Using hob offset to balance dynamic strength in spur gears
Abstract
This paper presents an analytical study on the effect of hob offset on the dynamic tooth strength of spur gears. The study was limited to equal and opposite offset values applied to the pinion and gear to maintain the standard operating center distance. The analysis presented in this paper was performed using a new version of the NASA gear dynamics code DANST. The operating speed of the transmission has a significant influence on the amount of hob offset required to equalize the dynamic stresses in the pinion and gear. In the transmission studied, at low speeds, the optimum hob offset value was found to fluctuate. At higher speeds, the optimum value was constrained by the minimum allowed thickness at the tip of the pinion tooth. For gears that must operate over a range of speeds, an average offset value may be used. Spur gears designed with the procedure presented here can have significant improvements in load capacity.
- Publication:
-
Presented at the 31st Joint Propulsion Conference and Exhibit
- Pub Date:
- May 1995
- Bibcode:
- 1995jpsd.confQ..10L
- Keywords:
-
- Dynamic Loads;
- Gear Teeth;
- Gears;
- Mechanical Properties;
- Stress Analysis;
- Thickness;
- Transmissions (Machine Elements);
- Computer Aided Design;
- Computer Programs;
- High Speed;
- Load Carrying Capacity;
- Loads (Forces);
- Low Speed;
- Mechanical Engineering