Railway wheels and axles – Wheels – Webs
Patent
1997-06-06
1999-05-04
Stormer, Russell D.
Railway wheels and axles
Wheels
Webs
295 1, B60B 1900
Patent
active
058995170
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a rail wheel having a wheel disc which connects a wheel hub and a wheel rim and which has a thickness decreasing from the wheel hub to the wheel rim and whose outer sides merge tangentially via compound curves as radially extending generatrices into the adjacent outer sides of the wheel hub and the wheel rim.
A rail wheel of the kind specified is known, for example, from DE-B-2 331 738.
In disc-braked rail wheels of the kind specified, stressing mainly takes place in the transition zones from the wheel disc to the wheel rim and the wheel hub, due to the forces operative between wheel and rail during travel. The stresses are concentrated solely on a small area and then very rapidly decrease. A typical stress curve for a conventional wheel is shown in FIG. 1 (ERRI,/ORE Report B136/RP9 of the Research and Experimental Office of European Railways). Due to the concentrations of stress in small areas, at this place the material is loaded to the limit of its fatigue strength, while adjacent areas are still only slightly loaded. The wheel is therefore overdimensioned in these areas of low stress.
DE-A-2 346 144 discloses a set of light wheels for rail wheel vehicles which has wheel discs of light metal and steel rims, the wheel disc being shrunk on to the hub and the steel rim on to the wheel disc respectively. To reduce stress in that set of light wheels, inter alia metal adhesion is provided for the wheel disc and the wheel set shaft and also for the steel rim and the wheel disc. The wheel disc is also constructed with a straight web, to avoid the stress peaks which occur with undulated wheel discs.
It is an object of the invention to provide a rail wheel of the kind specified wherein local concentrations of stress are reduced in comparison with a conventional wheel.
This problem is solved according to the invention in a rail wheel of the kind specified by the feature that the two outer sides of the wheel disc are determined geometrically in the radial central zone by radially extending straight generatrices which intersect one another on the wheel rim in the zone between the compound curves.
As a result of this shaping of the rail wheel, no stress peaks occur in locally narrowly limited zones. The stresses are distributed over fairly large zones and their peaks reduced. Shaping according to the invention therefore produces an optimum light construction.
The central plane of the wheel disc lies perpendicularly to the wheel axis; however, it can also be inclined in relation to the wheel axis by an angle of up to 5.degree..
The wheel can be further improved by further steps for the object of the invention.
For manufacturing reasons it is advantageous in the forging and rolling of the wheel if the outer sides of the wheel hub adjacent the wheel disc are conical, the intersecting point of the straight generatrices of said outer sides determining the foot of the wheel disc on the wheel hub. Correspondingly the outer sides of the wheel rim adjacent the wheel disc can be conical, the intersecting point of the straight generatrices of said outer sides determining the foot of the wheel disc on the wheel rim.
To reduce stress peaks, advantageously the wheel disc has its minimum thickness in the range 2/3 to 4/5 of the distance of its foot on the wheel hub. Optimum conditions are obtained if the wheel disc has its minimum thickness at a distance ##EQU1## from the foot of the wheel disc on the wheel hub (where D=distance of the foot of the wheel disc from the wheel axis, B=distance of the feet of the wheel disc and LD=running circle diameter).
The axial distance of the straight generatrices of the outer side of the wheel disc at the foot of the wheel hub can be determined by the formula diameter LD and f.sub.F =Q:500+Y:120 for the wheel force Q (radial axle loading) and the rail force Y (axial force) on the wheel rim.
As a rule the transitions are made up of different zones. Preferably the wheel disc side transition zone extends from the wheel hub and/or the wheel rim to the wheel disc over a radial
REFERENCES:
patent: 4307910 (1981-12-01), Rodney
Bittner Wilfried
Murawa Franz
Schneider Jurgen
Stormer Russell D.
VGS Verkehrstechnik GmbH
LandOfFree
Stress homogenized rail wheel having a wheel disc connecting whe does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stress homogenized rail wheel having a wheel disc connecting whe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stress homogenized rail wheel having a wheel disc connecting whe will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1864036