FR2591686A1 - TORQUE TRANSMISSION SEAL - Google Patents

Abstract

This axial retaining member 112, preferably a thermoplastic molded part in one piece, intended to lock, for example, a splined shaft 118 in a splined bore of a female element 114, for example of the inner cup d 'a constant velocity universal joint, has a cylindrical body 144 and, at one end, an inwardly projecting flange, which fits in a groove in the shaft and, at the other end, a protruding flange inwardly. 'outside and which fits in a groove in the bore of the female element. The body has a longitudinal region of reduced radial thickness to allow the retainer 112 to open while it is being mounted on the shaft 118. (CF DRAWING IN BOPI)

Description

l 2591686

  The present invention relates, in a first

  aspect, at a torque transmission joint comprising

  an axial retaining element intended to hold together

  two elements which can be separated by a displacement

  relative to one axis and, in another aspect, to a torque transmission joint comprising a shaft

  and a shaft receiving member which have

  cooperating with each other. The invention is particularly

  useful for preventing relative axial displacement in

  be a female element, such as a homokinetic universal joint inner cup belonging to a half-shaft assembly, and a shaft inserted into a countersunk bore

in the female element.

  It is well known, from GB-A-2 145 148, to provide such an axial retention member in the form of an axially extending annular collar made of an elastic material and having at one end , a

  flange protruding inwards for loosening

  ger in an annular groove of the tree. The other extreme

  collar has a protruding flange towards the ex-

  shell intended to mate with the bore formed in the female element. To mount the collar on the tree, one

  pushes it axially from one end of the

  the neck then deforming elastically temporally

  to take a larger diameter under the effect of the pressure exerted on the flange projecting inwards, which then snaps into position

in the annular groove.

  The degree of elasticity required for this

  the choice of materials Can be used for the collar and prevents the use of relatively rigid materials such as thermoplastics, which

  are very resistant to breakage resulting from

  during assembly or during the life of the universal joint. An object of the invention is to provide an axial retaining member of the type described

  above but which can be formed from a thermally

  moplastic harder, more dimensionally stable and more impact resistant than those used

until now.

  The object of the invention is therefore, in a first aspect, a torque transmission joint comprising a shaft coupled to a female shaft receiving element.

  in a way that prevents relative rotation, the

  bre and the separable shaft receiving element

  by a relative axial displacement and being held in

  against this relative axial displacement by an axial retaining member, said retaining member being formed of an elastic material and comprising a main body whose length extends along said axis and which has

  a first end, a second end and a step

  central sage that runs through said main body along

  the said axis; first coupling means,

  radially inwardly on said main body

  pal, disposed at said first end of this body or near this first end and engaged in

  a cavity of one of the elements constituted by

  bre and the shaft receiving member; and second

  coupling means, projecting radially towards the ex-

  on said main body, disposed at said second end of said body or near said second end and engaged in a cavity

  in the other of said elements, the shaft and the organ receiving

  tree tree; a plurality of longitudinal slots being formed in said main body and extending to

  from said second end to the first ex-

  trestle so as to divide said second end into

  a plurality of longitudinally flexible fingers, which sup-

  bear said second coupling means; character-

  in that the main body is equipped with a

  reduced radial thickness, which region

  extends longitudinally from the said former

  tremity and across said first coupling means

  to allow at least a portion of said main body in said region to cut in a controlled manner. Controlled cutting of at least a portion of the main body allows the axial retention member

  temporarily enlarge its inside diameter to

  calf of the first coupling means, to mount on the corresponding element, without requiring that the organ of

  axial restraint has a high elastic deformability

  only in the tangential direction. This makes it possible

  sea the axial retaining member in a harder, less deformable, more shock-resistant material, such as

than a thermoplastic material.

  Said region of reduced thickness extends

  in such a way as to meet one of the said

  longitudinal, so that the controlled break occurs over the entire length of the axial retaining member. The shaft is preferably sufficiently thick to prevent the second coupling means from disengaging from the cavity formed in the other of the two elements, the shaft and the shaft receiving member, thanks to the resistance that it opposes. to the radial deformation towards

  inside the second end of the retaining organ

  bare axial. This allows the tree to be much more

  that if we had to foresee means to

  put this radial deformation inward but,

  naturally, the axial retaining member must be

  on the shaft receiving member before insertion

of the tree does occur.

  The subject of the invention is also a process for

  the making of such an assembly, which consists in mounting

  axial retention member in the receiving member of

  engage said second coupling means of said axial retention member in said cavity of said

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  and then mounting said shaft in the axial retainer and the shaft receiving member, thereby forcing said portion of said main body to

  to cut himself into the said region, and to engage the aforesaid

  first coupling means in said closed cavity

in the tree.

