Browse Publications Technical Papers 360105
1936-01-01

Eliminating Crankshaft Torsional Vibration in Radial Aircraft Engines 360105

CRANKSHAFT torsional vibration has become a serious problem in aircraft engines. Thanks to much experimental work, we now have a good working knowledge of the two phases of the problem, the elastic and inertia characteristics of the crankshaft-propeller combination and the forces to which this system is subjected.
Methods used in the past to reduce vibration have been to change the elastic characteristics of the crankshaft, or to incorporate direct damping or some form of vibration damper of which the Lanchester and the resonant damper are examples. All of these methods have serious limitations. An interesting device which is capable of eliminating vibration in constant speed machinery is the undamped absorber. For variable speed machinery this absorber is of no value. By arranging an undamped absorber so that the restoring force varies with speed, it is possible, theoretically, to eliminate vibration in certain variable speed machinery. A pendulous weight rotating with the crankshaft of an engine can be constructed so that the restoring force has the desired variation with speed. The device is simple and has a number of outstanding advantages, chief of which is the extraordinary effectiveness of a comparatively small device. The principle has been utilized in a device applied to the Wright “Cyclone” series radial aircraft engines.
Torsiograph records taken on this engine show complete freedom from vibration with the device functioning.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Preview Document Add to Cart
Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Further Progress in Controlled Cooling of Radial Aircraft Engines

350113

View Details

TECHNICAL PAPER

Permissible Amplitudes of Torsional Vibration in Aircraft Engines

390160

View Details

TECHNICAL PAPER

An Implementation of Best Practices in Aircraft Flight Control Law Design

2007-01-2898

View Details

X