The transmission or transformation of motion in various mechanisms and devices is carried out using gears or worm gears. This is the most common way in modern engineering and designing various devices.
The main element of a worm or gear transmission is a gear. Modern engineers have not yet found a simpler and economically viable alternative to such a design invention. Motion converters in which the gear wheel is involved are reliable and durable in operation, compact and have a high efficiency. This type of transmission can transmit significant power for all its ease of use.
However, the manufacture of gears requires high precision. In case of incorrect calculations and design errors or incorrect installation of these parts, operation leads to quick wear and tear of equipment, the appearance of excess noise and damaging vibrations.
In modern instruments and mechanical engineering, various types of improved, specially machined steels are used as the main material for the production of parts, which have long established themselves as a durable, wear-resistant material. However, advanced technologies of Western and domestic manufacturers allow replacing
metal alloys with lighter plastics and composites.
A gear wheel, in the manufacture of which textolite, polyurethane, kapron or wood-laminated plastic was used, will facilitate the design, avoid vibration or additional noise and rattle. In mechanisms where transfer of large loads is not required, plastic will be more reliable and durable. The use of gears made of these materials will be much cheaper. And excellent anti-corrosion properties will extend the life of the part.
Classification of these elements is carried out depending on the location of their axes, gearing method, design and profile shape. Distinguish spur, helical and chevron wheels, with external or internal gearing, bevel, cylindrical, worm and helical gears.
Each gear wheel of the mechanism can rotate in one or in the opposite direction, convert the rotation of the shaft into translational motion using a rack and pinion transmission. The selection and calculation of a particular part is carried out depending on the purpose, technical characteristics and types of transmission of movement.
For the exact design of the gear, it is necessary to carry out mathematical calculations according to certain formulas, using information from regulatory documents and reference books for mechanical engineering. The main parameters of the part necessary for the design include the number of teeth, the diameter of the wheel along the outer protrusions and depressions, the pitch of the wheel, the height of the tooth, which is the height of the head and leg of the tooth, and the gear pitch.
When choosing a material for the gear, bending strength is calculated in dangerous sections at the base and in the gearing pole of the teeth.