Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
  • F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
  • F16D3/20—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members
  • F16D3/202—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints
  • F16D3/205—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints the pins extending radially outwardly from the coupling part
  • F16D3/2055—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members one coupling part having radially projecting pins, e.g. tripod joints the pins extending radially outwardly from the coupling part having three pins, i.e. true tripod joints
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D1/00—Couplings for rigidly connecting two coaxial shafts or other movable machine elements
  • F16D1/06—Couplings for rigidly connecting two coaxial shafts or other movable machine elements for attachment of a member on a shaft or on a shaft-end
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
  • F16D3/16—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts
  • F16D3/20—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members
  • F16D3/22—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members the rolling members being balls, rollers, or the like, guided in grooves or sockets in both coupling parts
  • F16D3/223—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members the rolling members being balls, rollers, or the like, guided in grooves or sockets in both coupling parts the rolling members being guided in grooves in both coupling parts
  • F16D3/224—Universal joints in which flexibility is produced by means of pivots or sliding or rolling connecting parts one coupling part entering a sleeve of the other coupling part and connected thereto by sliding or rolling members the rolling members being balls, rollers, or the like, guided in grooves or sockets in both coupling parts the rolling members being guided in grooves in both coupling parts the groove centre-lines in each coupling part lying on a sphere
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D1/00—Couplings for rigidly connecting two coaxial shafts or other movable machine elements
  • F16D1/10—Quick-acting couplings in which the parts are connected by simply bringing them together axially
  • F16D2001/103—Quick-acting couplings in which the parts are connected by simply bringing them together axially the torque is transmitted via splined connections

