CA2026839C - Symmetrical universal joint - Google Patents

Abstract

A universal having two identical powder metal housing parts containing a generally spherical drive sphere drivingly connected to the housing by drive balls.

Description

202~39 Page #l SYMMETRICAL UNIVERSAL JOINT
This,invention relates to a universal joint.

Background of the Invention Universal joints are^utilized in a wide variety of applications to interconnect two shafts which or may not be angularly aligned. Examples of universal joints include Rzeppa (fixed) outer joints, inner double offset plunging joints, Rzeppa cross-groove constant velocity joints, and tripod joints among others. These joints transmit rotary power or movement between two shafts which may or may not be axially angularly aligned. Typical applications for universal joints include constant velocity joints for front wheel drive vehicles, power take off drives for tractors, and steering wheel interconnect shafts. Other than their operative characteristics (transmitting power or rotation between shafts which may not be in axial angular alignment), these universal joints have another attribute in common, and this is their complexity of construction. This complexity includes the cages which retain the ball bearings in position (in ball type joints) and the intricate machining necessary to construct the housing, inner braces, and other functional parts of the universal joints.
This complexity increases the costs and physical sizes of universal joints as well as acting to reduce the number of available cost effective applications for such joints.

Objects of the Invention It is an object of this invention to reduce the manufacturing costs of universal joints.

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Page #2 It is an object of this invention to increase the number of applications for universal joints.
It is an object of this invention to increase the service life of universal joints.
It is an object of this invention to reduce the size of universal joints.
Other objects and a more complete understanding of the invention may be had by referring to the drawings in which:

Drawings FIGURE 1 is an exploded perspective view of a universal incorporating a preferred embodiment of the invention of the application;
FIGURE 2 is a side view of one of the housing parts of the universal of Figure l;
FIGURE 3 is a view of the other side of the housing part of Figure 2;
FIGURE 4 is an expanded side view of the actual universal of Figure 1;
FIGURE ~ is a longitudinal cross-sectional view of the universal of Figure 1;
FIGURE 6 is a longitudinal cross-sectional view of a universal like Figure 5 incorporating stamped housing members;

FIGURE 7 is a simplified side view of an engine drive shaft transmission combination incorporating two universals;
FIGURE 8 is an enlarged longitudinal cross-sectional view of the two universals of Figure 7; and, FIGURE 9 is a break away perspective view of a drive train incorporating two universals like Figure 1.

,_, ,, .,, _ ~o2b8~9 Page #3 Description of the Drawings This' invention relates to a improved universal joint.
The invention will be described in its preferred embodiment of a drive shaft universal for a front engine, rear transmission shaft drive lawn and garden tractor. The universal can be utilized in other applications involving rotary connected shafts if desired.
The preferred universal 10 includes a housing 11, a drive sphere 20, drive balls 21 and an adaptor 14. The total universal 10 is 2.75" in diameter and 2.20" long (of which length the operative housing 11 contributes about half).
The housing 11 serves as one of the two main drive parts for the universal. The primary purpose of the housing 11 is to mechanically interconnect the universal 10 to one of the two incoming drive shafts. This interconnection can be direct or via an intermediate part (such as the adaptor 14). The universal disclosed uses an intermediate part. The preferred housing 11 is constructed of two identical parts 12, 13 which are affixed together as a unit. In the particular embodiment disclosed in Figure'1, the parts are powder metal castings and this fixing together occurs via the use of a series of four bolts 15 which extend through holes 16 in the parts 12, 13.
These bol,ts 15 also hold the adaptor 14 (and later described end cap 17) to the housing 11. This use of a single fixing means for multiple purposes is preferred (but not necessary).
In the embodiment of Figure 6 the parts 12, 13 are stampings, again held together with bolts 15.
Each part 12, 13 includes a central cavity 18,with surrounding radially extending ball slots 19. It is preferred ~ 2~2~'~3~

