Machine element or mechanism – Gearing – Teeth
Patent
1989-11-28
1991-06-11
Herrmann, Allan D.
Machine element or mechanism
Gearing
Teeth
74DIG12, F16H 5508
Patent
active
050222805
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to mechanical engineering and, more particularly, to Novikov gearing.
At present, the use of gearing faces a problem of stepping up the load capacity of the gear drive and reducing its specific materials consumption. This problem is solved by diverse design and technological methods one of which consists in improving the tooth geometry.
BACKGROUND OF THE INVENTION
Known in the prior art is a Novikov gearing comprising at least two gear elements the teeth of each element consisting of an addendum whose profile in the normal section is described by a convex curve, a dedendum and a fillet between them. ("Spur-gear Novikov Gearing with two Lines of Action" GOST 15023-76, 1976). The fillet has an involute surface which provides for a comparatively small clearance between the surfaces of meshing teeth in the zone of rolling surfaces of the gear elements.
The gearing of the present invention can be used to improve the contact strength of only the teeth with a comparatively low hardness of the meshing surfaces.
The use of this gearing with very hard teeth is rather inexpedient since a small clearance brings the fillet into action comparatively soon and, featuring a low contact strength, it is subjected to progressive crumbling in the zone of rolling surfaces of gear elements. In addition, an insufficient thickness of the dedendum limits its fracture strength.
Also known in the prior art is a Novikov gearing comprising at least two gear elements the teeth of each element consisting of an addendum whose profile in the normal section is described by a convex curve, a dedendum and a fillet connecting the two (SU, A 735855). The fillet has a concave profile in the normal section which ensures, in the case of gear elements with very hard teeth, the required clearance in the zone of the rolling surfaces of gear elements. The teeth on some parts of the dedendum and addendum profile are offset from the axis of symmetry in such a manner that the thickness of the dedendum is substantially greater than the thickness of the addendum which raises the fracture strength of the dedendum and of the tooth as a whole.
However, further increase of the tooth load capacity is limited by the insuffucient fracture strength of its addendum.
The main object of the present invention resides in providing a Novikov gearing with its teeth so designed that, while retaining the necessary clearance between the interacting surfaces of teeth in the fillet zone, said gearing should ensure a relatively higher fracture strength of the addendum and its load capacity as a whole.
SUMMARY OF THE INVENTION
The object of the invention is accomplished by providing a Novikov gearing comprising at least two gear elements, the teeth of each element containing an addendum whose profile in the normal section is described by a convex curve, a dedendum and their interconnecting fillet wherein, according to the invention, a part of the fillet adjoining the addendum has a convex profile in the normal section with the radius of curvature smaller than that of the addendum.
The part of the fillet realized according to the invention permits increasing the thickness of the critical section of the addendum and thereby increasing its fracture strength while retaining the required clearance between the interacting surfaces of teeth in the zone of rolling surfaces of the gear elements.
BRIEF DESCRIPTION OF THE DRAWINGS
Given below is a description of the present invention by way of example with references to the appended drawings in which:
FIG. 1 illustrates a face section through the engaged gear elements;
FIG. 2 is a tooth of the gear element;
FIG. 3 is the tooth profile in normal section;
FIGS. 4 through 6 are fragments of the Novikov gearing according to the invention in various phases of meshing.
BEST MODE FOR CARRYING OUT THE INVENTION
The Novikov gearing comprises at least two gear elements 1 and 2 (FIG. 1). Teeth 3',3" of each of these elements 1 and 2 comprise and addendum 4 (FIG. 2), a dedendum 5 and a fillet
REFERENCES:
patent: 4031770 (1977-06-01), Ishikawa
"Spur-gear Novikov Gearing with two Lines of Action" GOST 15023-76, 1976).
Boiko Leonid S.
Chesnokov Viktor A.
Fedyakin Roman V.
Fei Valery M.
Galichenko Emma N.
Herrmann Allan D.
Laub David W.
LandOfFree
Novikov gearing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Novikov gearing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Novikov gearing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-775170