Definitions

• This invention relates to an assembly in which two components are connected to one another for torque transmission between them, one of the components being generally in the form of, or having a part in the form of, a sleeve which at least partially encircles the other component, the torque transmitting connection between the components being established through interengaging complementary teeth provided in the interior of the one component and on the exterior of the other component.
• Such teeth extending axially of components for the purpose of establishing a torque transmitting connection are commonly, and will herein be, referred to as splines, and the connection is known as a splined connection.
• the invention has been developed in relation to an assembly in which the two components having the splined connection therebetween are a shaft element and the inner member of a constant velocity ratio universal joint.
• the universal joint may be of the tripode type, in which the inner member comprises three limbs extending outwardly from a sleeve-like body, each limb carrying a respective roller assembly for engagement with a respective track provided in an outer member of the joint.
• the body of the inner joint member is provided internally with the splines for torque transmission with the drive shaft.
• An inner joint member which is generally in the form of a sleeve having a splined connection with a drive shaft is also found in the type of constant velocity ratio universal joint in which the outer and inner joint members have tracks in the form of axially extending grooves facing one another in pairs, and torque is transmitted between the joint members by balls engaging one in each facing pair of tracks in the joint members.
• the inner joint member may include portions where there is a comparatively small thickness of material outside the splined interior of the joint member. Such a small section of material, particularly when associated with a change in section which acts as a stress raiser, can lead to cracking and potential failure of the joint member.
• the potential failure points are at the sides of the roller- carrying limbs where they are connected to the body, in the direction circumferentially of the sleeve-like body of the inner joint member.
• the most significant potential failure points are where the ball- receiving tracks in the inner joint member extend closest to the splined interior of the inner joint member.
• Such potential failure points are of particular significance when, as is typical of modern practice, dimensions of joints or parts thereof are reduced to the minimum possible in order to save weight.
• a splined connection can have a double width tooth in order to retain a correct angular alignment between the connected parts by ensuring that they can only be assembled in the correct relative position. It has also been proposed, in Japanese Utility Model Laid-Open No. 5-1028, that the splined connection between a shaft and a constant velocity universal joint member can have portions without splines. In this case, the purpose of the omission of splines is to avoid distortion of the universal joint member during heat treatment, but the arrangement of the omitted splines weakens the joint member and does not address the problem with which the present invention is concerned.
• first and second components we provide an assembly of first and second components, the first component being generally of sleeve-like form and extending at least partially around the second component, the components having interengaging splines for torque transmission therebetween, wherein at least one circumferentially extending portion of the first component is without splines and in the or each of said portions the minimal radial dimension of the component between interior and exterior thereof is greater than the minimum such dimension which would exist in said portion if the splines were continued in said portion.
• the minimum radial dimension of the component which is the outermost one will exist at the major diameter of one or more of the splines provided in its interior.
• the increased radial dimension of the outer component between the interior and exterior thereof is conveniently provided by a configuration in which in the portions of the components without splines, the material of the outer component extends towards the other component by a distance greater than it does at the major diameter of the splines in the remaining portions of the component.
• the interior of the first component is of part-cylindrical configuration of a radius substantially equal to (in practice slightly greater than) the pitch circle radius of the splines in the splined portions of the inner component.
• the first component is the inner member of a constant velocity ratio ur.ivcrsal joint and the second component is a shaft element.
• the universal joint may be of the tripod type, the inner member comprising a sleeve-like body and three limbs extending outwardly therefrom.
• said portions without splines are preferably provided in regions circumferentially in alignment with the sides of the limbs where they join the body.
• the universal joint may be one in which torque is transmitted between inner and outer joint members by balls engaging facing pairs of tracks in the joint members.
• said portions of the inner joint member without splines are preferably provided in circumferential alignment with base regions the tracks in the inner joint member.
• Figure 1 is an axial view of an inner member of a constant velocity ratio universal joint, not in accordance with the present invention
• Figure 2 is a longitudinal section through the joint member of Figure l;
• Figure 3 is an axial view of an inner member of a constant velocity ratio universal joint, in accordance with the invention.
• Figure 4 is an axial view of the inner member of a further embodiment of inner member of a constant velocity ratio universal joint, in accordance with the invention.
• Figure 5 is a view as Figure 4 of yet a further embodiment of inner member of constant velocity ratio universal joint, in accordance with the invention.
• Figures 1 and 2 of the drawings show an inner member of a constant velocity ratio universal joint of the type in which torque is transmitted between inner and outer joint members by a plurality of balls spaced circumferentially around the joint and engaging in respective facing pairs of tracks in the inner and outer joint members.
• the universal joint inner member comprises a body 10 which is generally in the form of a sleeve having an opening 11 extending axially therethrough.