Page #4 that the cavity 18 be completely spherical so as to accommodate a great range of misalignment between the incoming and outgoing shafts (as later described). The shape of the ball slots 19 are selected to match the drive element (balls shown~ that mechanically interconnect the housing 11 and drive sphere 20.
Preferably the circumferential tolerances of the slots 19 are such that there is no shifting or chattering under uneven torque transfer type operation. In this respect it is also preferred that the sides of the slots 19 be substantially perpendicular to the torque loads at the union between the housing 11 and drive sphere 20. This allows for an efficient transfer of forces from the housing 11 to the drive balls 21 (as later described). It is also preferred that the ball slots 19 have an arcuate semi-circular cross sectional shape generally tracking the diameter of the spherical cavity 18.
This arcuate shape retains the drive balls 21 in their designed position throughout the operational angular shifting between the housing 11 and drive sphere 20 while spreading the outward forces that may exist over a large surface area. This allows a uniformity of operative characteristics throughout any angular misalignment and a'smooth power transfer between drive parts while also maintaining structure by reducing the possibility of stress caused deformation of parts. The size and number of ball slots 19 are as later described.
The parts 12, 13 shown in Figure 1 are identical castings which are made of powder metal construction. The split down the middle of the housing, the line 30, allows these two castings 12, 13 to be made of powder metal material in a pressing type operation in a single die due to the fact that ~:: 2026~39 ~ .

_ Page #5 all of the surfaces thereof are available to a two-piece solid die construction--i.e. all surfaces can be accessed from a given plane (see Figures 2 and 3). The use of powder metal construction for these castings 12, 13 significantly reduces the cost of the universal by allowing for the efficient manufacture of these parts.
In the preferred embodiment disclosed, each casting 12, 13 is a cylindrical part some 2.75" in diameter and .562"
thick. The spherical cavity 18 is some 1.62" in diameter with its center located at one of the planar end surfaces of the individual castings. The ball slots 19 extend symmetrically off of the cavity 18 some .625" in diameter with their central point displaced some .575" from the center of the spherical cavity 18. The outer edge of the ball slots 19 trace an arcuate line some 2.25" from the center of the spherical cavity 18. This line has a cross section of .625" in diameter. The .260" diameter mounting holes 16 extend axially through the casting between the ball slots 19 some 1.10" from the center of the spherical cavity 18.
The par~s 12A, 13A in Figure 6 are quasi-identical stampings. (Quasi-identity occurs through the incorporation of an adaptor 14A integrally with part 12A, later described. If desired full identity could be utilized with a separate adaptor 14.) The inner shape and dimensions of these parts 12A, 13A
match the inner shape and dimensions of the castings 12, 13 of Figure 1. The outer shape of the parts 12A, 13A is selected for strength and cost effectiveness. Flying buttress type folds could be utilized if desired (and indeed would be appropriate to strengthen the 12A to 14A joint).

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Page #6 The drive sphere 20 is the other main drive part for the universaI. This sphere 20 thus mechanically interconnects the universal 10 to the other of the drive shafts. The preferred drive sphere 20 of Figure 1 is a generally circular solid steel partially spherical element with a central hole 25 and a surrounding surface 26. This sphere 20 has been machined from steel.
The central hole 25 serves as the main mechanical interconnection between the drive sphere 20 and the other of the drive shafts. In the particular embodiment shown this mechanical interconnection is provided by a multiplicity of small grooves extending axially around the inner surface of the hole 25. Other connections could also be utilized.
The diameter of the outer surface 26 of the sphere 20 is preferably selected to match the inner diameter of the spherical cavity 18 of the housing 11. This retains the sphere 20 within the housing 11 for smooth movement. In respect thereto, the outer surface 26 of the drive sphere 20 thus serves to locate the drive sphere 20 in its operative position in the central cav~ty 18 of the housing 11 while also providing a bearing surface.for the relative rotation between these two parts. (The fact that the housing 11 is of powder metal construction facilitates this rotation.) Note that in the particular embodiment disclosed the drive sphere 20 has truncated flat ends 31 instead of a continuation of the outer curved surface 26 of the drive sphere 20. The use of these truncated surfaces 31 reduces the axial length of the universal and also serves to allow the use of stronger flanges than would otherwise be available for use with the universal (by allowing 3~