  According to another aspect, the subject of the invention is a torque transmission joint comprising a splined shaft and a female member, shaft receiver, grooved internally so as to be complementary to the splined shaft and to cooperate with this shaft, characterized in that

  at least one groove enters two flute teeth

  adjacent to the tree or the receiving organ of ar-

  is blocked at an intermediate point between the ex-

  axial trenches of the grooved region of the shaft or the receiving member, the other grooves being unconnected at this axial point, so as to limit the displacement

  relative axial axis of the shaft and the

  ber. When using an axial retaining member in the seal described above with respect to the first aspect of the invention, the plugging of the groove or grooves avoids the deterioration of the axial retaining member.

  under the effect of sudden axial forces during the

semblage.

  Other features and advantages of the

  will be better understood when reading the description of

  following example of an embodiment and with reference to the accompanying drawings, in which,

  Figure 1 is a side view with tear-off

  partial parts of a half shaft assembly partially shown, with a constant velocity universal joint using an axial retaining member according to the invention;

  FIG. 2 is a perspective view of an or-

  axial restraint according to the invention; FIG. 3 is a view, on an enlarged scale,

  part of the whole of Figure 1 and which

  be the axial retaining member of Figure 2; and FIG. 4 is a sectional view taken according to the

line 4-4 of Figure 3.

  As will now be seen with reference to FIG. 1, a partly-illustrated half-shaft assembly comprises a universal joint of constant velocity or homokinetic type 110 and is equipped with a

  axial restraint 112 according to the invention. The universal joint

  salt 110, in general, is well known and, in

  sequence, we will refrain from describing in detail the names

  many individual elements of this joint in this specification. In addition, it will be easy for those skilled in the art to understand that, although it is described

  of a universal joint, the invention is applicable to the

  appearance of different other elements. The body of

  Axial Nude is particularly suitable for

  fluted trees and fluted elements

  in such a way as to prohibit any axial displacement

  between these trees and organs, but it can be used

  for other different assembly functions.

  The universal joint 110 comprises a bowl of the balls or inner cup 114 having an axial bore 116. A shaft 118 is mounted in the bore 116 and is prevented from rotating relative to this bore by complementary spline teeth 120 and 122 (FIG. 3) which protrude respectively on the shaft 118 and

  on the inner bowl 114. The axially

  112 is provided to prohibit the axial displacement of the shaft 118 relative to the inner bowl 114 and, further, to facilitate rapid assembly of the joint

universal 110.

  As shown in FIG. 3, the shaft 118 is provided with an annular groove 124 directed

  towards the outside which has a bottom and walls

  lairds each of which extends from the bottom to the outer peripheral cylindrical surface of the shaft 118.

2591686

  annular walls form stops to retain the

  against the relative displacement with respect to the

inner bowl 114.

  The inner bowl 114 is provided with an

  coaxially bore-bore 116 and annular groove 136 inwardly extending along

  counter-bore and opens radially into the con-

  tre-bore. As indicated in FIG. 3, the inwardly directed annular groove 136 has a bottom portion and two annular walls, each of which extends from the bottom portion of the groove to the shaft 118. tapered slope 141 is planned

  adjacent to the counter-bore and is sloping towards the

laughter, towards the counter-bore.

  The axial retaining member 112 takes the place of the spacer ring and the retaining ring which

  previously used in universal joints

  salts and, in addition, it facilitates the assembly of the universal joint

  The axial retainer 112 includes an elongated member that has a main body portion 144, as best shown in FIG. 2. The main body portion 144 is formed

  elastic material and has a generally

  a cylindrical form or a similar form of hollow revolution. The main body portion 144 has a first end 146 having an inwardly directed radial flange 148 formed at that end.

  or near it. The radial collar 148 di-

  inward rim has a basic cylindrical surface

  drique and annular outer and inner walls

  which extend generally perpendicular to the

  king of cylindrical base. As shown in FIG. 3, the main body portion 144 of the axial retention member 112 can be rotatably mounted on the shaft

  118, with the radial flange 148 directed towards the interior.

  mounted in the annular groove 124 facing outwards. As shown in FIG. 2, the axial retaining member 112 is provided with a second end 156 situated opposite the first end 146. An outwardly directed radial flange 158 is provided at the second end 156 or near

  this second end, to engage with

  rotation tee in the annular groove 136 of the bowl

  interior. The radial flange 158 directed towards the ex-

  interior is provided with a frustoconical surface with a

  increasing diameter in the direction extending from the second

  end 156 towards the first end 146 of the or-

  Axial retainer 112. The radial collar 158 di-

  outward is also provided with a surface

  annular 162 which extends generally perpendicular-

  the main body part 144 and which extends

  an outer cylindrical surface of the main body portion 144 of the axial retaining member 112 and the frustoconical surface, with the interposition of a surface

intermediate cylindrical 166.

