Machine element or mechanism – Gearing – Teeth
Patent
1999-10-21
2000-11-07
Fenstermacher, David
Machine element or mechanism
Gearing
Teeth
74460, F16D 106
Patent
active
061420336
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
The invention relates to a shaft/hub unit having a toothing assembly for transmitting torque, comprising a shaft with shaft toothing and a hub with hub toothing, which sets of toothing engage one another, with torque being introduced by a shaft shank at whose end there is provided the shaft toothing and with the tooth profile of the shaft toothing, in the longitudinal direction, following a variable course.
Shaft/hub units of said type are used in particular for rotationally fast connections between an axle shaft and a component of a universal joint in the driveline of a vehicle.
DE 44 15 033 C1 describes such a shaft/hub unit wherein the tooth profile of the shaft toothing is variable in the longitudinal direction and wherein the tooth height of the shaft toothing continuously decreases in a run-out portion. As the shaft toothing is provided in the form of involute toothing and the hub toothing in the form of straight-flanked toothing, a line contact exists between the two sets of toothing. In consequence, a tooth flank play occurs above and below the line contact. In a run-out portion in which the tooth height of the shaft toothing is shorter than the height of the line contact, the teeth of the shaft toothing and those of the hub toothing do not contact one another. An introduction of torque leads to shaft torsion in the run-out portion, with the flanks of the shaft toothing, to an increasing extent, axially contacting the flanks of the hub toothing. The usually occurring stress peak at the shaft shank end of the toothing assembly is thus reduced and the portion of high stress values is extended to a greater length of the toothing assembly. The disadvantage of said shaft/hub unit is that the run-out portion can only be produced by an additional chip-forming machining operation.
FR 1 581 658 discloses a shaft with a set of shaft toothing for a shaft/hub unit wherein the base diameter and the major diameter in the longitudinal direction are positioned on a cone, with the tooth height being constant along the entire length of the toothing assembly. The base diameter and the major diameter are increased towards the shaft end where the torque is introduced. However, said type of toothing can be produced neither by established production methods with an axial direction of feed such as broaching or drawing nor by rolling with parallel rolling means. Furthermore, the axial position of the hub on the shaft depends on the tolerances of the cone. In the case of flat opening angles of the outer cone faces, even slight deviations in angle have a substantial effect on the axial position of the hub. For many applications this is unacceptable.
It is the object of the present invention to provide a shaft-hub unit wherein, with a given torque, the stresses at the shaft shank end of a toothing assembly are as low as possible and the toothing of which can be produced by simple production methods.
The objective is achieved in that the shaft toothing comprises a major diameter which, in the longitudinal direction, follows a constant course and that the hub toothing comprises a base diameter which, in the longitudinal direction, follows a constant course; that the toothing assembly comprises at least two axially extending portions in which each base diameter of the shaft toothing follows a constant course and in which each major diameter of the hub toothing follows a constant course, and that of each two adjoining portions, the portion facing the shaft shank comprises the greater base diameter of the shaft toothing and the greater major diameter of the hub toothing; and that, of each two adjoining portions, the portion facing the shaft shank comprises a tooth profile of the shaft toothing, which tooth profile corresponds to a head portion of the adjoining portion, which head portion forms the upper part of the tooth profile.
By increasing the base diameters from portion to portion towards the shaft shank, the resistance moment of the shaft becomes greater. In consequence, the stresses in the shaft shank end of th
REFERENCES:
patent: 4744263 (1988-05-01), Kuiken
patent: 5605518 (1997-02-01), Kogure et al.
LandOfFree
Shaft-hub unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Shaft-hub unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Shaft-hub unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1630645