Page #7 the flanges to overlay the central cavity 18--flanges later described). 'These truncated surfaces 31 have no significant effect on the rotary interconnection between the housing 11 and drive sphere 20--i.e. the rotary action remains smooth. The ball holes 27 in the outer s~rface 26 of the drive sphere 20 serve to hold the drive balls 21 which mechanically interconnect the housing 11 and drive sphere 20. The diameter of the ball holes 27 is selected to be substantially equal to the diameter of the drive balls 21 with the depth of the ball holes 27 being substantially equal to one-half of the diameter of the drive balls 21. This depth insures that the drive balls 21 pass the forces between the drive sphere 20 and the housing 11 at the ball's maximum diameter. This causes the forces to be transferred between the drive parts substantially perpendicularly to the interconnecting parts. This reduces the inefficient vector forces which may be present in other than a circumferential direction should the drive balls interconnect the drive sphere 20 and the housing 11 at a location other than substantially the center line of these drive balls. The-use of the maximum diameter of the balls 21 also optimizes the force transfer by equalizing the surface area available for the torque transfer--i.e. same surface area available to the housing 11 as to the drive sphere 20. The number of ball holes 27 matches the number of ball slots 19 in the housing 11. In the particular embodiment shown this is four in number.
In the preferred embodiment disclosed in Figure 1, the drive sphere~20 is a steel truncated sphere some 1.62" in diameter and .800" wide. The hole 25 is a maximum of .75" in diameter inclusive of spline depth (.718" at inner extension of ~ 202~8~9 ..~. ,, Page #8 the spline teeth). Four semi-circular cavities or ball holes 27 some .625" in diameter extend off of the outer surface 26 of the sphere towards the center of the drive sphere 20. The semi-circular ball holes 27 are centered in respect to the width of the drive sphere 20.
The drive sphere 20A of Figure 6 is an integral powder metal part having the external shape and dimensions of the sphere 20 of Figure 1 with the inclusion of the drive balls--i.e. a 1.62" diameter truncated sphere with four integral .625" diameter semi-circular protrusions 21A extending thereof.
The drive balls 21 mechanically interconnect the housing 11 and drive sphere 20 while also allowing for some angular misalignment therebetween. The number of ball slots l9 can vary. In general the greater the number of ball slots 19 (and balls), the smoother the drive transfer. (Note, however, that with increasing numbers of ball slots 19 and/or smaller balls the complexity of the universal increases. In addition dimensional and strength limitations are introduced.) The drive balls 21 accomplish this by angularly shifting in the ball slots 19 of-the housing 11 so as to automatically compensate between the angular misalignment between the drive sphere 20 and the housing 11. Normally this misalignment is plus or minus 10 degrees. This is the range of misalignment accommodated of the preferred embodiment. However, should the application warrant, universals built in accord with the invention can accommodate larger angular misalignments.
Normally the greater the number of drive balls 21 and/or the greater the tolerances--i.e. slop, the higher the angular 2 0 ~