  The axial retaining member 112 is furthermore

  or a plurality of longitudinal slots 168 which extend from the second end 156 of this member towards the first end 146 of this member, on a

  part of the length. The longitudinal slots 168 di-

  aim at the second end 156 of the axial retaining member 112 in a plurality of flexible fingers 170.

  longitudinal slots also divide the flange

  directed towards the outside in a plurality of

  independent collar parts. The example represents

  FIG. 2 has eight longitudinal slots 168 and therefore also eight flexible fingers 170. The first end 146 of the axial retainer 112 is provided with a region of substantially reduced thickness which extends along of a line

8 2591686

  longitudinal 180, the longitudinal line 180 beginning

  at the first end 146 of the axial retaining member

  112 and terminating at one of the longitudinal slots 168. The reduced thickness of the axial retaining member 112, measured along the longitudinal line 180, gives the axial retaining member a zone of weakness. which allows the axial retaining member to cut in a controlled manner along the longitudinal line 180 to assume a two-end or C-shaped configuration when the axial retaining member is mounted on the shaft 118 a universal joint 110 by inserting the end of the shaft 118 into the axial retaining member 112, after the axial retaining member 112 has been mounted in the bore 116 of the inner bowl

  114 of the universal joint 110. The thickness can be reduced

  to zero, so that the axial retaining member is then open, even before assembly. However, it is preferably reduced to a small fraction of

  the thickness of the adjacent areas, so that the

It cuts easily.

  The axial retaining member 112 can thus be mounted on the shaft 118 without requiring significant elastic deformation of this member in the tangential direction, which allows the use of a thermoplastic material

  harder, more dimensionally stable and more resistant

  shock aunt in the manufacture of the retaining organ.

  axial nude 112 that this would not be the case for an axial retainer that would not be designed to cut itself

  by taking such a configuration in C during the assembly

  wiring. The use of a hard, dimensionally stable, impact resistant thermoplastic material in the

  manufacture of the axial retaining member 112, is advan-

  as it strengthens the capacity for the organ

  axial restraint to resist failure at the following

  deformation under the loads of the type that one

  may meet during assembly of the universal joint

  for example, or during the service life of such a universal joint 110. A glass-impregnated nylon (polyamide) thermoplastic material has been found to be well suited for be used in the manufacture of

  the axial retaining member by injection molding.

  The axial retaining members advantageously have a one-piece configuration, the main body

  being in one piece with the collars.

  Because of its resistance to deformation under load, the axial retainer 112 can not be removed from the universal joint 110 without physical destruction of that member. In this way, the shaft 118 of the universal joint 110 does not have to present parts of surfaces of a reduced diameter to provide a recess that would allow to deposit the axial retaining member

  112 of the shaft 118. Indeed, the shaft 118 is sufficiently

  thick to prevent the radial flange 158

  outward to disengage from the annular groove

136.

  In the assembly of the universal joint 110, which will be described below, the spline teeth 120, in

  protruding outward, on the turn of the ex-part

  shaft 118., engage the spline teeth 122 which protrude inwardly on

  the bore 116 of the inner cup 114 of the universal joint

  versel 110. The advancement of the shaft 118 in the bowl

  114 is limited by plugging

  caught between certain pairs of flute teeth 120

  of the shaft 118, for example in four places 120 'apart from

  90 'intervals around the tree. The boulevard

  The spline groove extends axially from an intermediate point between the axial ends of the groove region of the shaft 118. In this way, if the universal joint 110 undergoes high axial loads in Dout during assembly or during its lifetime

2591686

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  useful, for example sudden axial loads, these end loads will be absorbed by the contact between the teeth of grooves 122 of the bore 116 and the plugged portions of the grooves 120 of the shaft 118, these elements being made of steel or other very strong metallic material and these heavy end loads will therefore not be applied to the axial retaining member 112, which is not as suitable for supporting such end loads because of makes it is

  formed of a thermoplastic material. This guarantees in

  that the axial retaining member 112 will not fail during assembly or during the duration of

useful life of the universal joint.

  we will now describe the assembly of the universal joint

  homokinetic verse 110. First of all, the organization

  in the bore 116 with snap-in arrangement, the radial flange 158 engaging

  in the annular groove 136. Next, the arm

  118 in the axial retaining member 112 and in the bore 116, which forces the member 112 to open in a controlled manner in the region of reduced thickness

  180. The flange 148 is directed inwardly

  snap then in place in the complementary groove 124 formed in the shaft 118. At the same time, the teeth of

  splines 120, 122 engage.

