ASPECTS REGARDING OPTIMIZATION OF MECHANICAL CONTACT BETWEEN TEETH WITH NON-STANDARD PROFILE IN PRECESSIONAL GEAR

Abstract

A basic problem in the operation of gears in conditions of insufficient lubrication is the intensification of the wear process of the teeth and the increase in the level of noise and vibrations, generated by the variability of the frictional forces. In precessional power transmissions, the teeth of the toothed crowns of the satellite block are executed in the form of conical rollers, ensuring the "tooth-conical roller" engagement, and in kinematic transmissions they are described by arc-shaped curves. The paper presents the real and compressed dynamic model of the precessional gear under the aspect of evaluating the limit frequency of the noise and vibration level. In the "bevel-roller" gear, rolling friction persists and approx. 4% sliding friction, and in the "tooth-tooth" gear, sliding friction persists, which can lead both to excessive wear of the teeth and to an increase in the level of noise and vibration generated by the spasmotic nature of the loads. To optimize the mechanical contact, a patented solution is proposed, which is based on the application of a superficial layer of elastomeric material with anti-friction and shock-absorbing properties on the working surface of the teeth . To ensure a major adhesion of the superficial layer to the coarse base of the teeth, the first layer of additive material is applied immediately after the last layer of the coarse print is applied. In the case of increased requirements regarding the vibro -acoustic behavior on the coarse surface of the teeth made of materials with high mechanical resistance, a layer of polymeric material with self-lubricating and shock-absorbing and adhesion properties is applied on the coarse surface of the tooth.

Keywords: precessional transmission , rollers, teeth, mechanical contact, optimization .