Page #9 misalignment is that can be accommodated. (Note, however, that a very limited number of balls--i.e. one ball or two balls 180 opposite to each other--could accommodate the highest misalignment irrespective of tolerances.~
In the preferred embodiment disclosed, each drive ball 21 is a steel sphere some .625" in diameter.
The adaptor 14 is an intermediate, optional part that mechanically interconnects the housing 11 with one of the two drive shafts. To accomplish this the adaptor 14 is bolted onto one side of the housing 11 as shown in Figure 1. sy having a separate adaptor 14 instead of making the adaptor integral with one of the parts 12, 13, two purposes are satisfied. The first purpose is to expand the number of applications which are possible for the universal 10: By having an independent adaptor 14 a wide variety of drive shafts can be accommodated by a single universal by using different adaptors. The second purpose which is served by having a separate adaptor 14 is that the adaptor 14 can be made out of a materlal different than the housing 11. This allows one to match the strength of the adaptor 14 to the particular application involved instead of needing to have a housing 11 which can match all applications.
In the particular embodiment disclosed the adaptor 14 has a solid flange 35 with a woodruff key interconnection with the contained shaft. The solid flange 35 has an external diameter to match the parts 12, 13. A reduced diameter section 36 extends from this flange 35 in order to increase the axial length available for interconnection to the contained shaft. A

hole 37 serves to align the contained shaft with the adaptor 14. (Note that in some applications the housing 11 could be 20268'~9 _ Page #10 bolted directly onto a shaft, thus eliminating the adaptor 14.
This could occur, for example, if the housing 11 was bolted directly onto an output flange of an engine as shown in Figures 7 and 8.) In the preferred embodiment disclosed, the flange 35 of the adaptor 14 is some 2.75" in diameter and .25" thick with a two step reduced diameter section 36 extending off thereof (1.62" diameter near the flange 35, then 1.25" in diameter).
Each step is substantially .5" in length. The hole 37 in the adaptor 14 is some .625" in diameter and .5" deep.
Note that under some circumstances having the adaptor 14 integral with the parts 12, 13 may be desirable. One of these circumstances is shown in Figure 6. The parts 12A, 13A
are stampings. Under this circumstance it is possible to design a more inexpensive mass produced unit through the use of a single stamping for both the housing part and adaptor 14.
This is especially so since the adaptor 14 would otherwise have to be of significant size to accomplish its purpose--i.e.
having to fit over the housing part in order to be bolted thereto.
An end cap 17 with integral resilient flange 40 is an optional part to the universal 10. This end cap 17 serves to retain the grease in the universal 10 as well as providing for a mechanical shield for the drive shaft which interconnects with the center hole of the drive sphere 20. The end cap 17 shown includes a steel circular member having an outer diameter substantially equal to the outer diameter of the housing 11 to which is integrally molded a hat shaped resilient flange 40.
The center diameter 41 of the resilient flange is so selected , ~- 2026839 _ Page #11 to substantially match the outer diameter of the drive shaft which will bè utilized with the drive sphere 20. The step 42 between the outer and inner portions of the resilient flange 40 allows for some angular misalignment of the shaft in respect to the housing 11 while allowing the flange 40 to retain some sort of mechanical seal to the shaft. This keeps the grease within the universal and contaminates out. Although this end cap 17 is not necessary for the mechanical operation of the universal 10 it is preferred for its ability to maintain the mechanical integrity of the universal 10. As with the adaptor 14 the end cap 17 has many variations to suit a particular application.
For example the end cap of Figure 1 is a device having a resilient flange 40. However, the device of Figure 7 includes an end cap 150 having a central resilient section 151 and a outwardly extending plastic fan 152. This end cap 150 therefore serves the dual purpose of providing a mechanical seal for the integrity of the universal 10 while also providing a mechanical drive and location for a auxiliary fan 152 for cooling an associated part.
In the ~referred embodiment, the end cap 17 includes a steel circular member some 2.75" in diameter punched out of 14 gauge steel. The hat shaped resilient flange 40 includes a section bonded to the 14 gauge steel (same 2.75" diameter some .05" thick) and an extending section some 1.56" in outer diameter and .745" in inner diameter. The total depth of the end cap is .9".

Note that in the instance of stamped parts 12A, 13A, it would be desirable to have the end cap 17A snap over the stamping as shown, thus eliminating extraneous material.