• the exterior of the body 10 is provided with a number in this case six, of tracks for receiving the respective balls for torque transmission, the tracks being equally circumferentially spaced about the joint member and in the form of grooves 12.
• the grooves 12 extend axially of the joint member and in longitudinal section the bases of the grooves 12 are of arcuate configuration as indicated at 13 in Figure 2.
• each of the grooves 12 is generally of U-shape and may, as is generally known for such universal joints, be of "gothic arch" cross-section so as to provide for angular contact with a ball received therein.
• the external surface 14 of the joint member is of part-spherical configuration.
• the interior of the joint member surrounding the opening 11 is provided with axis-parallel circumferentially spaced splines 15 so as to provide a torque transmitting connection with a portion of a drive shaft element received in the opening 11 and provided with complementary splines.
• a formation may be provided for engagement with a spring ring or the like for axially securing such a drive shaft element to the joint member; such a formation in the form of an annular groove is indicated at 16 in Figure 2.
• FIG. 3 of the drawings shows in axial view an inner joint member whose external configuration and arrangement of grooves for engagement by torque transmitting balls are the same as above described with reference to Figure 1.
• portions 18 which are not provided with splines.
• the portions 18 lie, in the direction circumferentially of the joint, in alignment with the base regions 13 of the grooves 12 for receiving the torque transmitting balls.
• the portions 18 are parts of a cylindrical surface whose radius is substantially equal to the pitch circle radius of the splines in the remaining portions of the joint member.
• This radius is slightly larger than the pitch circle radius of the splines which would be provided on a shaft member or the like having torque transmitting engagement with the inner joint member.
• a manufacturing process involving displacement of material rather than removal thereof is commonly used, and hence on a circumferentially extending portion of such a member not provided with splines the material surface will lie substantially at the pitch circle radius of the splines.
• This increased thickness of material in combination with the elimination of the notch effect above referred to, provides a considerably increased resistance to cracking which could lead to failure at these points.
• Figure 3 also shows a shaft 19 received in the opening 11 of the joint member for torque transmitting engagement therewith.
• the cross-sectional shape of the shaft 19 corresponds to that of the opening in the joint member, including portions without splines.
• FIG. 4 of the drawings shows in axial view an inner joint member in accordance with the invention, which is an inner member of a tripode type of universal joint.
• This joint member comprises a body 20 of sleeve-like form with an opening 21 extending axially through it, and three limbs or journals 22 extending radially outwardly from the exterior of the body 20 and equally circumferentially spaced thereabout.
• the limbs 22 have cylindrical surfaces as indicated at 23 for carrying respective roller assemblies which engage with respective tracks provided in an outer joint member.
• annular undercut 24 extending around the limb.
• Such an undercut which is commonly provided in tripode joint inner members for the purpose of providing required bearing conditions for the ends of needle bearing rollers forming part of the roller assembly, has a stress- raising effect at the end of the limb where it joins the body, and hence provides a potential failure point.
• the interior of the body 20 is provided with axially extending circumferentially spaced splines 25.
• These splines are arranged in groups rather than all around the circumference of the opening 21 and at each side of each limb 22 there is a portion which is without splines, as indicated at 26.
• the portions 26 are in alignment with the undercuts 24 at the bases of the limbs, so that an increased thickness of material is provided in the direction radially of the joint member, as indicated at 27, compared with that which would exist if the splines were provided all around the circumference of the opening 21.
• the surface of each portion 26 is part of a cylindrical surface of radius substantially equal to the pitch circle radius of the splines 25.
• the potential failure mode is that of cracking between the interior and exterior of the body 20 at the sides of the limbs 22, generally in the direction which has been indicated at 27.
• the absence of splines in portions 26 provides an increased thickness of material at these regions, thereby diminishing the tendency for cracking to occur and increasing the fatigue life of the component. Further, the notch effect of the spline opposite the annular undercut 24 is diminished.
• Figure 5 shows an inner member of a tripode type of constant velocity ratio universal joint, which is generally as that shown in Figure 4 with the difference that the splined circumference of the opening 21 has three groups of splines 30 which in the circumferential direction of the component lie between the limbs extending outwardly from the body thereof, and three groups of splines 31 which lie beneath the centres of the limb.
• the splines 31 are of larger dimensions both circumferentially and radially of the component than the splines in the groups of splines 30.
• there are non-splined circumferentially extending portions 32 in alignment, in axial view, with the sides of the limbs where they join the body of the component.
• the splines 31 may be of either smaller or larger dimensions, circumferentially and/or radially of the component, than the splines 30.
• the preferred arrangement for a specific component or assembly will be determined with the aim of minimising stress levels having regard to material sections and the notch effect of the spline fillet.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
• Steering Controls (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10729972

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (2)

Citations (6)

• 1993
  • 1993-02-06 GB GB939302359A patent/GB9302359D0/en active Pending
• 1994
  • 1994-01-28 WO PCT/GB1994/000168 patent/WO1994018466A1/en not_active IP Right Cessation
  • 1994-01-28 DE DE4490587T patent/DE4490587T1/de not_active Withdrawn
  • 1994-01-28 JP JP6517762A patent/JPH08506647A/ja not_active Ceased
  • 1994-02-04 FR FR9401291A patent/FR2701297B1/fr not_active Expired - Fee Related

Patent Citations (6)

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