ANALYSIS OF METHODS FOR CALCULATING SPUR GEAR FOR DEEP CONTACT STRENGTH

Spur gear is an integral part of transport and technological machines structure. To increase the load ability of the spur gear, chemical heat treatment of the working cogs surfaces is used. Spur gear with chemical heat treatment must be checked for deep contact strength. The article analyzes various methods (according to GOST 21354-87, methods using the generalized criterion of the limit state for structurally inhomogeneous material by Lebedev-Pisarenko, methods from the handbook describing reducers of power machines etc.) for calculating spur and helical gearing for deep contact strength. The author presents all necessary formulas and graphs for the implementation of each methods, and compares the calculations results of these methods with the results of experimental studies of cemented cylindrical rollers for deep contact destruction.

Analysis of Conceptual Solutions of Universal Helical Geared Reducers

Geared reducers are mechanisms designed to reduce the number of revolutions using geared elements and nowadays they present one of the most commonly used types of mechanical transmissions in mechanical engineering. Due to the different shapes of geared elements, there are different types of geared transmissions: helical, bevel, worm, special and combined transmissions. This paper analyses only helical geared transmissions, since there is a great extent of whole this matter. Helical transmissions are analysed only with external helical gearing, since internal geared pairs represent a special and very large group of gears. Within the external helical geared transmissions, only torque transmissions are analysed, while the transmissions of motion are not analysed and they represent another large group of transmissions. Only universal gear reducers with axial, or almost-axial, parallel shafts are considered (two-stage and three-stage transmissions). Although, single-stage gear reducer produced with parallel shafts are not considered by the paper in order to reduce the area of researching. Gear reducers are most commonly delivered to customer with electric motor, known as motor geared reducer, and they are studied here extensively. Gear reducer can be also delivered without motor, only with input shaft. The basic aim of this paper is to present all characteristics and specificities of motor geared reducer in one place.

Operational Characteristics of Internally Geared Positive Displacement Screw Machines

Cylindrical helical gearing profiles can allow an externally lobed inner gear to rotate inside an internally lobed outer gear while maintaining continuous lines of contact between the gears. A series of separate working chambers are formed between the rotors, and this paper investigates the use of ported end plates to control the period during which fluid is allowed to enter or leave these working chambers. A simple method of defining the rotor profiles is considered, allowing the geometry of such internally geared screw machines to be characterised. The performance of the machine is then investigated for particular applications. The key considerations in this preliminary study are the effect of geometry on the forces and torques that act on both the inner and outer rotors. The results suggest that low rotor contact forces are possible, which is necessary to ensure high efficiency and low wear in practical machines.

Research on Cutting-Tooth Outline Distortion of Internal Helical Gearing Machine Tool

Based on sports of machine tool and characteristic of involute outline internal helical gear , so gain mathematic model and tooth face equation of outline internal helical gear. Upbuild and analyzed milling load conditions of machine tool on the base of this, Upbuild milling load model of outline internal gear on the base of cutting-tooth distortion of machine tool, provide theory for involute outline internal helical gearing machine tool.