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_ Page #12 Normally the universals are used in multiple pairs (see Figures 7-9). In these Figures 7-9 there are two universals 50 and 51 which serve to mechanically interconnect a engine 53 and a transaxle 54 via a drive shaft 55. The engine 53 shown is a Koller engine having a output flange 57. This output flange 57 has a surface with four holes contained therein. In this particular embodiment the pitch circle of these four holes exactly matches the pitch circle of the hole 16 in the described preferred housing 11. For this reason the housing 11 can be bolted directly onto the output flange 57 of the engine 53 thereby eliminating the need for a separate adaptor 14. An end cap 17 is bolted on the other end of the housing 11 in this particular embodiment. The universal 51 in turn interconnects the shaft 55 with the transmission 54.
Since the particular transmission 54 is a hydrostatic transmission additional cooling is desirable. For this reason a fan 152 is incorporated into the end cap 150. Again there is a resilient section 151 on the inside of the end cap so as to maintain the integrity of the housing 11 of this universal 51.
A solid flange 35..is utilized with the adaptor 14 in order to interconnect the ~niversal 51 with the transmission 54. Note that the output flange 57 of the engine has a surface A which will not allow the drive shaft 55 to move beyond a certain point. Similarly the adaptor 14 of the universal 51 has a similar surface B which would prevent the passage of the end of the drive shaft 55 beyond a second certain point. The length of this drive shaft 55 is preferably selected to be just slightly less than the distance from A to B. This length of drive shaft will be retained in its operative position even Page #13 though there is no other mechanical stop to hold it, i.e. the ends of the drive shaft are slidingly fitted within the hole 25 of the drive spheres 20 such that the drive shaft 55 can move axially in respect to the spheres without disengaging the same.
This allows the drive shaft 55 to center itself in respect to the universals 50, 51 and to compensate for any thermal expansion, manufacturing tolerances, or other things which may serve to alter the distance A to B.
Although the invention has been described in its preferred form in a certain degree of particularity, it is to be understood that numerous changes can be made without deviating from the invention as hereinafter claimed. Material substitutions (for example plastic moldings or stampings) and other changes could be made including various combinations of parts without departing from the claimed invention.

Claims (27)

1. A universal joint for connecting two shafts comprising a first housing part, a second housing part, said first housing part being removably connected to said second housing part so as to form a housing, a spherical cavity, said spherical cavity being in said housing, a ball slot, said ball slot being in said housing extending off of said spherical cavity, a drive sphere, said drive sphere being in said spherical cavity, a drive ball part, said drive ball part extending off of said drive sphere and into said ball slot in said housing so as to drivingly interconnect said drive sphere to said housing, a drive hole, said drive hole being in said drive sphere connecting said drive sphere to one shaft of the two shafts, an adaptor, said adaptor being removably bolted to one side of said housing to mechanically interconnect said housing to the other shaft of the two shafts.

2. The universal joint of Claim 1 characterized in that said first housing part and said second housing part are identical.

3. The universal joint of Claim 1 characterized in that said first housing part and said second housing part are powder metal castings.

4. A universal joint for connecting two shafts comprising a first housing part, a second housing part, said first housing part and said second housing part being steel stampings, said first housing part being removably connected to said second housing part so as to form a housing, spherical cavity, said spherical cavity being in said housing, a ball slot, said ball slot being in said housing extending off of said spherical cavity, a drive sphere, said drive sphere being in said spherical cavity, a drive ball part, said drive ball part extending off of said drive sphere and into said ball slot in said housing so as to drivingly interconnect said drive sphere to said housing, a drive hole, said drive hole being in said drive sphere slidingly connecting said drive sphere to one shaft of the two shafts to allow axial movement between said drive sphere and said one shaft, adaptor means, said adaptor means being fixedly connected to one lateral side of said housing and said adaptor means mechanically interconnecting said housing to the other shaft of the two shafts.

5. The universal joint of Claim 1 characterized in that said drive sphere is truncated by flat surfaces in an axial direction.