  The flexible fingers 170 are preferably

  proportioned to flourish, in their

  to an outer diameter greater than the inside diameter of the bottom portion of the inwardly directed groove 136. In this way, when the flexible fingers 170 are trapped in the inwardly directed groove 136, as shown in FIG. 3, the flexible fingers 170 are resiliently biased inward, i.e. they are prestressed. and help to establish a mating on between the organ

  axial retention 112 and the inner cup 114. When

  it 2591686 that the fingers 170 are prestressed in this way, we

  may use a tool, retainer clip or other fastener

  very retaining means for temporarily bending the flexible fingers 170 to temporarily fix them during assembly. Of course, various modifications may be made by those skilled in the art to the device which

  just described as a non-limiting example.

  mitative without departing from the scope of the invention.

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R E V E N D ICAT IONS

  1 - Torque transmission seal comprising a shaft (118) coupled to a female member, shaft receiver (114) in a manner that opposes relative rotation, the shaft and the shaft receiving member being able to separate by relative axial displacement and being held against this relative axial displacement by

  an axial retaining member (112), said retaining member

  being formed of an elastic material and comprising a

  main body (144) whose length extends according to the-

  said axis and which has a first end (146), a second end (156) and a central passage which passes through said main body along said axis; of the

  first coupling means (148), radially projecting

  inwardly on said main body,

  at or near the first end of that body

  end of this first end and engaged in a cavi-

  tee (124) of one (118) of said shaft and shaft receiving member; and second coupling means (158), projecting radially outwardly on said main body, disposed at or near said second end of said body.

  second end and engaged in a cavity (136)

  in the other (114) of the said elements, the tree and the

  shaft receiver; a plurality of longitudinal slots

  dinals (168) being formed in said main body

  (144) and extending from said second end

  tee (156) to the first end (146) so as to

  aiming at said second end in a plurality of

  longitudinally flexible fingers (170), which support the

  so-called second coupling means; characterized in that the main body (144) is provided with a region (180)

  of reduced radial thickness, which region extends

  longitudinally from said first end

  (146) and across said first coupling means

  (148) to allow at least a portion of said main body (144) in said region (180) to

cut in a controlled way.

  2 - Joint according to claim 1, further characterized in that the region (180) of reduced radial thickness extends to meet one of the slots

* longitudinal (168).

  3 - Joint according to one of claims 1 and

  2, characterized in that said flexible fingers (170)

  are in a prestressed state in use.

  4 - Joint according to any one of the claims

  1 to 3, characterized in that the shaft (118) is suffi-

  thick enough to prevent the second means of

  - coupling (158) to disengage from the cavity (136)

  in the other of the composite elements of the tree and

  of the shaft receiving member by resisting deformation

  radial inward motion of the second end

  (156) of the axial retaining member (112).

  Seal according to any one of claims 1 to 4, characterized in that said main body

  (144) and said first and second coupling means

  (148 and 158) are molded into one piece of

plastic tiger.

  6 - Joint according to claim 5, further characterized in that the plastic material is a material

  hard thermoplastic, dimensionally stable, resistant

aunt to shocks.

  7 - Joint according to any one of the claims

  1 to 6, characterized in that said first coupling means (148) comprise a flange

extending radially.

  8 - Joint according to any one of the claims

  1 to 7, characterized in that said main body

  (144) is of generally cylindrical shape.

  9 - Joint according to any one of the claims

  1 to 8, characterized in that the shaft (118) is

  connected to said axial retaining member (112), its cavity being constituted by an annular groove which receives said first coupling means (148) and

  the shaft receiving member (114) has a bore

  which receives the spline teeth of said tree

  (118) and cooperates with these teeth, and has a counter

  bore having an annular groove, constituting said

  cavity which receives said second coupling means

(158).

  10 - Joint according to claim 9, characterized

  Moreover, in that at least one of the splines which cooperate with each other is plugged to allow the joint to withstand high axial end loads without imposing strong axial end forces to

the axial retaining member (112).

  11 - Method of manufacturing a seal according to

  any one of claims 1 to 10, characterized

  in that said axial retaining member (112) is engaged in the shaft receiving member (114), engaging

  said second coupling means (158) of the organism

  axial restraint (112) in said cavity (136) of

  this member, then said shaft (118) is inserted into the body

  axial retention member (112) and in the shaft receiving member (114) thereby forcing said main body portion (144) to cut into said region (180), and engaging said first coupling means (148); )

  in said cavity (124) of the shaft.

  12 - Torque transmission joint comprising a spline shaft (118) and a receiving female member

  shaft (114) grooved internally so as to be

  of the splined shaft (118) and to cooperate with this shaft, characterized in that at least one groove (120 ') between adjacent spline teeth of the shaft (118) or the receiving member tree (114)

  is blocked at an intermediate point between the extremes

  axial tees of the fluted region of this tree or of this

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  receiving member, while the other grooves of spline teeth (120) remain open at this axial point, so as to limit the relative axial displacement between the shaft (118) and the shaft receiving member

(114).