vent opening communicating with it at spaced positions, said adhesive substance having been injected through said inlet opening.

7. An assembly according to claim 6 wherein said cavity is defined by a plurality of axially spaced circumferentially extending grooves interconnected by axially extending grooves, said inlet and vent openings communicating with end ones of said grooves.

8. An assembly according to claim 6 wherein said cavity is defined by a helically extending groove, said inlet and vent openings communicating with opposite ends of said groove.

9. An assembly of shaft member and universal joint member substantially as hereinbefore described with reference to and as shown in Figures 1 to 3 of the accompanying drawings.

10. An assembly of shaft member and universal joint member substantially as hereinbefore described with reference to and as shown in Figure 4 of the accompanying drawings.

11. A method of making an assembly of shaft member and universal joint member substantiallv as herein described.