6. A universal joint for connecting two shafts comprising a first housing part, a second housing part, said first housing part and said second housing part being steel stampings, said first housing part being removably connected to said second housing part so as to form a housing, a spherical cavity, said spherical cavity being in said housing, said spherical cavity having a depth, a ball slot, said ball slot being in said housing extending off of said spherical cavity for the full depth thereof, a drive sphere, said drive sphere being in said spherical cavity, a drive ball part, said drive ball part extending off of said drive sphere and into said ball slot in said housing so as to drivingly interconnect said drive sphere to said housing, a drive hole, said drive hole being in said drive sphere connecting said drive sphere to one shaft of the two shafts, an adaptor, said adaptor being connected to one lateral side of said housing, said adaptor being integral with said integral housing, and said adaptor fixedly mechanically interconnecting said housing to the other shaft of the two shafts.

7. A universal joint for connecting two shafts comprising a first housing part, a second housing part, said first housing part being removably connected to said second housing part so as to form a housing, a spherical cavity, said spherical cavity being in said housing, a ball slot, said ball slot being in said housing extending off of said spherical cavity, a drive sphere, said drive sphere being shafts, an adaptor, said adaptor being removably bolted to one side of said housing to mechanically interconnect said housing to the other shaft of the two shafts.

8. The universal joint of Claim 7 characterized in that said first housing part and said second housing part are identical.

9. The universal joint of Claim 7 characterized in that said first housing part and said second housing part are powder metal castings.

10. The universal joint of Claim 7 characterized in that said first housing part and said second housing part are steel stampings.

11. The universal joint of Claim 7 characterized in that said drive sphere is truncated by flat surfaces in an axial direction.

12. The universal joint of Claim 7 characterized by the addition of an end cap, said end cap having a resilient flange with a hole therein, and said end cap being mounted to said integral housing with the one shaft connecting to said drive sphere running through said hole in said resilient flange.

13. The universal joint of Claim 12 characterized in that said end cap, said first housing part, said second housing part and said adaptor means are bolted together.

14. A universal joint for connecting two shafts comprising a first housing part, a second housing part, said second housing part being identical to said first housing part, said first housing part being removably connected to said second housing part so as to form a housing, a spherical cavity, said spherical cavity being in said housing, a multiplicity of ball slots, said ball slots being in said housing extending off of said spherical cavity, a drive sphere, said drive sphere being in said spherical cavity, a multiplicity of ball holes, said ball holes being in said drive sphere, said ball holes being equal in number to said ball slots, a multiplicity of drive balls, said drive balls being equal in number of said ball holes, each of said drive balls being in each of said ball holes in said drive sphere and said ball slots in said housing so as to drivingly interconnect said drive sphere to said housing, a drive hole, said drive hole being in said drive sphere connecting said drive sphere to one shaft of the two shafts, an adaptor, said adaptor being removably bolted on one side of said housing to mechanically interconnect said housing to the other shaft of the two shafts.

15. The universal joint of Claim 14 characterized in that said first housing part and said second housing part are powder metal castings.

16. The universal joint of Claim 14 characterized in that said first housing part and said second housing part are steel stampings.

17. The universal joint of Claim 14 characterized in that said drive sphere is truncated by flat surfaces in an axial direction.

18. The universal joint of Claim 14 characterized by the addition of an end cap, said end cap having a resilient flange with a hole therein, and said end cap being mounted to said integral housing with the one shaft connecting to said drive sphere running through said hole in said resilient flange.

19. The universal joint of Claim 18 characterized in that said resilient flange includes a fan extending externally thereof.

20. The universal joint of Claim 18 characterized in that said end cap, said first housing part, said second housing part and said adaptor are bolted together.

