Resource Assessment of Spiroid Gears Under Variable Loading Conditions

The brief analysis of reasons of failure of mechanisms and drives of lifting, construction, and road-building machines based on engagement drives, and worm-gear class drives, represented by contact destructions of active surfaces of cog-wheel cogs resulting in malfunctions, breakages, failures, such as wear and furrows, was carried out. The need to create a method for calculating the wear of spiroids with regard of variable loading mode and time was substantiated. The method developed allows, with regard of real modes of operation of handling machinery, equipment and machines, determine the wear intensity values and calculate the spiroid gear drive resource with regard of duration of action of diving torque values in accordance with the set variable loading schedule for lifting, construction, and road-building machines under the wear intensity of the spiroid wheel cog on values of driving torque on the spiroid gear drive output shaft, obtained from experiments.

The Effect of Materials on the Efficiency of the Spiroid Gearing

The contribution deals with is the material selection for spiroid gear. The combination of the softer material of one wheel with the harder material of the other wheel (or gear worm) is used for the trains of gears. The measurements were executed on the measurement stand comprising the machine aggregate with the spiroid drive. In Stage 1 of measurement, the spiroid gear was made of the steel gear worm and of the bronze wheel, in Stage 2 of measurements, it was made of the steel gear worm and of the plastic wheel. The efficiency was evaluated for various levels of the load moment, lubrication and material type used.

Modeling the process of shaping worm gears of spiroid gear

The article presents various methods of shaping cylindrical spiroid worm gear of asymmetrical outline using two tools. Cutting thread of worm gears is made on CNC lathes with blades in the form of universal inserts. Shows the geometric model and technological machining cylindrical worm gear spiroid on a CNC lathe. The correctness of the test results obtained in numerical developed program was tested through experimental studies of the process of cutting worm gears given parameters. Cutting process of worm gears was made on a lathe CTX210 using overlay ShopTurn in module for threading. The process uses a standard turning tool with interchangeable inserts and turning tools with a specially designed geometry. Studies performed on various cutting parameters and for a various materials of cutting inserts.

Method for Analysis of Elastically and Plastically Heavy-Loaded Low-Speed Spiroid Gear

Рассмотрена задача LTCA тяжелонагруженной низкоскоростной многопарной спироидной передачи с учетом влияния упругого контактного и изгибно-сдвигового и упругопластического контактного взаимодействия зубьев колеса и витков червяка. Задача LTCA упругопластически нагруженной передачи рассмотрена как комбинация двух задач: анализа - вычисление параметров нагруженного контакта; синтеза - поиска требуемой геометрии. Обоснован отказ от метода конечных элементов (МКЭ), обычно широко применяемого для решения задач LTCA. Приводится описание разработанного алгоритма расчета распределения нагрузки с учетом упругого и упругопластического характера многопарного контакта спироидной передачи, имеющей сложную пространственную геометрию. Предложена модель расчета величины пластической деформации в зависимости от первичной оценки перемещений в упругом контакте. Показано влияние погрешностей изготовления передачи на уровень нагруженности отдельных ее пар зуб - виток.

Design of double-crowned tooth geometry for spiroid gear produced by precision casting process

A novel double-crowned tooth geometry is proposed by the application of ease-off topography for spiroid gear manufactured by precision casting process, with the goals of localizing the bearing contact and obtaining a perfect function of transmission errors. The modified tooth surface is applied as the reference geometry to machine the die cavity geometry that will produce such geometry of the gears. The tooth geometry of crowned gear was achieved first from a pre-designed controllable function of transmission errors along the desired contact path. Then, the desired ease-off topography along the contact line is designed and calculated computationally from the given mathematic model of surface modification. The geometry of double-crowned spiroid gear could be reconstructed by superimposing the ease off of contact line direction on the profile-crowned tooth surface. The article provides numerical examples to validate the feasibility of ease-off modification methodology that was used to produce the double-crowned tooth geometry for the gears, while tooth contact analysis is performed computationally to investigate the stability of bearing contact and function of transmission errors to alignment.

Kinematical Analysis of Gearboxes with Spiroid Gears

The paper investigates the issue of the asymetric worms´ profile (Fig. 10) of the spiroid gear comprising the direct line worm surface which occurs by the motion of the constituent direct line u upon the helix regarding the steady-state coordinate system 0 (x,y,z). There are described the characteristic attributes of spiroid gears in the article. Some kinematical inaccuracies caused by mistakes in gearing assembly are analyzed there. A testing stand is supposed to carry out an experimental research of inaccuracies influence on smooth run of machine aggregate.

Spiroid Gear with Composite Profile of the Worm – Hob Mill Tool

The spiroid gears are known and used due to their performances: increased gear ratio; reduced overall dimensions; the simplicity of the construction; increased carrying capacity on the gear flanks etc. The gears construction demand assurance of a certain geometry of the worm, which constitutes, in the same time, the basics for the generating tool of the spiroid wheel. In this paper, a worm with a composite profile is proposed. The profile is composed by an assembly of circles arc, in order to increase the length of the flank active zone. This design is intended to increase the contact length between the flanks of the spiroid worm and spiroid wheel, in order to decrease the contact pressure between the two parts and to improve the gear function process.