21. A universal joint for connecting two shafts comprising a first housing part, said first housing part being of powder metal, said first housing part having a depth, a second housing part, said second housing part being identical to said first housing part, said second housing part being of powder metal, said second housing part having na axially extending depth, said first housing part being removably connected to said second housing part so as to form a housing having an axially extending depth substantially equal to the sum of said axially extending depths of said first housing part and second housing part, a spherical cavity, said spherical cavity being in said housing, a multiplicity of ball slots, said ball slots being in said housing extending off of said spherical cavity, a drive sphere, said drive sphere having truncated ends with an axial distance therebetween, said distance being less than said depth of said housing, said drive sphere being in said spherical cavity, a multiplicity of ball holes, said ball holes being in said drive sphere, said ball holes being equal in number to said ball slots, a multiplicity of drive balls, said drive balls being equal in number of said ball holes, each of said drive balls being in each of said ball holes in said drive sphere and said ball slots in said housing so as to drivingly interconnect said drive sphere to said housing, a drive hole, said drive hole being in said drive sphere connecting said drive sphere to one shaft of the two shafts, an adaptor, said adaptor being removably bolted to one side of said housing to mechanically interconnect said housing to the other shaft of the two shafts.

22. The universal joint of claim 21 characterized byu the addition of bolts and said bolts fixedly connecting said first housing part, said second housing part and said adaptor together as a unitary whole.

23. A universal joint for connecting two shafts comprising a first housing part, said first housing part being of stamped metal, said first housing part having an axially extending depth, a second housing part, said second housing part being of stamped metal, said second housing part having an axially extending depth, said second housing part being identical to said first housing part, said first housing part being removably connected to said second housing part so as to form a housing having an axially extending depth substantially equal to the sum of said axially extending depths of said first and second housing parts, a spherical cavity, said spherical cavity being in said housing, said spherical cavity having a depth, a multiplicity of ball slots, said ball slots being in said housing extending off of said spherical cavity for the full depth thereof, a drive sphere, said drive sphere having truncated ends with an axial distance therebetween, said distance being less than said depth of said housing, said drive sphere being in said spherical cavity, a multiplicity of ball holes, said ball holes being in said drive sphere, said ball holes being equal in number to said ball slots, a multiplicity of drive balls, said drive balls being equal in number of said ball holes, each of said drive balls being in each of said ball holes in said drive sphere and said ball slots in said housing so as to drivingly interconnect said drive sphere to said housing, a drive hole, said drive hole being in said drive sphere connecting said drive sphere to one shaft of the two shafts, an adaptor, said adaptor being removably bolted to one side of said housing to mechanically interconnect said housing to the other shaft of the two shafts.

24. The universal joint of Claim 23 characterized by the addition of bolts and said bolts fixedly connecting said first housing part, said second housing part and said adaptor together as a unitary whole.

25. The universal joint of Claim 23 characterized in that said adaptor is integral with one of said first housing part or said second housing part.

26. In a drive system having drive holes in two universal joints, such two universal joints each having a housing, such two universal joints separated by a distance, such joints interconnected by a drive shaft with two ends in the drive holes respectively, such drive shaft having a length, the improvement of each of the two universal joints including an adaptor removably bolted to one side of the respective housing to mechanically interconnect such housing to a drive part, the drive shaft being slidably moveable in an axial direction between two extremes, one end of the drive shaft being in a drive hole in one of the two universal joints allowing axial movement thereof, a stop in such drive hole so as to axially abut the one end of the two ends of the drive shaft so as to prevent the further movement of the drive shaft through said hole and beyond one of said two extremes of the drive shaft, the other end of the two ends of the drive shaft being in a second drive hole in the second of the two universal joints allowing axial movement thereof and a stop in said second drive hole so as to axially abut the other end of the drive shaft so as to prevent the further movement of the drive shaft through said second hole and beyond the other of said two extremes of the drive shaft, and the length of the drive shaft being greater than the distance separating the two universal joints.

27. The drive system of Claim 26 characterized in that said stop means and said second stop means are spaced by a distance greater than said length of the drive shaft.